Journal articles on the topic 'Locomotor mimicry'
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1
Srygley, Robert B. "Locomotor mimicry in Heliconius butterflies: contrast analyses of flight morphology and kinematics." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, no. 1380 (January 29, 1999): 203–14. http://dx.doi.org/10.1098/rstb.1999.0372.
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Müllerian mimicry is a mutualism involving the evolutionary convergence of colour patterns of prey on a warning signal to predators. Behavioural mimicry presumably adds complexity to the signal and makes it more difficult for Batesian mimics to parasitize it. To date, no one has quantified behavioural mimicry in Müllerian mimicry groups. However, morphological similarities among members of mimicry groups suggested that pitching oscillations of the body and wing–beat frequency (WBF) might converge with colour pattern. I compared the morphology and kinematics of four Heliconius species, which comprised two mimicry pairs. Because the mimics arose from two distinct lineages, the relative contributions of mimicry and phylogeny to variation in the species' morphologies and kinematics were examined. The positions of the centre of body mass and centre of wing mass and wing shape diverged among species within lineages, and converged among species within mimicry groups. WBF converged within mimicry groups, and it was coupled with body pitching frequency. However, body–pitching frequency was too variable to distinguish mimicry groups. Convergence in WBF may be due, at least in part, to biomechanical consequences of similarities in wing length, wing shape or the centre of wing mass among co–mimics. Nevertheless, convergence in WBF among passion–vine butterflies serves as the first evidence of behavioural mimicry in a mutualistic context.
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Shamble, Paul S., Ron R. Hoy, Itai Cohen, and Tsevi Beatus. "Walking like an ant: a quantitative and experimental approach to understanding locomotor mimicry in the jumping spider Myrmarachne formicaria." Proceedings of the Royal Society B: Biological Sciences 284, no. 1858 (July 12, 2017): 20170308. http://dx.doi.org/10.1098/rspb.2017.0308.
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Protective mimicry, in which a palatable species avoids predation by being mistaken for an unpalatable model, is a remarkable example of adaptive evolution. These complex interactions between mimics, models and predators can explain similarities between organisms beyond the often-mechanistic constraints typically invoked in studies of convergent evolution. However, quantitative studies of protective mimicry typically focus on static traits (e.g. colour and shape) rather than on dynamic traits like locomotion. Here, we use high-speed cameras and behavioural experiments to investigate the role of locomotor behaviour in mimicry by the ant-mimicking jumping spider Myrmarachne formicaria , comparing its movement to that of ants and non-mimicking spiders. Contrary to previous suggestions, we find mimics walk using all eight legs, raising their forelegs like ant antennae only when stationary. Mimics exhibited winding trajectories (typical wavelength = 5–10 body lengths), which resemble the winding patterns of ants specifically engaged in pheromone-trail following, although mimics walked on chemically inert surfaces. Mimics also make characteristically short (approx. 100 ms) pauses. Our analysis suggests that this makes mimics appear ant-like to observers with slow visual systems. Finally, behavioural experiments with predatory spiders yield results consistent with the protective mimicry hypothesis. These findings highlight the importance of dynamic behaviours and observer perception in mimicry.
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WIPFLER, BENJAMIN, PETR KOČÁREK, ADRIAN RICHTER, BRENDON BOUDINOT, MING BAI, and ROLF GEORG BEUTEL. "Structural features and life habits of †Alienoptera (Polyneoptera, Dictyoptera, Insecta)." Palaeoentomology 2, no. 5 (October 31, 2019): 465–73. http://dx.doi.org/10.11646/palaeoentomology.2.5.10.
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Structural features and life habits of described species of the extinct †Alienoptera are evaluated based on previously published studies on the group. Head structures and feedings habits are addressed, as are the locomotor organs, especially the wings and adhesive devices. Suggested pollen feeding habits and the possible role as pollinators are discussed, as well as hypothesized ant and wasp mimicry and myrmecophily. Species of †Alienoptera were likely predators, in the case of †Caputoraptor elegans Bai, Beutel et Wipfler, 2018 with a unique cephalo-prothoracic prey grasping mechanism. They were likely strong fliers with anatomical dipterism with functional hind wings. Wing joints protected by scale-like sclerotized fore wings probably allowed them to move very efficiently in dense foliage of trees or shrubs and to prey upon smaller insects. Ant mimicry, myrmecophily and “weevil mimicry” are rejected. †Meilia Vršanský et Wang, 2018 is a possible case of wasp mimicry but more evidence is required. Other suggested cases of mimicking wasps are unfounded.
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Golding, Y. C., A. R. Ennos, and M. Edmunds. "Similarity in flight behaviour between the honeybee Apis mellifera (Hymenoptera: apidae) and its presumed mimic, the dronefly Eristalis tenax (Diptera: syrphidae)." Journal of Experimental Biology 204, no. 1 (January 1, 2001): 139–45. http://dx.doi.org/10.1242/jeb.204.1.139.
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It is generally accepted that the dronefly Eristalis tenax is a Batesian mimic of the honeybee Apis mellifera. Previous work has established that the foraging behaviour of droneflies is more similar to that of its model than to that of other more closely related flies, suggesting that behaviour may be important in the mimicry. Locomotor mimicry has been demonstrated in mimetic Heliconius butterflies but not in hoverflies. This study therefore investigated aspects of the flight behaviour of Eristalis tenax, Apis mellifera and two other flies, Syrphus ribesii and a Musca sp. Insects were filmed foraging on Helichrysum bracteum flowers, and flight sequences were analysed to determine flight velocities, flight trajectories and the percentage of time spent hovering. It was found that the flight behaviour of droneflies was more similar to that of honeybees than to that of the other flies. This suggests that the flight behaviour of Eristalis tenax may be mimetic.
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Shine, Richard, David O'Connor, and Robert T. Mason. "Female mimicry in garter snakes: behavioural tactics of "she-males" and the males that court them." Canadian Journal of Zoology 78, no. 8 (August 1, 2000): 1391–96. http://dx.doi.org/10.1139/z00-089.
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Red-sided garter snakes (Thamnophis sirtalis parietalis) in central Manitoba court and mate in early spring soon after emerging from communal overwintering dens. Some males ("she-males") produce female-like skin pheromones, and hence attract courtship from other males. Studies at a den near Inwood, Manitoba, support and extend results from work at other dens. She-males were males that had recently emerged from hibernation and had not yet regained full locomotor capacity or muscle strength. She-males resembled "he-males" rather than females in their antipredator responses, including the thermal threshold at which they fled from a simulated predator (a plastic crow) rather than remaining stationary and displaying. Males courting she-males were cooler than those courting females; nonetheless they were more likely to flee when we approached them. Compared with courting groups focussed on females, groups around she-males were smaller, consisted predominantly of smaller he-males, and were found over a more restricted time of day (early afternoon). Arena trials confirmed that she-males are disproportionately courted by small rather than large he-males, and clarified other aspects of she-male attractiveness and behaviour. She-males attracted more intense courtship when large females were absent. She-males courted less vigorously when large he-males were present, especially when they were vigorously courted themselves. Overall, our data reveal hitherto-unsuspected complexity in the behavioural tactics of reproducing garter snakes.
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Nelson, Ximena J., and Ashley Card. "Locomotory mimicry in ant-like spiders." Behavioral Ecology 27, no. 3 (December 20, 2015): 700–707. http://dx.doi.org/10.1093/beheco/arv218.
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Bertels, Hannah, Guillem Vicente-Ortiz, Khadija El Kanbi, and Aya Takeoka. "Neurotransmitter phenotype switching by spinal excitatory interneurons regulates locomotor recovery after spinal cord injury." Nature Neuroscience 25, no. 5 (May 2022): 617–29. http://dx.doi.org/10.1038/s41593-022-01067-9.
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AbstractSevere spinal cord injury in adults leads to irreversible paralysis below the lesion. However, adult rodents that received a complete thoracic lesion just after birth demonstrate proficient hindlimb locomotion without input from the brain. How the spinal cord achieves such striking plasticity remains unknown. In this study, we found that adult spinal cord injury prompts neurotransmitter switching of spatially defined excitatory interneurons to an inhibitory phenotype, promoting inhibition at synapses contacting motor neurons. In contrast, neonatal spinal cord injury maintains the excitatory phenotype of glutamatergic interneurons and causes synaptic sprouting to facilitate excitation. Furthermore, genetic manipulation to mimic the inhibitory phenotype observed in excitatory interneurons after adult spinal cord injury abrogates autonomous locomotor functionality in neonatally injured mice. In comparison, attenuating this inhibitory phenotype improves locomotor capacity after adult injury. Together, these data demonstrate that neurotransmitter phenotype of defined excitatory interneurons steers locomotor recovery after spinal cord injury.
