A test for carrion fly full siblings: a tool for detecting postmortem relocation of a corpse

We propose a genetic test for full sibship for a pair of carrion flies that could reveal the postmortem relocation of a corpse. A carrion fly larva is sometimes left behind when a corpse is moved. The discovery of full sibling larvae of approximately the same developmental stage at two locations would strongly suggest that a corpse was moved between those two sites. Distributions of pairwise comparisons of relatedness (R) coefficients were generated using amplified fragment length polymorphism profiles for nine samples of laboratory-generated full siblings as well as for a reference sample of nonfull sibling Phormia regina (Diptera: Calliphoridae). The mean relative R coefficient, a pairwise measure of the proportion of shared alleles, was 0.479 (±0.289 SD) for full siblings, close to the theoretical expectation of 0.5. A likelihood ratio (LR) test was based on observed distributions of R. R >0.55 corresponded to an LR >1000 favoring full sibship for that pair of individuals.     

Publication rates of abstracts presented at the annual scientific meetings held by the American Academy of Forensic Sciences in 2011 and 2016

Prior research evaluating the papers presented in forensic sciences in international meetings is scant. This study determines the possible predictions concerning publications by comparing the publication rates, publication years, and presentation types, time until publication, participating countries, and criteria of the published journals in the American Academy of Forensic Sciences (AAFS). The publication rates of abstracts presented at scientific meetings of AAFS, a prestigious forensic science organization, along with the aforementioned components and the extent of their contribution in 2011 and 2016 were investigated. The abstracts presented at the AAFS meetings in 2011 and 2016 were reviewed retrospectively within the scope of this study. The Web of Science, PubMed, Scopus, Science Direct, and Google Scholar databases were searched using a specified process that included the title, first and last author surnames, and keywords. Results revealed that approximately 21% and 24% of the papers presented at the 2011 and 2016 AAFS meetings, respectively, were published. Considering the publication rates of abstracts according to sections, the publication rates for the 2011 AAFS meeting ranged from 4% (questioned documents) to 31% (anthropology) and from 5% (questioned documents) to 32% (pathology/biology), on average, for the 2016 AAFS meeting. It was determined that the papers were largely published in the Journal of Forensic Sciences for both annual scientific meetings. Future studies should concentrate on the obstacles to the publication of papers presented at such prestigious organizations and strategies to facilitate the publication process such that they do not lose their value over time.     

A quantitative assessment of the extent and distribution of textile fibre transfer to persons involved in physical assault

Knowledge of the number of fibres transferred during a particular activity is essential for the interpretation of findings in similar criminal cases. In this regard, violent contacts and physical assaults still present a challenge, due to a lack of robust published data. Hereby, we present the outcome of an empirical study where different assault activities were simulated by a Jiu Jitsu team and participants were asked to play either the role of an aggressive ‘assailant’ or a defensive ‘victim’, wearing cotton garments (i.e., Gi’s). Four different scenarios were simulated in replicates (n = 5), each of them involving different intensity levels (low and high) and duration times (30 and 60 s). Results showed that approximately 1,000 to 44,000 fibres were cross-transferred between the participants’ garments, with noticeable differences between the different scenarios. These values were significantly larger than those published in previous studies and, therefore, suggested the possibility of a current underestimation of the number of fibres transferred in physical assaults. Furthermore, statistical analysis by ANOVA indicated that the all the variables tested (i.e., intensity level, duration time, and participants role) had a significant effect on the number of transferred fibres (p < 0.001) and, consequently, that some knowledge of the case circumstances may be important to make more educated estimations. This is the first time that such a methodology has been applied for the quantitative assessment of fibre transfer between participants in assault activities. Data are expected to help practitioners with the interpretation of findings in real casework and lead to a more robust evidential assessment.     

Weight of authorship evidence with multiple categories of stylometric features: A multinomial-based discrete model

This study empirically demonstrates the efficacy of a two-level Dirichlet-multinomial statistical model (the Multinomial system) for computing likelihood ratios (LR) for linguistic, textual evidence with multiple stylometric feature types with discrete values. The LRs are calculated separately for each feature type, namely, word, character and part of speech N-grams (N = 1,2,3), which are combined as overall LRs through logistic regression fusion. The Multinomial system’s performance is compared with that of a previously proposed system with the cosine distance (the Cosine system) using the same data (i.e., documents collated from 2160 authors). The experimental results show that: (1) the Multinomial system outperforms the Cosine system with the fused feature types by a log-LR cost of ca. 0.01 ～ 0.05 bits; and (2) the Multinomial system is more advantageous in performance with longer documents than the Cosine system. Although the Cosine system is more robust overall against the sampling variability arising from the number of authors included in the reference and calibration databases, the Multinomial system can achieve reasonable stability in performance; for example, the standard deviation value of the log-LR cost becomes lower than 0.01 (10 random samplings of authors for the reference and calibration databases) with 60 or more authors in each database.     

犯罪压力下的警力资源不足之探讨

中国警力资源不足是客观存在的,造成中国警力资源不足最为主要的原因是犯罪压力太大,而不是警民比例"太低",警民比例"低"是受认识和计算方法的影响所至,仅用警民人数比例生搬硬套来说明警力不足既不全面也不科学,存在很多理论上的误区和漏洞.除犯罪压力影响外,经费保障不足和资源结构配置不够合理造成警力资源失衡、警察体制机制问题、警察工作倦怠以及警察大量的身心健康问题也加剧了警力资源的不足.针对警力资源不足,可采取的相应对策有进一步深化改革,推进"三基"工程建设,将工作落到实处,注重在科技强警上下功夫,给警力松绑,增加经费的投入,从制度上提供良好的后勤保障环境,从优待警,留住警察人才,以及关心警察、注重解决警察的身心健康问题等.     

经济增长、社会发展与男孩偏好:基于治理的视角

本文基于1990、2000年全国人口普查数据和1995、2005年全国1%人口抽样调查数据,采用了多层线性模型(HLM)方法,对经济增长、社会发展和男孩偏好之间的关系进行了分析。发现较高的经济增长水平和社会发展程度有助于出生人口性别比治理绩效的实现,但受到男孩偏好强弱程度的影响。论文结尾分析了研究结论对于出生人口性别比治理的政策启示,并指出了局限性和未来改进方向。     

我国国债市场的发展现状及存在的问题

近年来,我国的国债市场取得了令人瞩目的成就.但是,当前我国国债市场仍然面临着一系列问题,大力发展以国债市场为主的债券市场,发挥债券市场在金融商品的定价基准、投资组合和风险管理、有效配置社会资金资源的有效作用,已经成为各方共识.