Historical notes on the determination of distance by timed radio waves

The foregoing notes trace the history of the measurement of the propagation times of radio waves as a means for determining distance. While the reader may feel that undue emphasis has been placed upon the KHL height measurements, a survey of the literature will show that only a small proportion of the reported observations have been cited here. Out of the hundreds of published articles on KHL height measurements, the writer has endeavored to select those which present the step-by-step improvements in the methods and apparatus. In the period just prior to the War, the United States Patents offered the principal means for tracing the development of the art. In the war period the notes are necessarily incomplete because of the scarcity of publications; this is no doubt due to secrecy conditions.     

Relationship of Physique and Developmental Level to Physical Performance

Abstract

A study was made of the relationship of physique and developmental level, determined by use of the Wetzel Grid, to performance of junior high boys on four fitness tests: pull-ups, 50-yd. dash, standing broad jump, and softball throw. Subjects of different physique groups (heavy, medium, and thin) who were alike developmentally (accelerated, normal, and retarded) differed more markedly in performance than did subjects of different developmental levels who were alike with regard to physique. Subjects who were medium in physique and normal in development were the best performers. Subjects of heavy physique (many overweight) were the poorest performers. This would seem to indicate the need for a restudy of classification methods, particularly when norms are to be used for evaluating performance.     

Effectiveness of Four Track Starting Positions on Acceleration

Abstract

Four sprint starting positions—the bunch, medium, elongated, and hyperextended—were compared on mean elapsed times at distances of 10 and 30 yd. Averages of three starts for each of 30 inexperienced college undergraduate males on each type of start were derived from electronically-controlled measures, the times for both distances being recorded from the same start. Statistical analyses indicated significantly lower elapsed times with the hyperextended starting position.     

Quantum pharmacology

Quantum chemistry is based on the solution of the Schrödinger equation for a molecule. From starting data on the positions and nature of constituent atoms information is provided about the energy of the molecule and its electronic properties. The former can indicate what shapes drugs can adopt in binding to pharmacological receptors whilst electronic details, when compared using computer graphics, may highlight the factors responsible for biological activity. These techniques are beginning to show real successes in the design of drug molecules.     

Assessment of oxidative stress and effect of antioxidant supplementation during radiotherapy in carcinoma of upper digestive tract

Oxidative stress was studied by estimating plasma levels of malondialdehyde (MDA), beta carotene, vitamin E and erythrocytic superoxide dismutase(E-SOD) activity in 50 cases of carcinoma of upper digestive tract which included carcinoma of oral cavity, pharynx and oesophagus. While plasma MDA level was found to be increased (3.5±1.0 nmole/ml), a significant decrease in beta carotene (81.2±14.5mg%), vitamin E (8.5±1.1 mg/L) level and E-SOD activity (657.0±80.6 U/G Hb) were observed in carcinoma of upper digestive tract. Patients were treated with radiotherapy which itself was toxic enough and produced its deleterious effects by generation of reactive oxygen species (ROS). As antioxdiants can detoxify ROS, beneficial effect if any, of antioxidant administration during radiotherapy was studied in two groups of patients, group A (n=5, supplemented with antioxidants) and group B (n=5, without antioxidant supplementation). Plasma MDA level was found to be elevated in both the groups but the increase in group B was significant, compared to pretreatment level. Further, body weight was found to be significantly decreased in group B patients, which was maintained in group A patients. Moreover, group A patients showed significant elevation in beta carotene concentration, thus showing beneficial effect of administration of antioxidants during radiotherapy without disturbing the desirable therapeutic effect of radiotherapy.     

Relative efficiency of R&D activities: A cross-country study accounting for environmental factors in the DEA approach

This paper applies the production framework associated with the data envelopment analysis (DEA) method to evaluate the relative efficiency of R&D activities across countries. R&D capital stocks and manpower are treated as inputs while patents and academic publications are considered as outputs. A three-stage approach, which involves using DEA for evaluating efficiency and using Tobit regressions for controlling the external environment, is applied to 30 countries in recent years. The results show that less than one-half of the countries are fully efficient in R&D activities and that more than two-thirds are at the stage of increasing returns to scale. Most countries have a more significant advantage in producing SCI cum EI publications than in generating patents.     

秦始皇兵马俑博物馆室内含硫颗粒物的SEM-EDX研究

本文对秦始皇兵马俑博物馆室内采集的长短期降尘、大气悬浮颗粒物和彩绘漆层进行了SEM-EDX研究，在大气悬浮颗粒、短期和长期降尘中，含硫颗粒的粒径分别为0.9～22.8μm、1.0～29.0μm和1.2～37.7μm，多为石膏与粘土或石英以内部混合的状态存在。降尘中的附着型絮状硫酸钙多于大气悬浮颗粒物中，显示降尘和大气中的二氧化硫发生了累进的化学反应。彩绘漆层表面的坑和裂隙附近观察到原位生长的硫酸钙晶体，显示漆层材料或降尘颗粒物与大气二氧化硫之间的酸化学反应，可能是彩绘漆层表面受侵蚀形成微小坑和裂隙的原因之一。