The Economic Evaluation of Mastitis Control Strategies in Holstein-Friesian Dairy Herds.

The economic evaluation of mastitis control is challenging. The objective of this study was to perform the economic evaluation of mastitis control, under different intervention scenarios, quantifying the total cost of mastitis caused by in Holstein cows in Argentina. A model was set for a dairy herd of Holstein cows endemically infected with .

Effects of scarcity and excess of larval food on life history traits of Aedes aegypti (Diptera: Culicidae).

Few studies have assessed the effects of food scarcity or excess on the life history traits of Aedes aegypti (L.) (Diptera: Culicidae) independently from larval density. We assessed immature survival, development time, and adult size in relation to food availability.

A model for the development of Aedes (Stegomyia) aegypti as a function of the available food.

We discuss the preimaginal development of the mosquito Aedes aegypti from the point of view of the statistics of developmental times and the final body-size of the pupae and adults. We begin the discussion studying existing models in relation to published data for the mosquito. The data suggest a developmental process that is described by exponentially distributed random times.

Linear processes in stochastic population dynamics: theory and application to insect development.

We consider stochastic population processes (Markov jump processes) that develop as a consequence of the occurrence of random events at random time intervals. The population is divided into subpopulations or compartments. The events occur at rates that depend linearly on the number of individuals in the different described compartments.

Dispersal of Aedes aegypti: field study in temperate areas using a novel method.

Background & Objectives: Since Aedes aegypti was identified as vector of yellow fever and dengue, its dispersal is relevant for disease control. We studied the dispersal of Ae. aegypti in temperate areas of Argentina during egglaying, using the existing population and egg traps.

Modeling dengue outbreaks.

We introduce a dengue model (SEIR) where the human individuals are treated on an individual basis (IBM) while the mosquito population, produced by an independent model, is treated by compartments (SEI). We study the spread of epidemics by the sole action of the mosquito. Exponential, deterministic and experimental distributions for the (human) exposed period are considered in two weather scenarios, one corresponding to temperate climate and the other to tropical climate.

A stochastic spatial dynamical model for Aedes aegypti.

We develop a stochastic spatial model for Aedes aegypti populations based on the life cycle of the mosquito and its dispersal. Our validation corresponds to a monitoring study performed in Buenos Aires. Lacking information with regard to the number of breeding sites per block, the corresponding parameter (BS) was adjusted to the data.

Blowing-up of deterministic fixed points in stochastic population dynamics.

We discuss the stochastic dynamics of biological (and other) populations presenting a limit behaviour for large environments (called deterministic limit) and its relation with the dynamics in the limit. The discussion is circumscribed to linearly stable fixed points of the deterministic dynamics, and it is shown that the cases of extinction and non-extinction equilibriums present different features. Mainly, non-extinction equilibria have associated a region of stochastic instability surrounded by a region of stochastic stability.

A stochastic population dynamics model for Aedes aegypti: formulation and application to a city with temperate climate.

Aedes aegypti is the main vector for dengue and urban yellow fever. It is extended around the world not only in the tropical regions but also beyond them, reaching temperate climates. Because of its importance as a vector of deadly diseases, the significance of its distribution in urban areas and the possibility of breeding in laboratory facilities, Aedes aegypti is one of the best-known mosquitoes.

Modeling growth from the vapor and thermal annealing on micro- and nanopatterned substrates.

We propose a -dimensional mesoscopic model to describe the most relevant physical processes that take place while depositing and/or annealing micro- and nanopatterned solid substrates. The model assumes that a collimated incident beam impinges over the growing substrate; scattering effects in the vapor and reemission processes are introduced in a phenomenological way as an isotropic flow. Surface diffusion is included as the main relaxation process at the micro- or nanoscale.

Dynamics of solid growth under a gravitational field: influence of the formation of a diffusive layer.

We discuss the gravitational sedimentation of particles in terms of a stochastic model considering, in view of experimental evidence, that the aggregation to the growing surface (deposit) is mediated by the formation of a layer of suspended particles subject to gravitational forces, thermal agitation, as well as aggregation (contact) forces. The aggregation of such partially buoyant particles is ruled by the rates of occurrence of the different stochastic events: incorporation to the layer of suspended particles, sedimentation, and gravitationally biased diffusion. The model introduces bridges across different standard solid on solid deposition models which can be considered as limit cases of the present one.

Probing universality classes in solid-on-solid deposition.

We consider several stochastic processes corresponding to the same physical solid-on-solid deposition problem. Simplified models presenting the same (conditional) mean and variance for each process are also introduced as well as generalizations in terms of the deposition of blobs and probabilistic deposition rules. We compare the evolution of the roughness as a function of time for a three-parameter family that includes as limit cases the Family model and the Edwards-Wilkinson equation, showing that in all cases the derived models with the same mean and variance are indistinguishable from the originating models in terms of the evolution of the roughness.

Global bifurcations in a laser with injected signal: Beyond Adler's approximation.

We discuss the dynamics in the laser with an injected signal from a perturbative point of view showing how different aspects of the dynamics get their definitive character at different orders in the perturbation scheme. At the lowest order Adler's equation [Proc. IRE 34, 351 (1946)] is recovered.

Stochastic population dynamics: the Poisson approximation.

We introduce an approximation to stochastic population dynamics based on almost independent Poisson processes whose parameters obey a set of coupled ordinary differential equations. The approximation applies to systems that evolve in terms of events such as death, birth, contagion, emission, absorption, etc., and we assume that the event-rates satisfy a generalized mass-action law.