The State of NC Undergraduate Research & Creativity Symposium

State of North Carolina

Undergraduate Research & Creativity Symposium

Science Abstracts

 

 

 

 

Student Author(s): 

Amis, Jackie

Dept & College or University:                        

Guilford College

Research Mentor(s)

Moses Okello/Center for Wildlife Management, School for Field Studies, Nairobi, Kenya, East Africa

Title of Presentation:

The State and Contraction of Wildlife Corridors in Kimana Group Ranch near Amboseli, Kenya: Analysis of Human Impacts

 

 

The purpose of this study was to assess the amount of land available to wildlife in the Kimana Group Ranch, part of the corridor between Amboseli National Park and Tsavo West/ Chyulu Hills National Parks. The main techniques used were questionnaires, GPS surveys and spatial analysis. This study found that the structures that displace wildlife were bomas, or Maasai homesteads (0.23 ± 0.04 km), roads (0.18 ± 0.02 km), electric fences (.07 ±0.04 km) and institutions (0.18± 0.06 km). Livestock displaced wildlife 0.21 ± 0.02 km. The total area of KGR taken up by bomas including displacement was 28.11 km² (11.19% of KGR). The electric fence with displacement took up 69.29 km² (27.58% of KGR). All human activities displaced wildlife from 140.01 km² (55.74% of KGR), leaving about 44% of the land for wildlife and pastoralism. In addition, many of the clusters of bomas and agriculture block off the 5 km corridor between the Namelok and Kimana fences that leads to Kimana Wildlife Sanctuary leaving 1.82 km between the Namelok fence and the bomas and 0.112 km between the Kimana Fence and the bomas. If these main corridors are blocked off, the wildlife will be forced to find a new migratory route, most likely avoiding Kimana Wildlife Sanctuary (KCWS). The local opinions on conservation were found to be dependant on the benefits they receive from the KCWS and there were intense competitions for land and natural resources. These findings show that KGR status as a corridor and dispersal area for wildlife is severely threatened.

 

 

 

 

 

 

Student Author(s): 

Anderson, Marybeth

Dept & College or University:                        

Biology, UNC-Chapel Hill

Research Mentor(s)

Elaine Yeh/Biology, University of North Carolina at Chapel Hill

Title of Presentation:

The Dependence of Kinetochore Complexes on Centromere Binding

 

 

Correct mitotic segregation of chromosomes relies upon the attachment of the microtubule to the chromosome at the kinetochore complex. Unlike in other organisms, the attachment of microtubules to the yeast chromosomes requires only one microtubule per kinetochore; furthermore, each kinetochore is composed of at least nine protein complexes. Of these major complexes CBF3, containing the essential protein Ndc10, is located adjacent to the nucleosome and is important in formation of the kinetochore. This procedure tested whether known kinetochore proteins Ctf19 and Nuf2 localized to the kinetochore in an Ndc10 dependent manner. By comparing the intensity of GFP tagged Ctf19 in strains with and without Ndc10 it was determined that Ctf19, a member of the COMA complex, failed to assemble at the kinetochore in the absence of Ndc10. Nuf2, a member of the Ndc80 complex, was visualized as distinct foci along the spindle equator in the absence of Ndc10, however various abnormalities in the localization of Nuf2 were observed. We are currently looking at additional kinetochore complexes to determine their stability in the absence of kinetochore attachment.

 

 

 

 

Student Author(s): 

Anderson, Trevor

Dept & College or University:                        

Physics, NCSU

Research Mentor(s)

Keith Weninger/Physics, NCSU

Title of Presentation:

Exploring Different Pathways of SNARE Protein Complex Formation

 

 

For many normal biological events in cells, two membranes must merge into one.  SNARE’s are essential proteins that catalyze membrane fusion by assembling into a multi-protein

complex in many of these biological cellular settings.  For the past summer I have been using single molecule fluorescence to characterize complexes formed from a variety of different SNARE proteins (VAMP2, syntaxin, SNAP-25 and SNAP-29).  One of the complexes is well studied (VAMP:syntaxin:SNAP-25) and the other (VAMP:syntaxin:SNAP-29) is not.  I have used standard biochemistry tools (bacterial protein expression and protein purification) to generate the various proteins that I used to form the SNARE protein complexes.  Using electrophoresis and fluorescence resonant energy transfer, I have begun to compare the characteristics of the two complexes.

 

 

 

 

 

Student Author(s): 

Arnett, Kristen A.

Dept & College or University:                        

UNC-Pembroke

Research Mentor(s)

Paul Flowers/Chemistry and Physics, UNC-Pembroke

Title of Presentation:

Fluorescence Spectroelectrochemical Sensing for In-situ Determination of Heavy Metal Ions

 

 

This poster describes progress to-date on the development of a fiber optic spectroelectrochemical (FOSEC) fluorescence sensor for the in-situ determination of heavy metal ions. The sensor was fabricated by simple modification of a commercially available flow cell, and its electrochemical performance was determined to be satisfactory per voltammetric measurements using the aqueous ferri/ferrocyanide couple. Assessment of the sensor's spectral traits indicates a detection limit on the order of 10 nM for the copper-chelating ligand, calcein, suggesting the planned FOSEC analysis scheme may be capable of determining copper at ultratrace levels. The aqueous copper(II)/copper couple was chosen to investigate the analytical merit of an analysis involving (a) preconcentration of the analyte via cathodic electrodeposition, followed by (b) anodic stripping in an aqueous medium containing calcein and (c) subsequent measurement of calcein fluorescence quenching induced by its complexation with the analyte. Preliminary results are encouraging, though precision and sensitivity issues have been encountered and are presently being examined. This work was supported by funds from the National Science Foundation's Research Experiences for Undergraduates program (CHE- 0353724).

 

 

 

 

Student Author(s): 

Barnes, Charles A.

Dept & College or University:                        

Chemistry and Biochemistry, UNC-Greensboro

Research Mentor(s)

Norman H. L. Chiu/Chemistry and Biochemistry, UNC-Greensboro

Title of Presentation:

Structural Characterization of Modified 2’-Deoxyguanosine Nucleoside

 

 

Many toxic agents and their electrophilic metabolites readily react with DNA, and form different types of adduct with DNA. Clinically, DNA adducts have been linked to lung and bladder cancer. In this study, we have developed a high throughput matrix-assisted laser desorption/ionization (MALDI) mass spectroscopic (MS) method for the structural characterization of two different 2’-deoxyguanosine nucleoside adducts, namely N-(2’-deoxyguanosin-8-yl)-2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine (dG-C8-PhiP) and N-(2’-deoxyguanosin-8yl)-4-aminobiphenyl (dG-C8-ABP). In order to determine the molecular structure of the selected adducts including the position of adduction, each adduct molecule was dissociated into smaller chemical groups by using the collision induced dissociation (CID) technique, which has been incorporated as part of our MALDI mass spectrometer. To avoid any premature dissociation of the adducts during MALDI MS measurements, different MALDI matrices, sample preparation methods, and laser intensity were evaluated. Premature dissociation of the adducts was significantly reduced when 3-hydroxypicolinic acid matrix and layered dried droplets method were used. The CID experiments of the adducts produced reproducible fragmentation patterns that allow the identification of guanosine, PhIP or ABP, and the site of adduction at the C-8 position of guanosine. Depending on the choice of nucleases uses for breaking down a DNA fragment, the digested mononucleotides consist of terminal with either a hydroxyl or a phosphate group. Owing to this reason, the difference between dGMP and dG was investigated. The phosphate terminal has lowered the efficiency of desorption and/or ionization. Since, both dG-C8-PhIP and dG-C8-ABP are more soluble in DMF, the effects of DMF on MALDI MS measurements have also been examined.

 

 

 

 

Student Author(s): 

Belton, Jon-Matthew

Dept & College or University:                        

Molecular and Structural Biochemistry, NCSU

Research Mentor(s)

Linda Hanley-Bowdoin/Molecular and Structural Biochemistry, NCSU

Trino Ascencio-Ibanez/Molecular and Structural Biochemistry, NCSU

Title of Presentation:

Immunolocalization of AL1, geminivirus Replication Factor, in Arabidopsis Plants Infected with Cabbage Leaf Curl Virus

 

 

Cabbage Leaf Curl Virus (CaLCuV) is a member of the Geminiviridae family of plant viruses. Geminiviruses cause agricultural epidemics world wide, devastating a variety of crops including cassava, tomato, cotton and maize. Geminiviruses are characterized by their small, circular, single-stranded DNA genomes with either one or two chromosomes and by their double icosohedral viral particles. We used immunolocalization assays to study the viral replication protein, AL1, in wild type and mutant lines of Arabidopsis thaliana Col-0. Plants were inoculated with Agrobacterium tumefaciens carrying T-DNA constructs with the A and B genomes of CaLCuV. Microscopic analysis of vibratome-generated sections of infected plant tissues revealed the relative concentrations of virus in specific tissues. This information adds to our understanding of the infection process in the Arabidopsis model system.

 

 

 

 

 

Student Author(s): 

Blackwell, Valentene P.

Dept & College or University:                        

Biology, UNC-Greensboro

Research Mentor(s)

Dennis LaJeunesse/Biology, UNC-Greensboro

Title of Presentation:

The Drosophila Messy Mitochondria: It’s Not All about Mitochondria, or Is It?

 

 

In an F3 genetic screen of 700 late larval/pupal lethal chromosomes, we have identified a new mitochondrial morphology gene called messy mitochondria. messy mitochondria is an essential gene with a early pupal lethal period and an extended larval period. Loss of messy mitochondria results in an altered mitochondrial morphology phenotype in the Drosophila visceral muscles and other tissues. Interestingly, larvae mutant for messy mitochondria also express small and abnormal imaginal disc phenotype. The imaginal discs of messy mitochondria mutant larvae have lost their apical/basal polarity. The messy mitochondria phenotypes suggest a connection between intracellular organization of mitochondria and fundamental aspects of cellular organization.

 

 

 

 

Student Author(s): 

Boggess, Laura

Dept & College or University:                        

Biology, Carolina Environmental Program, UNC-Chapel Hill

Research Mentor(s)

Tom Goforth/Crow Dog Nursery

Title of Presentation:

The Correlation of pH Indicator Plant Species with the Geology of a Rich Mountain Cove in the Jocassee Gorges of Northern Pickens County, South Carolina: Preliminary Results

 

 

A stream cove located in the Inner Piedmont of South Carolina contains high and low pH indicator plant species in close association. Our project involves the analysis of all ecological factors contributing to the unusual mixture of plant species. Thus far, our research has included mapping the geology of the cove and conducting intensive surveys of plant species in selected plots. The terrain contains bedrock made up of the regionally dominant felsic Henderson Gneiss interlayered locally with a mafic hornblende/biotite gneiss. The preliminary results from the first three months of the study indicate that geological patterns directly influence the distribution of pH indicator species. Further study will include additional floristic surveys, analyses of soil chemistry, hydrology, slope, and aspect at the site, and graphic and statistical correlations of all ecological factors. Our results will provide a baseline for future studies of mixed indicator coves as well as providing components for developing predictive models that can be employed in both geological mapping and floristic surveys.

 

 

 

 

Student Author(s): 

Bond, Lisa M.

Dept & College or University:                        

Biology, UNC-Chapel Hill

Research Mentor(s)

Kerry Bloom/Biology, UNC-Chapel Hill

Title of Presentation:

Cohesin Is a Stable Component of Pericentric Chromatin

 

 

The biorientation of joined sister chromatids at metaphase permits the accurate transfer of genetic material to daughter cells during cell division. The cohesin complex, composed of Mcd1p/Scc1p, Scc3p, Smc1p, and Smc3p, facilitates accurate transfer by holding sister chromatids together until its cleavage at anaphase onset. This complex forms a cylindrical array around the mitotic spindle in the budding yeast Saccharomyces cerevisiae. A paradox is raised by the fact that 3-5 times more cohesin is bound at pericentric chromatin than along chromosome arms, but sister centromeres are separated by 600-800 nm prior to cohesin cleavage (Pearson et al, 2001). A recently proposed model accounts for cohesin enrichment at pericentric chromatin and sister centromere separation by suggesting that individual chromatids fold back upon themselves at each centromere to form “c-loops,” and that cohesin is distributed not only along the pericentric regions of juxtaposed sister chromatid arms (interstrand cohesin), but also along the overlapping regions of individual, folded chromatids (interstrand cohesin) (Bloom et al., 2006.). With this model in mind, this study focused on determining the stability of pericentric cohesin. Fluorescence Recovery after Photobleaching (FRAP) was used to monitor cohesin stability in cells expressing Smc3p-GFP. FRAP of histone H2B-GFP served as a positive control. Analysis revealed that cohesin fluorescence recovered above the background in only 2 of 12 cells, while histone H2B was dynamic in 5 out of 5 cells analyzed. These results suggest that cohesin is stably bound to pericentric chromatin. The stability of this structure may be important for establishing sister chromatid biorientation and/or contributing to stability of the mitotic spindle. Further use of FRAP analysis to ascertain the nature of specific forms of cohesin will contribute to the overall determination of the nature of pericentric cohesin.

 

 

 

 

 

Student Author(s): 

Braden, Amy K.

Eshraghi, Sarah

Dept & College or University:                        

Biology, Meredith College

Research Mentor(s)

Karthik Aghoram/Biology & Health Science, Meredith College

Title of Presentation:

Elucidation of the Mechanism of Activation of a Protein Kinase

 

 

Soybean Protein Kinase-1 (SPK1) is a 339 amino acid enzyme important to the functionality of drought response in some plants. When stimulated by osmotic stress (i.e. drought conditions), the protein is activated. The activation of SPK1 results in the phosphorylation of the lipid transfer protein Ssh1p which is thought to induce drought tolerance. The goal of this project is to determine the mechanism of activation of spk1 without the use of stress. The mechanism of activation is unknown but since it has been shown that other drought responsive protein kinases are activated by truncations we have formulated our experiments respectively. We hypothesize that by truncating amino acids off of the C terminus end of the protein sequence in four places, we will be able to produce a protein that is constitutively active. The truncated version of the protein will be used transform yeast cells. SPK1 activity will be assayed by immunoblotting experiments that are designed to track Ssh1p phosphorylation. If SPK1 is constitutively active, Ssh1p will be phosphorylated even in the absence of stress. I hypothesize that that a moderate truncation will result in constitutively activate SPK1, but the truncating too much may result in the complete inactivation of the protein.

 

 

 

 

 

Student Author(s): 

Bradshaw, Chelsea B.

Dept & College or University:                        

Animal Science, NCSU

Research Mentor(s)

Michael J. Yoder/Animal Science, NCSU

Title of Presentation:

Shackleford Wild Horse Nutrient Study

 

 

The wild horses living on Shackleford Island, in Cape Lookout National Seashore, North Carolina, are exposed to harsh climates; diets that vary in quality, quantity and nutritional value from season to season; and limited management schemes coordinated by the National Park Service.  This study examines diet content and nutrient value associated with nutritional maintenance, growth and reproductive efficiency.  Four collection periods, one for each of the four major seasons, were conducted to identify the types of forages consumed, and the nutrient value of these forages.  During each collection period, the ponies were observed until the forages they consumed were identified, a one-quart sample of the forage was then taken for analysis.  Nutrient analysis included crude protein, acid detergent fiber, calcium, phosphorous, sulfur, magnesium, sodium, potassium, copper, iron, manganese, zinc, and digestible energy.  The nutrient analysis results were then compared to daily nutrient requirements for mature weight ponies and horses, established by the National Research Council.  Initial analysis indicate that the diets consumed by the ponies of Shackleford Island are low in crude protein and several micronutrients including copper and zinc, yet are adequate in digestible energy.  In addition, calcium – phosphorus ratios vary between forage types and from one ecosystem to the next.  Knowledge gained from this study will increase our understanding of wild horse nutrition, will be useful in determining population limitations of the island, and will enhance management of the ponies that are removed from the island.

 

 

 

 

Student Author(s): 

Britt, Robin L.

Dept & College or University:                        

Appalachian State University

Research Mentor(s)

Dale E. Wheeler/Chemistry, Appalachian State University

Title of Presentation:

Synthesis and Characterization of Novel Heterobimetallic Ferrocene Imine Complexes

 

 

Heterobimetallic complexes containing π-bound metals connected through a conjugated aromatic bridge have the potential to exhibit nonlinear optical properties. Our research investigated the synthesis and characterization of several complexes containing ferrocene CpFe(C5H4) connected by CH=N to Cp*Ru(C6H4X)+ where X = Cl, OH, NO2, N(CH3)2 etc. Initially, several ferrocene benzylidene complexes were isolated from the reactions of ferrocenecarboxaldehyde with various aromatic aniline derivatives. Reactions of these products with Cp*Ru+ yielded novel heterobimetallic materials characterized by 1H and 13C NMR spectrometry and by visible spectrophotometry.

 

 

 

 

Student Author(s): 

Burroughs, James L.

Dept & College or University:                        

Molecular and Structural Biochemistry, Plant Pathology, Center for Integrated Fungal Research, NCSU

Research Mentor(s)

Gary A. Payne/Plant Pathology, NCSU

D. Ryan Georgianna/Functional Genomics, NCSU

Title of Presentation:

The afl-4 Mutation in Nontoxigenic A. flavus Strain 241 Is Caused by an Unknown Regulatory Element for aflR Transcription

 

 

Aflatoxins are extremely carcinogenic secondary metabolites produced by the filamentous fungus Aspergillus flavus. Our understanding of aflatoxin biosynthesis has been aided by the use of strains with mutations in the biosynthetic pathway for this carcinogen. The objective of the research reported here was to characterize the afl-4 mutation in strain 241, and determine if this mutation could be the result of a mutant copy of the global regulator of secondary metabolism, laeA. LaeA was chosen as a target gene because it regulates aflR, and our previous studies had shown that strain 241 fails to accumulate transcripts of aflR. We sequenced laeA from strain 241 and compared its sequence to a copy of laeA from an aflatoxin-producing strain of A. flavus. There were no detectable mutations in the copy of laeA in strain 241. We also isolated RNA transcripts from strain 241 grownunder conditions conducive for aflatoxin biosynthesis. Transcripts of laeA were produced in strain 241 under these conditions. We conclude from our studies that the afl-4 mutation in strain 241 is not a direct mutation of laeA.

 

 

 

 

Student Author(s): 

Cameron, Catherine M.

Dept & College or University:                        

Chemistry, UNC-Asheville

Research Mentor(s)

Jason Schmeltzer/Chemistry, UNC-Asheville

Title of Presentation:

Determination of the Growth Mechanism of Catalytically Grown Carbon Nanotubes

 

 

Carbon nanotubes are cylindrical carbon networks composed of single sheets of graphite rolled and capped at the ends. They exhibit extraordinary tensile strength, novel electrical properties, and efficient thermal conduction. When grown with a metal catalyst, a mixture of metallic and semiconducting nanotubes is obtained. Understanding the growth mechanism of carbon nanotubes has great importance; by attaining this knowledge, nanotubes can be tailored for specific applications where their physical and chemical properties play a significant role. Our investigations into nanotube growth are attempting to address the question of the role of nanoparticulates of gamma-iron mixed with carbon clusters on the surface of the 200-nm iron carbide (originally alpha-iron), which is the focal region of the growth of nanotubes. Currently, further studies are taking place in order to provide additional spatial information about the iron as well as to verify and reinforce our results. We are preparing a synthesis of ferrocene, the catalytic precursor, with the spectroscopically active 57Fe. Carbon nanotubes grown from this sample will improve results overall by producing reliable and unambiguous spectra. In addition, a thorough examination by TEM is in progress which would help to confirm the size distribution and location of alpha- and gamma-iron nanoparticles. We believe that gamma-iron nanoparticulates are stabilized by carbon nanoclusters, while the gamma-iron particles are clinging to the nanotube walls.

 

 

 

 

 

Student Author(s): 

Carroll, Turhan

Dept & College or University:                        

NCSU

Research Mentor(s)

Noah Finkelstein/Physics, University of Colorado, Boulder

Title of Presentation:

A Study of the Effectiveness of using PER-Based Course Transformations in a Summer Session Setting

 

 

Physics Education Research (PER) is a sub-discipline of physics that focuses on developing research-based models and practices of teaching, learning, and student understanding.  As a result of physics education research, many course transformations have been developed in an effort to improve students’ overall understanding of physics.  The success of these transformations has raised many questions about how and where these transformations can be replicated.  The University of Colorado at Boulder has developed a model of a transformed introductory physics course and since the fall of 2003, has been carrying out on-going research with several goals:  identifying causes of success (and failure) in these transformed classrooms, assessing the feasibility of repeating and sustaining transformations, and attempting to transfer transformations to non-PER faculty.  In this particular study, a University of Colorado’s transformed model was implemented during a summer semester and several instruments were used to assess the learning gains and shifts in attitudes and beliefs, about physics, of the students who took this course. 

