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TW Hydrae is a very young and nearby association with about 30 known members which is an excellent target for studies on stellar evolution since several of its members present a particular interest (planetary system, brown dwarfs, etc.). With the new data from TGAS and the Gaia DR1 eventually combined with others astrometric data we intend to improve our kinematic knowledge of this association.
Current Galactic surveys, including the Gaia mission, rely on the efficiency of the spectral analysis techniques to provide precise and accurate spectral information (i.e. effective temperature, surface gravity, metallicity, and chemical abundances) in the shortest computational time. In this work, we present a new package to preform complete spectral analyses based on the spectral synthesis technique (Tsantaki et al. 2017, submitted). We focus on deriving atmospheric parameters for FGK-type stars using both high and medium resolution (GIRAFFE) spectra. This method is implemented on the Gaia-ESO benchmark stars to confirm its validity, achieving similar accuracy for the two resolution setups.
Some studies suggested that the chemical abundance trend with the condensation temperature, Tc, is a signature of rocky planet formation. Very recently, a strong Tc trend was reported in ζ2 Ret relative to its companion (ζ1 Ret) and was explained by the presence of a debris disk around ζ2 Ret. We re-evaluated the presence and variability of the Tc trend in this system with a goal to understand the impact of the presence of the debris disk on a star. Our results confirm the reported abundance difference between ζ2 Ret and ζ1 Ret and its dependence on the Tc. However, we also found that the Tc trends depend on the individual spectrum used. We conclude that for the ζ Reticuli system, for example, nonphysical factors can be at the root of the Tc trends for the case of individual spectra. For more details see Adibekyan et al. (2016b).
Because of to its exceptional resolving power, Gaia should detect a few thousands gravitational lensed systems. These consist in multiple images of background quasars. The estimated number of lens phenomena in the sky, however, depends on the cosmological model considered. By taking into account the observational bias that will restrict the detection of lensed quasars, identification of these up to a given limiting magnitude will constrain the cosmological parameters.
We have investigated the known gravitationally lensed quasars present in the Gaia DR1, and found that a significant number of components of these systems have been measured and are present in the Gaia DR1 catalogue although quasi none of them have all their components detected. We additionally examined the immediate surroundings of QSOs from the large Quasar catalogue, LQAC3, and detected several configurations compatible with gravitational lensing phenomena. A more global strategy to systematically detect the potential candidates in the various releases of the Gaia catalogue is presented.
In this work we present chemical abundances of heavy elements (Z>28) for a homogeneous sample of 1059 stars from HARPS planet search program. We also derive ages using parallaxes from Hipparcos and Gaia DR1 to compare the results. We study the [X/Fe] ratios for different populations and compare them with models of Galactic chemical evolution. We find that thick disk stars are chemically disjunt for Zn adn Eu. Moreover, the high-alpha metal-rich population presents an interesting behaviour, with clear overabundances of Cu and Zn and lower abundances of Y and Ba with respect to thin disk stars. Several abundance ratios present a significant correlation with age for chemically separated thin disk stars (regardless of their metallicity) but thick disk stars do not present that behaviour. Moreover, at supersolar metallicities the trends with age tend to be weaker for several elements.
Understanding how young stars and their circumstellar disks form and evolve is key to explain how planets form. The evolution of the star and the disk is regulated by different processes, both internal to the system or related to their environment. The former include accretion of material onto the central star, wind emission, and photoevaporation of the disk due to high-energy radiation from the central star. These are best studied spectroscopically, and the distance to the star is a key parameter in all these studies. Here we present new estimates of the distance to a complex of nearby star-forming clouds obtained combining TGAS distances with measurement of extinction on the line of sight. Furthermore, we show how we plan to study the effects of the environment on the evolution of disks with Gaia, using a kinematic modelling code we have developed to model young star-forming regions.
Bacteraemia caused by Escherichia coli are particularly frequent and severe, contrasting with the commensal character of the strains found in the digestive tract. A better understanding of the relationships between strains of both origins is needed to unravel the pathogenesis of this disease. Two hundred and forty-three commensal strains were compared to 243 bacteraemic strains isolated from adult hosts matched in terms of gender and age, and from similar location and epoch. Phylogenetic grouping, O-type determination, virulence factor content and antibiotic resistance were compared. Compared to commensal strains, the bacteraemic strains were characterized by a higher proportion of B2, C and D phylogroups, and a lower proportion of A, E and F phylogroups. They also had a lower proportion of the B2 subgroup IV (STc141), a higher proportion of virulence factors, and a higher frequency of antibiotic resistance. These differences were more marked for the bacteraemic strains of urinary tract origin with the presence of specific clones, whereas the bacteraemic strains of digestive origin remained non-significantly different from the commensal strains, except for their antibiotic resistance. Thus, two levels of specialization from commensal strains were demonstrated in the bacteraemic strains: resistance to antibiotics in all cases, and virulence for those of urinary tract origin.
This paper aims to present the Integrated Atlas of Mental Health of Catalonia (2010) focusing on: (a) the importance of using a taxonomy-based coding and standard system of data collection when assessing health services; and (b) its relevance as a tool for evidence-informed policy.
