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991.
992.
993.
Using data on the ‘career’ paths of one thousand ‘leading scientists’ from 1450 to 1900, what is conventionally called the
‘rise of modern science’ is mapped as a changing geography of scientific practice in urban networks. Four distinctive networks
of scientific practice are identified. A primate network centred on Padua and central and northern Italy in the sixteenth
century expands across the Alps to become a polycentric network in the seventeenth century, which in turn dissipates into
a weak polycentric network in the eighteenth century. The nineteenth century marks a huge change of scale as a primate network
centred on Berlin and dominated by German-speaking universities. These geographies are interpreted as core-producing processes
in Wallerstein’s modern world-system; the rise of modern scientific practice is central to the development of structures of
knowledge that relate to, but do not mirror, material changes in the system.
相似文献
David M. EvansEmail: |
994.
O'Connor H Olds T Maughan RJ;International Association of Athletics Federations 《Journal of sports sciences》2007,25(Z1):S49-S60
Evidence of the importance of physique in the athletics disciplines is supported by the persistence of certain characteristics over long periods, despite marked secular changes in the source population. These characteristics may also result in physiological benefits such as effective thermoregulation or a greater power-to-weight ratio. Coaches and athletes are often convinced of weight or fat loss benefits based on personal or anecdotal experience, intuition, and "trained eye" observation of successful competitors. This may entice athletes into adopting unbalanced, erratic or highly restrictive eating patterns that increase the risk for nutrient deficiencies, and disordered eating. Despite heavy training loads and often extreme diets, some athletes fall short of their physique goals as ultimately phenotype is under genetic control. Professionals assisting athletes with physique management need to be highly skilled in anthropometry and require a thorough understanding of sports-specific nutrition requirements. Careful assessment of the risks and benefits of various approaches to weight and fat loss is required before they are recommended to athletes. 相似文献
995.
Although the importance of high motivation to engage in deliberate practice has been acknowledged, no research has directly tested this hypothesis. Therefore, the present study examined this relation in adolescent elite chess players by means of a questionnaire. In addition, to provide an explanation for dropout among promising chess players, differences in motivation between persistent and dropout chess players were analyzed. Competitiveness and the will to excel proved to be predictors of investments in deliberate practice. Moreover, achievement motivation and chess-specific motivation differed to a certain extent between persisters and dropouts. Our results suggest that motivation to engage in deliberate practice not only contains elements of the will to improve performance, but also of the will to attain exceptional levels of performance. 相似文献
996.
Excess protein intake can adversely affect the bone via an increase in calcium excretion, while suitable mechanical loading promotes osteogenesis. We therefore investigated whether vibration exposure could alleviate the bone mineral losses associated with a metabolic acidosis. Ten healthy individuals aged 22 - 29 years (median = 25) underwent three 5-day study periods while monitoring their dietary intake. The study consisted of recording the participants' usual dietary intake for 5 consecutive days. Participants were then randomly divided into two groups, one of which received a protein supplement (2 g x kg(-1) body mass x day(-1); n = 5) and the other whole-body low-magnitude (3.5 g), low-frequency (30 Hz) mechanical vibration (WBV) delivered through a specially designed vibrating plate for 10 min each day (n = 5). Finally, for the third treatment period, all participants consumed the protein supplement added to their normal diet and were exposed to WBV exercise for 10 min per day. Daily urine samples were collected throughout the experimental periods to determine the excretion of calcium, phosphate, titratable acid, urea, and C-telopeptide. As expected, when the participants underwent the high protein intake, there was an increase in urinary excretion rates of calcium (P < 0.001), phosphate (P < 0.003), urea (P < 0.001), titratable acid (P < 0.001), and C-telopeptide (P < 0.05) compared with baseline values. However, high protein intake coupled with vibration stimulation resulted in a significant reduction in urinary calcium (P = 0.006), phosphate excretion (P = 0.021), and C-telopeptide (P < 0.05) compared with protein intake alone, but did not affect titratable acid and urea output. The participants showed no effect of WBV exercise alone on urinary excretion of calcium, phosphate, urea, titratable acid, or C-telopeptide. The results indicate that vibration stimulation can moderate the increase in bone resorption and reduction in bone formation caused by a metabolic acidosis. 相似文献
997.
