106 research outputs found

    Depression and anxiety in adolescents and adults with cystic fibrosis in the UK: A cross-sectional study

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    Background The International Depression/anxiety Epidemiological Study (TIDES) in the UK aimed: (i) to establish the prevalence of anxiety and depression amongst people with CF compared to a normative sample; (ii) to establish the association between mood, demographic and clinical variables; and (iii) to provide guidance for specialist-referral decision-making. Methods Patients (≥ 12 years) completed the Hospital Anxiety and Depression Scale (HADS). CF-HADS scores, expressed as percentiles, were compared with a normative sample. Multiple-regression analysis explored associations between demographic, clinical and mood variables. Results Thirty-nine CF centres recruited 2065 patients. Adults with CF were similar in terms of anxiety and depression to the general population. Adolescents with CF were less anxious and depressed. For adult patients, older age, unemployment for health reasons and poor lung function were associated with disordered mood. Gender-specific CF-percentile scores were calculated. Conclusion Surveillance, with attention to gender and risk factors is advocated. This work provides unique benchmark scores to aid referral decision-making

    The LBDS Hercules sample of mJy radio sources at 1.4 GHz - II. Redshift distribution, radio luminosity function, and the high-redshift cut-off

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    {Abridged} A combination of spectroscopy and broadband photometric redshifts has been used to find the complete redshift distribution of the Hercules sample of millijansky radio sources. These data have been used to examine the evolution of the radio luminosity function (RLF) and its high-redshift cut-off. New redshifts have been measured for eleven sources, and a further ten upper limits are given. The total number of sources with known redshifts in the sample is now 47 (65%). We calculated broadband photometric redshifts for the remaining one-third of the sample. For the luminosity range probed by the present study (P_1.4 > 10^24.5 W/Hz/sr), we use the V/V_max test to show conclusively that there is a deficit of high-redshift (z > 2-2.5) objects. Comparison with the model RLFs of Dunlop & Peacock (1990) shows that our data can now exclude pure luminosity evolution. Two of the models of DP90, and the RLF deduced by direct binning of the data, both favour a luminosity dependence for the high-redshift cut-off, with lower-luminosity sources (P_1.4 \simeq 10^24 W/Hz/sr) in decline by z \simeq 1-1.5 while higher-luminosity sources (P_1.4 \simeq 10^{25-26} W/Hz/sr) decline in comoving number density beyond z \simeq 2-2.5.Comment: Revised version submitted to MNRAS. 16 pages, 12 figure

    Stability analysis of agegraphic dark energy in Brans-Dicke cosmology

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    Stability analysis of agegraphic dark energy in Brans-Dicke theory is presented in this paper. We constrain the model parameters with the observational data and thus the results become broadly consistent with those expected from experiment. Stability analysis of the model without best fitting shows that universe may begin from an unstable state passing a saddle point and finally become stable in future. However, with the best fitted model, There is no saddle intermediate state. The agegraphic dark energy in the model by itself exhibits a phantom behavior. However, contribution of cold dark matter on the effective energy density modifies the state of teh universe from phantom phase to quintessence one. The statefinder diagnosis also indicates that the universe leaves an unstable state in the past, passes the LCDM state and finally approaches the sable state in future.Comment: 15 pages, 12 figure

    Fitting the integrated Spectral Energy Distributions of Galaxies

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    Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time, attempting to keep up with the vastly increased volume and quality of available data. We review here the field of SED fitting, describing the modelling of ultraviolet to infrared galaxy SEDs, the creation of multiwavelength data sets, and the methods used to fit model SEDs to observed galaxy data sets. We touch upon the achievements and challenges in the major ingredients of SED fitting, with a special emphasis on describing the interplay between the quality of the available data, the quality of the available models, and the best fitting technique to use in order to obtain a realistic measurement as well as realistic uncertainties. We conclude that SED fitting can be used effectively to derive a range of physical properties of galaxies, such as redshift, stellar masses, star formation rates, dust masses, and metallicities, with care taken not to over-interpret the available data. Yet there still exist many issues such as estimating the age of the oldest stars in a galaxy, finer details ofdust properties and dust-star geometry, and the influences of poorly understood, luminous stellar types and phases. The challenge for the coming years will be to improve both the models and the observational data sets to resolve these uncertainties. The present review will be made available on an interactive, moderated web page (sedfitting.org), where the community can access and change the text. The intention is to expand the text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics & Space Scienc

    Microstructure and thermal stability of Fe, Ti and Ag implanted Yttria-stabilized zirconia

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    Yttria-stabilized zirconia (YSZ) was implanted with 15 keV Fe or Ti ions up to a dose of 8×1016 at cm−2. The resulting “dopant” concentrations exceeded the concentrations corresponding to the equilibrium solid solubility of Fe2O3 or TiO2 in YSZ. During oxidation in air at 400° C, the Fe and Ti concentration in the outermost surface layer increased even further until a surface layer was formed of mainly Fe2O3 and TiO2, as shown by XPS and ISS measurements. From the time dependence of the Fe and Ti depth profiles during anneal treatments, diffusion coefficients were calculated. From those values it was estimated that the maximum temperature at which the Fe- and Ti-implanted layers can be operated without changes in the dopant concentration profiles was 700 and 800° C, respectively. The high-dose implanted layer was completely amorphous even after annealing up to 1100° C, as shown by scanning transmission electron microscopy. Preliminary measurements on 50 keV Ag implanted YSZ indicate that in this case the amorphous layer recrystallizes into fine grained cubic YSZ at a temperature of about 1000° C. The average grain diameter was estimated at 20 nm, whereas the original grain size of YSZ before implantation was 400 nm. This result implies that the grain size in the surface of a ceramic material can be decreased by ion beam amorphisation and subsequent recrystallisation at elevated temperatures

    Age-related changes in gait biomechanics and their impact on the metabolic cost of walking: Report from a National Institute on Aging workshop

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    Changes in old age that contribute to the complex issue of an increased metabolic cost of walking (mass-specific energy cost per unit distance traveled) in older adults appear to center at least in part on changes in gait biomechanics. However, age-related changes in energy metabolism, neuromuscular function and connective tissue properties also likely contribute to this problem, of which the consequences are poor mobility and increased risk of inactivity-related disease and disability. The U.S. National Institute on Aging convened a workshop in September 2021 with an interdisciplinary group of scientists to address the gaps in research related to the mechanisms and consequences of changes in mobility in old age. The goal of the workshop was to identify promising ways to move the field forward toward improving gait performance, decreasing energy cost, and enhancing mobility for older adults. This report summarizes the workshop and brings multidisciplinary insight into the known and potential causes and consequences of age-related changes in gait biomechanics. We highlight how gait mechanics and energy cost change with aging, the potential neuromuscular mechanisms and role of connective tissue in these changes, and cutting-edge interventions and technologies that may be used to measure and improve gait and mobility in older adults. Key gaps in the literature that warrant targeted research in the future are identified and discussed

    ELECTRIC HYPERFINE INTERACTIONS OF IRON IN DIMERIC STATE IN METALS

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    On présente les résultats d'une étude systématique d'expériences d'implantation de 57Fe dans les métaux des séries de transition 3d, 4d et 5d, à partir d'observations en spectrométrie Mössbauer par électron de conversion. On observe une diminution de la densité électronique sur le fer des dimères, avec le nombre d'électrons périphériques des atomes de la matrice d'accueil. On a aussi mesuré l'effet quadrupolaire sur les dimères. La formation de dimères apparaît comme hautement probable dans les réseaux cfc alors qu'on observe une distribution au hasard dans les réseaux cc.The systematics for data on 57Fe implanted into hosts of the 3d, 4d, and 5d metal series are presented based on conversion electron Mössbauer measurements. The decrease in electron density at the iron nuclei in iron dimers with the number of outer electrons in the host was observed in each series. The quadrupole coupling in dimers was also determined. Iron dimers are formed with an increased probability in fcc lattices, while in bcc lattices the random distribution of impurities seems to be obeyed

    ENHANCEMENT OF MÖSSBAUER LINES BY ACTIVE DATA ACQUISITION

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    On propose un procédé d'acquisition de données actives. La méthode combine un processus fonctionnel instantané et un lissage des données. Un convertisseur analogique digital de type Gaussien est présenté. On obtient ainsi un fort accroissement de l'effet relatif et une diminution significative de la largeur de raie. La durée des temps d'accumulation est aussi largement réduite.A concept of active data acquisition was proposed. The method combines instant functional processing and smoothing of data. A Gaussian-type analog-to-digital converter is presented. A large increase in the relative effect and a significant line narrowing were obtained. The durations of some experiments were greatly reduced

    Cryogenic helium counter of particles

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