2,430 research outputs found

    Remotely-sensed, nocturnal, dew point correlates with malaria transmission in Southern Province, Zambia: a time-series study

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    Background: Plasmodium falciparum transmission has decreased significantly in Zambia in the last decade. The malaria transmission is influenced by environmental variables. Incorporation of environmental variables in models of malaria transmission likely improves model fit and predicts probable trends in malaria disease. This work is based on the hypothesis that remotely-sensed environmental factors, including nocturnal dew point, are associated with malaria transmission and sustain foci of transmission during the low transmission season in the Southern Province of Zambia. Methods: Thirty-eight rural health centres in Southern Province, Zambia were divided into three zones based on transmission patterns. Correlations between weekly malaria cases and remotely-sensed nocturnal dew point, nocturnal land surface temperature as well as vegetation indices and rainfall were evaluated in time-series analyses from 2012 week 19 to 2013 week 36. Zonal as well as clinic-based, multivariate, autoregressive, integrated, moving average ( ARIMAX) models implementing environmental variables were developed to model transmission in 2011 week 19 to 2012 week 18 and forecast transmission in 2013 week 37 to week 41. Results: During the dry, low transmission season significantly higher vegetation indices, nocturnal land surface temperature and nocturnal dew point were associated with the areas of higher transmission. Environmental variables improved ARIMAX models. Dew point and normalized differentiated vegetation index were significant predictors and improved all zonal transmission models. In the high-transmission zone, this was also seen for land surface temperature. Clinic models were improved by adding dew point and land surface temperature as well as normalized differentiated vegetation index. The mean average error of prediction for ARIMAX models ranged from 0.7 to 33.5%. Forecasts of malaria incidence were valid for three out of five rural health centres; however, with poor results at the zonal level. Conclusions: In this study, the fit of ARIMAX models improves when environmental variables are included. There is a significant association of remotely-sensed nocturnal dew point with malaria transmission. Interestingly, dew point might be one of the factors sustaining malaria transmission in areas of general aridity during the dry season

    A new route to α,ω-diamines from hydrogenation of dicarboxylic acids and their derivatives in the presence of amines

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    We thank the EPSRC for the critical mass grant 'Clean Catalysis for Sustainable Development' (EP/J018139/1), Sasol Technology, UK for a case studentship (Y. S.) and the EPSRC UK National Mass Spectrometry Facility at Swansea University for mass spectrometric analysisA new and selective route for the synthesis of polymer precursors, primary diamines or N-substituted diamines, from dicarboxylic acids, diesters, diamides and diols using a Ru/ triphos catalyst is reported. Excellent conversions and yields are obtained under optimised reaction conditions. The reactions worked very well using 1,4-dioxane as solvent, but the greener solvent, 2-methyl tetrahydrofuran, also gave very similar results. This method provides a potential route to converting waste biomass to value added materials. The reaction is proposed to go through both amide and aldehyde pathways.PostprintPeer reviewe

    Multilocus sequence typing (MLST) analysis of Vibrio cholerae O1 El Tor isolates from Mozambique that harbour the classical CTX prophage.

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    Vibrio cholerae O1 isolates belonging to the Ogawa serotype, El Tor biotype, harbouring the classical CTX prophage were first isolated in Mozambique in 2004. Multilocus sequence typing (MLST) analysis using nine genetic loci showed that the Mozambique isolates have the same sequence type (ST) as O1 El Tor N16961, a representative of the current seventh cholera pandemic. Analysis of the CTX prophage in the Mozambique isolates indicated that there is one type of rstR in these isolates: the classical CTX prophage. It was also found that the ctxB-rstR-rstA-rstB-phs-cep fragment was PCR-amplified from these isolates, which indicates the presence of a tandem repeat of the classical CTX prophage in the genome of the Mozambique isolates. The possible origin of these isolates and the presence of the tandem repeat of the classical prophage in them implicate the presence of the classical CTX phage

    Hsp90 Inhibition Suppresses NF-κB Transcriptional Activation via Sirt-2 in Human Lung Microvascular Endothelial Cells

