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An investigation into the accuracy and reliability of skull-photo superimposition in a South African sampleGordon, Guinevere Marianne 20 October 2011 (has links)
One of the aims of forensic sciences is to determine the identities of victims of crime. In some cases the investigators may have ideas as to the identities of the victims and in these situations, ante mortem photographs of the victims could be used and identities established through skull-photo superimposition. The aim of this study was to evaluate the accuracy of a newly developed digital photographic superimposition technique on a South African sample of cadaver photographs and skulls, from the Pretoria Bone Collection. Forty facial photographs were selected and for each photograph, 10 skulls (including the skull corresponding to the photograph) were used for superimposition. The investigator did not know which of the 10 skulls corresponded to the photograph in question. The skulls were scanned 3-dimensionally, using a Cyberware™ Model 3030 Colour-3D Scanhead scanner. Once scanned, the raw data for the skulls were ‘cleaned’ using Cysurf™ programme. The photographs were also scanned for superimposition in the 3D Studio Max programme. Superimposition in 3D Studio Max involves a morphological superimposition, whereby a skull is superimposed over the photograph and assessed for a morphological match. Superimposition using selected anatomical landmarks was also performed to assess the match. A total of 400 skull-photo superimpositions were carried out using the morphological assessment and another 400 using the anatomical landmarks. In 85% of cases the correct skull was included in the possible matches for a particular photograph using morphological assessment. However, in all of these cases, between zero and three other skulls out of 10 possibilities could also match a specific photograph. In the landmark based assessment, the correct skull was included in 80% of cases. Once again, however, between one and seven other skulls out of 10 possibilities also matched the photograph. When using the morphological and landmark assessments combined, 97.5% of correct skulls were included in the list of possibilities, but between one and seven false positives per case were found. This study indicates that skull-photo superimposition has limited use in the identification of human skeletal remains, but may be useful as an initial screening tool. Corroborative techniques should also be used in the identification process. / Thesis (PhD)--University of Pretoria, 2011. / Anatomy / unrestricted
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Cephalometric regional superimpositions -- digital vs. analog accuracy and precision : 1. the maxillaKrieger, Glenn 01 January 2014 (has links)
Introduction: The purpose of this study was to measure the displacement of defined dental structures, as a result of superimposition of cephalometric images across paired time-points by both digital and analog methods. The magnitudes of such displacements across three methods of superimposition were compared to each other and to a reference method constructed by registering superimposed cephalometric images on tantalum markers implanted in the study participants' maxillae. The defined dental structures were: 1) First molar mesial contact point; 2) First molar apical root bisection; 3) Central incisor root apex; 4) Central incisor crown incisal edge. Methods: Lateral cephalograms of 22 patients containing tantalum implants from the Mathews acquisition group were digitized, traced and superimposed using analog (implant and structural) and digital (Dolphin and QuickCeph) methods. Superimpositions were exported to Adobe Photoshop where they were scaled and displacement of defined dental landmarks measured using a Cartesian coordinate system. A random-effects, generalized linear model with Bonferroni adjustment was used to compare the different methods. Results: The structural method (p < 0.01) showed statistically significant differences versus the implant method and demonstrated the smallest 95% confidence interval range compared to Quick Ceph and Dolphin (0.45mm, 0.75mm, and 0.95mm, respectively). The four structural method landmarks demonstrated statistically significant differences versus the implant method (p
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A Practical Method to Superimpose Sella Turcica in Serial CBCT ImagesCampbell, Matthew Stephen January 2017 (has links)
Introduction: We argue, for studies of growth or treatment changes, superimposed CBCT images ought to be employed routinely. The location of 3D landmarks on curved structures, however, has been complex. In this study, a reliable method of CBCT superimposition was developed with the aid of AMIRA XImage® software. The specific focus was to develop a practical method for cranial base superimpositions at sella turcica in serial CBCT images. Subsequently, evaluations of the anterior curvature of hypophyseal fossa during growth were completed to confirm the stability. Comparisons of surface changes in the superimposed images in different regions were also made. Methods: Samples of pre- and post-orthodontic CBCT data were procured from Case Western Reserve University. Cranial base changes in 10 adolescent patients of Class I and II hypodivergent, normodivergent, and hyperdivergent malocclusions, were observed over an average interval of 2 years and 5 months. Cranial base models were superimposed using a rigid registration technique, and 3D models constructed from manual segmentation in the AMIRA software. Surface distance changes of the entire cranial base were compared to that of the anterior portion of sella turcica. Results: Mean surface