76 research outputs found

    Mycobacterium tuberculosis in vivo-expressed genes detection during active pulmonary tuberculosis

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    Indexación: Web of Science; ScieloEl estudio de la expresión génica de Mycobacterium tuberculosis ha involucrado la experimentación "in vitro ", "ex vivo " e "in vivo " (modelos animales), pero aún sin el éxito esperado. Proponemos que revelar los factores clave de la tuberculosis humana requiere investigar la expresión génica de M. tuberculosis dentro del ser humano ("in vivo "). Para ello, aislamos el mRNA total de M. tuberculosis, desde muestras clínicas respiratorias de pacientes con diagnóstico de tuberculosis pulmonar; posteriormente, sintetizamos el dscDNA y lo analizamos mediante RT-PCR cualitativo. Detectamos la expresión de la secuencia de inserción IS6110 y de los genes "housekeeping " 16SrRNA y sigA en M. tuberculosis creciendo in vivo (tuberculosis pulmonar) así como cultivado in vitro. La expresión de los genes mprA y mprB, que codifican el sistema de transducción de señales MprAB, sólo se detectó en M. tuberculosis crecido in vitro. Con nuestros resultados damos el primer paso hacia la implementación de un método no invasivo para el estudio del transcriptoma de M. tuberculosis, dentro de su único hospedero natural, con el fin de analizar la regulación "in vivo" de los determinantes genéticos requeridos para su virulencia y patogénesis.Mycobacterium tuberculosis gene expression studies have involved "in vitro", "ex vivo" and "in vivo" experiments (animal models), but without the expected success. We propose that key features of human tuberculosis could be discovered by studying the M. tuberculosis gene expression within the human host. Therefore, we isolated totalM. tuberculosis mRNA from human clinical respiratory specimens of patients diagnosed with pulmonary tuberculosis; after this, we synthesized the dscDNA and tested it by qualitative RT-PCR assays. We detected the expression of IS6110 insertion sequence and of the "housekeeping" genes 16SrRNA andsigA in M. tuberculosis grown in vivo (pulmonary tuberculosis) as well as grown in vitro M. tuberculosis. mprA and mprB genes expression, which code the MprAB signal transduction system, were only detected in M. tuberculosis grown in vitro. Our results provide the first step towards a non invasive methodfor the study of the transcriptome of M. tuberculosis within its native host, to analyze "in vivo" regulation of the genetic determinants required for virulence and pathogenesis.http://www.scielo.cl/pdf/rcher/v28n4/art04.pd

    Influence of environmental parameters on movements and habitat utilization of humpback whales (Megaptera novaeangliae) in the Madagascar breeding ground

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    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Royal Society Open Science 3 (2016): 160616, doi:10.1098/rsos.160616.Assessing the movement patterns and key habitat features of breeding humpback whales is a prerequisite for the conservation management of this philopatric species. To investigate the interactions between humpback whale movements and environmental conditions off Madagascar, we deployed 25 satellite tags in the northeast and southwest coast of Madagascar. For each recorded position, we collated estimates of environmental variables and computed two behavioural metrics: behavioural state of ‘transiting’ (consistent/directional) versus ‘localized’ (variable/non-directional), and active swimming speed (i.e. speed relative to the current). On coastal habitats (i.e. bathymetry < 200 m and in adjacent areas), females showed localized behaviour in deep waters (191 ± 20 m) and at large distances (14 ± 0.6 km) from shore, suggesting that their breeding habitat extends beyond the shallowest waters available close to the coastline. Males' active swimming speed decreased in shallow waters, but environmental parameters did not influence their likelihood to exhibit localized movements, which was probably dominated by social factors instead. In oceanic habitats, both males and females showed localized behaviours in shallow waters and favoured high chlorophyll-a concentrations. Active swimming speed accounts for a large proportion of observed movement speed; however, breeding humpback whales probably exploit prevailing ocean currents to maximize displacement. This study provides evidence that coastal areas, generally subject to strong human pressure, remain the core habitat of humpback whales off Madagascar. Our results expand the knowledge of humpback whale habitat use in oceanic habitat and response to variability of environmental factors such as oceanic current and chlorophyll level.Funding was provided by Total Foundation to NeuroPSI, and by individuals and foundations to the WCS Ocean Giants Program

    A Broad Assessment of Factors Determining Culicoides imicola Abundance: Modelling the Present and Forecasting Its Future in Climate Change Scenarios

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    Bluetongue (BT) is still present in Europe and the introduction of new serotypes from endemic areas in the African continent is a possible threat. Culicoides imicola remains one of the most relevant BT vectors in Spain and research on the environmental determinants driving its life cycle is key to preventing and controlling BT. Our aim was to improve our understanding of the biotic and abiotic determinants of C. imicola by modelling its present abundance, studying the spatial pattern of predicted abundance in relation to BT outbreaks, and investigating how the predicted current distribution and abundance patterns might change under future (2011–2040) scenarios of climate change according to the Intergovernmental Panel on Climate Change. C. imicola abundance data from the bluetongue national surveillance programme were modelled with spatial, topoclimatic, host and soil factors. The influence of these factors was further assessed by variation partitioning procedures. The predicted abundance of C. imicola was also projected to a future period. Variation partitioning demonstrated that the pure effect of host and topoclimate factors explained a high percentage (>80%) of the variation. The pure effect of soil followed in importance in explaining the abundance of C. imicola. A close link was confirmed between C. imicola abundance and BT outbreaks. To the best of our knowledge, this study is the first to consider wild and domestic hosts in predictive modelling for an arthropod vector. The main findings regarding the near future show that there is no evidence to suggest that there will be an important increase in the distribution range of C. imicola; this contrasts with an expected increase in abundance in the areas where it is already present in mainland Spain. What may be expected regarding the future scenario for orbiviruses in mainland Spain, is that higher predicted C. imicola abundance may significantly change the rate of transmission of orbiviruses

