35 research outputs found

    Priming, seed quality and flowering synchronism in a seed production field of the maize hybrid gnz 2004

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    Com o objetivo de avaliar o efeito do condicionamento fisiolĂłgico e da qualidade de sementes sobre a Ă©poca de florescimento de plantas de milho, foi realizado o presente trabalho. Foram utilizados lotes de sementes com qualidade fisiolĂłgica distinta de duas linhagens. Parte das sementes de cada lote foi condicionada em ĂĄgua, por perĂ­odo de 24 horas, totalizando quatro tratamentos, os quais foram avaliados na ausĂȘncia e presença do "split" (sincronia de plantio) recomendado. Na ĂĄrea experimental, cada parcela foi composta por seis linhas de quatro metros cada uma, seguindo o delineamento de blocos casualizados com quatro repetiçÔes. Foram avaliadas a porcentagem da emergĂȘncia das plantas em campo, altura das plantas, as datas em que ocorreram 50% e 100% de liberação do pĂłlen e de emissĂŁo do estilo-estigma e, ainda, a data da ausĂȘncia de liberação de pĂłlen das plantas do parental masculino e receptividade do estilo-estigma para as do parental feminino e a data em que as sementes estavam no estĂĄdio de desenvolvimento LL3. Quando foram utilizadas sementes com alta qualidade e sem condicionamento, nĂŁo houve necessidade de se efetuar o "split". O mesmo ocorreu com sementes nĂŁo condicionadas e com alta qualidade do parental mais tardio, associadas com sementes de baixa qualidade e condicionadas do parental mais precoce. Foi observado, tambĂ©m, que a diferença existente no florescimento dos parentais praticamente se estendeu atĂ© o desenvolvimento das sementes no estĂĄdio LL3.In order to evaluate the effect of priming and physiological seed quality on maize flowering aiming the production of hybrid seeds, the following experimental procedure was carried out. Seed lots with distinct physiological quality of two lines were used. Part of each seed lot obtained was primed in water for 24 hours on a total of four treatments, which were evaluated in the presence and absence of the recommended split. In the experimental field, each plot was composed of six lines of four meters each, following the experimental design which consisted of a randomized complete block in four replications. The following variables were measured: percentage of field emergence, plant height, dates when 50% and 100% of pollen release and the emission of "stigma-style" occurred; moreover the date of no pollen release of male parent and receptivity of "stigma-style" towards the female parent and the date when the seeds were at stage ML 3 of development. When high quality seeds and no priming were used, it was not necessary to use the split. The same happened to high quality non-primed seeds of the later parent associated with low quality and primed seeds of the earlier parent. It was also observed that the difference in flowering date between the parents extended until the date of ML 3

    Effects of supplementation with <i>Saccharomyces cerevisiae</i> and aerobic training on physical performance of Mangalarga Marchador mares

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    The objective of this study was to assess the effects of supplementation with Saccharomyces cerevisiae on the performance of Mangalarga Marchador equines and to verify the effectiveness of the aerobic training protocol adopted. The study used 14 Mangalarga Marchador mares in a completely randomized split-plot design. The plots were made up of two treatments (groups Probiotic and Control) and the split plots comprised two maximal-effort physical tests applied both before and after the six weeks of training. The animals’ spirometric parameters, heart rate, and plasma lactate levels were assessed. No difference was found between the Probiotic and Control groups in any of the parameters assessed. A difference was found in the physical tests for time-to-fatigue, aerobic and anaerobic thresholds, speed at which plasma lactate levels reached 2 and 4 mmol/L, speed at which the heart rate reached 200 bpm, and the lactate level at 30 min of the recovery period. Supplementation with Saccharomyces cerevisiae has no effect on physical conditioning of Mangalarga Marchador mares and the aerobic training protocol adopted increases the animals’ aerobic and anaerobic capacity.Instituto de GenĂ©tica Veterinari

    Pervasive gaps in Amazonian ecological research

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    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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    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 &lt; 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

    Digestibilidade da dieta e desempenho físico de éguas mangalarga marchador suplementadas com saccharomyces cerevisiae durante treinamento em esteira ergométrica

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    Exportado OPUSMade available in DSpace on 2019-08-13T00:02:24Z (GMT). No. of bitstreams: 1 garcia_tr___tese.pdf: 1504302 bytes, checksum: 976dc555f15f07999c7db3ca1b799120 (MD5) Previous issue date: 28Esse trabalho teve como objetivo avaliar o efeito da suplementação com leveduras Saccharomyces cerevisiae sobre a digestibilidade, consumo dos nutrientes e melhora no desempenho atlético de equinos da raça Mangalarga Marchador submetidos a treinamento. Objetivou também avaliar a eficåcia do protocolo de treinamento utilizado na preparação desses animais para provas de marcha. Quatorze éguas Mangalarga Marchador foram distribuídas em dois grupos: suplementado (S) e Controle (C). A dieta foi composta por volumoso e concentrado comercial, na proporção de 50:50. As éguas foram treinadas durante seis semanas, de segunda a såbado, alternando o exercício em esteira ergométrica e caminhador automåtico. A digestibilidade dos nutrientes foi avaliada utilizando o indicador LIPEŸ. Foram analisados MS, FDN, FDA, PB, EB, hemicelulose e consumo de matéria seca. Para avaliação do ensaio de digestibilidade, o delineamento experimental foi o inteiramente ao acaso e as médias comparadas pelo teste Fisher a 5%. Antes e após o treinamento, foram realizados testes de esforço måximo na esteira ergométrica, com utilização da måscara espirométrica, a fim de avaliar parùmetros físicos, metabólicos e respiratórios dos animais. Para avaliação do desempenho físico das éguas, o delineamento experimental foi inteiramente ao acaso em esquema de parcelas subdivididas e as médias comparadas pelo teste Fisher a 5%. Não foi observada diferença (P>0,05) nos coeficientes de digestibilidade aparente dos nutrientes da dieta e no consumo de matéria seca entre os grupos suplementado e controle. Houve diferença (P 0.05) on apparent digestibility coefficients of nutrients and dry matter intake between supplemented and control groups. There were differences (P <0.05) between tests performed before and after training in time to fatigue, aerobic and anaerobic thresholds, VLa2, VLA4, V200, baseline hemoglobin concentration, percentage of hemoglobin in aerobic and anaerobic thresholds, uric acid level at maximal speed, VO2MAX, VO2, pO2, VE in aerobic and anaerobic thresholds and EqO2 in aerobic threshold. These results demonstrated that the training protocol used in this experiment was able to improve athletic performance. The use of probiotic increased basal concentrations of hemoglobin and the percentage of VO2MAX in aerobic and anaerobic thresholds
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