The Hydrodynamics of Jellyfish Swimming

2021 ◽  
Vol 13 (1) ◽  
pp. 375-396 ◽  
Author(s):  
John H. Costello ◽  
Sean P. Colin ◽  
John O. Dabiri ◽  
Brad J. Gemmell ◽  
Kelsey N. Lucas ◽  
...  
Keyword(s):  
Animal Models ◽  
Force Production ◽  
Ease Of Use ◽  
Energetic Efficiency ◽  
Wall Effects ◽  
Laboratory Experimentation ◽  
Rotational Mechanics ◽  
Structural Simplicity ◽  
Insight Into ◽  
Fluid Interactions

Jellyfish have provided insight into important components of animal propulsion, such as suction thrust, passive energy recapture, vortex wall effects, and the rotational mechanics of turning. These traits are critically important to jellyfish because they must propel themselves despite severe limitations on force production imposed by rudimentary cnidarian muscular structures. Consequently, jellyfish swimming can occur only by careful orchestration of fluid interactions. Yet these mechanics may be more broadly instructive because they also characterize processes shared with other animal swimmers, whose structural and neurological complexity can obscure these interactions. In comparison with other animal models, the structural simplicity, comparative energetic efficiency, and ease of use in laboratory experimentation allow jellyfish to serve as favorable test subjects for exploration of the hydrodynamic bases of animal propulsion. These same attributes also make jellyfish valuable models for insight into biomimetic or bioinspired engineeringof swimming vehicles. Here, we review advances in understanding of propulsive mechanics derived from jellyfish models as a pathway toward the application of animal mechanics to vehicle designs.

Crowdsourcing the Evaluation of Design Concepts With Empathic Priming

2016 ◽  
Author(s):  
Michelle A. Pang ◽  
Carolyn C. Seepersad
Keyword(s):  
Rating Scales ◽  
Pairwise Comparison ◽  
Comparison Method ◽  
Ease Of Use ◽  
Primary Study ◽  
Design Concepts ◽  
The Impact ◽  
Further Development ◽  
Similar Evaluation ◽  
Insight Into

The evaluation of design concepts is a time consuming and resource intensive process. Crowdsourcing evaluations has been examined in previous work as a means to reduce the need for expert raters, while achieving similar evaluation results. This paper examines the impact of empathically priming novice raters on their evaluation of alternative design concepts. The rating system is based on a pairwise comparison method that requires minimal training of novice raters. In a pilot study the pairwise method for crowdsourcing evaluations is compared with crowdsourced evaluations using non-pairwise rating scales and with the evaluations of expert raters. The primary study incorporates written and empathic priming strategies to determine their impact on novice raters’ evaluation of concepts. Raters are asked to consider several criteria, including novelty, feasibility, clarity (of the concept), usefulness, ease of use, and overall worthiness of further development. Results offer insight into the criteria that are most relevant to novice raters and whether empathic priming has a significant effect on those evaluations.

scholarly journals Terrestrial force production by the limbs of a semi-aquatic salamander provides insight into the evolution of terrestrial locomotor mechanics

2021 ◽  
Author(s):  
Sandy Momoe Kawano ◽  
Richard W. Blob
Keyword(s):  
Adult Life ◽  
Force Production ◽  
Rear Wheel ◽  
Ambystoma Tigrinum ◽  
Terrestrial Locomotion ◽  
Hind Limbs ◽  
Wheel Drive ◽  
Reaction Forces ◽  
Pleurodeles Waltl ◽  
Insight Into

Amphibious fishes and salamanders are valuable functional analogs for vertebrates that spanned the water-to-land transition. However, investigations of walking mechanics have focused on terrestrial salamanders and, thus, may better reflect the capabilities of stem tetrapods that were already terrestrial. The earliest tetrapods were aquatic, so salamanders that are not primarily terrestrial may yield more appropriate data for modelling the incipient stages of terrestrial locomotion. In the present study, locomotor biomechanics were quantified from semi-aquatic Pleurodeles waltl, a salamander that spends most of its adult life in water, and then compared to a primarily terrestrial salamander (Ambystoma tigrinum) and semi-aquatic fish (Periophthalmus barbarus) to evaluate whether walking mechanics show greater similarity between species with ecological versus phylogenetic similarities. Ground reaction forces (GRFs) from individual limbs or fins indicated that the pectoral appendages of each taxon had distinct patterns of force production, but hind limb forces were comparable between the salamanders. The rate of force development ('yank') was sometimes slower in P. waltl but generally comparable between the three species. Finally, medial inclination of the GRF in P. waltl was intermediate between semi-aquatic fish and terrestrial salamanders, potentially elevating bone stresses among more aquatic taxa as they move on land. These data provide a framework for modelling stem tetrapods using an earlier stage of quadrupedal locomotion that was powered primarily by the hind limbs (i.e., "rear-wheel drive"), and reveal mechanisms for appendages to generate propulsion in three locomotor strategies that are presumed to have occurred across the water-to-land transition in vertebrate evolution.

