6,755 research outputs found
Ovinos Santa Inês: estado de arte e perspectivas.
[Santa Inês hair sheep: state of art and perspectives]. Abstract: The Santa Inês hair sheep breed is found in whole to areas of Brazil. Its origin has been object of vary speculations. However, the most probable could be traced starting from combinations of four genetic sources: a) Criuola is wool type of sheep, brought by Portuguese and Spanish settlers, but that eliminated the wool under tropical conditions was; b) Hair sheep breeds originating from of the African continent, which originated most of the hair sheep breeds from Brazil, Central America and Caribbean; c) Bergamácia sheep breed from Italian, which was crossed with the remaining sheep of those originating from of the African continent, and Morada Nova, followed by adaptation, selection and evolution for absence of wool; d) finally, in the end of the decade of 80, a small group of the breeders added to Santa Inês the Somalis and Suffolk breeds. The breed presents good reproductive, adaptability and growth potential. The pattern of the coat calor includes the white, the red, the black and the mailed. In field conditions the ewes reach weights of 40-60 kg and the males can reach up to 120 kg. The selection practiced in the breed has been done in direction for size and body weight, absence of wool and horns and, presence of an intense pigmentation. The females present good maternal ability and they get easily to give birth vigorous lambs. The age to the puberty and first lambing, lambing interval, fertility, the prolificacy and the survival rate from weaning found in the literature, vary from: 274 to 376 days, 442 to 551 days, 227 to 307 days, 83,6 to 93%, 1,1 to 1,4 and, from 69 to 87%, respectively. The Santa Inês lamb can reach 23-32 kg at weaning and gain 166 -336 kg. At slaughter, Santa Inês Lamb, had dressing percentage of approximately 48,0 %. The animals generally demonstrate capacity to develop a strong answer immunology against the nematodes gastrontestinais, even before of the weaning. That skin presents great market value, due to the high quality pattern, resultant of its largest elasticity and excellent flexibility, and great resistance, associated to a fine texture, being rendered for use in several manufactured products. In spite of the few studies involving the face Santa Inês the breed has been demonstrating to be an excellent alternative to increase the production of meat in the main areas of the country, considering its reproductive capacity, resistance sponges it gastrontestinais, skin quality and adaptability , besides good growth rate
Negative Energy Densities in Extended Sources Generating Closed Timelike Curves in General Relativity with and without Torsion
Near a spinning point particle in (2+1)-dimensional gravity (or near an
infinitely thin, straight, spinning string in 3+1 dimensions) there is a region
of space-time with closed timelike curves. Exact solutions for extended sources
with apparently physically acceptable energy-momentum tensors, have produced
the same exterior space-time structure. Here it is pointed out that in the case
with torsion, closed timelike curves appear only for spin densities so high
that the spin energy density is higher than the net effective energy density.
In models without torsion, the presence of closed time-like curves is related
to a heat flow of unphysical magnitude. This corroborates earlier arguments
against the possibility of closed timelike curves in space-time geometries
generated by physical sources.Comment: (to be published in Phys. Rev. D), 5 pages, REVTEX 3.0, NORDITA 93/62
A (Sept. 10/Revised Nov. 1, 1993
Factors affecting fertility of cattle and buffaloes in tropical environments.
The present artic1e summarizes the main aspects concerning the reproductive problems. related to milk and beef cattle as well as with buffaloes raised in the tropical areas of the world. Specific aspects which cause a low reproduction due to the genetic or hereditary condition as well as combined to the management and environrnental factors like heat stress, affecting mainly European breed originally from temperate climate areas, commonly introduced in the tropical areas, nutritional imbalances, reproductive diseases and other general systemic pathological condition which lead to sub-fertility, infertility or sterility and others constrains, were presented in practical form, pointing out the main problems which routinely, the Veterinary practitioner will find out in the tropical country conditions
Obtenção de híbridos de melão adaptados as condições da região Nordeste.
bitstream/CNPAT-2010/11937/1/Pa-042.pd
Melhoramento populacional do meloeiro para cultivo na Região Nordeste.
Este trabalho objetiva desenvolver e melhorar geneticamente populacoes de melao para os tipos de frutos rendilhado e amarelo, e adapta-las ao cultivo nas condicoes do Nordeste.bitstream/CNPAT-2010/5408/1/Pa-043.pd
Scalar-pseudoscalar meson behavior and restoration of symmetries in SU(3) PNJL model
The modification of mesonic observables in a hot medium is analyzed as a tool
to investigate the restoration of chiral and axial symmetries in the context of
the Polyakov-loop extended Nambu--Jona-Lasinio model. The results of the
extended model lead to the conclusion that the effects of the Polyakov loop are
fundamental for reproducing lattice findings. In particular, the partial
restoration of the chiral symmetry is faster in the PNJL model than in the NJL
one, and it is responsible for several effects: the meson-quark coupling
constants show a remarkable difference in both models, there is a faster
tendency to recover the Okubo-Zweig-Iizuka rule, and finally the topological
susceptibility nicely reproduces the lattice results around .Comment: 23 pages, 5 figures, PRD versio
Caracterização físico-química e funcional de diferentes genótipos de camu-camu (Myrciaria dubia (H.B.K.) Mc Vaugh).