Munroe-Chandler KJ Hall CR Fishburne GJ Strachan L 《Research quarterly for exercise and sport》2007,78(2):103-116
The purpose of this study was to investigate young athletes' imagery use from a developmental perspective. The participants were 110 male and female athletes competing in both team and individual sports. They represented four different age cohorts (i.e., 7-8, 9-10, 11-12, and 13-14 years). Sixteen focus groups, two for each age category and gender, were used as the method of data collection. The findings indicated "where," "when, " and "why" young athletes use imagery and how imagery use changes as children move from early childhood through to early adolescence. Overall, results revealed that all age cohorts reported using imagery in both training and competition and for both cognitive and motivational purposes. The present research also found support for studying imagery use by young athletes from a developmental perspective. 相似文献
998.
Effects of rest interval during high-repetition resistance training on strength, aerobic fitness, and repeated-sprint ability 总被引:1,自引:0,他引:1
The effect of altering the rest period on adaptations to high-repetition resistance training is not well known. Eighteen active females were matched according to leg strength and repeated-sprint ability and randomly allocated to one of two groups. One group performed resistance training with 20-s rest intervals between sets, while the other group employed 80-s rest intervals between sets. Both groups performed the same total training volume and load. Each group trained 3 days a week for 5 weeks [15- to 20-repetition maximum (RM), 2 - 5 sets]. Repeated-sprint ability (5x6-s maximal cycle sprints), 3-RM leg press strength, and anthropometry were determined before and after each training programme. There was a greater improvement in repeated-sprint ability after training with 20-s rest intervals (12.5%) than after training with 80-s rest intervals (5.4%) (P = 0.030). In contrast, there were greater improvements in strength after training with 80-s rest intervals (45.9%) than after training with 20-s rest intervals (19.6%) (P = 0.010). There were no changes in anthropometry for either group following training. These results suggest that when training volume and load are matched, despite a smaller increase in strength, 5 weeks of training with short rest periods results in greater improvements in repeated-sprint ability than the same training with long rest periods. 相似文献
999.
Despite the lack of a clear definition of the concept, “cultural diversity” has remained a core issue for more than a decade
(WTO, UNESCO, etc.). The aim of this paper is to begin to fill this gap. We argue that cultural diversity is a multi-dimensional
concept and that accurate metrics must rely on three criteria: variety, balance and disparity. We also stress that supplied
and consumed diversity have to be distinguished. We apply this set of multiple measures of diversity to publishing data for
France over the period 1990–2003. Our main result is that the situation of the publishing industry in terms of cultural diversity
is highly dependent on the dimension considered. Hence, diversity increases when variety is the sole consideration, whereas
taking balance or disparity into account leads to the opposite conclusion. This issue raises a series of questions about the
use of diversity measures in a policy debate concerned with furthering cultural diversity.
相似文献
Stéphanie PeltierEmail: |
1000.
Theatre experts generally agree that the Flemish theatre has flourished artistically over the period 1980–2000. Attendance,
on the other hand, has declined significantly. Following Lancaster’s characteristics approach, we identify several output
characteristics of individual theatre productions. Using a panel of 59 Flemish theatres, we examine the impact on demand of
both these output characteristics and of traditional determinants such as own price, income and the price of substitutes.
Differences in the relevant geographical market for touring and non-touring theatres are considered. We find that the nature
of the artistic output affects demand. Theatregoers prefer large productions (in terms of cast size), plays by Dutch-speaking
playwrights and revivals of old productions. Own price and consumer income have the expected negative and positive effects
on attendance. Observed trends toward a decreasing proportion of new plays, an increasing presence of plays by Dutch-speaking
playwrights, and increasing consumer income had a stimulating effect on attendance. These trends have been offset, however,
by trends toward smaller cast sizes and higher ticket prices as well as by unobserved factors captured by time dummies. The
net result has been a considerable drop in attendance.
相似文献
Kristien WerckEmail: |