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Romero Núñez, Eunice, Tonali Blanco Ayala, Gustavo Ignacio Vázquez Cervantes, Gabriel Roldán-Roldán, Dinora Fabiola González Esquivel, Saé Muñiz-Hernández, Alelí Salazar, et al. "Pregestational Exposure to T. gondii Produces Maternal Antibodies That Recognize Fetal Brain Mimotopes and Induces Neurochemical and Behavioral Dysfunction in the Offspring." Cells 11, no. 23 (November 29, 2022): 3819. http://dx.doi.org/10.3390/cells11233819.
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The activation of the maternal immune system by a prenatal infection is considered a risk factor for developing psychiatric disorders in the offspring. Toxoplasma gondii is one of the pathogenic infections associated with schizophrenia. Recent studies have shown an association between high levels of IgG anti-T. gondii from mothers and their neonates, with a higher risk of developing schizophrenia. The absence of the parasite and the levels of IgGs found in the early stages of life suggest a transplacental transfer of the anti-T. gondii IgG antibodies, which could bind fetal brain structures by molecular mimicry and induce alterations in neurodevelopment. This study aimed to determine the maternal pathogenic antibodies formation that led to behavioral impairment on the progeny of rats immunized with T. gondii. Female rats were immunized prior to gestation with T. gondii lysate (3 times/once per week). The anti-T. gondii IgG levels were determined in the serum of pregestational exposed females’ previous mating. After this, locomotor activity, cognitive and social tests were performed. Cortical neurotransmitter levels for dopamine and glutamate were evaluated at 60 PND in the progeny of rats immunized before gestation (Pregestational group). The maternal pathogenic antibodies were evidenced by their binding to fetal brain mimotopes in the Pregestational group and the reactivity of the serum containing anti-T. gondii IgG was tested in control fetal brains (non-immunized). These results showed that the Pregestational group presented impairment in short and long-term memory, hypoactivity and alteration in social behavior, which was also associated with a decrease in cortical glutamate and dopamine levels. We also found the IgG antibodies bound to brain mimotopes in fetuses from females immunized with T. gondii, as well as observing a strong reactivity of the serum females immunized for fetal brain structures of fetuses from unimmunized mothers. Our results suggest that the exposure to T. gondii before gestation produced maternal pathogenic antibodies that can recognize fetal brain mimotopes and lead to neurochemical and behavioral alterations in the offspring.
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Silva, Naiane Arantes, Gabriel Henrique de Oliveira Caetano, Pedro Henrique Campelo, Vitor Hugo Gomes Lacerda Cavalcante, Leandro Braga Godinho, Donald Bailey Miles, Henrique Monteiro Paulino, et al. "Effects of Caudal Autotomy on the Locomotor Performance of Micrablepharus Atticolus (Squamata, Gymnophthalmidae)." Diversity 13, no. 11 (November 4, 2021): 562. http://dx.doi.org/10.3390/d13110562.
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Caudal autotomy is a striking adaptation used by many lizard species to evade predators. Most studies to date indicate that caudal autotomy impairs lizard locomotor performance. Surprisingly, some species bearing the longest tails show negligible impacts of caudal autotomy on sprint speed. Part of this variation has been attributed to lineage effects. For the first time, we model the effects of caudal autotomy on the locomotor performance of a gymnophthalmid lizard, Micrablepharus atticolus, which has a long and bright blue tail. To improve model accuracy, we incorporated the effects of several covariates. We found that body temperature, pregnancy, mass, collection site, and the length of the regenerated portion of the tail were the most important predictors of locomotor performance. However, sprint speed was unaffected by tail loss. Apparently, the long tail of M. atticolus is more useful when using undulation amidst the leaf litter and not when using quadrupedal locomotion on a flat surface. Our findings highlight the intricate relationships among physiological, morphological, and behavioral traits. We suggest that future studies about the impacts of caudal autotomy among long-tailed lizards should consider the role of different microhabitats/substrates on locomotor performance, using laboratory conditions that closely mimic their natural environments.
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Benthall, Katelyn N., Ryan A. Hough, and Andrew D. McClellan. "Descending propriospinal neurons mediate restoration of locomotor function following spinal cord injury." Journal of Neurophysiology 117, no. 1 (January 1, 2017): 215–29. http://dx.doi.org/10.1152/jn.00544.2016.
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Following spinal cord injury (SCI) in the lamprey, there is virtually complete recovery of locomotion within a few weeks, but interestingly, axonal regeneration of reticulospinal (RS) neurons is mostly limited to short distances caudal to the injury site. To explain this situation, we hypothesize that descending propriospinal (PS) neurons relay descending drive from RS neurons to indirectly activate spinal central pattern generators (CPGs). In the present study, the contributions of PS neurons to locomotor recovery were tested in the lamprey following SCI. First, long RS neuron projections were interrupted by staggered spinal hemitransections on the right side at 10% body length (BL; normalized from the tip of the oral hood) and on the left side at 30% BL. For acute recovery conditions (≤1 wk) and before axonal regeneration, swimming muscle burst activity was relatively normal, but with some deficits in coordination. Second, lampreys received two spaced complete spinal transections, one at 10% BL and one at 30% BL, to interrupt long-axon RS neuron projections. At short recovery times (3–5 wk), RS and PS neurons will have regenerated their axons for short distances and potentially established a polysynaptic descending command pathway. At these short recovery times, swimming muscle burst activity had only minor coordination deficits. A computer model that incorporated either of the two spinal lesions could mimic many aspects of the experimental data. In conclusion, descending PS neurons are a viable mechanism for indirect activation of spinal locomotor CPGs, although there can be coordination deficits of locomotor activity. NEW & NOTEWORTHY In the lamprey following spinal lesion-mediated interruption of long axonal projections of reticulospinal (RS) neurons, sensory stimulation still elicited relatively normal locomotor muscle burst activity, but with some coordination deficits. Computer models incorporating the spinal lesions could mimic many aspects of the experimental results. Thus, after disruption of long-axon projections from RS neurons in the lamprey, descending propriospinal (PS) neurons appear to be a viable compensatory mechanism for indirect activation of spinal locomotor networks.
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Spée, Marion, Lorène Marchal, Anne-Mathilde Thierry, Olivier Chastel, Manfred Enstipp, Yvon Le Maho, Michaël Beaulieu, and Thierry Raclot. "Exogenous corticosterone mimics a late fasting stage in captive Adélie penguins (Pygoscelis adeliae)." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 300, no. 5 (May 2011): R1241—R1249. http://dx.doi.org/10.1152/ajpregu.00762.2010.
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Fasting is part of penguin's breeding constraints. During prolonged fasting, three metabolic phases occur successively. Below a threshold in body reserves, birds enter phase III (PIII), which is characterized by hormonal and metabolic shifts. These changes are concomitant with egg abandonment in the wild and increased locomotor activity in captivity. Because corticosterone (CORT) enhances foraging activity, we investigated the variations of endogenous CORT, and the effects of exogenous CORT on the behavioral, hormonal, and metabolic responses of failed breeder Adélie penguins. Untreated and treated captive male birds were regularly weighed and sampled for blood while fasting, and locomotor activity was recorded daily. Treated birds were implanted with various doses of CORT during phase II. Untreated penguins entering PIII had increased CORT (3.5-fold) and uric acid (4-fold; reflecting protein catabolism) levels, concomitantly with a rise in locomotor activity (2-fold), while prolactin (involved in parental care in birds) levels declined by 33%. In CORT-treated birds, an inverted-U relationship was obtained between CORT levels and locomotor activity. The greatest increase in locomotor activity was observed in birds implanted with a high dose of CORT (C100), locomotor activity showing a 2.5-fold increase, 4 days after implantation to a level similar to that of birds in PIII. Moreover, uric acid levels increased three-fold in C100-birds, while prolactin levels declined by 30%. The experimentally induced rise in CORT levels mimicked metabolic, hormonal, and behavioral changes, characterizing late fasting, thus supporting a role for this hormone in the enhanced drive for refeeding occurring in long-term fasting birds.
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RADKHAH, KATAYON, CHRISTOPHE MAUFROY, MORITZ MAUS, DORIAN SCHOLZ, ANDRE SEYFARTH, and OSKAR VON STRYK. "CONCEPT AND DESIGN OF THE BIOBIPED1 ROBOT FOR HUMAN-LIKE WALKING AND RUNNING." International Journal of Humanoid Robotics 08, no. 03 (September 2011): 439–58. http://dx.doi.org/10.1142/s0219843611002587.
