Electrical Pulse Generated Upon Discharging a Firearm and Its Implication for Gunshot Residue Analysis

Ammunition primers consisting of a mixture of lead styphnate, barium nitrate, and antimony (III) sulfide, upon deflagration, lead to the formation of inorganic gunshot residue (GSR). The cations, from their predeflagration form, undergo reduction reactions during burning to form the classic spheroidal, micron-sized particles indicative of GSR. However, the rapidly changing pressure and temperature of the reaction zone implies that the reactions cannot go to completion. In this study, we use a conductivity detector to show that GSR produces an electrical pulse which corroborates the incomplete redox chemistry. We find that the shape of some GSR formed in an electric field also suggests its nonneutral character. Tantalizingly, the formation of GSR might be a result of Coulombic repulsion shattering the molten droplets in to smaller spheroids. Lastly, we suggest that deposition or transfer of GSR could be influenced by static electricity, an area which should be further studied.     

Acute Respiratory Obstruction due to Accidental Inhalation of Perlite: A Novel Mechanism for Upper Airway Occlusion with Cast Formation

A 56-year-old man died following a fall resulting in complete submersion into a deep pit containing insulation material, expanded perlite. The most striking finding at autopsy was of impacted, moist pale yellow perlite that extended from the epiglottis into the main bronchi resulting in complete obstruction of the larger and smaller airways with cast formation. Perlite inhalation differs from inhalation of inert materials such as sand and wheat due to its hygroscopic properties and ability to expand forming an occlusive cast. Subsequent analyses of perlite from the worksite and within the airways indicated that hydration of perlite and adsorption of organic molecules into the perlite glass flakes had formed an interlocking, three-dimensional structure that was likely responsible for triggering a coagulation–flocculation process causing strong cohesion between the aggregates of glass flakes. This unique mechanism was likely responsible for the formation of the plug of perlite that obstructed the upper airway.     

Comparison of three collection methods for the sodium rhodizonate detection of gunshot residues on hands

The aim of this study was to compare three gunshot residue (GSR) collection methods used in conjunction with chemographic detection applied by different regional Swiss police services. The specimens were collected from the hands of a shooter with either filter paper (Filter method) or adhesive foil. The adhesive foil was then either applied against photographic paper during visualisation (AF Photo method) or coated with a layer of polyvinyl alcohol (AF PVAL method). The experiments involved two conditions of the examined hands, i.e. dry and humidified. The residues were revealed using the sodium rhodizonate test (SRT). Preliminary tests assessing the possibility of conducting a confirmatory Scanning Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy (SEM/EDX) analysis after the chemographic test were performed on a number of specimens by cutting positive spots and mounting them on stubs. Obtained results were compared in terms of effectiveness - number of positive spots, time requirements, quality of subsequent SEM-EDX analysis, ease of use and cost.The Filter method generally yielded a high-quality detection with both dry and humidified hands, as well as a simple, quick and efficient confirmation by SEM/EDX. The AF Photo performed well on dry hands, but not on humidified hands. The AF PVAL method performance was lower compared to the other methods in both examined conditions of the hands. The SEM/EDX analysis showed that the Filter and AF PVAL method provided satisfactory results when a sufficient carbon coating thickness was applied to the cuttings. It was also observed that the thinner the PVAL layer, the better the quality of the spectra and obtained images in SEM/EDX. Furthermore, the surface of the photographic paper did not seem to be conductive, even after the application of a thick layer of carbon.In conclusion, the Filter method gave the best overall results, but its application required slightly more time and expertise than the two other methods.     

“四风”隐形变异的特征、根源与治理对策

随着党风廉政建设的深入推进,“四风”问题隐形变异、反弹回潮的现象不容忽视,不仅影响了党群干群关系,而且关乎党心民心,是全党和人民群众的公敌。当前“隐蔽”送礼、“转战”吃喝、“套牌”公车、“拆分”婚丧嫁娶、“变相”占用办公用房、“调研”旅游、“痕迹”督查、“庸懒散慢”等“四风”表现,体现了其具有长期性、反复性、顽固性、隐蔽性等特征。新时代深化作风建设,务必要以习近平总书记关于纠正“四风”的重要论述为指导,持之以恒地进行治理:加强政治建设,提高政治站位,夯实主体责任;加强学习教育,规范党内生活,弘扬廉政文化;加强制度建设,完善考核机制,抓住“关键少数”;加强监督执纪,强化联防联查,发挥长效合力,全面营造风清气正的政治生态。     

