TWGDAM validation of AmpFlSTR PCR amplification kits for forensic DNA casework

Laboratory procedures used in short tandem repeat (STR) analysis were subjected to various scenarios that assessed reliability and identified potential limitations. These validation studies were designed as recommended by the Technical Working Group on DNA Analysis Methods (TWGDAM) and the DNA Advisory Board (DAB) (17,18). Various DNA samples were amplified by the polymerase chain reaction (PCR) using AmpFlSTR PCR Amplification Kits (i.e., AmpFlSTR Green I, Profiler, Profiler Plus, and COfiler kits), detected with ABI Prism instrumentation, and analyzed using GeneScan and Genotyper software. Data acquired in these studies reinforced an existing body of knowledge and expertise regarding application and interpretation of STR typing in the forensic science community. Consistent STR genotypes were detected in various body tissues and fluids. Inter-laboratory comparisons produced concordant genotype results. Quantitative interpretational aids for DNA mixtures were characterized. Ability of the typing systems to type potentially compromised samples reliably was evaluated. Nonprobative case evidentiary DNA was successfully amplified, genotyped, and interpreted. Potential limitations or cautionary factors in the interpretation of minimal fluorescence intensity were demonstrated. Differential amplification between loci was observed when PCR was inhibited; preferential amplification typically was not. Single AmpFlSTR locus amplification did not offer consistent benefit over AmpFlSTR multiplexing, even in cases of DNA degradation or PCR inhibition. During rigorous evaluation, AmpFlSTR PCR Amplification Kits reproducibly yielded sensitive and locus-specific results, as required in routine forensic analyses.     

Psychological mindedness and abstract reasoning in late childhood and adolescence: An exploration using new instruments

This study introduces two new measures of psychological mindedness, applying them in a study of the growth of abstract thinking in children and adolescents in a developmental design. The capacity to achieve psychological understanding of the self and of others involves comprehension of the motives, attitudes, and characteristics of the self and others. Psychological mindedness toward the self (PS) and toward others (PO) may be seen as complex cognitive capacities that should show a pattern of related development in childhood. Three groups of 60 fifth, eighth, and twelfth graders completed two measures of formal operations and two instruments to assess the two components of psychological mindedness. We find that psychological mindedness and abstract thinking both increase significantly with age, although the relationship between them is complex and varies with gender and age. Because the development of abstract reasoning skills does not correlate with the development of psychological mindedness in a simple way, a more complex model is necessary, taking age and gender differences into account. Performance on the two measures of psychological mindedness is found to be largely unrelated, suggesting that these are two different psychological skills. Implications of these findings are discussed, with special reference to education, peer counseling, and psychotherapy.Received Ph.D. from University of Michigan and psychoanalytic training from The Michigan Psychoanalytic Institute. Main research interests are psychoanalytic theory, the therapeutic alliance, and insight and self-observation.Received Ph.D. from University of Michigan. Main research interests are adolescent development, peer counseling, short-term psychotherapy, and the psychology of women.Received M.A. from The University of Michigan. Main research interests are infant mental health and attachment theory.Received M.A. from The University of Michigan. Main research interests are gender identity and children of divorce.Received B.A. from The University of Michigan. Main research interests are gender issues and adolescent development.