“
“Like many other bacteria, Escherichia coli remain as tiny viable individuals named persisters Poziotinib ic50 after being exposed to an antibiotic. These persisters are believed to be phenotypic heterogeneous one rather than mutants, because their progenies are as Susceptible to antibiotics

as their ancestors. Recently, two persister-related genes (hipB/hipA) were confirmed to belong to a toxin-antitoxin (TA) module. Their control circuit was believed to be responsible for generation of the persister subpopulation. For the well-studied TA module, we build a simple genetic regulation model to explain the phenotypic heterogeneity. We find that a sole double-negative feedback loop is not enough to explain the phenotypic heterogeneity:

the cooperation mechanisms in HipB and HipA are indispensable. Moreover, our model illustrates an important persister-related experimental phenomenon: the emergence of the persister depends on the growth rate in continuous culture. (C) 2008 Elsevier Ltd. All rights reserved”
“Sex differences in performance and in cortical activation patterns during mental rotation have rather consistently been reported. Data regarding sex differences of event-related potentials during the classic three-dimensional mental rotation task developed by Shepard and Metzler, however, are absent, and were therefore being addressed by this study. AZD6738 purchase Mental rotation-related event-related ACY-738 in vitro potential effects were observed 900-1000 ms poststimulus at parietal

electrodes and 600-700 as well as 800-900 ms poststimulus at right frontal leads, respectively. Sex differences, however, were observed already 400-700 ms poststimulus at right frontal electrodes. These findings suggest that sex differences during three-dimensional mental rotation occurred in relatively early cognitive processing stages presumably including perception and identification of stimuli instead of mental rotation itself. NeuroReport 20:43-47 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.”
“During the immune response, the generation of memory B lymphocytes in germinal centers involves affinity maturation of the cells’ antigen receptors, based on somatic hypermutation of receptor genes and antigen-driven selection of the resulting mutants. Affinity maturation is vital for immune protection, and is the basis Of humoral immune learning and memory. Lineage trees of somatically hypermutated immunoglobulin genes often serve to qualitatively illustrate claims concerning the dynamics of affinity maturation in germinal centers.