362 research outputs found
Estimates of genetic parameters of distal limb fracture and superficial digital flexor tendon injury in UK Thoroughbred racehorses
A retrospective cohort study of distal limb fracture and superficial digital flexor tendon (SDFT) injury in Thoroughbred racehorses was conducted using health records generated by the British Horseracing Authority (BHA) between 2000 and 2010. After excluding records of horses that had both flat and jump racing starts, repeated records were reduced to a single binary record per horse (<i>n</i> = 66,507, 2982 sires), and the heritability of each condition was estimated using residual maximum likelihood (REML) with animal logistic regression models. Similarly, the heritability of each condition was estimated for the flat racing and jump racing populations separately. Bivariate mixed models were used to generate estimates of genetic correlations between SDFT injury and distal limb fracture.
The heritability of distal limb fracture ranged from 0.21 to 0.37. The heritability of SDFT injury ranged from 0.31 to 0.34. SDFT injury and distal limb fracture were positively genetically correlated. These findings suggest that reductions in the risk of the conditions studied could be attempted using targeted breeding strategies
Evaluación de capturas de Homarus gammarus (Crustacea: Decapoda: Nephropidae) y potencial en pesquerÃas mediterráneas artesanales
The aim of this study was to obtain a better understanding of the exploitation pattern of the European lobster population in a fully representative small-scale fishery of the Mediterranean (Corsica, France) and to collect initial biological information on this species. Data were collected by scientific observers on board net fishing vessels for eight consecutive years from 2006 until 2013. Average annual catches were estimated at 6.7 t. Length frequencies indicated that exploitation focused on large individuals. Catch per unit of effort varied significantly as a function of month, fishing area and depth. Our approach to catch distribution revealed spatial heterogeneity with large catches in the south area. A fishery-independent survey was performed in 2013 and 2014 in west Cap Corse using 540 lobster traps; it showed an extremely low catch rate, confirming the low abundance for this area. This study provided new biological knowledge of a little-studied species in the Mediterranean.El objetivo de este estudio fue el de obtener una mejor comprensión del patrón de explotación y colectar datos iniciales de las poblaciones de bogavante europeo en una pesquera artesanal representativa del Mediterráneo (Córcega, Francia). Los datos fueron colectados por observadores cientÃficos a bordo de embarcaciones de pesca durante 8 años consecutivos, de 2006 a 2013. Las capturas anuales fueron estimadas a 6,7 toneladas. La frecuencia de las tallas indica que la explotación se concentra en los individuos de gran tamaño. La CPUE varÃa de manera significativa en función del mes, la zona de pesca y la profundidad. La distribución de las capturas revela que hay una heterogeneidad espacial, con capturas de gran tamaño en la zona sur. Un monitoreo pesquero independiente fue llevado a cabo durante 2013 y 2014 en Cap Corse occidental empleando 540 trampas; éste mostró una tasa de captura extremadamente baja, lo que confirma la escasez de bogavante europeo en esta área. Este estudio aportó nuevos conocimientos a la biologÃa de esta especie poco estudiada en el Mediterráneo
Deuteron Electroweak Disintegration
We study the deuteron electrodisintegration with inclusion of the neutral
currents focusing on the helicity asymmetry of the exclusive cross section in
coplanar geometry. We stress that a measurement of this asymmetry in the quasi
elastic region is of interest for an experimental determination of the weak
form factors of the nucleon, allowing one to obtain the parity violating
electron neutron asymmetry. Numerically, we consider the reaction at low
momentum transfer and discuss the sensitivity of the helicity asymmetry to the
strangeness radius and magnetic moment. The problems coming from the finite
angular acceptance of the spectrometers are also considered.Comment: 30 pages, Latex, 7 eps figures, submitted to Phys.Rev.C e-mail:
[email protected] , [email protected]
Best practice guidelines for environmental DNA biomonitoring in Australia and New Zealand
