372 research outputs found

    Fertilizer metering mechanism with helical conic cylindrical thread for family agriculture

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    Small rural farms are important for Brazilian agribusiness, but equipment suitable for distributing fertilizers on these properties is scarce. We studied a new fertilizer metering mechanism for use on the family farm. It combines a helical conic thread with a conventional fertilizer meter in a cylindrical section. The experimental plan was created using a 24 factorial design. An analysis of variance (ANOVA) was also conducted. The mechanism showed a positive result with respect to the uniformity of fertilizer flow (with a coefficient of variation of 3.1-5.8%), longitudinal distribution (with a coefficient of variation of 4%), and different types of fertilizers (in which variations between 2.7 and 3.5% were found).38693494

    Population structure of Araucaria angustifolia in the Iguaçu National Park.

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    Estrutura populacional de Araucaria angustifolia no Parque Nacional do Iguaçu. O objetivo do presente trabalho foi analisar a estrutura populacional, regeneração e distribuição espacial de Araucaria angustifolia (Bertol.) Kuntz no interior de uma floresta natural e na borda de uma floresta com monocultura agrícola. Todos os indivíduos de araucária a partir de 10 cm de altura foram registrados em 200 parcelas de 10 x 10 m, sendo amostrados 479 indivíduos (416 na borda e 63 no interior). Desses, 33 eram fêmeas, 37 machos, 49 juvenis e 360 regenerantes. A estrutura da população apresentou padrão semelhante ao J-invertido. Os indivíduos regenerantes apresentaram principalmente o padrão agregado de distribuição, já para os juvenis, machos e fêmeas o padrão foi uniforme. A densidade do dossel influenciou a frequência de indivíduos, sendo observadas maiores frequências em maiores densidades, indicando que a regeneração da espécie é mais efetiva em ambientes sombreados. Devido ao grande número de indivíduos amostrados em diferentes classes de tamanho, o Parque Nacional do Iguaçu representa um importante remanescente na conservação de A. angustifolia

    Lupus eritematoso sistémico asociado a vasculitis de vasos medianos

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    El Lupus Eritematoso Sistémico (LES) es una enfermedadautoinmune compleja que puede presentarsecon una amplia variedad de manifestacionesclínicas y serológicas, pudiendo afectarcualquier órgano.Las vasculitis se caracterizan por presencia deinfiltrado celular en la pared vascular de polimorfonuclearesy como consecuencia necrosis de lapared. Los síndromes vasculíticos se puedenagrupar en formas primarias, donde el procesofisiopatológico involucra directamente los vasossanguíneos y formas secundarias en las cualesla inflamación vascular ocurre como complicaciónde una enfermedad subyacente, principalmenteenfermedades autoinmunes, o desencadenadaspor factores exógenos como drogas, infeccioneso neoplasias...</p

    Universal photonic processors in a glass-based femtosecond laser writing platform

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    Femtosecond laser writing (FLW) can open new perspectives on universal photonic processors (UPPs). We propose here two building blocks for the realization of FLW-UPPs and we show the preliminary results obtained on a 6-mode device

    Universal photonic processors fabricated by femtosecond laser writing

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    Universal photonic processors (UPPs) are reconfigurable photonic integrated circuits able to implement arbitrary unitary transformations on an input photonic state. Femtosecond laser writing (FLW) allows for rapid and cost-effective fabrication of circuits with low propagation losses. A FLW process featuring thermal isolation allows for a dramatic reduction in dissipated power and crosstalk in integrated thermally-reconfigurable Mach-Zehnder interferometers (MZIs), especially when operated in vacuum, with 0.9 mW dissipation for full reconfiguration and 0.5% crosstalk at 785 nm wavelength. To demonstrate the potential of this technology we fabricated and characterized a 6-mode FLW-UPP in a rectangular MZI mesh with 30 thermal shifters

    Quantifying n -Photon Indistinguishability with a Cyclic Integrated Interferometer

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    We report on a universal method to measure the genuine indistinguishability of n photons - a crucial parameter that determines the accuracy of optical quantum computing. Our approach relies on a low-depth cyclic multiport interferometer with N=2n modes, leading to a quantum interference fringe whose visibility is a direct measurement of the genuine n-photon indistinguishability. We experimentally demonstrate this technique for an eight-mode integrated interferometer fabricated using femtosecond laser micromachining and four photons from a quantum dot single-photon source. We measure a four-photon indistinguishability up to 0.81±0.03. This value decreases as we intentionally alter the photon pairwise indistinguishability. The low-depth and low-loss multiport interferometer design provides an original path to evaluate the genuine indistinguishability of resource states of increasing photon number

    Diabetes Causes Bone Marrow Autonomic Neuropathy and Impairs Stem Cell Mobilization via Dysregulated p66Shc and Sirt1

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    Diabetes compromises the bone marrow (BM) microenvironment and reduces circulating CD34 + cells. Diabetic autonomic neuropathy (DAN) may impact the BM, because the sympathetic nervous system (SNS) is prominently involved in BM stem cell trafficking. We hypothesize that neuropathy of the BM affects stem cell mobilization and vascular recovery after ischemia in diabetes. We report that, in patients, cardiovascular DAN was associated with fewer circulating CD34 + cells. Experimental diabetes (STZ and Ob/Ob ) or chemical sympathectomy in mice resulted in BM autonomic neuropathy, impaired Lin - cKit + Sca1 + (LKS) cell and endothelial progenitor cells (EPC, CD34 + Flk1 + ) mobilization and vascular recovery after ischemia. DAN increased expression of p66Shc and reduced expression of Sirt1 in mice and humans. p66Shc KO in diabetic mice prevented DAN in the BM, and rescued defective LKS cell and EPC mobilization. Hematopoietic Sirt1 KO mimicked the diabetic mobilization defect, while hematopoietic Sirt1 overexpression in diabetes rescued defective mobilization and vascular repair. Through p66Shc and Sirt1 , diabetes and sympathectomy elevated the expression of various adhesion molecules, including CD62L . CD62L KO partially rescued the defective stem/progenitor cell mobilization. In conclusion, autonomic neuropathy in the BM impairs stem cell mobilization in diabetes with dysregulation of the lifespan regulators p66Shc and Sirt1
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