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61 papers found.
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Evolutionary sequences of stellar models with new radiative opacities. VI.

We present a large grid of stellar evolutionary models with the initial chemical composition . These tracks are conceived to extend the grid of stellar models described in the previous papers of this series, and are computed with the new radiative opacities by Iglesias et al. (1992) and convective overshoot. The tracks span the range of initial masses from to , and extend from...

Impact of metallicity on the evolution of young star clusters

We discuss the results of N-body simulations of intermediate-mass young star clusters (SCs) with three different metallicities (Z = 0.01, 0.1 and 1 Z⊙), including metallicity-dependent stellar evolution recipes and metallicity-dependent prescriptions for stellar winds and remnant formation. The initial half-mass relaxation time of the simulated young SCs (∼10 Myr) is comparable...

Extraction of high-quality DNA from ethanol-preserved tropical plant tissues

Background Proper conservation of plant samples, especially during remote field collection, is essential to assure quality of extracted DNA. Tropical plant species contain considerable amounts of secondary compounds, such as polysaccharides, phenols, and latex, which affect DNA quality during extraction. The suitability of ethanol (96% v/v) as a preservative solution prior to DNA...

Socioeconomic Disadvantage Moderates the Association between Peripheral Biomarkers and Childhood Psychopathology

Background Socioeconomic disadvantage (SED) has been consistently associated with early life mental health problems. SED has been shown to impact multiple biological systems, including the regulation of neurotrophic proteins, immune-inflammatory and oxidative stress markers, which, conversely, have been reported to be relevant to physiological and pathological neurodevelopment...

Combined photometric and asteroseismic constraints on the properties of NGC 6791

. Hekker , S. Mathur , R.A. García , T.R. Bedding , H. Kjeldsen et al., ApJ 737 , L10 ( 2011 ) [5] A. Bressan , P. Marigo , L. Girardi , B. Salasnich , C. Dal Cero , S. Rubele , A. Nanni , MNRAS 427 , 127

Evaluating the effectiveness of a training program that builds teachers’ capability to identify and appropriately refer middle and high school students with mental health problems in Brazil: an exploratory study

Background In Brazil, like many countries, there has been a failure to identify mental health problems (MHP) in young people and refer them to appropriate care and support. The school environment provides an ideal setting to do this. Therefore, effective programs need to be developed to train teachers to identify and appropriately refer children with possible MHP. We aimed to...

Effect of Chromosome Tethering on Nuclear Organization in Yeast

Interphase chromosomes in Saccharomyces cerevisiae are tethered to the nuclear envelope at their telomeres and to the spindle pole body (SPB) at their centromeres. Using a polymer model of yeast chromosomes that includes these interactions, we show theoretically that telomere attachment to the nuclear envelope is a major determinant of gene positioning within the nucleus only for...

The Salt Overly Sensitive (SOS) Pathway: Established and Emerging Roles

Soil salinity is a growing problem around the world with special relevance in farmlands. The ability to sense and respond to environmental stimuli is among the most fundamental processes that enable plants to survive. At the cellular level, the Salt Overly Sensitive (SOS) signaling pathway that comprises SOS3, SOS2, and SOS1 has been proposed to mediate cellular signaling under...

The Impact of Healthy Parenting As a Protective Factor for Posttraumatic Stress Disorder in Adulthood: A Case-Control Study

Background Early life social adversity can influence stress response mechanisms and is associated with anxious behaviour and reductions in callosal area later in life. Objective To evaluate the association between perceptions of parental bonding in childhood/adolescence, hypothalamic-pituitary-adrenal (HPA) axis response, and callosal structural integrity in adult victims of...

Ultra-luminous X-ray sources and remnants of massive metal-poor stars

Massive metal-poor stars might form massive stellar black holes (BHs), with mass 25 ≤mBH/M⊙≤ 80, via direct collapse. We derive the number of massive BHs (NBH) that are expected to form per galaxy through this mechanism. Such massive BHs might power most of the observed ultra-luminous X-ray sources (ULXs). We select a sample of 64 galaxies with X-ray coverage, measurements of the...

Starburst evolution: free–free absorption in the radio spectra of luminous IRAS galaxies

We describe radio observations at 244 and 610 MHz of a sample of 20 luminous and ultra-luminous IRAS galaxies. These are a subset of a sample of 31 objects that have well-measured radio spectra up to at least 23 GHz. The radio spectra of these objects below 1.4 GHz show a great variety of forms and are rarely a simple power-law extrapolation of the synchrotron spectra at higher...

A Saccharomyces cerevisiae Assay System to Investigate Ligand/AdipoR1 Interactions That Lead to Cellular Signaling

Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a Saccharomyces cerevisiae based method for investigating agonist-AdipoR interactions that is amenable for high-throughput scale-up and can be used...

PopStar I: evolutionary synthesis model description

We present new evolutionary synthesis models for simple stellar populations for a wide range of ages and metallicities. The models are based on the Padova isochrones. The core of the spectral library is provided by the medium resolution Lejeune et al. atmosphere models. These spectra are complemented by Non Local Thermodynamic Equilibrium (NLTE) atmosphere models for hot stars...

Epidemiology of Psychotropic Drug Use in Rio de Janeiro, Brazil: Gaps in Mental Illness Treatments

Objective Estimate the prevalence of psychotropic drugs use in the city of Rio de Janeiro, Brazil, and establish its relationship with the presence of mental disorders. Methods A probabilistic sample of non-institutionalized individuals, from the general population of Rio de Janeiro (n = 1208;turn out:81%), 15 years or older, who were interviewed using the Composite International...

Mid-infrared colour gradients and the colour–magnitude relation in Virgo early-type galaxies

We make use of Spitzer imaging between 4 and 16 μm and near-infrared data at 2.2 μm to investigate the nature and distribution of the mid-infrared emission in a sample of early-type galaxies (ETGs) in the Virgo cluster. These data allow us to conclude, with some confidence, that the emission at 16 μm in passive ETGs is stellar in origin, consistent with previous work concluding...

Increased Amygdalar and Hippocampal Volumes in Young Adults with Social Anxiety

Background Functional neuroimaging studies have consistently shown abnormal limbic activation patterns in socially anxious individuals, but structural data on the amygdala and hippocampus of these patients are scarce. This study explored the existence of structural differences in the whole brain, amygdala, and hippocampus of subjects with clinical and subthreshold social anxiety...

Linkage Replication for Chromosomal Region 13q32 in Schizophrenia: Evidence from a Brazilian Pilot Study on Early Onset Schizophrenia Families

We report analyses of a Brazilian study of early onset schizophrenia (BEOS) families. We genotyped 22 members of 4 families on a linkage SNP array and report here non-parametric linkage analyses using MERLIN® software. We found suggestive evidence for linkage on two chromosomal regions, 13q32 and 11p15.4. A LOD score of 2.71 was observed at 13q32 with a one LOD interval extending...

Nearby early-type galaxies with ionized gas - IV. Origin and powering mechanism of the ionized gas

Aims. A significant fraction of early-type galaxies (ETGs) exhibit emission lines in their optical spectra. We attempt to identify the producing the emission mechanism and the ionized gas in ETGs, and its connection with the host galaxy evolution.Methods. We analyzed intermediate-resolution optical spectra of 65 ETGs, mostly located in low density environments and exhibiting...

First star formation with dark matter annihilation

We include an energy term based on dark matter (DM) self-annihilation during the cooling and subsequent collapse of the metal-free gas, in haloes hosting the formation of the first stars in the Universe. We find that the feedback induced on the chemistry of the cloud does modify the properties of the gas throughout the collapse. However, the modifications are not dramatic, and...