846 research outputs found

    Mycochemical study of polysaccharides from the edible mushroom Cortinarius caperatus (Gypsy mushroom)

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    Among basidiomycete molecules, cell wall polysaccharides have been recognized as a major class of bioactive constituents. [1] They are safe molecules and they have a wide spectrum of biological activities, such as immunostimulatory and antioxidant, therefore they possess a prominent role in health benefits coming from mushroom consumption. These properties make mushroom polysaccharides potential candidates for nutraceutical applications and bioactive ingredients production. [2] Fractionation of the hot aqueous extract of Cortinarius caperatus led to isolation of two fractions characterized by spectroscopic analyses (1H-NMR, 13C-NMR, DEPT, 1H-1H COSY, DQCOSY, TOCSY, HSQC, HMBC and HMQC), mass spectrometry (EI-MS, ESI-MS), infrared spectroscopy (FT-IR), chemical reactions of hydrolysis and derivatization followed by GC and HPLC analyses. [3] This mycochemical study revealed a water-soluble fraction characterized as a \u3b2-(1\uf0e06)-D-glucan, whose presence inside C. caperatus has never, to the best of our knowledge, been reported before. Moreover, a water insoluble fraction purified has been characterized as a branched \uf061, (1\u21926) glucan which structure is assumed to be: [\u21926)-\u3b2-D-Glcp(1\u21926)]4-\u3b1-D-Glcp(1\u21924)-\u3b2-D-Glcp(1\u2192 6 \u2191 1 \u3b1-D-Glcp The antioxidant activity of the soluble polysaccharide fraction has been evaluated as radical-scavenging activity with the DPPH test, the \u3b2-(1\uf0e06)-D-glucan showed significative antioxidant activity

    Depinning of three-dimensional drops from wettability defects

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    Substrate defects crucially influence the onset of sliding drop motion under lateral driving. A finite force is necessary to overcome the pinning influence even of microscale heterogeneities. The depinning dynamics of three-dimensional drops is studied for hydrophilic and hydrophobic wettability defects using a long-wave evolution equation for the film thickness profile. It is found that the nature of the depinning transition explains the experimentally observed stick-slip motion.Comment: 6 pages, 9 figures, submitted to ep

    Characterization of the Hamamatsu R11410-10 3-Inch Photomultiplier Tube for Liquid Xenon Dark Matter Direct Detection Experiments

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    To satisfy the requirements of the next generation of dark matter detectors based on the dual phase TPC, Hamamatsu, in close collaboration with UCLA, has developed the R11410-10 photomultipler tube. In this work, we present the detailed tests performed on this device. High QE (>30%) accompanied by a low dark count rate (50 Hz at 0.3 PE) and high gain (10^7) with good single PE resolution have been observed. A comprehensive screening measurement campaign is ongoing while the manufacturer quotes a radioactivity of 20 mBq/PMT. These characteristics show the R11410-10 to be particularly suitable for the forthcoming zero background liquid xenon detectors.Comment: 19 pages, 18 figure

    Thin film evolution equations from (evaporating) dewetting liquid layers to epitaxial growth

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    In the present contribution we review basic mathematical results for three physical systems involving self-organising solid or liquid films at solid surfaces. The films may undergo a structuring process by dewetting, evaporation/condensation or epitaxial growth, respectively. We highlight similarities and differences of the three systems based on the observation that in certain limits all of them may be described using models of similar form, i.e., time evolution equations for the film thickness profile. Those equations represent gradient dynamics characterized by mobility functions and an underlying energy functional. Two basic steps of mathematical analysis are used to compare the different system. First, we discuss the linear stability of homogeneous steady states, i.e., flat films; and second the systematics of non-trivial steady states, i.e., drop/hole states for dewetting films and quantum dot states in epitaxial growth, respectively. Our aim is to illustrate that the underlying solution structure might be very complex as in the case of epitaxial growth but can be better understood when comparing to the much simpler results for the dewetting liquid film. We furthermore show that the numerical continuation techniques employed can shed some light on this structure in a more convenient way than time-stepping methods. Finally we discuss that the usage of the employed general formulation does not only relate seemingly not related physical systems mathematically, but does as well allow to discuss model extensions in a more unified way

    Modelagem bioeconômica da transferência de embriões em bovinos.

