嗜尸性昆虫证据在案发现场的分布研究

为了明确案发现场昆虫证据的分布,为法医昆虫学现场昆虫证据收集提供借鉴,我们利用猪尸体进行模拟,对现场昆虫的分布进行了调查,重点观察了大头金蝇、丝光绿蝇、绯颜裸金蝇、厚环黑蝇、阎甲科、隐翅甲科、埋葬甲科和皮蠹科昆虫的活动情况。结果表明,昆虫标本主要分布于尸体上及现场约10米范围的地面和地下,据此我们提出了法医昆虫学现场取样规范。     

期货收益率极端波动离散间隔的实证研究

本文基于极值理论,以沪铜、大连大豆和郑州硬麦期货为研究对象,应用最大信息熵原理、广义极值分布和K－S拟合检验,实证分析了我国商品期货收益率极端波动的时间间隔的统计分布特征。引入离散的时间间隔来刻画极端波动特征在学术上是个新的尝试。实证结果表明：极端波动的确定是与阈值紧密联系的;我国商品期货收益率的极端波动间隔时间服从广义极值分布;期货收益率极端波动时间间隔序列具有集聚性;运用条件期望值--波动模型预测极端波动间隔是可行的。这些成果为监管层度量极端波动强度和控制风险提供了有效的方法。     

Lipidic compounds found in soils surrounding human decomposing bodies and its use in forensic investigations – A narrative review

Following decomposition of a human body, a variety of decomposition products, such as lipids, are released into the surrounding environment, e.g. soils. The long-lasting preservation in soils and their high diagnostic potential have been neglected in forensic research. Furthermore, little is known about the preservation, chemical transformation, or degradation of those human derived lipids in soils. To date, several studies identified various lipids such as long-chain free fatty acids and steroids in soils that contained decomposition fluids. Those lipids are preserved in soils over time and could serve as markers of human decomposition in forensic investigations, e.g. for estimating the post-mortem interval or identifying the burial location of a human body. Therefore, this review focuses on the current literature regarding fatty acid and steroid that have been detected in soils and associated with human body decomposition. After a short introduction about human decomposition processes, this review summarises fatty acid and steroid analysis applied in current case studies and studies related to taphonomic research. This review provides an overview of the available studies that have used fatty acids and steroids as identifiers of human decomposition fluid in soils in a forensic context and discusses the potential for developing this innovative field of research with direct application in a forensic context.     

Informing regional taphonomy research using retrospective forensic anthropology cases in the Western Cape,South Africa

The post-mortem interval (PMI) is important in death investigations as it can assist in reconstructing the context of the case and the identification of the unknown individual. However, in some instances the PMI is challenging to estimate due to the absence of regional taphonomy standards. To conduct accurate and locally relevant forensic taphonomy research, investigators require insight into the regional hotspot recovery areas. Thus, forensic cases examined by the Forensic Anthropology Cape Town (FACT) in the Western Cape (WC) province of South Africa between 2006 and 2018 (n = 172 cases; n = 174 individuals) were retrospectively reviewed. In our study, a considerable number of individuals did not have the PMI estimations (31 %; 54/174) and the ability to estimate a PMI was significantly associated with skeletal completeness, unburnt remains, absence of clothing and the absence of entomological evidence (p < 0.05 for each). Significantly fewer cases had the PMI estimated after FACT was formalised in 2014 (p < 0.0001). One third of cases with PMI estimations were made with large open-ended ranges, making them less informative. Factors significantly associated with these broad PMI ranges were fragmented remains, absence of clothing and absence of entomological evidence (p < 0.05 for each). Most decedents (51 %; 87/174) were discovered in police precincts from high crime areas, yet a considerable number (47 %; 81/174) were also found in low crime and sparsely populated areas regularly used for recreational activities. Common sites of body discovery were vegetated areas (23 %; 40/174), followed by the roadside (15 %; 29/174), aquatic environments (11 %; 20/174) and farms (11 %; 19/174). Decedents were discovered exposed (35 %; 62/174), covered with items such as bedding or shrubs (14 %; 25/174) or buried (10 %; 17/174). Our data highlight gaps in forensic taphonomy studies and clearly informs what regional research is needed. Overall, our study demonstrates how forensic case information can inform regional forensic taphonomy studies to locate common areas and contexts for the discovery of decomposed bodies and encourages similar studies in other areas of the world.