49 research outputs found
Metabolic Syndrome as a Cardiovascular Disease Risk Factor: Patients Evaluated in Primary Care
To estimate the prevalence of metabolic syndrome (MS) in a population receiving attention in primary care centers (PCC) we selected a random cohort of ostensibly normal subjects from the registers of 5 basic-health area (BHA) PCC. Diagnosis of MS was with the WHO, NCEP and IDF criteria. Variables recorded were: socio-demographic data, CVD risk factors including lipids, obesity, diabetes, blood pressure and smoking habit and a glucose tolerance test outcome. Of the 720 individuals selected (age 60.3 ± 11.5 years), 431 were female, 352 hypertensive, 142 diabetic, 233 pre-diabetic, 285 obese, 209 dyslipemic and 106 smokers. CVD risk according to the Framingham and REGICOR calculation was 13.8 ± 10% and 8.8 ± 9.8%, respectively. Using the WHO, NCEP and IDF criteria, MS was diagnosed in 166, 210 and 252 subjects, respectively and the relative risk of CVD complications in MS subjects was 2.56. Logistic regression analysis indicated that the MS components (WHO set), the MS components (IDF set) and the female gender had an increased odds ratio for CVD of 3.48 (95CI%: 2.26–5.37), 2.28 (95%CI: 1.84–4.90) and 2.26 (95%CI: 1.48–3.47), respectively. We conclude that MS and concomitant CVD risk is high in ostensibly normal population attending primary care clinics, and this would necessarily impinge on resource allocation in primary care
Biases in abundance derivations for metal-rich nebulae
Using ab-initio photoionization models of giant HII regions, we test methods
for abundance determinations based on a direct measurement of the electron
temperature, now possible even for moderate to high-metallicity objects. We
find that, for metallicities larger than solar, the computed abundances deviate
systematically from the real ones, generally by larger amounts for more
metal-rich HII regions. We discuss the reasons for this, and present diagrams
allowing the reader to better understand the various factors coming into play.
We briefly discuss less classical methods to derive abundances in metal-rich
HII regions. In particular, we comment on the interest of the oxygen and carbon
recombination lines. We also show that, contrary to the case of giant HII
regions, the physical conditions in bright extragalactic planetary nebulae are
such that their chemical composition can be accurately derived even at high
metallicities. Thus, extragalactic planetary nebulae are promising potential
probes of the metallicity of the interstellar medium in the internal parts of
spiral galaxies as well as in metal-rich elliptical galaxies.Comment: 15 pages, 13 figures, Accepted for publication in A&
A modern guide to quantitative spectroscopy of massive OB stars
Quantitative spectroscopy is a powerful technique from which we can extract
information about the physical properties and surface chemical composition of
stars. In this chapter, I guide the reader through the main ideas required to
get initiated in the learning process to become an expert in the application of
state-of-the-art quantitative spectroscopic techniques to the study of massive
OB stars.
NB: This chapter is intended to serve to young students as a first approach
to a field which has attracted my attention during the last 20 years. I should
note that, despite its importance, at present, the number of real experts in
the field around the world is limited to less than 50 people, and about one
third of them are close to retirement. Hence, I consider that this is a good
moment to write a summary text on the subject to serve as guideline for the
next generations of students interested in joining the massive star crew. If
you are one of them, please, use this chapter as a first working notebook. Do
not stop here. Dig also, for further details, into the literature I quote along
the text. And, once there, dig even deeper to find all the original sources
explaining in more detail the physical and technical concepts that are
presently incorporated into our modern (almost) automatized tools.Comment: Accepted for publication in the book "Reviews in Frontiers of Modern
Astrophysics: From Space Debris to Cosmology" (eds Kabath, Jones and Skarka;
publisher Springer Nature) funded by the European Union Erasmus+ Strategic
Partnership grant "Per Aspera Ad Astra Simul" 2017-1-CZ01-KA203-03556
Biological invasion of European tomato crops by Tuta absoluta: ecology, geographic expansion and prospects for biological control
MUSE 3D spectroscopy of BA-type supergiants in NGC 300
We present the results obtained using spectroscopic data taken with the intermediateresolution Multi Unit Spectroscopic Explorer (MUSE) of B and A-type supergiants and bright giants in the Sculptor Group galaxy NGC 300. For our analysis, a hybrid local thermodynamic equilibrium (LTE) line-blanketing+non-LTE method was used to improve the previously published results for the same data. In addition, we present some further applications of this work, which includes extending the flux-weighted gravity luminosity relationship (FGLR), a distance determination method for supergiants. This pioneering work opens up a new window to explore this relation, and also demonstrates the enorm
MUSE crowded field 3D spectroscopy in NGC 300 II. Quantitative spectroscopy of BA-type supergiants
Aims. A quantitative spectral analysis of BA-type supergiants and bright giants in an inner spiral arm region of the nearby spiral galaxy NGC 300 is presented, based on observations with the Multi Unit Spectroscopic Explorer (MUSE) on the European Southern Obsevatory, Very Large Telescope. The flux-weighted gravity–luminosity relationship (FGLR), a stellar spectroscopic distance determination method for galaxies, is extended towards stars at lower luminosities.
Methods. Point spread function fitting 3D spectroscopy was performed with PampelMUSE on the datacube. The 16 stars with the highest signal-to-noise ratios are classified with regard to their spectral type and luminosity class using Galactic templates. They were analysed using hybrid non-local thermodynamic equilibrium model spectra to fit the strongest observed hydrogen, helium, and metal lines in the intermediate-resolution spectra. Supplemented by photometric data, this facilitates fundamental stellar parameters and interstellar reddening which have yet to be determined.
Results. Effective temperatures, surface gravities, reddening E(B−V), bolometric magnitudes and luminosities, as well as radii and masses are presented for the sample stars. The majority of the objects follow the FGLR as established from more luminous BA-type supergiants in NGC 300. An increase in the scatter in the flux-weighted gravity–luminosity plane is observed at these lower luminosities, which is in line with predictions from population synthesis models
Probing nucleation, reverse annealing, and chaperone function along the reaction path of HIV-1 single-strand transfer
Reverse transcription of the HIV-1 genome involves several nucleic acid rearrangement steps that are catalyzed (chaperoned) by the nucleocapsid protein (NC), including the annealing of the transactivation response region (TAR) RNA of the genome to the complementary sequence (TAR DNA) in minus-strand strong-stop DNA. It has been extremely challenging to obtain unambiguous mechanistic details on the annealing process at the molecular level because of the kinetic involvement of a complex and heterogeneous set of nucleic acid/protein complexes of variable structure and variable composition. Here, we investigate the in vitro annealing mechanism using a multistep single-molecule spectroscopy kinetic method. In this approach, an immobilized hairpin is exposed to a multistep programmed concentration sequence of NC, model complementary targeted-oligonucleotides, and buffer-only solutions. The sequence controllably “drags” single immobilized TAR hairpins among the kinetic stable states of the reaction mechanism; i.e., reactants, intermediates, and products. This single-molecule spectroscopy method directly probes kinetic reversibility and the chaperone (catalytic) role of NC at various stages along the reaction sequence, giving access to previously inaccessible kinetic processes and rate constants. By employing target oligonucleotides for specific TAR regions, we kinetically trap and investigate structural models for putative nucleation complexes for the annealing process. The new results lead to a more complete and detailed understanding of the ability of NC to promote nucleic acid/nucleic acid rearrangement processes. This includes information on the ability of NC to chaperone “reverse annealing” in single-strand transfer and the first observation of partially annealed, conformational substates in the annealing mechanism