Estimating the phase in ground-based interferometry: performance comparison between single-mode and multimode schemes

In this paper we compare the performance of multi and single-mode interferometry for the estimation of the phase of the complex visibility. We provide a theoretical description of the interferometric signal which enables to derive the phase error in presence of detector, photon and atmospheric noises, for both multi and single-mode cases. We show that, despite the loss of flux occurring when injecting the light in the single-mode component (i.e. single-mode fibers, integrated optics), the spatial filtering properties of such single-mode devices often enable higher performance than multimode concepts. In the high flux regime speckle noise dominated, single-mode interferometry is always more efficient, and its performance is significantly better when the correction provided by adaptive optics becomes poor, by a factor of 2 and more when the Strehl ratio is lower than 10%. In low light level cases (detector noise regime), multimode interferometry reaches better performance, yet the gain never exceeds 20%, which corresponds to the percentage of photon loss due to the injection in the guides. Besides, we demonstrate that single-mode interferometry is also more robust to the turbulence in both cases of fringe tracking and phase referencing, at the exception of narrow field of views (<1 arcsec).Comment: 9 pages (+ 11 online material appendices) -- 8 Figures. Accepted in A&

Tryptophan metabolism and bacterial commensals prevent fungal dysbiosis in Arabidopsis roots

In nature, roots of healthy plants are colonized by multikingdom microbial communities that include bacteria, fungi, and oomycetes. A key question is how plants control the assembly of these diverse microbes in roots to maintain host–microbe homeostasis and health. Using microbiota reconstitution experiments with a set of immunocompromised Arabidopsis thaliana mutants and a multikingdom synthetic microbial community (SynCom) representative of the natural A. thaliana root microbiota, we observed that microbiota-mediated plant growth promotion was abolished in most of the tested immunocompromised mutants. Notably, more than 40% of between-genotype variation in these microbiota-induced growth differences was explained by fungal but not bacterial or oomycete load in roots. Extensive fungal overgrowth in roots and altered plant growth was evident at both vegetative and reproductive stages for a mutant impaired in the production of tryptophan-derived, specialized metabolites (cyp79b2/b3). Microbiota manipulation experiments with single- and multikingdom microbial SynComs further demonstrated that 1) the presence of fungi in the multikingdom SynCom was the direct cause of the dysbiotic phenotype in the cyp79b2/b3 mutant and 2) bacterial commensals and host tryptophan metabolism are both necessary to control fungal load, thereby promoting A. thaliana growth and survival. Our results indicate that protective activities of bacterial root commensals are as critical as the host tryptophan metabolic pathway in preventing fungal dysbiosis in the A. thaliana root endosphere

Quelle R&D Mener pour le Développement Des Réseaux D'énergie De Demain ? Les Propositions de L'ancre en 2015

Feuille de route sur les réseaux électriques et stockage élaborée par le GP10 Réseaux et Stockages de l'Energie de l'ANCRECette feuille de route concerne les réseaux d’énergie électrique, de chaleur et de froid, les réseaux de gaz (hydrogène, gaz naturel), leurs stockages associés, ainsi que leurs couplages à venir dans le cadre de la transition énergétique et des évolutionsqui l’accompagneront, que ce soit sur les modes de production d’énergie ou sur l’évolution des usages.Le focus est porté sur les réseaux électriques qui seront les premiers impactés par cette transition énergétique. Hormisquelques éléments très spécifiques aux réseaux électriques (et qui seront notés dans le texte par une couleur différente)il est à souligner que la quasi-totalité des considérations et axes de R&D évoqués pour les réseauxélectriques et le développement de leur « intelligence » et/ou de leur flexibilité s’appliquentégalement aux autres réseaux d’énergie. Par ailleurs, si le groupe programmatique« Réseaux et Stockage » de l’ANCRE (GP10) s’est largement appuyé sur les nombreuses feuilles de route émises tant au niveau national, dont celles de l’ADEME, qu’européen, il a également souhaité s’en démarquer en insistantlargement et en détaillant les recherches scientifiques et technologiques à mener face aux verrous actuellement identifiés

Bacterial cellulose hydrogel loaded with lipid nanoparticles for localized cancer treatment

