Search results for "Transmission"
showing 10 items of 2080 documents
Transmission and Predictors of Burden of Lungworms of the Striped Dolphin (Stenella coeruleoalba) in the Western Mediterranean
2020
Pseudaliid lungworms infect the lungs and sinuses of cetaceans. Information on the life cycle and epidemiology of pseudaliids is very scarce and mostly concerns species that infect coastal or inshore cetaceans. Available evidence indicates that some pseudaliids are vertically transmitted to the host, whereas others are acquired via infected prey. We documented pseudaliid infections in an oceanic cetacean, the striped dolphin (Stenella coeruleoalba) in the western Mediterranean, and investigated the possibilities of vertical vs. horizontal transmission and the potential influence of host body size, sex, and season on infection levels. We found two species of lungworm in 87 dolphins that stra…
Understanding myxozoan infection dynamics in the sea: Seasonality and transmission of Ceratomyxa puntazzi
2013
Abstract Ceratomyxa puntazzi affects the sharpsnout seabream, Diplodus puntazzo , a recently explored aquaculture species in the Mediterranean. Little is known about the transmission and seasonality of marine myxozoans, although this knowledge is of considerable importance for the design of management strategies for aquaculture. In the present study on C. puntazzi we investigated the potential pathways of transmission as well as the parasite abundance in fish and its density in environmental water samples, throughout a full year. We performed monthly sentinel fish exposures in a C. puntazzi enzootic environment and quantified waterborne stages in seawater. Two novel C. puntazzi -specific PC…
Temporal coherency between receptor expression, neural activity and AP-1-dependent transcription regulates Drosophila motoneuron dendrite development.
2013
Neural activity has profound effects on the development of dendritic structure. Mechanisms that link neural activity to nuclear gene expression include activity-regulated factors, such as CREB, Crest or Mef2, as well as activity-regulated immediate-early genes, such as fos and jun. This study investigates the role of the transcriptional regulator AP-1, a Fos-Jun heterodimer, in activity-dependent dendritic structure development. We combine genetic manipulation, imaging and quantitative dendritic architecture analysis in a Drosophila single neuron model, the individually identified motoneuron MN5. First, Dα7 nicotinic acetylcholine receptors (nAChRs) and AP-1 are required for normal MN5 dend…
Ultrastructure of Spinal Dura Mater
2014
Pia mater is the innermost of the three meningeal membranes, closely surrounding the brain, the spinal cord, and the portion of spinal nerve roots extending towards their exit across the dura mater. A cellular layer and a subpial compartment shape the structure of the pia mater. The cellular layer is made up of flat, overlapping pial cells with amorphous, fundamental substance interposed among them. The surface of the cellular plane appears smooth and bright under scanning electron microscopy (SEM). Transmission electron microscopy shows that the cellular component is about three to five pial cells thick at the medullary level and two to three cells thick at the level of the nerve roots. Th…
Extending Quantum Links: Modules for Fiber‐ and Memory‐Based Quantum Repeaters
2020
We analyze elementary building blocks for quantum repeaters based on fiber channels and memory stations. Implementations are considered for three different physical platforms, for which suitable components are available: quantum dots, trapped atoms and ions, and color centers in diamond. We evaluate and compare the performances of basic quantum repeater links for these platforms both for present-day, state-of-the-art experimental parameters as well as for parameters that could in principle be reached in the future. The ultimate goal is to experimentally explore regimes at intermediate distances, up to a few 100 km, in which the repeater-assisted secret key transmission rates exceed the maxi…
Adaptive surface compression with geometric wavelets.
2008
The recent advances in computer graphics and digitization allow access to an ever finer three-dimensional modelling of the world. The critical challenges with 3D models lie in their transmission and rendering, which must fit the heterogeneity of the end resources (network bandwidth, display terminals . . . ). In this context, this thesis investigates the progressive compression and transmission of 3D models, based on multiresolution analysis, to provide a scalable representation of these geometric models. This work is part of "CoSurf", a collaborative research project involving LIRIS laboratory and France Télécom R&D in Rennes. The proposed hierarchical compression method is based on a wave…
The cost of an action potential.
2000
Neuronal modules, or 'cell-assemblies', comprising millions of mutually interconnected cells have been postulated to form the basis of many functions of the brain, such as mood, sleep, hunger, vigilance, and more. Depending on the extent of the module, neurocommunication in cell-assemblies might exceed metabolic resources. A medium-size (10000 neurons) module would require at least 10 J per l of brain, based on a calculated cost of an isolated action potential (AP) of 10(11)-10(12) molecules of ATP per cm(2) of cell membrane, with an absolute minimum of 10(6) ATP at a node of Ranvier. The figure matches the cost of depolarizing the unmyelinated axon of the large monopolar cell in the blowfl…
Synthesis and antibacterial activity of iron-hexacyanocobaltate nanoparticles.
2018
This paper deals with the synthesis and characterization of iron-hexacyanocobaltate (FeHCC) and its antibacterial properties. The nanoparticles were prepared by a facile co-precipitation technique. Crystal structure, particle morphology, and elemental composition were determined using X-ray Powder Diffraction, X-ray fluorescence spectroscopy, Transmission Electron Microscopy (TEM), and Infrared Spectroscopy (IR). The antibacterial activity of the FeHCC nanoparticles was tested against Escherichia coli and Staphylococcus aureus as models for Gram-negative and Gram-positive bacteria, respectively, by bacterial counting method and microscopic visualization (TEM, FEG-SEM, and fluorescence micro…
Small-Angle Scattering from Phase-Separated Metallic Alloys: From Experiment to Phase Diagrams
1994
In this paper, phase-separated metallic alloys are described in terms of concentration fluctuations. As a consequence, Small Angle Scattering equations which allow to calculate the entire scattering curve by incorporating particle-particle interference effects on the basis of the Percus-Yevick formalism, are obtained. It is shown that, for Aluminium-Lithium alloys, satisfactory fits of the experimental data can be obtained if it is assumed that Li rich elliptical monodisperse precipitate particles approach each other at average distances which are larger than the sum of the hard-sphere particle radii. It is also shown that a possible ambiguity of this model, within the Percus-Yevick formali…
Prevention of nosocomial infections and surveillance of emerging resistances in NICU
2011
Neonates hospitalized in NICU are at risk for healthcare associated infections because of their poor immune defenses, related to gestational age, colonization of mucous membranes and skin with nosocomial microorganisms, exposure to antibiotics, invasive procedures and frequent contacts with healthcare workers (HCWs). Healthcare associated infections are the major source of morbidity and mortality in NICU in the developed world. Most infections are caused by Gram-positive organisms, fulminant sepsis are often associated to Gram-negative organisms, fungal sepsis occurs frequently in ELBW infants. Hand hygiene is the most important preventive procedure, nevertheless hand hygiene compliance amo…