片段长度差异等位基因特异性PCR——一种改良的SNP分型新方法

目的建立一种基于等位基因特异性PCR原理的改良SNP分型新方法:片段长度差异等位基因特异性PCR,并考察特异性引物的3'端第3位、第4位碱基错配对特异性延伸的影响。方法以SNP位点rs759117和rs760887为例,设计两条长度不同、3'末端分别与SNP两个等位基因碱基配对的上游引物,同时在两个等位基因特异性引物3'端第3或第4位碱基引入错配以增加特异性,下游为公用引物。PCR产物经聚丙烯酰胺凝胶电泳、银染显带后确定样本的基因型。结果不同SNP纯合子为长度不同的单一谱带,杂合子则为两条带,其结果与直接测序完全一致。两条特异性上游引物3'端第3或第4位碱基引入错配后非特异性延伸显著减少,且对PCR反应条件的严格性要求明显降低。结论片段长度差异等位基因特异性PCR是一种简单快速而有效的SNP分型新方法;两条特异性引物3'端第3、第4位碱基引入错配可使特异性显著增加     

The application of CT for 3D visualization of concealed bodies

In forensic radiology, computed tomography (CT) is often used as a medical imaging technique to identify the cause and manner of death of deceased victims of a possible crime. In this study, medical imaging is used to examine concealed bodies and packaging materials. Medical imaging techniques, mainly CT scan, were used to scan packaged or concealed bodies inside containers to identify clues and evidence indicating whether a crime might have been committed. Also, scene integrity and scene safety along with a systematic search for relevant evidentiary items value were considered.Eighteen concealed bodies that had been assessed using medical imaging techniques between 2010 and 2018 at the request of the Dutch National Police were selected. The file records of each case contained imaging data, a photographic record of the unpacking procedure, a list of all items and traces found in the package, and the forensic pathology report. The images were assessed with respect to the different aspects of the case and through a systematic approach.The packages included adult males, adult females, newborn infants, and animals. All human cases were related to criminal offences. In nine adult cases, evidence of a possible violent death could be determined using CT imaging. The cause of death in newborn infants, however, could not be determined. In cases of dismemberment, the completeness of the body could be determined by CT imaging, and the cutting surfaces of bones could be matched on CT images. Regarding scene safety and integrity, in this study all relevant macroscopic items were detected on the CT images.The CT-scans were supplemented with fiduciary markers to better map CT data with the real objects. This information in combination with 2D and 3D images provided the forensic investigator with information on how to unwrap the package layer by layer and help determine different types of packaging materials. Different textiles could not always be identified. The orientation of the body within the packages was provided in all cases, and advice could be given on the optimal approach to access the contents. The overall detection rate of items was 78%.This is one of the first studies to illustrate the contribution of medical imaging, specifically CT scan, to the analysis of concealed bodies and packaging materials prior to unpacking. This demonstrates its contribution to a systematic approach of the investigation by ensuring the safety and health of the investigator while documenting and maintaining the integrity of the crime scene. Imaging also provides information that can be helpful to determine whether a crime might have been committed and reducing the risk of damaging a concealed body. Medical imaging also provides the forensic investigator with information to draw up a workplan prior to unpacking, minimising loss of evidence and determining whether different forensic specialists (e.g., digital or DNA) are needed. It is therefore strongly recommended to use medical imaging, especially CT scanning, before opening a package containing a concealed body.     

A test of the differential accuracy of the maxillary versus the mandibular dentition in age estimations of immature skeletal remains based on developing tooth length

Liversidge and colleagues developed a method for predicting the age of immature skeletal remains based on the length of developing teeth. This quantitative method combines dental data from both jaws, except for the permanent lateral incisor, and because there are reasons to suspect that these two types of data are not identical and should not be combined, it raises concerns regarding the accuracy of the technique when applied differently to each jaw. In this study, the differential accuracy of the method was test when applied to the maxillary and mandibular dentition. The test sample is comprised of 57 Portuguese subadult skeletons of known age at death. Results suggest an overall high consistency between estimates obtained from both jaws, but for the permanent dentition only. In the deciduous dentition the age estimates obtained from the maxillary teeth tend to be greater than the age estimates obtained from the mandibular pair, and the differences are significant for the incisors and canine. Additionally, ages obtained from the maxillary deciduous canine also differ significantly from true chronological age. In the permanent dentition there were no differences between the ages provided by both jaws but both the maxillary and mandibular second molars show a significant tendency to underestimate true chronological age. Although this study cannot validate completely the method presented by Liversidge and colleagues, it does provide an important test to its accuracy and calls for further research into its overall performance, particularly with respect to the results obtained from both jaws.     

Effort,incentives, and culture in the Czech Senate

This paper uses the natural experiment of seat allocation in the first Czech Senate to assess the effects of incentives on legislative effort. Contrary to previous work using similar research designs, the incentive of longer terms has little effect on the effort levels of legislators. This may reflect the parliamentary context, the newness of the Czech Senate, or, most interestingly, political culture.     

Insurgent Bodies in Cultural Responses to Reproductive Justice in Chile and Ireland

Transnational solidarity and comprehensive critiques of colonial legacies and patriarchal systems united the cultural responses created during the campaigns for reproductive justice in Ireland and Chile in 2018. This article considers the performance piece ‘Abortistas’ by the Yeguada Latinoamericana in Chile and the poem ‘Granuaile’ by Róisín Kelly in Ireland. Taking a decolonial feminist approach, this comparative study explores the interstices of art form and geopolitically distinct territories to examine how the creative practitioners' discursive construction of insurgent bodies aids critique of the lived experiences of women and pregnant people under the restrictive reproductive laws of both countries.