 

 

 

 

Student Author(s): 

Casserman, Lauren A.

Gapin, Jennifer

Kirk, Stephanie D.

Barella, Lisa

Dept & College or University:                        

Exercise and Sport Science, School of Health and Human Performance, UNC-Greensboro

Research Mentor(s)

Paul G. Davis/Exercise and Sport Science, School of Health and Human Performance, UNC-Greensboro

Jennifer L. Etnier/Exercise and Sport Science, School of Health and Human Performance, UNC-Greensboro

Title of Presentation:

Psychological Status and Misreporting of the Body Weight in Overweight and Obese Young Women

 

 

Overweight and obese women often under-report body weight. The purpose of this study was to compare the extent of mis-reporting of weight and height to measures of psychological variables. Young overweight and obese women requesting information about an exercise-training study gave their weight and height during a telephone interview. They followed this by having their weight and height measured in a laboratory. During this visit, the participants also completed questionnaires assessing various components of physical self-perception, as well as self-esteem and depression. Participants under-reported weight and over-reported height. The only significant relationships between reporting discrepancies and psychological variables were between strength self-perception and mis-reporting of weight (r=0.364, p=0.04) and between sport self-perception and mis-reporting of height (r=0.492, p=0.004). In addition, a significant relationship was not found between depression and mis-reporting of body mass index (calculated from self-reported weight and height), but the relationship approached significance among White participants (r=-0.526, p=0.10). These preliminary results suggest that physical self-perception, self-esteem, and depression do not seem to have a strong influence on the mis-reporting of body weight or height in overweight and obese young women. However, the relationships between psychological variables and mis-reporting of body weight and height may depend partially upon ethnicity.

 

 

 

 

Student Author(s): 

Corum, Daniel G.

Dept & College or University:                        

Biological Sciences, College of Agriculture and Life Sciences, NCSU

Research Mentor(s)

R. Michael Roe/Entomology, College of Agriculture and Life Sciences, NCSU

Title of Presentation:

Identification of Novel Neuropeptides from the Tick Synganglion

 

 

Ticks are obligate ectoparasites that vector a wide range of diseases that impact human and animal health (Sonenshine, 1993). There is a paucity of information on the role of the tick synganglion compared to insects. Identification of neuropeptides from the tick brain may lead to novel targets for tick control as well as increase our knowledge of the role of the CNS in tick endocrinology and molting. The first neurohormone identified from the CNS of an ixodid tick was identified via MALDI-TOF/TOF MS (Neupert et al. 2005). The de novo sequenced peptide was identified as a periviscerokinin, a peptide involved in water balance. Prior to this study, only two putative salivary secreted neuropeptide-like proteins from Ixodes pacificus had been identified. Lomas et al. (1997) found that the tick synganlion is capable of stimulating ecdysteriodogenesis in integumental tissue. Ecdysteroids initiate the cascade of events leading to vitellogenesis and egg production in ticks (Thompson et al. 2005). These studies elucidate the important role of the tick CNS in several key physiological events. In the current study 100 synganglia were dissected from fully engorged mated female Dermacentor variabils ticks in order to construct a subtractive cDNA library. We chose used a suppression subtraction PCR method (whole body cDNA without synganglian subtracted from synganglian cDNA) to preferentially enrich for sequences unique to the D. variablis brain. Our overall goal is to sequence 15,000 ESTs, construct EST microarrays, and examine global gene expression in order to identify candidate genes important in tick blood feeding and reproduction.

 

 

 

 

Student Author(s): 

Daniels, Ryan L.

Dept & College or University:                        

BM Performance, UNC-Greensboro

Research Mentor(s)

Patricia Gray/BioMusic, UNC-Greensboro

Title of Presentation:

Music Perception in Primates

 

 

The Bonobo, Pan paniscus, is the great ape species to which humans are most closely related and are an endangered species indigenous in the environs of the Democratic Republic of Congo. Bonobos share most of our DNA (99.797% of ours) and many of our social propensities, which make them a prime source for my research. This research project examines parallels between spoken language and music. Working with a group of a language-competent bonobos at the Great Ape Trust in Des Moines, Iowa, the research focuses on analyzing bonobo vocalizations captured during exchanges between a human caretaker and Nyota, Panbanisha and Kanzi. These are bonobos who have recorded with Paul McCartney and Peter Gabriel using synthesizers and who engage in musical activities by their own choice. Because the auditory range of Pan paniscus is not known, I am using sound analysis programs, such as CSL and Sound Forge, to track the bonobos’ auditory range. These analytical tools enable manipulation to slow down the vocalizations and to put the vocalizations’ frequency range within the range of human perception. Patterns in vocalizations are also being examined to identify the bonobos’ musical constructions and patterns. By examining musicality in Bonobo apes, we are expanding our understanding of the ‘culture of the ear’ while showing musical linkages in the evolution of language.

 

 

 

 

Student Author(s): 

Das, Riva

Dept & College or University:                        

Duke University

Research Mentor(s)

Goldschmidt, Pascal/Department of Medicine, Division of Cardiology, Duke University

Seo, David/Institute of Genome Sciences and Policy, Duke University

Title of Presentation:

Effects of Osteopontin Knockdown on Atherosclerosis

 

 

Because microarray analyses of human and mouse aortas have shown that osteopontin has significantly higher expression in atherosclerotic versus normal vascular tissues, we hypothesize that osteopontin may play a role in the development of atherosclerosis. Therefore, we would like to examine the effect of altering osteopontin levels in cells known to be involved in atherogenesis, vascular smooth muscle cells and macrophages. We would like to study the effects of osteopontin on the phenotype of these cells, as well as the molecular effects on other genes. This project represents the first step of our investigation, which is to develop a system for gene knockdown in cells using small interfering RNAs (siRNAs). siRNAs are double-stranded RNAs that can silence genes with a high degree of specificity by harnessing the intracellular RISC pathway. In this project, three siRNAs for osteopontin were designed and then cloned into a lentiviral vector, which will be used for future in vivo studies. We tested the siRNAs for efficiency of osteopontin gene expression knockdown in the HEK293T cell line. Western blot analysis showed that one of our siRNA constructs reduced osteopontin expression by 80-90%. Our next step will be to transfect vascular smooth muscle cells and macrophages with our siRNA construct and study the effects of reduced osteopontin expression.

 

 

 

 

Student Author(s): 

Davis, Ryan

Dept & College or University:                        

North Carolina Central University

Johns Hopkins University

Research Mentor(s)

A. Karoui/Natural Science and Mathematics, Shaw University

B. Vlahovic/Physics, NCSU

Title of Presentation:

Characterization of Electrically Active Defects in Solar Grade Polycrystalline Silicon

 

 

The examination of impurities in semiconductors is one of the most pertinent studies in optimizing electronic device performance.  In this study, we test solar grade polycrystalline Schottky diodes, using two highly sensitive techniques called Deep Level Transient Spectroscopy (DLTS) and Capacitance Voltage (CV).  These techniques enable the identification of doping levels, impurity content, and other device and material related parameters.   This allowed us to compute the defect capture cross section and the activation energy of deep level traps in our samples.  Such properties are essential to understanding the impact that defects have on the performance of the photovoltaic cells that are used in sub-micrometer and nanoscale electronic devices.

 

 

 

Student Author(s): 

Derballa, Nicole

Dept & College or University:                        

Psychology, UNC-Asheville

Research Mentor(s)

Mark Harvey/Psychology, UNC-Asheville

Title of Presentation:

Drama as a Form of Informal Science Education and Its Effectiveness in Promoting Science Literacy, Comprehension, and Memory

 

 

The present research study explored the use of drama to support children’s learning and interest in primary science. Working closely with the Health Adventure of Asheville as they launch their new science performance program, the present research sought to determine the effectiveness of a dramatic performance, revolving around the topic of the laws of motion, on student interest in science, science literacy, and memory for scientific facts presented in the play. The present research addressed the limitations of classroom science education and makes a contribution to the literature on informal science education. More specifically, the present study focused on drama as a method of informal science education via an evaluation of the drama performance as a means of informal science education and its effectiveness in achieving its goals. Preliminary data analyses show that drama is indeed an effective means for enhancing science learning.

 

 

 

 

 

Student Author(s): 

Desmarais, Jamie A.

Dept & College or University:                        

Zoology, NCSU

Research Mentor(s)

Jane Lubischer/Zoology, NCSU

Title of Presentation:

Changes in Expression of 4E2 after Denervation of Neonatal Rat Soleus Muscle

 

 

The expression of 4E2 in Schwann cells and in neurons after denervation of the soleus muscle was examined in neonatal rats at ages where reinnervation rarely occurs. It has been shown that plasticity at the neuromuscular junction in neonatal rats is limited in comparison to adults, and that this response is linked to Schwann cell death by apoptosis that occurs after denervation of muscle (Trachtenburg and Thompson, 1996; Lubischer and Thompson, 1999). Terminal Schwann cell reactivity is key for reinnervation of denervated muscle in adult rats, and involves a change in gene expression, including the upregulation of several proteins including the one of interest to this study, 4E2 (Son and Thompson, 1999). After denervation and before Schwann cell death (1 day after nerve cut) the soleus muscles were removed. Immunohistochemical procedures (antibody labeling) were used to identify the presence of the protein 4E2. Preliminary results showed that after denervation 4E2 was downregulated postsynaptically (in muscle fibers) and also decreased in the nerve. Preliminary observations also indicated that an upregulation of 4E2 in terminal Schwann cells did not occur after the one day survival time. These results suggest age-related changes in the expression of 4E2 in response to denervation, which may be linked to limited plasticity in neonates. Further questions remain about other factors preventing reinnervation, as well as the identification of a developmental time course for changes in 4E2 expression after denervation. Future studies will confirm these results and examine 4E2 expression along the nerve and in terminal Schwann cells at longer survival times after denervation, but before Schwann cell apoptosis occurs.

 

 

 

 

 

Student Author(s): 

Duggins, Luke M.

Dept & College or University:                        

Biology, UNC-Greensboro

Research Mentor(s)

Elizabeth P. Lacey/Biology, UNC-Greensboro

Title of Presentation:

Geographic Variation in Anthocyanin Deposition in Flowers of Plantago lanceolata

 

 

Flower color in the weedy perennial, Plantago lanceolata, is phenotypically plastic. Darker flowers are produced at cooler ambient temperatures, and existing evidence suggests that this is adaptive. Flowers darken at cooler temperature because of increasing anthocyanin production. Anthocyanins appear in multiple tissues of a flower: sepals, petal lobes, and subtending bract. However, anthocyanin deposition is genetically variable. Our goal was to examine the geographic variation in pattern of tissue-specific deposition. We grew samples of plants from 19 populations that spanned a range of latitudes and altitudes in Europe, where the species is native. Plants were grown at low temperature in growth chambers and the location of anthocyanins in flowers was recorded. Plants at all latitudes and altitudes produced anthocyanins in the subtending bract and fused sepals. However, the frequency of anthocyanin deposition in the lateral sepals and petal lobes was positively correlated with latitude but not altitude. The increase in number of tissues where anthocyanins are located helps to explain why flower color in P. lanceolata, on average, darkens with increasing latitude in Europe.

 

 

 

 

 

Student Author(s): 

Durojaiye, Modupeoluwa

Dept & College or University:                        

Biology, Bennett College

Research Mentor(s)

Sekara Basavaraju, Biology, Bennett College

Title of Presentation:

Streptozoticin Induced Type 1 Diabetes Mediated Reducation in Intrinsic Heart Rate of Murine Model (Mice)

 

 

Previous research showed a fall in heart rate of Type 1 induced diabetic mice. The purpose of the research was to see if the fall in heart rate was due to a decrease in intrinsic heart rate. The hypothesis of this study is that the fall in heart rate of Type 1 diabetic mice is not mediated by the autonomic nervous system, and thus will be mediated by a fall in intrinsic heart rate. Mice were surgically implanted with DSI EKG telemeters that were used to measure the heart rate, activity rate, and body temperature. Six out of twelve mice were randomly picked for Streptozoticin (STZ) injection, and the other six served as controls. Blood samples were drawn for the glucose assay test. Metoprolol and Atropine injections were used to test intrinsic heart rate. Diabetes was induced in the mice by injecting them with STZ that was dissolved in dilute sodium citrate solution. A glucose assay test was conducted on their blood plasma samples. The injected mice had a higher blood glucose concentration than the controls. We saw a relatively low heart rate in our diabetic mice as we had expected to see. We had hoped to see a lower intrinsic heart rate in our diabetic mice. We compared their intrinsic heart rate before and after they were injected. We did not notice much difference. Therefore, the fall in heart rate of Type 1 diabetic mice may not be due to decrease in intrinsic heart rate.

 

 

 

 

 

Student Author(s): 

Edathil, Roshen T.

Dept & College or University:                        

Biochemistry, NCSU

Research Mentor(s)

William L. Miller/Biochemistry, NCSU

Title of Presentation:

Identification of Transcription Factors that Partner with Smad3/4 to Induce Transcription of oFSHβ

 

 

 

Follicle Stimulating Hormone (FSH) is required for egg and sperm production in mammals.  FSH is an α/β heterodimer with FSHβ controlling overall expression. Because of its importance, FSHβ is controlled by more than 6 hormones, one of which is activin-A, a transforming growth factor beta (TGFβ) family member.  Activin typically activates Smad3, a nuclear transcription factor, that then binds Smad4 and other transcription factors to form DNA-enhancesome promoter complexes to induce gene transcription.  One Smad binding site in the FSHβ promoter seems especially important for FSH expression (-166GTTTAGAC-159).  My goal this summer has been to isolate the nuclear transcription complex containing Smad3/4 and all other proteins involved in inducing FSHβ transcription.  I increased Smad3 concentrations in FSH-producing cells (LβT2) by transient transfection of a Smad3 expression plasmid, isolated the nuclear proteins and incubated the nuclear extract with biotinylated DNA known to bind Smad3/4 most efficiently (GTCTAGAC-biotin).  The DNA-Smad3/4-enhancesome complex was isolated using Streptavidin-coated magnetic microbeads that were captured on a magnetic column.   Western blotting with antibodies was used to show efficient extraction of Smad3/4 (chemiluminescence).  Other proteins in the complex will be identified using HPLC-Mass Spectral analysis.  Optimization of this technique using Smad3/4 was necessary to ensure efficient extraction of enhancesome proteins.  Characterization of the Smad-associated transcription factors on the FSHβ promoter will identify proteins that can partner with Smad3/4 and may be important in hundreds of other activin induced promoters.

 

 

 

Student Author(s): 

Emery, Nathan

Dept & College or University:                        

Duke University

Research Mentor(s)

Art McKee/Forest Ecology, University of Montana

Title of Presentation:

Patterns of Plant Species Diversity in Floodplain Habitats

 

 

Riparian ecosystems are generally characterized by high levels of biodiversity and environmental heterogeneity. This study examines plant species diversity on the Nyack floodplain of the Middle Fork of the Flathead River, a free-flowing gravel-bed river in northwestern Montana, USA. Frequency of flooding, presence or absence of upwelling/downwelling zones, and relative elevation above base-flow conditions were examined to describe patterns of species diversity observed in the Nyack ecosystem. This study found no significant difference in species richness between upwelling and downwelling zones. Species richness was significantly higher in areas with moderate flooding frequency as opposed to high frequency of flooding. Elevation above base channel appears to be correlated with species richness as well as the variance in slopes of species-area curves for all sites on the floodplain. Sampled sites on average contained 28% invasive plant species. This is cause for concern over the long-term condition of floodplain habitats.

 

 

 

Student Author(s): 

Fagan-Tucker, Chloe L.

Dept & College or University:                        

Biomedical Engineering, Pratt School of Engineering, Duke University

Research Mentor(s)

Martha Delahunty/Division of Hematology, Department of Medicine, Duke University

Title of Presentation:

Identifying SS Red Blood Cell Proteins Responsible for Adherence to P-Selectin

 

 

 

 

P-selectin is a cell adhesion molecule -granules of activated platelets and granules ofa(CAM) expressed in  endothelial cells.  Proteins containing sialic acid moieties (SA) present on SS RBCs are known to bind to endothelial P-Selectin.  This study will identify these proteins by blocking SA-mediated adhesion using graduated height flow chamber analysis.  The vector Psel-Fc pEDdC encodes a chimeric protein of P-Selectin and the FC portion of immunoglobulin.  The P-Selectin/Fc plasmid was amplified using E.coli bacteria, and purified using a QIAPrep Spin Kit.  Chinese Hamster Ovary (CHO) cells were transfected with P-Selectin/Fc DNA and selected using Hypoxanthine-Thymidine (HT), which is produced by the Dihydrofolate Reductase (dHFr) gene in pEDdC.  CHO cells containing the plasmid grew and divided, eventually secreting protein into the growth media.  From that media, the presence of P-Selectin protein is detected using dot blot screening with mouse monoclonal antibody (msmAB) for human P-Selectin.  Further in vitro testing will be done using flow chamber analysis to observe interactions between P-Selectin and the SS RBCs.  P-Selectin adherence to SA will be tested by flowing SS RBCs over a slide coated with purified P-Selectin, then counting the adherent SS RBCs at different points along the chamber.  Antibodies to known SS RBC proteins or SA will also be tested for blocking adhesion to P-Selectin, which will identify what proteins are binding to P-Selectin.  Detection of P-Selectin protein thus far confirms the success of the methods performed through CHO cell transfection. 

 

 

 

 

Student Author(s): 

Fairey, Donta' J.

Dept & College or University:                        

Center for Earth Observation Forestry and Environmental Resources, NCSU

Research Mentor(s)

Justin M. Shedd/Forestry and Environmental Resources, NCSU

Stacy A. C. Nelson/Forestry and Environmental Resources, NCSU

Title of Presentation:

Implementation of GIS Techniques for Effective Wetland Delineations

 

 

The Blue Ridge Parkway part of National Park System contains many natural resources which are important to ecological and environmental productivity. The monitoring and assessment of wetland systems within park boundaries present logistical challenges to the National Park Service due to their widely distributed locations within local watersheds, and the budgetary expense, labor and time required surveying these systems over large areas. This study focuses on the implementation of effective techniques using high-resolution Digital Elevation Models and GIS hydrologic tools to identify wetland-containing watersheds within the Blue Ridge Parkway unit. The data from this study will then be used to aid ongoing projects involving wetland monitoring and assessment.

 

 

 

 

 

Student Author(s): 

Ferreyra, Jessica A.

Dept & College or University:                        

Biology, Duke University

Research Mentor(s)

James A. Alspaugh/Infectious Diseases, Duke University Medical Center

Connie Nichols/Infectious Diseases, Duke University Medical Center

Title of Presentation:

Surviving the Heat Wave: The Role of Ras1 in Mediating High Temperature Growth in Cryptococcus neoformans

 

 

Cryptococcus neoformans is an important human fungal pathogen. The highly conserved Ras1 GTPase is required for the survival of C. neoformans at the human body temperature of 37°C. In addition to temperature sensitivity, the ras1 mutant strain has defects in mating and cell morphology. To further explore the role of Ras1, we performed the following experiments. First, we used the yeast two-hybrid assay to define upstream regulators of Ras1, and we have tentatively identified one Ras1-interacting protein. In a second group of experiments, we characterized the function of three different ras1 mutant alleles by assessing their abilities to complement a ras1 knockout strain. The first mutant was a dominant negative version of ras1, and it did not complement any of the ras1 knockout strain phenotypes. In contrast, the second ras1 mutant allele, encoding a dominant active version of Ras1, complemented all of ras1  knockout strain phenotypes. The third ras1 mutant allele encodes a Ras1 protein defective in palmitoylation and localization. This mutant allele restored growth at 37°C but did not complement the mating defect of the ras1 knockout strain.