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Biomechanics research shows that the ability of the human locomotor system depends on the functionality of a highly compliant motor system that enables a variety of different motions (such as walking and running) and control paradigms (such as flexible combination of feedforward and feedback controls strategies) and reliance on stabilizing properties of compliant gaits. As a new approach of transferring this knowledge into a humanoid robot, the design and implementation of the first of a planned series of biologically inspired, compliant, and musculoskeletal robots is presented in this paper. Its three-segmented legs are actuated by compliant mono- and biarticular structures, which mimic the main nine human leg muscle groups, by applying series elastic actuation consisting of cables and springs in combination with electrical actuators. By means of this platform, we aim to transfer versatile human locomotion abilities, namely running and later on walking, into one humanoid robot design. First experimental results for passive rebound, as well as push-off with active knee and ankle joints, and synchronous and alternate hopping are described and discussed. BioBiped1 will serve for further evaluation of the validity of biomechanical concepts for humanoid locomotion.
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Owaki, Dai, Takeshi Kano, Ko Nagasawa, Atsushi Tero, and Akio Ishiguro. "Simple robot suggests physical interlimb communication is essential for quadruped walking." Journal of The Royal Society Interface 10, no. 78 (January 6, 2013): 20120669. http://dx.doi.org/10.1098/rsif.2012.0669.
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Quadrupeds have versatile gait patterns, depending on the locomotion speed, environmental conditions and animal species. These locomotor patterns are generated via the coordination between limbs and are partly controlled by an intraspinal neural network called the central pattern generator (CPG). Although this forms the basis for current control paradigms of interlimb coordination, the mechanism responsible for interlimb coordination remains elusive. By using a minimalistic approach, we have developed a simple-structured quadruped robot, with the help of which we propose an unconventional CPG model that consists of four decoupled oscillators with only local force feedback in each leg. Our robot exhibits good adaptability to changes in weight distribution and walking speed simply by responding to local feedback, and it can mimic the walking patterns of actual quadrupeds. Our proposed CPG-based control method suggests that physical interaction between legs during movements is essential for interlimb coordination in quadruped walking.
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Kulkarni, Siddharth, Craig Chapman, Hanifa Shah, Erika Anneli Parn, and David John Edwards. "Designing an efficient tidal turbine blade through bio-mimicry: a systematic review." Journal of Engineering, Design and Technology 16, no. 1 (February 5, 2018): 101–24. http://dx.doi.org/10.1108/jedt-08-2017-0077.
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Purpose This paper aims to conduct a comprehensive literature review in the tidal energy physics, the ocean environment, hydrodynamics of horizontal axis tidal turbines and bio-mimicry. Design/methodology/approach The paper provides an insight of the tidal turbine blade design and need for renewable energy sources to generate electricity through clean energy sources and less CO2 emission. The ocean environment, along with hydrodynamic design principles of a horizontal axis tidal turbine blade, is described, including theoretical maximum efficiency, blade element momentum theory and non-dimensional forces acting on tidal turbine blades. Findings This review gives an overview of fish locomotion identifying the attributes of the swimming like lift-based thrust propulsion, the locomotion driving factors: dorsal fins, caudal fins in propulsion, which enable the fish to be efficient even at low tidal velocities. Originality/value Finally, after understanding the phenomenon of caudal fin propulsion and its relationship with tidal turbine blade hydrodynamics, this review focuses on the implications of bio-mimicking a curved caudal fin to design an efficient horizontal axis tidal turbine.
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Nugent, Marilee M., and Theodore E. Milner. "Segmental specificity in belly dance mimics primal trunk locomotor patterns." Journal of Neurophysiology 117, no. 3 (March 1, 2017): 1100–1111. http://dx.doi.org/10.1152/jn.00693.2016.
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Belly dance was used to investigate control of rhythmic undulating trunk movements in humans. Activation patterns in lumbar erector spinae muscles were recorded using surface electromyography at four segmental levels spanning T10 to L4. Muscle activation patterns for movement tempos of 2 Hz, 3 Hz, and as fast as possible (up to 6 Hz) were compared to test the hypothesis that frequency modulates muscle timing, causing pattern changes analogous to gait transitions. Groups of trained and untrained female subjects were compared to test the hypothesis that experience modifies muscle coordination patterns and the capacity for selective motion of spinal segments. Three distinct coordination patterns were observed. An ipsilateral simultaneous pattern (S) and a diagonal synergy (D) dominated at lower frequencies. The S pattern was selected most often by novices and resembled the standing wave of activation underlying the alternating lateral trunk bending in salamander trotting. At 2 Hz, most trained subjects selected the D pattern, suggesting a greater capacity for segmental specificity compared with untrained subjects. At 3–4 Hz, there emerged an asynchronous pattern (A) analogous to the rostral-caudal traveling wave in salamander and lamprey swimming. The neural networks and mechanisms identified in primitive vertebrates, such as chains of coupled oscillators and segmental crossed inhibitory connections, could explain the patterns observed in this study in humans. Training allows modification of these patterns, possibly through improved capacity for selectively exciting or inhibiting segmental pattern generators. NEW & NOTEWORTHY Belly dance provides a novel approach for studying spinal cord neural circuits. New evidence suggests that primitive locomotor circuits may be conserved in humans. Erector spinae activation patterns during the hip shimmy at different tempos are similar to those observed in salamander walking and swimming. As movement frequency increases, a sequential pattern similar to lamprey swimming emerges, suggesting that primal involuntary control mechanisms dominate in fast lateral rhythmic spine undulations even in humans.
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Gabloffsky, Theo, Sadaf Gill, Anna Staffeld, Ralf Salomon, Nicole Power Guerra, Sarah Joost, Alexander Hawlitschka, Markus Kipp, and Linda Frintrop. "Food Restriction in Mice Induces Food-Anticipatory Activity and Circadian-Rhythm-Related Activity Changes." Nutrients 14, no. 24 (December 9, 2022): 5252. http://dx.doi.org/10.3390/nu14245252.
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Anorexia nervosa (AN) is characterized by emaciation, hyperactivity, and amenorrhea. To what extent AN-related symptoms are due to food restriction or neuronal dysfunction is currently unknown. Thus, we investigated the relevance of food restriction on AN-related symptoms. Disrupted circadian rhythms are hypothesized to contribute to the pathophysiology of AN. Starvation was induced by restricting food access in early adolescent or adolescent mice to 40% of their baseline food intake until a 20% weight reduction was reached (acute starvation). To mimic chronic starvation, the reduced weight was maintained for a further 2 weeks. Locomotor activity was analyzed using running wheel sensors. The circadian-rhythm-related activity was measured using the tracking system Goblotrop. Amenorrhea was determined by histological examination of vaginal smears. All cohorts showed an increase in locomotor activity up to 4 h before food presentation (food-anticipatory activity, FAA). While amenorrhea was present in all groups except in early adolescent acutely starved mice, hyperactivity was exclusively found in chronically starved groups. Adolescent chronically starved mice showed a decrease in circadian-rhythm-related activity at night. Chronic starvation most closely mimics AN-related behavioral changes. It appears that the FAA is a direct consequence of starvation. The circadian activity changes might underlie the pathophysiology of AN.
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La Corte, Giorgio, Yina Wei, Nick Chernyy, Bruce J. Gluckman, and Steven J. Schiff. "Frequency dependence of behavioral modulation by hippocampal electrical stimulation." Journal of Neurophysiology 111, no. 3 (February 1, 2014): 470–80. http://dx.doi.org/10.1152/jn.00523.2013.
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Electrical stimulation offers the potential to develop novel strategies for the treatment of refractory medial temporal lobe epilepsy. In particular, direct electrical stimulation of the hippocampus presents the opportunity to modulate pathological dynamics at the ictal focus, although the neuroanatomical substrate of this region renders it susceptible to altering cognition and affective processing as a side effect. We investigated the effects of three electrical stimulation paradigms on separate groups of freely moving rats (sham, 8-Hz and 40-Hz sine-wave stimulation of the ventral/intermediate hippocampus, where 8- and 40-Hz stimulation were chosen to mimic naturally occurring hippocampal oscillations). Animals exhibited attenuated locomotor and exploratory activity upon stimulation at 40 Hz, but not at sham or 8-Hz stimulation. Such behavioral modifications were characterized by a significant reduction in rearing frequency, together with increased freezing behavior. Logistic regression analysis linked the observed changes in animal locomotion to 40-Hz electrical stimulation independently of time-related variables occurring during testing. Spectral analysis, conducted to monitor the electrophysiological profile in the CA1 area of the dorsal hippocampus, showed a significant reduction in peak theta frequency, together with reduced theta power in the 40-Hz vs. the sham stimulation animal group, independent of locomotion speed (theta range: 4–12 Hz). These findings contribute to the development of novel and safe medical protocols by indicating a strategy to constrain or optimize parameters in direct hippocampal electrical stimulation.
