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Undulatory Locomotion
Undulatory locomotion is the type of motion characterized by wave-like movement patterns that act to propel an animal forward. Examples of this type of gait include crawling in snakes, or swimming in the lamprey. Although this is typically the type of gait utilized by limbless animals, some creatures with limbs, such as the salamander, forgo use of their legs in certain environments and exhibit undulatory locomotion. In robotics this movement strategy is studied in order to create novel robotic devices capable of traversing a variety of environments. Environmental interactions In limbless locomotion, forward locomotion is generated by propagating flexural waves along the length of the animal's body. Forces generated between the animal and surrounding environment lead to a generation of alternating sideways forces that act to move the animal forward. These forces generate thrust and drag. Hydrodynamics Simulation predicts that thrust and drag are dominated by viscous forces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Garter Snake Slithers Through A Muddy Area
Eastern may refer to: Transportation *China Eastern Airlines, a current Chinese airline based in Shanghai *Eastern Air, former name of Zambia Skyways *Eastern Air Lines, a defunct American airline that operated from 1926 to 1991 *Eastern Air Lines (2015), an American airline that began operations in 2015 *Eastern Airlines, LLC, previously Dynamic International Airways, a U.S. airline founded in 2010 *Eastern Airways, an English/British regional airline *Eastern Provincial Airways, a defunct Canadian airline that operated from 1949 to 1986 *Eastern Railway (other), various railroads *Eastern Avenue (other), various roads *Eastern Parkway (other), various parkways *Eastern Freeway, Melbourne, Australia *Eastern Freeway Mumbai, Mumbai, India *, a cargo liner in service 1946-65 Education *Eastern University (other) *Eastern College (other) Other uses * Eastern Broadcasting Limited, former name of Maritime Broadcasting System, Canada * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deformation (mechanics)
In physics, deformation is the continuum mechanics transformation of a body from a ''reference'' configuration to a ''current'' configuration. A configuration is a set containing the positions of all particles of the body. A deformation can occur because of external loads, intrinsic activity (e.g. muscle contraction), body forces (such as gravity or electromagnetic forces), or changes in temperature, moisture content, or chemical reactions, etc. Strain is related to deformation in terms of ''relative'' displacement of particles in the body that excludes rigid-body motions. Different equivalent choices may be made for the expression of a strain field depending on whether it is defined with respect to the initial or the final configuration of the body and on whether the metric tensor or its dual is considered. In a continuous body, a deformation field results from a stress field due to applied forces or because of some changes in the temperature field of the body. The relat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Locomotion In Space
Locomotion in space includes all actions or methods used to move one's body in microgravity conditions through the outer space environment. Locomotion in these conditions is different from locomotion in a gravitational field. There are many factors that contribute to these differences, and they are crucial when researching long-term survival of humans in space. Challenges of locomotion in reduced gravity Humans have evolved in a 1-G environment and are therefore accustomed to Earth's standard atmospheric conditions, and the microgravity environment of space can have huge effects on the human body and its locomotion. Environmental conditions The environmental conditions in space are harsh and require extensive equipment for survival and completion of daily activities. There are many environmental factors to consider both inside and outside of a spacecraft that astronauts work in. These factors include but are not limited to movement during weightlessness, general equipment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Locomotion
Aquatic locomotion or swimming is biologically propelled motion through a liquid medium. The simplest propulsive systems are composed of cilia and flagella. Swimming has evolved a number of times in a range of organisms including arthropods, fish, molluscs, amphibians, reptiles, birds, and mammals. Evolution of swimming Swimming evolved a number of times in unrelated lineages. Supposed jellyfish fossils occur in the Ediacaran, but the first free-swimming animals appear in the Early to Middle Cambrian. These are mostly related to the arthropods, and include the Anomalocaridids, which swam by means of lateral lobes in a fashion reminiscent of today's cuttlefish. Cephalopods joined the ranks of the nekton in the late Cambrian, and chordates were probably swimming from the Early Cambrian. Many terrestrial animals retain some capacity to swim, however some have returned to the water and developed the capacities for aquatic locomotion. Most apes (including humans), howeve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Locomotion
Animal locomotion, in ethology, is any of a variety of methods that animals use to move from one place to another. Some modes of locomotion are (initially) self-propelled, e.g., running, swimming, jumping, flying, hopping, soaring and gliding. There are also many animal species that depend on their environment for transportation, a type of mobility called passive locomotion, e.g., sailing (some jellyfish), kiting (spiders), rolling (some beetles and spiders) or riding other animals ( phoresis). Animals move for a variety of reasons, such as to find food, a mate, a suitable microhabitat, or to escape predators. For many animals, the ability to move is essential for survival and, as a result, natural selection has shaped the locomotion methods and mechanisms used by moving organisms. For example, migratory animals that travel vast distances (such as the Arctic tern) typically have a locomotion mechanism that costs very little energy per unit distance, whereas non-migratory a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesencephalic Locomotor Region
