Winner: Maria R. Torres, University of California, Irvine

Investigating the Role of Down Syndrome Astrocytes in Dendritic SpineMorphology

Background: Down syndrome (Trisomy 21; DS) is the most common cause of mental retardation. Cognitive deficits in DS have been associated with alterations in dendritic spine morphology. Dendritic spines are the primary sites of excitatory synapses; as a result, defects in spine density or structure may lead to synaptic and circuit alterations. Previous studies show that astrocytes modulate spine stability, dynamics, and maturation. In addition, astrocyte-secreted factors regulate the formation and maintenance of synapses. Methods: We investigated whether deficits in DS astrocytes contribute to spine pathology in DS using rat hippocampal neurons plated on top of human DS or normal astrocyte monolayers. After 21 days in vitro, cocultures were fixed and immunostained to assess spine pathology. Results: We found significant alterations in spine number and morphology in neurons grown on top of DS astrocytes. Filopodiumlike spines were increased significantly, while the total number of spines was decreased. We also show that thrombospondin-1 (TSP-1), an astrocyte-secreted protein, modulates spine development. TSP-1 induced a significant decrease in filopodium-like spines, and a marked increase in total spine number in DS cocultures. In addition, reduced synaptic density in hippocampal neurons grown on top of DS astrocytes was reversed by addition of TSP-1. Conclusions: Collectively, these results suggest that alterations in DS astrocytes can result in spine pathology. In addition, we identified TSP-1 and its signaling pathways as potential therapeutic targets to treat spine pathology in DS patients. Current experiments are aimed to identify the functional domains in TSP-1 which are responsible for its modulatory effects on dendritic spines.

Honorable Mention: Nicholas D. Olivas, University of California, Irvine

Cell-Type Specific Excitatory Connectivity of Hippocampal CA1 Interneurons Revealed by Laser Scanning Photostimulation

Central to hippocampal dependent learning and spatial navigation are local circuit interactions between excitatory and inhibitory neurons. While excitatory neurons are relatively uniform in their cell types and distribution throughout the hippocampal formation, immense interneuronal diversity exists both in their subtypes and spatial arrangement within the hippocampus. So far, how interneurons are functionally integrated within the hippocampus is poorly understood. To address this, we employed a functional mapping approach by combining laser scanning photostimulation (via glutamate uncaging) with whole cell recordings to study local excitatory connectivity to specific types of hippocampal interneurons, aided by using transgenic mice expressing GFP in subsets of defined interneurons. We found that different types of interneurons received different sources and of excitatory inputs. O-LM cells in Stratum Oriens of the Hippocampal CA1 region received inputs exclusively from CA1 pyramidal neurons, confirming O-LM involvement in mediating feedback inhibition onto CA1 pyramidal neurons. In contrast, R-LM cells in Stratum Radiatum of CA1 lacked input from both CA1 and CA3 pyramidal neurons, unveiling a non participatory role of R-LM cells in facilitating feed back inhibition, but rather inhibiting CA1 pyramidal neurons in a feed-forward manner. Fast-spiking basket cells and bistratisfied cells in Stratum Pyramidale in CA1 received extensive excitatory input from CA1, CA2, and CA3, suggesting their role in mediating both feedback and feedforward inhibition. Taken together, our data provide definitive evidence that interneurons are differentially integrated into hippocampal networks and have highly specialized roles in regulating hippocampal circuit information processing

Winner (tie): Kimberly Rebecca Kukurba, Arizona State University

Genome-Wide Discovery of Human Translation Enhancing Elements

Background: Non-classical translation sites are believed to play an important role in the human genome, but previous research has been hindered by the ab sence of effective tools needed to identify these sequences at the DNA level. Using a combined experimental-bioinformatic approach, this study provides a global view of translation enhancing elements (TEEs) in the human genome. Methods: An in vitro selection technique called mRNA display was used to select for TEEs from a pool of human genomic DNA by enriching for sequences that enhanced the translation of uncapped transcripts. Bioinformatic tools such as the UCSC Genome Browser and MEGA evolutionary genetic software were used to analyze TEE sequence variation, determine the genomic locations, and further characterize the sequences. Results: A family of sequences that contained a core 13-nucleotide motif that enhances protein translation in multiple mammalian cell lines was identified. This motif shows complementarity to the 18S ribosomal RNA. In addition, it was discovered that over 80% of the TEEs occur in regions of the genome that contain long interspersed nuclear elements (LINEs) from the L1 family of retrotransposons. Conclusions: These findings shed light on the mechanisms of eukaryotic translation and provide a comprehensive genome- wide analysis of human translation enhancing elements.

