The impact of burial period on compact bone microstructure: Histological analysis of matrix loss and cell integrity in human bones exhumed from tropical soil.

Human bone histological analysis is a useful tool to assess post mortem diagenesis and to predict successful nuclear DNA typing of forensic material. This study is part of a series of studies developed by the authors intended to improve the understanding of post mortem diagenesis and to develop applications for DNA analysis of skeletal species from tropical soils, in order to optimize genetic and anthropological protocols. The aim of this study was to analyze the impact of burial period on the integrity of exhumed compact bone microstructure from tropical climate. In fragments of exhumed human femora from 39 individuals from the same cemetery (exhumed group) and 5 fresh femora from routine autopsies (control group), sections stained by hematoxylin-eosin were analyzed in order to measure bone microstructural integrity. We found that bone integrity index in exhumed group was negatively influenced by the period of burial (r = -0.37, p < 0.05) and highly significantly decreased (p < 0.0001) in comparison to control group. The period of burial and nitric acid decalcification time was positively correlated (r = 0.51; p < 0.01), leading to imply a bone petrification process during inhumation. Exhumed group showed higher level of matrix bone loss (p < 0.001), as expected, and 87% of cases analyzed were "tunneled" as described by Hackett. Bone integrity index and bone matrix tend to decrease in bones buried in tropical soil between 8-14 years of inhumation. This period is short if we consider cases in which there are preserved bones interred for longer periods in other environments. These data must be considered in cases where genetic identification of exhumed skeletons from tropical environment is required. The diagenesis in these bones and the variations of results found are discussed, clarifying some challenges for forensic laboratories, especially in DNA analysis.

Conformational Dynamics Underlies Different Functions of Human KDM7 Histone Demethylases.

The human KDM7 subfamily histone H3 Nϵ-methyl lysine demethylases PHF8 (KDM7B) and KIAA1718 (KDM7A) have different substrate selectivities and are linked to genetic diseases and cancer. We describe experimentally based computational studies revealing that flexibility of the region linking the PHD finger and JmjC domains in PHF8 and KIAA1718 regulates interdomain interactions, the nature of correlated motions, and ultimately H3 binding and demethylation site selectivity. F279S an X-linked mental retardation mutation in PHF8 is involved in correlated motions with the iron ligands and second sphere residues. The calculations reveal key roles of a flexible protein environment in productive formation of enzyme-substrate complexes and suggest targeting the flexible KDM7 linker region is of interest from a medicinal chemistry perspective.

Conformational flexibility influences structure-function relationships in nucleic acid N-methyl demethylases.

N-Methylation of DNA/RNA bases can be regulatory or damaging and is linked to diseases including cancer and genetic disorders. Bacterial AlkB and human FTO are DNA/RNA demethylases belonging to the Fe(ii) and 2-oxoglutarate oxygenase superfamily. Modelling studies reveal conformational dynamics influence structure-function relationships of AlkB and FTO, e.g. why 1-methyladenine is a better substrate for AlkB than 6-methyladenine. Simulations show that the flexibility of the double stranded DNA substrate in AlkB influences correlated motions, including between the core jelly-roll fold and an active site loop involved in substrate binding. The FTO N- and C-terminal domains move in respect to one another in a manner likely important for substrate binding. Substitutions, including clinically observed ones, influencing catalysis contribute to the network of correlated motions in AlkB and FTO. Overall, the calculations highlight the importance of the overall protein environment and its flexibility to the geometry of the reactant complexes.

Forensic science policy and the question of governmental University research quality assessment.

Forensic science policy has been the subject of a series of judicial and parliamentary enquiries in the United Kingdom in recent decades. Forensic science research has been a recurrent theme in their reports, which have included recommendations for research into the economics of forensic service provision; for the development of expertise and centres of excellence; and for research to establish the validity of the forensic sciences. These recommendations reflect similar concerns expressed internationally-particularly in the United States. In the United Kingdom, however, the Forensic Science Service recently enjoyed a near monopoly in research, and limited research funding and activity in the Universities was exacerbated by the lack of visibility of forensic science in government audits of research quality. This study used established methods in evidence-based policy and research quality evaluation to analyse the range, quantity and quality of research submitted to the two most recent audits-RAE 2008 and REF 2014. Strengths and weaknesses in the methods used are discussed, and the findings analysed in relation to wider research policy issues in forensic science. The study concludes that consolidating forensic science as a peer-science in the academy is essential in order to establish a virtuous circle that will sustain research in the discipline-and address wider policy and socio-economic questions that persistently trouble the field.

