La construction récente des groupes de luxe français : mythes, discours et pratiques

Les recompositions récentes de l’industrie du luxe ont été peu étudiées. Le rachat de PME indépendantes liées à des marques prestigieuses a permis la constitution de groupes nouveaux pluriproduits et internationaux. Les synergies réalisées ont permis aux principaux groupes (LVMH, PPR et Richemont) de s’adapter aux évolutions du marché et des comportements des consommateurs. Derrière les combats médiatiques, comme celui autour du rachat de Gucci, se joue en fait une recomposition financière et industrielle de grande ampleur tant certains secteurs du luxe constituent des domaines fortement bénéficiaires.The current mergers in the luxury industry have received relatively little consideration. Nonetheless, the buying-up of small and medium-sized independent companies by luxury brands has produced new international and multiproduct business groups. These mergers and acquisitions have created opportunities for the major groups in this area (LVMH, PPR and Richemont) to adapt to consumer behaviours and other rapid changes in the sector. Beyond the more mediatised events, such as the purchase of the Gucci group, the profits generated in this area are of such a magnitude that there has been a drastic restructuring in the industry’s finance and production

Haffner 16: A Young Moving Group in the Making

The photometric properties of main sequence (MS) and pre-main sequence (PMS) stars in the young cluster Haffner 16 are examined using images recorded with the Gemini South Adaptive Optics Imager (GSAOI) and corrected for atmospheric blurring by the Gemini Multi-Conjugate Adapative Optics System (GeMS). A rich population of PMS stars is identified, and comparisons with isochrones suggest an age < 10 Myr assuming a distance modulus of 13.5 (D = 5 kpc). When compared with the solar neighborhood, Haffner 16 is roughly a factor of two deficient in objects with sub-solar masses. PMS objects in the cluster are also more uniformly distributed on the sky than bright MS stars. It is suggested that Haffner 16 is dynamically evolved, and that it is shedding protostars with sub-solar masses. Young low mass clusters like Haffner 16 are one possible source of PMS stars in the field. The cluster will probably evolve on time scales of ~ 100 - 1000 Myr into a diffuse moving group with a mass function that is very different from that which prevailed early in its life.Comment: To appear in the Publications of the Astronomical Society of the Pacifi

The Earliest Near-infrared Time-series Spectroscopy of a Type Ia Supernova

We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {\lambda}1.0693 {\mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {\lambda}1.0927 {\mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {\Delta}m15. The prominent break at ~1.5 {\mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {\Delta}m15. The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.Comment: 14 pages, 13 figures, accepted for publication in Ap

HST FOC spectroscopy of the NLR of NGC 4151. I. Gas kinematics

We present the results from a detailed kinematic analysis of both ground-based, and Hubble Space Telescope/Faint Object Camera long-slit spectroscopy at sub-arcsec spatial resolution, of the narrow-line region of NGC 4151. In agreement with previous work, the extended emission gas (R > 4") is found to be in normal rotation in the galactic plane, a behaviour that we were able to trace even across the nuclear region, where the gas is strongly disturbed by the interaction with the radio jet, and connects smoothly with the large scale rotation defined by the neutral gas emission. The HST data, at 0.029" spatial resolution, allow us for the first time to truly isolate the kinematic behaviour of the individual clouds in the inner narrow-line region. We find that, underlying the perturbations introduced by the radio ejecta, the general velocity field can still be well represented by planar rotation down to a radius of ~ 0.5" (30 pc), distance at which the rotation curve has its turnover. The most striking result that emerges from our analysis is that the galaxy potential derived fitting the rotation curve changes from a "dark halo" at the ENLR distances to dominated by the central mass concentration in the NLR, with an almost Keplerian fall-off in the 1"< R < 4" interval. The observed velocity of the gas at 0.5" implies a mass of M ~ 10E9 M(sol) within the inner 60 pc. The presence of a turnover in the rotation curve indicates that this central mass concentration is extended. The first measured velocity point (outside the region saturated by the nucleus) would imply an enclosed mass of ~ 5E7 M(sol) within R ~ 0.15" (10 pc) which represents an upper limit to any nuclear point mass.Comment: 30 pages (aaspp4.sty), 14 figures. Fig. 1, 2 and 4 available by anonymous FTP at 143.54.2.51 (cd /pub/winge) as GIF files; or upon request to [email protected]. Accepted for publication in the Astrophysical Journal (part 1

