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Biology subjects

Vural, D.

Publications and source records attributed to Vural, D..

3 recordsLinked to original sources

Interdependence Theory of Tissue Failure: Bulk and Boundary Effects

The mortality rate of many complex multicellular organisms increase with age, which suggests that net aging damage is accumulative, despite remodeling processes. But how exactly do little mishaps in the cellular level accumulate and spread to become a systemic catastrophe? To address this question we present experiments with synthetic tissues, an analytical model consistent with experiments, and a number of implications that follow the analytical model. Our theoretical framework describes how shape, curvature and density influences the propagation of failure in a tissue subject to oxidative damage. We propose that aging is an emergent property governed by interaction between cells, and that intercellular processes play a role that are at least as important as intracellular ones.

biophysics

Shearing in flow environment promotes evolution of social behavior in microbial populations

It is advantageous for microbes to form social aggregates when they commonly benefit from secreting a public good. However, cooperating microbial groups can be evolutionarily unstable, since a cheating strain that does not secrete the public good can reproduce quicker and take over. Here we study the effects of fluid advection patterns on group reproduction as a mechanism to enable or enhance social behavior in microbial populations. We use a realistic advection-diffusion-reaction model to describe microbial growth and mutation in a flow environment. Social groups arise naturally from our model as self-reproducing Turing patterns that can avoid mutant takeovers at steady state. Our central finding is that flow shear enables and promotes social behavior in microbes by limiting the spread of cheating strains. Regions of the flow domain with higher shear admits high cooperativity and large population density, whereas low shear regions are devoid of life due to opportunistic mutations.

bioinformatics

Cheater-altruist synergy in immunopathogenic ecological public goods games

Much research has focused on the deleterious effects of free-riding in public goods games, and a variety of mechanisms that suppresses cheating behavior. Here we argue that under certain conditions cheating behavior can be beneficial to the population. In a public goods game, cheaters do not pay for the cost of the public goods, yet they receive the benefit. Although this free-riding harms the entire population in the long run, the success of cheaters may aid the population when there is a common enemy that antagonizes both cooperators and cheaters. Here we study models in which an immune system antagonizes a cooperating pathogen. We investigate three population dynamics models, and determine under what conditions the presence of cheaters help defeat the immune system. The mechanism of action is that a polymorphism of cheaters and altruists optimizes the average growth rate. Our results give support for a possible synergy between cooperators and cheaters in ecological public goods games.

ecology