    Long Distance Movements and Disjunct Spatial Use of Harbor Seals (Phoca vitulina) in the Inland Waters of the Pacific Northwest

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    BACKGROUND: Worldwide, adult harbor seals (Phoca vitulina) typically limit their movements and activity to <50 km from their primary haul-out site. As a result, the ecological impact of harbor seals is viewed as limited to relatively small spatial scales. Harbor seals in the Pacific Northwest are believed to remain <30 km from their primary haul-out site, one of several contributing factors to the current stock designation. However, movement patterns within the region are not well understood because previous studies have used radio-telemetry, which has range limitations. Our objective was to use satellite-telemetry to determine the regional spatial scale of movements. METHODOLOGY/PRINCIPAL FINDINGS: Satellite tags were deployed on 20 adult seals (n=16 males and 4 females) from two rocky reefs and a mudflat-bay during April-May 2007. Standard filtering algorithms were used to remove outliers, resulting in an average (± SD) of 693 (± 377) locations per seal over 110 (± 32) days. A particle filter was implemented to interpolate locations temporally and decrease erroneous locations on land. Minimum over-water distances were calculated between filtered locations and each seal's capture site to show movement of seals over time relative to their capture site, and we estimated utilization distributions from kernel density analysis to reflect spatial use. Eight males moved >100 km from their capture site at least once, two of which traveled round trip to and from the Pacific coast, a total distance >400 km. Disjunct spatial use patterns observed provide new insight into general harbor seal behavior. CONCLUSIONS/SIGNIFICANCE: Long-distance movements and disjunct spatial use of adult harbor seals have not been reported for the study region and are rare worldwide in such a large proportion of tagged individuals. Thus, the ecological influence of individual seals may reach farther than previously assumed

    Characterization of a medium size Xe/TMA TPC instrumented with microbulk Micromegas, using low-energy gamma-rays

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    NEXT-MM is a general-purpose high pressure (10 bar, ~ 25 l active volume) Xenon-based TPC, read out in charge mode with an 0.8 cm × 0.8 cm-segmented 700 cm2 plane (1152 ch) of the latest microbulk-Micromegas technology. It has been recently commissioned at University of Zaragoza as part of the R&D of the NEXT 0νββ experiment, although the experiment's first stage is currently being built based on a SiPM/PMT-readout concept relying on electroluminescence. Around 2 million events were collected during the last months, stemming from the low energy γ-rays emitted by a 241Am source when interacting with the Xenon gas (Eγ = 26, 30, 59.5 keV). The localized nature of such events around atmospheric pressure, the long drift times, as well as the possibility to determine their production time from the associated α particle in coincidence, allow the extraction of primordial properties of the TPC filling gas, namely the drift velocity, diffusion and attachment coefficients. In this work we focus on the little explored combination of Xe and trimethylamine (TMA) for which, in particular, such properties are largely unknown. This gas mixture offers potential advantages over pure Xenon when aimed at Rare Event Searches, mainly due to its Penning characteristics, wave-length shifting properties and reduced diffusion, and it is being actively investigated by our collaboration. The chamber is currently operated at 2.7 bar, as an intermediate step towards the envisaged 10 bar. We report here its performance as well as a first implementation of the calibration procedures that have allowed the extension of the previously reported energy resolution to the whole readout plane (10.6% FWHM@30 keV)

    Wild boar density data generated by camera trapping in nineteen European areas

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    This report presents the results of field activities in relation to the generation of reliable wild boar density values by camera trapping (CT) in 19 areas in Europe, mainly in East Europe. Random Encounter Model (REM) densities ranged from 0.35±0.24 to 15.25±2.41 (SE) individuals/km2. No statistical differences in density among bioregions were found. The number of contacts was the component of the trapping rate that determined the coefficient of variation (CV) the most. The daily range (DR) significantly varied as a function of management; the higher values were detected in hunting grounds compared to protected areas, indicating that movement parameters are population specific, and confirming the potential role of hunting activities in increasing wild boar movement and contact rates among individual or groups. The results presented in this report illustrate that a harmonized approach to actual wildlife density estimation (namely for terrestrial mammals) is possible at a European scale, sharing the same protocols, collaboratively designing the study, processing, and analysing the data. This report adds reliable wild boar density values that have the potential to be used for wild boar abundance spatial modelling, both directly or to calibrate outputs of model based on abundance (such as hunting bags) or occurrence data. Future REM developments should focus on improving the precision of estimates (probably through increased survey effort). Next steps require an exhaustive and representative design of a monitoring network to estimate reliable trends of wild boar populations as a function of different factors in Europe. In this regard, the newly created European Observatory of Wildlife will be a network of observation points provided by collaborators from all European countries capable to monitor wildlife population at European level.EFSA-Q-2020-00677Peer reviewe

    Colombian consensus recommendations for diagnosis, management and treatment of the infection by SARS-COV-2/ COVID-19 in health care facilities - Recommendations from expert´s group based and informed on evidence

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    La Asociación Colombiana de Infectología (ACIN) y el Instituto de Evaluación de Nuevas Tecnologías de la Salud (IETS) conformó un grupo de trabajo para desarrollar recomendaciones informadas y basadas en evidencia, por consenso de expertos para la atención, diagnóstico y manejo de casos de Covid 19. Estas guías son dirigidas al personal de salud y buscar dar recomendaciones en los ámbitos de la atención en salud de los casos de Covid-19, en el contexto nacional de Colombia
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