Fine scale spatialised prospective modelling - a methodological approach. Application to water management in Brittany

International audienceThe main objective of this work is to elaborate a generic methodological approach to build prospective scenarios spatially explicit at a local scale. This approach is based on the scenario method used in prospective studies, and uses methodological techniques developed for the modelling of complex systems. The scenario-development process comprises four steps: construction of the basis, scenario building, giving a spatial dimension to the scenarios, and their evaluation. Applied in the framework of water planning in the Brittany region and more precisely of the application of the Water Planning and Management Schemes (WPMS) on the Blavet watershed, the approach is illustrated here by the example of one explanatory scenario and one normative scenario, both aiming at evaluating the potential impact of the 2006 Common Agricultural Policy and farms enlargement on futures land uses

Approche systémique du fonctionnement d'un territoire agricole bocager

International audienceCet article présente une approche systémique du fonctionnement de territoires bocagers porteurs d'enjeux environnementaux. Après l'étude des dynamiques spatiotemporelles passées et actuelles des paysages, l'identification et la hiérarchisation des facteurs explicatifs des changements observés, cette approche met en évidence les échelles auxquelles ils se produisent et les différents acteurs qui interviennent dans l'évolution de ces paysages. Cette approche illustre la complexité des changements d'usage des sols dans des paysages très fragmentés en région agricole intensive. Elle constitue un préalable à la simulation de changements futurs et à l'élaboration de politiques de gestion durable

Early biomarkers related to secondary primary cancer risk in radiotherapy treated prostate cancer patients: IMRT versus IMAT

AbstractPurposeTo investigate whether rotational techniques (Volumetric Modulated Arc Therapy – VMAT) are associated with a higher risk for secondary primary malignancies compared to step-and-shoot Intensity Modulated Radiation Therapy (ss-IMRT). To this end, radiation therapy (RT) induced DNA double-strand-breaks and the resulting chromosomal damage were assessed in peripheral blood T-lymphocytes of prostate cancer (PCa) patients applying γH2AX foci and G0 micronucleus (MN) assays.Methods and materialsThe study comprised 33PCa patients. A blood sample was taken before start of therapy and after the 1st and 3rd RT fraction to determine respectively the RT-induced γH2AX foci and MN. The equivalent total body dose (DETB) was calculated based on treatment planning data.ResultsA linear dose response was obtained for γH2AX foci yields versus DETB while MN showed a linear-quadratic dose response. Patients treated with large volume (LV) VMAT show a significantly higher level of induced γH2AX foci and MN compared to IMRT and small volume (SV) VMAT (p<0.01). Assuming a linear-quadratic relationship, a satisfactory correlation was found between both endpoints (R2 0.86).ConclusionsBiomarker responses were governed by dose and irradiated volume of normal tissues. No significant differences between IMRT and rotational therapy inherent to the technique itself were observed

Accuracy of impact broadening models in low-density magnetized hydrogen plasmas

International audienceThe impact approximation used in the modelling of Stark profiles is examined when a magnetic field is present. Motivated by tokamak plasma spectroscopy, we calculate line shapes and $S$-matrix elements for the first Lyman lines of hydrogen with two models proposed for retaining simultaneously Stark and Zeeman effects in the impact limit. An evaluation of the accuracy of the two approaches is made with the help of a numerical simulation

Semi-quantitative analysis of bulk chondritic material using X-Ray fluorescence spectroscopy

73rd Annual Meeting of the Meteoritical-Society, New York, NY, July 26-30, 2010International audienceSynchrotron radiation X-ray fluorescence (SR-XRF) is a method of choice to analyze fragile, unique meteoritic samples, requiring no sample preparation. It is a nondestructive, multielemental, quantitative method, easily coupled to diffraction and speciation for a detailed sample characterization. The composition of samples thicker than a few microns is however difficult to obtain due to the high attenuation of the characteristic X-rays resulting in non-detection of low-Z elements (Z≤ 14)

