Trisomy 19 ependymoma, a newly recognized genetico-histological association, including clear cell ependymoma

Ependymal tumors constitute a clinicopathologically heterogeneous group of brain tumors. They vary in regard to their age at first symptom, localization, morphology and prognosis. Genetic data also suggests heterogeneity. We define a newly recognized subset of ependymal tumors, the trisomy 19 ependymoma. Histologically, they are compact lesions characterized by a rich branched capillary network amongst which tumoral cells are regularly distributed. When containing clear cells they are called clear cell ependymoma. Most trisomy 19 ependymomas are supratentorial WHO grade III tumors of the young. Genetically, they are associated with trisomy 19, and frequently with a deletion of 13q21.31-31.2, three copies of 11q13.3-13.4, and/or deletions on chromosome 9. These altered chromosomal regions are indicative of genes and pathways involved in trisomy 19 ependymoma tumorigenesis. Recognition of this genetico-histological entity allows better understanding and dissection of ependymal tumors

Experiments on wind-perturbed rogue wave hydrodynamics using the Peregrine breather model

Being considered as a prototype for description of oceanic rogue waves, the Peregrine breather solution of the nonlinear Schrödinger equation has been recently observed and intensely investigated experimentally in particular within the context of water

Quels liens entre climatologie, occupation des sols et inondations dans le bassin versant de l'Yzeron (ouest Lyonnais) ? Apport de l'analyse conjointe de données hydroclimatiques et d'images satellitaires très haute résolution

Le bassin versant de l'Yzeron, situé en périphérie immédiate de la ville de Lyon, est un bassin représentatif des bassins versants périurbains français. Il connaît, depuis les années 1970, une augmentation importante de son urbanisation. Ces dernières années, des crues importantes, entraînant des inondations à l'aval du bassin versant ont marqué les esprits, posant la question de l'impact des modifications de l'occupation des sols dans le bassin versant sur le régime des crues. Dans cet article, nous utilisons l'analyse combinée de données hydroclimatiques (pluie, température, évapotranspiration de référence -ET0, débits) et de cartes de l'occupation des sols dérivées d'images satellites SPOT à haute et très haute résolution pour aborder cette question. L'analyse des débits montre l'existence d'une évolution du régime des crues, avec une augmentation significative des crues sub -seuils pour des durées de 1,5h, 3h, 6h, 12h et 36h sur la période 1970-2010. L'analyse de l'échantillon de crues obtenue par cette analyse débit-durée-fréquence montre que les crues les plus importantes sont plutôt liées à des épisodes ayant conduit à un cumul de pluie important (> 80 mm en quelques jours). Une corrélation significative est aussi obtenue entre débit de base et coefficient de ruissellement, ce qui montre que ces crues peuvent être associées à des écoulements sur surfaces saturées. Les évolutions du climat (pluviométrie, température, ET0) ne permettent pas d'expliquer l'augmentation des crues observées. En revanche, l'occupation des sols entre 1990 et 2008 montre une augmentation des sur faces imperméables qui passent de 15,2 % de la surface totale du bassin en 1990 à 18,2 % en 1999 et 22,6 % en 2008. Cette évolution de l'imperméabilisation est mise en regard de l'accroissement de la population du bassin sur cette même période. Enfin, nous illustrons la réponse hydrologique du bassin versant avec deux épisodes pour lesquels le rôle de l'occupation des sols est différent. Le premier, celui du 02/12/2003 est typique d'une réponse par saturation du bassin, avec une contribution majeure des zon es rurales, suite à des cumuls pluviométriques importants. Le second, celui du 09/08/2009 représente un orage d'été, très court mais avec des intensités importantes, conduisant essentiellement à une réponse rapide des zones urbaines et pour lequel l'occupation des sols joue un rôle majeur

Impact de l'urbanisation sur le cycle hydrologique dans un bassin versant periurbain. Application au bassin de l’Yzeron - ouest lyonnais, France

International audienceL’urbanisation croissante, en particulier dans les zones périphériques aux grandes villes (zones périurbaines) a des conséquences sur le cycle hydrologique en modifiant l’infiltrabilité des sols, la recharge des nappes, ainsi que les chemins naturels de l’eau via les différents réseaux (routiers, eau potable, assainissement). Une modélisation à l'aide du modèle hydrologique distribué J2000 est mise en ½uvre sur le bassin versant de l’Yzeron, en périphérie de Lyon, représentatif des bassins périurbains français. Nous montrons en particulier que l’urbanisation modifie les composantes des écoulements en accroissant le ruissellement de surface au détriment des écoulements de base ou de sub-surface (comparaison de simulations s’appuyant sur des cartes d’occupation du sol de 1990, 1999, 2008). La prise en compte des réseaux d’assainissement et des déversoirs d’orage dans la modélisation permettra d’améliorer la simulation des bilans hydrologiques dans le bassin. / Urban growth, in particular close to big cities impacts the hydrological cycle by modifying soil infiltration capacity, groundwater recharge, but also by modifying natural water pathways due to the various networks associated with urbanization (roads, drinkable and sewer networks). The distributed hydrological model J2000 is set up in the Yzeron catchment, close to Lyon city. We show that urban growth modifies the flow components by increasing surface runoff and decreasing base and sub-surface flows (comparison of simulations based on past land use mapping of 1990, 1999, 2008). The inclusion of sewer networks and sewer overflow devices in the model will improve the water balance simulations of the catchment

