24 research outputs found
The WISSH quasars project XI. The mean Spectral Energy Distribution and Bolometric Corrections of the most luminous quasars
Hyper-luminous Quasi-Stellar Objects (QSOs) represent the ideal laboratory to
investigate Active Galactic Nuclei (AGN) feedback mechanism since their
formidable energy release causes powerful winds at all scales and thus the
maximum feedback is expected.
We aim at deriving the mean Spectral Energy Distribution (SED) of a sample of
85 WISE-SDSS Selected Hyper-luminous (WISSH) quasars. Since the SED provides a
direct way to investigate the AGN structure, our goal is to understand if
quasars at the bright end of the luminosity function have peculiar properties
compared to the bulk of the population. We built a mean intrinsic SED after
correcting for the dust extinction, absorption and emission lines and
intergalactic medium absorption. We also derived bolometric, IR band and
monochromatic luminosities together with bolometric corrections at lambda =
5100 A and 3 micron. We define a new relation for the 3 micron bolometric
correction. We find that the mean SED of hyper-luminous WISSH QSOs is different
from that of less luminous sources, i.e. a relatively lower X-ray emission and
a near and mid IR excess which can be explained assuming a larger dust
contribution. WISSH QSOs have stronger emission from both warm and very hot
dust, the latter being responsible for shifting the typical dip of the AGN SED
from 1.3 to 1.1 micron. We also derived the mean SEDs of two sub-samples
created according to the presence of Broad Absorption Lines and equivalent
width of CIV line. We confirm that BALs are X-ray weak and that they have a
reddened UV-optical continuum. We also find that BALs tend to have stronger
emission from the hot dust component. This analysis suggests that
hyper-luminous QSOs have a peculiar SED compared to less luminous objects. It
is therefore critical to use SED templates constructed exclusively from very
bright quasars samples when dealing with particularly luminous sources.Comment: Accepted for publication in A&A. 20 pages, 15 figure
The SINS/zC-SINF survey of z~2 galaxy kinematics: Outflow properties
Based on SINFONI Ha, [NII] and [SII] AO data of 30 z \sim 2 star-forming
galaxies (SFGs) from the SINS and zcSINF surveys, we find a strong correlation
of the Ha broad flux fraction with the star formation surface density of the
galaxy, with an apparent threshold for strong outflows occurring at 1 Msun
yr^-1 kpc^-2. Above this threshold, we find that SFGs with logm_\ast>10 have
similar or perhaps greater wind mass loading factors (eta = Mdotout/SFR) and
faster outflow velocities than lower mass SFGs. This trend suggests that the
majority of outflowing gas at z \sim 2 may derive from high-mass SFGs, and that
the z \sim 2 mass-metallicity relation is driven more by dilution of enriched
gas in the galaxy gas reservoir than by the efficiency of outflows. The mass
loading factor is also correlated with the SFR and inclination, such that more
star-forming and face-on galaxies launch more powerful outflows. For galaxies
that have evidence for strong outflows, we find that the broad emission is
spatially extended to at least the half-light radius (\sim a few kpc). We
propose that the observed threshold for strong outflows and the observed mass
loading of these winds can be explained by a simple model wherein break-out of
winds is governed by pressure balance in the disk. Using the ratio of the [SII]
doublet in a broad and narrow component, we find that outflowing gas has a
density of \sim10-100 cm^-3, significantly less than that of the star forming
gas (600 cm^-3).Comment: 7 pages, 3 figures, accepted by Ap
A fast-rotator post-starburst galaxy quenched by supermassive black-hole feedback at z=3
There is compelling evidence that the most massive galaxies in the Universe
stopped forming stars due to the time-integrated feedback from their central
super-massive black holes (SMBHs). However, the exact quenching mechanism is
not yet understood, because local massive galaxies were quenched billions of
years ago. We present JWST/NIRSpec integral-field spectroscopy observations of
GS-10578, a massive, quiescent galaxy at redshift z=3.064. From the spectrum we
infer that the galaxy has a stellar mass of MSun
and a dynamical mass MSun. Half of its
stellar mass formed at z=3.7-4.6, and the system is now quiescent, with the
current star-formation rate SFR<9 MSun/yr. We detect ionised- and neutral-gas
outflows traced by [OIII] emission and NaI absorption. Outflow velocities reach
1,000 km/s, comparable to the galaxy escape velocity and
too high to be explained by star formation alone. GS-10578 hosts an Active
Galactic Nucleus (AGN), evidence that these outflows are due to SMBH feedback.
