Aims. Our aim is to measure the time delay between the two gravitationally lensed images of the z_{\rm qso} = 1.547 quasar SDSS J1650+4251, in order to estimate the Hubble constant H_{\rm0}. Methods. ...Our measurement is based on R-band light curves with 57 epochs obtained at Maidanak Observatory, in Uzbekistan, from May 2004 to September 2005. The photometry is performed using simultaneous deconvolution of the data, which provides the individual light curves of the otherwise blended quasar images. The time delay is determined from the light curves using two very different numerical techniques, i.e., polynomial fitting and direct cross-correlation. The time delay is converted into H_{\rm0} following analytical modeling of the potential well. Results. Our best estimate of the time delay is \Delta t = 49.5 \pm 1.9 days, i.e., we reach a 3.8% accuracy. The R-band flux ratio between the quasar images, corrected for the time delay and for slow microlensing, is F_{\rm A}/F_{\rm B} = 6.2 \pm 5%. Conclusions. The accuracy reached on the time delay allows us to discriminate well between families of lens models. As for most other multiply imaged quasars, only models of the lensing galaxy that have a de Vaucouleurs mass profile plus external shear give a Hubble constant compatible with the current most popular value (H_{\rm0} = 72 \pm 8 km s super(-1) Mpc super(-1)). A more realistic singular isothermal sphere model plus external shear gives H_{\rm0} = 51.7 super(+4.0) sub(-3.0) km s super(-1) Mpc super(-1).
Polysiloxane films were deposited on an AISI316L stainless steel by remote plasma assisted chemical vapour deposition from 1.1.3.3-tetramethyldisiloxane. Thicknesses up to 5 μm were developed at a ...maximum growth rate of 400 nm min
−
1
. The organosilicon films were then treated by remote plasma assisted oxidation and thermal treatment under air.
The remote plasma assisted oxidation modified the surface composition of the coatings but left the bulk properties unchanged. The thermal treatment allowed a full mineralization of the coatings. Below 450 °C the mineralization was partial and oxygen could not reach the coating core. This oxygen diffusion limitation was removed only for temperature of circa 600 °C. The final surface composition appeared to be SiO
1.8 which might represent a structure close to amorphous silica. After the most severe thermal treatment (600 °C), neither desquamation nor cracking of the deposit occurred. The final composite is a steel substrate covered by a coherent layer of silica glass material. The steel underneath remained non-oxidized which testified of a strong diffusion barrier role vs. O
2.
Les allergies à la Chlorhexidine sont en forte augmentation et parfois méconnues des professions de santé.
Nous rapportons 10 cas de patients ayant présenté une réaction allergique immédiate à la ...Chlorhexidine (2 réactions de grade I selon la classification de Ring et Messmer, 2 grade II, 5 grade III, 1 grade IV) diagnostiqués entre 2015 et 2018 (CHU de Rennes et Grenoble) avec une majorité d’hommes (7 hommes, 3 femmes) âgés de 3 ans à 60 ans. Le diagnostic allergologique a été confirmé par des tests cutanés (prick test plus ou moins intradermoréaction) associés au dosage des IgE spécifiques Chlorhexidine (méthode Immunocap).
Sur les 10 cas d’allergie à la Chlorhexidine, 6 récidives sont constatées, dont 5 pour lesquelles le diagnostic n’a été posé qu’après la seconde exposition et 1 cas antérieurement connu mais réexposé à l’allergène malgré tout. Lors des récidives, les symptômes sont plus importants dans 3 cas sur 6 (choc anaphylactique de grade III ou IV). Le diagnostic est seulement posé lors de la consultation d’allergologie en moyenne 4 mois après la récidive, avec contre-indication définitive de la Chlorhexidine.
Notre série retrouve une augmentation des réactions allergiques à la Chlorhexidine qui prédominent chez les hommes comme décrit dans la littérature. La récidive, souvent grave, se présente comme un phénomène particulier dans la pratique médicale dû à une méconnaissance et/ou au manque de vigilance des soignants non allergologues. Il existe également un déficit d’information du patient sur cet allergène nouveau contenu dans de nombreux produits pharmaceutiques.
L’incidence des réactions allergiques à la Chlorhexidine est en augmentation tout comme celle des récidives. Pour minimiser l’incidence globale, il est nécessaire de renforcer les actions de prévention primaire et secondaire auprès des soignants et des patients afin de l’évoquer plus précocement, et la confirmer par la réalisation rapide du bilan allergologique.
