Slit coordinates cardiac morphogenesis in Drosophila

AbstractSlit is a secreted guidance cue that conveys repellent or attractive signals from target and guidepost cells. In Drosophila, responsive cells express one or more of three Robo receptors. The cardial cells of the developing heart express both Slit and Robo2. This is the first report of coincident expression of a Robo and its ligand. In slit mutants, cardial cell alignment, polarization and uniform migration are disrupted. The heart phenotype of robo2 mutants is similar, with fewer migration defects. In the guidance of neuronal growth cones in Drosophila, there is a phenotypic interaction between slit and robo heterozygotes, and also with genes required for Robo signaling. In contrast, in the heart, slit has little or no phenotypic interaction with Robo-related genes, including Robo2, Nck2, and Disabled. However, there is a strong phenotypic interaction with Integrin genes and their ligands, including Laminin and Collagen, and intracellular messengers, including Talin and ILK. This indicates that Slit participates in adhesion or adhesion signaling during heart development

Low-Background gamma counting at the Kimballton Underground Research Facility

The next generation of low-background physics experiments will require the use of materials with unprecedented radio-purity. A gamma-counting facility at the Kimballton Underground Research Facility (KURF) has been commissioned to perform initial screening of materials for radioactivity primarily from nuclides in the 238U and 232Th decay chains, 40K and cosmic-ray induced isotopes. The facility consists of two commercial low-background high purity germanium (HPGe) detectors. A continuum background reduction better than a factor of 10 was achieved by going underground. This paper describes the facility, detector systems, analysis techniques and selected assay results.Comment: 7 pages, 7 figures. Submitted to NIM

Status of the MAJORANA DEMONSTRATOR experiment

The MAJORANA DEMONSTRATOR neutrinoless double beta-decay experiment is currently under construction at the Sanford Underground Research Facility in South Dakota, USA. An overview and status of the experiment are given.Comment: 8 pages, proceeding from VII International Conference on Interconnections between Particle Physics and Cosmology (PPC 2013), submitted to AIP proceeding