26 research outputs found

    Triplet lambs and their dams – a review of current knowledge and management systems

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    Triplet-bearing ewes and their lambs have the potential to improve flock productivity however, the lack of robust information on optimal nutrition and management is limiting their performance. In comparison to twins, the triplet lamb is; lighter, more metabolically challenged, has lower body temperature, and receives less colostrum and milk which combined results in lower survival rates and weaning weights. While scientifically based management guidelines are available for singletons and twins, guidelines are generally lacking for triplets. Although there is some knowledge on the impacts of nutrition, further studies are required to examine the impacts of varying feeding regimens in pregnancy and lactation, across the body condition range. Characterising the impacts of shelter and other paddock factors, stocking rate, mob size and human intervention would also be of benefit. Future studies must be large enough to allow for evaluation of lamb survival and litter birth weight variation

    Therapeutic and Prophylactic Potential of Vitamin D for Multiple Sclerosis

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    A plethora of investigations demonstrated that vitamin D (VitD) has a broad immunomodulatory potential. It induces tolerogenic dendritic cells in vitro leading to the development of regulatory T cells that have a key role in immunomodulation of autoimmune diseases including multiple sclerosis (MS). Studies showed that many MS patients present lower serum levels of VitD than healthy subjects. In addition, VitD supplementation has been associated with a reduced relative risk of developing MS. Considering the alterations in VitD levels in patients and also the immunomodulatory properties of VitD, it would be interesting to evaluate VitD potential as a tolerogenic adjuvant in experimental models of MS. In this context, our research team has been investigating strategies employing VitD to establish an in vivo tolerance state toward central nervous system antigens in experimental autoimmune encephalomyelitis (EAE). We observed that the association between a myelin peptide and VitD determined both therapeutic and prophylactic effects on EAE development

    Sharing Memory between Byzantine Processes Using Policy-Enforced Tuple Spaces

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    The Great Markarian 421 Flare of 2010 February: Multiwavelength Variability and Correlation Studies

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    We report on variability and correlation studies using multiwavelength observations of the blazar Mrk 421 during the month of 2010 February, when an extraordinary flare reaching a level of ∼27 Crab Units above 1 TeV was measured in very high energy (VHE) γ-rays with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) observatory. This is the highest flux state for Mrk 421 ever observed in VHE γ-rays. Data are analyzed from a coordinated campaign across multiple instruments, including VHE γ-ray (VERITAS, Major Atmospheric Gamma-ray Imaging Cherenkov), high-energy γ-ray (Fermi-LAT), X-ray (Swift, Rossi X-ray Timing Experiment, MAXI), optical (including the GASP-WEBT collaboration and polarization data), and radio (Metsahovi, Owens Valley Radio Observatory, University of Michigan Radio Astronomy Observatory). Light curves are produced spanning multiple days before and after the peak of the VHE flare, including over several flare "decline" epochs. The main flare statistics allow 2 minute time bins to be constructed in both the VHE and optical bands enabling a cross-correlation analysis that shows evidence for an optical lag of ∼25-55 minutes, the first time-lagged correlation between these bands reported on such short timescales. Limits on the Doppler factor (δ ⪆ 33) and the size of the emission region (δ-1RB≲ 3.8 × 1013cm) are obtained from the fast variability observed by VERITAS during the main flare. Analysis of 10 minute binned VHE and X-ray data over the decline epochs shows an extraordinary range of behavior in the flux-flux relationship, from linear to quadratic to lack of correlation to anticorrelation. Taken together, these detailed observations of an unprecedented flare seen in Mrk 421 are difficult to explain with the classic single-zone synchrotron self-Compton model.</p

    Mathematical analysis of maximum power generated by photovoltaic systems and fitting curves for standard test conditions Modelo matemático da potência máxima gerada por sistemas fotovoltaicos e curvas de ajuste às condições de teste em campo

