scholarly journals Locomotory stresses in the limb bones of two small mammals: the ground squirrel and chipmunk

1983 ◽  
Vol 103 (1) ◽  
pp. 131-154 ◽  
Author(s):  
A. A. Biewener
Keyword(s):  
Safety Factor ◽  
Ground Squirrel ◽  
High Speed ◽  
Bone Geometry ◽  
Direct Consequence ◽  
Material Strength ◽  
Small Animals ◽  
Limb Bones ◽  
Wide Range ◽  
Large Animals

Peak stresses acting in limb bones should increase with increasing size if the forces acting on the bones increase in direct proportion to the animal's body weight. This is a direct consequence of the scaling of limb bone geometry over a wide range in size in mammals. In addition, recent work has shown that the material strength of bone is similar in large and small animals. If the assumptions in this analysis are correct, large animals would have a lower safety factor to failure than small animals. The purpose of this study was to measure peak stresses acting in the limb bones of small animals during locomotion and compare the results with similar measurements available for larger animals. Locomotory stresses acting in the fore and hindlimb bones of two rodents, the ground squirrel (Spermophilus tridecemlineatus) and chipmunk (Tamais striatus), were calculated using ground force recordings and measurements of limb position taken from high speed x-ray cine films. Peak (compressive) stresses calculated to act in the bones of these animals (−31 to −86 MN/m2) are similar in magnitude to those determined for much larger mammals. The more proximal bones of the fore and hindlimb, the humerus and femur, were found to develop stresses (−31 to −42 MN/m2) significantly lower than those acting in the more distal bones of each limb: the radius, ulna and tibia (−58 to −86 MN/m2). All of the long bones from both species, except their femora, were found to be loaded principally in bending. The caudal cortices of each bone developed a peak compressive stress, whereas the cranial cortices were loaded in tension. Various features of the musculo-skeletal organization and manner of locomotion of these rodents are considered to explain how animals of different size maintain a uniform safety factor to failure.

Bone strength in small mammals and bipedal birds: do safety factors change with body size?

1982 ◽  
Vol 98 (1) ◽  
pp. 289-301 ◽  
Author(s):  
A. A. Biewener
Keyword(s):  
Body Size ◽  
Small Mammals ◽  
Bending Strength ◽  
Published Data ◽  
Small Animals ◽  
Safety Factors ◽  
Cross Sectional ◽  
Limb Bones ◽  
Significant Difference ◽  
Large Animals

Measurements of the cross-sectional geometry and length of bones from animals of different sizes suggest that peak locomotory stresses might be as much as nine times greater in the limb bones of a 300 kg horse than those of a 0.10 kg chipmunk. To determine if the bones of larger animals are stronger than those of small animals, the bending strength of whole bone specimens from the limbs of small mammals and bipedal birds was measured and compared with published data for large mammalian cortical bone (horses and bovids). No significant difference (P greater than 0.2) was found in the failure stress of bone over a range in size from 0.05-700 kg (233 +/− 53 MN/m2 for small animals compared to 200 +/− 28 MN/m2 for large animals). This finding suggests that either the limb bones of small animals are much stronger than they need to be, or that other aspects of locomotion (e.g. duty factor and limb orientation relative to the direction of the ground force) act to decrease peak locomotory stresses in larger animals.

scholarly journals Many ways to land upright: novel righting strategies allow spotted lanternfly nymphs to land on diverse substrates

2021 ◽  
Vol 18 (181) ◽  
pp. 20210367
Author(s):  
Suzanne Amador Kane ◽  
Theodore Bien ◽  
Luis Contreras-Orendain ◽  
Michael F. Ochs ◽  
S. Tonia Hsieh
Keyword(s):  
High Speed ◽  
Insect Pest ◽  
Small Animals ◽  
Plant Leaves ◽  
Flat Surfaces ◽  
Substrate Adhesion ◽  
Lycorma Delicatula ◽  
The Usa ◽  
Post Impact ◽  
Large Animals

