Forensic Use of A Subtropical Blowfly: The First Case Indicating Minimum Postmortem Interval (mPMI) in Southern Brazil and First Record of Sarconesia Chlorogaster from a Human Corpse

Southern Brazil is unique due to its subtropical climate. Here, we report on the first forensic entomology case and the first record of Sarconesia chlorogaster (Wiedemann) in a human corpse in this region. Flies' samples were collected from a body indoors at 20°C. Four species were found, but only Chrysomya albiceps (Wiedemann) and S. chlorogaster were used to estimate the minimum postmortem interval (mPMI). The mPMI was calculated using accumulated degree hour (ADH) and developmental time. The S. chlorogaster puparium collected was light in color, so we used an experiment to establish a more accurate estimate for time since initiation of pupation where we found full tanning after 3 h. Development of C. albiceps at 20°C to the end of the third instar is 7.4 days. The mPMI based on S. chlorogaster (developmental time until the third instar with no more than 3 h of pupae development) was 7.6 days.     

建立长效机制 推进职工素质工程

中国石油大港油田物资供销公司通过制定"公司职工素质工程实施意见",坚持以打造结构合理、精干高效、具有行业竞争力的"三支人才队伍"为目标,深入推进长效机制建设,努力强化组织领导、活动载体、持续动力三大保障,有力推进了职工素质工程工作的深入开展。     

新世纪中国警方面临的七大挑战

在刚刚到来的 2 1世纪里 ,中国警方既面临着前所未有的机遇 ,也面临着空前严峻的挑战。这种挑战主要来自七个方面 :一、公安工作乘势而上的要求对现行体制的挑战 ;二、社会变革对警察政治生活角色地位的挑战 ;三、新形势下犯罪活动出现的新情况对警察队伍素质的挑战 ;四、维护社会稳定繁重任务的挑战 ;五、公安队伍建设的紧迫性对各级公安机关领导者的挑战 ;六、警务实践中新问题层出不穷对中国警察理论匮乏的挑战 ;七、现代生活的多元化对警察应对能力的挑战     

Geoforensic search to crime scene: Remote sensing,geophysics, and dogs

In the absence of surface indications of burial sites, law enforcement or humanitarian organizations are faced with the difficult task of focusing large-scale ground searches to a manageable excavation area. A geoforensic-based survey may exclude parts of the landscape for reasons such as diggability or viewshed analysis but leave areas still too large for invasive exploration. This work examines how drone-based remote sensing, geophysics, and search dogs may be combined to narrow such searches. Here, we ask the reader to consider two examples where forensic geomorphology and land use provided a range of possible burial locations. Following this is a multi-proxy approach to similar dilemma, with a search-to-scene case study using remote sensing (drone photography), geophysics, ground probes, and search dogs. This approach is not presented as a definitive guide, but serves as an example of the conjunctive use of well-studied methods to approach a common problem in geoforensics.     

Stability studies of ALD-52 and its homologue 1P-LSD

With the emergence of new psychoactive substances (NPSs) over the years, the substances detected on stamps (also known as blotter papers) have also evolved from the traditional drug—lysergic acid diethylamide (LSD) to the multiple variants of lysergamides such as ALD-52 and 1P-LSD. The analysis of such blotter papers is usually done by solvent extraction followed by identification using gas chromatography–mass spectrometry (GC-MS). This study has shown that hydrolysis to form LSD was observed in GC-MS analysis when ALD-52 was extracted with methanol. The extraction of ALD-52 using other solvents such as acetonitrile, ethanol, isopropyl alcohol, ethyl acetate, and acetone, followed by GC-MS analysis, was investigated. It is shown that alcoholic solvents such as methanol and ethanol will result in the conversion of ALD-52 to LSD during GC-MS analysis, whereas the sterically hindered isopropyl alcohol will prevent this conversion. Investigation also shows that the hydrolysis of ALD-52 to LSD occurs at the GC injector port. It was also observed that the degree of hydrolysis was more pronounced at a lower concentration (0.1 mg/mL). The study was extended to a close analog—1P-LSD, and the results showed that 1P-LSD similarly hydrolyzes to LSD. However, 1P-LSD was observed to be more stable than ALD-52 due to steric hindrance because of the propanoyl group.     

