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1.
A method was developed to optimize simultaneous selection for a quantitative trait with a known QTL within a male and a female line to maximize crossbred performance from a two-way cross. Strategies to maximize cumulative discounted response in crossbred performance over ten generations were derived by optimizing weights in an index of a QTL and phenotype. Strategies were compared to selection on purebred phenotype. Extra responses were limited for QTL with additive and partial dominance effects, but substantial for QTL with over-dominance, for which optimal QTL selection resulted in differential selection in male and female lines to increase the frequency of heterozygotes and polygenic responses. For over-dominant QTL, maximization of crossbred performance one generation at a time resulted in similar responses as optimization across all generations and simultaneous optimal selection in a male and female line resulted in greater response than optimal selection within a single line without crossbreeding. Results show that strategic use of information on over-dominant QTL can enhance crossbred performance without crossbred testing. 相似文献
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Effect of postnatal development on calcium currents and slow charge movement in mammalian skeletal muscle 总被引:16,自引:3,他引:13 下载免费PDF全文
Single- (whole-cell patch) and two-electrode voltage-clamp techniques were used to measure transient (Ifast) and sustained (Islow) calcium currents, linear capacitance, and slow, voltage-dependent charge movements in freshly dissociated fibers of the flexor digitorum brevis (FDB) muscle of rats of various postnatal ages. Peak Ifast was largest in FDB fibers of neonatal (1-5 d) rats, having a magnitude in 10 mM external Ca of 1.4 +/- 0.9 pA/pF (mean +/- SD; current normalized by linear fiber capacitance). Peak Ifast was smaller in FDB fibers of older animals, and by approximately 3 wk postnatal, it was so small as to be unmeasurable. By contrast, the magnitudes of Islow and charge movement increased substantially during postnatal development. Peak Islow was 3.6 +/- 2.5 pA/pF in FDB fibers of 1-5-d rats and increased to 16.4 +/- 6.5 pA/pF in 45-50-d-old rats; for these same two age groups, Qmax, the total mobile charge measurable as charge movement, was 6.0 +/- 1.7 and 23.8 +/- 4.0 nC/microF, respectively. As both Islow and charge movement are thought to arise in the transverse-tubular system, linear capacitance normalized by the area of fiber surface was determined as an indirect measure of the membrane area of the t-system relative to that of the fiber surface. This parameter increased from 1.5 +/- 0.2 microF/cm2 in 2-d fibers to 2.9 +/- 0.4 microF/cm2 in 44-d fibers. The increases in peak Islow, Qmax, and normalized linear capacitance all had similar time courses. Although the function of Islow is unknown, the substantial postnatal increase in its magnitude suggests that it plays an important role in the physiology of skeletal muscle. 相似文献
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For a finite locus model, Markov chain Monte Carlo (MCMC) methods can be used to estimate the conditional mean of genotypic values given phenotypes, which is also known as the best predictor (BP). When computationally feasible, this type of genetic prediction provides an elegant solution to the problem of genetic evaluation under non-additive inheritance, especially for crossbred data. Successful application of MCMC methods for genetic evaluation using finite locus models depends, among other factors, on the number of loci assumed in the model. The effect of the assumed number of loci on evaluations obtained by BP was investigated using data simulated with about 100 loci. For several small pedigrees, genetic evaluations obtained by best linear prediction (BLP) were compared to genetic evaluations obtained by BP. For BLP evaluation, used here as the standard of comparison, only the first and second moments of the joint distribution of the genotypic and phenotypic values must be known. These moments were calculated from the gene frequencies and genotypic effects used in the simulation model. BP evaluation requires the complete distribution to be known. For each model used for BP evaluation, the gene frequencies and genotypic effects, which completely specify the required distribution, were derived such that the genotypic mean, the additive variance, and the dominance variance were the same as in the simulation model. For lowly heritable traits, evaluations obtained by BP under models with up to three loci closely matched the evaluations obtained by BLP for both purebred and crossbred data. For highly heritable traits, models with up to six loci were needed to match the evaluations obtained by BLP. 相似文献
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Frederick E. Hoxie Oonagh O'Brien Tamara Dragadze Samuel C. Heilman Nebahat S. Tokatli Terence Ranger 《Ethnic and racial studies》2013,36(3):433-447
Stephen Cornell, THE RETURN OF THE NATIVE: AMERICAN INDIAN POLITICAL RESURGENCE, New York and Oxford: Oxford University Press, 1988, 278 pp., $29.95. Jack D. Forbes, BLACK AFRICANS AND NATIVE AMERICANS: COLOR, RACE AND CASTE IN THE EVOLUTION OF RED‐BLACK PEOPLES, Oxford and New York: Basil Blackwell, 1988, 334 pp., £35.00. Maryon McDonald, ’WE ARE NOT FRENCH!’: LANGUAGE, CULTURE AND IDENTITY IN BRITTANY, London: Routledge, 1989, 384 pp., £40.00. Ronald Grigor Suny, THE MAKING OF THE GEORGIAN NATION, London: I. B. Taurus and Co. Ltd., 1989, ix‐395 pp., £29.50. Shlomo Deshen, THE MELLAH SOCIETY: JEWISH COMMUNITY LIFE IN SHERIFIAN MOROCCO, translated and revised from the Hebrew by the author. Chicago: The University of Chicago Press, 1989, xii + 152 pp., £23.95 and £9.50 (paper). Roger Waldinger, Howard Aldrich, Robin Ward and Associates, ETHNIC ENTREPRENEURS: IMMIGRANT BUSINESS IN INDUSTRIAL SOCIETIES, Sage Series on Race and Ethnic Relations, vol. 1., Newbury Park, CA: Sage Publications, 1990, 226 pp., £29.25 and £13.95 (paper). Saul Dubow, RACIAL SEGREGATION AND THE ORIGINS OF APARTHEID IN SOUTH AFRICA, 1919–36, St Antony's and Macmillan, London, 1989, xi and 250 pp., £35.00. Mark Duffield, BLACK RADICALISM AND THE POLITICS OF DE‐INDUSTRIALISATION: THE HIDDEN HISTORY OF INDIAN FOUNDRY WORKERS, Avebury, 1988, 226 pp., £24.50. John Eade, THE POLITICS OF COMMUNITY: THE BANGLADESHI COMMUNITY IN EAST LONDON, Avebury, 1989, 213 pp., £24.00. Nicole Hahn Rafter (ed.), WHITE TRASH: THE EUGENICS FAMILY STUDIES 1877–1919, Boston: Northeastern University Press, 1988, 382 pp., £36.00. Neil R. McMillen, DARK JOURNEY ‐ BLACK MISSISSIPPIANS IN THE AGE OF JIM CROW, Urbana, Ill: University of Illinois Press, 1989, N.P.L. 相似文献
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Background
Designing maximally selective ligands that act on individual targets is the dominant paradigm in drug discovery. Poor selectivity can underlie toxicity and side effects in the clinic, and for this reason compound selectivity is increasingly monitored from very early on in the drug discovery process. To make sense of large amounts of profiling data, and to determine when a compound is sufficiently selective, there is a need for a proper quantitative measure of selectivity. 相似文献9.
Pasquier CM; Promponas VI; Varvayannis NJ; Hamodrakas SJ 《Bioinformatics (Oxford, England)》1998,14(8):749-750
Summary : FT is a tool written in C++, which implements the Fourier
analysis method to locate periodicities in aminoacid or DNA sequences. It
is provided for free public use on a WWW server with a Java interface.
Availability : The server address is http://o2.db. uoa.gr/FT Contact :
shamodr@atlas.uoa.gr
相似文献
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