Fluctuations and Dispersal Rates in Population Dyanmics (2009)
Kessler, David A., Sander, Leonard M.
Dispersal of species to find a more favorable habitat is important in population dynamics. Dispersal rates evolve in response to the relative success of different dispersal strategies. In a...
Globally coupled chaotic maps and demographic stochasticity (2009)
Kessler, David A., Shnerb, Nadav M.
The affect of demographic stochasticity of a system of globally coupled chaotic maps is considered. A two-step model is studied, where the intra-patch chaotic dynamics is followed by a migration step...
Universal features of surname distribution in a subsample of a growing population (2009)
Maruvka, Yosef E., Shnerb, Nadav M., Kessler, David A.
We examine the problem of family size statistics (the number of individuals carrying the same surname, or the same DNA sequence) in a given size subsample of an exponentially growing population. We...
Wylie, C. Scott, Ghim, Cheol-Min, Kessler, David A., Levine, Herbert
This supplementary information contains detailed derivations, comparison to experiment, and discussion of other miscellaneous issues omitted from the main text.
Non-Hermitian delocalization and the extinction transition (2008)
Kessler, David A., Shnerb, Nadav M.
Logistic growth on a static heterogenous substrate is studied both above and below the drift-induced delocalization transition. Using stochastic, agent-based simulations the delocalization of the...
Extinction transition on diffusive substrate: a different universality class? (2008)
Evron, Galit, Kessler, David A., Shnerb, Nadav M.
The extinction transition on a one dimensional heterogeneous substrate with diffusive correlations is studied. Diffusively correlated heterogeneity is shown to affect the location of the transition...
Singularities in Speckled Speckle: Screening (2008)
Kessler, David A., Freund, Isaac
We study screening of optical singularities in random optical fields with two widely different length scales. We call the speckle patterns generated by such fields speckled speckle, because the major...
Singularities in Speckled Speckle: Statistics (2008)
Freund, Isaac, Kessler, David A.
Random optical fields with two widely different correlation lengths generate far field speckle spots that are themselves highly speckled. We call such patterns speckled speckle, and study their...
Novel exponents control the quasi-deterministic limit of the extinction transition (2008)
Kessler, David A., Shnerb, Nadav M.
The quasi-deterministic limit of the generic extinction transition is considered within the framework of standard epidemiological models. The susceptible-infected-susceptible (SIS) model is known to...
The fixation probability of rare mutators in finite asexual populations (2008)
Wylie, C. Scott, Ghim, Cheol-Min, Kessler, David A., Levine, Herbert
A mutator is an allele that increases the mutation rate throughout the genome by disrupting some aspect of DNA replication or repair. Mutators that increase the mutation rate by the order of 100 fold...
Singularities in Speckled Speckle (2007)
Freund, Isaac, Kessler, David A.
Speckle patterns produced by random optical fields with two (or more) widely different correlation lengths exhibit speckle spots that are themselves highly speckled. Using computer simulations and...
Epidemic Size in the Sis Model of Endemic Infec- Tions (2007)
We study the Susceptible-Infected-Susceptible model of the spread of an endemic infection. We calculate an exact expression for the mean number of transmissions for all values of the population and...
Transition Phenomena Induced by Internal Noise and Quasi-absorbing State (2007)
Ohkubo, Jun, Shnerb, Nadav, Kessler, David A.
We study a simple chemical reaction system and effects of the internal noise. The chemical reaction system causes the same transition phenomenon discussed by Togashi and Kaneko [Phys. Rev. Lett. 86...
A Critical Examination of the FDA's Efforts to Preempt Failure-to-Warn Claims (2007)
Kessler, David A., Vladeck, David C.
This article explores the legality and wisdom of the FDA's effort to persuade courts to find most failure-to-warn claims preempted. The article first analyzes the FDA's justifications for reversing...
Solution of an infection model near threshold (2007)
Kessler, David A., Shnerb, Nadav M.
We study the Susceptible-Infected-Recovered model of epidemics in the vicinity of the threshold infectivity. We derive the distribution of total outbreak size in the limit of large population size...
Extinction Rates for Fluctuation-Induced Metastabilities : A Real-Space WKB Approach (2006)
Kessler, David A., Shnerb, Nadav M.
