Cuticular hydrocarbons as a tool for determining the age of Chrysomya rufifacies (Diptera: Calliphoridae) larvae

Calliphoridae are one of the most important insect groups encountered as evidence collected from a crime scene. Age determination of the immature stages of these necrophagous flies is an important step toward estimating the time of colonization and inferring a minimum postmortem interval (PMI_min) in most instances. To determine if the cuticular hydrocarbons could be used to establish whether the development stages yield characteristics profiles, allowing for age estimation, hydrocarbons were extracted from 1st and 2nd, as well as feeding and post‐feeding 3rd instar Chrysomya rufifacies, the hairy maggot blow fly. Extracted hydrocarbons were analyzed using gas chromatography coupled to mass spectrometry with the aim to investigate the changes in chemical profiles of each larval stage. A total of 23 compounds were identified with most of them being alkanes (65%) with carbon chain lengths of 9–33 carbons, alkenes (18%), and methyl‐branched alkanes (17%). All the hydrocarbons except pentadecane (C15), hexadecane (C16), and nonacosane (C29) showed significant differences in their expression throughout larval development. For 1st instars, nonane was the most abundant (17% of the total hydrocarbons content) compound. Accounting for 11% and 10% of the cuticular hydrocarbons, tricosane and pentacosane, respectively, were the notable hydrocarbons in 2nd instars. For post‐feeding 3rd instars, hentriacontane and tritriacontane were present with relative abundances 18% and 15%, respectively. On average, there was a shift from low to high molecular weight hydrocarbons as the larvae aged. These results indicate the change in hydrocarbons makeup as larvae age and could potentially be used to determine the age of immature C. rufifacies and hence aid in PMI_min estimations. However, future research is needed to validate these results under natural conditions in the field.     

CHILDREN RESISTING POSTSEPARATION CONTACT WITH A PARENT: CONCEPTS, CONTROVERSIES, AND CONUNDRUMS

This article provides an overview of the key concepts, themes, issues, and possible mental health and legal interventions related to children's postseparation resistance to having contact with one parent. We maintain that the too often strongly gendered polemic on alienation and abuse is polarizing and needs to be replaced with a more nuanced and balanced discussion that recognizes the complexity of the issues so that the needs of children and families can be better met. This article reviews the historical development of the concept of alienation; discusses the causes, dynamics, and differentiation of various types of parent child contact problems; and summarizes the literature on the impact of alienation on children. These are complex cases. A significant portion of the cases in which alienation is alleged are not in fact alienation cases; for those where alienation is present, interventions will vary depending on the degree of the alienation. More severe alienation cases are unlikely to be responsive to therapeutic or psycho-educational interventions in the absence of either a temporary interruption of contact between the child and the alienating parent or a more permanent custody reversal. We conclude with a summary of recommendations for practice and policy, including the need for early identification and intervention to prevent the development of severe cases, interdisciplinary collaboration and further development and research of interventions.     

Diagnostic value of post-mortem examination of the cardiac conduction system

Introduction (Aim)

Sudden unexplained death (SUD) is a common problem in forensic pathology. In many of these cases, the autopsy findings, toxicological examinations and patient history are inconclusive. Many studies suggest that in such cases, the cardiac conduction system (CCS) should be histologically examined. We decided to determine the diagnostic value of histological examination of the CCS.

Methods

We reviewed autopsy files from the period 2005–2007 and selected those cases in which the CCS had been sampled. These were divided into two groups, the first comprising cases with an obvious cardiac pathology (e.g. severe coronary disease, myocardial infarction, significant myocardial hypertrophy/dilatation, valvular disease, etc.) and the second comprising cases without obvious cardiac pathology (i.e. fatal injuries, intoxications and deaths unexplainable by routine procedures). The CCS was sampled according to a detailed protocol and examined under a light microscope. On the basis of the findings of histological examination of CCS, we formed subgroups of the aforementioned main groups.

Results

We analyzed 118 cases, of which 83 were males and 35 females. In 57% of cases, autopsy revealed gross pathological abnormalities of the heart. In 10 (15%) of them, examination of the CCS showed significant pathological changes (narrowing of the nodal artery and its branches, moderate to severe interstitial fibrosis, calcifications in the central fibrous body impinging upon CCS). In some, especially those with no acute findings, CCS disease can be considered to have been the cause of fatal arrhythmias. In 43% of cases, autopsy revealed no gross abnormalities of the heart, while histological examination of the CCS disclosed significant pathological changes in 4 (8%). Among them, CCS disease was regarded as the cause of death in one case and as a possible cause in another case.

Conclusion

As with other similar studies, our study showed that examination of the CCS can provide valuable information on the cause of death. We therefore consider that examination of the CCS should be performed in all SUD cases, especially those in which the cause of death cannot be established by routine procedures. Although we had only 1 confirmed cause of death linked to CCS disease and one possible, we had 14 cases with significant pathological CCS changes. This leads us to the conclusion that post-mortem examination of the CCS is of diagnostic value.     

ASSESSMENTS FOR POSTSEPARATION PARENTING DISPUTES IN CANADA

There is controversy in Canada about the use of assessments by mental health professionals to assist in the resolution of postseparation disputes between parents about their children. Although the principles developed by the Supreme Court of Canada to govern the admission of expert evidence in criminal law cases provides guidance for judges in family law cases, in deciding whether to order an assessment or admit expert evidence, family law judges must also take account of the child-related context. Mental health professionals can provide valuable information that would otherwise be unavailable when making prospective decisions about children. Court-appointed assessors also have a significant institutional role in the family law cases that has no equivalent in the criminal law context. Assessors are important not only for the relatively rare cases that go to trial, but they also play a central role in helping to resolve the much larger number of cases that are settled.