Estimating postmortem interval for human cadavers in a sub‐tropical climate using UV‐Vis‐near‐infrared Spectroscopy

Estimating postmortem interval (PMI) of surface found skeletal remains is challenging. This novel study used UV‐Vis‐NIR spectroscopy to scan soil collected from cadaver decomposition islands (CDIs) ranging from 15‐ to 963‐d postmortem and control soils. A decomposition product spectra model (DPS model) was constructed by deducting the control soil spectra from the CDI soil spectra for the estimation of postmortem indices: PMI (d), ADD₄, ADD₁₀, and ADD₂₀. The DPS model (n = 55) was calibrated and subjected to a full cross‐validation. Calibration R² and RPD for the DPS model ranged from 0.97 to 0.99 and from 6.1 to 9.9, respectively, for the four postmortem interval indices. Validation R² and RPD for the DPS model ranged from 0.73 to 0.80 and from 1.9 to 2.2, respectively. The DPS model estimated postmortem intervals for three test CDIs in a clay soil under perennial grassland (test set 1; n = 3) and six CDIs in a sandy soil under a loblolly pine forest (test set 2; n = 6). Test set 1 had PMI prediction ranges from ?69 to ?117 days, ?796 to +832 ADD₄, +552 to +2672 ADD₁₀, and ?478 to ?20 ADD₂₀ of observed PMI. Test set 2 PMI prediction ranged from ?198 to ?65 days, ?9923 to +2629 ADD₄, ?6724 to +1321 ADD₁₀, and ?2850 to +540 ADD₂₀ of observed PMI. Test set 2 had poor predictions for two CDIs, for all measures of postmortem indices resulting in discussion of sampling depth, effect of body mass index (BMI), and scavenging.     

A novel multiplex assay system based on 10 methylation markers for forensic identification of body fluids

Identifying the source of body fluids found at a crime scene is an essential forensic step. Some methods based on DNA methylation played significant role in body fluids identification. Since DNA methylation is related to multiple factors, such as race, age, and diseases, it is necessary to know the methylation profile of a given population. In this study, we tested 19 body fluid-specific methylation markers in a Chinese Han population. A novel multiplex assay system based on the selected markers with smaller variation in methylation and stronger tissue-specific methylation were developed for the identification of body fluids. The multiplex assay were tested in 265 body fluid samples. A random forest model was established to predict the tissue source based on the methylation data of the 10 markers. The multiplex assay was evaluated by testing the sensitivity, the mixtures, and old samples. For the result, the novel multiplex assay based on 10 selected methylation markers presented good methylation profiles in all tested samples. The random forest model worked extremely well in predicting the source of body fluids, with an accuracy of 100% and 97.5% in training data and test data, respectively. The multiplex assay could accurately predict the tissue source from 0.5 ng genomic DNA, six-months-old samples and distinguish the minor component from a mixture of two components. Our results indicated that the methylation multiplex assay and the random forest model could provide a convenient tool for forensic practitioners in body fluid identification.     

态度改变模式对领导干部理想信念教育的启示

态度改变与理想信念教育存在着相似的机理,因此,通过影响态度改变模式的四个变量,我们可以提高理想信念教育的有效性：从劝说者变量来看,应注重从专业性、可靠性和吸引力三个方面提升教师的影响力;从沟通变量来看,要根据信息的差异性、情绪性和组织性,合理制定教学内容和教学方式;从劝说对象变量来看,须深入了解学员的原有态度、人格特质和心理免疫情况;从情境变量来看,应该充分优化教学环境的预警因素、分心因素和强化因素。     

检调对接机制研究

检调对接是新形势下检察机关执法办案的一种创新型工作机制,是检察工作参与社会矛盾化解的最佳方式。而纵观检调对接的流程,其工作机制实际是一系列程序的集合体。本文在分析各地检察机关开展检调对接工作的基础上,对检调对接的概念、建立基础、现状等问题进行研究,并对检调对接的适用范围、必要性进行探讨,对检调对接机制的模式完善提出建议与思考。     

Physical components of soft-tissue ballistic wounding and their involvement in the generation of blood backspatter*

Gunshot backspatter comprises biological material expelled backward through bullet entry holes. Crime scene investigators analyze backspatter patterns to infer wounding circumstances. An understanding of the mechanism of backspatter generation, and the relationship between spatter patterns and bullet and tissue characteristics, would enhance the predictive value of such analysis. We examined soft-tissue ballistic wounding responses to determine the underlying components and how these might be relevant to the generation of backspatter. We identified five mechanistic components to ballistic wounding (elastic, viscous, crushing, cutting, and thermal), each related to mechanical disciplines (respectively, solid mechanics, fluid mechanics, fracture mechanics, rheology, and thermodynamics). We identified potential roles for these five components in backspatter formation and provide a scenario whereby a sequence of events incorporating these components could lead to backspatter generation and expulsion. This research provides a framework for the mathematical representation, and subsequent computational predictive modeling, of backspatter generation and pattern formation.     

挑战与回应:当前我军先进军事文化建设论析

先进军事文化作为重要的军事软实力,渗透在我军战斗力生成系统的诸要素之中,成为该系统的"催化剂"。面对新的形势和任务,我军先进军事文化建设面临着严峻挑战。在推进军事文化繁荣发展过程中,应充分发挥广大官兵主体作用,抓住军营文化建设这个重点,积极打造平台、拓宽途径、锐意创新、提升活力。     

突发公共安全事件扩散动力学模型仿真研究

由于自然—社会—经济系统互动随社会发展不断增加,突发公共安全事件更多地呈现出扩散化的形式,产生的影响远大于单一事件的发生。本文以复杂系统理论和复杂网络理论为基础并借鉴灾害链的相关研究,分别针对单一突发公共安全事件、突发公共安全事件链式扩散和突发公共安全事件网络扩散的特征、共性进行探索,建立事件发生和扩散的复杂系统动力学模型,通过突发公共安全事件扩散网络的动力学模型进行仿真实验,进一步探索不同网络结构和影响因素下的突发事件扩散机理。在复杂网络中,不同网络结构、事件爆发阈值、事件间关联度都会对突发事件的扩散产生影响。     

刑事警察胜任特征模型的理论构建研究

基于国内外研究现状,采用描述研究方法,构建了刑警的胜任特征模型,包括通用胜任特征模型、职业胜任特征模型和人格胜任特征模型。建模步骤如下:通过职位分析、确定绩效标准和效标样本、获取胜任特征的数据资料、分析数据资料并建构胜任特征模型、验证胜任特征模型5个步骤。为刑警的选拔、考评、晋升等提供了理论模型和评价工具。     

街面警务模式的探索与思考

推行街面警务模式是新形势下公安机关维护社会治安秩序的需要,是解决长期存在的警力不足问题的有效途径,也为公安机关维护社会稳定提供了新的思路和工作机制。本文从街面警务模式的内涵出发,结合北京市公安局西城分局的实践探索,探讨了推行街面警务模式的现实意义,为我国公安实战改革提供思路。