对河南省城乡7-18岁学生身体素质的分析研究

通过对1991- -2000年河南省7-18岁学生身体素质的三次体质调研结果的分析,发现除15-18岁男女学生立定跳远、7-12岁乡村男生斜身引体、13-18岁女生仰卧起坐有明显提高外,其余指标均有不同程度的下降,其中男女学生柔韧、耐力素质严重下降.针对学生身体素质所存在的问题,为河南省21世纪的学校体育卫生工作及各级学校素质教育工作的开展提供帮助.     

Once the Capacity Development Initiative is Over: Using Communities of Practice Theory to Transform Individual into Social Learning

Abstract

Purpose: Capacity development for agricultural research and development is missing an opportunity. Initiatives tend to focus on developing capacity of individuals and even when the ultimate aim is social change leave the transformation of individual into social learning largely to chance. I use the lens of social learning systems, particularly concepts from Community of Practice theory, to explore how that theory can provide practical insights into transforming individual into social learning and the design considerations that would support this.

Design/methodology/approach: Using as a case study a professional development programme, African Women in Agricultural Research and Development (AWARD), I conducted a use-oriented systemic inquiry among 26 AWARD participants, with myself as informed investigator within the system of inquiry. Data from interviews and questionnaires were subjected to qualitative analysis using analytic induction with sensitizing concepts from Community of Practice theory.

Practical implications: I identify strengths and challenges, and provide five design considerations that might enable the individuals participating in a capacity development programme to continue to engage after the programme ends and self-organize for concerted action.

Originality/value: The originality of this research article is the use of the three central Community of Practice concepts of domain, community and practice as analytical tools for understanding individual and social learning among the alumni of a professional capacity development programme. This has value for designers of capacity development initiatives.     

高等教育治理体系和治理能力现代化的基本原则

高等教育治理体系与治理能力现代化是高等教育治理现代化的两个优先方面。改革开放30多年来,我国高等教育治理不断深化,要求日益清晰。高等教育治理体系与治理能力现代化应该遵循科学治理、民主治理、依法治理和过程治理等基本原则。     

Physiological requirements of cricket

Despite its long history and global appeal, relatively little is known about the physiological and other requirements of cricket. It has been suggested that the physiological demands of cricket are relatively mild, except in fast bowlers during prolonged bowling spells in warm conditions. However, the physiological demands of cricket may be underestimated because of the intermittent nature of the activity and the generally inadequate understanding of the physiological demands of intermittent activity. Here, we review published studies of the physiology of cricket. We propose that no current model used to analyse the nature of exercise fatigue (i.e. the cardiovascular–anaerobic model, the energy supply–energy depletion model, the muscle power–muscle recruitment model) can adequately explain the fatigue experienced during cricket. A study of players in the South African national cricket team competing in the 1999 Cricket World Cup revealed that, in a variety of measures of explosive ('anaerobic') power and aerobic endurance capacity, they were as 'fit' as South African national rugby players competing in the 1999 Rugby World Cup. Yet, outwardly, the physiological demands of rugby would seem to be far greater than those of cricket. This poses the question: 'Why are these international cricketers so fit if the physiological demands of cricket are apparently so mild?' One possibility is that this specific group of athletes are unusually proficient in a variety of sports; many achieved high standards of performance in other sports, including rugby, before choosing to specialize in cricket. Hence their apparently high fitness may simply reflect a superior genetic physical endowment, necessary to achieve success in modern international sports, including cricket. Alternatively, it could be hypothesized that superior power and endurance fitness may be required to cope with the repeated eccentric muscle contractions required in turning and in bowling and which may account for fatigue and risk of injury in cricket. If this is the case, the fitness of cricketers may be increased and their risk of injury reduced by more specific eccentric exercise training programmes.     

Acclimatization to altitude and normoxic training improve 400-m running performance at sea level

To investigate the benefits of ‘living high and training low' on anaerobic performance at sea level, eight 400-m runners lived for 10 days in normobaric hypoxia in an altitude house (oxygen content = 15.8%) and trained outdoors in ambient normoxia at sea level. A maximal anaerobic running test and 400-m race were performed before and within 1 week of living in the altitude house to determine the maximum speed and the speeds at different submaximal blood lactate concentrations (3, 5, 7, 10 and 13 mmol· l-1) and 400-m race time. At the same time, ten 400-m runners lived and trained at sea level and were subjected to identical test procedures. Multivariate analysis of variance indicated that the altitude house group but not the sea-level group improved their 400-m race time during the experimental period (P ? 0.05). The speeds at blood lactate concentrations of 5–13 mmol· l-1 tended to increase in the altitude house group but the response was significant only at 5 and 7 mmol·l-1 (P ? 0.05). Furthermore, resting blood pH was increased in six of the eight altitude house athletes from 0.003 to 0.067 pH unit (P ? 0.05). The results of this study demonstrate improved 400-m performance after 10 days of living in normobaric hypoxia and training at sea level. Furthermore, the present study provides evidence that changes in the acid–base balance and lactate metabolism might be responsible for the improvement in sprint performance.     

