The Role of Interface Shape on the Impact Characteristics and Cranial Fracture Patterns Using the Immature Porcine Head Model, ,

The forensic literature suggests that when adolescents fall onto edged and pointed surfaces, depressed fractures can occur at low energy levels. This study documents impact biomechanics and fracture characteristics of infant porcine skulls dropped onto flat, curved, edged, and focal surfaces. Results showed that the energy needed for fracture initiation was nearly four times higher against a flat surface than against the other surfaces. While characteristic measures of fracture such as number and length of fractures did not vary with impact surface shape, the fracture patterns did depend on impact surface shape. While experimental impacts against the flat surface produced linear fractures initiating at sutural boundaries peripheral to the point of impact (POI), more focal impacts produced depressed fractures initiating at the POI. The study supported case‐based forensic literature suggesting cranial fracture patterns depend on impact surface shape and that fracture initiation energy is lower for more focal impacts.     

家兔死后心血氧化还原电位值变化与死亡时间的关系

目的研究在不同温度条件下家兔死后心血氧化还原电位(oxidation reduction potential,ORP)值变化与死亡时间(postmortem interval,PMI)的关系。方法随机将48只家兔分为6组,以空气栓塞法处死后,取家兔右心室血液分别置于10、15、20、25、30和35℃温度下的水浴中,自取血即刻(0h)至死后132h内,每4 h用PB-21型电化学分析仪测定样本的ORP值。应用SPSS 17.0软件建立曲线回归方程,再应用MATLAB7.10.0软件建立曲面方程和三维曲面图。结果不同温度条件下家兔心血ORP值变化与PMI具有高度相关性,温度高时,ORP值上升明显,温度低时,ORP值上升缓慢,并获得拟合的曲面方程以及三维曲面图。结论拟合的ORP值与PMI的曲面方程及三维曲面图可进行温度变化条件下的PMI推断。     

Tracking the drift of a human body in the coastal ocean using numerical prediction models of the oceanic, atmospheric and wave conditions.

This paper describes the use of numerical models to infer the path of a floating human body in the Ligurian Sea (north-west Mediterranean) during the month of January 2001. The prevailing oceanic currents were obtained from a state-of-the-art real-time nowcast/forecast ocean circulation model, while the sea state was inferred from a numerical model of the surface gravity waves, both driven by regional atmospheric models. The surface currents (from the ocean model) and the drift ones at the ocean surface, as inferred from the wave model, were used to drive a Lagrangian model of the drifting body to deduce its plausible trajectory along the Ligurian coast. The inferred path is reasonably consistent with location and time of the discovery on the French coast. This note illustrates the utility of numerical prediction models at the disposal of modern forensic science in the fields of ocean sciences.     

The consequences of potentially differing distributions of the refractive indices of glass fragments from control and recovered sources

In forensic cases involving glass evidence, the variance of the recovered glass refractive index (RI) has been observed to be larger than the variance of the control glass RI. This has consequences for subsequent interpretation. To investigate this phenomenon, a study was made of the probable distributions of refractive indices of the recovered glass given a range of casework type scenarios involving breakage and backscatter. An investigation of the consequences of any distribution differences with regard to casework was also made. It was discovered that the inclusion of surface fragments from the float surface of the glass can have a profound effect on the comparison of recovered and control glass samples. The effect was largest when a breaker was striking the float surface of a window. In particular, it was found that the inclusion of a few surface fragments even post grouping is sufficient by itself to explain the observed differences in variance of RI between control and recovered groups. Surface fragments, if present, are very likely to be treated as outliers and to be deemed as non-matching. The findings of this paper challenge routine glass examination procedure and suggest that knowledge of which surface is facing the striker is valuable information in interpretation.     

A comparison of the length and width of static inked two-dimensional bare footprints found on a hard compared to a soft surface

In forensic intelligence-gathering it would be useful to evaluate if there are differences between static inked bare footprints captured on hard surfaces compared to soft surfaces. This was undertaken using samples from 30 undergraduate students. Initially a static footprint was taken for each participant on a hard surface and this was followed by a static footprint on a soft surface. On both occasions, the participants stood on an inkless mat and then on reactive paper, creating a two-dimensional print. The Reel method was used to analyse each footprint and the print was measured to see whether a difference existed between length and width (forefoot and rearfoot width) on a hard surface compared to a soft surface. The conclusion from this study was there is a statistically significant increase in length and width of a static bare footprint on a soft surface as opposed to a hard surface. If a forensic footprint examiner compares static bare footprints found on a soft surface and compares them to a static bare footprint of the same foot taken later, then the increase in both length and width of the footprints on a soft surface should be considered in the evaluation.     

