21个非CODIS STR基因座的遗传多态性

目的 调查华东汉族人群21个非CODIS STR基因座的遗传多态性并评价其法医学应用价值.方法 用AGCU 21+1 STR试剂盒,对华东地区汉族225个无关个体的21个非CODIS STR基因座进行扩增,用3130遗传分析仪检测扩增产物,GeneMapper ID v3.2软件进行分型,采用PowerStats v1...     

变截面桩竖向承载性状的模型实验研究

利用自行研发的试验装置进行了半桩模型试验研究,分析了变截面桩的荷载-沉降曲线、桩身轴力分布情况、桩身侧摩阻力分布情况,并与常规等截面桩进行比较.模型试验结果表明：变截面桩较等截面桩更有利于减小桩体的沉降量,但从单桩沉降变形的角度看,变截面桩存在最佳变径比.当变径比超过这一最佳值时,变径比越大,桩的沉降变形也就越大,甚至超过等截面桩的沉降量.桩顶荷载首先并主要通过变截面处以上桩身传递,该部分桩身段是主要承载部位.由于变截面处下部土体对桩的支撑作用,变截面桩的桩身轴力在变截面处附近有较大程度的衰减.变截面桩的桩身侧摩阻力比常规等截面桩发挥更加充分.     

Does the Prior Application of the Field Kit Bullet Hole Testing Kit 3 on a Suspected Bullet Hole Bias the Analysis of Atomic Absorption Spectrophotometry?

Forensic ballistics is the study of bullet trajectory and consists of determining gunshot residue (GSR) to identify bullet holes. Among several highly sensitive methods, atomic absorption spectrophotometry (AAS) is employed to analyze GSR in the laboratory. However, it is sometimes necessary to identify bullet holes immediately at a crime scene. The purpose of this examination was to determine whether the use of the field test Bullet Hole Testing Kit 3 (BTK3) on a suspected bullet hole would influence the outcome of AAS‐analysis: Three commonly encountered firearms (Glock17, Tokarev, and Colt) were fired at skin, wood, and cloth. AAS‐analysis was performed with and without previous BTK3 application. The results clearly indicate that there is no significant interaction on the grounds of BTK3 use (BTK3 vs. no‐BTK3 [kit_nokit] [Pb: p = 0.1309; Sb: p = 0.9111], material*kit_nokit [Pb: p = 0.5960; Sb: p = 0.9930], distance*kit_nokit [Pb: p = 0.4014; Sb: p = 0.9184], and firearm type*kit_nokit [Pb: p = 0.9662; Sb: p = 0.9885]); hence, applying this field kit does not falsify later AAS outcomes.     

法医毒物检验技术方法的评价方式

评价方式是评价技术中的重要组成部分。根据法庭科学领域毒物检验方法的技术特性与质量要求,在明确评价目标与原则的基础上,以评价指标为核心提出合理化的、可操作的评价方式。建立有效的评价方式,旨在通过科学的评价活动获得客观的评价结果。     

福建汉族人群亲权鉴定中基因突变现象的观察分析

观察福建地区亲权鉴定中常用STR基因座突变现象,分析福建汉族人群遗传突变率和一些常用位点的突变情况。在3702例亲权关系鉴定的案例中,观察到79例发生基因突变,D8S1179、D21S11、D7S820等15个位点发生突变。     

Clarifying the complex chemistry of cobalt(II) thiocyanate-based tests for cocaine using single-crystal X-ray diffraction and spectroscopic techniques