Unlike large animals, insects and other very small animals are so unsusceptible to impact-related injuries that they can use falling for dispersal and predator evasion. Reorienting to land upright can mitigate lost access to resources and predation risk. Such behaviours are critical for the spotted lanternfly (SLF) ( Lycorma delicatula ), an invasive, destructive insect pest spreading rapidly in the USA. High-speed video of SLF nymphs released under different conditions showed that these insects self-right using both active midair righting motions previously reported for other insects and novel post-impact mechanisms that take advantage of their ability to experience near-total energy loss on impact. Unlike during terrestrial self-righting, in which an animal initially at rest on its back uses appendage motions to flip over, SLF nymphs impacted the surface at varying angles and then self-righted during the rebound using coordinated body rotations, foot–substrate adhesion and active leg motions. These previously unreported strategies were found to promote disproportionately upright, secure landings on both hard, flat surfaces and tilted, compliant host plant leaves. Our results highlight the importance of examining biomechanical phenomena in ecologically relevant contexts, and show that, for small animals, the post-impact bounce period can be critical for achieving an upright landing.

scholarly journals Limb bone scaling in hopping macropods and quadrupedal artiodactyls

2018 ◽  
Author(s):  
Michael Doube ◽  
Alessandro A Felder ◽  
Melissa Y Chua ◽  
Kalyani Lodhia ◽  
Michał M Kłosowski ◽  
...  
Keyword(s):  
High Speed ◽  
Bone Adaptation ◽  
Scaling Relations ◽  
X Ray ◽  
Limb Bones ◽  
Scaling Relationships ◽  
Low Intensity ◽  
Wide Range ◽  
Mammalian Herbivore ◽  
Highly Loaded

AbstractBone adaptation is modulated by the timing, direction, rate, and magnitude of mechanical loads. To investigate whether frequent slow, or infrequent fast, gaits could dominate bone adaptation to load, we compared scaling of the limb bones from two mammalian herbivore clades that use radically different high-speed gaits, bipedal hopping (suborder Macropodiformes; kangaroos and kin) and quadrupedal galloping (order Artiodactyla; goats, deer and kin). Forelimb and hindlimb bones were collected from 20 artiodactyl and 15 macropod species (body mass M 1.05 – 1536 kg) and scanned in computed tomography or X- ray microtomography. Second moment of area (Imax) and bone length (l) were measured. Scaling relations (y = axb) were calculated for l vs M for each bone and for Imax vs M and Imax vs l for every 5% of length. Imax vs M scaling relationships were broadly similar between clades despite the macropod forelimb being nearly unloaded, and the hindlimb highly loaded, during bipedal hopping. Imax vs l and l vs M scaling were related to locomotor and behavioural specialisations. Low-intensity loads may be sufficient to maintain bone mass across a wide range of species. Occasional high-intensity gaits might not break through the load sensitivity saturation engendered by frequent low-intensity gaits.

scholarly journals Limb bone scaling in hopping macropods and quadrupedal artiodactyls

2018 ◽  
Vol 5 (10) ◽  
pp. 180152 ◽  
Author(s):  
Michael Doube ◽  
Alessandro A. Felder ◽  
Melissa Y. Chua ◽  
Kalyani Lodhia ◽  
Michał M. Kłosowski ◽  
...  
Keyword(s):  
High Speed ◽  
Bone Adaptation ◽  
Scaling Relations ◽  
X Ray ◽  
Limb Bones ◽  
Scaling Relationships ◽  
Low Intensity ◽  
Wide Range ◽  
Mammalian Herbivore ◽  
Highly Loaded

Bone adaptation is modulated by the timing, direction, rate and magnitude of mechanical loads. To investigate whether frequent slow, or infrequent fast, gaits could dominate bone adaptation to load, we compared scaling of the limb bones from two mammalian herbivore clades that use radically different high-speed gaits, bipedal hopping (suborder Macropodiformes; kangaroos and kin) and quadrupedal galloping (order Artiodactyla; goats, deer and kin). Forelimb and hindlimb bones were collected from 20 artiodactyl and 15 macropod species (body mass M 1.05–1536 kg) and scanned in computed tomography or X-ray microtomography. Second moment of area ( I max ) and bone length ( l ) were measured. Scaling relations ( y = ax b ) were calculated for l versus M for each bone and for I max versus M and I max versus l for every 5% of length. I max versus M scaling relationships were broadly similar between clades despite the macropod forelimb being nearly unloaded, and the hindlimb highly loaded, during bipedal hopping. I max versus l and l versus M scaling were related to locomotor and behavioural specializations. Low-intensity loads may be sufficient to maintain bone mass across a wide range of species. Occasional high-intensity gaits might not break through the load sensitivity saturation engendered by frequent low-intensity gaits.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Assessment of Commercial Off-the-Shelf Tissue Adhesives for Sealing Military-Relevant Corneal Perforation Injuries

