Preweaning growth traits for Senepol, Hereford, and reciprocal crossbred calves and feedlot performance and carcass characteristics of steers

We conducted a multiyear study in two phases to determine preweaning performance traits of Senepol (S x S), Hereford (H x H), and reciprocal (S x H and H x S) F1 crossbred calves and feedlot performance and carcass characteristics of steers. In Phase I, from 1985 to 1989, data from S x S (n = 194), H x H (n = 383), and S x H (n = 120) calves were used. Numbers of S x S cows were increased during Phase I so that data from H x S (n = 74) calves could be included in Phase II (1990 to 1992) in addition to S x S (n = 118), H x H (n = 130), and S x H (n = 56) calves. Also during Phase II, feedlot performance and carcass characteristics were determined for S x S (n = 30), H x H (n = 26), H x S (n = 36), and S x H (n = 26) steers. In Phase I, S x S calves had heavier (P < .01) birth weights and heavier (P < .01) 205-d adjusted weaning weights than H x H calves. Birth weights of S x H calves were heavier (P < .01) than the mean of the purebred calves, but 205-d adjusted weaning weights did not differ (P > .10). In phase II, direct heterosis was 3.5% for birth weight (P < .05) and 5.1% for 205-d adjusted weaning weight (P < .01). Senepol maternal breed effects were 1.9 kg for birth weight (P < .10) and 37.9 kg for 205-d adjusted weaning weight (P < .01). Levels of direct heterosis, Senepol maternal breed effects, and Hereford direct breed effects were significant for most feedlot performance traits of steer calves that were fed to a common end point. Breeds did not differ (P > .10) for USDA yield and quality grades, and direct heterosis was not significant for Warner-Bratzler shear force. These results demonstrate significant levels of heterosis in preweaning performance between S x S and H x H calves and in feedlot performance of steers. Levels of heterosis were smaller and nonsignificant for most carcass traits including meat tenderness, which did not differ between S x S and H x H steers in this study.     

Cognitive Correlates of Improvised Behaviour in Disaster Response: the Cases of the Murrah Building and the World Trade Center

While emergency response actions are known to range from conventional to improvised, less is known about the thinking processes that underlie these actions. This paper presents a statistical analysis of cognition and behaviour reported by police personnel who responded to two significant US disasters: the 1995 bombing of the Murrah Building in Oklahoma City and the 2001 attack on the World Trade Center in New York City. The results suggest the prominence of conventional behaviour coupled with cognitive processes closely tied to recognition, and of improvised behaviours that are linked to more explicit reasoning processes. The results underscore the value of exploring cognitive foundations of both conventional and improvised behaviours to enrich understanding of human response to disaster.     

Synchronization through Communication in a Massively Parallel Processor Array

Programming MPPAs for complex real-time embedded applications is difficult with conventional multiprogramming models, which usually treat communication and synchronization separately. Based on a programming model for massively parallel embedded computing that is reasonable and productive for software developers, we developed a scalable MPPA chip architecture that delivers tera-ops performance with very good energy efficiency in an ordinary 130-nm ASIC. This MPPA's architecture is based on the structural object programming model, which composes strictly encapsulated processing and memory objects in a structure of self-synchronizing channels. Small RISC CPUs and memories execute the objects.     

A statnet Tutorial

The statnet suite of R packages contains a wide range of functionality for the statistical analysis of social networks, including the implementation of exponential-family random graph (ERG) models. In this paper we illustrate some of the functionality of statnet through a tutorial analysis of a friendship network of 1,461 adolescents.     

