Jeremie Knuesel, Jean-Marie Cabelguen, and Auke Ijspeert
- Published in print:
- 2010
- Published Online:
- January 2011
- ISBN:
- 9780195395273
- eISBN:
- 9780199863518
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195395273.003.0018
- Subject:
- Neuroscience, Sensory and Motor Systems
The spinal mechanisms of gait generation and gait transition in vertebrates are still not properly understood. This chapter explores these mechanisms in the salamander, an amphibian capable of ...
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The spinal mechanisms of gait generation and gait transition in vertebrates are still not properly understood. This chapter explores these mechanisms in the salamander, an amphibian capable of swimming and walking. It reviews the current knowledge of salamander locomotion and the underlying locomotor networks, in particular the central pattern generator (CPG) networks in the spinal cord. It also presents how mathematical models and salamander-like robots are being used to test hypotheses concerning the organization of the CPGs and the mechanism of gait transition. Finally, based on new neurophysiological data, novel hypotheses are formulated concerning the role of sensory feedback in shaping the locomotor patterns. Preliminary modeling experiments are presented, showing how sensory feedback can significantly modify centrally generated patterns. Taken together, the findings suggest that the ability of salamanders to switch between swimming and walking can be explained by a spinal cord circuit that is based on a primitive neural circuit for swimming similar to the one found in the lamprey and that is extended by phylogenetically more recent limb oscillatory centers.Less
The spinal mechanisms of gait generation and gait transition in vertebrates are still not properly understood. This chapter explores these mechanisms in the salamander, an amphibian capable of swimming and walking. It reviews the current knowledge of salamander locomotion and the underlying locomotor networks, in particular the central pattern generator (CPG) networks in the spinal cord. It also presents how mathematical models and salamander-like robots are being used to test hypotheses concerning the organization of the CPGs and the mechanism of gait transition. Finally, based on new neurophysiological data, novel hypotheses are formulated concerning the role of sensory feedback in shaping the locomotor patterns. Preliminary modeling experiments are presented, showing how sensory feedback can significantly modify centrally generated patterns. Taken together, the findings suggest that the ability of salamanders to switch between swimming and walking can be explained by a spinal cord circuit that is based on a primitive neural circuit for swimming similar to the one found in the lamprey and that is extended by phylogenetically more recent limb oscillatory centers.
J. Eduardo P. W. Bicudo, William A. Buttemer, Mark A. Chappell, James T. Pearson, and Claus Bech
- Published in print:
- 2010
- Published Online:
- May 2010
- ISBN:
- 9780199228447
- eISBN:
- 9780191711305
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199228447.003.0005
- Subject:
- Biology, Ornithology
Birds are found in essentially all terrestrial environments, from lush tropical forests to barren deserts and polar regions, from the oceans to the highest mountains. This chapter describes how birds ...
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Birds are found in essentially all terrestrial environments, from lush tropical forests to barren deserts and polar regions, from the oceans to the highest mountains. This chapter describes how birds adapt to this huge array of strikingly different habitats, and the evolutionary consequences associated with these habitats and adaptations. Where appropriate information on those phylogenetic groups that have evolved unique specializations for particular environments are included.Less
Birds are found in essentially all terrestrial environments, from lush tropical forests to barren deserts and polar regions, from the oceans to the highest mountains. This chapter describes how birds adapt to this huge array of strikingly different habitats, and the evolutionary consequences associated with these habitats and adaptations. Where appropriate information on those phylogenetic groups that have evolved unique specializations for particular environments are included.
Andrew Biewener and Sheila Patek
- Published in print:
- 2018
- Published Online:
- May 2018
- ISBN:
- 9780198743156
- eISBN:
- 9780191803031
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198743156.001.0001
- Subject:
- Biology, Animal Biology, Ecology
This book provides a synthesis of the physical, physiological, evolutionary, and biomechanical principles that underlie animal locomotion. An understanding and full appreciation of animal locomotion ...