This study maps all the care-related services for people with mental disorders available in Catalonia in 2010, using the ‘Description and Evaluation of Services and Directories in Europe for long-term care’ (DESDE-LTC). The unit of analysis is the Basic Stable Input of Care (BSIC), which is the minimal organisation unit composed by a set of inputs with temporal stability. We presented data on: (a) availability of BSICs and their capacity; (b) the adequacy of the provision of care, taking into account availability and accessibility; (c) the evolution of BSCIs from 2002 to 2010; and (d) the perceived relevance of Atlas of Mental Health as a tool for evidence-informed policy.
We identified a total of 639 BSICs. A lack of Health services was detected in highly rural areas, although there was moderate availability of Social Services. Overall, more than 80% of the small mental health areas in Catalonia had an adequate core mental health service. Since 2002 the availability of mental health services has increased. Decision makers found the Atlas a useful and relevant tool for evidence informed policy.
Policy makers can use Atlases to detect gaps and inequities in the provision of care for people with mental health needs.
The intra-erythrocytic protozoan Babesia bovis is an economically important pathogen that causes an acute and often fatal infection in adult cattle. Babesiosis limitation depends on the early activation of macrophages, essential cells of the host innate immunity, which can generate an inflammatory response mediated by cytokines and nitric oxide (NO). Herein, we demonstrate in bovine macrophages that lipids from B. bovis attenuated R1A strain (LA) produced a stronger NO release, an early TNFα mRNA induction and 2-fold higher IL-12p35 mRNA levels compared to the lipids of virulent S2P strain (LV). Neither LA nor LV induced anti-inflammatory IL-10. Regarding signalling pathways, we here report that LA induced a significant phosphorylation of p38 and extracellular signal-regulated kinases 1 and 2 (ERK1/2) whereas LV only induced a reduced activation of ERK1/2. Besides, NF-κB was activated by LA and LV, but LA produced an early degradation of the inhibitor IκB. Interestingly, LV and the majority of its lipid fractions, exerted a significant inhibition of concanavalin A-induced peripheral blood mononuclear cell proliferation with respect to LA and its corresponding lipid fractions. In addition, we determined that animals infected with R1A developed a higher increase in IgM anti-phosphatidylcholine than those inoculated with S2P. Collectively, S2P lipids generated a decreased inflammatory response contributing to the evasion of innate immunity. Moreover, since R1A lipids induced a pro-inflammatory profile, we propose these molecules as good candidates for immunoprophylactic strategies against babesiosis.
Although it is accepted that impaired placental perfusion in complicated pregnancy can slow fetal growth and programme an increased risk of cardiovascular dysfunction at adulthood, the relative contribution of reductions in fetal nutrition and in fetal oxygenation as the triggering stimulus remains unclear. By combining high altitude (HA) with the chick embryo model, we have previously isolated the direct effects of HA hypoxia on embryonic growth and cardiovascular development before hatching. This study isolated the effects of developmental hypoxia on cardiovascular function measured in vivo in conscious adult male and female chickens. Chick embryos were incubated, hatched and raised at sea level (SL, nine males and nine females) or incubated, hatched and raised at HA (seven males and seven females). At 6 months of age, vascular catheters were inserted under general anaesthesia. Five days later, basal blood gas status, basal cardiovascular function and cardiac baroreflex responses were investigated. HA chickens had significantly lower basal arterial PO2 and haemoglobin saturation, and significantly higher haematocrit than SL chickens, independent of the sex of the animal. HA chickens had significantly lower arterial blood pressure than SL chickens, independent of the sex of the animal. Although the gain of the arterial baroreflex was decreased in HA relative to SL male chickens, it was increased in HA relative to SL female chickens. We show that development at HA lowers basal arterial blood pressure and alters baroreflex sensitivity in a sex-dependent manner at adulthood.
We have chosen the name of GYES, one of the mythological giants with one hundred arms,
offspring of Gaia and Uranus, for our instrument study of a multifibre spectrograph for
the prime focus of the Canada-France-Hawaii Telescope. Such an instrument could provide an
excellent ground-based complement for the Gaia mission and a northern complement to the
HERMES project on the AAT. The CFHT is well known for providing a stable prime focus
environment, with a large field of view, which has hosted several imaging instruments, but
has never hosted a multifibre spectrograph. Building upon the experience gained at GÉPI
with FLAMES-Giraffe and X-Shooter, we are investigating the feasibility of a high
multiplex spectrograph (about 500 fibres) over a field of view one degree in diameter. We
are investigating an instrument with resolution in the range 15 000 to 30 000, which
should provide accurate chemical abundances for stars down to 16th magnitude and radial
velocities, accurate to 1 km s-1 for fainter stars. The study is led by
GÉPI-Observatoire de Paris with a contribution from Oxford for the study of the
positioner. The financing for the study comes from INSU CSAA and Observatoire de Paris.
The conceptual study will be delivered to CFHT for review by October 1st 2010.
