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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The paranasal air sinuses in the human : an anatomical assessment using helical multislice computed tomography : applications to human forensic identification

Fernandes, Carmen Lee January 2018 (has links)
Introduction: Forensic pathologists may be asked to identify the race group or sex of a cranium of unknown origin. Race group refers to geographic ancestry and sex is biological sex. An analysis of the volumes and measurements of human paranasal sinuses, namely maxillary, ethmoid, sphenoid and frontal sinuses, in dried crania of different race and sex groups (European and Zulu male and female) was undertaken to search for a new improved approach of classifying crania according to race and sex. This anatomical assessment of the human paranasal sinuses identifies race and sex variations in the paranasal sinuses. Variations in paranasal sinus volumes and measurements may mean a variation in anatomical landmarks. The best combination of sinus measurements was selected to classify a cranium according to race group and sex making this research relevant to the field of forensic medicine. Objectives: To compare the paranasal sinus volumes and measurements of dried crania of European and Zulu descent with respect to race group and sex and to develop a method of classifying a cranium according to race group or sex by using dimensions of the paranasal sinuses. Methodology: Documented, cadaver derived, dried crania were obtained from the Raymond A. Dart Collection of Human Skeletons, housed at the School of Anatomical Sciences at the University of the Witwatersrand, Johannesburg, South Africa. Age, race and sex were recorded for each cranium within the collection and hence within the study sample. 26 Adult European crania; 13 male, 13 female. Age range 19-75yrs (mean 49.42yrs) and 27 Adult Zulu crania: 13 male, 14 female. Age range 16-90yrs (mean 40.16yrs) was selected for this study. An additional cranium of unknown origin was also analysed in the research. European crania were from descendants of Europe living in South Africa and Zulu crania were obtained from Zulu patients who were part of the Zulu tribe of South Africa. 53 crania with intact paranasal sinuses (106 individual sinuses for each of the maxillary, ethmoid, sphenoid and frontal sinuses) were studied. In addition, 2 sinuses from the unknown cranium were analysed. The dried crania of European and Zulu origin were assessed by helical, multislice computed tomography using 1mm coronal slices. The area for each slice was obtained by tracing the outline of each slice. A volume was calculated by the CT machine that totaled the slices for each sinus. Measurements of width, length and height were also assessed, as were other craniometrical measurements. Statistical analysis was performed for all European and Zulu male and female sinuses in respect of volumes and measurements. Further statistical analysis searched for classification patterns. In addition, forty patients' scans from the European and Zulu male and female groups in Southern Africa were also assessed. CT scans of 10 adult European males, 10 adult European females, 10 adult Zulu males and 10 adult Zulu females provided 40 pairs of maxillary, ethmoid, sphenoid and frontal sinuses for analysis. Europeans were South African persons of European descent and Zulus were from the Zulu tribe of Kwa Zulu Natal in South Africa. Results: The aim of identifying race and sex differences in this anatomical region is achieved. Significant race and sex variations were found in the European and Zulu, male and female groups when analysing the volumes and measurements of the paranasal sinuses. The very best combinations of classifiable measurements were described and are being put forward as a new tool in human forensic identification studies. The significant sex classification figure of 91.8% by combining ethmoid, sphenoid and frontal paranasal sinus measurements, is a new discovery for using a combination of the sinuses. The significant race classification figure of 95.9 % is an excellent classification figure for classification according to race. This was done using the measurements of maxillary, ethmoid and total distance across the sinuses. All this was achieved by using the measurements of the paranasal sinuses in a European and Zulu, male and female population. Conclusion: Forensic race and sex identification of crania is now possible using a combination of measurements from the paranasal sinuses. A new approach to classifying a cranium into an race or sex group is revealed by way of using a new combination of paranasal sinus measurements. This discovery is of importance to forensic medicine in the realm of identification as it provides a measurable way of assigning race or sex to a cranium within a particular region. Other studies based on other race groups may add further value. What is clear is that the paranasal sinuses are now of established value when assessing race or sex group of a unknown cranium. A new tool for forensic race and sex identification is provided to the armamentarium of the forensic pathologist and associated disciplines.
2

