Regulation of Helicobacter pylori Urease and Acetone Carboxylase Genes by Nitric Oxide and the CrdRS Two-Component System.

Helicobacter pylori colonizes the human gastric mucosa and causes various gastroduodenal diseases, including peptic ulceration and gastric cancer. Colonization requires the actions of two-component systems (TCSs) to sense and respond to changes in the host environment. In this study, we evaluated gene regulation mediated by the CrdRS TCS.

A triple-star system with a misaligned and warped circumstellar disk shaped by disk tearing.

Young stars are surrounded by a circumstellar disk of gas and dust, within which planet formation can occur. Gravitational forces in multiple star systems can disrupt the disk. Theoretical models predict that if the disk is misaligned with the orbital plane of the stars, the disk should warp and break into precessing rings, a phenomenon known as disk tearing.

Imaging fictive locomotor patterns in larval Drosophila.

We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca(2+) indicators. The Ca(2+) signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed.

Initiation of primary myogenesis in amniote limb muscles.

Background: Vertebrate muscles are defined and patterned at the stage of primary myotube formation, but there is no clear description of how these cells form in vivo. Of particular interest is whether primary myotubes are "seeded" by a unique myoblast population that differentiates as mononucleated myocytes, similar to the founder myoblasts of insects.

Results: We analyzed the cell populations and processes leading to initiation of primary myogenesis in limb buds of rats and mice.