474 research outputs found
The game transfer phenomena scale: an instrument for investigating the nonvolitional effects of video game playing
A variety of instruments have been developed to assess different dimensions of playing videogames and its effects on cognitions, affect, and behaviors. The present study examined the psychometric properties of the Game Transfer Phenomena Scale (GTPS) that assesses non-volitional phenomena experienced after playing videogames (i.e., altered perceptions, automatic mental processes, and involuntary behaviors). A total of 1,736 gamers participated in an online survey used as the basis for the analysis. Confirmatory factor analysis (CFA) was performed to confirm the factorial structure of the GTPS. The five-factor structure using the 20 indicators based on the analysis of gamers’ self-reports fitted the data well. Population cross-validity was also achieved and the positive associations between the session length and overall scores indicate the GTPS warranted criterion-related validity. Although the understanding of GTP is still in its infancy, the GTPS appears to be a valid and reliable instrument for assessing non-volitional gaming-related phenomena. The GTPS can be used for understanding the phenomenology of post-effects of playing videogames
Fluids in cosmology
We review the role of fluids in cosmology by first introducing them in
General Relativity and then by applying them to a FRW Universe's model. We
describe how relativistic and non-relativistic components evolve in the
background dynamics. We also introduce scalar fields to show that they are able
to yield an inflationary dynamics at very early times (inflation) and late
times (quintessence). Then, we proceed to study the thermodynamical properties
of the fluids and, lastly, its perturbed kinematics. We make emphasis in the
constrictions of parameters by recent cosmological probes.Comment: 34 pages, 4 figures, version accepted as invited review to the book
"Computational and Experimental Fluid Mechanics with Applications to Physics,
Engineering and the Environment". Version 2: typos corrected and references
expande
New Constraints (and Motivations) for Abelian Gauge Bosons in the MeV-TeV Mass Range
We survey the phenomenological constraints on abelian gauge bosons having
masses in the MeV to multi-GeV mass range (using precision electroweak
measurements, neutrino-electron and neutrino-nucleon scattering, electron and
muon anomalous magnetic moments, upsilon decay, beam dump experiments, atomic
parity violation, low-energy neutron scattering and primordial
nucleosynthesis). We compute their implications for the three parameters that
in general describe the low-energy properties of such bosons: their mass and
their two possible types of dimensionless couplings (direct couplings to
ordinary fermions and kinetic mixing with Standard Model hypercharge). We argue
that gauge bosons with very small couplings to ordinary fermions in this mass
range are natural in string compactifications and are likely to be generic in
theories for which the gravity scale is systematically smaller than the Planck
mass - such as in extra-dimensional models - because of the necessity to
suppress proton decay. Furthermore, because its couplings are weak, in the
low-energy theory relevant to experiments at and below TeV scales the charge
gauged by the new boson can appear to be broken, both by classical effects and
by anomalies. In particular, if the new gauge charge appears to be anomalous,
anomaly cancellation does not also require the introduction of new light
fermions in the low-energy theory. Furthermore, the charge can appear to be
conserved in the low-energy theory, despite the corresponding gauge boson
having a mass. Our results reduce to those of other authors in the special
cases where there is no kinetic mixing or there is no direct coupling to
ordinary fermions, such as for recently proposed dark-matter scenarios.Comment: 49 pages + appendix, 21 figures. This is the final version which
appears in JHE
Explosive Nucleosynthesis: What we learned and what we still do not understand
This review touches on historical aspects, going back to the early days of
nuclear astrophysics, initiated by BFH and Cameron, discusses (i) the
required nuclear input from reaction rates and decay properties up to the
nuclear equation of state, continues (ii) with the tools to perform
nucleosynthesis calculations and (iii) early parametrized nucleosynthesis
studies, before (iv) reliable stellar models became available for the late
stages of stellar evolution. It passes then through (v) explosive environments
from core-collapse supernovae to explosive events in binary systems (including
type Ia supernovae and compact binary mergers), and finally (vi) discusses the
role of all these nucleosynthesis production sites in the evolution of
galaxies. The focus is put on the comparison of early ideas and present, very
recent, understanding.Comment: 11 pages, to appear in Springer Proceedings in Physics (Proc. of
Intl. Conf. "Nuclei in the Cosmos XV", LNGS Assergi, Italy, June 2018
Nurse moral disengagement
Background: Ethics is a founding component of the nursing profession; however, nurses sometimes find it difficult to constantly adhere to the required ethical standards. There is limited knowledge about the factors that cause a committed nurse to violate standards; moral disengagement, originally developed by Bandura, is an essential variable to consider. Research objectives: This study aimed at developing and validating a nursing moral disengagement scale and investigated how moral disengagement is associated with counterproductive and citizenship behaviour at work. Research design: The research comprised a qualitative study and a quantitative study, combining a crossvalidation approach and a structural equation model. Participants and research context: A total of 60 Italian nurses (63% female) involved in clinical work and enrolled as students in a postgraduate master’s programme took part in the qualitative study. In 2012, the researchers recruited 434 nurses (76% female) from different Italian hospitals using a convenience sampling method to take part in the quantitative study. Ethical considerations: All the organisations involved and the university gave ethical approval; all respondents participated on a voluntary basis and did not receive any form of compensation. Findings: The nursing moral disengagement scale comprised a total of 22 items. Results attested the mono-dimensionality of the scale and its good psychometric properties. In addition, results highlighted a significant association between moral disengagement and both counterproductive and citizenship behaviours
The Formation and Evolution of the First Massive Black Holes
The first massive astrophysical black holes likely formed at high redshifts
(z>10) at the centers of low mass (~10^6 Msun) dark matter concentrations.
