Forensic science international
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We evaluate the distribution of sulfide and thiosulfate (TS) in biological samples of four dairy farmers died inside a pit connected to a manure lagoon. Autopsies were performed 4 days later. Toxicological analyses of sulfide and TS were made using an extractive alkylation technique combined with gas chromatography/mass spectrometry (GC/MS). ⋯ One by one, the other farmers entered the pit in attempts to rescue the coworkers but collapsed. Despite the rapid death, subject 3 was the only one with TS detectable in urine. This could be due to differences in metabolism of H2S.
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The aim of the present study is to develop effective and understandable classification models for sex estimation and to identify the most dimorphic linear measurements in adult crania by means of data mining techniques. Furthermore, machine learning models and models developed through logistic regression analysis are compared in terms of performance. Computed tomography scans of 393 adult individuals were used in the study. ⋯ Its accuracy was even better than the classification rates achieved by the logistic regression models. Concerning the second dataset of nonstandard measurements, the best accuracy (88.3 %) was obtained by using classification models learnt by two algorithms - JRIP with a dataset preprocessed by the BestFirst selection algorithm and Ridor with preprocessing by the GeneticSearch selection algorithm. Our experiments show that for the two datasets mentioned above the rule-based models contain smaller sets of rules with shorter lists of measurements and achieve better classification accuracy results in comparison with decision tree-based models.
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The introduction of new psychoactive substances (NPS) on the illicit drug market has led to major challenges for the analytical laboratories. Keeping screening methods up to date with all relevant drugs is hard to achieve and the risk of missing important findings in biological samples is a matter of concern. Aiming for an extended retrospective data analysis, diagnostic fragment ions from synthetic cannabinoids (n=251), synthetic opioids (n=88) and designer benzodiazepines (n=26) not included in our original analytical method were obtained from the crowdsourced database HighResNPS.com and converted to a personalized library in a format compatible with the analytical instrumentation. ⋯ Of these, only one finding of phenibut was considered plausible after checking retention times and signal-to-noise ratios. This study shows that new compounds can be detected retrospectively in data files from QTOF-MS using an updated library containing diagnostic fragment ions. Automatic screening procedures can be useful, but a manual re-evaluation of positive findings will always be necessary.
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The influence of two different variables on deflection was studied with 9mm Luger calibre bullets, fired through ballistic gelatine. To test whether bullet type affects trajectory deflection, bullets of four different types were fired (20 shots per type) through 25cm of 10% gelatine at a 5m muzzle-to target-distance. ⋯ To test whether muzzle-to target-distance affects trajectory deflection, additional shots were fired with one of the four bullet types (7.5g FMJ-RN) at 1 and 15m muzzle-to target distances (20 shots per distance), again through 25 cm of 10% gelatine. A Kruskal-Wallis test showed that there was no significant difference (p=.72, significance level of 0.05) in deflection between the three muzzle-to target distances of 1, 5 and 15m.
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In traffic accidents, the differentiation of run-over and other injuries is crucial because questions about the origin of fatal injuries often arise. It is sometimes difficult for forensic pathologists to answer them due to the superimposition of injuries or competing, potentially fatal findings. Therefore, using morphometric three-dimensional (3D) reconstructions offers new perspectives based on an interdisciplinary evaluation of all findings and traces. ⋯ Run-over accidents have received less attention than the topic of pedestrian, bicycle and motorbike accident analysis for which there is a large body of literature. Our goal is to add to the understanding of run-over accidents using morphometric reconstruction in order to improve their analysis in the future. The possibilities of morphometric reconstructions by means of 3D techniques in run-over accidents are wide-ranging and can provide new, unexpected and significant insights.