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This book provides a synthesis of the physical, physiological, evolutionary, and biomechanical principles that underlie animal locomotion. An understanding and full appreciation of animal locomotion requires the integration of these principles. Toward this end, we provide the necessary introductory foundation that will allow a more in-depth understanding of the physical biology and physiology of animal movement. In so doing, we hope that this book will illuminate the fundamentals and breadth of these systems, while inspiring our readers to look more deeply into the scientific literature and investigate new features of animal movement. Several themes run through this book. The first is that by comparing the modes and mechanisms by which animals have evolved the capacity for movement, we can understand the common principles that underlie each mode of locomotion. A second is that size matters. One of the most amazing aspects of biology is the enormous spatial and temporal scale over which organisms and biological processes operate. Within each mode of locomotion, animals have evolved designs and mechanisms that effectively contend with the physical properties and forces imposed on them by their environment. Understanding the constraints of scale that underlie locomotor mechanisms is essential to appreciating how these mechanisms have evolved and how they operate. A third theme is the importance of taking an integrative and comparative evolutionary approach in the study of biology. Organisms share much in common. Much of their molecular and cellular machinery is the same. They also must navigate similar physical properties of their environment. Consequently, an integrative approach to organismal function that spans multiple levels of biological organization provides a strong understanding of animal locomotion. By comparing across species, common principles of design emerge. Such comparisons also highlight how certain organisms may differ and point to strategies that have evolved for movement in diverse environments. Finally, because convergence upon common designs and the generation of new designs result from historical processes governed by natural selection, it is also important that we ask how and why these systems have evolved.Less
This book provides a synthesis of the physical, physiological, evolutionary, and biomechanical principles that underlie animal locomotion. An understanding and full appreciation of animal locomotion requires the integration of these principles. Toward this end, we provide the necessary introductory foundation that will allow a more in-depth understanding of the physical biology and physiology of animal movement. In so doing, we hope that this book will illuminate the fundamentals and breadth of these systems, while inspiring our readers to look more deeply into the scientific literature and investigate new features of animal movement. Several themes run through this book. The first is that by comparing the modes and mechanisms by which animals have evolved the capacity for movement, we can understand the common principles that underlie each mode of locomotion. A second is that size matters. One of the most amazing aspects of biology is the enormous spatial and temporal scale over which organisms and biological processes operate. Within each mode of locomotion, animals have evolved designs and mechanisms that effectively contend with the physical properties and forces imposed on them by their environment. Understanding the constraints of scale that underlie locomotor mechanisms is essential to appreciating how these mechanisms have evolved and how they operate. A third theme is the importance of taking an integrative and comparative evolutionary approach in the study of biology. Organisms share much in common. Much of their molecular and cellular machinery is the same. They also must navigate similar physical properties of their environment. Consequently, an integrative approach to organismal function that spans multiple levels of biological organization provides a strong understanding of animal locomotion. By comparing across species, common principles of design emerge. Such comparisons also highlight how certain organisms may differ and point to strategies that have evolved for movement in diverse environments. Finally, because convergence upon common designs and the generation of new designs result from historical processes governed by natural selection, it is also important that we ask how and why these systems have evolved.
Cindy S. Aron
- Published in print:
- 2001
- Published Online:
- October 2011
- ISBN:
- 9780195142341
- eISBN:
- 9780199849024
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195142341.003.0004
- Subject:
- History, Social History
During the 19th century, American resorts varied widely—in size, cost, location, clientele. Some resorts were small towns that swelled to crowded, minimetropolises during the summer season. Other ...
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During the 19th century, American resorts varied widely—in size, cost, location, clientele. Some resorts were small towns that swelled to crowded, minimetropolises during the summer season. Other resorts presented a more rural demeanor. Seaside resorts offered swimming; mountain resorts touted the pleasures of country walks and rides; inland springs added bathing to the pleasures of strolling or riding either through the town or countryside; lakes tendered the possibilities of fishing and sailing. Vacationers at summer resorts, perhaps reflecting the generalized and growing interest in competitiveness and physicality, participated in a range of sports and games. Summer resorts provided middle-class women with a significantly wider range of amusements and pleasures than normally available to them. Perhaps nowhere was the potential challenge to middle-class rules of conduct so great as when it came to two other popular resort pastimes—flirting and courting.Less
During the 19th century, American resorts varied widely—in size, cost, location, clientele. Some resorts were small towns that swelled to crowded, minimetropolises during the summer season. Other resorts presented a more rural demeanor. Seaside resorts offered swimming; mountain resorts touted the pleasures of country walks and rides; inland springs added bathing to the pleasures of strolling or riding either through the town or countryside; lakes tendered the possibilities of fishing and sailing. Vacationers at summer resorts, perhaps reflecting the generalized and growing interest in competitiveness and physicality, participated in a range of sports and games. Summer resorts provided middle-class women with a significantly wider range of amusements and pleasures than normally available to them. Perhaps nowhere was the potential challenge to middle-class rules of conduct so great as when it came to two other popular resort pastimes—flirting and courting.
