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201.
Carlos Martín-Alberca Héctor Carrascosa Itxaso San Román Luis Bartolomé Carmen García-Ruiz 《Science & justice》2018,58(1):7-16
Ignitable liquids such as fuels, alcohols and thinners can be used in criminal activities, for instance arsons. Forensic experts require to know their chemical compositions, as well as to understand how different modification effects could impact them, in order to detect, classify and identify them properly in fire debris. The acid alteration/acidification of ignitable liquids is a modification effect that sharply alters the chemical composition, for example, of gasoline and diesel fuel, interfering in the forensic analysis and result interpretation. However, to date there is little information about the consequences of this effect over other accelerants of interests. In this research paper, the alteration by sulfuric acid of several commercial thinners and other accelerants of potential use in arsons is studied in-depth. For that purpose, spectral (by ATR-FTIR) and chromatographic (by GC–MS) data were obtained from neat and acidified samples. Then, the spectral and chromatographic modifications of each studied ignitable liquid were discussed, proposing several chemical mechanisms that explain the new by-products produced and the gradual disappearance of the initial compounds. Hydrolysis, Fischer esterification and alkylation reactions are involved in the modification of esters, alcohols, ketones and aromatic compounds of the studied ignitable liquids. This information could be crucial for correctly identifying these accelerants. Additionally, an exploratory analysis revealed that some of the most altered ignitable liquid samples might be very similar with each other, which could have impact on casework. 相似文献
202.
Carlos J. Vilalta 《Journal of school violence》2018,17(3):392-404
Mexico, like other countries in Latin America, is currently facing significant problems with regard to juvenile antisocial behavior and crime. The current study explores some of the factors associated with school vandalism in public high schools. Multilevel modeling with survey data from 22,345 students from 249 schools, acquired over two years, was used to determine how much variation in the rates of school vandalism exists between and within schools, and to detect individual and contextual characteristics that explain significant proportions of the variance. Results demonstrated significant differences across schools in the rates of student vandalism, most of which were associated with gang involvement, drug use, bullying, no attachment to school rules, and unequal treatment of students by teachers. These results are discussed in relation to the literature on school vandalism, and implications for the prevention of school vandalism are discussed. 相似文献
203.
Marta R. P. Flores M.Sc. Carlos E. P. Machado Ph.D. Matteo D. Gallidabino Ph.D. Gustavo H. M. de Arruda Ph.D. Ricardo H. A. da Silva Ph.D. Flávio B. de Vidal Ph.D. Rodolfo F. H. Melani Ph.D. 《Journal of forensic sciences》2019,64(3):828-838
Positioning landmarks in facial photo‐anthropometry (FPA) applications remains today a highly variable procedure, as traditional cephalometric definitions are used as guidelines. Herein, a novel landmark‐positioning approach, specifically adapted for FPA applications, is introduced and, in particular, assessed against the conventional cephalometric definitions for the analysis of 16 landmarks on ten frontal images by two groups of examiners (with and without professional knowledge of anatomy). Results showed that positioning reproducibility was significantly better using the novel method. Indeed, in contrast to the classic approach, very low landmark dispersions were observed for both groups of examiners, which were usually below the strictest clinical standards (i.e., 0.575 mm). Furthermore, the comparison between the two groups of examiners highlighted higher dispersion consistencies, which supported a higher robustness. Thus, the use of an adapted landmark‐positioning approach proved to be highly advantageous in FPA analysis and future work in this field should consider adopting similar methodologies. 相似文献
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205.
Riudavets MA Colegial C Rubio A Fowler D Pardo C Troncoso JC 《The American journal of forensic medicine and pathology》2005,26(3):244-249
To determine the cause of death (as a result of neurologic or nonneurologic complications or accidents) in patients with multiple sclerosis (MS), we reviewed the autopsies of 50 subjects with MS from the Office of the Chief Medical Examiner of Maryland (OCME) between 1982 and 2004. The series included 32 females and 18 males (mean age, 45.8 years; range, 25-69 years) and the causes of death were classified into 3 categories: (A) neurologic complication directly related to MS; (B) nonneurologic complications or other medical causes; and (C) accidents, etc. Of the 50 cases, in 43 there was a history of MS, but in 7 subjects there was not, and the diagnosis was established by neuropathologic examination. In Group A, 21 (42%) cases, deaths were directly related to a neurologic complication; in Group B, 14 (28%) cases were related to the following nonneurologic and medical causes: ASCVD 9 (18%), metabolic disorder 1 (2%), pulmonary embolism 3 (6%), and bronchopneumonia 1 (2%); and in Group C, 15 (30%) cases, deaths were due to trauma, 9 (18%); intoxication, 5 (10%); and thermal injury, 1 (2%). Thus, among the 50 subjects, in 26, deaths occurred naturally; and in 24, from accidents, homicides, suicides, or undetermined causes. Pathologically, the majority of cases showed either chronic inactive (66.7%) or chronic active (15.6%) demyelinating lesions, mainly in the cerebral hemispheres. In some cases, it appears that demyelinating lesions, involving brain regions that regulate cardiorespiratory activity, could be considered as the immediate cause of death, but a large proportion appears to be due to other causes such as accidents and trauma. Thus, it seems likely that taking specific precautions could prevent some deaths in MS. 相似文献
206.
Olga Carolina Cárdenas-Gómez Carlos Hernán Sierra-Torres 《Revista de derecho y genoma humano》2004,(20):65-90
Nowadays, as a consequence of scientific advances in embryology, genetics and assisted reproduction techniques, the scientific community ask for new laws to establish new parameters to use with these recent discoveries. Discoveries that have changed the legal concept of "person". In many countries this concept is absolutely useless when facing new techniques such as cloning, stem cell research and embryo storage. That is why it is necessary to change its definition to guarantee the right to life and give a better protection to human embryos. 相似文献
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210.
In the past decade, Guangzhou (Canton), China, has produced mixed results in water pollution control: it has been successful in limiting pollution from industrial sources than from domestic ones. This article examines the case by reference to a growing body of literature in institutional analysis. The central arguments are that institutions affect the governance and management of natural resources by allocating decision-making authorities among different individuals, agencies and levels of governments, by affecting whether rules and regulations can be effectively enforced and by creating different incentive structures. These arguments help to explain the divergent governmental efforts and outcomes in the two types of water pollution control in Guangzhou. The article concludes by discussing the case's theoretical and practical implications. 相似文献