11,155 research outputs found

    Group-galaxy correlations in redshift space as a probe of the growth of structure

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    We investigate the use of the cross-correlation between galaxies and galaxy groups to measure redshift-space distortions (RSD) and thus probe the growth rate of cosmological structure. This is compared to the classical approach based on using galaxy auto-correlation. We make use of realistic simulated galaxy catalogues that have been constructed by populating simulated dark matter haloes with galaxies through halo occupation prescriptions. We adapt the classical RSD dispersion model to the case of the group-galaxy cross-correlation function and estimate the RSD parameter β\beta by fitting both the full anisotropic correlation function ξ(rp,π)\xi(r_p,\pi) and its multipole moments. In addition, we define a modified version of the latter statistics by truncating the multipole moments to exclude strongly non-linear distortions at small transverse scales. We fit these three observable quantities in our set of simulated galaxy catalogues and estimate statistical and systematic errors on β\beta for the case of galaxy-galaxy, group-group, and group-galaxy correlation functions. When ignoring off-diagonal elements of the covariance matrix in the fitting, the truncated multipole moments of the group-galaxy cross-correlation function provide the most accurate estimate, with systematic errors below 3% when fitting transverse scales larger than 10Mpc/h10Mpc/h. Including the full data covariance enlarges statistical errors but keep unchanged the level of systematic error. Although statistical errors are generally larger for groups, the use of group-galaxy cross-correlation can potentially allow the reduction of systematics while using simple linear or dispersion models.Comment: 18 pages, 16 figure

    Disinvestment in healthcare: An overview of HTA agencies and organizations activities at European level

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    Background: In an era of a growing economic pressure for all health systems, the interest for "disinvestment" in healthcare increased. In this context, evidence based approaches such as Health Technology Assessment (HTA) are needed both to invest and to disinvest in health technologies. In order to investigate the extent of application of HTA in this field, methodological projects/frameworks, case studies, dissemination initiatives on disinvestment released by HTA agencies and organizations located in Europe were searched. Methods: In July 2015, the websites of HTA agencies and organizations belonging to the European network for HTA (EUnetHTA) and the International Network of Agencies for HTA (INAHTA) were accessed and searched through the use of the term "disinvestment". Retrieved deliverables were considered eligible if they reported methodological projects/frameworks, case studies and dissemination initiatives focused on disinvestment in healthcare. Results: 62 HTA agencies/organizations were accessed and eight methodological projects/frameworks, one case study and one dissemination initiative were found starting from 2007. With respect to methodological projects/frameworks, two were delivered in Austria, one in Italy, two in Spain and three in U.K. As for the case study and the dissemination initiative, both came from U.K. The majority of deliverables were aimed at making an overview of existing disinvestment approaches and at identifying challenges in their introduction. Conclusions: Today, in a healthcare context characterized by resource scarcity and increasing service demand, "disinvestment" from low-value services and reinvestment in high-value ones is a key strategy that may be supported by HTA. The lack of evaluation of technologies in use, in particular at the end of their lifecycle, may be due to the scant availability of frameworks and guidelines for identification and assessment of obsolete technologies that was shown by our work. Although several projects were carried out in different countries, most remain constrained to the field of research. Disinvestment is a relatively new concept in HTA that could pose challenges also from a methodological point of view. To tackle these challenges, it is necessary to construct experiences at international level with the aim to develop new methodological approaches to produce and grow evidence on disinvestment policies and practices

    The synergistic effect between positivity, socio-demographic factors and smoking cessation: results of a cohort study

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    OBJECTIVE: To examine the extent to which a effect does exist between Positivity (POS), smoking and socio-demographic factors in determining quitting smoking in subjects participating in a Group Counselling Program (GCP) for smoking cessation.METHODS: 481 subjects were contacted through a telephone call. A logistic regression analysis was carried out. Possible interaction between sociodemographic variables and POS level was tested using the Synergism Index (SI).RESULTS: For individuals with a POS level over or equal to 3.4 the odds of being smoker was significantly higher among females (OR = 1.55), who smoked at home (OR = 2.16) and lower if there had children at home (OR = 0.53). For individuals with a POS level under 3.4, the only significant variable associated with smoking was beinga female (OR = 2.58). As far concerns the synergistic effect between the variables considered does exist between POS levels and having children at home (SI=1.13) and female gender (SI = 2.8).CONCLUSIONS: The synergistic effect between POS and sociodemographic factors adds evidence on the use of POS as possible determinants of individual happiness

    EPR before EPR: a 1930 Einstein-Bohr thought experiment revisited

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    In 1930 Einstein argued against consistency of the time-energy uncertainty relation by discussing a thought experiment involving a measurement of mass of the box which emitted a photon. Bohr seemingly triumphed over Einstein by arguing that the Einstein's own general theory of relativity saves the consistency of quantum mechanics. We revisit this thought experiment from a modern point of view at a level suitable for undergraduate readership and find that neither Einstein nor Bohr was right. Instead, this thought experiment should be thought of as an early example of a system demonstrating nonlocal "EPR" quantum correlations, five years before the famous Einstein-Podolsky-Rosen paper.Comment: 11 pages, revised, accepted for publication in Eur. J. Phy

    Cataract in professionals exposed to solar radiation: a cross sectional study

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    Purpose: To find out frequency of cataract in seaside workers and possible factors associated to its development. Study Design: Cross sectional observational. Place and Duration of Study: Tyrrhenian coast of Tuscany (Italy), between Rosignano Marittimo and Cecina municipalities in July 2021. Methods: Ninety-eight seaside workers were selected through convenience sampling technique. All the working subjects selected for this study had a bilateral natural vision equal to or greater than 6/10 in the anamnestic data collection, declared they had not eye diseases in the past and rarely used protective glasses during their work. Results: The mean age of 98 outdoor workers is 40. Patients with the cataract are older than people without cataract (median 41 vs 38) (p < 0.001) and have a lower visual acuity (0.6 vs 0.7) (p < 0.001); stratifying by job, refraction state and Intra Ocular Pressure (IOP), there aren’t significant association with cataract. The multivariate analysis confirms that age and visual acuity are associated with the development of the cataract (OR 1.99 and 0.01, respectively). Conclusion: Although senile cataract is an age related disease but Visually significant cataract is seen in persons working outdoors for longer hours

    The Pharmaceutical Industry in 2016. An Analysis of FDA Drug Approvals from a Perspective of the Molecules

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    This is an analysis from a chemical point of view of the 22 drugs accepted by the FDA during 2016. The different drugs from the 2016 "harvest" have been classified according to their chemical structure: antibodies; TIDES (oligonucleotides and peptides); amino acids and natural products; drug combination; and small molecules

    The Pharmaceutical Industry in 2017. An Analysis of FDA Drug Approvals from the Perspective of Molecules

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    This is an analysis from a chemical point of view of the 46 drugs (34 New Chemical Entities and 12 Biologics) approved by the FDA during 2017. The drugs included in the 2017 "harvest" have been classified on the basis of their chemical structure: biologics (antibodies and proteins); peptides; amino acids and natural products; drug combinations; and small molecules
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