359 research outputs found

    Bridging Anacostia

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    Countless cities face issues of disconnection. Washington, DC's Anacostia neighborhood remains physically, socially, and economically separated from the city at-large, while failing to take advantage of its proximity to an under utilized waterfront. This thesis explores ideas about "bridging", not only physically but also metaphorically and socially. Interstate 295, as a physical and perceptual barrier, has had the most negative impact on this area. This thesis proposes to create connections between Anacostia, the waterfront, and greater Washington, DC by engaging land use into and beneath the highway thereby creating thresholds between Anacostia, the waterfront, and greater Washington, DC. Furthermore, this thesis sites the Frederick Douglass neighborhood and heritage center which not only bridges the highway, but also creates a physical link between historic Anacostia and the waterfront

    A search engine to identify pathway genes from expression data on multiple organisms

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    <p>Abstract</p> <p>Background</p> <p>The completion of several genome projects showed that most genes have not yet been characterized, especially in multicellular organisms. Although most genes have unknown functions, a large collection of data is available describing their transcriptional activities under many different experimental conditions. In many cases, the coregulatation of a set of genes across a set of conditions can be used to infer roles for genes of unknown function.</p> <p>Results</p> <p>We developed a search engine, the Multiple-Species Gene Recommender (MSGR), which scans gene expression datasets from multiple organisms to identify genes that participate in a genetic pathway. The MSGR takes a query consisting of a list of genes that function together in a genetic pathway from one of six organisms: <it>Homo sapiens</it>, <it>Drosophila melanogaster</it>, <it>Caenorhabditis elegans</it>, <it>Saccharomyces cerevisiae</it>, <it>Arabidopsis thaliana</it>, and <it>Helicobacter pylori</it>. Using a probabilistic method to merge searches, the MSGR identifies genes that are significantly coregulated with the query genes in one or more of those organisms. The MSGR achieves its highest accuracy for many human pathways when searches are combined across species. We describe specific examples in which new genes were identified to be involved in a neuromuscular signaling pathway and a cell-adhesion pathway.</p> <p>Conclusion</p> <p>The search engine can scan large collections of gene expression data for new genes that are significantly coregulated with a pathway of interest. By integrating searches across organisms, the MSGR can identify pathway members whose coregulation is either ancient or newly evolved.</p

    Gut Microbiota Composition Modulates the Magnitude and Quality of Germinal Centers during Plasmodium Infections

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    Gut microbiota composition is associated with human and rodent Plasmodium infections, yet the mechanism by which gut microbiota affects the severity of malaria remains unknown. Humoral immunity is critical in mediating the clearance of Plasmodium blood stage infections, prompting the hypothesis that mice with gut microbiota-dependent decreases in parasite burden exhibit better germinal center (GC) responses. In support of this hypothesis, mice with a low parasite burden exhibit increases in GC B cell numbers and parasite-specific antibody titers, as well as better maintenance of GC structures and a more targeted, qualitatively different antibody response. This enhanced humoral immunity affects memory, as mice with a low parasite burden exhibit robust protection against challenge with a heterologous, lethal Plasmodium species. These results demonstrate that gut microbiota composition influences the biology of spleen GCs as well as the titer and repertoire of parasite-specific antibodies, identifying potential approaches to develop optimal treatments for malaria

    24-Month Overall Survival from KEYNOTE-021 Cohort G: Pemetrexed and Carboplatin with or without Pembrolizumab as First-Line Therapy for Advanced Nonsquamous Non–Small Cell Lung Cancer

