Firing distance estimation through the analysis of the gunshot residue deposit pattern around the bullet entrance hole by inductively coupled plasma-mass spectrometry: an experimental study

The use of inductively coupled plasma-mass spectrometry (ICP-MS) in the study of gunshot residues (GSR) is relatively recent, and only a few studies have been published on the subject. In the present paper, this instrumental technique has been used to study the deposit pattern of the GSR around the bullet entrance hole, through the analysis of antimony (Sb), barium (Ba), and lead (Pb). The data obtained were used to establish a mathematical model for estimating the firing distance. Test shots using a 6.35-mm pistol were made against a target of cotton tissue, and the amounts of Sb, Ba, and Pb deposited in quadrangular pieces of the target, cut from 4 radial positions, were determined by ICP-MS. In these experimental conditions, it was possible to estimate the firing distance on the interval [20-80] cm. The best linear correlation between ln m and d, where m is the mass of Sb, Ba, or Pb in the samples, expressed in mug/g of target tissue, and d the firing distance, was obtained at radial distances between 3.5 cm and 4.5 cm from the entrance hole. The best regression curve which adjusted to the data was a linear multiple regression between the firing distance and the logarithm of the mass of each element: d = a + b(1)X(1) + b(2)X(2) + b(3)X(3), where X(1) = ln m (Sb), X(2) = ln m(Ba) and X(3) = ln m (Pb). The accuracy of firing distance estimation using only 1 or 2 elements was not significantly different from the one obtained with the 3 elements.     

Genetic data of 10 X-STRs in a Spanish population sample

In this work, we present population genetic data of 10 X-chromosome STRs (DXS8378, DXS9898, DXS8377, HPRTB, GATA172D05, DXS7423, DXS6809, DXS7132, DXS101 and DXS6789) obtained from sample of 145 unrelated female individuals belonging to Valencia (Spain), a region located in the east of the Iberian Peninsula. All the markers studied present high genetic diversities, similar to those previously reported in other European population samples. No deviations from Hardy-Weinberg equilibrium were observed, with the exception of DXS101 locus. Allele frequencies and parameters of forensic interest for each X-STR were calculated. High mean exclusion chance and power of discrimination values were obtained by combining these 10 X-linked markers. Population comparisons (exact test of population differentiation; pairwise genetic distances) were carried out and low genetic distances were found between our sample and those from other Spanish or European regions.     

Identification of common impurities present in the synthetic routes leading to 4-methylthioamphetamine (4-MTA). Part II: Reductive amination and nitropropene route

In this paper the by-products arising during the synthesis of 4-methylthioamphetamine (4-MTA) by LiAlH(4) reduction of 1-(4-methylthiophenyl)-2-nitropropene (nitropropene route) and reductive amination of 4-methylthiophenyl-2-propanone in the presence of NaCNBH(4) are investigated. The identification of 4-methylthio derivatives of N-(β-phenylisopropyl)benzaldimine, 4-methylthio derivative of N-(β-phenylisopropyl)benzyl methyl ketimine, 1-(4-methylthiophenyl)-N-(4-methylthiobenzyl)-2-propanamine, (RS) and (SS/RR)-N,N-di-[β-(4-methylthiophenyl)isopropyl]amine, 4-methylthiobenzyl ether and methylthiobenzoic acid methyl ester as most prominent impurities in crude 4-MTA synthesised by reductive amination of 4-methylthiophenyl-2-propanone, is reported. Methylthio derivatives of 2-methyl-3-phenylaziridine, 2-benzylaziridine, and 4-methylthio derivative of BMK oxime as route-specific markers of nitropropene route leading to 4-MTA, were also characterized. The identity of these compounds was confirmed by their independent synthesis.     

Accuracy of different dental age estimation methods on Turkish children

Tooth development is widely used to estimate age or maturation. Dental age estimation is so important for various research works. Numerous methods have been described to estimate dental age based on the dental maturation. The aims of this study were to decide the best method to estimate dental age on Turkish children by reviewing several methods and to illustrate the differences among the methods and to assist future studies. The records of Turkish children between the ages of 7 and 13 years who visited the Department of Pediatric Dentistry of the Faculty of Dentistry of the Süleyman Demirel University in Isparta, Turkey were reviewed and a total of 425 healthy children with complete records, satisfactory panoramic radiographs, similar socio-economic background and ethnic origin were included. Panoramic radiographs were examined with Nolla's, Haavikko's and Demirjian's methods. Dental age was calculated for each method, and the differences between the estimated dental age and the chronological age were compared with paired t-test and Wilcoxon signed rank test. The accuracy of three methods was obtained with ICC (intraclass correlation coefficient). An under-estimation of the dental age was observed by using Nolla's and Haavikko's methods (boys -0.53±0.95, girls -0.57±0.91, both -0.54±0.93; boys -0.60±0.80, girls -0.56±0.81, both -0.58±0.80, respectively) and an over-estimation of the dental age was observed by using Demirjian's method (boys 0.52±0.86, girls 0.75±0.90, both 0.64±0.89). Haavikko's method was more accurate in the dental age estimation compared to the other methods. All of the three methods are not completely suitable for Turkish children and establishment of the population-specific standards is essential and crucial.     

Insurgent Strategies in the Post-Cold War: The Case of the Revolutionary Armed Forces of Colombia

This article analyzes the adaptation of the Revolutionary Armed Forces of Colombia (FARC) to the post-Cold War strategic scene. In this process of change the Colombian guerrilla organization has broken away from the traditional behavior patterns of Latin American armed groups in four key ways. First, the FARC has reduced the rigidity of its ideology in order to make its political message more attractive. Second, it has made a great effort to boost its military potential. Third, it has established independent channels of funding and arms supply. Finally, the Colombian rebels have developed a very decentralized organic structure that nevertheless maintains a sufficient degree of cohesion. These innovations have made the FARC a new model of insurgency that has managed to corner the Bogota government and destabilize a significant part of the Andean region.     

Turkish Popular Presidential Elections: Deepening Legitimacy Issues and Looming Regime Change

This paper examines the politics of presidential elections in Turkey with particular reference to the 10 August 2014 presidential elections. It starts by scrutinising the change in the presidential election system from parliamentary to direct popular vote. It then probes the implementation of the new election rules, candidate selection, and the conduct of the campaign, followed by analysis of the election results and their influence on the Turkish record of democratisation. The paper concludes that the move to a partisan president elected by popular vote entails democratic dangers if the new incumbent does not abide by his or her constitutional role and attempts to intervene in government policy.     

Defecting alone or splitting together? Individual and collective party switching by legislators

Public Choice - While the nature of party switching is expected to have significant consequences for democratic representation, the current literature has not explored sufficiently the different...     

社会背景下青少年对沟通渠道的选择

用来支持和维系现有社会关系的在线交流越来越多地融入到人们的日常生活中。文章研究调查了与偏爱当面交流、电话通讯和在线交流相关的因素。对强调关系来源、关系亲密程度和沟通内容会影响青少年选择何种沟通渠道的背景框架进行了实证检验。