26 research outputs found

    Human IgG subclass antibodies to the 19 kilodalton carboxy terminal fragment of Plasmodium Falciparum merozoite surface protein 1 (MSP119) and predominance of the MAD20 allelic type of MSP1 in Uganda

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    Objective: To determine the natural human humoral immune responses to the 19 kilodalton carboxy terminal fragment of Plasmodium falciparum merozoite surface protein 1 (MSP119), a malaria candidate vaccine antigen and to determine the prevalence of MAD20 and K1 alleles of P. falciparum MSP1.Design: Community based cross-sectional study.Setting: Atopi Parish, Apac District, Uganda, 1995.Subjects: Three hundred and seventy four Ugandans betwee

    Gerenciamento Descentralizado de Rede com Software Livre

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    Com uma proposta de um gerenciamento de rede descentralizado, neste trabalho desenvolveu-se uma ferramenta gråfica para uso via web, utilizando-se as linguagens shell script e PHP, com o objetivo de facilitar a configuração e monitoração de diferentes serviços necessårios em um servidor de rede, tais como: firewall, DHCP, squid/proxy, DNS, e-mail, dentre outros

    In vitro embryo rescue and plant regeneration following self-pollination with irradiated pollen in cassava (Manihot esculenta Crantz)

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    Cassava is a highly heterozygous species; hence, current methods used in classical cassava breedingcannot match the urgent need to high yielding varieties. Recently, progress was made through androgenesis and gynogenesis as pathways for raising doubled cassava haploid lines to overcome problems associated with cassava’s inherent reproductive biology, but these efforts were limited (nocandidate cassava plantlets were regenerated). For the first time, this study shows that pollen irradiation coupled with self-pollination and embryo rescue regenerated 62 candidate cassava plantlets. Plants of an elite cassava variety, Nase14, served as a mother plant and as the pollen donor for the irradiation. Irradiation dosages of 50 to 250 Gray studied across five pollination events and 300 or 500 Gray in one pollination event caused a reduction in pollen germination up to 67.0%. By 15 days after pollination (DAP) with irradiated pollen, up to 89.7% of the pollinated flowers had aborted. By embryo rescue time (42 DAP), significant differences were observed in number of fruits, seeds and embryos generated, with the non-irradiated pollen treatments having significantly higher numbers. Sixteen (16) heterozygous SSR markers in the parent and ploidy analysis showed that none of the regenerated plants was haploid or homozygous. However, the plantlets resulting from pollination with non-irradiated pollen had 56.2% homozygous loci, while progeny derived from irradiated treatments had frequencies of homozygous loci between 28.1 and 55.0%. This is the first time to use irradiated pollen in cassava as a pathway to generate candidate plantlets as an initial step in double haploid production.Key words: Cassava, doubled haploids, embryo rescue, plant regeneration, pollen germination, pollenirradiation

    Water pollution affects fish community structure and alters evolutionary trajectories of invasive guppies (Poecilia reticulata).

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    Anthropogenic habitat alterations have the potential to affect both, ecological dynamics of communities and populations, as well as evolutionary processes within populations. Invasive species may benefit from anthropogenic disturbance, such as water pollution, to which they sometimes seem more resistant than native ones. They also allow investigating evolutionary divergence among populations occurring along pollution gradients. We assessed fish communities at 55 sampling sites in the degraded and heavily overstocked Mutara Rangelands of north-eastern Rwanda (upper Nile drainage), which receive pollution from domestic wastewater and cattle dung. Diverse fish communities became apparent that included invasive guppies (Poecilia reticulata, Poeciliidae), and canonical correspondence analyses found significant differentiation of community structures along several environmental parameters (condensed into principal components), including pollution-effects. As predicted, generalized linear models found guppies to have a higher likelihood of occurrence at polluted sites. Local abundances of guppies, however, decreased at polluted sites. Since guppies are color-polymorphic, and color patterns have a heritable basis, they allow inferences regarding both pollution-induced suppression of male ornamentation (e.g., through xenestrogens) and evolutionary population divergence. We thus quantified different ornament types (numbers and percent body surface cover). ANCOVAs uncovered several weak (based on effect strengths), but statistically significant pollution-effects and interactions with other environmental parameters. The direction of several interaction effects was similar for blue/black and red/orange ornaments, while white/iridescent ornaments responded dissimilarly. As responses differed between ornament types, they likely reflect evolutionary divergence due to site-specific alterations of selective regimes rather than developmental inhibition of male secondary sexual characters. We propose that pollution affects local fitness landscapes resulting, e.g., from predation and mate competition (as a function of local abundances), altogether driving evolutionary divergence of sexually selected traits. This study highlights how human activities not only impact ecological dynamics, but-mediated by altered Eco-Evo dynamics-might change the evolutionary trajectories of populations

