Forensic analysis of video file formats

Video file format standards define only a limited number of mandatory features and leave room for interpretation. Design decisions of device manufacturers and software vendors are thus a fruitful resource for forensic video authentication. This paper explores AVI and MP4-like video streams of mobile phones and digital cameras in detail. We use customized parsers to extract all file format structures of videos from overall 19 digital camera models, 14 mobile phone models, and 6 video editing toolboxes. We report considerable differences in the choice of container formats, audio and video compression algorithms, acquisition parameters, and internal file structure. In combination, such characteristics can help to authenticate digital video files in forensic settings by distinguishing between original and post-processed videos, verifying the purported source of a file, or identifying the true acquisition device model or the processing software used for video processing.     

802.1X系统下校园网简易上网日志的实现

在校园网改造过程中，划分VLAN、将二层结构改为以三层交换为核心的路由网络、IP动态分配，增加802.1X网络身份认证都是常见的做法，但改造后许多原有的网关上网日志记录将无法使用。其实，无需增加经费投入，自行编写简单程序，直接提取802.1X认证系统数据库中的资料，也可以完成简单日志记录的功能。     

论医疗损害技术鉴定危机与改革

法律规定的不完善以及法官对鉴定结论的依赖性造成了目前医疗鉴定中,医疗事故技术鉴定与法医学医疗鉴定共存的二元化局面。侵权责任法在民事赔偿上否定了医疗事故的概念,提出以医疗损害责任为核心的民事责任制度,使医疗鉴定面临了新的问题。医疗事故技术鉴定机制和法医学医疗鉴定机制都存在种种缺陷,不能完全满足侵权责任法对医疗鉴定的新的需求。无论是鉴定结论的固有属性还是侵权责任法的新的技术内容都要求对现有的医疗事故技术鉴定模式进行改革,建立起符合《侵权责任法》要求的医疗损害技术鉴定制度。     

论医疗损害技术鉴定危机与改革

法律规定的不完善以及法官对鉴定结论的依赖性造成了目前医疗鉴定中,医疗事故技术鉴定与法医学医疗鉴定共存的二元化局面。侵权责任法在民事赔偿上否定了医疗事故的概念,提出以医疗损害责任为核心的民事责任制度,使医疗鉴定面临了新的问题。医疗事故技术鉴定机制和法医学医疗鉴定机制都存在种种缺陷,不能完全满足侵权责任法对医疗鉴定的新的需求。无论是鉴定结论的固有属性还是侵权责任法的新的技术内容都要求对现有的医疗事故技术鉴定模式进行改革,建立起符合《侵权责任法》要求的医疗损害技术鉴定制度。     

我国司法（法医）鉴定制度的历史、现状与改革设想

我国司法鉴定工作长期处于无序状态,无立法规范,无监管措施,司法鉴定行业问题不断,已严重影响到社会稳定。建立完善的鉴定体制已成为当务之急。文章对司法鉴定的基本概念、特征、我国司法体制的现状进行了阐述,提出了借鉴国外做法对我国司法体制进行改革的设想。     

Comparisons of protocols for enhanced DNA profile quality from FTA®-deposited urine samples

Disputes over the identity of a urine sample donor have been reported, and urine authentication by genetic profiling has helped resolved the cases. However, since genotyping of urine is not always required, many drug-testing laboratories may face sample storage issues. Several studies have investigated the use of FTA® cards as a convenient tool for keeping specimen at room temperature for extended periods of time. However, generating complete STR profile from some FTA®-deposited urine samples remains challenging due to low levels of genetic material content, necessitating amendments to the laboratory’s standard protocols. This work therefore aims to evaluate the effects of two DNA template preparation methods, both employing FTA® cards as the storage medium, on the success rates of STR profiling from urine. Specimen from a female volunteer, representing a particularly low-yield sample, was employed. Aliquots of 1 and 2 mL were used as the starting material to evaluate DNA template preparation using the FTA® manufacturer’s protocol for disc purification against elution of DNA from the FTA® using Prepfiler™ Forensic DNA Extraction Kit. AmpFℓSTR™ Identifiler™ Plus PCR Amplification Kit was used to amplify the STR markers, and the PCR products were analysed using Applied Biosystems™ 3500xL Genetic Analyzer. The DNA profile qualities were examined in terms of number of loci detected and peak height balance. Comparisons with the profiles obtained from DNA isolated using QIAamp® DNA Micro Kit from 1 and 2 mL of the same batch of urine were also made. The optimised protocol was then tested on urine samples from three male volunteers. The results showed that the purification of FTA® punches according to the manufacturer’s protocol enabled full DNA profiles to be obtained from both 1 and 2 mL of urine from all samples tested, including male samples. In contrast, no DNA profile could be generated from the DNA eluted with the Prepfiler™ kit. When compared with the more conventional solid-phase DNA extraction method, the profiles generated from the FTA® punches exhibited similar reproducibility and quality to those from the template isolated by the QIAamp® Kit. This work further demonstrated the feasibility of FTA® cards as a tool for specimen storage and DNA template preparation from small volumes of urine for authentication by STR profiling. Full STR profiles could be generated from sample from both sexes without modification of the PCR conditions or injection time.