Environmental DNA (eDNA)- based methods are increasingly used by government agencies to detect pests and threatened species, and for broader biodiversity monitor-ing. Given rapid technological advances and a growing number of commercial service providers, there is a need to standardize methods for quality assurance and to main-tain confidence in eDNA- based results. Here, we introduce two documents to pro-vide best- practice guidelines for Australian and New Zealand eDNA researchers and end- users (available from https://sedna socie ty.com/publications ): the Environmental DNA protocol development guide for biomonitoring provides minimum standard consid-erations for eDNA and environmental RNA projects across the complete workflow, from ethical considerations and experimental design to interpreting and communicat-ing results. The Environmental DNA test validation guidelines outline key steps to be used in assay development and validation for species-specific testing and metabar-coding. Both guidelines were developed as an initiative of the Australian Government Department of Agriculture, Fisheries and Forestry and led by the Southern eDNA Society in a collaborative process including multiple consultation rounds with eDNA experts, end-users, and stakeholders to adapt the guidelines to Australian and New Zealand needs. The aim of these guidelines is not to be prescriptive, but to set mini-mum standards to support a consistent and best- practice approach to eDNA testing. We anticipate that the guidelines will be reviewed and regularly updated as required. Our aspiration is that these best- practice guidelines will ensure environmental man-agers are provided with robust scientific evidence to support decision- making
A-dependence of nuclear transparency in quasielastic A(e,e'p) at high Q^2
The A-dependence of the quasielastic A(e,e'p) reaction has been studied at
SLAC with H-2, C, Fe, and Au nuclei at momentum transfers Q^2 = 1, 3, 5, and
6.8 (GeV/c)^2. We extract the nuclear transparency T(A,Q^2), a measure of the
average probability that the struck proton escapes from the nucleus A without
interaction. Several calculations predict a significant increase in T with
momentum transfer, a phenomenon known as Color Transparency. No significant
rise within errors is seen for any of the nuclei studied.Comment: 5 pages incl. 2 figures, Caltech preprint OAP-73
The Proton Spin and Flavor Structure in the Chiral Quark Model
After a pedagogical review of the simple constituent quark model and deep
inelastic sum rules, we describe how a quark sea as produced by the emission of
internal Goldstone bosons by the valence quarks can account for the observed
features of proton spin and flavor structures. Some issues concerning the
strange quark content of the nucleon are also discussed.Comment: 59 pages with table of contents, Lecture delivered at the Schladming
Winter School (March 1997), to be published by Springer-Verlag under the
title "Computing Particle Properties" (eds. C. B. Lang and H. Gausterer
Measurement of the Neutron Spin Structure Function with a Polarized ^3He Target
Results are reported from the HERMES experiment at HERA on a measurement of
the neutron spin structure function in deep inelastic scattering
using 27.5 GeV longitudinally polarized positrons incident on a polarized
He internal gas target. The data cover the kinematic range
and . The integral evaluated at a fixed of is . Assuming Regge behavior at low , the first
moment is .Comment: 4 pages TEX, text available at
http://www.krl.caltech.edu/preprints/OAP.htm
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Momentum transfer dependence of nuclear transparency from the quasielastic 12C(e,e’p) reaction
The cross section for quasielastic 12C(e,e’p) scattering has been measured at momentum transfer Q2=1, 3, 5, and 6.8 (GeV/c)2. The results are consistent with scattering from a single nucleon as the dominant process. The nuclear transparency is obtained and compared with theoretical calculations that incorporate color transparency effects. No significant rise of the transparency with Q2 is observed
Two-Body Photodisintegration of the Deuteron up to 2.8 GeV
Measurements were performed for the photodisintegration cross section of the deuteron for photon energies from 1.6 to 2.8 GeV and center-of-mass angles from 37° to 90°. The measured energy dependence of the cross section at θc.m.=90° is in agreement with the constituent counting rules
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