The outflow rates are 0.14-2.9 and 30-300 MSun/yr for the ionised and neutral
phases, respectively. The neutral outflow rate is ten times higher than the
SFR, hence this is direct evidence for ejective SMBH feedback, with
mass-loading capable of interrupting star formation by rapidly removing its
fuel. Stellar kinematics show ordered rotation, with spin parameter
, meaning GS-10578 is rotation supported. This study
shows direct evidence for ejective AGN feedback in a massive, recently quenched
galaxy, thus clarifying how SMBHs quench their hosts. Quenching can occur
without destroying the stellar disc.Comment: 40 pages, 9 figures, submitted to Nat. Ast., comments welcome
Give the planet a chance if we want our patients to have a future
Climate changes have never been as dramatically apparent in our everyday life as now. It is urgent to reduce greenhouse gas emissions and mitigate the consequences of climate changes both on the planet and on human health. The indiscriminate exploitation of natural resources and the lack of shared rules are among the major causes. Recently, some economists have called for a radical change in the present economic model towards a 'social solidarity economy' model. G.Giraud, a French economist, called for an ecological and social transition in order to reduce the ecological footprint and deal concretely with the problem of global warming. The good news is that the solutions are there and do not have to be punitive. Health consequences of climate changes have already caused serious draw backs on public health. Doctors and scientific institutions can and must contribute to help mitigate the effects of climate change through increasing commitment and support to goodenvironmental policies. Climate emergency requires the extension of ethics and medical practice beyond their traditional mission to involve the relationship between patients, doctors and society. We propose that medical scientific institutions quickly promote the birth of task forces dedicated to addressing this problem
Covid-19 and the role of smoking: the protocol of the multicentric prospective study COSMO-IT (COvid19 and SMOking in ITaly).
The emergency caused by Covid-19 pandemic raised interest in studying lifestyles and comorbidities as important determinants of poor Covid-19 prognosis. Data on tobacco smoking, alcohol consumption and obesity are still limited, while no data are available on the role of e-cigarettes and heated tobacco products (HTP). To clarify the role of tobacco smoking and other lifestyle habits on COVID-19 severity and progression, we designed a longitudinal observational study titled COvid19 and SMOking in ITaly (COSMO-IT). About 30 Italian hospitals in North, Centre and South of Italy joined the study. Its main aims are: 1) to quantify the role of tobacco smoking and smoking cessation on the severity and progression of COVID-19 in hospitalized patients; 2) to compare smoking prevalence and severity of the disease in relation to smoking in hospitalized COVID-19 patients versus patients treated at home; 3) to quantify the association between other lifestyle factors, such as e-cigarette and HTP use, alcohol and obesity and the risk of unfavourable COVID-19 outcomes. Socio-demographic, lifestyle and medical history information will be gathered for around 3000 hospitalized and 700-1000 home-isolated, laboratory-confirmed, COVID-19 patients. Given the current absence of a vaccine against SARS-COV-2 and the lack of a specific treatment for -COVID-19, prevention strategies are of extreme importance. This project, designed to highly contribute to the international scientific debate on the role of avoidable lifestyle habits on COVID-19 severity, will provide valuable epidemiological data in order to support important recommendations to prevent COVID-19 incidence, progression and mortality
Subsequent Event Risk in Individuals with Established Coronary Heart Disease:Design and Rationale of the GENIUS-CHD Consortium
BACKGROUND:
The "GENetIcs of sUbSequent Coronary Heart Disease" (GENIUS-CHD) consortium was established to facilitate discovery and validation of genetic variants and biomarkers for risk of subsequent CHD events, in individuals with established CHD.
