Mitochondrial DNA sequencing of beetle larvae (Nitidulidae: Omosita) recovered from human bone

The isolation, amplification, and characterization of human DNA from hematophagous (blood feeding) and necrophagous (carrion feeding) arthropods have been advanced significantly by the development of polymerase chain reaction (PCR) DNA sequencing methodologies. Historically, DNA technology has been successfully utilized to identify individual hosts upon which species of hematophagous arthropods have fed. The analysis of hematophagous insects' gut content blood meals has led to major advances in medical entomology and vector-borne disease epidemiology. In the forensic arena, the ability to apply similar techniques to insects recovered from badly decomposed remains has been greatly enhanced through the advent of mitochondrial DNA (mtDNA) techniques. Mitochondrial DNA analyses have been utilized to identify both the human remains upon which fly larvae (maggots) have fed and the species of the larvae themselves. The preliminary work detailed here demonstrates, for the first time, the successful application of mtDNA sequencing techniques to the analysis of necrophagous beetle larvae. A small sample of sap beetle larvae, Omosita spp. (Coleoptera: Nitidulidae), was collected from human skeletal remains during anthropological examination and analyzed for human DNA using mtDNA sequencing. The beetle larvae yielded mtDNA matching that of the host human bone. The results detailed here further demonstrate the robust nature of human mtDNA and the ability to recover valuable mtDNA evidence from forensically important, late decompositional stage insect species.     

Breaking point? An analysis of fatal stab wounds to the torso in Ireland between 2011 and 2018, examining the extent of rib fractures

This study examines the pattern of rib injuries occurring in cases of fatal torso stab wounds in Ireland between 2011 and 2018. It has been suggested by previous studies that rib fractures are not commonly sustained in stab wounds to the torso. We wanted to ascertain whether this was the case, as our data suggested that rib fractures were frequent, and where a rib is fractured there is a higher chance of organ injury and death, making this an important area of study. One hundred and forty seven cases of fatal stab wounds from an eight-year period were retrospectively reviewed. Fatal stab wounds to other body areas, were excluded; leaving a total of 104 cases with stab wounds to the torso. We found that 69.2% of cases had rib injuries, a figure significantly higher than previously reported. Our data suggests that stab wounds to the torso often fracture ribs, putting the underlying organs at increased risk of injury and perhaps contributing to fatality. The amount of force needed to cause a rib fracture can be difficult to quantify and indeed from the high percentage of rib fractures sustained in our data it appears that the ribs may be fractured regardless of the amount of force used; this is borne out by the finding that self-inflicted injuries also caused rib fractures. Our study shows that other factors, such as anatomical positioning and wound depth may have a greater bearing than force in terms of whether a rib fracture is sustained.     

Media malaise or a virtuous circle? Exploring the causal relationships between news media exposure,political news attention and political interest

Being politically interested is one of the most important norms from a democratic perspective, as it is a crucial antecedent for voting, political knowledge, civic and political participation, and attentiveness to political information. However, only limited research has focused on the relationship between media use and political interest, despite the notion that modern politics is mediated politics. Even more important is the fact that the causal relationship between media use and political interest still has not been firmly established. Against this background, the purpose of this study is to investigate the causal relationship between news media use and political interest. The results show that there are indeed causal and reciprocal relationships between political interest and attention to political news, and between political interest and exposure to some, but not all, news media. Overall these results lend stronger support to the perspective of media mobilisation theories than media malaise theories.