Genetic parameters of spontaneous spring ovulatory activity in Mérinos d'Arles sheep

The genetic parameters of spontaneous spring ovulatory activity were investigated in the Mérinos d’Arles breed under the usual pastoral and transhumant management conditions of this breed in southeastern France. Ovulatory activity was determined by assaying the plasma progesterone concentration in two blood samples taken 8-10 days apart. The data set consisted of 1 887 ovulatory activity performance measurements in 1995, 1996 and 1997 on 933 ewes, daughters of 176 rams. The effects of the ’physiological status’ (hoggets, adult ewes with or without lambing in the previous autumn), age and live weight just before the mating period were found to be highly significant. They were included in the linear animal model and the threshold sire model used to estimate genetic parameters. On average, 27.9 % of ewes exhibited ovulatory activity in April. Age and live weight just before the mating period had a marked positive effect on ovulatory activity. A difference of about 8-9 % was observed between extreme classes for these factors. The heritability and repeatability estimated through the linear model were 0.20 (standard error: 0.04) and 0.30 (0.07), respectively. When using the threshold model, the heritability was 0.37. These values led us to conclude that a genetic approach for improving spontaneous spring ovulatory activity should be further developed. Nevertheless, further studies are necessary to determine all the implications of such selection.Les paramètres génétiques de l’activité ovulatoire spontanée au printemps ont été estimés en race Mérinos d’Arles dans le système d’élevage pastoral traditionnel (transhumance estivale) du sud-est de la France. Le dosage de la progestérone plasmatique dans deux prélèvements sanguins effectués à 8-10 j d’intervalle a permis de déterminer l’activité ovulatoire des brebis. 1887 performances d’activité ovulatoire ont été enregistrées en 1995, 1996 et 1997, sur 933 brebis issues de 176 béliers. Le «statut physiologique » (antenaises, brebis adultes avec ou sans mise bas à l’automne précédent), l’âge et le poids au moment de la lutte des brebis ont des effets très significatifs sur l’activité ovulatoire. Ils ont été pris en compte dans le modèle animal linéaire et le modèle père à seuil utilisés pour estimer les paramètres génétiques. En moyenne, 27,9 % des brebis présentaient une activité ovulatoire en avril. L’âge et le poids au moment de la lutte ont un net effet positif sur l’activité ovulatoire. Une différence de 8-9 % a été observée entre les classes extrêmes pour ces facteurs. L’héritabilité et la répétabilité estimées avec le modèle linéaire sont de 0,20 (erreur standard : 0,04) et de 0,30 (0,07), respectivement. L’héritabilité calculée avec le modèle à seuil est de 0,37. En conclusion, compte tenu de ces valeurs, l’approche génétique visant à améliorer l’activité ovulatoire spontanée au printemps mérite d’être poursuivie. Néanmoins, d’autres études sont nécessaires pour connaître toutes les implications que supposent une telle sélection

Soft gamma-ray background and light Dark Matter annihilation

The bulk of the extragalactic background between 10 keV and 10 GeV is likely to be explained by the emission of Seyfert galaxies, type Ia supernovae, and blazars. However, as revealed by the INTEGRAL satellite, the bulge of our galaxy is an intense source of a 511 keV gamma-ray line, indicating the production of a large number of positrons that annihilate. The origin of the latter is debated, and they could be produced, in particular, by the (S- or P-wave) annihilation of light Dark Matter particles into e+e-. In any case, the cumulated effect of similar sources at all redshifts could lead to a new background of hard X-ray and soft gamma-ray photons. On the basis of the hierarchical model of galaxy formation, we compute analytically the SNIa contribution to the background, and add it to Seyfert and blazars emission models. We find that any extra contribution to this unresolved background at 511 keV should be lower than about 4 keV/cm^2/s/sr. We also estimate analytically the extragalactic background due to Dark Matter annihilation, increasing the accuracy of the earlier computations. Indeed, we take into account the large positron escape fraction from low mass dark matter halos, unable to confine a dense and magnetized interstellar medium. Our new background estimate turns out to be one order of magnitude lower, so that the hypothesis of a light Dark Matter candidate remains compatible with the observed extragalactic background for a wider range of particle masses and cross-sections.Comment: 10 pages, 8 figures, 1 table, accepted for publication in Physical Review D, improved with 4 new figures, 1 new table and 1 new par

The water regime of dwarf planet (1) Ceres

The traditional view of minor bodies in the (inner) Solar System is that they are split into icy comets and rocky asteroids. However this has been challenged by recent results, such as the discovery of comets on asteroidal orbits in the outer asteroid belt (between Mars and Jupiter) and the detection of water ice frost on the surface of asteroid (24) Themis. The discovery of water ice on the surface of asteroids has profound implications for how the Solar System formed, and challenges our ideas about the stability of ice in the inner Solar System. The study of volatiles in the asteroid belt places strong constraints on the temperature and composition distribution in the proto-planetary disk,and on possible sources of terrestrial water, and strongly constrains formation models of the early Solar System

First isolation of two colistin-resistant emerging pathogens, Brevundimonas diminuta and Ochrobactrum anthropi, in a woman with cystic fibrosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Cystic fibrosis afflicted lungs support the growth of many bacteria rarely implicated in other cases of human infections.</p> <p>Case presentation</p> <p>We report the isolation and identification, by 16S rRNA amplification and sequencing, of two emerging pathogens resistant to colistin, <it>Brevundimonas diminuta </it>and <it>Ochrobactrum anthropi</it>, in a 17-year-old woman with cystic fibrosis and pneumonia. The patient eventually responded well to a 2-week regime of imipenem and tobramycin.</p> <p>Conclusion</p> <p>Our results clearly re-emphasize the emergence of new colistin-resistant pathogens in patients with cystic fibrosis.</p

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at √s=0.9 and 2.36 TeV

Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at root s = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN(ch)/d eta vertical bar(vertical bar eta vertical bar and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date

Analyse des differents types de variabilite : individu, age, tissu, dans une etude de la lipogenese et une etude longitudinale de la taille des adipocytes chez le lapin en croissance

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc