Characterization and differentiation of aluminum powders used in improvised explosive devices – Part 1: Proof of concept of the utility of particle micromorphometry

Aluminum (Al) powders are commonly used in improvised explosive devices as metallic fuels, a component of explosive mixtures. These powders can be obtained readily from industrial‐scale and consumer products, and produced using unsophisticated “kitchen chemistry” techniques. This research demonstrates the potential of automated particle micromorphometry for comparisons between known source and questioned Al powders recovered from IEDs, as well as for insight into the method of Al powder manufacture. Al powder samples were obtained from legitimate manufacturers, and 56 samples were produced “in‐house” from Al‐containing spray paints and ball‐milled Al foils. Transmitted light microscope images of Al powder particles were acquired using an automated stage with automated z‐focus; 17 size and shape parameters were measured for all particles. Approximately 37,000–2,500,000 particles/sample were analyzed using an open‐source statistical package with customized code. Dimensionality reduction was required for processing the large datasets: eight of the 17 measured variables were selected based on inspection of the correlation matrix. Data from four subsamples from each of the 56 samples produced using “in‐house” methods were analyzed using ANOVA to assess the within‐ and between‐sample variation. High within‐sample variation was noted; however, ANOVA and post‐hoc Tukey's honestly significant difference (HSD) tests demonstrated that the between‐sample variation was substantially larger than the within‐sample variation. Each sample could be differentiated from all other samples in the test set. Future experiments will focus on ways to reduce the within‐sample variation, and additional statistical and microanalytical methods to classify sources and confidently constrain the method of Al powder manufacture.     

Firearm examination: Examiner judgments and computer‐based comparisons

Forensic firearm examination provides the court of law with information about the source of fired cartridge cases. We assessed the validity of source decisions of a computer‐based method and of 73 firearm examiners who compared breechface and firing pin impressions of 48 comparison sets. We also compared the computer‐based method's comparison scores with the examiners' degree‐of‐support judgments and assessed the validity of the latter. The true‐positive rate (sensitivity) and true‐negative rate (specificity) of the computer‐based method (for the comparison of both the breechface and firing pin impressions) were 94.4% and at least 91.7%, respectively. For the examiners, the true‐positive rate was at least 95.3% and the true‐negative rate was at least 86.2%. The validity of the source decisions improved when the evaluations of breechface and firing pin impressions were combined and for the examiners also when the perceived difficulty of the comparison decreased. The examiners were reluctant to provide source decisions for "difficult" comparisons even though their source decisions were mostly correct. The correlation between the computer‐based method's comparison scores and the examiners' degree‐of‐support judgments was low for the same‐source comparisons to negligible for the different‐source comparisons. Combining the outcomes of computer‐based methods with the judgments of examiners could increase the validity of firearm examinations. The examiners' numerical degree‐of‐support judgments for their source decisions were not well‐calibrated and showed clear signs of overconfidence. We suggest studying the merits of performance feedback to calibrate these judgments.     

Bruise dating using deep learning

The bruise dating can have important medicolegal implications in family violence and violence against women cases. However, studies show that the medical specialist has 50% accuracy in classifying a bruise by age, mainly due to the variability of the images and the color of the bruise. This research proposes a model, based on deep convolutional neural networks, for bruise dating using only images, by age ranges, ranging from 0–2 days to 17–30 days, and images of healthy skin. A 2140 experimental bruise photograph dataset was constructed, for which a data capture protocol and a preprocessing procedure are proposed. Similarly, 20 classification models were trained with the Inception V3, Resnet50, MobileNet, and MnasNet architectures, where combinations of learning transfer, cross‐validation, and data augmentation were used. Numerical experiments show that classification models based on MnasNet have better results, reaching 97.00% precision and sensitivity, and 99.50% specificity, exceeding 40% precision reported in the literature. Also, it was observed that the precision of the model decreases with the age of the bruise.     

Reviews

John N. Hazard, Managing Change in the USSR: The Political‐Legal Role of the Soviet Jurist, Cambridge: CUP, 1983, ix + 182 pp. £17.50.

Martin McCauley (ed.). The Soviet Union after Brezhnev, London: Heinemann, 1983 and New York: Holmes and Meier, 1983, xii + 160 pp. hardback £14.50, paperback £5.50.

Jonathan Haslam, Soviet Foreign Policy 1930–33: The Impact of the Depression, London: Macmillan, 1983, xii + 172 pp. £25.00.

Gavriel D. Ra'anan, International Policy Formation in the USSR: Factional ‘Debates’ during the Zhdanovshchina, foreword by Robert Conquest. Hamden, Connecticut: Archon Books, 1983. Distributed by Leicester UP, xi + 248 pp. £20.00.

Ivan Szelenyi, Urban Inequalities under State Socialism, Oxford: OUP, 1983, x + 158 pp. hardback £15.00, paperback £5.95.

Arvo Tuominen, The Bells of the Kremlin: An Experience in Communism, Hanover and London: University Press of New England, 1983, xvi + 333 pp. $27.00.

Gregory Guroff and Fred V. Carstensen (eds.), Entrepreneur ship in Imperial Russia and the Soviet Union, Princeton, New Jersey: Princeton University Press, 1983, 372 pp. hardback £34.50, paperback £11.30.

Robert C. Horn, Soviet‐Indian Relations: Issues and Influence, New York, Praeger, 1982, xviii+231 pp. hardback $24.95, paperback $8.95.

Stephen R. Sacks, Self‐Management and Efficiency: Large Corporations in Yugoslavia, London: George Allen & Unwin, 1983, xi + 163 pp. £15.00.

