Genetics statistics and relationships of teat and udder traits, somatic cell counts, and milk production

Teat lengths and diameters, udder clearance, cleft depth, and distances between teats were measured from 1967 to 1982 on Holstein cows. Numbers of observations per trait ranged from 5934 to 11,449. Cows were from six herds owned by the North Carolina Department of Agriculture and two research herds of North Carolina State University. Repeatabilities between adjacent lactations for physical traits of udder were mostly between .60 and .80. Repeatabilities between first and second lactations for average somatic cell count and mean log somatic cell count were .11 +/- .04 and .21 +/- .04. Heritabilities in first lactation were .63 for front teat length, .44 for teat diameter, .56 for rear udder clearance, .10 for cleft depth, .32 for mature equivalent milk, and .18 for somatic cell counts. Heritabilities of distances between teats ranged from .33 to .48. Cows with udder clearance higher from the ground, deeper clefts, smaller distances between teats, and teats of smaller diameter had lower somatic cell counts. Multiple regression analysis showed that dams' somatic cell counts and rear udder clearances were not significant predictors of daughters' somatic cell counts. Lactation average somatic cell counts of daughters were predicted with greater accuracy from averages of somatic cell counts of multiple lactations of dams than from single lactations of dams. Milk production and somatic cell counts seemed positively genetically correlated, more so in first than later lactations.     

Normal aging and prospective memory.

We develop a laboratory paradigm for studying prospective memory and examine whether or not this type of memory is especially difficult for the elderly. In two experiments, young and old subjects were given a prospective memory test (they were asked to perform an action when a target event occurred) and three tests of retrospective memory (short-term memory, free recall, and recognition). From the perspective that aging disrupts mainly self-initiated retrieval processes, large age-related decrements in prospective memory were anticipated. However, despite showing reliable age differences on retrospective memory tests, both experiments showed no age deficits in prospective memory. Moreover, regression analyses produced no reliable relation between the prospective and retrospective memory tasks. Also, the experiments showed that external aids and unfamiliar target events benefit prospective memory performance. These results suggest some basic differences between prospective and retrospective memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microchannel reactor architecture enables greener processes

Green Chemistry is a design philosophy that aims to reduce or eliminate negative environmental impacts resulting from the production and use of chemicals. Microchannel process technology offers process intensification, in the form of enhanced heat and mass transfer, to a wide range of chemical reactions. This paper describes how the application of microchannel technology can help producers achieve the goals of Green Chemistry and minimize the environmental consequences of chemical and fuel production. The examples used to illustrate these advantages are Velocys’ Fischer-Tropsch synthesis for biomass-to-liquids, DSM and Karlsruhe collaboration for fine chemical production, and Stevens Institute's work in applying microchannels to the production of hydrogen peroxide, as well as a detailed study of how microchannel architecture can minimize pollutant emissions from steam methane reforming.     

Solid-state nuclear magnetic resonance investigation of cation siting in LiNaLSX zeolites

The location of Li⁺ and Na⁺ cations in a series of dehydrated low-silica LiNaX zeolites (LiNaLSX, framework Si/Al ratio=1.0) were characterized by ⁷Li and ²³Na magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. Depending on the Li⁺ content, up to three lines were observed in the ⁷Li MAS NMR spectra attributed to Li⁺ cations on SI′, SII and SIII sites. The ²³Na MAS NMR spectra of the pure sodium form NaLSX and of LiNaLSX samples with low Li⁺ contents contain up to five lines belong to Na⁺ cations located on SI, SI′, SII, and two different SIII′ sites. LiNaLSX zeolites containing more than 40% of Li⁺ show only a single narrow line in the ²³Na MAS NMR spectra attributed to mobile sodium cations. The populations of the different cation sites were determined from the relative line intensities of the MAS NMR spectra. Below about 70% Li⁺ exchange, lithium cations are located only on sites SI′ and SII. Between 70% and 100% Li⁺ content these sites are fully occupied by Li⁺, and the population of site SIII by Li⁺ increases. It was found that the nitrogen-adsorption capacity correlates well with the occupation of Li⁺ at site SIII.     

Influence of porosity on PE molecular weight from the Phillips Cr/silica catalyst

The porosity of Phillips Cr/silica catalysts plays a major role in determining the molecular weight (MW) and molecular weight distribution obtained during ethylene polymerization. A survey of the many different families of silica was made to evaluate this connection. No one single physical catalyst property, such as surface area, pore volume, radius of curvature, or average pore diameter, could be universally correlated with the MW of polyethylene. Instead the data seem to suggest that the trends observed are the result of two independent influences. First, pore volume determines the fragility of the catalyst, which governs the degree of fragmentation during polymerization, and the fragment size. Secondly, pore diameter controls how easily the polymer can escape from the interior of the fragment. These variables are explored, and possible explanations for the observed behavior are discussed.     

