However, fluctuating environments likely favor a rise in redundancy over time. With greater redundancy, investment per individual control structure declines, causing a decay in the performance of each individual dimension of control. I conclude that the costs of control structures may influence regulatory architecture. (C) 2008 Elsevier Ltd. All rights reserved.”
“Many emerging and reemerging viruses, such as rabies, SARS, Marburg, and Ebola have bat populations as disease reservoirs. Understanding the
spillover from bats to humans and other animals, and the associated health risks requires an analysis of the disease dynamics in bat populations. Traditional compartmental epizootic models, which are relatively easy to implement and analyze, usually impose unrealistic aggregation assumptions about disease-related structure and depend on parameters www.selleckchem.com/products/bv-6.html that frequently are not measurable in field
conditions. We propose a novel combination of computational and adaptive modeling approaches that address the maintenance of emerging diseases in bat colonies through individual (intra-host) models of the response of the host to a viral challenge. The dynamics of the individual models are used to define survival, susceptibility and transmission conditions relevant to epizootics as well as to develop and parametrize models of the disease evolution into uniform and diverse populations. Applications of the proposed approach to modeling the effects of immunological heterogeneity on the dynamics of bat rabies are presented. DihydrotestosteroneDHT nmr (C) 2008 Elsevier Ltd. All rights reserved.”
“The divalent cation copper (Cu2+) has been shown to inhibit chloride currents mediated by the inhibitory glycine receptor (GlyR). Here, we analyzed Cu2+ inhibition of homo- and hetero-oligomeric GlyRs expressed in Xenopus oocytes. No significant
differences in Cu2+ inhibitory potency were found between alpha 1, alpha 2 and alpha 3 GlyRs as well as heteromeric alpha 1 beta receptors. Furthermore, GlyR alpha 1 mutations known to reduce inhibition or potentiation of GlyR currents by Zn2+ had no effect on Cu2+ inhibition. However, Cu2+ was found to competitively antagonize glycine binding, suggesting that Cu2+ binds at learn more the agonistbinding site. Mutations within the glycine-binding site of the GlyR alpha 1 subunit reduced the inhibitory potency of Cu2+ and led to an up to 4-fold potentiation of glycine-elicited currents by Cu2+. Molecular dynamics simulation suggests this to be due to increased Cu2+ binding energies. Our data show that GlyR binding-site mutations can convert inhibitors of agonist binding into highly effective positive modulators. (C) 2008 Elsevier Ltd. All rights reserved.”
“The dihydropyridines (DHPs), nifedipine and nicardipine, modulate native glycine receptors (GlyRs) at micromolar concentrations. Nicardipine has a biphasic potentiating and inhibitory effect, whereas nifedipine causes inhibition only.