The Effect of Soft Tissue on Temperature Estimation from Burnt Bone Using Fourier Transform Infrared Spectroscopy

This study investigated the effect of soft tissue and different exposure times on the prediction of burning temperatures of bone when using Fourier transform infrared spectroscopy (FTIR). Ovis aries rib bones were burnt at different temperatures and for varying time intervals. Results of a linear regression analysis indicated that burn temperatures can be predicted with a standard error of ±70°C from defleshed bone spectra. Exposure time does not have a significant impact on prediction accuracy. The presence of soft tissue has a significant impact on heat‐induced changes of the bone matrix in low (<300°C) as well as high temperatures (>800°C), slowing down combustion in the former and accelerating it in the latter (p < 0.05). At medium temperatures, no significant difference was noted. These results provide forensic investigators a new perspective with which to interpret the results of crystallinity measures derived from burnt bone.     

A meta-analytic review of the frequency and patterning of laryngohyoid and cervical fractures in cases of suicide by hanging

The frequency and distribution of fractures are commonly utilized to assist in interpreting the manner of death. In cases of alleged suicide by hanging, however, the evidence base for the frequency and patterning of laryngohyoid and cervical vertebrae fractures resulting from such blunt force traumatic events is limited and so fractures cannot be reliably used to assist in interpreting the manner. Using meta-analytic techniques, this study aimed to estimate frequency and distribution of fractures in the context of relevant intrinsic and extrinsic variables. A systematic review of the literature identified 20 studies with relevant data (8523 cases of suicide by hanging). Meta-analyses identified the frequency and distribution of fractures present and how fracture frequency was affected by the subgroups of age, sex, completeness of suspension, ligature knot position and study design. Results indicated that fracture frequency was variable, there was no unique patterning, and high levels of heterogeneity were present in all variable sub-groups. Age was the only subgroup to show differences. Findings suggest that neck fracture frequency is inconsistent and cannot be predicted by the chosen variables. Subsequently, neck fractures in isolation should not be given weight in medico-legal interpretations of a hanging death as suicidal.     

Effects of obesity on talar micro- and macro-morphology

The addition of information regarding obesity status to the forensic anthropological biological profile could significantly contribute to the identification of human skeletal remains since over 40% of the U.S. adult population is currently obese. This study examines the differences in talar shape and trabecular bone structure between obese and non-obese individuals. A sample of 20 obese and 20 non-obese divided evenly by sex was selected from the Texas State University Donated Skeletal Collection. Tali were imaged using x-ray computed tomography (voxel size: 28–38.7 μm). Image stacks were processed to produce binary images as well as trabecular thickness and spacing maps. Landmark-based geometric morphometric analyses were conducted to quantify shape variation. Shape coordinates were used to locate 100 geometrically homologous volumes of interest within each talus. Bone volume fraction, trabecular thickness, and trabecular spacing were extracted at each volume of interest. Within each sex, a one-way ANCOVA was used to determine if significant differences exist between obese and non-obese individuals in trabecular bone after controlling for age. The size of the talus as well as subtle aspects of shape were found to distinguish the sexes. The results further indicate that bone volume fraction significantly differs between obese and non-obese males. In females, bone volume fraction is correlated with age but does not differ between obese and non-obese. The study demonstrates that bone microstructure is a promising approach to estimating body mass or body mass index category but age effects diminish the potential for the talus to be used alone.     

Validation of the InnoXtract™ DNA extraction method for bone,teeth, and rootless hair

Forensic casework samples often include human hairs, teeth, and bones. Hairs with roots are routinely processed for DNA analysis, while rootless hairs are either not tested or processed using mitochondrial DNA. Bones and teeth are submitted for human remains identifications for missing persons and mass disaster cases. DNA extraction from these low templates and degraded samples is challenging. The new InnoXtract DNA extraction method utilizes magnetic beads that are optimized to bind small DNA fragments, as small as 100 base pairs, to purify high-yield DNA from compromised samples. This validation study evaluates InnoXtract's ability to obtain amplifiable DNA from samples such as rootless hairs and skeletal remains. Studies performed include sensitivity, stability, repeatability, reproducibility, non-probative samples, and comparison to standard organic extractions. Sensitivity studies demonstrate average yield recoveries ranging from 53% to 100% and 73% to 85% for the InnoXtract hair and bone methods, respectively. Studies demonstrate consistent results across a range of sample types, such as insulted and un-insulted bone and teeth, as well as hair shafts from donors of various ages, gender, race, and hair characteristics. The InnoXtract bone method outperformed organic extraction. The method was successfully automated on a MagMAX™ Express-96, with recoveries over 70% relative to the manual version. InnoXtract has the potential as an automated high-throughput, high-yield bone extraction method with 6 h of total extraction time for up to 96 samples. The validation study results demonstrate that the InnoXtract kits produce high-yield and high-quality DNA from compromised bone, teeth, and hair shaft samples.     

