345 research outputs found
Coherence in monoidal track categories
We introduce homotopical methods based on rewriting on higher-dimensional
categories to prove coherence results in categories with an algebraic
structure. We express the coherence problem for (symmetric) monoidal categories
as an asphericity problem for a track category and we use rewriting methods on
polygraphs to solve it. The setting is extended to more general coherence
problems, seen as 3-dimensional word problems in a track category, including
the case of braided monoidal categories.Comment: 32 page
Transition times and stochastic resonance for multidimensional diffusions with time periodic drift: A large deviations approach
We consider potential type dynamical systems in finite dimensions with two
meta-stable states. They are subject to two sources of perturbation: a slow
external periodic perturbation of period and a small Gaussian random
perturbation of intensity , and, therefore, are mathematically
described as weakly time inhomogeneous diffusion processes. A system is in
stochastic resonance, provided the small noisy perturbation is tuned in such a
way that its random trajectories follow the exterior periodic motion in an
optimal fashion, that is, for some optimal intensity . The
physicists' favorite, measures of quality of periodic tuning--and thus
stochastic resonance--such as spectral power amplification or signal-to-noise
ratio, have proven to be defective. They are not robust w.r.t. effective model
reduction, that is, for the passage to a simplified finite state Markov chain
model reducing the dynamics to a pure jumping between the meta-stable states of
the original system. An entirely probabilistic notion of stochastic resonance
based on the transition dynamics between the domains of attraction of the
meta-stable states--and thus failing to suffer from this robustness defect--was
proposed before in the context of one-dimensional diffusions. It is
investigated for higher-dimensional systems here, by using extensions and
refinements of the Freidlin--Wentzell theory of large deviations for time
homogeneous diffusions. Large deviations principles developed for weakly time
inhomogeneous diffusions prove to be key tools for a treatment of the problem
of diffusion exit from a domain and thus for the approach of stochastic
resonance via transition probabilities between meta-stable sets.Comment: Published at http://dx.doi.org/10.1214/105051606000000385 in the
Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute
of Mathematical Statistics (http://www.imstat.org
EXPRESSION OF DEFA1-3 AND RELATIONS WITH RISK FACTORSOF CARDIOVASCULAR DISEASES
The infiltration of immuno-inflammatory cells is one of the earliest and durable steps that lead to atherosclerosis. These cells produce many immune components that act as a double-edged sword in this inflammatory disease. Among these components, we note antimicrobial peptides, including defenses. Defenses are natural cationic peptides of the innate immune system. In Humans, these small peptides have a large antimicrobial spectrum. In addition, they play an important role in both infectious and inflammatory diseases. Our objective was to study the relation between alpha-defenses (DEFA) 1-3 genes expression and cardiovascular risk factors. This objective was built on the hypothesis that defenses may be involved in cardiovascular pathologies, and may serve as a new generation of biomarkers. To verify this hypothesis, we treated HL-60 differentiated cells with glucose decreased alphadefenses 1, 2 and 3 gene expression levels, while insulin treatment restored its expression. These findings suggest that DEFA1-3 are involved in the complex glucose-insulin metabolic pathway. In summary, DEFA1-3 genes expression is significantly correlated with glucose. These findings we suggest that DEFA1-3 could be involved in the evolution of cardiovascular complications
Abstract: EDS case
The aim of this paper is to understand and describe what factors and process lead to a relational performance in an outsourcing strategy. Based on the relational view model from Dyer and Singh (1998) and completed by a more processual and learning focused approach, we develop our own descriptive model. This model is applied to the Xerox-EDS outsourcing contract. We then find that our model is quite designed to understand how performance is built. Relational performance is compounded of a gestation performance, a maturation performance and an infiltration performance. Each stage of the relational performance is evaluated on equity and efficiency. In our study, we identify the global process which explain how this performance is built, integrating, for example, how relational specific investments influence learning exchange and how then, shared routines can be created in the relation. So this study helps us to better understand outsourcing as a relational agreement and identify both factors and processes that make this relation evolve and reach the partners goals
A Toolchain for Grammarians
We present a chain of tools used by grammarians and computer scientists to develop grammatical and lexical resources from linguistic knowledge, for various natural languages. The developed resources are intended to be used in Natural Language Processing (NLP) systems.
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