Estimation of Precision in DLW Studies Using the Two-Point Methodology

Previous attempts to estimate precision of doubly labeled water (DLW) estimates of CO₂ production, using propagation of error analyses, have necessarily made simplifying assumptions which may compromise the resultant error estimate. Using an empirical iteration approach, error distributions for the DLW calculation were generated which overcome these problems. The error distribution for CO₂ estimates generated by DLW is symmetrical but not normal. The distribution is significantly truncated such that the 99% inclusion limits are 2.034 SD and not 2.58 SD. The precision error (99% CI for mean as percent of the mean) in DLW experiments, when using duplicate analyses, varies between approximately 3% and 47% depending on the ratio of the elimination constants of the two labels (k_o/k_d), experimental duration and initial isotope dose. The error could be improved by approximately 10 fold by increasing the number of replicates at all six isotope determinations from 2 to 5. Estimating precision in actual experiments can be made using the same empirical approach. The resultant estimates can be of extreme value in evaluating the role of precision as a factor influencing deviations during validation studies, and also for weighting mean estimates in applications of the technique. The deviations of DLW estimates from those made simultaneously by indirect calorimetry in a small mammal validation study were generally greater than the precision of the DLW estimates of CO₂ production. This may indicate there are more problems with the technique than precision alone.     

Linear constrain relations in biochemical reaction systems III. Sequential application of data reconciliation for sensitive detection of systematic errors

This article presents a method to test the presence of relatively small systematic measurement errors; e.g., those caused by inaccurate calibration or sensor drift. To do this, primary measurements-flow rates and concentrations-are first translated into observed conversions, which should satisfy several constraints, like the laws of conservation of chemical elements. This study considers three objectives: 1.Modification of the commonly used balancing technique to improve error sensitivity to be able to detect small systematic errors. To this end, the balancing technique is applied sequentially in time.2.Extension of the method to enable direct diagnosis of errors in the primary measurements instead of diagnosing errors in the observed conversions. This was achieved by analyzing how individual errors in the primary measurements are expressed in the residual vector.3.Derivation of a new systematic method to quantitatively determine the sensitivity of the error, is that error size at which the expected value of the chisquare test function equals its critical value.The method is applied to industrial data demonstrating the effectiveness of the approach. It was shown that, for most possible error sources, a systematic errors of 2% to 5% could be detected. In given application, the variation of the N-content of biomass was appointed to be the cause of errors. (c) 1994 John Wiley & Sons, Inc.     

Glucose-free/high-protein diet improves hepatomegaly and exercise intolerance in glycogen storage disease type III mice

Glycogen disease type III (GSDIII), a rare incurable autosomal recessive disorder due to glycogen debranching enzyme deficiency, presents with liver, heart and skeletal muscle impairment, hepatomegaly and ketotic hypoglycemia. Muscle weakness usually worsens to fixed myopathy and cardiac involvement may present in about half of the patients during disease. Management relies on careful follow-up of symptoms and diet. No common agreement was reached on sugar restriction and treatment in adulthood.We administered two dietary regimens differing in their protein and carbohydrate content, high-protein (HPD) and high-protein/glucose-free (GFD), to our mouse model of GSDIII, starting at one month of age. Mice were monitored, either by histological, biochemical and molecular analysis and motor functional tests, until 10?months of age.GFD ameliorated muscle performance up to 10?months of age, while HPD showed little improvement only in young mice. In GFD mice, a decreased muscle glycogen content and fiber vacuolization was observed, even in aged animals indicating a protective role of proteins against skeletal muscle degeneration, at least in some districts. Hepatomegaly was reduced by about 20%. Moreover, the long-term administration of GFD did not worsen serum parameters even after eight months of high-protein diet. A decreased phosphofructokinase and pyruvate kinase activities and an increased expression of Krebs cycle and gluconeogenesis genes were seen in the liver of GFD fed mice.Our data show that the concurrent use of proteins and a strictly controlled glucose supply could reduce muscle wasting, and indicate a better metabolic control in mice with a glucose-free/high-protein diet.     

The biological standard of living in Taiwan under Japanese occupation

This paper presents evidence on the biological standard of living in Taiwan from 1842 to 1931 using Taiwanese height and weight data collected by the Japanese authorities from 1921 to 1931. This study shows that in the late Ch'ing adult heights were not increasing over time, while the adult heights of those born after the Japanese takeover did begin to increase rapidly. Evidence from children's heights confirms that this growth in height continued through the 1920s. The body mass index of Taiwanese, however, did not increase in the 1920s. By most measures, the biological standard of living was better in the north of the island. Comparison with modern data shows that heights have continued to increase.     

单病种限价收费标准研究

目前按病种付费已经是大趋势。参照国外医保基金付费方式,研究我院单病种限价收费标准:即如何选择单病种和确定单病种价格,制定出一套适合我院单病种限价收费标准。实践表明按单病种限价收费,既降低了病人的医疗费用,提高了社会效益,又因收治病人数增加,同时也提高了医院的经济效益,对于医患双方是"双赢"。因此我院单病种费用收费标准的制定将为我省医疗单位和医疗保险业单病种费用收费标准的制定起着积极的推动作用。     

Statistical Testing for Seasonality in Data with Multiple Peaks and Troughs

EDWARDS'S test for seasonality is extended to multiple peaks and troughs. It is shown how the extended statistic may be adjusted for the population at risk and for unequal lengths of time intervals in the cycle of seasons. A simulation study shows that the extended test statistic is, for sample sizes N ≧ 100, very specific in detecting the number of peaks and troughs for which it is intended. The associated method of parameter estimation is also assessed; for N ≦ 100, the amplitude of a possibly adequate simple harmonic model is estimated well, but the initial value of the phase angle is not. Estimated percentage points for the extended test statistic are tabulated, and some recommendations are offered regarding usage of this method.