Karen Throsby
- Published in print:
- 2016
- Published Online:
- January 2017
- ISBN:
- 9780719099625
- eISBN:
- 9781526114976
- Item type:
- book
- Publisher:
- Manchester University Press
- DOI:
- 10.7228/manchester/9780719099625.001.0001
- Subject:
- Anthropology, Social and Cultural Anthropology
This book is about the extreme sport of marathon swimming. It provides insight into a social world about which very little is known, while simultaneously exploring the ways in which the social world ...
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This book is about the extreme sport of marathon swimming. It provides insight into a social world about which very little is known, while simultaneously exploring the ways in which the social world of marathon swimming intersects and overlaps with other social worlds and configurations of power and identity. Drawing on extensive (auto) ethnographic data, Immersion explores the embodied and social processes of becoming a marathon swimming and investigates how social belonging is produced and policed. Using marathon swimming as a lens, this foundation provides a basis for an exploration of what constitutes the ‘good’ body in contemporary society across a range of sites including charitable swimming, fatness, gender and health. The book argues that the dominant representations of marathon swimming are at odds with its lived realities, and that this reflects the entrenched and limited discursive resources available for thinking about the sporting body in the wider social and cultural context. It argues that in spite of these constraints, novel modes of embodiment and pleasure seep out between the cracks of those entrenched understandings and representations, highlighting the inability of the dominant understandings of sporting embodiment to account for experiences of immersion. This in turn opens up spaces for resistance and alternative accounts of embodiment and identity both within and outside of marathon swimming.Less
This book is about the extreme sport of marathon swimming. It provides insight into a social world about which very little is known, while simultaneously exploring the ways in which the social world of marathon swimming intersects and overlaps with other social worlds and configurations of power and identity. Drawing on extensive (auto) ethnographic data, Immersion explores the embodied and social processes of becoming a marathon swimming and investigates how social belonging is produced and policed. Using marathon swimming as a lens, this foundation provides a basis for an exploration of what constitutes the ‘good’ body in contemporary society across a range of sites including charitable swimming, fatness, gender and health. The book argues that the dominant representations of marathon swimming are at odds with its lived realities, and that this reflects the entrenched and limited discursive resources available for thinking about the sporting body in the wider social and cultural context. It argues that in spite of these constraints, novel modes of embodiment and pleasure seep out between the cracks of those entrenched understandings and representations, highlighting the inability of the dominant understandings of sporting embodiment to account for experiences of immersion. This in turn opens up spaces for resistance and alternative accounts of embodiment and identity both within and outside of marathon swimming.
Joe B. Hall, Marianne Walker, and Rick Bozich
- Published in print:
- 2019
- Published Online:
- May 2020
- ISBN:
- 9780813178561
- eISBN:
- 9780813178578
- Item type:
- chapter
- Publisher:
- University Press of Kentucky
- DOI:
- 10.5810/kentucky/9780813178561.003.0003
- Subject:
- History, Cultural History
Relates the trouble Joe B., then six years old, and his brother get into for spending their days swimming in the ocean instead of going to school.
Relates the trouble Joe B., then six years old, and his brother get into for spending their days swimming in the ocean instead of going to school.
Carolyn M. King and Roger A. Powell
- Published in print:
- 2007
- Published Online:
- April 2010
- ISBN:
- 9780195322712
- eISBN:
- 9780199894239
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195322712.003.0006
- Subject:
- Biology, Animal Biology
Weasels are feisty little critters that hunt widely-dispersed and well-hidden prey with impressive predatory efficiency, willowy grace, and electric energy. Most predators tackling prey larger than ...