 

 

 

 

 

Student Author(s): 

Flores, Diana

Dept & College or University:                        

Biology, Mars Hill College

 

Research Mentor(s)

Scott Pearson/Biology, Mars Hill

College and Jo Ann Croom/Biology, Mars Hill College

Title of Presentation:

Validating and Comparing the Effects of Essential Oils on Bacterial Growth

 

 

 

Understanding the beneficial and detrimental effects of using herbal products would be conducive to the future of healthcare and agriculture.  Research is needed to determine the possible applications and dangers of these products.  This experiment was designed to assess and compare the potential of four essential oils (Origanum vulgare, Zingiber officinale, Eucalyptus globulus, and Melaleuca alternifolia) to inhibit growth of several species of bacteria (Bacillus aureus, Corynebacterium xerosis, Escherichia coli, Klebsiella pneumoniae, Micrococcus luteus, Pseudomonas aeruginosa, Pseudomonas fluorescens, and Staphylococcus aureus.  The research questions addressed were: 1) do essential oils inhibit bacterial growth; 2) do essential oils vary in their effectiveness in inhibiting bacterial growth; 3) is there variation in susceptibility to essential treatment between species of bacteria; 4) does gram status affect susceptibility to essential oil treatment?  The disc-diffusion method was used to assess bacterial growth inhibition.  The conclusions reached were: 1) essential oils do inhibit bacterial growth (p<.005); 2) essential oils vary in their ability to inhibit bacterial growth, with O. vulgare being the most effective (p<.005); 3) bacterial species vary in their susceptibility to essential oil treatment with E. coli being the most susceptible (p<.005); 4) there is no correlation between susceptibility and gram status (p=.88).  These results may be applied in food preparation to prevent bacteria related illness, in the development of natural and mild disinfectants, and in the protection of crops against problematic bacteria.

 

 

 

 

Student Author(s): 

Fulp, Myra F.

Dept & College or University:                        

Molecular and Structural Biochemistry, NCSU

Research Mentor(s)

Jeffrey A. Yoder/Molecular Biomedical Sciences, NCSU

Title of Presentation:

Novel Immune-Type Receptors in the Rainbow Trout

 

 

The purpose of this project is to identify and characterize the Novel Immune-Type Receptor (NITR) genes in rainbow trout (Oncorhyncus mykiss). NITR genes encode cell surface proteins that are hypothesized to play a role in innate immunity. NITRs are encoded by a complex multi-gene family in multiple fish species and are proposed to play a role in the detection of virally infected and transformed (cancer) cells. Although 36 NITR genes have been identified in zebrafish, only 4 NITR genes have been characterized in rainbow trout suggesting additional NITR genes remain to be identified in this agriculturally important species. We have utilized genomics and PCR strategies to identify partial sequences of additional NITR genes and transcripts in trout. The definition of these genes in trout will contribute to a better understanding of innate immunity in this species and may advance aquatic medicine by developing biomarkers for infection or cancer.

 

 

 

 

 

 

Student Author(s): 

Goldstein, Anna P.

Dept & College or University:                        

Chemistry, UNC-Asheville

Research Mentor(s)

Sally A. Wasileski/Chemistry, UNC-Asheville

Title of Presentation:

Dehydrogenation and Partial Oxidation of Ethanol over Rh(111): Elucidating the Reaction Mechanism from DFT

 

 

 

Proton-exchange membrane (PEM) fuel cells utilizing hydrogen gas as a fuel offer a viable source for energy production. However, the source of hydrogen must be considered in developing sustainable energy resources. Dehydrogenation of bioethanol could provide renewable hydrogen gas. Experimental studies have shown the success of Rh as a catalyst for the dehydrogenation of ethanol (CH3CH2OH + H2O --> 4H2 + CO), but the elementary steps of the reaction mechanism have not been determined. Ab initio methods such as density functional theory (DFT) have been widely utilized for probing energies and reaction pathways for a variety of heterogeneous catalytic systems. Here, periodic DFT calculations are used to investigate the elementary steps of ethanol dehydrogenation and partial oxidation over single-crystal Rh(111) surfaces as a model of the experimental Rh catalyst. The full dehydrogenation mechanism of ethanol over a Rh(111) catalyst surface will be presented, utilizing the Bell-Evans-Polanyi approximation that the kinetic pathway can be determined from the thermodynamic reaction energies. Briefly, from adsorbed ethanol (CH3CH2OH), the initial loss of a hydrogen atom is endothermic, forming one of three molecules (CH2CH2OH, CH3CHOH, and CH3CH2O) with similar thermodynamics. Both CH3CHOH and CH3CH2O can proceed to lose a second hydrogen atom in an exothermic reaction step to form CH3CHO. Therefore, the first two dehydrogenation steps are the loss of the OH hydrogen and the alpha-hydrogen, in no particular order. CH3CHO then undergoes a highly exothermic dehydrogenation (-0.53 eV) to lose another alpha-hydrogen and form CH3CO, limiting the degrees of freedom to consider in determining the elementary steps involved in C-C cleavage.

 

 

 

 

Student Author(s): 

Gregory, Jasmine M.

Dept & College or University:                        

Chemistry, UNC-Charlotte

Research Mentor(s)

Thomas A. Schmedake/Chemistry (Coas), UNC-Charlotte

Title of Presentation:

Development of An Improved Oxygen Sensor: Incorporating a Tris-bipyridyl Ruthenium(II) Dye into a Sub-Wavelength Optical Cavity

 

 

The purpose of conducting this experiment was to enhance photo-chemical and photo-physical processes through optical cavity design. I hypothesized that optical cavity design would inhibit the flourescence rate for sub-wavelength spheres doped in ruthenium dye. This would make flourescence via oxygen more competitive. The result would be a more sensitive oxygen sensor than currently available. For a proof of concept demonstration, the making of an improved oxygen sensor was attempted. Various processes such as doping, refractive index measurements, and spectroscopy were used in this experiment to support the hypothesis. Doping was used to attach the ruthenium dye to the silicas spheres. The refractive index measured the speed of light in a vacuum divided by the speed of light in a particular material. Spectroscopy was used to study the way the sample absorbed light(UV-Vis Spectrophotometer), emitted light(flourescence spectrometer) as we! ll as the rate at which it emitted light(flourescence lifetime spectrometer). The flourescence decay curve of the first generation of spheres was nonlinear which suggested a non-uniform system. The flourescence decay curve of the second generation of spheres was linear suggesting a more uniform system. In conclusion, the lifetime data supported the hypothesis: doping spheres in ruthenium dye can control the lifetime of sub-wavelength spheres.

 

 

 

 

 

Student Author(s): 

Grimsley, Megan L.

Dept & College or University:                        

Chemistry and Physics, UNC-Pembroke

Research Mentor(s)

Timothy Ritter/Chemistry and Physics, UNC-Pembroke

Title of Presentation:

The Effects of Varying Gravitational Fields on Enzymatic Reaction Rates

 

 

The results of our research that will be presented summarize the overall performance and completion of UNC-Pembroke’s participation in NASA’s Reduced Gravity Student Flight Opportunities Program. Two experiments were performed throughout a parabolic flight pattern, which created both micro- and hyper-gravity environments. The first experiment centered on exploring and quantifying properties of enzymatic reaction rates during the 0-g and 2-g gravitational fields. Before flight, the optimum ratio of enzyme to substrate concentration was established by creating solubility curves. After the enzyme reaction was performed on board the aircraft, the samples were quantified using spectral analysis. The average absorbance for the 0-g samples was 0.37 while the average of the 2-g measurements was 0.34. From these results we have concluded that there was no significant difference of enzyme reactivity in varying gravitational fields. Ground truth data was produced post-flight in the 1-g environment, resulting in an average absorbance value of 0.14. We contribute this significant difference from the 0-g and 2-g data to the inconsistent temperature of the enzyme solution and are exploring this anomaly in further detail. The second experiment visually demonstrated the effect of gravity using a ball- dropping apparatus and was designed primarily for outreach presentations for young audiences.

 

 

 

 

Student Author(s): 

Grove, Anna M.

Dept & College or University:                        

Lenoir-Rhyne College

Research Mentor(s)

David Donze/Biological Sciences, Louisiana State University

Title of Presentation:

Mutational Analysis of the Bromodomain Homology Region of the YTA7 Gene, which Encodes a Chromatin Binding Protein Involved in Heterochromatin Barrier Function

 

 

The S. cerevisiae YTA7 gene encodes a protein that functions to restrict the spread of heterochromatic gene silencing. It contains a region of bromodomain homology that is necessary for chromatin binding and barrier function, but differs from most bromodomains in certain key conserved amino acid residues. This study was designed to target point mutations to the bromodomain to assess which amino acids are required for Yta7p function and chromatin binding.

 

 

 

 

 

Student Author(s): 

Hair, Jessica

Flood, Brittany

Cecil, Angela

Lockhart, Elizabeth

Nowsheen, Somaira

Wukovich, Rebecca

Aziz, Khaled

Francisco, Dave

Peddi, Prakash

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

Alex Georgakilas/Biology, East Carolina University

George Sigounas/Department of Internal Medicine, Brody School of Medicine, Hematology/Oncology Department

Title of Presentation:

Accumulation of Oxidative Clustered DNA Lesions (OCDL) in Human Breast Cancer Cells (MCF-7)

 

 

Double stranded breaks (DSBs) and Oxidative clustered DNA lesions (OCDLs i.e. two or more closely spaced oxidative DNA lesions) are perhaps the most lethal and mutagenic forms of DNA damage. OCDL can be induced endogenously or by a number of external agents, including ionizing radiation and radiomimetic drugs. OCDLs when processed may result in DSBs, mutations, or cell death. There is no knowledge of the involvement of clustered DNA lesions in the susceptibility and progression to cancer. Taking into account the accepted significance of DNA damage and repair in the etiology of cancer, we propose these studies as the first step to assess the role of OCDL in the development of malignancies and more specifically, breast cancer. The human breast cell lines MCF-7 (malignant with reduced BRCA1 expression) and MCF-10A (non-malignant with normal BRCA1 expression), have been used as our study model. The methods of modified neutral Pulsed Field Gel Electrophoresis (PFGE), Alkaline Comet Assay and Number Average Length Analysis (NALA) with the use of highly sensitive enzymatic probes have been used for the measurements of clustered DNA damage. Immunofluorescence, Western Blotting and antioxidant assays have been used for the detection of several repair proteins including γ-H2AX as well as of the cellular antioxidant capacity. Preliminary data suggests an accumulation of DSBs, single strand breaks (SSBs) and clusters in MCF-7 cells compared to MCF-10A cells. Current studies are focusing on the elucidation role BRCA1 and other repair proteins in the processing OCDLs and DSBs in breast cancer cells and tissues.

 

 

 

Student Author(s): 

Hammond, Rebecca L.

Dept & College or University:                        

Plant Biology, NCSU

Research Mentor(s)

Heike Winter-Sederoff/Plant Biology, NCSU

Title of Presentation:

Is Transcriptional Regulation of Gravitropism Conserved Between Dicots and Monocots?

 

 

Gravity is a constant force that directs the course of plant growth. Plants sense the direction of the gravity vector and respond to changes in orientation by redirecting their growth. This response to gravity requires specific changes in gene expression to accomplish differential cell elongation. Previous studies on Arabidopsis root tips (Kimbrough et al. 2004) and the maize pulvinus (Heilmann et al. 2001, Myburg, unpublished) reveal that specfic genes are regulated within minutes of gravitropic stimulation. We are comparing gene expression patterns in response to gravity between maize pulvini and Arabidposis root tips to identify possible conserved mechanisms. Conserved and tissue specific gravity induced changes in trnascript abundances will further be analyzed for their temporal expression in maize root apices. In these experiments we will monitor changes in transcript abundances in the maize root over a time course during the first hour after reorientation using real-time PCR. The expression profile information genereated will then be compared between Arabidopsis root tips and the maize pulvinus to assess the level of conservation in transcriptional regulation between dicots and monocots.

 

 

 

 

Student Author(s): 

Haywood, Jackie B.

Dept & College or University:                        

UNC-Greensboro

Research Mentor(s)

Susan L. Phillips/Communication Sciences and Disorders, UNC-Greensboro

Title of Presentation:

Investigation of Clinical and Environmental Factors of Noise-Induced Hearing Loss

 

 

This study examines the clinical and environmental factors that contribute to noise- induced hearing loss, in order to better identify a phenotype useful for future genotypic studies. Hearing tests performed on students in a university School of Music show that 52% have a notch at 6000 Hz in at least one ear.  This unique population eliminates the confounds of age and extreme acoustic overexposure. Factors to be reported on include specific instrument and dosage measurements.

 

 

 

 

Student Author(s): 

Heighington, Cassandra

Dept & College or University:                        

Genetics, NCSU

Research Mentor(s)

Greg Gibson/Genetics, NCSU

Priscilla Hunt/Genetics, NCSU

Title of Presentation:

Imaging Variation in Pattern Formation during Drosophila Development

 

 

We have initiated a project to digitally image variation in normal expression of genes during early embryogenesis of the fruitfly, Drosophila melanogaster . The long term objective is to understand how embryonic patterning is buffered against the effects of environmental and genetic variation, preventing the appearance of birth defects. As a first step, we have begun to quantify variation in the boundaries of expression of so-called "gap" genes in a panel of 5 highly inbred lines from North Carolina. Gap genes are expressed in broad bands along the embryo, and the boundaries of the expression domains help to specify the future boundaries of segments. To measure differences in expression we used whole mount in situ hybridization to visualize the transcripts, Procrustes transformation to rotate and scale landmarks that represent the expression boundaries, and principal component analysis to define the major axes of variation. Analysis of variance indicates that the orthodentical (otd) transcripts show significant differences in the boundaries of expression among 5 of the North Carolina lines. For example, the posterior edge of otd expression in line 15 extends further to the posterior of the embryo than in the other lines. This is notable because line 15 has a deletion in the regulatory region of the otd gene that population genetic analysis indicates is under selection. We are currently measuring the expression in more lines in order to establish whether the deletion might cause the difference in expression.

 

 

 

 

 

Student Author(s): 

Howard, Michael B.

Dept & College or University:                        

Mathematics and Science, Nash Community College

Research Mentor(s)

Michael P. Shaner/Mathematics and Science, Nash Community College

Title of Presentation:

Identification of Two Zebrafish Prolactin Genes and Characterization of 5’ Regulatory Regions

 

 

Prolactin is a pituitary and extrapituitary hormone, belonging to the growth hormone family, which has numerous functions in vertebrate physiology. This study identifies two zebrafish prolactin (zfPRL) genes with differing 5’ regulatory regions. Genomic Southern blot analysis of zebrafish DNA reveals two zfPRL genes and a ~350bp region 270bp upstream of the transcription start site that is only present for one gene. Polymerase chain reaction (PCR) amplified 2576bp and 2204bp upstream regions. Analysis and comparison of the two cloned and sequenced 5’ regions show several differences. Within the ~350bp upstream region three putative pit-1 binding elements are present. For further analysis of the two zfPRLs, green fluorescent protein (GFP) reporter vectors driven by each promoter have been microinjected to create transgenic zebrafish. The findings of the study show two zfPRL genes and the potential for pit-1 independent transcription. The role of pit-1 independent expression of extrapituitary prolactin in higher vertebrates is well known, but its role is unclear in fish. This study provides evidence for a zfPRL gene that is expressed independent of pit-1. With no known fish model presently identified to express prolactin independent of pit-1, the findings of this study set the ground work for such a model, and a better understanding of prolactins versatility.

 

 

 

 

Student Author(s): 

Hunter, Melissa R.

Dept & College or University:                        

Plant Biology, NCSU

Research Mentor(s)

Wendy F. Boss/Plant Biology, NCSU

Imara Y Perera/Plant Biology, NCSU

Title of Presentation:

Molecular Characterization of Arabidopsis Plants with Altered Phosphoinositol Signaling in Response to Cold Stress

 

 

The phosphoinositide pathway (PI) is a critical signaling pathway in plants and animals.  In order to alter PI metabolism in plants, we have generated Arabidopsis plants constitutively expressing the human type-1 inositol polyphosphate 5-phosphatase (InsP 5-ptase), which specifically hydrolyzes the second messenger, 1,4,5-inositol trisphosphate (IP3).  Though the transgenic plants grow normally, they have altered response to many environmental stimuli, such as drought, gravity, and pathogen attack.  In order to understand the role of the plant PI pathway to cold stress, we compared gene expression patterns using RT-PCR with wild-type and transgenic Arabidopsis seedling in response to cold treatment.  Our results showed that expression of CBF2, a cold induced transcription factor, and COR15a, a cold responsive gene, increased in response to cold stress.  CBF2 transcript increased at 2 hours following the imposed stress, and COR15a at approximately 8 hours.  There appeared to be a slight delay in the induction of cold response of the transgenic plants. Interestingly, we noted the presence of multiple amplification products with COR15a, and that the intensity of the additional bands was higher at the early time points.  Sequencing the PCR products confirmed that the smaller band corresponded to the expected product, and the larger band was an unspliced transcript.  Although the PCR primers span an intron, several methods were taken to ensure that the unspliced product was not a result of genomic contamination.  During RNA isolation, all samples were subjected to DNase treatment.  Amplification of other genes, such as actin, and PLC7, with primers spanning an intron did not reveal multiple products.  Finally, amplification using a primer in the promoter region of COR15a did not result in any product.  In addition, we found other cold responsive genes, such as COR47, COR15b, and Elip1, also exhibited similar expression patterns.  Our results strongly suggest that alternative splicing occurs in genes in response to cold stress.

 

 

 

 

Student Author(s): 

Huntley, Anna M.

Dept & College or University:                        

Biology, UNC-Asheville

Research Mentor(s)

Michael Stuart/Biology, UNC-Asheville

Title of Presentation:

Does Altitude Affect Prevalence And Intensity Of Infection Of Trematode Parasites In Goniobasis Proxima?

 

 

The snail, Goniobasis proxima, commonly found in the small freshwater streams in the southeastern United States, is a known intermediate host of the trematode parasite Metagonimoides oregonensis. In a preliminary class study, samples of these snails were found to be heavily parasitized with M. oregonensis. A survey of the relevant literature conflicted with our observations, concerning one of the many variations on the life cycle of M. oregonensis. We established nine collection sites, at three different altitudes along the three first-order streams of the Shope Creek drainage system in Buncombe County in the Pisgah National Forrest to study this problem. Samples of thirty snails from each site were collected once a month beginning in March 2006 and will continue until December 2006. The primary goal of this study is to contrast the prevalence and intensity of trematode infection within G. proxima at different altitudes. We also hope to gain a better understanding of the basic ecology of M. oregonensis through this study and establish a model for the study of parasite-host relationships to be used in future studies. So far, results are suggestive of a correlation between size of the snail and prevalence of infection.

 

 

 

 

Student Author(s): 

Hutcherson, K.M.

Dept & College or University:                        

Entomology, NCSU

Research Mentor(s)

Sarah D. Ayroles/Genetics, NCSU

Christina M. Grozinger/Entomology; Genetics, NCSU

David R. Tarpy/Entomology, NCSU

Title of Presentation:

The Effects of Mating on A. mellifera Queen Behavior

 

 

Molecular mechanisms associated with post-mating behavior and physiological changes in females have not been explored in great detail.  Honey bees represent an excellent model system with which to address these questions, because they exhibit a range of “mating states”, from virgins, laying virgins, instrumentally-inseminated to naturally mated.  The two end states (virgins and naturally-mated) differ dramatically in their behavior, pheromone profiles, and physiology, while the “intermediate” states are intermediate in terms of the time to initiate egg-laying (Kaftanoglu and Peng. 1982, J Apic Res 21:3-6).  Once reaching reproductive maturity, queens take a limited number of mating flights within their first week of life, and then return to the hive and never fly again.  We were interested in what cues the queen uses to determine that she has mated sufficiently. These cues may include the stimulation of oviduct stretch receptors or the presence of certain seminal proteins in their spermathecae.  In order to discern the cause of this behavioral shift in mated queens, we monitored attempts to fly before and after mating using queens in each of the four possible mating states.  The only queens attempting post-mating flights were the naturally-mated and virgin queens.  The semen-inseminated and saline-inseminated queens did not attempt to fly following insemination.  Our results suggest that suggest that insemination volume, not mating flights or mating number, is important in triggering some post-mating changes in behavior.  Further research is being done to determine the genetic mechanisms underlying this behavioral and physiological switch.

 

 

 

Student Author(s): 

Jackson, Christopher M.

