scholarly journals Subspecies and sexual craniofacial size and shape variations in Japanese macaques (Macaca fuscata)

2018 ◽  
Author(s):  
Wataru Yano ◽  
Naoko Egi ◽  
Tomo Takano ◽  
Naomichi Ogihara
Keyword(s):  
Macaca Fuscata ◽  
Japanese Macaque ◽  
Three Dimensional ◽  
Principal Component ◽  
Shape Space ◽  
Size Difference ◽  
Shape Variation ◽  
Three Dimensional Model ◽  
Temporal Fossa ◽  
Size And Shape

AbstractIn order to investigate craniofacial size and three-dimensional shape variations independently in the Japanese macaque (Macaca fuscata) we used a geometric morphometries technique. A total of 55 specimens were CT scanned to generate a three-dimensional model of each cranium, and 57 landmarks were digitized to analyze the craniofacial shape variation in the Japanese macaque. The results showed that four intra-specific groups, consisting of two subspecies and the two sexes, differed in both size and shape space. In size, the cranium of the Macaca fuscata yakui (MFY) was smaller than that of Macaca fuscata fuscata (MFF) in both sexes, and female crania were smaller than male crania in both subspecies. Shape sexual dimorphisms in both subspecies were detected in the first axis of principal component analysis and were related to a relatively broad orbit, smaller neurocranium, enlarged snout, and broader temporal fossa in males. The shape differences between subspecies showed different features than those between sexes. Male subspecies shape differences were detected in the first and third axes, while those for females were in the first and second axes. Subspecies shape differences common to both sexes were a narrower orbit, relatively small neurocranium, longer snout, and postorbital constriction in MFY. Male MFY was specifically characterized by a more anterior and superior direction of snout protrusion. In contrast, female MFY showed an inferior direction of snout protrusion. Female MFY also had a taller orbit. With regard to the relationship between size and shape differences, shape sexual dimorphism for each subspecies was positively associated with size difference, but there was no such association between subspecies in either sex. Size does not seem to play an important role in subspeciation of Macaca fuscata.

Statistical Approach to Shape from Shading: Reconstruction of Three-Dimensional Face Surfaces from Single Two-Dimensional Images

1996 ◽  
Vol 8 (6) ◽  
pp. 1321-1340 ◽  
Author(s):  
Joseph J. Atick ◽  
Paul A. Griffin ◽  
A. Norman Redlich
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Practical Interest ◽  
Principal Component ◽  
Shape From Shading ◽  
Shape Space ◽  
Two Dimensional ◽  
Two Dimensional Image ◽  
Low Dimensional ◽  
Dimensional Object

The human visual system is proficient in perceiving three-dimensional shape from the shading patterns in a two-dimensional image. How it does this is not well understood and continues to be a question of fundamental and practical interest. In this paper we present a new quantitative approach to shape-from-shading that may provide some answers. We suggest that the brain, through evolution or prior experience, has discovered that objects can be classified into lower-dimensional object-classes as to their shape. Extraction of shape from shading is then equivalent to the much simpler problem of parameter estimation in a low-dimensional space. We carry out this proposal for an important class of three-dimensional (3D) objects: human heads. From an ensemble of several hundred laser-scanned 3D heads, we use principal component analysis to derive a low-dimensional parameterization of head shape space. An algorithm for solving shape-from-shading using this representation is presented. It works well even on real images where it is able to recover the 3D surface for a given person, maintaining facial detail and identity, from a single 2D image of his face. This algorithm has applications in face recognition and animation.

scholarly journals Joint modeling of cell and nuclear shape variation

2015 ◽  
Vol 26 (22) ◽  
pp. 4046-4056 ◽  
Author(s):  
Gregory R. Johnson ◽  
Taraz E. Buck ◽  
Devin P. Sullivan ◽  
Gustavo K. Rohde ◽  
Robert F. Murphy
Keyword(s):  
Cell Biology ◽  
Cell Shape ◽  
Computational Cost ◽  
Three Dimensional ◽  
Joint Modeling ◽  
Shape Space ◽  
Nuclear Shape ◽  
Shape Variation ◽  
Shape Spaces ◽  
Low Dimensional