    Effects of gamma irradiation and ethyl methane sulphonate on morphometric traits and prevalence of common viral diseases and whiteflies in cassava

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    Cassava ( Manihot esculenta Crantz) is an important staple and food security crop for millions of people in Africa. However, its nutritional value is limited; yet its productivity is constrained by several pests and diseases. Induced mutagenesis is one approach with the potential to overcome such biotic stresses. The objective of this study was to assess the variability in morphometric traits and prevalence of common viral diseases and whiteflies in cassava to different doses and concentrations of gamma irradiation and ethyl methane sulphonate (ems) treatments. The effects were assessed on seed germination and growth of stakes, as well as foliar viral disease symptoms and whitefly counts. Radio-sensitivity tests revealed LD50 for sprouting as 37.6Gy for \u3b3-irradiation and 0.08% for EMS treatment. There was notable decrease in sprout, epicotyl length, shoot height, petiole length and number of leaf lobes, with increasing \u3b3-ray doses and EMS concentrations. Contrastingly, total chlorophyll content increased with increasing doses of \u3b3-rays and EMS concentrations. Basing on foliar whitefly counts and disease symptoms, there was a general increase in susceptibility to whitefly infestation and cassava mosaic disease (CMD) incidence. Significantly varying levels of resistance or tolerance to whiteflies and CMD were observed among plantlets derived from irradiated and EMS treated stems, compared to the controls. These findings lay a foundation for more future research on breeding for various traits, including disease resistance in cassava using induced mutagenesis approach.Le manioc ( Manihot esculenta Crantz) est une culture de base et de la s\ue9curit\ue9 alimentaire importante pour des millions de personnes en Afrique. Cependant, sa valeur nutritionnelle est limit\ue9e; pourtant, sa productivit\ue9 est limit\ue9e par plusieurs ravageurs et maladies. La mutagen\ue8se induite est une approche ayant le potentiel de surmonter de tels stress biotiques. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer la variabilit\ue9 des traits morphom\ue9triques et la pr\ue9valence des maladies virales courantes et des aleurodes du manioc en raison de l\u2019exposition \ue0 diff\ue9rentes doses et concentrations des traitements par l\u2018 irradiation gamma et \ue9thyl m\ue9thane sulfonate (EMS). Les effets ont \ue9t\ue9 \ue9valu\ue9s sur la germination des graines et la croissance des tuteurs, ainsi que sur les sympt\uf4mes de la maladie virale foliaire et le nombre des aleurodes. Les tests de radiosensibilit\ue9 ont r\ue9v\ue9l\ue9 que la DL50 pour la germination \ue9tait de 37,6 Gy pour l\u2019irradiation et de 0,08 % pour le traitement EMS. Il y avait une diminution notable de la pousse, de la longueur de l\u2019\ue9picotyle, de la hauteur des pousses, de la longueur du p\ue9tiole et du nombre des lobes foliaires, avec l\u2019augmentation des doses de rayons et des concentrations EMS. En revanche, la teneur totale en chlorophylle augmentait avec l\u2019augmentation des doses de rayons et des concentrations EMS. Sur la base des d\ue9nombrements foliaires des aleurodes et des sympt\uf4mes de la maladie, il y avait une susceptibilit\ue9 g\ue9n\ue9ralement accrue \ue0 l\u2019infestation des aleurodes et \ue0 l\u2019incidence de la maladie de la mosa\uefque du manioc (CMD). Des niveaux significativement variables de r\ue9sistance ou de tol\ue9rance aux aleurodes et \ue0 la CMD ont \ue9t\ue9 observ\ue9s parmi les plantules d\ue9riv\ue9es de tiges irradi\ue9es et trait\ue9es par EMS, par rapport aux t\ue9moins. Ces r\ue9sultats jettent les bases des autres recherches futures sur la s\ue9lection pour les divers caract\ue8res, y compris la r\ue9sistance aux maladies du manioc en utilisant une approche de mutagen\ue8se induite

