Radiochirurgie des malformations arterio-veineuses du tronc cerebral stereotactic radiosurgery for brainstem arteriovenous malformations

Introduction: Les malformations artério-veineuses ou angiomes cérébraux sont des anomalies vasculaires congénitales qui se définissent par la présence d’un shunt artério-veineux anormal.Matériels et méthodes: Nous avons mené une étude rétrospective entre Janvier 1992 et Décembre 2010 au service de radiochirurgie de l’hôpital de la Timone, 1557 patients ont été traités par radiochirurgie pour une malformation artérioveineuse dont 61 patients pour une localisation du tronc cérébral (3.91%).Résultats: L’âge moyen de 35.8-/+16.6 ans (4-75).16 patients avaient bénéficié d’une embolisation préradiochirurgicale (26.23%). Le mode de découverte était une hémorragie pour 53 patients (87%). Le volume moyen de traitement était de 1.43+/-1.96 cm3 (0.09-14.20). Le score RBAS était en moyenne de 1.36 +/- 0.34 (0.64-2.35). La dose moyenne de prescription à l’enveloppe l’isodose 50% délivrée était de 22.9 +/-2.9 Gy (12-30), la dose médiane était de 24 Gy).Notre taux d’oblitération global après une ou deux procédures était de 67.27%, pour un délai moyen de suivi est de 56.7 mois+/-43.3 (8.1-251.7). Les facteurs en rapport avec une oblitération) : score RBAS bas (p=0.012), une dose de traitement supérieur à 20Gy (p=0.034). Nous avons eu une mortalité de 1.63% et un pourcentage de saignement après la procédure de 6.55% et 3.2% déficits neurologiques radio-induits.Conclusion: La radiochirurgie est maintenant devenue incontournable dans le traitement des malformations du tronc cérébral même s’il existe un risque hémorragique persistant jusqu’à la guérison (3.5%). Le taux d’oblitération complète est de 67.27%Mots clés: malformations artério-veineuses, tronc cérébral, radiochirurugieEnglish Title: Stereotactic radiosurgery for brainstem arteriovenous malformationsEnglish AbstractIntroduction: Arterioveinous malformations (AVM) or cerebral angiomas are congenital vascular abnormalities which are defined by the presence of abnormal arterio-veinous shunt.Methods:  We lead a retrospective study recruiting 1557 patients treated between January 1992 and December 2010 in the Radiosurgery Unit of La Timone hospital in Marseille. All patients received radiosurgery for management of an AVM, 61 of them being brainstem AVMs (3.91%).Results: Mean age was 35.8 +/- 16.6 years. Sixteen patients underwent arterial embolization before surgery (26.23%). Hemorrhage was the primary onset for 53 patients (87%). Mean volume before treatment was 1.43+/-1.96 cm3 (0.09-14.20). Average RBAS score was 1.36 +/-0.34 (0.64-2.35). Average prescripted dose for 50% delivered iso-dose was 22.9 +/-2.9 Gy (12-30), mean dose was 24 Gy. Our global occlusion rate after one or two treatments was 67.27%, considering an average follow-up of 56.7 months +/- 43.3 (8.1- 251.7). Occlusion related factors were: low RBAS score (p=0.012), received dose higher than 20Gy (p=0.034). Our death rate was 1.63% and our post-procedure bleeding rate was 6.55% with 3.2% of neurological post-procedure deficience.Conclusion: Having regard of remaining hemorrhage risk until complete recovery (3.5%), radiosurgery is nonetheless now a key treatment in the management brainstem AVMS. Complete occlusion rate in our study was 67.27%.Keywords: arteriovenous malformations, brainstem, radiosurger

Pest risk analysis for Bactrocera invadens : Guidelines on Pest Risk Analysis

Stripping related moisture damage has been recognized as one of the major pavement distresses since the early 1990s. The main objective of this study is to establish an effective test protocol to quantify moisture susceptibility of asphalt pavements. To this end, selective test methods (Texas Boiling test, Tensile Strength Ratio, Retained Stability, and Hamburg Wheel Test), and procedures based on surface chemistries and molecular-level mechanistic properties have been investigated in this study. Firstly, a comprehensive list of literature related to moisture damage in asphalts was reviewed. Based on the literature review, a detailed project plan and test matrix were developed. Binder samples originated from two different crude sources were collected. The moisture resistance related tests such as static contact angle measurements and Texas Boiling tests were conducted. Besides, asphalt binders’ nanomechanical properties using an Atomic Force Microscopy (AFM) and surface chemistries using a static contact were evaluated in the laboratory. Based on limited test data and analysis, it is concluded that there does not exist any single test method that all agencies are comfortable and equipped to follow in their daily work as each technique has some merits and demerits. However, the Texas Boiling test is found to be the simplest method that requires minimal time and resources. On the other hand, surface chemistry and atomic force microscope-based techniques are becoming popular among researchers and pavement professionals. Findings of this study are expected to help ARDOT in selecting an appropriate moisture resistance test method that is simple, reliable, and easy to implement in their routine work