The extinction of a single species due to demographic stochasticity is analyzed. The discrete nature of the individual agents and the Poissonian noise related to the birth-death processes result in...
Wylie, C. Scott, Levine, Herbert, Kessler, David A.
We study 2D fronts propagating up a co-moving reaction rate gradient in finite number reaction-diffusion systems. We show that in a 2D rectangular channel, planar solutions to the deterministic...
Analytic approach to the evolutionary effects of genetic exchange (2005)
Cohen, Elisheva, Kessler, David A., Levine, Herbert
We present an approximate analytic study of our previously introduced model of evolution including the effects of genetic exchange. This model is motivated by the process of bacterial transformation....
Front Propagation up a Reaction Rate Gradient (2005)
Cohen, Elisheva, Kessler, David A., Levine, Herbert
We expand on a previous study of fronts in finite particle number reaction-diffusion systems in the presence of a reaction rate gradient in the direction of the front motion. We study the system via...
Front Propagation Dynamics with Exponentially-Distributed Hopping (2005)
Cohen, Elisheva, Kessler, David A.
We study reaction-diffusion systems where diffusion is by jumps whose sizes are distributed exponentially. We first study the Fisher-like problem of propagation of a front into an unstable state, as...
Equation-free Dynamic Renormalization of a KPZ-type Equation (2005)
Kessler, David A., Kevrekidis, Ioannis G., Chen, Ligang
In the context of equation-free computation, we devise and implement a procedure for using short-time direct simulations of a KPZ type equation to calculate the self-similar solution for its ensemble...
Recombination dramatically speeds up evolution of finite populations (2004)
Cohen, Elisheva, Kessler, David A., Levine, Herbert
We study the role of recombination, as practiced by genetically-competent bacteria, in speeding up Darwinian evolution. This is done by adding a new process to a previously-studied Markov model of...
Crack (Non)Propagation in Amorphous Media (2004)
Hirsh, Tsviki Y., Kessler, David A.
We study Mode I crack propagation in amorphous material via a molecular dynamics simulation of a binary alloy with pairwise central-force interactions. We find that when the system is subjected to...
Fluctuation-regularized Front Propagation Dynamics (2004)
Cohen, Elisheva, Kessler, David A., Levine, Herbert
We introduce and study a new class of fronts in finite particle number reaction-diffusion systems, corresponding to propagating up a reaction rate gradient. We show that these systems have no...
Analytical study of the effect of recombination on evolution via DNA shuffling (2003)
Peng, Weiqun, Levine, Herbert, Hwa, Terence, Kessler, David A.
We investigate a multi-locus evolutionary model which is based on the DNA shuffling protocol widely applied in \textit{in vitro} directed evolution. This model incorporates selection, recombination...
Fluctuating Filaments Under Tension - From Flexible Chains to Rigid Rods (2003)
Kessler, David A., Rabin, Yitzhak
We develop a novel biased Monte-Carlo simulation technique to measure the force-extension curves and the distribution function of the extension of fluctuating filaments stretched by external force....
Equilibrium state of molecular breeding (2003)
Cohen, Elisheva, Kessler, David A.
We investigate the equilibrium state of the model of Peng, \textit{et al.} for molecular breeding. In the model, a population of DNA sequences is successively culled by removing the sequences with...
Does the continuum theory of dynamic fracture work? (2002)
Kessler, David A., Levine, Herbert
We investigate the validity of the Linear Elastic Fracture Mechanics approach to dynamic fracture. We first test the predictions in a lattice simulation, using a formula of Eshelby for the...
Stretching Instability of Helical Spring (2002)
Kessler, David A., Rabin, Yitzhak
We show that when a gradually increasing tensile force is applied to the ends of a helical spring with sufficiently large ratios of radius to pitch and twist to bending rigidity, the end-to-end...
Non-native beta-sheet formation: insights into protein amyloidosis (2002)
Guo, Chinlin, Levine, Herbert, Kessler, David A.
Protein amyloidosis is a cytopathological process characterized by the formation of highly beta-sheet-rich fibrils. How this process occurs and how to prevent/treat the associated diseases are not...
