Study on the tracking revision history of MS Word files for forensic investigation

Document forensics remains an important field of digital forensics. To date, previously existing methods focused on the last saved version of the document file stored on the PC; however, the drawback of this approach is that this provides no indication as to how the contents have been modified. This paper provides a novel method for document forensics based on tracking the revision history of a Microsoft Word file. The proposed method concentrates on the TMP file created when the author saves the file and the ASD file created periodically by Microsoft Word during editing. A process whereby the revision history lists are generated based on metadata of the Word, TMP, and ASD files is presented. Furthermore, we describe a technique developed to link the revision history lists based on similarity. These outcomes can provide considerable assistance to a forensic investigator trying to establish the extent to which document file contents have been changed and when the file was created, modified, deleted, and copied.     

法务会计在我国发展前景初探

法务会计又叫诉讼会计,它是通过对财务技能的运用以及对未决问题的调查方法,将证据规则与此相结合的一种会计学科,是会计、审计和调查技术的有机结合,是一门将经济事实和法律问题相联系和运用的行业。在法律化逐步完善的今天,发展法务会计是一个重要内容,从法务会计的定义,产生的必要性、存在的几大领域以及法务会计在我国的现状及发展前景为线索论述了法务会计必将成为未来世纪的热门行业之一。     

大学英语四级考试语法题的主要题型及应试策略探析

为了使学生能在全面了解英语语法的同时,把握测试重点,根据各语法项目在四级考试中所占的比例,我们归类出了带有规律性的出题倾向与出题重点,并佐以真题实例,逐类分析,提出相应的应试策略,以帮助考生提高语法结构题的应试能力。     

Validation of the Seratec® SeraQuant™ for the quantitation of prostate-specific antigen levels on immunochromatographic membranes

Abstract: Use of immunochromatographic membranes for the detection of prostate‐specific antigen (PSA) has become commonplace in forensic laboratories. Experiments were designed to test the newly developed Seratec^® SeraQuant? for accuracy, precision, and consistency in the quantitation of PSA. PSA standards were diluted with buffers and run on the instruments. Values obtained were examined for accuracy (was the correct value obtained?) and precision (were multiple sample values consistent?). To test for variation between instruments, large volumes of diluted PSA standard were run repeatedly on six units and the values obtained were plotted against the known PSA values to obtain a standard curve for each instrument. Fifty membranes having negative or weak positive results were then run on the six units, and the adjusted values were recorded and compared. Results of these experiments indicate that the instruments are accurate and precise in the quantitation of low levels of PSA.     

Identification of forensically important sarcophagid flies (Diptera: Sarcophagidae) in China, based on COI and 16S rDNA gene sequences

Insects attracted to cadavers may provide important indications of the postmortem interval (PMI). However, use of the flesh flies (Diptera: Sarcophagidae) for PMI estimation is limited as the species are often not morphologically distinct, especially as immatures. In this study, 23 forensically important flesh flies were collected from 13 locations in 10 Chinese provinces. Then, a 278-bp segment of the cytochrome oxidase subunits one (COI) gene and a 289-bp segment of the 16S rDNA gene of all specimens were successfully sequenced. Phylogenetic analysis of the sequenced segments showed that all sarcophagid specimens were properly assigned into four species (Boerttcherisca peregrina [Robineau-Desvoidy, 1830], Helicophagella melanura [Meigen, 1826], Parasarcophaga albiceps [Meigen, 1826], and Parasarcophaga dux [Thompson, 1869]) with relatively strong supporting values, thus indicating that the COI and 16S rDNA regions are suitable for identification of sarcophagid species. The difference between intraspecific threshold and interspecific divergence confirmed the potential of the two regions for sarcophagid species identification.     

A simulation for exploring the effects of the "trait list" method's subjectivity on consistency and accuracy of ancestry estimations

The nonmetric "trait list" methodology is widely used for estimating ancestry of skeletal remains. However, the effects of the method's embedded subjectivity on subsequent accuracy and consistency are largely unknown. We develop a mathematical simulation to test whether variation in the application of the "trait list" method alters the ancestry estimation for a given case. Our simulation explores how variations in (i) trait selection, (ii) number of traits employed, and (iii) ancestry choice thresholds affect the ancestry estimation of an unidentified skeleton. Using two temporally and geographically diverse samples, the simulation demonstrates that trait selection, trait quantity, threshold choices, and the exclusion of high-frequency traits had minimal effect on estimation of general ancestry. For all data sets and Runs, Accuracy(AS) was maintained above 90%. The authors close with a discussion on the logistical issues present when choosing traits, and how to avoid ancestry bias.     

Fatal acute intracranial injury, subdural hematoma, and retinal hemorrhages caused by stairway fall

We describe an infant with an acute subdural hematoma, a fatal head injury, and severe hemorrhagic retinopathy caused by a stairway fall. His cerebral and ocular findings are considered diagnostic of abusive head trauma by many authors. Our literature search of serious injuries or fatalities from stairway or low-height falls involving young children yielded 19 articles of primary data. These articles are discrepant, making the classification of a young child's death following a reported short fall problematic. This case report contradicts the prevalent belief of many physicians dealing with suspected child abuse that low-height falls by young children are without exception benign occurrences and cannot cause fatal intracranial injuries and severe retinal hemorrhages. The irreparable harm to a caregiver facing an erroneous allegation of child abuse requires physicians to thoroughly investigate and correctly classify pediatric accidental head injuries.     

Validation of thin layer chromatography with AccuTOF-DART™ detection for forensic drug analysis

Abstract: Thin layer chromatography (TLC) is a technique that is commonly employed in the forensic drug analysis of pharmaceutical preparations. Detection is typically accomplished using various visualization spray reagents. Conventional gas chromatography–mass spectrometry (GC‐MS) analysis is typically performed to confirm the TLC results. Depending on the drugs tested and the instrument conditions required, this confirmation can take up to an hour to complete. Direct analysis in real time (DART?) is an ionization source, coupled to an accurate‐mass time‐of‐flight mass spectrometer that has the capability to ionize materials under ambient conditions. To streamline analysis, the combination of TLC with DART? detection is proposed to screen and subsequently identify drug compounds, all from the same TLC plate. DART? confirmations of TLC analyses take <10 min to complete and compare favorably to GC‐MS in sensitivity and selectivity. This study validates the use of TLC‐DART in the forensic identification of the components of several pharmaceutical preparations.