Overview of the Greater Lyon weather radar advances from 90's to 2008

The local weather radar of Lyon, part of the Aramis network of Meteo-France, is currently located 40 km from the urban community. The measurement quality of this tool is subjected to constant improvements from Meteo-France. Indeed, its hydrological measurement quality has steadily evolved from the early 90's until today. This article, therefore, proposes a return on these innovations, assessing measurement quality over the territory of Greater Lyon. This study is based on two successive radar locations, and also on raw reflectivity data and on rain accumulation over the past 15 min (<i>Hydram</i>) or 5 min (<i>Panthere</i>). The measurement performed on the site Satolas was unsatisfactory because of too many ground clutters; and therefore the radar was moved to Saint-Nizier. This new location associated with radar <i>Hydram</i> rain accumulation has reduced the problem of ground clutters. These rain accumulation data have given correct results in comparison with local data of the raingauge network of Greater Lyon, after a global and spatially uniform correction, based on these gauges. The latest generation of radar rain accumulation (<i>Panthere</i>) has, nearly completely, eliminated the problem of ground clutter in the urban area and provides very satisfactory measurements, especially during intense rain events

Attosecond electronic recollision as field detector

We demonstrate the complete reconstruction of the electric field of visible-infrared pulses with energy as low as a few tens of nanojoules. The technique allows for the reconstruction of the instantaneous electric field vector direction and magnitude, thus giving access to the characterisation of pulses with an arbitrary time-dependent polarisation state. The technique combines extreme ultraviolet interferometry with the generation of isolated attosecond pulses.Comment: 5 figure

Photoluminescence of Fully Inorganic Colloidal Gold Nanocluster and Their Manipulation Using Surface Charge Effects

International audienceFully inorganic, colloidal gold nanoclusters (NCs) constitute a new class of nanomaterials that are clearly distinguishable from their commonly studied metal–organic ligand-capped counterparts. As their synthesis by chemical methods is challenging, details about their optical properties remain widely unknown. In this work, laser fragmentation in liquids is performed to produce fully inorganic and size-controlled colloidal gold NCs with monomodal particle size distributions and an fcc-like structure. Results reveal that these NCs exhibit highly pronounced photoluminescence with quantum yields of 2%. The emission behavior of small (2–2.5 nm) and ultrasmall (<1 nm) NCs is significantly different and dominated by either core- or surface-based emission states. It is further verified that emission intensities are a function of the surface charge density, which is easily controllable by the pH of the surrounding medium. This experimentally observed correlation between surface charge and photoluminescence emission intensity is confirmed by density functional theoretical simulations, demonstrating that fully inorganic NCs provide an appropriate material to bridge the gap between experimental and computational studies of NCs. The presented study deepens the understanding of electronic structures in fully inorganic colloidal gold NCs and how to systematically tune their optical properties via surface charge density and particle size

Surveying the surveyors to address risk perception and adaptive-behaviour cross-study comparability

One of the key challenges for risk, vulnerability and resilience research is how to address the role of risk perceptions and how perceptions influence behaviour. It remains unclear why people fail to act adaptively to reduce future losses, even when there is ever-richer information available on natural and human-made hazards (flood, drought, etc.). The current fragmentation of the field makes it an uphill battle to cross-validate the results of existing independent case studies. This, in turn, hinders comparability and transferability across scales and contexts and hampers recommendations for policy and risk management. To improve the ability of researchers in the field to work together and build cumulative knowledge, we question whether we could agree on (1) a common list of minimal requirements to compare studies, (2) shared criteria to address context-specific aspects of countries and regions, and (3) a selection of questions allowing for comparability and long-term monitoring. To map current research practices and move in this direction, we conducted an international survey – the Risk Perception and Behaviour Survey of Surveyors (Risk-SoS). We find that most studies are exploratory in nature and often overlook theoretical efforts that would enable the comparison of results and an accumulation of evidence. While the diversity of approaches is an asset, the robustness of methods is an investment to be made. Surveyors report a tendency to reproduce past research design choices but express frustration with this trend, hinting at a turning point. To bridge the persistent gaps, we offer several recommendations for future studies, particularly grounding research design in theory; improving the formalisation of methods; and formally comparing theories and constructs, methods, and explanations while collecting the themes and variables most in use

