3,055 research outputs found

    Inibição do crescimento micelial in vitro de Thielaviopsis paradoxa com utilização de fungicidas sistêmicos e de contato.

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    Single copy/knock-in models of ALS SOD1 in C. elegans suggest loss and gain of function have different contributions to cholinergic and glutamatergic neurodegeneration

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    Mutations in Cu/Zn superoxide dismutase 1 (SOD1) lead to Amyotrophic Lateral Sclerosis (ALS), a neurodegenerative disease that disproportionately affects glutamatergic and cholinergic motor neurons. Previous work with SOD1 overexpression models supports a role for SOD1 toxic gain of function in ALS pathogenesis. However, the impact of SOD1 loss of function in ALS cannot be directly examined in overexpression models. In addition, overexpression may obscure the contribution of SOD1 loss of function in the degeneration of different neuronal populations. Here, we report the first single-copy, ALS knock-in models in C. elegans generated by transposon- or CRISPR/Cas9- mediated genome editing of the endogenous sod-1 gene. Introduction of ALS patient amino acid changes A4V, H71Y, L84V, G85R or G93A into the C. elegans sod-1 gene yielded single-copy/knock-in ALS SOD1 models. These differ from previously reported overexpression models in multiple assays. In single-copy/knock-in models, we observed differential impact of sod-1 ALS alleles on glutamatergic and cholinergic neurodegeneration. A4V, H71Y, G85R, and G93A animals showed increased SOD1 protein accumulation and oxidative stress induced degeneration, consistent with a toxic gain of function in cholinergic motor neurons. By contrast, H71Y, L84V, and G85R lead to glutamatergic neuron degeneration due to sod-1 loss of function after oxidative stress. However, dopaminergic and serotonergic neuronal populations were spared in single-copy ALS models, suggesting a neuronal-subtype specificity previously not reported in invertebrate ALS SOD1 models. Combined, these results suggest that knock-in models may reproduce the neurotransmitter-type specificity of ALS and that both SOD1 loss and gain of toxic function differentially contribute to ALS pathogenesis in different neuronal populations.Peer reviewe

    Deslocamento de DMUS pela fronteira de eficiência em modelos de Análise de Envoltória de Dados com ganhos de soma zero.

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    O trabalho apresenta uma extensão do modelo DEA com Ganhos de Soma Zero (DEA-GSZ) para os casos em que devido à redução de outputs (para que a soma seja constante), há a possibilidade ou a imposição de redução dos inputs utilizados. Nesses casos, não há o deslocamento da fronteira, mas sim o deslocamento das DMUs pela fronteira eficiente (ou pelas camadas de iso-eficiência). São apresentados os casos bidimensional e multidimensional. Para este, devido à complexidade dos algoritmos de determinação de faces do poliedro envolvente (fronteira DEA), é proposto o uso do modelo de suavização da fronteira, que representa a fronteira inteira por uma única equação polinomial

    Normal Cones and Thompson Metric

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    The aim of this paper is to study the basic properties of the Thompson metric dTd_T in the general case of a real linear space XX ordered by a cone KK. We show that dTd_T has monotonicity properties which make it compatible with the linear structure. We also prove several convexity properties of dTd_T and some results concerning the topology of dTd_T, including a brief study of the dTd_T-convergence of monotone sequences. It is shown most of the results are true without any assumption of an Archimedean-type property for KK. One considers various completeness properties and one studies the relations between them. Since dTd_T is defined in the context of a generic ordered linear space, with no need of an underlying topological structure, one expects to express its completeness in terms of properties of the ordering, with respect to the linear structure. This is done in this paper and, to the best of our knowledge, this has not been done yet. The Thompson metric dTd_T and order-unit (semi)norms u|\cdot|_u are strongly related and share important properties, as both are defined in terms of the ordered linear structure. Although dTd_T and u|\cdot|_u are only topological (and not metrical) equivalent on KuK_u, we prove that the completeness is a common feature. One proves the completeness of the Thompson metric on a sequentially complete normal cone in a locally convex space. At the end of the paper, it is shown that, in the case of a Banach space, the normality of the cone is also necessary for the completeness of the Thompson metric.Comment: 36 page

    Modelagem AMMI para estudos de interação em modelos estatísticos de efeitos fixos.

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