Pitfalls of Computed Tomography 3D Reconstruction Models in Cranial Nonmetric Analysis*

Many studies in the literature have highlighted the utility of virtual 3D databanks as a substitute for real skeletal collections and the important application of radiological records in personal identification. However, none have investigated the accuracy of virtual material compared to skeletal remains in nonmetric variant analysis using 3D models. The present study investigates the accuracy of 20 computed tomography (CT) 3D reconstruction models compared to the real crania, focusing on the quality of the reproduction of the real crania and the possibility to detect 29 dental/cranial morphological variations in 3D images. An interobserver analysis was performed to evaluate trait identification, number, position, and shape. Results demonstrate a false bone loss in 3D models in some cranial regions, specifically the maxillary and occipital bones in 85% and 20% of the samples. Additional analyses revealed several difficulties in the detection of cranial nonmetric traits in 3D models, resulting in incorrect identification in circa 70% of the traits. In particular, pitfalls included the detection of erroneous position, error in presence/absence rates, in number, and in shape. The lowest percentages of correct evaluations were found in traits localized in the lateral side of the cranium and for the infraorbital suture, mastoid foramen, and crenulation. The present study highlights important pitfalls in CT scan when compared with the real crania for nonmetric analysis. This may have crucial consequences in cases where 3D databanks are used as a source of reference population data for nonmetric traits and pathologies and during bone-CT comparisons for identification purposes.     

Cost of ruling as a game of tones: The accumulation of bad news and incumbents’ vote loss

An extensive body of research documents how governing parties generally suffer electoral defeats. Varying explanations have been offered, most of which touch upon the liabilities of policy responsibility. Although media coverage is generally acknowledged as one of these liabilities, few empirical studies have examined how news content affect government support. Based on the fact that voters get their information about politics, policies and societal issues from the media, this article studies how the constant stream of negative news influences incumbent support over a 20-year period in Denmark. Modeling a previously untested argument on the cost of ruling, it shows that the accumulation of bad news throughout tenure exerts a substantial effect on government support.     

How migration policies moderate the diffusion of terrorism

There is an ongoing debate among practitioners and scholars about the security consequences of transnational migration. Yet, existing work has not, so far, fully taken into account the policy instruments states have at their disposal to mitigate these risks, and reliable evidence is lacking for the effectiveness of such measures. This article addresses both shortcomings as whether and to what extent national migration policies affect the diffusion of terrorism via population movements are analysed. Spatial analyses report robust support for a moderating influence of states’ policies: while terrorism can travel from one country to another via larger migration populations, this only applies to target countries with extremely lax regulations and control mechanisms. This research sheds new light on the security implications of population movements, and it crucially adds to our understanding of governments’ instruments for addressing migration challenges as well as their effectiveness.     

When new public management fails: Infrastructure public–private partnerships and political constraints in developing and transitional economies

Amidst calls for more scrutiny of the failure of infrastructure public–private partnerships (PPPs), uncertainty about how we can measure failure remains, and little systematic evidence illuminates its likelihood. Our mixed‐methods design explores the notion of failure and identifies the conditions under which it happens. The first phase of our research employs documentary analysis and semistructured expert interviews, and identifies project cancellation as capturing the most severe occurrences of failure. A second phase statistically analyzes a unique World Bank data set capturing the provisions of over 4,000 infrastructure PPPs launched between 1990 and 2015 in 89 countries. We find robust evidence supporting the theoretical claim that PPPs are less likely to be canceled in countries with more veto points among their political institutions to restrain politicians from intervening in policy implementation. Cancellation is a rare, but valid indicator of failure, and the importance of veto players clarifies how political risk operates in this context.     

Googling the requester: Identity‐questing and discrimination in public service provision

Innovating upon previous field experiments and theories of identity‐based discrimination, we test whether public officials are using searches (“identity‐questing”) to profile citizens and acting on latent biases. Pairs of “institutional” and “noninstitutional” requesters send lower and moderate burden freedom of information (FOI) requests—providing no identity cues apart from undistinctive names, e‐mails, and ID numbers—to nearly 700 of Brazil's largest municipalities. Results show institutional requesters receive one‐fifth more responses than noninstitutional comparators. For moderate versus lower burden requests, noninstitutional requesters are 11% less likely to receive a compliant response than their institutional comparators. The only plausible explanation for these results is identity‐questing, a phenomenon that has far‐reaching policy implications. Most of the world's FOI laws, for example, contain vague ID obligations, which translate incoherently from laws to regulation and practice. Results enjoin public service providers to protect the identities of citizens by default or upon request.     

