715 research outputs found
Effects of various dietary hay-concentrate ratios on nutrient utilization and production responses of dairy cows
Healing the Hurt: Trauma-Informed Approaches to the Health of Boys and Young Men of Color
From discrimination and poverty to alcoholism and assault, trauma in its varied forms plays a major part in the lives of Latino and African-American boys and young men. This paper outlines the ways in which violence prevention, family support, health care, foster care, and juvenile justice can incorporate a trauma-informed approach to improve the physical and mental health of young men and boys
Milk production functions, hay/grain substitution rates and economic optima in dairy cow rations
Interest in possibilities of forage-grain substitution in the dairy cow ration has been increased by recent agricultural developments. One development is acreage control which allows farmers to grow forage as a replacement crop for grain. Another is the continuing interest in conservation: Erosion control plans ordinarily require an increased acreage of grasses and legumes and fewer acres of grains and row crops. Both of these developments increase the supply of forages relative to grains and give rise to questions of using forage profitably. One possibility is the substitution of forage for grain in rations of ruminants. The feasibility of this adjustment depends, however, on the rate at which the various classes of feeds substitute for each other.
Recent changes in price structures, with dairy product prices depressed relative to feed and labor costs, also have caused farmers to examine substitution possibilities as a means of lowering costs and increasing profits. Then, too, yearly and geographic differentials in the costs of concentrates relative to forages and to the price of milk give rise to questions of the most profitable ration under particular economic circumstances. To what extent should the grain-forage ration be varied as the price of grain changes relative to the price of forage at particular locations? To what extent should the most profitable ration differ between grain surplus and grain deficit areas or other areas where concentrates are priced at different levels? These questions can be answered only if information is available on substitution ratios. The optimum ration, in terms of profit maximization, can be determined only by relating substitution ratios to price ratios. Finally, determining the nature of the milk production surface with its expression of feed/milk transformation ratios and feed substitution coefficients is a central problem in dairy cow nutrition
Theory of Coexistence of Superconductivity and Ferroelectricity : A Dynamical Symmetry Model
We propose and investigate a model for the coexistence of Superconductivity
(SC) and Ferroelectricity (FE) based on the dynamical symmetries for
the pseudo-spin SC sector, for the displaced oscillator FE sector, and
for the composite system. We assume a minimal
symmetry-allowed coupling, and simplify the hamiltonian using a double mean
field approximation (DMFA). A variational coherent state (VCS) trial
wave-function is used for the ground state: the energy, and the relevant order
parameters for SC and FE are obtained. For positive sign of the SC-FE coupling
coefficient, a non-zero value of either order parameter can suppress the other
(FE polarization suppresses SC and vice versa). This gives some support to
"Matthias' Conjecture" [1964], that SC and FE tend to be mutually exclusive.
For such a Ferroelectric Superconductor we predict: a) the SC gap
(and ) will increase with increasing applied pressure when pressure
quenches FE as in many ferroelectrics, and b) the FE polarization will increase
with increaesing magnetic field up to . The last result is equivalent to
the prediction of a new type of Magneto-Electric Effect in a coexistent SC-FE
material. Some discussion will be given of the relation of these results to the
cuprate superconductors.Comment: 46 page
Expression system of CotA-laccase for directed evolution and high-throughput screenings for the oxidation of high-redox potential dyes
Laccases are useful biocatalysts for many diverse biotechnological applications. In this study we have established efficient and reliable expression systems and high-throughput screenings for the recombinant CotA-laccase from Bacillus subtilis. The expression levels of cotA-laccase were compared in five different Escherichia coli host strains growing in 96-well microtiter plates under different culture conditions. Lower coefficients of variance (around 15%) were achieved using crude cell lysates of BL21 and KRX host strains growing under microaerobic conditions. Reproducible high-throughput screenings for the decolorization of high redox potential azo and anthraquinonic dyes were developed and optimized for identification of variants with increased redox potential. The enzymatic assays developed were tested for the screening of one mutant library from CotA-laccase created by error-prone PCR.(undefined
Recommended from our members
Regional changes in wind energy potential over Europe using regional climate model ensemble projections
The impact of climate change on wind power generation potentials over Europe is investigated by considering ensemble projections from two regional climate models (RCMs) driven by a global climate model (GCM). Wind energy density and its interannual variability are estimated based on hourly near-surface wind speeds. Additionally, the possible impact of climatic changes on the energy output of a sample 2.5-MW turbine is discussed. GCM-driven RCM simulations capture the behavior and variability of current wind energy indices, even though some differences exist when compared with reanalysis-driven RCM simulations. Toward the end of the twenty-first century, projections show significant changes of energy density on annual average across Europe that are substantially stronger in seasonal terms. The emergence time of these changes varies from region to region and season to season, but some long-term trends are already statistically significant in the middle of the twenty-first century. Over northern and central Europe, the wind energy potential is projected to increase, particularly in winter and autumn. In contrast, energy potential over southern Europe may experience a decrease in all seasons except for the Aegean Sea. Changes for wind energy output follow the same patterns but are of smaller magnitude. The GCM/RCM model chains project a significant intensification of both interannual and intra-annual variability of energy density over parts of western and central Europe, thus imposing new challenges to a reliable pan-European energy supply in future decades
Microtubules as a Critical Target for Arsenic Toxicity in Lung Cells in Vitro and in Vivo
To understand mechanisms for arsenic toxicity in the lung, we examined effects of sodium m-arsenite (As3+) on microtubule (MT) assembly in vitro (0â40 ”M), in cultured rat lung fibroblasts (RFL6, 0â20 ”M for 24 h) and in the rat animal model (intratracheal instillation of 2.02 mg As/kg body weight, once a week for 5 weeks). As3+ induced a dose-dependent disassembly of cellular MTs and enhancement of the free tubulin pool, initiating an autoregulation of tubulin synthesis manifest as inhibition of steady-state mRNA levels of ÎČI-tubulin in dosed lung cells and tissues. Spindle MT injuries by As3+ were concomitant with chromosomal disorientations. As3+ reduced the binding to tubulin of [3H]N-ethylmaleimide (NEM), an -SH group reagent, resulting in inhibition of MT polymerization in vitro with bovine brain tubulins which was abolished by addition of dithiothreitol (DTT) suggesting As3+ action upon tubulin through -SH groups. In response to As3+, cells elevated cellular thiols such as metallothionein. Taxol, a tubulin polymerization agent, antagonized both As3+ and NEM induced MT depolymerization. MTâassociated proteins (MAPs) essential for the MT stability were markedly suppressed in As3+-treated cells. Thus, tubulin sulfhydryls and MAPs are major molecular targets for As3+ damage to the lung triggering MT disassembly cascades
Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV
We present limits on anomalous WWZ and WW-gamma couplings from a search for
WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p
-> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron
Collider during the 1992-1995 run. The data sample corresponds to an integrated
luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling
parameters, the 95% CL limits on the CP-conserving couplings are
-0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a
form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also
presented.Comment: 11 pages, 2 figures, 2 table
Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV
We report the results of a study of color coherence effects in ppbar
collisions based on data collected by the D0 detector during the 1994-1995 run
of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8
TeV. Initial-to-final state color interference effects are studied by examining
particle distribution patterns in events with a W boson and at least one jet.
The data are compared to Monte Carlo simulations with different color coherence
implementations and to an analytic modified-leading-logarithm perturbative
calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
- âŠ