The effect of various stain carriers on the quality and quantity of DNA extracted from dried bloodstains

Bloodstains were made with 200 microliters blood on each of 11 different common substrates to examine the effect of the stain carrier on the amount and quality of DNA recoverable. High-molecular-weight DNA was extracted from all samples after 2 days. The yield of DNA from each sample varied considerably, not only between the different stain carriers but also within a given category. With a DNA yield of up to 10 micrograms, paper, glass, nylon, wood, smooth leather and wool gave the best results, followed by blue denim and wallpaper (up to 6 micrograms), cotton fabric and carpeting (up to 4 micrograms) and suede (up to 2 micrograms). For several stain carriers the DNA-containing solution was contaminated by chemical substances, which in the case of the blue denim, suede, and carpet samples inhibited the digestion of the DNA with restriction enzymes and prevented DNA typing. The different textures of the stain carriers tested and (as for varying yields on the same carrier) the differing degree of loss of DNA during extraction and the physiological variation in the number of leukocytes in human blood are discussed as possible reasons for the wide range of variation in the amounts of DNA it was possible to extract.     

CRIME IN EMERGING ADULTHOOD*

The extent to which local life circumstances influence criminal activity has been the focus of much theoretical debate. Although empirical research has been initiated, it remains limited. Herein, we use data on 524 serious offenders from the California Youth Authority for a seven‐year post‐parole period to examine the relationship between changes in local life circumstances and criminal activity. We extend previous research by employing a statistical model that accounts for the joint distribution of violent and nonviolent crime during the late teens and twenties in order to present information on patterns of criminal activity during a newly recognized developmental period of the life course, “emerging adulthood.”     

Parents' Reactions to Child Day Care Organizations: The Influence of Perceptions of Procedures and the Role of Organizations' Trustworthiness

On the basis of the uncertainty management model, we argue here that when people are uncertain about an organization's trustworthiness, they may resolve the question how they should react toward the organization by relying on their perceptions of the organization's procedures. As a consequence, we predicted that the reactions of parents whose child was in a day care center would be strongly influenced by their perceptions of the procedures used by the organization that was responsible for their children's day care when the parents would be uncertain about the organization's trustworthiness. However, when parents would be certain that the organization could be trusted they would be less in need of procedural information, yielding less strong effects of perceived procedure on parents' reactions. The findings of a survey study corroborate this line of reasoning. In the discussion it is argued that these findings suggest that people especially rely on their perceptions of procedures when they are uncertain about important aspects of their lives, such as the trustworthiness of organizations that are responsible for their children's day care.     

Understanding Recreation and Sport as a Rehabilitative Tool Within Juvenile Justice Programs

This article discusses relevant literature on the potential benefits of sport, recreation, and leisure, and how these benefits relate to rehabilitation of juveniles. Many professionals involved in juvenile rehabilitation believe sport and recreation are beneficial adjuncts to treatment programming; however, it can be difficult to structure sport and recreation in ways that directly correspond to treatment goals. The purpose of this article is to provide insights for professionals working with juveniles on how sport and recreation programming can be an effective means of helping to achieve rehabilitation goals. Attention is given to approaches, particularly the Teaching Games for Understanding model (Bunker & Thorpe, 1982), which can be used to effectively link recreation and sport to the rehabilitation process.     

颅脑损伤患者智能和记忆损害的相关因素研究

目的探讨交通事故所致颅脑损伤伤者的智能和记忆损害及相关因素。方法 统计分析成都市1999年1月1日至2001年12月31日间因交通事故造成颅脑损伤的652例伤者的心理测验、脑电图及脑影像学资料。结果研究组平均智商为77.85±15.97,27.9％的伤者智商低于70;51.9％的记忆商低于51。智力损害与文化程度、左颞叶损伤、≥3个脑叶损伤以及脑电图异常明显相关;记忆损害与文化程度、损伤和鉴定检查的间隔时间、脑于损伤、左颞叶损伤、脑电图异常明显相关。结论交通事故造成颅脑损伤的伤者多有不同程度的智力和记忆损害,且与左颞叶损伤、脑电图异常、文化程度、脑干损伤等因素有关。