NeuroReport 21:709-715 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.”
“Plasmids are important vehicles for horizontal gene transfer and rapid adaptation in bacteria, including the spread of antibiotic resistance genes. Conjugative transfer of a plasmid from a plasmid-bearing to a plasmid-free bacterial cell requires contact and attachment of the cells followed by plasmid DNA transfer prior to detachment. We introduce a system of differential equations for plasmid transfer in well-mixed populations that accounts for attachment, DNA transfer, and selleck inhibitor detachment dynamics. These equations offer advantages over classical

mass-action models that combine these three processes into a single “”bulk”" conjugation rate. By decomposing the

process of plasmid transfer into its constituent parts, this new model provides a framework that facilitates meaningful comparisons of plasmid transfer rates in surface and liquid environments. The model also allows one to account for experimental and environmental effects such as mixing intensity. To test the adequacy of the model and further explore the effects of mixing on plasmid transfer, we performed batch culture experiments using three different plasmids and a range of different mixing intensities. The results show that plasmid transfer is optimized at low to moderate shaking speeds and that vigorous shaking negatively affects plasmid transfer. Using reasonable assumptions on attachment and detachment C646 rates, the mathematical model Staurosporine in vivo predicts the same behavior. (C) 2009 Elsevier Ltd. All rights

reserved.”
“We assessed the effects of a single episode of maternal alcohol intoxication on fetal brain blood perfusion in three pregnant dams (baboons) at the 24th week of pregnancy using dynamic susceptibility contrast magnetic resonance imaging. After the oral administration of alcohol, there was a four-fold increase in the peak contrast concentrations in the fetal brain. In addition, we observed a two-to three-fold increase in the contrast uptake and washout rates in the fetal brain. The underlying mechanisms of these changes are unknown, but we hypothesized that these could include the alcohol-mediated changes in placental permeability and fetal cerebral blood flow. Our findings indicate that alcohol intoxication produces profound changes, which may detrimentally influence neurodevelopmental processes in the brain. NeuroReport 21:716-721 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.”
“Mathematical models accounting for well-known evidences relating to the dynamics of interleukin 2, helper and regulatory T cells are presented. These models extend an existent model (the so-called cross-regulation model of immunity), by assuming IL-2 as the growth factor produced by helper cells, but used by both helper and regulatory cells to proliferate and survive.