Veldt fires in South Africa: Implications on osteometry and the biological profile

Standard operating procedures for forensic anthropological analyses dictate that thermally altered remains should not be measured, hindering the creation of a biological profile. Few studies have addressed estimating biological parameters from burned remains, with the greatest focus of this research area being on cremated remains. However, veldt fires are more common than cremation in the South African forensic context. The aim of this study was to explore the degree of structural changes observed in domestic pig (Sus scrofa) bones associated with thermal destruction and the potential impact on the estimation of a biological profile using standard osteometric methods. A total of 96 pig femora were divided equally into two categories: fresh and dry. Within each category, equal samples were exposed to different durations of burning, namely, 5, 10, and 20 min. Ten standard femoral anthropological measurements were collected before and after burning. Technical error of measurement and Wilcoxon signed-rank tests were used to assess changes in the femoral dimensions before and after burning. Most measurements were significantly different after burning, with the fresh bones decreasing in size by up to 7.8% and the dry bones decreasing in size by up to 4.0%. The magnitude of post-burning measurement changes for both burn conditions was similar to, or smaller than has previously been reported for observer measurement errors of commonly used variables investigated for standard osteometric studies. Veldt fires are less intense than cremation, thus causing less shrinkage.     

Who are the most highly cited forensic scientists in the United States?

The most highly cited forensic practitioners in the United States were identified using a publicly available citation database that used six different citation metrics to calculate each person's composite citation score. The publication and citation data were gleaned from Elsevier's SCOPUS database, which contained information about ~7 million scientist each of whom had at least five entries in the database. Each individual was categorized into 22 scientific fields and 176 subfields, one of which was legal and forensic medicine (LFM). The database contained citation records for 13,388 individuals having LFM as their primary research discipline and 282 of these (2%) were classified as being highly cited. Another 99 individuals in the database had LFM as their secondary discipline, making a total of 381 highly cited forensic practitioners from 35 different countries. The career-long publication records of each individual were compared using their composite citation scores. Of the 381 highly cited scientists, 93 (24%) had an address somewhere in the United States. The various branches of forensics they specialized in were anthropology, criminalistics, DNA/genetics, odontology, pathology, statistics/epidemiology, and toxicology. The two most highly cited scientists, according to their composite citation score, were both specialists in DNA/genetics. Bibliometric methods are widely used for evaluating research performance in academia and a similar approach might be useful in jurisprudence, such as when an expert witness is instructed to testify in court and explain the meaning of scientific evidence.     

Detection of human chorionic gonadotropin (HCG) in fabric urine stains older than five years

Human chorionic gonadotropin (HCG) is used in clinical medicine as a particularly important indicator to determine pregnancy. In this study, it was necessary to determine whether the urine spots on car seat fabric from a murder 5 years previously were from a pregnant woman. The HCG in the dried urine spot on a car seat was detected using an immunochromatography kit. It was found that the HCG in urine can be detected for much longer periods of time than the previously reported period of approximately 6 months.     

Examination of acetone findings in suspected drug-facilitated sexual assaults: A case series

Acetone presence in human biological specimens can result from exogenous administration or endogenous production, resulting from diabetes, dietary composition, alcoholism, and stress response. Victims of drug-facilitated sexual assaults (DFSA) are understood to experience enhanced stress. At the Harris County Institute of Forensic Sciences (HCIFS), DFSA drug testing includes analysis of volatile compounds, ethanol, methanol, isopropanol, and acetone, by headspace gas chromatography/flame ionization detection. The prevalence of acetone-positive specimens in DFSA casework has been observed to exceed that of other human performance case types. In this report, DFSA cases received between 2019 and 2021 (n = 393) were reviewed and 41 acetone-positive cases were detailed. Overall, nearly 11% of the DFSA cases had acetone-positive blood or urine specimens, where 3% identified acetone only, 6% identified acetone and other drug(s), and 2% identified acetone, ethanol, and other drug(s). Acetone concentrations ranged from 0.010 to 0.147 g/100 mL in urine. Other drugs such as nor-carboxy-Δ⁹-tetrahydrocannabinol, amphetamine, methamphetamine, ethanol, and benzoylecgonine were commonly detected. Elevated stress response encountered during DFSAs may facilitate the mechanism behind enhanced acetone production leading to increased identification. Limited availability of victim medical history precludes understanding the contribution of other disease states or physiological conditions. Nonetheless, the identification of acetone in DFSA specimens supports its potential as a biomarker of trauma in forensic toxicology casework and warrants future research within the community.     

On the challenge of unambiguous identification of fentanyl analogs: Exploring measurement diversity using standard reference mass spectral libraries

Fentanyl analogs are a class of designer drugs that are particularly challenging to unambiguously identify due to the mass spectral and retention time similarities of unique compounds. In this paper, we use agglomerative hierarchical clustering to explore the measurement diversity of fentanyl analogs and better understand the challenge of unambiguous identifications using analytical techniques traditionally available to drug chemists. We consider four measurements in particular: gas chromatography retention indices, electron ionization mass spectra, electrospray ionization tandem mass spectra, and direct analysis in real time mass spectra. Our analysis demonstrates how simultaneously considering data from multiple measurement techniques increases the observable measurement diversity of fentanyl analogs, which can reduce identification ambiguity. This paper further supports the use of multiple analytical techniques to identify fentanyl analogs (among other substances), as is recommended by the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG).     