Technology Acceptance Model and Determinants of Technology Rejection

2012 ◽  
pp. 226-238
Author(s):  
Melih Kirlidog ◽  
Aygul Kaynak
Keyword(s):  
Information Systems ◽  
Technology Acceptance ◽  
Technology Acceptance Model ◽  
Ease Of Use ◽  
Perceived Usefulness ◽  
Perceived Ease Of Use ◽  
Key Factors ◽  
Perceived Difficulty ◽  
Acceptance Model ◽  
Insight Into

Technology Acceptance Model (TAM) is an important tool to understand the dynamics of acceptance of Information Systems in an organization. The model posits that perceived ease of use and perceived usefulness are key factors in the adoption. This study extends TAM for investigating the user rejection of technology by reversing the two key factors into perceived difficulty of use and perceived uselessness. The study was conducted by surveying the customers of an e-banking application in Turkey who disuse the system. The results reveal important hints for the organization that wants to get an insight into the causes of the system disuse.

State-of-the-Art Information Retrieval Tools for Biological Resources

2018 ◽  
pp. 77-96
Author(s):  
Shashi Bhushan Lal ◽  
Anu Sharma ◽  
Krishna Kumar Chaturvedi ◽  
Mohammad Samir Farooqi ◽  
Sanjeev Kumar ◽  
...  
Keyword(s):  
Information Retrieval ◽  
Statistical Analysis ◽  
Relevant Information ◽  
Ease Of Use ◽  
Video Data ◽  
Biological Databases ◽  
Biological Resources ◽  
Sequencing Technologies ◽  
Scientific Experiments ◽  
Insight Into

With the advancements in sequencing technologies, there is an exponential growth in the availability of the biological databases. Biological databases consist of information and knowledge collected from scientific experiments, published literature and statistical analysis of text, numerical, image and video data. These databases are widely spread across the globe and are being maintained by many organizations. A number of tools have been developed to retrieve the information from these databases. Most of these tools are available on web but are scattered. So, finding a relevant information is a very difficult, and tedious task for the researchers. Moreover, many of these databases use disparate storage formats but are linked to each other. So, an important issue concerning present biological resources is their availability and integration at single platform. This chapter provides an insight into existing biological resources with an aim to provide consolidated information at one place for ease of use and access by researchers, academicians and students.

Mouse Models of Schizophrenia and Bipolar Disorder

2013 ◽  
pp. 287-300
Author(s):  
Mikhail V. Pletnikov ◽  
Christopher A. Ross
Keyword(s):  
Bipolar Disorder ◽  
Animal Models ◽  
Mouse Models ◽  
Recent Progress ◽  
Neuropsychiatric Disorders ◽  
Environmental Interventions ◽  
The Future ◽  
Underlying Mechanisms ◽  
Insight Into ◽  
Genetic Mouse Models

Despite the recent advances in research into schizophrenia and bipolar disorder, the neurobiology of these maladies remains poorly understood. Animal models can be instrumental in elucidating the underlying mechanisms of neuropsychiatric disorders. Early animal models of schizophrenia and bipolar disorder used lesion methods, pharmacologic challenges or environmental interventions to mimic pathogenic features of the diseases. The recent progress in genetics has stimulated the development of etiological models that have begun to provide insight into pathogenesis. In this review, we evaluate the strengths and weaknesses of the existing genetic mouse models of schizophrenia and discuss potential developments for the future.

scholarly journals How to Improve the Antioxidant Defense in Asphyxiated Newborns—Lessons from Animal Models

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 898
Author(s):  
Hanna Kletkiewicz ◽  
Maciej Klimiuk ◽  
Alina Woźniak ◽  
Celestyna Mila-Kierzenkowska ◽  
Karol Dokladny ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Animal Models ◽  
Iron Chelation ◽  
Therapeutic Effects ◽  
Therapeutic Approaches ◽  
Protective Capacity ◽  
Neonatal Asphyxia ◽  
New Therapeutic Approaches ◽  
The Brain ◽  
Insight Into

Oxygen free radicals have been implicated in brain damage after neonatal asphyxia. In the early phase of asphyxia/reoxygenation, changes in antioxidant enzyme activity play a pivotal role in switching on and off the cascade of events that can kill the neurons. Hypoxia/ischemia (H/I) forces the brain to activate endogenous mechanisms (e.g., antioxidant enzymes) to compensate for the lost or broken neural circuits. It is important to evaluate therapies to enhance the self-protective capacity of the brain. In animal models, decreased body temperature during neonatal asphyxia has been shown to increase cerebral antioxidant capacity. However, in preterm or severely asphyxiated newborns this therapy, rather than beneficial seems to be harmful. Thus, seeking new therapeutic approaches to prevent anoxia-induced complications is crucial. Pharmacotherapy with deferoxamine (DFO) is commonly recognized as a beneficial regimen for H/I insult. DFO, via iron chelation, reduces oxidative stress. It also assures an optimal antioxidant protection minimizing depletion of the antioxidant enzymes as well as low molecular antioxidants. In the present review, some aspects of recently acquired insight into the therapeutic effects of hypothermia and DFO in promoting neuronal survival after H/I are discussed.