Dept & College or University:                        

Biology, Wake Forest University

Research Mentor(s)

Susan E. Fahrbach/Biology, Wake Forest University

Title of Presentation:

Can Honey Bees Discriminate Multiple Patterns?

 

 

The honey bee (Apis mellifera) is a promising model for memory and cognition as many of the processes described in the honey bee brain are also found in mammalian systems. Honey bees and other Hymenoptera are unique among insects in that their mushroom bodies (locus associated with memory and cognition) receive extensive input from the optic lobes, suggesting that vision is closely linked to learning and memory. Previous studies have revealed that bees are remarkably capable of using visual cues to solve navigation tasks. This study implemented a Y-maze paradigm to examine how bees perform when asked to successively discriminate multiple pattern sets in the absence of external context cues. Overall performance was lower when multiple pattern sets were presented successively than when a single pattern set was presented in isolation. When grating pattern sets were alternated, performance exhibited a roughly direct correlation, suggesting a degree of overlap in the tuning curves of the orientation-sensitive channels that process these patterns. In contrast, when bees that had previously learned a grating pattern set and a set of concentric patterns were presented with these pattern sets in an alternating manner, performance exhibited a roughly inverse correlation; suggesting that the pathways that process these patterns inhibit one another. Behavioral experiments such as these provide insight into brain anatomy and physiology and may be especially useful for studying experience-dependent brain plasticity in the context of memory and learning.

 

 

 

 

 

 

Student Author(s): 

Jackson, Jeffrey T.

Dept & College or University:                        

Biology, Wake Forest University

Research Mentor(s)

Susan E. Fahrbach/Biology, Wake Forest University

Title of Presentation:

The Effect of 20-hydroxyecdysone and Juvenile Hormone on the Growth of Kenyon Cells of the Honey Bee

 

 

The mushroom bodies of the honey bee, Apis mellifera, are a collection of neurons (Kenyon cells) that are central to processes of learning and memory. The lipophilic hormones, 20-hydroxyecdysone (20E) and juvenile hormone (JH), are key components in the regulation of insect development and maturation. Performing activities that require higher learning skills and memory, such as foraging and navigation via a sun compass, increase the size of the mushroom bodies (Withers et al., 1993). In Drosophila, cultured pupal Kenyon cells respond to 20E through increased total neurite length and branch number (Kraft et al., 1998). Based on this knowledge, we predicted that, in response to 20E, the Kenyon cells of A. mellifera would exhibit an increase in the frequency of growth as well as the frequency of branching. We also predicted that exposure to JH would mimic the response of 20E exposure in Kenyon cells. Low density dissociated Kenyon cell cultures were established and analyzed using fluorescence microscopy for frequency of growth, pattern of growth, frequency of branching, number of branches and main branch length to test the prediction. This information serves as a model for understanding the effect of hormones on growth in the mature nervous system.

 

 

 

 

 

 

Student Author(s): 

Johnson, Mary B.

Dept & College or University:                        

Biology, Meredith College

Research Mentor(s)

Karthik Aghoram/Biology & Health Sciences, Meredith College

Title of Presentation:

Digital Imaging Analysis of the Role of a Phospholipid Transfer Protein on Lateral Root Morphology

 

 

Phospholipid transfer proteins (PITP) have been associated with several aspects of plant growth and development. In the model plant Arabidopsis, a protein PITP designed AtSec14p is implicated to play a role in the plant’s response to hyperosmotic stress, specifically in lateral root development. In my project we will be comparing the wild-type’s and the AtSec14p mutants’ root systems under hyperosmotic stress using a variety of digital imagining techniques. Two week old Arabidopsis plants grown on nutrient agar media will be used for all experiments. We will measure lateral root number and lengths using magnetic resonance imaging, scanning electron microscopy and digital volume rendering techniques. Our objective is to further clarify the role of AtSec14p in plant development with specific interest on lateral root morphology during osmotic stress.

 

 

 

 

Student Author(s): 

Kalogerinis, Peter T.

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

Alex Georgakilas/Biology, East Carolina University

John E. Poulos/Fayetteville Gastroenterology Associates

Title of Presentation:

Granular Cell Tumor of the Gastrointestinal Tract

 

 

Granular cell tumors (GCTs) are submucosal neoplasms that are thought to be derived from Schwann cells. Disagreement does exist concerning GCT potential for malignancy and origin. Some propose that granular change signify a degenerative phenomenon that may take place in non-neoplastic or neoplastic cells. GCTs occur throughout the body most commonly in the tongue and skin, but also in the breast, respiratory tract, biliary tree, nervous system, and gastrointestinal tract. GI GCTs while very uncommon have distinguishing pathological features. In this case study of a 50-year-old black female with a granular cell tumor of the GI tract discussion will be focused on findings and treatment of tumor. Correlations with mutations of PTEN, expression of S100 protein and nestin will also be discussed.

 

 

 

 

Student Author(s): 

Kalogerinis, Peter T.

Tsao, Doug

Tabrizi, Isla

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

Alex Georgakilas/Biology, East Carolina University

Michael Dingfelder/Physics, East Carolina University

Rob D. Stewart/School of Health Sciences, Purdue University

Title of Presentation:

Induction and Processing of Oxidative Clustered DNA Lesions in 56Fe-Irradiated Human Monocytes

 

 

Space and cosmic radiation is characterized by energetic heavy ions of high linear energy transfer (LET). Although both low and high LET radiations can create oxidative clustered DNA lesions (OCDL) and double strand breaks (DSBs), the local complexity of OCDL tends to increase with increasing LET. We have irradiated human monocytes 28SC with doses from 0-10 Gy of 56Fe ions (1.046 GeV/nucleon, LET=148 keV/µm), and determined the induction and processing of prompt DSBs and OCDL using the Pulsed Field Gel Electrophoresis (PFGE) assay and Number Average Length Analysis (NALA). The 56Fe ions produced decreased yields of DSBs (10.9 DSB Gy-1 Gbp-1) and clusters (1 DSB: ~0.8 Fpg-clusters: ~0.7 Endo III-clusters :~0.5 Endo IV-clusters) compared to previous data for 137Cs γ-rays. The difference in relative biological effectiveness (RBE) of the measured and predicted DSB yields may be due to the formation of spatially correlated DSB (regionally multiply damaged sites) which result in small DNA fragments that are difficult to detect with the PFGE assay. The processing data suggest enhanced difficulty in the processing of DSBs compared with γ-rays but not for clusters for the 28SC. At the same time, apoptosis is increased compared to g-rays. The enhanced levels of apoptosis observed after exposure to 56Fe ions may be due to the elimination of cells carrying high levels of persistent DNA clusters which are removed only by cell death and/or ‘splitting’ during DNA replication.

 

 

 

 

Student Author(s): 

Kirbach, Ezra Root

Vorren, Kris

Dept & College or University:                        

Physics, UNC-Asheville

Research Mentor(s)

Charles A. Bennett/Physics, UNC-Asheville

Brian Kenneth Dennison/Physics, UNC-Asheville

Title of Presentation:

Measurements of Preamplifier Gain and Noise Power

 

 

Four microwave amplifiers were tested for use on the interferometer being developed with two 26-meter radio telescopes at the Pisgah Astronomical Research Institute in Rosman, NC. Using a spectrum analyzer and a network analyzer, we measured the gain and noise power as a function of temperature. Specific tests were also carried out to characterize the gain and noise fluctuations over time. Our tests showed that these amplifiers were very suitable for interferometer use with gain fluctuations of less than 0.8%. A radio frequency interference survey was also conducted with results indicating the existence of interference free bands for interferometry. This work was carried out through the 2006 PARSEC Internship Program, and was supported by NASA Award NNG05GQ66, the North Carolina Space Grant, and the Glaxo-Wellcome Endowment at UNCA.

 

 

 

 

Student Author(s): 

Lambert, Tonya L.

Dept & College or University:                        

Psychology, UNC-Wilmington

 

Research Mentor(s)

Christine E. Hughes/Psychology, UNC-Wilmington

Raymond C. Pitts/Psychology, UNC-Wilmington

Title of Presentation:

Effects of d-amphetamine on Self-control Choices under Signaled and Unsignaled Delays

 

 

Choosing a larger more delayed reinforcer over a smaller, more immediate reinforcer is said to show “self-control,” whereas choosing the smaller, more immediate reinforcer is said to show “impulsivity.”  This has been modeled in laboratory animals, and researchers have used these models to test the effects of drugs such as d-amphetamine on self-control.  However, there have been some discrepancies shown in the overall effects of such stimulants.  This brings forth the possibility of an associated stimulus causing changes in self-control.  In the present study, we examined the effects of d-amphetamine on self-control in 8 rats.  The larger reinforcer was defined as four dipper presentations of sugar water at delays of 2, 10, 20, 30, and 40 s; delays increased within sessions across 5 blocks of 10 choice trials.  The smaller reinforcer consisted of one dipper presentation of sugar water delivered after a 2-s delay.  For 4 subjects, the delays to both the smaller and larger reinforcers were signaled by a unique stimulus; for the other 4 subjects, there was no unique stimulus associated with the delay.  The rats received an injection of saline or one of several doses of d-amphetamine (0.3, 1.0, 1.78, and 3.0 mg/kg) every fifth day.  The effects of d-amphetamine were modulated by the signaling conditions. For the most part, the rats in the unsignaled condition chose the smaller, more delayed reinforcer more often following d-amphetamine administration than under control conditions.   In some, but not all, of the rats in the signaled condition, intermediate doses of d-amphetamine increased choices of the larger, more delayed reinforcer.

 

 

 

Student Author(s): 

LaRoque, Benjamin H.

Dept & College or University:                        

Environmental and Molecular Toxicology, Center for Marine Sciences and Technology, NCSU

Research Mentor(s)

Patricia D. McClellan-Green/Environmental and Molecular Toxicology, Center for Marine Sciences and Technology, NCSU

Title of Presentation:

Examination of the Effects on Body Condition Index and ATP Production following exposure to Fullerenes and Hypoxia in Fundulus heteroclitus

 

 

Buckminster fullerenes are engineered nano-sized particles which are becoming significantly more economic to produce and increasingly useful in industry. As a result of their increased production and usage, it has become necessary to understand the possible toxic effects of fullerene exposure. This study examined the potential metabolic effects of short term exposure to both fullerenes and hypoxia on Fundulus heteroclitus . Mitochondrial ATP levels were measured following both in vitro and in vivo exposures to fullerenes and hypoxia. The body condition index was calculated comparing the liver with body size in exposed organisms. Liver mitochondrial ATP levels were determined using the recombinant firefly Luciferin/Luciferase reaction. ATP measurements in both the in vitro and in vivo exposed mitochondria revealed no statistical difference between control fish and any of the exposure groups. The body condition comparisons demonstrated that fish exposed to fullerenes in hypoxic conditions have a larger liver to body mass ratio than fish exposed to fullerenes alone. This distinction was, however, only statistically significant when using a lower limit of 90% confidence. As a result, this study does not support any impact by fullerenes or hypoxia on mitochondria at the dose levels used.

 

 

 

 

Student Author(s): 

Laurore, Jessika

Smith,  Lacie

Dept & College or University:                        

UNC-Wilmington

Research Mentor(s)

Sridhar Varadarajan/Chemistry and Biochemistry, UNC-Wilmington

Jeffery L. Wright/Marine Science, UNC Wilmington

Title of Presentation:

Synthesis of Novel Quorum Sensing Molecules

 

 

Quorum sensing is the phenomenon of communication between bacterial cells. Bacteria communicate with each other through signaling molecules.  When a “quorum” is reached the signaling molecules induce virulence factors which allow the bacteria to work in concert to harm the host. This project describes the synthesis of novel quorum sensing molecules that can interfere with bacterial communication.  These new molecules are acyl homoserine lactones, similar in structure to that of N-3-(4-hydroxyphenyl)propanoyl homoserine lactone, which had been identified earlier to be a good signaling molecule.  These molecules have been made to determine the structural features of N-3-(4-hydroxylphenyl)propanoyl homoserine lactone that are important for its signaling properties.  There are several molecules being made in this project and the details of their synthesis are described.  In all these molecules an acyl component containing methoxy-phenyl connected to the homoserine lactone.  The molecules differ with respect to the length of the carbon chain and functional group attached to benzene ring connected to the homoserine lactone, and with respect to the placement and composition of the substituent on the methoxy-phenyl ring.

 

 

 

 

 

Student Author(s): 

Locklear, Joshua D.

Harris, Jamie R.

Dept & College or University:                        

Chemistry and Physics, UNC-Pembroke

Research Mentor(s)

Meredith L. Storms/Chemistry and Physics, UNC-Pembroke

Title of Presentation:

The Determination of Metformin in Human Serum Using Solid-Phase Extraction and HPLC

 

 

A high-performance liquid chromatography method has been developed for the determination of metformin in human serum.  The separation and quantitation are achieved on a 150-cm Luna C18 column using a mobile phase of 50:50% v/v 10 mM sodium phosphate buffer containing 10 mM SDS (pH 5.1) and acetonitrile at a flow rate of 0.5 mL/min with detection of all analytes at 226 nm.  Recoveries found from a solid-phase extraction (SPE) of metformin from human serum were above 70% for metformin using Strata cartridges, while other cartridges yielded much lower recoveries. 

 

 

 

Student Author(s): 

Lodhi, Aadil M.

Dept & College or University:                        

Hypertension and Vascular Disease Center, Wake Forest University School of Medicine

Research Mentor(s)

Hossam A. Shaltout/Hypertension and Vascular Disease Center, Wake Forest University School of Medicine

David B. Averill/Hypertension and Vascular Disease Center, Wake Forest University School of Medicine

Debra I. Diz/Hypertension and Vascular Disease Center, Wake Forest University School of Medicine

Title of Presentation:

Effect of Antenatal Glucocorticoids on Angiotensin Receptors in Fetal Sheep Kidney

 

 

The intrauterine environment is extremely important in determining the health of the individual later in life. Drug intervention, genetic, and environmental factors can have programming effect on the developing fetus. Recently the role of prenatal programming as a determinant of adult diseases has become increasingly clear. Betamethasone, a drug administered to the mother to accelerate fetal pulmonary maturation in preterm delivery, has been shown to induce hypertension in adulthood. The effects of Ang II are mediated via receptor subtypes AT1 and AT2. The two receptor subtypes can be pharmacologically distinguished. The Ang II receptors are expressed early during nephrogenesis. Another component is the RAS is Ang-(1-7). We examined the effects of antenatal glucocorticoids given at late gestation (135 days) on the spatial and temporal distributions of AT1, AT2, and Ang-(1-7) receptors and the protein level in fetal sheep kidneys. Betamethasone treatment increased A1-7 receptor density in the female tubules and medulla and lowered A1-7 in the male VR and medulla. There were significant effects of betamethasone treatment on different receptor subtypes in fetal sheep kidney. Antenatal betamethasone exposure altered the receptor subtypes in the developing Kidney. The AT2 receptor subtype was the major receptor and dominated the overall receptor population of the developing kidney. At this late gestation period, Ang-(1-7) receptors were also present at low levels. The AT2 receptor subtype dominated the overall receptor population of the developing kidney. At this late gestation period, Ang-(1-7) receptors were also present at low levels, which were modulated by betamethasone treatment.

 

 

 

 

Student Author(s): 

Lomax, Aaron

Dept & College or University:                        

Plant Biology, NCSU

Research Mentor(s)

Wendy Boss/Plant Biology, NCSU

Imara Perera/Plant Biology, NCSU

Title of Presentation:

Biochemical Characterization of Transgenic Tobacco Cells Expressing the Type I Inositol Polyphosphate 5-phosphatase

 

 

In plants, the phosphoinositide pathway (PI) has been associated with the transduction of signals after a stimulus, specifically inositol 1,4,5-triphosphate (InsP3) which acts as a second messenger within the cell. In order to alter InsP3 signaling in plants, the lab has generated a transgenic tobacco cell line expressing the human Type I inositol polyphosphate 5-phosphatase (InsP 5-ptase) (Perera et al. 2002). This enzyme is localized to the plasma membrane and hydrolyzes InsP3. To determine how altering InsP3 metabolism at the plasma membrane or the cytosol differentially affects PI metabolism, we propose to compare the plasma membrane-associated InsP 5-ptase with an inactive and a cytosolic form of the enzyme. Transgenic tobacco cell lines containing the 3 different forms InsP 5-ptase gene were generated using co-cultivation with Agrobacterium tumefaciens. Transgenic callus was grown on selective media and tested for gene expression byreverse transcription – polymerase chain reaction (RT-PCR). Suspension cultures established from these lines are maintained through weekly subculture. We first tested the subcellular localization of the InsP 5-ptase proteins. Cells were harvested, and the proteins separated into soluble, microsomal and plasma membrane-enriched fractions. The fractions were analyzed by gel electrophoresis and immunoblotting using antibodies that specifically recognize the InsP 5-ptase. We have also measured InsP3 levels in the cells lines. These cell lines will be a useful system to compare the effects of the plasma membrane vs cytosolic InsP 5-ptase on the levels of PI pathway metabolites.

 

 

 

 

 

Student Author(s): 

McLaughlin, Letisha A.

 

Dept & College or University:                        

Physics, UNC-Wilmington

Research Mentor(s)

David McKenzie/Solar Physics, Montana State University

Title of Presentation:

FindSADs and Supra-Arcade Downflows

 

 

In 1999, Montana State University’s Dr. David McKenzie discovered dark x-ray voids in Yohkoh satellite images focused on the solar limb.  Since the first observation, further investigation utilizing other solar instruments, such as SOHO and TRACE, have revealed a multitude of occurrences in which these dark voids may be detected.  After some scrutiny, he concluded the most supported explanation for this phenomenon entails magnetic reconnection taking place in the arcade fan of a Long Duration Event flare, or LDE.  The tadpole-like regions observed retracting toward the surface of the sun are now referred to as SADs, or Supra-Arcade Downflows.  This summer as an REU participant I aided Dr. McKenzie in the continuing development and testing of a computer program called FindSADs, which is currently used to extract data concerning these solar events.

 

 

 

 

Student Author(s): 

McLaurin, Danielle

Lotstein, Alina

Dept & College or University:                        

Microbiology, NCSU

Research Mentor(s)

James W. Brown/Microbiology, NCSU

Title of Presentation:

RNase P in Pyrobaculum?

 

 

When the genome sequence of the hyperthermophilic archaeon Pyrobaculum aerophilum was released in 2002, genes encoding neither the catalytically-active RNA subunit of the enzyme, nor any of the four highly-conserved protein subunits of the enzyme could be identified. Although essential for 5’ processing in the biosynthetic pathway of transfer RNAs, the apparent lack of all of the subunits of this enzyme was rationalized by the observation that consensus promoters could be identified immediately upstream of most tRNA genes; it was thought that tRNAs must be transcribed without 5’ leaders, and thus without the need for RNase P processing. However, in collaboration with Todd Lowe's group at UC Santa Cruz, we have recently identified a conserved putative RNase P RNA gene in an "intergenic spacer" in all 4 currently available Pyrobaculum species genome sequences. This RNA contains all of the most highly conserved sequence and structural elements known to be directly involved in substrate binding and catalysis, but lacks the otherwise highly conserved second domain involved in modulating substrate specificity and perhaps also containing the binding sites for the protein subunits. We are currently testing the functional competence of this RNA, and cell extracts, using a series of potential substrates including tRNA precursors with very short leaders.

 

 

 

Student Author(s): 

McLean, Kaitlin J.

Dept & College or University:                        

Biology, Salem College

Research Mentor(s)

Jennifer Cruse-Sanders/Biology, Salem College

Teresa Porter/Biology, Salem College

Title of Presentation:

A Comparison of Reproductive Structure Densities in Populations of Stenocereus stellatus (Cactaceae) in the Tehuacán Valley, Central Mexico

 

 

The economically valuable columnar cactus, Stenocereus stellatus, is cultivated in central Mexico for greater fruit production. It is possible that the domestication and use directly impacts the growth and reproduction of S. stellatus. Local people manage the species in three population types, which include cultivated managed in situ, and wild populations. If management does affect plant densities, it is possible densities of flowers and fruits are also affected by the type of management used on S. stellatus.

 

 

 

 

 

Student Author(s): 

Meadows, Jarrod P.

Braddy, W. K.

Gragg, B. L.

Coley, J. S. S.