Cartographie des grands types de végétation par télédétection : étude de faisabilité (Bretagne, Basse-Normandie et Pays-de-la-Loire)

annexes sur demanderapport de rechercheL'objectif de cette étude est d'évaluer les potentialités qu'offrent l'imagerie aérienne et satellitaire à haute et très haute résolution spatiale pour la cartographie des grands types de végétation des régions Bretagne, Basse-Normandie et Pays de la Loire. Pour ce faire, différents types d'images (BDORTHO® IRC, SPOT5, Worldview-2) ont été acquises sur quatre sites représentatifs de la diversité des végétations présentes sur ce territoire. Des procédures de classification ont été établies et leur reproductibilité à d'autres sites a été vérifiée. La typologie des végétations utilisée est celle proposée par le Conservatoire Botanique National de Brest (CBN de Brest) qui articule par une démarche " bottom-up ", la typologie phytosociologique utilisée sur le terrain, avec une typologie physionomique (structurale) pouvant être " comprise " par une approche télédétection. L'approche orientée-objet non supervisée a été privilégiée pour ce projet. Seules les procédures de classification des images Worldview-2 (démarche plus exploratoire) combinent l'approche orientée-objet non supervisée à la méthode pixel supervisée. Les performances globales des procédures pour chaque image sont calculées par l'intermédiaire d'un indice kappa pour les niveaux " occupation du sol ", " grands types de végétations " et " types de formations végétales ". Les résultats les plus concluants sont obtenus, pour la plupart des végétations étudiées, à partir de l'image Worldview-2, puis la BDORTHO® IRC et enfin les images SPOT5. L'identification de certaines végétations donne des résultats médiocres ; des recommandations sont proposées pour les améliorer

The HIV RNA setpoint theory revisited

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Use of the 3D radon transform to examine the properties of oceanic Rossby waves

One of the most successful applications of satellite-borne radar altimeter data over the oceans in recent years has been the extraction of information about long-wavelength baroclinic Rossby (or planetary) waves, which play a significant role in ocean circulation and climate dynamics. These waves cross ocean basins from east to west at speeds of few centimetres per second at mid-latitudes. The cross-basin propagation time may therefore be several months or even years and an accurate estimation of the speed of the waves is important. We review the methods for obtaining information on Rossby wave velocity from altimetry data, particularly the two-dimensional Radon transform. Unfortunately the use of longitude-time plots, although it allows the estimation of the zonal phase speeds, does not give any information on the speed vector when the propagation of the waves is not purely zonal (east-west). We show how the two-dimensional Radon Transform can be generalised to three dimensions, enabling not only the true propagation velocity component to be determined, but also the direction of the waves and thus any deviation from the pure-westward case. As examples of the application of this extended technique, we show maps of direction, speed and energy of Rossby waves in the North Atlantic Ocean

Noninfectious Wound Complications in Clean Surgery: Epidemiology, Risk Factors, and Association with Antibiotic Use

Background: Noninfectious wound complications are frequent and often are confused with and treated as infection. Methods: We assessed the epidemiology, impact, risk factors, and associations with antibiotic use of noninfectious wound complications in clean orthopedic and trauma surgery. We report a single-center, prospective, observational study in an orthopedic department. Results: Among 1,073 adult patients, 630 (59%) revealed clinically relevant postoperative noninfectious wound complications, leading to a significant prolongation of hospital stay (14 vs. 12days; Wilcoxon rank-sum test; p<0.02) compared with patients without complications. The most frequent and severe complications were discharge with dehiscence (n=437; 41%) and hematoma (n=379; 35%). Forty-seven patients (47/630; 7%) underwent reoperation for dehiscence (n=39) or hematoma (n=8). These patients made up 4.3% of the entire study population (47/1,073). In multivariate analysis, an ASA score ≥2 points, age≥60years, surgery duration for ≥90min, implant-related surgery, and poor compliance toward nurses' recommendations were pronounced risk factors for these complications, whereas antibiotic-related parameters had no influence. Staple use was significantly associated with wound discharge but not with hematoma. Conclusions: Wound complications, such as dehiscence with discharge or hematoma after clean orthopedic and trauma surgery, are frequent with an overall incidence of 60%. Although they lead to few surgical reinterventions, they prolong hospital stay by 2days. Few clinical parameters show association with wound complications. Among them, improvements of patient compliance and avoidance of staples use for skin closure are the most promising actions to decrease complication ris