Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) detection limits for blood on fabric: Orientation and coating uniformity effects

Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was used to analyze four types of forensically relevant fabrics coated with varying dilutions of blood. The blood was applied in two manners, dip coating with a smooth and uniform layer and drip coating with droplets from pipettes. Spectra of neat and dip coated fabrics were acquired using controlled orientations, and these were compared to spectra collected on samples with random orientations. The improved reproducibility seen in visual inspection of the spectra is confirmed by principal component and linear discriminant projections of the spectra, as well as by statistical hypothesis testing. Principal component regression (PCR), using the regions of the IR spectra associated with the amide A/B, I, II, and III vibrational bands (3500–2800, 1650, 1540, and 1350 cm⁻¹), was employed on the more uniform dip coated spectra to estimate limits of detection for blood on two of the four fabrics – acrylic and nylon. These results demonstrate that detection limits for blood on fabrics can be decreased significantly by controlling for the orientation and face of the fabric samples while collecting spectra. Limits of detection for acrylic and nylon were found to be 196 × and 227 × diluted blood, respectively.     

红外光谱结合化学计量学方法在激光打印原装黑色墨粉分析中的应用研究

目的 采用红外光谱比较分析不同原装黑色墨粉（31个样本）的差异,探讨化学计量学方法在墨粉种类识别中的适用性.方法 对打印样本纸张上的黑色墨粉进行烫熨提取后直接分析检测.IR分析条件：显微红外光谱仪,常温透射模式,扫描范围为4 000～400 cm-1,分辨率为16cm-1,累计扫描次数为64次.结果 墨粉树脂主要为聚苯乙烯/甲基丙烯酸甲酯和聚对苯二甲酸/环氧树脂.采用主成分析（Principal Component Analysis,PCA）与系统聚类法（Hierarchical Cluster Analysis,HCA）对不同种类墨粉进行聚类分析与建模预报.基于前两主成分得分值（53.3％）不同树脂成分的墨粉样本聚类效果明显,同时在第三个主成分方向上黑白与彩色激光墨粉样本获得良好区分.结论 红外光谱法结合化学计量学方法用于不同种类树脂及打印类型原装黑色墨粉的聚类分析与建模预报方法可行,结果准确可靠.     

积极稳妥地推行社会稳定风险评估工作

社会稳定风险评估机制就是一项社会管理的制度创新,文章通过对近几年我国社会稳定风险评估机制的实践研究,提出要正确认识和理解社会稳定风险评估,了解社会稳定风险评估的实践状况,分析其问题与原因,进而提出积极推行社会稳定风险评估的建议。     

积极刑法观的反思与批判

面对日益增加的社会风险,我国刑事立法不断扩张处罚的范围,这种立法的积极姿态也得到了学者的认同,从而形成了积极刑法观的主张。积极刑法观的含义包括理念、立法、司法三个方面,其与预防刑法观、风险刑法观与功能主义刑法观都存在不同。无论从现实还是从法理层面而言,积极刑法观都存在许多疑问。在现实层面,我国现行刑法的结构并非是厉而不严,而是又严又厉。刑法的但书规定意味着立法采取定性加定量的模式,这与积极刑法观的立论或多或少存在冲突。我国司法机关一直采取扩张解释乃至于类推解释来适用刑法,因此指望通过司法实践来限缩处罚范围的观点并不现实。在法理层面,积极刑法观导致了刑罚权的过度扩张,冲击了人的基本自由,因而抵触宪法;同时它也违反了谦抑原则和比例原则的具体要求,并且作为其依据的积极一般预防理论的根基并不稳固。在方法论上,必须重提"李斯特鸿沟"的重要法治意义。     

铁路公安主动勤务探索

主动勤务是在消极、被动警务或反应式警务基础上更高层次的发展,是适应社会发展、推进警务改革、破解警力不足等难题的重要途径和手段。必须全面实施以"信息警务、素质警务、效能警务、阳光警务"为内涵的主动勤务模式,不断深化"平安站段、平安站区、平安线路、平安列车、平安队伍"建设。     