Quantifying the strength of evidence in forensic fingerprints

Forbes, Peter G. M. January 2014 (has links)
Part I presents a model for fingerprint matching using Bayesian alignment on unlabelled point sets. An efficient Monte Carlo algorithm is developed to calculate the marginal likelihood ratio between the hypothesis that an observed fingerprint and fingermark pair originate from the same finger and the hypothesis that they originate from different fingers. The model achieves good performance on the NIST-FBI fingerprint database of 258 matched fingerprint pairs, though the computed likelihood ratios are implausibly extreme due to oversimplification in our model. Part II moves to a more theoretical study of proper scoring rules. The chapters in this section are designed to be independent of each other. Chapter 9 uses proper scoring rules to calibrate the implausible likelihood ratios computed in Part I. Chapter 10 defines the class of compatible weighted proper scoring rules. Chapter 11 derives new results for the score matching estimator, which can quickly generate point estimates for a parametric model even when the normalization constant of the distribution is intractable. It is used to find an initial value for the iterative maximization procedure in §3.3. Appendix A describes a novel algorithm to efficiently sample from the posterior of a von Mises distribution. It is used within the fingerprint model sampling procedure described in §5.6. Appendix B includes various technical results which would otherwise disrupt the flow of the main dissertation.
3

The petrous portion of the human temporal bone: potential for forensic individuation

Wiersema, Jason Matthew 02 June 2009 (has links)
In this dissertation I evaluate the potential of the morphology of the petrous portion of the human temporal bone as seen on axial CT scans of the head as a means to generate identifications of fragmentary human skeletal remains. The specific goals are threefold: (1) To investigate variability in the shape of the petrous portion of the human temporal bone using two-dimensional morphometric analysis; (2) to evaluate the reliability of the resultant method in forensic identification; and (3) to consider the results within the framework of Bayesian theory in light of recent rulings regarding the admissibility of forensic testimony. The data used in this research were collected from axial CT images of the cranium. Two sets of images were collected for each of the 115 individuals in the sample so that Euclidean distance comparisons could be made between images of the same individual and images from different individuals. I collected two-dimensional coordinate data from 36 landmarks on each of the CT images and calculated the distances between each of the coordinate points to generate the data used in the statistical analyses. I pared down this set of measurements using two different models (referred to as the biological and PCFA models). The measurement sets of both models were then compared to one another using nearest neighbor analysis, to test their relative efficiency in matching replicate images to one another. The results of both models were highly accurate. Three incorrect nearest neighbor matches resulted from the biological model and 5 from the PCFA model. The errors appear to have been the result of variation in the axial plane between the first and second scans. The results of the nearest neighbor comparisons were then considered within the context of Bayes' Theorem by calculating likelihood ratios and posterior probabilities. The likelihood ratios and posterior probabilities were very high for both models, indicating that: 1) there is significant individual variability in the measurements of the petrous portion used in this research, and 2) this variation represents a high level of potential accuracy in the application of this method in the identification of forensic remains.
4

Kriminalistické zkoumání ručního písma / Forensic Handwriting Examination

Stehlík, Matěj January 2015 (has links)
Forensic Handwriting Examination The aim of this thesis is to introduce the Forensic handwriting examination as one of the disciplines of Forensic identification, to describe its methods and procedures, and to demonstrate them on specific examples. The aim of the practical part of the thesis is to apply the findings described in the theoretical part of the thesis to the handwriting examination carried out by the author of the thesis, to experimentally verify some of hypotheses presented in the thesis, such as the influence of various factors on the handwriting of an individual, and to examine the most frequent methods of deliberate alteration of one's handwriting. The first chapter of the thesis is focused on the definition of the term "Handwriting Examination", on a brief examination of the history of this branch of forensic science, and on the analysis of its relations to other fields of forensic science, especially to the graphology. The following chapter describes the procedure of establishing one's handwriting habits, the influence of the Czech handwriting system taught to children, and some of the internal and external factors which influence one's handwriting. The third chapter examines the major subject matters of handwriting examination, describes several specific attributes of letters,...
5

Genetic variation in Atlantic yellowfin tuna (Thunnus albacares) to assess stock structure and reproductive variance

Farnham, Tiffany Talley 17 February 2005 (has links)
The population genetic structure of Atlantic yellowfin tuna (Thunnus albacares) has received little attention despite the substantial fishing mortality of juveniles caused by purse seining around fish aggregating devices in the Gulf of Guinea targeting multi-species schools that also include similarly sized skipjack tuna (Katsuwonus pelamis) and bigeye tuna (T. obesus). We used sequence data from 355 bp of the mitochondrial control region I as well as six microsatellite loci to examine: (1) population structure, and (2) to look for evidence of reproductive variance. We analyzed two samples of adults from the Gulf of Mexico (GOM) and one sample of early juveniles (20-50 mm) from the Gulf of Guinea (GOG). We found no evidence of geographic or temporal differentiation among the samples. Accordingly, the null hypothesis of panmixia for yellowfin tuna in the Atlantic Ocean could not be rejected. A sudden expansion analysis based on mtDNA control region I sequence data of yellowfin tuna was highly significant. Time estimates for expansion were between 40,000 and 80,000 years before present. The associated high levels of homoplasy could be masking any existing population structure. Additional sampling from additional locations and across several years will be needed to test the hypothesis of panmixia. We also provide preliminary evidence of the Allendorf-Phelps effect, which may contribute to reproductive variance. This is the first evidence of this effect in any other tuna or pelagic species. Data indicates that early juveniles sharing the same mtDNA control region I haplotype were caught in the same tow and had a significant probability of halfsibship status as calculated from their haplotype and genotype at one microsatellite locus through kinship analysis. Sampling throughout the spawning season and across several years, as well as analysis with additional microsatellite loci that have a more even distribution of alleles, will be needed to more fully identify the sibling status of larvae and early juveniles caught in the same tow as well as the extent of this reproductive variance.
6

