Systems of interacting diffusions with partial annihilation through membranes

We introduce an interacting particle system in which two families of reflected diffusions interact in a singular manner near a deterministic interface $I$. This system can be used to model the transport of positive and negative charges in a solar cell or the population dynamics of two segregated species under competition. A related interacting random walk model with discrete state spaces has recently been introduced and studied in Chen and Fan (2014). In this paper, we establish the functional law of large numbers for this new system, thereby extending the hydrodynamic limit in Chen and Fan (2014) to reflected diffusions in domains with mixed-type boundary conditions, which include absorption (harvest of electric charges). We employ a new and direct approach that avoids going through the delicate BBGKY hierarchy.Comment: Published at http://dx.doi.org/10.1214/15-AOP1047 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

FITNESS OF \u3ci\u3eALTERNARIA ALTERNATA\u3c/i\u3e FIELD ISOLATES WITH MULTIPLE FUNGICIDES RESISTANCE

Field isolates of Alternaria alternata from peach were previously characterized for their sensitivity to succinate dehydrogenase (SDH) inhibitor fungicides and the underlying molecular basis of resistance was determined. In the present study we report that isolates resistant to the SDHI fungicide, boscalid, regardless of genotype, were also resistant to pyraclostrobin and thiophanate-methyl. Resistance to pyraclostrobin was due to the G143A mutation in the cytb gene and resistance to thiophanate-methyl was due to a mutation of 167Y in the β-tubulin gene. Representatives of the two most commonly-isolated, SDHI resistance genotypes H277Y in sdh subunit B and H134R in sdh subunit C, as well as genotype D123E in sdh subunit D were selected for fitness evaluations. Genotypes H277Y and H134R suffered no fitness penalties based on mycelial growth on PDA, spore production in vitro, osmotic sensitivity, oxidative sensitivity, germination ability, or the ability to cause disease on peach fruit. Hypersensitivity to oxidative stress and weak sporulation was observed only in genotype D123E. No competitive advantage was detected for sensitive isolates over the course of five consecutive transfers on peach fruit when spores were mixed with genotypes H277Y or H134R. Results suggest that in the absence of fungicide pressure, A. alternata isolates resistant to MBC, QoI, and SDHI fungicides carrying the H277Y mutation in SDHB and the H134R mutation in SDHC may effectively compete with the boscalid-sensitive populations