431 research outputs found

    Both cetaceans in the Brazilian Amazon show sustained, profound population declines over two decades

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    <div><p>Obligate river dolphins occur only in the rivers of Asia and South America, where they are increasingly subject to damaging pressures such as habitat degradation, food competition and entanglement in fishing gear as human populations expand. The Amazon basin hosts two, very different, dolphins—the boto or Amazon river dolphin (<i>Inia geoffrensis</i>) and the smaller tucuxi (<i>Sotalia fluviatilis</i>). Both species have wide geographical ranges and were once considered to be relatively abundant. Their IUCN Red List conservation status of Data Deficient (DD), due to limited information on threats, ecology, population numbers and trends, did not initially cause alarm. However, the development of dolphin hunting to provide fish bait at around the beginning of this millennium broadly coincided with the onset of a widespread perception that numbers of both species were in decline. Consequently, the need for population trend data to inform conservation advice and measures became urgent. This paper presents a 22-year time series of standardised surveys for both dolphins within the Mamirauá Reserve, Amazonas State, Brazil. Analysis of these data show that both species are in steep decline, with their populations halving every 10 years (botos) and 9 years (tucuxis) at current rates. These results are consistent with published, independent information on survival rates of botos in this area, which demonstrated a substantial drop in annual survival, commencing at around the year 2000. Mamirauá is a protected area, and is subject to fewer environmental pressures than elsewhere in the region, so there is no reason to suspect that the decline in dolphins within the Reserve is more pronounced than outside it. If South America's freshwater cetaceans are to avoid following their Asian counterparts on the path to a perilous conservation status, effective conservation measures are required immediately. Enforcement of existing fishery laws would greatly assist in achieving this.</p></div

    Influence of environmental factors on tenuazonic acid production by Epicoccum sorghinum: An integrative approach of field and laboratory conditions

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    Sorghum is the fifth most cultivated and consumed grain in the world. However, this grain is frequently contaminated with toxins from fungi. The present study evaluated the effects of environmental factors on tenuazonic acid (TeA) production by Epicoccum sorghinum in the field and in controlled laboratory conditions. In this study, 50 sorghum grain samples were collected from summer and autumn growing seasons and analyzed for TeA contamination using LC-MS/MS. To further understand the ecophysiology of this fungus, an isolated strain of E. sorghinum from the field was investigated for its development and TeA production under controlled environmental conditions in the laboratory. In the ecophysiological investigation, the effects of water activity (0.90, 0.95, 0.99) and temperature (18, 22, 26 and 30?°C) were evaluated on the radial growth, enzymatic production and expression of TAS1, which is the gene involved in TeA production. Results showed that in the field, the summer season presented the highest TeA average level in the grains (587.8??g/kg) compared to level found in the autumn (440.5??g/kg). The ecophysiological investigation confirmed that E. sorghinum produces more actively TeA under environmental conditions simulating the summer season. Optimum growth, maximum TAS1 gene expression, and higher extracellular enzymatic production were observed at 26?°C with a water activity of 0.99. Pearson correlation analyses showed that the production of TeA highly correlates with fungal growth. The present study demonstrates that abiotic factors in a combined approach of field and laboratory conditions will assist in predicting the driving environmental factors that could affect growth of E. sorghinum and TeA production in sorghum grains

    Quantum chemical topological analysis of hydrogen bonding in HX…HX and CH3X…HX dimers (X = Br, Cl, F)

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    We present a systematic investigation of the nature and strength of the hydrogen bonding in HX···HX and CH3X…HX (X = Br, Cl and F) dimers using ab initio MP2/aug-cc-pVTZ calculations in the framework of the quantum theory of atoms in molecules (QTAIM) and electron localisation functions (ELFs) methods. The electron density of the complexes has been characterised, and the hydrogen bonding energy, as well as the QTAIM and ELF parameters, is consistent, providing deep insight into the origin of the hydrogen bonding in these complexes. It was found that in both linear and angular HX…HX and CH3X…HX dimers, F atoms form stronger HB than Br and Cl, but they need short (∼2 Å) X…HX contacts.The authors are grateful to FAPESP and FAPEMIG for financially supporting this research and for a scholarship (to R.A.C.), to CAPES for the scholarships (to F.A.L. and R.T.S.) and to CNPq for the fellowships (to T.C.R., M.P.F., E.F.F.C. and R.R.). J.A. also thanks Universitat Jaume I-Fundacio´n Bancaixa (Project P1.1B2010-10), Generalitat Valenciana for Prometeo/2009/053 project, Ministerio de Ciencia e Innovacio´n for project CTQ2009-14541-C02 and Programa de Cooperacio´n Cientı´fica con Iberoamerica (Brazil), Ministerio de Educacio´n (PHB2009-0065-PC)

