2,501 research outputs found
The NuSTAR Extragalactic Surveys: unveiling rare, buried AGNs and detecting the contributors to the peak of the Cosmic X-ray Background
We report on the results of active galactic nuclei (AGNs) detection by NuSTAR
performed in three extragalactic survey fields (COSMOS, UDS, ECDFS) in three
hard bands, namely H1 (8-16 keV), H2 (16-24 keV) and VH (35-55 keV). The
aggregated area of the surveys is deg. While a large number of
sources is detected in the H1 band (72 at the level of reliability), the
H2 band directly probing close to the peak of the Cosmic X-ray Background (CXB)
returns four significant detections, and two tentative, although not
significant, detections are found in the VH band. All the sources detected
above 16 keV are also detected at lower energies. We compute the integral
number counts for sources in such bands, which show broad consistency with
population synthesis models of the CXB. We furthermore identify two
Compton-thick AGNs, one in the COSMOS field, associated with a hard and faint
Chandra source, and one in the UDS field, never detected in the X-ray band
before. Both sources are at the same redshift , which shifts their
Compton-hump into the H1 band, and were previously missed in the usually
employed NuSTAR bands, confirming the potential of using the H1 band to
discover obscured AGNs at in deep surveys.Comment: 12 pages, 5 figures, accepted for publication in The Astrophysical
Journa
Evaluation of a gender-sensitive physical activity programme for inactive men in Ireland: Protocol paper for a pragmatic controlled trial
The excess burden of ill-health, mortality and premature death experienced by many men, and poorer men in particular, across the developed world has prompted calls for the development of gender sensitised health related services for men. An emergent body of evidence indicates that successful public health work with men can be accomplished when it utilises elements with which men are familiar and secure. In particular, physical activity (PA) is proven here to be a useful ‘hook’ to engage men. ‘Men on the Move’ (MoM) is a community-based PA programme designed to engage inactive men to improve their overall health and well-being. The MoM programme was delivered by practitioner partnerships in diverse communities and among diverse groups of men under ‘real world’ conditions to assess both its efficacy and replicability with a view to scaling-up the programme nationally for population wide impact. Establishing appropriate protocols is critical when conducting research that translates into practice, is replicable in practice and can be disseminated at a population level. The purpose of this paper is to detail the protocols used in the design, implementation and evaluation of the MoM programme. Specifically, the process of engaging men in a community based PA intervention and sustaining that engagement over the 12 weeks and the protocols used to evaluate the impact of participation in MoM on biopsychosocial health up to 52 weeks will be outlined. If the intervention proves successful, gender-sensitive community based PA interventions for men could be a promising avenue to address their health needs. These findings may be of support to both practitioners endeavouring to engage men and others engaged in translational research to ensure their research translates to meaningful action in practice
The impact of a gender-specific physical activity intervention on the fitness and fatness profile of men in Ireland
Background: Amid increasing concerns about rising obesity rates and unhealthy lifestyle behaviours, physical activity (PA) is seen as a prophylactic to many chronic conditions affecting men. Men respond best to community-based PA programmes, using gender-specific promotional and delivery strategies. ‘Men on the Move’ (MOM) was developed on this basis and targeted inactive adult men in Ireland.
Methods: Sedentary men (n=927; age=50.7±10.9yr; Weight=92.7±16.0kg; METS=6.06±2.13) were recruited across 8 counties; 4 ‘intervention group’ (IG; n=501), and 4 ‘comparison-in-waiting group’ (CG; n=426). The MOM programme involved structured group exercise twice weekly for 12 weeks, along with health-related workshops with the groups maintained up to 52W. Primary outcome measures (aerobic fitness, bodyweight and waist circumference (WC)) together with self-administered questionnaires were used to gather participant data at baseline, 12, 26 and 52 weeks (W).
Results: Results show a net positive effect on aerobic fitness, bodyweight and WC, with significant (p<0.05) net change scores observed in the IG compared to the CG (METS: 12W=+2.20, 26W=+1.89, 52W=+0.92; Weight: 12W=-1.72kg, 26W=-1.95kg, 52W=-1.89kg; WC: 12W=-4.54cm, 26W=-2.69cm, 52W=-3.16cm). The corresponding reduction in cardiovascular disease risk is particularly significant in the context of a previously inactive and overweight cohort. The high ‘dropout’ (42.7% presenting at 52W) however, is of particular concern, with ‘dropouts’ having lower levels of aerobic fitness and higher bodyweight/WC at baseline.
Conclusions: Notwithstanding dropout issues, findings address an important gap in public health practice by informing the translational scale-up of a small controllable gender-specific PA intervention, MOM, to a national population based PA intervention targeting inactive men
Effect of topography on subglacial discharge and submarine melting during tidewater glacier retreat.
