1,433 research outputs found

    Semi-Automatic Classification of Skeletal Morphology in Genetically Altered Mice Using Flat-Panel Volume Computed Tomography

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    Rapid progress in exploring the human and mouse genome has resulted in the generation of a multitude of mouse models to study gene functions in their biological context. However, effective screening methods that allow rapid noninvasive phenotyping of transgenic and knockout mice are still lacking. To identify murine models with bone alterations in vivo, we used flat-panel volume computed tomography (fpVCT) for high-resolution 3-D imaging and developed an algorithm with a computational intelligence system. First, we tested the accuracy and reliability of this approach by imaging discoidin domain receptor 2- (DDR2-) deficient mice, which display distinct skull abnormalities as shown by comparative landmark-based analysis. High-contrast fpVCT data of the skull with 200 μm isotropic resolution and 8-s scan time allowed segmentation and computation of significant shape features as well as visualization of morphological differences. The application of a trained artificial neuronal network to these datasets permitted a semi-automatic and highly accurate phenotype classification of DDR2-deficient compared to C57BL/6 wild-type mice. Even heterozygous DDR2 mice with only subtle phenotypic alterations were correctly determined by fpVCT imaging and identified as a new class. In addition, we successfully applied the algorithm to classify knockout mice lacking the DDR1 gene with no apparent skull deformities. Thus, this new method seems to be a potential tool to identify novel mouse phenotypes with skull changes from transgenic and knockout mice on the basis of random mutagenesis as well as from genetic models. However for this purpose, new neuronal networks have to be created and trained. In summary, the combination of fpVCT images with artificial neuronal networks provides a reliable, novel method for rapid, cost-effective, and noninvasive primary screening tool to detect skeletal phenotypes in mice

    A Survey on Artificial Intelligence Techniques for Biomedical Image Analysis in Skeleton-Based Forensic Human Identification

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    This paper represents the first survey on the application of AI techniques for the analysis of biomedical images with forensic human identification purposes. Human identification is of great relevance in today’s society and, in particular, in medico-legal contexts. As consequence, all technological advances that are introduced in this field can contribute to the increasing necessity for accurate and robust tools that allow for establishing and verifying human identity. We first describe the importance and applicability of forensic anthropology in many identification scenarios. Later, we present the main trends related to the application of computer vision, machine learning and soft computing techniques to the estimation of the biological profile, the identification through comparative radiography and craniofacial superimposition, traumatism and pathology analysis, as well as facial reconstruction. The potentialities and limitations of the employed approaches are described, and we conclude with a discussion about methodological issues and future research.Spanish Ministry of Science, Innovation and UniversitiesEuropean Union (EU) PGC2018-101216-B-I00Regional Government of Andalusia under grant EXAISFI P18-FR-4262Instituto de Salud Carlos IIIEuropean Union (EU) DTS18/00136European Commission H2020-MSCA-IF-2016 through the Skeleton-ID Marie Curie Individual Fellowship 746592Spanish Ministry of Science, Innovation and Universities-CDTI, Neotec program 2019 EXP-00122609/SNEO-20191236European Union (EU)Xunta de Galicia ED431G 2019/01European Union (EU) RTI2018-095894-B-I0