Deep learning for sex determination: Analyzing over 200,000 panoramic radiographs

The objective of this study is to assess the performance of an innovative AI-powered tool for sex determination using panoramic radiographs (PR) and to explore factors affecting the performance of the convolutional neural network (CNN). The study involved 207,946 panoramic dental X-rays and their corresponding reports from 15 clinical centers in São Paulo, Brazil. The PRs were acquired with four different devices, and 58% of the patients were female. Data preprocessing included anonymizing the exams, extracting pertinent information from the reports, such as sex, age, type of dentition, and number of missing teeth, and organizing the data into a PostgreSQL database. Two neural network architectures, a standard CNN and a ResNet, were utilized for sex classification, with both undergoing hyperparameter tuning and cross-validation to ensure optimal performance. The CNN model achieved 95.02% accuracy in sex estimation, with image resolution being a significant influencing factor. The ResNet model attained over 86% accuracy in subjects older than 6 years and over 96% in those over 16 years. The algorithm performed better on female images, and the area under the curve (AUC) exceeded 96% for most age groups, except the youngest. Accuracy values were also assessed for different dentition types (deciduous, mixed, and permanent) and missing teeth. This study demonstrates the effectiveness of an AI-driven tool for sex determination using PR and emphasizes the role of image resolution, age, and sex in determining the algorithm's performance.     

Quantitative PCR overestimation of DNA in samples contaminated with tin

Metals can pose challenges while conducting forensic DNA analysis. The presence of metal ions in evidence-related DNA extracts can degrade DNA or inhibit PCR as applied to DNA quantification (real-time PCR or qPCR) and/or STR amplification, leading to low success in STR profiling. Different metal ions were spiked into 0.2 and 0.5 ng of human genomic DNA in an “inhibition study” and the impact was evaluated by qPCR using the Quantifiler™ Trio DNA Quantification Kit (Thermo Fisher Scientific) and an in-house SYBR Green assay. This study reports on a contradictory finding specific to tin (Sn) ions, which caused at least a 38,000-fold overestimation of DNA concentration when utilizing Quantifiler Trio. This was explained by the raw and multicomponent spectral plots, which indicated that Sn suppresses the Quantifiler Trio passive reference dye (Mustang Purple™, MP) at ion concentrations above 0.1 mM. This effect was not observed when DNA was quantified using SYBR Green with ROX™ as the passive reference, nor when DNA was extracted and purified prior to Quantifiler Trio. The results show that metal contaminants can interfere with qPCR-based DNA quantification in unexpected ways and may be assay dependent. The results also highlight the importance of qPCR as a quality check to determine steps for sample cleanup prior to STR amplification that may be similarly impacted by metal ions. Forensic workflows should recognize the risk of inaccurate DNA quantification of samples that are collected from substrates containing tin.     

Persistence of cellular material after exposure to water

Disposing of items of forensic relevance in bodies of water is one countermeasure offenders can use to avoid detection. The impact of immersion in water has been explored for blood, saliva, and semen; however, few studies have assessed touch DNA. Here we report on the effect of exposure to water on the persistence of touch DNA over prolonged periods of time. To evaluate the persistence of cells from touch DNA, after water exposure, three substrates and two water types were tested: plastic, metal, and ceramic, submerged into seawater or tap water. Diamond™ Nucleic Acid Dye was used to stain cells deposited by touch. Cell counts before and after water exposure were compared to investigate cell loss over time, ranging from 6 hours to 5 days. A logarithmic increase in the percent of cells lost was observed over time when the data for substrate and water type conditions were combined. Substrate type influenced the persistence of cells, with the metal substrate retaining cells longer than plastic or ceramic. The influence of water type appeared dependent on the substrate, with varied cell persistence on metal whereas plastic and ceramic recorded similar cell loss over time between water types. The ability to visualize cells after exposure to water could assist in triaging evidence within operational forensic laboratories and allow for targeted sampling. This proof-of-concept study demonstrated that greater than 50% of cells can persist on various items submerged in aqueous environments for at least 5 days, highlighting the possibility for downstream DNA testing.     

CT测量在眶内壁骨折损伤程度鉴定中的应用

目的 利用CT测量眶内壁骨折案件中伤者眶容积扩大率及眶内壁骨质缺损面积,探讨两种CT测量值用于评估眶内壁骨折范围的可行性.方法 选取20例无眼眶骨折案件作为对照组,使用CT测量双侧眶容积,并比较两例是否存在差异.选取本院2018-2020年间受理的眶内壁骨折案件39例作为实验组,并根据鉴定意见分为轻伤组与轻微伤组.分别...     

论道德教育关系性价值存在的基本特征

社会性与历史性的统一是道德教育中各种价值关系最基本的特征之一,作为一种能动的实践活动,道德教育的本体价值及其构成要素间的价值关系具有鲜明的社会性;作为一种历史活动,道德教育的总体目标和具体内容都是历史的产物.存在客观性与评价主观性的统一是其价值论特征,不同的认识论和不同的发展观必然导致对道德教育价值的不同评价.关系存在相对性和绝对性的统一是其认识论特征,道德教育对人类发展的价值及其各类要素之间的价值关系是显性的,但实践与评价的结果常常是流变和动态的.