On the relevance of numerical simulations to booming sand

We have performed a simulation study of 3D cohesionless granular flows down an inclined chute. We find that the oscillations observed in [L.E. Silbert, Phys. Rev. Lett., 94, 098002 (2005)] near the angle of repose are harmonic vibrations of the lowest normal mode. Their frequencies depend on the contact stiffness as well as on the depth of the flow. Could these oscillations account for the phenomena of "booming sand"? We estimate an effective contact stiffness from the Hertz law, but this leads to frequencies several times higher than observed. However, the Hertz law also predicts interpenetrations of a few nanometers, indicating that the oscillations frequencies are governed by the surface stiffness, which can be much lower than the bulk one. This is in agreement with previous studies ascribing the ability to sing to the presence of a soft coating on the grain surface.Comment: accepted for publication in Physical Review E http://pre.aps.org; Physical Review E (2012) to be publishe

Eating disorder literacy and stigmatising attitudes towards anorexia, bulimia and binge eating disorder among adolescents

Little research has investigated adolescents’ understanding of eating disorders (EDs) or attitudes towards people affected by EDs. This impedes the development of targeted health promotion interventions. In the current study, 290 adolescents viewed a vignette depicting a target with either Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder, Depression or Type 1 Diabetes. Subsequent questionnaires assessed understanding of and attitudes towards the disorder described . Adolescents recognised the symptoms of depression significantly more frequently than any ED. Relative to depression and Type 1 diabetes, participants held targets with EDs more personally responsible for their illness and ascribed them more negative personality characteristics. The data revealed a particularly unfavourable view of Binge Eating Disorder, which was conceptualised as a failure of self-discipline rather than a medical condition. The results confirm previous findings that EDs are more stigmatised than other mental or physical health conditions and extend the findings to an adolescent cohort

Stigma and treatment of eating disorders in Ireland: healthcare professionals' knowledge and attitudes

Objectives: This study examines aspects of health professionals’ knowledge and attitudes about eating disorders (EDs) , which might impede the effective detection or treatment of EDs in Ireland. Methods: 1,916 health professionals were invited to participate in a web-based survey. Participants were randomly allocated to view one of five vignettes depicting a young person with symptoms consistent with Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder, Depression or Type 1 Diabetes. Study-specific questions examined participants’ responses to the vignettes and ED knowledge and experience

Adolescents' and parents' views of Child and Adolescent Mental Health Services (CAMHS) in Ireland

Aim: To explore adolescents’ and parents’ experiences of CAMHS in relation to accessibility, approachability, and appropriateness. Methods: Using a descriptive qualitative design, a combination of focus group and single interviews were conducted with adolescents (n=15) and parents (n=32) from three mental health clinics. Data were transcribed verbatim and analysed using thematic analysis. Results: Accessing mental health services was a challenging experience due to knowledge deficit, lack of information and limited availability of specialist services. Participants desired more information, involvement in decision-making, single and shared consultations, flexible scheduling of appointments, continuity with clinicians, school support and parent support groups. Participants seem to be generally satisfied, however adolescents felt less involved in decision making than they would have liked. Frequent staff changes was problematic as it disrupted continuity of care and hindered the formation of a trusting relationship. Implications for practice: Parents and adolescents expressed similar views of the positive and negative aspects of mental health services. Their need for more information-sharing and involvement in decision-making underline the importance of collaborative practice. Clinician continuity contributed to trusting therapeutic relationships and was valued. These are key principles that with attention, could lead to quality service provision for adolescents and families

Hot Atmospheres, Cold Gas, AGN Feedback and the Evolution of Early Type Galaxies: a Topical Perspective

Most galaxies comparable to or larger than the mass of the Milky Way host hot, X-ray emitting atmospheres, and many such galaxies are radio sources. Hot atmospheres and radio jets and lobes are the ingredients of radio-mechanical active galactic nucleus (AGN) feedback. While a consensus has emerged that such feedback suppresses cooling of hot cluster atmospheres, less attention has been paid to massive galaxies where similar mechanisms are at play. Observation indicates that the atmospheres of elliptical and S0 galaxies were accreted externally during the process of galaxy assembly and augmented significantly by stellar mass loss. Their atmospheres have entropy and cooling time profiles that are remarkably similar to those of central cluster galaxies. About half display filamentary or disky nebulae of cool and cold gas, much of which has likely cooled from the hot atmospheres. We review the observational and theoretical perspectives on thermal instabilities in galactic atmospheres and the evidence that AGN heating is able to roughly balance the atmospheric cooling. Such heating and cooling may be regulating star formation in all massive spheroids at late times.Comment: Final versio

Eating disorder services for young people in Ireland: perspectives of service providers, service users and the general adolescent population