The Role of Interface on the Impact Characteristics and Cranial Fracture Patterns Using the Immature Porcine Head Model

The role of impact interface characteristics on the biomechanics and patterns of cranial fracture has not been investigated in detail, and especially for the pediatric head. In this study, infant porcine skulls aged 2–19 days were dropped with an energy to cause fracturing onto four surfaces varying in stiffness from a rigid plate to one covered with plush carpeting. Results showed that heads dropped onto the rigid surface produced more extensive cranial fracturing than onto carpeted surfaces. Contact forces generated at fracture initiation and the overall maximum contact forces were generally lower for the rigid than carpeted impacts. While the degree of cranial fracturing from impacts onto the heavy carpeted surface was comparable to that of lower‐energy rigid surface impacts, there were fewer diastatic fractures. This suggests that characteristics of the cranial fracture patterns may be used to differentiate energy level from impact interface in pediatric forensic cases.     

人民调解的关系/事件和行动策略分析

人民调解是个复杂的构成体,它表面上是对个别纠纷的解决,实质上是对社会关系的一次重新梳理。每个纠纷的解决都不是我们表面上所看上去的那么简单,有众多因素在背后影响着人民调解的进行。我们重点从关系/事件的分析角度入手,找出其背后的影响因素和行动策略,进而为人民调解的发展提供一定的建议。     

胶带粘面手印荧光显现剂的研发与应用

目的根据胶带粘面上潜在手印的特点,利用染料和潜手印的理化性质,研究开发胶带粘面手印荧光显现剂。方法在各种胶带粘面上显现潜在手印,并与常规的碳素墨水染色法进行比较。结果在长波紫外线照射下手印呈黄色明亮荧光,手印纹线清晰、连贯,基本不受手印遗留时间、客体表面颜色和性质的影响。结论胶带粘面上的汗潜手印和血潜手印用荧光显现剂显现效果优于碳素墨水染色法,在实际案件的侦破中有较好的应用前景。     

Study of the adhesion of explosive residues to the finger and transfer to clothing and luggage

It is important to understand the extent of transfer of explosive particles to different surfaces in order to better evaluate potential cross-contamination by explosives in crowded security controls such as those at airports. This work investigated the transfer of nine explosive residues (ANFO, dynamite, black powder, TNT, HMTD, PETN, NH₄NO₃, KNO₃, NaClO₃) through fingerprints from one surface to another. First, the extent of adhesion of explosive residues from different surfaces to the bare finger, nitrile and latex gloves was studied. Then, the transfer of explosive residues from one surface to another through fingerprints was investigated. Cotton fabric (hereinafter referred to as cotton) as clothing material and polycarbonate plastic (hereinafter referred to as polycarbonate) as luggage material were chosen for the experiments. These surfaces containing explosive particles were imaged using a reflex camera before and after the particles were transferred. Afterwards the images were processed in MATLAB where pixels corresponding to explosive residues were quantified. Results demonstrated that transfer of explosive residues frequently occurred with certain differences among materials. Generally, the amount of explosive particles adhered to the finger decreased in the following order: skin>latex>nitrile, while the transfer of particles from the finger to another surface was the opposite. The adhesion of explosive residues from polycarbonate to the finger was found to be better compared to cotton, while the amount of particles transferred to cotton was higher.     

An investigation of refractive index anomalies at the surfaces of glass objects and windows

Results obtained using GRIM equipment show that the refractive index (RI) of surface layers of float and non-float flat glass, glass containers and tableware can vary significantly from that of the bulk glass. The results also suggest that, using the oil immersion method with GRIM, it is not possible to obtain surface RI measurements which are useful for discrimination. Instead, a range of values is obtained for each sample, the individual results probably being dependent upon the thickness and geometry of the particular edge under examination.     

