978 research outputs found

    Gestión ambiental de los sistemas agroforestales en el Valle de Paraíba del Sur, Estado de Sao Paulo, Brasil.

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    En el año de 2011 se analizó el desempeño ambiental de la finca Coruputuba, en Pindamonhangaba, Estado de São Paulo, Brasil. La metodología utilizada fué el sistema APOIA-NovoRural, con 62 indicadores de sustentabilidad en el contexto para el análisis de la implementación de los sistemas agroforestales con Calophyllum braziliense y Acacia mangium. Antes de la implementación de los sistemas agroforestales, la finca estuvo plantada con arroz en el valle y eucalipto en las terrazas. Con el proyecto se logró sustituir 10 ha en el valle y 4 ha de terraza con Calophyllum, especie que ofrece una madera fina. Otra especie que se introdujo en la terraza fue la acacia (50 ha), sustituta del eucalipto. La finca aporta un valor agregado a la gestión dirigida a procesos de recuperación de la viabilidad económica y ambiental mediante el rescate de la vocación agrícola. Se fue reintroducido la Manihot esculenta, Maranta arundinaceae, Colocasia esculenta, Euterpe edulis, Musa sp., Cajanus cajan, y especies forestales en asociación con Calophyllum: Inga sp., Schinnus terebinthifolius, Alchornea triplinervia, Sesbania sp., repartidas entre 159 ha productivas y 50 ha para hábitats naturales de conservación. Las variables como efecto de los sistemas agroforestales estuvieron repartidas en suelos, caracteristicas productivas, apropiación y mejoramiento de las condicones de los trabajadores, aspectos ambientales y socioeconónicos que en conjunto arrojaron indices de desempeño para el sistema APOIA-NovoRural. Se encontraron contribuciones de los sistemas agroforestales para la sustentabilidad, destacándose la calidad del agua con índice (0,94) comparado con (0,85) obtenido en los sedimentos que drenan del cultivo de arroz; valores económicos (0,85) y de ecología del paisaje (0,77). El índice integrado medio, llegó a 0,79 en una escala de 0 a 10, con referencia de 0,70. La Finca Coruputuba estuvo entre los cinco valores más altos de desempeño ambiental de un universo de 178 casos

    A study to guide breeding of new cultivars of organic cherry tomato following a consumer-driven approach.

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    Agricultural studies focusing on the development and/or improvement of new varieties of fruits and vegetables usually prioritize the productivity, disease resistance, response to fertilization, and higher nutrient content. However, new product development needs to take into account not only flavour preference, but also consumer preference for appearance since without tasting products, consumers have to make decisions based on the way a product looks. The present study evaluated the sensory characteristics and consumer preference of ten promising accessions of organic cherry tomato for fresh consumption aiming at identifying the sensory attributes related to appearance that contributed to consumer liking/disliking the fruit. More specifically, the objective of the study was to guide producers regarding the target appearance attributes that play a role on consumer acceptance of cherry tomatoes. Ten accessions of organic cherry tomatoes were evaluated by a trained panel using the QDA methodology, and also by 80 tomato consumers for the acceptance of appearance and intention to purchase. The results achieved after integrating these two data sets (from the trained panel and consumers) in a multidimensional map allowed the elucidation of consumer liking of tomatoes in relation to the appearance, i.e. drivers of liking/disliking were identified. Results revealed that tomatoes with round shape and red colour (reddish) (cultivar ENAS 1031, ENAS 1010, ?Perinha Agua Branca?, Super Sweet, and ?Joana?) were the most liked cherry tomatoes. Those genotypes were also liked by the smallest segment (17.5% of participants) but for them unusual shapes (oblong and pear), orange-yellow colour, and bigger size were also liked. Despite the small number of participants in this study (80 consumers), new shapes and colours for the organic cherry tomatoes could be considered promising alternatives in the Brazilian market, and can be an opportunity for the producers of the state of Rio de Janeiro

