We report on a complete CCD imaging survey of 226 elliptical galaxies in the North-East quadrant of the Virgo cluster, representative of the properties of giant and dwarf elliptical galaxies in this ...cluster. We fit their radial light profiles with the Sersic $r^{1/n}$ model of light distribution. We confirm the result of Graham & Guzman (CITE, AJ, 125, 2936) that the apparent dichotomy between E and dE galaxies in the luminosity–$\langle \mu\rangle_{\rm e}$ plane no longer appears when other structural parameters are considered and can be entirely attributed to the onset of “core” galaxies at $B_T \sim -20.5$ mag. When “core” galaxies are not considered, E and dE form a unique family with n linearly increasing with the luminosity. For 90 galaxies we analyze the $B-I$ color indices, both in the nuclear and in the outer regions. Both indices are bluer toward fainter luminosities. We find also that the outer color gradients do not show any significant correlation with the luminosity. The scatter in all color indicators increases significantly toward lower luminosities, e.g. galaxies fainter than $B_T \sim -15$ have a $B-I$ spread > 0.5 mag.
Dehydroepiandrosterone (DHEA) and its sulfonated form dehydroepiandrosterone sulfate (DHEAS) are the main circulating steroid hormones and many epidemiological studies show an inverse relationship ...between DHEA/DHEAS levels and muscle loss for which the primary cause is the accelerated protein breakdown. The aim of this work was to determine whether DHEA/DHEAS supplementation in differentiating C2C12 skeletal muscle cells might influence the expression of the atrophy-related ubiquitin ligase, MuRF-1, and thereby impact key molecules of the differentiation program. DHEA is the prohormone crucial for sex steroid synthesis, and DHEAS is thought to be its reservoir. However, our preliminary experiments showed that DHEAS, but not DHEA, is able to influence MuRF-1 expression. Therefore, we treated differentiating C2C12 cells with various concentrations of DHEAS and analyzed the expression of MuRF-1, Hsp70, myosin heavy chain (MHC), myogenin, and the activity of creatine kinase. We observed that DHEAS at physiological concentrations downregulates MuRF-1 expression and affects muscle differentiation, as shown by the increased levels of MHC, which is a sarcomeric protein that undergoes MuRF-1-dependent degradation, and also by an increase in creatine kinase activity and myogenin expression, which are two other well-known markers of differentiation. Moreover, we found that DHEAS might have a protective effect on differentiating cells as suggested by the augmented levels of Hsp70, a member of heat shock proteins family that, besides its cytoprotective action, seems to have a regulatory role on key atrophy genes such as MuRF-1. In conclusion, our data shed light on the role of DHEAS at physiologic concentrations in maintaining muscle mass.
AGILE is a mission of the Italian Space Agency (ASI) Scientific Program dedicated to γ-ray astrophysics, and has operated in a low Earth orbit since 2007 April 23. It is designed to be a very light ...and compact instrument, capable of simultaneously detecting and imaging photons in the 18-60 keV X-ray energy band and in the 30 MeV-50 GeV γ-ray energy range with a good angular resolution ( 1◦ @ 1 GeV). The core of the instrument is the Silicon Tracker, supplemented by a CsI calorimeter and an AntiCoincidence system, which form the Gamma Ray Imaging Detector (GRID). Before launch, the GRID needed on-ground calibration with a tagged γ-ray beam to estimate its performance and validate the Monte Carlo simulation. The GRID was calibrated using a tagged γ-ray beam with energy up to 500 MeV at the Beam Test Facilities at the INFN Laboratori Nazionali di Frascati. These data are used to validate a GEANT 3-based simulation by comparing the data and the Monte Carlo simulation by measuring the angular and energy resolutions. The GRID angular and energy resolutions obtained using the beam agree well with the Monte Carlo simulation. Therefore the simulation, can be used to simulate the same performance on-flight with high reliability.
Objective To assess availability of timely orthopedic fracture care to children. Study design Fifty randomly selected orthopedic practices were contacted twice with an identical scenario to request ...an appointment for a fictitious child with an arm fracture, once with the staff told that the child had private insurance and once with Medicaid. Access to appointments on the basis of insurance was compared with rates 10 years earlier.1 Results Forty-five practices were contacted successfully. An appointment was offered within 7 days to a child with private insurance by 42% of the practices (19/45) and to a child with Medicaid by 2% of the practices (1/45; P < .0001). There was no difference in timely access (appointment within 7 days) for children with Medicaid in this study (2%) compared with 10 years ago (1%; P = 1.0). There was a significant decrease in timely access for children with private insurance in the past decade, with a rate of 42% (19/45) in this study, compared with 100% (50/50) 10 years ago ( P < .0001). Conclusion There has been a substantial decrease in the last decade in the willingness, availability, or both of orthopedic surgeons in Los Angeles to care for children with fractures whose families have private insurance. Children with Medicaid continue to have limited access.
