The effects of crossfostering pigs at birth on subsequent survival and performance

Data from 144 crossbred Duroc, Hampshire, Yorkshire and Landrace litters were used to study effects of crossfostering pigs at birth on subsequent performance traits. There were 1,413 pig births from six farrowings during 1977 included in the study. Pigs were ear notched, weighed, needle teeth clipped and male pigs castrated on day one. Crossfostering was accomplished within 24 hours of birth. Two randomly selected litters of pigs were crossfostered as a group. The smallest one-half of the pigs by weight were placed with one sow and the largest one-half by weight with the other sow. The pigs were weaned at 5 weeks of age, weighed and placed in the nursery. The largest one-third of the pigs by weight were randomly assigned to four nursing pens, the middle third to four pens and the light-weight one third to the remaining four pens. The pigs were weighed and moved as a pen of pigs to the finishing barns. Crossfostering reduced the variation within litters and enlarged variation among litters. The small crossfostered litter pigs were superior in uniformity of daily gain compared to small pigs from control litters. The smaller pigs (control and crossfostered) did not perform as well as larger pigs in terms of average daily gain. Average daily gain to weaning was shown to be an important factor in determining succeeding performance traits. Crossfostering appears advantageous in developing more uniformity in size and weight among pigs produced

TDN efficiency of angus and hereford cows raising straightbred and reciprocal cross calves as affected by cow and calf traits

Mature Angus and Hereford cows raising straightbred and reciprocal cross calves were individually fed during their lactations. A total of 92 preweaning lactations and 66 postweaning growth curves were observed. Cows were offered, ad libitum, a diet of grass silage and alfalfa pellets were added as an energy source when needed. Calves were creep fed alfalfa pellets from approximately 80 days of age until weaning. Following weaning calves were individually fed a complete growing and finishing ration until the calves were slaughtered at their maximum efficiency point (MEP). Unit TON was the sum of cow and calf TON. Cow-calf unit weaning efficiency was calculated as the ratio of unit TON to calf weaning weight. Cow-calf unit efficiency, calf age and calf weight were determined for endpoints at 12 mm fat and at MEP. Calf fat was determined at MEP. Postweaning efficiency, postweaning ADG and daily postweaning TON were determined from weaning to 12 mm fat and MEP, respectively. Angus cow units were more efficient than were Hereford cow units (P\u3c.001) but the effect was reduced when the covariates, milk production and calf weaning weight were added to the basic model. Crossbred calves were slightly heavier (P\u3c.10) at weaning than straightbreds, but because of their higher calf TON intake, they could not be declared more (P\u3c.10) efficient. Calf weaning weight accounted for about 51 percent of the variation in cow-calf unit efficiency. Calves with improved efficiencies at weaning consumed (P\u3c.001) more daily postweaning TDN. Younger calves were associated (P\u3c.10) with improved postweaning AD6. When adjusted for calf weaning age crossbreds were heavier (P\u3c.05) than straightbreds. Calves of Hereford sires were more efficient (P .01) than calves of Angus sires. Calf weight, at each respective endpoint, adjusted for calf weaning age, increased (P\u3c.05) as cow-calf unit efficiency improved. Units with younger calves at each endpoint tended to be more efficient (P\u3c.10) than units with older calves. Units with smaller cows were more efficient (P\u3c.05) at MEP and (P\u3c.10) at 12 mm fat than were units with larger cows

Integrating a professional apprenticeship model with clinical simulation for psychiatric nursing students

In this article, we present a theory-based application of clinical simulation in psychiatric-mental health nursing education. As described by Benner, Sutphen, Leonard, and Day, a three-pronged apprenticeship that integrates intellectual, practical, and ethical aspects of the professional role is critical in the development of practical reasoning in nursing education and training. Clinical encounters are often fraught with ambiguity and uncertainty. Therefore, educating for a practice discipline requires experiential and situated learning. Using the three-pronged experiential model in simulated psychiatric-mental health nursing practice supports the development of critical nursing skills, ethics, and theoretical concepts. A clinical scenario is presented that demonstrates the application of this model of professional apprenticeship in psychiatric-mental health education. Applications of the concept presented may be used in training nurses new to the practice of psychiatric-mental health nursing

Interpreting the Ionization Sequence in Star-Forming Galaxy Emission-Line Spectra

High ionization star forming (SF) galaxies are easily identified with strong emission line techniques such as the BPT diagram, and form an obvious ionization sequence on such diagrams. We use a locally optimally emitting cloud model to fit emission line ratios that constrain the excitation mechanism, spectral energy distribution, abundances and physical conditions along the star-formation ionization sequence. Our analysis takes advantage of the identification of a sample of pure star-forming galaxies, to define the ionization sequence, via mean field independent component analysis. Previous work has suggested that the major parameter controlling the ionization level in SF galaxies is the metallicity. Here we show that the observed SF- sequence could alternatively be interpreted primarily as a sequence in the distribution of the ionizing flux incident on gas spread throughout a galaxy. Metallicity variations remain necessary to model the SF-sequence, however, our best models indicate that galaxies with the highest and lowest observed ionization levels (outside the range -0.37 < log [O III]/H\b{eta} < -0.09) require the variation of an additional physical parameter other than metallicity, which we determine to be the distribution of ionizing flux in the galaxy.Comment: 41 pages, 17 figures, 9 tables, accepted to MNRA