distance changes for the entire cranial base and anterior sella were 0.73-1.57 ± 0.71-1.30 mm and 0.37-0.63 ± 0.29-0.43 mm, respectively. The area above a threshold of 0.5 mm was 61.02-74.11% (cranial base) and 40.70-50.94% (anterior sella) as well. Paired t-tests were applied to compare differences between the mean distance and area above the threshold for data of cranial base versus anterior sella. Both illustrated p-values less than 0.0001 and were statistically significant. Intra-rater reliability was evaluated by completing segmentation and registration three consecutive times on each CBCT volume. Mean surface differences were within 0.01 mm with the exception of one patient. In addition, all subjects exhibited less than 1.00% deviation except three patients, which deviated by 1.03%, 1.46%, and 1.64%, respectively. Conclusions: A practical method of superimposition of serial CBCT images was developed. Through production of color maps, the surface distance of the anterior portion of sella turcica was shown to change much less than the clivus and remaining cranial base structures in pre- and post-treatment scans of growing children. Lastly, the method of superimposition developed here may assist future studies of skeletal changes with accuracy. / Oral Biology
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Superimposition of Contractional Structures in Models and NatureDeng, Hongling January 2015 (has links)
Superimposition of contractional structures is widely observed in different scales in the world. Superimposed structures form due to different processes: change in strain accommodation from one type of structure to another during a single progressive shortening; successive coaxial shortening phases separated by an unconformity; superimposition of different non-coaxial shortening phases. Using results of a series of systematic analogue models and detailed field structural mapping, this thesis focuses on the geometry and kinematics of such superimposed structures that are formed by these three processes. During a single progressive folding, thrusts develop within a fold to accommodate stain variations in different regime of the fold. Limited displacement along these thrusts does not significantly modify the geometry of the fold. However, during multiple shortening phases (coaxial or non-coaxial), early formed structures are modified by the later phase ones. The later thrusts can cut and displace the pre-existing structures. The early folds are tightened or interfered by the later folding phase. Pre-existing thrusts may be reactivated either in dip direction and/or along strike during the later shortening. The pre-existing structures in turn influence development of the later structures, which results in change in structure spacing. An angular unconformity between two shortening phases clearly truncates the early phase structures and separates structures of different levels. Unlike in the post-erosional layers, in the layers below the unconformity, complicated superimposed structures are visible. This thesis shows that geometry and sequence of structures formed during one progressive shortening or multiple shortening phases strongly depend on the mode of the superimposition (coaxial, orthogonal or oblique) and the orientation of pre-existing structures.
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Computational bioinformatics on three-dimensional structures of ribosomes using multiresolutional analysisHsiao, Chiaolong 25 August 2008 (has links)
RNA is amazing. We found that without changing the backbone connectivity, RNA can maintain structural conservation in 3D via topology switches, at a single residue level. I developed a method of representing RNA structure in multiresolution, called the PBR approach (P stands for Phosphate; B stands for Base; R stands for Ribose). In this method, structural data is viewed through a series of resolutions from finest to coarsest. At a single nucleotide resolution (fine resolution), RNA is abstruse and elaborate with structural insertions/deletions, strand clips, and 3,2-switches. The compilation of structural deviations of RNA, called DevLS (Deviations of Local Structure), provides a new descriptive language of RNA structure, allowing one to systematize and investigate RNA structure.
Using PBR analysis, a total of 103 tetraloops within the crystal structures of the 23s rRNA of H. marismortui and the 70s rRNA of T. thermophilus are found and classified. Combining them, I constructed a 'tetraloop family tree', using a tree formalism, to unify and re-define the tetraloop motif and to represent relationships between tetraloops, as grouped by DevLS.
To date, structural alignment of very large RNAs remains challenge due to the large size, intricate backbone choreography, and tertiary interactions. To overcome these obstacles, I developed a concept of structural anchors along with a 'Divide and Conquer' strategy for performing superimposition of 23s rRNAs. The successful alignment and superimpositions of the 23s rRNAs of T. thermophilus and H. marismortui gives an overall RMSD of atomic positions of 1.2 Å, as utilized 73% of RNA backbone atoms (~ 2129 residues).
By using principles of inorganic chemistry along with structural alignment technique as described above, a recurrent magnesium-binding motif in large RNAs is revealed. These magnesium-binding motifs play a critical role in the framework of the ribosomal PTC by their locations, topologies, and coordination geometries. Common features of Mg2+-mc's include direct phosphate chelation of two magnesium ions in the form of Mg2+(i)-(O1P-P-O2P)-Mg2+(j), phosphate groups of adjacent RNA residues as ligands of a given Mg2+, and undulated RNA surfaces with unpaired and unstacked bases.