Prevalence of xylazine in overdose cases: An analysis of Miami-Dade County medical examiner case data

Xylazine sedative, muscle relaxant, and analgesic used in a veterinary setting. Although xylazine was never approved for therapeutic use in humans, it has become popular in the street drug market as a cutting or bulking agent in the fentanyl and heroin supply. Recently, there has been a significant increase in the detection of xylazine in postmortem forensic toxicology casework. Xylazine can be identified during routine toxicology screening utilizing instrumentation such as gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry. Using the Miami-Dade Medical Examiner's LIMS system, all cases received between 2015 and 2022 in which xylazine was reported were reviewed. The cases studied include accidental drug overdose deaths in Miami-Dade County as well as Collier County (Naples), Florida. In total, there are 170 cases; the majority are accidental polydrug overdoses involving White males between the ages of 25 and 44 years old. Of the 170 cases, 37% listed xylazine as the cause of death. 13% of cases contained only xylazine and fentanyl while the remaining 87% of deaths were attributed to polydrug toxicity involving two or more substances. The prevalence of xylazine can be attributed to its increasing popularity rather than an increase in caseload. In 2019, xylazine was present in only 4% of all accidental fentanyl overdoses. By 2021, this percentage has increased sixfold, with xylazine present in 24% of all accidental fentanyl overdoses. Despite a decrease in fentanyl overdoses in 2022, the percentage of xylazine detection remained the same.     

The effectiveness of various strategies to improve DNA analysis of formaldehyde-damaged tissues from embalmed cadavers for human identification purposes

Formalin-fixed tissues provide the medical and forensic communities with alternative and often last resort sources of DNA for identification or diagnostic purposes. The DNA in these samples can be highly degraded and chemically damaged, making downstream genotyping using short tandem repeats (STRs) challenging. Therefore, the use of alternative genetic markers, methods that pre-amplify the low amount of good quality DNA present, or methods that repair the damaged DNA template may provide more probative genetic information. This study investigated whether whole genome amplification (WGA) and DNA repair could improve STR typing of formaldehyde-damaged (FD) tissues from embalmed cadavers. Additionally, comparative genotyping success using bi-allelic markers, including INDELs and SNPs, was explored. Calculated random match probabilities (RMPs) using traditional STRs, INDEL markers, and two next generation sequencing (NGS) panels were compared across all samples. Overall, results showed that neither WGA nor DNA repair substantially improved STR success rates from formalin-fixed tissue samples. However, when DNA from FD samples was genotyped using INDEL and SNP-based panels, the RMP of each sample was markedly lower than the RMPs calculated from partial STR profiles. Therefore, the results of this study suggest that rather than attempting to improve the quantity and quality of severely damaged and degraded DNA prior to STR typing, a more productive approach may be to target smaller amplicons to provide more discriminatory DNA identifications. Furthermore, an NGS panel with less loci may yield better results when examining FD samples, due to more optimized chemistries that result in greater allelic balance and amplicon coverage.     

Toward maintaining canine training aid integrity: Visualizing contamination and testing storage materials for a non-hazardous canine training aid

Contamination of canine training aids is a pervasive issue that may lead to incorrect canine discrimination of target odors. It is therefore important to properly store training materials to maintain their integrity and efficiency. First, this study demonstrated the potential for contamination using GloGerm™ as a proxy for odor/particulate transfer. Then, eight types of containers were evaluated to determine (1) the ability to prevent odor permeation and (2) the likelihood of maintaining the ab/adsorbed odor. Lastly, a longitudinal study evaluated how the permeation of the target odor changed over time. Analysis occurred using a direct analysis in real-time mass spectrometer (DART-MS) to detect triacetone triperoxide (TATP) from the non-hazardous canine training aid known as the polymer odor capture-and-release (POCR) system. Results showed that Mylar and Opsak bags were most effective for short-term storage, maintaining low levels of ab/adsorption. Over time, the amount of TATP permeating through the primary containers and collecting in a secondary container (i.e., outer packaging) increased at 1 week and decreased thereafter (up to 4 months). The amount of TATP collecting in the primary containers, however, increased up to 1 month and decreased thereafter.     

东亚FTA体系中的原产地规则与东亚生产体系

原产地规则是FTA的重要组成部分。本文首先分析了东亚FTA体系中原产地规则的特征,然后从理论上研究了现有的原产地规则对东亚生产体系的不利影响,重点分析了影响机制和渠道。最后,结合东亚现状提出了一些建议。     

公平原则及相关情况规则探讨——兼析中国东海大陆架划界基本主张

新近,国际法院在相关的司法判例中提出了公平原则及相关情况规则,尤其在2009年罗马尼亚诉乌克兰黑海划界案中确认了这一具体规则及其适用方法。该项规则是建立在公平基础之上的,相比其他划界方法而言,更强调原则的属性。实际上,公平原则常常使用各种方法的结合以便取得公平结果。由于公平原则在划界领域可以平衡各种公平因素,因此在海洋边界划分中具有习惯法的地位。据此原则,中国有关东海大陆架划界的基本主张不容置疑。