Reverberation Mapping and the Physics of Active Galactic Nuclei

Reverberation-mapping campaigns have revolutionized our understanding of AGN. They have allowed the direct determination of the broad-line region size, enabled mapping of the gas distribution around the central black hole, and are starting to resolve the continuum source structure. This review describes the recent and successful campaigns of the International AGN Watch consortium, outlines the theoretical background of reverberation mapping and the calculation of transfer functions, and addresses the fundamental difficulties of such experiments. It shows that such large-scale experiments have resulted in a ``new BLR'' which is considerably different from the one we knew just ten years ago. We discuss in some detail the more important new results, including the luminosity-size-mass relationship for AGN, and suggest ways to proceed in the near future.Comment: Review article to appear in Astronomical Time Series, Proceedings of the Wise Observatory 25th Ann. Symposium. 24 pages including 7 figure

Characterisation and localisation of the endocannabinoid system components in the adult human testis

International audienceHeavy use of cannabis (marijuana) has been associated with decreased semen quality, which may reflect disruption of the endocannabinoid system (ECS) in the male reproductive tract by exogenous cannabinoids. Components of ECS have been previously described in human spermatozoa and in the rodent testis but there is little information on the ECS expression within the human testis. In this study we characterised the main components of the ECS by immunohistochemistry (IHC) on archived testis tissue samples from 15 patients, and by in silico analysis of existing transcriptome datasets from testicular cell populations. The presence of 2-arachidonoylglycerol (2-AG) in the human testis was confirmed by matrix-assisted laser desorption ionization imaging analysis. Endocannabinoid-synthesising enzymes; diacylglycerol lipase (DAGL) and N-acyl-phosphatidylethanolamine-specific phospholipase D (NAPE-PLD), were detected in germ cells and somatic cells, respectively. The cannabinoid receptors, CNR1 and CNR2 were detected at a low level in post-meiotic germ cells and Leydig- and peritubular cells. Different transcripts encoding distinct receptor isoforms (CB1, CB1A, CB1B and CB2A) were also differentially distributed, mainly in germ cells. The cannabinoid-metabolising enzymes were abundantly present; the α/β-hydrolase domain-containing protein 2 (ABHD2) in all germ cell types, except early spermatocytes, the monoacylglycerol lipase (MGLL) in Sertoli cells, and the fatty acid amide hydrolase (FAAH) in late spermatocytes and post-meiotic germ cells. Our findings are consistent with a direct involvement of the ECS in regulation of human testicular physiology, including spermatogenesis and Leydig cell function. The study provides new evidence supporting observations that recreational cannabis can have possible deleterious effects on human testicular function. Author Correction:https://www.nature.com/articles/s41598-020-58153-

Mass of the Southern Black Hole in NGC 6240 from Laser Guide Star Adaptive Optics

NGC 6240 is a pair of colliding disk galaxies, each with a black hole in its core. We have used laser guide star adaptive optics on the Keck II telescope to obtain high-resolution ($\sim 0.06$") near-infrared integral-field spectra of the region surrounding the supermassive black hole in the south nucleus of this galaxy merger. We use the K-band CO absorption bandheads to trace stellar kinematics. We obtain a spatial resolution of about 20 pc and thus directly resolve the sphere of gravitational influence of the massive black hole. We explore two different methods to measure the black hole mass. Using a Jeans Axisymmetric Multi-Gaussian mass model, we investigate the limit that a relaxed mass distribution produces all of the measured velocity dispersion, and find an upper limit on the black hole mass at 2.0 \pm 0.2 \times 10^9 M_{\sun}. When assuming the young stars whose spectra we observe remain in a thin disk, we compare Keplerian velocity fields to the measured two-dimensional velocity field measured and fit for a mass profile containing a black hole point mass plus a radially-varying spherical component, which suggests a lower limit for the black hole mass of 8.7 \pm 0.3 \times 10^8 M_{\sun}. Our measurements of the stellar velocity dispersion place this AGN within the scatter of the $M_{BH}$-$\sigma_{*}$ relation. As NGC 6240 is a merging system, this may indicate that the relation is preserved during a merger at least until the final coalescence of the two nuclei.Comment: 10 pages, 12 figures; accepted to Ap

