1,102 research outputs found
Estimulação Térmica Dos EmbriÔes Da Linhagem RossŸ Em Escala Comercial
Artificial incubation is an essential process to obtain healthy birds with good performance; nevertheless, it requires sustained improvement. During this process, incubation temperature is considered a critical factor, which has been studied. The objective of this study was to evaluate the development of RossÂź embryos after hot and cold thermal stimulation. To this end, temperatures 1.39ÂșC above the standard temperature and a temperature fixed at 36.00ÂșC that varied 1.00 to 0.30ÂșC below the standard temperature were applied during the final embryonic development period (days 14 to 18) for three hours, on a commercial scale. Results revealed that hot and cold thermal stimulations did not cause embryo mortality; the hatching and chick quality index were maintained and even increased. Therefore, we believe that thermal stimulation has the potential to improve hatchery index, and thus grange performance; however, adjustments are needed, varying according to each individual hatchery, before it can used as a protocol. © 2016, Universidade Federal de Santa Maria. All rights reserved.4691668167
Classes of exact wavefunctions for general time-dependent Dirac Hamiltonians in 1+1 dimensions
In this work we construct two classes of exact solutions for the most general
time-dependent Dirac Hamiltonian in 1+1 dimensions. Some problems regarding to
some formal solutions in the literature are discussed. Finally the existence of
a generalized Lewis-Riesenfeld invariant connected with such solutions is
discussed
Erratum To: Quality Of Sweat Test (st) Based On The Proportion Of Sweat Sodium (na) And Sweat Chloride (cl) As Diagnostic Parameter Of Cystic Fibrosis: Are We On The Right Way?
During production of the original article [1] the Methods section included an incorrect sentence. The following sentence "For the analysis of variables with numerical distribution, Fisher's exact test and one-way analysis of variance were used" should be corrected as "For the analysis of variables with numerical distribution, Student's t-test and one-way analysis of variance were used". © The Author(s).12
Body condition score, weight variation and reproductive performance of beef cows in rangelands from the Pantanal region
Objetivou-se avaliar a influĂȘncia do escore de condição corporal (ECC) sobre a eficiĂȘncia reprodutiva de vacas de cria nos perĂodos prĂ© e pĂłs-parto e a probabilidade de parição, usando o escore de condição corporal e a variação ponderal no perĂodo crĂtico do ciclo reprodutivo. Utilizaram-se 248 vacas multĂparas mantidas em pastagens nativas distribuĂdas em quatro estratĂ©gias de suplementação: mistura mineral (controle); suplemento farelado; suplemento lĂquido; suplemento lĂquido para vacas e bezerros. As avaliaçÔes de peso e ECC, na escala de 1 a 9, foram realizadas no perĂodo crĂtico: em agosto (perĂodo prĂ©-parto, 60-90 dias antes da parição) e em janeiro (perĂodo pĂłs-parto e reprodutivo) durante quatro anos consecutivos. Para a anĂĄlise dos anos consecutivos de reprodução, criou-se um escore de reprodução, ou seja, somou-se o nĂșmero de pariçÔes de cada vaca durante os quatro anos pecuĂĄrios avaliados. O escore de condição corporal nos perĂodos prĂ© e pĂłs-parto e a idade da vaca influenciaram o escore de reprodução. Portanto, para avaliação da probabilidade de parição, foram utilizadas todas as vacas, classificadas em paridas e vazias. Utilizando equaçÔes de estimação generalizadas (EEG), foi modelada a probabilidade de as matrizes serem classificadas como paridas considerando variĂĄveis exploratĂłrias ao longo do tempo. Para se obter probabilidade de parição superior a 80%, as vacas devem possuir escore de aproximadamente 5,5 no perĂodo prĂ©-parto. Aproximadamente 60% das vacas paridas mantiveram ou ganharam peso no perĂodo crĂtico do ano, o que levou a maior probabilidade de reconcepção, similar ao observado para as vacas vazias, porĂ©m com probabilidade menor de parição. O perĂodo prĂ©-parto Ă© o melhor para estimar a probabilidade de parição das vacas por meio da avaliação do escore corporal. A seleção de vacas adaptadas Ă s condiçÔes bioclimĂĄticas do Pantanal aumenta a probabilidade de produção de um bezerro por vaca por ano. _________________________________________________________________________________ ABSTRACTThe aim of this study was to evaluate the influence of body condition score (BCS) on reproductive performance of beef cows before and after calving and to evaluate the calving probability using body condition score and weight variation during critical periods of the cow reproductive cycle. From 2001 to 2005, the body condition score was recorded in 248 multiparous cows raised in native pastures, submitted to different supplementation treatments (mineral mixture only - control; dry supplement; liquid supplement and liquid supplement for cow and calves). Weighing and body condition evaluation were made on a 1-9 point scale in August (prepartum period, 60-90 days before parturition) and January (postpartum and reproductive period). A reproduction score was created in function of the body scores in four consecutive years. Except for the treatment, the other factors (body condition score in the prepartum and postpartum periods and cow age) influenced the reproduction score. Thus, the calving probabilities were estimated for all cows. Generalized estimating equations (GEE) were used to evaluate the calving probability in function of the exploratory variables over time. Calving probability higher than 80% was obtained when cows scored 5,5 before calving. In relation to weight, the results showed that about 60% of calving cows maintained or gained weight in the postpartum period, leading to increase in the rebreeding probability. Similar situation occurred with single cows; however, the calving probability was lower. These results indicate that the calving probability using BCS is better estimated before calving. Furthermore, it indicates the presence of cows more adapted to the Pantanal climatic and feeding conditions than others
Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum
We report a first measurement for ultra-high energy cosmic rays of the
correlation between the depth of shower maximum and the signal in the water
Cherenkov stations of air-showers registered simultaneously by the fluorescence
and the surface detectors of the Pierre Auger Observatory. Such a correlation
measurement is a unique feature of a hybrid air-shower observatory with
sensitivity to both the electromagnetic and muonic components. It allows an
accurate determination of the spread of primary masses in the cosmic-ray flux.
Up till now, constraints on the spread of primary masses have been dominated by
systematic uncertainties. The present correlation measurement is not affected
by systematics in the measurement of the depth of shower maximum or the signal
in the water Cherenkov stations. The analysis relies on general characteristics
of air showers and is thus robust also with respect to uncertainties in
hadronic event generators. The observed correlation in the energy range around
the `ankle' at differs significantly from
expectations for pure primary cosmic-ray compositions. A light composition made
up of proton and helium only is equally inconsistent with observations. The
data are explained well by a mixed composition including nuclei with mass . Scenarios such as the proton dip model, with almost pure compositions, are
thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray
flux at Earth.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
flavour tagging using charm decays at the LHCb experiment
An algorithm is described for tagging the flavour content at production of
neutral mesons in the LHCb experiment. The algorithm exploits the
correlation of the flavour of a meson with the charge of a reconstructed
secondary charm hadron from the decay of the other hadron produced in the
proton-proton collision. Charm hadron candidates are identified in a number of
fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is
calibrated on the self-tagged decay modes and using of data collected by the LHCb
experiment at centre-of-mass energies of and
. Its tagging power on these samples of
decays is .Comment: All figures and tables, along with any supplementary material and
additional information, are available at
http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm
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