人与狗、猪、牛、羊长骨哈氏系统图像分析的比较

目的探讨人与狗、猪、牛、羊长骨的哈氏系统的形态特点、图像分析特点及其鉴别要点。方法制作人与狗、猪、牛、羊长骨中段横切磨片35张,光镜下观察比较哈氏系统,并在研究型显微镜下进行图像分析。结果人骨无丛状骨和骨单位带;人与狗、猪、牛、羊骨的哈氏系统在形状、大小、分布位置、均匀程度等方面存在明显差异;人骨哈佛骨板层数最多,哈氏系统直径最大;中央管直径和面积百分比的图像分析结果显示人与动物骨的差异均有显著意义。结论(1)丛状骨、骨单位带在种属鉴定中可作为人骨的排除指标;(2)人骨与狗、猪、牛、羊骨在哈氏系统结构方面有明显区别;(3)利用图像分析进行种属鉴定,中央管面积百分比是区别人骨与动物骨的重要参考指标。     

Citrate Content of Bone for Time Since Death Estimation: Results from Burials with Different Physical Characteristics and Known PMI

A recently introduced method to determine the postmortem interval (PMI) based on quantification of the citrate content in bone was applied on the temporal bones and femora of 20 individuals buried in wooden coffins (WO) and body bags (BB), respectively. Concerning known vs. calculated PMI, a significant difference between the temporal and the femur bone samples of the same individuals was observed in the BB group (p = 0.012). In contrast, differences were insignificant for the WO group (p = 0.400). Moreover, similar levels of underestimation of PMIs resulted from the analysis of the femora for both burial groups (p = 0.247). Also, there was consistently less citrate preserved in the flat temporal bones as compared to the femora, indicating that the cortical layer of the long bones should be preferentially employed for citrate‐based PMI estimations. The results call for additional research on subsurface‐buried and surface‐deposited remains to enhance the accuracy of the published PMI equation.     

Long Bone (Humerus,Femur, Tibia) Measuring Procedure in Cadavers

In this work, we present a measuring methodology for long bones of the limbs (humerus, femur, and tibia) of human corpses. Measurements of cadaveric height and long bone lengths were conducted on 72 corpses (20 females and 52 males) from the School of Medicine at the National Autonomous University of Mexico. Additionally, these measurements were compared with those taken from dry bones of a subsample of individuals. Our results show marginal differences (TEM% = 0.59) between cadaveric and dry bone measurements, resulting from different osteometric technical procedures. This note outlines the measuring methodology, which will be subsequently used to create regression formulas for stature estimation.     

人与动物骨组织特征的比较研究

目的研究区别骨骼残片是否为人类骨骼的方法。方法提取人体骨骼及鱼类、两栖类、爬行类、鸟类、哺乳类、灵长类等动物的骨骼标本制做骨骼组织学片,在显微镜下观察,将显微镜下的图像录入电脑进行分析。结果内、外环骨板,骨单位,骨细胞的显微镜下的结构,人类与动物存在明显差别。结论根据骨骼的组织学特征可以区别人类与动物的骨骼。     

Microscopic Pattern of Bone Fractures as an Indicator of Blast Trauma: A Pilot Study

The assessment of fractures is a key issue in forensic anthropology; however, very few studies deal with the features of fractures due to explosion in comparison with other traumatic injuries. This study focuses on fractures resulting from blast trauma and two types of blunt force trauma (manual compression and running over), applied to corpses of pigs; 163 osteons were examined within forty fractures by the transmission light microscopy. Blast lesions showed a higher percentage of fracture lines through the Haversian canal, whereas in other types of trauma, the fractures went across the inner lamellae. Significant differences between samples hit by blast energy and those runover or manually compressed were observed (p < 0.05). The frequency of pattern A is significantly higher in exploded bones than in runover and compressed. Microscopic analysis of the fracture line may provide information about the type of trauma, especially for what concerns blast trauma.     