Modeling cell shape variation is critical to our understanding of cell biology. Previous work has demonstrated the utility of nonrigid image registration methods for the construction of nonparametric nuclear shape models in which pairwise deformation distances are measured between all shapes and are embedded into a low-dimensional shape space. Using these methods, we explore the relationship between cell shape and nuclear shape. We find that these are frequently dependent on each other and use this as the motivation for the development of combined cell and nuclear shape space models, extending nonparametric cell representations to multiple-component three-dimensional cellular shapes and identifying modes of joint shape variation. We learn a first-order dynamics model to predict cell and nuclear shapes, given shapes at a previous time point. We use this to determine the effects of endogenous protein tags or drugs on the shape dynamics of cell lines and show that tagged C1QBP reduces the correlation between cell and nuclear shape. To reduce the computational cost of learning these models, we demonstrate the ability to reconstruct shape spaces using a fraction of computed pairwise distances. The open-source tools provide a powerful basis for future studies of the molecular basis of cell organization.

Head shape analysis of National Football League Players

2021 ◽  
pp. 175433712110206
Author(s):  
Gwansik Park ◽  
Lee F Gabler ◽  
Ann M Bailey ◽  
Nathan Z Dau ◽  
Chris Sherwood ◽  
...  
Keyword(s):  
Shape Analysis ◽  
National Football League ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Principal Component ◽  
Shape Variation ◽  
Head Shape ◽  
Two Factors ◽  
Football Helmets ◽  
Statistical Shape

Understanding the size and shape variations of the head is important to the design of football helmets used to mitigate the risk of head injury. Current guidelines for selecting helmets use only the circumference of the player’s head to determine an appropriate size that may not offer the best fit and protection for every player. The goal of this study was to quantify key measurements of head shape to sufficiently characterize variability among players in the National Football League (NFL), focusing on the shape variation of the cranial region. Statistical shape analysis was performed on three-dimensional head scans of 87 contemporary NFL players to identify key features of head shape variability among the players’ heads. The principal component analysis revealed two factors that explained 87% of the head shape variance: (1) height and length of the head in the sagittal plane and (2) prominent back of the head with an oval shape in the transverse plane versus prominent forehead with a round shape. Four head shape measurements (circumference, length, breadth, and height) were then defined and quantified to describe the first two principal components. This information can facilitate improvements in the design of football helmets.

scholarly journals Three-dimensional morphological variability of Recent rhynchonellide brachiopod crura

Paleobiology ◽  
10.1666/13042 ◽  
2014 ◽  
Vol 40 (4) ◽  
pp. 640-658 ◽  
Author(s):  
Holly A. Schreiber ◽  
Peter D. Roopnarine ◽  
Sandra J. Carlson
Keyword(s):  
Imaging Techniques ◽  
Morphological Variability ◽  
Three Dimensional ◽  
Principal Component ◽  
Shape Space ◽  
Ontogenetic Changes ◽  
Cross Sectional ◽  
Evolutionary Transitions ◽  
Geometric Morphometric ◽  
Computed Microtomography