Winner (tie): Aida Mohammadreza, Arizona State University

Measuring Oxygen Consumption Rates of Esophageal Cancer Cells at the Single Cell Level

Barrett’s esophagus is a condition in which the tissue lining the esophagus is replaced by tissue that is similar to the lining the intestine- intestinal metaplasia. In many cases, esophageal adenocarcinoma is not identified until later stages when treatments are not always effective. Although the causes of Barrett’s esophagus are not known, a condition known as GERD, acid reflux, is a risk factor. Estimates show that approximately 10 to 20% of Americans experience GERD on a weekly basis. Furthermore, due to its well characterized normal-to-cancer progression path, the Barrett’s esophagus can be used as a model system for cancer induction and development studies. By studying the respiration rates and other phenotypes of Barrett’s esophageal cells from different pre-cancerous and cancerous developmental stages at the single cell level the objective of the Center for Biosignatures Discovery Automation is to identify and characterize early aberrant transformations and cancerogenesis. By using the cell manipulation system, the Microscle Life Sciences Center (MLSC) team is able to place single Barrett’s cancer cells into arrays of microwells. The oxygen consumption rate (“drawdown”) system is based on measurements of the emission intensity of specifically designed extracellular optical sensors as a function of oxygen concentration. This system is capable of measuring oxygen consumption rates of single cells enclosed in microvolumes (~140pL) containing the sensor. During the measurement an array of lids arranged in a symmetric pattern with the pre-deposited sensors is aligned and closed over an array of microwells (substrate) containing single cells using a specialized microscope setup to produce an air-tight seal. When single Barrett’s cells in microwells were tested using the drawdown system, results indicated that sterile loading and drawdown conditions need to be obtained for successful results. Additionally, data collected from the drawdowns showed that adequate incubation times are necessary in order to obtain and maintain the physiological homeostasis of the cells in wells after the loading step. By instituting optimal conditions for cell loading prior to oxygen consumption testing, the MLSC is working towards better understanding and prediction of cell function and dysfunction in Barrett’s esophagus. Cell-cell interactions play a central role in cell proliferation, differentiation, and physiological homeostasis. By combining single cell loading, qRTPCR analysis and cell harvesting, we will be able to determine the genes that are most affected by the presence of cell-cell interactions, and detect changes in cellular metabolic rates. Through cell harvesting techniques, we are able to detach adherent single cells from substrates using liquid flow and trypsin. The gene expression of the cells can be analyzed through qRT-PCR. As a result, cell heterogeneity and cell-cell signaling at the single cell level will provide deeper insights into the prevention and diagnosis of serious diseases.

