STAR Scholar

STAR Scholars Abstract

Only editable by group admins

  • Last updated September 11, 2015 at 10:43 AM
  • Evidence visible to group members and anyone with the link
Please include the following information: (1) the year you participated in STAR and (2) the title and text of your STAR Scholars project here. This should be the final version of your STAR Scholars abstract.

All posted evidence

Niche Modeling for Management of Invasive Crayfish

Worldwide, invasive species are a primary threat to biodiversity and local economies. Nearly half of all endangered and threatened species are in competition with invasive species. Orconectes virilis, a species of crayfish naturally found within the central United States, has been introduced throughout the country as live bait. By displacing indigenous crayfish species, O. virilis reduces fish population densities, quality of aquatic habitats, and increases risks of local extirpation of other native fauna. Approaches to management are either reactive in nature or cost prohibitive. The most effective method of control remains education to prevent further territory expansion from occurring. To be effective, these efforts to restrict population movement must be coordinated across state boundaries and strictly enforced. In order to better coordinate these programs and target limited resources effectively, our research focuses on using ecological niche models to identify vulnerable locations to introduction of O. virilis. Using the free program MAXENT and publicly available data, the ecological niche of O. virilis was estimated. We plan to refine this model to accurately reflect hydrologic features that would naturally restrict movement. This has not been included in past models for other species. Aquatic species are difficult to track in situ, while management programs have limited budgets and personnel. By incorporating public data into this new model, an accurate and testable prediction of O. virilis potential territory expansion is created. Local management programs can then use this model to target the most vulnerable areas.



vincentoleary Over 9 years ago

(1) Summer 2013-14 (2) Mechanisms of HIV-associated Neurocognitive Disorders: Effect of HIV protein gp120 on Dendritic Arbor

The Human Immunodeficiency Virus (HIV) affects not only the immune system, but also the Central Nervous System (CNS).  Invasion of the CNS by HIV can cause HIV-associated neurocognitive disorders (HAND) and damage is usually observed through non-apoptotic pathways.  One prominent pathway is synaptodendritic injury, which compromises the ability of neurons to communicate with each other. However, the mechanisms involved in the neuronal damage are still unclear. Previous studies from our lab show that the HIV-1 envelope protein, gp120, increases neuronal expression of the protein ferritin heavy chain (FHC), which is essential in iron homeostasis. FHC also plays a critical role in maintenance of dendritic spines and disrupts the CXCL12/CXCR4 axis, a signaling pathway involved in pro-survival signaling, neurogenesis, and excitotoxic pathways in the CNS. In this study, we specifically focus on the effects of the HIV-1 envelope protein, gp120, on the dendritic arbor of pyramidal neurons in different areas of the rat cerebral cortex. We have utilized gp120-treated rats and compared their dendritic spine density, length, and type with those of untreated rats using the neurolucida tracing software in conjunction with a compound microscope. The animals had also gone through behavioral studies to determine cognitive deficits caused by the viral protein. The ultimate goal is to be able to correlate the observed dendritic changes with the ability to learn new tasks. 
matt Over 9 years ago

Grant Grothusen STAR 2013

Year: 2013
Title: Requirement of alcohol dehydrogenase-related genes for preventing DNA damage
Abstract:

Acetaldehyde, the primary metabolite of alcohol, plays a major role in alcohol-related esophageal cancer. Acetaldehyde is a possible carcinogen because it crosslinks proteins with DNA and disrupts the DNA replication process, causing DNA damage and genomic instability. In addition, acetaldehyde is also responsible for causing the symptoms of a “hangover.” Alcohol consumption leads to a buildup of acetaldehyde in the body. Humans possess genes specialized for the detoxification of this harmful chemical into harmless acetic acid (vinegar). However, approximately fifty percent of the East Asian population has a variant of the acetaldehyde dehydrogenase gene ALDH2, and is unable to efficiently metabolize acetaldehyde to acetic acid. The result is an “alcohol flush reaction,” or reddening of the face due to capillary dilation, as well as increased risks of esophageal and intestinal cancers. Using the fission yeast Schizosaccharomyces pombe as a model organism, we have characterized genes crucial for the dehydration of alcohol-related substances. Serial dilution growth assays were conducted to assess alcohol or aldehyde sensitivity of different alcohol or aldehyde dehydrogenase mutants. Work is ongoing to further investigate how these mutations affect cellular processes related to genome maintenance mechanisms, including DNA protection, DNA repair, and cell cycle checkpoint control.
grantgrothusen Over 9 years ago

