908 research outputs found
Discovery of a Low-Mass Brown Dwarf Companion of the Young Nearby Star G196-3
A substellar-mass object in orbit at about 300 astronomical units (AU) from
the young low-mass star G196-3 was detected by direct imaging. Optical and
infrared photometry and low- and intermediate-resolution spectroscopy of the
faint companion, hereafter referred to as G196-3B, confirms its cool atmosphere
and allows its mass to be estimated at 25^{+15}_{-10} Jupiter masses. The
separation between both objects and their mass ratio suggest the fragmentation
of a collapsing cloud as the most likely origin for G196-3B, but alternatively
it could have originated from a proto-planetary disc which has been dissipated.
Whatever the formation process was, the young age of the primary star (about
100 Myr) demonstrates that substellar companions can form in short time scales.Comment: Published in Science (13 Nov). One color figur
Análisis del tamaño de partÃculas en areniscas de las Catedrales de Salamanca. Independencia entre granulometrÃa y deterioro
11 sandstone samples from the cathedrals of Salamanca were analysed granulometrically. The study was to establish whether there is a direct connection between the particle size of such stone and the surface deterioration of some of the ashlars in the facades. This was carried out with the help of diffraction spectrometry by laser beams.
The results show that there is no connection between the nature of the stone texture and their degree of surface deterioration.Se analizan granulométricamente 11 muestras de arenisca de las Catedrales de Salamanca. El objetivo del estudio es establecer si existe relación directa entre el tamaño de las partÃculas de tales piedras y el deterioro superficial de alguno de los sillares de las fachadas. Esto se lleva a cabo con la ayuda de la espectrometrÃa de difracción por rayos láser.
Los resultados muestran que no hay conexión entre la finura textural de las piedras estudiadas y el grado de deterioro superficial que éstas presentan
Effect of a variable delay in delayed dynamical systems
We report numerical evidence of the effects of a periodic modulation in the delay time of a delayed dynamical system. By referring to a Mackey-Glass equation and by adding a modula- tion in the delay time, we describe how the solution of the system passes from being chaotic to shadow periodic states. We analyze this transition for both sinusoidal and sawtooth wave mod- ulations, and we give, in the latter case, the relationship between the period of the shadowed orbit and the amplitude of the modulation. Future goals and open questions are highlighted
Desenvolvimento de uma prova de imunoadsorcao enzimática para detecção de anticorpos contra Trypanosoma vivax em bovinos: resultados preliminares.
bitstream/item/137691/1/PESQ-EM-ANDAMENTO-50.pdfCNPGC
Efeito do grupo genético sobre a qualidade da carne de cordeiros terminados em pastagem irrigada no semiárido nordestino.
Resumo: O objetivo desse estudo foi comparar quatro grupos genéticos de ovinos deslanados quanto à s caracterÃsticas relacionadas à qualidade da carne. Trinta e três cordeiros, contemporâneos, nascidos de parto simples e sem relação de parentesco foram utilizados no experimento, sendo treze da raça Santa Inês (SI), seis da raça Morada Nova (MN), sete da raça Somalis Brasileira (SB) e sete ½ Dorper - ½ Morada Nova (F1). Nesse estudo, a média geral explica bem o comportamento das respostas, uma vez que, com exceção da intensidade de vermelho (a*) e da perda de peso por cocção (PPC), não houve influência do grupo genético sobre as caracterÃsticas analisadas. As boas caracterÃsticas apresentadas pelos diferentes grupos genéticos os tornam excelentes opções para abastecer um mercado mais exigente. [Effect of genetic group on meat quality of lambs finished in irrigated pasture in the semiarid northeastern Brazil]. Abstract: The aim of this study was to compare four genetic groups of hair sheep on the characteristics related to meat quality. Thirty-three male lambs, ontemporary and unrelated were used in the experiment, being thirteen of Santa Inês (SI) breed, seven of Brazilian Somali breed (SB), six of Morada Nova (MN) breed and seven ½ Dorper x ½ Morada Nova (F1) crossbred. All lambs were of simple birth. In this study, the overall average explains the behavior of the responses, since, except for redness (a*) and cooking loss (PPC), there is no influence of genetic group on characteristics analyzed. The genetics groups present good quality and are excellent choices to fill a more demanding market
Avaliação preliminar de parâmetros epidemiológicos da tristeza parasitaria bovina no Mato Grosso do Sul.
Epidemiologia; Bovino; Tristeza parasitaria; Praga; Sanidade; America do Sul; Brasil; Mato Grosso do Sul.bitstream/item/137587/1/PESQ-EM-ANDAMENTO-38.pdfCNPGC
Um método para determinar o volume comercial do Schizolobium amazonicum (Huber) ducke utilizando redes neurais artificiais.
Este trabalho apresenta um método para determinar o volume comercial do Schizolobium amazonicum (Huber) Ducke, com casca, utilizando Redes Neurais Artificiais (RNAs). Compara os resultados com estimativas obtidas pelo método de regressão linear e quadrática. O modelo neural artificial utiliza uma RNA multicamada direta com uma camada intermediária e, o algoritmo de treinamento supervisionado backpropagation. Os resultados obtidos pelo modelo neural foram mais próximos do real que os obtidos pelos métodos de regressão linear e quadrática. O erro médio absoluto obtido pela RNA foi aproximadamente 50% menor quando comparado com o obtido pelo modelo de regressão quadrática e o erro padrão da estimativa cerca de 30% menor do que os obtidos pelos modelos de regressão linear e quadrática. Com o uso do modelo neural, não foi necessário utilizar o fator de forma, já que este varia de acordo com a idade, diâmetro e altura das árvores
Fatty acid profile of cheese from dairy goats fed a diet enriched with castor, sesame and faveleira vegetable oils.
Abstract: The addition of vegetable oils to the diets of dairy goats is an alternative to supplemental feeding during the dry period and improves the lipid profile of milk and by-products. Cheeses were produced using milk from cross bred goats (Saanen×Alpina) fed diets enriched with 4% vegetable oil (faveleira, sesame or castor), the fatty acid profile of cheeses was studied. Supplementation with vegetable oils did not increase the total fat percentage of the cheese (p?0.05) but did increase the percentage of CLA isomers, long-chain fatty acids (LCFA) and polyunsaturated fatty acids (PUFA); in addition, the index of desirable fatty acids (DFA--expressed as the sum of unsaturated fatty acids plus stearic acid) was increased for cheese made from milk from goats fed sesame or faveleira oil. Cheeses may have had increased percentages of cis-9,trans-11-CLA due to the supplementation of animal diets with vegetable oils rich in C18:2, such as faveleira and sesame oils. The fatty acid profile of goat cheese did not change significantly in response to the use of castor oil. Thus, the addition of sesame and faveleira oils to goat diets positively altered the fatty acid profile, which improved the nutritional characteristics of the fat present in goat cheese
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