The Future of RICH Detectors through the Light of the LHCb RICH

The limitations in performance of the present RICH system in the LHCb experiment are given by the natural chromatic dispersion of the gaseous Cherenkov radiator, the aberrations of the optical system and the pixel size of the photon detectors. Moreover, the overall PID performance can be affected by high detector occupancy as the pattern recognition becomes more difficult with high particle multiplicities. This paper shows a way to improve performance by systematically addressing each of the previously mentioned limitations. These ideas are applied in the present and future upgrade phases of the LHCb experiment. Although applied to specific circumstances, they are used as a paradigm on what is achievable in the development and realisation of high precision RICH detectors

Analysis and correction of the magnetic field effects in the Hybrid Photo-Detectors of the RICH2 Ring Imaging Cherenkov detector of LHCb

The Ring Imaging Cherenkov detectors of the LHCb experiment at the Large Hadron Collider at CERN are equipped with Hybrid Photo-Detectors. These vacuum photo-detectors are affected by the stray magnetic field of the LHCb magnet, which degrades their imaging properties. This effect increases the error on the Cherenkov angle measurement and would reduce the particle identification capabilities of LHCb. A system has been developed for the RICH2 Ring Imaging Cherenkov detector to perform a detailed characterisation of the magnetic distortion effects. It is described, along with the methods implemented to correct for these effects, restoring the optimal resolution.Comment: 16 pages, 11 figure

Common features between neoplastic and preneoplastic lesions of the biliary tract and the pancreas

The bile duct system and pancreas show many similarities due to their anatomical proximity and common embryological origin. Consequently, preneoplastic and neoplastic lesions of the bile duct and pancreas share analogies in terms of molecular, histological and pathophysiological features. Intraepithelial neoplasms are reported in biliary tract, as biliary intraepithelial neoplasm (BilIN), and in pancreas, as pancreatic intraepithelial neoplasm (PanIN). Both can evolve to invasive carcinomas, respectively cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary neoplasms arise in biliary tract and pancreas. Intraductal papillary neoplasm of the biliary tract (IPNB) share common histologic and phenotypic features such as pancreatobiliary, gastric, intestinal and oncocytic types, and biological behavior with the pancreatic counterpart, the intraductal papillary mucinous neoplasm of the pancreas (IPMN). All these neoplastic lesions exhibit similar immunohistochemical phenotypes, suggesting a common carcinogenic process. Indeed, CCA and PDAC display similar clinic-pathological features as growth pattern, poor response to conventional chemotherapy and radiotherapy and, as a consequence, an unfavorable prognosis. The objective of this review is to discuss similarities and differences between the neoplastic lesions of the pancreas and biliary tract with potential implications on a common origin from similar stem/progenitor cells

Formation des prix au producteur et impact de la dévaluation du franc CFA sur les stratégies de production des petits ruminants

Les cheptels ovins et caprins des provinces du Nord et de l'Extrême-Nord représentent 57,8 % et 51,7 % du cheptel national camerounais. Avant la dévaluation du franc CFA, les prix à la production étaient peu incitatifs et n'encourageaient pas les éleveurs à accroître la production et à améliorer la productivité de leurs élevages. Cette étude avait pour objectif de faire ressortir, à partir des informations collectées sur les prix de vente, l'âge, le sexe, l'espèce, l'année, le mois et le nombre d'animaux achetés par espèce et le prix d'achat, les facteurs qui influencent le prix au niveau de l'éleveur. Le second objectif est de mettre en évidence la tendance évolutive des prix sur six années : avant et après la dévaluation du franc CFA. Les résultats montrent que la progression des prix a été régulière pour les caprins et les ovins de 1994 à 1995. L'analyse de variance a fait ressortir les trois principales variables qui influencent d'une manière significative le prix des ovins : le sexe, l'âge de l'animal et son mois de vente. En ce qui concerne les caprins, les quatre principales variables sont : l'année de sortie de l'animal, le mois de cession, l'âge et le sexe.. Les analyses des séries chronologiques permettent d'affirmer que la dévaluation du franc CFA a eu un impact positif sur les prix des ovins aux producteurs. En revanche, la tendance est restée continue pour les caprins. Le pic de vente pour les ovins au mois de mai (fête de Tabaski) et en fin d'année (fêtes de Noël et du nouvel an

Anthracycline-Induced Cardiotoxicity: Cardiac Monitoring by Continuous Wave-Doppler Ultrasound Cardiac Output Monitoring and Correlation to Echocardiography

