1,681 research outputs found
Shortening Sow Restraint Period During Lactation Improves Production and Decreases Hair Cortisol Concentrations in Sows and Their Piglets
Food animal welfare is an issue of great concern, as society has a responsibility for animals under human care. Pork is the most consumed meat worldwide, with more than a billion pigs being slaughtered globally every year. Still, in most countries, sows are restrained in farrowing crates throughout lactation. In these crates, sows arc confined with bars to an area that is just slightly larger than their body. Thus, moving and turning around, grooming, or expressing other natural behaviors are typically impossible. In this study, we utilized a simple and practical modification of conventional farrowing crates to designed farrowing pens, by removable confinement bars, which provide the flexibility to change the housing system from one to another. Our objective was to examine the parameters of production and hair cortisol concentrations after different restraint periods during lactation. Analyses included data from 77 sows and their 997 piglets. Sows were housed in farrowing crates, but the confinement bars were removed after different periods, from 3 days post-farrowing to full restraint. For certain analyses, sows were grouped into Short or Long Restraint groups (3-10 days vs 13-24 days, respectively). Multiple linear regression revealed that for any additional day in restraint of the sows, piglets\u27 weaning rate decreases by 0.4% (P \u3c 0.05). Moreover, the total number of weaned piglets per litter was higher in the Short Restraint group as compared to the Long Restraint group (10.4 +/- 0.3 vs 9.7 +/- 0.3, respectively; P \u3c 0.05). Accordingly, total litter weight on the weaning day tended to be higher in the Short Restraint group (68.8 +/- 2.2 vs 64.9 +/- 1.8 kg; P = 0.1210). The requirement for medical treatments during lactation (e.g., antibiotics, NSAID) tended to be less frequent in the Short Restraint group (Sows: 21.9% vs 40%; P = 0.1219. Piglets: 2.4% vs 17.1%; P = 0.0609). Hair cortisol as a marker for chronic stress during lactation decreased when the restraint period was shortened in both sows and piglets. Our analysis revealed that sows\u27 hair cortisol is a significant mediator between the restraint of the sow and its piglets\u27 hair cortisol (Sobel test; P \u3c0.05). For every day of sows\u27 restraint sows\u27 hair cortisol increased by 05 pg/mg, and for any additional unit of sows\u27 hair cortisol, piglets\u27 hair cortisol increased by 0.36 pg/mg. In condusion, sustainable swine farming management can be beneficial for both animals and farmers; limiting sow restraint during lactation is expected to reduce stress, enhance welfare and production, and potentially improve the economics of swine operations. (C) 2020 The Authors. Published by Elsevier Inc. on behalf of The Animal Consortium
Electronic Control of Spin-Crossover Properties in Four-Coordinate Bis(formazanate) Iron(II) Complexes
The transition between spin states in d-block metal complexes has important ramifications for their structure and reactivity, with applications ranging from information storage materials to understanding catalytic activity of metalloenzymes. Tuning the ligand field (Delta(O)) by steric and/or electronic effects has provided spin-crossover compounds for several transition metals in the periodic table, but this has mostly been limited to coordinatively saturated metal centers in octahedral ligand environments. Spin-crossover complexes with low coordination numbers are much rarer. Here we report a series of four-coordinate, (pseudo)tetrahedral Fe(II) complexes with formazanate ligands and demonstrate how electronic substituent effects can be used to modulate the thermally induced transition between S = 0 and S = 2 spin states in solution. All six compounds undergo spin-crossover in solution with T-1/2 above room temperature (300-368 K). While structural analysis by X-ray crystallography shows that the majority of these compounds are low-spin in the solid state (and remain unchanged upon heating), we find that packing effects can override this preference and give rise to either rigorously high-spin (6) or gradual spin-crossover behavior (5) also in the solid state. Density functional theory calculations are used to delineate the empirical trends in solution spin-crossover thermodynamics. In all cases, the stabilization of the low-spin state is due to the pi-acceptor properties of the formazanate ligand, resulting in an "inverted" ligand field, with an approximate "two-over-three" splitting of the d-orbitals and a high degree of metal-ligand covalency due to metal -> ligand pi-backdonation. The computational data indicate that the electronic nature of the para-substituent has a different influence depending on whether it is present at the C-Ar or N-Ar rings, which is ascribed to the opposing effect on metal-ligand sigma- and pi-bonding
Phase coherence phenomena in superconducting films
Superconducting films subject to an in-plane magnetic field exhibit a gapless
superconducting phase. We explore the quasi-particle spectral properties of the
gapless phase and comment on the transport properties. Of particular interest
is the sensitivity of the quantum interference phenomena in this phase to the
nature of the impurity scattering. We find that films subject to columnar
defects exhibit a `Berry-Robnik' symmetry which changes the fundamental
properties of the system. Furthermore, we explore the integrity of the gapped
phase. As in the magnetic impurity system, we show that optimal fluctuations of
the random impurity potential conspire with the in-plane magnetic field to
induce a band of localized sub-gap states. Finally, we investigate the
interplay of the proximity effect and gapless superconductivity in thin normal
metal-superconductor bi-layers.Comment: 13 pages, 8 figures include
Polarized Hydrogen Gas Target in the Cooler
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Installation of the Polarized Hydrogen Target and Detector System in the Cooler A-Region
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Polarization Measurements of a Storage Cell Target
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Towards Longitudinal Beam Polarization in the Cooler
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Spin Correlation in PP Scattering at 200 MeV
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Microscopic model analyses of proton scattering from 12C, 20Ne, 24Mg, 28Si and 40Ca
Differential cross sections and analyzing powers for elastic scattering from,
and for inelastic proton scattering to a set of states in, C,
Ne, Mg, Si and Ca, and for a set of
energies between 35 to 250 MeV, have been analyzed. A -folding model has
been used to determine optical potentials and a microscopic distorted wave
approximation taken to analyze the inelastic data. The effective
nucleon-nucleon interactions used to specify the optical potentials have also
been used as the transition operators in the inelastic scattering processes.
Shell and large space Hartree-Fock models of structure have been used to
describe the nuclear states.Comment: 27 pages, 18 figure
Reaction rate for two--neutron capture by He
Recent investigations suggest that the neutrino--heated hot bubble between
the nascent neutron star and the overlying stellar mantle of a type--II
supernova may be the site of the r--process. In the preceding --process
building up the elements to , the He(2n,)He--
and He(,n)Be--reactions bridging the instability gap at
and could be of relevance. We suggest a mechanism for
He(2n,)He and calculate the reaction rate within the
+n+n approach. The value obtained is about a factor 1.6 smaller than
the one obtained recently in the simpler direct--capture model, but is at least
three order of magnitude enhanced compared to the previously adopted value. Our
calculation confirms the result of the direct--capture calculation that under
representative conditions in the --process the reaction path proceeding
through He is negligible compared to He(n,)Be.Comment: 13 pages, 4 postscript figures, to appear in "Zeitschrift f. Physik
A", changed internet address and filename, the uuencoded postscript file
including the figures is available at
ftp://is1.kph.tuwien.ac.at/pub/ohu/twoneutron.u
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