11,930 research outputs found

    Comparative Phylogenomics of Pathogenic and Nonpathogenic Species.

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    The Ascomycete Onygenales order embraces a diverse group of mammalian pathogens, including the yeast-forming dimorphic fungal pathogens Histoplasma capsulatum, Paracoccidioides spp. and Blastomyces dermatitidis, the dermatophytes Microsporum spp. and Trichopyton spp., the spherule-forming dimorphic fungal pathogens in the genus Coccidioides, and many nonpathogens. Although genomes for all of the aforementioned pathogenic species are available, only one nonpathogen had been sequenced. Here, we enhance comparative phylogenomics in Onygenales by adding genomes for Amauroascus mutatus, Amauroascus niger, Byssoonygena ceratinophila, and Chrysosporium queenslandicum--four nonpathogenic Onygenales species, all of which are more closely related to Coccidioides spp. than any other known Onygenales species. Phylogenomic detection of gene family expansion and contraction can provide clues to fungal function but is sensitive to taxon sampling. By adding additional nonpathogens, we show that LysM domain-containing proteins, previously thought to be expanding in some Onygenales, are contracting in the Coccidioides-Uncinocarpus clade, as are the self-nonself recognition Het loci. The denser genome sampling presented here highlights nearly 800 genes unique to Coccidiodes, which have significantly fewer known protein domains and show increased expression in the endosporulating spherule, the parasitic phase unique to Coccidioides spp. These genomes provide insight to gene family expansion/contraction and patterns of individual gene gain/loss in this diverse order--both major drivers of evolutionary change. Our results suggest that gene family expansion/contraction can lead to adaptive radiations that create taxonomic orders, while individual gene gain/loss likely plays a more significant role in branch-specific phenotypic changes that lead to adaptation for species or genera

    Banana Value Chains in Central Africa: Constraints and Opportunities

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    Smallholder farmers in developing countries need to improve their position in food value chains in order to improve their margins and as a strategy for coping with agricultural food price volatility through innovations within the chains. Value chain mappings and gross margin analysis were employed to assess constraints and opportunities for existing value chains for bananas in Central Africa using market survey data. The results showed weak linkages within the banana value chains with poor integration of value chain actors and minimal involvement with regional markets and high-value domestic chains such as supermarkets. Value addition in terms of agroprocessing was carried out at small scale levels using rudimentary techniques limiting the final product to low value markets. Transaction costs comprising transport, handling and storage comprised a high proportion of cost items in the value chain. Generally, the findings suggest that efforts aimed at strengthening linkages within the value chains, collective marketing, penetration into high-value chains and improved processing techniques may provide a potential avenue for enhancing banana value chains in Central Africa.banana value chains, smallholder farmers, Central Africa, collective action, Crop Production/Industries,

    Tackling resistance: Emerging antimalarials and new parasite targets in the era of elimination [version 1; referees: 2 approved]

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    Malaria remains a significant contributor to global human mortality, and roughly half the world’s population is at risk for infection with Plasmodium spp. parasites. Aggressive control measures have reduced the global prevalence of malaria significantly over the past decade. However, resistance to available antimalarials continues to spread, including resistance to the widely used artemisinin-based combination therapies. Novel antimalarial compounds and therapeutic targets are greatly needed. This review will briefly discuss several promising current antimalarial development projects, including artefenomel, ferroquine, cipargamin, SJ733, KAF156, MMV048, and tafenoquine. In addition, we describe recent large-scale genetic and resistance screens that have been instrumental in target discovery. Finally, we highlight new antimalarial targets, which include essential transporters and proteases. These emerging antimalarial compounds and therapeutic targets have the potential to overcome multi-drug resistance in ongoing efforts toward malaria elimination

    Epigenetic silencing of SOCS3 expression contributes to fibrosis in Crohn’s disease

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    Identified risk polymorphisms affecting the Jak-STAT3 pathway in patients with Crohn’s disease could affect TGF-β1 and collagen I expression and in the pathway’s negative regulator, SOCS3. Genetic factors, however, account for only ~25% of disease. Epigenetic events also shape gene expression. Recent experiments showed that autocrine IL-6 production in mesenchymal cells, subepithelial myofibroblasts (SEMF) and muscle cells, of patients with fibrostenotic Crohn’s disease causes sustained Jak-STAT3 activity, excess TGF-β1 and Collagen I production and fibrosis. SOCS3 paradoxically decreased in these cells. We now identify epigenetic mechanisms that silence SOCS3 expression in SEMF of patients with fibrostenotic Crohn’s disease. In a previous experiment, using isolated SEMF of normal ileum and affected ileum from patients with each Crohn’s phenotype, inflammatory (Montreal B1), fibrostenotic (B2) and penetrating (B3), we confirmed decreased SOCS3 protein levels were unique to B2 patients. Expression of miR-19b increased in SEMF of affected ileum. SOCS3 transcriptional activity decreased after transfection of miR-19b mimic and increased when antagomiR-19b was expressed. Epigenetic silencing of SOCS3 in ileal SEMF of patients with fibrostenotic Crohn’s disease occurs by increased miR-19b mediated inhibition of SOCS3

    Russians Back Protests, Political Freedoms and Putin, Too

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    Presents survey findings about Russians' reaction to the December 2011 parliamentary and March 2012 presidential elections and subsequent protests, attitudes toward democracy, and views of leaders, nationalism, and Russia?s global image

    Medicaid Spending Growth Over the Last Decade and the Great Recession, 2000-2009

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    Analyzes Medicaid enrollment and per-capita spending growth by service and compared with other areas of the healthcare system. Examines contributing factors, potential program cuts as a result of states' budget woes, and implications for the safety net
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