The electric dipole response of 76^{76}Se above 4 MeV

The dipole response of $^{76}_{34}$Se in the energy range 4 to 9 MeV has been analyzed using a $(\vec\gamma,{\gamma}')$ polarized photon scattering technique, performed at the High Intensity $\gamma$-Ray Source facility, to complement previous work performed using unpolarized photons. The results of this work offer both an enhanced sensitivity scan of the dipole response and an unambiguous determination of the parities of the observed J=1 states. The dipole response is found to be dominated by $E1$ excitations, and can reasonably be attributed to a pygmy dipole resonance. Evidence is presented to suggest that a significant amount of directly unobserved excitation strength is present in the region, due to unobserved branching transitions in the decays of resonantly excited states. The dipole response of the region is underestimated when considering only ground state decay branches. We investigate the electric dipole response theoretically, performing calculations in a 3D cartesian-basis time-dependent Skyrme-Hartree-Fock framework.Comment: 20 pages, 18 figures, to be submitted to PR

Multiwavelength Observations of GX 339-4 in 1996. I. Daily Light Curves and X-ray and Gamma-Ray Spectroscopy

As part of our multiwavelength campaign of GX 339-4 observations in 1996 we present our radio, X-ray, and gamma-ray observations made in July, when the source was in a hard state (= soft X-ray low state). The radio observations were made at the time when there was a possible radio jet. We show that the radio spectrum was flat and significantly variable, and that the radio spectral shape and amplitude at this time were not anomalous for this source. Daily light curves from our pointed observation July 9-23 using OSSE, from BATSE, and from the ASM on RXTE also show that there was no significant change in the X- and gamma-ray flux or hardness during the time the possible radio jet-like feature was seen. The higher energy portion of our pointed RXTE observation made July 26 can be equally well fit using simple power law times exponential (PLE) and Sunyaev-Titarchuk (ST) functions. An additional soft component is required, as well as a broad emission feature centered on 6.4 keV. This may be an iron line that is broadened by orbital Doppler motions and/or scattering off a hot medium. Its equivalent width is 600 eV. Our simplistic continuum fitting does not require an extra reflection component. Both a PLE and a ST model also fit our OSSE spectrum on its own. Although the observations are not quite simultaneous, combining the RXTE and CGRO spectra we find that the PLE model easily fits the joint spectrum. However, the ST model drops off too rapidly with increasing energies to give an acceptable joint fit.Comment: Submitted to Astrophysical Journal. 25 pages. 11 figure

Genetic Structure of American Black Bears in the Desert Southwest of North America

Abstract American black bears (Ursus americanus) have recolonized parts of their former range in the Trans-Pecos region of western Texas after a \u3e40-year absence. Assessment of genetic variation, structuring, gene flow, and dispersal among bear populations along the borderlands of Mexico and Texas is important to gain a better understanding of recolonization by large carnivores. We evaluated aspects of genetic diversity and gene flow for 6 sampling areas of black bears in southwestern North America using genotypic data from 7 microsatellite loci. Our results indicated that genetic diversity generally was high in the metapopulation of black bears in northern Mexico and western Texas. The episodic gene flow occurring via desert corridors between populations in northern Mexico and those in western Texas has permitted the establishment of only moderate levels of genetic structuring. Bayesian clustering analyses and assignment testing depicted the presence of 3 subpopulations among our 6 sampling areas and attested to the generally panmictic nature of bear populations in the borderlands region. The potentially ephemeral nature of the small populations in western Texas and genotypic characteristics of bears recolonizing these habitats attest to the importance of linkages along this portion of the borderlands of the United States and Mexico to effectively conserve and manage the species in this part of its range

Enhanced low-energy γ\gamma-decay strength of 70^{70}Ni and its robustness within the shell model

Neutron-capture reactions on very neutron-rich nuclei are essential for heavy-element nucleosynthesis through the rapid neutron-capture process, now shown to take place in neutron-star merger events. For these exotic nuclei, radiative neutron capture is extremely sensitive to their $\gamma$-emission probability at very low $\gamma$ energies. In this work, we present measurements of the $\gamma$-decay strength of $^{70}$Ni over the wide range $1.3 \leq E_{\gamma} \leq 8$ MeV. A significant enhancement is found in the $\gamma$-decay strength for transitions with $E_\gamma < 3$ MeV. At present, this is the most neutron-rich nucleus displaying this feature, proving that this phenomenon is not restricted to stable nuclei. We have performed $E1$-strength calculations within the quasiparticle time-blocking approximation, which describe our data above $E_\gamma \simeq 5$ MeV very well. Moreover, large-scale shell-model calculations indicate an $M1$ nature of the low-energy $\gamma$ strength. This turns out to be remarkably robust with respect to the choice of interaction, truncation and model space, and we predict its presence in the whole isotopic chain, in particular the neutron-rich $^{72,74,76}\mathrm{Ni}$.Comment: 9 pages, 9 figure