A Preliminary Study of the Reliability of Anatomical Facial Landmarks Used in Facial Comparison

Anatomical landmarks are considered the most objective indicators for use in forensic facial comparisons. Therefore, accurately identifying and locating these landmarks is the beginning of reliable facial comparison. This study evaluated the accuracy with which facial landmarks are located and examined their reliability according to type of landmark, head posture, and image quality. Nine operators located a series of landmarks on prepared facial images used to produce comparison images. Then, the average distances between the reciprocal landmarks (ADRL) on the reference and the comparison images were measured as indicators of landmark reliability. We found that a set of landmarks had higher or lower reliability as a function of the head angle and image quality. More reliable landmarks were associated with certain head postures and degrees of image quality. These should be used for facial comparison analysis depending on various head and image conditions.     

早期断乳应激性腹泻对仔猪肠道形态结构与肠道菌群的影响

为研究早期断奶应激性腹泻对仔猪肠道形态结构和肠道菌群的影响,选取21日龄体况相近的早期断奶腹泻仔猪6只,于腹泻次日采集各肠段样本进行病理组织学观察,并测定其肠道菌群。结果显示,早期断奶应激性腹泻仔猪的十二指肠黏膜呈轻度卡他性炎,黏膜上皮脱落,核溶解,绒毛稀少;空肠和回肠肠绒毛脱落,顶端凝固性坏死;空肠和直肠固有层大量中性粒细胞、巨噬细胞浸润;各段肠上皮细胞出现充血、出血、水肿、空泡变性等形态结构的改变。仔猪肠道菌群改变,主要表现为与健康仔猪相比,腹泻仔猪各肠段的类杆菌、大肠杆菌、梭菌数量显著升高(P<0.05),双歧杆菌、乳杆菌数量显著降低(P<0.05)。证实早期断乳应激性腹泻能引起肠道形态结构的破坏和肠道菌群失调,从而加重仔猪腹泻。     

现代人面颅角度测量的种族差异性

目的探索面颅角度指标在种族鉴定方面的差异性。方法选取现代人头骨57例,其中中国黄种人头骨30例（女性9例,男性21例）,包括吉林1例,河北5例,山东4例,青海4例,安徽4例,江西3例,云南3例,贵州3例,广西3例。欧洲自种人头骨27例,性别不详,取自欧洲Zellemdorf、Vresovice、Kysperka3地。按体质人类学测量方法,通过参考相关文献和对颅骨形态特点的观察,设计面颅左侧眶角、右侧眶角、鼻颌角3个角度指标进行测量。对测量数据进行描述性统计分析和两独立样本之间的t检验。结果3个角度指标在种族差异性方面,眶角的种族差异性具有显著统计学意义（P〈0．01）,而鼻颌角之间的种族差异性无统计学意义（P〉0．05）。结论有些角度指标显示出明显的种族差异性,今后需要加强此方面的研究。     

面颅种族判定的测量研究

通过对国内外面颅种族判定测量研究现状的回顾和评析,指出目前尚没有进行中国黄种人面颅测量种族判定的有效方法。在已进行的面颅种族判定测量研究中,上面部指标的种族判定效果最好,而上腭区和下颌骨指标的种族判定效果较差。所以对于中国黄种人面颅种族判定的测量研究应当更多借鉴上面部的研究成果。     

Application of superimposition-based personal identification using skull computed tomography images

Superimposition has been applied to skulls of unidentified skeletonized corpses as a personal identification method. The current method involves layering of a skull and a facial image of a suspected person and thus requires a real skeletonized skull. In this study, we scanned skulls of skeletonized corpses by computed tomography (CT), reconstructed three-dimensional (3D) images of skulls from the CT images, and superimposed the 3D images with facial images of the corresponding persons taken in their lives. Superimposition using 3D-reconstructed skull images demonstrated, as did superimposition using real skulls, an adequate degree of morphological consistency between the 3D-reconstructed skulls and persons in the facial images. Three-dimensional skull images reconstructed from CT images can be saved as data files and the use of these images in superimposition is effective for personal identification of unidentified bodies.     

Can Handedness be Determined from Skeletal Remains? A Chronological Review of the Literature

Abstract: Research indicates that considerable bilateral asymmetry exists in the skeletons of primates, including humans. The published literature suggests that although this asymmetry may be influenced by handedness, it reflects other factors as well. Although exact statistics of handedness in the modern population are not available because definitions of handedness vary greatly, it is known that we live in a predominantly right‐handed world. This knowledge makes the determination of handedness in forensic cases not as paramount in importance as other determinations. Review of the published scientific evidence clearly reveals that observations and measurements of the human skeleton cannot determine handedness with the degree of confidence needed for forensic applications.     

Variation in the Measurement of Cranial Volume and Surface Area Using 3D Laser Scanning Technology

Abstract: Three‐dimensional (3D) laser scanner models of human crania can be used for forensic facial reconstruction, and for obtaining craniometric data useful for estimating age, sex, and population affinity of unidentified human remains. However, the use of computer‐generated measurements in a casework setting requires the measurement precision to be known. Here, we assess the repeatability and precision of cranial volume and surface area measurements using 3D laser scanner models created by different operators using different protocols for collecting and processing data. We report intraobserver measurement errors of 0.2% and interobserver errors of 2% of the total area and volume values, suggesting that observer‐related errors do not pose major obstacles for sharing, combining, or comparing such measurements. Nevertheless, as no standardized procedure exists for area or volume measurements from 3D models, it is imperative to report the scanning and postscanning protocols employed when such measurements are conducted in a forensic setting.     

An Exploration of Sample Representativeness in Anthropometric Facial Comparison*

Abstract: Faces are assumed to be unique, but their use in court has remained problematic as no method of comparison with known error rates has been accepted by the scientific community. Rather than relying on the assumed uniqueness of facial features, previous research has been directed at estimations of face shape frequency. Here, the influence of age, sex, and ancestry on variation was investigated. Statistical shape analysis was used to examine the necessity for sub‐divisions in forensic comparisons, using a large sample of facial images on which 30 anthropometric landmark points had been placed in 3D. Results showed a clear pattern of separation of the sexes in all age groups, and in different age groups in men. It was concluded that sub‐division of databases by sex will be necessary in forensic comparisons. Sub‐division by age may be necessary in men (although not necessarily in women), and may be necessary by ancestry.     

Positive Personal Identification of Human Remains Based on Thoracic VertebralMargin Morphology

Abstract: Radiography has long been used by anthropologists to establish positive personal identification of human remains in forensic cases. These methods have been largely ad hoc and depend upon specific congenital or pathological bone markers. Court rulings, such as Daubert and Mohan have, however, pushed the discipline toward more statistically supportable methods of identification. This study describes the use of normal morphological variation of the thoracic vertebrae to identify human remains. Radiographs from healthy, male individuals, aged 18–55 were examined to identify normally varying features of vertebral morphology. The frequency of occurrence of these features was calculated, tested, and found to be stable in the given sample. The frequencies were compared to establish which sets of traits varied independently of one another. Finally, unknown radiographs were compared to known samples to test the applicability of this method in determining positive identification, with 21 of 24 (87.5%) unknown radiographs positively identified.