The heterodonty of Albertosaurus sarcophagus and Tyrannosaurus rex: biomechanical implications inferred through 3-D modelsThis article is one of a series of papers published in this Special Issue on the theme Albertosaurus.

2010 ◽  
Vol 47 (9) ◽  
pp. 1253-1261 ◽  
Author(s):  
Miriam Reichel
Keyword(s):  
Stress Distribution ◽  
Yield Criterion ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Distribution Patterns ◽  
Shear Stresses ◽  
Form And Function ◽  
Southern Alberta ◽  
Tooth Form ◽  
And Function

The objective of this study is to analyze how different crown morphologies and different root lengths respond to stresses generated by the bite forces of Albertosaurus sarcophagus and Tyrannosaurus rex . Six well-preserved teeth of A. sarcophagus from the Albertosaurus bonebed in Dry Island Park (southern Alberta) were selected to study their biomechanics, and T. rex teeth were included for comparison. The three-dimensional (3-D) models were obtained through computerized tomography (CT) scanning and 3-D digitizing. Finite element analyses were performed in Strand7®. Bite forces for Albertosaurus and Tyrannosaurus were calculated based on cranial and jaw proportions. The results were viewed with the Tresca yield criterion. The ratios of shear stresses observed along the mesio-distal versus labio-lingual axes of all models allows the identification of similar stress distribution patterns in the upper and lower jaws of Albertosaurus and the upper jaws of Tyrannosaurus, with a higher amount of shear along the mesio-distal axis occurring in the mid-maxillary teeth. The dentary teeth of Tyrannosaurus, however, show a different stress distribution pattern, with a higher amount of shear occurring along the labio-lingual axis of the mid-dentary teeth. These differences in jaw mechanics suggest that the function of teeth in the lower jaw of Tyrannosaurus shifted a few positions to compensate different proportions in the dentary that cause the anterior dentary teeth to be aligned with the largest maxillary teeth in Tyrannosaurus. These results suggest that heterodonty in these groups is different and that tooth form and function are sensitive to jaw proportions.

scholarly journals Weighing trees with lasers: advances, challenges and opportunities

2018 ◽  
Vol 8 (2) ◽  
pp. 20170048 ◽  
Author(s):  
M. I. Disney ◽  
M. Boni Vicari ◽  
A. Burt ◽  
K. Calders ◽  
S. L. Lewis ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Three Dimensional ◽  
Point Clouds ◽  
3D Models ◽  
Tree Form ◽  
Form And Function ◽  
Challenges And Opportunities ◽  
And Function ◽  
Non Destructive

Terrestrial laser scanning (TLS) is providing exciting new ways to quantify tree and forest structure, particularly above-ground biomass (AGB). We show how TLS can address some of the key uncertainties and limitations of current approaches to estimating AGB based on empirical allometric scaling equations (ASEs) that underpin all large-scale estimates of AGB. TLS provides extremely detailed non-destructive measurements of tree form independent of tree size and shape. We show examples of three-dimensional (3D) TLS measurements from various tropical and temperate forests and describe how the resulting TLS point clouds can be used to produce quantitative 3D models of branch and trunk size, shape and distribution. These models can drastically improve estimates of AGB, provide new, improved large-scale ASEs, and deliver insights into a range of fundamental tree properties related to structure. Large quantities of detailed measurements of individual 3D tree structure also have the potential to open new and exciting avenues of research in areas where difficulties of measurement have until now prevented statistical approaches to detecting and understanding underlying patterns of scaling, form and function. We discuss these opportunities and some of the challenges that remain to be overcome to enable wider adoption of TLS methods.

scholarly journals Quantitative analysis of subcellular distributions with an open-source, object-based tool

Biology Open ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. bio055228 ◽  
Author(s):  
Pearl V. Ryder ◽  
Dorothy A. Lerit
Keyword(s):  
Image Analysis ◽  
Open Source ◽  
Three Dimensional ◽  
Analysis Data ◽  
Form And Function ◽  
Object Based Image Analysis ◽  
Object Based ◽  
And Function ◽  
Microscopy Images ◽  
Complete Process