Honorable Mention: Nathan Gamarra, University of California, Irvine

Antibiotic Resistance in Aquatic Stentrophomonas maltophilia

The gram-negative gammaproteobacteria species Stenotrophomonas maltophilia is an ubiquitous environmental organism whose role as an opportunistic pathogen is of growing concern. Although initially considered extremely rare, the incidence and virulence of S. maltophilia infections has increased drastically among immunocompromised patients in recent years. S. maltophilia infections are often particularly problematic due to the species’ high level of intrinsic resistance to a wide range of antibiotics including the otherwise efficacious carbapenems. Consequentially, few antibiotics are indicated for clinical use, and increased resistance in this species is of great concern to the medical community. Although resistance in this species has been explored in great depth for clinical isolates, few studies have noted the resistance patterns of environmental or aquatic isolates. We hypothesize that aquatic environments harbor S. maltophilia isolates that are resistant to medically relevant antibiotics. To test this hypothesis, water was collected and filtered from Southern Californian streams, beaches, and restaurants. These samples were then grown in various selective enrichment tubes, isolated on Chromagar Orientation plates, and identified through MALDI-TOF mass spectrometry. Twenty antibiotics were then screened against the identified isolates using a disk diffusion assay according to Clinical and Laboratory Standards Institute protocols and resistance breakpoints. Of the 1059 isolates collected, 12 were unequivocally identified as S. maltophilia strains (5 from freshwater, 4 from saltwater, and 3 from restaurant ice). Strains demonstrated a broad range of resistance to multiple classes including the carbapenem, Meropenem (5 isolates). Among the clinically indicated antibiotics tested, we observed resistance to the inhibitor combinations Ticaricillin/Clavulanic acid and Piperacillin/Tazobactam (1 and 4 isolates respectively), however, they were susceptible to quinolones, polymyxins, and sulfonamides. Although these results are largely consistent with reported clinical and environmental data, the presence of resistance to clinically indicated antibiotics suggests the significance of aquatic environments as sources for antibiotic resistance in S. maltophilia. Given this information, further study involving targeted PCR and other molecular techniques are necessary to understand the mechanisms that underlie these resistant phenotypes. Continued sampling of aquatic environments will help to reveal the presence and scope of these resistance elements. Supported by NIH-MARC Grant GM-069337

Winner: Dayan Li, Harvard University

The Role of PRDM8 in Sonic Hedgehog-Dependent Neural Tube Development

The Sonic Hedgehog (Shh) signaling pathway plays a critical role in shaping the vertebrate body plan by regulating cellular differentiation, growth, and patterning during embryo development. To understand how Shh signaling engenders such a variety of cellular responses, we must analyze the pathway’s genetic targets and characterize their tissue-specific roles in embryogenesis. In this project, we investigate the function of a newly uncovered Shh transcriptional target, PRDM8, a histone lysine methyltransferase that is highly expressed in the embryonic central nervous system. Specifically, we focus on the role of PRDM8 in the developing vertebrate neural tube. With whole-mount in situ hybridization of mouse embryos at stage E10.5, we mapped PRDM8 transcripts along the entire length of the neural tube. When Shh signaling was inhibited in E10.5 mouse embryos, PRDM8 mRNA levels in the neural tube decreased, indicating an in vivo dependence of PRDM8 transcription on Shh signaling activation. In early E8.5 embryos, PRDM8 transcripts first occupied the intermediate portion of the neural tube and then expanded anteriorly and posteriorly later in development. The presence of PRDM8 transcripts in the rhombencephalon, mesencephalon, and prosencephalon by stage E11.5 is consistent with the post-mitotic restriction of PRDM8 expression in the murine brain cortex at advanced developmental stages. These results, together with available data showing that PRDM8 is expressed in specific neural progenitors and their descendants, suggest that PRDM8 is involved in neural cell differentiation, perhaps acting as a cell fate switch for certain populations of neurons or neuroglia.

Honorable Mention: Cristian Aguilar, University of California, Irvine

Epigenetic Modifications During Dedifferentiation in the Axolotl Regenerating Limb

Ambystoma mexicanum, more commonly known as the axolotl, is unique among vertebrate species in that it retains the ability to regenerate many complete body parts as an adult. This salamander has become the focus of intense research aimed at understanding the mechanisms of regeneration with the eventual goal of being able to apply the information gained to improving human therapies. One of the earliest events of regeneration is dedifferentiation, in which differentiated cells return to a stem-like state and give rise to a blastema which then progresses into the regenerated limb. This process is extremely important, yet not well understood. Here we have begun an investigation into the various epigenetic modifications that occur during regeneration. Blastemas were generated through gross amputation or nerve deviation and collected for RNA extraction and subsequent qRT-PCR. Quantitative PCR analysis showed elevated levels of transcripts for DNA methyltransferase (DNMT) 1 and 3a in the blastema as compared to non-regenerating tissues. Analysis of global DNA methylation levels also showed an increase in methylation of blastema cell DNA as compared to non-regenerating tissue. Immunohistochemistry detection of DNMT3a within blastema cryosections demonstrates specific localization of the enzyme within blastemal tissue. The increased levels of DNA methylation may serve as a mechanism through which genes associated with a differentiated state are silenced, allowing for the conversion of differentiated cells into blastema cells with the potential to give rise to all of the tissues of a complete limb.