手套类检材DNA分型的取材部位初步研究

目的探讨手套类检材进行法医DNA分型时的最佳取材部位。方法构建手套模型,对手套内表面分区取样,常规chelex-100法提取DNA,选取常用法医学STR基因座进行PCR扩增,PAGE检测条带,Quantity One和SPSS软件识别并分析条带。结果手套内表面不同部位的D1S1656和D12S1064基因座扩增条带光密度存在显著的组间差异（P〈0.05）,来自右手掌指关节和左手小鱼际对应部位的扩增条带光密度差异显著性最大。结论选取与手掌指关节、小鱼际相对应的手套内表面部位,有可能获得更多的DNA以利于分型,这一判断可直接用于指导法医实践。     

不同温度下离体人静脉血ATP含量与死亡时间的关系

目的探讨在环境温度变化条件下,人体静脉血ATP降解与死亡时间的关系。方法健康志愿者48名,随机分为6组,肱静脉取静脉血,置于10℃、15℃、20℃、25℃、30℃和35℃下保存;每4h应用ATP检测仪对不同温度下的ATP含量进行检测;应用SPSS统计软件进行回归分析,MATLAB软件进行差值函数分析拟合。结果各温度组ATP值随死亡时间延长均呈下降趋势,从取血即刻的1 573.683 E-13mol/L,降至6.00 E-13mol/L左右,所经历的时间分别为236h(10℃)、163h(15℃)、124h(20℃)、92h(25℃)、72h(30℃)和64h(35℃),对所得数据进行回归分析,得到各温度组下ATP含量变化与PMI关系的二元三次曲线方程(R2范围为0.976～0.990);进行差值拟合,得到10～35℃范围内ATP含量变化与PMI关系的三元四次曲面方程。结论在不同温度下,人体静脉血ATP降解与PMI关系符合三元四次方程分布,利用差值函数拟合的方法可在温度变化条件下进行死亡时间推断。     

人体体表损伤法医学鉴定软件开发及应用

通过运用人体体表损伤法医学鉴定软件,进行各种体表损伤和瘢痕面积、长度、骨折畸形愈合角度和关节活动度等测算。用于人体轻伤和重伤、交通事故损伤、工伤、军人伤残、意外伤害保险等损伤程度的法医学鉴定,亦可用于临床烧烫伤等损伤面积和程度准确计算。本软件基于 Windows平台,应用 Visual Basic6.0编程,设计了扫描照片、数码照相、联机摄象和鼠标多种录入损伤图象路径,打印输出图文格式化鉴定书。测算结果具客观性和重复性好,克服了传统方法的弊端。软硬件环境通用,界面友好,简单易学。经数家法医学鉴定机构 3年多的两百多例实际检案应用,取得了较好的社会效益。     

电击兔肢体所致骨损伤后的实验性研究

目的220V交流电击兔肢体后,观察电击部位骨表面的病理改变,为法医病理诊断电击伤提供客观、量化的指标。方法用220V交流电作为损伤电压。动物分为:生前电击组、死后5m in电击组、腐败组及正常对照组。每组骨骼标本均进行肉眼检察、X线检测及SEM观察;同时运用能谱仪测量电击部位元素的种类及含量。结果①电击部位骨皮质SEM下骨皮质紊乱、小孔穴形成、周围高密度影环绕,且钙、磷元素升高,碳元素下降是诊断电击伤的指标,并能鉴别生前、死后电击伤及腐败骨。②小孔穴的形态及钙、磷、碳元素的变化可用于推断电击时间。结论电击造成骨组织的形态及电击部位元素的改变可作为鉴别生前、死后电击伤、腐败骨和推断电击时间的指标。     

A Test of Sex Estimation in Subadults Using the Elevation of the Auricular Surface from Four Samples of Known Age and Sex

Biological sex is foundational to the work of forensic anthropologists and bioarcheologists. The lack of reliable biological sex estimation methods for subadults has, thus, greatly limited forensic and bioarcheological analyses. Auricular surface elevation showed promise as a subadult sex estimation method in previous studies. This study examined two auricular surface elevation evaluation methods on four subadult samples of known age, sex, and ancestry. Samples were scored as “male,” “female,” or “indeterminate” and results were examined with chi‐square analysis. No consistent sex estimation pattern, accuracy, or predictive value was produced between samples. Only one test was significant using Fisher's exact test analysis (FET = 7.501, p < 0.022): the composite approach on the Hamann‐Todd sample. While age, sample size, or developmental factors may play a role in these results, clearly sample variation does as well. This study found auricular surface elevation was not a useful subadult sex estimation method.     