    Resumen de la Tarea de Análisis de Sentimientos Basado en Aspectos en Portugués (ABSAPT) en IberLEF 2022

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    Este artículo presenta la Tarea sobre Análisis de Sentimientos basado en Aspectos en Portugués (ABSAPT), realizada en el IberLEF 2022. Les pedimos a los participantes que desarrollaran sistemas capaces de identificar aspectos (AE) y extraer la polaridad (ASC) en textos escritos en portugués. Doce equipos se inscribieron en la tarea, entre los cuales cinco presentaron predicciones e informes técnicos. El sistema con mejor rendimiento logró un valor de precisión (Acc) de 0,67 para la subtarea de AE (Equipo Deep Learning Brasil) y un valor de precisión equilibrada (Bacc) de 0,82 para la subtarea de ASC (Equipo Deep Learning Brasil).This paper presents the task on Aspect-Based Sentiment Analysis in Portuguese (ABSAPT), held within Iberian Languages Evaluation Forum (IberLEF 2022). We asked the participants to develop systems capable of extracting aspects (AE) and classifying sentiment of aspects (ASC) in texts. We created one corpora containing reviews about hotels. Twelve teams registered to the task, among which five submitted predictions and technical reports. The best performing system achieved an Accuracy (Acc) value of 0.67 in AE sub-task (Team Deep Learning Brasil) and a Balanced Accuracy (Bacc) value of 0.82 in ASC sub-task (Team Deep Learning Brasil).This work was financed in part by the following Brazilian research agencies: CAPES and CNPq

    Decomposition of Cattle Dung on Mixed Grass-Legume Pastures

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    Animal excreta contribute positively to nutrient cycling and can improve the quality of soil (Dubeux et al. 2009, Carvalho et al. 2010). Cattle excrement, when evenly distributed over a pasture, can help to maintain plant nutrition without the application of fertilizers. The introduction of legumes intercropped with grasses benefits the soil by means of nitrogen fixation. Also, when ruminant animals eat legumes, the excrement produced may have lower C:N, C:P, lignin:N and lignin:P ratios promoting better nutrient return to the soil compared to when cattle eat only grass. Given the importance of nutrient return and decomposition time of cattle excreta on pastures, the objective of this study was to evaluate the decomposition of excrement of heifers managed in mixed grass-shrubby legume pastures and grass-only pastures

    Lamivudine’s hypersensitivity in an HIV infected patient: case report

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    Importância do problema: Relatar um caso de hipersensibilidade à lamivudina, droga considerada segura e antirretroviral indicado como de primeira linha para início de tratamento para pacientes infectados pelo HIV. Comentários: É relatado o caso de paciente infectada pelo HIV que evoluiu com farmacodermia associada à terapia antirretroviral (TARV) utilizando tenofovir, lamivudina e efavirenz. Inicialmente, a hipersensibilidade foi atribuída ao efavirenz, pela maior incidência de eventos desta natureza com este medicamento e este foi substituído por fosamprenavir/ ritonavir. Apesar da substitui- ção, paciente desenvolveu síndrome de Stevens-Johnson. Foi hospitalizada e iniciou novo esquema, com introdução de droga a droga, com atazanavir/ritonavir, seguido de zidovudina e lamivudina, desenvolvendo manifestação de eritema multiforme após a última droga, sendo esta considerada a responsá- vel pela hipersensibilidadeRelevance: To report a case of hypersensitivity to lamivudine, a medicine that is considered safe and is indicated as part of the initial therapy for HIV infected patients. Comments: It is reported the evolution of an HIV patient who developed a drug eruption due to the following antirretroviral therapy: tenofovir, lamivudine and efavirenz. It initially was attributed to efavirenz, due to its higher incidence in these adverse reactions and it was replaced by fosamprenavir/ritonavir. In spite of the replacement, the patient developed Stevens-Johnson's Syndrome. She was hospitalized and began a new therapy with atazanavir/ritonavir, followed by zidovudine and lamivudine and presented a drug reaction with the last one, which was considered to be the responsible for the hypersensitivit
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