Evaluation of a group acceptance commitment therapy intervention for people with knee or hip osteoarthritis: a pilot randomized controlled trial

Objectives: The aim was to evaluate an Acceptance Commitment Therapy (ACT) intervention for people with knee or hip osteoarthritis; a related aim was to compare treatment effects from Rasch-transformed and standard scales. Methods: Participants were recruited from a research database and outpatient rheumatology and orthopaedic clinics at two hospitals. Eligible participants were randomly allocated to either intervention or usual care. Intervention comprised six-sessions of group ACT. Outcomes were assessed two and four months after randomisation. Rasch-transformed and standard self-report measures were compared. Qualitative interviews also explored the acceptability of the intervention. Results: Of 8 people assessed for eligibility, 31 (36%) were randomised. The main reason for non-randomisation was that participants received surgery. Of the 16 participants randomised to intervention, 64% completed ≥50% of the scheduled group sessions. Follow-up data was complete for 84% participants at two months and 68% at four months. Outcome analysis demonstrated important differences between the Rasch-transformed and standard scales. There were significant differences between the groups in pain. Qualitative interviews with 7 participants suggested the intervention was acceptable. Conclusions: ACT for osteoarthritis is likely to be an acceptable treatment option for people with osteoarthritis. Progress to a definitive trial is warranted. Rasch-transformed outcome scales are preferable in clinical trials where possible

Hair cortisol as a biomarker of stress in mindfulness training for smokers.

OBJECTIVES: Stress is a well-known predictor of smoking relapse, and cortisol is a primary biomarker of stress. The current pilot study examined changes in levels of cortisol in hair within the context of two time-intensity matched behavioral smoking cessation treatments: mindfulness training for smokers and a cognitive-behavioral comparison group. PARTICIPANTS: Eighteen participants were recruited from a larger randomized controlled trial of smoking cessation. OUTCOME MEASURES: Hair samples (3 cm) were obtained 1 month after quit attempt, allowing for a retrospective analysis of hair cortisol at preintervention and post-quit attempt time periods. Self-reported negative affect was also assessed before and after treatment. INTERVENTION: Both groups received a 7-week intensive intervention using mindfulness or cognitive-behavioral strategies. RESULTS: Cortisol significantly decreased from baseline to 1 month after quit attempt in the entire sample (d=-0.35; p=.005). In subsequent repeated-measures analysis of variance models, time by group and time by quit status interaction effects were not significant. However, post hoc paired t tests yielded significant pre-post effects among those randomly assigned to the mindfulness condition (d=-0.48; p=.018) and in those abstinent at post-test (d=-0.41; p=.004). Decreased hair cortisol correlated with reduced negative affect (r=.60; p=.011). CONCLUSIONS: These preliminary findings suggest that smoking cessation intervention is associated with decreased hair cortisol levels and that reduced hair cortisol may be specifically associated with mindfulness training and smoking abstinence. RESULTS support the use of hair cortisol as a novel objective biomarker in future research

Psychiatric Symptoms, Risk, and Protective Factors Among University Students in Quarantine During the COVID-19 Pandemic in China

Background: The COVID-19 pandemic has made unprecedented impact on the psychological health of university students, a population vulnerable to distress and mental health disorders. This study investigated psychiatric symptoms (anxiety, depression, and traumatic stress) during state-enforced quarantine among university students in China (N = 1912) through a cross-sectional survey during March and April 2020. Results: Psychiatric symptoms were alarmingly prevalent: 67.05% reported traumatic stress, 46.55% had depressive symptoms, and 34.73% reported anxiety symptoms. Further, 19.56% endorsed suicidal ideation. We explored risk and protective factors of psychological health, including demographic variables, two known protective factors for mental health (mindfulness, perceived social support), four COVID-specific factors (COVID-19 related efficacy, perceived COVID-19 threat, perceived COVID-19 societal stigma, COVID-19 prosocial behavior) and screen media usage. Across symptom domains, mindfulness was associated with lower symptom severity, while COVID-19 related financial stress, perceived COVID-19 societal stigma, and perceived COVID-19 threat were associated with higher symptom severity. COVID-19 threat and COVID-19 stigma showed main and interactive effects in predicting all mental health outcomes, with their combination associated with highest symptom severity. Screen media device usage was positively associated with depression. Female gender and COVID-19 prosocial behavior were associated with higher anxiety, while COVID-19 self-efficacy associated with lower anxiety symptoms. Conclusions: Findings suggest high need for psychological health promotion among university students during the COVID-19 pandemic and inform an ecological perspective on the detrimental role of stigma during an emerging infectious disease outbreak. Interventions targeting multi-level factors, such as promoting mindfulness and social support at individual and interpersonal levels while reducing public stigma about COVID-19, may be particularly promising. Attending to the needs of disadvantaged groups including those financially impacted by COVID-19 is needed

A spacetime characterization of the Kerr metric

We obtain a characterization of the Kerr metric among stationary, asymptotically flat, vacuum spacetimes, which extends the characterization in terms of the Simon tensor (defined only in the manifold of trajectories) to the whole spacetime. More precisely, we define a three index tensor on any spacetime with a Killing field, which vanishes identically for Kerr and which coincides in the strictly stationary region with the Simon tensor when projected down into the manifold of trajectories. We prove that a stationary asymptotically flat vacuum spacetime with vanishing spacetime Simon tensor is locally isometric to Kerr. A geometrical interpretation of this characterization in terms of the Weyl tensor is also given. Namely, a stationary, asymptotically flat vacuum spacetime such that each principal null direction of the Killing form is a repeated principal null direction of the Weyl tensor is locally isometric to Kerr.Comment: 23 pages, No figures, LaTeX, to appear in Classical and Quantum Gravit

Stability of closed gaps for the alternating Kronig-Penney Hamiltonian

We consider the Kronig-Penney model for a quantum crystal with equispaced periodic delta-interactions of alternating strength. For this model all spectral gaps at the centre of the Brillouin zone are known to vanish, although so far this noticeable property has only been proved through a very delicate analysis of the discriminant of the corresponding ODE and the associated monodromy matrix. We provide a new, alternative proof by showing that this model can be approximated, in the norm resolvent sense, by a model of regular periodic interactions with finite range for which all gaps at the centre of the Brillouin zone are still vanishing. In particular this shows that the vanishing gap property is stable in the sense that it is present also for the "physical" approximants and is not only a feature of the idealised model of zero-range interactions. \ua9 2015, Springer Basel

Contribution of Direct Heating, Thermal Conduction and Perfusion During Radiofrequency and Microwave Ablation

Both radiofrequency (RF) and microwave (MW) ablation devices are clinically used for tumor ablation. Several studies report less dependence on vascular mediated cooling of MW compared to RF ablation. We created computer models of a cooled RF needle electrode, and a dipole MW antenna to determine differences in tissue heat transfer