Validation of a standard forensic anthropology examination protocol by measurement of applicability and reliability on exhumed and archive samples of known biological attribution.

Forensic anthropology makes an important contribution to human identification and assessment of the causes and mechanisms of death and body disposal in criminal and civil investigations, including those related to atrocity, disaster and trafficking victim identification. The methods used are comparative, relying on assignment of questioned material to categories observed in standard reference material of known attribution. Reference collections typically originate in Europe and North America, and are not necessarily representative of contemporary global populations. Methods based on them must be validated when applied to novel populations. This study describes the validation of a standardized forensic anthropology examination protocol by application to two contemporary Brazilian skeletal samples of known attribution. One sample (n=90) was collected from exhumations following 7-35 years of burial and the second (n=30) was collected following successful investigations following routine case work. The study presents measurement of (1) the applicability of each of the methods: used and (2) the reliability with which the biographic parameters were assigned in each case. The results are discussed with reference to published assessments of methodological reliability regarding sex, age and-in particular-ancestry estimation.

A new approach for the analysis of facial growth and age estimation: Iris ratio.

The study of facial growth is explored in many fields of science, including anatomy, genetics, and forensics. In the field of forensics, it acts as a valuable tool for combating child pornography. The present research proposes a new method, based on relative measurements and fixed references of the human face-specifically considering measurements of the diameter of the iris (iris ratio)-for the analysis of facial growth in association with age in children and sub-adults. The experimental sample consisted of digital photographs of 1000 Brazilian subjects, aged between 6 and 22 years, distributed equally by sex and divided into five specific age groups (6, 10, 14, 18, and 22 year olds ± one month). The software package SAFF-2D® (Forensic Facial Analysis System, Brazilian Federal Police, Brazil) was used for positioning 11 landmarks on the images. Ten measurements were calculated and used as fixed references to evaluate the growth of the other measurements for each age group, as well the accumulated growth (6-22 years old). The Intraclass Correlation Coefficient (ICC) was applied for the evaluation of intra-examiner and inter-examiner reliability within a specific set of images. Pearson's Correlation Coefficient was used to assess the association between each measurement taken and the respective age groups. ANOVA and Post-hoc Tukey tests were used to search for statistical differences between the age groups. The outcomes indicated that facial structures grow with different timing in children and adolescents. Moreover, the growth allometry expressed in this study may be used to understand what structures have more or less proportional variation in function for the age ranges studied. The diameter of the iris was found to be the most stable measurement compared to the others and represented the best cephalometric measurement as a fixed reference for facial growth ratios (or indices). The method described shows promising potential for forensic applications, especially as part of the armamentarium against crimes involving child pornography and child abuse.

Critical issues in the historical and contemporary development of forensic anthropology in Australia: An international comparison.

The aim of this brief critical qualitative analysis is to examine the development of forensic anthropology in Australia, at a time of significant change in the discipline. It will briefly summarise its historical establishment, making comparative reference to other regions-particularly the United Kingdom and United States, and the influence of the Bali Bombings of 2002, Indian Ocean earthquake and tsunami of 2004 and Black Saturday Bushfires of 2009. The analysis goes on to consider key factors in research in forensic anthropology in the United States, and the development of standards and regulation in the US and UK. The significance of research in post-mortem diagenesis in Brazil-a country sharing aspects of climate, soil types and demography with Australia-is also considered, as well as the significance of patterns of casework encountered in Australia compared with those of other jurisdictions. While forensic anthropology as a discipline has grown remarkably in recent years, this analysis suggests that research and training tailored to the specific pattern of casework encountered in Australia is now essential to support the development of national standards in science, education, and professional regulation. The significance of the establishment of the first taphonomy research facility outside of the US-the Australian Facility for Taphonomic Experimental Research-is briefly considered with reference to what this facility may offer to the development of forensic anthropology in Australia.

Tissue Microarray Analysis Applied to Bone Diagenesis.