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Um processo fotográfico em sobreposição no espaço urbanoTedesco, Elaine Athayde Alves January 2009 (has links)
A instalação de projeções no espaço urbano é o tema desta pesquisa, que aborda um processo de criação artística realizado no período 2002-2007. Construções arquitetônicas precárias e/ou abandonadas situadas em cidades brasileiras foram fotografadas e, posteriormente, retornaram às cidades como imagens projetadas sobre paredes de outras edificações. Ao longo do texto observo e analiso o campo experimental da prática artística onde os diferentes estatutos do conceito operatório sobreposição - tal como é operado e que lugar ocupa no processo de criação - são tratados como desdobramentos do mesmo. A fotografia tem um papel fundamental na pesquisa, pois é através dela que são operadas as articulações com a arquitetura. Ao não ser entendida apenas enquanto dispositivo, nem havendo a preocupação em redefinir sua ontologia, a fotografia aqui é material de trabalho inserido em um processo de criação. A projeção de fotografias sobre as paredes das edificações escolhidas para servirem como tela produz uma fusão entre as imagens projetadas e a arquitetura, transformando ambos - diapositivo e lugar - temporariamente. Este efeito, que é provocado pela baixa luminosidade dos projetores, propõe aos observadores a experiência da percepção visual sobre o espaço físico e a duração. A sobreposição da fotografia projetada em contato com a arquitetura transforma-se em documento do trabalho, além de ser potencializada como material passível de uso em outras propostas artísticas que desenvolvo. / The subject of this research is the installation of projections in the urban environment, which addresses a process of art practice carried out from 2002-2007. Fragile and/or abandoned architectural constructions in Brazilian cities were photographed and then returned to the cities as images projected onto the walls of other buildings. The text observes and analyses the experimental field of art practice in which the different usages of the operational concept of superimposition - such as how it is brought about and its place in the creative process - are treated as developments of that process. Photography plays a key role in the research, as that is the medium through which the connections with architecture are established. While not considered merely as a device, nor concerned with redefining its ontology, photography is here the working material inserted into the creative process. The projection of photographs onto the walls of buildings chosen to act as a screen produces a fusion between the projected images and the architecture, temporarily transforming both slide and place. This effect is caused by the low illumination of the projectors and offers spectators the experience of visual perception and duration on the physical space. The superimposition of the photograph projected onto the architecture transforms it into a working document and also enables it to be used as material in the development of other art practices.
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Um processo fotográfico em sobreposição no espaço urbanoTedesco, Elaine Athayde Alves January 2009 (has links)
A instalação de projeções no espaço urbano é o tema desta pesquisa, que aborda um processo de criação artística realizado no período 2002-2007. Construções arquitetônicas precárias e/ou abandonadas situadas em cidades brasileiras foram fotografadas e, posteriormente, retornaram às cidades como imagens projetadas sobre paredes de outras edificações. Ao longo do texto observo e analiso o campo experimental da prática artística onde os diferentes estatutos do conceito operatório sobreposição - tal como é operado e que lugar ocupa no processo de criação - são tratados como desdobramentos do mesmo. A fotografia tem um papel fundamental na pesquisa, pois é através dela que são operadas as articulações com a arquitetura. Ao não ser entendida apenas enquanto dispositivo, nem havendo a preocupação em redefinir sua ontologia, a fotografia aqui é material de trabalho inserido em um processo de criação. A projeção de fotografias sobre as paredes das edificações escolhidas para servirem como tela produz uma fusão entre as imagens projetadas e a arquitetura, transformando ambos - diapositivo e lugar - temporariamente. Este efeito, que é provocado pela baixa luminosidade dos projetores, propõe aos observadores a experiência da percepção visual sobre o espaço físico e a duração. A sobreposição da fotografia projetada em contato com a arquitetura transforma-se em documento do trabalho, além de ser potencializada como material passível de uso em outras propostas artísticas que desenvolvo. / The subject of this research is the installation of projections in the urban environment, which addresses a process of art practice carried out from 2002-2007. Fragile and/or abandoned architectural constructions in Brazilian cities were photographed and then returned to the cities as images projected onto the walls of other buildings. The text observes and analyses the experimental field of art practice in which the different usages of the operational concept of superimposition - such as how it is brought about and its place in the creative process - are treated as developments of that process. Photography plays a key role in the research, as that is the medium through which the connections with architecture are established. While not considered merely as a device, nor concerned with redefining its ontology, photography is here the working material inserted into the creative process. The projection of photographs onto the walls of buildings chosen to act as a screen produces a fusion between the projected images and the architecture, temporarily transforming both slide and place. This effect is caused by the low illumination of the projectors and offers spectators the experience of visual perception and duration on the physical space. The superimposition of the photograph projected onto the architecture transforms it into a working document and also enables it to be used as material in the development of other art practices.