零容忍执法政策若干理论问题之评析

零容忍意味着我国警察机关原来的执法活动存在执法不严、违法不究现象,比较典型的就是"抓大放小"。零容忍与刑罚世轻世重中的"刑乱国用重典"思想有些相似,但不完全相同。零容忍不等同于攻击性行为,更不能说是警察机关的对抗式管理。虽然零容忍执法政策在实践中取得了较好的效果,但是由于我国警力的局限性,加之零容忍本身就是一个社会治安综合治理的过程,需要社会多个部门的协助和支持,所以如何能够长期保持,值得关注。     

Detection and analyses of latent DNA

Latent DNA detection has the potential to transform aspects of DNA collection at scenes and from items. In the absence of being able to visualise the location of cellular material, all collection of samples at crime scenes is currently performed blind. With the advent of the application of a nucleic acid staining dye, the DNA within skin cells (commonly called keratinocytes and corneocytes) can be visualised. Diamond Dye fluoresces when it binds to the backbone of DNA. This fluorescence can be recorded using a simple mini-microscope allowing the location and number of cells to be recorded. The potential to visualise cells on a wide range of substrates opens the possibility to target sample collection and to triage samples for further analyses to only those containing DNA. Diamond Dye has been found to be safe at the concentration used, inexpensive, available commercially, easy to apply, is highly sensitive, and does not inhibit further analyses such as PCR. This work presented at the ISFG congress gives an overview of the current developments on using DNA staining dyes to record the number of cells present on a wide range of substrates. It is essential to firstly understand the composition of cellular material deposited by touch, where it originates and the relative composition of corneocytes and cell-free DNA. Insight into the origins of touch DNA will be presented along with the staining of nuclei using a range of dyes to show corneocyte degradation. The presentation will cover how DNA binding dyes can be used to effectively triage sample collection, monitor cell collection using different swabs and tapes.     

Quantitative Assessment of the Sternal Rib End Morphology and Implications for Its Application in Aging Human Remains

Intercostal and age differences in the sternal rib end morphology of documented female skeletons from Spitalfields and St. Bride's are examined. The morphology was captured using three‐dimensional morphometrics and the statistical analyses employed included parametric and nonparametric MANOVA, discriminant analysis, and multilinear regressions. It was found that the quantified morphology of the sternal rib end was statistically significantly different between rib four and all other ribs except for the third one and that the morphological characteristics of all ribs varied with age. However, due to the inherent variability in sternal rib end morphology, nonstatistically significant results were obtained among the various age groups and neither disciminant nor multilinear regression analysis could be used for the estimation of the age of an individual based on digitized coordinates of the sternal rib end of individuals of known age, raising some concern as to the rigorousness of the fourth rib aging method.     

从跨文化角度析品牌翻译

品牌是商品的识别标志,而其翻译是实现商品国际化最根本的途径。品牌翻译是一种跨文化的交际方式,涉及许多跨文化因素。品牌翻译过程中常使用的几种翻译方法有音译法、直译法、意译法、音直结合法、音意结合法以及调整法等。把握中西文化因素对品牌翻译的影响作用,对开拓商品市场、取得商品进一步的销售渠道是十分有必要的。     

The Influence of Lying Body Position on Handwriting

Although the problem of handwriting variability due to lying body position has practical significance, particularly for last will cases, it has not been sufficiently studied. The presented experiment aimed to recognize how such posture may influence handwriting features. Samples of text and signatures were collected from 50 healthy individuals, aged 23–58, produced in three postures: typical sitting position (SP) and two different lying positions (LP1 & LP2). Using the SP sample of each individual as a specimen, eleven characteristics in LP1 and LP2 samples were evaluated as similar or different. Nine other features were measured with a specialized software, and their conformity was tested with Student's t‐test. Although none of the characteristics differed significantly in most cases, variation occurred in pen pressure, margins, baselines, and heights of letters. Additionally, a series of blind tests revealed that lying position of the individuals did not hinder the possibility to identify their writings.     

当面说理、强化修辞与重点推进——关于提高我国判决书制作水平的思考

我国当前的判决书存在的问题主要是：说理场合不当,当面不说,背后乱说;修辞力度不够,有法无情,自言自语;案件难易不分,千篇一律,大同小异。这些问题都属于判决书的说理问题,解决这些问题必须考察影响判决书说理的各种因素。除判例制度、政治制度和文化传统等影响判决书说理的一般因素外,我国行政化的审判管理体制、僵化的诉讼文书样式、判决书狭隘的法律意义和对判决书表达错误的容忍等一些细微的体制机制是导致当前的判决书出现问题的直接原因。提高我国判决书制作水平的基本措施是：废除和改进约束法官的制度,保障法官审判的能动性;建立判例制度,鼓励法官有重点地当面说理和加强修辞;突出最高人民法院和高级人民法院在判决书制作中的重点示范作用。