The phenomenon of switching in-between the purifying selection and haplotype complementation has a phase transition character, and many relations between the effective population size, coding density, chromosome size and recombination frequency are those of the power law type. (C) 2010 Elsevier Ltd. All rights reserved.”
“Spinal muscular atrophy Stattic (SMA), a neurodegenerative disorder primarily affecting motor neurons, is the most common

genetic cause of infant death. This incurable disease is caused by the absence of a functional SMN1 gene and a reduction in full length survival of motor neuron (SMN) protein. In this study, a neuroprotective function of SMN was investigated in differentiated human SH-SY5Y cells using an adenoviral vector to over-express SMN protein. The pro-survival capacity of SMN was assessed in an Akt/PI3-kinase inhibition (LY294002) model, as well as an oxidative stress (hydrogen peroxide) and excitotoxic (glutamate) model. SMN over-expression Cyclopamine in SH-SY5Y cells protected against Akt/phosphatidylinositol 3-kinase (PI3-kinase)

inhibition, but not oxidative stress, nor against excitotoxicity in rat cortical neurons. Western analysis of cell homogenates from SH-SY5Y cultures over-expressing SMN harvested pre- and post-Akt/PI3-kinase inhibition indicated that SMN protein inhibited caspase-3 activation via blockade of calpain-mediated procaspase-3 cleavage. This study has revealed a novel anti-apoptotic function for the SMN protein in differentiated SH-SY5Y cells. Finally, the cell death model described herein will allow the assessment of future therapeutic agents or strategies aimed at increasing SMN protein levels. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Biotic

recoveries following mass extinctions are characterized by a complex set of dynamics, including the rebuilding of whole Etomoxir mouse ecologies from low-diversity assemblages of survivors and opportunistic species. Three broad classes of diversity dynamics during recovery have been suggested: an immediate linear response, a logistic recovery, and a simple positive feedback pattern of species interaction. Here we present a simple model of recovery which generates these three scenarios via differences in the extent of species interactions, thus capturing the dynamical logic of the recovery pattern. The model results indicate that the lag time to biotic recovery increases significantly as biotic interactions become more important in the recovery process. (C) 2010 Elsevier Ltd. All rights reserved.”
“One of the most promising models of Parkinson’s disease to have emerged in recent years is one in which the pesticide, rotenone, is administered systemically to laboratory rats.