Electron impact double ionization of helium from classical trajectory calculations

With a recently proposed quasiclassical ansatz [Geyer and Rost, J. Phys. B 35 (2002) 1479] it is possible to perform classical trajectory ionization calculations on many electron targets. The autoionization of the target is prevented by a M\o{}ller type backward--forward propagation scheme and allows to consider all interactions between all particles without additional stabilization. The application of the quasiclassical ansatz for helium targets is explained and total and partially differential cross sections for electron impact double ionization are calculated. In the high energy regime the classical description fails to describe the dominant TS1 process, which leads to big deviations, whereas for low energies the total cross section is reproduced well. Differential cross sections calculated at 250 eV await their experimental confirmation.Comment: LaTeX, 22 pages, 10 figures, submitted to J. Phys.

Modulation OFDM Suréchantillonnée pour l’Amélioration de la Transmission Haut débit sur Canal CPL

Au cours des dernières années, on assiste à une expansion de la transmission multimédia via la technologie courants porteurs en lignes (CPL). La plupart des travaux sur CPL ont opté pour la modulation multi-porteuse OFDM (Orthogonal Frequency Division Multiplexing) comme technique de transmission. Mais cette modulation, basée sur une mise en forme spectrale rectangulaire, possède des inconvénients notables comme une densité spectrale de puissance ayant des lobes secondaires très élevés. D'autres modulations ont été développées pour lutter contre ce problème. Nous proposons dans ce papier l’étude de la modulation OFDM suréchantillonnée sur plusieurs aspects critiques, afin de l’adapter à la transmission d’information via un canal CPL. Notre contribution sera focalisée sur l'étude de la densité spectrale de puissance (DSP) du signal OFDM suréchantillonné, afin d’optimiser une chaîne de transmission numérique haut débit sur les canaux CPL indoor. Cette méthode consiste à adapter les paramètres de modulation pour diminuer les pertes d’information. Pour cela nous allons examiner trois schémas de modulations OFDM, pour montrer l’efficacité de la méthode proposée

A One Health Framework for the Evaluation of Rabies Control Programmes: A Case Study from Colombo City, Sri Lanka

<div><p>Background</p><p>One Health addresses complex challenges to promote the health of all species and the environment by integrating relevant sciences at systems level. Its application to zoonotic diseases is recommended, but few coherent frameworks exist that combine approaches from multiple disciplines. Rabies requires an interdisciplinary approach for effective and efficient management.</p><p>Methodology/Principal Findings</p><p>A framework is proposed to assess the value of rabies interventions holistically. The economic assessment compares additional monetary and non-monetary costs and benefits of an intervention taking into account epidemiological, animal welfare, societal impact and cost data. It is complemented by an ethical assessment. The framework is applied to Colombo City, Sri Lanka, where modified dog rabies intervention measures were implemented in 2007. The two options included for analysis were the control measures in place until 2006 (“baseline scenario”) and the new comprehensive intervention measures (“intervention”) for a four-year duration. Differences in control cost; monetary human health costs after exposure; Disability-Adjusted Life Years (DALYs) lost due to human rabies deaths and the psychological burden following a bite; negative impact on animal welfare; epidemiological indicators; social acceptance of dogs; and ethical considerations were estimated using a mixed method approach including primary and secondary data. Over the four years analysed, the intervention cost US $1.03 million more than the baseline scenario in 2011 prices (adjusted for inflation) and caused a reduction in dog rabies cases; 738 DALYs averted; an increase in acceptability among non-dog owners; a perception of positive changes in society including a decrease in the number of roaming dogs; and a net reduction in the impact on animal welfare from intermediate-high to low-intermediate.</p><p>Conclusions</p><p>The findings illustrate the multiple outcomes relevant to stakeholders and allow greater understanding of the value of the implemented rabies control measures, thereby providing a solid foundation for informed decision-making and sustainable control.</p></div