Winner: Nathaniel Mueller, University of Minnesota

Are Changes in Agricultural Management More Crucial to Food Security than Climate Change?

Considerable research attention has been devoted to assessing the impact of climate change on crop yields and thus food availability – the “first dimension” of food security. In addition to climate, crop yields are also dramatically influenced by management practices, especially nutrient inputs and irrigation. Here we compare the relative magnitude of projected yield changes due to climate change with projected yield changes from agricultural intensification. Crop yield changes under IPCC A1B and B1 climate scenarios are calculated for multiple GCMs using an empirical climate analog approach (see Gerber et al. companion poster). To assess capacity for agricultural intensification, we constructed statistical global crop models that define yields as a function of climate and agricultural management. Preliminary results suggest global crop yields generally decrease under A1B and B1 climate scenarios, although they are sensitive to the choice of GCM. We find broad capacity for agricultural intensification using our statistical crop yield models, especially in Africa and Eastern Europe. In these areas, the magnitude of projected yield increases from agricultural intensification is often several times larger than the magnitude of yield decreases projected due to climate change. These results suggest the detrimental impacts of climate change on crop yields and food availability could be overcome in many regions through sustained investment in agricultural intensification.

Honorable Mention: Erica Warkus, Arizona State University; Martine Wagstaff and Scott Morello, University of Massachusetts, Boston

Do Macroalgae Use Allelochemicals To Outcompete Invertebrates for Space in the Gulf of Maine?

Macroalgae dominate horizontal surfaces in shallow subtidal habitats, whereas sessile invertebrates dominate vertical surfaces. Prolonged shading of horizontal surfaces in the subtidal allowed sessile invertebrates to colonize areas previously dominated by macroalgae (Miller and Etter 2008). The algaes’ competitive advantage on horizontal substrates may be due to a variety of factors including whiplash effects, changes in the flow dynamics required for food and respiration, micropredators sheltering in the algae or allelopathic interactions via secondary metabolites. We investigate whether macroalgae in the Gulf of Maine show allelopathic effects on larvae of sessile invertebrates to determine whether algal dominance of unshaded horizontal surfaces in the subtidal reflects chemical inhibition of recruitment. To explore the possibility of allelopathic effects causing the observed shift in community composition, we reared larval polychaetes with several selected species of macroalgae commonly found in the Gulf of Maine. Survivorship of larval polychaetes was lower in all macroalgae treatments relative to the controls. Polysiphonia denudata in particular strongly reduced the survivorship of larvae suggesting the chemicals released by this red algae may inhibit local recruitment. Our results indicate that algal allelopathy may play an important and unrecognized role in structuring temperate shallow subtidal and intertidal marine communities.

Winner: Yakov Kronrod, Chang Hu, Olivia Buzek, and Alex Quinn, University of Maryland

