A fully reversible 25-hydroxy steroid kinase involved in oxygen-independent cholesterol side-chain oxidation.

The degradation of cholesterol and related steroids by microbes follows fundamentally different strategies in aerobic and anaerobic environments. In anaerobic bacteria, the primary C26 of the isoprenoid side chain is hydroxylated without oxygen via a three-step cascade: (i) water-dependent hydroxylation at the tertiary C25, (ii) ATP-dependent dehydration to form a subterminal alkene, and (iii) water-dependent hydroxylation at the primary C26 to form an allylic alcohol. However, the enzymes involved in the ATP-dependent dehydration have remained unknown.

Characterizing ice particles using two-dimensional reflections of a lidar beam.

We report a phenomenon manifesting itself as brief flashes of light on the snow's surface near a lidar beam. The flashes are imaged and interpreted as specular reflection patterns from individual ice particles. Such patterns have a two-dimensional structure and are similar to those previously observed in forward scattering.

[Insomnia Between Neuro- and Social Sciences - A Psycho-Socio-Somatic Outview].

Insomnia is one of the most prevalent neuropsychiatric disorders throughout Europe. It is associated with a number of health-relevant problems including an increased risk of psychiatric and organic disorders. A variety of organic, social and psychological risk factors takes part in the genesis of these sleep disturbances.

Relationships of peripheral IGF-1, VEGF and BDNF levels to exercise-related changes in memory, hippocampal perfusion and volumes in older adults.

Animal models point towards a key role of brain-derived neurotrophic factor (BDNF), insulin-like growth factor-I (IGF-I) and vascular endothelial growth factor (VEGF) in mediating exercise-induced structural and functional changes in the hippocampus. Recently, also platelet derived growth factor-C (PDGF-C) has been shown to promote blood vessel growth and neuronal survival. Moreover, reductions of these neurotrophic and angiogenic factors in old age have been related to hippocampal atrophy, decreased vascularization and cognitive decline.

Sleep-dependent memory consolidation and its implications for psychiatry.

Both sleep disturbance and memory impairment are very common in psychiatric disorders. Since sleep has been shown to play a role in the process of transferring newly acquired information into long-term memory, i.e.