The Probabilistic Genotyping Software STRmix: Utility and Evidence for its Validity

Forensic DNA interpretation is transitioning from manual interpretation based usually on binary decision‐making toward computer‐based systems that model the probability of the profile given different explanations for it, termed probabilistic genotyping (PG). Decision‐making by laboratories to implement probability‐based interpretation should be based on scientific principles for validity and information that supports its utility, such as criteria to support admissibility. The principles behind STRmix? are outlined in this study and include standard mathematics and modeling of peak heights and variability in those heights. All PG methods generate a likelihood ratio (LR) and require the formulation of propositions. Principles underpinning formulations of propositions include the identification of reasonably assumed contributors. Substantial data have been produced that support precision, error rate, and reliability of PG, and in particular, STRmix?. A current issue is access to the code and quality processes used while coding. There are substantial data that describe the performance, strengths, and limitations of STRmix?, one of the available PG software.     

Remembering Benalla migrant camp

Abstract

The former migrant camp at Benalla (1949–1967) is one of the least publicly remembered of twenty-three similar centres which provided temporary housing for non-British arrivals in post-war Australia. One of Benalla’s keenest observers saw it as ‘a sad and tragic camp where widows and single mothers were sent’. Another claimed that, as a consequence, it had ‘peculiar difficulties’. The camp ended miserably with the forced relocation of several widows and their families who had been resident in Benalla’s ‘short-term accommodation’ ever since their arrival in Australia seventeen years before. Migrant camps, like Benalla, are difficult heritage places. They raise embarrassing questions about discrimination against the non-British, family separation, forced movement and the inadequacy of support services for the most vulnerable. Benalla has hitherto seen no grand camp reunion, plaque, memorial, public history or heritage listing which raises questions about the perceptions and experiences of the facility while it operated and broader questions about remembering and heritage-making. Benalla was a unique migrant centre and as such provides rare insight into the place of single refugee women and their children within the frames of national/state, local and migrant family heritage.     

Quantification of human mitochondrial DNA using synthesized DNA standards

Successful mitochondrial DNA (mtDNA) forensic analysis depends on sufficient quantity and quality of mtDNA. A real-time quantitative PCR assay was developed to assess such characteristics in a DNA sample, which utilizes a duplex, synthetic DNA to ensure optimal quality assurance and quality control. The assay's 105-base pair target sequence facilitates amplification of degraded DNA and is minimally homologous to nonhuman mtDNA. The primers and probe hybridize to a region that has relatively few sequence polymorphisms. The assay can also identify the presence of PCR inhibitors and thus indicate the need for sample repurification. The results show that the assay provides information down to 10 copies and provides a dynamic range spanning seven orders of magnitude. Additional experiments demonstrated that as few as 300 mtDNA copies resulted in successful hypervariable region amplification, information that permits sample conservation and optimized downstream PCR testing. The assay described is rapid, reliable, and robust.     

Choosing relatives for DNA identification of missing persons

DNA-based analysis is integral to missing person identification cases. When direct references are not available, indirect relative references can be used to identify missing persons by kinship analysis. Generally, more reference relatives render greater accuracy of identification. However, it is costly to type multiple references. Thus, at times, decisions may need to be made on which relatives to type. In this study, pedigrees for 37 common reference scenarios with 13 CODIS STRs were simulated to rank the information content of different combinations of relatives. The results confirm that first-order relatives (parents and fullsibs) are the most preferred relatives to identify missing persons; fullsibs are also informative. Less genetic dependence between references provides a higher on average likelihood ratio. Distant relatives may not be helpful solely by autosomal markers. But lineage-based Y chromosome and mitochondrial DNA markers can increase the likelihood ratio or serve as filters to exclude putative relationships.     

Confidence interval of the likelihood ratio associated with mixed stain DNA evidence

Likelihood ratios are necessary to properly interpret mixed stain DNA evidence. They can flexibly consider alternate hypotheses and can account for population substructure. The likelihood ratio should be seen as an estimate and not a fixed value, because the calculations are functions of allelic frequency estimates that were estimated from a small portion of the population. Current methods do not account for uncertainty in the likelihood ratio estimates and are therefore an incomplete picture of the strength of the evidence. We propose the use of a confidence interval to report the consequent variation of likelihood ratios. The confidence interval is calculated using the standard forensic likelihood ratio formulae and a variance estimate derived using the Taylor expansion. The formula is explained, and a computer program has been made available. Numeric work shows that the evidential strength of DNA profiles decreases as the variation among populations increases.     