-We explored secular variations in subglacial discharge and submarine melting with an idealized model
-Subglacial discharge increases as tidewater glaciers retreat along retrograde beds
-Submarine melting depends on subglacial discharge and therefore promotes unstable retreat on
retrograde bedsTo first order, subglacial discharge depends on climate, which determines precipitation fluxes and glacier mass balance, and the rate of glacier volume change. For tidewater glaciers, large and rapid changes in glacier volume can occur independent of climate change due to strong glacier dynamic feedbacks. Using an idealized tidewater glacier model, we show that these feedbacks produce secular variations in subglacial discharge that are influenced by subglacial topography. Retreat along retrograde bed slopes (into deep water) results in rapid surface lowering and coincident increases in subglacial
discharge. Consequently, submarine melting of glacier termini, which depends on subglacial discharge and ocean thermal forcing, also increases during retreat into deep water. Both subglacial discharge and submarine melting subsequently decrease as glacier termini retreat out of deep water and approach new
steady state equilibria. In our simulations, subglacial discharge reached peaks that were 6–17% higher than preretreat values, with the highest values occurring during retreat from narrow sills, and submarine melting increased by 14% for unstratified fjords and 51% for highly stratified fjords. Our results therefore
indicate that submarine melting acts in concert with iceberg calving to cause tidewater glacier termini to be unstable on retrograde beds. The full impact of submarine melting on tidewater glacier stability remains uncertain, however, due to poor understanding of the coupling between submarine melting and iceberg calving.Funding was provided by the National Oceanic and Atmospheric Association
(NA13OAR4310098) and the U.S. National Science Foundation (PLR-1504288 and PLR-1504521).Ye
A quantum mechanical relation connecting time, temperature, and cosmological constant of the universe: Gamow's relation revisited as a special case
Considering our expanding universe as made up of gravitationally interacting
particles which describe particles of luminous matter and dark matter and dark
energy which is described by a repulsive harmonic potential among the points in
the flat 3-space, we derive a quantum mechanical relation connecting,
temperature of the cosmic microwave background radiation, age, and cosmological
constant of the universe. When the cosmological constant is zero, we get back
the Gamow's relation with a much better coefficient. Otherwise, our theory
predicts a value of the cosmological constant
when the present values of cosmic microwave background temperature of 2.728 K
and age of the universe 14 billion years are taken as input.Comment: 4 pages, 1 figure, Study of the Universe from a condensed matter
point of view, section III corrected with a single body potentia
Geometrical Constraints on the Cosmological Constant
The cosmological constant problem is examined under the assumption that the
extrinsic curvature of the space-time contributes to the vacuum. A compensation
mechanism based on a variable cosmological term is proposed. Under a suitable
hypothesis on the behavior of the extrinsic curvature, we find that an
initially large rolls down rapidly to zero during the early stages
of the universe. Using perturbation analysis, it is shown that such vacuum
behaves essentially as a spin-2 field which is independent of the metric.Comment: [email protected], 17 pages, Latex, 2 figures obtained by reques
South-South Cooperation and Neo-liberal hegemony in a Post-aid world
YesSouth-South Cooperation SSC) has returned as a significant trope in the contemporary
rhetoric of the aid industry. We compare the way that the idea of SSC is being currently
constructed. In the 1960s and 1970s, SSC was discussed as constituting a challenge to the
ideological dominance of the global north, presented initially as a counter-hegemonic
challenge to neo-colonialism. Currently it is framed similarly as a challenge to neoliberalism.
However, the current iteration of SSC differs fundamentally from the first round in the early
1970s, largely because of differences in assumptions about who is co-operating with whom
and to what end, in the context of SSC. These differences are significant for the material
practice of SSC and the ideological function of SSC rhetoric
Meeple Centred Design: A Heuristic Toolkit for Evaluating the Accessibility of Tabletop Games
Evaluation of accessibility within a tabletop context is much more complicated than it is within a video game environment. There is a considerable amount of variation in game systems, game mechanisms, and interaction regimes. Games may be entirely verbal, or completely non-verbal. They might be real-time or turn based, or based on simultaneous actions. They can be competitive or co-operative, or shift from one to the other during a single game session. They might involve visual pattern recognition or force players to memorise game state without visual cues. They may involve touch, or smell. They might involve social deduction or betrayal. They can encompass all sensory faculties, in differing degrees. Almost all games have accessibility considerations that should be taken into account, but there is currently no comprehensive tool by which this can be done that encompasses the rich variety of tabletop gaming interaction metaphors. In this paper, the authors discuss the heuristic lens that is used by the Meeple Centred Design tabletop accessibility project. This is a tool that has been applied to one hundred and sixteen games to date, and the full results of these have been published for analysis and consideration within the wider tabletop gaming community
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