The joint law of the extrema, final value and signature of a stopped random walk

A complete characterization of the possible joint distributions of the maximum and terminal value of uniformly integrable martingale has been known for some time, and the aim of this paper is to establish a similar characterization for continuous martingales of the joint law of the minimum, final value, and maximum, along with the direction of the final excursion. We solve this problem completely for the discrete analogue, that of a simple symmetric random walk stopped at some almost-surely finite stopping time. This characterization leads to robust hedging strategies for derivatives whose value depends on the maximum, minimum and final values of the underlying asset

Probing pre-formed alpha particles in the ground state of nuclei

In this Letter, we report on alpha particle emission through the nuclear break-up in the reaction 40Ca on a 40Ca target at 50A MeV. It is observed that, similarly to nucleons, alpha particles can be emitted to the continuum with very specific angular distribution during the reaction. The alpha particle properties can be understood as resulting from an alpha cluster in the daughter nucleus that is perturbed by the short range nuclear attraction of the collision partner and emitted. A time-dependent theory that describe the alpha particle wave-function evolution is able to reproduce qualitatively the observed angular distribution. This mechanism offers new possibilities to study alpha particle properties in the nuclear medium.Comment: 4 pages, 3 figure

HIGH EXCITATION ENERGY STRUCTURES IN HEAVY ION COLLISIONS ON A208Pb TARGET

Energy spectra of fragments from the 36Ar +208Pb reaction at 11 MeV/n and 20Ne + 208Pb reaction at 30 MeV/n were measured using a time of flight spectrometer. Structures ranging up to 130 MeV excitation energy are observed in the inelastic spectra. These structures are shown to be due to an excitation of the208Pb target nucleus

Fish consumption and the risk of gastric cancer: systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Gastric cancer is the fourth most frequently occurring malignancy after lung, breast, and colorectal cancer, and the second most common cause of death from cancer worldwide. Epidemiologic studies have examined the possible association between fish consumption and gastric cancer, but the results were inconclusive. We conducted a systematic review and meta-analysis to examine the association between fish intake and the risk of gastric cancer.</p> <p>Methods</p> <p>PubMed was searched for studies published in English-language journals from 1991 through 2009. We identified 17 epidemiologic studies (15 case-control and 2 cohort studies) that included relative risks (RRs) or odds ratios (ORs) estimates with 95% confidence intervals (CIs) of the relationship between gastric cancer and fish consumption. Data were extracted using standardized data forms. Summary RRs or ORs for the highest versus non/lowest fish consumption levels were calculated using random-effects model. Heterogeneity among studies was examined using Q and I²statistics.</p> <p>Results</p> <p>In this study, 5,323 cases of gastric cancer and over 130,000 non-cases were included. The combined results from all studies indicated that the association between high fish consumption and reduced gastric cancer risk was not statistically insignificant (RR = 0.87, 95% CI = 0.71-1.07).</p> <p>Conclusions</p> <p>Current evidence indicated that the association between fish consumption and risk of gastric cancer remains unclear.</p

Quatre années de guerre au prisme de la langue : la correspondance de Jacques Vaché, soldat, interprète, et poète d’avant-garde

Jacques Vaché (1895-1919) est passé à la postérité grâce à André Breton, chez qui il déclencha l’étincelle surréaliste lorsqu’ils se rencontrèrent à Nantes fin 1915, alors qu’ils étaient l’un hospitalisé après une blessure reçue sur le front de Champagne, l’autre infirmier militaire. Toute sa vie, le fondateur du surréalisme n’eut de cesse de rappeler cette influence déterminante. Une fois rétabli, Vaché retourna au front comme interprète auprès des armées anglophones et fut successivement au service des troupes britanniques, australiennes et américaines. Tout au long de la guerre, Vaché entretint une correspondance dont cent-cinquante-huit lettres sont actuellement connues. Elles sont adressées à ses parents, à une auxiliaire d’un hôpital militaire nantais et à plusieurs amis, dont J. Sarment, A. Breton, T. Fraenkel et L. Aragon. Appliquer le filtre de la langue à ce corpus permet d’en dégager trois thèmes principaux. D’abord décrypter le témoignage original d’un combattant, dont le ton déréalise très souvent la guerre, la rend lointaine, presque inoffensive. Ensuite offrir un aperçu précieux sur la vie d’un interprète et sur la question de la circulation des langues au front, à la fois entre soldats et entre militaires et civils. Enfin approfondir l’analyse d’une révolution esthétique qui voit le jour en pleine guerre. En effet, les lettres adressées aux futurs membres du groupe surréaliste, influencées par Jarry, dressant l’éloge de la vitesse et annonçant l’écriture automatique, contiennent autant d’éléments caractéristiques de la modernité littéraire des premières années du XXe siècle

Resuspension of carbon dust collected in Tore Supra and exposed to turbulent airflow Controlled experiments and comparison with model

International audienceThis work presents the results of experiments conducted with carbon microparticles collected in the tokamak Tore Supra in order to characterize their resuspension behaviour from a stainless-steel substrate when exposed to turbulent airflow. Experiments were conducted in a wind tunnel with controlled velocity profiles and monitored environmental conditions. A consequent amount of dust has been collected in the vessel of the tokamak and a bimodal particle size distribution of samples is first demonstrated. Comparison with resuspension of alumina powders with equivalent particle size distributions under turbulent airflow is also discussed. Results for both carbon and alumina microparticles are then compared to a theoretical resuspension model. Data reveal that exposing multilayer deposits with bimodal particle size distributions to low-speed flows (i.e. 3-10 m/s) induces a significant reduction of the mobilized fractions compared to what was predicted by the model. In addition, results helped to highlight some limitations in the model to physically describe changes in the adhesive strength that can occur with a polydisperse deposit. © 2014 Published by Elsevier B.V