Fatality involving complications of bupivacaine toxicity and hypersensitivity reaction

This case represents unusual findings of elevated bupivacaine and tryptase concentrations following local anesthetic, bupivacaine, administered as a scalene nerve block for elective rotator cuff repair surgery. Following bupivacaine injection, the patient exhibited almost immediate seizure activity, bradycardia, and cardiac arrest. Resuscitative efforts including cardiopulmonary bypass restored a cardiac rhythm. However, the clinical medical status of the patient progressively declined and he died 7 h following administration of the local anesthetic. Autopsy revealed several abnormalities of the heart including cardiomegaly, myocardial bridging, and lipomatous hypertrophy of the intraatrial septum, which may have contributed to bradycardia and arrhythmia. Postmortem toxicology results revealed elevated bupivacaine and tryptase concentrations. Elevated postmortem bupivacaine concentrations 7 h following administration and abrupt onset of seizures indicate unintentional intravascular injection instead of nerve and tissue infiltration. An elevated postmortem tryptase concentration points to the possibility of a hypersensitivity reaction to bupivacaine.     

INTEREST IN MARITAL RECONCILIATION AMONG DIVORCING PARENTS

This study offers the first research data on the interest of divorcing parents in marital reconciliation. A sample of 2,484 divorcing parents was surveyed after taking required parenting classes. They were asked about whether they believed their marriage could still be saved with hard work, and about their interest in reconciliation services. About 1 in 4 individual parents indicated some belief that their marriage could still be saved, and in about 1 in 9 matched couples both partners did. As for interest in reconciliation services, about 3 in 10 individuals indicated potential interest. In a sub‐sample of 329 matched couples, about 1 in 3 couples had one partner interested but not the other, and in 1 in 10 couples both partners were interested in reconciliation services. Findings were consistent across most demographic and marital factors. The only strong predictors of reconciliation interest were gender, with males being more interested than females, and initiator status, with far greater interest among those whose partner initiated the divorce. These findings are discussed in terms of attachment theory and future prospects of divorce services.     

A theory of entangled political economy, with application to TARP and NRA

The recent financial crisis has provoked a raft of contending claims as to whether the cause of the crisis is better attributed to market failure or political failure. Such claims are predicated on a presumption that markets and polities are meaningfully separate entities. To the contrary, we argue that contemporary arrangements create an entangled political economy that renders theorizing based on separation often misleading. Within this alternative framework of entangled political economy, we illuminate both the recent Troubled Assets Relief Program (TARP) and the New Deal??s National Recovery Administration (NRA).     

STR data for the 15 AmpFlSTR identifiler loci in the Western Romanian population

Allele frequencies for the 15 tetranucleotide short tandem repeat loci contained in the AmpFlSTR Identifiler kit were obtained from a population sample of 219 unrelated individuals born in the western part of Romania.     

Intentional mixed buccal cell reference sample in a paternity case

We report a case where an alleged father (AF) attempted to substitute someone else's saliva sample for his reference sample in a paternity analysis. Buccal cells were collected from the AF and the child, and DNA analysis was performed using an autosomal STR loci (Identifiler). The profile from the AF showed extra peaks in some loci, as well as a much higher "X" allele peak relative to the "Y" allele peak at the amelogenin locus. After conducting reanalysis by another technician with another set of positive and negative controls, it was concluded that the only source of the mixed profile was by intentional introduction by the AF, at the time of sampling, of some foreign human biological material, most likely saliva from a woman. Owing to the inconclusive results, when the AF was called back to the lab and the peculiar results were explained to him, he admitted that he had introduced into his mouth saliva from another person in an attempt to be excluded as the father of the child. Although tampering with DNA reference samples is not common, some individuals may attempt to contaminate or otherwise adulterate specimens before DNA tests. Personnel responsible for sampling should be aware of this possibility and should try to establish procedures to avoid the problem.