Growth and reproduction characteristics of purebred and crossbred dairy cattle in first lactation

Breed additive, maternal, and heterozygotic effects on 11 monthly postpartum body weights, average size, weight gain, age at first calving, and days open were estimated by linear regression analyses from records of 680 purebred and crossbred animals. Calving year, age, and milk yield were significant environmental effects. Positive regressions of age on body weights indicated late calving cows were heaviest postpartum and had most days open. Negative regressions of milk yield on weight gain and postpartum weight showed greatest losses of weight associated with highest yields. There were breed differences in growth; purebreds highest to lowest were Brown Swiss, Holstein, Red Dane, Jersey, and Ayrshire and for weight gain, Brown Swiss, Ayrshire, and for weight gain, Brown Swiss, Ayrshire, Jersey, Holsteins, and Red Dane. Crosses were superior to purebreds in these traits. Additive effects of Holstein were greater than Ayrshire, Jersey, and Red Dane for postpartum body weights and average size. All constants for heterozygotic effect combinations were significant for postpartum weights and average size. Heterozygosity effects increased in magnitude with advancing lactation. Generally, age at first calving and postpartum interval to conception reflected little heterozygotic or maternal effects. There was some indication of breed differences in mean and additive effects for age at first calving.     

Geometrical optics prediction of surface scattering statistics

A composite-roughness formulation of the geometrical optics approximation is applied to study the statistics of near-nadir electromagnetic scattering from the sea surface. For scattering from Gaussian random surfaces, the scattering cross section is dependent only on the probability density of surface slopes. The statistical distribution of the scattered intensity depends on both the slope probability density function and <|/spl Omega/|> $the mean absolute value of the surface curvature. The curvature is of interest because it provides a measure of capillary wave spectra. Numerical results are obtained for scattering from isotropic surfaces for a fixed number N of specular scatterers and for N Poisson distributed. Obtaining viable estimates of <|/spl Omega/|>, and hence of capillary wave spectra, from backscatter data at microwave frequencies may not be practical. Optical measurements for which individual point scatterers can be identified may, however, yield estimates of the surface curvature.     

Manual materials handling capabilities in non-standard postures.

Research efforts to establish manual materials handling (MMH) capabilities of individuals and populations have been conducted for many years. Most of the previous efforts have explored 'standard postures', utilizing two-handed, symmetric, sagittal plane MMH using unrestricted postures. Recognizing that many industrial MMH activities do not utilize 'standard postures', recent research projects have explored psychophysically determined MMH capacities in a variety of non-standard postures. Among the non-standard postures examined were: twisting while lifting or lowering, lifting and lowering from lying, sitting, kneeling, and squatting positions, and carrying loads under conditions of constricted ceiling heights. This paper presents the results of a series of previous research efforts at Texas Tech University. The results are presented in the form of population capabilities of both males and females for 99 MMH tasks using 'non-standard postures'. The data tables contain means and standard deviations of the data, as well as percentile distributions for the subject populations. Sample sizes for the experimental populations ranged from 45 to 50 subjects of each sex in the first three experiments to 20 subjects of each sex in the fourth set of experiments.     

Severe mental illness and HIV-related medical and neuropsychiatric sequelae

Medical and neuropsychiatric sequelae of HIV infection present a spectrum of diagnostic and treatment challenges to mental health clinicians. Both HIV and the many opportunistic infections that manifest in patients due to their immunocompromised state also can affect the central nervous system (CNS). Thus, mental health clinicians need to be familiar with the diagnosis and management of HIV-related medical and psychiatric complications. This article provides an overview of the CNS-related manifestations resulting from HIV disease, including HIV-related dementia, psychotic disorders, delirium, CNS opportunistic infections and tumors, systemic abnormalities, psychoactive substances, and the adverse effects of certain medical treatments. Treatment strategies for individuals with HIV disease and comorbid severe mental illness are outlined and recommendations for future research are offered.     

Sensory characterization of human milk

Fore and hind milks from a single morning feed collected from 24 nursing mothers over 3 consecutive d were evaluated for sweetness, viscosity, and mouthcoat by a trained adult panel using magnitude estimation. Milks were perceived as sweet, thin, and low in mouthcoat. Hind milks were slightly more viscous and mouthcoating than fore milks. The higher fat content in hind milk was associated with higher estimation of physical viscosity. Milk fat content decreased as maternal age increased. Significant differences occurred between milks in lactose, fat, and protein contents. By use of a sweetness power function curve, the sweetness intensity of human milk was estimated as equivalent to a 2.12% sucrose solution.