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    The rural electrification is characterized by geographical dispersion of the population, low consumption, high investment by consumers and high cost. Moreover, solar radiation constitutes an inexhaustible source of energy and in its conversion into electricity photovoltaic panels are used. In this study, equations were adjusted to field conditions presented by the manufacturer for current and power of small photovoltaic systems. The mathematical analysis was performed on the photovoltaic rural system I-100 from ISOFOTON, with power 300 Wp, located at the Experimental Farm Lageado of FCA/UNESP. For the development of such equations, the circuitry of photovoltaic cells has been studied to apply iterative numerical methods for the determination of electrical parameters and possible errors in the appropriate equations in the literature to reality. Therefore, a simulation of a photovoltaic panel was proposed through mathematical equations that were adjusted according to the data of local radiation. The results have presented equations that provide real answers to the user and may assist in the design of these systems, once calculated that the maximum power limit ensures a supply of energy generated. This real sizing helps establishing the possible applications of solar energy to the rural producer and informing the real possibilities of generating electricity from the sun.<br>A eletrificação rural é caracterizada pela dispersão geográfica da população, baixo consumo, alto investimento por consumidor e elevado custo operacional. Por outro lado, a radiação solar constitui-se numa inesgotável fonte energética, e para sua conversão em energia elétrica são utilizados painéis fotovoltaicos. Neste trabalho, foram determinadas equações ajustadas às condições de campo apresentadas pelo fabricante para corrente e potência de sistemas fotovoltaicos de pequeno porte. A análise matemática foi feita sobre o sistema fotovoltaico rural I-100 da ISOFOTON, com potência de 300 Wp, localizado na Fazenda Experimental Lageado da FCA/UNESP. Para o desenvolvimento de tais equações, procurou-se estudar o circuito elétrico de células fotovoltaicas, aplicar os métodos numéricos iterativos para a determinação de parâmetros elétricos e analisar possíveis erros na adequação das equações existentes da literatura à realidade. Sendo assim, foi proposta a simulação de um painel fotovoltaico por meio de equações matemáticas que foram ajustadas segundo os dados de radiação locais. Os resultados apresentam equações que fornecem respostas reais para o usuário e podem auxiliar no dimensionamento destes sistemas, uma vez que a potência máxima calculada garante um limite de fornecimento da energia gerada. Este real dimensionamento auxilia a determinação das possíveis aplicações da energia solar para o produtor rural, informando as possibilidades reais de geração de energia elétrica pelo Sol

    Suplementação de taurina em dietas com duas concentrações proteicas para pós-larvas de camarão-branco-do-pacífico

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    Este estudo foi realizado com o objetivo de avaliar a possibilidade de reduzir a concentração proteica da dieta para pós-larvas de camarão-branco-do-pacífico (Litopenaeus vannamei) por meio da suplementação do aminoácido taurina. Seis dietas práticas, isoenergéticas (15,48 kJ EM/g), foram formuladas para conter duas concentrações de proteína (35% e 45% proteína bruta, PB), com três níveis de suplementação de taurina (0, 5 e 10 g/kg), em arranjo fatorial 2 × 3, com quatro repetições. Cem pós-larvas (peso inicial de 0,14 ± 0,01 g) foram estocadas em cada um dos 24 tanques de 45 litros conectados a um sistema de recirculação de água marinha. As dietas experimentais foram distribuídas aos camarões (10% da biomassa) três vezes ao dia, durante 30 dias. A concentração proteica da dieta não influenciou o crescimento nem a utilização alimentar das pós-larvas, mas o efeito benéfico da suplementação das dietas com taurina foi evidente em ambos os níveis proteicos testados. As póslarvas alimentadas com as dietas com maior concentração de taurina (10 g/kg) alcançaram maior peso final, ganho em peso e taxa de crescimento específico e melhor conversão alimentar em comparação àquelas alimentadas com as demais dietas. A taxa de sobrevivência média foi superior a 92% e não foi afetada pelas dietas experimentais. O nível de 35% de PB na dieta (22,58 mg PB/kJ EM) é suficiente para promover o crescimento adequado de pós-larvas de L. vannamei, e o desempenho dos camarões pode ser melhorado com a suplementação de 10 g taurina/kg de ração.The present study aimed to evaluate the possibility of reducing the dietary protein content for post-larvae of Pacific white shrimp (Litopenaeus vannamei) through diet supplementation with taurine amino acid. Six practical isoenergetic (15.48 kJ ME/g) diets were formulated to contain two protein concentrations (35% and 45% crude protein, CP) and 3 levels of taurine supplementation (0, 5 and 10 g/kg) in a 2 × 3 factorial scheme, with four replicates. One hundred postlarvae (initial weight 0.14 ± 0.01 g) were stocked in each of twenty-four 45–L tanks, connected with recirculating marine water system. Shrimps were fed the experimental diets (10% biomass) 3 times a day for 30 days. Dietary protein concentration did not influence growth neither feed utilization of the post-larvae, but a benefic effect of the diet supplementation with taurine on both protein levels tested was evident. Post-larvae fed diets with the highest taurine supplementation (10 g/kg) achieved significant higher final weight, weight gain, specific growth rate and better feed conversion than those fed the other diets. Average survival rate was greater than 92% and it was not affected by experimental diets. Crude protein level of 35% in the diet (22.58 mg CP/kJ ME) is enough to promote adequate growth of L. vannamei post-larvae and shrimp performance can be improved with supplementation of 10 g taurine/kg of ration
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