ABSTRACTThe subcellular localization of objects, such as organelles, proteins, or other molecules, instructs cellular form and function. Understanding the underlying spatial relationships between objects through colocalization analysis of microscopy images is a fundamental approach used to inform biological mechanisms. We generated an automated and customizable computational tool, the SubcellularDistribution pipeline, to facilitate object-based image analysis from three-dimensional (3D) fluorescence microcopy images. To test the utility of the SubcellularDistribution pipeline, we examined the subcellular distribution of mRNA relative to centrosomes within syncytial Drosophila embryos. Centrosomes are microtubule-organizing centers, and RNA enrichments at centrosomes are of emerging importance. Our open-source and freely available software detected RNA distributions comparably to commercially available image analysis software. The SubcellularDistribution pipeline is designed to guide the user through the complete process of preparing image analysis data for publication, from image segmentation and data processing to visualization.This article has an associated First Person interview with the first author of the paper.

scholarly journals Virtual paleontology: computer-aided analysis of fossil form and function

2014 ◽  
Vol 88 (4) ◽  
pp. 633-635 ◽  
Author(s):  
Imran A. Rahman ◽  
Selena Y. Smith
Keyword(s):  
Imaging Techniques ◽  
Three Dimensional ◽  
Fossil Plants ◽  
Element Analysis ◽  
X Ray ◽  
Form And Function ◽  
Wide Range ◽  
History Of ◽  
Micro Tomography ◽  
And Function

‘Virtual paleontology’ entails the use of computational methods to assist in the three-dimensional (3-D) visualization and analysis of fossils, and has emerged as a powerful approach for research on the history of life. Three-dimensional imaging techniques allow poorly understood or previously unknown anatomies of fossil plants, invertebrates, and vertebrates, as well as microfossils and trace fossils, to be described in much greater detail than formerly possible, and are applicable to a wide range of preservation types and specimen sizes (Table 1). These methods include non-destructive high-resolution scanning technologies such as conventional X-ray micro-tomography and synchrotron-based X-ray tomography. In addition, form and function can be rigorously investigated through quantitative analysis of computer models, for example finite-element analysis.

A Map of the Heart: Gap Junctions, Connexin Diversity and Retroviral Studies of Conduction Myocyte Lineage

1995 ◽  
Vol 88 (3) ◽  
pp. 257-262 ◽  
Author(s):  
Robert G. Gourdie
Keyword(s):  
Gap Junctions ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Electrical Current ◽  
Distribution Patterns ◽  
Electrical Contacts ◽  
Cardiac Conduction ◽  
Developing Heart ◽  
Heart Muscle Cells ◽  
And Function

1. The heartbeat is co-ordinated by organized propagation of electrical excitation through cardiac muscle. Intercellular conduction and propagation of the cardiac action potential is dependent on electrical connections between myocytes, termed gap junctions. 2. In the last few years, our conception of the structure and function of cardiac gap junctions has been revised substantially. It seems that these structures show unexpected levels of specialization within the myocardium and they can no longer be viewed simply as passive conduits for the regulated movement of electrical current between heart muscle cells. 3. In this article, some of the contributions to this field by the author and his collaborators are summarized. Studies using confocal microscopy and digital imaging techniques to characterize the three-dimensional organization of electrical contacts between myocytes in the mature and developing heart are described, data on the unique expression and spatial distribution patterns of gap-junctional subunit proteins (connexins) are given, and finally the author's current work on the differentiation of cardiac conduction tissues, and how this work arose from studies of gap junctions in the heart, is introduced.

A three-dimensional muscle model: A quantified relation between form and function of skeletal muscles

1984 ◽  
Vol 182 (1) ◽  
pp. 95-113 ◽  
Author(s):  
R. D. Woittiez ◽  
P. A. Huijing ◽  
H. B. K. Boom ◽  
R. H. Rozendal
Keyword(s):  
Skeletal Muscles ◽  
Three Dimensional ◽  
Muscle Model ◽  
Form And Function ◽  
And Function

scholarly journals Stress distributions in maxillary central incisors restored with different high-stiffness post models: 3-D FEA

2018 ◽  
Vol 6 (1) ◽  
pp. 45
Author(s):  
Bassam Srayeddin ◽  
Ali Almuntashri
Keyword(s):  
Stress Distribution ◽  
Root Canal ◽  
Gold Alloy ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Distribution Profile ◽  
Maxillary Central Incisor ◽  
Group I ◽  
Group Ii ◽  
Restoration Failure

