Individual molecular species of phosphatidylcholine and phosphatidylethanolamine in myelin turn over at different rates

Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of the myelin membrane exhibit heterogeneity with respect to metabolic turnover rate (Miller, S. L., Benjamins, J. A., and Morell, P. (1977) J. Biol. Chem. 212, 4021-4037). To test the hypothesis that this is due to differential turnover of individual molecular species (which differ in acyl chain composition), we have examined the relative turnover of individual molecular species of myelin PC and PE. Phospholipids were labeled by injection of [2-3H]glycerol into the brains of young rats.Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of the myelin membrane exhibit heterogeneity with respect to metabolic turnover rate (Miller, S. L., Benjamins, J. A., and Morell, P. (1977) J. Biol. Chem. 212, 4021-4037). To test the hypothesis that this is due to differential turnover of individual molecular species (which differ in acyl chain composition), we have examined the relative turnover of individual molecular species of myelin PC and PE. Phospholipids were labeled by injection of [2-3H]glycerol into the brains of young rats

Effectiveness of a brief lifestyle intervention targeting mental health staff: analysis of physical fitness and activity in the Keeping Our Staff in Mind study.

BackgroundPeople with mental illness die on average 15 years less than the general population, primarily to cardiometabolic disease. Lifestyle interventions are effective in reducing cardiometabolic risk but are not routinely provided to mental health consumers. Lifestyle interventions targeting mental health staff may be beneficial in changing culture surrounding physical health and subsequently improving consumer outcomes. This study examines exercise and fitness outcomes of a targeted lifestyle intervention directed at Australian mental health staff.MethodsA pragmatic single-arm intervention study was conducted within an Australian public mental health service. Mental health staff were provided a five-session individualised lifestyle intervention (incorporating exercise and nutritional counselling) over 5 weeks. Two waves of the programme were delivered between 2015 and 2016. This paper examines the exercise and fitness outcomes of the second wave of the study. Participants were assessed at baseline and at a 16-week follow-up. The primary exercise outcome was a measurement of cardiorespiratory fitness. Secondary outcomes included self-reported physical activity and a measurement of handgrip strength.ResultsA total of 106 staff participated in this component of the study. Cardiorespiratory fitness increased significantly from baseline to follow-up (pConclusionLifestyle interventions incorporating exercise counselling may improve the physical health of mental health staff. Such strategies may be effective in improving culture surrounding physical health and/or increasing the effectiveness of lifestyle interventions targeting mental health consumers

Silicon Encapsulated Carbon Nanotubes

A dual stage process of depositing bamboo-like carbon nanotubes (BCNTs) by hot filament chemical vapor deposition (HFCVD) and coating Si using Radio frequency sputtering (RFS) technique. The films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron field emission studies (EFE). SEM results suggest a dense network of homogeneous silicon-coated BCNTs. From the comprehensive analysis of the results provided by these techniques emerges the picture of Si encapsulated BCNTs

Overall evaluation of Skylab imagery for mapping of Latin America

The author has identified the following significant results. Skylab imagery is both desired and needed by the Latin American catographic agencies. The imagery is cost beneficial for the production of new mapping and maintenance of existing maps at national topographic series scales. If this information was available on a near time routine coverage basis, it would provide an excellent additional data base to the Latin American cartographic community, specifically Argentina, Bolivia, Chile, Colombia, Dominican Republic, Guatemala, Paraguay, and Venezuela

Sources of cholesterol during development of the rat fetus and fetal organs

Female rats at various stages of pregnancy were injected intraperitoneally with [3H]water; 4 h later, they were killed, the uterus was removed, and the fetuses were dissected. Lipids were isolated and fractionated by HPLC and the total amount of cholesterol in each organ, as well as radioactivity incorporated into cholesterol and cholesterol precursors, were determined. From the data for cholesterol content at each age we calculated the rate of accumulation of cholesterol during fetal development. As incorporation of label from [3H]water takes place with a stoichiometry defined by a known biosynthetic pathway, we were also able to determine the fraction of cholesterol accumulating in each organ that had been newly synthesized. For the fetus as a whole, more than 93% of the cholesterol accumulating during development was newly synthesized. As the specific radioactivity of cholesterol in the maternal circulation was negligible (because synthesis of cholesterol by maternal liver was suppressed by inclusion of cholesterol in the diet), we conclude that the fetus synthesizes nearly all of its own cholesterol; neither the maternal circulation nor the placenta/yolk sac contribute significant amounts of cholesterol to the fetus. We were also able to quantitate trafficking of cholesterol between fetal organs. Fetal brain is responsible for the synthesis of all of its own cholesterol. In contrast, fetal liver exports cholesterol into the fetal circulation and supplies about half of the cholesterol for development of heart, lung, and kidney

The importance of quantum decoherence in brain processes

Based on a calculation of neural decoherence rates, we argue that that the degrees of freedom of the human brain that relate to cognitive processes should be thought of as a classical rather than quantum system, i.e., that there is nothing fundamentally wrong with the current classical approach to neural network simulations. We find that the decoherence timescales ~10^{-13}-10^{-20} seconds are typically much shorter than the relevant dynamical timescales (~0.001-0.1 seconds), both for regular neuron firing and for kink-like polarization excitations in microtubules. This conclusion disagrees with suggestions by Penrose and others that the brain acts as a quantum computer, and that quantum coherence is related to consciousness in a fundamental way.Comment: Minor changes to match accepted PRE version. 15 pages with 5 figs included. Color figures and links at http://www.physics.upenn.edu/~max/brain.html or from [email protected]. Physical Review E, in pres

Diurnal and dietary-induced changes in cholesterol synthesis correlate with levels of mRNA for HMG-CoA reductase

We determined the extent to which diurnal variation in cholesterol synthesis in liver is controlled by steady-state mRNA levels for the rate-limiting enzyme in the pathway, hydroxymethylglutaryl (HMG)-CoA reductase. Rats 30 days of age and maintained on a low-cholesterol diet since weaning were injected intraperitoneally wit