Meiotic recombination, an essential aspect of sexual reproduction, is initiated by programmed DNA double-strand breaks (DSBs). DSBs are catalyzed by the widely-conserved Spo11 enzyme; however, the activity of Spo11 is regulated by additional factors that are poorly conserved through evolution. To expand our understanding of meiotic regulation, we have characterized a novel gene, dsb-1, that is ...

Wave functions and the screening mass spectrum in the 3D SU(2)–Higgs model near to the phase transition line below the endpoint and in the crossover region are calculated. In the crossover region the changing spectrum versus temperature is examined showing the aftermath of the phase transition at lower Higgs mass. Large sets of operators with various extensions are used allowing to identify wav...

Here we address the controversy between plant pathologists and invertebrate zoologists as to the genetic basis of infection. We show that the alternative models proposed by these groups represent two ends of a continuum. Specifically, the gene-for-gene (GFG) model of plant pathologists represents one end of a continuum, where a very broad host range is expected to occur in one pathogen genotype...

Resumen. Database schemas and user queries are continuously growing with the need for storing and accessing large amounts of structured information. Among the several proposals to deal with the Large Join Query Problem, genetic optimizers have been shown to be a competitive approach. We propose a new search strategy to improve the quality and convergence of genetic query optimizers. We call our...

This paper gives an introduction to the Random Field Ising Model (RFIM). Since its rst discussion in the paper by Imry and Ma 1] there has been great interest in this model, since Ising or Ising-like systems in random elds are a good representation of a large number of impure materials. These show features that can not be understood by studying ideal systems (i.e. Ising model). There are a lot ...

The Bechgaard salts are made of weakly coupled one dimensional chains. This particular structure gives the possibility to observe in these systems a dimensional crossover between a high temperature (or high energy) one dimensional phase and a two or three dimensional system. Since the filling of the chains is commensurate the system thus undergoes a deconfinement transition from a one dimension...

A two dimensional model for quantum percolation with variable tunnel-ing range is considered. We employ a numerical method to analyze the level statistics of this model. It turnes out that the level repulsion is strongest around the percolation threshold. As we go away from the maximum level repulsion a crossover from a GOE type behaviour to a Poisson like distribution is indicated. The localiz...

Sharing methods promote the formation and maintenance of stable subpopulations or niches in genetic algorithms. This paper derives, for various models of sharing, lower bounds on the population size required to maintain, with probability , a xed number of niches. The rst model assumes all niches are equivalent with respect to tness and that crossover is minimally disruptive. The next two models...

Periodic density functional calculations combined with the Hubbard model (DFT+U) have been performed for the archetype spin crossover complex Fe(phen)2(NCS)2 with phen = 1,2-phenanthroline. The relative energies of the 16 different configurations of two possible spin states for each of the four molecules in the unit cell have been calculated in order to determine from first principles the pheno...

Gene conversion plays an important part in shaping genetic diversity in populations, yet estimating the rate at which it occurs is difficult because of the short lengths of DNA involved. We have developed a new statistical approach to estimating gene conversion rates from genetic variation, by extending an existing model for haplotype data in the presence of crossover events. We show, by simula...