scholarly journals Which line to follow? The utility of different line-fitting methods to capture the mechanism of morphological scaling

2017 ◽  
Author(s):  
Alexander W. Shingleton
Keyword(s):  
Morphological Variation ◽  
Body Shape ◽  
Relative Size ◽  
The Body ◽  
Morphological Data ◽  
Scaling Relationships ◽  
Developmental Mechanisms ◽  
Fitting Method ◽  
Pattern Of Variation ◽  
Line Fitting

AbstractBivariate morphological scaling relationships describe how the size of two traits co-varies among adults in a population. In as much as body shape is reflected by the relative size of various traits within the body, morphological scaling relationships capture how body shape varies with size, and therefore have been used widely as descriptors of morphological variation within and among species. Despite their extensive use, there is continuing discussion over which line-fitting method should be used to describe linear morphological scaling relationships. Here I argue that the ‘best’ line-fitting method is the one that most accurately captures the proximate developmental mechanisms that generate scaling relationships. Using mathematical modeling, I show that the ‘best’ line-fitting method depends on the pattern of variation among individuals in the developmental mechanisms that regulate trait size, and the morphological variation this pattern of developmental variation produces. For Drosophila traits, this pattern of variation indicates that major axis regression is the best line-fitting method. For morphological traits in other animals, however, other line-fitting methods may be more accurate. I provide a simple web-based application for researchers to explore how different line-fitting methods perform on their own morphological data.

scholarly journals Which Line to Follow? The Utility of Different Line-Fitting Methods to Capture the Mechanism of Morphological Scaling

2019 ◽  
Vol 59 (5) ◽  
pp. 1399-1410 ◽  
Author(s):  
Alexander W Shingleton
Keyword(s):  
Body Shape ◽  
Relative Size ◽  
Major Axis ◽  
The Body ◽  
Morphological Data ◽  
Scaling Relationships ◽  
Developmental Mechanisms ◽  
Fitting Method ◽  
Pattern Of Variation ◽  
Line Fitting

Abstract Bivariate morphological scaling relationships describe how the sizes of two traits co-vary among adults in a population. In as much as body shape is reflected by the relative size of various traits within the body, morphological scaling relationships capture how body shape varies with size, and therefore have been used widely as descriptors of morphological variation within and among species. Despite their extensive use, there is continuing discussion over which line-fitting method should be used to describe linear morphological scaling relationships. Here I argue that the “best” line-fitting method is the one that most accurately captures the proximate developmental mechanisms that generate scaling relationships. Using mathematical modeling, I show that the “best” line-fitting method depends on the pattern of variation among individuals in the developmental mechanisms that regulate trait size. For Drosophila traits, this pattern of variation indicates that major axis regression is the best line-fitting method. For morphological traits in other animals, however, other line-fitting methods may be more accurate. I provide a simple web-based application for researchers to explore how different line-fitting methods perform on their own morphological data.

scholarly journals High morphological variation of vestibular system accompanies slow and infrequent locomotion in three-toed sloths

2012 ◽  
Vol 279 (1744) ◽  
pp. 3932-3939 ◽  
Author(s):  
Guillaume Billet ◽  
Lionel Hautier ◽  
Robert J. Asher ◽  
Cathrin Schwarz ◽  
Nick Crumpton ◽  
...  
Keyword(s):  
Inner Ear ◽  
Morphological Variation ◽  
Relative Size ◽  
Semicircular Canals ◽  
High Resolution Computed Tomography ◽  
Bony Labyrinth ◽  
Wide Range ◽  
Pattern Of Variation ◽  
High Level ◽  
Intraspecific Morphological Variation

The semicircular canals (SCs), part of the vestibular apparatus of the inner ear, are directly involved in the detection of angular motion of the head for maintaining balance, and exhibit adaptive patterns for locomotor behaviour. Consequently, they are generally believed to show low levels of intraspecific morphological variation, but few studies have investigated this assumption. On the basis of high-resolution computed tomography, we present here, to our knowledge, the first comprehensive study of the pattern of variation of the inner ear with a focus on Xenarthra. Our study demonstrates that extant three-toed sloths show a high level of morphological variation of the bony labyrinth of the inner ear. Especially, the variation in shape, relative size and angles of their SCs greatly differ from those of other, faster-moving taxa within Xenarthra and Placentalia in general. The unique pattern of variation in three-toed sloths suggests that a release of selection and/or constraints on their organ of balance is associated with the observed wide range of phenotypes. This release is coincident with their slow and infrequent locomotion and may be related, among other possible factors, to a reduced functional demand for a precise sensitivity to movement.

