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Geometric morphometry

M Dadáková, V Cagáňová, J Dupej, E Hoffmannová, J Borský, J Velemínská
PURPOSE: To evaluate the facial morphology of pre-school patients with various types of orofacial cleft after neonatal cheiloplasty in pre-school aged children; and to compare facial variability and mean shape with age-corresponding healthy controls. MATERIALS AND METHODS: The sample included 40 patients with unilateral cleft lip (CL), 22 patients with unilateral cleft lip and palate (UCLP), and 10 patients with bilateral cleft lip and palate (BCLP). Patients were divided into two age categories, with a mean age of 3 years and 4...
September 2016: Journal of Cranio-maxillo-facial Surgery
Ljiljana Šašić, Jelena Ačanski, Ante Vujić, Gunilla Ståhls, Snežana Radenković, Dubravka Milić, Dragana Obreht Vidaković, Mihajla Đan
The Merodon aureus species group (Diptera: Syrphidae: Eristalinae) comprises a number of different sub-groups and species complexes. In this study we focus on resolving the taxonomic status of the entity previously identified as M. cinereus B, here identified as M. atratus species complex. We used an integrative approach based on morphological descriptions, combined with supporting characters that were obtained from molecular analyses of the mitochondrial cytochrome c oxidase I gene as well as from geometric morphometry of wing and surstylus shapes and environmental niche comparisons...
2016: PloS One
Junbin Huang, He Liu, Defeng Wang, James F Griffith, Lin Shi
OBJECTIVE: The purpose of our study is to give a relatively objective definition of talar dome and its shape approximations to sphere (SPH), cylinder (CLD) and bi-truncated cone (BTC). MATERIALS AND METHODS: The "talar dome" is well-defined with the improved Dijkstra's algorithm, considering the Euclidean distance and surface curvature. The geometric similarity between talar dome and ideal shapes, namely SPH, CLD and BTC, is quantified. 50 unilateral CT datasets from 50 subjects with no pathological morphometry of tali were included in the experiments and statistical analyses were carried out based on the approximation error...
July 18, 2016: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
Beatriz Gamarra, Mónica Nova Delgado, Alejandro Romero, Jordi Galbany, Alejandro Pérez-Pérez
Morphology has been widely used for inferring the phylogenies of numerous taxonomic groups. Recent molecular studies performed on extant non-human primates, however, have cast doubt on the reliability of cranial and postcranial characters for characterizing evolutionary affinities. Because molecular evidence is often not available for fossil specimens, detecting phylogenetic signals in anatomical features is of great relevance. Here we have analyzed molar (M1 and M2) crown shape by means of geometric morphometrics in a large sample of both extant and fossil Miocene catarrhine primates to detect the phylogenetic signal in molar morphometry...
May 2016: Journal of Human Evolution
C A Bulant, P J Blanco, T P Lima, A N Assunçã, G Liberato, J R Parga, L F R Ávila, A C Pereira, R A Feijóo, P A Lemos
This work presents a computational framework to perform a systematic and comprehensive assessment of the morphometry of coronary arteries from in-vivo medical images. The methodology embraces image segmentation, arterial vessel representation, characterization and comparison, data storage and finally analysis. Validation is performed using a sample of 48 patients. Data mining of morphometric information of several coronary arteries is presented. Results agree to medical reports in terms of basic geometric and anatomical variables...
May 11, 2016: International Journal for Numerical Methods in Biomedical Engineering
Jaeil Kim, Maria del C Valdés Hernández, Natalie A Royle, Susana Muñoz Maniega, Benjamin S Aribisala, Alan J Gow, Mark E Bastin, Ian J Deary, Joanna M Wardlaw, Jinah Park
BACKGROUND: Structural changes of the brain's third ventricle have been acknowledged as an indicative measure of the brain atrophy progression in neurodegenerative and endocrinal diseases. To investigate the ventricular enlargement in relation to the atrophy of the surrounding structures, shape analysis is a promising approach. However, there are hurdles in modeling the third ventricle shape. First, it has topological variations across individuals due to the inter-thalamic adhesion. In addition, as an interhemispheric structure, it needs to be aligned to the midsagittal plane to assess its asymmetric and regional deformation...
June 2016: Computer Methods and Programs in Biomedicine
Allison P Gremba, Seth M Weinberg, J Douglas Swarts, Margaretha L Casselbrant
OBJECTIVES: Past studies using traditional morphometric approaches have reported a handful of differences in craniofacial dimensions between individuals with and without otitis media (OM). In this study, a geometric morphometry (GM) approach was used to determine if craniofacial shape is different among children with no history of OM and a history of recurrent acute OM (RAOM) at two different ages. METHODS: Nineteen standard landmarks were identified on lateral cephalometric radiographs from 79 children (41 Control, 38 RAOM) at 4 years and 52 children (27 Control, 25 RAOM) at 6 years of age...
