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951.
Brandão RB Martin CC Catirse AB de Castro E Silva M Evison MP Guimarães MA 《Journal of forensic sciences》2007,52(4):913-919
The objective was to investigate color change and surface damage in dental resin composites exposed to high temperatures over different time intervals for comparative purposes. Samples were prepared using two resins - Z100(R) (R1) and Charisma (R2), heated at the following temperatures: 200 degrees C, 400 degrees C, 600 degrees C, 1000 degrees C, for 15, 30 and 45 min (n = 104 for each resin sample). Color (DeltaE) and brightness (DeltaL) changes were analyzed by spectrophotometry using the CIE Lab system and surface changes by Scanning Electron Microscopy (SEM). R1 showed more intense color changes after heat exposure than R2. DeltaL values were found to be the best parameter for evaluation of light and color change. A biphasic pattern after thermal exposure was detected, from dark brown to light white. SEM showed more intense alterations in R2 than in R1. These results indicate that the parameters observed in both resins are useful as a guide in forensic analyses. 相似文献
952.
Aiming to evaluate the effects of population substructure on the reliability of a DNA correspondence in the process of human identification, we used the model of "in silico" constructed populations with and without substructure. Effects of population substructure were evaluated at the level of locus heterozygosity, Hardy-Weinberg equilibrium and mini-haplotype distribution. Inbreeding in a subpopulation of 100 individuals through 10 generations did not significantly alter the level of heterozygosity and Hardy-Weinberg equilibrium. However, analysis of mini-haplotype distribution revealed a significant homogenization in separated subpopulations. Average observed mini-haplotype frequency (f(o)) increased to threefold from expected values (f(e)), and the number of mini-haplotypes with f(o)/f(e) above 10 increased over sixfold, suggesting that the effects of population substructure on calculated likelihood ratios (LR) might be larger than previously estimated. In most criminal cases, this would not represent a problem, whereas for identifications in large-scale mass fatality events, population substructure might considerably increase the risk of false identification. 相似文献
953.
Methods to estimate adult age from observations of skeletal elements are not very accurate and motivate the development of better methods. In this article, we test recently published method based on the acetabulum and Bayesian inference, developed using Coimbra collection (Portugal). In this study, to evaluate its utility in other populations, this methodology was applied to 394 specimens from four different documented Western European collections. Four strategies of analysis to estimate age were outlined: (a) each series separately; (b) on Lisbon collection, taken as a reference Coimbra collection; (c) on Barcelona collection, taken as a reference both Portuguese collections; and (d) on London collection taken as reference the three Iberian collections combined. Results indicate that estimates are accurate (83-100%). As might be expected, the least accurate estimates were obtained when the most distant collection was used as a reference. Observations of the fused acetabulum can be used to make accurate estimates of age for adults of any age, with less accurate estimates when a more distant reference collection is used. 相似文献
954.
Allison M. Curran Ph.D. ; Paola A. Prada B.S. ; Kenneth G. Furton Ph.D. 《Journal of forensic sciences》2010,55(1):50-57
Abstract: Human scent evidence is utilized as an investigative tool through canine scent discriminations based on the premise that human scent is an individualizing characteristic. This study describes the development of what is effectively a human scent barcode consisting of the relative ratios of an individual's "primary odor" compounds utilized to determine a reproducible and individualizing profile which can be stored in a searchable database for a proof of concept of human scent as a biometric measure. Triplicate hand odor samples were evaluated from 10 subjects utilizing solid phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS) and compared via Spearman Rank Correlations. Narrowing the compounds considered for each subject to only those common in all three samples, or a subject's "primary odor constituents," produced a greater degree of both individualization and discrimination; at both correlation thresholds of 0.9 and 0.8, the individuals were correctly discriminated and identified in 99.54% of the cases. 相似文献
955.
Abstract: This study examined the effects of heat on the amplification of DNA from the dental pulp of Sus scrofa molars and investigated the protection afforded to the pulp tissue by the dental enamel, alveolar process, and soft tissue of the head. Segments of defleshed maxilla and mandible encasing the first molar (n = 60) were subject to a range of temperatures for 15 min. Dental pulps were retrieved. Amplifications using three‐primer and four‐primer multiplexes showed no degradation of the largest fragment following exposure to 450°C. Amplifications in the three‐primer multiplex (283 bp) were successful following exposure to 525°C in maxillary samples only. This study revealed the enamel density of maxillary molars to be greater than mandibular molars in Sus scrofa. Following incineration of intact heads for 15 min (n = 10) and 1 h (n = 4) at an average temperature of 625°C, amplifications of the largest fragment (450 bp) were successful from both maxillary and mandibular teeth. 相似文献
956.