2021 ◽  
Author(s):  
Eric J Snider ◽  
Lauren E Cornell ◽  
Brandon M Gross ◽  
David O Zamora ◽  
Emily N Boice
Keyword(s):  
Intraocular Pressure ◽  
High Speed ◽  
Anterior Segment ◽  
Ocular Tissue ◽  
Corneal Tissue ◽  
Corneal Perforation ◽  
Tissue Adhesives ◽  
Open Globe ◽  
Wide Range ◽  
Commercial Off The Shelf

ABSTRACT Introduction Open-globe ocular injuries have increased in frequency in recent combat operations due to increased use of explosive weaponry. Unfortunately, open-globe injuries have one of the worst visual outcomes for the injured warfighter, often resulting in permanent loss of vision. To improve visual recovery, injuries need to be stabilized quickly following trauma, in order to restore intraocular pressure and create a watertight seal. Here, we assess four off-the-shelf (OTS), commercially available tissue adhesives for their ability to seal military-relevant corneal perforation injuries (CPIs). Materials and Methods Adhesives were assessed using an anterior segment inflation platform and a previously developed high-speed benchtop corneal puncture model, to create injuries in porcine eyes. After injury, adhesives were applied and injury stabilization was assessed by measuring outflow rate, ocular compliance, and burst pressure, followed by histological analysis. Results Tegaderm dressings and Dermabond skin adhesive most successfully sealed injuries in preliminary testing. Across a range of injury sizes and shapes, Tegaderm performed well in smaller injury sizes, less than 2 mm in diameter, but inadequately sealed large or complex injuries. Dermabond created a watertight seal capable of maintaining ocular tissue at physiological intraocular pressure for almost all injury shapes and sizes. However, application of the adhesive was inconsistent. Histologically, after removal of the Dermabond skin adhesive, the corneal epithelium was removed and oftentimes the epithelium surface penetrated into the wound and was adhered to inner stromal tissue. Conclusions Dermabond can stabilize a wide range of CPIs; however, application is variable, which may adversely impact the corneal tissue. Without addressing these limitations, no OTS adhesive tested herein can be directly translated to CPIs. This highlights the need for development of a biomaterial product to stabilize these injuries without causing ocular damage upon removal, thus improving the poor vision prognosis for the injured warfighter.

scholarly journals A System-Agnostic, Adaptable and Extensible Animal Support Cradle System for Cardio-Respiratory-Synchronised, and Other, Multi-Modal Imaging of Small Animals

Tomography ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 39-54
Author(s):  
Veerle Kersemans ◽  
Stuart Gilchrist ◽  
Philip Danny Allen ◽  
Sheena Wallington ◽  
Paul Kinchesh ◽  
...  
Keyword(s):  
Scientific Data ◽  
Cardiac Monitoring ◽  
Small Animals ◽  
Maintenance System ◽  
Wide Range ◽  
Set Up ◽  
Animal Handling ◽  
Imaging Performance ◽  
Significant Effort

Standardisation of animal handling procedures for a wide range of preclinical imaging scanners will improve imaging performance and reproducibility of scientific data. Whilst there has been significant effort in defining how well scanners should operate and how in vivo experimentation should be practised, there is little detail on how to achieve optimal scanner performance with best practices in animal welfare. Here, we describe a system-agnostic, adaptable and extensible animal support cradle system for cardio-respiratory-synchronised, and other, multi-modal imaging of small animals. The animal support cradle can be adapted on a per application basis and features integrated tubing for anaesthetic and tracer delivery, an electrically driven rectal temperature maintenance system and respiratory and cardiac monitoring. Through a combination of careful material and device selection, we have described an approach that allows animals to be transferred whilst under general anaesthesia between any of the tomographic scanners we currently or have previously operated. The set-up is minimally invasive, cheap and easy to implement and for multi-modal, multi-vendor imaging of small animals.