Mode I fracture in a nonlinear lattice with viscoelastic forces (2001)
Heizler, Shay I., Kessler, David A., Levine, Herbert
We study Mode I fracture in a viscoelastic lattice model with a nonlinear force law, with a focus on the velocity and linear stability of the steady-state propagating solution. This study is a...
Frenet algorithm for simulations of fluctuating continuous elastic filaments (2001)
Kats, Yevgeny, Kessler, David A., Rabin, Yitzhak
We present a new algorithm for generating the equilibrium configurations of fluctuating continuous elastic filaments, based on a combination of statistical mechanics and differential geometry. We use...
Comment on ``Solidification of a Supercooled Liquid in a Narrow Channel'' (2001)
Brener, Efim A., Kessler, David A.
Comment on PRL v. 86, p. 5084 (2001) [cond-mat/0101016]. We point out that the authors' simulations are consistent with the known theory of steady-state solutions in this system.
Phase-Field Model of Mode III Dynamic Fracture (2001)
Karma, Alain, Kessler, David A., Levine, Herbert
We introduce a phenomenological continuum model for mode III dynamic fracture that is based on the phase-field methodology used extensively to model interfacial pattern formation. We couple a scalar...
Mechanisms underlying sequence-independent beta-sheet formation (2001)
Guo, Chinlin, Levine, Herbert, Cheung, Margaret S., Kessler, David A.
We investigate the formation of beta-sheet structures in proteins without taking into account specific sequence-dependent hydrophobic interactions. To accomplish this, we introduce a model which...
Microscopic Selection of Fluid Fingering Pattern (2001)
Kessler, David A., Levine, Herbert
We study the issue of the selection of viscous fingering patterns in the limit of small surface tension. Through detailed simulations of anisotropic fingering, we demonstrate conclusively that no...
Nonlinear lattice model of viscoelastic Mode III fracture (2000)
Kessler, David A., Levine, Herbert
We study the effect of general nonlinear force laws in viscoelastic lattice models of fracture, focusing on the existence and stability of steady-state Mode III cracks. We show that the hysteretic...
Steady-state mode III cracks in a viscoelastic lattice model (2000)
Pechenik, Leonid, Levine, Herbert, Kessler, David A.
We extend the Slepyan solution of the problem of a steady-state crack in an infinite ideally brittle lattice model to include dissipation in the form of Kelvin viscosity. As a demonstration of this...
Steady-state mode I cracks in a viscoelastic triangular lattice (2000)
Pechenik, Leonid, Levine, Herbert, Kessler, David A.
We continue our study of the exact solutions for steady-state cracks in ideally brittle viscoelastic lattice models by focusing on mode I in a triangular system. The issues we address include the...
Steady-State Cracks in Viscoelastic Lattice Models II (1999)
We present the analytic solution of the Mode III steady-state crack in a square lattice with piecewise linear springs and Kelvin viscosity. We show how the results simplify in the limit of large...
Arrested Cracks in Nonlinear Lattice Models of Brittle Fracture (1999)
Kessler, David A., Levine, Herbert
We generalize lattice models of brittle fracture to arbitrary nonlinear force laws and study the existence of arrested semi-infinite cracks. Unlike what is seen in the discontinuous case studied to...
Steady-State Cracks in Viscoelastic Lattice Models (1998)
Kessler, David A., Levine, Herbert
We study the steady-state motion of mode III cracks propagating on a lattice exhibiting viscoelastic dynamics. The introduction of a Kelvin viscosity $\eta$ allows for a direct comparison between...
The Universal Gaussian in Soliton Tails (1998)
Kessler, David A., Schiff, Jeremy
We show that in a large class of equations, solitons formed from generic initial conditions do not have infinitely long exponential tails, but are truncated by a region of Gaussian decay. This...
Front Propagation: Precursors, Cutoffs and Structural Stability (1998)
Kessler, David A., Ner, Zvi, Sander, Leonard M.
We discuss the problem of fronts propagating into metastable and unstable states. We examine the time development of the leading edge, discovering a precursor which in the metastable case propagates...
Mutator Dynamics on a Smooth Evolutionary Landscape (1997)
Kessler, David A., Levine, Herbert
We investigate a model of evolutionary dynamics on a smooth landscape which features a ``mutator'' allele whose effect is to increase the mutation rate. We show that the expected proportion of...
