Plain tales from the rice trade: Indications of vertical integration in foodgrain markets in Bangladesh

Through a series of case studies of the interactions between foodgrain traders and between traders and producers, this article questions the widespread belief that foodgrain markets in Bangladesh are characterised by low trading margins, no vertical integration and a general competitive health. The article indicates that merchant's capital plays two key roles in the market (i) in some areas of the country, the provision of merchant's credit deprives the poor producer of access to the market price for his or her output; (ii) working capital extended to subordinate traders may also enable a small group of large traders to influence prices. Further case studies of the interaction between traders and the state food distribution system indicate ways in which the private market may be able to frustrate or limit policies intended to regulate its operation. These insights suggest that the domination of merchant's capital may be one factor explaining low levels of productivity in the Bangladesh countryside. They also raise questions about the consequences of policies intended to increase the role of private trade in the economy.     

A new typology for R&D laboratories: Implications for policy analysts

Science policy analysts have traditionally classified R&D laboratories as government, private, or university. The authors argue that this view is outmoded and provides little help in understanding the rapidly changing environment of R&D laboratories. They provide and test an alternative scheme designed to cope with “sector blurring” and the intermingling of market and political influences on R&D laboratories. The authors also discuss implications of their scheme for a variety of contemporary science policy issues.     

The effect of childhood trauma on later psychological adjustment

This study examined whether adult attachment and cognitive distortion mediate the relationship between childhood trauma and psychological adjustment. The participants were 219 students (40 men and 117 women) enrolled in a university degree. Participants completed the Childhood Trauma Questionnaire, which assessed retrospective accounts of childhood trauma; the Relationships Scales Questionnaire, which measured two dimensions of adult attachment (model-of-self and model-of-other); the Cognitive Distortions Scale, which measured internal attributions and perceptions of controllability; and the Trauma Symptom Inventory, which assessed posttraumatic symptoms and was used in this study to measure psychological adjustment. Results supported the hypothesis that model-of-self and cognitive distortion are related constructs. The influence of model-of-self on psychological adjustment however was only via its effect on cognitive processes. In other words, a negative model-of-self influenced cognitive distortion, which in turn influenced the expression of symptoms in adults reporting a history of childhood trauma. The implications for therapy were considered.     

Trajectories of Substance Use Among Young American Indian Adolescents: Patterns and Predictors

Substance use often begins earlier among American Indians compared to the rest of the United States, a troubling reality that puts Native youth at risk for escalating and problematic use. We need to understand more fully patterns of emergent substance use among young American Indian adolescents, risk factors associated with escalating use trajectories, and protective factors that can be parlayed into robust prevention strategies. We used growth mixture modeling with longitudinal data from middle-school students on a Northern Plains reservation (Wave 1 N = 381, M age at baseline = 12.77, 45.6 % female) to identify subgroups exhibiting different trajectories of cigarette, alcohol, and marijuana use. We explored how both risk (e.g., exposure to stressful events, deviant peers) and protective (e.g., positive parent–child relationships, cultural identity) factors were related to these trajectories. For all substances, most youth showed trajectories characterized by low rates of substance use (nonuser classes), but many also showed patterns characterized by high and/or escalating use. Across substances, exposure to stress, early puberty, and deviant peer relationships were associated with the more problematic patterns, while strong relationships with parents and prosocial peers were associated with nonuser classes. Our measures of emergent cultural identity were generally unrelated to substance use trajectory classes among these young adolescents. The findings point to the importance of early substance use prevention programs for American Indian youth that attenuate the impact of exposure to stressful events, redirect peer relationships, and foster positive parent influences. They also point to the need to explore more fully how cultural influences can be captured.     

Book reviews

Conversations with lillian hellman edited by Jackson R. Bryer‐Jackson and London: University Press of Mississippi, 1986, 298 pp. $19.95 (cloth), $9.95 (paper).

PROVINCE OF REASON: AMERICAN LIVES IN A NEW AGE OF SCIENCE by Sam Bass Warner, Jr. Harvard University Press, 1984. (cloth, $20.00)     

Real-time forensic DNA analysis at a crime scene using a portable microchip analyzer

An integrated lab-on-a-chip system has been developed and successfully utilized for real-time forensic short tandem repeat (STR) analysis. The microdevice comprises a 160-nL polymerase chain reaction reactor with an on-chip heater and a temperature sensor for thermal cycling, microvalves for fluidic manipulation, a co-injector for sizing standard injection, and a 7-cm-long separation channel for capillary electrophoretic analysis. A 9-plex autosomal STR typing system consisting of amelogenin and eight combined DNA index system (CODIS) core STR loci has been constructed and optimized for this real-time human identification study. Reproducible STR profiles of control DNA samples are obtained in 2 h and 30 min with ≤0.8 bp allele typing accuracy. The minimal amount of DNA required for a complete DNA profile is 100 copies. To critically evaluate the capabilities of our portable microsystem as well as its compatibility with crime scene investigation processes, real-time STR analyses were carried out at a mock crime scene prepared by the Palm Beach County Sheriff's Office (PBSO). Blood stain sample collection, DNA extraction, and STR analyses on the portable microsystem were conducted in the field, and a successful “mock” CODIS hit was generated on the suspect's sample within 6 h. This demonstration of on-site STR analysis establishes the feasibility of real-time DNA typing to identify the contributor of probative biological evidence at a crime scene and for real-time human identification.