Search results for "T wave"
showing 10 items of 94 documents
Extensive tailorability of sound absorption using acoustic metamaterials
2017
We present an experimental demonstration of sound absorption tailorability, using acoustic metamaterials made of resonant cavities that does not rely on any dissipative material. As confirmed by numerical calculation, we particularly show that using quarter-wave-like resonators made of deep subwavelength slits allows a high confinement of the acoustic energy of an incident wave. This leads to enhance the dissipation in the cavities and, consequently, generates strong sound absorption, even over a wide frequency band. We finally demonstrate experimentally the key role of the filling ratio in tailoring such an absorption, using a metamaterial constituted of space-coiled cavities embedded in a…
Tema starosti v romane Gajto Gazdanova "Nočnye dorogi"
2016
Do tematu starości niejednokrotnie zwracał się w swojej twórczości przedstawiciel młodszego pokolenia pierwszej fali emigracji rosyjskiej, Gajto Gazdanow, najczęściej rozpatrując starość w kontekście sensu życia i śmierci. Ważna w tym zakresie jest powieść Nocne drogi, w której temat starości i stosunek do niej zostały zrealizowane głównie w historii właścicielki kawiarni, historii prostytutki Raldi, staruszka-kierowcy itd. Wszyscy bohaterowie mają cechy indywidualne, precyzyjnie uchwycone i wyrażone przez narratora. Temat starości dla Gazdanowa to przede wszystkim możliwość rozważania o sensie życia i śmierci, pokazania kontrastu pomiędzy ograniczonością, bezsensem istnienia i przeżywaniem…
Spotlight on fundus autofluorescence
2018
Ana M Calvo-Maroto,1 Alejandro Cerviño2 1Department of Ophthalmology, Clínica Universidad de Navarra, University of Navarra, Madrid, Spain; 2Optometry Research Group, Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia, Spain Abstract: Fundus autofluorescence (FAF) imaging is based on the fluorescence from ocular endogenous fluorophores located in the retinal pigment epithelium and choroid, mainly lipofuscin and melanin. It is a noninvasive technique that provides information about the spatial distribution of lipofuscin/melanin and retinal pigment epithelium health status. An overview about the fluorophores responsible for FAF imaging and t…
Heat wave occurrences over Senegal during spring: regionalization and synoptic patterns.
2020
18 pages; International audience; Based on 12 Senegalese stations of the Global Summary of the Day (GSOD) database (1979–2014), heat waves (HW) are defined for each station in spring (March–April–May, the hottest season in Senegal) as the daily maximum temperature (Tx), minimum temperature (Tn), or average apparent temperature of the day (AT), exceeding the corresponding 95% mobile percentile for at least three consecutive days. A hierarchical cluster analysis used to regionalize HW in these 12 stations is applied to simultaneous occurrences of daily temperature peaks over their 95% mobile percentiles. Three homogeneous zones of four stations each are identified (Zone 1, Zone 2 and Zone 3),…
Infection success of Echinoparyphium aconiatum (Trematoda) in its snail host under high temperature: role of host resistance
2014
Background Extreme weather events such as summer heat waves become more frequent owing to global climate change and are predicted to alter disease dynamics. This is because high temperatures can reduce host immune function. Predicting the impact of climate change on host-parasite interactions is, however, difficult as temperature may also affect parasite infective stages and other host characteristics determining the outcome of interaction. Methods Two experiments were conducted to investigate these phenomena in a Lymnaea stagnalis–Echinoparyphium aconiatum (Trematoda) interaction. In the first experiment, the effects of exposure of snails to experimental heat waves [maintenance at 25°C vs.…
Urban Heat Island (UHI) and heat waves: what relations?
2018
With four years of measurements and alarge sample of stations, the MUSTARDijon network allows for a detailed characterization of the Urban HeatIsland (UHI), a warm season phenomenon. But UHI and maximum temperature values are out of phase at twodistinct time-scales. Seasonally, the maxima of UHI occur from May to July, i.e. before the annual peak oftemperature (July to August). At a daily time-scale, analysis of the two heat waves of July 2015 shows a lag of afew days between the peak of UHI and the heat wave. Two hypotheses are suggested to explain these lags:changes in radiative conditions and/or energy fluxes between the ground surface and the atmosphere.
Les vagues de chaleur au Sahel : caractérisation, mécanismes, prévisibilité.
2016
The mechanisms controlling Sahelian heat wave (HW) variability are examined on the period 1979-2014 using the GSOD observational database and ERA-Interim reanalyses. HW events are analyzed through all terms of the atmospheric energy balance, showing a predominant role of incoming shortwave radiation on daily maximum temperature (Tx) and atmospheric water vapor on minimum temperature (Tn). The low-frequency warming trend, not explained by the previous terms, is thought to relate to the increase of greenhouse gases concentrations, due to anthropogenic emissions. The predictability of Sahelian HW events is assessed for lead times reaching up to 15 days. The model's skill, biases and uncertaint…
Les Local Climate Zones face à la canicule de 2018 à Dijon.
2019
Air temperatures measured by the MUSTARDijon network are analyzed during the summer 2018 (July 24 - August 8) heat wave. The WUDAPT method is applied to Dijon to identify Local Climate Zones (LCZs). Diurnal rhythms and nighttime mean temperatures are analyzed according to LCZs as well as to altitude and distance to the city center. During warm nights, altitude plays a negligible role. The temperatures depend to the distance of the city center. They are also associated to the anthropization summarized by the LCZs. Form of the building and vegetation are the two keys to understand and modulate the night temperatures which have the greatest impact on human health during heat waves.
Spectral dynamics of incoherent waves with a noninstantaneous nonlinear response
2013
We study the influence of a constant background noise on the dynamics of spectral incoherent solitons, which are incoherent structures sustained by a noninstantaneous (Raman-like) nonlinearity. As the level of the noise background increases, the incoherent wave enters a novel nonlinear regime characterized by oscillatory dynamics of the incoherent spectrum, which develop within a spectral cone during the propagation. In contrast to the conventional Raman-like spectral red shift, such incoherent spectral dynamics can be characterized by a significant spectral blue shift. On the basis of the kinetic wave theory, we derive explicit analytical expressions of these incoherent oscillatory spectra…
0137 : Takotsubo cardiomyopathy following acute cerebral events
2016
International audience; ObjectiveTakotsubo cardiomyopathy is characterized by a transient apical ventricular dysfunction typically induced by an acute stress. Acute cerebral events including ischemic stroke (IS) or Epileptic Event (EE) may both be associated with massive catecholamine release. We aimed to identify the characteristics and outcomes of patients who experienced Takotsubo syndrome complicating an IS or EE.MethodsBetween 2008 and 2013, 87 patients were admitted in our Intensive Care Unit for suspected Takotsubo syndrome, of whom 6 previously experienced acute cerebral symptoms with either IS or EE, within two days. Takotsubo syndrome was diagnosed on Cardiac Magnetic Resonance, e…