Friction Marks of Stabbing Tools in Tires

When receiving a stabbed tire for examination, forensic toolmark examiners can determine whether a suspect tool was used in a specific crime based on class-characteristics and individual-characteristics marks that have been left by the tool on the tire. This study discusses friction marks and their forensic value during the examination of a punctured tire. The term friction mark refers to the noticeable mark around the penetration area on a tire's surface. Tires designed to create high friction when contacting a road. Due to this design, friction is created between the stabbing tool shank and the sides of the hole. As a result of this friction, the shank of the stabbing tool wears the outer layer of tire around the hole. This leaves a friction mark whose general shape reflects the cross-sectional shape of the stabbing tool’s shank. This phenomenon was observed and named by Locke (7) in his evaluation of tire puncture marks with knives. This article demonstrates the same phenomenon with other types of stabbing tools. Test stabs were produced with different tools representing a variety of cross-sectional shapes of shanks, and the resulting friction marks were photo-documented and discussed. Correlations between the various cross-sectional shapes and their corresponding friction marks are shown. Based on friction mark examination, the examiner: (i) can infer suspect tool shank cross-sectional shape with the evaluation of the friction mark shape and (ii) can deduce the maximum dimensions of the shank. This examination simplifies and accelerates the forensic comparison procedure and the investigation time.     

Pelvis and hip joint injuries as a reconstructive factors in car-to-pedestrian accidents.

The pelvic girdles of 371 pedestrian victims of road traffic accidents were evaluated during postmortem examinations. Additionally, 144 hip joints were opened. The pelvic injuries were found in 28% of the pedestrians hit exclusively in their upright position and 52% of the victims run over by a vehicle. The side of the body hit by a car was determined on the basis of the location of blood suffusions within the subcutaneous tissues and muscles of lower limbs as well as the character of injuries found in the knee and upper ankle joints. The findings were verified with the data from court records. It was shown that the injuries of the sacroiliac joints or vertical fractures of the posterior parts of iliac bones were useful parameters for determining the side (left or right) of the body hit by a vehicle. Moreover, it was found that a direct impact on the hip region was evidenced by the ipsilaterally localized fractures of the iliac ala, central hip fractures and intraosseous blood suffusions within the greater trochanter of the femur. The external dislocations of the hip joints (always) and bilateral injuries to the sacroiliac joints (usually) were observed in the victims run over by vehicles.     

汉族人肩、髋关节活动范围及与年龄、性别间的关系

目的探讨汉族人肩、髋两大关节的活动范围(range of motion,ROM)与现行《法医临床检验规范SF/ZJD0103003-2011》的差异性,并初步阐明性别、年龄因素对其ROM产生的影响。方法法医临床案件中选取仅单侧肩或髋关节受伤的汉族样本案例,将其健侧关节的ROM与现行标准《法医临床检验规范SF/ZJD0103003-2011》中的参考值的平均值进行比较分析,并对比该侧的不同年龄段(0~25岁、26~40岁、41~50岁、51~60岁及60岁以上)及性别间的差异。结果正常人体肩、髋关节的ROM的实际值与标准中参考值的平均值有较大的差异;5个不同年龄段肩、髋关节的部分方向ROM正常值存在差异且均随年龄的增长呈进行性下降的趋势。50岁以上人群在肩关节外展上举和髋关节内收、外旋等部分方向ROM正常值存在性别差异。结论正常汉族人肩、髋关节ROM存在年龄差异性,性别差异在50岁以上人群中较为明显。《法医临床检验规范SF/Z JD0103003-2011》标准所提供的参考值范围与实测值存在一定的差异。     

电动两轮车侧翻倒地滑动摩擦系数实验研究

目的两轮车侧翻倒地后的滑行摩擦系数是利用两轮车碰撞后倒地滑行距离进行速度计算的关键参数,论文通过试验研究提出用于道路交通事故速度计算的电动两轮车侧翻倒地滑动摩擦系数。方法在综合分析电动两轮车侧倒滑行摩擦系数影响因素的基础上,利用正交试验设计摩擦系数实验方案,并采用实车牵引的方法,在不同速度条件下,分别在干燥、潮湿的沥青混凝土路面及水泥混凝土路面上进行实验。结果实验所得数据显示,电动两轮车侧翻倒地滑动摩擦系数的范围为0.40～0.60。结论通过对所得数据进行处理,提出适用于电动两轮车交通事故再现的摩擦系数范围。     