STAR Scholar Abstract, June-September 2013

Year: 2013
STAR Project Title: Osteonal Parameters in Skeletally Immature Porcine Tibia
STAR Project Abstract: 
There is limited information on the microstructure of pediatric bone tissue. Due to a dearth of post-mortem pediatric human specimens, there is a need to identify an age-equivalent animal model for pediatric long bones. The objective of this study is to quantify the microstructure of skeletally immature porcine tibia. Tibia from three-month old (n=14) and six-month old (n=16) pigs were used for the study. Five millimeter thick sections were made at 38% and 50% sites from the distal end of the tibia using an Isomet 1000 precision saw (Buehler, Lake Bluff, IL) and block-mounted in a slow curing epoxy resin. The epoxy blocks were ground using 400- and 600-grit sandpaper and polished with 1.0- and 0.05-micron alumina slurry using a PowerPro 4000 (Buehler, Lake Bluff, IL). For each bone section, several regions of interest were imaged at 100X magnification using a Leica DM 4000-B upright microscope, and processed using ImageJ software. Population, distribution and size of the primary and secondary osteons were computed. Initial findings show a greater number of secondary osteons in the periosteal region than the endosteal region. Knowledge of immature porcine bone microstructure could help provide insight into identifying a suitable animal surrogate for pediatric bone.
asp79 Over 9 years ago

Discrimination Against the Roma: A Comparative Analysis of Media Coverage Based on Political Ideologies

The Roma people make up one of the largest ethnic groups scattered across "Europe, highly concentrated in the Balkan region. In 2007, a massive flux of migration of the Roma to Western Europe was seen after Bulgaria and Romania joined the European Union. This led to anti-Roma sentiment in France, as well as massive deportations. The issue gained spotlight as members of the European Union began debating as to whether or not France was racially discriminating against the Roma. With the media acting as a powerful tool, capable of shaping public support, it was deemed essential to see whether or not French newspapers were reporting differently on the situation. By analyzing articles written in two major French newspapers, Monde and Figaro--centered politically left and right respectively--I was able to compare reports on the Roma deportations. It became evident that the politically left newspaper felt more sentiment towards the harsh living conditions of the Roma, while the other merely supported the government's decision on the deportations. This information is vital to see whether the media aids in the polarization of the public along ideological lines, which undermines the quality of democracy, the good functioning of which depends on compromise" 

Summer 2013. 
gretajusyte Over 9 years ago

STAR - Summer 2014

The purpose of this research project was to see if it is possible to assess students’ levels of intercultural communication competence. The project started with the conduction of a literature review in order to identify what it means to be “interculturally competent” and to look at pre-existing models of assessment. After completion of the literature review, we created our own pre- and post-survey, where the Bennett Model of Cultural Competency and the Toomey Staircase Model of Intercultural Communication Competence were used as our foundations. The survey relies on students’ self-assessment, where they evaluate themselves on the three areas of content introduced by Bennett—knowledge, skills, and attitudes—and the students placed themselves within one of the four stages introduced by Toomey. Currently, the project is still in progress. In the future, we plan to collect our data by administering the surveys to students participating in study abroad and in globally-oriented coursework. The students will take the test once before the program or class begins, and once after it has been completed. We will then use the data to determine if the Drexel programs help students improve their levels of intercultural communication competence.
cjwalczyk Over 9 years ago

STAR 2014

Hatchling and Juvenile Diamondback Terrapin (Malaclemys terrapin) Prey Availability in Two Marshes in the Barnegat Bay Ecosystem  

The diamondback terrapin (Malaclemys terrapin) is endemic to
estuarine environments in North America. Hatchling and juvenile terrapins typically utilize the high salt marsh for cover and foraging. We conducted a prey availability study at Sedge Island and High Bar Harbor (HBH) to compare differences in physiognomy and food resources between the two salt marsh locations.  We used a 0.25 m2 quadrat to sample 30 sites at each salt marsh where we recorded the time, date, location (GPS coordinates), marsh type (low/mixed/high), edaphic conditions (flooded/saturated/moist), and tidal cycle. Within each quadrat, we identified plant species, estimated vegetation cover, inventoried invertebrates, and noted the presence or absence of crab burrows. As Melampus bidentatus is a primary food source for young terrapins, we measured the length and width (mm) of all M. bidentatus found in each quadrat and calculated density. We collected 10 adult M. bidentatus from the high and low marsh at each location and measured their mass (g). There was a positive relationship between M. bidentatus length/mass and marsh type for both locations (Sedge, r2 = 0.92; HBH, r2 = 0.88) with a higher density of smaller-sized snails occurring in the high marsh.  The mean length of snails was 9.61 mm (± 1.21) for the low marsh and 7.73 mm (± 0.99) for the high marsh. These data suggest that the foraging pressure of young terrapins may influence the distribution of M. bidentatus in the marsh. However, more research is needed to determine how differences in marsh type influence juvenile terrapin foraging behavior.
eno26 Over 9 years ago

I participated in STAR the summer of 2013.