Dept & College or University:                        

Biology, UNC-Charlotte

Research Mentor(s)

Francis "Monty" Hughes Jr../Biology, UNC-Charlotte

Title of Presentation:

Aquaporins 8 and 9 in RUCA-1 Cells Translocate to the Plasma Membrane during Apoptosis: Potential Involvement of the v-SNARES VAMP1b, 2, and 2b

 

 

Apoptosis (programmed cell death) is important in a number of physiological and pathophysiological conditions. One early event in this process, the apoptotic volume decrease (AVD), involves a loss of intracellular water through protein water channels called aquaporins (AQPs). Notably, the rate of apoptosis is controlled by the amount of AQPs on the plasma membrane (PM). At least two AQP isoforms, AQP8 and 9, were found predominantly in cytoplasmic vesicles in adherent RUCA-1 (rat uterine cancer adenocarcinoma) cells. Because AQPs in vesicles cannot assist with the loss of water during the AVD, we hypothesized that during apoptosis they translocate to the PM. Indeed, in response to apoptotic stimuli such as growth factor withdrawal and UV exposure, both AQP8 and 9 translocated to the PM. For additional biochemical evidence of translocation, we performed a Western Blot for AQP9 in vesicular and membrane fractions of adherent and non-adherent cells. The results indicate that AQP9 is more concentrated in vesicular fractions of adherent cells and more concentrated in the PM fractions of non-adherent cells. A key event in translocation is docking and fusion of vesicles to the PM, which is mediated by SNARES (soluble N-ethylmaleamide-sensitive factor attachment protein receptors). In the kidney collecting duct, vasopressin-induced translocation of AQP2 is dependent on the v-SNARE, VAMP2. Using PCR we have identified the presence of VAMP2, 2b, and 1b in RUCA-1 cells. Further studies will assess the importance of these v-SNARES in the translocation of AQP-9.

 

 

 

 

 

 

Student Author(s): 

Meserve, Margaret M.

Dept & College or University:                        

Biology, Guilford College

Research Mentor(s)

Melanie Lee-Brown/Biology, Guilford College

Title of Presentation:

Social Context of the Behavior and Vocalizations of the California Gray Whale (Eschrichtius robustus)

 

 

The behaviors and vocalizations of gray whale mother-calf pairs and non-mother-calf groups were investigated in Bahia Magdalena, Mexico in order to determine whether or not gray whale mother-calf pair behaviors affect the behavior and vocalizations of non-mother-calf groups. Background research on previous studies of California gray whale behaviors and vocalizations was used to link and reinforce the results of this research to the results of previous studies. Fifteen-minute sessions of behavioral observations and acoustic recordings of gray whales in various social contexts were collected from February to April 2006 (n=30). The Cool Edit ® program was used to carry out the analysis of sound production. The full length acoustic tracks that included mother-calf pairs as well as non-mother-calf groups were examined in order to identify possible vocalizations. The acoustic times were correlated to the behavior data sheet times to see if any gray whale vocalizations could be linked to surface behaviors. Preliminary acoustic analysis found no correlation with social contexts or behaviors. Initial behavioral results indicate significant differences in frequencies of high surface behaviors (p=0.0477) of groups that include mother-calf pairs. As analysis continues, possible correlations between social context and use of sounds could allow for acoustics to be an indicator of group composition, seasonal movements, social patterns and also help determine the functions of sounds. [Work supported by SFS, NFWF, and Guilford College].

 

 

 

 

Student Author(s): 

Miller, Sean E.

Dept & College or University:                        

UNC-Wilmington

Research Mentor(s)

Sridhar Varadarajan/Chemistry and Biochemistry, UNC-Wilmington

Title of Presentation:

HPLC Measurement of DNA Damage Caused by Site-Specific DNA Methylating Agents

 

 

Several compounds are being synthesized in our laboratory that can potentially make exclusively 3-methyl adenine adducts in specific cells. These 3-methyl adenine adducts are known to be highly cytotoxic and non-mutagenic. The goals of this project are to measure and quantitate the DNA adducts formed by these new molecules. The adducts of interest are 3-methly adenine, 3-methyl guanine, and 7-methyl guanine. These compounds are reacted with genomic DNA and adduct distribution will be measured by HPLC techniques using UV and EC detection. This poster describes the development of methodology for measuring these adducts.

 

 

 

 

 

 

Student Author(s): 

Murphy-Ryan, Maureen O.

Mistry, Maanasi

Dept & College or University:                        

Duke University

Research Mentor(s)

Jeffrey Baron/Developmental Endocrinology Branch, National Institute of Child Health and Human Development

Elizabeth Parker/Developmental Endocrinology Branch, National Institute of Child Health and Human Development

Title of Presentation:

Changes in Cell-cycle Kinetics During Postnatal Growth

 

 

Mammals experience growth velocity deceleration with age. This growth deceleration occurs in multiple organs. Two cellular mechanisms may govern this process: a decrease in the fraction of actively proliferating cells (growth fraction), an increase in cell-cycle duration, or both. Mouse kidney and liver growth rates were investigated through staggered BrdU and tritiated thymidine treatment at various timepoints during postnatal growth. The results indicate that different mechanisms may be governing these two organs. Future research will also focus on the heart and lung.

 

 

 

 

 

Student Author(s): 

Nelson, Jessica

Dept & College or University:                        

Molecular and Structural Biochemistry, NCSU

Research Mentor(s)

Dennis Brown/Molecular and Structural Biochemistry, NCSU

Raquel Hernandez/Molecular and Structural Biochemistry, NCSU

Title of Presentation:

Characterization of Furin Protease Sensitive Sindbis Virus Mutants

 

 

Sindbis virus is an arbovirus member of the Togaviridae family. The inner and outer capsid shells of the virus particles are composed of three structural proteins (Capsid/E1/E2). The E1 glycoprotein ectodomain is composed of two disulfide-bridge constrained domains necessary for virus infectivity, and the E2 glycoprotein is responsible for receptor binding. Ectodomain mutants with furin protease sensitive sites were produced previously in both membrane glycoproteins. These mutations should cause the release of the specific protein domain after correct folding in the ER, generating truncated proteins that impede virus assembly and result in the formation of irregular virus structures. The phenotypes associated with the introduction of these motifs produced in virus from mosquito cells were analyzed. When compared to wild type, mutants consistently showed a lower virus titer with high heat resistance profiles that suggest the virus structure was similar to wild type, indicating infectious virus structures have limited tolerance for the truncated proteins.

 

 

 

 

 

Student Author(s): 

Nemetz, Heather K.

Jones, Jon M.

Dept & College or University:                        

Physics and Astronomy, Appalachian State University

Research Mentor(s)

Tonya S. Coffey/Physics and Astronomy, Appalachian State University

Title of Presentation:

QCM Studies of Alcohols as Vapor Phase Lubricants for MEMS

 

 

The future of nanotechnology depends in part upon the development of successful lubrication for micromachines (MEMS).  Atomic Force Microscopy (AFM) research at Pennsylvania State University* has suggested alcohols such as propanol, ethanol, butanol, and pentanol to be potential vapor phase lubricants for MEMS; propanol at its vapor pressure can greatly reduce the friction on silicon dioxide surfaces.   Due to the relatively high vapor pressure of these alcohols, all surfaces of a MEMS, including buried interfaces not easily reached by solid coatings, should become coated in thin layers of the alcohol upon exposure.  We are testing the ability of the alcohols to migrate to buried interfaces in the MEMS.  The mass uptake of the alcohols will be measured using the quartz crystal microbalance (QCM) in a vacuum chamber.   The resonant frequency of the QCM drops as alcohols adsorb on its face.  The uptake of the alcohols is measured as the pressure increases using different geometries of the canned crystals, allowing us to simulate a buried interface.  The aforementioned alcohols are first thermally distilled, then leaked into the chamber until vapor pressure of the alcohol is reached.  We see significant mass uptake even in extreme geometries, where the entire QCM face is only accessible through a tiny hole in the can encasing the QCM, 0.0006” in diameter.   *K. Strawhecker et al., Trib. Lett. 19, 17 (2005).

 

 

 

 

Student Author(s): 

Ojo, Adesanmi A.

Benders, Dicy M.

Small, Ja Sae L.

Dept & College or University:                        

Biology, UNC-Greensboro

Research Mentor(s)

Dennis LaJeunesse/Biology, UNC-Greensboro

Title of Presentation:

The Larval Midgut Function of five Drosophila Mutants

 

 

We have developed two phenotypic assays to characterize the functionality of the Drosophila midgut. Much like the organization of vertebrate intestines, the Drosophila midgut contains two distinct groups of muscles: an inner group of circular muscles and an outer group of longitudinal muscles that traverse the length of the midgut. Unlike the vertebrate intestines, however, the visceral musculature of the Drosophila midgut contains a striated muscle type most similar in structure to cardiac striated muscle. A combination of nervous system regulation as well as possible regulation from within the gut itself controls the movement of food along the Drosophila alimentary canal. The idea behind our experiments was to determine whether genes that altered midgut morphology (spastin), mitochondrial morphology (dmiro, messy mitochondria, fragmented mitochondria), or the function in the intracellular communication between nerve and muscle cells (Cha and Ddc) effect visceral muscle function. In these experiments we characterize two aspects of midgut function: ingestion and excretion in larval midguts mutant for these five genes. We will discuss the implications of our results in the context of structural and biochemical consequences of our mutant phenotypes and the potential roles that these genes play in larval midgut function.

 

 

 

 

 

Student Author(s): 

Onori, John E..

Dept & College or University:                        

Polymer and Color Chemistry, NCSU

Research Mentor(s)

Richard Kotek/Polymer and Color Chemistry, NCSU

Title of Presentation:

Characterization of Cellulose KSCN/ED

 

 

Cellulose is a natural polymer which is found in trees and plants and is commonly used for making milk and juice cartons. The problem with cellulose is that it does not melt and dissolve in the common solvents. Cuen (copper-Ethylenediamine complex) solution is the only solvent used for viscosity measurements of cellulose. The objective of this experiment is to take a similar solvent like potassium Thiocyanate Ethylenediamine system, dissolve different types of cellulose and take viscosity measurements to find there intrinsic viscosities. Each cellulose sample was ground up, dried in a vacuum oven over night and measured on an analytical balance. 50 ml glass reactor equipped with a mechanical stirrer was used for dissolution. Ethylenediamine and potassium Thiocyanate were added in first to create the solvent, and then the cellulose sample was added in, it took about 24-48 hours for the complete cellulose dissolution. An Ubbelohde viscometer, the constant temperature bath (held at 25oC) and a stop watch was used to determine the flow times of each solution. Intrinsic viscosity was calculated using a series of equations that included relative, specific, reduced, and inherent viscosities. Intrinsic viscosity was found by plotting reduced and inherent viscosity vs. cellulose concentration and extrapolating reduced and inherent viscosity back to the zero concentration. These two viscosities should meet at the same point. We were successful in finding the intrinsic viscosity of AV CELL and Tycell. Both Inherent and reduced viscosity agreed with each other. Future work will be to use their intrinsic viscosity to help determine the molecular weight and Degree of polymerization of AV Cell and Tycell.

 

 

 

 

 

Student Author(s): 

Overstreet, Monica P.

Dept & College or University:                        

Marine, Earth, and Atmospheric Sciences, NCSU

Research Mentor(s)

Gary M. Lackmann/Marine, Earth, and Atmospheric Sciences, NCSU

Title of Presentation:

Improving Prediction of Clear Air Turbulence for Aviation

 

 

Clear Air Turbulence (CAT) occasionally occurs at the jet stream level, consists of random turbulent eddies in cloudless regions over a large horizontal domain but small vertical region, and frequently occurs during the cool season at high latitudes. CAT induces economic loss and physical hazards for commercial and military aviation. Because of these threats, there is a great need for accurate CAT forecasts. This study assessed the concept of generating a CAT forecast from the direct analysis of the Turbulent Kinetic Energy from the Mellor-Yamada-Janjić Planetary Boundary Layer scheme (TKE_MYJ) using the Weather Research and Forecasting (WRF) Model. A brief climatology of cool season turbulence was conducted in addition to WRF experiments which examined the sensitivity of the simulation to lead time before a turbulence event, number of model vertical levels, and horizontal grid spacing. A representative case study from 11-12 November 2002 was selected for in-depth analysis. Consistent with other cases examined, this event featured a cyclonically curved jet stream with core velocities ≥140 knots, regions of small static stability, and areas of vertical shear of 90-150 knots within the 300-500 hPa level. Comparison of the model TKE_MYJ field to pilot reports of turbulence lends further support to this method; WRF simulation closely verified with pilot reports and matched physical expectations. Based on these findings, the WRF model output of TKE_MYJ has proven to be a capable forecasting tool for CAT.

 

 

 

 

Student Author(s): 

Park, Ji-Seon

Dept & College or University:                        

Biochemistry, NCSU

 

Research Mentor(s)

Robert B. Rose/Biochemistry, NCSU

Title of Presentation:

The Use of DCoH/HNF-1 Fusion Protein as a Tool to Analyze the Activities of a Bifunctional Protein DCoH

 

 

DCoH (dimerization cofactor of HNF-1) is a bifunctional protein which functions as a metabolic enzyme in the cytoplasm and a transcriptional coactivator in the nucleus. In the nucleus, DCoH interacts with the transcription factor HNF-1-alpha (hepatocyte nuclear factor-1-alpha) and stabilizes HNF-1-alpha dimers. Significantly, mutations in HNF-1-alpha are the most common cause of Maturity-onset diabetes of the young (MODY). We have generated a DCoH/HNF-1 fusion protein to determine: 1) whether the two functions of DCoH are independent and 2) how DCoH increases the transcriptional activity of HNF-1. The DCoH and HNF-1 coding sequences were linked by Polymerase Chain Reaction (PCR) using a primer overlap strategy and ligated into a mammalian expression vector. The DCoH/HNF-1 fusion protein will be tested for enzymatic activity to determine whether formation of the interaction with HNF-1 might regulate the enzymatic activity of DCoH. One study has concluded that DCoH does not lose its enzymatic activity when it is bound to HNF-1. However, this study did not determine whether the DCoH/HNF-1 complex was stable throughout the study. Structural studies of the DCoH/HNF-1-alpha complex indicate an active site residue of DCoH is involved in interaction with HNF-1, suggesting the DCoH/HNF-1 complex should be enzymatically inactive. The fusion protein will prevent dissociation of the complex during the enzyme assay. The fusion protein will also allow us to determine how DCoH increases the transcriptional activity of HNF-1. Our current hypothesis is that DCoH increases the half-life of HNF-1.

 

 

 

 

 

 

Student Author(s): 

Penders, Carla

Benner, Will

Anderson, Joey

Dept & College or University:                        

Physics and Astronomy, Appalachian State University

Research Mentor(s)

Chris Thaxton/Physics & Astronomy, Appalachian State University

Carol Babyak/Chemistry,  Appalachian State University

Bill Anderson/Geology, Appalachian State University

Title of Presentation:

Case Study: Boone Creek Monitoring Project - Boone, NC

 

 

We present the initial results of a comprehensive baseline study of Boone Creek – an urbanized, high gradient stream located in the Western North Carolina mountains. The study reach was restricted to a two mile section of Boone Creek within or adjacent to the campus of Appalachian State University in Boone, NC. Boone creek is characterized as an urban stream with over 50 direct outfall pipes, minimal or non-existent riparian buffers, litter, several culverts, and adjacent roadways and parking lots. Water depth and temperature were continuously monitored at three locations in the study reach in addition to pH, dissolved oxygen, conductivity, and turbidity at the midstream location. Data was complimented by two automated samplers from which total suspended solids, alkalinity, acidity, and metal content were obtained for selected rain events. Grab samples of the stream were also performed at several locations monthly and quarterly over a 12 month period. At select cross sections along the study reach, bed sediment samples were obtained. The study reach was also surveyed. Hourly rainfall and temperature data were obtained for comparison to the study data. Results show a steep hydrographic response to rainfall, high variability in temperatures, and episodic peaks in chemical and turbidity signals well above EPA regulation for trout streams. Future work includes continued baselining of Boone Creek and the expansion of monitoring efforts into reference reaches.

 

 

 

 

 

Student Author(s): 

Phillips, Roslyn J.

Dept & College or University:                        

Guilford College

Research Mentor(s)

Melanie J. Lee-Brown/Biology, Builford College

Title of Presentation:

Neonatal Unit Outbreak Caused by Staphylococcus aureus Isolates Harboring lnuA Gene in Argentina

 

 

Macrolides, lincosamides, and streptogramins are three groups of antibiotics that have similar modes of action; they bind to the 23S rRNA and interfere with translation. Macrolides are composed of two or more amino or neutral sugars linked to a 14-26 member lactone ring. Lincosamides, as well as lincomycin and other derivatives of clindomycin, are alky derivatives of proline. Streptogramins are composed of two compounds that work synergically. The MLS (Macrolide, Lincosamide, and Streptogramin) phenotype is cross-resistance to all of these three groups of antibiotics. Bacterial isolates that contain the MLS phenotype synthesize an enzyme that dimethylates the 23S rRNA. In Staphylococcus aureus, the genes ermA, ermB, and ermC confer MLS resistance. This methylation of the 23S rRNA leads to a conformational change in the ribosome that reduces the affinity, and therefore antimicrobial activity, of all three antibiotic classes. In contrast to the MLS cross resistance, resistance to lincosamide alone is due to drug modification. The enzyme lincosamide nucleotidyltransfersase, that inactivates the lincosamide drug, is encoded for by the gene lnu (previously referred to as lin). Nucleotidyltransferase modifies the drug by adding methyl groups to the hydroxyl groups at positions 3 and 4 of lincosamide. Six lnu genes have been identified and characterized: lnuA, lnuB, lnu(B-like), lnuA N2, and lnuF. The gene lnuA has been described in both Staphylococcus haemolyticus and Staphylococcus aureus. The lnuA gene is on on a 2.5Kbp plasmid known as pIP855. This poster describes clinical isolates of Staphylococcus collected from patients and hospital workers in Hospital Evita, located in Lanus city, Argentina. This research confirmed that all strains are phelogenetically related, in that the strains contained similar drug resistant genes. Inactivation of lincosamide by drug modification was observed in 11 of the 12 strains studied.

 

 

 

 

Student Author(s): 

Poston, Jaclyn N.

Dept & College or University:                        

Molecular and Structural Biochemistry, NCSU

Research Mentor(s)

Luisa Lopez-Ochoa/Molecular and Structural Biochemistry, NCSU

Linda Hanley-Bowdoin/Molecular and Structural Biochemistry, NCSU

Title of Presentation:

Localization of Beet Curly Top Virus in Arabidopsis

 

 

Geminiviruses are single-stranded DNA viruses and are a serious threat to crops worldwide. The viral Replication protein (Rep) contains conserved motifs essential to initiate rolling-circle replication and activate host gene expression. Therefore, it constitutes a good target for disease resistance. As part of a larger project oriented to obtain resistance to Geminiviruses, the model plant Arabidopsis thaliana was inoculated with two viruses - Beet curly top virus (BCTV) and Cabbage leaf curl virus (CaLCuV), which belong to different genera. Symptom development and viral replication was followed in a spatial/time course. Quantification of the viral replication during infection was quantified by DNA gel and squash blot analyses. Rep protein was detected using immunohistochemistry with 3 different antibodies. Symptom development for each virus was different in Arabidopsis. BCTV symptoms (leaf-curling and darkening of the younger leaves) appeared at about 21 days post inoculation (dpi). In contrast, CaLCuV symptoms (leaf-curling and chlorosis) were evident at 13 dpi. The BCTV DNA was most abundant in leaves 6 to 8 at 21dpi, while CaLCuV DNA was highest in leaves 1 to 6 at 13 dpi. The CaLCuV Rep protein was detected in infected nuclei of leaves at 13 dpi. However, the BCTV Rep protein could not be detected using anti-CaLCuV and anti-TGMV (Tomato golden mosaic virus) Rep proteins, although there were many identical regions in all three Rep proteins.

 

 

 

 

Student Author(s): 

Powell, Amanda M.