三维动态标记下髋关节活动度与下肢功能权重

目的探讨髋关节在下肢功能中合理的权重系数范围。方法通过LUKOtronic运动捕捉与分析系统记录健康受试者髋关节在正常状态下的下肢运动情况以及髋关节在功能位、屈曲位和伸直位三个不同位置固定时的下肢运动情况,经Fugl-Meyer下肢运动功能评定量表计算获得髋关节在上述三个不同位置固定时的下肢功能丧失程度,通过单因素方差分析和Tamhane’s T2法进行统计分析,推算髋关节合理的权重系数范围。结果髋关节在屈曲位和伸直位固定时导致的下肢功能丧失程度与功能位固定导致的下肢功能丧失程度比较,差异具有统计学意义;而屈曲位固定与伸直位固定时下肢功能丧失程度之间比较,差异无统计学意义。根据95%的置信区间计算,髋关节在下肢功能的权重系数范围为61.05%~73.34%。结论在髋关节残损功能评价中,除了确定合理的权重系数以外,还需考虑功能位与非功能位因素对下肢功能丧失程度的影响。     

A Test of the DSP Sexing Method on CT Images from a Modern French Sample

The hip bone is considered to be one of the most reliable indicators in sex determination. The aim of this study was to test the reliability of the DSP method for the hip bone proposed by Murail et al. (Bull Mem Soc Anthropol Paris, 17, 2005, 167) on a sample from a present‐day population in France (52 males and 54 females). Ten linear measurements were collected from three‐dimensional models derived from computed tomography images (CTI). To quantify the proportions of correct sex determinations, a more rigorous posterior probability threshold of 0.95 was applied. Using all 10 measurements, 92.3% of males and 97.2% of females were sexed correctly. The percentage of undetermined specimens varied depending on the used combination of measurements; however, all sexes were assigned with a 100% accuracy. This study proves that DSP is an appropriate and reliable tool for sex determination, based on dimensions obtained from CTI.     

Sudden death from pelvic hemorrhage after bilateral central fracture dislocations of the hip due to an epileptic seizure

Fracture and dislocation of major joints may be caused by the forceful tonic muscular contractions of seizure activity. A 77-year-old man who was found dead in bed with no sign of external trauma had bilateral central fracture dislocations of the femoral head through the acetabular floor with fatal pelvic hemorrhage and extensive pulmonary fat and bone marrow embolism. He had epilepsy, but the last seizure was 6 years earlier, and he had long discontinued medication. The fractures were attributed to a new unwitnessed seizure. This is the twentieth case of central fracture dislocation of the hip since 1970, when better anesthesia eliminated convulsive therapy-induced fractures. The authors review these 20 cases. Seizures followed inflammation, infarction or neoplasia of the brain, eclampsia, metabolic or iatrogenic causes, or epilepsy (6 cases, 2 of which had no prior seizures for 5 years). There were 11 men (mean age, 64 years) and 9 women (mean age, 47 years). Fractures were unilateral in 13 and bilateral in 7. Additional fractures (in vertebrae, shoulders, or femur) were present in eight. Only eight had prior bone disease. Local symptoms led to diagnosis in most, but two were identified incidentally on imaging. The current patient was the only one to die suddenly, but six other patients presented with shock and three died (one of whom had injuries that led to a suspicion of manslaughter). Central fracture-dislocation of the hip is a rare and little known consequence of seizures, with strong potential for misdiagnosis and lethal complications.     

The role of center of mass kinematics in predicting peak utilized coefficient of friction during walking

Slips frequently occur when the friction required between the foot and floor exceeds available surface slip resistance. To date, the ability to identify variables that predict an individual's friction needs during walking, or utilized coefficient of friction (COFU), remains limited. Understanding COFU in the context of pedestrian/walkway accidents is important as individuals who demonstrate higher COFU are at a greater risk of slipping. This study determined if whole body center of mass (CM) kinematics were predictive of peak COFU during walking. Ground reaction forces and kinematic data were recorded simultaneously as subjects walked. Stepwise regression analysis determined that the combination of the subject's CM-to-center-of-pressure angle and CM anterior (i.e., forward) velocity predicted 62% of the variance in peak COFU during weight acceptance (p < 0.001). The identified relationships between CM kinematics and peak COFU provide insight into how gait and individual anthropometric characteristics may increase risk for slip initiation.     

