As part of the Early Release Observations (ERO) programme, we analysed deep, wide-field imaging from the VIS and NISP instruments of two Milky Way globular clusters (GCs), namely NGC 6254 (M10) and ...NGC 6397, to look for observational evidence of their dynamical interaction with the Milky Way. We searched for such an interaction in the form of structural and morphological features in the clusters' outermost regions, which would be suggestive of the development of tidal tails on scales larger than those sampled by the ERO data. From our multi-band photometric analysis, we obtained deep and well-behaved colour--magnitude diagrams that, in turn, enabled an accurate membership selection. The surface brightness profiles built from these samples of member stars are the deepest ever obtained for these two Milky Way GCs, reaching down to $ mag/arcsec$^2$, which is $ mag/arcsec$^2$ lower than before. The investigation of the two-dimensional density map of NGC 6254 reveals an elongated morphology of the cluster peripheries in the direction and with the amplitude predicted by $N$-body simulations of the cluster's dynamical evolution, at high statistical significance. We interpret this as strong evidence for the first detection of tidally induced morphological distortion around this cluster. The density map of NGC 6397 reveals a slightly elliptical morphology, in agreement with previous studies, which requires further investigation on larger scales to be properly interpreted. This ERO project thus demonstrates the power of in studying the outer regions of GCs at an unprecedented level of detail, thanks to the combination of the large field of view, high spatial resolution, and depth enabled by the telescope. Our results highlight the future survey as the ideal dataset for investigating GC tidal tails and stellar streams.
We present evolutionary population synthesis models for the study of the cool and luminous intermediate age stellar populations in resolved galaxies with particular emphasis on carbon star ...populations. We study the effects of the star formation history, the age and the metallicity on the populations of intermediate mass stars. In the case of instantaneous bursts, we confirm that lower metallicity results in higher contributions of carbon stars to the total star number, and in higher number ratios of carbon stars to late-type M stars. Chemically consistent models are used to study the effect of the star formation history on the relations between carbon star population properties and global parameters of the parent galaxy (age, metallicity). Our models are able to account, for the first time, for those correlations, as observed in the galaxies of the Local Group. For stellar populations older than about 1 Gyr, the properties of carbon star populations are linked to the current metallicity in a way that is quite independent of the star formation scenario. The number ratio of carbon stars to late-type M stars forms a metallicity sequence along which stellar populations with very different star formation histories are found. For the same populations, we find that both the mean bolometric luminosity of carbon stars and their normalized number to the luminosity of the parent galaxy are quite independent of metallicity over a large range in metallicity. This is in good agreement with the observational constraints. The observed statistics of carbon star populations can be interpreted by two principal effects: (i) the carbon star formation efficiency is higher in metal-poor systems, (ii) the typical star formation time-scale along the Hubble sequence of galaxies is much longer than the typical time-scale for the production of carbon stars at any metallicity.
Resveratrol produced by several plants, berries and fruits, including grapes, is one of the best known natural food microcomponents with potent chemopreventive properties towards the most severe ...contemporary human diseases: cardiovascular sickness, cancer and neurodegenerative pathologies. Demonstration of its mechanism of action also implies the elucidation of the steps of bioavailability and bioabsorption in cells and tissues. In order to estimate the relationships between the amounts of resveratrol taken up by food or drink intake, and the several possible benefits illustrated from in vitro/in vivo experiments and from epidemiological studies, it is essential to demonstrate step by step the route of resveratrol from plasma to the cell active site. In plasma, resveratrol was shown to interact with lipoproteins. This commentary also contains previously unpublished results about interactions between resveratrol and albumin and the enhancement of this binding in presence of fatty acids. We have previously described that resveratrol uptake by hepatic cells involves two processes – a passive one and a carrier-mediated one. Thanks to this last process, resveratrol, while tightly bound to blood proteins, could be largely delivered to body tissues. The intracellular proteic targets of resveratrol remain to be identified.
Expanding cysts of the septum pellucidum, although rare, may be a cause of significant neurological dysfunction. Most become symptomatic as a result of obstruction of the interventricular foramina ...and produce headaches, papilledema, emesis, and loss of consciousness. Behavioral, autonomic, and sensorimotor symptoms occur when an expanding cyst impinges on the structures of the hypothalamoseptal triangle or impairs the deep cerebral venous drainage. Neuroophthalmological symptoms may develop as a consequence of hydrocephalus or direct compression of visual structures. The authors describe the case of a young boy with an expanding septum pellucidum cyst who presented with a sudden, severe headache and loss of consciousness. In addition, he had a history of hyperactivity and progressively declining school performance. All symptoms resolved following decompression of the cyst. Seventeen cases from the literature are reviewed. The pathophysiological mechanisms underlying the development of symptoms secondary to expanding septum pellucidum cysts are outlined, and the related clinical neuroanatomy is described. A model is proposed for the natural history of expanding septum pellucidum cysts that provides a rational basis for understanding their clinical behavior and response to intervention. In most cases, fenestration or shunting will relieve the obstructive hydrocephalus and mass effect caused by the cyst and will produce rapid symptomatic improvement.
