Motivated by upcoming data from astrometric and spectroscopic surveys of the Galaxy, we explore the chemical abundance properties and phase-space distributions in hierarchically formed stellar halo ...simulations set in a CDM universe. Our stellar halo metallicities increase with stellar halo mass. The slope of the Fe/H-M sub(*) trend mimics that of the satellite galaxies that were destroyed to build the halos, implying that the relation propagates hierarchically. All simulated halos contain a significant fraction of old stellar populations accreted more than 10 Gyr ago, and in a few cases some intermediate-age populations exist. In contrast with the Milky Way, many of our simulated stellar halos contain old stellar populations that are metal-rich, originating in the early accretion of massive satellites (M sub(*) 6 10 super(9) M sub( )). We suggest that the (metal-rich) stellar halo of M31 falls into this category, while the more metal-poor halo of the Milky Way is lacking in early massive accretion events. Interestingly, our hierarchically formed stellar halos often have nonnegligible metallicity gradients in both Fe/H and a/Fe. These gradients extend a few tens of kiloparsecs, and can be as large as 0.5 dex in Fe/H and 0.2 dex in a/Fe, with the most metal-poor halo stars typically buried within the central 65 kpc of the galaxy. Finally, we find that chemical abundances can act as a rough substitute for time of accretion of satellite galaxies, and, based on this finding, we propose a criterion for identifying tidal streams spatially by selecting stars with a/Fe ratios below solar.
Very high energy (VHE) Delta *g-ray emission from the flat spectrum radio quasar (FSRQ) PKS 1222+21 (4C 21.35, z = 0.432) was detected with the MAGIC Cherenkov telescopes during a short observation ...(~0.5 hr) performed on 2010 June 17. The MAGIC detection coincides with high-energy MeV/GeV Delta *g-ray activity measured by the Large Area Telescope (LAT) on board the Fermi satellite. The VHE spectrum measured by MAGIC extends from about 70 GeV up to at least 400 GeV and can be well described by a power-law dN/dE E -- Delta *G with a photon index Delta *G = 3.75 ? 0.27stat ? 0.2syst. The averaged integral flux above 100 GeV is (4.6 ? 0.5) X 10--10 cm--2 s--1 (~1 Crab Nebula flux). The VHE flux measured by MAGIC varies significantly within the 30 minute exposure implying a flux doubling time of about 10 minutes. The VHE and MeV/GeV spectra, corrected for the absorption by the extragalactic background light (EBL), can be described by a single power law with photon index 2.72 ? 0.34 between 3 GeV and 400 GeV, and is consistent with emission belonging to a single component in the jet. The absence of a spectral cutoff constrains the Delta *g-ray emission region to lie outside the broad-line region, which would otherwise absorb the VHE Delta *g-rays. Together with the detected fast variability, this challenges present emission models from jets in FSRQs. Moreover, the combined Fermi/LAT and MAGIC spectral data yield constraints on the density of the EBL in the UV-optical to near-infrared range that are compatible with recent models.
While there is a hereditary component to tori, this does not explain all cases. Tori tend to appear more frequently during middle age of life; the torus palatinus is more commonly observed in ...females, but this is not the case with the torus mandibularis. Certain ethnic groups are more prone to one torus or the other. The torus is mainly removed due to prostodontic reasons, as it may also be used as biomaterial, not only in periodontology, but also in implantology. The aim of this study was a review of the literature from the past twenty years.
Cell membrane water permeability is an important determinant of epithelial fluid secretion, tissue swelling, angiogenesis, tumor spread and other biological processes. Cellular water channels, ...aquaporins, are important drug targets. Water permeability is generally measured from the kinetics of cell volume change in response to an osmotic gradient. Here, we developed a microfluidic platform in which cells expressing a cytoplasmic, volume-sensing fluorescent dye are rapidly subjected to an osmotic gradient by solution mixing inside a ~0.1 nL droplet surrounded by oil. The solution mixing time was <10 ms. Osmotic water permeability was deduced from a single, time-integrated fluorescence image of an observation area in which the time after mixing was determined through spatial position. Water permeability was accurately measured in aquaporin-expressing erythrocytes with half-times for osmotic equilibration down to <50 ms. Compared with conventional water permeability measurements using costly stopped-flow instrumentation, the microfluidic platform here utilizes sub-microliter blood sample volume, does not suffer from mixing artifacts, and replaces challenging kinetic measurements by single image capture using a standard laboratory fluorescence microscope.