Dept & College or University:                        

Natural Sciences and Mathematics, Shaw University

Research Mentor(s)

Brenda J. Grubb/Zoology, NCSU

Title of Presentation:

Analysis of the Effect of Estrogen on Claudin Tight Junction Proteins

 

 

Estrogen plays a vital role in cell differentiation during mammary tissue development.To understand the basic mechanism of estrogen during development, Xenopus frog embryos were exposed to estrogen and an estrogen inhibitor at a critical stage of sensitivity. The embryos were then fixed, embedded and sectioned for analysis of the effect of estrogen on morphogenesis. An E.L.I.S.A was done to test for claudin 4, 5 and 7 protein level changes. Claudin levels were also monitored in mouse mammary tissue using histology. Both tumor and normal mammary tissue was observed for the presence or lack of the proteins. Claudins are a family of tight junction proteins necessary for cell to cell interaction and adhesion. It has been shown that low levels of certain claudins result in metastasis and tumorogenesis. Loss of claudin results in reduced cell adhesion, allowing cells to break away and metastasize. We are trying to monitor the effects of estrogen on claudin levels. It is hypothesized that there is a direct correlation between estrogenic affects on morphogenesis and altered claudin levels.

 

 

 

 

Student Author(s): 

Pradhan, Arjana

Dept & College or University:                        

Salem College

Research Mentor(s)

Michael Sikes/Microbiology, NCSU

Title of Presentation:

Identifying a Unique Transcriptional Promoter Upstream of TCR Dβ2

 

 

T cells are members of the family of white blood cells that protect our bodies against pathogens. They recognize pathogens through the T cell receptor (TCR), which is composed of two chains of proteins, alpha and beta. Each of the proteins is composed of constant and variable regions. The variable region of TCR is encoded by DNA, which allows identification of millions of pathogens. Between each variable (V) and constant region are diversity (D) and joining (J) gene segments. Each variable region pairs with a gene segment of diversity and joining through V(D)J recombination, which encodes for the TCR and gives it specificity. Evidence has shown that V(D)J recombination is controlled by transcriptional promoters associated with each V and D gene segment. The purpose of this project was to locate the position of an additional promoter upstream of the second Dβ (Dβ2).

 

 

 

Student Author(s): 

Presnell, Jason

Dept & College or University:                        

Biology, UNC-Greensboro

Research Mentor(s)

Dennis LaJeunesse/Biology, UNC-Carolina Greensboro

Title of Presentation:

Characterization of the SCANS Region of the Drosophila Larval Midgut

 

 

The Drosophila midgut is divided into five regions: the proventriculus/ anterior midgut, an acidic region, and three basic regions (Galloni, 2003). The anterior midgut region is innervated by neurons emanating from the proventricular ganglion that extend to the beginning of the copper cell/acidic region (Budnik et al., 1989; personal observation Dennis LaJeunesse). The Drosophila midgut is populated by groups of neurosecretory enteroendocrine cells (Marqués et al., 2003; Nichols, 2003, Ohlstein and Spradling, 2006). One cluster of enteroendrocrine cells resides at the juncture of the anterior midgut and the cupric/acid region of the midgut. We have defined this region the SCANS region (Superior Cupric Autonomic Nervous system) of the anterior midgut. Although distinct from the CNS or PNS, the enteroendocrine cells of the SCANS region express a number of genes found otherwise in nervous system tissue. The morphology of the cells and the organization of these cells within the SCANS region suggest that they may be part of a midgut regulatory system that receives signals emanating from within the lumen of the gut itself.

 

 

 

 

Student Author(s): 

Qian, Yushen

Dept & College or University:                        

Biochemistry, Duke University

Research Mentor(s)

Tao-shih Hsieh/Biochemistry, Duke University

Title of Presentation:

Probing the Function of Reverse Gyrase in the Unusual Hyperthermophile Nanoarchaeum equitans

 

 

Reverse gyrase, an ATP-dependent type IA topoisomerase found in hyperthermophilies, can positively supercoil DNA using energy derived from ATP hydrolysis, and thus reanneal denatured DNA. Reverse gyrase usually exists as a single polypeptide chain with twin functional domains: helicase at the N-terminus and topoisomerase I at the C-terminus. Nanoarchaeum equitans, which possesses the smallest known cellular genome at 490,885 bps, is a hyperthermophilic archaebacteria that lives in a parasitic relationship with its host Ignicoccus. Intriguingly, the reverse gyrase of N. equitans is split into a topoisomerase I (NEQ318) domain and a helicase (NEQ434) domain, each encoded by sequences in different locations of the genome. We determined that a strong homology exists between the amino acid sequences of the helicase and topoisomerase modules of N. equitans reverse gyrase and their corresponding functional domains located on the N-terminus and C-terminus, respectively, of reverse gyrase in Archaeologlobus fulgidus. Using full length N. equitans DNA as the template for the Polymerase Chain Reaction (PCR), we isolated and amplified gene fragments coding for the topoisomerase I and helicase subunits of reverse gyrase. The fragments were inserted into a pET-23b DNA expression vector containing an N-terminal T7 and C-terminal His6 tag. E. coli cultures of DH5α were transformed with this recombinant DNA and screened. Finally, cell cultures of E. coli BL21(DE3)pLysS were transformed and induced to overexpress the topoisomerase I and helicase protein subunits. Future studies will explore the individual catalytic activity of each subunit, as well as reconstitution mechanisms to form the functional reverse gyrase.

 

 

 

 

 

Student Author(s): 

Quintero-Varca, Tatiana

Dept & College or University:                        

Molecular Biology, Meredith College

Research Mentor(s)

Amy Grunden/Microbiology, NCSU

Title of Presentation:

Expression and Biochemical Characterization of Pyrococcus horikoshii Prolidase Homolog 1 and Homolog 2 for Potential use in Organophosphorous Nerve Agent Detoxification

 

 

The enzyme prolidase is a proline dipeptidase, which cleaves dipeptides having proline as the C-terminal residue. Prolidase has also been reported to hydrolyze the model organophosphorus (OP) nerve agent diisopropylfuorophosphate (DFP). The prolidase from the hyperthermophilic archeaon, *Pyrococcus furiosus, *has been biochemically and structurally characterized. The potential use of *Pyrococcus* *furiosus *prolidase for detoxification of OP nerve agents is particularly attractive due to its extreme thermostability; however, its cobalt-dependence for activity and low activity at temperatures below 50 ¡ÆC currently limit its utility in OP nerve agent detoxification. Recently it was determined that the hyperthermophilic archeaon *Pyrococcus horikoshii* has a prolidase gene equivalent to the previously characterized *P. furiosus* prolidase as well as two other prolidase homolog genes. For future evaluation of the use of P. *horikoshii*prolidase homolog 1 (55% similar to *P. furiosus *prolidase) and homolog 2 (42% similar to *P. furiosus *prolidase) genes for detoxification of OP nerve agents, these genes were cloned into the T7 RNA polymerase-based expression vector pET 21b. Overexpression of the *P. horikoshii *prolidase homolog 1 and homolog 2 proteins in *Escherichia* *coli* strain BL21(¥ëDE3) was evaluated in small scale expression experiments using both LB and autoinduction media. Thermostability and activity studies were conducted using the recombinant *P. horikoshii *prolidase homologs 1 and 2. It was determined that both proteins were thermostable and that prolidase homolog 1 had significant activity when cobalt is present in the reaction mixture and when the dipeptide leucine-proline is used as the substrate.

 

 

 

Student Author(s): 

Randall, Rachel M.

Dept & College or University:                        

College of Textiles, NCSU

Research Mentor(s)

Nancy Powell/Textile Technology, College of Textiles, NCSU

Title of Presentation:

Exploring the Importance of the Fabric Hand of a T-Shirt

 

Multiple studies have been implemented to determine influences on consumer purchasing decisions concerning textile and apparel goods. Based on previous research, the product attributes which most influence a consumer to purchase a T-shirt are fit, comfort, style, color, and workmanship. Supporting evidence shows that sensory feelings and comfort are predominant in the choice of textile goods and garments by female consumers. Although comfort may be interpreted differently to different people, other researchers examine comfort in terms of softness and “quality” of touch. These characteristics are relevant because they are seemingly the new technical constraints in the product development process as a response to consumer demands. The feel of the fabric (handle) is a sub-component of the attribute of comfort, so it is known that this attribute is of some importance but not to what degree.  This project attempts to determine the relative importance of the attribute of fabric hand in a T-shirt. Several methods of exploration were utilized to accomplish the objective including secondary literature review and primary research methodology consisting of personal interviews with industry professionals and a consumer survey. The purpose of the research was to develop an accurate marketing research method to be implemented and analyzed. Although the research method based on conjoint analysis was developed, it was found to be too demanding (in terms of resources and time) to actually implement. However, other qualitative research revealed that the significance of fabric handle is relevant to the overall appeal of a T-shirt, but the degree of relevance varies among consumers.

 

 

 

Student Author(s): 

Rankin, Susanna K.

Dept & College or University:                        

Zoology, NCSU

Research Mentor(s)

John Godwin/Zoology, NCSU

James Gilliam/Zoology, NCSU

Title of Presentation:

Domestication and Genetic Contributions to Anxiety-related Behaviors in Danio rerio (Zebrafish)

 

 

In recent years the zebrafish (Danio rerio) has become an important biomedical research model for the National Institutes of Health. Because of this, we are using this species to assess genetic and environmental contributions to the display of anxiety-related behaviors and differences between wild and domestic stocks. Research in this model organism could lead to a better understanding of mood disorders in humans and advances in aquaculture where stress-responsiveness impacts growth and disease resistance. We have tested lab reared zebrafish derived from two stocks (a wild stock from India and a domestic one from a local supplier) in an open field test. We found similar differences between the wild and domestic stocks in this assay in what we interpret as anxiety-related behaviors. Wild-derived zebrafish showed significantly more ‘stationary’ behavior and greater variation in this behavior than zebrafish bred from domestic stocks when tested in the open field test (Source, F1,1= 7.823, p=0.0129). Domestic zebrafish also swam much greater distances than the wild-derived fish (Source, F1,1=11.939,p=0.003) and again the wild-derived zebrafish showed a greater variation. These results suggest that domestication involves a selective advantage for ‘bold’ fish and loss of ‘shy’ individuals. Both wild and domestic F1 fish reacted to an alarm pheromone, emitted by zebrafish when injured, by freezing. The wild-derived fish froze for significantly greater periods than domestic F1 fish, consistent with the results for freezing in a novel environment and suggesting this reaction to alarm pheromone is another useful indicator of a reactive or ‘shy’ behavioral phenotype.

 

 

 

 

Student Author(s): 

Reeb, Carter W.

Dept & College or University:                        

Forestry, Environmental Technology, NCSU

Research Mentor(s)

Elizabeth G. Nichols/Forestry/Environmental Technology, NCSU

S.T. Gregory/Environmental Toxicology, NCSU

Title of Presentation:

Use of FTIR to Determine Changes to Sediment Composition when Vegetation Is Present

 

 

Petrogenic polycyclic aromatic hydrocarbons (PAHs) are persistent environmental contaminants in soils and sediment. Petrogenic PAHs derive from petroleum products and have a variety of harmful human health effects. Prior research has shown that vegetated sediments reduce PAH concentrations in sediments and may alter PAH release to water (desorption) relative to non-vegetated sediments. Reductions in PAH concentrations and PAH desorption are most evident in vegetated sediments where plant carbon inputs are significant. The presence of plant derived organic material is thought to enhance microbial growth and activity. Microbial turnover of both plant carbon and PAH carbon should result in changes to the sediment carbon matrix, specifically the presence or absence of functional groups. Vegetated and non-vegetated sediment samples were collected from petroleum waste sites that have naturally re-vegetated. Sediments were fractionated to chemically and physically separate different sediment carbon pools, and sediment fractions were analyzed by Fourier Transform Infrared (FTIR) spectroscopy. FTIR spectroscopy measures the infrared absorbance of the sediment sample at a variety of different wavelengths. The resulting spectra give detailed information about what functional groups are present in the sediment. This research was designed to answer two questions. Does vegetation alter the types of functional groups in sediment? If so, do those functional groups explain observed differences in PAH release (desorption) between vegetated and non-vegetated sediment fractions? I hypothesize that sediment fractions with greater PAH desorption will contain more polar functional groups than sediment fractions with slower PAH desorption.

 

 

 

 

 

Student Author(s): 

Richardson, Bryan T.

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

Jason L. Brown/Biology, East Carolina University

Kyle Summers/Biology, East Carolina University

Title of Presentation:

The Transition from Male Parental Care to Biparental Care in Dendrobates Imitator

 

 

The wide diversity of parental care types exhibited in Anurans is an important facet of the evolution of mating systems. Poison frogs of the genus Dendrobates are excellent tools for studying mating systems, as they are widespread, locally common, and exhibit some of the cost complicated and diverse reproductive strategies. One of these relationships is the evolutionary transition from male parental care to biparental care. In particular we were interested in the investigation into which key environmental and behavioral factors were correlated between these two parental care types. For our study we went to the Cainarachi Valley in Northern Peru where two sympatric species of poison frogs occur: Dendrobates imitator and Dendrobates variabilis. D. imitator exhibited biparental care and D. variabilis exhibited male parental care. We experimentally tested adult pool choice preferences, tadpole reciprocal transplant experiments, and the presences of egg/tadpole cannibalism in effort to elucidate the traits associated with each parental care type.

 

 

 

 

Student Author(s): 

Ricks, Jennifer L.

Dept & College or University:                        

Biochemistry, NCSU

Research Mentor(s)

Xianming Huang/Pharmacology, University of Texas Southwestern Medical Center at Dallas
Philip Thorpe/Pharmacology, University of Texas Southwestern Medical Center at Dallas

Title of Presentation:

Anti-Proliferative Effect of Interferon-Beta May Be Dependent on Expression of Interferon-Receptor 2 on Cell Surface

 

 

Interferons are a class of cytokines that are known to have antiviral and anti-tumor properties.  It is known that different types of tumor cells respond differently to interferon treatment, however, the reason for this discrepancy in responses is not clear.  One possible explanation points to the differences in the expression levels of interferon receptor between cell lines.  This hypothesis has been investigated using human cancer cells and patients with hepatitis, but with mixed results.  In this project, interferon alpha/beta receptor-2 (IFNAR2) expression levels were measured via cell enzyme-linked immunosorbent assay (ELISA) and Western blotting, and compared with the results of anti-proliferation assays performed on six mouse cancer cell lines using both recombinant and fusion protein forms of interferon-beta.  Cell lines used in this study were breast cancer (4T1), colorectal carcinoma (colo26), lymphoma (A20), neuroblastoma (c1300), fibrosarcoma (MethA), and melanoma (B16).  Results obtained were too inconclusive to establish a clear presence or absence of correlation between receptor expression and response to treatment, so more investigation must be done.

 

 

 

 

Student Author(s): 

Rogers, Carlyle

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

John Stiller/Biology, East Carolina University

Title of Presentation:

Evolutionary Conservation of the RNAP II C-Terminal Domain Global Structure

 

The C-terminal domain (CTD) of the largest subunit in DNA-dependent RNA polymerase II (RNAP II) is known to be essential for mRNA syntheses in animals and yeast. In yeast a minimum of eight heptapeptide repeats with the consensus sequence of Y-S-P-T-S-P-S must be present to confer viability. Previous research has shown that the essential unit of function within this repetitive domain is contained in pairs of heptapeptide repeats, or diheptads. When diheptads are separated by one or two alanine residues there is little deleterious effect. In addition, within each diheptad repeat, certain amino acids serve no apparent function, except to keep the global amino acid register of seven present. My research is aimed at addressing several questions related to the global conservation of the CTD’s repetitive structure. Yeast CTD mutants are examined to determine whether the diheptad units function independently, by increasing the separation of diheptads, and also if yeast can tolerate condensing diheptads to contain only essential residues. Flow cytometry, has shown that alteration in the global CTD structure can lead to aneuploidy, which helps to explain decreased growth rates we have observed as cell generations progress. The overall goal of this investigation is to better understand the constraints that natural selection has placed on the CTD to keep a tandemly repeated structure.

 

 

 

 

Student Author(s): 

Ross, Brittany J.

Dept & College or University:                        

Biology, Meredith College

Research Mentor(s)

Matthew R. Keogh/Crop Science, NCSU

Ralph E. Dewey/Crop Science, NCSU

Karthik Aghoram/Biology, Meredith College

Title of Presentation:

Drought-responses in Plants – the Role of a Lipid-transfer Protein

 

 

RATIONALE Fresh water is the most limiting resource for plant growth and development, and drought is the leading cause of crop losses the world over. Breeding crop plants that are more tolerant to drought is thus an economic imperative. The effort to breed such crop varieties relies on our understanding of the biochemical, genetic and molecular basis of how plants respond to drought. THE CELLULAR ROLE OF AtSsh1p PROTEIN Plant responses to drought are extremely complex. When a plant is subjected to drought stress, genes encoding a remarkable array of proteins are turned on or off. One such protein, AtSsh1p transports phospholipids required by cellular membranes. AtSsh1p can also regulate lipid metabolism, and may have a critical role in controlling membrane dynamics and signaling during periods of water-deficit. Here, we explore the physiological role of AtSsh1p, especially in drought-responses. For this study, we used “T-DNA insertion mutants” of the model plant Arabidopsis thaliana. In these mutants, a large piece of DNA (T-DNA) has been used to disrupt the AtSsh1 gene. Therefore, no AtSsh1 transcript or protein is made. By analyzing these mutants, we can identify specific aspects of plant responses to drought that are controlled by AtSsh1p. Our results indicated that AtSsh1p plays a role in seed germination as well as lateral root growth under osmotic stress.

 

 

 

 

Student Author(s): 

Sharma, Balram J.

Dept & College or University:                        

UNC-Greensboro

Research Mentor(s)

Elizabeth P. Lacey/Biology, UNC-Greensboro

Title of Presentation:

Testing the Adaptive Significance of Phenotypic Plasticity in Floral Reflectance in Plantago lanceolata

 

 

Flower reflectance in the weedy perennial Plantago lanceolata is phenotypically plastic. Flowers produced at cool ambient temperatures are less reflective and darker than flowers produced at warm ambient temperatures. Floral reflectance influences internal floral temperature in P. lanceolata (Lacey and Herr 2005). Lacey and Herr hypothesized that the plasticity in floral reflectance is adaptive because it allows individual plants to partially thermoregulate their own reproduction. In spring when it is cool, the production of poorly reflective flowers helps to warm flowers. In summer, when it is hot, the production of highly reflective flowers helps to cool flowers. In both situations, this should increase individual fitness. Our experiment tests this hypothesis by comparing the seed production (our fitness measure) of high and low plasticity genotypes. We compared production for unmanipulated flowers and for flowers whose colors were artificially modified with paints. The high and low plasticity genotypes were induced to develop flowers at two different temperatures in growth chambers. Plants were then placed in outdoor field plots at two times, April and July, during the normal flowering season so that flowers could reach anthesis and set seed in natural conditions. The higher overall seed production of high-plasticity genotypes and the fitness responses to artificial manipulations in April provide support for the hypothesis that reflectance plasticity is adaptive.

 

 

 

Student Author(s): 

Sherrill, Laura W.

Dept & College or University:                        

Guilford College

Research Mentor(s)

Melanie Lee-Brown/Biology, Guilford College

Title of Presentation:

Habitat Utilization in Captive Pinnipeds: A Behavioral Study

 

 

The physical similarities within the taxonomic order Pinnipediae are a product of convergent evolution. This study seeks to identify the similarities and differences in the behavioral adaptations of the two families of Pinnipeds, the Phocidae (true seals) and the Otariidae (sea lions). Captive individuals of both families were observed in their shared habitat at the North Carolina Zoo. An ethogram was developed for both species, and behaviors were classified as active or non-active. A map of the habitat was created, and all locations within the habitat were categorized as water or land. The Otariids spent 36% or their time in active states and 64% in non-active states. The Phocids spent similar amounts of time in both active (40%) and nonactive (60%) states. The Phocids remained in water regions of their habitat for 99% of the study period, while the Otariids divided their time more evenly between water (60%) and land (40%). The marked differences in habitat preferences between the Otariids and Phocids in this study indicate a marked difference in behavioral adaptation to the same environment.

 

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Student Author(s): 

Shuffler, Jessica L.