Objectives: This paper illuminates how national eating disorder (ED) policy translates into day-to-day practice by exploring how ED services are experienced by those who deliver and use them. Methods: A mixed-methods approach was used, which combined qualitative and quantitative techniques. The paper collates data from three studies: (i) an interview study exploring the lived experiences of young people with EDs (n =8), their parents (n =5) and their healthcare professionals (n =3); (ii) a national survey of health professionals’ perspectives on existing ED services (n =171); (iii) a nationwide survey of secondary-school students’ eating concerns and patterns of help - seeking (n=290). Results: The qualitative interviews with young people and their parents revealed feelings of isolation and helplessness. Young people expressed interest in patient support groups, while parents desired greater support for the family unit. Parents were highly critical of available services, particularly in relation to access. These criticisms were echoed in the survey of healthcare professionals, who reported many barriers to delivering effective care. Clinicians were almost unanimous in calling for care pathways to be clarified via a standardised treatment protocol. The survey of adolescents indicated widespread reluctance to seek help regarding eating concerns: over one-third expressed concern about their own eating habits, but half of these had not divulged their concerns to anyone. Participants’ preferred pathways of help-seeking revolved around family and friends, and adolescents were unsure about routes of access to professional support. 3 Conclusions: The research demonstrates that many aspects of national ED policy have not been implemented in practice. The paper highlights specific gaps and suggests ways they can be redressed

"Everyone here wants everyone else to get better": the role of social identity in eating disorder recovery

Retention of a positively valued illness identity contributes to poor outcomes for individuals with eating disorders. Consequently, dis-identification from the illness identity and the adoption of a recovery identity is vital for successful recovery. While social identity processes have been shown to influence eating disorder maintenance, their role in recovery is rarely considered. This study explores how a sense of shared identity helps individuals with eating disorders manage their condition and promotes recovery. Transcripts from 18 online support sessions involving 75 participants were thematically analysed. Our findings suggest that the illness identity initially operates as a social identity that forms the basis for connections with similar others. For those wishing to recover, identity-based support is then perceived to be more effective than that found outside the group. Online interactions also facilitate construction of a new shared recovery identity which promotes a shift from the illness identity as a primary source of definition and endorses group norms of illness disclosure and treatment engagement. While in the clinical literature, eating disorder identity is seen as problematic and interventions are targeted at challenging an individual’s self-concept, we suggest that interventions could instead harness identity resources to support a transition to a recovery identity

A Large Atom Number Metastable Helium Bose-Einstein Condensate

We have produced a Bose-Einstein condensate of metastable helium (4He*) containing over 1.5x10^7 atoms, which is a factor of 25 higher than previously achieved. The improved starting conditions for evaporative cooling are obtained by applying one-dimensional Doppler cooling inside a magnetic trap. The same technique is successfully used to cool the spin-polarized fermionic isotope (3He*), for which thermalizing collisions are highly suppressed. Our detection techniques include absorption imaging, time-of-flight measurements on a microchannel plate detector and ion counting to monitor the formation and decay of the condensate.Comment: 4 pages, 3 figures (changed content

Instability of the symmetric Couette-flow in a granular gas: hydrodynamic field profiles and transport

We investigate the inelastic hard disk gas sheared by two parallel bumpy walls (Couette-flow). In our molecular dynamic simulations we found a sensitivity to the asymmetries of the initial condition of the particle places and velocities and an asymmetric stationary state, where the deviation from (anti)symmetric hydrodynamic fields is stronger as the normal restitution coefficient decreases. For the better understanding of this sensitivity we carried out a linear stability analysis of the former kinetic theoretical solution [Jenkins and Richman: J. Fluid. Mech. {\bf 171} (1986)] and found it to be unstable. The effect of this asymmetry on the self-diffusion coefficient is also discussed.Comment: 9 pages RevTeX, 14 postscript figures, sent to Phys. Rev.

The Growth of Black Holes and Bulges at the Cores of Cooling Flows

Central cluster galaxies (cDs) in cooling flows are growing rapidly through gas accretion and star formation. At the same time, AGN outbursts fueled by accretion onto supermassive black holes are generating X-ray cavity systems and driving outflows that exceed those in powerful quasars. We show that the resulting bulge and black hole growth follows a trend that is roughly consistent with the slope of the local (Magorrian) relation between bulge and black hole mass for nearby quiescent ellipticals. However, a large scatter suggests that cD bulges and black holes do not always grow in lock-step. New measurements made with XMM, Chandra, and FUSE of the condensation rates in cooling flows are now approaching or are comparable to the star formation rates, alleviating the need for an invisible sink of cold matter. We show that the remaining radiation losses can be offset by AGN outbursts in more than half of the systems in our sample, indicating that the level of cooling and star formation is regulated by AGN feedback.Comment: 3 pages, 4 figures, to appear in the proceedings of "Heating vs. Cooling in Galaxies and Clusters of Galaxies," edited by H. Boehringer, P. Schuecker, G. W. Pratt, and A. Finogueno