Studies on asphyxia: on the changes of the alveolar walls of rats in the hypoxic state

The morphological changes of the alveolar wall of adult rats in the hypoxic state were studied by light and electron microscopy. The remarkable findings were the appearance of a large amount of lamellar, lattice- and thread-like structures together with a massive homogeneous substance on the surface of the alveoli which seemed to be closely connected with each other and with the surface of the cells lining the alveolus, especially in the 5%-group. The appearance of the above-mentioned structures with the homogeneous substance is considered to be the reaction of lung tissue to the decreased content of oxygen in the inhaled gas.     

Determining the age at death of females in the Chinese Han population: using quantitative variables and statistical analysis from pubic bones

Determining the age at death of females by skeletal features is extremely difficult and important, both in forensics and in physical anthropology. Our previous study of male pubic symphysis suggests that the indicators of morphological changes provide the best results for personal age identification. The indicators that help deduce of the age of females was approximately the same as males except for two specific indicators, which are bone density of the symphysial surface and viz. Viz are ridges and furrows on the symphysial surface, ossific nodules, lower extremities, ventral and ridge of the rampart, dorsal margin, ventral beveling and general macroscopic changes on the symphysial surface. Samples were drawn from 338 female individuals. The study procedures are as follows: Firstly, we examined the morphological features of pubic symphysis using the criteria similar to Hanihara's, Gilbert-McKern and Suchey-Brooks's methods. Secondly, we evaluated each stage with an appropriate score. Thirdly, we deduced four equations to assess the morphological features of the ages of females by statistic analysis. The results were discussed by comparing with Hanihara's, Gilbert-McKern and Suchey-Brooks's methods. The results were consistent and the developing methods for determining the age of death of females were produced.     

Deposition and incorporation of trace objects on the bone in blunt injury

A total of 457 cases with the impact of blunt hard objects and cars on the surface of different bones with formation of sites of deposition and incorporation of trace objects are analyzed. Variants of incorporation of fragments of hairs, fibers, metals, varnish into bone surface and microstructure are described, their diagnostic significance, mechanism of formation, and relationship with bone injuries are discussed.     

On racial-ethnic features of the mucosal structure of the gingival edge and tongue

The structure of the mucosal membrane of the gingiva and dorsal surface of the tongue was studied in 415 residents (men and women aged 18-35 years) of Africa, Southern, Central, and Northern Asia, and Russia in order to detect racial and ethnic differences. A complex of modern methods of investigation was used (use of intraoral videotape recorder, digital photo, computer analysis, plaster models, uni- and multi-dimensional mathematical analysis). The data can be practically important in forensic medical personality identification.     

The informative aspects of the wound surface for determining vitality and wound age in skin cuts

A histological study was carried out on skin cut wounds of guinea pigs at various time intervals during the first day after infliction of the cut. At the same time intervals, blood cells were obtained from the wound surface prints and analyzed cytologically and cytochemically. Histological examination showed that a central and peripheral zone formed in the wound area, demonstrating that necrobiotic and inflammatory processes were even occurring in the early hours after injury. However, changes in the quantitative relationships between individual kinds of cells were much more differentiated cytologically and reflected much more precisely. Functional and structural macrophage and lymphocyte changes in the wound region during inflammation were also revealed. In correlation, cytochemical analysis confirmed the concept concerning the development of the inflammatory process in the wound area, as enzyme-activity changes clearly detectable, which reflected the rapid, energetic, plastic cellular processes on the wound surface. Our combined results suggest that the wound surface is a zone of vital processes, but that it is not a "dead," "necrobiotic" area. The dynamics of the cellular alterations in the wound surface, reflecting the vital processes developing there, can be successfully used when the problem of vitality, especially the time lapse after the skin injury, is to be resolved.