Visualising DNA transfer: Latent DNA detection using Diamond Dye

A central question is ‘how did DNA get there’? To help answer this, we visually monitored and recorded DNA transfer from one substrate to another. When an individual touches a substrate, traces of their DNA are transferred (primary/direct) which can then subsequently be transferred to a second substrate (secondary/indirect). Currently DNA transfer and how much remains can only be determined by collecting the biological material from the substrate, isolating the DNA and quantifying the amount recovered. However, Diamond™ Dye (DD) enables such DNA transfer events to be visualised by monitoring the movement of cellular material.We examined primary and secondary DNA transfer using aluminium as a primary substrate with cotton, polyester, aluminium and plastic as secondary substrates and four contact types between two substrates (passive, pressure, friction and friction with pressure). Participants pressed their index finger against the aluminium for 15 s and then DD was applied to the area of contact; cellular material was detected via a fluorescence microscope. Contact between that substrate and a second substrate was performed, using one of the four contact types. After this contact between substrates each was viewed microscopically and transfer of cellular material was recorded.Cellular material could be recorded as having transferred from one substrate to another. Substrate and contact type had an effect on the extent DNA transfers. DNA transferred at a high rate with aluminium as a primary substrate and cotton, polyester and aluminium as secondary substrates when pressure with friction was applied. This information expands our understanding of how DNA transfers and which factors affect it, thus assisting greatly with activity level reporting as to how DNA came to be where it was found.     

典型电动两轮车倒地滑动摩擦系数实验研究

目的 为获得典型电动两轮车倒地滑动摩擦系数,研究倒地滑行速度、路面干湿、路面材料以及电动两轮车结构等因素对电动两轮车倒地滑动摩擦系数的影响.方法 采用实车牵引法测试了“标准”和“非标”两种类型电动两轮车在四种常见路面上的0～50km/h速度区间内的倒地滑动摩擦系数.结果 电动两轮车在实验混凝土路面倒地滑动摩擦系数为0....     

Changes in Fingerprints Depending on Physiological Factors

The aim of the study was to determine the effect of gender, body mass index, and time on the width of friction ridge impressions in fingerprints and the content of sweat and sebum forming the print. The research showed that the friction ridge impressions of women are significantly wider than those of men, and this tendency persists throughout the existence of the print. The differences may result from the anatomical structure of the skin, as well as from the use of protective products such as creams, which are used more often by women. The width of friction ridge impression is similar in underweight and overweight people, but greater than in those with normal body weight, and the amount of sweat and sebum increases with body weight. The passage of time significantly reduces both the width of the friction ridge impression and the content of sweat and sebum secretions in the print.     

The influence of footwear sole hardness on slip initiation in young adults

Slips occur when the friction demand of an individual exceeds the friction available from the shoe/floor interface. Shoe sole hardness is one of the factors thought to influence friction demand and available friction. The purpose of this study was to determine the influence of footwear sole hardness on the probability of slip initiation. Forty young adults were randomized into a hard or soft sole group. Slip events during the slippery floor trials were documented using a motion analysis system. The proportion of slip events in the hard sole group was greater than that in the soft sole group. The difference between utilized and available friction accurately predicted 90% of slip outcomes. Our data support the premise that individuals wearing shoes with harder soles are at greater risk for slipping. The results of this study suggest that shoe sole hardness should be considered when designing footwear aimed at decreasing slip risk.     

基于正交试验的汽车制动纵滑摩擦系数研究

目的通过进行不同因素条件下的汽车制动纵滑摩擦试验,得到不同因素下的摩擦系数,缩小摩擦系数参考值范围,提高事故再现精度。方法在制动纵滑摩擦试验中引入正交试验方法,通过极差分析确定不同因素对摩擦系数的影响程度,对汽车摩擦系数的选取进行可靠计算。结果提出了摩擦系数修正值的使用方法,有效减小摩擦系数参考值的范围,提高事故再现精度。结论事故再现中,通过试验研究方法,准确地选取汽车制动摩擦系数,有效提高了事故再现的精度。     

Consistency and reproducibility in fingermark deposition

A review of the available literature and previous research has suggested that there are several factors associated with the deposition of friction ridge skin marks that can affect the quality of the resultant marks, including the quantity of force applied, the angle of friction ridge and surface contact and the duration of friction ridge and surface contact. A device referred to as a fingerprint sampler was designed and constructed to facilitate the deposition of fingermarks for research projects. Fingermarks were deposited with and without the fingerprint sampler and examined for evidence of distortion. The quality of the marks was also assessed. The results of this study suggested that the fingerprint sampler deposited fingermarks without distortion caused by some physical factors associated with deposition and that the marks were of a statistically significantly higher quality than marks deposited without its use.     

Abrasion Collar Around Shrapnel Entry Wound

Abrasion collar is usually described as a feature of bullet entry wounds caused by friction and indentation. The present case is that of the peculiar entry wound caused by a piece of flying shrapnel which was ejected from a furnace in a steel plant. The scrap metal which exploded in the plant was sourced from the West Asia region. The entry wound on the chest was circular and had an abrasion collar around it. The projectile was a cylindrical object of obscure origin. The forensic science laboratory put forth the possibility that the projectile was a component of an artillery fuze. A decades old study which employed high‐speed photography has rejected the possibility that abrasion collars are produced by friction. High‐velocity projectiles other than bullets can also produce abrasion collars as the rubbing of the bullet against the skin or its rotation are not the causative mechanisms.     

