Effect of Dietary Energy Source and Free Choice Feeding on Performance of High Lean Pigs

The effects of dietary energy sources in corn on the growth responses and carcass composition of high lean pigs fed from 55 to 110 kg body weight were evaluated. Low fiber composite corns were created by replacing the fiber in normal corn with isocaloric amounts of either corn starch or corn oil. Feeding the low fiber, composite corns reduced the amount of feed required per unit of body weight compared with that of pigs fed the high fiber, normal corns. However, the daily body weight and muscle gains and efficiency of metabolizable energy (ME) utilization for body weight and muscle gain were similar among pigs fed the low and high fiber corns. Body composition (backfat, loin muscle area, and muscle mass) at 110 kg body weight also were similar among corn treatments. When given the choice between the normal and composite corns, pigs consumed more of the low fiber composite corn with added fat but not with added starch. The feed required per unit of gain also was reduced in pigs allowed free choice access to normal and composite corns compared with pigs self-fed the normal corns. Pig growth and body composition were not altered by free choice selection of normal and composite corns

Establishment of the Minimum Biological Capacity for Nitrogen Excretion in Pigs

To determine the minimum biological capacity for nitrogen (N) excretion for pigs, dietary regimens were created and fed that were designed to eliminate fecal excretion of undigested feed N, minimize endogenous N secretions and minimize intakes of nitrogenous compounds (amino acids) above those of the pigs biological needs. Excretion of undigested fecal N was eliminated by feeding ingredients containing highly digestible (≈100%) sources of nitrogen and by eliminating compounds that bind N. Endogenous secretions were minimized by eliminating antinutritional factors from the diet and by minimizing enteric bacterial populations. Intakes of amino acids above the animal\u27s needs were minimized by providing a pattern of amino acids that closely matched that needed by the pig. Furthermore, dietary amino acids were provided to the pigs in amounts above, at, and below their biological needs based on the amounts of urea N excreted in the urine and the amounts of N accrued in the body. From two-slope breakpoint analysis, apparent digestible N intake resulting in maximum N retention (2.58g⋅kg-1BW.75⋅d-1) was determined to be 3.66g⋅kg-1BW.75⋅d-1. When daily apparent digestible nitrogen intakes were below the pigs\u27 determined need, the amount of digestible N (mg⋅kg-1BW.75⋅d-1) lost for body maintenance processes was estimated as .239 in urine and .080 in feces. The amount lost in urine as unusable for body N accretion was .206 g⋅kg-1BW.75⋅d-1 of each gram of digestible N consumed above body maintenance needs. When daily apparent digestible N intakes were above the pigs determined need, .900 g of each gram of additional N consumed above that needed for body N accretion was excreted. The minimum biological capacity for N excretion in pigs, defined as total (urinary plus fecal) obligatory losses of N, is estimated to be .287g⋅kg-1BW.75⋅d-1 to support pigs at N maintenance and 1.11 g⋅kg-1BW.75⋅d-1 for pigs at maximum body N accretion. Using these estimates, the minimal biological capacity for N excretion can be calculated for pigs at various stages of growth. For example, in 60 kg pigs, minimum capacity for N excretion is estimated at .10 and .39 g/kg body weight/day in pigs in states of N maintenance and maximum body N accretion, respectively. These values are 12 and 44%, respectively, of N excretion relative to published standards (ASAE D384.1). Similarly, the N content of excreta from animals excreting N at their biological minimum was determined to be 2.57 g N/liter, or 18% of standard excreta N content (corrected for volatilization, ASAE D384.1). Based on these data, the minimum biological capacity for the excretion of N in pigs is substantially less than current estimates of N excretion and can be achieved by eliminating dietary factors that contribute to N excretion. Furthermore, dietary regimens that allow the minimum biological capacity for N excretion to be achieved are biologically capable of supporting maximum rates of body accretion (i.e., lean tissue growth) in pigs

Taille de la population d’Avahi laniger dans la réserve d’Ambodiriana-Manompana, Nord-est de Madagascar

Avahi laniger est le seul lémurien nocturne appartenant à la famille des Indriidae qui habite les forêts humides de l’est de Madagascar (Mittermeier et. al., 2010) dont une partie disparaît chaque année (exploitation du bois, pratique du «tavy» ou culture sur brûlis) (Beaucent and Fayolle, 2011; Lehman and Wright, 2000). La fragmentation et la destruction de leur habitat ainsi que la chasse menacent la survie de nombreuses espèces de lémuriens incluant celle de A. laniger (Jenkins et. al., 2011; Rakotondravony and Rabenandrasana, 2011; Anderson, Rowcliffe and Cowlishaw, 2007). Nous avons réalisé, entre fin Avril et Mai 2012, une étude de densité de la population de A. laniger au sein de l’aire protégée de Manompana-Ambodiriana afin d’estimer la taille de la population totale et de déterminer l’impact du projet de conservation menée par l’Association de Défense de la Forêt d’Ambodiriana (ADEFA) qui recherche l’évolution démographique à moyen terme de cette espèce."LABEX" TULIP: (ANR-10-LABX-41), fct fellowship: (SFRH/BD/64875/2009)

A Global Plate Model Including Lithospheric Deformation Along Major Rifts and Orogens Since the Triassic

