4,243 research outputs found
Capybara (Hydrochoerus hydrochaeris) distribution in agroecosystems: a cross-scale habitat analysis.
Chirikov Diffusion in the Asteroidal Three-Body Resonance (5,-2,-2)
The theory of diffusion in many-dimensional Hamiltonian system is applied to
asteroidal dynamics. The general formulations developed by Chirikov is applied
to the Nesvorn\'{y}-Morbidelli analytic model of three-body (three-orbit)
mean-motion resonances (Jupiter-Saturn-asteroid system). In particular, we
investigate the diffusion \emph{along} and \emph{across} the separatrices of
the (5,-2,-2) resonance of the (490) Veritas asteroidal family and their
relationship to diffusion in semi-major axis and eccentricity. The estimations
of diffusion were obtained using the Melnikov integral, a Hadjidemetriou-type
sympletic map and numerical integrations for times up to years.Comment: 27 pages, 6 figure
Synchronization in Von Bertalanffy’s models
Many data have been useful to describe the growth of marine mammals, invertebrates and reptiles, seabirds, sea turtles and fishes, using the logistic, the Gom-pertz and von Bertalanffy's growth models. A generalized family of von Bertalanffy's maps, which is proportional to the right hand side of von Bertalanffy's growth equation, is studied and its dynamical approach is proposed. The system complexity is measured using Lyapunov exponents, which depend on two biological parameters: von Bertalanffy's growth rate constant and the asymptotic weight.
Applications of synchronization in real world is of current interest. The behavior of birds ocks, schools of fish and other animals is an important phenomenon characterized by synchronized motion of individuals. In this work, we consider networks having in each node a von Bertalanffy's model and we study the synchronization interval of these networks, as a function of those two biological parameters. Numerical simulation are also presented to support our approaches
Phenotypic plasticity of composite beef cattle performance using reaction norms model with unknown covariate.
The objective of the present study was to determine the presence of genotype by environment interaction (G × E) and to characterize the phenotypic plasticity of birth weight (BW), weaning weight (WW), postweaning weight gain (PWG) and yearling scrotal circumference (SC) in composite beef cattle using the reaction norms model with unknown covariate. The animals were born between 1995 and 2008 on 33 farms located throughout all Brazilian biomes between latitude −7° and −31°, longitude −40° and −63°. The contemporary group was chosen as the environmental descriptor, that is, the environmental covariate of the reaction norms. In general, higher estimates of direct heritability were observed in extreme favorable environments. The mean of direct heritability across the environmental gradient ranged from 0.05 to 0.51, 0.09 to 0.43, 0.01 to 0.43 and from 0.12 to 0.26 for BW, WW, PWG and SC, respectively. The variation in direct heritability observed indicates a different response to selection according to the environment in which the animals of the population are evaluated. The correlation between the level and slope of the reaction norm for BW and PWG was high, indicating that animals with higher average breeding values responded better to improvement in environmental conditions, a fact characterizing a scale of G × E. Low correlation between the intercept and slope was obtained for WW and SC, implying re-ranking of animals in different environments. Genetic variation exists in the sensitivity of animals to the environment, a fact that permits the selection of more plastic or robust genotypes in the population studied. Thus, the G × E is an important factor that should be considered in the genetic evaluation of the present population of composite beef cattle.Firstview article 27 set. 2012
Descriptive analysis of copy number variation regions in a population of dairy Gyr cattle.
The aim of this work was to investigate, based on a high density BovineHD SNP array, the abundance and distributions of CNVs and CNVR in a Gyr cattle population from Brazil. Genotype data of representative bulls were recorded, totaling 476 Gyr animals. For CNV identification was used the PennCNV software and the CNVRs were determined by the CNVRuler software. A total of 26,672 CNVs were found, beingon average 62 CNV per animal. Also, 1,898 CNVRs were detected on the autosomal chromosomes. Also, 1,898 CNVRs were detected on the autosomal chromosomes with 96% of these between 1.1 Kb to 100 Kb. The Ensembl's VEP tool, using the CNVRs information as input, found 913 coding regions, suggesting that exon regions were duplicated. In summary, the results help to better understand the Gyr genome and suggest that CNVRs might have some relationship with production traits.WCGALP 2014
Descriptive analysis of copy number variation regions in a population of dairy Gyr cattle.
The aim of this work was to investigate, based on a high density BovineHD SNP array, the abundance and distributions of CNVs and CNVR in a Gyr cattle population from Brazil. Genotype data of representative bulls were recorded, totaling 476 Gyr animals. For CNV identification was used the PennCNV software and the CNVRs were determined by the CNVRuler software. A total of 26,672 CNVs were found, beingon average 62 CNV per animal. Also, 1,898 CNVRs were detected on the autosomal chromosomes. Also, 1,898 CNVRs were detected on the autosomal chromosomes with 96% of these between 1.1 Kb to 100 Kb. The Ensembl's VEP tool, using the CNVRs information as input, found 913 coding regions, suggesting that exon regions were duplicated. In summary, the results help to better understand the Gyr genome and suggest that CNVRs might have some relationship with production traits
Exact integral equation for the renormalized Fermi surface
The true Fermi surface of a fermionic many-body system can be viewed as a
fixed point manifold of the renormalization group (RG). Within the framework of
the exact functional RG we show that the fixed point condition implies an exact
integral equation for the counterterm which is needed for a self-consistent
calculation of the Fermi surface. In the simplest approximation, our integral
equation reduces to the self-consistent Hartree-Fock equation for the
counterterm.Comment: 5 pages, 1 figur
Associação de polimorfismos no gene da u-calpaÃna com a maciez da carne em animais da raça Nelore.
