Search results for "threshold"
showing 10 items of 688 documents
Radial electron fluence around ion tracks as a new physical parameter for the detection threshold of PADC using Geant4-DNA toolkit
2018
International audience; The detection threshold of poly(allyl dyglycol carbonate), PADC, for C ions is determined as 55 eV/nm in stopping power, which is significantly higher than that for proton and He ions. The stopping power is not a universal parameter for expressing the detection threshold of PADC. A new physical parameter of Radial Electron Fluence around Ion Tracks, REFIT, is proposed to describe the detection threshold of PADC. It is defined as the number density of electrons passing through the surface of a cylinder of a certain radius that is co-axial with the trajectory. Furthermore, preliminary calculations are presently being performed using the Monte Carlo simulation code of G…
Ex Ante evaluation of gene flow in oilseed rape with cropping system models
2013
Chapitre 4; Oilseed rape (OSR) genes can escape fields in space via pollen and seeds, and in time via volunteers resulting from seeds lost before or during oilseed rape harvest. When varieties co-exist, e.g. genetically-modified (GM) and non-GM varieties, this spatio-temporal gene flow can lead to the adventitious presence of GM seeds in non-GM harvests and thus cause financial losses for farmers and cooperatives. Gene flow depends on crop locations, succession, and management, as well as the location and management of semi-natural areas such as roadverges. The objective of this investigation was to present a simulation methodology using the spatially-explicit cropping system model GENESYS …
Impacts of obesity on the oro-sensory perception of lipids in Human
2010
Accumulating evidences support the existence of a fatty acid taste both in rodents and humans. A recent study performed in lean subjects suggests the existence of a positive correlation between the oro-sensory perception of dietary lipids and body mass index (BMI) in Human. It was extrapolated that obesity might promote overconsumption of fatty foods by decreasing the detection of lipids in oral cavity. To explore this hypothesis, linoleic acid (LA) detection threshold was determined in lean (18>BMI 30, n=29) volunteers using a 3-alternative force choice ascending concentration presentation procedure in conditions known to minimize other sensory cues. A large distribution of LA detection wa…
The bitter taste of vitamins is mediated by human TAS2R activation
2021
Vitamins play an important role in maintaining normal physiologic and metabolic functions. Vitamins are known to generate bitterness, which may contribute to the off-taste of nutritional supplements. This negative sensation may decrease product acceptability and patient compliance. Few studies have examined taste thresholds and sensory sensing mechanisms at the origin of vitamin taste detection. To better understand vitamin bitterness perception, we combined human sensory analysis and taste receptor functional assays. We measured the aqueous taste detection threshold of four B vitamins using sensory difference tests. Challenging the 25 human bitter taste 2 receptors (TAS2Rs), we found that …
New Decision-making Tools for sustainable Weed Control
2021
En 2017, le Conseil fédéral suisse a adopté le pland’action visant à la réduction des risques et à l’utilisation durable des produits phytosanitaires. L’une desmesures de ce plan est «la renonciation complète oupartielle aux herbicides». Or, celle-ci n’est réalisablequ’au travers d’une stratégie de gestion globale desadventices, à l’échelle de la culture et de la rotation. Eneffet, les adventices sont nuisibles pour la culture enplace l’année en cours, mais aussi de manière pluriannuelle par le biais de leur stock semencier. La mise enœuvre de mesures préventives et curatives basées surles principes de la protection intégrée nécessite denouveaux outils d’aide à la décision. Des indicateursd…
Dielectric properties of graphite-based epoxy composites
2014
International audience; Composite materials based on epoxy resin filled with various kinds of graphite particles: exfoliated graphite, natural graphite, and coarse, medium and fine artificial graphites have been prepared. Results of broadband dielectric investigations of such materials in wide temperature (25-450 K) and frequency (20 Hz-3 THz) ranges are presented. The dielectric permittivity strongly increases with graphite particle size. The graphite particle size and shape also have a strong impact on freezing temperature, conductivity activation energy and composite electromagnetic absorption properties at room temperature. The lowest percolation threshold is observed for exfoliated gra…
Functionnalized Surface Acoustic Wave Sensors for the Detection of Hazardous Gases
2018
International audience; In this work, we show the capabilities of Surface Acoustic Wave (SAW) devices to probe the properties of gas sensitive materials for the manufacturing of hazardous gas sensors. The great capabilities of cobalt corroles for the trapping of carbon monoxide (CO) were exploited to produce selective sensors. These corroles were deposited on SAW delay lines surfaces and then exposed to carbon monoxide (CO) in standard conditions. Concentrations of a few hundreds of ppb were measured emphasizing the interest of such sensors for the detection of CO. Another type of sensitive layers exhibiting specific porosity adapted to the trapping of formaldehyde (CH$_2$O) were deposited …
Nonlinear resonances and some of their applications to information processing
2021
The study of resonance phenomena in nonlinear dynamical systems has drawn considerable attention for years. The most studied nonlinear resonance is undoubtedly the famous stochastic resonance, which consists of perturbing a nonlinear system with an appropriate amount of noise to enhance the detection of a subthreshold input signal. Since the introduction of stochastic resonance in the context of climate dynamics, it was later observed that a deterministic high frequency perturbation can replace noise leading to vibrational resonance. Even if this latter resonance was investigated in many areas of science for more than two decades now, it is still receiving attentions. It is the subject of t…
A Robust Multi Stage Technique for Image Binarization of Degraded Historical Documents
2017
International audience; Document image binarization is a central problem in many document analysis systems. Indeed, it represents one of the basic challenges, especially in case of historical documents analysis. In this paper, we propose a novel robust multi stage framework that combines different existing document image thresholding methods for the purpose of getting a better binarization result. CLAHE technique is introduced to significantly enhance contrast in some poor images. The proposed method then uses a hybrid algorithm to partition image into foreground and background. A special procedure is finally applied in order to remove small noise and correct characters morphology. Experime…
Fuzzy temporal random sets with an application to cell biology
2007
Total Internal Reflection Fluorescence Microscopy (TIRFM) greatly facilitates to imaging the first steps of endocytosis, a process whereby cells traffic cargo from the cell surface to endosomes. Using TIRFM, fluorescent-tagged endocytic proteins are observed as overlapped areas forming random clumps of different sizes, shapes and durations. A common procedure to segment these objects consists of thresholding the original gray-level images to produce binary sequences in which a pixel is covered or not by a given fluorescent-tagged protein. This binary logic is not appropriate because it leaves a free tuning parameter to be set by the user which can influence on the conclusions of the statist…