410 research outputs found
Evaluation of Replacements by Selection Index Methods
A computer program has been developed that will aid producers in using selection index methods for evaluation of prospective replacement animals. Justification for use of selection index methods and a demonstration of the program are presented
Property in the Welfare State
A primary goal of the welfare state is to promote individual dignity by guaranteeing a decent standard of living for all. The individual\u27s ability to achieve a sense of self-worth turns on the opportunity to participate in, and contribute to, society in a meaningful fashion. Achievement of such goals is seriously undermined for those who do not have their basic needs guaranteed; shelter, food, health, and education are vital interests of the individual which, if not available in sufficient quantity or quality, hamper or make impossible the opportunity to achieve self-dignity and respect. The instruments for guaranteeing the substratum of support in a welfare state can be multilayered and variegated in nature. Ideally, all individuals would be able to look after their own needs by having access to work. However, it is clear that no modem society has ever been able to guarantee productive jobs for all. There are many who cannot work, such as the young, the infirm, and the elderly. During processes of rapid change, workers are forced out of jobs because they possess skills which are not readily adaptable to new environments, processes, and technologies
Retained Ownership of Beef Cattle When Considering Production and Price Risk
Livestock Production/Industries,
Genetic Correlations Among Sex-Limited Traits
Monte Carlo simulation techniques were used to assess the merits of three methods for calculation of the genetic correlation when traits have been measured on half-sibs of each sex. The restricted maximum likelihood, path coefficient and covariance component estimators did not differ significantly in their accuracy. Path coefficient and covariance component methodologies gave nearly unbiased estimators for traits of high heritability. Across both levels of heritability, the restricted maximum likelihood methodology resulted in genetic correlations being estimated with significantly smaller sampling variance than the other methods. Genetic correlations were estimated for age of puberty, weight at puberty, conceptions per service, gestation length, calving difficulty, progeny birth weight, progeny preweaning daily gain and mature weight measured on females, with postweaning daily gain, carcass weight, fat trim weight, and retail product weight measured on male half-sibs. Correlations of the female traits with postweaning daily gain, carcass weight, and retail product weight generally were similar to each other. Correlations of fat trim weigh with the female traits were similar in magnitude and opposite in sign to the correlations of postweaning daily gain, carcass weight, and retail product weight with the female traits. Predicted correlated responses to one phenotypic standard deviation of selection for increased postweaning daily gain were increased age at puberty 3.39 days, weight at puberty 1.02 kg, dam’s progeny birth weight .50 kg and mature weight 1.45 kg and reduced g station length .20 days and the frequency of calving difficulty .07 percent. The estimated genetic correlations of postweaning daily gain of the dam’s steer half-sibs with conceptions per service and dam’s progeny preweaning daily gain had absolute values greater than one and were positive and negative, respectively. Predicted correlated responses to one phenotypic standard deviation of selection for reduced fat trim weight at a constant age were increased age at puberty 7.22 days, weight at puberty 5.29 kg, gestation length .17 days, the frequency of calving difficulty .05 percent, birth weight, .12 kg and mature weight .22 kg and decreased conceptions per service .01 units. The estimated genetic correlation of age constant fat trim weigh with dam’s progeny preweaning daily gain was less than negative one
The DSM-5: hyperbole, hope or hypothesis?
The furore preceding the release of the new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is in contrast to the incremental changes to several diagnostic categories, which are derived from new research since its predecessor’s birth in 1990. While many of these changes are indeed controversial, they do reflect the intrinsic ambiguity of the extant literature. Additionally, this may be a mirror of the frustration of the field’s limited progress, especially given the false hopes at the dawn of the “decade of the brain”. In the absence of a coherent pathophysiology, the DSM remains no more than a set of consensus based operationalized adjectives, albeit with some degree of reliability. It does not cleave nature at its joints, nor does it aim to, but neither does alternate systems. The largest problem with the DSM system is how it’s used; sometimes too loosely by clinicians, and too rigidly by regulators, insurers, lawyers and at times researchers, who afford it reference and deference disproportionate to its overt acknowledged limitations
Solitary waves in focussing and defocussing nonlinear, nonlocal optical media
Nonlinear, nonlocal optical media has emerged as an ideal setting for experimentally
observing and studying spatial optical solitary waves which otherwise cannot occur in
Kerr media. Of particular interest is the eventual application to all-optical circuits.
However, there is considerable work left to do on the theoretical end before this is a
possibility. In this thesis we consider three problems. The first is how to solve the governing
equations for optical beam propagation in the particular medium of the nematic
liquid crystal (NLC), which is used as a prototypical example, exactly and approximately.
In this respect we provide the first known, explicit solutions to the model as
well as a comprehensive assessment on how to use variational, or modulation theory,
in this context. This leads to the discovery of a novel form of bistability in the system,
which shows there are two stable solitary wave solutions for a fixed power or L2 norm.
We then consider how to approximate solutions for optical solitary waves propagating
in a more general class of nonlocal nonlinear media using asymptotic methods. This
is a long open problem and is resolved in the form of a simple to implement method
with excellent accuracy and general applicability to previously intractable models. We
conclude with the discovery and characterization of an instability mechanism in a coupled,
defocussing nonlinear Schrodinger system. We show there is no stable, coupled,
localized solution. This result is compared with the more well-studied bright solitary
wave system and physical and mathematical explanations are offered
Putative Loci Causing Early Embryonic Mortality in Duroc Swine
Lethal recessive alleles that act prenatally may be detected from the absence of homozygous individuals in a population. However, these alleles may be maintained at relatively low frequencies in populations as heterozygotes. In pigs, they may reduce litter size. This study aimed to detect putative lethal variants in the Duroc breed. Phenotypes for the numbers of piglets born (TNB), born live (BA), alive at 24 h (L24), stillborn (SB), and born as mummified fetuses (MM) were available from 5340 recorded litters which resulted from mating of 192 genotyped boars with sows of unknown genotype (dataset 1). An additional 50 litters were produced from parents that were both genotyped (dataset 2). Imputed genotypes of 650K SNPs for 1359 Duroc boars were used in this study. One significant SNP (Bonferroni corrected P = 5.5E-06) was located on SSC14 with 45.3 homozygous individuals expected but none observed. This SNP was significant for mummified fetuses. One hundred fifty two haplotypes were also found to potentially harbor recessive lethal mutations. Twenty-one haplotypes had a significant harmful effect on at least one trait. Two regions, located on SSC8 (144.9–145.5 Mb) and SSC9 (19–19.4 Mb) had significant effects on fertility traits in both datasets. Additionally, regions on SSC1 (82.0–82.8 Mb), SSC3 (73.3–73.7 and 87.1–87.5 Mb) and SSC12 (35.8–36.2 and 50.0–50.5 Mb) had significant deleterious effects on TNB or BA or L24 in dataset 1. Finally, a region on SSC17 (28.7–29.3 Mb) had significant effects on TNB, BA and L24 in dataset 2. A few candidate genes identified within these regions were described as being involved in spermatogenesis and male fertility (TEX14, SEP4, and HSF5), or displayed recessive lethality (CYP26B1, SCD5, and PCF11) in other species. The putative loci detected in this study provide valuable information to potentially increase Duroc litter size by avoiding carrier-by-carrier matings in breeding programs. Further study of the identified candidate genes responsible for such lethal effects may lead to new insights into functions regulating pig fertility
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