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Théry, Marc, and Jérôme Casas. "The multiple disguises of spiders: web colour and decorations, body colour and movement." Philosophical Transactions of the Royal Society B: Biological Sciences 364, no. 1516 (November 6, 2008): 471–80. http://dx.doi.org/10.1098/rstb.2008.0212.
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Diverse functions have been assigned to the visual appearance of webs, spiders and web decorations, including prey attraction, predator deterrence and camouflage. Here, we review the pertinent literature, focusing on potential camouflage and mimicry. Webs are often difficult to detect in a heterogeneous visual environment. Static and dynamic web distortions are used to escape visual detection by prey, although particular silk may also attract prey. Recent work using physiological models of vision taking into account visual environments rarely supports the hypothesis of spider camouflage by decorations, but most often the prey attraction and predator confusion hypotheses. Similarly, visual modelling shows that spider coloration is effective in attracting prey but not in conveying camouflage. Camouflage through colour change might be used by particular crab spiders to hide from predator or prey on flowers of different coloration. However, results obtained on a non-cryptic crab spider suggest that an alternative function of pigmentation may be to avoid UV photodamage through the transparent cuticle. Numerous species are clearly efficient locomotory mimics of ants, particularly in the eyes of their predators. We close our paper by highlighting gaps in our knowledge.
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Karakasiliotis, K., R. Thandiackal, K. Melo, T. Horvat, N. K. Mahabadi, S. Tsitkov, J. M. Cabelguen, and A. J. Ijspeert. "From cineradiography to biorobots: an approach for designing robots to emulate and study animal locomotion." Journal of The Royal Society Interface 13, no. 119 (June 2016): 20151089. http://dx.doi.org/10.1098/rsif.2015.1089.
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Robots are increasingly used as scientific tools to investigate animal locomotion. However, designing a robot that properly emulates the kinematic and dynamic properties of an animal is difficult because of the complexity of musculoskeletal systems and the limitations of current robotics technology. Here, we propose a design process that combines high-speed cineradiography, optimization, dynamic scaling, three-dimensional printing, high-end servomotors and a tailored dry-suit to construct Pleurobot: a salamander-like robot that closely mimics its biological counterpart, Pleurodeles waltl . Our previous robots helped us test and confirm hypotheses on the interaction between the locomotor neuronal networks of the limbs and the spine to generate basic swimming and walking gaits. With Pleurobot, we demonstrate a design process that will enable studies of richer motor skills in salamanders. In particular, we are interested in how these richer motor skills can be obtained by extending our spinal cord models with the addition of more descending pathways and more detailed limb central pattern generator networks. Pleurobot is a dynamically scaled amphibious salamander robot with a large number of actuated degrees of freedom (DOFs: 27 in total). Because of our design process, the robot can capture most of the animal's DOFs and range of motion, especially at the limbs. We demonstrate the robot's abilities by imposing raw kinematic data, extracted from X-ray videos, to the robot's joints for basic locomotor behaviours in water and on land. The robot closely matches the behaviour of the animal in terms of relative forward speeds and lateral displacements. Ground reaction forces during walking also resemble those of the animal. Based on our results, we anticipate that future studies on richer motor skills in salamanders will highly benefit from Pleurobot's design.
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Soll, Matan, Hagit Goldshtein, Ron Rotkopf, Niva Russek-Blum, and Zeev Gross. "A Synthetic SOD/Catalase Mimic Compound for the Treatment of ALS." Antioxidants 10, no. 6 (May 22, 2021): 827. http://dx.doi.org/10.3390/antiox10060827.
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Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting motor neurons. To date, the etiology of the disease is still unclear, with evidence of reactive oxygen species, mitochondrial dysfunction, iron homeostasis perturbation, protein misfolding and protein aggregation as key players in the pathology of the disease. Twenty percent of familial ALS and two percent of sporadic ALS instances are due to a mutation in Cu/Zn superoxide dismutase (SOD1). Sporadic and familial ALS affects the same neurons with similar pathology; therefore, the underlying hypothesis is that therapies effective in mutant SOD1 models could be translated to sporadic ALS. Corrole metal complexes have lately been identified as strong and potent catalytic antioxidants with beneficial effects in oxidative stress-related diseases such as Parkinson’s disease, Alzheimer’s disease, atherosclerosis, diabetes and its complications. One of the most promising candidates is the iron complex of an amphiphilic corrole, 1-Fe. In this study we used the SOD1 G93R mutant zebrafish ALS model to assess whether 1-Fe, as a potent catalytic antioxidant, displays any therapeutic merits in vivo. Our results show that 1-Fe caused a substantial increase in mutant zebrafish locomotor activity (up to 30%), bringing the locomotive abilities of the mutant treated group close to that of the wild type untreated group (50% more than the mutated untreated group). Furthermore, 1-Fe did not affect WT larvae locomotor activity, suggesting that 1-Fe enhances locomotor ability by targeting mechanisms underlying SOD1 ALS specifically. These results may pave the way for future development of 1-Fe as a viable treatment for ALS.
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Hossie, Thomas John, and Thomas N. Sherratt. "Does defensive posture increase mimetic fidelity of caterpillars with eyespots to their putative snake models?" Current Zoology 60, no. 1 (February 1, 2014): 76–89. http://dx.doi.org/10.1093/czoolo/60.1.76.
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Abstract Organisms often evolve behaviours that increase or reinforce the protection from predators afforded by their morphological defences. For example, mimetic animals may adopt postures or locomotory behaviours that emulate a characteristic feature of their model to increase predator deception. Caterpillars with eyespots are thought to mimic snakes, and when threatened many of these caterpillars adopt a posture that appears to enhance this resemblance. Herein we evaluate the quantitative strength of evidence of behavioural mimicry in the caterpillars of 14 species by comparing how closely a series of putative snake-mimicking caterpillars resemble snakes while at rest and when threatened. Specifically, we quantified the head morphology and eye position of a range of snake species, as well as the shape of the apparent head (i.e. anterior body segments) and position of eyespots in caterpillars resting or in their defensive posture. This allowed us to objectively examine evidence for an increased resemblance to either snakes generally, or to Viperidae snakes specifically, upon adopting the defensive posture. Widening the anterior body segments during the defensive posture typically made caterpillars appear more viper-like as opposed to more snake-like in general. Enhanced resemblance to vipers upon mounting the defensive posture was apparent only from the dorsal view. Laterally, caterpillars more closely resembled snakes in the resting posture and shifting to the defensive posture instead reduced mimetic fidelity. Overall we found evidence for behavioural mimicry in all 14 species examined. We highlight that objectively quantifying mimetic fidelity can help identify key features involved in deception.
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Chan, Betty, Adriana Villella, Pablo Funes, and Jeffrey C. Hall. "Courtship and Other Behaviors Affected by a Heat-Sensitive, Molecularly Novel Mutation in the cacophony Calcium-Channel Gene of Drosophila." Genetics 162, no. 1 (September 1, 2002): 135–53. http://dx.doi.org/10.1093/genetics/162.1.135.
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Abstract The cacophony (cac) locus of Drosophila melanogaster, which encodes a calcium-channel subunit, has been mutated to cause courtship-song defects or abnormal responses to visual stimuli. However, the most recently isolated cac mutant was identified as an enhancer of a comatose mutation’s effects on general locomotion. We analyzed the cacTS2 mutation in terms of its intragenic molecular change and its effects on behaviors more complex than the fly’s elementary ability to move. The molecular etiology of this mutation is a nucleotide substitution that causes a proline-to-serine change in a region of the polypeptide near its EF hand. Given that this motif is involved in channel inactivation, it was intriguing that cacTS2 males generate song pulses containing larger-than-normal numbers of cycles—provided that such males are exposed to an elevated temperature. Similar treatments caused only mild visual-response abnormalities and generic locomotor sluggishness. These results are discussed in the context of calcium-channel functions that subserve certain behaviors and of defects exhibited by the original cacophony mutant. Despite its different kind of amino-acid substitution, compared with that of cacTS2, cacS males sing abnormally in a manner that mimics the new mutant’s heat-sensitive song anomaly.
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Marvi, Hamidreza, Jacob Bridges, and David L. Hu. "Snakes mimic earthworms: propulsion using rectilinear travelling waves." Journal of The Royal Society Interface 10, no. 84 (July 6, 2013): 20130188. http://dx.doi.org/10.1098/rsif.2013.0188.