Two sequential outbreaks caused by multidrug-resistant Acinetobacter baumannii isolates producing OXA-58 or OXA-72 oxacillinase in an intensive care unit in France

International audienc

Experiments on wind-perturbed rogue wave hydrodynamics using the Peregrine breather model

International audienceBeing considered as a prototype for description of oceanic rogue waves (RWs), the Peregrine breather solution of the nonlinear Schrodinger equation (NLS) has been recently observed and intensely investigated experimentally in particular within the context of water waves. Here, we report the experimental results showing the evolution of the Peregrine solution in the presence of wind forcing in the direction of wave propagation. The results show the persistence of the breather evolution dynamics even in the presence of strong wind and chaotic wave eld generated by it. Furthermore, we have shown that characteristic spectrum of the Peregrine breather persists even at the highest values of the generated wind velocities thus making it a viable characteristic for prediction of rogue waves

Spectral up- and downshifting of Akhmediev breathers under wind forcing

We experimentally and numerically investigate the effect of wind forcing on the spectral dynamics of Akhmediev breathers, a wave-type known to model the modulation instability. We develop the wind model to the same order in steepness as the higher order modifcation of the nonlinear Schroedinger equation, also referred to as the Dysthe equation. This results in an asymmetric wind term in the higher order, in addition to the leading order wind forcing term. The derived model is in good agreement with laboratory experiments within the range of the facility's length. We show that the leading order forcing term amplifies all frequencies equally and therefore induces only a broadening of the spectrum while the asymmetric higher order term in the model enhances higher frequencies more than lower ones. Thus, the latter term induces a permanent upshift of the spectral mean. On the other hand, in contrast to the direct effect of wind forcing, wind can indirectly lead to frequency downshifts, due to dissipative effects such as wave breaking, or through amplification of the intrinsic spectral asymmetry of the Dysthe equation. Furthermore, the definitions of the up- and downshift in terms of peak- and mean frequencies, that are critical to relate our work to previous results, are highlighted and discussed.Comment: 30 pages, 11 figure

Investigating the impact of two decades of urbanization on the water balance of the Yzeron peri-urban catchment, France

International audienceThis paper addresses the impact of 18 years of urbanization (1990-2008) on the Yzeron meso-scale peri-urban catchment (150 km²), located close to Lyon, France. A simplified version of the distributed hydrological model J2000 was used to perform long term simulations at a daily time step for several land use scenarios. These scenarios were derived from satellite SPOT images from years 1990, 1999 and 2008. The corresponding land use maps were classified into 5 classes depending on the percentage of impervious surfaces and the dominant non-impervious land use (agriculture or forest). The paper presents the methodology for the model setup and the simulation results for the main water balance components of the catchment: total runoff, runoff components, evapotranspiration and soil moisture. The results highlight the change of the catchment seasonal response from 1990 to 2008, mainly due to a change of the respective contributions of groundwater flow / surface runoff (+ 92% / - 28%, respectively). Monthly mean summer discharge unexpectedly appears to be higher in summer. It is provided by intermittent surface runoff generated by summer storm events. As surface runoff generated on urban surfaces is likely to carry a wide range of contaminants, this has a potential large impact on water quality

Highly selective recovery of Ni(II) in neutral and acidic media using a novel Ni(II)-ion imprinted polymer

In this work, an original ion-imprinted polymer (IIP) was synthetized for the highly selective removal of Ni(II) ions in neutral and acidic media. First a novel functional monomer (AMP-MMA) was synthetized through the amidation of 2-(aminomethyl)pyridine (AMP) with methacryloylchloride. Following Ni(II)/AMP-MMA complex formation study, the Ni(II)-IIP was produced via inverse suspension polymerization (DMSO in mineral oil) and characterized with solid state 13C CPMAS NMR, FT-IR, SEM and nitrogen adsorption/desorption experiments. The Ni(II)-IIP was then used in solid-phase extraction of Ni(II) exploring a wide range of pH (from neutral to strongly acidic solution), several initial concentrations of Ni(II) (from 0.02 to 1 g/L), and the presence of competitive ions (Co(II), Cu(II), Cd(II), Mn(II), and Mg(II)). The maximum Ni(II) adsorption capacity at pH 2 and pH 7 reached values of 138.9 mg/g and 169.5 mg/g, that are among the best reported in literature. The selectivity coefficients toward Cd(II), Mn(II), Co(II), Mg(II) and Cu(II) are also very high, with values up to 38.6, 32.9, 25.2, 23.1 and 15.0, respectively. The Ni(II)-IIP showed good reusability of up to 5 cycles both with acidic and basic Ni(II) eluents.Peer reviewe