Restriction fragment length polymorphisms (RFLP) analysis using the Southern blot technique can be used to recognize copy number variation of variable number of tandem repeats (VNTR) of conserved core sequences at several regions of the human genome. This new class of polymorphisms reveals a high degree of genetic variation, useful for individual identification purposes. Criticisms against forensic applications of such DNA typing data include the limitation of employing Hardy-Weinberg expectation of genotype frequencies, since several surveys indicate apparent deficiency of heterozygosity (or excess homozygosity) in comparison with Hardy-Weinberg expectations. This research postulates an alternative explanation of deficiency of apparent heterozygosity which is caused by the inability to detect extremely small-sized alleles (called 'non-detectable' alleles) due to the sensitivity of Southern gel electrophoresis. We show that the presence of 'non-detectable' alleles can produce pseudo-homozygosity and their frequencies can be predicted from the observed proportional heterozygote deficiency. Furthermore, in the covert presence of such 'non-detectable' alleles, we show that the gene-count method provides over-estimates of allele frequencies in the sample population, and hence the Hardy-Weinberg predictions of genotype frequencies avoid wrongful bias against suspects in forensic applications of DNA typing data. Applications of this theory to population data on six VNTR loci in US Caucasians and US Blacks suggest that the presence of 'non-detectable' alleles could be the major cause of apparent heterozygote deficiency, and the current approaches of predicting the population frequency of specific DNA phenotypes are practically free of the possible wrongful bias in courtroom applications of DNA typing data.
The market in electronic cigarettes (e-cigarettes) has grown rapidly over the past few years. Many small manufacturers have emerged, and the tobacco industry has also taken an active interest in the sector, buying up independent operators and openly strategising about the business opportunities. Press releases show that 121 product trademark applications were made in the UK alone between
Population-level compliance with health protective behavioral advice to prevent and control communicable disease is essential to optimal effectiveness. Multiple factors affect perceptions of trustworthiness, and trust in advice providers is a significant predeterminant of compliance. While competency in assessment and management of communicable disease risks is critical, communications competency may be equally important. Organizational reputation, quality of stakeholder relationships and risk information provision strategies are trust moderating factors, whose impact is strongly influenced by the content, timing and coordination of communications. This article synthesizes the findings of 2 literature reviews on trust moderating communications and communicable disease prevention and control. We find a substantial evidence base on risk communication, but limited research on other trust building communications. We note that awareness of good practice historically has been limited although interest and the availability of supporting resources is growing. Good practice and policy elements are identified: recognition that crisis and risk communications require different strategies; preemptive dialogue and planning; evidence-based approaches to media relations and messaging; and building credibility for information sources. Priority areas for future research include process and cost-effectiveness evaluation and the development of frameworks that integrate communication and biomedical disease control and prevention functions, conceptually and at scale.
This was a qualitative study in one region, and perception of e-cigarettes was not an a priori topic. However, it provides insights into youth perceptions of e-cigarettes. How they discerned e-cigarettes reflects their marketing environment. The relative harmlessness of nicotine, affordability of e-cigarettes, coolness of vaping, absence of second-hand harms and availability of innovative products are all key marketing features. Conflicting messages on safety, efficacy, potential 'gateway' to smoking and nicotine may be contributing to teenagers' confusion. The allure of 'youthful cool' to vaping offers no public health gain, so children should be protected from misleading promotion. Consistent tobacco-education initiatives need to account for this popular trend.
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