178 research outputs found

    Does predation risk affect spatial use in an introduced ungulate species? The case of a Mediterranean mouflon alpine colony

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    Predation risk is known to affect the spatial use of prey species, imposing a trade-off between feeding requirements and predation avoidance. As a result, prey species can leave high-quality forage areas to use sub-optimal, but safer, habitat patches, defined as “refuge areas.” In this study, we describe changes in the spatial use of an introduced ungulate species, the Mediterranean mouflon Ovis aries musimon, following the recolonization (in 1996) of wolves Canis lupus into the Albergian Hunting Estate (Italian Western Alps). Since 1988, we monitored the mouflon population by spring counts from vantage points. We georeferenced all observations and recorded the size and structure of the spotted groups. Finally, we identified available refuges by selecting patches characterized by (i) the presence of rocks and (ii) high values of steepness and ruggedness. We found that mouflons significantly reduced the average distance from refuge areas over the years, with the yearly average distance from refuges being 56% lower after wolves recolonized the area (i.e., 93.8 ± 32.1 vs. 213.1 ± 40.9 m). The analysis of orographic parameters showed that mouflons used patches with higher values in elevation, slope, ruggedness, and a significant difference in all three parameters when comparing years pre and post wolf return. Both sexes were significantly affected, but ewes were particularly sensitive and selected patches closer to refuge areas (75.8 ± 30.3 m) than males (131.0 ± 53.6 m). Our results suggest that the presence of new predators can alter the distribution of an introduced species such as the Mediterranean mouflon, triggering the resurgence of anti-predation behavior

    No time to rest: How the effects of climate change on nest decay threaten the conservation of apes in the wild

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    Since 1994, IUCN Red List assessments apply globally acknowledged standards to assess species distribution, abundance and trends. The extinction risk of a species has a major impact on conservation science and international funding mechanisms. Great ape species are listed as Endangered or Critically Endangered. Their populations are often assessed using their unique habit of constructing sleeping platforms, called nests. As nests rather than apes are counted, it is necessary to know the time it takes for nests to disappear to convert nest counts into ape numbers. However, nest decomposition is highly variable across sites and time and the factors involved are poorly understood. Here, we used 1,511 bonobo (Pan paniscus) nests and 15 years of climatic data (2003–2018) from the research site LuiKotale, Democratic Republic of the Congo, to investigate the effects of climate change and behavioural factors on nest decay time, using a Bayesian gamma survival model. We also tested the logistic regression method, a recommended time-efficient option for estimating nest decay time. Our climatic data showed a decreasing trend in precipitation across the 15 years of study. We found bonobo nests to have longer decay times in recent years. While the number of storms was the main factor driving nest decay time, nest construction type and tree species used were also important. We also found evidence for bonobo nesting behaviour being adapted to climatic conditions, namely strengthening the nest structure in response to unpredictable, harsh precipitation. By highlighting methodological caveats, we show that logistic regression is effective in estimating nest decay time under certain conditions. Our study reveals the impact of climate change on nest decay time in a tropical remote area. Failure to account for these changes would invalidate biomonitoring estimates of global significance, and subsequently jeopardize the conservation of great apes in the wild

    52-week efficacy and safety of telbivudine with conditional tenofovir intensification at week 24 in HBeAg-positive chronic Hepatitis B

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    Background and Aims: The Roadmap concept is a therapeutic framework in chronic hepatitis B for the intensification of nucleoside analogue monotherapy based on early virologic response. The efficacy and safety of this approach applied to telbivudine treatment has not been investigated. Methods: A multinational, phase IV, single-arm open-label study (ClinicalTrials.gov ID NCT00651209) was undertaken in HBeAg-positive, nucleoside-naive adult patients with chronic hepatitis B. Patients received telbivudine (600 mg once-daily) for 24 weeks, after which those with undetectable serum HBV DNA (<300 copies/mL) continued to receive telbivudine alone while those with detectable DNA received telbivudine plus tenofovir (300 mg once-daily). Outcomes were assessed at Week 52. Results: 105 patients commenced telbivudine monotherapy, of whom 100 were included in the efficacy analysis. Fifty-five (55%) had undetectable HBV DNA at Week 24 and continued telbivudine monotherapy; 45 (45%) received tenofovir intensification. At Week 52, the overall proportion of undetectable HBV DNA was 93% (93/100) by last-observation-carried-forward analysis (100% monotherapy group, 84% intensification group) and no virologic breakthroughs had occurred. ALT normalization occurred in 77% (87% monotherapy, 64% intensification), HBeAg clearance in 43% (65% monotherapy, 16% intensification), and HBeAg seroconversion in 39% (62% monotherapy, 11% intensification). Six patients had HBsAg clearance. Myalgia was more common in the monotherapy group (19% versus 7%). No decrease in the mean glomerular filtration rate occurred in either treatment group at Week 52. Conclusions: Telbivudine therapy with tenofovir intensification at Week 24, where indicated by the Roadmap strategy, appears effective and well tolerated for the treatment of chronic hepatitis B. Trial Registration: ClinicalTrials.gov NCT0065120