Deformable Blade Element and Unsteady Vortex Lattice Fluid-Structure Interaction Modeling of a 2D Flapping Wing

2020 ◽  
Author(s):  
Joseph Reade ◽  
Mark A. Jankauski
Keyword(s):  
Vortex Lattice ◽  
Normal Force ◽  
Aerodynamic Force ◽  
Fluid Structure Interaction ◽  
Force Production ◽  
Flapping Wing ◽  
Energetic Efficiency ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Blade Element

Abstract Flapping insect wings experience appreciable deformation due to aerodynamic and inertial forces. This deformation is believed to benefit the insect’s aerodynamic force production as well as energetic efficiency. However, the fluid-structure interaction (FSI) models used to estimate wing deformations are often computationally demanding and are therefore challenged by parametric studies. Here, we develop a simple FSI model of a flapping wing idealized as a two-dimensional pitching-plunging airfoil. Using the Lagrangian formulation, we derive the reduced-order structural framework governing wing’s elastic deformation. We consider two fluid models: quasi-steady Deformable Blade Element Theory (DBET) and Unsteady Vortex Lattice Method (UVLM). DBET is computationally economical but does not provide insight into the flow structure surrounding the wing, whereas UVLM approximates flows but requires more time to solve. For simple flapping kinematics, DBET and UVLM produce similar estimates of the aerodynamic force normal to the surface of a rigid wing. More importantly, when the wing is permitted to deform, DBET and UVLM agree well in predicting wingtip deflection and aerodynamic normal force. The most notable difference between the model predictions is a roughly 20° phase difference in normal force. DBET estimates wing deformation and force production approximately 15 times faster than UVLM for the parameters considered, and both models solve in under a minute when considering 15 flapping periods. Moving forward, we will benchmark both low-order models with respect to high fidelity computational fluid dynamics coupled to finite element analysis, and assess the agreement between DBET and UVLM over a broader range of flapping kinematics.

scholarly journals Metabolomics in Psychiatric Disorders: What We Learn from Animal Models

Metabolites ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 72 ◽  
Author(s):  
Elke Humer ◽  
Thomas Probst ◽  
Christoph Pieh
Keyword(s):  
Animal Models ◽  
Psychiatric Disorders ◽  
Treatment Strategies ◽  
Mood Stabilizers ◽  
Psychiatric Medication ◽  
Mitochondrial Regulation ◽  
Novel Treatment Strategies ◽  
Insight Into ◽  
Test Treatment

Biomarkers are a recent research target within biological factors of psychiatric disorders. There is growing evidence for deriving biomarkers within psychiatric disorders in serum or urine samples in humans, however, few studies have investigated this differentiation in brain or cerebral fluid samples in psychiatric disorders. As brain samples from humans are only available at autopsy, animal models are commonly applied to determine the pathogenesis of psychiatric diseases and to test treatment strategies. The aim of this review is to summarize studies on biomarkers in animal models for psychiatric disorders. For depression, anxiety and addiction disorders studies, biomarkers in animal brains are available. Furthermore, several studies have investigated psychiatric medication, e.g., antipsychotics, antidepressants, or mood stabilizers, in animals. The most notable changes in biomarkers in depressed animal models were related to the glutamate-γ-aminobutyric acid-glutamine-cycle. In anxiety models, alterations in amino acid and energy metabolism (i.e., mitochondrial regulation) were observed. Addicted animals showed several biomarkers according to the induced drugs. In summary, animal models provide some direct insights into the cellular metabolites that are produced during psychiatric processes. In addition, the influence on biomarkers due to short- or long-term medication is a noticeable finding. Further studies should combine representative animal models and human studies on cerebral fluid to improve insight into mental disorders and advance the development of novel treatment strategies.

scholarly journals The Representative Porcine Model for Human Cardiovascular Disease

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Yoriyasu Suzuki ◽  
Alan C. Yeung ◽  
Fumiaki Ikeno
Keyword(s):  
Animal Models ◽  
Porcine Model ◽  
Small Animal ◽  
Large Animal ◽  
Murine Models ◽  
Practical Applications ◽  
Large Animal Models ◽  
Small Animal Models ◽  
Insight Into

To improve human health, scientific discoveries must be translated into practical applications. Inherent in the development of these technologies is the role of preclinical testing using animal models. Although significant insight into the molecular and cellular basis has come from small animal models, significant differences exist with regard to cardiovascular characteristics between these models and humans. Therefore, large animal models are essential to develop the discoveries from murine models into clinical therapies and interventions. This paper will provide an overview of the more frequently used large animal models, especially porcine models for preclinical studies.

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