A genetic basis for anomalous band patterns encountered during DNA STR profiling

Since 1995 the Forensic Science Service (FSS) has carried out DNA profiling of reference samples for the UK National DNA Database and in forensic casework using two multiplex STR profiling systems. During this period, profiles with anomalous banding patterns, although comparatively rare, have been encountered regularly. The FSS has collected instances of triallelic patterns and aberrant diallelic patterns. A systematic examination of these patterns has provided insight into their underlying genetic cause. The triallelic patterns could be classified into two types based on the relative intensities of their component alleles. In the Type 1 pattern the alleles were of uneven intensity, whereas in the Type 2 pattern, all three alleles were of even intensity. Evidence is presented that the more frequent Type 1 pattern is the result of somatic mutation at a heterozygous locus, and the Type 2 pattern is the result of a localized chromosomal rearrangement at a heterozygous locus. Directly from the Type 1 pattern, it was possible to deduce the size difference between the progenitor and mutated allele. All mutational changes were found to be multiples of four nucleotides, suggesting the loss or addition of one or more tetrameric repeat units. Aberrant diallelic patterns were identified by analysts due to an unexpectedly large difference in intensity between alleles at a heterozygous locus. While some of these diallelic patterns are likely caused by the same genetic phenomena described above occurring at a homozygous locus, others are demonstrated to be caused by a mutation in the primer binding sequence, leading to a reduction in amplification efficiency of one allele. It is concluded that based on a visual inspection of a profile, it is possible to infer a likely genetic basis directly from the triallelic pattern. By contrast, the aberrant diallelic patterns can be due to any one of a number of possible genetic effects.     

Correlates of self-concept among black early adolescents

This study examines the self-concept of Black eighth-grade students from the Midwest in relation to Black acceptance, social intimacy, locus of control, and sex-role type. Twenty-eight students high in self-concept were compared with 31 students whose self-concept was low. As predicted, the high self-concept group scored higher than the low self-concept group in intimacy, internality, and acceptance of black identity. As also predicted, the high self-concept group had a significantly greater number of adolescents with masculine and androgynous sex roles than the low self-concept group; Black females with high self-concepts included a larger proportion of individuals with androgynous sex roles than low self-concept females. However, the prediction that high self-concept males would have a larger proportion of masculine sex roles than low self-concept males was not supported. The difficult situation of the low self-concept adolescents is discussed, along with the implications for intervention.On clinic internship at Smolian Psychiatric Clinic in Birmingham, Alabama. Major interests are clinical psychology and Black identity.Received Ph.D. in social psychology from the University of Colorado. Major interests are the development of intimacy and identity in adolescence and young adulthood.     

Toward a contemporary tradition for menarche

A cultural tradition to acknowledge a girl's first menstrual period is proposed in order to overcome the negative connotation of the event. Three basic questions regarding such a tradition are addressed: Who would participate? What would it mean? What type of activity should it be? A research team consisting of a psychologist, a nurse, and a social worker suggests answers based on their interviews with mothers and daughters, as well as their collection of menarche anecdotes from women psychologists.     

School Socioeconomic Contexts and Adolescent Self-Descriptions in India

Many Western developmental theorists (e.g., Baumeister, 1986; Erikson, 1968) propose an increasingly autonomous self-construal during adolescence (e.g., Erikson, 1968). In this study self-construal among 191 older children and young adolescents (ages 9 through 16) from private and public schools in Madras, India, was assessed by means of the self attitudes instrument (Kuhn and McPartland, 1954) and the scoring system of Trafimow et al. (1991). Individuality in self-construal did not increase with age across all groups but was mediated by socioeconomic strata (SES, as indexed by school) and gender. Boys from high SES schools best conformed to the Western conceptualization of self-concept development. Boys from lower SES schools exhibited opposite patterns with higher group responses in the older age group. The findings highlight the importance of social context in individual development.     

JOINT CUSTODY AND THE PRESCHOOL CHILD

A longitudinal study of 25 families, with children aged 14 months—5 years, in joint custody, is reported. Varying motivations that lead divorcing parents to undertake and sustain joint custody are discussed, together with the stresses and gratifications of these arrangements for the parents and children. Findings are that where both parents are motivated primarily by interest in the child, where the parenting is sensitive and where the child is shielded from interparental conflict, young children do well. Such families were not the majority in this study. Significant differences emerged in the adjustment of the 1–3 age group as compared with the 3–5 age group which point to greater difficulties for the 3–5 year-olds.     

‘I Wasn’t Really Bonded with My Family’: Attachment,Loss and Violence among Adolescent Female Offenders

This study analyzes the role of trauma and disrupted attachments in the development of adolescent girls’ violent behavior. A grounded theory approach was applied to the narratives of 24 young women (age 13–16 years old) who were adjudicated and remanded to custody for an assault or robbery. Three types of loss were inductively derived from the data (death of a loved one, physical absence, and psychological unavailability) as were two categories of violence (in the home and in the community). Findings suggest that extensive losses and violent experiences disrupted the young women’s attachment to their caregivers, and these experiences were disregarded or inadequately addressed. Detachment and the absence of supportive others left the young women poised to engage in a variety of maladaptive behaviors including violence. Theoretical and programmatic implications are discussed.     

Y-STR analysis on DNA mixture samples—Results of a collaborative project of the ENFSI DNA Working Group

The ENFSI (European Network of Forensic Science Institutes) DNA Working Group undertook a collaborative project on Y-STR typing of DNA mixture samples that were centrally prepared and thoroughly tested prior to the shipment. Four commercial Y-STR typing kits (Y-Filer, Applied Biosystems, Foster City, CA, USA; Argus Y Nonaplex, Biotype, Dresden, Germany; Powerplex Y, Promega, Madison, WI, USA; and DYSplex-3, SERAC, Bad Homburg, Germany) were used for the amplification of the mixture samples. The results of the study showed a striking inter-laboratory difference of kit performance as determined from the peak heights of the obtained Y-STR genotypes. Variation in quantity and quality of the shipped DNA can be excluded as reason for the observed differences because both samples and shipping conditions were found to be reproducible in an earlier study. The results suggest that in some cases a laboratory-specific optimization process is indicated to reach a comparable sensitivity for the analysis of minute amounts of DNA.     

The experimental psychologist in court

This special issue comprises articles by psychologists, legal scholars, and ethicists on the ethics of expert testimony by experimental psychologists. In it the major ethical questions facing the prospective expert witness are clarified, and alternative positions on these issues are defined and debated. Fundamentals of moral reasoning are discussed, and the realities of interaction with a judicial system that subjects the psychologist to a variety of pressures and limitations are made apparent. The aim is not to offer final answers to complex ethical questions, but rather to provide a framework within which the questions can be considered by the individual psychologist.The conference on ethics of expert testimony by experimental psychologists was supported by National Science Foundation grant No. ISP-8209940. We thank Rachelle Hollander of the Ethics and Values in Science and Technology Program, Joe Young of the Memory and Cognitive Processes Program, and Eric Juengst of the National Endowment for the Humanities for their help in bringing about the conference.