Leisure Time Physical Activity and Job Performance

In this study, the dual-task paradigm was used to determine peak attentional demand during the free-throw process. Thirty participants completed 40 free-throw trials. The free throw was the primary task, but participants also verbally responded to a tone administered at one of four probe positions (PP). Repeated measures analysis of variance showed no significant difference in free-throw performance across PPs, indicating participants were able to keep the free throw as the primary task. Repeated measures analysis of response time (RT) showed significant differences, with RT at PP1 (preshot routine) and PP2 (first upward motion of the ball) significantly higher than baseline RT. These results suggest that PP1 requires the greatest attentional demand, followed by PP2.     

Accelerating Technology: The Pace of Transmission Systems

The growths in capacity of various generations of transmission technology were studied. The results show that the growth rates for different transmission technologies are themselves increasing, which means that the pace of transmission technology is accelerating. What is somewhat surprising is that long-distance rates are not decreasing more steeply. What is not surprising is the bandwidth glut in backbone networks. However, the increasing availability of transmission capacity in the bandwidth-rich world of the future could herald a return to circuit switching for data telecommunication.     

Antioxidant effect of methanolic extract of<Emphasis Type="Italic">Solanum nigrum</Emphasis> berries on aspirin induced gastric mucosal injury

The antiulcerogenic effects of the methanolic extract ofSolanum nigrum berries (SBE) on aspirin induced ulceration in rats with respect to antioxidant status in the gastric mucosa have been investigated. Oxygen free radicals are considered to be important factors in the pathogenesis of gastric ulcer. The level of lipid peroxides, which were elevated highly in rats with acute gastric mucosal injury was taken as an index of oxidative stress. The activities of antioxidant defense enzymes were also decreased considerably by oral gastric administration of aspirin. The decreased levels of antioxidant enzymes and increased mucosal injury were altered to near normal status upon pretreatment with (SBE) when compared to the ulcer induced rats. The results indicate that (SBE) may exert its gastroprotective effect by a free radical scavenging action. Our observations suggest that (SBE) may have considerable therapeutic potential in the treatment of gastric diseases.     

Antioxidant activity and protective effect of Clitoria ternatea flower extract on testicular damage induced by ketoconazole in rats

Background

Ketoconazole (KET), an antifungal drug, has adverse effects on the male reproductive system. Pre-treatments with antioxidant plant against testicular damage induced by KET are required. The flowers of Clitoria ternatea (CT) are proven to have hepatoprotective potential. However, the protective effect on KET-induced testicular damage has not been reported.

Objective

To investigate the protective effect of CT flower extracts with antioxidant activity on male reproductive parameters including sperm concentration, serum testosterone level, histopathology of the testis, and testicular tyrosine phosphorylation levels in rats induced with KET.

Methods

The antioxidant activity of CT flower extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Male rats were treated with CT flower extracts (10, 50, or 100 mg/kg BW) or distilled water via a gastric tube for 28 d (preventive period: Days 1–21) and induced by KET (100 mg/kg BW) via intraperitoneal injection for 7 d (induction period: Days 22–28). After the experiment, all animals were examined for the weights of the testis, epididymis plus vas deferens and seminal vesicle, serum testosterone levels, sperm concentration, histological structures and diameter of testis, and testicular tyrosine phosphorylation levels by immunoblotting.

Results

The CT flower extracts had capabilities for DPPH scavenging and high reducing power. At 100 mg/kg BW, the extract had no toxic effects on the male reproductive system. Significantly, in CT+KET groups, CT flower extracts (50 and 100 mg/kg BW) alleviated the reduction of reproductive organ weight parameters, testosterone levels, and sperm concentration. In addition, CT flower extracts gave protection from testicular damage in KET-induced rats. Moreover, in the CT100+KET group, CT flower extracts significantly enhanced the expression of a testicular 50-kDa tyrosine phosphorylated protein compared with that of other groups.

Conclusions

C. ternatea flower extracts possessing antioxidant activity are not harmful to the male reproductive system and can protect against testicular damage in KET-induced rats.     

Expression of three essential antioxidants of Helicobacter pylori in clinical isolates

Objective

Helicobacter pylori maintains long-term persistence in the host and combats oxidative stress via many antioxidant proteins, which are expected to be relevant to bacterial-associated gastric diseases. We aimed to investigate the expression of three essential antioxidants in H. pylori strains isolated from patients with different clinical outcomes. Methods: Forty H. pylori strains were isolated from endoscopic biopsy specimens of gastric mucosa from 13 patients with gastric cancer, 13 with peptic ulcer, and 14 with gastritis. The expression of thioredoxin 1 (Trx1), arginase (RocF), and alkyl hydroperoxide reductase (AhpC) in H. pylori was measured by real-time PCR. Comparisons among multiple sample sets were analyzed using a one-way ANOVA test. Pearson’s correlation test was used to assess relationships among multiple continuous variables.

Results

Trx1 expression of H. pylori in gastric cancer and peptic ulcer tissues was higher than that in tissues with gastritis. RocF expression of H. pylori in gastric cancer tissues was higher than that in tissues exhibiting peptic ulcer and gastritis. However, we did not find any differences in AhpC expression in samples from patients with different clinical outcomes. The expression of Trx1 and RocF had a positive, linear correlation. The expression of Trx1 and AhpC had a positive correlation without a linear trend. We found no correlation between the expression of RocF and AhpC.

Conclusions

Our observations indicate that the expression of Trx1 and RocF in H. pylori might be related to gastric carcinogenesis. In H. pylori, the expression of members of the antioxidant system may be correlated and relevant to gastric cancer.