Phonon sidebands of color centers in hexagonal boron nitride

Low temperature photoluminescence spectra of a color center in hexagonal boron nitride are analyzed. The acoustic phonon sideband can be described by a deformation coupling proportional to strain to a phonon bath that is effectively two dimensional. The optical phonon band is described by Frohlich coupling to the LO-branches, and a deformation coupling proportional to lattice displacement for the TO-branch. The resonances expressed in the optical band vary from defect to defect, in some emitters, coupling to out-of-plane polarized phonons is reported.Comment: 7 pages, 4 fig

Book reviews

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Peering Forward, 10 Years After: International Policy and Consumer Credit Regulation

A key change since the financial crisis of 2008 is the internationalization of interest in consumer finance. International institutions monitor household credit because of its impact on financial stability and market expansion. Macroprudential concerns drove this interest, resulting in a sea change in approaches to consumer credit regulation in many jurisdictions. This article critically analyses the emerging international policy paradigm, contrasting pre-and post-crisis regulatory approaches and highlighting continuing tensions about key policy choices. It then uses two recent sites of contestation, debt adjustment and the regulation of high-cost credit to demostrate the persistence of conflict over the positioning of consumers within an emergent stability focused paradigm of financial consumer protection

X-ray spectroscopy and photometry of the long-period polar AI Tri with XMM-Newton

Context. The energy balance of cataclysmic variables with strong magnetic fields is a central subject in understanding accretion processes on magnetic white dwarfs. With XMM-Newton, we perform a spectroscopic and photometric study of soft X-ray selected polars during their high states of accretion. Aims. On the basis of X-ray and optical observations of the magnetic cataclysmic variable AI Tri, we derive the properties of the spectral components, their flux contributions, and the physical structure of the accretion region in soft polars. Methods. We use multi-temperature approaches in our xspec modeling of the spectra to describe the physical conditions and the structures of the post-shock accretion flow and the accretion spot on the white-dwarf surface. In addition, we investigate the accretion geometry of the system by a timing analysis of the photometric data. Results. Flaring soft X-ray emission from the heated surface of the white dwarf dominates the X-ray flux during roughly 70% of the binary cycle. This component deviates from a single black body and can be described by a superimposition of mildly absorbed black bodies with a Gaussian temperature distribution. In addition, weaker hard X-ray emission is visible nearly all the time. The spectrum from the cooling post-shock accretion flow is most closely fitted by a combination of thermal plasma mekal models with temperature profiles adapted from prior stationary two-fluid hydrodynamic calculations. The soft X-ray light curves show a dip during the bright phase, which can be interpreted as self-absorption in the accretion stream. Phase-resolved spectral modeling supports the picture of one-pole accretion and self-eclipse. One of the optical light curves corresponds to an irregular mode of accretion. During a short XMM-Newton observation at the same epoch, the X-ray emission of the system is clearly dominated by the soft component.Comment: A&A, in press; 11 pages, 9 figures, 3 table

XMM-Newton observations of the X-ray soft polar QS Telescopii

Context. On the basis of XMM-Newton observations, we investigate the energy balance of selected magnetic cataclysmic variables, which have shown an extreme soft-to-hard X-ray flux ratio in the ROSAT All-Sky Survey. Aims. We intend to establish the X-ray properties of the system components, their flux contributions, and the accretion geometry of the X-ray soft polar QS Tel. In the context of high-resolution X-ray analyses of magnetic cataclysmic variables, this study will contribute to better understanding the accretion processes on magnetic white dwarfs. Methods. During an intermediate high state of accretion of QS Tel, we have obtained 20 ks of XMM-Newton data, corresponding to more than two orbital periods, accompanied by simultaneous optical photometry and phase-resolved spectroscopy. We analyze the multi-wavelength spectra and light curves and compare them to former high- and low-state observations. Results. Soft emission at energies below 2 keV dominates the X-ray light curves. The complex double-peaked maxima are disrupted by a sharp dip in the very soft energy range (0.1-0.5 keV), where the count rate abruptly drops to zero. The EPIC spectra are described by a minimally absorbed black body at 20 eV and two partially absorbed MEKAL plasma models with temperatures around 0.2 and 3 keV. The black-body-like component arises from one mainly active, soft X-ray bright accretion region nearly facing the mass donor. Parts of the plasma emission might be attributed to the second, virtually inactive pole. High soft-to-hard X-ray flux ratios and hardness ratios demonstrate that the high-energy emission of QS Tel is substantially dominated by its X-ray soft component.Comment: Accepted for publication in Astronomy and Astrophysics. 7 pages, 4 figures, 2 table

Six month durability of targeted cognitive training supplemented with social cognition exercises in schizophrenia.

