Comparison of models including cytoplasmic effects for traits of Rambouillet sheep

The objective was to determine appropriate analytical models considering cytoplasmic inheritance for birth weight (BWT, n = 35,604), weaning weight (WWT, n = 34,114), fleece weight (FWT, n = 38,113) and number born (NB, n = 39,029) for Rambouillet sheep. For BWT, models that included dam by year, dam by number born, and sire by dam effects, in addition to direct and maternal effects, were significantly better than the basic maternal effects model. For WWT, variances due to direct, maternal, and maternal permanent environmental effects (0.05 of variance) were not zero. For FWT, heritability was 0.55 for all models, but models with dam by year (0.02), sire by dam (0.05), and sire by cytoplasmic line (0.02) were jointly significantly better than models with permanent environmental effects. For NB, only direct heritability (0.08) and relative permanent environmental variance (0.04) were not zero. No trait showed evidence of variation due to cytoplasmic effects. Adding seldom considered effects to the model did not change estimates of variance due to direct and maternal genetic effects. Variance due to dominance effects may be important for BWT and FWT. The basic direct–maternal effects model seems sufficient for genetic evaluations for WWT and FWT but models for BWT and NB may need to include other effects

Use of modified cages attached to growing calves to measure the effect of stable flies on dry matter intake and digestibility, and defensive movements

The effects of stable flies on growing calves were examined using fly cages attached to the animals. Dry matter intake, DM digestibility (DMD), and behavioral responses of calves were monitored. Nine Holstein calves were exposed to 3 levels of stable flies (0, 10, 100 flies/animal) 3 times daily for 30 min. The study consisted of a 4-period crossover design; each period included 5-d adaptation, 7-d exposure, and 5-d postexposure. Calves were weighed at the beginning and end of each period. Feed consumption was continuously recorded. Fecal samples taken during and after exposure were used to determine DMD. Three calves were monitored for activity and defensive behavior during exposure. Caged stable flies successfully fed on the calves and invoked defensive behaviors similar to those observed in field studies. Defensive behaviors were proportionate to exposure level, and calves became more proficient at interfering with fly feeding over time. Stable fly exposure increased DMI relative to calf weight and decreased ADG/DMI. Calves initially exposed to 100 flies exhibited more defensive behaviors and lower relative DMI and ADG across all exposure levels relative to calves initially exposed to 10 flies. Stable fly exposure did not affect DMD, number of meals, time eating, or amount eaten per meal. Host defensive behavior, not reduced DMI or DMD, appears to be reducing ADG of calves exposed to stable flies. Results indicate that cages placed on calves may be used to study the effects of stable flies, but host exposure history and behavioral variables must be considered

Seroprevalence of T. Cruzi infection in blood donors and chagas cardiomyopathy in patients from the coal mining region of coahuila, Mexico

Context and Objective: Chagas disease is considered a worldwide emerging disease; it is endemic in Mexico and the state of Coahuila and is considered of little relevance. The objective of this study was to determine the seroprevalence of T. cruzi infection in blood donors and Chagas cardiomyopathy in patients from the coal mining region of Coahuila, Mexico. Design and Setting: Epidemiological, exploratory and prospective study in a general hospital during the period January to June 2011. Methods: We performed laboratory tests ELISA and indirect hemagglutination in three groups of individuals: 1) asymptomatic voluntary blood donors, 2) patients hospitalized in the cardiology department and 3) patients with dilated cardiomyopathy. Results: There were three levels of seroprevalence: 0.31% in asymptomatic individuals, 1.25% in cardiac patients and in patients with dilated cardiomyopathy in 21.14%. Conclusions: In spite of having detected autochthonous cases of Chagas disease, its importance to local public health remains to be established as well as the details of the dynamics of transmission so that the study is still in progress

Impairment of D-alanine biosynthesis in \u3ci\u3eMycobacterium smegmatis\u3c/i\u3e determines decreased intracellular survival in human macrophages