Crura, the calcareous support structures of the lophophore in rhynchonellide brachiopods, have historically been used to justify higher-level rhynchonellide classification and reveal major evolutionary lineages within rhynchonellides. Seventeen crural types have been described and categorized into four groups based on variation in overall structure and cross-sectional shape, but not evaluated in a quantitative or comprehensive manner. Heterochrony has been hypothesized to play a role in the evolutionary transitions among some types, but the structural, developmental, and phylogenetic context for testing these hypotheses has not yet been established. In this study, we use three-dimensional geometric morphometric techniques to quantify morphological disparity among all six crural morphs in Recent adult rhynchonellides, with the goal of delineating more objective criteria for identifying and comparing crural morphs, ultimately to test hypotheses explaining morphological transformations in ontogeny and phylogeny. We imaged the crura of seven Recent rhynchonellide species, using X-ray computed microtomography. We used landmarks and semi-landmarks to define the dimensions and curvature of the crura and the surrounding hinge area. Procrustes-standardized landmark coordinates were analyzed using a principal component analysis to test the discreteness of the individual crural morphs and named groups of morphs, and to identify features that vary most among the crural configurations.Our results demonstrate that microCT imaging techniques provide novel ways to investigate the morphology of small features that may be otherwise impossible to quantify using more conventional imaging techniques. Although we predicted overlap among crural morphs in the 3-D shape space, the principal component analyses suggest that five of the six crural morphs differ distinctly from one another. Some but not all previously designated crural groups appear to exhibit morphological cohesion. This study establishes a quantitative morphological foundation necessary to begin an investigation of the phylogenetic significance of ontogenetic changes in crura, which will allow hypotheses of heterochrony to be tested.

scholarly journals Initial Investigations of the Cranial Size and Shape of Adult Eurasian Otters (Lutra lutra) in Great Britain

2020 ◽  
Vol 6 (10) ◽  
pp. 106
Author(s):  
Damian J. J. Farnell ◽  
Chern Khor ◽  
Wayne Nishio Ayre ◽  
Zoe Doyle ◽  
Elizabeth A. Chadwick
Keyword(s):  
Great Britain ◽  
Geographical Area ◽  
Three Dimensional ◽  
Cranial Morphology ◽  
Lutra Lutra ◽  
Shape Variation ◽  
Distance Measurements ◽  
Size And Shape ◽  
3D Surface ◽  
Shape Data

Three-dimensional (3D) surface scans were carried out in order to determine the shapes of the upper sections of (skeletal) crania of adult Eurasian otters (Lutra lutra) from Great Britain. Landmark points were placed on these shapes using a graphical user interface (GUI) and distance measurements (i.e., the length, height, and width of the crania) were found by using the landmark points. Male otters had significantly larger skulls than females (P < 0.001). Differences in size also occurred by geographical area in Great Britain (P < 0.05). Multilevel Principal Components Analysis (mPCA) indicated that sex and geographical area explained 31.1% and 9.6% of shape variation in “unscaled” shape data and that they explained 17.2% and 9.7% of variation in “scaled” data. The first mode of variation at level 1 (sex) correctly reflected size changes between males and females for “unscaled” shape data. Modes at level 2 (geographical area) also showed possible changes in size and shape. Clustering by sex and geographical area was observed in standardized component scores. Such clustering in a cranial shape by geographical area might reflect genetic differences in otter populations in Great Britain, although other potentially confounding factors (e.g., population age-structure, diet, etc.) might also drive regional differences. This work provides a successful first test of the effectiveness of 3D surface scans and multivariate methods, such as mPCA, to study the cranial morphology of otters.

A three-dimensional geometric morphometric analysis of variation in cranial size and shape in tammar wallaby (Macropus eugenii) populations

2009 ◽  
Vol 57 (5) ◽  
pp. 337 ◽  
Author(s):  
Claire Hadley ◽  
Nick Milne ◽  
Lincoln H. Schmitt
Keyword(s):  
Three Dimensional ◽  
Tammar Wallaby ◽  
Shape Variation ◽  
Isolated Populations ◽  
Geometric Morphometric ◽  
Island Populations ◽  
Macropus Eugenii ◽  
Size And Shape ◽  
Geographic Separation ◽  
Analysis Of Variation

This study uses geometric morphometric techniques to examine cranial size and shape variation in nine isolated populations of the tammar wallaby (Macropus eugenii). A set of 36 three-dimensional landmarks were digitised on 143 tammar crania from two mainland and seven island populations. While there was no evidence of island dwarfism or gigantism, cranial size increased with both increasing island size and increasing latitude. As latitude increased, the palate narrowed relative to the nasal bones, cranial flexion and nasal height increased, and the zygomatic arches spread out laterally from the cranium. Overall, the anterior nasal aperture (nares) narrowed with increasing latitude. Mean shapes were calculated for each population, and pair-wise comparisons were made; most of these were significantly different. There was a clear tendency for island populations and those with greater geographic separation to show greater shape differentiation. Thus, regional and population differences in the cranial size and shape of tammar wallabies provide examples of selection, founder effect and random genetic drift.