Dept & College or University:                        

Genetics, NCSU

Research Mentor(s)

Trudy F. C. Mackay/Genetics, NCSU

Alexis Edwards/Genetics, NCSU

Title of Presentation:

Analysis of Aggressive Behavior in Drosophila

 

One of the many tools at the disposal of Drosophila geneticists is a class of transposable element mutant lines called P-elements. These insertional mutants may affect the expression level of proximal genes. Aggression is a complex behavior that can fluctuate depending on the expression of certain genes. We screened eighty-four mutant lines for aggression levels using a behavioral assay that quantifies male aggressive behavior after a brief starvation period and subsequent exposure to a food droplet. Using analysis of variance, we identified sixteen lines that were statistically significantly different from the control, with five lines exhibiting lower levels of aggression than the control and eleven lines having higher levels of aggression. The candidate genes identified in this mutant screen warrant further investigation to elucidate their role in the modification of aggressive behavior in Drosophila.

 

 

 

 

Student Author(s): 

Sibbett, James C.

Locklear, Rebekah

Dept & College or University:                        

Chemistry and Physics, UNC-Pembroke

Research Mentor(s)

Siva Mandjiny/Biological Engineering, Universite de Technologie de Compiegne; Chemistry and Physics, UNC-Pembroke

Title of Presentation:

Sorption Study of Cu2+ and Zn2+ using Alginate as Gel Matrix

 

In this study it is intended to decontaminate Cu2+ from drinking water. Simple chromatographic experiments were conducted with alginate gel to see if this could chelate Cu2+. Alginate is a natural polymer found in seaweed. The results are comparable with Sepharose-IDA, a commercial gel. The encouraging positive results lead this project to see if some of the possible chelating free ligands could be encapsulated within the alginate gel to augment the adsorption of Cu2+. The affinity constant (KD) was determined experimentally using adsorption isotherm.

 

 

 

 

Student Author(s): 

Sirkisoon, Sherona R.

Dept & College or University:                        

Biology, UNC-Greensboro

Research Mentor(s)

Dennis LaJeunesse/Biology, UNC-Greensboro

Title of Presentation:

A Fungus Among Us: Characterization of the Early Mycorrhizal Interaction between the Orchid Embryos Dactylorhiza maculata and the Fungus, Rhizoctonia stahlii

 

 

Orchid embryos lack any endosperm and rely on a specific symbiotic interaction with a soil fungus to promote and facilitate germination. In this relationship, the fungus provides the orchid embryo the basal nutrition that it has extracted from the surrounding soil.  I have begun to characterize the cellular and intracellular changes that occur during the germination of the terrestrial orchid Dactylorhiza maculata in the presence of its symbiotic fungus Rhizoctonia stahlii.  In my poster, I will discuss the methods that I use to study these interactions and present data showing the changes in cellular proliferation and mitochondrial organization in the cells of the orchid embryo during germination.

 

 

 

 

Student Author(s): 

Slate, Candice N.

Dismukes, Joy C.

Rudd, Samantha K.

Dept & College or University:                        

Psychology, East Carolina University

Research Mentor(s)

Susan L. McCammon/Psychology, East Carolina University

Title of Presentation:

An Academic Service Learning Course: Promoting Assistance to Families with a Child Experiencing Emotional Problems

 

A service learning course was developed as a model for promoting college student learning, as well as meeting a need of youth with emotional/behavior disorders and their families. The course has now been offered for two semesters. Following training, students were put in pairs to provide respite care (short-term planned care for youth with emotional or behavioral problems) in the family’s home and community. The students assisted the youth with their homework, went on outings in the community, and provided enriching activities for development and growth. The students went through First Aid and CPR training provided by the American Red Cross, behavior modification and redirecting techniques, medication administration, crisis intervention, emergency protocols, liability and confidentiality, and activity planning. Evaluation measures of this course included five attitudinal measure scales. Eight students completed the attitudinal measures prior to and following course participation. No significant changes were found in self-esteem or civic attitudes. Attitudes toward community-based treatment for mental health problems showed higher endorsement of community-based treatment. Attitudes toward parents changed in the direction of being less blaming of parents for their children’s mental health problems, and showed higher endorsement of validating parents’ concerns. Parents reported high satisfaction with the services they received. Student and parent participants concluded that the service learning course is a viable model for offering field experience for students interested in serving children with special needs and their families.

 

 

 

 

Student Author(s): 

Smith, Adam B.

Dept & College or University:                        

Physics and Astronomy, Appalachian State University

Research Mentor(s)

Daniel B. Caton/Astronomy, Appalachian State University

Title of Presentation:

The Light Curve and Parameters of Eclipsing Binary System FL Orionis

 

As part of Appalachian State University’s program of photometry of eclipsing binary star systems, two stars resolved as a single point which, while orbiting each other, eclipse one another causing the total light of that point we see to dim, we determined the period of the binary star system FL Orionis. Since the discovery and the determination of the system’s period, we have continued using Appalachian State’s Dark Sky Observatory’s 32” telescope to obtain images of the system at all phases of its orbit, observing through three different color filters to provide information that is used to determine stellar temperatures. Using astronomical image processing software (MIRA), we reduced the data to get a full light curve of the system- a plot of the brightness versus orbital position. These light curves were then analyzed using a computer modeling program (BinaryMaker3), which produces a synthetic light curve to compare to the observed data. The model’s input parameters (stellar temperature, stellar radii, spacing, etc.), are then adjusted until the synthetic light curve matches the observed data, yielding a solution of the physical parameters of the star system. Analysis of binary star systems provides the only way to determine fundamental stellar data like the masses and the radii of stars. The light curve and parameters of FL Orionis have never before been published and soon will be submitted by our group for publication in the international astronomical journal, the Information Bulletin on Variable Stars.

 

 

 

 

Student Author(s): 

Smith, Weston J.

Dept & College or University:                        

Toxicology, Center for Marine Science, NCSU

Research Mentor(s)

Patricia McClellan-Green/ Toxicology, Center for Marine Science, NCSU

Title of Presentation:

The Effect of Fecal Coliforms and PAH Contaminants on the Immune Response of Crassotrea virginica

 

All over the world, fishing communities are reliant on the income created by shellfish harvesting. As demand for shellfish such as oysters increase, the shellfish beds are becoming endangered. Thus, it is advisable to determine whether pollution, such as fecal coliforms and petroleum byproducts, affect the immune system of the eastern oyster Crassastrea virginica. Five collection sites were selected to achieve a gradient of contaminants based on land use. A most probable number (MPN) of bacteria was determined for the oysters to assess the levels of fecal coliforms. Next, the phenoloxidase activity was determined using hemolymph collected from the abductor muscle of the oysters. Finally, the PAH concentrations were determined using oyster tissues collected from each of the sites. The results obtained from the MPN assay showed a relatively weak correlation between fecal coliform levels and phenoloxidase activity. As the fecal coliforms! increased, the phenoloxidase increased but only in select samples. The relationship between the PAH data and phenoloxidase activity was much more conclusive. Low concentrations of total PAH contaminants led to a greater variability in phenoloxidase activity levels. At higher levels of total PAH contaminants a greater constriction of phenoloxidase activity was seen. Upon further examination, it was apparent that increasing concentrations of low molecular weight PAHs (e.g. naphthalene and pyrene) were positively correlated to higher levels of PO activity while the higher molecular PAHs had no correlation. The implications of this data are unclear at this time and further investigation is warranted.

 

 

 

 

Student Author(s): 

Soung, Jennifer Y.

Dept & College or University:                        

Duke University

Research Mentor(s)

David Seo/Duke University Medical Center

Camille Frazier/Duke University Medical Center

Title of Presentation:

Genomics and Metabolomics in Congestive Heart Failure

 

Congestive Heart Failure is recognized as a world-wide epidemic. It currently affects 4.9 million people in the United States alone, with approximately 500,000 new cases diagnosed annually. Heart failure (HF) is a type of cardiovascular disease involving dysfunction of the ventricle’s ability to eject blood (systole) or dysfunction of ventricular relaxation (diastole).Despite decades of research on heart failure, the search for clinically-effective protocols has remained predominantly futile. However, recent advances in gene array technology have expanded the study of heart failure – primarily, the introduction of two DNA microarray techniques, which allow for large-scale profiling in the evaluation of heart disease: Affymetrix chip (Affychip) and spotted cDNA arrays (Cardiochip). Other genomic techniques, including Real-time (RT) and quantitative PCR, have also been utilized to confirm expression patterns elucidated by microarray techniques and to correlate data findings. The objectives of this Project include identifying metabolomic expression and genomic expression differences in the following: 1) Decompensated heart failure subjects with left ventricular dysfunction (LVD), 2) Subjects with heart failure, but preserved LV function (“diastolic dysfunction”) 3) Heart failure subjects with LVD followed in heart failure clinic and 4) Normal LV function and no heart failure symptoms (controls). Clinical parameters, medications, and expression patterns will be used to provide further insight into the pathophysiology of heart failure with LVD and preserved LV function. The results obtained from this Project will provide direction for diagnostic evaluation and targeted therapy of Congestive Heart Failure.

 

 

 

 

Student Author(s): 

Spruill, Chad L.

Marek, Paul E.

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

Jason E. Bond/Biology, East Carolina University

Title of Presentation:

Compensatory Scaling of Mouthparts in Response to Character Displacement in Sibling Millipede Species

 

We show that between two sympatric clades of millipedes, the functional "scraping” and “wedging” mouthpart areas co-vary proportionally with body size-- an expectation of general isometric growth. However, the functional grinding area (the molar plate surface) does not co-vary proportionally with body size. We propose a decoupling of proportional co-variation between molar plate area with respect to body size. This relationship suggests a trade-off between a minimal grinding area required for efficient nutrient assimilation and selection-mediated body size character displacement in sympatry.

 

 

 

Student Author(s): 

Stainback, Betsy

Shaver, Matthew

Ritchie, Michael

Long, Jacquelyn

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

Mary A. Farwell/Biology, East Carolina University

Rebecca U. Cooper/Biology, East Carolina University

Title of Presentation:

Lactate Dehydrogenase Activity in Leiostomus xanthurus (spot) in Response to Hypoxia

 

Estuarine organisms along the southeastern United States regularly experience hypoxic conditions. In response to hypoxia, we expect to see a suite of behavioral and physiological changes including changes in metabolic respiration. We explored metabolic respiration in Leiostomus xanthurus (spot), an estuarine fish, after hypoxic exposure. Three experiments were performed in which individual spot were placed in tanks at 10% oxygen saturation (0.8 mg/L) for various time intervals (0, 24, 48, or 72 hours). In addition, two fish were placed in tanks that experienced no hypoxic conditions and were removed at the same time intervals to act as controls. Individual muscle samples from each fish were homogenized and subjected to analysis. Also, homogenates from each time point were pooled and the same analysis was performed on the pooled samples. Lactate dehydrogenase (LDH) activity in muscle tissue, a measure of anaerobic metabolism, was determined spectrophotometrically. Graphs were generated containing results of the individual muscle tissue and the pooled tissue samples. A large amount of variation occurred between each of the three experiments in both individual and pooled samples. When pooled data from the three experiments was analyzed together an increase in LDH activity was present that remained for at least 24 hours. In fact, the average LDH activity in spot after 24 hours of hypoxia nearly doubled from spot that did not experience hypoxia. Though variation was shown between individual fish, it is suggested in the pooled data that hypoxic conditions increase anaerobic respiration in spot. 

 

 

 

 

 

Student Author(s): 

Stallsworth, Matthew

Dept & College or University:                        

Center for Marine Sciences and Technology, NCSU

Research Mentor(s)

Félix Del-Toro Silva/Zoology, NCSU

Time A. Ellis/Zoology, NCSU

Title of Presentation:

Response of Benthic Invertebrates to Changes in Environmental Conditions (Temperature and Oxygen) within Estuarine Habitats

 

During the summer of 2005, southern flounder were studied in estuarine habitats in the Pamlico and Albemarle Sounds. Water samples were taken to see if the prey stayed in the estuary when the environmental conditions (temperature and dissolved oxygen) became harsher. The main objective of my project was to identify the abundance and diversity of the prey in the estuaries. Another objective of the study was to try to eliminate another reason of why the flounder may leave the estuary. If it is discovered that the prey leaves when the environment becomes harsher, why should the flounder stay? Four or five water samples at each site were collected last summer with a benthic sled and were kept in glass mason jars with 70 percent ethanol. Before examination with a microscope, the alcohol was sieved out and the samples rinsed with water. The samples were viewed under a scope and the prey was identified and counted for each site. In the case of one site, three sub-samples were taken due to the large volume of prey. The totals from each jar were averaged together at the different sites. The environmental data and the prey data were compared statistically and the prey and environment showed no correlation. No pattern was provided by the different sites, so the prey was not affected by the change in environment.

 

 

 

Student Author(s): 

Stewart, Harris W.

Dept & College or University:                        

Environmental Studies, UNC-Asheville

Research Mentor(s)

Dee Eggers/Environmental Studies, UNC-Asheville

Title of Presentation:

Wind Energy Modeling for the Fort Dauphin Region, Madagascar; Implications for Conservation and Sustainable Development

 

As a nation, the Republic of Madagascar is characterized by both unsurpassed levels of biological diversity and disparate levels of poverty. It exhibits one of the highest deforestation rates in the world, with the southeast exhibiting the lowest electrification rate, per capita GDP as well as the highest rates of infant mortality and infectious disease. These synergistic facts have driven conservation and development initiatives in the area, providing the basis for the largest mining operation in Malagasy history, occurring in the southeast province of Fort Dauphin. Previous studies have scrutinized claims of deforestation trends, but thus far no studies have been devoted to quantifying energy alternatives that could potentially offset biomass fuel requirements. This study will attempt to quantify kilowatt potentials in the winds of Fort Dauphin and locations that will be most appropriate for generator siting through a combination of groundwork and advanced computer models. Geographic positioning system waypoints of land cover types have been colleted by a local non-governmental organization. Additionally, long-term sources of wind data have been identified with the Malagasy government. These inputs are being combined with National Climatic Data Center (Asheville, NC) reference data into the Weather Research and Forecasting Model (WRF). Doing so WRF will produce the first visual dataset of wind speeds across Fort Dauphin. Then the 3-dimensional output of WRF will be imported into a Geographic Information System (GIS) to determine kilowatt potentials and overlay future data sources such as infrastructure, population distributions and water source points. The integration of GIS and WRF will be an innovative use of these new technologies. This will provide a baseline study of wind speeds and a potentially useful tool in the effort to continue tackling the issues of extreme poverty through renewable energy development.

 

 

Student Author(s): 

Sword, Courtney J.

Dept & College or University:                        

Plant Biology, NCSU

Research Mentor(s)

Heike Winter-Sederoff/Plant Biology, NCSU

Mariya Khodakovskaya/Plant Biology, NCSU

Title of Presentation:

Physiological and Morphological Characterization of Transgenic Tomato Lines Expressing Inositol Polyphosphate 5-phosphatase

 

Plants are adapted to the physical conditions they encounter on earth in their specific environment. Most of the environmental factors such as temperature, water availability, light, atmospheric pressure, and radiation will be dramatically different in space and on other planets. The only possible approach to increase the tolerance of crop plants to multiple and extreme environmental condition is genetic engineering. It has been shown that inositol-1,4,5-trisphosphate (InsP3) is involved in several signal transduction pathways. Plant responses to salt, drought, cold, and osmotic stresses as well as tropic responses to light and gravity are mediated by inositolphosphate metabolism (Meijer and Munnik, 2003, Perera et al. 2006 and unpublished data). We generated transgenic tomato plants expressing the human inositol polyphosphate 5-phosphatase (InsP3 5-ptase), an enzyme that hydrolyzes InsP3. These plants have an enhanced tolerance to drought stress (Khodakovskaya et. al. 2006, unpublished data). To understand the mechanisms involved in stress tolerance of these transgenic tomato plants we characterized morphological and physiological parameters of independent homozygeous transgenic lines in comparison with wild type and vector control lines. The average leaf thickness was significantly increased in the transgenic lines and the diameter of the main stems increased. Even though their tolerance to drought stress dramatically increased, no significant physiological differences were observed between wild type and transgenic tomato lines in stomatal conductance, electron transport rate, and maximum quantum yield. We are presenting data of detailed morphological characterization and discussing possible mechanisms of the basis of those observed morphological changes in the genetically modified lines.

 

 

 

 

Student Author(s): 

Tatum, Elizabeth

Dept & College or University:                        

Plant Biology, NCSU

Research Mentor(s)

LiLi Zhou/Plant Biology, NCSU

DeYu Xie/Plant Biology, NCSU

Title of Presentation:

Development of New Tobacco Crops for Antioxidant Proanthocyanidins

 

 

We are presenting the potential of developing a new model of tobacco crop for antioxidant proanthocyanidins through a metabolic engineering approach. Proanthocyanidins are a group of natural flavonoids with potent antioxidative activities, which give these natural products important nutritive and medicinal values to protect against cancers, cardiovascular and bacterial infection diseases. Our laboratory?s previous work showed the success of the metabolic engineering of proanthocyanidins in model tobacco plant, Nicotiana tobaccum, by over-expression of PAP1 and ANR transgenes. We are developing new tobacco crops for novel values by introducing the genes into commercial tobacco plants. Using Agrobacterium-mediated approach, we transform a haploid tobacco plant, Kentucky 326, which is used by tobacco breeders for new agricultural traits. We have obtained a number of antibiotics resistant callus and shoots, which are predicted to be transgenic. Id! entification of transgenic plants and the metabolic profiling of proanthocyanidins and other related compounds will be carried out in the future.

 

 

 

 

Student Author(s): 

Toor, Simranjeet K.

Sikes, Kimber

Howard, Michael B.

Dept & College or University:                        

Math and Science, Nash Community College

Research Mentor(s)

Michael P. Shaner/Math and Science, Nash Community College

Charles W. Bell/Math and Science, Nash Community College

Title of Presentation:

Characterization of 5' Regulatory Regions of Two Membrane Progestin Receptors, mPRα and mPRβ

 

 

A new class of steroid receptors, membrane progestin receptors (mPR), was recently cloned. Multiple forms of mPR have been identified (mPRα, mPRβ, and mPRγ) in various tissues and are linked to many nongenomic steroid actions that are tissue specific. Furthermore, these receptors are putative intermediaries of meiotic maturation of fish oocytes, suggested by gene knockdown technologies. Recent studies have suggested that both mPRα and mPRβ transcripts and proteins are upregulated following induction of hormones. However, transcriptional regulation of the mPRs is not well understood. In this study we have successfully cloned the 5’ regulatory regions for zebrafish mPRα and mPRβ and mapped its prospective transcription regulatory elements. Differences in cis-binding elements were compared between both mPRs. These findings suggest that the mPRs have the following cis-binding elements: AhR/Arnt, responsive element for aryl hydrocarbon receptor and its nuclear translocation factor; CRE, cAMP responsive element; Egr, binding site for early growth response genes; SF-1, steroidogenic factor-1 binding site; ERE, estrogen responsive element; GRE/PRE/ARE, glucocorticoid/progestin/androgen responsive element. The presence of these transcription regulatory elements implies that hormonal regulation is plausible. To further address the transcriptional regulation, green fluorescent protein (GFP) reporter vectors driven by each promoter have been microinjected to create transgenic zebrafish.

 

 

 

 

Student Author(s): 

Uraizee, Imran

Dept & College or University:                        

Division of Pediatric Infectious Disease, Department of Molecular Genetics and Microbiology, Duke University

Research Mentor(s)

William J. Steinbach/Pediatrics, Division of Pediatric Infectious Disease, Molecular Genetics and Microbiology

Robert A. Cramer, Jr./Molecular Genetics and Microbiology, Duke University

Title of Presentation:

Agrobacterium tumefaciens-Mediated Transformation of Aspergillus fumigatus

 

 

Aspergillus fumigatus, a ubiquitous opportunistic fungal pathogen, has emerged as a major cause of death among immunocompromised individuals. The recently-mapped 29.4-megabase genome sequence of A. fumigatus will serve as a foundation for analysis and identification of pathogenesis mechanisms. Current methods of analysis include molecular transformation of  A. fumigatus  involving polyethylene glycol (PEG) or electroporation-mediated transformation of protoplasts. However, these techniques are very time-consuming and often inefficient. This study investigated an Agrobacterium tumefaciens-mediated transformation system (ATMT) for A. fumigatus  as an easier, more efficient technique for genetic analysis. ATMT of Af293.1 and  Af 293.6, uracil/uridine and arginine auxotrophs respectively, was performed with A. tumefaciens strains carrying vectors with PyrG, a uracil synthetase gene, or ArgB, an arginine synthetase gene. Transformations were performed by mixing equal volumes of A. tumefaciens cells containing the appropriate vector with a suspension of 10^6, 10^7, or 10^8 corresponding  A. fumigatus  conidia/mL on co-cultivation medium superimposed with nylon filters at 24ºC for 48 hours. Filters were transferred to selection plates with cefotaxime to kill A. tumefaciens, and transformants appeared after two days. PCR and Southern blot analysis confirmed random insertion of PyrG into A. fumigatus . We conclude that ATMT of  A. fumigatus  is a promising alternative to lengthy protoplast techniques. Future studies will seek to improve the efficiency of this system and establish the most effective transformation protocol. ATMT has great potential to enable targeted gene knockouts in A. fumigatus  and ultimately identify virulence factors.