    Distributed Edge Connectivity in Sublinear Time

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    We present the first sublinear-time algorithm for a distributed message-passing network sto compute its edge connectivity λ\lambda exactly in the CONGEST model, as long as there are no parallel edges. Our algorithm takes O~(n11/353D1/353+n11/706)\tilde O(n^{1-1/353}D^{1/353}+n^{1-1/706}) time to compute λ\lambda and a cut of cardinality λ\lambda with high probability, where nn and DD are the number of nodes and the diameter of the network, respectively, and O~\tilde O hides polylogarithmic factors. This running time is sublinear in nn (i.e. O~(n1ϵ)\tilde O(n^{1-\epsilon})) whenever DD is. Previous sublinear-time distributed algorithms can solve this problem either (i) exactly only when λ=O(n1/8ϵ)\lambda=O(n^{1/8-\epsilon}) [Thurimella PODC'95; Pritchard, Thurimella, ACM Trans. Algorithms'11; Nanongkai, Su, DISC'14] or (ii) approximately [Ghaffari, Kuhn, DISC'13; Nanongkai, Su, DISC'14]. To achieve this we develop and combine several new techniques. First, we design the first distributed algorithm that can compute a kk-edge connectivity certificate for any k=O(n1ϵ)k=O(n^{1-\epsilon}) in time O~(nk+D)\tilde O(\sqrt{nk}+D). Second, we show that by combining the recent distributed expander decomposition technique of [Chang, Pettie, Zhang, SODA'19] with techniques from the sequential deterministic edge connectivity algorithm of [Kawarabayashi, Thorup, STOC'15], we can decompose the network into a sublinear number of clusters with small average diameter and without any mincut separating a cluster (except the `trivial' ones). Finally, by extending the tree packing technique from [Karger STOC'96], we can find the minimum cut in time proportional to the number of components. As a byproduct of this technique, we obtain an O~(n)\tilde O(n)-time algorithm for computing exact minimum cut for weighted graphs.Comment: Accepted at 51st ACM Symposium on Theory of Computing (STOC 2019

    Skeletal muscle and the maintenance of vitamin d status

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    © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Vitamin D, unlike the micronutrients, vitamins A, E, and K, is largely obtained not from food, but by the action of solar ultraviolet (UV) light on its precursor, 7-dehydrocholesterol, in skin. With the decline in UV light intensity in winter, most skin production of vitamin D occurs in summer. Since no defined storage organ or tissue has been found for vitamin D, it has been assumed that an adequate vitamin D status in winter can only be maintained by oral supplementation. Skeletal muscle cells have now been shown to incorporate the vitamin D-binding protein (DBP) from blood into the cell cytoplasm where it binds to cytoplasmic actin. This intracellular DBP provides an array of specific binding sites for 25-hydroxyvitamin D (25(OH)D), which diffuses into the cell from the extracellular fluid. When intracellular DBP undergoes proteolytic breakdown, the bound 25(OH)D is then released and diffuses back into the blood. This uptake and release of 25(OH)D by muscle accounts for the very long half-life of this metabolite in the circulation. Since 25(OH)D concentration in the blood declines in winter, its cycling in and out of muscle cells appears to be upregulated. Parathyroid hormone is the most likely factor enhancing the repeated cycling of 25(OH)D between skeletal muscle and blood. This mechanism appears to have evolved to maintain an adequate vitamin D status in winter

    Fornecimento de recursos para inimigos naturais por picão de flor (Cosmos sulphureus - Asteraceae).

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    O objetivo deste trabalho é relatar as observações visuais de IN utilizando os recursos fornecidos a eles por cosmos

    Estudo sobre gestão ambiental na transição agroflorestal no Vale do Paraíba, São Paulo, Brasil.

