sigma(B), the general stress response sigma factor of Bacillus subtilis, is activated when the cell's energy levels decline or the bacterium is exposed to environmental stress (e.g., heat shock, ethanol). Physical stress activates sigma(B) through a collection of regulatory kinases and phosphatases (the Rsb proteins) which catalyze the release of sigma(B) from an anti-sigma(B) factor inhibitor....

A hallmark of sporulation of Bacillus subtilis is the formation of two distinct cells by an asymmetric division. The development programs in these two cells involve the compartmentalized activities of sigma E in the larger mother cell and of sigma F in the smaller prespore. Activation of sigma E requires expression of the sigma F-directed gene spoIIR. By immunofluorescence microscopy of a strai...

Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP) that play critical roles in transcription initiation, including the recognition and opening of promoters as well as the initial steps in RNA synthesis. This review focuses on the structure and function of the major sigma-70 class that includes the housekeeping sigma factor (Group 1) that directs the bulk of transcription...

Liquid-vapor coexistence curves and critical parameters for hard-core 1:1 electrolyte models with diameter ratios lambda = sigma(-)/sigma(+) = 1 to 5.7 have been studied by fine-discretization Monte Carlo methods. Normalizing via the length scale sigma(+/-) = 1 / 2(sigma(+)+sigma(-)), relevant for the low densities in question, both T(*)(c) ( = k(B)T(c)sigma(+/-)/q(2)) and rho(*)(c) ( = rho(c)s...

Quasi-periodic oscillations (QPOs) are often present in the X-ray flux from accreting stellar-mass black holes (BHs). If they due to relativistic (Lense-Thirring) precession of an inner accretion flow which is misaligned with disc, iron emission line caused by irradiation disc will rock systematically between red and blue shifted during each QPO cycle. Here we conduct phase-resolved spectroscop...

Investigations of the formation young stellar objects (YSOs) and planets require detailed analysis individual sources as well statistical a larger number objects. The Hubble UV Legacy Library Young Stars Essential Standards (ULLYSES) project provides such unique opportunity by establishing spectroscopic library high- low-mass stars in local universe. Here we analyse optical photometry three ULL...