May 2016: International Journal of Pediatric Otorhinolaryngology
Alice Ching Ching Lau, Masakazu Asahara, Sung Yong Han, Junpei Kimura
Sexual dimorphism of the craniodental morphology of the Eurasian otter in South Korea was studied with geometric morphometrics. 29 adult skulls (15 males and 14 females) were used. Images of the dorsal and ventral view of the cranium and right lateral view of the mandible were taken and then digitized, and measurements were taken on the right side. Results showed that size difference between males and females was significant. Correlations between the size and shape variations have not been observed in this study...
July 1, 2016: Journal of Veterinary Medical Science
Tsung Fei Khang, Oi Yoon Michelle Soo, Wooi Boon Tan, Lee Hong Susan Lim
Background. Anchors are one of the important attachment appendages for monogenean parasites. Common descent and evolutionary processes have left their mark on anchor morphometry, in the form of patterns of shape and size variation useful for systematic and evolutionary studies. When combined with morphological and molecular data, analysis of anchor morphometry can potentially answer a wide range of biological questions. Materials and Methods. We used data from anchor morphometry, body size and morphology of 13 Ligophorus (Monogenea: Ancyrocephalidae) species infecting two marine mugilid (Teleostei: Mugilidae) fish hosts: Moolgarda buchanani (Bleeker) and Liza subviridis (Valenciennes) from Malaysia...
2016: PeerJ
Ruoliang Tang, Celal Gungor, Richard F Sesek, Kenneth Bo Foreman, Sean Gallagher, Gerard A Davis
PURPOSE: Variability of the human lower lumbar geometry is related to complications of disc arthroplasty surgery. Accurate morphometric descriptions are essential for the design of artificial intervertebral discs to ensure good prothesis-vertebra contact and better load distribution, and can improve spinal biomechanics. Unfortunately, current knowledge of the lower lumbar geometry is limited either in the representativeness of sample populations or the accuracy and comprehensiveness of measurements...
February 12, 2016: European Spine Journal
Zs Bräger, T Moritz, A C Tsikliras, J Gonzalvo, M Radulović, Á Staszny
Landmark-based geometric morphometric analysis revealed differences in scale shape between European sardine Sardina pilchardus and round sardinella Sardinella aurita as well as among the local populations of each species. Fish scale measurements from four different areas in the central and eastern Mediterranean Sea showed that the mean scale shape of the two species using landmark data could be differentiated with high certainty. Populations of S. aurita from the central and eastern Mediterranean Sea could be separated reliably (P < 0·001) with an average discrimination rate of 91%, whereas the average discrimination of the S...
March 2016: Journal of Fish Biology
Bridget F B Algee-Hewitt, Amber D Wheat
OBJECTIVES: The use of geometric morphometry to study cranial variation has steadily grown in appeal over the past decade in biological anthropology. Publication trends suggest that the most popular methods for three-dimensional data acquisition involve landmark-based coordinate data collection using a digitizer. Newer laser scan approaches are seeing increasing use, owing to the benefits that densely sampled data offer. While both of these methods have their utility, research that investigates their compatibility is lacking...
May 2016: American Journal of Physical Anthropology
Ambrosio Torres, Daniel R Miranda-Esquivel
We evaluated the directional asymmetry between right and left wings and quantified the intraspecific and interspecific variation of the wing shape of 601 specimens of the genus Diachlorus to determine to what extent the geometrical variation discriminates six species distributed in six protected areas of Colombia. Geometric analyses were performed, integrating Procrustes methods, principal component analyses, cluster analyses, linear and quadratic discriminant analyses, and evaluations of shape changes. In Diachlorus, left and right wings did not present significant asymmetry but a geometrical analysis was allowed for species identification and, in some cases, the origin of the specimens using the variation of wing shape; the best-assigned species was Diachlorus leticia Wilkerson & Fairchild, while the worst was Diachlorus jobbinsi Fairchild, which also had the highest intraspecific variation, while Diachlorus fuscistigma Lutz had the lowest variation...
April 2016: Neotropical Entomology
Yong-Jin Liu
The skeleton of a 2D shape is an important geometric structure in pattern analysis and computer vision. In this paper we study the skeleton of a 2D shape in a two-manifold M , based on a geodesic metric. We present a formal definition of the skeleton S(Ω) for a shape Ω in M and show several properties that make S(Ω) distinct from its Euclidean counterpart in R(2). We further prove that for a shape sequence {Ωi} that converge to a shape Ω in M, the mapping Ω→ S̅(Ω) is lower semi-continuous. A direct application of this result is that we can use a set P of sample points to approximate the boundary of a 2D shape Ω, and the Voronoi diagram of P inside Ω ⊂ M gives a good approximation to the skeleton S(Ω) ...
