Quantum Monte Carlo study of ring-shaped polariton parametric luminescence in a semiconductor microcavity

We present a quantum Monte Carlo study of the quantum correlations in the parametric luminescence from semiconductor microcavities in the strong exciton-photon coupling regime. As already demonstrated in recent experiments, a ring-shaped emission is obtained by applying two identical pump beams with opposite in-plane wavevectors, providing symmetrical signal and idler beams with opposite in-plane wavevectors on the ring. We study the squeezing of the signal-idler difference noise across the parametric instability threshold, accounting for the radiative and non-radiative losses, multiple scattering and static disorder. We compare the results of the complete multimode Monte Carlo simulations with a simplified linearized quantum Langevin analytical model

Sea surface temperature of the coastal zones of France

Thermal gradients in French coastal zones for the period of one year were mapped in order to enable a coherent study of certain oceanic features detectable by the variations in the sea surface temperature field and their evolution in time. The phenomena examined were mesoscale thermal features in the English Channel, the Bay of Biscay, and the northwestern Mediterranean; thermal gradients generated by French estuary systems; and diurnal heating in the sea surface layer. The investigation was based on Heat Capacity Mapping Mission imagery

Sea surface temperature of the coastal zones of France

The results of an investigation to map the various thermal gradients in the coastal zones of France are presented. Paricular emphasis is given to the natural phenomena and man made thermal effluents. It is shown that a close correlation exist between wind speed direction and the offshore width of the effluent

New development of a Radiation-Hard Polycrystalline CdTe Detector for LHC Luminosity Monitoring

Detectors presently considered for monitoring and control of the LHC luminosity will sample the hadronic/electromagnetic showers produced by neutrons and photons in copper absorbers designed to protect the superconducting magnets from quenching. At this location the detectors will have to withstand extreme radiation levels and their long term operation will have to be assured without requiring human intervention. For this application we have successfully tested thick polycrystalline-CdTe detectors. The paper summarizes the results obtained on rise-times, sensitivity and resistance to neutron irradiation up to a dose of 10 ^15/cm 2

Surveillance and control of Aedes aegypti in Uruguay, achievements and challenges

Uruguay has monitored the presence of Aedes aegypti since 1997, when its reintroduction was reported. Since then, different methodologies have been used (larval surveys, control of strategic points, method of rapid survey of Aedes aegypti indices, traps). The LIRAa methodology is effective in detecting the main containers that are acting as breeding sites for Ae. aegypti in a certain area. However, the larval indices obtained are not sufficient to estimate the risk of arbovirus transmission because they do not provide a reliable estimate of the adult population, they do not take into account the distribution in transmission clusters and are heavily operator-dependant. The objective of this work was to improve the surveillance system in order to identify sites and periods with high Aedes density and help prevent future outbreaks of arbovirosis.Sociedad Latinoamericana de Ecología de Vectore

The singular continuous diffraction measure of the Thue-Morse chain

The paradigm for singular continuous spectra in symbolic dynamics and in mathematical diffraction is provided by the Thue-Morse chain, in its realisation as a binary sequence with values in $\{\pm 1\}$. We revisit this example and derive a functional equation together with an explicit form of the corresponding singular continuous diffraction measure, which is related to the known representation as a Riesz product.Comment: 6 pages, 1 figure; revised and improved versio

CdTe Photoconductors for LHC Luminosity Monitoring

Detectors using CdTe photoconductors are being used with great success in LEP to monitor the vertical beam emittance. They can withstand tremendous irradiation, of up to 10^13 Gy, from hard X-rays. For the LHC, monitors measuring the relative luminosity will be placed inside absorbers located 142 m from the interaction points, where they will receive about 10^8 Gy per year due to gamma radiation and neutrons. Thick-polycristalline-CdTe detectors were recently tested for speed, sensitivity and radiation resistance before and after receiving up to 10^15 neutrons per cm^2. The test results are presented here, along with a comparison of the calculated charge deposition in Silicon, Diamond and GaAs detectors

Acute changes in peritoneal morphology and transport properties with infectious peritonitis and mechanical injury

Acute changes in peritoneal morphology and transport properties with infectious peritonitis and mechanical injury. Peritoneal clearance studies were performed in rats undergoing acute peritoneal dialysis. Some of these animals were then exposed to laparotomy and mechanical drying of the peritoneum. Peritoneal clearance studies were repeated at intervals up to 11 days. Another group of rats was placed on daily peritoneal dialysis and allowed to spontaneously develop peritonitis which was not treated. These rats underwent peritoneal transport studies at differing durations of infection. In all groups, animals were sacrificed at the time of the last transport studies for morphological assessment of the peritoneum by light microscopy, scanning electron microscopy, and transmission electron microscopy. The results showed similar decreases in drainage volume and increases in glucose absorption and protein losses with both infection and drying. Both types of injury resulted in extensive mesothelial structural changes. While drying caused mainly denudation of the mesothelial surface, infectious peritonitis was associated with separation of mesothelial cells, and the appearance of numerous white blood cells between and on mesothelial cells. Exposure to peritoneal dialysis alone had no obvious effects on anatomy. Although changes in the peritoneal microcirculation and deeper structures cannot be excluded as contributing to peritoneal transport alterations, the findings suggest that alterations of mesothelium might explain some of the changes in peritoneal transport properties under the conditions of these studies.Modifications aiguës de la morphologie et des propriétés de transport du péritoine par péritonite infectieuse et lésion mécanique. Des études de clearance péritonéale ont été entreprises chez des rats en dialyse péritonéale aiguë. Certains de ces animaux étaient soumis à une laparotomie et à un séchage mécanique du péritoine. Les études de clearance péritonéale étaient répétées à des intervalles allant jusqu'à 11 jours. Un autre groupe de rat était placé en dialyse péritonéale journalière, et il pouvait développer spontanément une péritonite qui n'était pas traitée. Chez ces rats ont été effectuées des études de transport péritonéal à différents stades d'infection. Dans tous les groupes, les animaux étaient sacrifiés lors de la dernière étude de transport afin d'étudier morphologiquement le péritoine par microscopie optique, microscopie électronique à balayage, et microscopie électronique par transmission. Les résultats ont montré des diminutions du volume de drainage et des augmentations de l'absorption du glucose et des pertes protéiques identiques avec l'infection ou le séchage. Les deux types de lésions ont entrainé des modifications structurelles mésothéliales importantes. Tandis que le séchage entrainait principalement une dénudation de la surface mésothéliale, la péritonite infectieuse était associée à une séparation des cellules mésothéliales, et à l'apparition de nombreux globules blancs entre et sur les cellules mésothéliales. L'exposition à la dialyse péritonéale seule n'avait pas d'effets anatomiques évidents. Bien que la contribution aux altérations du transport péritonéal de modifications de la micro-circulation péritonéale et des structures plus profondes ne puisse être exclue, ces résultats suggèrent que les altérations du mésothélium pourraient expliquer certaines des modifications des propriétés de transport péritonéal dans les conditions de ces études