Search results for "Ibers"
showing 10 items of 578 documents
ANALYTICAL DETERMINATION OF INITIAL CONDITIONS LEADING TO FIRING IN NERVE FIBERS
2007
International audience; An analytical solution characterizing initial conditions leading to action potential firing in smooth nerve fibers is determined, using the bistable equation. In the first place, we present a nontrivial stationary solution wave, then, using the perturbative method, we analyze the stability of this stationary wave. We show that it corresponds to a frontier between the initiation of the travelling waves and a decay to the resting state. Eventually, this analytical approach is extended to FitzHugh-Nagumo model.
Vulnerability of peripheral catecholaminergic neurons to MPTP is not regulated by alpha-synuclein.
2010
Although generally considered a prototypical movement disorder, Parkinson's disease is commonly associated with a broad-spectrum of non-motor symptoms, including autonomic dysfunctions caused by significant alterations in catecholaminergic neurons of the peripheral sympathetic nervous system. Here we present evidence that alpha-synuclein is highly expressed by sympathetic ganglion neurons throughout embryonic and postnatal life and that it is found in tyrosine hydroxylase-positive sympathetic fibers innervating the heart of adult mice. However, mice deficient in alpha-synuclein do not exhibit any apparent alterations in sympathetic development. Sympathetic neurons isolated from mouse embryo…
Focal adhesions are hotspots for keratin filament precursor formation
2006
Recent studies showed that keratin filament (KF) formation originates primarily from sites close to the actin-rich cell cortex. To further characterize these sites, we performed multicolor fluorescence imaging of living cells and found drastically increased KF assembly in regions of elevated actin turnover, i.e., in lamellipodia. Abundant KF precursors (KFPs) appeared within these areas at the distal tips of actin stress fibers, moving alongside the stress fibers until their integration into the peripheral KF network. The earliest KFPs were detected next to actin-anchoring focal adhesions (FAs) and were only seen after the establishment of FAs in emerging lamellipodia. Tight spatiotemporal …
The Innervation of Taste Buds in the Soft Palate and Circumvallate Papilla of the Rat as Revealed by the Zinc Iodide-Osmium Tetroxide Technique.
1998
The taste buds in the soft palate and the circumvallate papillae of the rat were investigated by the zinc iodide-osmium tetroxide technique. In addition, electron micrographs of taste buds stained with this method were presented for the first time. Differences in taste bud structures were found between the examined regions. The taste buds of the soft palate showed a complicated plexus of intragemmal nerve fibers. Some fibers exhibited terminal polymorphic swellings. Single branches could be traced close to the space of the taste pore. In the soft palate, the taste bud cells remained unstained, whereas in the circumvallate papillae of the tongue, a subpopulation of taste bud cells could be s…
Intrinsic Point Defects in Silica for Fiber Optics Applications
2021
Due to its unique properties, amorphous silicon dioxide (a-SiO2) or silica is a key material in many technological fields, such as high-power laser systems, telecommunications, and fiber optics. In recent years, major efforts have been made in the development of highly transparent glasses, able to resist ionizing and non-ionizing radiation. However the widespread application of many silica-based technologies, particularly silica optical fibers, is still limited by the radiation-induced formation of point defects, which decrease their durability and transmission efficiency. Although this aspect has been widely investigated, the optical properties of certain defects and the correlation betwee…
Mechanical and Thermal Properties of Insulating Sustainable Mortars with Ampelodesmos mauritanicus and Pennisetum setaceum Plants as Aggregates
2021
The use of natural fibers in cement composites is a widening research field as their application can enhance the mechanical and thermal behavior of cement mortars and limit their carbon footprint. In this paper, two different wild grasses, i.e., Ampelodesmos mauritanicus, also called diss, and Pennisetum setaceum, also known as crimson fountaingrass, are used as a source of natural aggregates for cement mortars. The main purpose is to assess the possibility of using the more invasive crimson fountaingrass in place of diss in cement-based vegetable concrete. The two plant fibers have been characterized by means of scanning electron microscopy (SEM), helium picnometry and thermogravimetric an…
The dynamics of a developing CW supercontinuum: Analytical predictions and experiments
2010
International audience; We show that the development of the supercontinuum spectrum in the quasi-CW regime can be interpreted analytically in terms of Akhmediev Breathers. Theory and experiment are in excellent agreement.
Novel method for functionalising and patterning textile composites:Liquid resin print
2016
Abstract The paper reports a novel method of integrating resin into continuous textile reinforcement. The method presents a print of liquid reactive resin into textile preforms. A series of targeted injections forms a patch which upon consolidation and curing transforms into a stiff region continuously spanning through preform thickness. Enhancing the injected resin with conductive phase allows creating a pattern of patches with controlled dimensions and added functionalities. Patterned composites reveal features which are not typical for conventional composites such as fibre bridged interfaces, regular thickness variation, and gradient matrix properties. The presented study explores the ro…
Inter-Model Consistency and Complementarity: Learning from ex-vivo Imaging and Electrophysiological Data towards an Integrated Understanding of Cardi…
2011
International audience; Computational models of the heart at various scales and levels of complexity have been independently developed, parameterised and validated using a wide range of experimental data for over four decades. However, despite remarkable progress, the lack of coordinated efforts to compare and combine these computational models has limited their impact on the numerous open questions in cardiac physiology. To address this issue, a comprehensive dataset has previously been made available to the community that contains the cardiac anatomy and fibre orientations from magnetic resonance imaging as well as epicardial transmembrane potentials from optical mapping measured on a per…
Concurrent fast and slow synchronized efferent phrenic activities in time and frequency domain.
1990
Abstract In urethane-anesthetized or decerebrated vagotomized rabbits efferent multifiber activity of the phrenic nerve was investigated for synchronized activities both in time and frequency domains. When respiratory drive was steadily increased by either an elevation of end-tidal CO2 concentration or i.v. administration of 4-aminopyridine, medium-frequency oscillations (MFO) first increased, then decreased and finally became absent. The power of high-frequency oscillations (HFO) steadily rose with increasing respiratory drive. In contrast to HFO which revealed a unimodal spectral peak of mostly small bandwidth, the MFO spectrum in most cases consisted of a broad complex. This complex in s…