325 research outputs found

    ALBUM: a tool for the analysis of slitless spectra and its application to ESO WFI data

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    ALBUM is a general-purpose tool to visualize and screen large amounts of slitless spectra. It was developed for a search for emission-line stars in SMC and LMC clusters. The observations were obtained with ESO's Wide Field Imager (WFI) and comprise ~8 million low-resolution spectra. The tool as well as the results of its application to the SMC part of the database are presented. The inferred frequency of Be stars is compared to the one in the higher-metallicity environment of the Milky Way.Comment: The 2007 ESO instrument calibration workshop, Garching bei Muenchen : Allemagne (2007); 4 page

    Be stars in open clusters in the Small Magellanic Cloud

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    We report on the study of the population of B and Be stars in SMC young clusters, performed with the Wide Field Imager in slitless spectroscopic mode at ESO/T2.2m with a filter centered at Halpha. First, we explain the reduction methods we used and our selection of different types of objects. Second, we present results on the proportion of Be stars in SMC clusters, and we compare this proportion to the one observed in the Milky Way. Finally, we also present results on a statistical study of variability of Be stars with OGLE.Comment: sf2a 200

    Analysis of gene regulatory networks of maize in response to nitrogen

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    Nitrogen (N) fertilizer has a major influence on the yield and quality. Understanding and optimising the response of crop plants to nitrogen fertilizer usage is of central importance in enhancing food security and agricultural sustainability. In this study, the analysis of gene regulatory networks reveals multiple genes and biological processes in response to N. Two microarray studies have been used to infer components of the nitrogen-response network. Since they used different array technologies, a map linking the two probe sets to the maize B73 reference genome has been generated to allow comparison. Putative Arabidopsis homologues of maize genes were used to query the Biological General Repository for Interaction Datasets (BioGRID) network, which yielded the potential involvement of three transcription factors (TFs) (GLK5, MADS64 and bZIP108) and a Calcium-dependent protein kinase. An Artificial Neural Network was used to identify influential genes and retrieved bZIP108 and WRKY36 as significant TFs in both microarray studies, along with genes for Asparagine Synthetase, a dual-specific protein kinase and a protein phosphatase. The output from one study also suggested roles for microRNA (miRNA) 399b and Nin-like Protein 15 (NLP15). Co-expression-network analysis of TFs with closely related profiles to known Nitrate-responsive genes identified GLK5, GLK8 and NLP15 as candidate regulators of genes repressed under low Nitrogen conditions, while bZIP108 might play a role in gene activation

    The ATLAS3D project - XXIX : The new look of early-type galaxies and surrounding fields disclosed by extremely deep optical images

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    Date of Acceptance: 25/09/2014Galactic archaeology based on star counts is instrumental to reconstruct the past mass assembly of Local Group galaxies. The development of new observing techniques and data reduction, coupled with the use of sensitive large field of view cameras, now allows us to pursue this technique in more distant galaxies exploiting their diffuse low surface brightness (LSB) light. As part of the ATLAS3D project, we have obtained with the MegaCam camera at the Canada-France-Hawaii Telescope extremely deep, multiband images of nearby early-type galaxies (ETGs). We present here a catalogue of 92 galaxies from the ATLAS3D sample, which are located in low- to medium-density environments. The observing strategy and data reduction pipeline, which achieve a gain of several magnitudes in the limiting surface brightness with respect to classical imaging surveys, are presented. The size and depth of the survey are compared to other recent deep imaging projects. The paper highlights the capability of LSB-optimized surveys at detecting new prominent structures that change the apparent morphology of galaxies. The intrinsic limitations of deep imaging observations are also discussed, among those, the contamination of the stellar haloes of galaxies by extended ghost reflections, and the cirrus emission from Galactic dust. The detection and systematic census of fine structures that trace the present and past mass assembly of ETGs are one of the prime goals of the project. We provide specific examples of each type of observed structures - tidal tails, stellar streams and shells - and explain how they were identified and classified. We give an overview of the initial results. The detailed statistical analysis will be presented in future papers.Peer reviewedFinal Accepted Versio