Orthopedic devices: reclassification of the hip joint metal/polymer constrained cemented or uncemented prosthesis. Final Rule

The Food and Drug Administration (FDA) is reclassifying the hip joint metal/polymer constrained cemented or uncemented prosthesis intended to replace a hip joint from class III (premarket approval) to class II (special controls). FDA is also [[Page 21172]] identifying the guidance document entitled "Class II Special Controls Guidance Document: Hip Joint Metal/Polymer Constrained Cemented or Uncemented Prosthesis" as the special control that the agency believes will reasonably ensure the safety and effectiveness of the device. This reclassification is being undertaken based on new information regarding the device contained in a reclassification petition submitted by the Orthopedic Surgical Manufacturers Association (OSMA), under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the 1976 Amendments), the Safe Medical Devices Act of 1990 (SMDA), and the Food and Drug Administration Moderization Act of 1997 (FDAMA). FDA is also revising the device identification to accurately describe the device.     

Validation of Walkway Tribometers: Establishing a Reference Standard*

Abstract: Tribometers are mechanical devices used to measure walkway coefficient of friction (COF) for the purpose of assessing slip risk. The purpose of this study was to define a tribometer reference standard and use it to assess the performance of various tribometers. Eighty subjects were randomly assigned to walk across one of four wet walkway surfaces (polished black granite, porcelain, vinyl composition tile, and ceramic tile) to establish the relative slipperiness of each surface. Eleven tribometers were subsequently used to measure and rank the COF of all four surfaces. Our results revealed that only four of the 11 tribometers (Wessex pendulum, Sigler pendulum, Mark II, and Mark III) met our compliance criteria by both correctly ranking all four surfaces and differentiating between surfaces of varying degrees of slipperiness. Our protocol demonstrates that human gait‐based measures of slipperiness can be used to create reference standards against which tribometer measurements can be validated.     

中美贸易摩擦中的法律战--从不可靠实体清单制度到阻断办法

中美贸易摩擦有明暗两条主线。明线是两国政府就贸易摩擦所涉议题展开谈判,以期达成协议,解决贸易争端;暗线是中美之间就制裁和反制裁、遏制和反遏制展开的法律战。法律战是中美贸易摩擦所呈现的国家之间的法律和制度之争,是美国法律霸权主义背景下中国参与国际经济治理无法回避和必须回应的法律竞争和法律反遏制。法律战的工具具有多元性,这导致法律战呈现出复杂性。以长臂管辖和次级制裁为主要特征和核心的法律战对于中国完善国内法和参与国际法实践提出了更高的规则和制度要求。以不可靠实体清单制度和阻断办法为代表的法律战需要实体法、程序法、国内法、国际法多重要素的整体配合,才能达到政策目标。     

Factors moderating physical and psychological symptoms of battered women

Physical and psychological symptoms of battered women were investigated based on the theory that their ongoing victimization would produce stress-related symptoms. It was hypothesized that moderating variables (e.g., frequency and severity of abuse, predictability and controllability of abuse, social support networks) would influence the effects of abuse. Battered women (N = 234) were interviewed according to a structured format which allowed for behavioral indices of the data and categorization of the women's responses. Results indicated that frequency of abuse was a strong predictor of the number and severity of symptoms. Those women who could predict abuse experienced more symptoms. Severity of physical and psychological symptoms was predicted by a model including women with more injuries requiring medical attention, women adhering to traditional sex role values, and the presence of one type of emotional abuse. Battered women perceived their physical and emotional health as deteriorating during the relationship and during the abuse, but as getting healthier after the abuse ended. Future research needs to replicate these findings with a representative group of battered women who are still in the battering relationship.     

Will the introduction of an emotional context affect fingerprint analysis and decision-making?

Fingerprint identification relies on an expert's ability to accurately recognise differences and similarities in friction ridge detail. The process is open to the questioning of an expert's ability to accurately analyse and interpret friction ridges. It has been suggested that the interpretation and analysis of fingermarks becomes more subjective as clarity decreases and as a consequence the expert is more vulnerable to external stimuli. An experiment involving 70 fingerprint experts was conducted to establish whether the introduction of an emotional context would alter the experts' judgement of an ambiguous or poor quality mark. The emotional context did have a perceived effect on the experts' analysis, as more stated they were affected by the information they were given. However, it did not have any actual effect on their final opinions as no difference was observed between the high- and low-emotional contexts.