The Effect of Temperature and Exposure Time on Stability of Cholesterol and Squalene in Latent Fingermarks Deposited on PVDF Membrane

Cholesterol and squalene are fatty materials of latent fingermarks that can be utilized for dating methodologies and visualization techniques. Previous studies have suggested these compounds undergo degradation in fingermarks as a function of time (days) and light at ambient temperature. However, studies assessing how their composition changes at low and high temperatures over short periods of time (hours) have not been published previously. Here, we performed quantitative analysis of cholesterol and squalene in natural fingermark residue using PVDF membrane, after exposure to a range of temperatures (−20 to 100°C) for 4 and 8 h. We found that levels of both fatty materials remained constant at −20 to 60°C, but both showed significant reduction at 100°C, over short exposure times. These results indicate that cholesterol and squalene are detectable at −20 to 60°C, whereas at 100°C or higher, both are lost due to rapid thermal degradation.     

Evaluating Bioinformatic Pipeline Performance for Forensic Microbiome Analysis*,†,‡

Microbial communities have potential evidential utility for forensic applications. However, bioinformatic analysis of high-throughput sequencing data varies widely among laboratories. These differences can potentially affect microbial community composition and downstream analyses. To illustrate the importance of standardizing methodology, we compared analyses of postmortem microbiome samples using several bioinformatic pipelines, varying minimum library size or minimum number of sequences per sample, and sample size. Using the same input sequence data, we found that three open-source bioinformatic pipelines, MG-RAST, mothur, and QIIME2, had significant differences in relative abundance, alpha-diversity, and beta-diversity, despite the same input data. Increasing minimum library size and sample size increased the number of low-abundant and infrequent taxa detected. Our results show that bioinformatic pipeline and parameter choice affect results in important ways. Given the growing potential application of forensic microbiology to the criminal justice system, continued research on standardizing computational methodology will be important for downstream applications.     

Molecular Identification of Necrophagous Dermestes Species in South Korea Using Cytochrome c Oxidase Subunit I Nucleotide Sequences (Genus Dermestes)

Species identification of necrophagous insects found on a dead body is an essential key in applying medicolegal entomology to the estimation of postmortem interval (PMI). Due to limited morphological identification of insect evidence, several studies have identified species using molecular information such as DNA markers. While considerable cytochrome c oxidase subunit I (COI) gene sequence data of necrophagous fly species have been collected and annotated, those of necrophagous beetle species have not. Since necrophagous beetles such as Dermestes species have a larval period longer than that of flies, beetles are useful in even the late decomposition phase in estimating minimum PMI. To obtain the full-length COI gene sequences of six Dermestes species collected from South Korea, we designed primers for polymerase chain reaction amplification and sequencing. The obtained full COI nucleotide sequences were used for performing phylogenic analysis and comparison with previously reported sequences. The results demonstrated that the COI gene sequences could be used to identify forensically important Dermestes species in South Korea.     

Volatile Organic Compound Profiling from Postmortem Microbes using Gas Chromatography–Mass Spectrometry

Volatile organic compounds (VOCs) are by-products of cadaveric decomposition and are responsible for the odor associated with decomposing remains. The direct link between VOC production and individual postmortem microbes has not been well characterized experimentally. The purpose of this study was to profile VOCs released from three postmortem bacterial isolates (Bacillus subtilis, Ignatzschineria indica, I. ureiclastica) using solid-phase microextraction arrow (SPME Arrow) and gas chromatography–mass spectrometry (GC-MS). Species were inoculated in headspace vials on Standard Nutrient Agar and monitored over 5 days at 24°C. Each species exhibited a different VOC profile that included common decomposition VOCs. VOCs exhibited upward or downward temporal trends over time. Ignatzschineria indica produced a large amount of dimethyldisulfide. Other compounds of interest included alcohols, aldehydes, aromatics, and ketones. This provides foundational data to link decomposition odor with specific postmortem microbes to improve understanding of underlying mechanisms for decomposition VOC production.     

Improved Area of Origin Estimation for Bloodstain Pattern Analysis Using 3D Scanning

An important component of crime scene reconstruction is bloodstain pattern analysis (BPA). Where BPA concerns impact patterns, estimating the area of origin is critical information for scene reconstruction. Traditionally, this is achieved by measuring individual bloodstains and performing trigonometric calculations; however, 3D scanning has been proposed as a viable alternative for overcoming logistical and practical concerns with the manual method. Therefore, this project aimed to establish whether the FARO Focus 3D scanner and FARO Zone 3D software can improve the accuracy of area of origin estimates relative to the manual method. We created a series of eight bloodstain impact patterns and performed paired analysis using the two methods to estimate areas of origin for each pattern. Our data suggested that FARO-derived estimates were generally more accurate than using the manual method. FARO-estimated heights of origin areas were generally closer to the true distance. Both methods underestimated the distance from the wall for most patterns originating 150mm or greater from the wall, but overestimated distances for patterns originating closer to the wall. The degree to which distances were underestimated increased significantly the further the blood source was from the wall and was greater for FARO-derived estimates. The results of this research contribute to the validation of these instruments for operational implementation for BPA and should be considered alongside the practical benefits of 3D scanning relative to manual methods. Further, 3D scanning can provide reliable BPA reconstruction documentation for technical review and court presentation.