    Golden gravitational lensing systems from the Sloan Lens ACS Survey. II. SDSS J1430+4105: A precise inner total mass profile from lensing alone

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    We study the SLACS strong lensing system SDSSJ1430+4105 at z=0.285. The lensed source (z=0.575) of this system has a complex morphology with several subcomponents. Its subcomponents span a radial range from 4 to 10kpc in the lens plane. Therefore we can constrain the slope of the total projected mass profile around the Einstein radius (R_E) from lensing alone. We measure a density profile that is slightly but not significantly shallower than isothermal at R_E. We decompose the mass of the lensing galaxy into a de Vaucouleurs (deV) component to trace the stars and an additional dark component. The spread of multiple image components over a large radial range also allows us to determine the amplitude of the deV and dark matter components separately. We get a mass to light ratio of M_deV/L_B~5.5\pm1.5M/L_sun,B and a dark matter fraction within R_E of ~20 to 40%. Modelling the star formation history assuming composite stellar populations at solar metallicity to the galaxy's photometry yields a mass to light ratio of M_star,salp/L_B~4.0_{-1.3}^{+0.6}M/L_sun,B and M_star,chab/L_B~2.3_{-0.8}^{+0.3}M/L_sun,B for Salpeter and Chabrier IMFs, respectively. Hence, the mass to light ratio derived from lensing is more Salpeter-like, in agreement with results for massive Coma galaxies and other nearby massive early type galaxies. We examine the consequences of the galaxy group in which the lensing galaxy is embedded, showing that it has little influence on the mass to light ratio obtained for the deV component of the lensing galaxy. Finally, we decompose the projected, azimuthally averaged 2D density distribution of the deV and dark matter component of the lensing signal into spherically averaged 3D density profiles. We can show that the 3D dark and luminous matter density within R_E~0.6R_eff of this SLACS galaxy is similar to the values of Coma galaxies with the same velocity dispersions.Comment: 24 pages, 21 figures, 11 tables, accepted for publication by MNRA

    Effect of long-term deficit irrigation on tomato and goji berry quality: from fruit composition to in vitro bioaccessibility of carotenoids

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    Drought is a persistent challenge for horticulture, affecting various aspects of fruit development and ultimately fruit quality, but the effect on nutritional value has been under-investigated. Here, fruit quality was studied on six tomato genotypes and one goji cultivar under deficit irrigation (DI), from fruit composition to in vitro bioaccessibility of carotenoids. For both species, DI concentrated most health-related metabolites in fresh fruit. On a dry mass basis, DI increased total phenolic and sugar concentration, but had a negative or insignificant impact on fruit ascorbic acid, organic acid, and alcohol-insoluble matter contents. DI also reduced total carotenoids content in tomato (−18.7% on average), especially β-carotene (−32%), but not in goji berry DW (+15.5% and +19.6%, respectively). DI reduced the overall in vitro bioaccessibility of carotenoids to varying degrees depending on the compound and plant species. Consequently, mixed micelles produced by digestion of fruits subjected to DI contained either the same or lesser quantities of carotenoids, even though fresh fruits could contain similar or higher quantities. Thus, DI effects on fruit composition were species and genotype dependent, but an increase in the metabolite concentration did not necessarily translate into greater bioaccessibility potentially due to interactions with the fruit matri

    Neurotrophins are expressed in giant cell arteritis lesions and may contribute to vascular remodeling