Zwitterion functionalized gold nanoclusters for multimodal near infrared fluorescence and photoacoustic imaging

Gold nanoclusters (Au NCs) are an emerging type of theranostic agents combining therapeutic and imaging features with reduced toxicity. Au NCs stabilized by a zwitterion ligand with a fine control of the metal core size and the ligand coverage were synthesized by wet chemistry. Intense fluorescence signal is reported for the highest ligand coverage, whereas photoacoustic signal is stronger for the largest metal core. The best Au NC candidate with an average molecular weight of 17 kDa could be detected with high sensitivity on a 2D-near-infrared imaging instrument (limit of detection (LOD) = 2.3 μM μM ) and by photoacoustic imaging. In vitro and in vivo experiments demonstrate an efficient cell uptake in U87 cell lines, a fast renal clearance (t 1/2α t1/2α = 6.5 ± 1.3 min), and a good correlation between near infrared fluorescence and photoacoustic measurements to follow the early uptake of Au NCs in liver

Canola no Cerrado: performance de híbridos para incorporação no sistema de cultivo sob irrigação.

A cultura da canola possui grande importância mundial, ocupando a terceira posição da oleaginosa mais produzida, antecedida pela soja e palma de óleo. O Brasil ainda não consolidou a produção dessa espécie, sendo necessários mais estudos para promover sua tropicalização, principalmente em regiões com temperaturas mais altas. Nesse contexto, o trabalho teve como objetivo avaliar os componentes fenológicos e produtivos de canola sob irrigação visando sua tropicalização. O experimento foi conduzido em área experimental da Embrapa Cerrados, Planaltina, DF, situada a 15°35?30?? S e 47°42?30?? W, a 1.007 m altitude. Utilizou&#8209;se o delineamento experimental de blocos ao acaso, com 16 genótipos de canola e quatro repetições. O híbrido Diamond foi o mais precoce com ciclo próximo aos 100 dias, de forma geral, a maioria dos híbridos foi agrupada como precoce. Os híbridos Diamond, ALHT B4, Hyola 50, Hyola 433 e a população F2 originária da Hyola 50, apresentaram destaque com números de sementes por síliqua superiores a 25, contudo, os demais genótipos apresentaram número de grãos superiores a 20 grãos por síliqua. Os híbridos de canola apresentam redução no seu ciclo quando cultivados no Cerrado. A produtividade de grãos da canola sob irrigação é superior à média nacional em 2019 (1.371 kg ha&#8209;1), demonstrando o alto potencial do seu cultivo no Cerrado

Mechanomyography versus Electromyography, in monitoring the muscular fatigue

BACKGROUND: The use of the mechanomyogram (MMG) which detects muscular vibrations generated by fused individual fiber twitches has been refined. The study addresses a comparison of the MMG and surface electromyogram (SEMG) in monitoring muscle fatigue. METHODS: The SEMG and MMG were recorded simultaneously from the same territory of motor units in two muscles (Biceps, Brachioradialis) of the human (n = 18), during sustained contraction at 25 % MVC (maximal voluntary contraction). RESULTS: The RMS (root mean square) of the SEMG and MMG increased with advancing fatigue; MF (median frequency) of the PSD (power density spectra) progressively decreased from the onset of the contraction. These findings (both muscles, all subjects), demonstrate both through the SEMG and MMG a central component of the fatigue. The MF regression slopes of MMG were closer to each other between men and women (Biceps 1.55%; Brachialis 13.2%) than were the SEMG MF slopes (Biceps 25.32%; Brachialis 17.72%), which shows a smaller inter-sex variability for the MMG vs. SEMG. CONCLUSION: The study presents another quantitative comparison (MF, RMS) of MMG and SEMG, showing that MMG signal can be used for indication of the degree of muscle activation and for monitoring the muscle fatigue when the application of SEMG is not feasible (chronical implants, adverse environments contaminated by electrical noise)