Natural DNA mixtures generated in fraternal twins in utero

Analysis of multiple genetic loci using short tandem repeats (STR) is widely used in human identity testing because the extensive polymorphism at these loci allows for a high degree of discrimination among individuals. We recently received a forensic case that included several pieces of evidence and reference blood samples. Upon initial testing, one of the suspects had a DNA profile that included three alleles at four of the nine loci tested (vWA, FGA, TH01, and D5S818). At each locus, two of the alleles appeared to be "major" alleles with a third "minor" allele present. The profile appeared to be a mixture of two people. Contamination of this first reference sample was suspected and a second, unopened blood specimen was requested from this individual. The DNA profile from this second reference specimen was identical to that of the original specimen at each locus. One of the evidence samples also displayed an identical mixed DNA profile matching that of the reference specimens mentioned above. The relative peak heights of the two "major" and one "minor" allele remained constant in all three samples. Additional background information revealed that the suspect had not received a bone marrow transplant or blood transfusion. However, it was disclosed that this individual is a fraternal (dizygotic) twin. We hypothesize that an exchange of blood cells between the fetuses occurred in utero and that the additional alleles present in these reference samples are derived from cells contributed by his twin sibling. No additional specimens from the suspect or his twin could be obtained for confirmation, and our hypothesis remains untested. Forensic scientists should be aware of this possibility when faced with a DNA profile in which extra alleles at multiple loci are detected.     

Effective child support policy for low‐income families: evidence from street level research

Since 1984, policymakers have increasingly turned their attention to reforming the child support system. Despite this attention, the child support system has often failed to increase the economic security of single‐parent families. This article analyzes findings from recent qualitative studies to explain why the child support system breaks down for so many low‐income families. This research suggests that parents often prefer informal arrangements of support and do not comply with child support regulations they perceive to be unfair, counterproductive, or punitive. It also suggests that there is a mismatch between the premises and goals of child support policy and what low‐income parents desire from the system. This mismatch impedes low‐income parents' willingness and ability to comply with existing policy, even when they wish to do so, and will make reform difficult. © 2001 by the Association for Public Policy Analysis and Management.     

Modeling Temperature Variations Using Monte Carlo Simulation: Implications for Estimation of the Postmortem Interval Based on Insect Development Times*†

The association between insect development and temperature is well established. Thermal summation using accumulated degree-day measures is commonly used. However, the time at which evidence is collected is important in these estimates. The aim of this study was to provide a simulated model of the effect of temperatures on six dipteran species commonly associated with cadavers, from the death scene to the refrigerator, and finally at the time of autopsy. Temperatures measurements were sampled over a 16-month period from the external environment (external to the mortuary), within the mortuary refrigerator, and within the mortuary autopsy suite. Monte Carlo simulation using accumulated degree-days (ADD) was used to estimate the variations based on the mean and standard deviation of the temperature measurements. It was found that there was a negative correlation between the base temperature of the fly species (lowest temperature at which the flies will survive) and developmental likelihood. Species with high base temperatures (Chrysomya albiceps, Chrysomya chloropyga, and Musca domestica) were less likely to continue development in refrigerators than species with lower base temperatures (Lucilia sericata and Piophila casei). The findings of this study highlight the importance of recording temperature measurements and the period of refrigeration on PMI estimation especially when continued development occurs in spite of a period of cooling of the insect evidence.     

The Role of Violent Media Preference in Cumulative Developmental Risk for Violence and General Aggression

The impact of exposure to violence in the media on the long-term development and short-term expression of aggressive behavior has been well documented. However, gaps in this literature remain, and in particular the role of violent media exposure in shaping violent and other serious antisocial behavior has not been investigated. Further, studies of violent media effects typically have not sampled from populations with confirmed histories of violent and/or nonviolent antisocial behavior. In this study, we analyzed data on 820 youth, including 390 juvenile delinquents and 430 high school students, to examine the relation of violent media use to involvement in violence and general aggression. Using criterion scores developed through cross-informant modeling of data from self, parent/guardian, and teacher/staff reports, we observed that childhood and adolescent violent media preferences contributed significantly to the prediction of violence and general aggression from cumulative risk totals. Findings represent a new and important direction for research on the role of violent media use in the broader matrix of risk factors for youth violence.

‘The perfect equality of all persons before the law’: the Personal Rights Association and the discourse of civil rights in Britain, 1871–1885

The Personal Rights Association was established in 1871 to watch, restrain and influence legislation ‘in matters affecting the personal rights and liberties of the people’. Though initially its remit was to scrutinise legislation for terms that would be prejudicial to women, this soon extended to criticism of increasing incursions into male freedom. The PRA's membership, which comprised both sexes, included a cohort of male parliamentarians and intellectuals who took their commitment to civil liberties into the heart of government. Classified by one critic as ‘fussy busy-bodies [and] fourth-rate politicians’, this article reveals a ‘feminisation’ of these elite men hardly considered in the rhetoric of the middle-class radical.     

Rural and Non-Rural African American Youth: Does Context Matter in the Etiology of Problem Behaviors?

The current study provides new information on the etiology of adolescent problem behaviors in African American youth by testing the importance of known predictors, namely parenting measures (monitoring, support, and communication), peers, and neighborhood characteristics across rural and non-rural developmental contexts. More specifically, the study examined whether rural versus non-rural developmental contexts moderated the relationships between known predictors and a variety of problem behaviors (alcohol use, drug use, delinquency, and violence). Data were collected from N = 687 rural and N = 182 non-rural African American adolescents (mean age = 15.8 years). Findings indicate that both parenting constructs and peer deviance had significant effects on problem behaviors and that these effects were consistent across rural and non-rural developmental contexts. The study results are discussed in terms of their implications for ecological frameworks for testing problem behavior etiology.

A chromatic presence: Barbara Hammer and “What You Are Not Supposed to Look At”

Since the 1970s, Barbara Hammer has been known for her photographs and experimental films chronicling and exploring lesbian experience. Since her 2006 diagnosis of ovarian cancer, she has ventured into an unflinching depiction of her own illness, aging, and dying. In “What You Are Not Supposed to Look At,” a 2014 collage series collaboration with Ingrid Christie, Hammer and Christie illuminate new modes of thinking about life, illness, and what we are describing the prismatic gaze: a mode of looking that subverts objectification and objectivity by positing sensuality, relationality, and spectacularity.