The objectives of this study were 1) to study the genetic diversity of the
Alexandrium,
Dinophysis and
Karenia genera along the French coasts in order to design probes targeting specific DNA regions, ...and 2) to apply PCR-based detection to detect these three toxic dinoflagellate genera in natural samples. Genetic diversity of these toxic taxa was first studied from either cultures or cells isolated from Lugol-fixed field samples. By this way, partial sequences of the large ribosomal subunit (LSU rDNA) including the variable domains D1 and D2 of
A. minutum,
Alexandrium species inside the
tamarensis complex, the
D. acuminata complex and
K. mikimotoi were obtained. Next, specific primers were designed for a selection of toxic algae and used during semi-nested PCR detection. This method was tested over a 3-month period on water samples from the Bay of Concarneau (Brittany, France) and on sediment from the Antifer harbor (The English Channel, France). Specificity and sensitivity of this molecular detection were evaluated using the occurrence of target taxa reported by the IFREMER (Institut Français de Recherche pour l'Exploitation de la Mer) monitoring network based on conventional microscopic examination. This work presents the first results obtained on the biogeographical distribution of genotypes of these three toxic genera along the French coasts.
Context. A number of microlensing dark-matter surveys have produced tens of millions of light curves of individual background stars. These data provide an unprecedented opportunity for systematic ...studies of whole classes of variable stars and their host galaxies. Aims. We aim to use the EROS-2 survey of the Magellanic Clouds to detect and study the population of beat Cepheids (BCs) in both Clouds. BCs pulsating simultaneously in the first overtone and fundamental modes (FO/F) or in the second and first overtone modes (SO/FO) are of particular interest. Methods. Using special software designed to search for periodic variables, we have scanned the EROS-2 data base for variables in the typical period range of Cepheids. Metallicities of FO/F objects were then calculated from linear nonadiabatic convective stellar models. Results. We identify 74 FO/F BCs in the LMC and 41 in the SMC, and 173 and 129 SO/FO pulsators in the LMC and SMC, respectively; 185 of these stars are new discoveries. For nearly all the FO/F objects we determine minimum, mean, and maximum values of the metallicity. Conclusions. The EROS data have expanded the samples of known BCs in the LMC by 31%, in the SMC by 110%. The FO/F objects provide independent measures of metallicities in these galaxies. The mean value of metallicity is 0.0045 in the LMC and 0.0018 in the SMC.
HD 172189 is a spectroscopic eclipsing binary system with a rapidly-rotating pulsating δ Scuti component. It is also a member of the open cluster IC 4756. These combined characteristics make it an ...excellent laboratory for asteroseismic studies. To date, HD 172189 has been analysed in detail photometrically but not spectroscopically. For this reason we have compiled a set of spectroscopic data to determine the absolute and atmospheric parameters of the components. We determined the radial velocities (RV) of both components using four different techniques. We disentangled the binary spectra using KOREL, and performed the first abundance analysis on both disentangled spectra. By combining the spectroscopic results and the photometric data, we obtained the component masses, 1.8 and 1.7 $M_{\odot}$, and radii, 4.0 and 2.4 $R_{\odot}$, for inclination $i = 73.2^{\circ}$, eccentricity $e = 0.28$, and orbital period $\Pi = 5.70198$ days. Effective temperatures of 7600 K and 8100 K were also determined. The measured $v \sin i$ are 78 and 74 km s-1, respectively, giving rotational periods of 2.50 and 1.55 days for the components. The abundance analysis shows Fe/H = –0.28 for the primary (pulsating) star, consistent with observations of IC 4756. We also present an assessment of the different analysis techniques used to obtain the RVs and the global parameters.
The type Iax supernova, SN 2015H Magee, M R; Kotak, R; Sim, S A ...
Astronomy and astrophysics (Berlin),
05/2016, Volume:
589
Journal Article
Peer reviewed
We present results based on observations of SN 2015H which belongs to the small group of objects similar to SN 2002cx, otherwise known as type Iax supernovae. The availability of deep pre-explosion ...imaging allowed us to place tight constraints on the explosion epoch. Our observational campaign began approximately one day post-explosion, and extended over a period of about 150 days post maximum light, making it one of the best observed objects of this class to date. We find a peak magnitude of M sub()r -17.27+ or - 0.07, and a (Deltam sub(15)) sub()r 0.69 + or - 0.04. Comparing our observations to synthetic spectra generated from simulations of deflagrations of Chandrasekhar mass carbon-oxygen white dwarfs, we find reasonable agreement with models of weak deflagrations that result in the ejection of ~0.2M sub(middot in circle) of material containing ~0.07 M sub(middot in circle) of super(56) Ni. The model light curve however, evolves more rapidly than observations, suggesting that a higher ejecta mass is to be favoured. Nevertheless, empirical modelling of the pseudo-bolometric light curve suggests that <, ~0.6M sub(middot in circle) of material was ejected, implying that the white dwarf is not completely disrupted, and that a bound remnant is a likely outcome.
Five years of eros data towards the Small Magellanic Cloud have been searched for gravitational microlensing events, using a new, more accurate method to assess the impact of stellar blending on the ...efficiency. Four long-duration candidates have been found which, if they are microlensing events, hint at a non-halo population of lenses. Combined with results from other eros observation programs, this analysis yields strong limits on the amount of Galactic dark matter made of compact objects. Less than 25% of a standard halo can be composed of objects with a mass between $2\times10^{-7}~M_\odot$ and 1 $M_\odot$ at the 95% C.L.
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