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In rectilinear locomotion, snakes propel themselves using unidirectional travelling waves of muscular contraction, in a style similar to earthworms. In this combined experimental and theoretical study, we film rectilinear locomotion of three species of snakes, including red-tailed boa constrictors, Dumeril's boas and Gaboon vipers. The kinematics of a snake's extension–contraction travelling wave are characterized by wave frequency, amplitude and speed. We find wave frequency increases with increasing body size, an opposite trend than that for legged animals. We predict body speed with 73–97% accuracy using a mathematical model of a one-dimensional n -linked crawler that uses friction as the dominant propulsive force. We apply our model to show snakes have optimal wave frequencies: higher values increase Froude number causing the snake to slip; smaller values decrease thrust and so body speed. Other choices of kinematic variables, such as wave amplitude, are suboptimal and appear to be limited by anatomical constraints. Our model also shows that local body lifting increases a snake's speed by 31 per cent, demonstrating that rectilinear locomotion benefits from vertical motion similar to walking.
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Zhang, Zhi, Frederico Machado, Li Zhao, Charlotte A. Heinen, Ewout Foppen, Mariette T. Ackermans, Jiangning Zhou, et al. "Administration of Thyrotropin-Releasing Hormone in the Hypothalamic Paraventricular Nucleus of Male Rats Mimics the Metabolic Cold Defense Response." Neuroendocrinology 107, no. 3 (2018): 267–79. http://dx.doi.org/10.1159/000492785.
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Background: Cold exposure increases thyrotropin-releasing hormone (TRH) expression primarily in the hypothalamic paraventricular nucleus (PVN). The PVN is a well-known hypothalamic hub in the control of energy metabolism. TRH terminals and receptors are found on PVN neurons. We hypothesized that TRH release in the PVN plays an important role in the control of thermogenesis and energy mobilization during cold exposure. Methods: Male Wistar rats were exposed to a cold environment (4°C) or TRH retrodialysis in the PVN for 2 h. We compared the effects of cold exposure and TRH administration in the PVN on plasma glucose, corticosterone, and thyroid hormone concentrations, body temperature, locomotor activity, as well as metabolic gene expression in the liver and brown adipose tissue. Results: Cold exposure increased body temperature, locomotor activity, and plasma corticosterone concentrations, but blood glucose concentrations were similar to that of room temperature control animals. TRH administration in the PVN also promptly increased body temperature, locomotor activity and plasma corticosterone concentrations. However, TRH administration in the PVN markedly increased blood glucose concentrations and endogenous glucose production (EGP) compared to saline controls. Selective hepatic sympathetic or parasympathetic denervation reduced the TRH-induced increase in glucose concentrations and EGP. Gene expression data indicated increased gluconeogenesis in liver and lipolysis in brown adipose tissue, both after cold exposure and TRH administration. Conclusions: We conclude that TRH administration in the rat PVN largely mimics the metabolic and behavioral changes induced by cold exposure indicating a potential link between TRH release in the PVN and cold defense.
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Rogóż, Mikołaj, Hao Zeng, Chen Xuan, Diederik Sybolt Wiersma, and Piotr Wasylczyk. "Light-Driven Soft Robot Mimics Caterpillar Locomotion in Natural Scale." Advanced Optical Materials 4, no. 11 (August 12, 2016): 1689–94. http://dx.doi.org/10.1002/adom.201600503.
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Duband, J. L., S. Dufour, S. S. Yamada, K. M. Yamada, and J. P. Thiery. "Neural crest cell locomotion induced by antibodies to beta 1 integrins. A tool for studying the roles of substratum molecular avidity and density in migration." Journal of Cell Science 98, no. 4 (April 1, 1991): 517–32. http://dx.doi.org/10.1242/jcs.98.4.517.
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Migration of neural crest cells depends on direct, transient interactions between fibronectin molecules and their corresponding Arg-Gly-Asp integrin receptors. We have previously suggested that the moderate-activity interaction between integrin receptors and fibronectin may be critical for the transient association of the cells with their substratum. In order to test this hypothesis, we have examined the in vitro locomotory behavior of neural crest cells on substrata of differing apparent avidities for integrin receptors. As substrata, we used a variety of monoclonal and polyclonal antibodies to the integrin beta 1 subunit that were characterized for their respective relative apparent avidities for the receptor. Neural crest cells were able to migrate on these antibodies and exhibited an organization of substratum-adhesion sites and of cytoskeletal elements virtually identical to that observed on fibronectin, indicating that they can at least partially mimic the migration-promoting activity of fibronectin. However, the number of migrating cells as well as their morphology and their speed of locomotion varied significantly with both the concentration of the antibody substratum and its relative avidity for the receptor. Thus, on high-avidity monoclonal antibodies and on polyclonal divalent antibodies at high concentrations only a limited number of cells escaped from the neural tube, and the rate of their migration was reduced compared to that on fibronectin (23 +/− 5 microns h-1 versus 65 +/− 10 microns h-1). In addition, cells were unusually flattened and cohesive. Time-lapse videomicroscopy revealed that, on high-avidity substrata, neural crest cells were able to extend cell processes that adhered to the substratum, but showed a dramatically reduced capability of breaking pre-existing substratum contacts. In contrast, the same antibodies at low concentrations produced neural crest cell migration at rates very similar to those on fibronectin at the same concentrations. Low-avidity monoclonal antibodies and polyclonal monovalent antibodies at all concentrations tested permitted extensive migration of neural crest cells, which exhibited the same morphology and locomotory behavior as on fibronectin. These results indicate that both the avidity of receptors for the substratum and the number of receptors bound to the substratum are critical in regulating the locomotory behavior of neural crest cells in vitro, and therefore might help to regulate the directionality of migration and final localization pattern of neural crest cells in vivo.
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Wang, Meng, Xin-Bao Hu, Bo Zuo, Shuai Huang, Xu-Man Chen, and Hong Yang. "Liquid crystal elastomer actuator with serpentine locomotion." Chemical Communications 56, no. 55 (2020): 7597–600. http://dx.doi.org/10.1039/d0cc02823a.
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Liu, Xiyang, Seong-Ku Kim, and Xiaogong Wang. "Thermomechanical liquid crystalline elastomer capillaries with biomimetic peristaltic crawling function." Journal of Materials Chemistry B 4, no. 45 (2016): 7293–302. http://dx.doi.org/10.1039/c6tb02372j.
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Hoover, Alexander P., Antonio J. Porras, and Laura A. Miller. "Pump or coast: the role of resonance and passive energy recapture in medusan swimming performance." Journal of Fluid Mechanics 863 (January 29, 2019): 1031–61. http://dx.doi.org/10.1017/jfm.2018.1007.
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Diverse organisms that swim and fly in the inertial regime use the flapping or pumping of flexible appendages and cavities to propel themselves through a fluid. It has long been postulated that the speed and efficiency of locomotion are optimized by oscillating these appendages at their frequency of free vibration. In jellyfish swimming, a significant contribution to locomotory efficiency has been attributed to the effects passive energy recapture, whereby the bell is passively propelled through the fluid through its interaction with stopping vortex rings formed during each expansion of the bell. In this paper, we investigate the interplay between resonance and passive energy recapture using a three-dimensional implementation of the immersed boundary method to solve the fluid–structure interaction of an elastic oblate jellyfish bell propelling itself through a viscous fluid. The motion is generated through a fixed duration application of active tension to the bell margin, which mimics the action of the coronal swimming muscles. The pulsing frequency is then varied by altering the length of time between the application of applied tension. We find that the swimming speed is maximized when the bell is driven at its resonant frequency. However, the cost of transport is maximized by driving the bell at lower frequencies whereby the jellyfish passively coasts between active contractions through its interaction with the stopping vortex ring. Furthermore, the thrust generated by passive energy recapture was found to be dependent on the elastic properties of the jellyfish bell.
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Yahashi, Satowa, Ki Sung Kang, Hiroyuki Kaiya, and Kouhei Matsuda. "GHRP-6 mimics ghrelin-induced stimulation of food intake and suppression of locomotor activity in goldfish." Peptides 34, no. 2 (April 2012): 324–28. http://dx.doi.org/10.1016/j.peptides.2012.01.025.
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Shahsavan, Hamed, Amirreza Aghakhani, Hao Zeng, Yubing Guo, Zoey S. Davidson, Arri Priimagi, and Metin Sitti. "Bioinspired underwater locomotion of light-driven liquid crystal gels." Proceedings of the National Academy of Sciences 117, no. 10 (February 24, 2020): 5125–33. http://dx.doi.org/10.1073/pnas.1917952117.
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Soft-bodied aquatic invertebrates, such as sea slugs and snails, are capable of diverse locomotion modes under water. Recapitulation of such multimodal aquatic locomotion in small-scale soft robots is challenging, due to difficulties in precise spatiotemporal control of deformations and inefficient underwater actuation of existing stimuli-responsive materials. Solving this challenge and devising efficient untethered manipulation of soft stimuli-responsive materials in the aquatic environment would significantly broaden their application potential in biomedical devices. We mimic locomotion modes common to sea invertebrates using monolithic liquid crystal gels (LCGs) with inherent light responsiveness and molecular anisotropy. We elicit diverse underwater locomotion modes, such as crawling, walking, jumping, and swimming, by local deformations induced by selective spatiotemporal light illumination. Our results underpin the pivotal role of the physicomechanical properties of LCGs in the realization of diverse modes of light-driven robotic underwater locomotion. We envisage that our results will introduce a toolbox for designing efficient untethered soft robots for fluidic environments.
