They also performed better on a written calculation task when problems were presented as a monetary transaction compared to a standard arithmetic problem. A reference group of patients with Alzheimer’s disease
(AD) showed the reverse pattern. The findings provide convincing evidence that autobiographical relevance influences SD patients’ arithmetic performance. Moreover, they challenge current views on conceptual number knowledge as a unitary, abstract competence. (C) PF-6463922 purchase 2009 Elsevier Ltd. All rights reserved.”
“We study the plasticity of a delayed stochastic model of a genetic toggle switch as a multipotent differentiation pathway switch, at the single cell and cell population levels, by observing distributions of differentiation pathways choices of genetically homogeneous cell populations. Assuming a model of stochastic pathway determination of cell differentiation that is regulated by the proteins of the switch, we vary the proteins’ expression level and degradation rates, which cells are known to be able to regulate, to vary mean level , noise, and bias of the proteins’ expression levels. It is shown that small changes in each of these dynamical features significantly and distinctively affects the dynamics of the switch at the single cell level and thus,
the cell differentiation patterns. The regulation of SNX-5422 molecular weight these features allows cells to regulate their pluripotency and cell populations’ distribution of lineage choice, suggesting that the stochastic switch has high plasticity regarding differentiation pathway choice regulation, thus providing adaptability to environmental stresses and changes. (C) 2009 Elsevier Ltd. All rights reserved.”
“A comparison is made between orthologous proteins from a methanogen (Methanopyrus kandleri) and from a non-methanogen (Pyrococcus abyssi) in order to determine the amino
acid substitution pattern. This analysis makes it possible to establish which amino acids are significantly and asymmetrically utilised by these two organisms. A methanophily index (MI) based on this asymmetry makes it possible for any protein to be associated with a numerical value which, when calculated for the same orthologous protein from methanogenic and non-methanogenic Cediranib (AZD2171) organisms, turns out to have the power to discriminate between these two groups of organisms, even if only for about 20% of the analysed proteins. The MI can also be associated to the genetic code under the assumption that the frequency of synonymous codons specifying the amino acids in the genetic code also reflects the frequency with which amino acids appeared in ancestral proteins. Finally a t-test shows that the MI value associated to the genetic code is not different from the mean value of the MI deriving from methanogen proteins, but it differs from the mean MI of non-methanogen proteins. This might indicate that the genetic code evolved in a methanogenic ‘organism’. (C) 2009 Elsevier Ltd. All rights reserved.
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