Observational evidence for self-interacting cold dark matter

Cosmological models with cold dark matter composed of weakly interacting particles predict overly dense cores in the centers of galaxies and clusters and an overly large number of halos within the Local Group compared to actual observations. We propose that the conflict can be resolved if the cold dark matter particles are self-interacting with a large scattering cross-section but negligible annihilation or dissipation. In this scenario, astronomical observations may enable us to study dark matter properties that are inaccessible in the laboratoryComment: 4 pages, no figures; added references, pedagogical improvements, to appear in PR

Disordered eating behaviours and cognitions in young women with obesity: relationship with psychological status

Objective: To examine levels of eating disorder behaviours and cognitions of young women with obesity in the Australian Capital Territory, Australia and assess the impact upon psychological status.\ud \ud \ud Design: General population cross-sectional survey.\ud \ud Subjects: A total of 4891 young women from the community aged 18–42 years, of which 630 were in the obese weight range.\ud \ud Measurements: Body mass index (BMI), eating disorder psychopathology (eating disorder examination questionnaire), and psychological distress (K-10).\ud \ud Results: Women with obesity had significantly higher levels of dietary restraint, eating concern, weight concern, shape concern, binge eating, misuse of diuretics, use of diet pills and fasting compared to other women in the community. These eating disorder cognitions and behaviours were associated with increased levels of psychological distress. In women with obesity, eating concern, weight concern, shape concern, dietary restraint and decreased age predicted psychological distress in a multivariate model. Among other women in the community, behaviours such as laxative misuse, 'hard' exercise and subjective bulimic episodes also contributed to the model predicting psychological distress.\ud \ud Conclusion: As disordered eating psychopathology is high in young obese women and negatively impacts upon psychological status, obesity prevention and treatment should consider eating disorder psychopathology and mental health outcomes