ABSTRACT
We analyse near‐infrared integral field spectroscopy of the central starburst region of NGC 1140, obtained at the Gemini‐South telescope equipped with CIRPASS. Our ∼1.45–1.67 μm wavelength ...coverage includes the bright Fe iiλ 1.64‐μm emission line, as well as high‐order Brackett (hydrogen) lines. While strong Fe ii emission, thought to originate in the thermal shocks associated with supernova remnants, is found throughout the galaxy, both Br 12–4 and Br 14–4 emission, and weak CO(6,3) absorption, is predominantly associated with the northern starburst region. The Brackett lines originate from recombination processes occurring on smaller scales in (young) H ii regions. The time‐scale associated with strong Fe ii emission implies that most of the recent star‐formation activity in NGC 1140 was induced in the past ∼35–55 Myr. Based on the spatial distributions of the Fe ii versus Brackett line emission, we conclude that a galaxy‐wide starburst was induced several tens of Myr ago, with more recent starburst activity concentrated around the northern starburst region.
This scenario is (provisionally) confirmed by our analysis of the spectral energy distributions of the compact, young massive star clusters (YMCs) detected in new and archival broad‐band Hubble Space Telescope images. The YMC ages in NGC 1140 are all ≲20 Myr, consistent with independently determined estimates of the starburst age of the galaxy, while there appears to be an age difference between the northern and southern YMC complexes in the sense expected from our CIRPASS analysis. Our photometric mass estimates of the NGC 1140 YMCs, likely upper limits, are comparable to those of the highest‐mass Galactic globular clusters and to spectroscopically confirmed masses of (compact) YMCs in other starburst galaxies. Our detection of similarly massive YMCs in NGC 1140 supports the scenario that such objects form preferentially in the extreme environments of interacting and starburst galaxies.
Purpose Age‐related Macular Degeneration (AMD) is a pathology driven by inflammatory and angiogenic processes. The aim of this work was to study the in vitro anti‐inflammatory and anti‐angiogenic ...potential of a new resveratrol‐based formula (Resvega, Laboratoires THEA, France) on Human retinal pigment epithelium cell line ARPE‐19 after an inflammation induced by the bacterial lipopolysaccharide (LPS).
Methods Human ARPE‐19 cells were subjected to inflammation by LPS (0128:B12) and co‐treated during 24 hours with Resveratrol (50,30,10 or 1µM) or the Resvega formula (50,30,10 or 1 µM expressed in Resveratrol equivalent). Cell media were collected and the levels of 6 cytokines were measured by the multiplex Cytometric Bead Array Kit (BD Bioscience) : IL‐8, IL‐1 beta, IL‐6, IL‐10, TNF alpha and IL‐12p70. Finally the level of the major angiogenic factor VEGF‐A was measured in these media by ELISA (eBioscience)
Results The results showed that among the 6 cytokines only IL‐6 and IL‐8 were over‐expressed during the inflammation triggered by the LPS treatment. These two pro‐inflammatory cytokines were down‐regulated by Resveratrol and Resvega treatments by at least 50‐60% in all conditions even at the very low concetrations (1 µM). Concerning VEGF‐A levels, Resveratrol and Resvega showed a dose‐dependent inhibition. The maximum inhibition was observed for the highest concentration of Resvega (50 µM resveratrol equivalent)with a decrease by 74%.
Conclusion In conclusion, we demonstrated that Resvega had an anti‐inflammatory and anti‐angiogenic effect in vitro, on the human retinal pigment epithelial cells.
In a previous paper, we assembled a collection of medium-resolution spectra of 35 carbon stars, covering optical and near-infrared wavelengths from 400 to 2400 nm. The sample includes stars from the ...Milky Way and the Magellanic Clouds, with a variety of (J−Ks) colors and pulsation properties. In the present paper, we compare these observations to a new set of high-resolution synthetic spectra, based on hydrostatic model atmospheres. We find that the broad-band colors and the molecular-band strengths measured by spectrophotometric indices match those of the models when (J−Ks) is bluer than about 1.6, while the redder stars require either additional reddening or dust emission or both. Using a grid of models to fit the full observed spectra, we estimate the most likely atmospheric parameters Teff, log (g), Fe/H and C/O. These parameters derived independently in the optical and near-infrared are generally consistent when (J−Ks) < 1.6. The temperatures found based on either wavelength range are typically within ±100 K of each other, and log (g) and Fe/H are consistent with the values expected for this sample. The reddest stars ((J−Ks) > 1.6) are divided into two families, characterized by the presence or absence of an absorption feature at 1.53 μm, generally associated with HCN and C2H2. Stars from the first family begin to be more affected by circumstellar extinction. The parameters found using optical or near-infrared wavelengths are still compatible with each other, but the error bars become larger. In stars showing the 1.53 μm feature, which are all large-amplitude variables, the effects of pulsation are strong and the spectra are poorly matched with hydrostatic models. For these, atmospheric parameters could not be derived reliably, and dynamical models are needed for proper interpretation.
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