05式警用转轮手枪弹壳接触DNA检验方法的比较

目的比较05式警用转轮手枪弹壳表面接触性DNA检验方法,为实际检验提供参考和借鉴。方法制备40例击发后手枪弹壳的模拟样本,分别用两步转移法提取弹壳表面不同部位检材,采用两种DNA提取法和两种扩增试剂盒对样本进行STR分型检验,比较评价检验结果。结果避开发射药残留区域采用两步转移法提取样本,有助于提高检出率;Chelex-100联合Microcon-100法提取模板DNA的产量最高可达1.18ng,高于Mini M48试剂盒法(0.91ng);MiniFilerTM试剂盒的等位基因检出率(23.61%)高于IdentifilerTM试剂盒(6.41%)。结论采用选择适当区域提取检材,采用Chelex-100联合Microcon-100法提取DNA,经MiniFilerTM试剂盒扩增,进行弹壳接触DNA分型的效果较好。     

Sibship Analysis Based on Parental Genotype Reconstruction from Any Number of Reference Siblings

Previous analyses of alleged siblings have calculated the conditional probability of a test sibling's genotype given a reference sibling's genotype; however, more genetic information is available when two or more reference siblings are tested. Based on the root concept of identity by descent (IBD), we present a sibship method of parental genotype reconstruction (PGR) that can use any number of reference sibs. Nine PGR patterns, along with their respective IBD proportions of full‐sibs and half‐sibs, were identified and used to calculate joint sibship probabilities and likelihood ratio formulas. In addition, a correction PGR was developed for situations involving the same genotype repeating in the reference sibs. The method is simple and can be applied to any number of alleged full or half‐siblings.     

The Diagnostic Value of Quantitative Assessment of Diatom Test for Drowning: An Analysis of 128 Water‐related Death Cases using Microwave Digestion‐Vacuum Filtration‐Automated Scanning Electron Microscopy

The value of diatom test for the diagnosis of drowning remains controversial. The conventional forensic diatom test with low sensitivity is not a useful tool to provide accurate information about diatom in the tissues and organs. To improve the sensitivity of the diatom test, we developed a novel method called the Microwave Digestion‐Vacuum Filtration‐Automated Scanning Electron Microscopy (MD‐VF‐Auto SEM) method which resulted in a high recovery of diatoms. In this article, we analyzed 128 water‐related death cases. Our results showed that the MD‐VF‐Auto SEM method could achieve a much higher positive rate (0.97) in drowning cases. Large amounts of diatoms are retained, even concentrated, in the lung tissues during the intense breathing movement in drowning process. This might be useful for the diagnosis of drowning. Our research indicates that the MD‐VF‐Auto SEM method would be a valuable methodology in the study of diatom test for the forensic community.     

俄罗斯外汇储备的理论与实证分析

随着世界经济恢复和国内经济形势好转,俄罗斯外汇储备规模逐渐扩大。在俄外汇储备中,美元和欧元是最重要的储备币种,但目前俄罗斯外汇储备正处于相对过剩的状态。影响俄罗斯外汇储备的主要原因有对外贸易顺差上升、FDI流入扩大,以及世界石油价格攀升。为解决俄罗斯外汇储备的现实问题,应加强经济结构调整、实施积极的外汇储备政策、完善外汇市场机制、积极参与区域经济合作等方面的对策研究。     

高校应重视学生考试成绩的分析与反馈

当前,高校对学生评价最主要的指标仍是考试成绩.对学生考试成绩的分析,是教学工作的一项重要内容,也是教学反思的一个过程.试卷分析既可作为教学评估的手段,又是教学研究的重要环节.建立对考试成绩分析的反馈利用机制,有助于全面提高教育教学质量.     

A single mutation in the FGA locus responsible for false homozygosities and discrepancies between commercial kits in an unusual paternity test case

We report an unusual paternity test case showing multiple peculiarities. Using AmpFlSTR Profiler Plus and AmpFlSTR Identifiler PCR Amplification kits, the alleged father and the two children were apparently homozygous at the FGA locus, but using the PowerPlex 16 kit the three individuals were found to be heterozygous. Drop-out was caused by a single mutation event in the presumptive binding site of the reverse primer. In addition, three inconsistencies were detected between the daughter and the alleged father among 18 STR markers. The occurrence of the rare null allele at the FGA locus and case history suggested that the true father was the brother of the alleged father. Furthermore, a single-step repeat maternal mutation was also detected at D16S539. This puzzling case was solved by using multiple analytical approaches, including the use of different primer pairs, the use of a high number of STR markers, and the characterization of the mutation causing the "null allele."     

Resolving paternity relationships using X-chromosome STRs and Bayesian networks

X-chromosomal short tandem repeats (X-STRs) are very useful in complex paternity cases because they are inherited by male and female offspring in different ways. They complement autosomal STRs (as-STRs) allowing higher paternity probabilities to be attained. These probabilities are expressed in a likelihood ratio (LR). The formulae needed to calculate LR depend on the genotype combinations of suspected pedigrees. LR can also be obtained by the use of Bayesian networks (BNs). These are graphical representations of real situations that can be used to easily calculate complex probabilities. In the present work, two BNs are presented, which are designed to derive LRs for half-sisters/half-sisters and mother/daughter/paternal grandmother relationships. These networks were validated against known formulae and show themselves to be useful in other suspect pedigree situations than those for which they were developed. The BNs were applied in two paternity cases. The application of the mother/daughter/paternal grandmother BN highlighted the complementary value of X-STRs to as-STRs. The same case evaluated without the mother underlined that missing information tends to be conservative if the alleged father is the biological father and otherwise nonconservative. The half-sisters case shows a limitation of statistical interpretations in regard to high allelic frequencies.     

The Comparison Question Test: Does It Work and If So How?

In a mock crime study of the comparison question test (CQT), 35 subjects decided to participate as guilty and 30 as innocent. Two conditions were varied: Explaining the comparison questions in the pretest interview and re-discussing comparison questions between charts. Higher identification rates (approximately 90% for guilty and innocent participants) were achieved in groups with explanation of comparison questions than in groups without explanation. Re-discussing comparison questions had no effect on identification rates. Ratings of subjective stress due to relevant and comparison questions were also obtained and can be seen as indicators of the significance of the questions. The significance of comparison questions was hardly affected by the different testing conditions. When effects are detectable at all, they contradict theoretical expectations in their direction. Results are discussed in terms of the significance of comparison questions used in polygraph testing.     

Extracting Concealed Information from Groups*

Abstract: Lie detection procedures are typically aimed at determining guilt or innocence of a single suspect. Serious security threats, however, often involve groups, such as terrorist networks or criminal organizations. In this report, we describe a variant of the skin conductance‐based Concealed Information Test (CIT) that allows for the extraction of critical information from such groups. Twelve participants were given information about an upcoming (mock) terrorist attack, with specific instructions not to reveal this information to anyone. Next, each subject was subjected to a CIT, with questions pertaining to the details of the attack. Results showed that for every question, the average skin conductance response to the correct answer option differed significantly (p < 0.05) from those to all other options. These results show that the information about the upcoming attack could be extracted from the group of terror suspects as a whole.     

字库在文书检验中应用

机制文书及印章的制作越来越依赖于计算机系统,而其文字形态、细节特征反映了计算机系统的字库种类,间接反映了计算机的操作系统、排版软件等软件环境以及文书制作过程。因此,通过对计算机字库的系统研究,对由文书上反映的字库特征判断其制作过程、制作软件环境具有重要意义,它为文书检验提供一种新的视角以及方法手段。