    The cost‐effectiveness of prophylaxis strategies for individuals with advanced HIV starting treatment in Africa

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    Introduction Many HIV‐positive individuals in Africa have advanced disease when initiating antiretroviral therapy (ART) so have high risks of opportunistic infections and death. The REALITY trial found that an enhanced‐prophylaxis package including fluconazole reduced mortality by 27% in individuals starting ART with CD4 <100 cells/mm3. We investigated the cost‐effectiveness of this enhanced‐prophylaxis package versus other strategies, including using cryptococcal antigen (CrAg) testing, in individuals with CD4 <200 cells/mm3 or <100 cells/mm3 at ART initiation and all individuals regardless of CD4 count. Methods The REALITY trial enrolled from June 2013 to April 2015. A decision‐analytic model was developed to estimate the cost‐effectiveness of six management strategies in individuals initiating ART in the REALITY trial countries. Strategies included standard‐prophylaxis, enhanced‐prophylaxis, standard‐prophylaxis with fluconazole; and three CrAg testing strategies, the first stratifying individuals to enhanced‐prophylaxis (CrAg‐positive) or standard‐prophylaxis (CrAg‐negative), the second to enhanced‐prophylaxis (CrAg‐positive) or enhanced‐prophylaxis without fluconazole (CrAg‐negative) and the third to standard‐prophylaxis with fluconazole (CrAg‐positive) or without fluconazole (CrAg‐negative). The model estimated costs, life‐years and quality‐adjusted life‐years (QALY) over 48 weeks using three competing mortality risks: cryptococcal meningitis; tuberculosis, serious bacterial infection or other known cause; and unknown cause. Results Enhanced‐prophylaxis was cost‐effective at cost‐effectiveness thresholds of US300andUS300 and US500 per QALY with an incremental cost‐effectiveness ratio (ICER) of US157perQALYintheCD4<200cells/mm3populationprovidingenhanced‐prophylaxiscomponentsaresourcedatlowestavailableprices.TheICERreducedinmoreseverelyimmunosuppressedindividuals(US157 per QALY in the CD4 <200 cells/mm3 population providing enhanced‐prophylaxis components are sourced at lowest available prices. The ICER reduced in more severely immunosuppressed individuals (US113 per QALY in the CD4 <100 cells/mm3 population) and increased in all individuals regardless of CD4 count (US722perQALY).Resultsweresensitivetopricesoftheenhanced‐prophylaxiscomponents.Enhanced‐prophylaxiswasmoreeffectiveandlesscostlythanallCrAgtestingstrategiesasenhanced‐prophylaxisstillconveyedhealthgainsinCrAg‐negativepatientsandsavingsfromtargetingprophylaxisbasedonCrAgstatusdidnotcompensateforcostsofCrAgtesting.CrAgtestingstrategiesdidnotbecomecost‐effectiveunlessthepriceofCrAgtestingfellbelowUS722 per QALY). Results were sensitive to prices of the enhanced‐prophylaxis components. Enhanced‐prophylaxis was more effective and less costly than all CrAg testing strategies as enhanced‐prophylaxis still conveyed health gains in CrAg‐negative patients and savings from targeting prophylaxis based on CrAg status did not compensate for costs of CrAg testing. CrAg testing strategies did not become cost‐effective unless the price of CrAg testing fell below US2.30. Conclusions The REALITY enhanced‐prophylaxis package in individuals with advanced HIV starting ART reduces morbidity and mortality, is practical to administer and is cost‐effective. Efforts should continue to ensure that components are accessed at lowest available prices

    Late Presentation With HIV in Africa: Phenotypes, Risk, and Risk Stratification in the REALITY Trial.

