Nouvelles précisions sur la carte génétique du système de groupes sanguins B des bovins

Onze nouveaux cas de recombinaison au sein du système de groupes sanguins B ont été observés dans les races bovines Charolaise, Normande, Montbéliarde et Française Frisonne Pie-Noire. Par rapport aux conclusions précédentes (GROSCLAUDE et al., 1979), l’analyse de ces cas permet de localiser avec plus de précision, dans la carte du système, les déterminants génétiques des facteurs P1, P2, 01, E’1, P’2, F20, BG2K et celui du facteur E’3 voisin de T. Les déterminants des facteurs A" et B" ont été introduits dans la carte. Il est vérifié que les facteurs E’1 et E’2 sont sous le contrôle de déterminants génétiques distincts. Par ailleurs, dans l’un des cas, on observe à nouveau l’absence du groupe E’3G" dans un phénogroupe recombiné, pourtant issu d’un génotype homozygote pour ce groupe, ce qui conduit à admettre l’existence d’au moins deux sites non contigus pour E’3G". La relation entre le taux apparent de recombinaison intra-race au système B et le taux de recombinaison entre les bornes du système fait l’objet d’une analyse préliminaire.Eleven additional cases of recombination within the B blood group system have been. observed in the Charolais, Normande, Montbéliard and French Friesian cattle breeds. As compared to previous conclusions (GROSCLAUDE et al., 1979), examination of those cases made possible a more precise localisation in the map of the system, of the genetic determinants of factors P1, P2, 01, E’1, P’2, F20, BG2K and of the E’3 factor close to T. The determinants of factors A" and B" have been introduced in the map. Evidence is presented for the factors E’1 and E’2 having distinct genetic determinants. In addition, in one of the cases, the absence of the group E’3G" in the recombined phenogroup derived from a genotype homozygous for this group was observed again ; this led to the postulate that there are at least two sites for E’3G". The relation between the apparent within breed rate of recombination of the B system, and the rate of recombination between the limits of the system was preliminarily investigated

Polymorphisme de la caséine αs2 bovine: étroite liaison du locus αs2-Cn avec les loci αs1-Cn, β-Cn et κ-Cn; mise en évidence d'une délétion dans le variant αs2-Cn D

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Mechanical Design Analysis of MQXFB, the 7.2-m-Long Low-β Quadrupole for the High-Luminosity LHC Upgrade

As part of the High-Luminosity Large Hadron Collider (LHC) Project, a set of Nb Snquadrupoles are being developed, aiming to enhance the performance of the inner triplets. The new magnets, identified as MQXFA and MQXFB, will share the same cross section with two different lengths, 4.2 and 7.2 m, respectively. During the magnet development, three short models were tested, along with a number of mechanical models, demonstrating the capability of the magnet cross section to achieve the specified performances. The same performances are now required for the full-length magnets. To ensure this, the authors studied the impact of the magnet length on the capability of the structure to provide an adequate support to the coils. Finite element and simplified analytical models were used to evaluate the impact of the magnet length on the stresses in the magnet ends and coil elongation during powering. The models were calibrated using the results from the short model tests, and used to provide an indication on the required prestress and its foreseen impact on the magnet performance.

Mechanical Performance of Short Models for MQXF, the Nb3Sn Low-β Quadrupole for the Hi-Lumi LHC

In the framework of the Hi-Lumi LHC Project, CERN and U.S. LARP are jointly developing MQXF, a 150-mm aperture high-field Nb3Sn quadrupole for the upgrade of the inner triplet of the low-beta interaction regions. The magnet is supported by a shell-based structure, providing the preload by means of bladder-key technology and differential thermal contraction of the various components. Two short models have been produced using the same cross section currently considered for the final magnet. The structures were preliminarily tested replacing the superconducting coils with blocks of aluminum. This procedure allows for model validation and calibration, and also to set performance goals for the real magnet. Strain gauges were used to monitor the behavior of the structure during assembly, cool down and also excitation in the case of the magnets. The various structures differ for the shell partitioning strategies adopted and for the presence of thick or thin laminations. This paper presents the results obtained and discusses the mechanical performance of all the short models produced up to now