Synthesis of layered sodium lanthanum selenide through ion exchange reactions

Layered hexagonal KLaSe2 (α-NaFeO₂-type) was synthesized using the reactive flux method and analyzed by powder XRD to determine its lattice constants (space group R-3m, a = 4.40508(5) Å, c = 22.7838(5) Å). NaLaSe₂, which normally crystallizes as a disordered rock salt structure with mixed Na+/La + 3 sites, was synthesized through a solid state ion exchange reaction at 585 °C from a 1:3 molar ratio mixture of KLaSe₂:NaI. The product of this reaction was hexagonally layered NaLaSe₂ (space group R-3m, a = 4.3497(3) Å, c = 20.808(2) Å) isostructural to KLaSe₂. This product was analyzed by comparison with members of the set of solid solutions Na_(1−x)K_(x)LaSe₂ to confirm that the extent ion exchange in this reaction was complete. Cubic (disordered) NaLaSe₂ was also reacted with KI to yield the poorly crystalline hexagonally layered product with the approximate formula Na_0.79K_0.21LaSe₂.     

Effect of the vaccines for children program on inner-city neighborhood physicians

PURPOSE: Atorvastatin (Lipitor) was developed as an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase for treatment of serum lipid disorders. Other reductase inhibitors (RIs) induce cataracts in dogs exposed to relatively high levels of the drugs for extended periods of time. The purpose of these studies was to assess the cataractogenic potential of atorvastatin, when administered for up to 2 years in beagle dogs. METHODS: Atorvastatin was administered at doses up to 150 mg/kg/day in 2-week, 13-week or 104-week studies. A 52-week interim sacrifice and a reversal group in which dosing was terminated at week 52 and the dogs sacrificed at week 64, was included in the 104-week study. RESULTS: Serum cholesterol was significantly lowered in all studies. No clinical or histologic evidence of drug-induced cataracts was found in any study. Lens biochemical analyses in the 13-week study revealed no statistically significant changes in lenticular weight, reduced or oxidized glutathione content, adenosine nucleotide content, glucose-6-phosphate dehydrogenase activity or phosphofructokinase activity in any treatment group. Modest (11-17%) and transient decreases in lens protein, potassium and glucose content were noted in the 13-week study and at week 52 (glucose only) in the 104-week study, at the doses > or = 40 mg/kg. CONCLUSIONS: These studies demonstrated that, in spite of marked reduction in serum cholesterol, atorvastatin was not cataractogenic in dogs at any tested dose. We conclude that atorvastatin differs from other RIs in this regard.     

Treatment and prophylaxis of disseminated Mycobacterium avium complex in HIV-infected individuals

OBJECTIVE: To review the pathophysiology, epidemiology, treatment, and prophylaxis of disseminated Mycobacterium avium complex (MAC) infection in HIV-infected individuals. DATA SOURCES: A MEDLINE (January 1966-July 1997) and AIDSLINE (January 1980-July 1997) search of basic science articles pertinent to the MAC infection in HIV-infected patients. STUDY SELECTION AND DATA EXTRACTION: All articles were considered for possible inclusion in the review. Pertinent information, as judged by the authors, was selected for discussion. DATA SYNTHESIS: The organism, epidemiology, and pathophysiology of disseminated MAC are discussed for background. A review of clinical trials for the treatment and prophylaxis of disseminated MAC are presented, along with unresolved issues concerning these topics. CONCLUSIONS: The incidence of disseminated MAC has increased dramatically with the AIDS epidemic. The infection can lead to increased morbidity and mortality in HIV-infected patients. Treatment regimens for patients with a positive culture for MAC from a sterile site should include two or more drugs, including clarithromycin. Prophylaxis against disseminated MAC should be considered for patients with a CD4 cell count of less than 50/mm3.     

Frequency spectra for the geometric representation of wavefront distortions due to atmospheric turbulence

The wavefronts of a point source of radiation that is immersed in a turbulent atmosphere become distorted and deformed as they propagate outward. The phase surfaces incident on an unobscured collecting aperture therefore will not be perfectly spherical, but instead will be aberrated in some way. We have expanded this phase profile in a set of orthonormal functions closely related to the Zernike polynomials and then determined the respective power spectra of the time dependent expansion coefficients. The results show, for all spectra, a sharp cutoff off^{-11/3}for frequenciesf > (nu/2R), wherenuis the wind velocity transverse to the point source and the receiver, andRis the aperture radius. In particular, for the tilt component expansion coefficients, this result differs from the usual phase difference power spectra previously used by many workers.