29 research outputs found

    AVALIAÇÃO CLÍNICO-ANDROLÓGICA EM TOUROS NELORE E TESTES DE VIABILIDADE ESPERMÁTICA, INTEGRIDADE DE ACROSSOMA E FRAGMENTAÇÃO DE CROMATINA AO LONGO DE TRÊS ESTAÇÕES REPRODUTIVAS

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    Com os objetivos de verificar a evolução da qualidade dos ejaculados de touros da raça Nelore ao longo três anos, através do exame clínico-andrológico associado de testes de viabilidade espermática, integridade de acrossoma e a fragmentação da cromatina, e estabelecer relações entre estas características e com a prenhez com grupos de diferentes tipos de fêmeas, utilizaram-se 46 touros da raça Nelore com idade entre 30 e 120 meses, para avaliação da qualidade seminal e da aptidão reprodutiva. Os animais foram mantidos em condições extensivas, com alimentação a pasto, recebendo suplementação mineral e servindo um rebanho com 3.782 fêmeas de várias categorias (novilhas, vacas primíparas e pluríparas). Realizaram-se colheitas de dados que abrangiam medidas de circunferência escrotal e avaliação do sêmen colhido por eletroejaculação e avaliaram-se as características físicas (volume, turbilhonamento, motilidade, vigor), morfológicas (defeitos maiores, menores e totais) e de integridade espermática (integridade de membrana plasmática, de acrossoma e de cromatina) no período que antecedeu três estações de monta consecutivas (2003, 2004 e 2005). Submeteram-se os dados à analise de variância, compararam-se as médias pelo teste SNK e calculou-se o coeficiente de correlação de Pearson utilizando o SAS. Os touros apresentaram circunferência escrotal de 33,8 ± 2,8cm, 15,6 ± 8,5% de defeitos espermáticos totais, 40,1 ± 23,1% de gametas com membrana e acrossoma íntegros e 8,8 ± 3,8% de cromatina fragmentada. As relações entre circunferência escrotal, as características físicas, morfológicas e de integridade espermática e o desempenho reprodutivo do rebanho foram baixas e não significativas (P>0,05). As características reprodutivas dos touros permaneceram dentro de padrões aceitáveis ao longo de três anos de avaliação. Nos touros deste experimento, os defeitos espermáticos, a integridade de membrana plasmática, integridade de acrossoma e fragmentação de cromatina nuclear não foram frequentes a ponto de comprometer a qualidade seminal e o desempenho reprodutivo dos animais. Não houve relação entre os defeitos espermáticos com a integridade acrossômica e/ou a fragmentação da cromatina nuclear. Não houve relação entre a prenhez com as características apresentadas pelos touros estudados PALAVRAS-CHAVES: Acrossoma, cromatina, espermatozoides, Nelore, reprodução, sêmen, touros

    A list of land plants of Parque Nacional do Caparaó, Brazil, highlights the presence of sampling gaps within this protected area

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    Brazilian protected areas are essential for plant conservation in the Atlantic Forest domain, one of the 36 global biodiversity hotspots. A major challenge for improving conservation actions is to know the plant richness, protected by these areas. Online databases offer an accessible way to build plant species lists and to provide relevant information about biodiversity. A list of land plants of “Parque Nacional do Caparaó” (PNC) was previously built using online databases and published on the website "Catálogo de Plantas das Unidades de Conservação do Brasil." Here, we provide and discuss additional information about plant species richness, endemism and conservation in the PNC that could not be included in the List. We documented 1,791 species of land plants as occurring in PNC, of which 63 are cited as threatened (CR, EN or VU) by the Brazilian National Red List, seven as data deficient (DD) and five as priorities for conservation. Fifity-one species were possible new ocurrences for ES and MG states

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
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