Exercise-induced BCL2-regulated autophagy is required for muscle glucose homeostasis

Exercise has beneficial effects on human health, including protection against metabolic disorders such as diabetes. However, the cellular mechanisms underlying these effects are incompletely understood. The lysosomal degradation pathway, autophagy, is an intracellular recycling system that functions during basal conditions in organelle and protein quality control. During stress, increased levels of autophagy permit cells to adapt to changing nutritional and energy demands through protein catabolism. Moreover, in animal models, autophagy protects against diseases such as cancer, neurodegenerative disorders, infections, inflammatory diseases, ageing and insulin resistance. Here we show that acute exercise induces autophagy in skeletal and cardiac muscle of fed mice. To investigate the role of exercise-mediated autophagy in vivo, we generated mutant mice that show normal levels of basal autophagy but are deficient in stimulus (exercise- or starvation)-induced autophagy. These mice (termed BCL2 AAA mice) contain knock-in mutations in BCL2 phosphorylation sites (Thr69Ala, Ser70Ala and Ser84Ala) that prevent stimulus-induced disruption of the BCL2-beclin-1 complex and autophagy activation. BCL2 AAA mice show decreased endurance and altered glucose metabolism during acute exercise, as well as impaired chronic exercise-mediated protection against high-fat-diet-induced glucose intolerance. Thus, exercise induces autophagy, BCL2 is a crucial regulator of exercise- (and starvation)-induced autophagy in vivo, and autophagy induction may contribute to the beneficial metabolic effects of exercise.     

火炸药燃烧与爆轰产物的非理想普适状态方程

本文研究火炸药燃烧与爆轰反应产物的非理想状态方程的建立和应用。通过对载短维里方程、Haar—Shenker方程和BKW状态方程的评估,用“多方程组合法”建立的普适方程适用于从理想气体到类固体气体宽广的密度范围。该方程用于燃烧转爆轰研究。与过去使用的方程比较表明,燃烧转爆轰理论预测的准确性得到了提高。文中提供了奥克托金炸药反应产物的大量数据和方程的参数值。     

Quantification of actinide alpha-radiation damage in minerals and ceramics

There are large amounts of heavy alpha-emitters in nuclear waste and nuclear materials inventories stored in various sites around the world. These include plutonium and minor actinides such as americium and curium. In preparation for geological disposal there is consensus that actinides that have been separated from spent nuclear fuel should be immobilized within mineral-based ceramics rather than glass because of their superior aqueous durability and lower risk of accidental criticality. However, in the long term, the alpha-decay taking place in these ceramics will severely disrupt their crystalline structure and reduce their durability. A fundamental property in predicting cumulative radiation damage is the number of atoms permanently displaced per alpha-decay. At present, this number is estimated to be 1,000-2,000 atoms/alpha in zircon. Here we report nuclear magnetic resonance, spin-counting experiments that measure close to 5,000 atoms/alpha in radiation-damaged natural zircons. New radiological nuclear magnetic resonance measurements on highly radioactive, 239Pu zircon show damage similar to that caused by 238U and 232Th in mineral zircons at the same dose, indicating no significant effect of half-life or loading levels (dose rate). On the basis of these measurements, the initially crystalline structure of a 10 weight per cent 239Pu zircon would be amorphous after only 1,400 years in a geological repository (desired immobilization timescales are of the order of 250,000 years). These measurements establish a basis for assessing the long-term structural durability of actinide-containing ceramics in terms of an atomistic understanding of the fundamental damage event.     

Flight enhances juvenile hormone inactivation inDanaus plexippus plexippus L. (Lepidoptera: Danaidae)

Summary Adult Monarch butterflies injected with³H-juvenile hormone (JH) showed a significant increase in haemolymph JH metabolites after a 40 min flight compared to unflown controls. In addition, haemolymph enzymatic JH metabolism was shown to increase with thoracic temperature increases previously shown to be associated with flight.We thank Paul Cherubini for supplying California Monarchs, Dr L.I. Gilbert for his helpful suggestions, Jeanne Whitaker for secretarial assistance, and Henry Lessman for aid in insect culture.     

爆炸产物JCZ状态方程的单组分当量值的确定方法

本文提出了一种确定Jacob?—Cowperthwaite—Zwisler状态方程单组分当量分子阱深?和σ的改进方法。此法用调整爆炸产物比热比的方法代替降低化学能方法,从而使确定单组分当量值的方法得到了显著改进。奥克托金炸药爆炸产物的单组分当量值已被精确地求得,并与TIGER编码的结果取得一致。这种单组分当量JCZ方程首先被用于燃烧转爆轰模型研究。它对奥克托金炸药的C—J特性给出了足够精确的预测。     

Effect of age,ambient temperature,and exposure to hormone on the posteclosion diuretic response of the monarch butterfly

Summary The monarch butterfly loses sensitivity to the posteclosion diuretic hormone of this species within 12 h of eclosion. This de-sensitization can be accelerated by exposure to the diuretic hormone, and decelerated by both hormone deficiency and reduced temperature.