Alterations of Length Heteroplasmy in Mitochondrial DNA Under Various Amplification Conditions*

Abstract: There are several areas within mitochondrial DNA that show length heteroplasmy. If the heteroplasmy pattern is unique and consistent for each person, it may be used to support an interpretation of exclusion in identity testing. We investigated whether the length heteroplasmy pattern would be consistent under different amplification conditions. We also determined whether various amplification parameters would affect the homopolymeric cytosine stretches (C‐stretch) in HV1. Monoclonal samples tended to be heteroplasmic after amplification. After several repetitions, C‐stretch patterns of all samples were inconsistent even under the same amplification conditions. Increased PCR cycles and high template concentrations resulted in a more frequent heteroplasmic tendency. These amplification parameters seem to have little effect if samples are not long enough in C‐stretch or total length of the segment from nt 16180 to nt 16193. It is suggested that the pattern of length heteroplasmy cannot be used as an additional polymorphic marker.     

浅析当前强奸犯罪中的证据把握问题

近年来,强奸案件出现了一些特殊的变化。强奸案件的新特点,导致办案人员对该类案件证据的认定产生了较多困惑。为了正确定性,需要提出强奸犯罪证据的审查要素问题。     

Macroscopic, histological and toxicological aspects of early Gammarus pulex scavenging

Two cases of scavenging postmortem freshwater shrimps (Gammarus pulex) are presented. We report the two first illustrated observations of cutaneous postmortem injuries inflicted by a G. pulex population, a small freshwater crustacean, on two non putrefied drowning victims, and we describe their particular histological features and their potential in forensic investigations.     

Seasonal and habitat abundance and distribution of some forensically important blow flies (Diptera: Calliphoridae) in Central California

Seasonal and habitat calliphorid abundance and distribution were examined weekly for two years (2001-2003) in Santa Clara County, California, using sentinel traps baited with bovine liver. Of the 34,389 flies examined in three defined habitats (rural, urban, and riparian), 38% of the total catch represented Compsomyiops callipes (Bigot) and 23% represented Phormia regina (Meigen). Other flies collected in this survey included Calliphora vomitoria (Linnaeus), Calliphora latifrons (Hough), Lucilia sericata (Meigen), Lucilia cuprina (Wiedemann), and Lucilia mexicana (Macquart), which is a new record for the area. Multivariate MANOVA and ANOVA (P ≤ 0.05) analysis indicate significant seasonal habitat preference for all fly species examined. This information may be used to identify potentially forensically impo rtant fly species within Santa Clara County, California.     

Development and validation of the AmpFℓSTR® Identifiler® Direct PCR Amplification Kit: a multiplex assay for the direct amplification of single-source samples

Abstract: The AmpF?STR^® Identifiler^® Direct PCR Amplification Kit is a new short tandem repeat multiplex assay optimized to allow the direct amplification of single‐source blood and buccal samples on FTA^® card without the need for sample purification and quantification. This multiplex assay has been validated according to the FBI/National Standards and SWGDAM guidelines. Validation results revealed that slight variations in primer concentration, master mix component concentration, and thermal cycling parameters did not affect the performance of the chemistry. The assay’s sensitivity was demonstrated by amplifying known amounts of white blood cells spotted onto FTA^® cards, and the assay’s specificity was verified by establishing minimal cross‐reactivity with nonhuman DNA. No effect on the age of the sample stored on the FTA^® substrate was observed and full concordance was established in the population study. These findings of the validation study support the use of the Identifiler^® Direct Kit for forensic standards and database samples genotyping.     

Sudden infant death syndrome: diagnostic practices and investigative policies, 2004

Using a 2004 population-based survey of all US medical examiner and coroner offices, we examined the characteristics of offices accepting an infant death case and calculated the percentage of offices that had death scene investigation or autopsy policies for the investigation of sudden unexpected infant death (SUID). We also calculated the percentage of offices that used and did not use sudden infant death syndrome (SIDS) as a cause of death, and we compared differences in characteristics among those offices.Of medical examiner and coroner offices, 52% did not report an infant death in 2004. Of the 7957 infant deaths reported, 43% occurred in jurisdictions that experienced 1 or 2 infant deaths. Of the offices that used SIDS as a classification, 34% did not have policies for conducting death scene investigations and autopsies for SUID. At least 5% of offices that reported an infant death did not use SIDS as a cause of death classification. These findings have important implications for understanding recent trends in SIDS and SUID. Supporting the implementation of national standards for investigating and certifying infant deaths could provide guidelines for consistent practices in medical examiner and coroner offices.     

Volatile organic compounds released by blowfly larvae and pupae: new perspectives in forensic entomology

To evaluate postmortem intervals (PMIs), one should take into account the determined age of necrophagous flies present on the cadaver. However, PMI determination needs further improvement, and rapid and accurate approaches have therefore to be developed. While previous studies have focussed on insect cuticular hydrocarbons, here we explore the volatile profile released by larvae and pupae of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). We monitored changes in volatile compounds daily, by headspace solid-phase microextraction, followed by gas chromatography-mass spectrometry. Branched and unbranched hydrocarbons, alcohols, esters and acids were identified, and the volatile profile was shown to vary, in both composition and quantity, with the age of the larva/pupa under investigation. We concluded, based on the analysis of the released volatile organic compounds, that it is possible to increase the accuracy of the estimated PMI, through improved estimation of the age of blowflies present on the cadaver.     

Integrity management in post-1997 Hong Kong: Challenges for a rule-based system

Unlike some of its Western counterparts, where the first line of defence against corruption and unethical behavior has been a reliance on a public service ethos, the Hong Kong government has traditionally relied on strict compliance with rules and regulations in its successful drive against bureaucratic malpractices. Since 1997, however, a changing political, economic and administrative environment has also seen efforts to introduce a more value-based approach to integrity. This article examines the factors that have led to the modification of the Hong Kong government??s strategy and evaluates its success in the wider theoretical context of the relationship between a predominantly rule-based and a value-based approach to integrity management.