The use of hybrid materials, where a matrix sustains nanoparticles controlling the release of the chemotherapeutic drug, could be beneficial for the treatment of primary tumors prior or after surgery. This localized chemotherapy would guarantee high drug concentrations at the tumor site while precluding systemic drug exposure minimizing undesirable side effects. We combined bacterial cellulose hydrogel (BC) and nanostructured lipid carriers (NLCs) including doxorubicin (Dox) as a drug model. NLCs loaded with cationic Dox (NLCs-H) or neutral Dox (NLCs-N) were fully characterized and their cell internalization and cytotoxic efficacy were evaluated in vitro against MDA-MB-231 cells. Thereafter, a fixed combination of NLCs-H and NLCs-N loaded into BC (BC-NLCs-NH) was assayed in vivo into an orthotopic breast cancer mouse model. NLCs-H showed low encapsulation efficiency (48%) and fast release of the drug while NLCs-N showed higher encapsulation (97%) and sustained drug release. Both NLCs internalized via endocytic pathway, while allowing a sustained release of the Dox, which in turn rendered IC50 values below of those of free Dox. Taking advantage of the differential drug release, a mixture of NLCs-N and NLCs-H was encapsulated into BC matrix (BC-NLCs-NH) and assayed in vivo, showing a significant reduction of tumor growth, metastasis incidence and local drug toxicities.Fil: Cacicedo, Maximiliano Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Islan, German Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Leon, Ignacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Chourpa, Igor. Université Francois-Rabelais de Tours; FranciaFil: Allard Vannier, E.. Université Francois-Rabelais de Tours; FranciaFil: García Aranda, N.. Universitat Autònoma de Barcelona; EspañaFil: Díaz Riascos, Z.V.. Universidad Autonoma de Barcelona. Hospital Vall D' Hebron. Instituto de Investigación Vall D'hebron; España. Universitat Autònoma de Barcelona; EspañaFil: Fernández, Y.. Universidad Autonoma de Barcelona. Hospital Vall D' Hebron. Instituto de Investigación Vall D'hebron; España. Universitat Autònoma de Barcelona; EspañaFil: Schwartz, S.. Universitat Autònoma de Barcelona; España. Universidad Autonoma de Barcelona. Hospital Vall D' Hebron. Instituto de Investigación Vall D'hebron; EspañaFil: Abasolo, Ibane. Universidad Autonoma de Barcelona. Hospital Vall D' Hebron. Instituto de Investigación Vall D'hebron; España. Universitat Autònoma de Barcelona; EspañaFil: Castro, Guillermo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin

A 3D view of the outflow in the Orion Molecular Cloud 1 (OMC-1)

The fast outflow emerging from a region associated with massive star formation in the Orion Molecular Cloud 1 (OMC-1), located behind the Orion Nebula, appears to have been set in motion by an explosive event. Here we study the structure and dynamics of outflows in OMC-1. We combine radial velocity and proper motion data for near-IR emission of molecular hydrogen to obtain the first 3-dimensional (3D) structure of the OMC-1 outflow. Our work illustrates a new diagnostic tool for studies of star formation that will be exploited in the near future with the advent of high spatial resolution spectro-imaging in particular with data from the Atacama Large Millimeter Array (ALMA). We use published radial and proper motion velocities obtained from the shock-excited vibrational emission in the H2 v=1-0 S(1) line at 2.122 $\mu$m obtained with the GriF instrument on the Canada-France-Hawaii Telescope, the Apache Point Observatory, the Anglo-Australian Observatory and the Subaru Telescope. These data give the 3D velocity of ejecta yielding a 3D reconstruction of the outflows. This allows one to view the material from different vantage points in space giving considerable insight into the geometry. Our analysis indicates that the ejection occurred <720 years ago from a distorted ring-like structure of ~15" (6000 AU) in diameter centered on the proposed point of close encounter of the stars BN, source I and maybe also source n. We propose a simple model involving curvature of shock trajectories in magnetic fields through which the origin of the explosion and the centre defined by extrapolated proper motions of BN, I and n may be brought into spatial coincidence.Comment: Accepted for publication in Astronomy and Astrophysics (A&A), 12 pages, 9 figure

Bacterial cellulose hydrogel loaded with lipid nanoparticles for localized cancer treatment