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Kong, TaeHo, Jung-Kyoung Choi, Hyeonseon Park, Byung Hyune Choi, Brian Jeffrey Snyder, Shefqat Bukhari, Na-Kyeong Kim, et al. "Reduction in programmed cell death and improvement in functional outcome of transient focal cerebral ischemia after administration of granulocyte-macrophage colony-stimulating factor in rats." Journal of Neurosurgery 111, no. 1 (July 2009): 155–63. http://dx.doi.org/10.3171/2008.12.jns08172.
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Object Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent hematopoietic growth factor that both enhances the survival and drives the differentiation and proliferation of myeloid lineage cells. Recent studies have suggested that GM-CSF has a neuroprotective effect against CNS injury. In this paper, the authors investigated the neuroprotective effect of GM-CSF on neuron survival and locomotor behavior in a rat model of focal cerebral ischemic injury. Materials To understand its neuroprotective effect in vitro, GM-CSF was administered to a glutamate-induced excitotoxicity neuronal injury cell culture model that mimics the pathophysiology of focal hypoxic cerebral injury. In the animal study, the authors prepared a rat focal cerebral ischemia model by occluding the unilateral middle cerebral artery. They then examined the effects of GM-CSF administration on changes in infarct volume, apoptosis-related gene expression, and improvement in locomotor behavior. Results Treatment with GM-CSF significantly increased cell viability in a cell culture model of glutamate-induced neuronal injury. Furthermore, in vivo administration of GM-CSF at 60 μg/kg body weight daily for 5 consecutive days beginning immediately after injury decreased infarction volume, altered the expression of several apoptosis-related genes (Bcl-2, Bax, caspase 3, and p53), and improved locomotor behavior in the focal cerebral ischemia model. Conclusions The GM-CSF had neuroprotective effects in in vitro and in vivo experiments and resulted in decreased infarction volume and improved locomotor behavior. Although the specific mechanism involved in stroke recovery was not fully elucidated as it was not the primary focus of this study, administration of GM-CSF appeared to decrease the extent of neuronal apoptosis by modulating the expression of several apoptosis-related genes such as Bcl-2, Bax, caspase 3, and p53. Further investigations are necessary to better understand the role of GM-CSF on neural regeneration during the recovery phase of a stroke, as well as the intracellular signal transduction pathways that mediate neuroprotection.
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Dominici, Nadia, Elena Daprati, Daniele Nico, Germana Cappellini, Yuri P. Ivanenko, and Francesco Lacquaniti. "Changes in the Limb Kinematics and Walking-Distance Estimation After Shank Elongation: Evidence for a Locomotor Body Schema?" Journal of Neurophysiology 101, no. 3 (March 2009): 1419–29. http://dx.doi.org/10.1152/jn.91165.2008.
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Little is known on the role that knowledge about body dimensions plays within this process. Here we directly addressed this question by evaluating whether changes in body proportions interfere with computation of traveled distance for targets located outside the reaching space. We studied locomotion and distance estimation in an achondroplastic child (ACH, 11 yr) before and after surgical elongation of the shank segments of both lower limbs and in healthy adults walking on stilts, designed to mimic shank-segment elongation. Kinematic analysis of gait revealed that dynamic coupling of the thigh, shank, and foot segments changed substantially as a result of elongation. Step length remained unvaried, in spite of the significant increase in total limb length (∼1.5-fold). These relatively shorter strides resulted from smaller oscillations of the shank segment, as would be predicted by proportional increments in limb size and not by asymmetrical segmental increment as in the present case (length of thighs was not modified). Distance estimation was measured by walking with eyes closed toward a memorized target. Before surgery, the behavior of ACH was comparable to that of typically developing participants. In contrast, following shank elongation, the ACH walked significantly shorter distances when aiming at the same targets. Comparable changes in limb kinematics, stride length, and estimation of traveled distance were found in adults wearing on stilts, suggesting that path integration errors in both cases were related to alterations in the intersegmental coordination of the walking limbs. The results are consistent with a dynamic locomotor body schema used for controlling step length and path estimation, based on inherent relationships between gait parameters and body proportions.
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Bailey, Timothy W., and Joseph A. Dimicco. "Chemical stimulation of the dorsomedial hypothalamus elevates plasma ACTH in conscious rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 280, no. 1 (January 1, 2001): R8—R15. http://dx.doi.org/10.1152/ajpregu.2001.280.1.r8.
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The hallmark neuroendocrine response to stress is increased plasma ACTH. Inhibition of neurons in the region of the dorsomedial hypothalamus (DMH) attenuates experimental air stress-induced elevation of heart rate (HR), mean arterial pressure (MAP), and plasma ACTH. We hypothesized that, under basal conditions, stimulation of the DMH would mimic the neuroendocrine and cardiovascular response to air stress. We examined the effects of unilateral microinjection (100-nl vol) of bicuculline methiodide (BMI, 10 pmol), kainate (KA, 1 or 3 pmol), and N-methyl-d-aspartate (5 pmol) into the DMH or the paraventicular nucleus (PVN) on HR, MAP, locomotor activity, and plasma ACTH in conscious rats. Chemical stimulation of the DMH with KA or BMI produced increased locomotor activity and effects on HR, MAP, and plasma ACTH that together mimicked the pattern seen in experimental stress. Similar treatment in the PVN produced only small increases in MAP. Thus activation of neurons in the region of the DMH results in increased secretion of ACTH along with other changes typically seen in experimental stress.
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Sellers, William Irvin, and Eishi Hirasaki. "Quadrupedal locomotor simulation: producing more realistic gaits using dual-objective optimization." Royal Society Open Science 5, no. 3 (March 2018): 171836. http://dx.doi.org/10.1098/rsos.171836.
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In evolutionary biomechanics it is often considered that gaits should evolve to minimize the energetic cost of travelling a given distance. In gait simulation this goal often leads to convincing gait generation. However, as the musculoskeletal models used get increasingly sophisticated, it becomes apparent that such a single goal can lead to extremely unrealistic gait patterns. In this paper, we explore the effects of requiring adequate lateral stability and show how this increases both energetic cost and the realism of the generated walking gait in a high biofidelity chimpanzee musculoskeletal model. We also explore the effects of changing the footfall sequences in the simulation so it mimics both the diagonal sequence walking gaits that primates typically use and also the lateral sequence walking gaits that are much more widespread among mammals. It is apparent that adding a lateral stability criterion has an important effect on the footfall phase relationship, suggesting that lateral stability may be one of the key drivers behind the observed footfall sequences in quadrupedal gaits. The observation that single optimization goals are no longer adequate for generating gait in current models has important implications for the use of biomimetic virtual robots to predict the locomotor patterns in fossil animals.
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Schmid, Maurizio, Francesco Riganti-Fulginei, Ivan Bernabucci, Antonino Laudani, Daniele Bibbo, Rossana Muscillo, Alessandro Salvini, and Silvia Conforto. "SVM versus MAP on Accelerometer Data to Distinguish among Locomotor Activities Executed at Different Speeds." Computational and Mathematical Methods in Medicine 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/343084.
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Two approaches to the classification of different locomotor activities performed at various speeds are here presented and evaluated: a maximum a posteriori (MAP) Bayes’ classification scheme and a Support Vector Machine (SVM) are applied on a 2D projection of 16 features extracted from accelerometer data. The locomotor activities (level walking, stair climbing, and stair descending) were recorded by an inertial sensor placed on the shank (preferred leg), performed in a natural indoor-outdoor scenario by 10 healthy young adults (age 25–35 yrs.). From each segmented activity epoch, sixteen features were chosen in the frequency and time domain. Dimension reduction was then performed through 2D Sammon’s mapping. An Artificial Neural Network (ANN) was trained to mimic Sammon’s mapping on the whole dataset. In the Bayes’ approach, the two features were then fed to a Bayes’ classifier that incorporates an update rule, while, in the SVM scheme, the ANN was considered as the kernel function of the classifier. Bayes’ approach performed slightly better than SVM on both the training set (91.4% versus 90.7%) and the testing set (84.2% versus 76.0%), favoring the proposed Bayes’ scheme as more suitable than the proposed SVM in distinguishing among the different monitored activities.
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Moored, Keith W., Peter A. Dewey, Megan C. Leftwich, Hilary Bart-Smith, and Alexander J. Smits. "Bioinspired Propulsion Mechanisms Based on Manta Ray Locomotion." Marine Technology Society Journal 45, no. 4 (July 1, 2011): 110–18. http://dx.doi.org/10.4031/mtsj.45.4.3.