scholarly journals Vibration of Rotating and Revolving Planet Rings with Discrete and Partially Distributed Stiffnesses

2020 ◽  
Vol 11 (1) ◽  
pp. 127
Author(s):  
Fuchun Yang ◽  
Dianrui Wang
Keyword(s):  
High Speed ◽  
Differential Operators ◽  
Natural Frequencies ◽  
Rotation Speed ◽  
Distribution Area ◽  
Vibration Modes ◽  
Governing Equations ◽  
Vibration Properties ◽  
Wide Range ◽  
Forced Responses

Vibration properties of high-speed rotating and revolving planet rings with discrete and partially distributed stiffnesses were studied. The governing equations were obtained by Hamilton’s principle based on a rotating frame on the ring. The governing equations were cast in matrix differential operators and discretized, using Galerkin’s method. The eigenvalue problem was dealt with state space matrix, and the natural frequencies and vibration modes were computed in a wide range of rotation speed. The properties of natural frequencies and vibration modes with rotation speed were studied for free planet rings and planet rings with discrete and partially distributed stiffnesses. The influences of several parameters on the vibration properties of planet rings were also investigated. Finally, the forced responses of planet rings resulted from the excitation of rotating and revolving movement were studied. The results show that the revolving movement not only affects the free vibration of planet rings but results in excitation to the rings. Partially distributed stiffness changes the vibration modes heavily compared to the free planet ring. Each vibration mode comprises several nodal diameter components instead of a single component for a free planet ring. The distribution area and the number of partially distributed stiffnesses mainly affect the high-order frequencies. The forced responses caused by revolving movement are nonlinear and vary with a quasi-period of rotating speed, and the responses in the regions supported by partially distributed stiffnesses are suppressed.

scholarly journals Towards a Glass New World: The Role of Ion-Exchange in Modern Technology

2021 ◽  
Vol 11 (10) ◽  
pp. 4610
Author(s):  
Simone Berneschi ◽  
Giancarlo C. Righini ◽  
Stefano Pelli
Keyword(s):  
Ion Exchange ◽  
Communication Networks ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Modern Technology ◽  
Historical Background ◽  
Wide Range ◽  
Happy Marriage

Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.

scholarly journals Prototype Design and Experimental Evaluation of Autonomous Collaborative Communication System for Emerging Maritime Use Cases

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3871
Author(s):  
Jiri Pokorny ◽  
Khanh Ma ◽  
Salwa Saafi ◽  
Jakub Frolka ◽  
Jose Villa ◽  
...  
Keyword(s):  
Communication System ◽  
Autonomous Vehicles ◽  
High Speed ◽  
High Capacity ◽  
Workplace Safety ◽  
Unmanned Vehicles ◽  
Use Cases ◽  
Automated Systems ◽  
Collaborative Communication ◽  
Wide Range

Automated systems have been seamlessly integrated into several industries as part of their industrial automation processes. Employing automated systems, such as autonomous vehicles, allows industries to increase productivity, benefit from a wide range of technologies and capabilities, and improve workplace safety. So far, most of the existing systems consider utilizing one type of autonomous vehicle. In this work, we propose a collaboration of different types of unmanned vehicles in maritime offshore scenarios. Providing high capacity, extended coverage, and better quality of services, autonomous collaborative systems can enable emerging maritime use cases, such as remote monitoring and navigation assistance. Motivated by these potential benefits, we propose the deployment of an Unmanned Surface Vehicle (USV) and an Unmanned Aerial Vehicle (UAV) in an autonomous collaborative communication system. Specifically, we design high-speed, directional communication links between a terrestrial control station and the two unmanned vehicles. Using measurement and simulation results, we evaluate the performance of the designed links in different communication scenarios and we show the benefits of employing multiple autonomous vehicles in the proposed communication system.

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