Background: Dental root posts are recommended for endodontically treated weakened teeth.Objectives: The present computational FEA study aims to evaluate the effect of material and design of the post on the stress distribution under load in different root canal shapes of endodontically treated maxillary central incisor (MCI).Methods: Three-dimensional models of (MCI) were created by using CAD modeling software and divided into two groups. Group-I comprised five models of a weakened root restored using different post materials (stainless steel, titanium, gold-alloy, Ni-Cr, and zirconium). Group-II: involved four models of (MCI) with two different root canal shapes (small and wide) restored using cylindrical (C-Post) and two-stage tapered (T-Post) posts. Each tooth model was subjected to a 100 N oblique load at the palatal surface of the crown. Von Mises equivalent stresses on dentin and post, as well as shear stresses on the post cement, were evaluated.Results: In Group-I: Ni-Cr produced the lowest stress values on the dentin, where titanium and gold-alloy posts produced the lowest stresses in the post and post/root interfaces. In Group-II: Roots restored with a T-Post showed a lower concentration stress in the dentin and lower shear stresses in the cement layer compared with those restored with a C-Post.Conclusion: The geometry of the post and the corresponding material play an important role in the stress behavior of restored teeth. The use of titanium or gold-alloy T-Posts seems a good way to improve the stress distribution profile and reduce the risk of restoration failure.   

scholarly journals Under pressure: the relationship between cranial shape and burrowing force in caecilians (Gymnophiona)

2021 ◽  
Author(s):  
Aurélien Lowie ◽  
Barbara De Kegel ◽  
Mark Wilkinson ◽  
John Measey ◽  
James C. O'Reilly ◽  
...  
Keyword(s):  
Phylogenetic Signal ◽  
Three Dimensional ◽  
Form And Function ◽  
Biomechanical Models ◽  
Cranial Osteology ◽  
Head Morphology ◽  
And Function ◽  
The Relationship ◽  
Cranial Shape

Caecilians are elongate, limbless, and annulated amphibians that, with the exception of one aquatic family, all have an at least partly fossorial lifestyle. It has been suggested that caecilian evolution resulted in sturdy and compact skulls with fused bones and tight sutures, as an adaptation to their head-first burrowing habits. However, although their cranial osteology is well described, relationships between form and function remain poorly understood. In the present study, we explored the relationship between cranial shape and in vivo burrowing forces. Using µCT-data, we performed three-dimensional geometric morphometrics to explore whether cranial and mandibular shapes reflected patterns that might be associated with maximal push forces. The results highlight important differences in maximal push forces, with the aquatic Typhlonectes producing a lower force for a given size compared to other species. Despite substantial differences in head morphology across species, no relation between overall skull shape and push force could be detected. Although a strong phylogenetic signal may partly obscure the results, our conclusions confirm previous studies using biomechanical models and suggest that differences in the degree of fossoriality do not appear to be driving the evolution of head shape.

scholarly journals Controls on creek margin stability by the root systems of saltmarsh vegetation, Beaulieu Estuary, Southern England

2019 ◽  
Vol 2 (1) ◽  
pp. 21-38 ◽  
Author(s):  
Yining Chen ◽  
Charlotte Thompson ◽  
Michael Collins
Keyword(s):  
High Resistance ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Root Systems ◽  
Distribution Patterns ◽  
Root Diameter ◽  
Diameter Distribution ◽  
Southern England ◽  
Quantitative Measurements ◽  
Atriplex Portulacoides

The retreat of cliffs (lateral expansion) within tidal creeks results in a net loss of saltmarshes, but this retreat process can be retarded by root systems. To understand the interaction between root presence and bank sediment, quantitative measurements of two saltmarsh species root systems (Atriplex portulacoides and Juncus maritima) were carried out in a saltmarsh in Southern England, and their relationships with bank stability were examined. Computed Tomography (CT) Scanning techniques were used to investigate three-dimensional root architecture. The data obtained (e.g., root volume, diameter, and distribution patterns of roots) were examined alongside more traditional root density measurements. The volumetric percentage, ratio between horizontal (lateral) and vertical roots (H/V ratio), and root diameter distribution are discussed in relation to their influence on bank sediment erosion threshold and shear strength. The results suggest that Atriplex portulacoides is more effective than Juncus maritimus in stabilising banks. This is because root systems that provide a high resistance to flow-induced erosion are better than those that provide a high resistance to gravity-induced erosion in stabilising cliff banks. This conclusion is relevant to future saltmarsh protection and re-establishment.

scholarly journals Form and Function in the Platyrrhine Skull: A Three-Dimensional Analysis of Dental and TMJ Morphology

2014 ◽  
Vol 298 (1) ◽  
pp. 29-47 ◽  
Author(s):  
Claire E. Terhune ◽  
Siobhán B. Cooke ◽  
Erik Otárola-Castillo
Keyword(s):  
Dimensional Analysis ◽  
Three Dimensional ◽  
Form And Function ◽  
And Function ◽  
Tmj Morphology
Sign in / Sign up

Export Citation Format

Share Document