 

 

 

Student Author(s): 

Valdes-Wochinger, Irene

Lee, Doris

Dept & College or University:                        

Anthropology and Sociology, University of Puerto Rico-Río Piedras

Psychology, Pomona College

Research Mentor(s)

Betsy Lozoff/Center of Human Growth and Development, University of Michigan-Ann Arbor

Title of Presentation:

Long-Lasting Effects of Iron Supplementation in Children's Behavior and Development at 10 Years

 

 

Up to 20% to 25% of infants worldwide suffer from iron-deficiency anemia (IDA), and many more have iron-deficiency without anemia. Although IDA is the most common single nutrient disorder in the world, many countries have not made routine iron supplementation for infants a priority. The purpose of this project is to evaluate children's behavior and development at age 10 and to determine if there are long-lasting effects of iron supplementation in infancy on social-emotional behavior. A Jenga game of 3-5 minutes duration was designed to assess shared positive affect between 579 Chilean children and their mothers. T-test and ANOVAs were used to analyze how overall performance and positive affect varied, if at all, by supplemented and unsupplemented groups. The 10-year-olds who received iron supplements in infancy had significantly longer durations of shared positive affect with their mothers at age 10 than unsupplemented children (p<.05) Unsupplemented children had significantly longer durations of no shared positive affect (p<.001). They also looked at the tester more often (p<.001) and took longer to take their first turn at the game (p<.05) than supplemented children. Unsupplemented children and their mothers also showed more instances of directing one another's behavior (p<.05 and p<.001) than supplemented children and their mothers. Our findings suggest that there are long term benefits of iron supplementation in infancy on the social/emotional domain. The double randomized experimental design allows us to conclude that the social/emotional differences we found are the result of supplementation and not environmental factors that stem from socio-economic stress. Progress is being made towards reducing cases of IDA via food additives such as sprinkles, spreads, and other food-based solutions. However, the data indicates that it is worthwhile to adopt a preventative approach to dealing with IDA in children. Having ever had IDA has long-term negative repercussions for development. It may not be sufficient to wait until it occurs to address the issue, especially for less advantaged families that may not have the resources to circumvent the developmental issues that result from inadequate blood iron at any point in childhood development.

 

 

 

 

Student Author(s): 

Vo, Christopher K.

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

Yumin Li/Chemistry, East Carolina University

Charles Griswold/Entomology, California Academy of Sciences

Title of Presentation:

Retrofitting Film-Based Scanning Electron Microscopes with Consumer Digital SLR Cameras

 

 

Modern digital imaging, high-resolution scanning electron microscopes (SEMs) have displaced the older film-based SEMs of the past. However, these older instruments still have a place in the research lab as a number of techniques have since retrofitted these film-based SEMs with digital imaging capabilities. Some of these techniques have required expensive additional specialized hardware and software to accomplish the digitization feat. Here we present a solution to retrofitting older, film-based SEMs with digital imaging capabilities and a cheaper alternative to other highly specialized techniques. Our simplistic technique consists of mounting a Canon Rebel XT consumer digital SLR (DSLR) to the Polaroid film bracket located on many of the older film-based SEMs. The same photographic principles responsible for creating Polaroid images of SEM specimens are applied to the CCD chip of the DSLR (the CCD chip in digital cameras is analogous to the film in SLRs). Given the proper exposure time, aperture and ISO settings on a DSLR the SEM’s scanning line of light can effectively be used to “paint” an image onto the CCD chip – as opposed to Polaroid film. Once the “painting” has occurred, then the photograph is recorded digitally at high resolutions, and the image can be processed digitally. This DSLR technique can be universally applied to film-based SEMs that utilize the Polaroid film mounting bracket. The limitations to this technique are purely physical. Camera lens, mounting bracket, and manual settings are required for proper function; however, these requirements are easily and cheaply met in consumer electronics. Images produced from this technique are of high quality – arguably better than Polaroid quality – and are acceptable for publication – not to mention they are of a digital medium and of little cost to produce (as opposed to antiquated and expensive Polaroid SEM film). Sample images can be found at http://personal.ecu.edu/ckv0212

 

 

 

 

Student Author(s): 

Watts, Cynthia L.

Dept & College or University:                        

Natural Science – Biology, Lenoir-Rhyne College

Research Mentor(s)

Marsha Fanning/Natural Science – Biology, Lenoir-Rhyne College

Karen McDougal/Natural Science – Biology, Lenoir-Rhyne College

Title of Presentation:

Differences in Growth of Chaetomium globosum on Three Different Species of Wood

 

 

Soft-rot fungi, including Chaetomium globosum, decompose cellulose and lignin within wood. In this experiment, C. globosum  was grown on one inch squares of three different species of wood: Quercus alba ,  Liriodendron tulipifera , and  Pinus taeda . The fungal coverage was measured at zero, six, twelve, twenty-four, forty-eight, and seventy-two hours after inoculation. The percentage of the coverage and the thickness of the fungus was recorded. The mean area covered on all three types of wood was above ninety percent at the seventy-two hour time period. However, there was a significant difference at the forty-eight hour observation, with  Q. alba  showing less fungal coverage when compared to the other two species. The experiment was repeated, and observed after thirty-six and forty-eight hours. Again, Q. alba  had significantly less coverage than L. tulipifera , and was significantly lower from the  P. taeda  in one of the two replicates. The growth of C. globosum seemed to have a greater lag time when growing on Q. alba . It would be valuable to determine if there are specific components in wood that are involved in resistance to fungal growth.

 

 

 

 

Student Author(s): 

White, Johnithan

Dept & College or University:                        

UNC-Pembroke

Research Mentor(s)

Mark R. McClure/Chemistry and Physics, UNC-Pembroke

Title of Presentation:

H-1 and C-13 NMR Spectroscopy of Cobalt(III) Complexes Containing the Tripodal Tetradentate Ligand Tris(2-Aminoethyl)amine

 

 

We present proton and carbon NMR data for a series of cobalt(III) complexes containing the tripodal tetradentate ligand tris(2-aminoethyl)amine with ammonia, ethylenediamine, and propylenediamine. It was possible in most cases to assign the carbon spectra of these complexes. The proton spectra were found to be quite complex, and the propylenediamine complex was substantially different from the others due to the presence of the three-carbon linkage.

 

 

 

 

Student Author(s): 

Wilkins, Joshua W.

Dept & College or University:                        

Microbiology and Biomanufacturing Training and Education Center, NCSU

Research Mentor(s)

José M. Bruno-Bárcena/Microbiology and Biomanufacturing Training and Education Center, NCSU

Title of Presentation:

Analytical Method Validation of a Refractive Index Detector

 

 

In order to track fermentation processes, the ability to identify and quantify individual chemical compounds as they are being consumed and produced is extremely valuable.  One method of performing this is by utilizing High Pressure Liquid Chromatography, or HPLC.  The HPLC accomplishes fast separation by specialized columns that separate the individual chemicals by size and/or charge.  Once this separation has occurred, a measuring device called a refractive index detector (RID) within the HPLC measures the signal generated by the separated chemicals.  Since each HPLC system is unique to its applied environment, each chemical to be analyzed must be individually determined by the HPLC.  This is achieved by obtaining pure samples of each pertinent chemical at different concentrations and performing the analysis on each of these concentrations.  From each pure chemical sample analyzed, a characteristic curve is obtained that corresponds to that chemical specifically.  From this curve, the area under the peak is proportional to the concentration of each compound along with a characteristic retention time.  From the HPLC derived data sets of varying concentrations, an averaged peak retention time is procured and a linear regression line can be produced to relate chemical concentrations to the observed peak areas.  Once this is achieved for each chemical of interest, the method is considered validated since we have predetermined the degree of acceptable variability and its associated detection limit.  Any further unknown mixtures containing these validated chemicals can then be determined and analyzed for their concentrations.

 

 

 

 

Student Author(s): 

Wissink, Erin M.

Dept & College or University:                        

Genetics, NCSU

Research Mentor(s)

Mary Anna Carbone/Genetics, NCSU

Trudy FC Mackay/Genetics, NCSU

Title of Presentation:

Association Analysis of Polymorphisms in the Immune induced molecule 10 (IM10) and Ethanol Resistance in a Natural Population of Drosophila melanogaster

 

 

Microarray data allows us to measure the expression-level of thousands of genes in a single experiment. The gene-expression profile can be used to identify candidate genes for a particular trait. In Drosophila melanogaster, the IM10 gene was significantly up-regulated upon exposure to ethanol. To investigate the role of IM10 in ethanol resistance, the gene was sequenced in 48 fly lines, and polymorphisms in the gene were identified. Tests of associations were performed on the polymorphisms and various quantitative traits including ethanol resistance, lifespan, locomotion, olfaction and starvation resistance. It was discovered that four polymorphisms in the IM10 gene were significantly associated with ethanol resistance in this population of Drosophila melanogaster.

 

 

 

 

 

Student Author(s): 

Woodbine, Karlene D.

Dept & College or University:                        

Genetics, Guilford College

Research Mentor(s)

Melanie Lee-Brown/Biology, Guilford College

Title of Presentation:

Polyclonal Antibody Analysis for Niacin Receptor

 

 

Niacin is one of the most powerful available drugs for reducing cholesterol levels leading to the progression of cardiovascular diseases. Pharmacological doses of niacin induce beneficial changes in serum lipids, particularly HDL-C (the so-called good cholesterol). In addition to raising HDL-C, niacin also lowers the level of VLDL and LDL (the so-called bad cholesterol) by inhibiting the break down and mobilization of free fatty acid from adipose tissues. As a result, the circulation of plasma cholesterol and free fatty acid in the bloodstream reduces, which in turn decreases the mortality from cardiovascular diseases. Early research showed that niacin accumulates and works directly on the adipose tissues to inhibit fatty acid mobilization. This was later explained by the recent discovery of the niacin receptor, a G-coupled receptor found in adipocytes and myeloid-lineage immune cells with a high affinity for niacin. It is widely believed that changes in HDL-C with niacin therapy are mediated by the niacin receptor. No specific antibodies for this receptor have yet been described. Since quality antibodies are limited, there is an inability to perform basic biological experiments such as testing in which tissues the niacin receptor is expressed. Rabbit polyclonal antibodies have been raised to several peptides derived from the primary amino acid sequence of the niacin receptor. To address the above issue, western imaging containing human and mouse receptors have been probed to observe whether serum from the rabbit display specificity for the recombinant receptor. So far, four different serum lots have been found from four different animals with reactivity to this protein. These antibodies are now being tested in other assay (immunohistochemistry with whole cells) and will be tested in human tissues if they prove positive in this round of assay as well.

 

 

 

 

 

Student Author(s): 

Wright, Robert C.

Dept & College or University:                        

Molecular Pharmacology, NCSU

Research Mentor(s)

Larry Blanton/Plant Biology, NCSU

Title of Presentation:

Methods for Detection of Histamine-mediated Eosinophil Degranulation in Human Leukocyte Populations

 

 

Allergic and asthmatic inflammation is closely linked with eosinophil infiltration into the effected tissue. As a granulocyte the eosinophils’ dominant inflammatory function is viewed as the release of its granule contents. Through the release of eosinophil-specific granule proteins, cytokines, chemokines, lipid mediators, enzymes, and reactive oxygen intermediates this leukocyte provides an essential local immune response to parasitic infection, tumor growth, and allergic disease. By detecting the release of eosinophil-specific inflammatory mediators, including eosinophil peroxidase (EPO) and eosinophil cationic protein (ECP), as well as more general mediators such as cytokines, the inflammatory response of the eosinophil can be further characterized. Methods for isolating human leukocyte populations and detecting EPO, ECP, and cytokines have been developed and validated. This research optimizes the use of these assays for developing a c! haracterization of histamine-mediated eosinophilic degranulation in allergy.

 

 

 

Student Author(s): 

Yang, Mee

Dept & College or University:                        

Nursing, Lenoir-Rhyne College

Research Mentor(s)

Linda W. Reece/Nursing, Lenoir-Rhyne College

Title of Presentation:

Adherence to Hmong Cultural Beliefs

 

 

This study described adherence to traditional Hmong ethno-medical knowledge and practices pertaining to health and wellness. A convenience sample completed a Forced Liket Scale of twelve random Hmong ethno-medical beliefs. Participants who were eligible were Hmong war refugees from Laos or their descendents, eighteen years old, and a resident of North Carolina. The questionnaires were written in English and Hmong. The 91 participants revealed 47% adherence to traditional healthcare beliefs. The researcher concluded that adherence to cultural beliefs has declined due to many influences, such as Hmong culture illiteracy, successful acculturation and assimilation, and Western philosophy such as the concept of the individual. However, the Hmong have preserved enough cultural practices to maintain their ethnic identity as Hmong Americans. The data also indicated the Older Generation and shamans continue to be the primary sources of consultation for many Hmong Americans. The data showed adherence to cultural beliefs affirmed and strengthened connection to Hmong culture and community identity. It is important for medical professionals to gather information about cultural concerns in order to implement culturally competent care and encourage patient compliance. Healthcare providers should understand that actions taken by family, clan members, and community leaders are not intended to bring harm to the patients, but rather to bring help from their cultural perspective. Medical professionals should be mindful that traditional health practices have served the Hmong well for centuries.

 

 

 

 

 

Student Author(s): 

Yimbu, Kenneth N.

Conner, Ramsey F.

Jones, Gwen B.

Dept & College or University:                        

Biology, East Carolina University

Research Mentor(s)

Rachel Roper, Microbiology and Immunology, Brody School of Medicine

Title of Presentation:

The Poxvirus A35R Gene Suppresses Immune Response

 

 

The poxvirus family is a group of double-stranded DNA viruses that infect both vertebrates and invertebrates and replicate in the cytoplasm.  While smallpox has been successfully eradicated from nature, most of the world’s population is susceptible to it as a biowarfare agent.  In addition, numerous poxviruses infect humans worldwide indicating the importance of poxvirus research.  Because vaccinia virus infects humans, attenuated strains have been used for vaccination, and it is the most widely studied poxvirus.  In all mammalian-tropic poxviruses, the A35R gene is conserved, suggesting it plays a crucial role in either virulence or replication.  A mutant virus was made with the A35R gene removed.  Tropism studies performed with 20 different cell lines from 6 different mammals suggested that the gene is not required for replication.  To find out whether the gene plays a role in virulence, mice were intranasally challenged with both the wildtype (normal) and mutated virus.  A35R was shown to be important in virulence (measured as weight loss and death). Further studies showed that A35R blocks antigen presentation to T lymphocytes.  However, it was not known what step of antigen presentation was blocked.  Thus, the virus effects on primary antigen presenting cells (APC, peritoneal exudate cells, PEC) and a model macrophage cell line (Raw 264) were tested.  Our data showed that VV decreased metabolism and nitric oxide (NO) production in PEC and Raw cells but showed no A35R dependent difference.  These data suggest that A35R is not directly affecting the antigen presenting cells in these ways.   New data suggest that A35R is acting by decreasing MHC class II on APC.

 

 

 

 

Student Author(s): 

Younts, Thomas J.

Gragg, Bianca L.

Jablonski, Elizabeth M.

McConnell, Nisha A.

Dept & College or University:                        

Biology, UNC-Charlotte

Research Mentor(s)

Francis "Monty" Hughes Jr../Biology, UNC-Charlotte

Title of Presentation:

Aquaporin 9 Translocates to the Plasma Membrane Early during Anoikis and Is Stimulated by Death Associated Protein Kinase

 

 

Following detachment from the substratum, cells die by anoikis, a form of apoptosis or programmed cell death. Understanding anoikis will give insight into the mechanisms of cancer metastasis. Early during anoikis/apoptosis, a cell will lose water through protein channels called aquaporins (AQPs) in a process known as the apoptotic volume decrease (AVD). Interestingly, analysis of primary cells and several cell lines localized AQP8 and 9 to vesicles in the cytoplasm, where they are unable to contribute to water loss during the AVD. Since the level of AQPs on the plasma membrane regulates the rate of apoptosis, we hypothesize that AQPs translocate to the cell surface following initiation of anoikis to allow cells to die quickly. Using an AQP9-GFP fusion construct we detected a strong translocation within five minutes of initiating anoikis by trypsin treatment in RUCA-1 cells. Further evidence of translocation was provided by co-localizing the membrane marker TNF-R1 and AQP9. To explore the pathways responsible for AQP9 translocation, we have examined Death Associated Protein Kinase (DAPK) which is known to be activated during anoikis. AQP9-GFP was co-transfected with constitutively active (CA) or dominant negative (DN) DAPK into RUCA-1 cells and the location of AQP9-GFP assessed by confocal microscopy. The results demonstrate CA-DAPK stimulates the movement of AQP9 to the plasma membrane even when cell adhesion is not disrupted. Conversely, DN-DAPK prevented AQP9 translocation when anoikis was induced. Collectively, these data suggest activation of DAPK during anoikis stimulates AQP9 translocation to the plasma membrane, enhancing the rate of apoptosis.

 

 

 

Student Author(s): 

Zachary, Christopher

Dept & College or University:                        

Plant Biology, NCSU

Research Mentor(s)

Lili Zhou/Plant Biology, NCSU

Deyu Xie/Plant Biology, NCSU

Title of Presentation:

Antioxidant Proanthocyanidin Profiling from the Ornamental Plant Desmodium canadense

 

 

Proanthocyanidins are potent antioxidants with multiple medicinal and nutritive benefits to human health, for example anti-cancer and anti-arthrosclerosis. The goal of our research is to identify the presence of proanthocyanidins from Desmodium canadense, which is an ornamental plants gown in garden and landscapes. To our knowledge, this is the first time that proanthocyanidins have been identified in this ornamental plant. We grew the plants in greenhouse to a sufficient size and harvested the leaf tissues for our studies. Protocols for extraction, purification, HPLC profiling, and histological assay were developed for the identification of proanthocyanidin in D. canadense plants. We ground fresh leaf tissues in liquid nitrogen, and then extracted proanthocyanidins using the organic solvents acetone, chloroform, and methanol. We analyzed proanthocyanidins on thin layer chromatography and visualized the separation with a DMACA reagent, whic! h showed different molecular size proanthocyanidins produced in the leaf tissues. HPLC-MS spectrum profiling identified the presence of catechin (monomer) and procyanidin B2 (a dimer). The identification of other unknown oligomeric proanthocyanidins is under way. The application of proanthocyanidins from D. canadense will be discussed in the poster presentation.

 

 

 

 

Student Author(s): 

Zettl, Kathryn L.

Dept & College or University:                        

Elon University

Research Mentor(s)

Chris Taylor/Zoology, Center for Marine Sciences and Technology, NCSU

Title of Presentation:

Population Trends in Lagadon rhombiodes in North Carolina Estuaries

 

 

Pinfish, Lagodon rhomboides, are not recognized by many as playing a significant role in marine fisheries harvest. Their increased numbers and local abundance suggests that their role in marine ecosystems may be an important one. This summer I participated in an ongoing study that sampled larval fish that were immigrating into the estuaries of North Carolina through Beaufort Inlet. Samples were collected once a week on incoming tides. A two square-meter plankton net was used to sample a fixed volume of water and its contents were recovered and preserved in vials for further examination. This sampling has been going on for over 20 years. From this the population trends of pinfish was assessed. There are indications of significant explosions of pinfish abundance in recent years. I also compared the number of larval pinfish moving into the estuaries to data collected from another source that shows the number of juvenile pinfish in the area to see if there is any correlation between the two. I discuss some possible reasons for this rapid increase in pinfish abundance. Pinfish may not be vital organisms in marine fisheries harvest, but they may be an indicator of changes that have occurred in North Carolina’s coastal ecosystem.

 

 

 

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