Search results for "fluid"

The short-circuited everted sac of rat colon mucosa.

1981

A short-circuited preparation of everted rat colon sacs is described. The serosal current electrode is a AgAgCl wire. A cylindrical agar bridge or AgAgCl electrode may be employed on the mucosal side. Effects of Ag+ ions liberated from the electrodes on ion transport could not be demonstrated. Fluid and sodium are absorbed and bicarbonate secreted. Potassium and chloride movements are not significantly different from zero. The preparation remains stable for at least 2 h. Sodium absorption is diminished by 50% and bicarbonate secretion abolished in the absence of glucose. In principle, similar ion transport properties were found as in Ussing-chamber preparations. The advantage of the everted…

MR imaging of bilateral paramedian thalamic and mesencephalic infarcts: A case report

2010

We describe MR imaging of bilateral infarction of the paramedian portion of the mesencephalus and thalamus due to an occlusion of the Percheron artery. This entity is due to one of the anatomic variants of the perforating arteries supplying the thalamus and mesenchephalus. Clinically this kind of infarction presents with neurologic impairment as a disorder of consciousness, memory dysfunctions, various types of vertical gaze palsy and psychic changes, which need to be differentiated from delirium and coma. At MRI evaluation infarction of the paramedian portion of thalami and midbrain, with a “butterfly wings” pattern, was demonstrated as high signal intensity areas on FLAIR and FSE-T2W ima…

Classification générique de synthèses temps minimales avec cible de codimension un et applications

1997

In this article we consider the problem of constructing the optimal closed loop control in the time minimal control problem, with terminal constraints belonging to a manifold of codimension one, for systems of the form v = X + uY, v ϵ R2, R3, |u| ≤ 1 under generic assumptions. The analysis is localized near the terminal manifold and is motivated by the problem of controlling a class of chemical systems.

Many Common Odour Cues and (at Least) One Pheromone Shaping the Behaviour of Young Rabbits

2008

Enzymatic alteration of C1q, the collagen-like subcomponent of the first component of complement, leads to cross-reactivity with type II collagen

1988

AbstractNative serum C1q, the collagenous-like subcomponent of the first component of complement, is not recognized by polyclonal anti-collagen type II antibodies. However, when purified C1q was subjected to limited proteolysis by collagenase it showed antigenic cross-reactivity with collagen type II. The same cross-reactivity was observed with hemolytically active C1q in synovial fluids of patients with rheumatoid arthritis (RA), whereas C1q from synovial fluids of patients with osteoarthritis (OA), villo-nodular synovitis and ankylosing spondylitis was not recognized by this antibody. However, incubation of synovial fluid C1q of OA patients with synovial fluid leucocytes from RA patients …

Evidence for the presence of autoantibodies to the collagen-like portion of C1q in systemic lupus erythematosus.

1988

We investigated the connection between the C1q solid-phase binding assay (C1q SPBA) and double-stranded DNA antibodies, and analyzed the immune complex material in systemic lupus erythematosus (SLE) sera. Comparison with a new monoclonal assay for C1q-bearing immune complexes (the 242G3 assay) revealed that the immune complexes in SLE bind specifically to solid-phase C1q, and not to fluid-phase C1q. The C1q solid-phase binding activity sedimented as 7S IgG, was insensitive to DNase treatment, and could be selectively absorbed by C1q-coupled beads and by bovine serum albumin-anti-bovine serum albumin C1q beads, but not by DNA. Thus, antibodies to double-stranded DNA do not interfere in the C…

Digital information receiver based on stochastic resonance

2003

International audience; An electronic receiver based on stochastic resonance is presented to rescue subthreshold modulated digital data. In real experiment, it is shown that a complete data restoration is achieved for both uniform and Gaussian white noise.

Viscous-Inviscid Interactions in a Boundary-Layer Flow Induced by a Vortex Array

2014

In this paper we investigate the asymptotic validity of boundary layer theory. For a flow induced by a periodic row of point-vortices, we compare Prandtl's solution to Navier-Stokes solutions at different $Re$ numbers. We show how Prandtl's solution develops a finite time separation singularity. On the other hand Navier-Stokes solution is characterized by the presence of two kinds of viscous-inviscid interactions between the boundary layer and the outer flow. These interactions can be detected by the analysis of the enstrophy and of the pressure gradient on the wall. Moreover we apply the complex singularity tracking method to Prandtl and Navier-Stokes solutions and analyze the previous int…

Singularity formation for Prandtl’s equations

2009

Abstract We consider Prandtl’s equations for an impulsively started disk and follow the process of the formation of the singularity in the complex plane using the singularity tracking method. We classify Van Dommelen and Shen’s singularity as a cubic root singularity. We introduce a class of initial data, uniformly bounded in H 1 , which have a dipole singularity in the complex plane. These data lead to a solution blow-up whose time can be made arbitrarily short within the class. This is numerical evidence of the ill-posedness of the Prandtl equations in H 1 . The presence of a small viscosity in the streamwise direction changes the behavior of the singularities. They stabilize at a distanc…

Complex singularities in KdV solutions

2016

In the small dispersion regime, the KdV solution exhibits rapid oscillations in its spatio-temporal dependence. We show that these oscillations are caused by the presence of complex singularities that approach the real axis. We give a numerical estimate of the asymptotic dynamics of the poles.