Passive early-type galaxies (ETGs) provide an ideal laboratory for studying the interplay between dust formation around evolved stars and its subsequent destruction in a hot gas. Using Spitzer-IRS ...and Herschel data we compare the dust production rate in the envelopes of evolved AGB stars with a constraint on the total dust mass. Early-type galaxies which appear to be truly passively evolving are not detected by Herschel. We thus derive a distance independent upper limit to the dust grain survival time in the hostile environment of ETGs of \textless46 +/- 25 Myr for amorphous silicate grains. This implies that ETGs which are detected at far-infrared wavelengths have acquired a cool dusty medium via interaction. Given likely time-scales for ram-pressure stripping, this also implies that only galaxies with dust in a cool (atomic) medium can release dust into the intra-cluster medium.
Toxic effects of trace metals on digestive gland and gill cytoarchitecture were studied in the mussel Mytilus platensis after metal detection in the environment. Mussels were collected from the Port ...of San Antonio Este and from a reference site called Isla Mejillón, both in Rio Negro province (Argentina). Histological techniques, morphometrical analysis and lipofuscin detection with Nile blue method were performed. Mussels from the seaport presented dilated hemolymphatic vessels with numerous hemocytes in the gill filaments and fused filaments in the frontal zone. Morphometric analysis of the gill filaments showed an increase in the epithelial thickness of the lateral zone that bears cilia, and we infer that water filtering might be affected. The sublateral zone was also thickened, probably interfering with gas exchange. A reduction in the abfrontal zone epithelial thickness was also noticed, so water pumping, lubrication and cleaning of the gills might be impaired. Digestive glands of seaport mussels accumulated lipofuscin granules within the digestive cells, accounting for lipid and protein peroxidation. The observed histological alterations in gill and digestive gland in mussels from North Patagonia seaport are relevant findings to be considered as biomarkers of effect after exposure to metals.
We have carried out a fully sampled large area (4°× 8°) 21-cm H i line survey of part of the Virgo cluster using the Jodrell Bank multibeam instrument. The survey has a sensitivity some three times ...better than the standard HIJASS (H i Jodrell All Sky Survey) and HIPASS (H i Parkes All Sky Survey) surveys. We detect 31 galaxies, 27 of which are well-known cluster members. The four new detections have been confirmed in the HIPASS data and by follow-up Jodrell Bank pointed observations. One object lies behind M86, but the other three have no obvious optical counterparts upon inspection of the digital sky survey fields. These three objects were mapped at Arecibo with a smaller 3.6-arcmin half power beam width (HPBW) and a four times better sensitivity than the Jodrell Bank data, which allow an improved determination of the dimensions and location of two of the objects, but surprisingly failed to detect the third. The two objects are resolved by the Arecibo beam, giving them a size far larger than any optical images in the nearby field. To our mass limit of 5 × 107(Δv/50 km s−1) M⊙ and column density limit of 3 × 1018(Δv/50 km s−1) atom cm−2, these new detections represent only about 2 per cent of the cluster atomic hydrogen mass. Our observations indicate that the H i mass function of the cluster turns down at the low-mass end, making it very different to the field galaxy H i mass function. This is quite different to the Virgo cluster optical luminosity function, which is much steeper than that in the general field. Many of the sample galaxies are relatively gas-poor compared with H i selected samples of field galaxies, confirming the ‘anaemic spirals’ view of Virgo cluster late-type galaxies. The velocity distribution of the H i detected galaxies is also very different to that of the cluster as a whole. There are relatively more high-velocity galaxies in the H i sample, suggesting that they form part of a currently infalling population. The H i sample with optical identifications has a minimum H i column density cut-off more than an order of magnitude above that expected from the sensitivity of the survey. This observed column density is above the normally expected level for star formation to occur. The two detections with no optical counterparts have very much lower column densities than that of the rest of the sample, below the star formation threshold.
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