Molecular Identification of Three Indian Snake Species Using Simple PCR–RFLP Method*

Abstract: Three endangered Indian snake species, Python molurus, Naja naja, and Xenochrophis piscator are known to be significantly involved in illegal trade. Effective authentication of species is required to curb this illegal trade. In the absence of morphological features, molecular identification techniques hold promise to address the issue of species identification. We present an effective PCR–restriction fragment length polymorphism method for easy identification of the three endangered snake species, Python molurus, Naja naja, and Xenochrophis piscator. A 431‐bp amplicon from cytochrome b gene was amplified using novel snake‐specific primers following restriction digestion with enzymes Mbo II and Fok I. The species‐specific reference fragment patterns were obtained for the target species, which enabled successful identification of even highly degraded shed skin sample confirming the utility of the technique in case of poor‐quality DNA. The assay could be effectively used for forensic authentication of three Indian snake species and would help strengthen conservation efforts.     

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.     

Identification of the Edentulous Individual: An Investigation into the Accuracy of Radiographic Identifications*

Abstract: The dental identification of edentulous individuals can be challenging based on the lack of antemortem materials and unique features visible on radiographs. The constant resorption of the alveolar ridges further complicates the process. The purpose of this study was to quantify the error rate and reliability of dental identifications based on a comparison of synthesized antemortem and postmortem radiographs of edentulous individuals. Ten observers examined ten cases on two occasions and reported dichotomous and conclusion level decisions. These were analyzed using Kappa and Receiver Operator Characteristics. The mean area under the curve was 0.75 and the mean sensitivity was 0.57 and specificity was 0.83. These results suggest that dental identifications of edentulous individuals using radiographs alone have a high error rate and should be dual reported. These data add further weight to the argument that all dental prostheses should be labeled.     

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.     

檵木化学成分研究

目的研究檵木的化学成分。方法采用硅胶柱色谱和葡聚糖凝胶LH-20进行分离纯化,通过理化性质和波谱技术进行结构测定。结果从950 ml/L乙醇渗漉液中分离得到4个化合物。结论化合物鉴定为β-谷甾醇(Ⅰ)、3β-Hydroxy-glutin-5-ene(Ⅱ)、3α-Hydroxy-glutin-5-ene(Ⅲ)、β-胡萝卜苷(Ⅳ)。     

SMCY性别特异融合抗原的克隆表达及其抗体制备

目的利用蛋白检测的快速性优势,研究不同性别在SMCY抗原氨基酸序列的差异,筛选出特异性氨基酸序列,并克隆表达性别特异融合抗原,制备相应抗体,建立一种快速鉴别法医物证性别的方法。方法通过对人SMCY和SMCX进行序列分析,发现了三段差异片段,采用搭桥PCR方法获得差异片段全长基因,连接入p ET-28a载体进行原核表达,用Ni柱纯化后的性别特异融合抗原免疫制备多克隆抗体,用ELISA法和western blot检测SMCY多抗与抗原的反应特异性,制作胶体金试纸条检测样本。结果筛选出具有性别特异性的氨基酸序列,获得SMCY性别特异融合抗原,成功制备出多克隆抗体及胶体金试纸条。结论获得SMCY性别特异融合抗原具有很好的抗原活性,制备的多克隆抗体可以与抗原特异性地结合,用于性别鉴定。     

直接扩增法用于重大灾难事故中软骨的个体识别

目的探讨直接扩增法对软骨STR检验的有效性,以提高灾难受害者身源鉴定工作效率。方法采用Power Plex~21试剂盒对88份软骨进行直接扩增法检验,同步进行磁珠法比较分型结果。结果 88份软骨检材中,直接扩增法与磁珠法均成功检出84份检材的STR基因型,两者分型结果完全一致。结论Power Plex~21试剂盒直接扩增法可以应用于软骨STR分型检验,且操作简便、快速,在重大灾难事故身源鉴定中具有很好的应用前景。     

应用数字图像识别系统研究正畸治疗前后腭皱形态变化

目的利用腭皱数字图像识别系统对正畸治疗前后腭皱形态匹配正确率的分析研究,为法医学中同一认定提供理论依据。方法利用正畸患者治疗前后腭皱形态数字图像,通过腭皱数字图像识别系统对图像的特征进行提取并收录到腭皱数字库,运用Matlab软件完成对腭皱形态数字图像的信息匹配处理。结果正畸治疗前后,个体性检测匹配正确率各自都达到100%。正畸治疗前后腭皱形态匹配正确率为95.67%,配对检验结果 P0.05,具有统计学意义。结论腭皱形态具有高度的个体特异性,正畸治疗后腭皱形态会发生多种变化,但对同一认定的影响不大。腭皱形态识别为法医学同一认定提供一种新的方法和途径。