Cobalt(II) thiocyanate-based tests are routinely used to screen cocaine products, with the formation of a blue species interpreted as a positive response. An array of other organic bases has been identified as false positives – including well-documented cocaine product adulterant lidocaine and its salt. False positives prompt continued test development, though improvements are hindered by unresolved product structures and reaction pathways. Toward greater clarity, cobalt(II) thiocyanate reactions with cocaine hydrochloride, along with lidocaine and its salt, were investigated using multiple analytical techniques. Reactions involving cocaine hydrochloride yielded glassy, amorphous blue material while reactions of lidocaine hydrochloride monohydrate produced larger, needle-like crystals whose structure was determined via single-crystal X-ray diffraction to be an ion pair (Hlidocaine⁺)₂([Co(SCN)₄]²⁻)·H₂O. While the blue precipitate isolated from reactions involving cocaine hydrochloride was unsuitable for crystallographic structure determination, comparative ultraviolet–visible, attenuated total reflectance infrared, and Raman spectroscopic analysis – along with elemental analysis – supports that this solid is comprised of a comparable ion pair (Hcocaine⁺)₂[Co(SCN)₄]²⁻. Pink crystals isolated from lidocaine reaction vessels were identified as coordination compounds cis-[CoL₂(SCN)₂] and trans-[CoL₂(SCN)₂] where L = lidocaine, while pink crystals from both cocaine hydrochloride and lidocaine hydrochloride monohydrate reaction vessels were the coordination polymer trans-[Co(H₂O)₂(SCN)₂]·H₂O. The results presented herein enable reaction optimization to favor a desired product, whether ion pair or coordination species.     

Cheikh Anta Diop: The social sciences,humanities, physical and natural sciences and transdisciplinarity

ABSTRACT

This article presents a critical exposition of the contributions of Cheikh Anta Diop to a scientific understanding of ancient African history, race, and the study of culture. It sets out the history of Diop's successful struggle against flawed Eurocentric scholarship which sought to deny the contributions of ancient black Egyptians to world civilisation. Diop's intellectual odyssey across physics, linguistics, through anthropology, ethnology, genetics and history is recounted here to demonstrate the limitations of mono-, inter- and multidisciplinarity and clearly identifies him as a pioneer of transdisciplinarity in the field of knowledge production.     

被洗织物上潜血痕迹发现方法的比较

目的探索被洗涤后衣物上潜血痕迹的发现方法。方法用联苯胺法、鲁米诺法和新型仪器TL-445激光生物检材发现仪寻找不同织物上不同洗涤强度的潜在血迹。结果联苯胺仅能发现部分纯棉织物上潜血,鲁米诺能显示全部纯棉织物上血迹,TL-445激光生物检材发现仪能显示所有纯棉、纯化纤织物上血迹。结论用TL-445激光生物检材发现仪检测相比联苯胺法和鲁米诺法更适合洗涤后织物上潜血痕迹的发现。     

Statistical Evaluation of Alternative Light Sources for Bloodstain Photography

Bloodstain photography is important in forensic applications, especially for bloodstain pattern analysis. This study compares the enhancement effect of bloodstain photography using three different types of light source: fluorescent white light, near‐ultraviolet (UV) light‐emitting diode (LED) light, and 410 nm LED light. Randomized complete block designs were implemented to identify the lighting that would statistically produce the best enhancement results for bloodstains on different types of surfaces. Bloodstain samples were prepared on white cotton, brown carpet, tar road, and wood. These samples were photographed in darkroom conditions using a Canon EOS 50D digital SLR camera, with Canon EFS 60 mm f/2.8 Macro USM lens. Two‐way analysis of variance and Fisher's least significant difference test were used to analyze the contrast of the images. The statistical analysis showed that 410 nm light is the best among the tested lights for enhancing bloodstains on the tested surfaces, where the contrast of bloodstain to background was the highest.     

On the meaning of the likelihood ratio: Is a large number always an indication of strength of evidence?

There is general lack of awareness that high LR based on complex propositions e.g. three contributors, does not necessarily translate into probative evidence against a suspect. In some cases there is an increased chance of false inclusion of a person of interest. This is an issue for all LR-based models. One way to address this issue is to further evaluate or qualify the estimated LR by a performance test. Based on simulations, this was achieved by non-contributor-testing: replacing the reference profile of interest (typically the suspect's profile), by the profile of a simulated random man. An exact p-value can also be calculated, giving the chance of observing an LR-value exceeding the estimated if the defense hypothesis is true.