Chang Liu B.Sc. Hyun M. Park Ph.D. Maria V. Monsalve Ph.D. David D. Y. Chen Ph.D. 《Journal of forensic sciences》2010,55(4):1039-1043
Abstract: Adipocere is a postmortem decomposition product consisting of mostly a mixture of free fatty acids (FFAs) that are formed because of the hydrolysis of triglycerides in adipose tissues. This article describes a simple and robust method for the extraction, identification, and quantification of FFA commonly found in adipocere using gas chromatography–mass spectrometry (GC/MS). This method was applied to analyze tissues from Kwäday Dän Ts’ìnchí, ancient remains discovered in a retreating glacier in the Tatshenshini‐Alsek Park, British Columbia, Canada in August 1999. The lyophilized tissues were grinded and extracted with hexane. The trimethylsilyl fatty acid derivatives were analyzed by GC/MS, and the relative abundances of myristic acid, palmitic acid, oleic acid, and stearic acid were determined. Milligram per gram levels of saturated fatty acids were found in the tissues of the ancient remains, while the levels of unsaturated fatty acids, such as palmitoleic acid, were found to be negligible. The results provided further evidence of the existence of adipocere found during forensic examination of the Kwäday Dän Ts’ìnchí ancient remains. 相似文献
957.
Laurent Fanton M.D. Fabien Bévalot Pharm.D. Nathalie Cartiser Pharm.D. Cristian Palmiere M.D. Catherine Le Meur Pharm.D. Daniel Malicier Ph.D. 《Journal of forensic sciences》2010,55(3):792-794
Abstract: Postmortem human chorionic gonadotrophin (HCG) blood assay can confirm postmortem diagnosis of pregnancy or document situations in which HCG levels are elevated. In some cases, however, blood sampling is not possible at autopsy. In this study, HCG was quantified by enzyme‐linked fluorescent assay (ELFA) in the bile (n = 5), vitreous humor (n = 4), and postmortem blood (n = 4) of five pregnant women. There were no false negatives in the pregnant subjects (n = 5) or false positives in controls (n = 34), enabling this test to be recommended for routine use in forensic contexts in which the detection of elevated HCG levels could be of interest. 相似文献
958.
Hugo F. V. Cardoso Ph.D. 《Journal of forensic sciences》2010,55(6):1557-1560
Abstract: Three studies have proposed discriminant functions for sex determination from deciduous tooth crown dimensions, and this study tests the existing functions on a sample of 46 Portuguese immature skeletons of known sex, aged from birth to 10 years. Deciduous teeth were measured in their mesiodistal and faciolingual crown dimensions, and percentage of correct allocation accuracy in determining sex using each specific function was determined. Discriminant functions were also calculated from data collected for this study and tested using cross‐validation. Results show poor overall accuracy (33.3–75%) and poor cross‐validation (46.2–60.0%). This is related to low sexual dimorphism in deciduous tooth crown size, as well as differences in degree of sexual dimorphism and in overall tooth size between different samples. For these reasons, deciduous crown size does not seem to show significant forensic value as discriminator of sex, particularly when methods developed on one population are applied to individuals of another population. 相似文献
959.
Karen M. Kester Ph.D. Mary H. Toothman M.S. Bonnie L. Brown Ph.D. W. Scott Street IV Ph.D. Tracey D. Cruz Ph.D. 《Journal of forensic sciences》2010,55(6):1543-1551
Abstract: We tested the hypotheses that foraging insects can acquire human DNA from the environment and that insect‐delivered human DNA is of sufficient quantity and quality to permit standard forensic analyses. Houseflies, German cockroaches, and camel crickets were exposed to dusty surfaces and then assayed for human mitochondrial and nuclear loci by conventional and qPCR, and multiplex STR amplification. Over two experiments, 100% of insect groups and 94% of dust controls tested positive for human DNA. Of 177 individuals, 33–67% tested positive and 13 yielded quantifiable human DNA (mean = 0.022 ± 0.006 ng; mean dust control = 2.448 ± 0.960 ng); four had at least one positive allele call for one or more locus; eight others showed multiple peaks at some loci. Results imply that application to routine forensic casework is limited given current detection methodology yet demonstrate the potential use of insects as environmental samplers for human DNA. 相似文献
960.
Christopher Rodgers 《The Modern law review》2010,73(3):461-486
The Commons Act 2006 is the first statute since the Commons Registration Act 1965 to address the problems associated with the management of common land in England and Wales. A key focus for the 2006 Act is the introduction of mechanisms for the sustainable management of common land, including self‐regulatory commons councils. This article examines the ‘sustainable’ management of common land in historical and contemporary perspective. It sets the 2006 Act, and the sustainable management of common land, in the wider context of the ongoing debate triggered by Hardin's ‘Tragedy of the Commons’ and subsequent institutional and post‐institutional scholarship on common pool resource management. It uses historical and qualitative research data drawn from three case studies to demonstrate the irrelevance of Hardin's thesis in an English context, and identifies the Commons Registration Act of 1965 as the true ‘tragedy’ of the English and Welsh commons. The case studies also illustrate the challenges posed by the introduction of legal mechanisms to promote the ecologically sustainable management of the modern commons, and inform the critique of the Commons Act 2006 developed in the article. 相似文献