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    Introduction Cohort G of KEYNOTE-021 (NCT02039674) evaluated the efficacy and safety of pembrolizumab plus pemetrexed-carboplatin (PC) versus PC alone as first-line therapy for advanced nonsquamous NSCLC. At the primary analysis (median follow-up time 10.6 months), pembrolizumab significantly improved objective response rate (ORR) and progression-free survival (PFS); the hazard ratio (HR) for overall survival (OS) was 0.90 (95% confidence interval [CI]: 0.42‒1.91). Herein, we present an updated analysis. Methods A total of 123 patients with previously untreated stage IIIB/IV nonsquamous NSCLC without EGFR and/or ALK receptor tyrosine kinase gene (ALK) aberrations were randomized 1:1 to four cycles of PC with or without pembrolizumab, 200 mg every 3 weeks. Pembrolizumab treatment continued for 2 years; maintenance pemetrexed was permitted in both groups. Eligible patients in the PC-alone group with radiologic progression could cross over to pembrolizumab monotherapy. p Values are nominal (one-sided p < 0.025). Results As of December 1, 2017, the median follow-up time was 23.9 months. The ORR was 56.7% with pembrolizumab plus PC versus 30.2% with PC alone (estimated difference 26.4% [95% CI: 8.9%‒42.4%, p = 0.0016]). PFS was significantly improved with pembrolizumab plus PC versus PC alone (HR = 0.53, 95% CI: 0.33‒0.86, p = 0.0049). A total of 41 patients in the PC-alone group received subsequent anti‒programmed death 1/anti‒programmed death ligand 1 therapy. The HR for OS was 0.56 (95% CI: 0.32‒0.95, p = 0.0151). Forty-one percent of patients in the pembrolizumab plus PC group and 27% in the PC-alone group had grade 3 to 5 treatment-related adverse events. Conclusions The significant improvements in PFS and ORR with pembrolizumab plus PC versus PC alone observed in the primary analysis were maintained, and the HR for OS with a 24-month median follow-up was 0.56, favoring pembrolizumab plus PC

    Validation of food store environment secondary data source and the role of neighborhood deprivation in Appalachia, Kentucky

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    Background Based on the need for better measurement of the retail food environment in rural settings and to examine how deprivation may be unique in rural settings, the aims of this study were: 1) to validate one commercially available data source with direct field observations of food retailers; and 2) to examine the association between modified neighborhood deprivation and the modified retail food environment score (mRFEI). Methods Secondary data were obtained from a commercial database, InfoUSA in 2011, on all retail food outlets for each census tract. In 2011, direct observation identifying all listed food retailers was conducted in 14 counties in Kentucky. Sensitivity and positive predictive values (PPV) were compared. Neighborhood deprivation index was derived from American Community Survey data. Multinomial regression was used to examine associations between neighborhood deprivation and the mRFEI score (indicator of retailers selling healthy foods such as low-fat foods and fruits and vegetables relative to retailers selling more energy dense foods). Results The sensitivity of the commercial database was high for traditional food retailers (grocery stores, supermarkets, convenience stores), with a range of 0.96-1.00, but lower for non-traditional food retailers; dollar stores (0.20) and Farmer’s Markets (0.50). For traditional food outlets, the PPV for smaller non-chain grocery stores was 38%, and large chain supermarkets was 87%. Compared to those with no stores in their neighborhoods, those with a supercenter [OR 0.50 (95% CI 0.27. 0.97)] or convenience store [OR 0.67 (95% CI 0.51, 0.89)] in their neighborhood have lower odds of living in a low deprivation neighborhood relative to a high deprivation neighborhood. Conclusion The secondary commercial database used in this study was insufficient to characterize the rural retail food environment. Our findings suggest that neighborhoods with high neighborhood deprivation are associated with having certain store types that may promote less healthy food options

    Selection for Higher Gene Copy Number after Different Types of Plant Gene Duplications

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    The evolutionary origins of the multitude of duplicate genes in the plant genomes are still incompletely understood. To gain an appreciation of the potential selective forces acting on these duplicates, we phylogenetically inferred the set of metabolic gene families from 10 flowering plant (angiosperm) genomes. We then compared the metabolic fluxes for these families, predicted using the Arabidopsis thaliana and Sorghum bicolor metabolic networks, with the families' duplication propensities. For duplications produced by both small scale (small-scale duplications) and genome duplication (whole-genome duplications), there is a significant association between the flux and the tendency to duplicate. Following this global analysis, we made a more fine-scale study of the selective constraints observed on plant sodium and phosphate transporters. We find that the different duplication mechanisms give rise to differing selective constraints. However, the exact nature of this pattern varies between the gene families, and we argue that the duplication mechanism alone does not define a duplicated gene's subsequent evolutionary trajectory. Collectively, our results argue for the interplay of history, function, and selection in shaping the duplicate gene evolution in plants
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