Search results for "Locomotion"
showing 10 items of 201 documents
Comparing the different morphotypes of a fish pathogen - implications for key virulence factors in Flavobacterium columnare
2014
Background: Flavobacterium columnare (Bacteroidetes) is the causative agent of columnaris disease in farmed freshwater fish around the world. The bacterium forms three colony morphotypes (Rhizoid, Rough and Soft), but the differences of the morphotypes are poorly known. We studied the virulence of the morphotypes produced by F. columnare strain B067 in rainbow trout ( Onconrhynchus mykiss ) and used high-resolution scanning electron microscopy to identify the fine structures of the cells grown in liquid and on agar. We also analysed the proteins secreted extracellularly and in membrane vesicles to identify possible virulence factors. Results: Only the Rhizoid morphotype was virulent in rain…
Muscle fascicle and tendon behavior during human locomotion revisited.
2008
High-speed ultrasonography has revealed that, in human locomotion, the nature of fascicle and tendon length changes varies depending on the task, contraction intensity, and the muscles involved. The findings emphasize that the active fascicles of the gastrocnemius muscle are suddenly stretched, although they are shortening. This short-lasting stretch triggers the stretch reflex, timing of which is dependent on running speed.
Muscle-Tendon Interaction During Human Dolphin-Kick Swimming
2019
Without high impact forces, it is not clear how humans can utilize tendon elasticity during low-impact activities. The purpose of the present study was to examine the muscle-tendon behavior together with the electromyographic (EMG) activities of the vastus lateralis (VL) muscle during the human dolphin-kicking. In a swimming pool, each subject (n = 11) swam the 25 m dolphin-kicking at two different speeds (NORMAL and FAST). Surface EMGs were recorded from the VL and biceps femoris (BF) muscles. Simultaneous recordings of the knee joint angle by electro-goniometer and of the VL fascicle length by ultrasonography were used to calculate the muscle-tendon unit and tendinous length of VL (LMTU a…
Analysis of a spatial orientation memory in Drosophila.
2008
Flexible goal-driven orientation requires that the position of a target be stored, especially in case the target moves out of sight. The capability to retain, recall and integrate such positional information into guiding behaviour has been summarized under the term spatial working memory. This kind of memory contains specific details of the presence that are not necessarily part of a long-term memory. Neurophysiological studies in primates indicate that sustained activity of neurons encodes the sensory information even though the object is no longer present. Furthermore they suggest that dopamine transmits the respective input to the prefrontal cortex, and simultaneous suppression by GABA s…
Pool choice in a vertical landscape: Tadpole‐rearing site flexibility in phytotelm‐breeding frogs
2021
Abstract Many species of Neotropical frogs have evolved to deposit their tadpoles in small water bodies inside plant structures called phytotelmata. These pools are small enough to exclude large predators but have limited nutrients and high desiccation risk. Here, we explore phytotelm use by three common Neotropical species: Osteocephalus oophagus, an arboreal frog that periodically feeds eggs to its tadpoles; Dendrobates tinctorius, a tadpole‐transporting poison frog with cannibalistic tadpoles; and Allobates femoralis, a terrestrial tadpole‐transporting poison frog with omnivorous tadpoles. We found that D. tinctorius occupies pools across the chemical and vertical gradient, whereas A. fe…
The effect of cannabinoid receptor agonist WIN 55,212-2 on anxiety-like behavior and locomotion in a genetic model of absence seizures in the elevate…
2022
GAERS and NEC rats were treated with cannabinoid 1/2 receptor agonist WIN 55,212-2 2 mg/kg and tested on the Elevated Plus-Maze
Force-, power-, and elasticity-velocity relationships in walking, running, and jumping
1980
Ground reaction forces and mechanical power were investigated when the subjects walked normally, while they were racing or running at four speeds, and when they performed the running long jump take-off. In addition, the apparent spring constants of the support leg in eccentric and concentric phases were investigated at the four running speeds, during the running long jump take-off, and in the triple jump. Six club level track and field athletes, four national level long jumpers, and six national level triple jumpers took part in the study. Cinematographic technique and a mathematical model of hopping (Alexander and Vernon 1975) were employed in the analysis. Force and power values were foun…
Construct and predictive validity of a self-reported measure of preclinical mobility limitation.
2007
Abstract Manty M, Heinonen A, Leinonen R, Tormakangas T, Sakari-Rantala R, Hirvensalo M, von Bonsdorff MB, Rantanen T. Construct and predictive validity of a self-reported measure of preclinical mobility limitation. Objectives To validate self-reported preclinical mobility limitation concept and self-report assessment method against muscle power and walking speed, and to study the predictive validity of preclinical mobility limitation with respect to future risk of manifest mobility limitation. Design Observational prospective cohort study and cross-sectional analysis. Setting Research laboratory and community. Participants A total of 632 community-living (age range, 75−81y) women and men t…
Differences in inner ear asymmetry levels between slow-moving and fast-moving primates
2021
International audience; The vestibular system of the inner ear, highly involved in maintaining balance during activities and positional behaviour of animals, has been deeply studied in order to link its morphology with the specific type of locomotion. Previous studies (e.g. Perier et al. 2016, Gonzales et al. 2018) have shown that, in primates, the amount of morphological variation is higher in slow-moving species than in fast-moving ones. These results indicate a lower selective pressure and a reduced functional demand for postural adjustments in the former group, and a higher selective pressure for balance and postural capabilities in the latter. In this study, we assessed if the differen…
Bortezomib Partially Improves Laminin α2 Chain–Deficient Muscular Dystrophy
2014
Congenital muscular dystrophy, caused by mutations in LAMA2 (the gene encoding laminin α2 chain), is a severe and incapacitating disease for which no therapy is yet available. We have recently demonstrated that proteasome activity is increased in laminin α2 chain-deficient muscle and that treatment with the nonpharmaceutical proteasome inhibitor MG-132 reduces muscle pathology in laminin α2 chain-deficient dy(3K)/dy(3K) mice. Here, we explore the use of the selective and therapeutic proteasome inhibitor bortezomib (currently used for treatment of relapsed multiple myeloma and mantle cell lymphoma) in dy(3K)/dy(3K) mice and in congenital muscular dystrophy type 1A muscle cells. Outcome measu…