Controlling instabilities along a 3DVar analysis cycle by assimilating in the unstable subspace: a comparison with the EnKF

A hybrid scheme obtained by combining 3DVar with the Assimilation in the Unstable Subspace (3DVar-AUS) is tested in a QG model, under perfect model conditions, with a fixed observational network, with and without observational noise. The AUS scheme, originally formulated to assimilate adaptive observations, is used here to assimilate the fixed observations that are found in the region of local maxima of BDAS vectors (Bred vectors subject to assimilation), while the remaining observations are assimilated by 3DVar. The performance of the hybrid scheme is compared with that of 3DVar and of an EnKF. The improvement gained by 3DVar-AUS and the EnKF with respect to 3DVar alone is similar in the present model and observational configuration, while 3DVar-AUS outperforms the EnKF during the forecast stage. The 3DVar-AUS algorithm is easy to implement and the results obtained in the idealized conditions of this study encourage further investigation toward an implementation in more realistic contexts

Avances en el manejo eficiente del olivar surbonaerense

Cinco años de vinculación entre la Cámara de Productores Olivícolas “Sur Oliva”, con sede en la cabecera del partido surbonaerense de Coronel Dorrego, el Programa Nacional de Reconversión Productiva (Cambio Rural) dependiente de la Chacra Experimental Integrada Barrow del Instituto Nacional de Tecnología Agropecuaria y las asignaturas Propiedades Edáficas y Fertilidad (módulo Física de Suelo), Fruticultura, Utilización de Residuos Orgánicos, Zoología Agrícola y Patología Vegetal del Departamento de Agronomía de la Universidad Nacional del Sur han consolidado un grupo de trabajo interdisciplinario y una vía de comunicación con el medio productivo. Se comenzó con la detección de problemáticas que originaron distintas líneas de investigación con la participación de estudiantes y graduados y el apoyo de organismos provinciales (Comisión de Investigaciones Científicas) y municipales. Luego surgieron actividades de asistencia técnica a productores y se instalaron parcelas experimentales en una de las fincas, las cuales generan conocimientos y experiencias, que también enriquecen la labor docente con la incorporación curricular de nuevos contenidos. La difusión de resultados y conclusiones se canaliza a través de revistas, jornadas y reuniones científicas, y mediante el contacto directo con integrantes del sistema productivo. También se publicó material en la revista “AgroUNS”, órgano de difusión del Departamento de Agronomía

Correlation between homogeneous propane pyrolysis and pyrocarbon deposition

International audiencePyrocarbon deposition through propane pyrolysis is studied in a 1-D hot-wall CVD furnace. The gas-phase pyrolysis is modelled with a partially reduced kinetic mechanism leading to polycyclic aromatic compounds (PAHs). The C2-C4 and C3 reaction paths are in competition for benzene formation. There is also an independent C3-C5 path leading to naphthalene. The gas-phase concentrations are correlated with experimental data including in-situ FTIR spectra intensities, pyro- carbon deposition rates, and pyrocarbon nanotextures. Rough Laminar pyrocarbon deposition appears to be more related to PAHs than Smooth Laminar pyrocarbon

Kinetic modeling of gas-phase decomposition of propane : correlation with pyrocarbon deposition

International audienceA chemical kinetic model for gas-phase pyrolysis of propane has been set up, partially reduced, and validated against FTIR measurements in a tubular hot-wall reactor at P = 2 kPa, and T = 900 to 1400 K. It confirms the notion of "maturation" from propane to lighter hydrocarbons, the to aromatic compounds and PAHs. The gas-phase composition above the substrate has been correlated to pyrocarbon deposition rates and to the deposit nanostructure. It is confirmed that the growth of the rough laminar (RL) form would be related to heavier gaseous species than for the smooth laminar (SL) form

Is there something of the MCT in orientationally disordered crystals ?

Molecular Dynamics simulations have been performed on the orientationally disordered crystal chloroadamantane: a model system where dynamics are almost completely controlled by rotations. A critical temperature T_c = 225 K as predicted by the Mode Coupling Theory can be clearly determined both in the alpha and beta dynamical regimes. This investigation also shows the existence of a second remarkable dynamical crossover at the temperature T_x > T_c consistent with a previous NMR and MD study [1]. This allows us to confirm clearly the existence of a 'landscape-influenced' regime occurring in the temperature range [T_c-T_x] as recently proposed [2,3].Comment: 4 pages, 5 figures, REVTEX

Surgery using plasma energy for deep endometriosis: A quality of life assessment

OBJECTIVE: The principal objective of our study was to assess women\u27s quality of life (QoL) after surgery for Deep Endometriosis (DE), according to the surgical technique used. MATERIAL AND METHODS: Qualitative single-center survey in the department of obstetrics and gynecology, Angers University Hospital Center, France. All women who underwent surgery for DE from January 2011 to December 2015 were contacted by phone. The Endometriosis Health Profile-5 score was used to assess QoL before and after the surgery. Fifty-two women (response rate=86%) were included and classified into 3 groups according to the surgical technique used: simple shaving, shaving exclusively or in part by plasma vaporization (plasma), and resection. RESULTS: The 3 groups were comparable for surgical history, preoperative QoL score, and characteristics of endometriotic lesions (size and site). All DE symptoms and QoL scores improved significantly after the surgery, all techniques combined (P<0.01). QoL scores for women who had plasma shaving or complete resection were significantly higher than those for women with simple shaving (respectively, 375 [225-800] and 450 [-50 to 725] vs 275 [-100 to 600]; P=0.04). Self-image significantly improved only in the plasma group (P=0.03). The complete resection group had longer hospitals stays than the other groups (P=0.001), as well as a higher surgical revision rate (23% vs 0%; P=0.02). CONCLUSION: Plasma and complete resection improved QoL similarly for women with DE, both more than shaving alone. The advantage of plasma vaporization lies in the lesser morbidity and better self-image, both better than in women with resection

New European guidelines for the management of dyslipidaemia in cardiovascular prevention

The new guidelines from the European Atherosclerosis Society and the European Society of Cardiology include a number of updated items. In this paper, we summarize 4 of these changes that we consider to be the most pertinent. Firstly, cardiovascular risk is now stratified according to 4 (previously 2) categories: "very high risk" (patients with cardiovascular disease, patients with diabetes > 40 years old who have at least one other risk factor, patients with kidney failure, or patients in primary prevention with a SCORE value > or = 10%); "high risk" (patients in primary prevention with a SCORE value > or = 5% and or = 1% and < 5%); and "low risk" (primary prevention with SCORE < 1%). The SCORE value for patients in primary prevention is estimated using the SCORE table (calibrated for Belgium). Risk in this table may now be corrected according to HDL cholesterol level. Secondly, the therapeutic targets for each category are now more stringent: LDL cholesterol < 70 mg/dl (or reduced by at least 50%) if the risk is "very high"; < 100 mg/dl if the risk is "high"; and < 115 mg/dl if the risk is "moderate". Thirdly, for patients at "high" or "very high" risk, particularly in patients with combined dyslipidaemia, two further therapeutic targets should be considered: non-HDL cholesterol and apolipoprotein B levels. Fourthly, the follow-up of efficacy (lipid profile) and tolerance (hepatic and muscular enzymes) is described in more details so as to harmonize case management in clinical practice.Peer reviewe