The Effect of Growth on Drag in Young Swimmers

1990 ◽  
Vol 6 (1) ◽  
pp. 18-28 ◽  
Author(s):  
Huub M. Toussaint ◽  
Michiel de Looze ◽  
Bas Van Rossem ◽  
Marijke Leijdekkers ◽  
Hans Dignum
Keyword(s):  
Body Shape ◽  
The Body ◽  
Morphological Data ◽  
Cross Sectional ◽  
Ship Building ◽  
Building Technology ◽  
Complex Process ◽  
The Mean ◽  
The Relationship ◽  
Active Drag

In this study the relationship between morphological data and active drag, as measured on the MAD system (system to measure active drag), and the effect of a 2.5-year period of growth was examined in a group of children (mean age at the start of the study, 12.9 years). During this period the children showed a mean increase in height from 1.52 to 1.69 m, and in weight from 40.0 to 54.7 kg. Also the body cross-sectional area (Ap), previously reported to relate strongly to drag in a group of adult swimmers, showed an increase in size of 16%. However, the drag did not change; the mean drag force for all subjects swimming at 1.25 m•s−1was 30.1 N (±2.37) in 1985 and 30.8 N (±4.50) in 1988. The increase in height resulted in a decrease in the Froude Number (Fr) and hence in a decrease in wave-making resistance. Furthermore, form indices derived from ship-building technology demonstrated changes that indicated a more streamlined body form. Therefore it was concluded that during growth a complex process takes place in which different factors determining drag, such as height, body shape (Cd), and Ap, change in directions, having opposite effects on drag.

scholarly journals Intelligent Measurement of Morphological Characteristics of Fish Using Improved U-Net

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1426
Author(s):  
Chuang Yu ◽  
Zhuhua Hu ◽  
Bing Han ◽  
Peng Wang ◽  
Yaochi Zhao ◽  
...  
Keyword(s):  
Relative Error ◽  
Data Augmentation ◽  
Least Squares Method ◽  
Morphological Characteristics ◽  
Training Model ◽  
The Body ◽  
Average Relative Error ◽  
Fitting Method ◽  
Intelligent Measurement ◽  
Line Fitting

In the smart mariculture, batch testing of breeding traits is a key issue in the breeding of improved fish varieties. The body length (BL), body width (BW) and body area (BA) features of fish are important indicators. They are of great significance in breeding, feeding and classification. To accurately and intelligently obtain the morphological characteristic sizes of fish in actual scenes, data augmentation is first used to greatly expand the published fish dataset, thereby ensuring the robustness of the training model. Then, an improved U-net segmentation and measurement algorithm is proposed, which uses a dilated convolution with a dilation rate 2 and a convolution to partially replace the convolution in the original U-net. This operation can enlarge the partial convolution receptive field and achieve more accurate segmentation for large targets in the scene. Finally, a line fitting method based on the least squares method is proposed, which is combined with the body shape features of fish and can accurately measure the BL and BW of inclined fish. Experimental results show that the Mean Intersection over Union (mIoU) is 97.6% and the average relative error of the area is 0.69%. Compared with the unimproved U-net, the average relative error of the area is reduced to about half. Moreover, with the improved U-net and the line fitting method, the average relative error of BL and the average relative error of BW of inclined fish decrease to 0.37% and 0.61%, respectively.

Scanning electron microscopy of freeze-fractured prescapular lymph node of caprine

1984 ◽  
Vol 42 ◽  
pp. 244-245
Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer
Keyword(s):  
Lymph Node ◽  
Lymph Nodes ◽  
Lymphatic System ◽  
Three Dimensional ◽  
Meat Products ◽  
The Body ◽  
Morphological Data ◽  
The World ◽  
Cellular Constituent ◽  
Scanning Electron

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.

Updating long-held assumptions about fat stigma: For women, body shape plays a critical role

2020 ◽  
Author(s):  
Jaimie Krems ◽  
Steven L. Neuberg
Keyword(s):  
Body Shape ◽  
Critical Role ◽  
The Body ◽  
Theoretical Assumption ◽  
Obesity Stigma ◽  
Obese Female ◽  
Three Samples ◽  
Female Bodies ◽  
Different Parts ◽  
Fat Stigma

Heavier bodies—particularly female bodies—are stigmatized. Such fat stigma is pervasive, painful to experience, and may even facilitate weight gain, thereby perpetuating the obesity-stigma cycle. Leveraging research on functionally distinct forms of fat (deposited on different parts of the body), we propose that body shape plays an important but largely underappreciated role in fat stigma, above and beyond fat amount. Across three samples varying in participant ethnicity (White and Black Americans) and nation (U.S., India), patterns of fat stigma reveal that, as hypothesized, participants differently stigmatized equally-overweight or -obese female targets as a function of target shape, sometimes even more strongly stigmatizing targets with less rather than more body mass. Such findings suggest value in updating our understanding of fat stigma to include body shape and in querying a predominating, but often implicit, theoretical assumption that people simply view all fat as bad (and more fat as worse).