C. K. Chase‐Dunn (ed.), Socialist States in the World System. Beverly Hills, Calif.: Sage Publications, 1982, 304 pp. hardback $28.00, paperback $14.00.

David Kideckel (ed.), Political Rituals and Symbolism in Socialist Eastern Europe. Special issue of Anthropological Quarterly, April 1983, vol. 56, no. 2, pp. 52–104. Anthropological Quarterly, 620 Michigan Avenue N.E., Washington D.C. 20064. $5.00.     

Prototypicality analysis of the Comprehensive Assessment of Psychopathic Personality (CAPP): A cross-cultural perspective

The Comprehensive Assessment of Psychopathic Personality (CAPP) model is a new lexically based concept of psychopathy that has potential clinical utility. The main purpose of this research is to investigate the generalizability of the CAPP conceptual model in South Korea. In the current study, 88 experts and 1727 laypeople in South Korea were asked to evaluate the prototypicality of the symptoms of psychopathy (CAPP items) by using a Korean translation of the CAPP model (K-CAPP). In addition, 11 international prototypicality studies were systematically compared to the ratings by experts in the present study. As a result, it indicated that Korean experts and laypeople, on average, rated K-CAPP symptoms as moderately to highly prototypical of psychopathy, and more prototypical of psychopathy than symptoms theoretically unrelated to psychopathy (foils). Also, prototypicality ratings of K-CAPP symptoms made by those two groups were similar to each other as well as to ratings by experts and laypeople using the CAPP in other 11 countries. In conclusion, these results clearly show that both experts and laypeople in the current study conceptualized PPD in almost the same way as experts and laypeople from previous studies using the CAPP model.     

Fatal non-accidental pediatric cranial fracture risk and three-layered cranial architecture development

This study examines the influence of three-layered cranial architecture development upon blunt force trauma (BFT) cranial outcomes associated with pediatric non-accidental injury (NAI). Macroscopic and microscopic metric and morphological comparisons of subadult crania ranging from perinatal to 17 years of age chronicle the ontogenetic development and spatial and temporal variability in the emergence of a mature cranial architecture. Cranial vault thickness increases with subadult age, accelerating in the first 2 years of life due to rapid brain growth during this period. Three-layer differentiation of the cranial tables and diploë initiates by 3–6 months but is not consistently observed until 18 months to 2 years; diploë formation is not well developed until after age 4 and does not manifest a mature appearance until after age 8. These results allow topographic documentation of cortical and diploic development and temporal and spatial variability across the growing cranium. The lateral cranial vault is identified as expressing delayed development and reduced expression of the three-layer architecture, a pattern that continues into adulthood. Comparison of fracture locations from known BFT pediatric cases with identified cranial fracture high-risk impact regions shows a concordance and suggests the presence of a higher fracture risk associated with non-accidental BFT in the lateral vault region in subadults below the age of 2. The absence or lesser development of a three-layered architecture in subadults leaves their cranial bones, particularly in the lateral vault, thin and vulnerable to the effects of BFT.     

Colonization of diatoms in and on porcine bone substrate and considerations of diatom ecology for forensic science

The presence of diatom algae in bone marrow has been used as forensic evidence of drowning for several decades; however, these studies are based on known or suspected recent drowning events. This study addresses the potential for diatoms to enter the bone marrow of skeletal remains, that is, de-fleshed long bones post-mortem. In laboratory and field experiments, bones were either inflicted with two access points by a cut and acid pitting or left intact. The bones were submerged in water for at least 1 week and up to 3 months. Samples of the bone surface and marrow were inspected for diatoms. The analysis considered the time required for diatoms to enter marrow and whether genus characteristics like size or mobility affect entry. The presence of an access point influenced diatom entry in that bones without an introduced access point had zero to one diatom present in the marrow, whereas a bone with an access point had >150 diatoms present in the marrow. The results of both laboratory and field phases suggest that diatoms will reliably colonize bone in as quickly as 1 week, establishing and maintaining communities for at least 3 months. However, the bone surface assemblages differ from the source community. Bone marrow displayed even more restrictive access to diatom colonization, resulting in communities dominated by small raphid diatoms. Based on these findings, we suggest some caveats on the use of diatoms as trace evidence in forensic science with recommendations for future avenues of research.     

“同舟共济”与适应性变革:经济增长、权力转移及中美关系

由于经济增长的差异,新兴市场日益崛起,亚太地区日益崛起,其中中国崛起尤为瞩目。纵观权力转移历史、理论与现实,中国积极寻求融入当前美国主导的国际制度安排,在战略上是正确的,中国成为这一制度的得利较多者,也是满意者和维护者。因此综合长期战略和当前金融危机冲击下的策略,除了积极推动美国对当前制度进行适应性变革外,对于美国目前的困境,中国应该量力积极帮助,共同促进全球经济早日复苏和全球善治,与美国"同舟共济"符合中国战略利益,中国需要战略规划;同时,需要面向未来,准备好美国经济复苏后的策略变化。美国凭其发达的金融业在全球财富再分配中占领制高点,金融业的发展意味着可以在财富的再分配中获得竞争优势,因此中国需要大力发展现代金融业。     

Piling On: Multilevel Government and the Fiscal Common‐Pool

This article discusses the common‐pool problems that arise when multiple territorially overlapping governments share the authority to provide services and levy taxes in a common geographic area. Contrary to the traditional Tiebout model in which increasing the number of competing governments improves efficiency, I argue that increasing the number of overlapping governments results in “overfishing” from the shared tax base. I test the model empirically using data from U.S. counties and find a strong positive relationship between the number of overlapping jurisdictions and the size of the local public sector. Substantively, the “overlap effect” amounts to roughly 10% of local revenue.