The interaction of aging and 10 years of racing on ultraendurance running performance

The aim of this study was to examine the interaction between aging and 10 years of racing in endurance runners. Race-time data from 194 runners who had completed 10 consecutive 56-km ultramarathons were obtained. The runners were either 20.5 +/- 0.7, 30.0 +/- 1.0, 39.9 +/- 0.9, or 49.4 +/- 1.0 years old at their first race. Each runner's race speed was determined for each race over the 10 years. Data were analyzed using repeated-measures ANOVA, one-way ANOVA, and independent t tests and showed that performance improved and declined at greater rates for younger runners; younger runners had a greater capacity for improvement than older runners; approximately 4 years were required to reach peak racing speed, regardless of age; it was not possible to compete at peak speed for more than a few years; and the combined effects of 10 years of aging and racing neither improve nor worsen net performance. In conclusion, these data suggest that although these runners showed similar patterns of change in race speed over a 10-year period, the extent of change in performance was greater in younger than in older runners.     

Peep show establishments, police activity, public place, and time: a study of secondary effects in San Diego, California

An empirical study was undertaken in San Diego, California, to test assumptions made by the government and by conservative religious policy advocates that there is a greater incidence of crime in the vicinity of peep show establishments. We asked two questions: (a) Is criminal activity in San Diego particularly acute at peep show establishments compared to surrounding control locations? and (b) Is criminal activity in San Diego disproportionately greater at or near peep show establishments between the hours of 2 a.m. and 6 a.m. compared to other times of the day? The levels of crime activity and the expenditure of police resources were examined by measuring the number of calls-for-service (CFSs) to the police within a 1,000-ft. area on either side of the peep show establishments and comparably-sized control areas beyond the immediate 1,000-foot area. A more focused late-night (2 a.m. to 6 a.m.) analysis was also undertaken. The results showed no reliable evidence of differences in crime levels between the control and test areas, nor was there any evidence of disproportionately greater amounts of crime within the 2 a.m. to 6 a.m. time period in the areas surrounding the peep show establishments. We concluded that San Diego does not have a problem with crime at the peep show establishments generally, nor is there a heightened problem with crime during the 2 a.m. to 6 a.m. period. We discuss the implications of assuming that peep show establishments are associated with negative effects in the community and the possibility of viewpoint discrimination against sex communication.     

A comparison of three methods of estimating the logistic regression coefficients

A Sampling experiment performed using data collected for a large clinical trial shows that the discriminant function estimates of the logistic regression coefficients for discrete variables may be severely biased. The simulations show that the mixed variable location model coefficient estimates have bias which is of the same magnitude as the bias in the coefficient estimates obtained using conditional maximum likelihood estimates but require about one-tenth of the computer time.     

Is Adolescent Employment Still a Risk Factor for High School Dropout?

Past cohorts of teenagers who spent long hours in jobs were more likely to drop out of high school than those who worked moderate hours or did not work at all. This article examines the association between employment intensity and dropout among adolescents in the High School Longitudinal Study of 2009 who traversed high school during a time of decreased prevalence of both employment and dropout relative to earlier cohorts. Analyses reveal that a relatively small percentage of teenagers nowadays are characterized as either intensive workers or dropouts (around 11% each). Yet, despite declines in intensive employment and dropout, disadvantaged youth remain overrepresented in both groups, and intensive work is still a risk factor for poor grades and dropout.     

Olympic Games in Japan and East Asia: Images and Legacies: An Introduction

This is the Introduction to the special issue entitled "The Olympic Games in Japan and East Asia: Images and Legacies.”