19 research outputs found

    CMB constraints on noncommutative geometry during inflation

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    We investigate the primordial power spectrum of the density perturbations based on the assumption that spacetime is noncommutative in the early stage of inflation. Due to the spacetime noncommutativity, the primordial power spectrum can lose rotational invariance. Using the k-inflation model and slow-roll approximation, we show that the deviation from rotational invariance of the primordial power spectrum depends on the size of noncommutative length scale L_s but not on sound speed. We constrain the contributions from the spacetime noncommutativity to the covariance matrix for the harmonic coefficients of the CMB anisotropies using five-year WMAP CMB maps. We find that the upper bound for L_s depends on the product of sound speed and slow-roll parameter. Estimating this product using cosmological parameters from the five-year WMAP results, the upper bound for L_s is estimated to be less than 10^{-27} cm at 99.7% confidence level.Comment: 8 pages, 1 figure, References added, Accepted for publication in EPJC (submitted version

    IgG recognizing 21-24 kDa and 30-33 kDa tachyzoite antigens show maximum avidity maturation during natural and accidental human toxoplasmosis IgG reconhecendo antígenos de taquizoita de 21-24 kDa e 30-33 kDa mostra avidez máxima de maturação na toxoplasmose humana natural e acidental

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    We describe the avidity maturation of IgGs in human toxoplasmosis using sequential serum samples from accidental and natural infections. In accidental cases, avidity increased continuously throughout infection while naturally infected patients showed a different profile. Twenty-five percent of sera from chronic patients having specific IgM positive results could be appropriately classified using exclusively the avidity test data. To take advantage of the potentiality of this technique, antigens recognized by IgG showing steeper avidity maturation were identified using immunoblot with KSCN elution. Two clusters of antigens, in the ranges of 21-24 kDa and 30-33 kDa, were identified as the ones that fulfill the aforementioned avidity characteristics.<br>Descrevemos a avidez de maturação de IgGs na toxoplasmose humana usando amostras sequenciais de soro de infecções naturais e acidentais. Em casos acidentais, a avidez aumentou continuamente através da infeção enquanto os pacientes naturalmente infectados mostraram perfil diferente. 25% dos soros de pacientes crônicos que possuiam resultados positivos de IgM específica puderam ser classificados apropriadamente usando exclusivamente os dados do teste de avidez. Para se aproveitar a potencialidade desta técnica, antígenos reconhecidos pela IgG mostrando progressiva avidez de maturação foram identificados usando-se Imunoblot com eluição com KSCN. Dois grupos de antígenos, com limites de 21-24 kDa e 30-33 kDa, foram identificados como aqueles que preenchem as características de avidez acima mencionadas

    Biodiesel synthesis from Ceiba pentandra oil by microwave irradiation-assisted transesterification: ELM modeling and optimization

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    © 2019 Elsevier Ltd In this study, microwave irradiation-assisted transesterification was used to produce Ceiba pentandra biodiesel, which accelerates the rate of reaction and temperature within a shorter period. The improvement of biodiesel production requires a reliable model that accurately reflects the effects of input variables on output variables. In this study, an extreme learning machine integrated with cuckoo search algorithm was developed to predict and optimize the process parameters. This model will be useful for virtual experimentations in order to enhance biodiesel research and development. The optimum parameters of the microwave irradiation-assisted transesterification process conditions were obtained as follows: (1) methanol/oil ratio: 60%, (2) potassium hydroxide catalyst concentration: 0.84%(w/w), (3) stirring speed: 800 rpm, and (4) reaction time: 388 s. The corresponding Ceiba pentandra biodiesel yield was 96.19%. Three independent experiments were conducted using the optimum process parameters and the average biodiesel yield was found to be 95.42%. In conclusion, microwave irradiation-assisted transesterification is an effective method for biodiesel production because it is more energy-efficient, which will reduce the overall cost of biodiesel production

    Redução da proteína em dietas para tilápias-do-nilo por meio da suplementação de aminoácidos com base no conceito de proteína ideal Protein reduction in diets for Nile tilapia by amino acids supplementation based on the ideal protein concept

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    Este trabalho foi realizado para avaliar os efeitos da redução da proteína da dieta, por meio da suplementação com aminoácidos sintéticos, sobre o desempenho produtivo, a digestibilidade e o diâmetro da fibra muscular de tilápias-do-nilo. Os aminoácidos (lisina, metionina, treonina e arginina) foram suplementados de forma a manter o perfil de aminoácidos da dieta-referência. Foram utilizados 160 peixes com peso vivo médio inicial de 105,7 ± 2,5 g, distribuídos em 16 tanques (1 m³ cada) e alimentados com dietas contendo 26,74; 25,82; 23,09 ou 22,16% de proteína digestível durante 110 dias. Não foi observado efeito dos níveis de proteína nas dietas sobre o ganho de peso diário, o índice hepatossomático, a gordura visceral, o rendimento de filé, os teores corporais de umidade, proteína bruta e cinzas, o teor de cinzas no filé, a taxa de sobrevivência e o diâmetro das fibras do músculo dorsal. Com a redução dos níveis de proteína na dieta, foi observada redução linear dos coeficientes de digestibilidade aparente da energia bruta, proteína bruta, extrato etéreo e fósforo das dietas. Houve efeito quadrático dos níveis de proteína sobre a conversão alimentar, a taxa de eficiência proteica, a retenção de nitrogênio, o nitrogênio excretado, a umidade no filé, a gordura corporal e no filé e proteína no filé, de modo que os melhores valores foram estimados com 24,53; 24,25; 24,04; 25,15; 24,67; 24,14; 24,34; 25,11% de proteína digestível, respectivamente. É possível reduzir, de 26,74 para 24,53%, a proteína digestível em dietas para tilápias-do-nilo na fase de 100 a 500 g.<br>The objective of this work was to evaluate the effects of reduction of protein in diets for Nile tilapia by supplementation of synthetic amino acids on performance, digestibility and diameter of muscle fiber of Nile tilapias. The amino acids (lysine, methionine, threonine and arginine) were supplemented to keep the profile of amino acids in the reference diet. It was used 160 fish with initial live weight of 105.7 ± 2.5 g, distributed in 16 tanks (1 m³ each tank) fed diets containing 26.74; 25.82; 23.09 or 22.16% of digestible protein for 110 days. It was not observed any effects of protein levels in the diets on daily weight gain, hepatosomatic index, visceral fat, fillet yield, carcass humidity, crude protein and ash, fillet ash, survival rate and on the white muscle fiber diameter. A linear decrease on apparent digestibility coefficients, gross energy, crude protein, ether extract and phosphorus was observed when protein levels in the diet were reduced. There was a quadratic effect on feed conversion ratio, protein efficiency rate, nitrogen retention, nitrogen excretion, fillet humidity, carcass and fillet fat and fillet protein, in which the best-fit responses were estimated with 24.53, 24.25, 24.04, 25.15, 24.67, 24.14, 24.34 and 25.11% of digestible protein, respectively. It is possible to reduce the dietary protein level from 26.74 to 24.53% for Nile tilapia 100 to 500-g phase
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