Kinematics of cycling in relation to anterior knee pain and patellar tendinitis

The coronal and sagittal plane leg movements of 24 experienced male cyclists were assessed using video analysis while cycling on a Kingcycle windload simulator. The cyclists were grouped into those with a history of injury and an asymptomatic group on the basis of self-reported injury status. The ages, cycling experience, competition distances and competition speeds of the two groups were compared using Student's t-test. No significant differences (P < 0.05) were found for any of these variables. The maximum and minimum shank adduction, shank adduction velocities, knee flexion and ankle dorsiflexion values were also compared using Student's t-test. Significant differences were found at the point of maximum adduction (1.9 degrees; P = 0.019) and minimum dorsiflexion (4.9 degrees; P = 0.014). These differences indicated more dorsiflexion and greater abduction on the part of the symptomatic cyclists, supporting previous research that found that cyclists with a history of injury differ from those without a history of injury in the coronal plane leg movement patterns they adopt. Also, the most extreme medial position of the knee relative to the ankle occurred during knee extension. This supports the potential injury mechanism proposed by Francis (1986), which had previously only been examined using coronal plane kinematics.     

Touch your toes! Developing a direct measure of behavioral regulation in early childhood

Behavioral aspects of self-regulation, including controlling and directing actions, paying attention, and remembering instructions, are critical for successful functioning in preschool and elementary school. In recent years, several direct assessments of these skills have appeared, but few studies provide complete psychometric data and many are not easy to administer. We developed a direct measure of children's behavioral regulation, the Head-to-Toes Task, and report performance of participants aged 36–78 months, including a group of Spanish-speaking children, from two different sites (N = 353; N = 92). We examined construct validity, examiner reliability, sources of variation, and associations between task scores and background characteristics. Results showed that the task was valid, reliable, and demonstrated variability in children's scores. A cross-classified hierarchical growth curve analysis indicated that girls, participants assessed in English, and higher-socioeconomic status (SES) children achieved slightly higher average scores than did boys, Spanish-speaking and lower-SES children, but effect sizes were small. Older participants achieved higher scores than did younger children, and there were no effects for site. Results suggest that the Head-to-Toes Task is an informative and easy-to-administer direct assessment of children's behavioral regulation. We discuss implications for its use in early childhood settings.     

Substituting SAT II: Subject Tests for SAT I: Reasoning Tests: Impact on Admitted Class Composition and Quality

Using data from a sample of 10 colleges at which most students had taken both SAT I: Reasoning tests and SAT II: Subject tests, we simulated the effects of making selection decisions using SAT II scores in place of SAT I scores. Specifically, we treated the students in each college as forming the applicant pool for a more select college, and then selected the top two thirds (and top one third) of the students using high school grade point average combined with either SAT I scores or the average of SAT II scores. Success rates, in terms of first-year grade point averages, were virtually identical for students selected by the different models. The percentage of African American, Asian American, and White students selected varied only slightly across models. Appreciably more Mexican American and Other Latino students were selected with the model that used SAT II scores in place of SAT I scores because these students submitted subject test scores for the Spanish test on which they had high scores.     

A two-stage proxy variable approach to estimating movie box office receipts

This paper advances the ongoing discussion of methods for predicting movie box office revenues with two contributions to the methodology and an out-of-sample test of the model. The first innovation is the development of a two-stage model using publicly available pre-release indicators to predict (1) initial week and (2) subsequent run box office revenues. To incorporate the experience-good nature of movies, the second stage is estimated by incorporating a proxy variable for box office success during the first week relative to predicted first week success. The second contribution is an empirical test of De Vany and Walls’ (J Econ Dyn Control 28:1035–1057, 2004) finding that the distribution of movie revenues has “heavy tails” and follows a non-Gaussian stable distribution with infinite variance. We estimate the two-stage model of a movie’s box office success on all general release movies in 1 year with both the Gaussian and stable distribution with heavy tails and infinite variance and find no evidence for the stable distribution in either stage of the estimation. This two-stage model is validated by comparing all general release movies in 3 future years (out-of-sample data) to the model’s predictions.     

Association between self-reported health and physical and/or sexual abuse experienced before age 18

OBJECTIVE: The present study evaluated the association between women's health and physical and sexual abuse suffered before age 18. METHODS: A total of 3,568 randomly sampled insured women ages 18-64 completed a telephone interview to assess history of physical only, sexual only, or both physical and sexual abuse before age 18 (Behavioral Risk Factor Surveillance System); and current health (Short Form-36, Center for Epidemiologic Studies-Depression, Presence of Symptoms surveys). Adjusted analyses compared the health of women with physical abuse only, sexual abuse only, or physical and sexual abuse to the health of women without these abuse histories. RESULTS: Poorest health status was observed in women with a history of both physical and sexual child abuse compared to women without these abuse histories. In models that adjusted for age and income, women with both abuse types had increased prevalence of depression (prevalence ratio, 2.16), severe depression (PR, 2.84), physical symptoms (PR range, 1.33 for joint pain to 2.78 for nausea/vomiting), fair/poor health (PR, 1.84), and lower SF-36 scores (3.15-5.40 points lower). Women with physical abuse only or sexual abuse only also had higher prevalence of symptoms and lower SF-36 scores but the associations were not as strong. CONCLUSIONS: This study adds to the literature showing a graded association between multiple adverse events in childhood and adult health.     

The influence of partner cues on the extinction of causal judgments in people

Studies in laboratory animals have shown that the extinction of a conditioned stimulus, A, is regulated by the associative history of a second stimulus, X, when the two are extinguished in simultaneous compound: An inhibitory X protects A from extinction (Rescorla Learning & Behavior, 31, 124–132, 2003), whereas an excitatory X facilitates, and under some circumstances deepens, the extinction of A (Rescorla Journal of Experimental Psychology: Animal Behavior Processes, 26, 251–260, 2000, Journal of Experimental Psychology: Animal Behavior Processes, 32, 135–144, 2006). In the present study, we used the allergist task to examine whether the extinction of causal judgments in people is similarly regulated by the causal status of co-present stimuli. Experiment 1 showed that a cue trained as a conditioned inhibitor protected a target cue from extinction: The target extinguished in compound with the inhibitor was rated as being more causal of the outcome than was a target extinguished in compound with a control cue lacking inhibitory properties. In contrast, the remaining experiments showed that the extinction of a target cue was regulated by the presence, but not the causal status, of a partner cue: Target cues extinguished in compound were protected from extinction, and no evidence showed that an already extinguished partner conferred more protection (Exp. 2), or that an excitatory partner conferred any less protection (Exps. 2 and 3), or that an excitatory partner deepened the extinction of its already extinguished target. These findings are inconsistent with elemental models that rely on a common error term to explain associative changes in extinction. They are largely, but not completely, consistent with the configural model proposed by Pearce (Psychological Review, 94, 61–73, 1987), which predicts an ordering of levels of protection that was not observed.