Histological Determination of the Human Origin of Bone Fragments

Abstract:  A frequently encountered task in the forensic scenario is verification of the human origin of severely degraded fragments of bone. In these cases histological methods which consider osteon size and morphology can prove to be useful. The authors in the present study verify the applicability of published algorithms to flat and subadult bones from human, dog, cat, cow, rabbit, sheep, pig, chicken, quail, and turkey samples. Metric analysis was performed on 2031 Haversian canals. Analyses carried out on human samples confirmed a success rate of around 70% on long adult bones; however the percentage of wrong answers was particularly high in the case of newborns and older subadults as well as on flat bones in general. Results therefore suggest that such regression equations should be limited only to bone fragments from long adult bones.     

The postmortem diagnosis of magnesium deficiency: studies in an animal model for the human infant.

Weanling rats were studied as a model for the human infant to determine the optimal tissue in which to assess the status of magnesium after death. Control rats were fed laboratory chow or purified diets that provided a surfeit of magnesium and accommodated a normal rate of growth. Other rats were fed diets that resulted in two degrees of magnesium deficiency: one that might result in spontaneous death within one week, and the other, within two weeks. These times may correlate with six months and one year in the human infant, the period during which the sudden infant death syndrome usually occurs. There was no consistent difference between the magnesium concentration found in the vitreous humor, liver, heart, or skeletal muscle of magnesium-deficient and control rats. However, bone accurately reflected the level of dietary magnesium. There was a significant difference between the magnesium concentration of the anterior and posterior halves of the ribs, indicating irregular distribution of magnesium within the bone. Significant differences were found in the magnesium concentrations of different bones from the same animals. Therefore one entire bone, such as the sternum or the rib, should be studied. The need to match control and study subjects for age was apparent.     

儿童骨骼特征的组织学研究

目的研究儿童骨骼的组织学特征,为儿童骨骼残片的法医学鉴定提供科学依据。方法提取儿童四肢长骨骨片,制作骨骼的组织切片,在显微镜下观察内、外环骨板,骨单位,骨细胞的组织学结构,比较儿童骨骼与动物及成人骨骼的组织学区别。结果儿童骨骼的骨单位形态与成人相似,骨单位间存在大量的内层骨板,与动物的骨组织特征相似。结论根据骨组织学特征,可以确定儿童的骨骼残片。     

A Preliminary Investigation into the Accuracy of 3D Modeling and 3D Printing in Forensic Anthropology Evidence Reconstruction,

There is currently no published empirical evidence‐base demonstrating 3D printing to be an accurate and reliable tool in forensic anthropology, despite 3D printed replicas being exhibited as demonstrative evidence in court. In this study, human bones (n = 3) scanned using computed tomography were reconstructed as virtual 3D models (n = 6), and 3D printed using six commercially available printers, with osteometric data recorded at each stage. Virtual models and 3D prints were on average accurate to the source bones, with mean differences from ?0.4 to 1.2 mm (?0.4% to 12.0%). Interobserver differences ranged from ?5.1 to 0.7 mm (?5.3% to 0.7%). Reconstruction and modeling parameters influenced accuracy, and prints produced using selective laser sintering (SLS) were most consistently accurate. This preliminary investigation into virtual modeling and 3D printer capability provides a novel insight into the accuracy of 3D printing osteological samples and begins to establish an evidence‐base for validating 3D printed bones as demonstrative evidence.     