METHODS:
The consortium currently includes 57 studies from 18 countries, recruiting 185,614 participants with either acute coronary syndrome, stable CHD or a mixture of both at baseline. All studies collected biological samples and followed-up study participants prospectively for subsequent events.
RESULTS:
Enrollment into the individual studies took place between 1985 to present day with duration of follow up ranging from 9 months to 15 years. Within each study, participants with CHD are predominantly of self-reported European descent (38%-100%), mostly male (44%-91%) with mean ages at recruitment ranging from 40 to 75 years. Initial feasibility analyses, using a federated analysis approach, yielded expected associations between age (HR 1.15 95% CI 1.14-1.16) per 5-year increase, male sex (HR 1.17, 95% CI 1.13-1.21) and smoking (HR 1.43, 95% CI 1.35-1.51) with risk of subsequent CHD death or myocardial infarction, and differing associations with other individual and composite cardiovascular endpoints.
CONCLUSIONS:
GENIUS-CHD is a global collaboration seeking to elucidate genetic and non-genetic determinants of subsequent event risk in individuals with established CHD, in order to improve residual risk prediction and identify novel drug targets for secondary prevention. Initial analyses demonstrate the feasibility and reliability of a federated analysis approach. The consortium now plans to initiate and test novel hypotheses as well as supporting replication and validation analyses for other investigators
Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry
Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase
Can Procalcitonin Be Dosed in Bovine Milk Using a Commercial ELISA Kit?
The aim was to evaluate the use of a bovine procalcitonin (PCT) ELISA kit (Cusabio, China) for assessing PCT in bovine milk samples. Validation was performed by using 10 plasma and corresponding milk samples from mastitic cows. The limit of detection (LOD) was calculated. The coefficient of variation (CV%) of the readings of five plasma samples measured five times in the same plate (intra-assay) and the CV% of the same five samples read five times in three separate plates was evaluated. Parallelism was determined by serial twofold dilutions of five plasma and corresponding milk samples. Milk samples were analyzed with and without centrifugation. Regarding plasma PCT, the method presented an inter- and intra-CV < 23.7% and parallelism had very good recovery values. The ELISA kit studied can measure bovine plasma PCT concentrations. The kit antibodies fail in binding PCT in milk samples because all centrifuged milk samples showed a lower LOD than blank samples. Only three uncentrifuged milk samples showed measurable PCT concentrations. Due to these results, the commercial ELISA kit investigated could not be employed for the detection of PCT in milk samples
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(So) Big Data and the transformation of the city
The exponential increase in the availability of large-scale mobility data has fueled the vision of smart cities that will transform our lives. The truth is that we have just scratched the surface of the research challenges that should be tackled in order to make this vision a reality. Consequently, there is an increasing interest among different research communities (ranging from civil engineering to computer science) and industrial stakeholders in building knowledge discovery pipelines over such data sources. At the same time, this widespread data availability also raises privacy issues that must be considered by both industrial and academic stakeholders. In this paper, we provide a wide perspective on the role that big data have in reshaping cities. The paper covers the main aspects of urban data analytics, focusing on privacy issues, algorithms, applications and services, and geo-referenced data from social media. In discussing these aspects, we leverage, as concrete examples and case studies of urban data science tools, the results obtained in the "City of Citizens" thematic area of the Horizon 2020 SoBigData initiative, which includes a virtual research environment with mobility datasets and urban analytics methods developed by several institutions around Europe. We conclude the paper outlining the main research challenges that urban data science has yet to address in order to help make the smart city vision a reality.Peer reviewe