Assessing three soil removal methods for environmental DNA analysis of mock forensic geology evidence

Soil is useful in criminal investigations as it is highly variable and readily transferred. Forensic geologists use several different techniques to removal soil from evidence prior to the analysis of inorganic components. There has been recent interest from the forensic science community to analyze environmental deoxyribonucleic acid (eDNA) associated with soil to augment existing forensic analyses. Notably however, limited research has been conducted to compare commonly used soil removal methods for downstream eDNA analysis. In this study, three soil removal methods were assessed: picking/scraping, sonication, and swabbing. Three mock evidence types (t-shirts, boot soles, and trowels) were sampled in triplicate with each removal method (n = 27). Soil samples underwent DNA isolation, quantification, and amplification of four genomic barcode regions: 16S for bacteria, ITS1 for fungi, ITS2 for plants, and COI for arthropods. Amplicons were prepared into libraries for DNA sequencing on an Illumina^® MiniSeq. DNA concentrations were highest in picked/scraped samples and were statistically significant compared with swabbed and sonicated samples. Amplicon sequence variants (ASVs) were identified, and removal methods had no impact on the recovery of the total number of target ASVs. Additionally, when assessing each sample in multidimensional space, picked/scraped samples tended to cluster separately from swabbed and sonicated samples. The soil core used a reference in this study also clustered with the picked/scraped samples, indicating that these samples may be more reflective of the communities collected from soil cores. Based on these data, we identified that picking/scraping is an acceptable soil removal method for eDNA analysis.     

CT‐Guided,Minimally Invasive,Postmortem Needle Biopsy Using the B‐Rob II Needle‐Positioning Robot

CT‐guided, minimally invasive needle biopsy techniques can be used to retrieve tissue or body fluid samples for histologic tissue diagnoses in forensic investigations. The purpose of this study was an evaluation of CT‐guided needle‐positioning robot B‐Rob II. To operate under CT guidance, we adopted the B‐Rob II robotic needle placement system and its workflow. The accuracy and speed of the procedure were tested on a gelatin phantom in a series of 21 biopsies. We achieved an average needle placement accuracy of 1.8 mm (±1.1 mm) using robotic assistance. The procedure required an average of 2 min 21 s. The needle placement accuracy for minimally invasive needle biopsies using the B‐Rob II biopsy robot is sufficiently accurate and fast for forensic postmortem examinations of focal organ changes. Further tests will be performed to test the feasibility of the robot for performing biopsies of focal organ changes in human bodies.     

Pneumomediastinum and Soft Tissue Emphysema in Pediatric Hanging

Postmortem computed tomography (CT) is increasingly being used as a tool in forensic pathology. The exact value of postmortem imaging in detecting specific conditions has not yet been established, but in specific cases, it can be used as a diagnostic tool demonstrating findings that remain undetected during autopsy, as in this case. Pneumomediastinum and soft tissue emphysema were detected with postmortem CT in a 3‐year‐old girl after hanging. It was not found during autopsy. This radiological finding matches 3 adult cases previously described. It is assumed that in this case, the first reported in a child, hanging was the most likely cause as well. In the adult cases, it was interpreted as a vital sign; the person must have been alive to create a pressure gradient causing rupture of the alveoli. This case demonstrates one of the added values of postmortem imaging, the possibility of demonstrating findings that remain undetected during autopsy.     

Application of Volume‐of‐Fluid Method to Analyze the Viscosity Effect on the Spine Formation of Bloodstains

In bloodstain pattern analysis, the blood droplet volume and surface impact velocity play an important role, and many related experimental studies have been carried out. If an appropriate computational fluid dynamics (CFD) model that could solve bloodstain patterns, especially spine formation bloodstain patterns, can be obtained, the blood droplet volume and impact speeds at various crime scenes can be predicted more accurately. For this purpose, Flow‐3D software using the volume‐of‐fluid method was applied to analyze the behavior of human blood droplets during an impact event, especially focusing on the viscous effect on splashing, which forms the spine which can be used to predict the impact velocity. To obtain a non‐Newtonian viscosity model of blood for a computational fluid dynamic analysis, the venous blood samples of 163 people were tested using a hemorheology instrument. Among the venous blood samples of 163 people, 37 samples for which all blood test results were in a normal range were selected for the non‐Newtonian viscosity modeling. From the CFD analysis, it could be concluded that a non‐Newtonian viscosity model is more appropriate than a constant viscosity model for predicting splashing that forms the spine. The gradient of the non‐Newtonian model at a high shear rate has more of an effect on spine formation than that at a low shear rate. The lowest viscosity with a high velocity at the outer front of the radiating flow plays an important role in forming the splashing pattern.     

Acute Aortic Dissection Diagnosed after Embalming: Macroscopic and Microscopic Findings

A 58‐year‐old man died suddenly in Madagascar and poisoning was suspected. The body was embalmed after death and the general state of preservation was good. We found a major aortic dissection with a large false lumen from the aortic root to the common iliac arteries and a hemopericardium with formalinized blood clot. The intimal tear was on the ascending aorta, and an intramural hemorrhage was noted at the right coronary artery, attesting to a retrograde dissection. Microscopic studies confirmed aortic dissection with extensive intramural hemorrhage and also confirmed the retrograde dissection to the right coronary artery with a reduction of 90% of the true lumen. Classically, aortic dissection occurs in individuals with hypertension and individuals with genetic disorders of collagen formation. The diagnosis is often first established at the postmortem examination. Aortic dissection is therefore dealt with largely in necropsy studies. The usual cause of death is rupture into the pericardial sac. One case of bloodless dissection has been reported but the sudden death was explained by acute myocardial ischemia secondary to dissection of the left coronary artery. In our case, we found major hemopericardium and also intramural hemorrhage at the right coronary artery. We were able to make the diagnosis of aortic dissection and exclude the suspicion of homicide 15 days after death and after embalming.     

Long Bone (Humerus,Femur, Tibia) Measuring Procedure in Cadavers

In this work, we present a measuring methodology for long bones of the limbs (humerus, femur, and tibia) of human corpses. Measurements of cadaveric height and long bone lengths were conducted on 72 corpses (20 females and 52 males) from the School of Medicine at the National Autonomous University of Mexico. Additionally, these measurements were compared with those taken from dry bones of a subsample of individuals. Our results show marginal differences (TEM% = 0.59) between cadaveric and dry bone measurements, resulting from different osteometric technical procedures. This note outlines the measuring methodology, which will be subsequently used to create regression formulas for stature estimation.     

What Should We Do? Public Attitudes about How Local Government Officials Should Confront Fiscal Stress

Despite strong scholarly interest in the topic of fiscal stress, little attention has been paid to understanding how the general public thinks local governments should respond to situations where declining revenues endanger service levels. This study reports findings from a survey of 660 residents undertaken between November 2006 and January 2007 in the US state of Michigan to examine their support for eight potential strategies to cope with fiscal stress in five different local government services. We find that the public has a surprisingly nuanced perspective about these strategies and on their use for different services. Our findings may provide local policymakers with some insights about how to respond to fiscal stress.     

Measuring the efficiency of Spanish municipal refuse collection services

The aim of this article is to analyse the technical efficiency of the refuse collection services in 75 municipalities located in Catalonia, Spain. The analysis has been carried out using a great variety of techniques, both parametric and non‐parametric. Although the results naturally differ according to the technique used, they nevertheless are consistent in ranking the units analysed. Finally, we have looked into the relation existing between efficiency and the public or private management of the service. The results seem to support the idea that the framework for competition in which the service is provided could be more relevant than the private‐public management dichotomy.