A Comparative Assessment of the Chen et al. and Suchey‐Brooks Pubic Aging Methods on a North American Sample, ,

Accurately estimating the age‐at‐death of adult human skeletons is fundamental in forensic anthropology. This study evaluates the accuracy of two pubic bone age estimation methods—Chen et al. and Suchey‐Brooks. Specimens were obtained from a known collection of modern pubic bones curated at the Maricopa County Forensic Science Center in Phoenix, Arizona. A sample of 296 left male pubic bones of European ancestry was statistically evaluated via bias, absolute mean error, and intra‐ and inter‐observer error. Results indicate that the two methods are similar; the Suchey‐Brooks method is the most accurate for aging young adults (error c. 7 years), while the Revised Chen et al. method is most accurate for aging middle‐age adults (error c. 6 years). Thus, the Chen et al. method is an important contribution to forensic anthropology for aging older adult skeletal remains. There are, however, some limitations such as subjectivity and the intricate scoring system of Chen et al. method.     

Determination of DNA yield rates in six different skeletal elements in ancient bones

Current sampling strategy for laboratories typing bones for human identification include samples obtained from femur, tooth and temporal bone. Latest studies suggest that the small bones of the hands and feet were very similar or even better in DNA yield. These bones can be easily sampled with a disposable scalpel and thus reduce potential DNA contamination. The aim of our study was to determine the suitability of metatarsals, metacarpals and phalanges for genetic identification. 48 bone samples from 8 different skeletons (six from 18^th century and two from 3rd century) were obtained from 5 archaeological sites in Slovenia. In each skeleton, 6 different skeletal elements were sampled (temporal bone, molar, femur, metacarpal bone, metatarsal bone and proximal phalanx of the hand), and strict precautions followed to prevent contamination. Half of gram of bone powder was decalcified using full demineralization extraction method. The DNA was purified in a Biorobot EZ1 (Qiagen), DNA content determined with the PowerQuant kit (Promega), and autosomal STR typing performed with the Investigator ESSplex Plus kit (Qiagen). Up to 8.75 ng DNA/g of powder was obtained from samples analyzed. The highest yields were detected in temporal bone and the lowest in femur. The success rate of STR typing was evaluated according to the number of successfully typed loci and a strong correlation between the success rate of STR typing and the amount of extracted DNA was confirmed. For all eight skeletons full consensus genetic profiles were determined from skeletal elements analyzed. Our findings suggest it would be suitable to include metatarsal and metacarpal bones in sampling strategy for human identification although further research is needed to substantiate the findings of this study.     

Determining Postmortem Interval Using Glycoproteinous Adhesion Deposits by Balanus improvisus on Human Skeletal and Dental Remains

An anthropological analysis was conducted on skeletal and dental remains brought to the Galveston County Medical Examiner's office. The skeletal remains were dry, fragmented, and absent of typical fluvial characteristics. During microscopic examination, semitransparent, circular objects were discovered on the dentition, the mandible, tibial plateau, and distal femur. The objects were glycoproteinous adhesions deposited by the acorn barnacle, Balanus improvisus. B. improvisus is an intertidal barnacle found in estuaries in Galveston Bay. Basal diameter of the adhesions on the dentition were significantly smaller than those found on the postcranial bones (p = 0.010), indicating two consecutive cohorts adhered to the bone and dentition. As settlement typically occurs once a year, this would indicate that the remains were in the fluvial environment for at least 375–410 days. It is important in geographic areas that have prevalent fluvial environments that human remains, particularly dentition, are microscopically examined for marine life evidence.     

Bullet Caliber and Type Categorization from Gunshot Wounds in Sus Scrofa (Linnaeus) Long Bone

Studies on ballistic trauma to the ribs and thorax, cranium, and long bones demonstrate the potential of obtaining a bullet caliber from an entrance wound. In order to validate prior research on caliber estimation in bone tissue and assess the viability of bullet type determination based on the macroscopic evidence at the entrance wound, thirty fleshed pork (Sus scrofa) shoulders (humeri) were shot with either lead or copper jacketed bullets in one of three calibers; 0.22, 9 mm, or 0.38. Overall, our findings are consistent with previous research indicating that calibers can be grouped into “small” and “large” categories. Bullet type, lead or copper jacket, can be ascertained based on cortical flaking and the analysis of materials deposited around the entry wound. The addition of this evidence holds value in cases where no firearm or ballistic evidence is recovered from a crime scene.     

