Relativistically rotating dust

Dust configurations play an important role in astrophysics and are the simplest models for rotating bodies. The physical properties of the general--relativistic global solution for the rigidly rotating disk of dust, which has been found recently as the solution of a boundary value problem, are discussed.Comment: 18 pages, 11 figure

Sleep disorders and the hypothalamus

As early as the 1920s, pathological studies of encephalitis lethargica allowed Von Economo to correctly identify hypothalamic damage as crucial for the profound associated sleep-related symptoms that helped define the condition. Only over the last 3 decades, however, has the key role of the hypothalamus in sleep-wake regulation become increasingly recognized. As a consequence, a close relation between abnormal sleep symptomatology and hypothalamic pathology is now widely accepted for a variety of medical disorders. Narcolepsy is discussed in some detail as the cardinal primary sleep disorder that is caused directly and specifically by hypothalamic pathology, most notably destruction of hypocretin (orexin)-containing neurons. Thereafter, various conditions are described that most likely result from hypothalamic damage, in part at least, producing a clinical picture resembling (symptomatic) narcolepsy. Kleine-Levin syndrome is a rare primary sleep disorder with intermittent symptoms, highly suggestive of hypothalamic involvement but probably reflecting a wider pathophysiology. ROHHAD (rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation) and Prader-Willi syndrome are also covered as hypothalamic syndromes with prominent sleep-related symptoms. Finally, sleep issues in several endocrine disorders are briefly discussed

An Individual, Community-Based Treatment for Obese Children and Their Families: The Solution-Focused Approach

Background: This study evaluates an individual, community-based treatment for obese children and their families. In this program, a treatment team applied solution-focused techniques to develop a custom-made treatment plan in collaboration with the participants. The treatment plan consisted of community-based lifestyle activities. Methods: 559 obese children with an average BMI z-score of 2.76 ± 0.54 took part in the 12-month study, and 372 children with an average BMI z-score of 2.75 ± 0.52 took part in the 24-month study. At the start of the study, ethnicity and special school needs were recorded. Before, after 12 months, and after 24 months of the treatment, body weight and height were measured. The effect of the treatment on body weight was evaluated using BMI z-scores. Results: 291 children (52%) completed 12 months of treatment, whereas 22 children (4%) were dismissed earlier due to a good response. After 12 months, the children showed a significant decrease in BMI z-score by 0.16 (95% confidence interval (CI) 0.11-0.20; p Conclusions: Children showed a significant decrease in BMI z-score after the treatment. We found a negative correlation of age and weight loss. Special attention to patients with a high risk of drop-out might further improve these results. We advise a referral to obesity treatment as early as possible since a ‘wait and see' policy might have adverse results in obese children

Tracing from fat tissue, liver, and pancreas: a neuroanatomical framework for the role of the brain in type 2 diabetes

The hypothalamus uses hormones and the autonomic nervous system to balance energy fluxes in the body. Here we show that the autonomic nervous system has a distinct organization in different body compartments. The same neurons control intraabdominal organs (intraabdominal fat, liver, and pancreas), whereas sc adipose tissue located outside the abdominal compartment receives input from another set of autonomic neurons. This differentiation persists up to preautonomic neurons in the hypothalamus, including the biological clock, that have a distinct organization depending on the body compartment they command. Moreover, we demonstrate a neuronal feedback from adipose tissue that reaches the brainstem. We propose that this compartment-specific organization offers a neuroanatomical perspective for the regional malfunction of organs in type 2 diabetes, where increased insulin secretion by the pancreas and disturbed glucose metabolism in the liver coincide with an augmented metabolic activity of visceral compared with sc adipose tissu