    Sex determination in a brazilian sample from cranial morphometric parameters

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    Orientador: Luiz Francesquini JúniorTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: A necessidade da identificação humana enraíza-se na inata natureza social do homem, zelo pelos seus direitos de propriedade e identidade, e incoercíveis anseios de diferenciar-se dos seus semelhantes. Em decorrência desses princípios e das transformações acontecidas nas organizações coletivas que ele integra, nos dias atuais, já não se discutem os alcances legais nem as repercussões sociais e midiáticas daquela. Nesse contexto, a determinação do sexo, passo-chave para a reconstrução do perfil biológico individual, constitui um dos alvos capitais dos peritos médico-legistas e odontolegistas, quando responsáveis pelo exame antropológico de ossadas incólumes ou fragmentadas. No presente estudo, foram realizadas onze medidas, quatro no plano sagital e sete no horizontal, em dois grupos de 186 crânios cada, com 101 do sexo masculino e 85 do feminino para as do plano sagital, e 100 e 86, respectivamente, para as concernentes ao horizontal, de sujeitos com idades compreendidas entre 18 e 94 anos ao momento do óbito, pertencentes ao Biobanco osteológico e tomográfico Professor Doutor Eduardo Daruge da Faculdade de Odontologia de Piracicaba da Universidade Estadual de Campinas, com os objetivos de instituir um método confiável para determinar o sexo e elaborar protótipos matemáticos, capazes de auxiliar nas ações de investigação ou identificação. Constatou-se que das medidas efetivadas (Lâmbda-Násio, Lâmbda-Rínio, Lâmbda-Espinha Nasal Anterior, Rínio-Espinha Nasal Anterior, Zigomaxilar-Zigomaxilar, Lâmbda-Forame Incisivo, Lâmbda-Zigomaxilar Direito, Lâmbda-Zigomaxilar Esquerdo, Básio-Forame Incisivo, Básio-Zigomaxilar Direito e Básio-Zigomaxilar Esquerdo), só a Lâmbda-Espinha Nasal Anterior e Rínio-Espinha Nasal Anterior, no plano sagital, e a Zigomaxilar-Zigomaxilar e Lâmbda-Forame Incisivo, no horizontal, mostraram-se significativamente dimórficas. Para cada par delas, conceberam-se dois modelos matemáticos preditivos de sexo, um de regressão logística e outro de árvore de classificação condicional, com índices de acerto de 78,5% e 77,42%, e de 68,28% e 72,04%, respectivamente. Concluiu-se que existe a possibilidade de aplicar os referidos subsídios à antropologia forense, como ferramentas coadjuvantes nos processos de investigação ou identificaçãoAbstract: The need for human identification is rooted in man's innate social nature, zeal for his property and identity rights, and unquenchable yearnings to differentiate himself from his peers. In consequence of these principles and the transformations that took place in the collective organizations that he is part of, nowadays, legal scopes neither social nor media repercussions of it are no longer discussed. In this context, sex determination, key step for the reconstruction of the individual biological profile, is one of the major goals of forensic medical and odontology experts, when they are responsible for anthropological examination of intact or fragmented skeletons. In the present study, eleven measurements were carried out, four in the sagittal plane and seven in the horizontal plane, in two groups of 186 skulls each, with 101 from males and 85 from females for those of the sagittal plane, and 100 and 86, respectively, for those concerning the horizontal, of subjects aged between 18 and 94 years at the time of death, belonging to the Osteological and Tomographic Biobank Professor Doctor Eduardo Daruge of the Piracicaba Dental School of the University of Campinas, with the aims of establishing a reliable method to determine sex and to elaborate mathematical prototypes, capable of assisting in investigation or identification actions. It was found that of the measurements performed (Lambda-Nasion, Lambda-Rhinion, Lambda-Nasospinale, Rhinion-Nasospinale, Zygomaxillare-Zygomaxillare, Lambda-Incisive Foramen, Lambda-Right Zygomaxillare, Lambda-Left Zygomaxillare, Basion-Incisive Foramen, Basion-Right Zygomaxillare and Basion-Left Zygomaxillare), only the Lambda-Nasospinale and Rhinion-Nasospinale, in the sagittal plane, and the Zygomaxillare-Zygomaxillare and Lambda-Incisive Foramen, in the horizontal plane, were significantly dimorphic. For each pair of them, two predictive mathematical models of sex were formulated, one of logistic regression and another of conditional inference trees, with accuracy rates of 78,5% and 77,42%, and of 68,28% and 72,04%, respectively. It was concluded that there is the possibility of applying the aforementioned data in forensic anthropology, as auxiliary tools in the investigation or identification processesDoutoradoAnatomiaDoutor em Biologia Buco-DentalCAPE

    Gender Determination Using Diagnostic Values of Foramen Magnum

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    Background: Foramen magnum is a big hole in the base of the skull. Its appearance can be useful in gender determination. So far, no study has been conducted in Iran that evaluates the value of foramen magnum in sex determination and calculates the cut-off points. This study aimed to evaluating of diagnostic value of the foramen magnum and to calculate the cut-off points for sex determination.Methods: In this cross sectional study 50 male and 50 female patients referring to the radiology department of Rasol Akram Hospital in Tehran were evaluated. The required information about the sagittal diameter, transverse diameter, and diameter of foramen magnum were assessed by brain CT scan. Chi-square and independent t test was used for the comparison of different shapes and diameters between the sexes. ROC curve was used to determine the optimal cut-off point for each indicator.Results: The best cut-off point to distinguish males from females along the anterior-posterior foramen magnum was calculated as 36.45 mm, at the transverse diameter of 30.4 mm. The proper cut-off points for the area of the foramen magnum were 877.477 mm2 and 870.29 mm2, based on the Teixeria formula and Routal formula respectively. Overall, the accuracy of these indicators was calculated as 85%.Conclusion: Based on the results of this study using CT scans images, the diameter of the foramen magnum and its area had a high accuracy in sex determination

    The computerization of archaeology: survey on AI techniques

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    This paper analyses the application of artificial intelligence techniques to various areas of archaeology and more specifically: a) The use of software tools as a creative stimulus for the organization of exhibitions; the use of humanoid robots and holographic displays as guides that interact and involve museum visitors; b) The analysis of methods for the classification of fragments found in archaeological excavations and for the reconstruction of ceramics, with the recomposition of the parts of text missing from historical documents and epigraphs; c) The cataloguing and study of human remains to understand the social and historical context of belonging with the demonstration of the effectiveness of the AI techniques used; d) The detection of particularly difficult terrestrial archaeological sites with the analysis of the architectures of the Artificial Neural Networks most suitable for solving the problems presented by the site; the design of a study for the exploration of marine archaeological sites, located at depths that cannot be reached by man, through the construction of a freely explorable 3D version

    The Development And Application Of A Statistical Shape Model Of The Human Craniofacial Skeleton