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    International audienceIntroduction: Giant cell arteritis (GCA) is characterized by intimal hyperplasia leading to ischaemic manifestations that involve large vessels. Neurotrophins (NTs) and their receptors (NTRs) are protein factors for growth, differentiation and survival of neurons. They are also involved in the migration of vascular smooth muscle cells (VSMCs). Our aim was to investigate whether NTs and NTRs are involved in vascular remodelling of GCA.Methods: We included consecutive patients who underwent a temporal artery biopsy for suspected GCA. We developed an enzymatic digestion method to obtain VSMCs from smooth muscle cells in GCA patients and controls. Neurotrophin protein and gene expression and functional assays were studied from these VSMCs. Neurotrophin expression was also analysed by immunohistochemistry in GCA patients and controls.Results: Whereas temporal arteries of both GCA patients (n = 22) and controls (n = 21) expressed nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB) and sortilin, immunostaining was more intense in GCA patients, especially in the media and intima, while neurotrophin-3 (NT-3) and P75 receptor (P75NTR) were only detected in TA from GCA patients. Expression of TrkB, a BDNF receptor, was higher in GCA patients with ischaemic complications. Serum NGF was significantly higher in GCA patients (n = 28) vs. controls (n = 48), whereas no significant difference was found for BDNF and NT-3. NGF and BDNF enhanced GCA-derived temporal artery VSMC proliferation and BDNF facilitated migration of temporal artery VSMCs in patients with GCA compared to controls.Conclusions: Our results suggest that NTs and NTRs are involved in vascular remodelling of GCA. In GCA-derived temporal artery VSMC, NGF promoted proliferation and BDNF enhanced migration by binding to TrkB and p75NTR receptors. Further experiments are needed on a larger number of VSMC samples to confirm these results

    Short-Term Efficacy of Rofecoxib and Diclofenac in Acute Shoulder Pain: A Placebo-Controlled Randomized Trial

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    OBJECTIVES: To evaluate the short-term symptomatic efficacy of rofecoxib and diclofenac versus placebo in acute episodes of shoulder pain. DESIGN: Randomized controlled trial of 7 days. SETTING: Rheumatologists and/or general practitioners totaling 47. PARTICIPANTS: Acute shoulder pain. INTERVENTIONS: Rofecoxib 50 mg once daily, diclofenac 50 mg three times daily, and placebo. OUTCOME MEASURES: Pain, functional impairment, patient's global assessment of his/her disease activity, and local steroid injection requirement for persistent pain. The primary variable was the Kaplan-Meier estimates of the percentage of patients at day 7 fulfilling the definition of success (improvement in pain intensity and a low pain level sustained to the end of the 7 days of the study; log-rank test). RESULTS: There was no difference in the baseline characteristics between the three groups (rofecoxib n = 88, placebo n = 94, and diclofenac n = 89). At day 7, the Kaplan-Meier estimates of successful patients was higher in the treatment groups than in the placebo (54%, 56%, and 38% in the diclofenac, rofecoxib, and placebo groups respectively, p = 0.0070 and p = 0.0239 for placebo versus rofecoxib and diclofenac, respectively). During the 7 days of the study, there was a statistically significant difference between placebo and both active arms (rofecoxib and diclofenac) in all the evaluated outcome measures A local steroid injection had to be performed in 33 (35%) and 19 (22%) patients in the placebo and rofecoxib group respectively. Number needed to treat to avoid such rescue therapy was 7 patients (95% confidence interval 5–15). CONCLUSION: This study highlights the methodological aspects of clinical trials, e.g., eligibility criteria and outcome measures, in acute painful conditions. The data also establish that diclofenac and rofecoxib are effective therapies for the management of acute painful shoulder and that they reduce the requirement for local steroid injection

    Drying nano particles solution on an oscillating tip at an air liquid interface: what we can learn, what we can do

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    Evaporation of fluid at micro and nanometer scale may be used to self-assemble nanometre-sized particles in suspension. Evaporating process can be used to gently control flow in micro and nanofluidics, thus providing a potential mean to design a fine pattern onto a surface or to functionalize a nanoprobe tip. In this paper, we present an original experimental approach to explore this open and rather virgin domain. We use an oscillating tip at an air liquid interface with a controlled dipping depth of the tip within the range of the micrometer. Also, very small dipping depths of a few ten nanometers were achieved with multi walls carbon nanotubes glued at the tip apex. The liquid is an aqueous solution of functionalized nanoparticles diluted in water. Evaporation of water is the driving force determining the arrangement of nanoparticles on the tip. The results show various nanoparticles deposition patterns, from which the deposits can be classified in two categories. The type of deposit is shown to be strongly dependent on whether or not the triple line is pinned and of the peptide coating of the gold nanoparticle. In order to assess the classification, companion dynamical studies of nanomeniscus and related dissipation processes involved with thinning effects are presented
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