scholarly journals Three-dimensional geometric morphometric studies of modern human occipital variation

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245445
Author(s):  
Yameng Zhang ◽  
Lynne A. Schepartz
Keyword(s):  
Three Dimensional ◽  
Principal Component ◽  
Modern Human ◽  
Foramen Magnum ◽  
European Ancestry ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Phylogenetic Studies ◽  
Males And Females ◽  
Ct Data

Objectives To investigate three-dimensional morphological variation of the occipital bone between sexes and among populations, to determine how ancestry, sex and size account for occipital shape variation and to describe the exact forms by which the differences are expressed. Methods CT data for 214 modern crania of Asian, African and European ancestry were compared using 3D geometric morphometrics and multivariate statistics, including principal component analysis, Hotelling’s T2 test, multivariate regression, ANOVA, and MANCOVA. Results Sex differences in average occipital morphology are only observed in Europeans, with males exhibiting a pronounced inion. Significant ancestral differences are observed among all samples and are shared by males and females. Asian and African crania have smaller biasterionic breadths and flatter clivus angles compared to Europeans. Asian and European crania are similar in their nuchal and occipital plane proportions, nuchal and occipital angles, and lower inion positions compared to Africans. Centroid size significantly differs between sexes and among populations. The overall allometry, while significant, explains little of the shape variation. Larger occipital bones were associated with a more curved occipital plane, a pronounced inion, a narrower biasterionic breadth, a more flexed clivus, and a lower and relatively smaller foramen magnum. Conclusions Although significant shape differences were observed among populations, it is not recommended to use occipital morphology in sex or population estimation as both factors explained little of the observed variance. Other factors, relating to function and the environment, are suggested to be greater contributors to occipital variation. For the same reason, it is also not recommended to use the occiput in phylogenetic studies.

Egg Size and Shape Variation in Rufous Bush Chats Cercotrichas Galactotes Breeding in Date Palm Plantations: Hatching Success Increases with Egg Elongation

2018 ◽  
Vol 11 (2) ◽  
pp. 100-107 ◽  
Author(s):  
Ala-Eddine Adamou ◽  
Rabie Tabib ◽  
Mohamed Kouidri ◽  
Mohamed Laïd Ouakid ◽  
Michał Glądalski ◽  
...  
Keyword(s):  
Egg Size ◽  
Date Palm ◽  
Hatching Success ◽  
Principal Component ◽  
Laying Date ◽  
Egg Mass ◽  
Shape Variation ◽  
Size And Shape ◽  
Factor Effect ◽  
Investment In Reproduction

In oviparous taxa such as birds, clutch characteristics (e.g. egg size, egg mass and the number of eggs) can be considered as energetic investment in reproduction. In this paper, we study variation in the principal component indices of egg size and shape in Rufous Bush Chats (Cercotrichas galactotes) breeding in date palm plantations in the Al Amri Oasis, north Algeria, in 2008–2009 and 2011–2013. For descriptive and comparative purposes, we also present characteristics of egg length, breadth, volume, shape and mass. The size and shape indices as well as dimensions and masses of the eggs laid by particular females tended to be similar to one another, with most variation occurring between clutches (significant repeatabilities for all egg traits). Variation in the size of eggs was influenced by the year-laying date interaction, while variation in the shape (elongation) of eggs was marginally significantly affected by the year-laying date interaction. Year had a significant factor effect on the size of eggs. We also found that hatching success was affected by interactions between year and egg size and shape principal components, thus confirming the existence of fitness-related consequences of variation in the traits of Rufous Bush Chat eggs. Notably, we found that in some years hatching success increased with the elongation of eggs.

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