Diversidade genética do Banco Ativo de Germoplasma de Pera avaliada com o uso de marcadores moleculares SSR.

O objetivo deste trabalho foi caracterizar e avaliar a diversidade genética entre os acessos de pereira existentes no Banco Ativo de Germoplasma de Pera (BAG-Pera) com o uso de marcadores moleculares SSR (Simple Sequence Repeats), visando organizar os recursos genéticos da espécie e apoiar as atividades de melhoramento genético

Avaliação da diversidade genética do banco ativo de germoplasma de pera (BAG-Pera) utilizando marcadores moleculares SSR.

O objetivo deste trabalho foi caracterizar e avaliar a diversidade genética entre os acessos de pereira existentes no BAG-Pera utilizando marcadores moleculares SSR, visando organizar os recursos genéticos e apoiar as atividades de melhoramento genético

Low-Intensity, High-Frequency Grazing Positively Affects Defoliating Behavior, Nutrient Intake and Blood Indicators of Nutrition and Stress in Sheep

The intensity and frequency of grazing affect the defoliating strategy of ruminants, their daily nutrient intake, thus nutrition and physiological status. Italian ryegrass (Lolium multiflorum Lam.) pastures were grazed by sheep either under a low-intensity/high-frequency grazing strategy (Rotatinuous stocking; RN) with nominal pre- and post-grazing sward heights of 18 and 11 cm, respectively, or under a high-intensity/low-frequency strategy (traditional rotational stocking; RT) with nominal pre- and post-grazing sward heights of 25 and 5 cm, respectively. Treatments were arranged under a complete randomized design and evaluated over two periods, in different years. In 2017, the aim was to depict the type of bites that sheep perform during the grazing-down and associate them to the grazing management strategy according to their relative contribution to the diet ingested. In 2018 we estimated the total nutrient intake and evaluated blood indicators of the nutritional status and immune response to stress of sheep. The bite types accounting the most for the diet ingested by RN sheep were those performed on the “top stratum” of plants with around 20, 15, and 25 cm, whereas the type of bites accounting the most for the diet of RT sheep were those performed on “grazed plants” with around 10, 5, and ≤ 3 cm. In 2018, the RN sheep increased by 18% the total organic matter (OM) intake and by 20–25% the intake of soluble nutrients (i.e., crude protein, total soluble sugars, crude fat), digestible OM and of metabolizable energy, and had 17.5, 18, and 6.1% greater blood concentration of glucose, urea nitrogen (BUN) and albumin, respectively, but 17% lower blood neutrophil-to-lymphocyte (N:L) ratio. Sheep grazing vegetative Italian ryegrass pastures under the low-intensity/high-frequency grazing strategy (RN) ingested a diet of better quality from bites allocated on the top stratum of plants, had greater intake of soluble nutrients and blood parameters positively associated with nutritional status and immune response to stress

Computing and visually analyzing mutual information in molecular co-evolution

<p>Abstract</p> <p>Background</p> <p>Selective pressure in molecular evolution leads to uneven distributions of amino acids and nucleotides. In fact one observes correlations among such constituents due to a large number of biophysical mechanisms (folding properties, electrostatics, ...). To quantify these correlations the mutual information -after proper normalization - has proven most effective. The challenge is to navigate the large amount of data, which in a study for a typical protein cannot simply be plotted.</p> <p>Results</p> <p>To visually analyze mutual information we developed a matrix visualization tool that allows different views on the mutual information matrix: filtering, sorting, and weighting are among them. The user can interactively navigate a huge matrix in real-time and search e.g., for patterns and unusual high or low values. A computation of the mutual information matrix for a sequence alignment in FASTA-format is possible. The respective stand-alone program computes in addition proper normalizations for a null model of neutral evolution and maps the mutual information to <it>Z</it>-scores with respect to the null model.</p> <p>Conclusions</p> <p>The new tool allows to compute and visually analyze sequence data for possible co-evolutionary signals. The tool has already been successfully employed in evolutionary studies on HIV1 protease and acetylcholinesterase. The functionality of the tool was defined by users using the tool in real-world research. The software can also be used for visual analysis of other matrix-like data, such as information obtained by DNA microarray experiments. The package is platform-independently implemented in <monospace>Java</monospace> and free for academic use under a GPL license.</p

Aprendizado de máquina com base na resposta espectral de imagens aéreas obtidas por VANTs e aplicado no manejo de pastagens.