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AbstractMobuliform swimmers are inspiring novel approaches to the design of underwater vehicles. These swimmers, exemplified by manta rays, present a model for new classes of efficient, highly maneuverable, autonomous undersea vehicles. To improve our understanding of the unsteady propulsion mechanisms used by these swimmers, we report detailed studies of the performance of robotic swimmers that mimic aspects of the animal propulsive mechanisms. We highlight the importance of the undulatory aspect of producing efficient manta ray propulsion and show that there is a strong interaction between the propulsive performance and the flexibility of the actuating surfaces.
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Truong, Huynh Kim Thoa, Man Anh Huynh, My Dung Vuu, and Thi Phuong Thao Dang. "Evaluating the Potential of Portulaca oleracea L. for Parkinson’s Disease Treatment Using a Drosophila Model with dUCH-Knockdown." Parkinson's Disease 2019 (April 18, 2019): 1–13. http://dx.doi.org/10.1155/2019/1818259.
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Parkinson’s disease (PD), which is characterized by the decreased motor function and the loss of dopaminergic neurons, is a common neurodegenerative disorder in elders. There have been numerous in vitro and in vivo models developed to study mechanisms of PD and screen potential drug. Recently, dUCH-knockdown Drosophila model has been established and showed potential for screening antioxidants for PD treatment. The dUCH-knockdown Drosophila model of PD mimics most of main PD pathologies such as dopaminergic neurons degeneration, locomotor dysfunction, and shortage of dopamine in the brain. Common purslane (Portulaca oleracea L.) is a nutritious vegetable containing a variety of antioxidants, levodopa, and dopamine, a neurotransmitter closely related to PD. Purslane has been reported to exert neuroprotective effects against several neurotoxins including rotenone and 6-OHDA in PD models. However, the recent data have not provided sufficient evidence for using purslane to treat PD or decelerate disease progression. Therefore, in this study, we utilized dUCH-knockdown fly to evaluate the capacity of purslane extracts for PD treatment. The results showed that purslane extracts improved locomotor ability in the larval stage and decelerated disease progression in the adult stage. Additionally, purslane extracts also reduced dopaminergic neuron degeneration. Taken together, our data strongly demonstrated that purslane extracts effectively rescued PD-like phenotypes in the fly model. This result contributed a foundation for further study on the application of purslane in PD treatment.
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Sinclair, J., P. J. Taylor, and S. Andrews. "Influence of barefoot, barefoot inspired and conventional shoes on tibial accelerations and loading kinetics during running in natural rearfoot strikers." Comparative Exercise Physiology 9, no. 3-4 (January 1, 2013): 161–67. http://dx.doi.org/10.3920/cep13023.
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Running barefoot and in footwear designed to mimic barefoot locomotion, has received considerable attention in footwear research. This study examined the differences in impact force and tibial acceleration parameters. Ten male participants completed 10 trials when running barefoot, in vibram five-fingers and in conventional footwear at three locomotion velocities: walk, jog and run (1.25, 3.5 and 5.0 m/s, respectively). Impact force and tibial acceleration parameters were synchronously obtained and contrasted between footwear and velocities using 3 (footwear) x 3 (velocity) repeated measures ANOVA's. Significant main effects were obtained for both footwear and velocity which suggest that barefoot running at higher velocities is associated with increases in impact loading magnitude. This leads to the conclusion that barefoot locomotion may be associated with increased risk of injury regardless of running velocity and that more specifically running barefoot at higher velocities should be undertaken with caution.
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Kalyn, Michael, Khang Hua, Suzita Mohd Noor, Chee Ern David Wong, and Marc Ekker. "Comprehensive Analysis of Neurotoxin-Induced Ablation of Dopaminergic Neurons in Zebrafish Larvae." Biomedicines 8, no. 1 (December 28, 2019): 1. http://dx.doi.org/10.3390/biomedicines8010001.
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Neurotoxin exposure of zebrafish larvae has been used to mimic a Parkinson’s disease (PD) phenotype and to facilitate high-throughput drug screening. However, the vulnerability of zebrafish to various neurotoxins was shown to be variable. Here, we provide a direct comparison of ablative effectiveness in order to identify the optimal neurotoxin-mediated dopaminergic (DAnergic) neuronal death in larval zebrafish. Transgenic zebrafish, Tg(dat:eGFP), were exposed to different concentrations of the neurotoxins MPTP, MPP+, paraquat, 6-OHDA, and rotenone for four days, starting at three days post-fertilization. The LC50 of each respective neurotoxin concentration was determined. Confocal live imaging on Tg(dat:eGFP) showed that MPTP, MPP+, and rotenone caused comparable DAnergic cell loss in the ventral diencephalon (vDC) region while, paraquat and 6-OHDA caused fewer losses of DAnergic cells. These results were further supported by respective gene expression analyses of dat, th, and p53. Importantly, the loss of DAnergic cells from exposure to MPTP, MPP+, and rotenone impacted larval locomotor function. MPTP induced the largest motor deficit, but this was accompanied by the most severe morphological impairment. We conclude that, of the tested neurotoxins, MPP+ recapitulates a substantial degree of DAnergic ablation and slight locomotor perturbations without systemic defects indicative of a Parkinsonian phenotype.
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Shaw, Bethan, Michelle Fountain, and Herman Wijnen. "Control of Daily Locomotor Activity Patterns in Drosophila suzukii by the Circadian Clock, Light, Temperature and Social Interactions." Journal of Biological Rhythms 34, no. 5 (August 22, 2019): 463–81. http://dx.doi.org/10.1177/0748730419869085.
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Understanding behavioral rhythms in a pest species can contribute to improving the efficacy of control methods targeting that pest. However, in some species, the behavioral patterns recorded in artificial conditions contrast greatly with observed wild-type behavioral rhythms. In this study, we identify the determinants of daily activity rhythms of the soft and stone fruit pest Drosophila suzukii. The impact of gender, space, social housing, temperature, light, fly morph, and the circadian clock on D. suzukii locomotor rhythms was investigated. Assays were performed under artificial laboratory conditions or more natural semifield conditions to identify how these factors affected daily locomotor behavior. Daily locomotor activity patterns collected under semifield conditions varied very little between the various sex and social condition combinations. However, in lab-based assays, individual and group-housed males often exhibited divergent activity patterns, with more prominent hyperactivity at light/dark transitions. In contrast, hyperactivity responses were suppressed under lab protocols mimicking summer conditions for groups of females and mixed-sex groups. Moreover, when environmental cues were removed, flies held in groups displayed stronger rhythmicity than individual flies. Thus, social interactions can reinforce circadian behavior and resist hyperactivity responses in D. suzukii. Fly morph appeared to have little impact on behavioral pattern, with winter and summer morph flies displaying similar activity profiles under April semifield and laboratory mimic environmental conditions. In conclusion, separate and combined effects of light, temperature, circadian clock function, and social interactions were apparent in the daily activity profiles of D. suzukii. When groups of female or mixed-sex flies were used, implementation of matching photoperiods and realistic daily temperature gradients in the lab was sufficient to re-create behavioral patterns observed in summer semifield settings. The ability to leverage lab assays to predict D. suzukii field behavior promises to be a valuable asset in improving control measures for this pest.
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Svenson, Gavin J., and Henrique M. Rodrigues. "A novel form of wasp mimicry in a new species of praying mantis from the Amazon rainforest, Vespamantoida wherleyi gen. nov. sp. nov. (Mantodea, Mantoididae)." PeerJ 7 (October 17, 2019): e7886. http://dx.doi.org/10.7717/peerj.7886.
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A wasp mimicking praying mantis (Mantodea) of the early evolving Mantoididae family was discovered in 2013 at a research station near the Amazon River in Northern Peru. This adult specimen exhibited a striking bright red/orange and black coloration pattern that was undocumented in all known praying mantis species. We tested the status of this new specimen using external morphology, male genital dissections, and geographic distribution. Our findings demonstrate the specimen to represent a new species, Vespamantoida wherleyi gen. nov. sp. nov., that is closely allied with a recently described species, Mantoida toulgoeti Roy, 2010, both of which are included within the newly erected genus. To support our actions, we present high resolution images of museum preserved and living specimens, morphological illustrations, a generic-level distribution map, and recorded video of the behavior of the holotype taken in the field at the time of collection. The bright red/orange coloration contrasted with black markings, the general appearance of a hymenopteran that includes a narrowed wasp waist, and the locomotory patterns and antennal movements mark this newly discovered species as unique among all hymenopteran mimicking Mantoididae as well as all other praying mantises.