Diffusive Boundary Layers in the Free-Surface Excitable Medium Spiral (1997)
Kessler, David A., Levine, Herbert
Spiral waves are a ubiquitous feature of the nonequilibrium dynamics of a great variety of excitable systems. In the limit of a large separation in timescale between fast excitation and slow...
Evolution on a smooth landscape (1996)
Kessler, David A., Levine, Herbert, Ridgway, Douglas, Tsimring, Lev
We study in detail a recently proposed simple discrete model for evolution on smooth landscapes. An asymptotic solution of this model for long times is constructed. We find that the dynamics of the...
Theory of the spiral core in excitable media (1994)
Kessler, David A., Levine, Herbert, Reynolds, William N.
A rigorous asymptotic spiral solution to an excitable reaction diffusion system is found by separating space into two scaling regions: an "outer region", having the same spatial scaling as the...
Anomalous fluctuations in surface growth (1991)
Yan, H, Kessler, David A., Sander, Leonard M.
The authors have studied fluctuations in the steady state of a modified ballistic deposition model. The ensemble fluctuations of the surface width averaged over a time sequence, which involves...
Spiral selection as a free boundary problem (1991)
Kessler, David A., Levine, Herbert
We present a new formulation of the spiral selection problem for the Belousov-Zhabotinsky reaction. In particular, we focus on deriving an exact integro-differential shape equation and discuss the...
Effect of diffusion on patterns in excitable Belousov-Zhabotinskii systems (1989)
Kessler, David A., Levine, Herbert
Travelling wave patterns occur frequently in chemically reacting systems; these include planar fronts, target patterns and spiral structures. We review the dispersion relation for planar waves,...
Computational approach to steady-state eutectic growth (1989)
Kessler, David A., Levine, Herbert
We formulate a boundary integral approach to the determination of periodic steady-state eutectic growth patterns. The numerical implementation of this method allows us to compute the band of allowed...
The Regulation of Investigational Drugs (1989)
This article examines the process, including recent revisions, by which the FDA regulates new investigational drugs.
Pattern selection in three dimensional dendritic growth (1988)
Kessler, David A., Levine, Herbert
We study the selection of the shape and growth velocity of three dimensional dendritic crystals in cubically anisotropic materials. We demonstrate that aside from minor additional complexities due to...
Growth oscillations in ballistic aggregation (1987)
Cheng, Zheming, Jacobs, Laurence, Kessler, David A., Savit, R.
The authors demonstrate the existence of growth oscillations in single clusters of particles grown stochastically according to a synchronous (finite density) version of ballistic aggregation, which...
The geometrical model of dendritic growth: The small velocity limit (1986)
Dashen, Roger F., Kessler, David A., Levine, Herbert, Savit, Robert
We present a systematic analysis of the geometrical model of dendritic growth in the small velocity limit. Velocity selection is demonstrated analytically and the allowed velocities are explicitly...
How does a β-hairpin fold/unfold? Competition between topology and heterogeneity in a solvable model
Guo, Chinlin, Levine, Herbert, Kessler, David A.
We study the competition between topological effects and sequence inhomogeneities in determining the thermodynamics and the un/folding kinetics of a β-hairpin. Our work utilizes a new exactly...
How does a β-hairpin fold/unfold? Competition between topology and heterogeneity in a solvable model
Guo, Chinlin, Levine, Herbert, Kessler, David A.
We study the competition between topological effects and sequence inhomogeneities in determining the thermodynamics and the un/folding kinetics of a β-hairpin. Our work utilizes a new exactly...
Directional sensing in eukaryotic chemotaxis: A balanced inactivation model
Levine, Herbert, Kessler, David A., Rappel, Wouter-Jan
Many eukaryotic cells, including Dictyostelium discoideum amoebae, fibroblasts, and neutrophils, are able to respond to chemoattractant gradients with high sensitivity. Recent studies have...
Analytical Study of the Interplay Between Architecture and Predictability
Avner Priel, Ido Kanter, David A. Kessler
We study model feed forward networks as time series predictors in the stationary limit. The focus is on complex, yet non-chaotic, behavior. The main question we address is whether the asymptotic...