Taphonomic processes affecting bone post mortem are important in forensic, archaeological and palaeontological investigations. In this study, the application of tissue microarray (TMA) analysis to a sample of femoral bone specimens from 20 exhumed individuals of known period of burial and age at death is described. TMA allows multiplexing of subsamples, permitting standardized comparative analysis of adjacent sections in 3-D and of representative cross-sections of a large number of specimens. Standard hematoxylin and eosin, periodic acid-Schiff and silver methenamine, and picrosirius red staining, and CD31 and CD34 immunohistochemistry were applied to TMA sections. Osteocyte and osteocyte lacuna counts, percent bone matrix loss, and fungal spheroid element counts could be measured and collagen fibre bundles observed in all specimens. Decalcification with 7% nitric acid proceeded more rapidly than with 0.5 M EDTA and may offer better preservation of histological and cellular structure. No endothelial cells could be detected using CD31 and CD34 immunohistochemistry. Correlation between osteocytes per lacuna and age at death may reflect reported age-related responses to microdamage. Methodological limitations and caveats, and results of the TMA analysis of post mortem diagenesis in bone are discussed, and implications for DNA survival and recovery considered.

Forensic facial comparison: issues of admissibility in the development of novel analytical technique.

Much contemporary debate in forensic science concerns validity and admissibility of scientific evidence in court. In this paper, three current approaches to facial identification--image superimposition, photogrammetry, and morphological analysis--are considered with regard to criteria for scientific evidence in the United States, and England, and Wales. The aim of the paper is to assess the extent to which facial image comparison meets criteria of admissibility in these jurisdictions. The method used is a comparative evaluation of the methods of facial image comparison and their underlying premises against the range of admissibility criteria reported in court rulings and relevant judicial and scientific inquiries in the United States and the United Kingdom. While the techniques of facial image comparison are generally accepted within their practitioner communities, they are not tested, and their error rates are unknown. On that basis, the methods of facial image comparison would appear not to meet the anticipated standards. They are, nevertheless, admitted in court in the United States, and England, and Wales. This paper concludes that further research in science and law will be necessary to more definitively establish admissibility of facial image comparison evidence, as it will for other nascent and novel methods that are potentially influential in court proceedings.

An exploration of sample representativeness in anthropometric facial comparison.

Faces are assumed to be unique, but their use in court has remained problematic as no method of comparison with known error rates has been accepted by the scientific community. Rather than relying on the assumed uniqueness of facial features, previous research has been directed at estimations of face shape frequency. Here, the influence of age, sex, and ancestry on variation was investigated. Statistical shape analysis was used to examine the necessity for sub-divisions in forensic comparisons, using a large sample of facial images on which 30 anthropometric landmark points had been placed in 3D. Results showed a clear pattern of separation of the sexes in all age groups, and in different age groups in men. It was concluded that sub-division of databases by sex will be necessary in forensic comparisons. Sub-division by age may be necessary in men (although not necessarily in women), and may be necessary by ancestry.

Key parameters of face shape variation in 3D in a large sample.

Improvement of methods for evidential facial comparison for the Courts relies on the collection of large databases of facial images that permit the analysis of face shape variation and the development of statistical tools. In this paper, we present a short description and key findings of an anthropometric study of face shape variation in three-dimensions. We used Statistical Shape Analysis to investigate a large database sample (n = 1968), classified by age and gender. We found that size, shape of the bilateral features and midline contributed successively to overall variation. Face size is associated with age. Sexual dimorphism is evident in size and shape, and shows patterns that affect male and female subjects differently. We anticipate this approach will lend itself to the development of methods for analysis of variation within subject groups and the establishment of the relative uniqueness or abundance of facial measurements within them.

Dados médico-legais sobre afogamentos na região de Ribeirão Preto (SP, Brasil): um passo para a prevenção / Medico-legal data on drowning in Ribeirão Preto region (SP, brazil): a step for prevention

Este é um estudo de prevalência com a primeira descrição específica de casos de afogamento em uma área não-costeira do Brasil, em Ribeirão Preto, estado de São Paulo, uma região com padrão de vida comparável ao de países desenvolvidos, com o objetivo de estabelecer medidas preventivas para este tipo específico de trauma. Metodologia: Uma análise da documentação médico-legal de 89 casos de afogamento ocorridos entre 2001 e 2004. O padrão de mortes por afogamento foi estudado através de parâmetros como idade, sexo, características sócio-econômicas e avaliação do consumo de álcool. Resultados: um índice de 2,69 casos por 100.000 habitantes foi observado. O perfil predominante entre as vítimas de afogamento foi o do homem caucasiano em idade economicamente produtiva (15-59 anos), afogados acidentalmente em rios e represas na área rural durante o verão e o outono, sendo inviável a avaliação do consumo de álcool. Conclusão e Relevância: a observação do perfil da vítima de afogamento através dos relatórios médico-legais permitiu o desenvolvimento de um projeto piloto de sucesso na prevenção de afogamentos que pode ser expandido para outras áreas não-costeiras do Brasil, visando à redução do número de vítimas através da prevenção. As dificuldades de investigar a influência do consumo de álcool são discutidas.

