A call for mtDNA data quality control in forensic science

There is increasing evidence that many of the mitochondrial DNA (mtDNA) databases published in the fields of forensic science and molecular anthropology are flawed. An a posteriori phylogenetic analysis of the sequences could help to eliminate most of the errors and thus greatly improve data quality. However, previously published caveats and recommendations along these lines were not yet picked up by all researchers. Here we call for stringent quality control of mtDNA data by haplogroup-directed database comparisons. We take some problematic databases of East Asian mtDNAs, published in the Journal of Forensic Sciences and Forensic Science International, as examples to demonstrate the process of pinpointing obvious errors. Our results show that data sets are not only notoriously plagued by base shifts and artificial recombination but also by lab-specific phantom mutations, especially in the second hypervariable region (HVR-II). (C) 2003 Elsevier Ireland Ltd. All rights reserved.

More evidence for non-maternal inheritance of mitochondrial DNA?

Background: A single case of paternal co-transmission ofmitochondrial DNA (mtDNA) in humans has been reported so far. Objective: To find potential instances of non-maternal inheritance of mtDNA. Methods: Published medical case studies (of single patients) were searched for irregular mtDNA patterns by comparing the given haplotype information for different clones or tissues with the worldwide mtDNA database as known to date-a method that has proved robust and reliable for the detection of flawed mtDNA sequence data. Results: More than 20 studies were found reporting clear cut instances with mtDNAs of different ancestries in single individuals. As examples, cases are reviewed from recent published reports which, at face value, may be taken as evidence for paternal inheritance of mtDNA or recombination. Conclusions: Multiple types (or recombinant types) of quite dissimilar mitochondrial DNA from different parts of the known mtDNA phylogeny are often reported in single individuals. From re-analyses and corrigenda of forensic mtDNA data, it is apparent that the phenomenon of mixed or mosaic mtDNA can be ascribed solely to contamination and sample mix up.

基于安全操作系统的电子证据获取与存储

基于实时取证的思想,提出了一种安全可取证操作系统(security forensics operating system,简称SeFOS)的概念和实现思路.提出了其总体结构,建立了该系统的取证行为模型,对其取证服务和取证机制进行了分析并作了有关形式化描述,阐述了证据数据的采集和安全保护方法,提出把取证机制置于内核,基于进程、系统调用、内核资源分配和网络数据等获取证据的方法,并通过模拟实验验证了SeFOS的可取证性.可取证操作系统的研究对于进一步研究可取证数据库管理系统(forensic database management system,简称FDBMS)和可取证网络系统(forensic network,简称FNetWork)具有重要意义.

面向入侵的取证系统框架

在分析常见入侵攻击的基础上抽象出入侵过程的一般模式，提出针对入侵攻击的取证系统应满足的特征。提出了入侵取证模型，并基于这一取证模型在操作系统内核层实现了取证系统原型KIFS（kernel intrusion forensic system）。在对实际入侵的取证实验中，根据KIFS得到的证据，成功记录并重构了一个针对FreeBSD系统漏洞的本地提升权限攻击的完整过程。

DNA diagnosis by capillary electrophoresis and microfabricated electrophoretic devices

DNA diagnosis is experiencing an impressive progression towards the development of novel technology to identity various clinically relevant categories of genetic changes and to meet the exponential growth of genomics. The introduction of capillary electrophoresis has dramatically accelerated the completion of the first draft of the human DNA sequence in the Human Genome Project, and thus, has become the method of choice for analysis of various genetic variants. The recent development of microfabricated electrophoretic devices has led to the possibility of integrating multiple sample handling with the actual measurement steps required for automation of molecular diagnostics. This review highlights the most recent progress in capillary electrophoresis and electrophoretic microdevices for DNA-based diagnostics, including the important areas of genotyping for point mutation, single nucleotide polymorphisms, short tandem repeats and organism identification. The application of these techniques for infectious and genetic disease diagnosis, as well as forensic identification purpose, are covered. The promising development and the challenges for techinical problems are also discussed.

One step to detect the latent fingermarks with gold nanoparticles

A simple and environment friendly chemical route for detecting latent fingermarks by one-step single-metal nanoparticles deposition method (SND) was achieved successfully on several non-porous items. Gold nanoparticles (AuNPs) synthesized using sodium borohydride as reducing agent in the presence of glucose, were used as working solution for latent fingermarks detection. The SND technique just needs one step to obtain clear ridge details in a wide pH range (2.5-5.0), whereas the standard multi-metal deposition (MMD) technique requires six baths in a narrow pH range (2.5-2.8). The SND is very convenient to detect latent fingermarks in forensic scene or laboratory for forensic operators. The SND technique provided sharp and clear development of latent fingermarks, without background staining, dramatically diminished the bath steps.