We have carried out a conceptual design study for a near-infrared
(NIR) wide-field camera and a mid-infrared (MIR) camera-spectrograph
for a 2.5 m telescope at Dome C. The main scientific drivers are the
characterisation of young embedded objects, the evolution of
crystalline silicates in circumstellar disks and the observation of
exoplanet secondary transits. Both instrument exploit the unique
features of Dome C: improved infrared transmission, reduced sky
background, superb seeing, low temperature, and increased
atmospheric stability. The NIR camera covers the wavelength range
0.8–5.5 μm and is optimized for the Kdark and L
bands. The MIR instrument is sensitive in the range 7–40 μm
with a possible extension to the sub-mm. It is optimized for the
Q window, including the Q+ extended portion (25–40 μm) only
observable from the Antarctic Plateau.
The partial contributions of reductions in fetal nutrition and oxygenation to slow fetal growth and a developmental origin of cardiovascular disease remain unclear. By combining high altitude with the chick embryo model, we have previously isolated the direct effects of high-altitude hypoxia on growth. This study isolated the direct effects of high-altitude hypoxia on cardiovascular development. Fertilized eggs from sea-level or high-altitude hens were incubated at sea level or high altitude. Fertilized eggs from sea-level hens were also incubated at high altitude with oxygen supplementation. High altitude promoted embryonic growth restriction, cardiomegaly and aortic wall thickening, effects which could be prevented by incubating eggs from high-altitude hens at sea level or by incubating eggs from sea-level hens at high altitude with oxygen supplementation. Embryos from high-altitude hens showed reduced effects of altitude incubation on growth restriction but not on cardiovascular remodeling. The data show that: (1) high-altitude hypoxia promotes embryonic cardiac and vascular disease already evident prior to hatching and that this is associated with growth restriction; (2) the effects can be prevented by increased oxygenation; and (3) the effects are different in embryos from sea-level or high-altitude hens.
To assess the prevalence and clinical impact of co-morbid social anxiety disorder (SAD) and alcohol use disorders (AUD, i.e. alcohol abuse and alcohol dependence) in a nationally representative sample of adults in the United States.
Data came from a large representative sample of the US population. Face-to-face interviews of 43093 adults residing in households were conducted during 2001–2002. Diagnoses of mood, anxiety, alcohol and drug use disorders and personality disorders were based on the Alcohol Use Disorder and Associated Disabilities Interview Schedule – DSM-IV version.
Lifetime prevalence of co-morbid AUD and SAD in the general population was 2.4%. SAD was associated with significantly increased rates of alcohol dependence [odds ratio (OR) 2.8] and alcohol abuse (OR 1.2). Among respondents with alcohol dependence, SAD was associated with significantly more mood, anxiety, psychotic and personality disorders. Among respondents with SAD, alcohol dependence and abuse were most strongly associated with more substance use disorders, pathological gambling and antisocial personality disorders. SAD occurred before alcohol dependence in 79.7% of co-morbid cases, but co-morbidity status did not influence age of onset for either disorder. Co-morbid SAD was associated with increased severity of alcohol dependence and abuse. Respondents with co-morbid SAD and alcohol dependence or abuse reported low rates of treatment-seeking.
Co-morbid lifetime AUD and SAD is a prevalent dual diagnosis, associated with substantial rates of additional co-morbidity, but remaining largely untreated. Future research should clarify the etiology of this co-morbid presentation to better identify effective means of intervention.
From February to July of 1994, 328 faecal samples from 32 herds were collected and verotoxin-producing Escherichia coli (VTEC) found on 84% of the farms. The proportion of animals infected varied from 0–63%. VTEC were recovered from 52 (20%) of 257 cows and from 16 (23%) of 71 calves. Although the VTEC belonged to 25 different serogroups, 7 (O8. O20, O22, O77, O113, O126 and O162) accounted for 46% of strains. Nearly 45% of the 83 bovine VTEC strains belonged to serogroups associated with haemorrhagic colitis and haemolytic uraernic syndrome in humans. However, only 2 (2%) of 83 VTEC strains isolated from cattle belonged to enterohaemorrhagic E. coli (EHEC) serotypes (O26:H11 and O157:H7), and only 8 (10%) were positive for the attaching and effacing E. coli (eae) gene sequence. Polymerase chain reaction (PCR) showed that 17 (20%) of VTEC strains carried VT1 genes. 43 (52%) possessed VT2 genes, and 23 (28%) carried both VT1 and VT2 genes. Characterization of VTEC isolates revelated a heterogeneous population in terms of serogroup and toxin type in the positive herds. This study confirms that healthy cattle are a reservoir of VTEC, but, the absence of eae genes in most bovine VTEC strains suggests that they may be less virulent for humans than eae-positive EHEC.
Results of industrial converter operation have been analyzed with
several approaches, based on statistics or on the kinetics of the
various reactions. Cogent results have also been obtained through
the follow up of gas emissions. The kinetics models that have been
developed constitute a significant contribution to the implementation
of new strategies for converter operation.