O camu-camu é um fruto nativo da região Amazônica, sendo reconhecido como uma das maiores fontes de vitamina C na atualidade. Além dessa excepcional característica, apresenta em sua composição compostos bioativos que fazem deste fruto uma matéria-prima potencial para a indústria de alimentos. A Embrapa Amazônia Oriental possui um Banco Ativo de Germoplasma de camu-camu e a identificação de genótipos quanto às características físico-químicas e funcionais é importante no apoio ao melhoramento genético da espécie. Neste estudo, avaliaram-se oito genótipos (polpa e casca separadamente), sendo que dois foram ainda submetidos a um processamento, onde a casca foi incorporada a polpa. Os resultados quanto à caracterização físico-química mostraram que os genótipos indicaram médias de sólidos solúveis de 6,76 a 9,96ºBrix e pH de 2,53 a 3,13, caracterizando a forte acidez dos frutos (teores entre 2,13 a 3,24%). Quanto aos compostos bioativos, observou-se na polpa teores de vitamina C entre 11,73 a 36,17 g/100g e antocianinas totais de 12,66 a 131,64 mg/100g. A casca do camu-camu concentra a maior parte das antocianinas do fruto, com teores variando entre 16,07 a 174,74 mg/100g. Observou-se diferença significativa (Tukey p≤0,05) entre a maioria dos genótipos estudados e que o processamento proporcionou um aumento de antocianinas na polpa. Dessa forma, conclui-se que identificação de genótipos é importante para o lançamento de cultivares em potencial
Efeito materno sobre a curva de crescimento de ovinos Santa Inês por meio de modelos de regressão aleatória.
Utilizaram-se 17.767 registros de pesos de 4.210 cordeiros da raça Santa Inês com o objetivo de avaliar a importância da inclusão do efeito materno nos modelos de estimação de componentes de (Co) variância e parâmetros genéticos resultantes para a curva de crescimento, por meio de modelos de regressão aleatória. As regressões fixas e aleatórias foram ajustadas por meio de polinômios de Legendre de ordem três, testando-se quatro modelos que diferiram quanto à inclusão dos efeitos genético aditivo materno e ambiente permanente materno. Observou-se considerável aumento no Log L e diminuição nos critérios AIC e BIC quando se adicionou o efeito materno (genético ou ambiente permanente), evidenciando sua importância. O efeito genético materno explicou maior proporção da variância fenotípica que o ambiente permanente materno ao longo da curva de crescimento. A variância genética aditiva direta estimada foi inflacionada pelo efeito materno, quando este não foi incluído no modelo de análise, refletindo o mesmo comportamento nas herdabilidades. O efeito de ambiente permanente materno contribuiu para a variância materna, como também, inflacionou variância genética materna, quando não foi considerado no modelo. Comportamento semelhantemente foi verificado com a herdabilidade materna. As correlações entre pesos nas diferentes idades estimadas pelos quatro modelos praticamente não diferiram em função da modelagem do efeito materno. O efeito materno deve ser considerado nos estudos genéticos da curva de crescimento da população em estudo. Maternal effect or growth curve of Santa Inês sheep by random regression models. Abstract - Data set of 17.767 weight records of 4.210 Santa Inês lambs were used aiming to evaluate the importance of the inclusion of the maternal effect in the model to estimate components of (Co) variance and resulting genetic parameters for the growth curve through random regression models. The fixed and random regressions were fitted using Legendre Polynomials of order three, being fit four models that differed in relation to the inclusion of the additive genetic and permanent environmental maternal effects. Considerable increase was observed in Log L and decrease in the criteria AIC and BIC when the maternal effect was included (genetic or permanent environmental), evidencing its importance. The maternal genetic effect explained larger proportion of the phenotypic variance than the maternal permanent environmental along the growth curve. The direct additive genetic variance was inflated by maternal effect, when this last one was not considered in the analysis model, reflecting the same behavior in the heritabilities. The maternal permanent environmental effect contributed to maternal variance, as well as, it inflated maternal genetic variance, when it was not considered in the model. Similar behavior was verified with maternal heritability. The correlation estimated for the four models hardly differed in function of maternal effect. The maternal effect should be considered in the genetic studies of the growth curve of Santa Inês sheep
Sounding stellar cycles with Kepler - II. Ground-based observations
We have monitored 20 Sun-like stars in the Kepler field-of-view for excess
flux with the FIES spectrograph on the Nordic Optical Telescope since the
launch of Kepler spacecraft in 2009. These 20 stars were selected based on
their asteroseismic properties to sample the parameter space (effective
temperature, surface gravity, activity level etc.) around the Sun. Though the
ultimate goal is to improve stellar dynamo models, we focus the present paper
on the combination of space-based and ground-based observations can be used to
test the age-rotation-activity relations.
In this paper we describe the considerations behind the selection of these 20
Sun-like stars and present an initial asteroseismic analysis, which includes
stellar age estimates. We also describe the observations from the Nordic
Optical Telescope and present mean values of measured excess fluxes. These
measurements are combined with estimates of the rotation periods obtained from
a simple analysis of the modulation in photometric observations from Kepler
caused by starspots, and asteroseismic determinations of stellar ages, to test
relations between between age, rotation and activity.Comment: Accepted for publication in MNRA
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