Nonlinear compression of high energy fiber amplifier pulses in air-filled hypocycloid-core Kagome fiber

International audienceWe report on the generation of 34 fs and 50 µJ pulses from a high energy fiber amplifier system with nonlinear compression in an air-filled hypocycloid-core Kagome fiber. The unique properties of such fibers allow bridging the gap between solid core fibers-based and hollow capillary-based post-compression setups, thereby operating with pulse energies obtained with current state-of-the-art fiber systems. The overall transmission of the compression setup is over 70%. Together with Yb-doped fiber amplifier technologies, Kagome fibers therefore appear as a promising tool for efficient generation of pulses with durations below 50 fs, energies ranging from 10 to several hundreds of µJ, and high average powers

Large Scale Cross-Correlations in Internet Traffic

The Internet is a complex network of interconnected routers and the existence of collective behavior such as congestion suggests that the correlations between different connections play a crucial role. It is thus critical to measure and quantify these correlations. We use methods of random matrix theory (RMT) to analyze the cross-correlation matrix C of information flow changes of 650 connections between 26 routers of the French scientific network `Renater'. We find that C has the universal properties of the Gaussian orthogonal ensemble of random matrices: The distribution of eigenvalues--up to a rescaling which exhibits a typical correlation time of the order 10 minutes--and the spacing distribution follow the predictions of RMT. There are some deviations for large eigenvalues which contain network-specific information and which identify genuine correlations between connections. The study of the most correlated connections reveals the existence of `active centers' which are exchanging information with a large number of routers thereby inducing correlations between the corresponding connections. These strong correlations could be a reason for the observed self-similarity in the WWW traffic.Comment: 7 pages, 6 figures, final versio

Alcoholic fermentation drives the selection of Oenococcus oeni strains in wine but not in cider

Oenococcus oeni is the predominant lactic acid bacteria species in wine and cider, where it performs the malolactic fermentation (MLF). The O. oeni strains analyzed to date form four major genetic lineages named phylogroups A, B, C and D. Most of the strains isolated from wine, cider, or kombucha belong to phylogroups A, B + C, and D, respectively, although B and C strains were also detected in wine. This study was performed to better understand the distribution of the phylogroups in wine and cider. Their population dynamics were determined by qPCR all through wine and cider productions, and the behavior of the strains was analyzed in synthetic wines and ciders. Phylogroups A, B and C were all represented in grape must and throughout the alcoholic fermentation, but on the transition to MLF, only phylogroup A remained at high levels in all wine productions. In the case of cider, phylogroups A, B and C were detected in stable levels during the process. When they were tested in synthetic wine and cider, all phylogroups performed MLF, but with different survival rates depending on the ethanol content. In this sense, ethanol and fermentation kinetics are the main agent that drives the selection of phylogroup A strains in wine, while B and C strains dominates in cider containing less ethanol

Identification of Restricted Subsets of Mature microRNA Abnormally Expressed in Inactive Colonic Mucosa of Patients with Inflammatory Bowel Disease

International audienceBACKGROUND: Ulcerative Colitis (UC) and Crohn's Disease (CD) are two chronic Inflammatory Bowel Diseases (IBD) affecting the intestinal mucosa. Current understanding of IBD pathogenesis points out the interplay of genetic events and environmental cues in the dysregulated immune response. We hypothesized that dysregulated microRNA (miRNA) expression may contribute to IBD pathogenesis. miRNAs are small, non-coding RNAs which prevent protein synthesis through translational suppression or mRNAs degradation, and regulate several physiological processes. METHODOLOGY/FINDINGS: Expression of mature miRNAs was studied by Q-PCR in inactive colonic mucosa of patients with UC (8), CD (8) and expressed relative to that observed in healthy controls (10). Only miRNAs with highly altered expression (>5 or 100 -fold and 0.05-0.19 -fold for over- and under- expression, respectively; 0.00

Coherent beam combining with an ultrafast multicore Yb-doped fiber amplifier

International audienceActive coherent beam combination using a 7-non-coupled core,polarization maintaining, air-clad, Yb-doped fiber is demonstrated as amonolithic and compact power-scaling concept for ultrafast fiber lasers. Amicrolens array matched to the multicore fiber and an active phasecontroller composed of a spatial light modulator applying a stochasticparallel gradient descent algorithm are utilized to perform coherentcombining in the tiled aperture geometry. The mitigation of nonlineareffects at a pulse energy of 8.9 μJ and duration of 860 fs is experimentallyverified at a repetition rate of 100 kHz. The experimental combiningefficiency results in a far field central lobe carrying 49% of the total power,compared to an ideal value of 76%. This efficiency is primarily limited bygroup delay differences between cores which is identified as the maindrawback of the system. Minimizing these group delay issues, e.g. by usingshort and straight rod-type multicore fibers, should allow a practical powerscaling solution for femtosecond fiber systems