Prevalence of fibromyalgia and associated factors in Spain Font Gayà, Teresa; Bordoy Ferrer, Carolina; Juan Mas, Antonio ...
Clinical and experimental rheumatology,
2020 Jan-Feb, 20200101, Letnik:
38 Suppl 123, Številka:
1
Journal Article
Recenzirano
The prevalence of fibromyalgia (FM) differs depending on the population studied. The main objective of the EPISER2016 study was to estimate the prevalence of FM in adults in Spain. The secondary ...objective was to evaluate the association with sociodemographic and anthropometric characteristics and smoking.
This is a population-based cross-sectional multicentre study. The random selection was based on multistage stratified cluster sampling. The final sample comprised 4916 persons aged ≥20 years. Participants were contacted by telephone for completion of a screening survey. Investigating rheumatologists evaluated positive results (review of medical records and/or telephone interview, with medical visit if needed) to confirm the diagnosis. Prevalence and 95% confidence interval were calculated, taking into account the sample design. Weighing was applied based on age, sex, and geographic origin. Predictive models were constructed to analyse which sociodemographic, anthropometric and lifestyle variables in the call centre questionnaire were associated with the presence of FM.
602 subjects (12.25%) had a positive screening result for FM, of which 24 were missing (3.99%). A total of 141 cases of FM were recorded. The estimated prevalence was 2.45% (95% CI, 2.06-2.90). Female sex was the variable most associated with FM, with an odds ratio (OR) of 10.156 (95% CI, 5.068-20.352). Peak prevalence was at 60-69 years (p=0.009, OR=6.962). FM was 68% more frequent in obese individuals (OR, 1.689; 95% CI, 1.036-2.755).
The prevalence of FM in adults in Spain barely changed between 2000 and 2016 and it is similar to that observed in Europe as a whole.
Resumen Este estudio tiene por objetivo analizar las prácticas que realiza un profesor con sus estudiantes para resolver un problema de medida de superficies en las que intervienen aspectos de ...carácter metacognitivo. Se diseñó una propuesta didáctica, basada en una metodología de enseñanza por diagnóstico, en la que el profesor propone una tarea para hacer aflorar diferentes significados personales acerca de las magnitudes longitud y superficie, utilizando el tangram de Fletcher. La instrucción fue llevada a cabo en una clase de 26 estudiantes de 14 años que cursaban 2º año de la Educación Secundaria Obligatoria en España. Para el análisis se tomaron, como referente teórico, constructos de metacognición y del Enfoque Ontosemiótico. Entre las conclusiones está que cognición y metacognición pueden ser mejoradas con una instrucción bien planeada y responsablemente ejecutada.
Context. The gamma-ray binary LS I +61°303 is a well-established source from centimeter radio up to very high energy (VHE; E> 100 GeV). The broadband emission shows a periodicity of ~26.5 days, ...coincident with the orbital period. A longer (super-orbital) period of 1667 ± 8 days was proposed from radio variability and confirmed using optical and high-energy (HE; E> 100 MeV) gamma-ray observations. In this paper, we report on a four-year campaign performed by MAGIC together with archival data concentrating on a search for a long-timescale signature in the VHE emission from LS I +61°303. Aims. We focus on the search for super-orbital modulation of the VHE emission, similar to that observed at other energies, and on the search for correlations between TeV emission and an optical determination of the extension of the circumstellar disk. Methods. A four-year campaign has been carried out using the MAGIC telescopes. The source was observed during the orbital phases when the periodic VHE outbursts have occurred (φ = 0.55–0.75, one orbit = 26.496 days). Additionally, we included archival MAGIC observations and data published by the VERITAS collaboration in these studies. For the correlation studies, LS I +61°303 has also been observed during the orbital phases where sporadic VHE emission had been detected in the past (φ = 0.75–1.0). These MAGIC observations were simultaneous with optical spectroscopy from the LIVERPOOL telescope. Results. The TeV flux of the periodical outburst in orbital phases φ = 0.5–0.75 was found to show yearly variability consistent with the long-term modulation of ~4.5 years found in the radio band. This modulation of the TeV flux can be well described by a sine function with a best-fit period of 1610 ± 58 days. The complete data, including archival observations, span two super-orbital periods. There is no evidence for a correlation between the TeV emission and the mass-loss rate of the Be star, but this may be affected by the strong, short-timescale (as short as intra-day) variation displayed by the Hα fluxes.
