670 research outputs found

    Soluble CD40 ligand can replace the normal T cell-derived CD40 ligand signal to B cells in T cell-dependent activation

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    We have constructed a soluble chimeric fusion protein between the mouse CD8 alpha chain and the mouse CD40 T cell ligand. This protein binds to both human and mouse B cells. By itself it induced a modest degree of B cell proliferation, but together with anti-immunoglobulin (anti-Ig) antibody it greatly stimulated B cell proliferation, as determined by both [3H]thymidine uptake and increase in cell numbers. These data are evidence that the CD40 ligand on T cells provides a signal that drives B cell proliferation. This signal is synergistic with that delivered by anti-Ig antibody

    Thermomechanical behavior of plasma-sprayed ZrO2-Y2O3 coatings influenced by plasticity, creep and oxidation

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    Thermocycling of ceramic-coated turbomachine components produces high thermomechanical stresses that are mitigated by plasticity and creep but aggravated by oxidation, with residual stresses exacerbated by all three. These residual stresses, coupled with the thermocyclic loading, lead to high compressive stresses that cause the coating to spall. A ceramic-coated gas path seal is modeled with consideration given to creep, plasticity, and oxidation. The resulting stresses and possible failure modes are discussed

    Simulation of fractionally damped mechanical systems by means of a Newmark-diffusive scheme

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    A Newmark-diffusive scheme is presented for the time-domain solution of dynamic systems containing fractional derivatives. This scheme combines a classical Newmark time-integration method used to solve second-order mechanical systems (obtained for example after finite element discretization), with a diffusive representation based on the transformation of the fractional operator into a diagonal system of linear differential equations, which can be seen as internal memory variables. The focus is given on the algorithm implementation into a finite element framework, the strategies for choosing diffusive parameters, and applications to beam structures with a fractional Zener model

    Biomassa microbiana do solo sob sistemas de manejo com diferentes coberturas vegetais.

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    bitstream/item/66226/1/31294.pdfOrganizado por: Alberto Feiden, Milton Parron Padovan, Adalgiza Inês Campolim, Aurélio Vinícius Borsato, Ivo de Sá Motta, João Batista Catto, Tércio Jacques Fehlaue

    Densidade e volume total de poros do solo cultivado com adubos verdes perenes consorciados com a bananeira em um sistema sob transição agroecológica em Mato Grosso do Sul.

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    bitstream/item/68859/1/041-carneiro-densidade.pdfPublicado também no Cadernos de Agroecologia, v. 7, n.2, 2012

    Macro e microporosidade do solo cultivado com adubos verdes perenes consorciados com a bananeira em um sistema sob transição agroecológica em Mato Grosso do Sul.

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    bitstream/item/69053/1/066-carneiro-macro.pdfPublicado também no Cadernos de Agroecologia, v. 7, n.2, 2012

    Contrasting multi-taxa diversity patterns between abandoned and non-intensively managed forests in the southern Dolomites

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    The abandonment of silvicultural activities can lead to changes in species richness and composition of biological communities, when compared to those found in managed forests. The aim of this study was to compare the multi-taxonomical diversity of two mature silver fir-beech-spruce forests in the southern Dolomites (Italy), corresponding to the European Union habitat type 9130. The two sites share similar ecological and structural characteristics, but differ in their recent management histories. In the last 50 years, one site underwent non-intensive management, while the other was left unmanaged and was included in a forest reserve. The species richness and composition of eight taxa were surveyed in the two sites between 2009 and 2011. The difference in mean species richness between the two forest management types was tested through permutation tests, while differences in species composition were tested by principal coordinates analysis and the permutational multivariate analysis of variance. Mean species richness of soil macrofungi, deadwood lichens, bark beetles, and longhorn beetles were significantly higher in the abandoned than in the non-intensively managed forests. Deadwood fungi and epiphytic lichens did not differ in mean species richness between the two study sites, while mean species richness of ground beetles and birds were higher in the non-intensively managed than in the abandoned forest. Significant differences in species composition between the two sites were found for all the taxa, except for longhorn beetles. These results indicate that improving forest landscape heterogeneity through the creation of a mosaic of abandoned and extensively managed forests should better fulfill the requirements of ecologically different taxa

    Neuropsychiatric systemic lupus erythematosus: where are we now?

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    When dealing with neuropsychiatric Systemic Lupus Erythematosus (NPSLE) there are still many controversial topics. In 1999 the American College of Rheumatology gave classification criteria for 19 clinical syndromes. However major problems are still related to low specificity of some of them such as headache, cognitive impairment or mood disorders. Even though a frequency of CNS involvement from 14 to 75% has been described, depending on both the population studied and the methodology of assessment, a lower frequency ranging from 21 to 28 % derived by larger case series seems more realistic. The introduction of the concept of "borderline cases", proposed by Italian Study Group for NP-SLE, is based both on clinical and instrumental evaluation and could represent a useful tool when dealing with conditions which do not fulfil ACR classification. Also the relationship between SLE activity and NP involvement is a debated issue. Concerning pathogenesis, it seems reasonable to consider multifactorial mechanisms related to antibody-mediated damage, antiphospholipid pro-thrombotic effect, non-inflammatory vasculopathy and cytokines mediated cytotoxycity. However, direct and unequivocal evidence for the implication of any of the above-mentioned mechanisms is still lacking. Although a wide range of neuroimaging tools have been used to evaluate CNS involvement, no single technique has proven to be definitive and, when dealing with a patient with suspected NPSLE, it is important to combine different diagnostic techniques. Due to the lack of effective imaging along with limitation in knowledge of underlying pathogenetic mechanisms and paucity of histopathologic findings, therapeutic approach in NPSLE remains a difficult issue and is currently based on personal experience. Italian Study Group for NP-SLE proposes the creation of a national registry on NPSLE to validate ACR classification criteria. Furthermore, the possibility to collect large series and stratifying them for each of the included neuro-psychiatric syndromes seems a good strategy for planning multicentric controlled therapeutic trials in the near future

    Agroecologia em Mato Grosso do Sul: princípios, fundamentos e experiências.

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    Agricultura ecológica: heteronomia e servidão? Histórico, conceitos e principios da agroecologia; Agricultura ecológica e agricultura familiar; Manejo ecológico do solo; As doenças infecciosas das lavouras dentro de uma visão agroecológica; Sistema integrado de produção agroecológica: uma experiência de pesquisa em agricultura orgânica; Homeopatia na produção de leite; Manejo de plantas infestantes em agroecologia; Comercialização e certificação de produtos ecològicos - a experiência da rede Ecovida de Agroecologia; Experiências em agroecologia no Sul do brasil; Experiência da FEPAGRO na pesquisa em agroecologia no Estado do Rio Grande do Sul; A importância da conscientização do consumidor no mercado de produtos orgânicos; A conversão de sistemas convencionais para sistemas orgânicos de produção no Brasil; A agroecologia em Mato Grosso do Sul.bitstream/item/38821/1/LV20022.pdfContém palestras apresentadas no I Seminário de Agroecologia de Mato Grosso do Sul, Campo Grande, MS, nov. 2002
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