Results 231 to 240 of about 4,012 (254)

Survival Probability of Quasi-Species under Environmental Changes

Journal of the Korean Physical Society, 2008
We investigate the evolution of biological organisms under changing environments by using a Monte Carlo simulation of the parallel mutation-selection model for quasi-species, as well as a mean-eld analysis. For a given severity (how large the change is) and frequency (how often the change occurs) of the environmental change, biological organisms evolve
Yung-Gyung Kang, Jeong-Man Park
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Genetic variation and quasi-species

Current Opinion in Genetics & Development, 1992
During the past year the relative fitness, that is, overall replication ability, and the fitness gain of animal virus variants have been quantified, providing new insight into the dynamics for the generation of RNA virus quasi-species. Measurements of mutant frequencies and rates of genetic diversification have confirmed the extreme complexity of RNA ...
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Viral quasi-species and recombination

Proceedings of the Royal Society of London. Series B: Biological Sciences, 1996
Virus populations are complex ensembles of distinct but related genomes (so called quasi-species). Mathematical descriptions of viral quasi-species focus on point mutations as the principal source of variation. However, retroviruses (and many other viruses) are able to recombine their genomes.
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Emergence of Novel Enzyme Quasi-Species Depends on the Substrate Matrix

Journal of Molecular Biology, 2008
Current research on enzyme evolution has shown that many enzymes are promiscuous and have activities with alternative substrates. Mutagenesis tends to relax substrate selectivity, and evolving enzymes can be regarded (summed over evolutionary time) as clusters of enzyme variants, or "quasi-species," tested against a "substrate matrix" defined by all ...
Sanela, Kurtovic, Abeer, Shokeer, Bengt, Mannervik   +2 more
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Effect of epistasis on the evolution of the quasi-species model

Journal of the Korean Physical Society, 2012
Epistasis is a phenomenon of non-additive interactions between genes in determining phenotypes. We investigate how epistasis affects the evolution of the quasi-species model by using the parallel mutation-selection (ParaMuSe) quasi-species evolution model.
Yung-Gyung Kang, Jeong-Man Park
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A Quasi-Species Approach for Modeling the Dynamics of Polymorphic Worms

Proceedings IEEE INFOCOM 2006. 25TH IEEE International Conference on Computer Communications, 2006
Polymorphic worms can change their byte sequence as they replicate and propagate, thwarting the traditional signature analysis techniques used by many intrusion detection systems (IDSes). As the incidence of such worms becomes more frequent, it is important to understand their behavior and interaction with the IDSes in order to develop effective ...
B. Stephenson, B. Sikdar
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Molecular evolution and quasi-species

1994
Abstract As our first model of a primitive biochemical system, we will examine a model originally proposed by Manfred Eigen in 1971, and developed further by Eigen in collaboration with Peter Schuster in 1977. The model assumes the existence of molecules of an indeterminate structure which have the ability to replicate themselves without
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Mathematical Models of Quasi-Species Theory and Exact Results for the Dynamics

2015
We formulate the Crow-Kimura, discrete-time Eigen model, and continuous-time Eigen model. These models are interrelated and we established an exact mapping between them. We consider the evolutionary dynamics for the single-peak fitness and symmetric smooth fitness.
David B, Saakian, Chin-Kun, Hu
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A Quasi-Species Model for the Propagation and Containment of Polymorphic Worms

IEEE Transactions on Computers, 2009
Polymorphic computer worms are characterized by their ability to change their byte sequence as they replicate and propagate, thereby aiming to thwart intrusion detection systems (IDSes). In this letter, we propose a model based on coevolution of biological quasi-species to characterize the propagation of polymorphic worms and the effect of IDSes on ...
B. Stephenson, B. Sikdar
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Dynamics of quasi-species models with a complex spin coherent state representation

Journal of the Korean Physical Society, 2012
We investigate the dynamics of the parallel mutation-selection quasi-species model of biological evolution for various fitness landscapes. By using the semiclassical propagator for spin coherent states, for the linear fitness landscape, we find the expression for the transition rate from an arbitrary initial state to an arbitrary final state and ...
Mark Ancliff, Jeong-Man Park
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