Electron-impact rotational and hyperfine excitation of HCN, HNC, DCN and DNC

Rotational excitation of isotopologues of HCN and HNC by thermal electron-impact is studied using the molecular {\bf R}-matrix method combined with the adiabatic-nuclei-rotation (ANR) approximation. Rate coefficients are obtained for electron temperatures in the range 5$-$6000 K and for transitions among all levels up to J=8. Hyperfine rates are also derived using the infinite-order-sudden (IOS) scaling method. It is shown that the dominant rotational transitions are dipole allowed, that is those for which $\Delta J=1$. The hyperfine propensity rule $\Delta J=\Delta F$ is found to be stronger than in the case of He$-$HCN collisions. For dipole allowed transitions, electron-impact rates are shown to exceed those for excitation of HCN by He atoms by 6 orders of magnitude. As a result, the present rates should be included in any detailed population model of isotopologues of HCN and HNC in sources where the electron fraction is larger than 10$^{-6}$, for example in interstellar shocks and comets.Comment: 12 pages, 4 figures, accepted in MNRAS (2007 september 3

How to Use Fewer Markers in Admixture Studies

Swiss Fleckvieh has been established from 1970 as a composite of Simmental and Red Holstein Friesian cattle. Breed composition is currently reported based on pedigree information. Information on ancestry informative molecular markers potentially provides more accurate information. For the analysis Illumina Bovine SNP50 Beadchip data for 495 bulls were used. Markers were selected based on difference in allele frequencies in the pure populations, using FST as an indicator. Performance of sets with decreasing number of markers was compared. The scope of the study was to see how much we can reduce the number of markers based on FST to get a reliability that is close to that with the full set of markers. On these sets of markers hidden Markov models (HMM) and methods used in genomic selection (BayesB, partial least squares regression, LASSO variable selection) were applied. Correlations of admixture levels were estimated and compared with admixture levels based on pedigree information. FST chosen SNP gave very high correlations with pedigree based admixture. Only when using 96 and 48 SNP with the highest FST, correlations dropped to 0.92 and 0.90, respectively

Hierarchical structure of the Sicilian goats revealed by Bayesian analyses of microsatellite information

Genetic structure and relationship amongst the main goat populations in Sicily (Girgentana, Derivata di Siria, Maltese and Messinese) were analysed using information from 19 microsatellite markers genotyped on 173 individuals. A posterior Bayesian approach implemented in the program STRUCTURE revealed a hierarchical structure with two clusters at the first level (Girgentana vs. Messinese, Derivata di Siria and Maltese), explaining 4.8% of variation (AMOVA ФST estimate). Seven clusters nested within these first two clusters (further differentiations of Girgentana, Derivata di Siria and Maltese), explaining 8.5% of variation (AMOVA ФSC estimate). The analyses and methods applied in this study indicate their power to detect subtle population structure

Inbreeding, Microsatellite Heterozygosity, and Morphological Traits in Lipizzan Horses

While the negative effects of inbreeding and reduced heterozygosity on fecundity and survival are well established, only a few investigations have been carried out concerning their influence on morphological traits. This topic is of particular interest for a small and closed population such as the Lipizzan horse. Thus, 27 morphological traits were measured in 360 Lipizzan mares and were regressed on the individual inbreeding coefficients, as well as on the individual heterozygosity and mean squared distances (mean d2) between microsatellite alleles within an individual. Both individual heterozygosity and mean d2 were based on 17 microsatellite loci dispersed over 14 chromosomes. The results obtained by multivariate analysis reveal significant effects of stud (P <.0001), age at measurement (P <.0001), and mean d2 (P =.0143). In univariate analyses, significant associations were obtained between length of pastern-hindlimbs and inbreeding coefficient (P <.01), length of cannons-hindlimb and mean d2 (P <.01), and length of neck and mean d2 (P <.001). After adjustment of single-test P values for multiple tests (Hochberg's step-up Bonferroni method), only the association of the length of neck and mean d2 remained significant (P =.0213). Thus, no overall large effects of inbreeding, microsatellite heterozygosity, and mean d2 on morphological traits were observed in the Lipizzan hors

Non-relativistic quantum scattering from non-local separable potentials: the eigenchannel approach

A recently formulated version of the eigenchannel method [R. Szmytkowski, Ann. Phys. (N.Y.) {\bf 311}, 503 (2004)] is applied to quantum scattering of Schr\"odinger particles from non-local separable potentials. Eigenchannel vectors and negative cotangents of eigenphase-shifts are introduced as eigensolutions to some weighted matrix spectral problem, without a necessity of prior construction and diagonalization of the scattering matrix. Explicit expressions for the scattering amplitude, the total cross section in terms of the eigenchannel vectors and the eigenphase-shifts are derived. An illustrative example is provided.Comment: 10 pages, slightly improved versio

The Impact of Cytoplasmic Inheritance on Sperm Quality in Fleckvieh Bulls

Detrimental impact of certain mitogenome mutations on sperm quality traits, and consequently on male fertility is well documented in humans. With a quantitative genetic mixed model, we analysed the impact of cytoplasmic effects, maternal lineages treated as random effect, on sperm quality traits in 554 Austrian Fleckvieh bulls. We have observed that 2% of the phenotypic variance for transformed total number of spermatozoa is due to cytoplasmic (maternal lineage) effects. Regarding percent of viable live spermatozoa, no cytoplasmic effects were detected. However, the observed effects still need to be further evaluated from three perspectives, the analysis of the mitogenome polymorphism effects and the impact of the mitogenome effects on the realised fertility as well as on the whole production economically