EC97-277 Minerals and Vitamins For Beef Cows

Introduction Mineral supplementation programs range from elaborate, cafeteria-style delivery systems to simple white salt blocks put out periodically by producers. The reason for this diversity: little applicable research available for producers to evaluate mineral supplement programs. There is a need of information regarding mineral composition and availability from various feedstuffs (i.e. pasture grasses, hays, by-products, etc.) and the possible interactions between minerals in the digestive system. Also lacking is a data base to establish accurate estimates of mineral requirements for beef cattle. Assessing the consequence of mineral deficiencies in the cow, calf or stocker animal is difficult because slightly lowered weight gains in calves, reduced milk production and/or decreased reproduction rates may occur without visible signs of deficiency. At the same time, excess mineral consumption may cause reduced cow and/or calf performance without obvious signs of toxicity. Potential problems can occur due to mineral undernutrition in the cow herd; however, producers need sufficient information to establish a least cost method of correcting mineral undernutrition

COMPUTED EFFECT OF RUB-GROOVE SIZE ON STEPPED LABYRINTH SEAL PERFORMANCE

ABSTRACT A numerical study was undertaken to explore the effects of the size of wear-in mb grooves that are typically cut into the abradable land of stepped labyrinth seals. The elliptic form of the 2-D axisymmetric Navier-Stokes equations for compressible turbulent flow were solved. The relationships among the friction coefficient, the leakage Reynolds number, the groove depth and width and the pre-rub radial clearance were examined. It was found that the standard k-s turbulence model and wall functions are effective for computing the friction coefficient and leakage for labyrinth seals with honeycomb land surfaces, both with and without the presence of mb grooves. The so-called rub grooves are the result of labyrinth teeth cutting wear grooves into the abradable surface of the land (stationary housing of the seal). Furthermore, it was found that the case of a small pre-mb tooth radial clearance, a wide rub groove and an intermediate step height is the most sensitive to the presence of a rub groove, with a leakage increase over the no-groove case of about 100 percent and 194 percent for the shallow and deep grooves, respectively. It was also found, for example, that the leakage varied with pre-rub clearance and groove width, in order from lowest to highest leakage, as: (a) small clearance and narrow groove, (b) small clearance and wide groove, (c) large clearance and narrow groove and (d) large clearance and wide groove

A novel analytical ultracentrifugation based approach to the low resolution structure of gum arabic

Under investigation are the structural properties of gum arabic, an industrially important biopolymer for use as a stabilizer or in drug delivery, using Analytical Ultracentrifugation—a well-established, matrix-free probe for macromolecular size and shape. These results are combined with chromatographically-coupled methods (multi-angle light scattering, differential press imbalance viscometry) to provide a global analysis of its structure in varying ionic strength conditions. This analysis indicates that gum Arabic may have a compact, elliptical structure in solution, the significance of which for biotechnological use is indicated. This modelling method can be applied to other biopolymers and synthetic polymers

Analysis of Fascin-1 in Relation to Gleason Risk Classification and Nuclear ETS-Related Gene Status of Human Prostate Carcinomas:An Immunohistochemical Study of Clinically Annotated Tumours From the Wales Cancer Bank

Although prostate-specific antigen (PSA) testing can identify early-stage prostate cancers, additional biomarkers are needed for risk stratification. In one study, high levels of the actin-bundling protein, fascin-1, were correlated with lethal-phase, hormone-refractory prostate cancer. Analyses of independent samples are needed to establish the value of fascin-1 as a possible biomarker. We examined fascin-1 by immunohistochemistry in tumour specimens from the Wales Cancer Bank in comparison with nuclear-located ETS-related gene (ERG), an emerging marker for aggressive prostate cancer. Fascin-1 was elevated in focal areas of a minority of tumours, yet fascin-1-positivity did not differentiate tumours of low-, intermediate-, or high-risk Gleason scores and did not correlate with PSA status or biochemical relapse after surgery. Stromal fascin-1 correlated with high Gleason score. Nuclear ERG was upregulated in tumours but not in stroma. The complexities of fascin-1 status indicate that fascin-1 is unlikely to provide a suitable biomarker for prediction of aggressive prostate cancer

The Imprint of Gravitational Waves on the Cosmic Microwave Background

Long-wavelength gravitational waves can induce significant temperature anisotropy in the cosmic microwave background. Distinguishing this from anisotropy induced by energy density fluctuations is critical for testing inflationary cosmology and theories of large-scale structure formation. We describe full radiative transport calculations of the two contributions and show that they differ dramatically at angular scales below a few degrees. We show how anisotropy experiments probing large- and small-angular scales can combine to distinguish the imprint due to gravitational waves.Comment: 11 pages, Penn Preprint-UPR-

Scattering and self-adjoint extensions of the Aharonov-Bohm hamiltonian

We consider the hamiltonian operator associated with planar sec- tions of infinitely long cylindrical solenoids and with a homogeneous magnetic field in their interior. First, in the Sobolev space $\mathcal H^2$, we characterize all generalized boundary conditions on the solenoid bor- der compatible with quantum mechanics, i.e., the boundary conditions so that the corresponding hamiltonian operators are self-adjoint. Then we study and compare the scattering of the most usual boundary con- ditions, that is, Dirichlet, Neumann and Robin.Comment: 40 pages, 5 figure