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    Resumo: A integração agroecológica do componente arbóreo e agrícola na propriedade rural favorece a sustentabilidade ambiental e econômica. Este artigo apresenta uma análise de sustentabilidade ambiental de uma centenária fazenda do Vale do Paraíba, em Pindamonhangaba - SP, dedicada à diversificação arbórea, conversão agroflorestal da produção de guanandi (Calophyllum brasiliense Cambess.) para madeira nativa e atividades não-agrícolas. A análise do desempenho ambiental do estabelecimento foi feita com o sistema APOIA-NovoRural abrangendo 62 indicadores em cinco dimensões: Ecologia da paisagem, Qualidade ambiental, Valores socioculturais, Valores econômicos e Gestão e administração. Com o sistema Ambitec-Agro determinou-se o impacto das pesquisas na gestão da fazenda. O estabelecimento rural obteve elevado desempenho ambiental em todos os índices: Qualidade da água (0,94); Valores econômicos (0,85); Valores socioculturais (0,76) e Ecologia da paisagem (0,77) com oportunidade de avanços na Gestão e administração (0,69) e na Qualidade do solo (0,65), conferindo um elevado índice integrado de sustentabilidade (0,79), situando-se entre os cinco mais elevados índices dentre 178 estudos de caso com o sistema APOIA-NovoRural. Com o sistema Ambitec-Agro o índice geral de desempenho ambiental foi de 4,14 com tendência positiva para praticamente todos os critérios analisados. Práticas agroflorestais melhoram a qualidade dos solos, aumentam a diversidade de fontes de renda e os métodos de pesquisa participativa melhoram o relacionamento interinstitucional na unidade de produção. -- Abstract: The agroecological integration of the tree and agricultural component in rural property favors environmental and economic sustainability. This article presents an environmental sustainability analysis of a centennial farm in the Paraíba Valley, in Pindamonhangaba - SP, dedicated to the tree diversification, agroforestry conversion of the production of Guanandi (Calophyllum brasiliense Cambess.) - Native timber and non-agricultural activities. The analysis of the environmental performance of the establishment was made with the system APOIA-NovoRural, covering 62 indicators in five dimensions: landscape ecology, environmental quality, socio-cultural values, economic values and management and administration. With the Ambitec-Agro system, the impact of the research on the management of the farm was determined. The rural establishment achieved high environmental performance in all indices: Water quality (0.94); Economic values (0.85); Socio-cultural values (0.76) and landscape ecology (0.77) with opportunity for advances in management and administration (0.69) and soil quality (0.65), conferring a high integrated sustainability index (0.79), which is among the five highest indexes, of 178 case studies with the system APOIA-NovoRural. With the Ambitec-Agro system the general index of environmental performance was 4.14 with a positive trend for virtually all the criteria analyzed. Agroforestry practices improve the quality of soils, increase the diversity of income sources and participatory research methods improve the interinstitutional relationship

    Mechanisms underlying lumbopelvic pain during pregnancy: A proposed model

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    Up to 86% of pregnant women will have lumbopelvic pain during the 3rd trimester of pregnancy and women with lumbopelvic pain experience lower health-related quality of life during pregnancy than women without lumbopelvic pain. Several risk factors for pregnancy-related lumbopelvic pain have been identified and include history of low back pain, previous trauma to the back or pelvis and previous pregnancy-related pelvic girdle pain. During pregnancy, women go through several hormonal and biomechanical changes as well as neuromuscular adaptations which could explain the development of lumbopelvic pain, but this remains unclear. The aim of this article is to review the potential pregnancy-related changes and adaptations (hormonal, biomechanical and neuromuscular) that may play a role in the development of lumbopelvic pain during pregnancy. This narrative review presents different mechanisms that may explain the development of lumbopelvic pain in pregnant women. A hypotheses-driven model on how these various physiological changes potentially interact in the development of lumbopelvic pain in pregnant women is also presented. Pregnancy-related hormonal changes, characterized by an increase in relaxin, estrogen and progesterone levels, are potentially linked to ligament hyperlaxity and joint instability, thus contributing to lumbopelvic pain. In addition, biomechanical changes induced by the growing fetus, can modify posture, load sharing and mechanical stress in the lumbar and pelvic structures. Finally, neuromuscular adaptations during pregnancy include an increase in the activation of lumbopelvic muscles and a decrease in endurance of the pelvic floor muscles. Whether or not a causal link between these changes and lumbopelvic pain exists remains to be determined. This model provides a better understanding of the mechanisms behind the development of lumbopelvic pain during pregnancy to guide future research. It should allow clinicians and researchers to consider the multifactorial nature of lumbopelvic pain while taking into account the various changes and adaptations during pregnancy
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