A black-hole mass measurement from molecular gas kinematics in NGC4526

The masses of the supermassive black-holes found in galaxy bulges are correlated with a multitude of galaxy properties, leading to suggestions that galaxies and black-holes may evolve together. The number of reliably measured black-hole masses is small, and the number of methods for measuring them is limited, holding back attempts to understand this co-evolution. Directly measuring black-hole masses is currently possible with stellar kinematics (in early-type galaxies), ionised-gas kinematics (in some spiral and early-type galaxies) and in rare objects which have central maser emission. Here we report that by modelling the effect of a black-hole on the kinematics of molecular gas it is possible to fit interferometric observations of CO emission and thereby accurately estimate black hole masses. We study the dynamics of the gas in the early-type galaxy NGC4526, and obtain a best fit which requires the presence of a central dark-object of 4.5(+4.2-3.0)x10^8 Msun (3 sigma confidence limit). With next generation mm-interferometers (e.g. ALMA) these observations could be reproduced in galaxies out to 75 megaparsecs in less the 5 hours of observing time. The use of molecular gas as a kinematic tracer should thus allow one to estimate black-hole masses in hundreds of galaxies in the local universe, many more than accessible with current techniques.Comment: To appear in Nature online on 30/01/2013. 3 Pages, 2 Figures (plus two pages of supplementary information

Spectral properties of a two-orbital Anderson impurity model across a non-Fermi liquid fixed point

We study by NRG the spectral properties of a two-orbital Anderson impurity model in the presence of an exchange splitting which follows either regular or inverted Hund's rules. The phase diagram contains a non-Fermi liquid fixed point separating a screened phase, where conventional Kondo effect occurs, from an unscreened one, where the exchange-splitting takes care of quenching the impurity degrees of freedom. On the Kondo screened side close to this fixed point the impurity density of states shows a narrow Kondo-peak on top of a broader resonance. This narrow peak transforms in the unscreened phase into a narrow pseudo-gap inside the broad resonance. Right at the fixed point only the latter survives. The fixed point is therefore identified by a jump of the density of states at the chemical potential. We also show that particle-hole perturbations which simply shift the orbital energies do not wash out the fixed point, unlike those perturbations which hybridize the two orbitals. Consequently the density-of-state jump at the chemical potential remains finite even away from particle-hole symmetry, and the pseudo-gap stays pinned at the chemical potential, although it is partially filled in. We also discuss the relevance of these results for lattice models which map onto this Anderson impurity model in the limit of large lattice-coordination. Upon approaching the Mott metal-insulator transition, these lattice models necessarily enter a region with a local criticality which reflects the impurity non-Fermi liquid fixed point. However, unlike the impurity, the lattice can get rid of the single-impurity fixed-point instability by spontaneously developing bulk-coherent symmetry-broken phases, which we identify for different lattice models.Comment: 43 pages, 11 figures. Minor corrections in the Appendi

Revealing the tidal scars of the Small Magellanic Cloud

Due to their close proximity, the Large and Small Magellanic Clouds (SMC/LMC) provide natural laboratories for understanding how galaxies form and evolve. With the goal of determining the structure and dynamical state of the SMC, we present new spectroscopic data for $\sim$ 3000 SMC red giant branch stars observed using the AAOmega spectrograph at the Anglo-Australian Telescope. We complement our data with further spectroscopic measurements from previous studies that used the same instrumental configuration and proper motions from the \textit{Gaia} Data Release 2 catalogue. Analysing the photometric and stellar kinematic data, we find that the SMC centre of mass presents a conspicuous offset from the velocity centre of its associated \mbox{H\,{\sc i}} gas, suggesting that the SMC gas is likely to be far from dynamical equilibrium. Furthermore, we find evidence that the SMC is currently undergoing tidal disruption by the LMC within 2\,kpc of the centre of the SMC, and possibly all the way in to the very core. This is evidenced by a net outward motion of stars from the SMC centre along the direction towards the LMC and apparent tangential anisotropy at all radii. The latter is expected if the SMC is undergoing significiant tidal stripping, as we demonstrate using a suite of $N$-body simulations of the SMC/LMC system disrupting around the Milky Way. These results suggest that dynamical models for the SMC that assume a steady state will need to be revisited.Comment: Revised version submitted to MNRAS after referee report, 18 pages, 18 figure

HBsAg clearance by Peg-interferon addition to a long-term nucleos(t)ide analogue therapy.

