322 research outputs found
Relationships among estimates of inbreeding depression, dominance and additive variance for linear traits in Holsteins
Estimates of dominance and additive variances were obtained for 14 linear traits. The data included 600 678 first parity records on 14 linear traits in Holsteins. The model included management groups, age at calving, additive and dominance effects, and regression on inbreeding percentage. The estimate of the dominance variance was 9.8% of the phenotypic variance for body depth: 8.0% for strength, 6.9% for stature, and was less than 5% for the remaining traits. The additive variance ranged from 12.2% for foot angle to 45.3% for stature. No clear relationship was found between the estimates of dominance and additive variance. larger negative estimates of the inbreeding depression were associated with higher estimates of the dominance variance
Constructing and Leveraging “Flight and Expulsion”: Expellee Memory Politics and Victimhood Narratives in the Federal Republic of Germany, 1944-1970
My dissertation examines the construction, instrumentalization, and institutionalization of a homogenized “master narrative” of “flight and expulsion” in West Germany between 1945 and 1990. I argue that expellee groups, historians, and politicians cemented a victimhood narrative and idealized past that emphasized German suffering and Soviet barbarity in museums, literature, and the media in order to underpin arguments for social, material, and political claims. In this manner, the expellee organizations fashioned a central concept of “flight and expulsion” and colonized public debates for decades, leaving a lasting impact on how contemporary Germany remembers the war and the integration of 10-12 million refugees. By examining the trajectory of the expulsion narrative, I seek to show the layering of memory, how it was used over time, and the defining impact that this victimhood discourse has had on German public memory and academic interpretation of the phenomenon. My work investigates the origins and evolution of a discourse that continues to inform German historical consciousness, thereby providing fresh insights into the relationship between memory politics, the production and narration of history, and political interest group advocacy.Doctor of Philosoph
Estimation of Genetic Parameters for Growth, Feed Consumption, and Conformation Traits for Double-Muscled Belgian Blue Bulls Performance-Tested in Belgium
For 1,442 Belgian Blue bulls performance- tested at the Centre de Selection de la Race Blanc-Bleue Belge, nine traits were observed: height at withers at 7 mo, height at withers at 13 mo, weight at 7 mo, weight at 13 mo, average feed consumption of concentrates, average daily gain, average feed consumption of concentrates per average daily gain, average feed consumption of concentrates per mean metabolic weight, and price per kilogram of live weight. This price is based on muscle conformation and is therefore used as muscle conformation score. Restricted maximum likelihood with a derivative-free algorithm was used to estimate (co)variance components because there were different models and missing values per trait. Estimates of heritabilities were above .50 except for average feed consumption per average daily gain (.16) and average feed consumption per mean metabolic weight (.33). Estimates of genetic and phenotypic correlations between height at withers and weight traits were positive and moderate to high. Average daily gain showed a negative genetic correlation with weight at 7 mo ( -.68) but had positive correlations with height at withers at 13 mo and weight at 13 mo (.22 and .43). Muscle conformation expressed as price per kilogram of live weight was related to low average feed consumption per average daily gain. Average feed consumption showed high correlations with weight at 7 mo and weight at 13 mo. Average feed consumption per average daily gain had a high negative genetic correlation with average daily gain ( -.89)
Generating new magnetic properties in organic-inorganic hybrids
Organic-inorganic hybrids are a rapidly developing class of multifunctional materials, which can present properties different from those of either of their building blocks. Control over the structure during the assembly process is crucial to achieve the desired functions. Here we present the layer-by-layer deposition in ambient conditions of CoCl4-octahedra or MnCl4-octahedra and organic layers to tailor their magnetic properties. The Langmuir-Blodgett technique used to assemble these structures provides intrinsic control over the film structure down to the molecular level. Magnetic characterization reveals that MnCl4-based hybrid Langmuir-Blodgett films order antiferromagnetically like the bulk hybrid, while the CoCl4-based hybrid Langmuir-Blodgett films show ferromagnetic coupling in contrast to the bulk hybrid, which is a paramagnet.</p
Contribution de la biologie moléculaire à la sélection animale: les marqueurs génétiques
Avec la domestication des animaux de rente, les éleveurs ont cherché d'une part, à
accroître les performances de leurs animaux en sélectionnant dans la population mise à leur
disposition les sujets les plus performants pour la (les) caractéristique(s) recherchée(s) et
d'autre part, à réduire l'impact des zoonoses en sélectionnant les animaux résistants. Toutefois,
si cette approche de la sélection a permis inconsciemment de favoriser au sein de la
population les génotypes intéressants pour les critères recherchés, il importe de garder en
mémoire que la production et la santé animale résultent non seulement du potentiel génétique
mais également d'interactions entre l'alimentation, le statut physiologique, les facteurs environnementaux et le savoir-faire de l'éleveur
Insertion of Iron Decorated Organic-Inorganic Cage-Like Polyhedral Oligomeric Silsesquioxanes between Clay Platelets by Langmuir Schaefer Deposition
