Quantum Interference in Superconducting Wire Networks and Josephson Junction Arrays: Analytical Approach based on Multiple-Loop Aharonov-Bohm Feynman Path-Integrals

We investigate analytically and numerically the mean-field superconducting-normal phase boundaries of two-dimensional superconducting wire networks and Josephson junction arrays immersed in a transverse magnetic field. The geometries we consider include square, honeycomb, triangular, and kagome' lattices. Our approach is based on an analytical study of multiple-loop Aharonov-Bohm effects: the quantum interference between different electron closed paths where each one of them encloses a net magnetic flux. Specifically, we compute exactly the sums of magnetic phase factors, i.e., the lattice path integrals, on all closed lattice paths of different lengths. A very large number, e.g., up to $10^{81}$ for the square lattice, exact lattice path integrals are obtained. Analytic results of these lattice path integrals then enable us to obtain the resistive transition temperature as a continuous function of the field. In particular, we can analyze measurable effects on the superconducting transition temperature, $T_c(B)$, as a function of the magnetic filed $B$, originating from electron trajectories over loops of various lengths. In addition to systematically deriving previously observed features, and understanding the physical origin of the dips in $T_c(B)$ as a result of multiple-loop quantum interference effects, we also find novel results. In particular, we explicitly derive the self-similarity in the phase diagram of square networks. Our approach allows us to analyze the complex structure present in the phase boundaries from the viewpoint of quantum interference effects due to the electron motion on the underlying lattices.Comment: 18 PRB-type pages, plus 8 large figure

Evolution des paramètres biochimiques chez les chevaux de sport pendant un test d’effort

L’étude avait pour objectif d’évaluer les modifications des paramètres biochimiques chez les chevaux de sport (course de saut d’obstacle) durant un test d’effort. Vingt-trois chevaux de sport de race barbe espagnol âgés de 9,34±1,02 ans ont servi d’animaux d’expérimentation. Des prélèvements sanguins ont été effectués sur chaque animal avant, juste après et 30 minutes après le test d’effort. Les variations significatives des paramètres biochimiques ont été notées. Les valeurs de l’hématocrite, de la créatinine kinase (CK), de l’aspartate aminotransférase (ASAT), de la créatinine, des protéines totales et du phosphore ont varié significativement selon la période de prélèvement (p˂0,05). Le niveau de compétition a eu aussi un effet significatif sur les valeurs des protéines totales, de l’albumine, du phosphore, du calcium, du magnésium et du glucose (p˂0,05). De même, les valeurs de l’ASAT, de la créatinine, de l’albumine et du glucose (p˂0,05) ont varié significativement en fonction de la fréquence de compétition. L’évaluation de la forme de ces chevaux de sport est d’une grande utilité dans l’appréciation des conditions physiques.© 2016 International Formulae Group. All rights reserved.Mots clés: Cheval de sport, paramètres biochimiques, test d’effort, SénégalEnglish Title: Evolution of biochemical parameters in sport horses subjected to a stress testEnglish AbstractThe study aimed to assess changes in biochemical parameters in jumping race horses during a stress test. Twenty-three Spanish barb racehorses aged in average of 9.34 ± 1.02 years were used as experimental animals. Blood samples were collected from each animal before, immediately after and 30 minutes after the stress test. Significant changes in biochemical parameters were noted. The values of hematocrit, Creatinine Kinase, Aspartate aminotransferase (AST), creatinine, total proteins and phosphorus varied significantly according to the sampling period (p˂0.05). The level of competition had also a significant effect on the values of total proteins, albumin, phosphorus, calcium, magnesium and glucose (p˂0.05). Similarly, the values of AST, creatinine, albumin and glucose (p˂0.05) varied significantly depending on the competition frequency. The evaluation of the fitness of these racehorses is of great use in assessing the physical conditions.© 2016 International Formulae Group. All rights reserved.Keywords: Racehorses, biochemical parameters, stress test, Senega

Facteurs de variation genetique de la productivite du zebu Gobra: Croissance avant et apres sevrage

Presentation des resultats d'une etude sur les possibilitis d'amelioration genetique du zebu Gobra au Senegal dependant beaucoup sur les correlations genetiques et phenotypiques et sur les heritabilites de la croissance de cette race

Results of five years of research on Peul and Touabire sheep at Dahra (Senegal)

Presents results of a five year research on peul and Touabire sheep at Dahra (Senegal) with partic. ref. to fertility, prolificity, lamb mortality, weight, growth, and productivity

Technical and economic study of three methods of reproduction in Sahel sheep at Dahra, Senegal

Presents results of a technical and economic study of three methods of reproduction in Sahel sheep at Dahra, Senegal. Compares the different modern technologies with natural breeding to find out the profitability of increased reproductive rates

Application of population genetic analysis of linked, mapped microsatellites to the identification of loci under selection for disease resistance

We have sought to test the possibility of detecting regions of the genome under selection through effects on variation at linked neutral genetic markers. Particularly, we investigated three genomic regions identified by mapping in a cross-bred pedigree as harbouring QTL for trypanosomiasis tolerance. Population genetic analysis is used with mapped microsatellites to try to infer selection for trypanotolerance in West African cattle populations

Variation in chicken populations may affect the enzymatic activity of lysozyme

The chicken lysozyme gene encodes a hydrolase that has a key role in defence, especially in ovo. This gene was resequenced in global chicken populations [red, grey, Ceylon and green jungle fowl (JF)] and related bird species. Networks, summary statistics and tests of neutrality indicate that although there is extensive variation at the gene, little is present at coding sites, with the exception of one non-synonymous site. This segregating site and a further fixed non-synonymous change between red JF and domestic chicken populations are spatially close to the catalytic sites of the enzyme and so might affect its activity