Using Monolingual Crowds To Improve Translation

Background: For most languages, translation is limited to either: high quality at high cost via bilingual translators or low quality at low cost via Machine translation(MT). The spectrum between these two extremes is poorly populated and limited to a fraction of the world’s languages. Our goal is to improve the translation process to use a combination of technology and people. Methods: We note that for any language pair there are a lot more people who know one than both. We can use them to improve translation availability/quality and reduce cost. In our division of labor, technology provides the crosslanguage bridge, and people provide the ability to identify errors and propose paraphrases. We call this method Targeted Paraphrasing (TP). The steps include: A) Initial machine translation, B) Identification of mistranslated spans, C) Source paraphrase generation, D) Translation of paraphrased sentences and, E) Evaluation of output. Results: We conducted three experiments. First, a pilot study of 12 Chinese-English sentences, evaluating results via judgments of fluency and adequacy on a 5-point scale. Then we did an evaluation of 49 Chinese-English translations, evaluating results using MT metrics of TER and BLEU. Finally, we examined automatic error detection on a set of 1000 English-Chinese translations. We used Amazon Mechanical Turk for all our human participants and Google Translate (GT) for our machine translation.Our pilot study yielded gains of 1.21 and 0.82 for fluency and adequacy. Oracle evaluation of our Chinese-English data yielded an improvement of 2.46 BLEU points. We found a TER improvement for 65.3% of sentences, with an average gain of 8.36 TER points. This automatic evaluation confirms the subjective rating results obtained in our pilot study. With automatic error span detection, we found better translations for 313 of the 1000 sentences and obtained an average TER improvement of 12.16 points for those sentences. Further, our costs were only $0.12 per SENTENCE compared to $0.25 per WORD for a professional translator. Conclusions: In this paper we have focused on a relatively less explored space on the spectrum between high quality and low cost translation, sharing the burden of the translation task among a fully automatic system and monolingual human participants. Our experimental results provide strong support for the argument that targeted paraphrasing can lead to significant improvements in translation. Further, our approach sets up a process that provides a rich framework within which to do further research on collaborative human/machine translation.

Honorable Mention: Charles A. Forman, Virginia Polytechnic Institute and State University

Superconducting RF Accelerator Cavity: Examination of the Interior Surface

Niobium superconducting radio-frequency (SRF) cavities are used to accelerate electrons at the Thomas Jefferson National Accelerator Facility. Since niobium superconductivity occurs in a 40 nm near-surface layer, roughness negatively affects SRF performance and thereby decreases efficiency. SRF cavities are electropolished and subjected to extensive production processes in an attempt to achieve greatest smoothness but there are a percentage of finished cavities that do not perform well. Researchers have analyzed poor-performing cavities and claim to have found responsible defects. However, no one has ever examined a cavity with a high performance quality factor to see if the “defects” are actually meaningful. The focus of this project was to study surface topography of a high-performance cavity in an effort to better understand relationships between electropolishing (EP), topographical features, and SRF performance. Replicating tape was applied inside a seven-cell cavity and the tape retains the surface topography. Replicas were analyzed using a High Resolution Optical Microscope (HiROX). For further analysis, the tape samples were coated with gold and inspected with a Phenon Tabletop and Hitachi Scanning Electron Microscope (SEM). Grain boundaries were found throughout the cavity and were more prominent near the equator than the iris. Grain boundaries of the observed magnitude do not significantly affect SRF performance since they were located on a cavity with a high quality factor. Iris regions experience more thermal energy during EP which suggests that higher electrolyte temperatures near 43° Celsius are more effective. High-performing cavity data will be compared with dysfunctional cavity topography to specifically find flaws and ultimately develop production methods to increase SRF performance.

Winner: Allen Clayton, Rachel M. Serafin, Chau C. Quach, Seth W. Brittle, Stephanie Cabey, and Christine Gurdon, Marist College

Emerging Contaminants: Silver Nanoparticles Bioaccumulation and Genotoxicity in Aquatic Organisms

The use of nanotechnology has become widespread in commercial, industrial, and medical applications. However, the very property that makes nanoparticles desirable, their high level of reactivity, raises concerns that they may also pose risks to the environment and human health. Silver nanoparticles (AgNP) are proven to be very effective bacterial filters; nonetheless, the qualities that make them such effective filtering agents could also negatively affect waterways and living organisms. Presently, there are no laws regulating the use of nanoparticles. We hope that with our results, steps can be taken to implement regulations on these particles until more research can be done to show their health and environmental effects. Crayfish (Orconectes virilis) were purchased from Northeastern Aquatics in Rhinebeck, NY. The organisms were exposed to different concentrations of AgNP: 0.0, 40.0, 80.0, 120.0, and 160.0 mL dissolved in 20 L of raw Hudson River water. After 10 days of exposure, the crayfish were harvested and tissue analyzed using graphite furnace atomic absorption spectrometry (GFAAS). DNA damage was analyzed by comet assay. In the 160 mL/20 L exposure accumulation was ~0.25 μg of Ag/g of dry liver tissue. There was significant DNA damage in the AgNP treatments where comets ranged from 95 to 130 μm. The results raise concern about the impact of AgNPs on the environment and possibyl human health.