Skeletal Indicators of Shark Feeding on Human Remains: Evidence from Florida Forensic Anthropology Cases

This research examines a series of six Florida forensic anthropology cases that exhibit taphonomic evidence of marine deposition and shark‐feeding activities. In each case, we analyzed patterns of trauma/damage on the skeletal remains (e.g., sharp‐force bone gouges and punctures) and possible mechanisms by which they were inflicted during shark predation/scavenging. In some cases, shark teeth were embedded in the remains; in the absence of this evidence, we measured interdental distance from defects in the bone to estimate shark body length, as well as to draw inferences about the potential species responsible. We discuss similarities and differences among the cases and make comparisons to literature documenting diagnostic shark‐inflicted damage to human remains from nearby regions. We find that the majority of cases potentially involve bull or tiger sharks scavenging the remains of previously deceased, adult male individuals. This scavenging results in a distinctive taphonomic signature including incised gouges in cortical bone.     

Examination of Hacking and Blunt Force Skeletal Trauma

Hacking trauma is prevalent in forensic cases involving genocide and dismemberment, but research into the identification of this type of trauma is lacking. The present study examines characteristics of hacking and blunt force skeletal trauma in order to determine if there is a point at which blunt force trauma becomes distinguishable from hacking trauma. Ten implements with a range of blade angles (i.e., the striking surface of the implement) were used in conjunction with a controlled-force hacking device to impact 100 limb bones of white-tailed deer (Odocoileus virginianus). Observations of the trauma included the occurrence and degree of fragmentation, the entrance widths of the impacts, and composite scores of six hacking characteristics, especially the distinctive V-shaped kerf. ANOVA tests and regression analyses were used to assess the relationships between these characteristics and the blade angles. A significant relationship (p-value = 0.011) was found between the composite hacking scores and the blade angles, indicating that blunt force and hacking trauma can be distinguished. The entrance widths of the impacts exhibited a significant relationship with the blade angles (p-value = 0.037). There was also a significant relationship between the visibility of a V-shaped kerf in the bones (p-value = 0.003), with visibility decreasing around the 60° blade angle. These data should assist in establishing guidelines to differentiate hacking and blunt force skeletal trauma in cases where the implement is on a spectrum between sharp and blunt.     

The Erratic Behavior of Lesions in Burnt Bone

This study analyses depressed fractures (by blunt force trauma) and circular full‐thickness injuries (drill injuries and gunshot wounds) in charred bones. Fifty bovine ribs (total 104 lesions) were divided into three groups. The first group consisted in 20 depressed hammer‐produced fractures; in the second one, 60 round drill‐holes were produced (30 circular, 30 semicircular); in the third group, 12 fleshed and 12 skeletonized ribs were hit by 9‐mm bullets. Each specimen was carbonized in an electric oven up to 800°C. Morphological and metric analyses were performed before and after: morphological features were preserved, but depressed fractures showed an increase in their dimensions (p‐value < 0.05); the drilled holes shrunk (p‐value < 0.01); the charring cycle increased the number of fractures in samples with gunshot wounds differently in fleshed and defleshed ribs. This study showed the complex behavior of charred bone, for what concerns the interpretation of trauma and how caution should be applied.     

Preliminary investigation into the use of Micro-CT scanning on impact damage to fabric,tissue and bone caused by both round and flat nosed bullets

Firearm offences in the UK, though not as high as in the USA, are increasing year upon year within both countries (Office for National Statistics, 2018 & Mervosh, 2018). This preliminary study looked into using Micro-CT scanning as a method to visualise impact damage and spray patterns caused by 12 test firings of both round and flat nosed bullets to porcine bone (shoulder and leg) suspended in ballistic gelatine and left with no covering, covered with a skin substitute, or covered with fabric (cotton or denim). Micro-CT scanning alongside VG Studio Max showed that overall, in the case of the shoulder bones the round nosed produced longer spray patterns (35.37 mm) within the gelatine blocks compared to the flat nosed bullet (27.33 mm); while with the leg bones the spray patterns were shorter, round nosed bullet (15.64 mm) and the flat nosed bullet (20.78 mm). These initial results showed that both bullet types produced considerable damage, from splitting to full penetration, which in turn illustrates how Micro-CT scanning has benefits within forensic ballistics, which should be further investigated.     