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    Biomechanical investigations involving the characterization of biomaterials or improvement of implant design often employ finite element (FE) analysis. However, the contemporary method of developing a FE mesh from computed tomography scans involves much manual intervention and can be a tedious process. Researchers will often focus their efforts on creating a single highly validated FE model at the expense of incorporating variability of anatomical geometry and material properties, thus limiting the applicability of their findings. The goal of this thesis was to address this issue through the use of a statistical shape model (SSM). A SSM is a probabilistic description of the variation in the shape of a given class of object. (Additional scalar data, such as an elastic constant, can also be incorporated into the model.) By discretizing a sample (i.e. training set) of unique objects of the same class using a set of corresponding nodes, the main modes of shape variation within that shape class are discovered via principal component analysis. By combining the principal components using different linear combinations, new shape instances are created, each with its own unique geometry while retaining the characteristics of its shape class. In this thesis, FE models of the human craniofacial skeleton (CFS) were first validated to establish their viability. A mesh morphing procedure was then developed to map one mesh onto the geometry of 22 other CFS models forming a training set for a SSM of the CFS. After verifying that FE results derived from morphed meshes were no different from those obtained using meshes created with contemporary methods, a SSM of the human CFS was created, and 1000 CFS FE meshes produced. It was found that these meshes accurately described the geometric variation in human population, and were used in a Monte Carlo analysis of facial fracture, finding past studies attempting to characterize the fracture probability of the zygomatic bone are overly conservative

    Masculinization of postmenopausal female crania: fact or fiction?

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    The use of the Daubert Standard in court proceedings has highlighted the need to substantiate scientific findings or claims beyond simply accepting the word of a respected expert. The concept of postmenopausal masculinization of the skull in female crania falls into this category. Dr. Walker references this concept in several articles but there is no research to support this hypothesis. This project examines the theory of postmenopausal masculinization of female crania from several perspectives, using the visual sex estimation method set forth in Standards for Data Collection from Human Skeletal Remains edited by Jane E. Buikstra and Douglas H Ubelaker, photographic seriation of these sex estimation traits, and metric measurements in conjunction with Fordisc 3.1. A sample of 395 crania from the Hamann-Todd Collection at the Cleveland Museum of Natural History was analyzed using all three of these methods to determine if there was a pattern of masculinization in the postmenopausal female sample. The average age for the onset of menopause in the United States is 50, thus there should be an increase in "masculinization" observable through more rugged sex estimation traits, a higher number of females 50 or over being found below the midpoint in photographic seriations of sex estimation traits, and an increase in Fordisc 3.1 sex identification misclassifications in females in this age category. The results of the analyses revealed that there were statistically significant differences between ancestry groups, the sexes, and in some cases, age-groups. The results of this research indicate that though there are some differences between comparison groups, there does not appear to be a cohesive pattern of masculinization in female crania at or after the average age of onset of menopause. Human variation is endless, and even in areas of the skeleton for which it has been established that there is a significant degree of sexual dimorphism, there will be individuals who do not fit neatly into a binary conception of sexual divergence. Though these individuals may be misidentified as the opposite sex using one or all of the methods utilized in this project, this falls short of being classified as a part of the menopausal process in females

    Automatic landmarking identifies new loci associated with face morphology and implicates Neanderthal introgression in human nasal shape

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    We report a genome-wide association study of facial features in >6000 Latin Americans based on automatic landmarking of 2D portraits and testing for association with inter-landmark distances. We detected significant associations (P-value <5 × 10−8) at 42 genome regions, nine of which have been previously reported. In follow-up analyses, 26 of the 33 novel regions replicate in East Asians, Europeans, or Africans, and one mouse homologous region influences craniofacial morphology in mice. The novel region in 1q32.3 shows introgression from Neanderthals and we find that the introgressed tract increases nasal height (consistent with the differentiation between Neanderthals and modern humans). Novel regions include candidate genes and genome regulatory elements previously implicated in craniofacial development, and show preferential transcription in cranial neural crest cells. The automated approach used here should simplify the collection of large study samples from across the world, facilitating a cosmopolitan characterization of the genetics of facial features

    Effective 3D Geometric Matching for Data Restoration and Its Forensic Application

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    3D geometric matching is the technique to detect the similar patterns among multiple objects. It is an important and fundamental problem and can facilitate many tasks in computer graphics and vision, including shape comparison and retrieval, data fusion, scene understanding and object recognition, and data restoration. For example, 3D scans of an object from different angles are matched and stitched together to form the complete geometry. In medical image analysis, the motion of deforming organs is modeled and predicted by matching a series of CT images. This problem is challenging and remains unsolved, especially when the similar patterns are 1) small and lack geometric saliency; 2) incomplete due to the occlusion of the scanning and damage of the data. We study the reliable matching algorithm that can tackle the above difficulties and its application in data restoration. Data restoration is the problem to restore the fragmented or damaged model to its original complete state. It is a new area and has direct applications in many scientific fields such as Forensics and Archeology. In this dissertation, we study novel effective geometric matching algorithms, including curve matching, surface matching, pairwise matching, multi-piece matching and template matching. We demonstrate its applications in an integrated digital pipeline of skull reassembly, skull completion, and facial reconstruction, which is developed to facilitate the state-of-the-art forensic skull/facial reconstruction processing pipeline in law enforcement
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