D-alanine is a structural component of mycobacterial peptidoglycan. The primary route of d-alanine biosynthesis in eubacteria is the enantiomeric conversion from l-alanine, a reaction catalyzed by d-alanine racemase (Alr). Mycobacterium smegmatis alr insertion mutants are not dependent on d-alanine for growth and display a metabolic pattern consistent with an alternative pathway for d-alanine biosynthesis. In this study, we demonstrate that the M. smegmatis alr insertion mutant TAM23 can synthesize d-alanine at lower levels than the parental strain. The insertional inactivation of the alr gene also decreases the intracellular survival of mutant strains within primary human monocyte-derived macrophages. By complementation studies, we confirmed that the impairment of alr gene function is responsible for this reduced survival. Inhibition of superoxide anion and nitric oxide formation in macrophages suppresses the differential survival. In contrast, for bacteria grown in broth, both strains had approximately the same susceptibility to hydrogen peroxide, acidified sodium nitrite, low pH and polymyxin B. In contrast, TAM23 exhibited increased resistance to lysozyme. d-alanine supplementation considerably increased TAM23 viability in nutritionally deficient media and within macrophages. These results suggest that nutrient deprivation in phagocytic cells combined with killing mediated by reactive intermediates underlies the decreased survival of alr mutants. This knowledge may be valuable in the construction of mycobacterial auxotrophic vaccine candidates

Microsoft Word - Extended abstract _Parametric Effects .doc

ABSTRACT Gas holdup tests were performed in bench-scale and small-scale mechanically-agitated mixing systems at the Savannah River National Laboratory (SRNL) for a simulant of waste from the Hanford Tank 241-AZ-101. These featured additions of DOW Corning Q2-3183A anti-foam agent. Results indicated that this anti-foam agent (AFA) increased gas holdup in the waste simulant by about a factor of four and, counterintuitively, that the holdup increased as the non-newtonian simulant shear strength decreased (apparent viscosity decreased). Such results raised the potential of increased flammable gas retention in Hanford Waste Treatment and Immobilization Plant (WTP) vessels mixed by air sparging and pulse-jet mixers (PJMs) during a Design Basis Event (DBE). Additional testing was performed to determine the effects of simulant properties, composition of alternate AFAs, and presence of trace noble metals. Key results are that: • Increased gas holdup resulting from addition of Q2-3183A is due to a decrease in surface tension that supports small bubbles which have low rise velocities. • Dow Corning 1520-US AFA shows it to be a viable replacement to Dow Corning Q2-3183A AFA. This alternative AFA, however, requires significantly higher dosage for the same anti-foam function. • Addition of noble metals to the AZ-101 waste simulant does not produce a catalytic gas retention effect with the AFA. INTRODUCTION The Waste Treatment Plant at the Hanford Site in Washington state utilizes combined Pulse Jet Mixers and spargers for mixing of radioacative waste slurries and release of hydrogen gas. The anti-foam agent DOW Corning Q2-3183A will be added to waste streams in the WTP to prevent foaming. These waste streams with finely divided solids are subject to foaming due to a phenomenon called particle-stabilized foaming (i) increases with increasing superficial velocity 2 1 The vessel dimensions are 1/9 th linear scale of the plant but no other geometrical similarities exist with the plant. 2 . Superficial Velocity = Gas Generation Rate Per Unit Volume ÷ Slurry Surface Area; the slurry surface area being the area of the slurry at the surface level of the vessel

Wet Distillers Grains and Ratios of Steam-Flaked and Dry-Rolled Corn

Feeding different ratios of dryrolled corn (DRC) and steam-flaked corn (SFC) in diets that contain 0 or 35% wet distillers grains plus solubles (WDGS) was evaluated. As SFC replacedDRC in diets containing no WDGS, F:G improved. Varying SFC and DRC ratio in diets containing 35% WDGS did not impact F:G. Feeding WDGS increased hot carcass weight, and fat depth while feeding different ratios of corn impacted marbling deposition. Wet distillers grains appears to reducethe positive impacts of feeding SFC in finishing diets when included at 35% of diet DM

The Effect of Lameness on Average Daily Gain in Feedlot Steers

The objective of this study was to test the effects of lameness on average daily gain (ADG) of feedlot steers. We evaluated two feedlot health data sets: 1) 14,798 steers from a 14-year period (1993 to 2006) at the Meat Animal Research Center (USDA MARC) near Clay Center, Neb.; and 2) 16,766 steers from an 8-year period (2002 to 2009) at the University of Nebraska Agricultural Research and Development Center (ARDC) near Mead, Neb. The ADG for USDA MARC steers with lameness late in the feeding period (≥ 60 days) was 0.04 lb./day less than steers without lameness. The ADG for ARDC steers with lameness later in the experimental trial period (≥ 60 days) was 0.2 lb./day less than steers without lameness. Lameness in steers had a significant and meaningful negative effect on ADG later in the feeding period