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Um processo fotográfico em sobreposição no espaço urbanoTedesco, Elaine Athayde Alves January 2009 (has links)
A instalação de projeções no espaço urbano é o tema desta pesquisa, que aborda um processo de criação artística realizado no período 2002-2007. Construções arquitetônicas precárias e/ou abandonadas situadas em cidades brasileiras foram fotografadas e, posteriormente, retornaram às cidades como imagens projetadas sobre paredes de outras edificações. Ao longo do texto observo e analiso o campo experimental da prática artística onde os diferentes estatutos do conceito operatório sobreposição - tal como é operado e que lugar ocupa no processo de criação - são tratados como desdobramentos do mesmo. A fotografia tem um papel fundamental na pesquisa, pois é através dela que são operadas as articulações com a arquitetura. Ao não ser entendida apenas enquanto dispositivo, nem havendo a preocupação em redefinir sua ontologia, a fotografia aqui é material de trabalho inserido em um processo de criação. A projeção de fotografias sobre as paredes das edificações escolhidas para servirem como tela produz uma fusão entre as imagens projetadas e a arquitetura, transformando ambos - diapositivo e lugar - temporariamente. Este efeito, que é provocado pela baixa luminosidade dos projetores, propõe aos observadores a experiência da percepção visual sobre o espaço físico e a duração. A sobreposição da fotografia projetada em contato com a arquitetura transforma-se em documento do trabalho, além de ser potencializada como material passível de uso em outras propostas artísticas que desenvolvo. / The subject of this research is the installation of projections in the urban environment, which addresses a process of art practice carried out from 2002-2007. Fragile and/or abandoned architectural constructions in Brazilian cities were photographed and then returned to the cities as images projected onto the walls of other buildings. The text observes and analyses the experimental field of art practice in which the different usages of the operational concept of superimposition - such as how it is brought about and its place in the creative process - are treated as developments of that process. Photography plays a key role in the research, as that is the medium through which the connections with architecture are established. While not considered merely as a device, nor concerned with redefining its ontology, photography is here the working material inserted into the creative process. The projection of photographs onto the walls of buildings chosen to act as a screen produces a fusion between the projected images and the architecture, temporarily transforming both slide and place. This effect is caused by the low illumination of the projectors and offers spectators the experience of visual perception and duration on the physical space. The superimposition of the photograph projected onto the architecture transforms it into a working document and also enables it to be used as material in the development of other art practices.
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Philosophy of the Teacher Without Contradictions : An Exploration into Indian Philosophy (Advaita Vedanta of Sankara)Jonnalagadda, Naga Satya January 2022 (has links)
As human beings, we come across situations where our reasons, experience, or guidance from adults can be contradictory. A teacher also experiences these contradictory situations in the educational setting. In such cases, what should be the teacher's philosophy is my main idea or research question of this paper. To address this question, I started my exploration with the Philosophy of the Teacher by Nigel Tubbs, which states that contradictions exist as part of the teaching process and narrates the experience of the teacher as master, servant, and/or spiritual teacher. As part of this reading, I understood that the central contradiction is how the teacher can communicate the truth to the student in an educational practice where freedom for the child is given importance. On the other hand, Sankara from Indian Advaita Vedanta Philosophy states that teaching is defect free with no contradictions in teaching Brahma Vidya (Inquiry of Brahman). This view of Sankara made me explore more of Advaita Vedanta philosophy. In this exploration process, I learned from Sankara's Dakshinamoorthy stotram that interpretation of truth or reality as Brahman and further to the question why teaching is free from contradictions, I explore Brahma Sutra Bhashyam with the aid of Ahdyasa Bhashyam (error analysis) of Sankara. Adhyasa Bhashyam employed the method of superimposition and elimination (neti-neti or negation) along with methods like questioning, illustration of examples, and story.
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Positional Accuracy of Prosthetic Treatment Plan Incorporation Into Cone-beam Computed Tomography Scans Using Surface Scan SuperimpositionJamjoom, Faris Zainalabedeen 27 October 2017 (has links)
No description available.
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