Feeding of the megamouth shark (Pisces: Lamniformes: Megachasmidae) predicted by its hyoid arch: A biomechanical approach

2011 ◽  
Vol 272 (5) ◽  
pp. 513-524 ◽  
Author(s):  
Taketeru Tomita ◽  
Keiichi Sato ◽  
Kenta Suda ◽  
Junro Kawauchi ◽  
Kazuhiro Nakaya
Keyword(s):  
Hyoid Arch ◽  
Megamouth Shark ◽  
Biomechanical Approach

scholarly journals Is Acceleration a Valid Proxy for Injury Risk in Minimal Damage Traffic Crashes? A Comparative Review of Volunteer, ADL and Real-World Studies

2021 ◽  
Vol 18 (6) ◽  
pp. 2901
Author(s):  
Paul S. Nolet ◽  
Larry Nordhoff ◽  
Vicki L. Kristman ◽  
Arthur C. Croft ◽  
Maurice P. Zeegers ◽  
...  
Keyword(s):  
Real World ◽  
Injury Risk ◽  
Angular Acceleration ◽  
Traffic Crashes ◽  
Rear Impact ◽  
Comparative Review ◽  
Minimal Damage ◽  
Injury Causation ◽  
Crash Tests ◽  
Biomechanical Approach

Injury claims associated with minimal damage rear impact traffic crashes are often defended using a “biomechanical approach,” in which the occupant forces of the crash are compared to the forces of activities of daily living (ADLs), resulting in the conclusion that the risk of injury from the crash is the same as for ADLs. The purpose of the present investigation is to evaluate the scientific validity of the central operating premise of the biomechanical approach to injury causation; that occupant acceleration is a scientifically valid proxy for injury risk. Data were abstracted, pooled, and compared from three categories of published literature: (1) volunteer rear impact crash testing studies, (2) ADL studies, and (3) observational studies of real-world rear impacts. We compared the occupant accelerations of minimal or no damage (i.e., 3 to 11 kph speed change or “delta V”) rear impact crash tests to the accelerations described in 6 of the most commonly reported ADLs in the reviewed studies. As a final step, the injury risk observed in real world crashes was compared to the results of the pooled crash test and ADL analyses, controlling for delta V. The results of the analyses indicated that average peak linear and angular acceleration forces observed at the head during rear impact crash tests were typically at least several times greater than average forces observed during ADLs. In contrast, the injury risk of real-world minimal damage rear impact crashes was estimated to be at least 2000 times greater than for any ADL. The results of our analysis indicate that the principle underlying the biomechanical injury causation approach, that occupant acceleration is a proxy for injury risk, is scientifically invalid. The biomechanical approach to injury causation in minimal damage crashes invariably results in the vast underestimation of the actual risk of such crashes, and should be discontinued as it is a scientifically invalid practice.

scholarly journals Regional infarction identification from cardiac CT images: a computer-aided biomechanical approach

2016 ◽  
Vol 11 (9) ◽  
pp. 1573-1583 ◽  
Author(s):  
Ken C. L. Wong ◽  
Michael Tee ◽  
Marcus Chen ◽  
David A. Bluemke ◽  
Ronald M. Summers ◽  
...  
Keyword(s):  
Cardiac Ct ◽  
Ct Images ◽  
Computer Aided ◽  
Biomechanical Approach

scholarly journals A Biomechanical Approach for Bone Regeneration inside Scaffolds

2015 ◽  
Vol 110 ◽  
pp. 82-89 ◽  
Author(s):  
Carolina Gorriz ◽  
Frederico Ribeiro ◽  
José M. Guedes ◽  
Paulo R. Fernandes
Keyword(s):  
Bone Regeneration ◽  
Biomechanical Approach

scholarly journals The hyoid arch and braincase anatomy of Acanthodes support chondrichthyan affinity of ‘acanthodians’

2015 ◽  
Vol 282 (1821) ◽  
pp. 20152210 ◽  
Author(s):  
Martin D. Brazeau ◽  
Valerie de Winter
Keyword(s):  
Computed Tomography ◽  
Jugular Vein ◽  
Evolutionary Relationships ◽  
Current Debate ◽  
Hyoid Arch ◽  
Computed Tomography Scanning ◽  
Tomography Scanning

Solving the evolutionary relationships of the acanthodians is one of the key problems in reconstructing ancestral anatomical conditions for the jawed vertebrates (gnathostomes). Current debate concerns whether acanthodians are an assemblage of stem chondrichthyans, or a more generalized grade encompassing some early stem osteichthyans. The skull anatomy of Acanthodes bronni has been pivotal in these debates, owing to tension between chondrichthyan- and osteichthyan-like models of reconstruction. We use computed tomography scanning and traditional palaeontological techniques to resolve the long-standing debate about the anatomy of the jaw suspension. We establish the correct length of the hyomandibula and show that it attaches to a process on the ventrolateral angle of the braincase below the jugular vein groove. This condition corresponds precisely to that in chondrichthyans. This character represents an unambiguously optimized synapomorphy with chondrichthyans given current gnathostome phylogenies, corroborating the growing consensus of the chondrichthyan affinity of acanthodians.

scholarly journals Author response: Bichir external gills arise via heterochronic shift that accelerates hyoid arch development

2019 ◽  
Author(s):  
Jan Stundl ◽  
Anna Pospisilova ◽  
David Jandzik ◽  
Peter Fabian ◽  
Barbora Dobiasova ◽  
...  
Keyword(s):  
Author Response ◽  
Hyoid Arch

scholarly journals Bichir external gills arise via heterochronic shift that accelerates hyoid arch development

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Jan Stundl ◽  
Anna Pospisilova ◽  
David Jandzik ◽  
Peter Fabian ◽  
Barbora Dobiasova ◽  
...  
Keyword(s):  
Pharyngeal Arch ◽  
Developmental Sequence ◽  
Free Living ◽  
Pharyngeal Arches ◽  
Hyoid Arch ◽  
Early Appearance ◽  
Evolutionary Changes ◽  
Insight Into ◽  
Living Group ◽  
Early Larvae

In most vertebrates, pharyngeal arches form in a stereotypic anterior-to-posterior progression. To gain insight into the mechanisms underlying evolutionary changes in pharyngeal arch development, here we investigate embryos and larvae of bichirs. Bichirs represent the earliest diverged living group of ray-finned fishes, and possess intriguing traits otherwise typical for lobe-finned fishes such as ventral paired lungs and larval external gills. In bichir embryos, we find that the anteroposterior way of formation of cranial segments is modified by the unique acceleration of the entire hyoid arch segment, with earlier and orchestrated development of the endodermal, mesodermal, and neural crest tissues. This major heterochronic shift in the anteroposterior developmental sequence enables early appearance of the external gills that represent key breathing organs of bichir free-living embryos and early larvae. Bichirs thus stay as unique models for understanding developmental mechanisms facilitating increased breathing capacity.

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