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    This article has been accepted for publication in Clinical Infectious Diseases Published by Oxford University PressBackground: Severely immunocompromised human immunodeficiency virus (HIV)-infected individuals have high mortality shortly after starting antiretroviral therapy (ART). We investigated predictors of early mortality and "late presenter" phenotypes. Methods: The Reduction of EArly MortaLITY (REALITY) trial enrolled ART-naive adults and children ≄5 years of age with CD4 counts .1). Results: Among 1711 included participants, 203 (12%) died. Mortality was independently higher with older age; lower CD4 count, albumin, hemoglobin, and grip strength; presence of World Health Organization stage 3/4 weight loss, fever, or vomiting; and problems with mobility or self-care at baseline (all P < .04). Receiving enhanced antimicrobial prophylaxis independently reduced mortality (P = .02). Of five late-presenter phenotypes, Group 1 (n = 355) had highest mortality (25%; median CD4 count, 28 cells/”L), with high symptom burden, weight loss, poor mobility, and low albumin and hemoglobin. Group 2 (n = 394; 11% mortality; 43 cells/”L) also had weight loss, with high white cell, platelet, and neutrophil counts suggesting underlying inflammation/infection. Group 3 (n = 218; 10% mortality) had low CD4 counts (27 cells/”L), but low symptom burden and maintained fat mass. The remaining groups had 4%-6% mortality. Conclusions: Clinical and laboratory features identified groups with highest mortality following ART initiation. A screening tool could identify patients with low CD4 counts for prioritizing same-day ART initiation, enhanced prophylaxis, and intensive follow-up. Clinical Trials Registration: ISRCTN43622374.REALITY was funded by the Joint Global Health Trials Scheme (JGHTS) of the UK Department for International Development, the Wellcome Trust, and Medical Research Council (MRC) (grant number G1100693). Additional funding support was provided by the PENTA Foundation and core support to the MRC Clinical Trials Unit at University College London (grant numbers MC_UU_12023/23 and MC_UU_12023/26). Cipla Ltd, Gilead Sciences, ViiV Healthcare/GlaxoSmithKline, and Merck Sharp & Dohme donated drugs for REALITY, and ready-to-use supplementary food was purchased from Valid International. A. J. P. is funded by the Wellcome Trust (grant number 108065/Z/15/Z). J. A. B. is funded by the JGHTS (grant number MR/M007367/1). The Malawi-Liverpool–Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine (grant number 101113/Z/13/Z) and the Kenya Medical Research Institute (KEMRI)/Wellcome Trust Research Programme, Kilifi (grant number 203077/Z/16/Z) are supported by strategic awards from the Wellcome Trust, United Kingdom. Permission to publish was granted by the Director of KEMRI. This supplement was supported by funds from the Bill & Melinda Gates Foundation

    Occurrence of Citropsis articulata in Tropical Forests in Uganda: Implication for Ex Situ Conservation

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    Citropsis articulata is a medicinal plant that is increasingly threatened by unsustainable methods of harvesting and habitat degradation. Owing to the fact that this plant species is highly utilized for herbal medicine and is currently restricted to a few forest reserves in Uganda, this has significant implications for ex situ conservation. Therefore, the aim of this study was to assess how physiographical factors influence the occurrence and distribution of C. articulata in the three forest reserves in Uganda, namely, Budongo, Mabira, and Kibale National Park. The study was carried out in 15 compartmental sites in each of the three forests. In each compartmental site, 4 plots of 60 m × 60 m were systematically established, and within each plot, 4 subplots each of size 20 m × 20 m were randomly setup. A total of 240 subplots were assessed for occurrence of Citropsis articulata in each forest. The results indicated a significant (p<0.05) variation in the density of C. articulata with the highest recorded in Kibale National Park. Citropsis articulata generally occurred at moderate altitudinal landscapes (overall elevation = 1200.0 ± 20.73 m) with soils that are moderately acidic (overall pH = 5.7 ± 0.10), low in salinity (overall salinity = 84.0 ± 3.84 mg/l), and moderate levels of macro- and micronutrients. Citropsis articulata was generally associated with plant communities dominated by canopy tree species of genera such as Chryosphyllum, Celtis, Markhamia, Cynometra, Lasiodiscus, Trilepisium, Funtumia, and Diospyros, thus suggesting that C. articulata is a shade-tolerant species. Establishing the ecological requirements of this plant species among other things informs the potential for ex situ production of this plant. This will not only provide alternative sources of plant harvest but also go a long way in relieving the current harvest pressures exerted on the conserved wild populations of this plant species
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