    Discovery of novel herpes simplexviruses in wild gorillas, bonobos, and chimpanzees supports zoonotic origin of HSV-2

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    Viruses closely related to human pathogens can reveal the origins of human infectious diseases. Human herpes simplexvirus type 1 (HSV-1) and type 2 (HSV-2) are hypothesized to have arisen via host-virus codivergence and cross-species transmission. We report the discovery of novel herpes simplexviruses during a large-scale screening of fecal samples from wild gorillas, bonobos, and chimpanzees. Phylogenetic analysis indicates that, contrary to expectation, simplexviruses from these African apes are all more closely related to HSV-2 than to HSV-1. Molecular clock-based hypothesis testing suggests the divergence between HSV-1 and the African great ape simplexviruses likely represents a codivergence event between humans and gorillas. The simplexviruses infecting African great apes subsequently experienced multiple cross-species transmission events over the past 3 My, the most recent of which occurred between humans and bonobos around 1 Ma. These findings revise our understanding of the origins of human herpes simplexviruses and suggest that HSV-2 is one of the earliest zoonotic pathogens

    A novel patient-derived tumorgraft model with TRAF1-ALK anaplastic large-cell lymphoma translocation.

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    Although anaplastic large-cell lymphomas (ALCL) carrying anaplastic lymphoma kinase (ALK) have a relatively good prognosis, aggressive forms exist. We have identified a novel translocation, causing the fusion of the TRAF1 and ALK genes, in one patient who presented with a leukemic ALK+ ALCL (ALCL-11). To uncover the mechanisms leading to high-grade ALCL, we developed a human patient-derived tumorgraft (hPDT) line. Molecular characterization of primary and PDT cells demonstrated the activation of ALK and nuclear factor kB (NFkB) pathways. Genomic studies of ALCL-11 showed the TP53 loss and the in vivo subclonal expansion of lymphoma cells, lacking PRDM1/Blimp1 and carrying c-MYC gene amplification. The treatment with proteasome inhibitors of TRAF1-ALK cells led to the downregulation of p50/p52 and lymphoma growth inhibition. Moreover, a NFkB gene set classifier stratified ALCL in distinct subsets with different clinical outcome. Although a selective ALK inhibitor (CEP28122) resulted in a significant clinical response of hPDT mice, nevertheless the disease could not be eradicated. These data indicate that the activation of NFkB signaling contributes to the neoplastic phenotype of TRAF1-ALK ALCL. ALCL hPDTs are invaluable tools to validate the role of druggable molecules, predict therapeutic responses and implement patient specific therapies

    Control químico de tizón bacteriano en trigo: Experiencia III

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    El Tizón bacteriano en trigo (Triticum aestivum L.) es causado por el agente bacteriano Pseudomonas syringae pv. Syringae (Duveiller, et al., 1997). En Argentina aún no se conoce el impacto que esta enfermedad tiene sobre la producción en trigo. La enfermedad se inicia a partir de condiciones de humedad, bajas temperaturas (heladas) y acción del viento con daños sobre los tejidos foliares, permitiendo así el ingreso de la bacteria al tejido vegetal y a partir de allí el crecimiento de colonias bacterianas.El manejo de la enfermedad no resulta fácil porque no se cuenta con resistencia genética efectiva y su sobrevivencia está asegurada por la presencia de muchas especies hospedantes, incluidas maíz y sorgo y porque su vía principal de transmisión es a través de semilla infectada, además de ser un epífito sobre la superficie de las hojas (Alberione et al, 2017). Con el objetivo de evaluar distintas posibilidades de control químico, por tercer año consecutivo se condujeron en la EEA INTA Marcos Juárez durante el año 2018, dos ensayos con distintos tratamientos de aplicación foliar empleando fungicidas y principios activos en base a cobre, solos y en mezcla, ensayando así nuevas alternativas basadas en el manejo químico de la enfermedad. Estos resultados se suman a los obtenidos en similares experiencias anteriores durante los años 2016 y 2017.Fil: Alberione, Enrique Javier. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Donaire, Alejandro Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Salines, Nicolas. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Conde, María Belén. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Mir, Leticia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Bessone, Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Paletti Rovey, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto; ArgentinaFil: Sotello, Javier. Universidad Nacional de Río Cuarto; ArgentinaFil: Carezzano, Maria Evangelina. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Biotecnologia Ambiental y Salud. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Biotecnologia Ambiental y Salud.; ArgentinaFil: Oliva, Maria de Las Mercedes. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Ciencias de la Tierra, Biodiversidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencias de la Tierra, Biodiversidad y Ambiente; ArgentinaFil: Marcomini, Pedro. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Básicas y Aplicadas; ArgentinaFil: Ramadori, L.. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Básicas y Aplicadas; Argentin
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