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    The ability of anti-heat shock protein 90 (Hsp90) drugs to attenuate NF-κB-mediated transcription is the major basis for their anti-inflammatory properties. While the molecular mechanisms underlying this effect are not clear, they appear to be distinct in human endothelial cells. We now show for the first time that type 2 sirtuin (Sirt-2) histone deacetylase binds human NF-κB target gene promoter and prevents the recruitment of NF-κB proteins and subsequent assembly of RNA polymerase II complex in human lung microvascular endothelial cells. Hsp90 inhibitors stabilize the Sirt-2/promoter interaction and impose a “transcriptional block,” which is reversed by either inhibition or downregulation of Sirt-2 protein expression. Furthermore, this process is independent of NF-κB (p65) Lysine 310 deacetylation, suggesting that it is distinct from known Sirt-2-dependent mechanisms. We demonstrate that Sirt-2 is recruited to NF-κB target gene promoter via interaction with core histones. Upon inflammatory challenge, chromatin remodeling and core histone H3 displacement from the promoter region removes Sirt-2 and allows NF-κB/coactivator recruitment essential for RNA Pol II-dependent mRNA induction. This novel mechanism may have important implications in pulmonary inflammation

    The Lantern Vol. 42, No. 1, Fall 1975

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    • The House • The Empty Man • Time • Corporea • Take Me • Elements of Nature • Hope • Acclimation • Road to Elat • Sinai • Jerusalem • Fatman • Ode to Grand Rapids • Ode to Cora • The Apple Cart • Next Time You\u27re Down South • Star Wreck • Eulogy to John Doe • A Postal Preoccupation • The Interview May Be Real (But Don\u27t Bet On It) • Winter Eve • My Love • God\u27s Children • A View From a Hill • Freedom For Us • Sleep Demonhttps://digitalcommons.ursinus.edu/lantern/1107/thumbnail.jp

    Price Floors and Employer Preferences: Evidence from a Minimum Wage Experiment

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    Minimum hourly wages were randomly imposed on firms posting job openings in an online labor market. A higher minimum wage raised the wages of hired workers substantially. However, there was some reduction in hiring and large reductions in hours-worked. Treated firms hired more productive workers, which can explain, in part, the reduction in hours-worked: with more productive workers, projects were completed in less time. At the conclusion of the experiment, the platform imposed a market-wide minimum wage. A difference-in-differences analysis shows that, in equilibrium, firms still substitute towards more productive workers, adversely affecting less productive workers

    Organizational Mortality of Small Firms: The Effects of Entrepreneurial Age and Human Capital

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    This paper addresses the issue of internal determination of organizational outcomes. It is argued that in small and simply structured organizations a considerable proportion of the variance in organizational activities and outcomes is associated with individuals. In particular, the paper uses human capital theory to derive hypotheses about individual determinants of organizational mortality. These hypotheses are tested with event-history data of firm registrations and de-registrations in a West German region. The hypotheses are corroborated by the data, but the effects may nonetheless be due to processes linking individual characteristics with organizational performance other than those suggested by the human capital approach

    MHC-I expression renders catecholaminergic neurons susceptible to T-cell-mediated degeneration

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    Subsets of rodent neurons are reported to express major histocompatibilty complex class I (MHC-I), but such expression has not been reported in normal adult human neurons. Here we provide evidence from immunolabel, RNA expression, and mass spectrometry analysis of postmortem samples that human catecholaminergic substantia nigra and locus coeruleus neurons express MHC-I, and that this molecule is inducible in human stem cell derived dopamine (DA) neurons. Catecholamine murine cultured neurons are more responsive to induction of MHC-I by gamma-interferon than other neuronal populations. Neuronal MHC-I is also induced by factors released from microglia activated by neuromelanin or alpha-synuclein, or high cytosolic DA and/or oxidative stress. DA neurons internalize foreign ovalbumin and display antigen derived from this protein by MHC-I, which triggers DA neuronal death in the presence of appropriate cytotoxic T-cells. Thus, neuronal MHC-I can trigger antigenic response, and catecholamine neurons may be particularly susceptible to T cell-mediated cytotoxic attack
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