Os bovinos de origem Bos indicus são preferidos nos trópicos devido a sua maior resistência as adversidades ambientais. No entanto, estes animais não produzem carne tão macia quanto os taurinos. A seleção assistida por marcadores relacionados à maciez da carne, como é o caso da protease calpaÃna, pode auxiliar na melhoria da caracterÃstica. Nesse trabalho, foram utilizados 229 animais da raça Nelore. Após a extração do DNA de amostras de sangue, por desproteinização em presença de NaCl a identificação e determinação dos polimorfismos para três marcadores (CAPN316, CAPN530 e CAPN4751) foi realizada pelo sistema de detecção TaqManTM utilizando-se PCR em Tempo Real. A análise de maciez da carne, aos 7, 14 e 21 dias de maturação, foi realizada com amostras de carne do Longissimus dorsi, retiradas entre a 12a e 13ª costela e cisalhadas utilizando-se um Warner Braztler Shear Force. Os polimorfismos dos marcadores CAPN316 e CAPN530 não apresentaram efeitos significativos (P>0,05) para a maciez da carne aos 7, 14 e 21 dias de maturação. Foram verificados efeitos significativos para os polimorfismos do CAPN4751 em relação à maciez da carne aos 7 (P=0.001), 14 (P=0.005) e 21 (P=0.006) dias de maturação
Ação de prolil-leucil-gliclnamida (PLG) na via nigroestriatal do rato
In order to study the nigrostriatal pathway, we obtained the rotatory behavior model in male Wistar rats by electrolytic lesion of the left lateral hypothalamic region. Animals thus lesioned displayed rotations toward the same side of lesion when apomorphine was administered, a result in disagreement with what has been obtained in the model with 6-hydroxydopamine lesion. The administration of PLG alone was not followed by rotatory behavior but when the compound was administered in low doses (0.25 to 1mg/kg) simultaneously with apomorphine to animals previously submitted to REM sleep deprivation, a significant increase in the number of rotations was observed in comparison with controls and groups receiving higher doses of PLG. These results indicate that PLG may act as, a modulator on dopamine receptors in the striatum.No intuito de estudar a via nigroestriatal, produzimos uma lesão na região hipotalâmica lateral de ratos Wistar. Os animais passavam a apresentar comportamento rotatório para o mesmo lado da lesão. A administração isolada do PLG não induziu o comportamento rotatório. Entretanto, com doses baixas do composto, concomitantemente à administração de apomorfina em animais previamente submetidos à privação de sono REM, observou-se aumento no número de rotações auando comparado ao grupo controle e aos grupos aue receberam doses altas de PLG. Estes achados sugerem que o PLG age como um modulador sobre os receptores dopaminérgicos do estriado.Escola Paulista de Medicina Department of Neurology and Neurosurgery Division of Extrapyramidal Diseases InvestigationEscola Paulista de Medicina Department of Neurology and Neurosurgery Head of the Division - Division of Extrapyramidal Diseases InvestigationUNIFESP, EPM, Department of Neurology and Neurosurgery Division of Extrapyramidal Diseases InvestigationEscola Paulista de Medicina Department of Neurology and Neurosurgery Head of the Division - Division of Extrapyramidal Diseases InvestigationSciEL
Tidal evolution of exo-planetary systems: WASP-50, GJ 1214 and CoRoT-7
We perform numerical simulations to investigate tidal evolution of two
single-planet systems, that is, WASP-50 and GJ 1214 and a two-planet system
CoRoT-7. The results of orbital evolution show that tidal decay and
circularization may play a significant role in shaping their final orbits,
which is related to the initial orbital data in the simulations. For GJ 1214
system, different cases of initial eccentricity are also considered as only an
upper limit of its eccentricity (0.27) is shown, and the outcome suggests a
possible maximum initial eccentricity (0.4) in the adopted dynamical model.
Moreover, additional runs with alternative values of dissipation factor
are carried out to explore tidal evolution for GJ 1214b, and these
results further indicate that the real of GJ 1214b may be much
larger than its typical value, which may reasonably suggest that GJ 1214b bears
a present-day larger eccentricity, undergoing tidal circularization at a slow
rate. For the CoRoT-7 system, tidal forces make two planets migrating towards
their host star as well as producing tidal circularization, and in this process
tidal effects and mutual gravitational interactions are coupled with each
other. Various scenarios of the initial eccentricity of the outer planet have
also been done to investigate final planetary configuration. Tidal decay
arising from stellar tides may still work for each system as the eccentricity
decreases to zero, and this is in association with the remaining lifetime of
each planet used to predict its future.Comment: 9 pages, 12 figures, accepted for publication in "SCIENCE CHINA
Physics,Mechanics & Astronomy
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