Chemical Abundances in Twelve Red Giants of the Large Magellanic Cloud from High-Resolution Infrared Spectroscopy

High-resolution infrared spectra (R=50,000) have been obtained for twelve red-giant members of the LMC with the Gemini South 8.3-meter telescope plus Phoenix spectrometer. Quantitative chemical abundances of carbon-12, carbon-13, nitrogen-14, and oxygen-16 were derived from molecular lines of CO, CN, and OH, while sodium, scandium, titanium, and iron abundances were derived from neutral atomic lines. The LMC giants have masses from about 1 to 4 solar masses and span a metallicity range from [Fe/H]= -1.1 to -0.3. The program red giants all show evidence of first dredge-up mixing, with low 12C/13C ratios, and low 12C correlated with high 14N abundances. Comparisons of the oxygen-to-iron ratios in the LMC and the Galaxy indicate that the trend of [O/Fe] versus [Fe/H] in the LMC falls about 0.2 dex below the Galactic trend. Such an offset can be modeled as due to an overall lower rate of supernovae per unit mass in the LMC relative to the Galaxy, as well as a slightly lower ratio of supernovae of type II to supernovae of type Ia.Comment: 25 pages, 6 tables, 10 figures. "In press" in The Astronomical Journal (scheduled for December 2002

NGC6240: Merger-Induced Star Formation & Gas Dynamics

We present spatially resolved integral field spectroscopic K-band data at a resolution of 0.13" (60pc) and interferometric CO(2-1) line observations of the prototypical merging system NGC6240. Despite the clear rotational signature, the stellar kinematics in the two nuclei are dominated by dispersion. We use Jeans modelling to derive the masses and the mass-to-light ratios of the nuclei. Combining the luminosities with the spatially resolved Br-gamma equivalent width shows that only 1/3 of the K-band continuum from the nuclei is associated with the most recent star forming episode; and that less than 30% of the system's bolometric luminosity and only 9% of its stellar mass is due to this starburst. The star formation properties, calculated from typical merger star formation histories, demonstrate the impact of different assumptions about the star formation history. The properties of the nuclei, and the existence of a prominent old stellar population, indicate that the nuclei are remnants of the progenitor galaxies' bulges.Comment: 18 pages, 14 figures. Accepted for publication in A&

Filaggrin Genotype Determines Functional and Molecular Alterations in Skin of Patients with Atopic Dermatitis and Ichthyosis Vulgaris

BACKGROUND: Several common genetic and environmental disease mechanisms are important for the pathophysiology behind atopic dermatitis (AD). Filaggrin (FLG) loss-of-function is of great significance for barrier impairment in AD and ichthyosis vulgaris (IV), which is commonly associated with AD. The molecular background is, however, complex and various clusters of genes are altered, including inflammatory and epidermal-differentiation genes. OBJECTIVE: The objective was to study whether the functional and molecular alterations in AD and IV skin depend directly on FLG loss-of-function, and whether FLG genotype determines the type of downstream molecular pathway affected. METHODS AND FINDINGS: Patients with AD/IV (n = 43) and controls (n = 15) were recruited from two Swedish outpatient clinics and a Swedish AD family material with known FLG genotype. They were clinically examined and their medical history recorded using a standardized questionnaire. Blood samples and punch biopsies were taken and trans-epidermal water loss (TEWL) and skin pH was assessed with standard techniques. In addition to FLG genotyping, the STS gene was analyzed to exclude X-linked recessive ichthyosis (XLI). Microarrays and quantitative real-time PCR were used to compare differences in gene expression depending on FLG genotype. Several different signalling pathways were altered depending on FLG genotype in patients suffering from AD or AD/IV. Disease severity, TEWL and pH follow FLG deficiency in the skin; and the number of altered genes and pathways are correlated to FLG mRNA expression. CONCLUSIONS: We emphasize further the role of FLG in skin-barrier integrity and the complex compensatory activation of signalling pathways. This involves inflammation, epidermal differentiation, lipid metabolism, cell signalling and adhesion in response to FLG-dependent skin-barrier dysfunction