Search for antihelium in cosmic rays

The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320 and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.Comment: 18 pages, Latex, 9 .eps figure

A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01

The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the $\sim 100 \mathrm{MeV}$ to $1 \mathrm{TeV}$ range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected $10^8$ cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary $\pi^-$ and $\mu^-$ emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor stylistic and grammer change

Protons in near earth orbit

The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ~ 70 m^-2 sec^-1 sr^-1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.Comment: 19 pages, Latex, 7 .eps figure

Ponte et stratégie de la reproduction chez les femelles du tacaud Trisopterus luscus (Gadidés) du plateau continental de la Galice, nord-ouest de l'Espagne

[EN] Pouting, Trisopterus luscus is harvested commercially on the Galician shelf by the Spanish inshore artisanal fleet. In spite of a substantial decrease in pouting catches, fishery regulations are limited to size length restrictions. This study provides biological data including length-at-maturity based on histological methods, seasonal maturation, spawning and fecundity. A collection 443 females, from 17 to 42 cm in total length, were sampled from landings (December 2003 to December 2004). Pouting length-at-maturity was estimated as 19.2 cm on average. Pouting females in spawning condition were observed throughout the year and the number of developing oocytes ranged from 20 000 to 1 327 000. Peak spawning was observed between February and April, which correlated well with trends in gonadosomatic index, and inverse to condition factor and hepatosomatic index. Histological examination of the gonads revealed that pouting ovarian development organization is asynchronous, and fecundity is probably determinate.[FR] Le tacaud, Trisopterus luscus est pêché par la flotte artisanale espagnole. En dépit d'une diminution substantielle des captures de tacaud, la pêche est réglementée uniquement à partir d'une taille minimum commerciale. Cette étude fournit des données biologiques comprenant la taille à maturité sexuelle basée sur l'histologie, la maturation saisonnière, la ponte et la fécondité. Un échantillon de 443 femelles, de 17 à 42 cm longueur totale, est examiné à partir des débarquements durant une année (de décembre 2003 à décembre 2004). La taille moyenne à maturité sexuelle est estimée à 19,2 cm. Les femelles de tacaud en condition de ponte sont observée tout au long de l'année et le nombre d'ovocytes s'étend de 20 000 to 1 327 000 par individu. Les pics de ponte sont observés entre février et avril, ce qui est bien corrélé avec l'évolution du rapport gonado-somatique et inverse de celle du facteur de condition et du rapport hépato-somatique. L'étude histologique révèle que le développement ovarien chez le tacaud est asynchrone, et que la fécondité est probablement déterminée.Peer reviewe

Experimental study of a proximity focusing Cherenkov counter prototype for the AMS experiment

A study prototype of Proximity Focussing Ring Imaging Cherenkov counter has been built and tested with several radiators using separately cosmic-ray particles and 12C beam fragmentation products at several energies. Counter prototype and experimental setup are described, and the results of measurements reported and compared with simulation results.The performances are discussed in the perspective of the final counter design.Comment: 27 pages, 16 figures, submitted to NIM

Comparing Approaches to Deal with Non-Gaussianity of Rainfall Data in Kriging-Based Radar-Gauge Rainfall Merging

Merging radar and rain gauge rainfall data is a technique used to improve the quality of spatial rainfall estimates and in particular the use of Kriging with External Drift (KED) is a very effective radar-rain gauge rainfall merging technique. However, kriging interpolations assume Gaussianity of the process. Rainfall has a strongly skewed, positive, probability distribution, characterized by a discontinuity due to intermittency. In KED rainfall residuals are used, implicitly calculated as the difference between rain gauge data and a linear function of the radar estimates. Rainfall residuals are non-Gaussian as well. The aim of this work is to evaluate the impact of applying KED to non-Gaussian rainfall residuals, and to assess the best techniques to improve Gaussianity. We compare Box-Cox transformations with λ parameters equal to 0.5, 0.25, and 0.1, Box-Cox with time-variant optimization of λ, normal score transformation, and a singularity analysis technique. The results suggest that Box-Cox with λ = 0.1 and the singularity analysis is not suitable for KED. Normal score transformation and Box-Cox with optimized λ, or λ = 0.25 produce satisfactory results in terms of Gaussianity of the residuals, probability distribution of the merged rainfall products, and rainfall estimate quality, when validated through cross-validation. However, it is observed that Box-Cox transformations are strongly dependent on the temporal and spatial variability of rainfall and on the units used for the rainfall intensity. Overall, applying transformations results in a quantitative improvement of the rainfall estimates only if the correct transformations for the specific data set are used.ISSN:0043-1397ISSN:1944-797

Ethnographie d’un atelier à domicile. Les visuels de terrain comme support méthodologique pour représenter une frontière poreuse entre travail et loisirs

From March 2020 to May 2021, several lockdowns have modified field access for anthropologists observing professional spaces. If professional work was rather slowed down than fully suspended, the amount of people in working spaces was regulated by sanitary measures. I was only able to carry on my ethnographic fieldwork in leather workshops by observing a young Parisian brand that received me in one of the two co-founders’ flat, where both had set their workshop. The participant observation of private life and professional work in this hybrid space raises the following question : is there a border isolating personal life from work ? Working at home is both faithful to the historic tradition of crafts and illustrates new forms of professional activity as reshaped by Internet since the 1990’es.By trying to overcome the hurdle of identifying what belongs to work and what belongs to private life, a visual anthropology’s method has been set. Using pictures (drawings based on photographs) and texts, a hybrid format close to comics has been adopted. Working on the layer boards gather the visual notes taken during the field study, the analysis of the data and is used to return the ethnographic survey

Etude de l'intermittence et de la variabilite des champs de precipitation par une approche stochastique

SIGLEINIST T 73430 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc