Development and Validation of a Virtual Examination Tool for Firearm Forensics, ,

The transition from 2D imaging to 3D scanning in the discipline of firearms and toolmark analysis is likely to provide examiners an unprecedented view of microscopic surface topography. The digital examination of measured 3D surface topographies has been referred to as virtual microscopy (VM). The approach offers several potential advantages over traditional comparison microscopy. Like any new analytic method, VM must be validated prior to its use in a crime laboratory. This paper describes one of the first validation studies of virtual microscopy. Fifty‐six participants at fifteen laboratories used virtual microscopic tools to complete two proficiency‐style tests for cartridge case identification. All participating trained examiners correctly reported 100% of the identifications (known matches) while reporting no false positives. The VM tools also allowed examiners to annotate compared surfaces. These annotations provide insight into the types of marked utilized in comparative analysis. Overall, the results of the study demonstrate that trained examiners can successfully use virtual microscopy to conduct firearms toolmark examination and support the use of the technology in the crime laboratory.     

Profiling the scent of weathered training aids for blood-detection dogs

At outdoor crime scenes, cadaver-detection and blood-detection dogs may be tasked with locating blood that is days, weeks or months old. Although it is known that the odour profile of blood will change during this time, it is currently unknown how the profile changes when exposed to the environment. Such variables must be studied in order to understand when the odour profile is no longer detectable by the scent-detection dogs and other crime scene tools should be implemented. In this study, blood was deposited onto concrete and varnished wood surfaces and weathered in an outdoor environment over a three-month period. Headspace samples were collected using solid phase microextraction (SPME) and analysed using comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (GC×GC–TOFMS). The chemical odour profiles were compared with the behavioural responses of cadaver-detection and blood-detection dogs during training. Data interpretation using principal component analysis (PCA) and hierarchical cluster analysis (HCA) established that the blood odour could no longer be detected using SPME–GC×GC–TOFMS after two months of weathering on both surfaces. Conversely, the blood-detection dogs had difficulty locating the blood samples after one month of weathering on concrete and after one week of weathering on varnished wood. The scent-detection dogs evaluated herein had not been previously exposed to environmentally weathered blood samples during training. Given that this study was conducted to test the dogs' baseline abilities, it is expected that with repeated exposure, the dogs' capabilities would likely improve. The knowledge gained from this study can assist in providing law enforcement with more accurate training aids for blood-detection dogs and can improve their efficiency when deployed to outdoor crime scenes.     

Verjährung von Zinsen für unerlaubte Ablöse

Die "gesetzlichen Zinsen", deren Rückzahlung § 27 Abs 3 MRG anordnet, unterliegen – unbeschadet der für die Rückforderung geltenden Verj?hrungsbestimmungen von drei bzw zehn Jahren – jedenfalls der Verj?hrungsfrist des § 1480 ABGB.     

SMTP和POP3协议高级编程

本文探讨了SMTP协议和POP3协议的工作原理和工作过程以及通过SMTP协议利用VB的WinSock从控件发送电子邮件的客户端程序的编写步骤。     

科学马克思主义观的深化与拓展--论党的第三代中央领导集体的马克思主义观

党的第三代中央领导集体的马克思主义观,经历了一个确立、成熟和深入发展的阶段.从发生论、本质论、结构论、特征论和价值论等方面回答了什么是马克思主义的问题;从认真地学习和研究、完整准确地理解、既坚持又发展、不断进行理论创新、理论联系实际等方面说明了怎样对待马克思主义的问题.这一科学的马克思主义观具有重要的理论价值和实践意义.     

Genetics and genomics of core short tandem repeat loci used in human identity testing

Over the past decade, the human identity testing community has settled on a set of core short tandem repeat (STR) loci that are widely used for DNA typing applications. A variety of commercial kits enable robust amplification of these core STR loci. A brief history is presented regarding the selection of core autosomal and Y-chromosomal STR markers. The physical location of each STR locus in the human genome is delineated and allele ranges and variants observed in human populations are summarized as are mutation rates observed from parentage testing. Internet resources for additional information on core STR loci are reviewed. Additional topics are also discussed, including potential linkage of STR loci to genetic disease-causing genes, probabilistic predictions of sample ethnicity, and desirable characteristics for additional STR loci that may be added in the future to the current core loci. These core STR loci, which form the basis for DNA databases worldwide, will continue to play an important role in forensic science for many years to come.     

Immunohistochemical staining as a potential method for the identification of vaginal epithelial cells in forensic casework

There is currently no accurate method to identify vaginal epithelial cells uniquely. This study aimed to use a cell extraction procedure compatible with routine forensic sampling methods, and to investigate the expression of cytokeratin (CK), estrogen receptor-alpha (ERalpha), and phosphodiesterase 5 (PDE5) in order to distinguish between skin, buccal, vaginal, and external penile epithelial cells. Seminal fluid samples were also examined. Epithelial cell samples were fixed in formalin, embedded in agarose, and processed using histological methods. Antigen-antibody reactions were detected using the DAKO Envision+ detection system. CK was present in all cells from all five sources confirming the origin of cells as epithelial. Both ERalpha and PDE5 positively labeled vaginal, buccal, and skin epithelial cells. Although an antigen unique to vaginal epithelial cells was not identified, we have described a cell extraction procedure for use in the immunohistochemical detection of a wide range of antigens, an approach compatible with forensic diagnostics.     

Genetic analysis of 15 STR loci of Chinese Ewenki ethnic population

POPULATION: Almost all the Ewenki are found in HulunBuir Ewenki Autonomous Banner, Inner Mongolia province of China. Some Ewenki are nomads; others are farmers or farmer-hunters. A small number of them are hunters. Its national characters and languages belong to the Altai phylum.     

高效液相色谱法测定人血清中安眠酮及其苯甲基羟化代谢物的浓度

本文建立了用反相高效液相色谱法(RP-HPLC)测定人血清中安眠酮及其苯甲基羟化代谢物-2-甲基-3[2-(羟甲基)-苯基]-4(3H)喹唑酮(Ⅰ)的浓度。安眠酮浓度在1-35μg/ml范围内呈直线相关(相关系数r=0.9980;回归方程y=0.06324x—0.1029),方法回收率平均为102.08±9.987(SD)％(n=5),检出限为1ng。其代谢物Ⅰ按原型安眠酮的线性浓度测定其相对量。本法为测定中毒者体内安眠酮及其代谢物Ⅰ的血浓度提供可行的手段。