3,780 research outputs found
Diseases affecting pigs: an overview of common bacterial, viral and parasitic pathogens of pigs
Recent events such as the 2009 pandemic influenza outbreak, the continuous spread of African swine fever virus in Eastern Europe and the introduction of several new pathogens into the United States and their spread to Canada, Mexico, Central and South America have emphasized the ability of pig diseases to cross borders rapidly and the importance of global cooperation to improve the health and welfare of pigs. This chapter summarizes recent research on the causes and epidemiology of major bacteria, viruses and parasites found in pig production, focusing on those with a particular impact on safety and global production
Swine Biological Risk Management
The purpose of this document is to serve as a reference for individuals involved in the swine industry to understand steps which can be taken to mitigate the risk of disease transmission. Biological risk management (BRM) is essential to all swine operations regardless of their size or mode of operation. Disease risk can never be completely eliminated. A full awareness of all risks is critical in mitigating threats of endemic, emerging, and foreign animal diseases. This document illustrates the best available “standard operating procedures” for a wide range of management practices. This is a working document that needs to be adjusted as new information is available
Fluctuations of the front in a one dimensional model of X+Y-->2X
We consider a model of the reaction on the integer lattice in
which particles do not move while particles move as independent
continuous time, simple symmetric random walks. particles are transformed
instantaneously to particles upon contact. We start with a fixed number
of particles at each site to the right of the origin, and define a
class of configurations of the particles to the left of the origin having a
finite norm with a specified exponential weight. Starting from any
configuration of particles to the left of the origin within such a class,
we prove a central limit theorem for the position of the rightmost visited site
of the particles
Nafta and industrial efficiency in Baja California
The figures before and after the North America Free Trade Agreement between Canada, Mexico and United States, suggest the intensification of the North region economic dynamics, particularly in the sates of Baja California. This paper attempts to determine whether the state’s extraordinary growth has been led by efficiency improvement or just by factor growth as a consequence of Free Trade and Foreign Direct Investment. The paper finds empirical evidence in both ways.Economic efficiency; productivity; and free trade
One Thousand and One Bubbles
We propose a novel strategy that permits the construction of completely
general five-dimensional microstate geometries on a Gibbons-Hawking space. Our
scheme is based on two steps. First, we rewrite the bubble equations as a
system of linear equations that can be easily solved. Second, we conjecture
that the presence or absence of closed timelike curves in the solution can be
detected through the evaluation of an algebraic relation. The construction we
propose is systematic and covers the whole space of parameters, so it can be
applied to find all five-dimensional BPS microstate geometries on a
Gibbons-Hawking base. As a first result of this approach, we find that the
spectrum of scaling solutions becomes much larger when non-Abelian fields are
present. We use our method to describe several smooth horizonless multicenter
solutions with the asymptotic charges of three-charge (Abelian and non-Abelian)
black holes. In particular, we describe solutions with the centers lying on
lines and circles that can be specified with exact precision. We show the power
of our method by explicitly constructing a 50-center solution. Moreover, we use
it to find the first smooth five-dimensional microstate geometries with
arbitrarily small angular momentum.Comment: 33 pages. v2: typos correcte
Fluctuations of the front in a stochastic combustion model
We consider an interacting particle system on the one dimensional lattice
modeling combustion. The process depends on two integer parameters
. Particles move independently as continuous time simple
symmetric random walks except that 1. When a particle jumps to a site which has
not been previously visited by any particle, it branches into particles; 2.
When a particle jumps to a site with particles, it is annihilated. We start
from a configuration where all sites to the left of the origin have been
previously visited and study the law of large numbers and central limit theorem
for , the rightmost visited site at time .
The proofs are based on the construction of a renewal structure leading to a
definition of regeneration times for which good tail estimates can be
performed.Comment: 19 page
Front propagation in an exclusion one-dimensional reactive dynamics
We consider an exclusion process representing a reactive dynamics of a pulled
front on the integer lattice, describing the dynamics of first class
particles moving as a simple symmetric exclusion process, and static second
class particles. When an particle jumps to a site with a particle,
their position is intechanged and the particle becomes an one.
Initially, there is an arbitrary configuration of particles at sites , and particles only at sites , with a product Bernoulli law
of parameter . We prove a law of large numbers and a central
limit theorem for the front defined by the right-most visited site of the
particles at time . These results corroborate Monte-Carlo simulations
performed in a similar context. We also prove that the law of the particles
as seen from the front converges to a unique invariant measure. The proofs use
regeneration times: we present a direct way to define them within this context.Comment: 19 page
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