Effects of L-lysine administration on certain aspects of ascorbic acid metabolism in weanling rats

Summary L-lysine administration to male weanling rats at a dose of 110.4 mg (25% LD₅₀) per 100 g body weight per day for 15 days reduced the liver total ascorbic acid level. The biosynthesis as well as the degradation of L-ascorbic acid was diminished under these conditions. The fall in liver total ascorbic acid level after L-lysine administration was ascribed to its reduced synthesis.Acknowledgment. The authors are thankful to the Council of Scientific and Industrial Research, India, for providing Junior Research Fellowships to Miss J. Basu and Miss K. Sen Gupta.     

Protection from body weight loss by 2-mercaptopropionylglycine (MPG) in growing mice irradiated in utero with gamma radiation

Summary 2-Mercaptopropionylglycine administered during fetal growth period, protected significantly young mice against loss of body weight during postnatal development induced by 50 R gamma irradiation.Acknowledgment. The work was supported by a grant from CSIR, New Delhi, to P.K.D. which is gratefully acknowledged. The authors are also thankful to Prof. P. Navlakha for the irradiation facilities.     

Mixed-frequency forecasting of crude oil volatility based on the information content of global economic conditions

This paper subjects six alternative indicators of global economic activity to empirically examine their relative predictive powers in the forecast of crude oil market volatility. GARCH-MIDAS approach is constructed to accommodate all the relevant series at their available data frequencies, thereby circumventing information loss and any associated bias. We find evidence in support of global economic activity as a good predictor of energy market volatility. Our forecast evaluation of the various indicators places a higher weight on the newly developed indicator of global economic activity which is based on a set of 16 variables covering multiple dimensions of the global economy, whereas other indicators do not seem to capture. Furthermore, we find that accounting for any inherent asymmetry in the global economic activity proxies improves the forecast accuracy of the GARCH-MIDAS-X model for oil volatility. The results leading to these conclusions are robust to multiple forecast horizons and consistent across alternative energy sources.     

Judgement in learning‐curve forecasting: a laboratory study

This study investigates whether human judgement can be of value to users of industrial learning curves, either alone or in conjunction with statistical models. In a laboratory setting, it compares the forecast accuracy of a statistical model and judgemental forecasts, contingent on three factors: the amount of data available prior to forecasting, the forecasting horizon, and the availability of a decision aid (projections from a fitted learning curve). The results indicate that human judgement was better than the curve forecasts overall. Despite their lack of field experience with learning curve use, 52 of the 79 subjects outperformed the curve on the set of 120 forecasts, based on mean absolute percentage error. Human performance was statistically superior to the model when few data points were available and when forecasting further into the future. These results indicate substantial potential for human judgement to improve predictive accuracy in the industrial learning‐curve context. Copyright © 1999 John Wiley & Sons, Ltd.