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 km˛ (11.19% of KGR). The electric fence with displacement took up 69.29 km˛ (27.58% of KGR). All human activities displaced wildlife from 140.01 km˛ (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.