The mesencephalic locomotor region (MLR) is a functionally defined area of the midbrain that is associated with the initiation and control of locomotor movements in vertebrate species. Neuroanatomical organization The MLR was first described by Shik and colleagues in 1966 when they observed that electrical stimulation of a region of the midbrain in decerebrate cats produced walking and running behavior on a treadmill. Twenty-eight years later, Masdeu and colleagues described the presence of a MLR in humans. It is now widely acknowledged that, along with other motor control centers of the brain, the MLR plays an active role in initiating and modulating the spinal neural circuitry to control posture and gait. Anatomically, as the name suggests, the MLR is located in the mesencephalon (or midbrain), ventral to the inferior colliculus and near the cuneiform nucleus. Although identifying the exact anatomical substrates of the MLR has been subject to considerable debate, the pedunculo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Pattern Generator
Central pattern generators (CPGs) are self-organizing biological neural circuits that produce rhythmic outputs in the absence of rhythmic input. They are the source of the tightly-coupled patterns of neural activity that drive rhythmic and stereotyped motor behaviors like walking, swimming, breathing, or chewing. The ability to function without input from higher brain areas still requires modulatory inputs, and their outputs are not fixed. Flexibility in response to sensory input is a fundamental quality of CPG-driven behavior. To be classified as a rhythmic generator, a CPG requires: # "two or more processes that interact such that each process sequentially increases and decreases, and # that, as a result of this interaction, the system repeatedly returns to its starting condition." CPGs have been found in invertebrates, and practically all vertebrate species investigated, including humans. General anatomy and physiology Intrinsic properties of CPG neurons CPG neurons can h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penaeus Diagram Pleopods
''Penaeus'' is a genus of prawns, including the giant tiger prawn (''P. monodon''), the most important species of farmed crustacean worldwide. The genus has been reorganised following a proposition of Pérez Farfante and Kensley based on morphological differences, in particular the genital characteristics of these animals, although this revision has not been universally accepted. Following the revision, many species formerly in the genus ''Penaeus'' have been reassigned to new genera in the family Penaeidae: ''Farfantepenaeus'', '' Fenneropenaeus'', ''Litopenaeus'' and ''Marsupenaeus''. The following table gives an overview: A few more species that are sometimes given as ''Penaeus'' spp. are actually assigned to the genus ''Melicertus ''Melicertus'' is a genus of "king" prawns, comprising eight species which were previously classified as members of the genus ''Penaeus'': *''Melicertus canaliculatus'' (Olivier, 1811) - witch prawn *''Melicertus hathor'' (Burkenroad, 1959) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leech
Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodies that can lengthen and contract. Both groups are hermaphrodites and have a clitellum, but leeches typically differ from the oligochaetes in having suckers at both ends and in having ring markings that do not correspond with their internal segmentation. The body is muscular and relatively solid, and the coelom, the spacious body cavity found in other annelids, is reduced to small channels. The majority of leeches live in freshwater habitats, while some species can be found in terrestrial or marine environments. The best-known species, such as the medicinal leech, '' Hirudo medicinalis'', are hematophagous, attaching themselves to a host with a sucker and feeding on blood, having first secreted the peptide hirudin to prevent the blo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Pattern Generator
Central pattern generators (CPGs) are self-organizing biological neural circuits that produce rhythmic outputs in the absence of rhythmic input. They are the source of the tightly-coupled patterns of neural activity that drive rhythmic and stereotyped motor behaviors like walking, swimming, breathing, or chewing. The ability to function without input from higher brain areas still requires modulatory inputs, and their outputs are not fixed. Flexibility in response to sensory input is a fundamental quality of CPG-driven behavior. To be classified as a rhythmic generator, a CPG requires: # "two or more processes that interact such that each process sequentially increases and decreases, and # that, as a result of this interaction, the system repeatedly returns to its starting condition." CPGs have been found in invertebrates, and practically all vertebrate species investigated, including humans. General anatomy and physiology Intrinsic properties of CPG neurons CPG neurons can h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature'' cover the full ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrative And Comparative Biology
''Integrative and Comparative Biology'' is the scientific journal for the Society for Integrative and Comparative Biology (formerly the American Society of Zoologists The Society for Integrative and Comparative Biology is organized to integrate the many fields of specialization which occur in the broad field of biology.. The society was formed in 1902 as the American Society of Zoologists, through the merger of ...). Prior to volume 42 (2002), the journal was known as ''American Zoologist'' . See also * List of zoology journals External links Society for Integrative and Comparative Biology Zoology journals Oxford University Press academic journals English-language journals Scientific comparisons Publications established in 1961 Bimonthly journals Academic journals associated with learned and professional societies of the United States {{biology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
