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Displaying 1441 –
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1854
The aim of this study was to describe and analyze the regulation and spatio-temporal
dynamics of melanocyte migration in vitro and its coupling to cell
division and interaction with the matrix. The melanocyte lineage is particularly
interesting because it is involved in both embryonic development and
oncogenesis/metastasis (melanoma). Biological experiments were performed on two melanocyte
cell lines established from wild-type and β-catenin-transgenic...
The existence, uniqueness and large time behaviour of radially symmetric solutions to a chemotaxis system in the plane ℝ² are studied for the (supercritical) value of mass greater than 8π.
This paper presents a new model of asymmetric bifurcating autoregressive process with random coefficients. We couple this model with a Galton−Watson tree to take into account possibly missing observations. We propose least-squares estimators for the various parameters of the model and prove their consistency, with a convergence rate, and asymptotic normality. We use both the bifurcating Markov chain and martingale approaches and derive new results in both these frameworks.
We survey recent developments about random real trees, whose prototype is the Continuum Random Tree (CRT) introduced by Aldous in 1991. We briefly explain the formalism of real trees, which yields a neat presentation of the theory and in particular of the relations between discrete Galton-Watson trees and continuous random trees. We then discuss the particular class of self-similar random real trees called stable trees, which generalize the CRT. We review several important results concerning stable...
Background: Community-acquired methicillin-resistant Staphylococcus
aureus (CA-MRSA), a novel strain of MRSA, has recently emerged and rapidly
spread in the community. Invasion into the hospital setting with replacement of the
hospital-acquired MRSA (HA-MRSA) has also been documented. Co-colonization with both
CA-MRSA and HA-MRSA would have important clinical implications given differences in
antimicrobial susceptibility profiles and the potential...
We describe the fields of rational constants of generic four-variable Lotka-Volterra derivations. Thus, we determine all rational first integrals of the corresponding systems of differential equations. Such systems play a role in population biology, laser physics and plasma physics. They are also an important part of derivation theory, since they are factorizable derivations. Moreover, we determine the fields of rational constants of a class of monomial derivations.
This paper proposes a quantitative model of the reaction-diffusion type to examine the
distribution of interferon-α (IFNα) in a lymph node
(LN). The numerical treatment of the model is based on using an original unstructured mesh
generation software Ani3D and nonlinear finite volume method for diffusion equations. The
study results in suggestion that due to the variations in hydraulic conductivity of
various zones of the secondary lymphoid organs...
Reaction-diffusion systems are studied under the assumptions guaranteeing diffusion driven instability and arising of spatial patterns. A stabilizing influence of unilateral conditions given by quasivariational inequalities to this effect is described.
In this paper we explore a new model of field carcinogenesis, inspired by lung
cancer precursor lesions, which includes dynamics of a spatially distributed population of
pre-cancerous cells c(t, x), constantly supplied by an influx μ of mutated normal cells. Cell
proliferation is controlled by growth factor molecules bound to cells, b(t, x). Free growth
factor molecules g(t, x) are produced by precancerous cells and may diffuse before they become
bound to other cells. The purpose of modelling is...
In this paper the authors raise the issue of automatic discrimination of atherosclerotic plaques within an artery lumen based on numerical and statistical thresholding of Computerized Tomography Angiographic (CTA) images and their advanced dimensioning as a support for preoperative vessel assessment. For the study, a set of tomograms of the aorta, as well as the ilio-femoral and femoral arteries were examined. In each case a sequence of about 130-480 images of the artery cutoff planes were analyzed...
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