The use of hybrid materials, where a matrix sustains nanoparticles controlling the release of the chemotherapeutic drug, could be beneficial for the treatment of primary tumors prior or after surgery. This localized chemotherapy would guarantee high drug concentrations at the tumor site while precluding systemic drug exposure minimizing undesirable side effects. We combined bacterial cellulose hydrogel (BC) and nanostructured lipid carriers (NLCs) including doxorubicin (Dox) as a drug model. NLCs loaded with cationic Dox (NLCs-H) or neutral Dox (NLCs-N) were fully characterized and their cell internalization and cytotoxic efficacy were evaluated in vitro against MDA-MB-231 cells. Thereafter, a fixed combination of NLCs-H and NLCs-N loaded into BC (BC-NLCs-NH) was assayed in vivo into an orthotopic breast cancer mouse model. NLCs-H showed low encapsulation efficiency (48%) and fast release of the drug while NLCs-N showed higher encapsulation (97%) and sustained drug release. Both NLCs internalized via endocytic pathway, while allowing a sustained release of the Dox, which in turn rendered IC50 values below of those of free Dox. Taking advantage of the differential drug release, a mixture of NLCs-N and NLCs-H was encapsulated into BC matrix (BC-NLCs-NH) and assayed in vivo, showing a significant reduction of tumor growth, metastasis incidence and local drug toxicities.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesCentro de Química Inorgánic

Bacterial cellulose hydrogel loaded with lipid nanoparticles for localized cancer treatment

The use of hybrid materials, where a matrix sustains nanoparticles controlling the release of the chemotherapeutic drug, could be beneficial for the treatment of primary tumors prior or after surgery. This localized chemotherapy would guarantee high drug concentrations at the tumor site while precluding systemic drug exposure minimizing undesirable side effects. We combined bacterial cellulose hydrogel (BC) and nanostructured lipid carriers (NLCs) including doxorubicin (Dox) as a drug model. NLCs loaded with cationic Dox (NLCs-H) or neutral Dox (NLCs-N) were fully characterized and their cell internalization and cytotoxic efficacy were evaluated in vitro against MDA-MB-231 cells. Thereafter, a fixed combination of NLCs-H and NLCs-N loaded into BC (BC-NLCs-NH) was assayed in vivo into an orthotopic breast cancer mouse model. NLCs-H showed low encapsulation efficiency (48%) and fast release of the drug while NLCs-N showed higher encapsulation (97%) and sustained drug release. Both NLCs internalized via endocytic pathway, while allowing a sustained release of the Dox, which in turn rendered IC50 values below of those of free Dox. Taking advantage of the differential drug release, a mixture of NLCs-N and NLCs-H was encapsulated into BC matrix (BC-NLCs-NH) and assayed in vivo, showing a significant reduction of tumor growth, metastasis incidence and local drug toxicities.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesCentro de Química Inorgánic

AMBER/VLTI interferometric observations of the recurrent Nova RS Ophiuchii 5.5 days after outburst

International audienceAims.We report on spectrally dispersed interferometric AMBER/VLTI observations of the recurrent nova RS Oph five days after the discovery of its outburst on 2006 Feb. 12. Methods: Using three baselines ranging from 44 to 86 m, and a spectral resolution of λ/δλ=1500, we measured the extension of the milliarcsecond-scale emission in the K band continuum and in the Brγ and He I 2.06 μm lines, allowing us to get an insight into the kinematics of the line forming regions. The continuum visibilities were interpreted by fitting simple geometric models consisting of uniform and Gaussian ellipses, ring and binary models. The visibilities and differential phases in the Brγ line were interpreted using skewed ring models aiming to perform a limited parametric reconstruction of the extension and kinematics of the line forming region. Results: The limited uv coverage does not allow discrimination between filled models (uniform or Gaussian ellipses) and rings. Binary models are discarded because the measured closure phase in the continuum is close to zero. The visibilities in the lines are at a low level compared to their nearby continuum, consistent with a more extended line forming region for He I 2.06 μm than Brγ. The ellipse models for the continuum and for the lines are highly flattened (b/a˜0.6) and share the same position angle (PA˜140°). Their typical Gaussian extensions are 3.1×1.9 mas, 4.9×2.9 mas and 6.3×3.6 mas for the continuum, Brγ and He I 2.06 μm lines, respectively. Two radial velocity fields are apparent in the Brγ line: a slow expanding ring-like structure (v_rad≤1800 km s-1), and a fast structure extended in the E-W direction (v_rad˜ 2500{-}3000 km s-1), a direction that coincides with the jet-like structure seen in the radio. These results confirm the basic fireball model, contrary to the conclusions of other interferometric observations conducted by Monnier et al. (2006a, ApJ, 647, L127). Based on observations collected at the European Southern Observatory, Paranal, Chile, within the programme 276.D-5049