This is a prevalence study with the first specific description of drowning cases ina non-coastal area of Brazil, in the locality of Ribeirão Preto, State of São Paulo—a region with standards of living comparable to those in developed countries—regarding the establishment of preventative measures for this specific kind of injury. Methodology: An analysis of the forensic documentation of 89 drowning cases occurred between 2001 and 2004. The pattern of drowning fatalities was studied in relation to parameters like age, sex, socio-economic background and evaluation of alcohol consumption. Results: rate of 2.69 cases per 100,000 habitants per year was observed. The predominant profile among drowning victims was that of the Caucasian male of economically productive age (15 to 59 years), accidentally drowned in rivers and dams in rural areas during the summer and autumn, being impossible the evaluation of alcohol consumption. Conclusion and Relevance: the observation of the victim profile through the analysis of forensic reports allowed the development of a successful pilot program of drowning prevention that can be expanded to other non-coastal areas in Brazil, regarding the reduction of the number of victims by prevention. The difficulties in alcohol consumption analysis are discussed.

Laf 1. 0: implantação de um sistema informatizado para laboratórios de antropologia forense / Laf 1. 0: establishment of a computerized system for laboratories of forensic anthropology

Desenvolvimento de um software para cadastro e recuperação de informações em Antropologia Forense baseado no protocolo desenvolvido durante o projeto “UK –Brazil Scientific Cooperation – Forensic Anthropology and Identification of Human Remains”. Metodologia: Por se tratar de um aplicativo acessado via Browser (software que permite o acesso à Internet, como o Microsoft Internet Explorer®) foi necessária a escolha de uma linguagem de programação que se enquadrasse nesse requisito juntamente com uma aplicação servidora. A linguagem escolhida foi PHP® e a aplicação servidora foi o Apache®. Para o armazenamento dos dados foi escolhido o Sistema Gerenciador de Banco de Dados MySQL®...

A Software development for registration and recovery of information on Objective: A Software development for registration and recovery of information on Forensic Anthropology, based on the protocol developed during the project “UK – Brazil Scientific Cooperation – Forensic Anthropology and Identification of Human Remains”. Methods: Considering it is a Browser accessed application (software that allows Internet access, as Microsoft Internet Explorer®), it was necessary to choose an adequate programming language to this requirement as the server application. The chosen language was PHP® and the server application was Apache®. For data storage it was chosen the Data Bank Managing System MySQL®. Forensic Anthropology, based on the protocol developed during the project “UK – Brazil ScientificCooperation – Forensic Anthropology and Identification of Human Remains”. Methods: Considering it is a Browser accessed application (software that allows Internet access, as Microsoft InternetExplorer®), it was necessary to choose an adequate programming language to this requirement as the server application. The chosen language was PHP® and the server application was Apache®. For data storage it was chosen the Data Bank Managing System MySQL®...

Heat induced changes to dental resin composites: a reference in forensic investigations?

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.

Three-dimensional computer visualization of forensic pathology data.

Despite a decade of use in US courtrooms, it is only recently that forensic computer animations have become an increasingly important form of communication in legal spheres within the United Kingdom. Aims Research at the University of Nottingham has been influential in the critical investigation of forensic computer graphics reconstruction methodologies and techniques and in raising the profile of this novel form of data visualization within the United Kingdom. The case study presented demonstrates research undertaken by Aims Research and the Department of Forensic Pathology at the University of Sheffield, which aims to apply, evaluate, and develop novel 3-dimensional computer graphics (CG) visualization and virtual reality (VR) techniques in the presentation and investigation of forensic information concerning the human body. The inclusion of such visualizations within other CG or VR environments may ultimately provide the potential for alternative exploratory directions, processes, and results within forensic pathology investigations.