The Perseus galaxy cluster was observed by the MAGIC Cherenkov telescope for a total effective time of 24.4 hr during 2008 November and December. The resulting upper limits on the gamma-ray emission ...above 100 GeV are in the range of 4.6-7.5 x 10{sup -12} cm{sup -2} s{sup -1} for spectral indices from -1.5 to -2.5, thereby constraining the emission produced by cosmic rays, dark matter annihilations, and the central radio galaxy NGC 1275. Results are compatible with cosmological cluster simulations for the cosmic-ray-induced gamma-ray emission, constraining the average cosmic ray-to-thermal pressure to <4% for the cluster core region (<8% for the entire cluster). Using simplified assumptions adopted in earlier work (a power-law spectrum with an index of -2.1, constant cosmic ray-to-thermal pressure for the peripheral cluster regions while accounting for the adiabatic contraction during the cooling flow formation), we would limit the ratio of cosmic ray-to-thermal energy to E{sub CR}/E{sub th} < 3%. Improving the sensitivity of this observation by a factor of about 7 will enable us to scrutinize the hadronic model for the Perseus radio mini-halo: a non-detection of gamma-ray emission at this level implies cosmic ray fluxes that are too small to produce enough electrons through hadronic interactions with the ambient gas protons to explain the observed synchrotron emission. The upper limit also translates into a level of gamma-ray emission from possible annihilations of the cluster dark matter (the dominant mass component) that is consistent with boost factors of {approx}10{sup 4} for the typically expected dark matter annihilation-induced emission. Finally, the upper limits obtained for the gamma-ray emission of the central radio galaxy NGC 1275 are consistent with the recent detection by the Fermi-LAT satellite. Due to the extremely large Doppler factors required for the jet, a one-zone synchrotron self-Compton model is implausible in this case. We reproduce the observed spectral energy density by using the structured jet (spine-layer) model which has previously been adopted to explain the high-energy emission of radio galaxies.
Low emission zones (LEZ) are an increasingly common, but unevaluated, intervention aimed at improving urban air quality and public health. We investigated the impact of London's LEZ on air quality ...and children's respiratory health.
We did a sequential annual cross-sectional study of 2164 children aged 8–9 years attending primary schools between 2009–10 and 2013–14 in central London, UK, following the introduction of London's LEZ in February, 2008. We examined the association between modelled pollutant exposures of nitrogen oxides (including nitrogen dioxide NO2) and particulate matter with a diameter of less than 2·5 μm (PM2·5) and less than 10 μm (PM10) and lung function: postbronchodilator forced expiratory volume in 1 s (FEV1, primary outcome), forced vital capacity (FVC), and respiratory or allergic symptoms. We assigned annual exposures by each child's home and school address, as well as spatially resolved estimates for the 3 h (0600–0900 h), 24 h, and 7 days before each child's assessment, to isolate long-term from short-term effects.
The percentage of children living at addresses exceeding the EU limit value for annual NO2 (40 μg/m3) fell from 99% (444/450) in 2009 to 34% (150/441) in 2013. Over this period, we identified a reduction in NO2 at both roadside (median −1·35 μg/m3 per year; 95% CI −2·09 to −0·61; p=0·0004) and background locations (−0·97; −1·56 to −0·38; p=0·0013), but not for PM10. The effect on PM2·5 was equivocal. We found no association between postbronchodilator FEV1 and annual residential pollutant attributions. By contrast, FVC was inversely correlated with annual NO2 (−0·0023 L/μg per m3; −0·0044 to −0·0002; p=0·033) and PM10 (−0·0090 L/μg per m3; −0·0175 to −0·0005; p=0·038).
Within London's LEZ, a smaller lung volume in children was associated with higher annual air pollutant exposures. We found no evidence of a reduction in the proportion of children with small lungs over this period, despite small improvements in air quality in highly polluted urban areas during the implementation of London's LEZ. Interventions that deliver larger reductions in emissions might yield improvements in children's health.
National Institute for Health Research Biomedical Research Centre at Guy's and St Thomas' National Health Service (NHS) Foundation Trust and King's College London, NHS Hackney, Lee Him donation, and Felicity Wilde Charitable Trust.
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