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Zhao, Ze, Youngkyu Hwang, Yun Yang, Tengfei Fan, Juha Song, Subra Suresh, and Nam-Joon Cho. "Actuation and locomotion driven by moisture in paper made with natural pollen." Proceedings of the National Academy of Sciences 117, no. 16 (April 6, 2020): 8711–18. http://dx.doi.org/10.1073/pnas.1922560117.
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Here we describe the development of a humidity-responsive sheet of paper that is derived solely from natural pollen. Adaptive soft material components of the paper exhibit diverse and well-integrated responses to humidity that promote shape reconfiguration, actuation, and locomotion. This mechanically versatile and nonallergenic paper can generate a cyclically high contractile stress upon water absorption and desorption, and the rapid exchange of water drives locomotion due to hydrodynamic effects. Such dynamic behavior can be finely tuned by adjusting the structure and properties of the paper, including thickness, surface roughness, and processing conditions, analogous to those of classical soapmaking. We demonstrate that humidity-responsive paper-like actuators can mimic the blooming of the Michelia flower and perform self-propelled motion. Harnessing the material properties of bioinspired systems such as pollen paper opens the door to a wide range of sustainable, eco-friendly, and biocompatible material innovation platforms for applications in sensing, actuation, and locomotion.
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Prochazka, Arthur, Deborah Gillard, and David J. Bennett. "Positive Force Feedback Control of Muscles." Journal of Neurophysiology 77, no. 6 (June 1, 1997): 3226–36. http://dx.doi.org/10.1152/jn.1997.77.6.3226.
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Prochazka, Arthur, Deborah Gillard, and David J. Bennett. Positive force feedback control of muscles. J. Neurophysiol. 77: 3226–3236, 1997. This study was prompted by recent evidence for the existence of positive force feedback in feline locomotor control. Our aim was to establish some basic properties of positive force feedback in relation to load compensation, stability, intrinsic muscle properties, and interaction with displacement feedback. In human subjects, muscles acting about the wrist and ankle were activated by feedback-controlled electrical stimulation. The feedback signals were obtained from sensors monitoring force and displacement. The signals were filtered to mimic transduction by mammalian tendon organ and muscle spindle receptors. We found that when muscles under positive force feedback were loaded inertially, they responded in a stable manner with increased active force. The activation attenuated the muscle stretch (yield) that would otherwise occur in the absence of feedback. With enough positive force feedback gain, yield could actually reverse. This behavior, which we termed the affirming reaction, was reminiscent of the mammalian positive supporting reaction, a postural response elicited by contact of the foot with the ground. Muscles under positive force feedback remained stable, even when the loop gain ( G f) was set at levels of 2 or 3. In a linear system, if G f > 1, instability occurs when the loop is closed. On further investigation, we found that G f changed with joint angle: it declined as the load-bearing muscle actively shortened. We inferred that in closed-loop operation, the active muscles always shortened until G f approached unity. In other words, the length-tension curve of active muscle ensures stability even when force-related excitation of motoneurons is very large. Concomitant negative displacement feedback reinforced and stabilized load compensation up to a certain gain, beyond which instability occurred. In further trials we included delays of up to 40 ms in the positive force feedback pathway, to model the delays recently described for tendon organ reflexes in cat locomotion. Contrary to expectations, this did not destabilize the loop. Indeed, when instability was deliberately evoked by setting displacement feedback gain high, delays in the positive force feedback pathway actually stabilized control. The stabilization of positive force feedback by inherent properties of the neuromuscular system increases the functional scope to be expected of feedback from force receptors in biological motor control. Our results provide a rationale for the delayed excitatory action of Ib heteronymous input on extensor motoneurons in cat locomotion.
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Wang, Yang Wei, Bao Tong Gu, Jin Bo Tan, and Peng Fei Sang. "Motion Control for a Stingray-Like Robotic Fish with Undulating Pectoral Fins." Key Engineering Materials 620 (August 2014): 502–7. http://dx.doi.org/10.4028/www.scientific.net/kem.620.502.
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Stingrays have expanded and highly flexible pectoral fins that extend over the entire length of their body. Locomotion is controlled by modulations of the undulating fin surface which produce steady swimming, acceleration, or complex maneuvers. In this paper, a robotic fish inspired by stingray was presented. Structure of the biomimetic prototype and layout of the control system were illustrated. In order to mimic the undulations, parameters of the biomimetic pectoral fin need to be accurately controlled including frequency, amplitude, wavelength, and undulatory mode. Several control strategies were proposed to realize different kinds of locomotion. Lastly, swimming experiments were carried out in the water tank according to the control methods. Experiment results demonstrate the viability of our methods.
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Park, Yunyoung, Yongsam Kim, and Sookkyung Lim. "Locomotion of a single-flagellated bacterium." Journal of Fluid Mechanics 859 (November 21, 2018): 586–612. http://dx.doi.org/10.1017/jfm.2018.799.
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Single-flagellated bacteria propel themselves by rotating a flagellar motor, translating rotation to the filament through a compliant hook and subsequently driving the rotation of the flagellum. The flagellar motor alternates the direction of rotation between counterclockwise and clockwise, and this leads to the forward and backward directed swimming. Such bacteria can change the course of swimming as the hook experiences its buckling caused by the change of bending rigidity. In this paper, we present a comprehensive model of a monotrichous bacterium as a free swimmer in a viscous fluid. We describe a cell body as a rigid body using the penalty method and a flagellum as an elastic rod using Kirchhoff rod theory. The hydrodynamic interaction of the bacterium is described by the regularized Stokes formulation. Our model of a single-flagellated micro-organism is able to mimic a swimming pattern that is well matched with the experimental observation. Furthermore, we find the critical thresholds of the rotational frequency of the motor and the bending modulus of the hook for the buckling instability, and investigate the dependence of the buckling angle and the reorientation of the swimming cell after buckling on the physical and geometrical parameters of the model.
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Keil, Sabine, Hainan Gu, and Silvia Dorn. "Diel patterns of locomotor activity in Cydia pomonella : age and sex related differences and effects of insect hormone mimics." Physiological Entomology 26, no. 4 (December 2001): 306–14. http://dx.doi.org/10.1046/j.0307-6962.2001.00247.x.
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Wang, Chunlei, and Shigang Wang. "Bionic Control of Cheetah Bounding with a Segmented Spine." Applied Bionics and Biomechanics 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/5031586.
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A cheetah model is built to mimic real cheetah and its mechanical and dimensional parameters are derived from the real cheetah. In particular, two joints in spine and four joints in a leg are used to realize the motion of segmented spine and segmented legs which are the key properties of the cheetah bounding. For actuating and stabilizing the bounding gait of cheetah, we present a bioinspired controller based on the state-machine. The controller mainly mimics the function of the cerebellum to plan the locomotion and keep the body balance. The haptic sensor and proprioception system are used to detect the trigger of the phase transition. Besides, the vestibular modulation could perceive the pitching angle of the trunk. At last, the cerebellum acts as the CPU to operate the information from the biological sensors. In addition, the calculated results are transmitted to the low-level controller to actuate and stabilize the cheetah bounding. Moreover, the delay feedback control method is employed to plan the motion of the leg joints to stabilize the pitching motion of trunk with the stability criterion. Finally, the cyclic cheetah bounding with biological properties is realized. Meanwhile, the stability and dynamic properties of the cheetah bounding gait are analyzed elaborately.
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Curtin, Nancy A. "First Catch the Fish: Efficiency during Stretch-Shortening Cycles That Mimic Natural Locomotion." Journal of Applied Biomechanics 13, no. 4 (November 1997): 429–32. http://dx.doi.org/10.1123/jab.13.4.429.
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Bogue, Robert. "Bioinspired designs impart robots with unique capabilities." Industrial Robot: the international journal of robotics research and application 46, no. 5 (August 19, 2019): 561–67. http://dx.doi.org/10.1108/ir-05-2019-0100.
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Purpose This paper aims to provide an insight into robot developments that use bioinspired design concepts. Design/methodology/approach Following a short introduction to biomimetics, this paper first provides examples of bioinspired terrestrial, aerial and underwater robot navigation techniques. It then discusses bioinspired locomotion and considers a selection of robotic products and developments inspired by snakes, bats, diving birds, fish and dragonflies. Finally, brief concluding comments are drawn. Findings The application of design concepts that mimic the capabilities and processes found in living creatures can impart robots with unique abilities. Bioinspired techniques used by insects and other organisms, notably optic flow and sunlight polarisation sensing, allow robots to navigate without the need for methods such as simultaneous localisation and mapping, GPS or inertial measurement units. Bioinspired locomotion techniques have yielded robots capable of operating in water, air and on land and in some cases, making the transition between different media. Originality/value This shows how bioinspired design concepts can impart robots with innovative and enhanced navigation and locomotion capabilities.