Resumo ? O monitoramento de áreas agrícolas tem sido beneficiado com a evolução das novas tecnologias de sensoriamento remoto. O advento dos veículos aéreos não tripulados (VANTs) revolucionou o mundo do sensoriamento remoto nos últimos anos. Progressivamente, o custo dos equipamentos está se tornando mais acessível, permitindo aos profissionais ampliar a sua gama de atuação e fornecer produtos de melhor qualidade para escalas maiores. Essas novas tecnologias aliadas a técnicas tradicionais de monitoramento de pastagens podem prover ganhos do ponto de vista operacional ao produtor rural. Sendo assim, o objetivo do presente trabalho foi avaliar o uso de imagens de VANT para estimar e monitorar a cobertura e altura do pasto. As imagens utilizadas foram capturadas na área experimental da Fazenda Trijunção, localizada em Cocos, Bahia. Relacionou-se o comportamento espectral de imagens RGB com 3 classes de cobertura do solo em áreas sob pastejo (pré-pastejo, em pastejo e pós-pastejo), além de uma classe de solo exposto, em diferentes épocas, durante dois anos. Adicionalmente relacionou-se a altura de planta medida em campo com as bandas da imagem RGB. No software R Studio o banco de dados foi dividido em conjuntos de treinamento e validação, com a relação de 75% e 25%, respectivamente. Considerando todo o conjunto de dados, o modelo ajustado alcançou 66% de exatidão e índice Kappa 0,53 na predição das 4 classes, sendo 3 dessas relativas às classes de manejo de pastagem e 1 de solo exposto. Quando avaliado apenas as imagens do período seco do ano, o modelo ajustado alcançou 68% de exatidão e índice Kappa de 0,56. Já o conjunto de dados do período chuvoso apresentou 70% de exatidão e índice Kappa de 0,58. Ao aplicar o modelo em novos conjuntos de imagens observou-se índice de assertividade satisfatório ao analisar as classes de manejo com base na cobertura do solo e a altura do dossel medidas em campo. Os resultados demonstram o potencial da rotina de processamento implantada para o processamento em imagens de VANT, via aprendizado de máquina, como ferramenta auxiliar no manejo de pastagens. Proporciona também uma solução em tempo reduzido para a avaliação e manejo de áreas de pastagens de diferentes dimensões

Molecular basis of Lys11-polyubiquitin specificity in the deubiquitinase Cezanne

The post-translational modification of proteins with polyubiquitin regulates virtually all aspects of cell biology. Eight distinct chain linkage types in polyubiquitin co-exist and are independently regulated in cells. This ‘ubiquitin code’ determines the fate of the modified protein1. Deubiquitinating enzymes of the Ovarian Tumour (OTU) family regulate cellular signalling by targeting distinct linkage types within polyubiquitin2, and understanding their mechanisms of linkage specificity gives fundamental insights into the ubiquitin system. We here reveal how the deubiquitinase Cezanne/OTUD7B specifically targets Lys11-linked polyubiquitin. Crystal structures of Cezanne alone and in complex with mono- and Lys11-linked diubiquitin, in combination with hydrogen-deuterium exchange mass spectrometry, enable reconstruction of the enzymatic cycle in exquisite detail. An intricate mechanism of ubiquitin-assisted conformational changes activate the enzyme, and while all chain types interact with the enzymatic S1 site, only Lys11-linked chains can bind productively across the active site and stimulate catalytic turnover. Our work highlights the fascinating plasticity of deubiquitinases, and indicates that new conformational states can occur when a true substrate, such as diubiquitin, is bound at the active site