Genetic variation in Atlantic yellowfin tuna (Thunnus albacares) to assess stock structure and reproductive variance

Farnham, Tiffany Talley 17 February 2005 (has links)
The population genetic structure of Atlantic yellowfin tuna (Thunnus albacares) has received little attention despite the substantial fishing mortality of juveniles caused by purse seining around fish aggregating devices in the Gulf of Guinea targeting multi-species schools that also include similarly sized skipjack tuna (Katsuwonus pelamis) and bigeye tuna (T. obesus). We used sequence data from 355 bp of the mitochondrial control region I as well as six microsatellite loci to examine: (1) population structure, and (2) to look for evidence of reproductive variance. We analyzed two samples of adults from the Gulf of Mexico (GOM) and one sample of early juveniles (20-50 mm) from the Gulf of Guinea (GOG). We found no evidence of geographic or temporal differentiation among the samples. Accordingly, the null hypothesis of panmixia for yellowfin tuna in the Atlantic Ocean could not be rejected. A sudden expansion analysis based on mtDNA control region I sequence data of yellowfin tuna was highly significant. Time estimates for expansion were between 40,000 and 80,000 years before present. The associated high levels of homoplasy could be masking any existing population structure. Additional sampling from additional locations and across several years will be needed to test the hypothesis of panmixia. We also provide preliminary evidence of the Allendorf-Phelps effect, which may contribute to reproductive variance. This is the first evidence of this effect in any other tuna or pelagic species. Data indicates that early juveniles sharing the same mtDNA control region I haplotype were caught in the same tow and had a significant probability of halfsibship status as calculated from their haplotype and genotype at one microsatellite locus through kinship analysis. Sampling throughout the spawning season and across several years, as well as analysis with additional microsatellite loci that have a more even distribution of alleles, will be needed to more fully identify the sibling status of larvae and early juveniles caught in the same tow as well as the extent of this reproductive variance.
7

Molecular-Genetic Methods for Predicting Bio-Geographical Ancestry From Bone Specimens to Aid in Forensic Identification

Josey, Michelle 01 January 2007 (has links)
Positive identification of a deceased individual is one of the major aspects of modem forensic death investigations. Incomplete or fragmented skeletal remains pose a problem for identification because the normal methods forensic anthropologists employ for compiling a biological profile of the decedent are of no use. Ancestry is an important aspect of the biological profile that, when known, can help narrow the focus of investigations by excluding many individuals from the search scope. This thesis describes molecular genetic methods which can be used to estimate ancestry in order to aid in forensic identification when other methods fail. The Y chromosome is one aspect of the genome shown to contain markers which are associated with the geographical origins of its possessor. The laboratory aspect of this research involved taking bone samples from humerii, extracting DNA from these samples and then sequencing a number of Y-SNPs in order to predict the biogeographical origins of each sample. Performing this research demonstrated the steps involved in this type of genetic ancestral analysis. At present, anthropology can only distinguish between major population groups. However, as research continues to be performed, the discriminatory power of molecular genetic ancestral analyses such as this has the potential to be further refined so that sub-populations may be distinguished between. This could be of great value if introduced into the forensic community.
8

Využití biologických metod v kriminalistice / Use of Biological Methods in Criminology

Müllerová, Nikola January 2014 (has links)
Criminology is a science dealing with the protection of citizens and state from infringement. Criminology uses mostly biological or genetic methods for crime detection. Forensic traces which are collected by forensic experts on the scene are the key items of those methods. Forensic genetics is among the most important forensic subdisciplines. Forensic genetics uses DNA analysis for identification. The main aims of this study are description and importance of biological, anthropological and genetic methods in criminology, different ways of forensic identification, division and collection of forensic traces, characterization and course of forensic DNA analysis and DNA profiling. Key words Criminology, forensic methods, forensic identification, forensic trace, forensic biology, anthropology and genetics, information systems, forensic DNA analysis, DNA profile.

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