48 research outputs found
Giant fluctuations of topological charge in a disordered wave guide
We study the fluctuations of the total topological charge of a scalar wave
propagating in a hollow conducting wave guide filled with scatterers inside. We
investigate the dependence of the screening on the scattering mean free path
and on the presence of boundaries. Near the cut-off frequencies of the wave
guide, screening is strongly suppressed near the boundaries. The resulting huge
fluctuations of the total topological charge are very sensitive to the
disorder.Comment: 8 pages 5 figures, submitted to Waves in Random and Complex Medi
Phase statistics of seismic coda waves
We report the analysis of the statistics of the phase fluctuations in the
coda of earthquakes recorded during a temporary experiment deployed at Pinyon
Flats Observatory, California. The practical measurement of the phase is
discussed and the main pitfalls are underlined. For large values, the
experimental distributions of the phase first, second and third derivatives
obey universal power-law decays whose exponents are remarkably well predicted
by circular Gaussian statistics. For small values, these distributions are
flat. The details of the transition between the plateau and the power-law
behavior are governed by the wavelength. The correlation function of the first
phase derivative along the array shows a simple algebro-exponential decay with
the mean free path as the only length scale. Although only loose bounds are
provided in this study, our work suggests a new method to estimate the degree
of heterogeneity of the crComment: 4 figures, submitted to Physical Review Letter
Mesoscopic phase statistics of diffuse ultrasound in dynamic matter
Temporal fluctuations in the phase of waves transmitted through a dynamic,
strongly scattering, mesoscopic sample are investigated using ultrasonic waves,
and compared with theoretical predictions based on circular Gaussian
statistics. The fundamental role of phase in Diffusing Acoustic Wave
Spectroscopy is revealed, and phase statistics are also shown to provide a
sensitive and accurate way to probe scatterer motions at both short and long
time scales.Comment: 4 pages, 4 figures, submitted to Physical Review Letter
Estrus identification methods as an alternative to optimize IATF results.
The objective of the present study was to compare the efficacy of different techniques for detection of estrus in Nellore cows submitted to FTAI protocols and their relationships with fertility
Hydrological trade-offs due to different land covers and land uses in the Brazilian Cerrado
Farmland expansion in the Brazilian Cerrado, considered one of the largest
agricultural frontiers in the world, has the potential to alter water fluxes
on different spatial scales. Despite some large-scale studies being
developed, there are still few investigations in experimental sites in this
region. Here, we investigate the water balance components in experimental
plots and the groundwater table fluctuation in different land covers: wooded
Cerrado, sugarcane, pasture and bare soil. Furthermore, we identify possible
water balance trade-offs due to the different land covers. This study was
developed between 2012 and 2016 in the central region of the state of São
Paulo in southern Brazil. Hydrometeorological variables, groundwater table,
surface runoff and other water balance components were monitored inside
experimental plots containing different land covers; the datasets were
analyzed using statistical parameters; and the water balance components
uncertainties were computed. Replacing wooded Cerrado by pastureland and
sugarcane shifts the overland flow (up to 42 mm yr−1) and the water
balance residual (up to 504 mm yr−1) and may affect groundwater table
behavior. This fact suggests significant changes in the water partitioning in
a transient land cover and land use (LCLU) system, as the evapotranspiration
is lower (up to 719 mm yr−1) in agricultural land covers than in the
undisturbed Cerrado. We recommend long-term observations for continuing the
evaluations initiated in this study, mainly because there are few basic studies on tropical environments
at the hillslope scale and more assessments are needed
for a better understanding of the real field conditions. Such efforts should
be made to reduce uncertainties, validate the water balance hypothesis and
catch the variability of hydrological processes.</p
Suplementação com gordura protegida na produção de leite de búfalas Murrah (Bubalus bubalis): resultados preliminares.
Objetivou-se avaliar o efeito da suplementação com gordura protegida na produção de leite de búfalas Murrah.Na publicação: MELO-STERZA, F. A
Embryos produced in vitro with sexed semen - technique application for superior beef calves production.
Due the relevance of the Zebu and the increasing use of production in vitro (PIV) of embryo in Brazil, we evaluated the pregnancy rates of Nelore recipients inovulated with fresh or vitrified IVP embryos obtained from Nelore donor oocytes from slaughterhouse (SLAUGHTER, n = 66 embryos) or OPU in vivo (VIVO, n = 299 embryos).Proceedings of the 30th Annual Meeting of the Brazilian Embryo Technology Society (SBTE); Foz do Iguaçu, PR, Brazil, August 25th to 27th, 2016, and 32nd Meeting of the European Embryo Transfer Association (AETE); Barcelona, Spain, September 9th and 10th, 2016. A040. Título em português: Utilização de embriões produzidos in vitro com sêmen sexado ? aplicação da técnica para produção de bezerros de corte superiores. Na publicação: Juliana Correa Borges
GnRH application in cows with low or no estrus expression evaluated with tail-chalk increases the pregnancy rate in beef cows submitted to TAI.
The objective was to evaluate the GnRH application in cows with low or poor estrus expression evaluated using tail chalk removal Score (ESCT) to increase TAI pregnancy rates.Proceedings of the 30th Annual Meeting of the Brazilian Embryo Technology Society (SBTE); Foz do Iguaçu, PR, Brazil, August 25th to 27th, 2016, and 32nd Meeting of the European Embryo Transfer Association (AETE); Barcelona, Spain, September 9th and 10th, 2016. A083. Título em português: Aplicação de GnRh em vacas com baixa ou sem expressão de estro avaliadas com bastões marcadores aumenta a taxa de prenhez em vacas de corte submetidas a IATF. Na publicação: Juliana Correa Borges
Effects of narasin on the pregnancy rate of Nellore cows maintained under grazing and performance of calves - preliminary results.
Ionophores have been used to improve forage conversion in animal protein and to increase nutrient utilization efficiency in cattle. The effects of the mineral mix (MM) with addition of narasin (Zimprova®; Elanco, Brazil) on the performance of calves and pregnancy rate of Nellore cows were evaluated.Edição dos Proceedings of the 32nd Annual Meeting of the Brazilian Embryo Technology Society (SBTE)