CT在法医人类学中的应用与展望

计算机X线断层摄影术具有分辨率高、成像清晰、可进行三维重建等优点,对骨骼和牙齿的成像效果较好。近十年来,国外有学者将其用于推断年龄和身高,判定种族和性别,在相关文献中介绍了有关的研究方法和数据,并对这些方法和数据在法医人类学个体识别中的应用价值进行了客观的评估。笔者对近几年发表的部分文献进行综述,希望能够为法医人类学科研和办案提供新的方法和思路。     

Effect of Substrate Interferences from High‐Density Polyethylene on Association of Simulated Ignitable Liquid Residues with the Corresponding Liquid

The effect of substrate interferences from high‐density polyethylene (HDPE) on the ability to associate an ignitable liquid residue with the corresponding liquid standard, using statistical procedures, is demonstrated. Gasoline, kerosene, and lighter fluid, at three different evaporation levels, were spiked onto HDPE and subsequently burned to generate simulated ignitable liquid residues (ILRs). Samples were extracted using a passive headspace procedure and analyzed by gas chromatography–mass spectrometry. The total ion chromatograms were subjected to data pretreatment procedures prior to principal components analysis and Pearson product moment correlation. Using the combination of these statistical procedures, simulated ILRs were successfully associated with the corresponding liquid type, despite the presence of compounds inherent to the HDPE substrate, as well as those resulting from pyrolysis of the substrate.     

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.     

FTA框架下中蒙矿产资源合作模式

中国矿产资源短缺,与矿产资源丰富的国家签署自贸协定是中国利用国外资源的重要举措。蒙古是矿产资源丰裕的国家,中国已连续多年成为蒙古最大的贸易伙伴和投资国,两国具有坚固的建立自贸区的经济基础。中国可以采取以市场换资源、以技术换资源、以资金换资源、以资源换资源等四种模式,获取蒙古稳定的矿产资源供给,实现互利共赢。     

Tibia and Fibula Stature Formulae for Modern Female Populations Based on Digital Radiographic Measurements

Abstract: This study demonstrates the feasibility of creating bone lengths and stature databases of significant size for modern living human populations from digital radiographic archives and medical records. Tibia and fibula lengths were taken from digital radiographic images of 250 women. The images, drawn from the University of California, Los Angeles Medical Center’s Radiology Department’s General Electric Picture Archiving and Communication System, were taken between 2003 and 2007. Stature measurements were obtained from medical records on 83 individuals, 50 of which were used to regress stature equations for the tibia and fibula. Bone lengths obtained from radiographic images are almost 3 cm longer than those obtained from skeletalized collections. The formulae produce ranges up to 10 cm lower than current formulae. Accuracy could be improved as methods are developed to correct for the small magnification produced by digital images.     

Less‐Lethal Hybrid Ammunition Wounds: A Forensic Assessment Introducing Bullet‐Skin‐Bone Entity

Abstract: Agencies all around the world now use less‐lethal weapons with homogeneous missiles such as bean bag or rubber bullets. Contusions and sometimes significant morbidity have been reported. This study focuses on wounds caused by hybrid ammunition with the pathologists’ flap‐by‐flap procedure. Twenty‐four postmortem human subjects were used, and lesions caused on frontal, temporal, sternal, and left tibial regions by a 40‐mm hybrid ammunition (33 g weight) were evaluated on various distance range. The 50% risk of fractures occurred at 79.2 m/sec on the forehead, 72.9 m/sec on the temporal, 72.5 m/sec on the sternum, and 76.7 m/sec on the tibia. Skin lesions were not predictors of bone fracture. There was no correlation between soft and bone tissue observed lesions and impact velocity (correlated to distance range). Lesions observed with hybrid ammunition were the result of bullet‐skin‐bone entity as the interaction of the projectile on skin and bone tissues.