Critique of interpretation of high levels of heteroplasmy in the human mitochondrial DNA hypervariable region I from hair

The phenomenon known as heteroplasmy can be operationally observed in some human mitochondrial DNA (mtDNA) samples. Typically, heteroplasmy manifests itself in an individual presenting two mtDNA species that differ at a single base. Heteroplasmy at two, and even possibly three sites, also may occur, but at very low rates. A recent report (Grzybowski, 2000, see ref. [13]) suggests that much higher levels of mtDNA (point substitution) heteroplasmy can occur in hair. This observation is contrary to the experience of the forensic mtDNA community. There are several explanations for the unusual findings of high levels of heteroplasmy. First, the template quantities of DNA are approximately three orders of magnitude higher than required for mtDNA sequencing, and an excessive number of amplification cycles were used. Thus, the protocol used did not follow routine practices by the forensic community. Second, there are misidentifications and tabular errors that call into question the reliability of the findings. Third, by comparing the natural human mtDNA variation with a reference sample population with that observed in the heteroplasmy in hair study, the data are inconsistent with population genetic expectations. The observation of high levels of heteroplasmy may be due to contamination of the samples and/or possibly the amplification of nuclear pseudogenes. The results observed in the heteroplasmy in hair study do not apply to other methods of mtDNA analysis and cannot be used to question the reliability of the current forensic mtDNA practices.     

Recommendations for consistent treatment of length variants in the human mitochondrial DNA control region

Human mitochondrial DNA (mtDNA) analysis is a valuable forensic tool, useful in cases where the amount of extracted DNA is low or highly degraded. Population databases are used to determine the relative rarity of a particular profile obtained in a forensic case. Rather than full DNA sequence information, sequence profiles are compared to a reference sequence, and the differences from the reference are recorded in forensic databases. A standard method is proposed for characterizing length variants, and examples are described using actual human control region mtDNA profiles. Consistency in alignment and nomenclature avoids inadvertently describing two sequences as different when in fact they are the same.     

A survey of extraction techniques for drugs of abuse in urine

Sixty nine participants in the United Kingdom national external quality assessment scheme for drugs of abuse in urine reported details of their sample extraction technique by questionnaire. Laboratories were categorised by differences in technique and their analytical test results compared for samples containing D-amfetamine 0.4 (4) and 0.8 (3) mg/l, morphine 0.4 (4) and 0.8 (4)mg/l, and benzoylecgonine 0.15/0.2 (2) and 0.45/0.5 (4) mg/l. Values in parentheses are numbers of samples. For amfetamine, there was no significant difference in the frequency of true positive results between liquid-liquid or solid phase extraction and the Toxi-Lab A system at 0.8 mg/l. Toxi-Lab A gave significantly fewer positives when operating below its specified threshold at 0.4 mg/l. Paradoxically, laboratories using >5 ml urine volume performed less well. Acidification of the extract before volume reduction gave significantly more true positives. For extraction of morphine, solid phase systems significantly outperformed both liquid-liquid and the Toxi-Lab A system at both 0.8 and 0.4 mg/l. No significant differences between extraction techniques were demonstrated for analysis of benzoylecgonine.     

On Coase and COVID-19

European Journal of Law and Economics - From an epidemiological perspective, the COVID-19 pandemic is a public health crisis. From an economic perspective, it is an externality and a social cost....     

Envisioning Public Child Welfare Agencies as Learning Organizations: Applying Beer's Viable System Model to Title IV-E Program Evaluation

The idea of a learning organization emerges from organizational cybernetics and results in agency staff having the means to use their skills and expertise to meet the needs of the organization's clients. Relevant to Title IV-E training programs, such organizational processes would maximize the use of knowledge and skills the graduates bring back to the agency. This article uses focus group data to explore how Title IV-E graduates perceive the potentialities of their agency as a learning organization. This analysis results in recommendations to improve organizational performance without impinging on existing agency resource constraints.     

Spatial and Temporal Proximity: Examining the Effects of Protests on Political Attitudes

This article utilizes data from the Latino National Survey (2006) to analyze temporal and spatial variation in the effects of the immigrant rights marches in 2006 on Latino attitudes towards trust in government and self‐efficacy. Using a unique protest dataset, we examine the effects of proximity and scale by mapping respondents’ specific geographic location against the location of the marches as well as size of the protests using Geographic Information Systems (GIS). We find that local proximity to small marches had a positive impact on feelings of efficacy, whereas large‐scale protests led to lower feelings of efficacy. The results shed light on the role localized political events can play in shaping feelings towards government, the importance of conceptions of space and time to the study of social movements, and the positive outcomes that can result from contentious politics.     

How Do States Implement Liberal Immigration Policies? Control Signals and Skilled Immigration Reform in Australia

States often face immigration “control dilemmas” between popular pressures for tighter immigration controls versus economic pressures for more liberal work visa controls. Using a systematic process analysis of recent policy developments in Australia, this article argues that the Howard government's large expansion of “wanted” forms of immigration hinged upon its ability to control “unwanted” forms of immigration. The concept of “control signals” is introduced to account for the government's success in exiting an immigration control dilemma, which allowed it to pursue skilled immigration reforms that would have otherwise proven difficult. A research agenda is established for examining the conditions under which the use of control signals is likely to be successful and for applying the concept to other realms of public policy where states face control dilemmas.