Global deep‐time plate motion models have traditionally followed a classical rigid plate approach, even though plate deformation is known to be significant. Here we present a global Mesozoic–Cenozoic deforming plate motion model that captures the progressive extension of all continental margins since the initiation of rifting within Pangea at ~240 Ma. The model also includes major failed continental rifts and compressional deformation along collision zones. The outlines and timing of regional deformation episodes are reconstructed from a wealth of published regional tectonic models and associated geological and geophysical data. We reconstruct absolute plate motions in a mantle reference frame with a joint global inversion using hot spot tracks for the last 80 million years and minimizing global trench migration velocities and net lithospheric rotation. In our optimized model, net rotation is consistently below 0.2°/Myr, and trench migration scatter is substantially reduced. Distributed plate deformation reaches a Mesozoic peak of 30 × 106 km2 in the Late Jurassic (~160–155 Ma), driven by a vast network of rift systems. After a mid‐Cretaceous drop in deformation, it reaches a high of 48 x 106 km2 in the Late Eocene (~35 Ma), driven by the progressive growth of plate collisions and the formation of new rift systems. About a third of the continental crustal area has been deformed since 240 Ma, partitioned roughly into 65% extension and 35% compression. This community plate model provides a framework for building detailed regional deforming plate networks and form a constraint for models of basin evolution and the plate‐mantle system

Extended X-ray emission from the classic nova DQ Her -- On the possible presence of a magnetized jet

We present an analysis of archival Chandra and XMM-Newton observations of the magnetically-active cataclysmic variable DQ Her and the shell around it ejected in a nova event in 1934. A careful revision of the Chandra observations confirms previous claims on the presence of extended X-ray emission around DQ Her and reveals that it actually corresponds to a bipolar jet-like structure extending $\simeq$32$''$ along a direction from NE to SW. Therefore, this X-ray emission extends beyond the optical nova shell and is perpendicular to its major axis. The XMM-Newton observations confirm the presence of the extended X-ray emission detected by Chandra, suggesting the additional presence of a diffuse X-ray emission from a hot bubble filling the nova shell. This hot bubble was very likely produced by the explosion that created the nebular shell detected in optical images. The bipolar feature can be modelled by the combination of an optically thin plasma emission component with temperature $T\approx2\times10^{6}$ K and a power law component with a photon index of $\Gamma=1.1\pm0.9$. Its X-ray luminosity in the 0.3 - 5 keV energy range is $L_\mathrm{X}=(2.1\pm1.3)\times10^{29}$ erg s$^{-1}$, for an electron density $n_\mathrm{e}\approx2$ cm$^{-3}$ and a mass $m_\mathrm{X}\approx 3\times10^{-6}$ M$_{\odot}$. We suggest that the X-ray bipolar structure in DQ Her is a jet and interpret its non-thermal X-ray emission in terms of a magnetized jet.Comment: 8 pages, 4 figures, 1 table; accepted to MNRA

IPHAS and the symbiotic stars. I. Selection method and first discoveries

The study of symbiotic stars is essential to understand important aspects of stellar evolution in interacting binaries. Their observed population in the Galaxy is however poorly known, and is one to three orders of magnitudes smaller than the predicted population size. IPHAS, the INT Photometric Halpha survey of the Northern Galactic plane, gives us the opportunity to make a systematic, complete search for symbiotic stars in a magnitude-limited volume, and discover a significant number of new systems. A method of selecting candidate symbiotic stars by combining IPHAS and near-IR (2MASS) colours is presented. It allows us to distinguish symbiotic binaries from normal stars and most of the other types of Halpha emission line stars in the Galaxy. The only exception are T Tauri stars, which can however be recognized because of their concentration in star forming regions. Using these selection criteria, we discuss the classification of a list of 4338 IPHAS stars with Halpha in emission. 1500 to 2000 of them are likely to be Be stars. Among the remaining objects, 1183 fulfill our photometric constraints to be considered candidate symbiotic stars. The spectroscopic confirmation of three of these objects, which are the first new symbiotic stars discovered by IPHAS, proves the potential of the survey and selection method.Comment: Accepted for publication on Astronomy and Astrophysics. 12 pages, 8 figure

Molecular-orbital theory for the stopping power of atoms in the low velocity regime:the case of helium in alkali metals

A free-parameter linear-combination-of-atomic-orbitals approach is presented for analyzing the stopping power of slow ions moving in a metal. The method is applied to the case of He moving in alkali metals. Mean stopping powers for He present a good agreement with local-density-approximation calculations. Our results show important variations in the stopping power of channeled atoms with respect to their mean values.Comment: LATEX, 3 PostScript Figures attached. Total size 0.54

Nuclear Effects on Bremsstrahlung Neutrino Rates of Astrophysical Interest

We calculate in this work the rates for the neutrino pair production by nucleon-nucleon bremsstrahlung taking into account the full contribution from a nuclear one-pion-exchange potential. It is shown that if the temperatures are low enough ($T \leq 20 MeV$), the integration over the nuclear part can be done for the general case, ranging from the completely degenerate (D) to the non-degenerate (ND) regime. We find that the inclusion of the full nuclear contribution enhances the neutrino pair production by $nn$ and $pp$ bremsstrahlung by a factor of about two in both the D and ND limits when compared with previous calculations. This result may be relevant for the physical conditions of interest in the semitransparent regions near the neutrinosphere in type II supernovae, cooling of neutron stars and other astrophysical situations.Comment: 11 pages, no figures, LaTex file. submitted to PR