Sex Determination from the Frontal Bone: A Geometric Morphometric Study

Sex estimation in human skeletal remains when using the cranium through traditional methods is a fundamental pillar in human identification; however, it may be possible to incur in a margin of error due because of the state of preservation in incomplete or fragmented remains. The aim of this investigation was sex estimation through the geometric morphometric analysis of the frontal bone. The sample employed 60 lateral radiographs of adult subjects of both sexes (30 males and 30 females), aged between 18 and 40 years, with mean age for males of 28 ± 4 and 30 ± 6 years for females. Thin‐plate splines evidenced strong expansion of the glabellar region in males and contraction in females. No significant differences were found between sexes with respect to size. The findings suggest differences in shape and size in the glabellar region, besides reaffirming the use of geometric morphometrics as a quantitative method in sex estimation.     

Tooth hop variability in human and nonhuman bone: Effect on the estimation of saw blade TPI

Forensic research has demonstrated that tooth hop (TH) is a valuable measurement from saw-cut bones as it can be used to estimate teeth-per-inch (TPI) of a saw used in postmortem dismemberment cases. However, error rates for TPI estimation are still under development and knowledge of how bone tissue affects TH measurements remains unclear. The purpose of this research was to investigate the effects of tissue variability through the use of different taxa on the accuracy and precision of TH measurements in the bone to estimate TPI of the blade. A total of 1766 TH measurements were analyzed from human, pig, and deer long bones cut by two 7 TPI saw blades of different tooth type. Fifty distance-between-teeth measurements before and after sawing were collected directly from each blade for comparison to bone-measured TH to assess potential effects of tooth wear on TH variability. ANOVA and F tests were used to compare mean TH and variance, respectively, by saw-species (i.e., crosscut-deer, rip-deer) and species groups (i.e., all deer, all pig), with significance determined at the p < 0.05 level. TH measurements were converted to usable TPI ranges, which would typically be presented in a forensic report. It is concluded that significant differences in TH (mm) do not necessarily reflect significant differences in associated TPI ranges of suspect blades. Forensic reports should report mean TPI ± 1.5–2.5 TPI while providing a sample size indicating number of TH measured rather than just number of cuts or cut surfaces examined.     

The evaluation of a synthetic long bone structure as a substitute for human tissue in gunshot experiments

Our goal was to compare experimental gunshot wounds in our non-biological bone model with similarly created wounds in swine bones, and evaluate the results. The design of the synthetic (polyurethane) bone was patterned after human bone structure, with a compact outer layer covering a porous inner layer. Ordnance gelatin, as substitute bone marrow, was injected into the bone's hollow core. To simulate the periostium, the bone was covered with a layer of latex. Then the bone was embedded in gelatin used to simulate surrounding soft tissue. For comparison, fresh swine bones were also embedded in gelatin, and fired upon under the same guidelines. All gunshots were high-speed filmed. In our experimental study, gunshot wounds to swine bones, and to our synthetic, non-biological bones were compared. The results (the comparison between the biological swine bones and the non-biological model bones) in regard to the following points are absolutely equal: the loss of velocity and energy after striking bone, bone fragmentation, bullet deformation, and the penetrating wound channel. Continuing studies with our synthetic bone model will bring about an even greater understanding of the mechanisms of "bullet-bone interaction". For this reason, we have extended our variety of bone models to include other skeletal structures such as skull, spine, pelvis and flat bones for further gunshot experiments.