2,326 research outputs found

    A model for phenotype change in a stochastic framework

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    some species, an inducible secondary phenotype will develop some time after the environmental change that evokes it. Nishimura (2006) [4] showed how an individual organism should optimize the time it takes to respond to an environmental change ("waiting time''). If the optimal waiting time is considered to act over the population, there are implications for the expected value of the mean fitness in that population. A stochastic predator-prey model is proposed in which the prey have a fixed initial energy budget. Fitness is the product of survival probability and the energy remaining for non-defensive purposes. The model is placed in the stochastic domain by assuming that the waiting time in the population is a normally distributed random variable because of biological variance inherent in mounting the response. It is found that the value of the mean waiting time that maximises fitness depends linearly on the variance of the waiting time

    Collective patterns arising out of spatio-temporal chaos

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    We present a simple mathematical model in which a time averaged pattern emerges out of spatio-temporal chaos as a result of the collective action of chaotic fluctuations. Our evolution equation possesses spatial translational symmetry under a periodic boundary condition. Thus the spatial inhomogeneity of the statistical state arises through a spontaneous symmetry breaking. The transition from a state of homogeneous spatio-temporal chaos to one exhibiting spatial order is explained by introducing a collective viscosity which relates the averaged pattern with a correlation of the fluctuations.Comment: 11 pages (Revtex) + 5 figures (postscript

    Gene expression profiling in the Cynomolgus macaque Macaca fascicularis shows variation within the normal birth range

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    BACKGROUND: Although an adverse early-life environment has been linked to an increased risk of developing the metabolic syndrome, the molecular mechanisms underlying altered disease susceptibility as well as their relevance to humans are largely unknown. Importantly, emerging evidence suggests that these effects operate within the normal range of birth weights and involve mechanisms of developmental palsticity rather than pathology. METHOD: To explore this further, we utilised a non-human primate model Macaca fascicularis (Cynomolgus macaque) which shares with humans the same progressive history of the metabolic syndrome. Using microarray we compared tissues from neonates in the average birth weight (50-75(th )centile) to those of lower birth weight (5-25(th )centile) and studied the effect of different growth trajectories within the normal range on gene expression levels in the umbilical cord, neonatal liver and skeletal muscle. RESULTS: We identified 1973 genes which were differentially expressed in the three tissue types between average and low birth weight animals (P < 0.05). Gene ontology analysis identified that these genes were involved in metabolic processes including cellular lipid metabolism, cellular biosynthesis, cellular macromolecule synthesis, cellular nitrogen metabolism, cellular carbohydrate metabolism, cellular catabolism, nucleotide and nucleic acid metabolism, regulation of molecular functions, biological adhesion and development. CONCLUSION: These differences in gene expression levels between animals in the upper and lower percentiles of the normal birth weight range may point towards early life metabolic adaptations that in later life result in differences in disease risk

    Knowledge Exchange Through Science Diplomacy to Assist Disaster Risk Reduction. Progress in Disaster Science

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    This paper analyses science diplomacy efforts to reduce disaster risks and proposes establishing national knowledge exchange centers (KECs) to help individual states adhere to their Sendai Framework goals. KECs are considered to be interconnected globally and work together to promote resilience efforts by facilitating sharing of information and strategies in risk monitoring, assessment, and ultimately reduction across the globe. KECs can provide high-quality scientific evidence for informed decisionmaking along with a component related to disaster science media to ensure that appropriate knowledge reaches a variety of people who need it in different forms tailored for them. KECs can promote transdisciplinary education in disaster-related science diplomacy (i.e., disaster diplomacy). The United Nations Office for Disaster Risk Reduction (UNDRR) and the International Science Council (ISC) can provide assistance to KECs through UNDRR National Platforms and ISC Members

    E2F1 Orchestrates Transcriptomics and Oxidative Metabolism in Wharton's Jelly-Derived Mesenchymal Stem Cells from Growth-Restricted Infants

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    10.1371/journal.pone.0163035PloS one119e0163035GUSTO (Growing up towards Healthy Outcomes
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