Generation of an intense cold-atom beam from a pyramidal magneto-optical trap: experiment and simulation

An intense cold-atom beam source based on a modified pyramidal magneto-optical trap has been developed and characterized. We have produced a slow beam of cold cesium atoms with a continuous flux of 2.2× 10^9 atoms/s at a mean velocity of 15 m/s and with a divergence of 15 mrad. The corresponding radiant intensity is 1.2×10^13 atom s^−1 sr^−1. We have characterized the performance of our beam source over a range of operating conditions, and the measured values for atom flux, mean velocity, and divergence are in good agreement with results from detailed Monte Carlo numerical simulations

Diversity analysis of cotton (Gossypium hirsutum L.) germplasm using the CottonSNP63K Array

Cotton germplasm resources contain beneficial alleles that can be exploited to develop germplasm adapted to emerging environmental and climate conditions. Accessions and lines have traditionally been characterized based on phenotypes, but phenotypic profiles are limited by the cost, time, and space required to make visual observations and measurements. With advances in molecular genetic methods, genotypic profiles are increasingly able to identify differences among accessions due to the larger number of genetic markers that can be measured. A combination of both methods would greatly enhance our ability to characterize germplasm resources. Recent efforts have culminated in the identification of sufficient SNP markers to establish high-throughput genotyping systems, such as the CottonSNP63K array, which enables a researcher to efficiently analyze large numbers of SNP markers and obtain highly repeatable results. In the current investigation, we have utilized the SNP array for analyzing genetic diversity primarily among cotton cultivars, making comparisons to SSR-based phylogenetic analyses, and identifying loci associated with seed nutritional traits. (Résumé d'auteur