Predicting Adolescents' Initiation of Intercourse and Contraceptive Use

This paper examines whether variables consistent with problem behavior theory predict grade of onset of first intercourse and adoption of effective contraception. A total sample of 3,419 Wisconsin adolescents in Grades 7, 9, and 11 participated in a survey of health-related behaviors administered 3 times across a 6-year period. The sample is 87% White. Multiple regression methods generated different models for onset of sexual intercourse vs. contraceptive adoption. Consistent with problem behavior theory, sexual onset is predicted by the adolescent's behavioral system, perceived peer substance use/abuse, importance of friends, and extent to which the adolescent felt harried and believed it was okay to break laws. Contraceptive adoption is predicted by family structure, socioeconomic variables, and self-esteem. Age and gender model differences emerged.     

Validation of a full body 3-D dynamic linked segment model

In studies related to human movement, linked segment models (LSM's) are often used to quantify forces and torques, generated in body joints. Some LSM's represent only a few body segments. Others, for instance used in studies on the control of whole body movements, include all body segments. As a consequence of the complexity of 3-dimensional (3-D) analyses, most LSM's are restricted to one plane of motion. However, in asymmetric movements this may result in a loss of relevant information. The aim of the current study was to develop and validate a 3-D LSM including all body segments. Braces with markers, attached to all body segments, were used to record the body movements. The validation of the model was accomplished by comparing the measured with the estimated ground reaction force and by comparing the torques at the lumbo-sacral joint that resulted from a bottom-up and a top-down mechanical analysis. For both comparisons, reasonable to good agreement was found. Sources of error that could not be analysed this way, were subjected to an additional sensitivity analysis. It was concluded that the internal validity of the current model is quite satisfactory.     

An investigation of the validity of the SPSI and SPSI-R in differentiating high-suicidal from depressed,low-suicidal college students

The present study examined the validity of the Social Problem-Solving Inventory (SPSI) and SPSI—Revised in differentiating 65 high-suicidal from 63 depressed, low-suicidal college students. Results from multivariate analyses indicated overall differences in problem-solving between these two groups as measured by the SPSI but not by the SPSI-R. Further examination of these differences revealed the high-suicidal group was different in problem-solving orientation, rather than problem-solving skills, compared to the depressed, low-suicidal group. However, when depression was statistically controlled in hierarchical regression analyses, none of the problem-solving measures predicted group membership. The superiority of the SPSI to the SPSI-R in differentiating these two groups appears to be accounted for by the elimination of 28 items in the revised version, many of which measure orientation to problem-solving. Also explored was the possibility that objective measures of problem-solving provide a better prediction of adjustment than do self-report measures.     

THE VISUAL SYSTEM'S MEASUREMENT OF INVARIANTS NEED NOT ITSELF BE INVARIANT

Abstract— When two shapes that differ in orientation or size have to be compared or objects have to be recognized from different viewpoints, the response time and error rate art systematically affected by the size of the geometric difference. In this report, we argue that these effects are not necessarily solid evidence for the use of mental transformations and against the use of invariants by the visual system. We report an experiment in which observers were asked to give affine-invariant coordinates of a point located in an affine frame defined by three other points. The angle subtended by the coordinate axes and the ratio of the lengths of their unit vectors systematically affected the measurement errors. This finding demonstrates that the visual system's measurement of invariants need not itself be invariant.     

Philosophy of medicine in the Netherlands

This report explores the relationship between philosophy and medicine in the Netherlands. In Section 1 we outline the ups and downs of medico-philosophical research in our country: pre-war flourishing, post-war decline, and modern renaissance. In Section 2 we review recent Dutch literature in the philosophy of medicine. The topics dealt with include methodology of medical science, alternative medicine, the basic concepts of medicine, anthropological medicine, medicalization, medicine and culture, and health care ethics.     

Meaning,amount of processing,and memory for words

Two experiments were carried out in order to try to resolve the controversy about whether the semantic processing of a word necessarily involves all the elements of its meaning. In the first experiment, subjects categorized a list of auditorially presented words according to whether or not they were natural consumable solids (e.g., “apple“). They were then given an unexpected test of their ability to recall the whole list, which contained equal numbers of words with none, one, two, or all three of the target components. The results confirmed the prediction that the greater the number of components a word has in common with a target category, the better it will be recalled. The second experiment used a visual presentation of a list of words, which subjects scanned for members of a particular target category. There were four different target categories assigned to independent groups of subjects. The results again confirmed the prediction. On the assumption that memorability in such tasks is determined by amount of processing, we conclude that some elements of the meaning of a word can be processed without having to process all of them.