VHF discharges in storm cells producing microbursts

An experiment was carried out in which 3-D mapping of VHF sources was compared to a 3-D description of the reflectivity and dynamics of associated cloud cells observed by a radar network. Data from 61 microbursts were analyzed and it was found that, in 93 pct. of the cases, electrical activity precedes outflow development. The results confirm that the peak in intracloud activity precedes the maximum value of the outflow

Survival of Campylobacter spp. on inoculated pork skin or meat.

Campylobacter is one of the main causes of human foodborne bacterial zoonoses due to food consumption in developed countries. Nine to 32% of pig carcasses are contaminated by Campylobacter. The purpose of the study was to improve our knowledge of the survival of implanted campylobacters from the two kinds of pork matrix meat (skin, muscle) during meat cold domestic storage. One hundred and twenty pork skin and 120 skinless chine samples (25 cm2/sample) were inoculated with two C. jejuni and four C. coli strains and stored in closed box at 4 oc for 1, 4, 8, 15 and 22 days. Campylobacter were isolated from sample suspensions after mechanical pummeling and numbered by direct plating. We calculated the shoulder time (ST), the D value (the time for one log decrease} and the R, value (the time to reach 10% of the initial population R, = ST +D). We compared them in a stratified approach according to pork matrix and strain. According to matrixes, mean D, TS and R, value varied significantly between pork skin (4.3 days, 1.3 days, 5.6 days, respectively} and spare rib (7 .2 days, 3.5 days, 10.8 days, respectively}. On spare rib, R1 was higher (16 days) with one C. coli strain (CCV55). Statistical effects between TS and R, value on spare rib and strain were noticed. This study shows that the survival of campylobacters on pork meat is similar to the survival of Campylobacter on poultry meat. Consequently, good hygiene practices are needed to manage the risk of pork Campylobacter contamination and further studies focusing on survival factors may complete this risk analysis on the pork food chain

Campylobacter in the Pork Food Chain : a quantitative hazard analysis

Campylobacter are one of the most frequent causes of bacterial enteritis in industrialized countries and are widespread in food animals. Pigs are known to be largely contaminated in farms, but few data exist about the status of the pork food chain. The purpose of this study was to quantify the Campylobacter contamination of the French pork food chain: prevalence, contamination level, bactenal species in primary production (piglets and fattening pigs when slaughtered), and in first and second transformation process (from carcasses before chilling to deboned meat cuts)

Formation and transportation of sand-heap in an inclined and vertically vibrated container

We report the experimental findings of formation and motion of heap in granular materials in an inclined and vertically vibrated container. We show experimentally how the transport velocity of heap up container is related to the driving acceleration as well as the driving frequency of exciter. An analogous experiment was performed with a heap-shaped Plexiglas block. We propose that cohesion force resulted from pressure gradient in ambient gas plays a crucial role in enhancing and maintaining a heap, and ratchet effect causes the movement of the heap. An equation which governs the transport velocity of the heap is presented.Comment: 9 pages, 5 figures, submitted to PR

Economic evaluations of interventions to optimize medication use in older adults with polypharmacy and multimorbidity: A systematic review

Purpose: To conduct a systematic review of the economic impact of interventions intended at optimizing medication use in older adults with multimorbidity and polypharmacy. Methods: We searched Ovid-Medline, Embase, CINAHL, Ageline, Cochrane, and Web of Science, for articles published between 2004 and 2020 that studied older adults with multi-morbidity and polypharmacy. The intervention studied had to be aimed at optimizing medication use and present results on costs. Results: Out of 3,871 studies identified by the search strategy, eleven studies were included. The interventions involved different provider types, with a majority described as a multidisciplinary team involving a pharmacist and a general practitioner, in the decision-making process. Interventions were generally associated with a reduction in medication expenditure. The benefits of the intervention in terms of clinical outcomes remain limited. Five studies were cost-benefit analyses, which had a net benefit that was either null or positive. Cost-utility and cost-effectiveness analyses resulted in incremental cost-effectiveness ratios that were generally within the willingness-to-pay thresholds of the countries in which the studies were conducted. However, the quality of the studies was generally low. Omission of key cost elements of economic evaluations, including intervention cost and payer perspective, limited interpretability. Conclusion: Interventions to optimize medication use may provide benefits that outweigh their implementation costs, but the evidence remains limited. There is a need to identify and address barriers to the scaling-up of such interventions, starting with the current incentive structures for pharmacists, physicians, and patients

Heap Formation in Granular Media

Using molecular dynamics (MD) simulations, we find the formation of heaps in a system of granular particles contained in a box with oscillating bottom and fixed sidewalls. The simulation includes the effect of static friction, which is found to be crucial in maintaining a stable heap. We also find another mechanism for heap formation in systems under constant vertical shear. In both systems, heaps are formed due to a net downward shear by the sidewalls. We discuss the origin of net downward shear for the vibration induced heap.Comment: 11 pages, 4 figures available upon request, Plain TeX, HLRZ-101/9

Optical extinction in a single layer of nanorods

We demonstrate that almost 100 % of incident photons can interact with a monolayer of scatterers in a symmetrical environment. Nearly-perfect optical extinction through free-standing transparent nanorod arrays has been measured. The sharp spectral opacity window, in the form of a characteristic Fano resonance, arises from the coherent multiple scattering in the array. In addition, we show that nanorods made of absorbing material exhibit a 25-fold absorption enhancement per unit volume compared to unstructured thin film. These results open new perspectives for light management in high-Q, low volume dielectric nanostructures, with potential applications in optical systems, spectroscopy, and optomechanics

Observation of intermittency in wave turbulence

We report the observation of intermittency in gravity-capillary wave turbulence on the surface of mercury. We measure the temporal fluctuations of surface wave amplitude at a given location. We show that the shape of the probability density function of the local slope increments of the surface waves strongly changes across the time scales. The related structure functions and the flatness are found to be power laws of the time scale on more than one decade. The exponents of these power laws increase nonlinearly with the order of the structure function. All these observations show the intermittent nature of the increments of the local slope in wave turbulence. We discuss the possible origin of this intermittency.Comment: new version to Phys. Rev. Let