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    O objetivo deste trabalho foi desenvolver um modelo matemático orientado a eventos de simulação, para auxiliar tomadas de decisão relativas à transferência de embriões em bovinos, considerando-se as dinâmicas de dois componentes da transferência de embriões: receptoras e embriões. Na simulação, não se avaliaram respostas individuais de doadoras a coletas consecutivas e eventos correspondentes na transferência de embriões. Simulou-se o mesmo protocolo para superovulação a todas as doadoras. Receptoras foram sincronizadas simulando-se o uso de prostaglandina. O número de embriões viáveis produzido por doadora e sua variabilidade tiveram como base um processo aleatório de simulação de Monte Carlo, que pressupôs uma distribuição exponencial negativa de densidade de probabilidade. Custos e receitas foram inseridos no modelo por meio de um cenário-base para calcular indicadores econômicos de rentabilidade. A análise sugeriu a impraticabilidade da atividade, se realizada diante do cenário proposto (VPL ? R:57.596,69).Apartirdocenaˊrioproposto,ocustomeˊdioestimadofoideR: 57.596,69). A partir do cenário proposto, o custo médio estimado foi de R 1.178,19, e de R$ 980,03, para se obter uma prenhez a partir de uma situação otimizada, sugerida pelo modelo (5/100; 5/190)

    Análise da produção de embriões na fertilização in vitro e transferência de embriões para doadoras Nelore.

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    Ajustou-se uma função de densidade probabilidade para o número de embriões viáveis produzidos após fertilização in vitro em doadoras da raça Nelore, a partir de dados fornecidos pela Associação Brasileira de Criadores de Zebu (ABCZ), referente à análise de 20.619 doadoras, 71.602 aspirações e um total de 509.643 embriões. Modelou-se a densidade probabilidade do número de embriões viáveis mediante a função exponencial, executando-se a determinação dos parâmetros por meio da máxima verossimilhança, em um método de gradiente não linear. O nível de precisão obtido foi de RMSE = 0,040 e R2 = 0,98, para a representação da probabilidade do número de embriões viáveis produzidos por doadoras Nelore na técnica de fertilização in vitro(FIV). Para comparar os modelos (curvas de probabilidade de transferência de embriões ajustada por Beltrame, em 2006, e de FIV, neste trabalho), aplicou-se a técnica de comparação de curvas com o teste F (Silva e Azevedo, 2002). Não foram encontradas diferenças entre as curvas do número de embriões viáveis obtidos após coleta e produzidos após aspiração de doadoras na raça Nelore. Ainda, sugere-se a existência de um fator único limitante que afete biologicamente a produção de embriões nas técnicas de transferência de embriões e fertilização in vitro

    Health and welfare assessment of beef cattle during the adaptation period in a specialized commercial fattening unit

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    Beef cattle welfare and health status are influenced by housing and management systems. The present study aimed to assess the welfare and health status in the first 15 days after arrival of Limousine bulls imported from France and fattened in a commercial fattening unit in Italy. A total of 264 bulls were included in the study. Welfare, biosecurity, and major hazard and warning system were assessed on days 2 (T1) and 15 (T2) after arrival to the unit. At T1 and T2 an inspective clinical examination was performed on all bulls. At T1 and T2 blood samples were collected from 88 bulls for haematological analysis. Both at T1 and T2, the welfare, biosecurity, and major hazards and warning systems were classified with a general score of medium but with a decrease on animal-based measurements in T2. At T1 and T2 the clinical examination revealed a significant increase (p-value≤0.05) of skin lesions and lameness in T2. A high incidence of respiratory disease was noticed in both assessed times. Leucocytes and all differentials count, and platelets were significantly increased (p-value≤0.05) at T2, while the fibrinogen was significantly decreased. The haematological changes suggest that the bulls were under higher stress in T2 when compared with T1 linked with a difficult adaptation response to the fattening unit. A multi-factorial approach that integrates the indicators of the checklist and the clinical and haematological findings of animals can be a useful method to deepen the assessment of welfare in beef cattle

    Characterization of the QUartz Photon Intensifying Detector (QUPID) for Noble Liquid Detectors

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    Dark Matter and Double Beta Decay experiments require extremely low radioactivity within the detector materials. For this purpose, the University of California, Los Angeles and Hamamatsu Photonics have developed the QUartz Photon Intensifying Detector (QUPID), an ultra-low background photodetector based on the Hybrid Avalanche Photo Diode (HAPD) and entirely made of ultraclean synthetic fused silica. In this work we present the basic concept of the QUPID and the testing measurements on QUPIDs from the first production line. Screening of radioactivity at the Gator facility in the Laboratori Nazionali del Gran Sasso has shown that the QUPIDs safely fulfill the low radioactive contamination requirements for the next generation zero background experiments set by Monte Carlo simulations. The quantum efficiency of the QUPID at room temperature is > 30% at the xenon scintillation wavelength. At low temperatures, the QUPID shows a leakage current less than 1 nA and a global gain of 10^5. In these conditions, the photocathode and the anode show > 95% linearity up to 1 uA for the cathode and 3 mA for the anode. The photocathode and collection efficiency are uniform to 80% over the entire surface. In parallel with single photon counting capabilities, the QUPIDs have a good timing response: 1.8 +/- 0.1 ns rise time, 2.5 +/- 0.2 ns fall time, 4.20 +/- 0.05 ns pulse width, and 160 +/- 30 ps transit time spread. The QUPIDs have also been tested in a liquid xenon environment, and scintillation light from 57Co and 210Po radioactive sources were observed.Comment: 15 pages, 22 figure
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