Tuning the architecture of multilayer nanostructures by exploiting the properties of their constituents is a versatile way to develop multifunctional films. Herein, we report a bottom-up approach for the fabrication of highly ordered hybrid films consisting of dimethyldioctadecylammonium (DODA), iron decorated polyhedral oligomeric silsesquioxanes (POSS), and montmorillonite clay platelets. Clay platelets provided the template where Fe/POSS moieties were grafted by the use of the surfactant. Driven by the iron ions present, DODA adopted a staggered arrangement, which is essential to realize the controllable layer-by-layer growth of the film. The elemental composition of the film was studied by X-ray photoelectron spectroscopy and X-ray reflectivity confirmed the existence of smooth interfaces between the different layers
Effects of Acetate on Cation Exchange Capacity of a Zn-Containing Montmorillonite:Physicochemical Significance and Metal Uptake
Fundamental properties such as cation exchange capacity (CEC), permanent charge, pH(PZC), and metal uptake of a Zn-containing montmorillonite are modified, in a predictable manner, by a mild chemical treatment using acetate. Acetate treatment allows a controllable increase of the CEC of montmorillonite up to 180 mequiv/100 g. The CEC of the clay is increasing for decreasing Zn content, with a slope of Delta[Zn/Delta[CEC] approximate to -2. X-ray powder diffraction analysis shows that the lamellar structure of the clay remains unaltered by the acetate treatment, while XPS substantiates the removal of Zn. H(+) uptake data show that the intrinsic protonation pK values and concentration of the variable charge sites ( SOH) are not modified by the acetate treatment. In contrast, the concentration of the permanent charge sites ( X(-)) increased linearly with Zn removal by acetate, leading to a significant H(+) and Cd(2+) uptake enhancement. A physical model is suggested where acetate removes Zn ions strongly bound in the clay, and this in turn modulates the permanent charge and the CEC of the clay
Studies on the value of incorporating the effect of dominance in genetic evaluations of dairy cattle, beef cattle and swine
Nonadditive genetic effects are currently ignored in national genetic evaluations of farm animals because of ignorance of thelevel of dominance variance for traits of interest and the difficult computational problems involved. Potential gains fromincluding the effects of dominance in genetic evaluations include “purification” of additive values and availability ofpredictions of specific combining abilities for each pair of prospective parents. This study focused on making evaluation withdominance effects feasible computationally and on ascertaining benefits of such an evaluation for dairy cattle, beef cattle,and swine. Using iteration on data, computing costs for evaluation with dominance effects included costs could be less thantwice expensive as with only an additive model. With Method Â, variance components could be estimated for problemsinvolving up to 10 millions equations. Dominance effects accounted for up to 10% of phenotypic variance; estimates werelarger for growth traits. As a percentage of additive variance, the estimate of dominance variance reached 78% for 21-d litterweight of swine and 47% for post weaning weight of beef cattle. When dominance effects are ignored, additive evaluationsare “contaminated”; effects are greatest for evaluations of dams in a single large family. These changes in ranking wereimportant for dairy cattle, especially for dams of full-sibs, but were less important for swine. Specific combining abilitiescannot be included in sire evaluations and need to be computed separately for each set of parents. The predictions of specificcombining abilities could be used in computerized mating programs via the Internet. Gains from including the dominanceeffect in genetic evaluations would be moderate but would outweigh expenditures to produce those evaluations
National single-step genomic method that integrates multi-national genomic information
The aim of this paper was to develop a national single-step genomic BLUP that integrates multi-national genomic estimated breeding values (EBV) and associated reliabilities without double counting dependent data contributions from the different evaluations. Simultaneous use of all data, including phenotypes, pedigree, and genotypes, is a condition to obtain unbiased EBV. However, this condition is not always fully met, mainly due to unavailability of foreign raw data for imported animals. In dairy cattle genetic evaluations, this issue is traditionally tackled through the multiple across-country evaluation (MACE) of sires, performed by Interbull Centre (Uppsala, Sweden). Multiple across-country evaluation regresses all the available national information onto a joint pedigree to obtain country-specific rankings of all sires without sharing the raw data. In the context of genomic selection, the issue is handled by exchanging sire genotypes and by using MACE information (i.e., MACE EBV and reliabilities), as a valuable source of “phenotypic” data. Although all the available data are considered, these “multi-national” genomic evaluations use multi-step methods assuming independence of various sources of information, which is not met in all situations. We developed a method that handles this by single-step genomic evaluation that jointly (1) uses national phenotypic, genomic, and pedigree data; (2) uses multi-national genomic information; and (3) avoids double counting dependent data contributions from an animal’s own records and relatives’ records. The method was demonstrated by integrating multi-national genomic EBV and reliabilities of Brown Swiss sires, included in the InterGenomics consortium at Interbull Centre, into the national evaluation in Slovenia. The results showed that the method could (1) increase reliability of a national (genomic) evaluation; (2) provide consistent ranking of all animals: bulls, cows, and young animals; and (3) increase the size of a genomic training population. These features provide more efficient and transparent selection throughout a breeding program
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