Background: Anthracyclines are agents with a well-known cardiotoxicity. The study sought to evaluate the hemodynamic response to an anthracycline using real-time continuous-wave (CW)-Doppler ultrasound cardiac output monitoring (USCOM) and echocardiography in combination with serum biomarkers. Methods: 50 patients (26 male, 24 female, median age 59 years) suffering from various types of cancer received an anthracycline-based regimen. Patients' responses were measured at different time points (T0 prior to infusion, T1 6 h post infusion, T2 after 1 day, T3 after 7 days, and T4 after 3 months) with CW-Doppler ultrasound (T0-T4) and echocardiography (T1, T4) for hemodynamic parameters such as stroke volume (SV; SVUSCOM ml) and ejection fraction (EF; EFechocardiography%) and with NT-pro-BNP and hs-Troponin T (T0-T4). Results: During the 3-month observation period, the relative decrease in the EF determined by echocardiography was -2.1% (Delta T0-T4, T0 71 +/- 7.8%, T4 69.5 +/- 7%, p = 0.04), whereas the decrease in SV observed using CW-Doppler was -6.5% (Delta T0-T4, T0 54 +/- 19.2 ml, T4 50.5 +/- 20.6 ml, p = 0.14). The kinetics for serum biomarkers were inversely correlated. Conclusions: Combining real-time CW-Doppler USCOM and serum biomarkers is feasible for monitoring the immediate and chronic hemodynamic changes during an anthracycline-based regimen; the results obtained were comparable to those from echocardiography

Identification d'une nouvelle salmonelle multirésistante dans une viande de poulet de chair au Sénégal

L'analyse microbiologique d'une carcasse de poulet de chair au Sénégal a permis de mettre en évidence un nouveau sérotype de salmonelle. Celui-ci présente la particularité de posséder deux gènes de résistance aux antibiotiques ; il n'est sensible qu'aux quinolones de dernière génération. L'existence de ce nouveau sérotype est inquiétante parce qu'il a été retrouvé dans des prélèvements humains, associé à de l'hyperthermie et de la diarrhée profuse. L'apparition d'une telle salmonelle peut éventuellement s'expliquer par l'utilisation anarchique des antibiotiques dans l'élevage des volailles. (Résumé d'auteur

L'élevage porcin au Nord-Cameroun : situation actuelle et possibilités d'amélioration

Un diagnostic a été effectué en février 1996 dans une trentaine de villages au Nord-Cameroun et répondait à un double objectif : connaître l'environnement actuel de la production porcine (contraintes, atouts), la productivité des populations porcines (potentialités) et proposer des thèmes de vulgarisation en vue de l'amélioration de cette production. Six contraintes majeures à l'élevage porcin ont été identifiées : l'absence de géniteurs, l'inadéquation des logements, la mauvaise utilisation des ressources alimentaires, les conditions sanitaires précaires, le poids de la religion islamique et les problèmes de nuisance et de salubrité publique. Des thèmes vulgarisables dans les domaines du choix de géniteurs, du logement, de l'alimentation et de la santé ont été présentés. Des propositions ont été faites pour appuyer l'élevage porcin au Nord du Cameroun (encadrement des éleveurs, conservation de la région indemne de PPA, disponibilité de géniteurs et d'intrants, et facilités de crédits). Des actions de recherches à court terme (prophylaxie et alimentation) et à moyen terme (santé, nutrition et sélection) pour fournir des solutions appropriées aux producteurs ont été identifiée

Global Production Increased by Spatial Heterogeneity in a Population Dynamics Model

Spatial and temporal heterogeneity are often described as important factors having a strong impact on biodiversity. The effect of heterogeneity is in most cases analyzed by the response of biotic interactions such as competition of predation. It may also modify intrinsic population properties such as growth rate. Most of the studies are theoretic since it is often difficult to manipulate spatial heterogeneity in practice. Despite the large number of studies dealing with this topics, it is still difficult to understand how the heterogeneity affects populations dynamics. On the basis of a very simple model, this paper aims to explicitly provide a simple mechanism which can explain why spatial heterogeneity may be a favorable factor for production.We consider a two patch model and a logistic growth is assumed on each patch. A general condition on the migration rates and the local subpopulation growth rates is provided under which the total carrying capacity is higher than the sum of the local carrying capacities, which is not intuitive. As we illustrate, this result is robust under stochastic perturbations

Cardiovascular toxicity induced by chemotherapy, targeted agents and radiotherapy: ESMO Clinical Practice Guidelines

Cardiovascular (CV) toxicity is a potential short- or long-term complication of various anticancer therapies. Some drugs, such as anthracyclines or other biological agents, have been implicated in causing potentially irreversible clinically important cardiac dysfunction. Although targeted therapies are considered less toxic and better tolerated by patients compared with classic chemotherapy agents, rare but serious complications have been described, and longer follow-up is needed to determine the exact profile and outcomes of related cardiac side-effects. Some of these side-effects are irreversible, leading to progressive CV disease, and some others induce reversible dysfunction with no long-term cardiac damage to the patient. Assessment of the prevalence, type and severity of cardiac toxicity caused by various cancer treatments is a breakthrough topic for patient management. Guidelines for preventing, monitoring and treating cardiac side-effects are a major medical need. Efforts are needed to promote strategies for cardiac risk prevention, detection and management, avoiding unintended consequences that can impede development, regulatory approval and patient access to novel therapy. These new ESMO Clinical Practice Guidelines are the result of a multidisciplinary cardio-oncology review of current evidence with the ultimate goal of providing strict criteria-based recommendations on CV risk prevention, assessment, monitoring and management during anticancer treatmen