Honorable Mention: Hansa Thompson and Susan Holechek, Arizona State University

Independent Expression and Analysis of the Two Domains of Vaccinia Virus's E3L Gene

Vaccinia virus (VACV) is a large double-stranded DNA virus that has been extensively studied as a safe alternative for a vaccine or gene therapy delivery vector, and can easily be manipulated to construct recombinants. Replication of the VACV virus has been shown to be resistant to pre-treatment of cells with type-I interferon (IFN). The activity of the E3L gene has been shown to cause this phenotype. This gene encodes a 190-amino acid protein has a C-terminal double-stranded RNAbinding domain and a N-terminal half that is a member of the Za family of Z-DNAbinding domains. Our study, headed by Dr. Bertram Jacobs and Susan Holechek of ASU’s Biodesign Institute, will explore the IFN inhibition properties E3L’s two domains when they are expressed independently. The N-terminus will be inserted in the E3L locus of a recombinant VACV virus lacking E3L, while the C-terminus will be inserted into the Vaccinia Virus thymidine kinase locus. Mutants expressing both domains of E3L separately will be constructed and assayed for equivalent expression. Viral replication as well as activation of the IFN system will be evaluated in previously characterized cell lines and under conditions that require both domains to be present in order to inhibit the IFN pathway upon VACV infection. If pathogenesis is retained, it can be concluded that fusion of the two domains is not necessary in order to inhibit the IFN response. This work will provide a better understanding of the function of the E3L protein and how VACV is evading the activation of the IFN pathway. Because VACV is used as a vector against other diseases, further understanding of how VACV evades the immune system could lead to the development of better and safer vaccines.

Winner: Matthew R. Edwards and Clayton E. Myers, Princeton University

Temperature Effects on Electrical Properties of Superconducting Flux Conservers

The Princeton Field-Reversed-Configuration (PFRC) experiment creates plasma to study basic physics related to space plasma, plasma processing, and spacecraft propulsion, with an end goal of developing a small-scale magneticallyconfined controlled-fusion device. The current PFRC-1 uses room-temperature passive flux conservers (FCs) to provide magnetic confinement in the radial direction. The next generation device, the PFRC-2, will use LN2-cooled rings of copper with embedded bismuth strontium calcium copper oxide (BSCCO) high temperature superconductor (HTS) tapes. The change in magnetic flux within the PFRC due to plasma formation and heating induces currents in the FCs; the FC array exerts a magnetic force on the plasma which is proportional to its current. Designing the PFRC-2 device requires knowledge of the temperature dependence of the maximum current sustainable in the BSCCO-copper HTS-FC (critical current), the time constant of the current decay rate (skin time), and the underlying physics driving the current behavior. Several different designs of solid copper and copper-BSCCO FC rings were tested in a solenoid which simulated the magnetic field caused by the formation of the PFRC plasma. The current in each FC over an entire ramp up and decay cycle was calculated from Hall probe magnetic field measurements made every millisecond at temperatures between 77 and 110 K. A magnetostatics code was used to interpret the data. Maximum currents of 2 kA, critical currents of 1 kA, and skin times between 30 ms and 1300 s have been achieved at 77 K. Critical current and skin time dependence on temperature has been shown to be roughly linear between 77 and 110 K. The mechanics of current decay for most FC designs are now understood to be due to currents in the copper rings. These results show that the desired currents of several kA and skin times of 500 ms for the PFRC-2 are reachable and that they can be achieved at temperatures significantly warmer than 77 K, allowing a liquid nitrogen cooling system to be used and construction of the next PFRC device to move forward. This experiment has also contributed to an understanding of how superconductors interact with nearby materials when close to their maximum current capacity.