These black holes grow by mergers and gas accretion, evolve into the population
of bright quasars observed at lower redshifts, and eventually leave the
supermassive black hole remnants that are ubiquitous at the centers of galaxies
in the nearby universe. The astrophysical processes responsible for the
formation of the earliest seed black holes are poorly understood. The purpose
of this review is threefold: (1) to describe theoretical expectations for the
formation and growth of the earliest black holes within the general paradigm of
hierarchical cold dark matter cosmologies, (2) to summarize several relevant
recent observations that have implications for the formation of the earliest
black holes, and (3) to look into the future and assess the power of
forthcoming observations to probe the physics of the first active galactic
nuclei.Comment: 39 pages, review for "Supermassive Black Holes in the Distant
Universe", Ed. A. J. Barger, Kluwer Academic Publisher
Utilising daily diaries to examine oral health experiences associated with dentine hypersensitivity
Background: The current investigation examined the determinants of oral health experiences associated with dentine hypersensitivity using prospective diary methodology.
Methods: Staff and students from a large UK university who had self-diagnosed dentine hypersensitivity completed an online daily diary and text survey for two weeks recording their mood, oral health-related coping behaviours, coping and pain appraisals, pain experiences and functional limitations. Cross sectional and lagged path analyses were employed to examine relationships.
Results: 101 participants took part in the diary study. Participants had a mean age of 26.3 years (range=18-63) and most were female (N=69). Individuals who used more oral health-related coping behaviours predicted and experienced greater levels of pain on subsequent days. Negative mood also predicted worse pain outcomes. The daily diary method provided a useful avenue for investigating variations in oral health experiences and relationships between variables that can fluctuate daily.
Conclusions: Psychological variables such as coping and mood play an important role in the pain experiences of people with dentine hypersensitivity. The study highlights the benefits of using prospective methods to elucidate the experiences of people with oral condition
Dark Energy Surveyed Year 1 results: calibration of cluster mis-centring in the redMaPPer catalogues
The centre determination of a galaxy cluster from an optical cluster finding algorithm can be offset from theoretical prescriptions or N-body definitions of its host halo centre. These offsets impact the recovered cluster statistics, affecting both richness measurements and the weak lensing shear profile around the clusters. This paper models the centring performance of the redMaPPer cluster finding algorithm using archival X-ray observations of redMaPPer selected clusters. Assuming the X-ray emission peaks as the fiducial halo centres, and through analysing their offsets to the redMaPPer centres, we find that ∼75 ± 8 per cent of the redMaPPer clusters are well centred and the mis-centred offset follows a Gamma distribution in normalized, projected distance. These mis-centring offsets cause a systematic underestimation of cluster richness relative to the well-centred clusters, for which we propose a descriptive model. Our results enable the DES Y1 cluster cosmology analysis by characterizing the necessary corrections to both the weak lensing and richness abundance functions of the DES Y1 redMaPPer cluster catalogue
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Dark Energy Survey Year 1 Results: Tomographic cross-correlations between Dark Energy Survey galaxies and CMB lensing from South Pole Telescope+Planck
We measure the cross-correlation between redMaGiC galaxies selected from the Dark Energy Survey (DES) year 1 data and gravitational lensing of the cosmic microwave background (CMB) reconstructed from South Pole Telescope (SPT) and Planck data over 1289 deg2. When combining measurements across multiple galaxy redshift bins spanning the redshift range of 0.1
Dark energy survey year 1 results: weak lensing shape catalogues
We present two galaxy shape catalogues from the Dark Energy Survey Year 1 data set, covering 1500 deg2 with a median redshift of 0.59. The catalogues cover two main fields: Stripe 82, and an area overlapping the South Pole Telescope survey region. We describe our data analysis process and in particular our shape measurement using two independent shear measurement pipelines, METACALIBRATION and IM3SHAPE. The METACALIBRATION catalogue uses a Gaussian model with an innovative internal calibration scheme, and was applied to riz bands, yielding 34.8M objects. The IM3SHAPE catalogue uses amaximum-likelihood bulge/disc model calibrated using simulations, and was applied to r-band data, yielding 21.9M objects. Both catalogues pass a suite of null tests that demonstrate their fitness for use in weak lensing science. We estimate the 1σ uncertainties in multiplicative shear calibration to be 0.013 and 0.025 for the METACALIBRATION and IM3SHAPE catalogues, respectively
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