Background:Deficits in cognition, social cognition, and motivation are significant predictors of poor functional outcomes in schizophrenia. Evidence of durable benefit following social cognitive training is limited. We previously reported the effects of 70 h of targeted cognitive training supplemented with social cognitive exercises (TCT + SCT) verses targeted cognitive training alone (TCT). Here, we report the effects six months after training. Methods:111 participants with schizophrenia spectrum disorders were randomly assigned to TCT + SCT or TCT-only. Six months after training, thirty-four subjects (18 TCT + SCT, 16 TCT-only) were assessed on cognition, social cognition, reward processing, symptoms, and functioning. Intent to treat analyses was used to test the durability of gains, and the association of gains with improvements in functioning and reward processing were tested. Results:Both groups showed durable improvements in multiple cognitive domains, symptoms, and functional capacity. Gains in global cognition were significantly associated with gains in functional capacity. In the TCT + SCT group, participants showed durable improvements in prosody identification and reward processing, relative to the TCT-only group. Gains in reward processing in the TCT + SCT group were significantly associated with improvements in social functioning. Conclusions:Both TCT + SCT and TCT-only result in durable improvements in cognition, symptoms, and functional capacity six months post-intervention. Supplementing TCT with social cognitive training offers greater and enduring benefits in prosody identification and reward processing. These results suggest that novel cognitive training approaches that integrate social cognitive exercises may lead to greater improvements in reward processing and functioning in individuals with schizophrenia

What are the key influences and challenges around weight management faced by patients in UK adult secure mental health settings? A focused ethnographic approach

Objectives Excess weight is highly prevalent in secure (forensic) mental health services and impacts negatively on patients’ physical and mental health. This study sought to identify the key influences and challenges around weight management in United Kingdom (UK) adult secure mental health settings. Design Qualitative focussed ethnography. Analysis of written fieldnotes was undertaken through a combined inductive and deductive approach, informed by thematic analysis. Setting Low secure male mental health ward and associated patient activities and events, in a National Health Service (NHS) Trust delivering mental health, intellectual disability and neurorehabilitation services in the UK. Participants Twelve males (primarily White British) on the low secure ward; other male participants from low and medium secure services, who took part in group events and activities; and multidisciplinary low and medium secure services staff. Approximately 23 hours of observation were undertaken over a six-month period from April 2022. Results Secure mental healthcare delivered an overall ‘obesogenic’ environment, predisposing patients to excessive weight gain and sedentary behaviour, which was often perceived as inevitable. Key themes highlighted the heightened salience of food in secure settings; inadequacy of catered hospital food and shortcomings of alternative food options; limited physical activity opportunities; and understaffing. Ward culture was not conducive to healthy behaviours. Perceptions and behaviour towards the ethnographer were primarily positive and accepting. Conclusions Weight management in secure services is a complex challenge. In future, whole settingbased interventions to promote healthy weight are likely to be required. These should integrate physical and mental health, incorporate underpinning determinants such as adequate staffing and a culture promoting weight management, and involve both patients and staff

Understanding weight management in adult secure mental health services: findings from a mixed-methods study in Northern England

Obesity and associated morbidity and mortality are major challenges for people with severe mental illness (SMI, including schizophrenia and bipolar disorder), particularly in secure (forensic) mental healthcare (patients who have committed a crime or have threatening behaviour). This research aimed to explore experiences of obesity in secure mental health settings, through a survey, focus groups and interviews. The survey was delivered to secure mental healthcare staff in a National Health Service (NHS) mental health trust in Northern England, and received 79 responses. Nine focus groups were conducted with current and former patients, carers and multidisciplinary staff in the same trust. Eleven semi-structured interviews were undertaken with multidisciplinary staff in a second NHS mental health trust in Northern England. Through thematic analysis two overarching issues were identified, concerning the contrasting perspectives expressed by different stakeholder groups, and the importance of a whole system approach. Overall, secure care was highlighted as an ‘obesogenic’ environment, conducive to excessive weight gain. Seven key influences included: medication, sedentary behaviour, patient motivation and intrinsic factors, catered food and alternatives, role of staff, and service delivery. In future, complex interventions engaging wide-ranging stakeholders are likely to be needed, with linked longitudinal studies to evaluate feasibility and impact