September 2015: IEEE Transactions on Pattern Analysis and Machine Intelligence
Moises Thiago de Souza Freitas, Claudia Maria Ríos-Velasquez, César Raimundo Lima Costa, Carlos Alberto Santiago Figueirêdo, Nádia Consuelo Aragão, Lidiane Gomes da Silva, Marcus Vinicius de Aragão Batista, Teresa Cristina Leal Balbino, Felipe Arley Costa Pessoa, Valdir de Queiroz Balbino
BACKGROUND: In South America, Lutzomyia umbratilis is the main vector of Leishmania guyanensis, one of the species involved in the transmission of American tegumentary leishmaniasis. In Brazil, L. umbratilis has been recorded in the Amazon region, and in the state of Pernambuco, Northeastern region, where an isolated population has been identified. This study assessed the phylogeographic structure and size and shape differences of the wing of three Brazilian populations. METHODS: Samples of L...
2015: Parasites & Vectors
Denise Navia, Cecília B S Ferreira, Aleuny C Reis, Manoel G C Gondim
Cryptic diversity has been confirmed for several phytophagous mites in the Eriophyoidea superfamily previously considered as presenting low host specificity. Among generalist eriophyoids is the phytoptid Retracrus johnstoni Keifer, which has been reported in 19 palm species belonging to 11 genera, causing severe damage on some of them. Surprisingly this species was recently reported on another monocot family, Heliconiaceae, infesting Heliconia plants in Costa Rica and Brazil, being the only in the tribe Mackiellini to not be associated with palm trees...
September 2015: Experimental & Applied Acarology
Chengfeng Wen, Defeng Wang, Lin Shi, Winnie C W Chu, Jack C Y Cheng, Lok Ming Lui
The analysis of the vestibular system (VS) is an important research topic in medical image analysis. VS is a sensory structure in the inner ear for the perception of spatial orientation. It is believed several diseases, such as the Adolescent Idiopathic Scoliosis (AIS), are due to the impairment of the VS function. The morphology of the VS is thus of great research significance. A major challenge is that the VS is a genus-3 surface. The high-genus topology of the VS poses great challenges to find accurate pointwise correspondences between the surfaces and whereby perform accurate shape analysis...
September 2015: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
Romina Valeria Piccinali, Ricardo Esteban Gürtler
The patterns of genetic structure in natural populations provide essential information for the improvement of pest management strategies including those targeting arthropod vectors of human diseases. We analyzed the patterns of fine-scale genetic structure in Triatoma infestans in a well-defined rural area close to Pampa del Indio, in the Argentine Arid-Humid Chaco transition, where a longitudinal study on house infestation and wing geometric morphometry is being conducted since 2007. A total of 228 insects collected in 16 domestic and peridomestic sites from two rural communities was genotyped for 10 microsatellite loci and analyzed...
August 2015: Infection, Genetics and Evolution
María Sol Gaspe, Yael Mariana Provecho, Romina Valeria Piccinali, Ricardo Esteban Gürtler
House re-invasion by native triatomines after insecticide-based control campaigns represents a major threat for Chagas disease vector control. We conducted a longitudinal intervention study in a rural section (Area III, 407 houses) of Pampa del Indio, northeastern Argentina, and used wing geometric morphometry to compare pre-spray and post-spray (re-infestant bugs) Triatoma infestans populations. The community-wide spraying with pyrethroids reduced the prevalence of house infestation by T. infestans from 31...
May 2015: Memórias do Instituto Oswaldo Cruz
Konstantinos Toutouzas, Yiannis S Chatzizisis, Maria Riga, Andreas Giannopoulos, Antonios P Antoniadis, Shengxian Tu, Yusuke Fujino, Dimitrios Mitsouras, Charalampos Doulaverakis, Ioannis Tsampoulatidis, Vassilis G Koutkias, Konstantina Bouki, Yingguang Li, Ioanna Chouvarda, Grigorios Cheimariotis, Nicos Maglaveras, Ioannis Kompatsiaris, Sunao Nakamura, Johan H C Reiber, Frank Rybicki, Haralambos Karvounis, Christodoulos Stefanadis, Dimitris Tousoulis, George D Giannoglou
BACKGROUND: Geometrically-correct 3D OCT is a new imaging modality with the potential to investigate the association of local hemodynamic microenvironment with OCT-derived high-risk features. We aimed to describe the methodology of 3D OCT and investigate the accuracy, inter- and intra-observer agreement of 3D OCT in reconstructing coronary arteries and calculating ESS, using 3D IVUS and 3D QCA as references. METHODS-RESULTS: 35 coronary artery segments derived from 30 patients were reconstructed in 3D space using 3D OCT...
June 2015: Atherosclerosis
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