Chaos in body–vortex interactions

2010 ◽  
Vol 466 (2119) ◽  
pp. 1871-1891 ◽  
Author(s):  
Johan Roenby ◽  
Hassan Aref
Keyword(s):  
Body Shape ◽  
Mass Density ◽  
Relative Equilibrium ◽  
Large Body ◽  
Point Vortex ◽  
Cylindrical Body ◽  
The Body ◽  
Body Motion ◽  
Single Vortex ◽  
Vortex Interactions

The model of body–vortex interactions, where the fluid flow is planar, ideal and unbounded, and the vortex is a point vortex, is studied. The body may have a constant circulation around it. The governing equations for the general case of a freely moving body of arbitrary shape and mass density and an arbitrary number of point vortices are presented. The case of a body and a single vortex is then investigated numerically in detail. In this paper, the body is a homogeneous, elliptical cylinder. For large body–vortex separations, the system behaves much like a vortex pair regardless of body shape. The case of a circle is integrable. As the body is made slightly elliptic, a chaotic region grows from an unstable relative equilibrium of the circle-vortex case. The case of a cylindrical body of any shape moving in fluid otherwise at rest is also integrable. A second transition to chaos arises from the limit between rocking and tumbling motion of the body known in this case. In both instances, the chaos may be detected both in the body motion and in the vortex motion. The effect of increasing body mass at a fixed body shape is to damp the chaos.

scholarly journals Tentacle Morphological Variation Coincides with Differential Expression of Toxins in Sea Anemones

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 452
Author(s):  
Lauren M. Ashwood ◽  
Michela L. Mitchell ◽  
Bruno Madio ◽  
David A. Hurwood ◽  
Glenn F. King ◽  
...  
Keyword(s):  
Differential Expression ◽  
Morphological Variation ◽  
Expression Profiles ◽  
The Body ◽  
Sea Anemones ◽  
Tissue Specific ◽  
Venom Composition ◽  
Specific Manner ◽  
Branched Structures ◽  
Morphological Variants

Phylum Cnidaria is an ancient venomous group defined by the presence of cnidae, specialised organelles that serve as venom delivery systems. The distribution of cnidae across the body plan is linked to regionalisation of venom production, with tissue-specific venom composition observed in multiple actiniarian species. In this study, we assess whether morphological variants of tentacles are associated with distinct toxin expression profiles and investigate the functional significance of specialised tentacular structures. Using five sea anemone species, we analysed differential expression of toxin-like transcripts and found that expression levels differ significantly across tentacular structures when substantial morphological variation is present. Therefore, the differential expression of toxin genes is associated with morphological variation of tentacular structures in a tissue-specific manner. Furthermore, the unique toxin profile of spherical tentacular structures in families Aliciidae and Thalassianthidae indicate that vesicles and nematospheres may function to protect branched structures that host a large number of photosynthetic symbionts. Thus, hosting zooxanthellae may account for the tentacle-specific toxin expression profiles observed in the current study. Overall, specialised tentacular structures serve unique ecological roles and, in order to fulfil their functions, they possess distinct venom cocktails.

scholarly journals Sea stars generate downforce to stay attached to surfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mark Hermes ◽  
Mitul Luhar
Keyword(s):  
Body Shape ◽  
Control Volume ◽  
Water Channel ◽  
Morphological Plasticity ◽  
The Body ◽  
Sea Star ◽  
Sea Stars ◽  
Hydrodynamic Loads ◽  
Spherical Dome ◽  
Star Models

AbstractIntertidal sea stars often function in environments with extreme hydrodynamic loads that can compromise their ability to remain attached to surfaces. While behavioral responses such as burrowing into sand or sheltering in rock crevices can help minimize hydrodynamic loads, previous work shows that sea stars also alter body shape in response to flow conditions. This morphological plasticity suggests that sea star body shape may play an important hydrodynamic role. In this study, we measured the fluid forces acting on surface-mounted sea star and spherical dome models in water channel tests. All sea star models created downforce, i.e., the fluid pushed the body towards the surface. In contrast, the spherical dome generated lift. We also used Particle Image Velocimetry (PIV) to measure the midplane flow field around the models. Control volume analyses based on the PIV data show that downforce arises because the sea star bodies serve as ramps that divert fluid away from the surface. These observations are further rationalized using force predictions and flow visualizations from numerical simulations. The discovery of downforce generation could explain why sea stars are shaped as they are: the pentaradial geometry aids attachment to surfaces in the presence of high hydrodynamic loads.

The development and validation of the body shape questionnaire

1987 ◽  
Vol 6 (4) ◽  
pp. 485-494 ◽  
Author(s):  
Peter J. Cooper ◽  
Melanie J. Taylor ◽  
Zafra Cooper ◽  
Christopher G. Fairbum
Keyword(s):  
Body Shape ◽  
The Body ◽  
Development And Validation
Sign in / Sign up

Export Citation Format

Share Document