Potential Use of Hydrocarbons for Aging Lucilia sericata Blowfly Larvae to Establish the Postmortem Interval

Previous studies on Diptera have shown the potential for the use of cuticular hydrocarbons' analysis in the determination of larval age and hence the postmortem interval (PMI) for an associated cadaver. In this work, hydrocarbon compounds, extracted daily until pupation from the cuticle of the blowfly Lucilia sericata (Diptera: Calliphoridae), have been analyzed using gas chromatography–mass spectrometry (GC–MS). The results show distinguishing features within the hydrocarbon profile over the period of the larvae life cycle, with significant chemical changes occurring from the younger larvae to the postfeeding larvae. Further interpretation of the chromatograms using principal component analysis revealed a strong correlation between the magnitudes of particular principal components and time. This outcome suggests that, under the conditions of this study, the cuticular hydrocarbons evolve in a systematic fashion with time, thus supporting the potential for GC–MS analysis as a tool for establishing PMI where such a species is present.     

Facial Age Synthesis Using Sparse Partial Least Squares (The Case of Ben Needham)

Automatic facial age progression (AFAP) has been an active area of research in recent years. This is due to its numerous applications which include searching for missing. This study presents a new method of AFAP. Here, we use an active appearance model (AAM) to extract facial features from available images. An aging function is then modelled using sparse partial least squares regression (sPLS). Thereafter, the aging function is used to render new faces at different ages. To test the accuracy of our algorithm, extensive evaluation is conducted using a database of 500 face images with known ages. Furthermore, the algorithm is used to progress Ben Needham's facial image that was taken when he was 21 months old to the ages of 6, 14, and 22 years. The algorithm presented in this study could potentially be used to enhance the search for missing people worldwide.     

基于BP神经网络的高校院系科研绩效评价模型

本文在分析当前各种高校院系的科研绩效评价指标体系的基础上．针对目前各种评价指标多、定量难、人为干扰因素多等问题,采用主成分法从大量评价因素中筛选出绩效评估的主要因素,即在保留评价信息的前提下对数据进行有效降维。并通过BP神经网络的自学习功能计算出高校院系的科研绩效。该模型能较为科学地评估高校院系科研团队的科研成效、核心竞争力及研究潜力,为高校科研管理提供一种新方法。     

中国城市生活垃圾处理绩效的影响因素：基于VAR模型的实证研究

文章通过主成分分析的方法构建和评价中国2006-2015年9年间各省(区、市)及整体的城市生活垃圾处理绩效综合水平,在此基础上利用VAR模型检验了多种因素对中国城市生活垃圾处理绩效影响做以实证研究。研究发现：直接影响中国城市生活垃圾处理绩效的主要因素是劳动力因素和运营模式因素。同时,运营模式因素是一种外生嵌套因素,没有外生驱动紧靠自身调整是无法实现的;而劳动力因素则除了自身调整外,还受到经费因素以及政府监管因素的间接驱动,即经费因素和政府监管因素通过劳动力因素路径间接影响绩效水平。据此,文章根据研究结论提出较具建设性的建议,以期对提升中国城市生活垃圾处理绩效水平以及指导公共事业的政府监管工作做以绵薄之力。     

Crisis (hostage) negotiators weigh in: the skills,behaviors, and qualities that characterize an expert crisis negotiator

This research identified what skills, behaviors, and qualities experienced crisis (hostage) negotiators believe enhance or harm their success during negotiation. 188 negotiators from various countries (primarily United States) voluntarily completed an online survey in which they listed the aforementioned characteristics and reported on various aspects of their own background and behaviors. Open-response questions were coded and quantitative methods revealed what qualities were listed most frequently by negotiators. Active listening, displays of empathy, effective communication, and remaining calm and collected appear at the top of their to-do lists. Conversely, being confrontational, arguing, yelling, and interrupting were reported as behaviors to be avoided. Most negotiators attend trainings multiple times a year and read on the topic of crisis negotiation. About half follow a model during negotiations, typically the FBI’s Behavioral Change Stairway Model. Findings are discussed with relevance to future research directions and improvement of negotiator trainings.