The ideal endpoint of hepatitis B virus (HBV) antiviral therapy is HBsAg loss, a difficult goal to obtain, especially in HBeAg negative patients. Herein, we report the results obtained by the addition of peg-interferon α-2a to a long-lasting nucleos(t)ide analogue therapy in a HBeAg negative, genotype D patient with steadily HBV-DNA negative/HBsAg positive values. In 2002, our Caucasian 44-year-old male patient received lamivudine and, 4 years later, added adefovir because of a virological breakthrough. In 2011, considering his young age, liver stiffness (4.3 kPa) and HBsAg levels (3533 IU/mL), we added Peg-interferon α-2a for six months (3 in combination with nucleos(t)ide analogues followed by 3 mo of Peg-interferon α-2a monotherapy). A decrease of HBsAg levels was observed after 1 mo (1.21 log) of Peg-interferon and 3 mo (1.88 log) after the discontinuation of all drugs. Later, a complete clearance of HBsAg was obtained with steadily undetectable HBV-DNA serum levels (< 9 IU/mL). HBsAg clearance by the addition of a short course of Peg-interferon α-2a represents an important result with clinical and pharmaco-economic implications, considering that nucleos(t)ide analogues therapy in HBeAg negative chronic hepatitis B patients is considered a long-lasting/life-long treatment

Evoluzione del trattamento in elezione degli aneurismi dell'aorta addominale:risultati a breve termine e costi

Lo scopo di questo studio è quello di delineare il panorama attuale delle metodiche operatorie ed il loro impatto sul trattamento degli aneurismi nella pratica clinica. In questo modo si vuole mettere a confronto tra le diverse procedure le indicazioni, i risultati perioperatori ed i costi. L’originalità di questa analisi risiede nella possibilità di ricorrere ad un grosso campione di malati trattati in un unico centro. Infine, da questi risultati si possono delineare le prospettive di sviluppo futuro nel trattamento degli aneurismi dell’aorta addominale

Al-Si10-Mg Manufactured by Selective Laser Melting: Microstructure Sensitivity to Close Values of the Heat Input

Selective Laser Melting (SLM) is an attractive Additive Manufacturing (AM) technology for the fabrication of metallic components with complex structures and high performances. This process fulfills the goals of sustainable production by reducing material waste, optimizing product topology, and recycling metallic powder. Aluminum alloys exhibit also sustainable performances being lightweight and recyclable. Al-Si10-Mg alloy is suitable for SLM processing due to its good castability, good strength, wear, and corrosion resistance. However, the laser processing of aluminum alloys to date needs to be optimized. In this study, the authors have analyzed the role of close values of heat input on microstructure and defects (Electron and Optical microscope, DRX analysis), porosity (optical microscope and X-ray tomography), melting pool geometries (both in transversal and longitudinal sections of the samples) and mechanical performance (hardness and tensile test) of Al-Si10-Mg samples. The results have shown that even at very close values of energy density, the microstructure and properties of the samples differ from each other

Remote Sensing Based Yield Estimation in a Stochastic Framework – Case Study of Durum Wheat in Tunisia

Multitemporal optical remote sensing constitutes a useful, cost efficient method for crop status monitoring over large areas. Modelers interested in yield monitoring can rely on past and recent observations of crop reflectance to estimate aboveground biomass and infer the likely yield. Therefore, in a framework constrained by the information availability, remote sensing data to yield conversion parameters are to be estimated. Statistical models are suitable for this purpose given their ability to deal with statistical errors. This paper explores the performance in yield estimation of various remote sensing indicators based on varying degrees of bio-physical insight, in interaction with statistical methods (linear regressions) that rely on different hypotheses. Jackknifed results (leave one year out) are presented for the case of wheat yield regional estimation in Tunisia using the SPOT-VEGETATION instrument.JRC.H.4-Monitoring Agricultural Resource

A Review of Exposure Assessment Methods in Epidemiological Studies on Incinerators

Incineration is a common technology for waste disposal, and there is public concern for the health impact deriving from incinerators. Poor exposure assessment has been claimed as one of the main causes of inconsistency in the epidemiological literature. We reviewed 41 studies on incinerators published between 1984 and January 2013 and classified them on the basis of exposure assessment approach. Moreover, we performed a simulation study to explore how the different exposure metrics may influence the exposure levels used in epidemiological studies. 19 studies used linear distance as a measure of exposure to incinerators, 11 studies atmospheric dispersion models, and the remaining 11 studies a qualitative variable such as presence/absence of the source. All reviewed studies utilized residence as a proxy for population exposure, although residence location was evaluated with different precision (e.g., municipality, census block, or exact address). Only one study reconstructed temporal variability in exposure. Our simulation study showed a notable degree of exposure misclassification caused by the use of distance compared to dispersion modelling. We suggest that future studies (i) make full use of pollution dispersion models; (ii) localize population on a fine-scale; and (iii) explicitly account for the presence of potential environmental and socioeconomic confounding