Detection and characterization of differences in plasma corticoid response to treatments.

Ten experiments involving 3013 observations and 103 animals were studied to characterize variation associated with bovine plasma corticoid concentrations (ng/ml). Total corticoids, corticosterone, or cortisol were measured by competitve protein binding assay. Animals were noncystic or cystic, and measurements were made to establish basal concentrations or to estimate response to stimulation by adrenocorticotrophic hormone injection. Data were analyzed by least squares with the nested model: treatment regimen, animal in treatment, sample in animal in treatment, and sampling time to the highest order of regression (up to seventh) which was statistically significant (P less than .05). Estimates of error variances ranged from .31 for basal cortisol in cystic animals to 233.27 for total corticoids in noncystic, stimulated animals. Coefficients of variation among experiments ranged from 33 to 87% with mean 61%. In most analyses, estimates of experimental error were large indicating need for careful attention to experimental design to insure efficient least-cost experimentation. Use of the power function for nested analysis of variance to accomplish this is demonstrated.     

Effects of administration of bovine somatotropin on milk yield and composition

Thirty-two Holstein cows were assigned to four treatment groups in a continuous lactation trial to evaluate effects of daily subcutaneous injections of 0 (A), 5.15 (B), 10.3 (C), and 20.6 mg (D) of recombinantly derived bovine somatotropin monomer. Responses were milk yield and composition, component yields, net energy intake, body weight, and somatic cell counts. Treatments began in fall, 28 to 35 d postpartum, and continued for 266 d. Base ration was corn silage and concentrate. Least squares means of milk and constituent yields and gross efficiency of milk production differed among treatments, but percentage fat and protein, energy intake, body weights, and somatic cell counts did not. Least squares means of 3.5% FCM were 21.3 (A), 25.0 (B), 26.2 (C), and 28.5 kg/d (D); fat and protein yields showed similar response to treatment. Milk yields adjusted for pretreatment yields were 21.1 (A), 25.5 (B), 26.5 (C), and 29.3 kg/d (D). Orthogonal contrasts showed lower milk and constituent yields and net energy intake for control (A) than for hormone-injected cows (B, C, D), but no differences were detected between treatments B, C, and D. Gross efficiency of production (3.5% FCM/feed net energy intake) was greater for hormone-injected cows.     

Degradation action of water on S-glass

Glass fiber reinforced composites have been used to an increasing extent as structural components because of their high strength at relatively low densities. They are more resistant to moisture and weathering than most other structural materials. However, under environments of high humidity and temperature, glass fiber composites with an epoxy or polyester matrix lose a considerable fraction of their.strength- after a relatively short time. For high strength glass reinforced composites, the glass filaments are mostly of the S-glass and E-glass types. This investigation reports the solvent effect of water on S-glass rovings (filament strands) and powders. S-glass is the strongest silicate glass developed in the past decade, the composition of which in weight percent is: A1₂O₃/MgO/SiO₂ = 25/10/65. In the temperature range covered (30 to 50°C), analyses of aluminum, magnesium, and silicon in water after different time periods indicate that magnesium is preferentially leached out of S-glass, either as filaments or as powders, by water. The concentrations of magnesium and silicon in the water reached 2 mg/litre or more depending on the temperature and length of contact time, while the aluminum concentration reached no more than 0.2 mg/litre. Decomposition products of the ingredients present in a composite, including the coupling and curing agents, could further complicate the degradation process. Rate relations are proposed and discussed based on the dissolution data.     

Free convection about a rectangular prismatic crystal growing from a solution

Sodium chlorate crystals growing from unstirred aqueous solutions were observed by schlieren techniques. Growth rate data were best correlated by Sh = 0.48 Ra^0.25 with finite interface kinetics and a characteristic length L equal to the crystal height plus the inverse reciprocal sum of the horizontal dimensions. The growth rate was slightly higher when the plume was laminar than when it was irregular. The horizontal growth rate was greater than the vertical growth rate, with the ratio tending to decrease with increasing plume instability. The threshold Grashof number for plume instability was greatly decreased with decreasing height for crystals with the same horizontal dimensions. The frequency of eddy emission was proportional to L⁻²Ra^0.8. The velocity of the eddies approached a constant value with increasing distance above the crystal surface, the terminal value being roughly proportional to Ra^1/2/L.     

Effects of variations in the preparatory interval on the reaction time of retardates and normals.

Conducted 2 studies to evaluate the effects, on simple RTs, of warning signal duration (WSD) and preparatory interval (PI) with normal and mentally retarded Ss. In Exp. I PIs of 2, 4, 8, and 12 sec. were presented in an unpredictable sequence. For 1/2 of the Ss the warning signal remained on throughout the entire PI (filled condition) and for the remainder of the Ss, the warning signal was present for only 1.5 sec. of the PI. Significant effects of intelligence, PI, and WSD were found. The interaction Intelligence * PI was also significant. The unfilled condition resulted from produced faster RTs for both normals and retardates. The interaction resulted from the particularly poor performance of the retardates at the short PIs. Exp. II employed a 1.5 sec WSD with PIs of 2, 4, 8, 16, and 32 sec. An interaction was found involving intelligence and PI. Results are discussed in terms of temporal uncertainty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vital statistics and reasons for disposal of United States and Canadian artificial insemination dairy sires

Vital statistics were evaluated for artificial insemination sires leaving service during 1939 through 1974. Data consisted of 11,704 sires of six breeds. The major cause for leaving service was reproductive failure at a frequency of 32.5%; next ranked was undesirable characteristics of offspring with a frequency of 20.7%. Overall culling rate for low yields of daughters was 14.8%, but after 1965 this cause accounted for about 30%. Mean life span was 3.4 yr with small differences among years. Breed differences were detected for service life and causes for leaving service. Modifications of classic life table techniques are needed to reflect entry of sires into service at various ages and evaluation of vital statistics subsequent to 1974.