Designing a Mobile Web Application for ADHD Patients
 
Attention Deficit/Hyperactivity Disorder (ADHD) is very common, affecting 8 million adults in the United States. The Adult ADHD Self Report Scale (ASRS), developed by the World Health Organization, is a form including 6 out of 18 possible questions for patients to fill out during a doctor’s appointment. These questions assess 3 main symptoms: Inattention, Hyperactivity, and Impulsivity. Doctors use the results of this form to appropriately prescribe medication. Unfortunately, many ADHD patients either forget to make this appointment, or don’t follow through after scheduling. An online adaptation of the ASRS was created to help in solving that, but there are other issues. The existing layout of the ASRS is not ideal on smaller displays. In our increasingly mobile world where convenience is key, it is logical to adapt the form for a mobile device. My job was to collect existing information on ADHD and user interface design, and then apply my findings to design an interface for a customized mobile version of the ASRS. I optimized the interface for people with ADHD, more specifically college aged patients using many design considerations like color scheme, typography, and button size and style to reduce distractions.
psarahdactyl Over 9 years ago

STAR Abstract

Interface behavior in La1−xSrxFeO3−δ /Nb:SrTiO3 perovskite oxide heterostructures CAROLINE (LIGE) ZHANG, MARK SCAFETTA, STEVEN MAY, Drexel University — We report the interfacial transport behavior in La1−xSrxFeO3−δ /Nb:SrTiO3 perovskite oxide heterostructures. Strained epitaxial films were deposited on SrTiO3 and Nb:SrTiO3 substrates using oxide molecular beam epitaxy. Oxygen concentration was controlled by heating and re-annealing in a tube furnace with a mixture of O2 and O3. Temperature dependent currentvoltage (I-V) characteristics were measured from the junctions. From these I-V data, ideality factors for the heterojunctions were obtained. The ideality factors are found to be much larger than 1, indicating transport differs substantially compared to conventional semiconductor heterostructures. 
caroline Almost 10 years ago

Enhanced Photoelectrochemical Water Splitting with Hematite Nanostructures

The search for clean fuel sources has been driven by a rising energy demand and increasing awareness of anthropogenic climate change. One attractive strategy is the storage of solar energy in the bonds of H2 and O2 by photoelectrolysis, or photoelectrochemical water splitting. Hematite (α-Fe2O3) has emerged as a promising photoanode material for solar-driven water splitting due to its relative abundance, non-toxicity, chemical robustness, and suitable bandgap (~2.1 eV), which corresponds to a maximum solar-to-hydrogen efficienc of 15%. However, its performance to date has been limited primarily by poor charge transport properties and sluggish oxygen evolution reaction kinetics. These limitations can be overcome with combined efforts in nanostructuring and surface catalysis. Hematite nanorods were grown on fluorine-doped tin oxide substrates via chemical bath deposition, a low cost, facile synthesis method. A TiO2 interlayer showed greatly improved conductivity in the nanorods due to diffusion of Ti into the α-Fe2O3 lattice. Nanorods with catalyst overlayers of Sn, Nb, and Co-Pi demonstrated better performance as a result of reduced surface limitations. The roles of annealing, bulk dopants, and catalysts were characterized by Mott-Schottky analysis, electrochemical impedance spectroscopy, and photoelectrolysis. The photoanodes developed compare favorably with state-of-the-art, especially considering the extreme ease of synthesis methods used herein.
aja88 Almost 10 years ago

Participated in STAR 2012

Nanostructured Copper Oxide (Cu2O) Solar Cells
Nanostructured solar cells with copper (I) oxide absorber layers provide considerable promise for the future of solar cell technology. Because it is abundant, nontoxic, inexpensive, and photoactive, copper (I) oxide has great potential as a p-type absorber material. The purpose of this project was to develop a solid state copper (I) oxide solar cell with maximum efficiency. The components of the solar cells included a conductive glass substrate of fluorine doped tin oxide and an array of vertical zinc oxide nanowires grown on the substrate by chemical bath deposition. The zinc oxide nanowires served as the n-type electron conductor in the cell. A layer of copper (I) oxide was then electrodeposited directly onto the nanowires, followed by thermal evaporation of gold contacts. The current-voltage characteristics of the cells will be measured using a potentiostat in order to determine the open circuit voltage, short circuit current density, and overall cell efficiency. One limiting factor for solar cell efficiency is unfavorably low shunt resistance. Low shunt resistance allows charges to flow in different pathways without adding to the photocurrent, decreasing overall cell efficiency. In the future, a blocking layer between the nanowire and copper (I) oxide will be investigated to increase shunt resistance.


amp394 Almost 10 years ago

Effects of Music and Gender on Cognitive Performance Makwana, B., Tart-Zelvin, A., Pollak, A., & Williams, J.M.

Effects of Music and Gender on Cognitive Performance Makwana, B., Tart-Zelvin, A., Pollak, A., & Williams, J.M. Department of Psychology, Drexel University A correlation between listening to music and test performance has been looked at from several different perspectives. Cockerton, Moore, & Norman (1997) found that participants who listened to music while tested, completed more questions with increased accuracy than those who did not. Additionally, Parente’s (1976) found that test performance was better while listening to preferred music rather than less preferred music. The current study will be conducted through a survey using the Matching Familiar Figures test on male and female participants ages 18-65 while listening to music of their choice.  The main hypothesis for this study is that those who believe music will enhance their performance will perform better when listening to music.  Additionally, this study will examine possible gender differences in test performance while listening to music and note the types of music participants chose to listen to while being tested. The findings of this study could greatly help to improve testing environments.  
bkm47 Almost 10 years ago