Honorable Mention: Makrete Krikorian and Jeffrey Meisner, Columbia University

Single-Molecule Conductance of Disubstituted Stilbenes

This poster details the single-molecule electrical measurements of disubstituted stilbenes using STM-based break junctions. Results show that 4,4’-dithiomethylstilbene has an unusually high bias dependence. The interpretation of this result is that the Fermi level or work function of the gold contact electrode is aligned properly with the Highest Occupied Molecular Orbital (HOMO) of the molecule, which allows for resonant tunneling through the system and a greater bias dependence. Further experimentation showed that the 3,4’-disubtituted stilbenes formed molecular junctions and measurable conductance—despite resonance predictions. In this case, the molecules chemically bind to the gold electrodes through both linker groups, but conduct through only the 4-substituted linker group. This experimental evidence broadens our understanding of fundamentals governing single-molecule conductance and may lead to predictive power in single-molecule design.

Winner: Eric Michael Johnson, University of British Columbia

Demographics, Inequality, and Entitlements in the Russian Famine of 1891

Twentieth-century scholarship has framed the Russian famine of 1891 in largely Malthusian terms. According to this interpretation, as the rural population expanded in the Central and Eastern Agricultural Regions a “demographic revolution” took place that overran land resources and outstripped food production. A crop failure then resulted in famine and the loss of an estimated 500,000 lives. Climate data and documentary records are consistent with the interpretation that a convergence of Azores and Arctic anticyclones precipitated a crop failure. However, a meta-analysis reveals that the crisis was not a failure of food availability, but a failure of food entitlements. Government records show that the amount of grain available nationwide had increased despite the crop failure, but high cost put it out of reach for those most in need. Prior to the crisis, rapid industrialization had disrupted the traditional agricultural existence for many rural provinces and labor migration was crucial for supplementing rural income. Provinces within proximity to industrial development were able to supplement their agricultural income and improve their maximum entitlement. However, the average migration rate between 1881-1890 for the twelve Russian provinces most affected by the famine was inversely correlated with the percent of increase in death rate following the crop failure. In contrast to the Malthusian explanation, the famine merely exposed already existing fault lines of economic inequality. By understanding the demographic causes of this entitlement failure that resulted in famine, we can better understand the conditions that led to the downfall of Tsarism in Russia.

Honorable Mention: Trent James Bowen, Arizona State University

Educational Barriers to Preventative Medicine in Accra, Ghana

Glaucoma is the second leading cause of blindness in Ghana. Preventative vision care screenings are essential for diagnosing and treating glaucoma early to ensure the disease does not advance to cause irreparable blindness. At Emmanuel Eye Centre in Accra, Ghana, a large portion of glaucoma patients is not receiving glaucoma treatment until the disease has progressed to an advanced stage. To identify possible barriers between glaucoma patients and vision care, patients who arrived at the clinic with both early and late stages of glaucoma were selected for semi-structured interviews. This IRB approved study had three targets: knowledge of what glaucoma is, perception of the need for eye care before treatment, and specific barriers to glaucoma care. The responses were thematically analyzed in terms of these three categories for 49 patients. More than half of the participants (28/49) expressed no feeling of need to seek care from an eye doctor until they noticed a problem, and a sizable number did not know what glaucoma was (14/49). Only 4 noted a specific barrier to care, notably lack of funds. These findings suggest that the “invisibility” of early stage glaucoma is a significant barrier to care, and indicate a need for education about glaucoma and its effects. As many groups seek to integrate preventative medical care into developing health care systems, it is important to realize that availability of care and funds do not directly provide medical care uptake.

Sign up at www.aaas.org/meetings to receive announcements about the 2012 AAAS Annual Meeting 16-20 February in Vancouver, BC.

The 2012 Poster Submission site opens on 12 July 2011. The Student Poster Competition recognizes the individual research efforts of undergraduate- and graduate-level students who are enrolled in a degree program. Posters are judged at the meeting. Winners in each category receive a cash award and framed certificate. Individuals holding doctoral degrees are not eligible and are invited to submit for the General Poster session.