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Weasels are feisty little critters that hunt widely-dispersed and well-hidden prey with impressive predatory efficiency, willowy grace, and electric energy. Most predators tackling prey larger than themselves hunt in groups, but the larger weasels are astonishingly bold, often acting alone to attack a bird or rabbit twice their own size. Smaller weasels hunt by searching every hole, sniffing under fallen logs, following scent trails, and responding to any small sounds that might betray a hidden rodent. They climb trees and swim streams confidently; they burrow under snow and leaves, and patrol underground runways and nests, day and night. They make up in agility what they lack in stature by wrapping their long bodies around a struggling victim to hold it. Their galloping metabolism makes weasels always hungry, and the energy equations of weasel hunting are marginal at most times, but critical when rodent populations decline.Less
Weasels are feisty little critters that hunt widely-dispersed and well-hidden prey with impressive predatory efficiency, willowy grace, and electric energy. Most predators tackling prey larger than themselves hunt in groups, but the larger weasels are astonishingly bold, often acting alone to attack a bird or rabbit twice their own size. Smaller weasels hunt by searching every hole, sniffing under fallen logs, following scent trails, and responding to any small sounds that might betray a hidden rodent. They climb trees and swim streams confidently; they burrow under snow and leaves, and patrol underground runways and nests, day and night. They make up in agility what they lack in stature by wrapping their long bodies around a struggling victim to hold it. Their galloping metabolism makes weasels always hungry, and the energy equations of weasel hunting are marginal at most times, but critical when rodent populations decline.
Cathal Kilcline
- Published in print:
- 2019
- Published Online:
- May 2020
- ISBN:
- 9781781382899
- eISBN:
- 9781789629323
- Item type:
- chapter
- Publisher:
- Liverpool University Press
- DOI:
- 10.3828/liverpool/9781781382899.003.0002
- Subject:
- Society and Culture, Cultural Studies
Recent years have seen a proliferation of sport-themed cultural, artistic, commemorative and pedagogical productions that interpret and illuminate identitarian debates in France, particularly in ...
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Recent years have seen a proliferation of sport-themed cultural, artistic, commemorative and pedagogical productions that interpret and illuminate identitarian debates in France, particularly in relation to immigration and ethnic diversity. This chapter analyses a series of these exhibitions, monuments and texts, demonstrating the relevance of sport in the contemporary commemorative landscape. It points to evolutions in the processes of memory-making globally, and explores how the mediatisation and aesthetics of sporting practices may relate to these developments.Less
Recent years have seen a proliferation of sport-themed cultural, artistic, commemorative and pedagogical productions that interpret and illuminate identitarian debates in France, particularly in relation to immigration and ethnic diversity. This chapter analyses a series of these exhibitions, monuments and texts, demonstrating the relevance of sport in the contemporary commemorative landscape. It points to evolutions in the processes of memory-making globally, and explores how the mediatisation and aesthetics of sporting practices may relate to these developments.
Mike Dennis
- Published in print:
- 2019
- Published Online:
- May 2020
- ISBN:
- 9781503610187
- eISBN:
- 9781503611016
- Item type:
- chapter
- Publisher:
- Stanford University Press
- DOI:
- 10.11126/stanford/9781503610187.003.0009
- Subject:
- History, World Modern History
Although the German Democratic Republic is well known for its highly centralized and clandestine doping program, the elite sports edifice was not the orderly mechanism associated with the Communist ...
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Although the German Democratic Republic is well known for its highly centralized and clandestine doping program, the elite sports edifice was not the orderly mechanism associated with the Communist dictatorship. Recent research has uncovered intrinsic operational malfunctions, divergent group interests, and rivalries as clubs and national associations pursued status and material rewards. Despite elaborate internal controls, one of the outcomes was widespread “wild doping,” exceeding officially prescribed norms on the level and types of dosages administered to athletes who received unauthorized experimental steroid substances by coaches and physicians, posing potentially serious health threats to both youngsters and adults.Less
Although the German Democratic Republic is well known for its highly centralized and clandestine doping program, the elite sports edifice was not the orderly mechanism associated with the Communist dictatorship. Recent research has uncovered intrinsic operational malfunctions, divergent group interests, and rivalries as clubs and national associations pursued status and material rewards. Despite elaborate internal controls, one of the outcomes was widespread “wild doping,” exceeding officially prescribed norms on the level and types of dosages administered to athletes who received unauthorized experimental steroid substances by coaches and physicians, posing potentially serious health threats to both youngsters and adults.
Anette E. Hosoi
- Published in print:
- 2011
- Published Online:
- September 2011
- ISBN:
- 9780199605835
- eISBN:
- 9780191729522
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199605835.003.0001
- Subject:
- Physics, Soft Matter / Biological Physics
This chapter presents three lectures intended as an introduction to locomotion at low Reynolds numbers. It covers swimming, crawling, and burrowing. For those who desire a more in-depth treatment, ...
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This chapter presents three lectures intended as an introduction to locomotion at low Reynolds numbers. It covers swimming, crawling, and burrowing. For those who desire a more in-depth treatment, references throughout the text are included. These notes are written in an informal tone to match the lectures, which included a mix of chalk talks and PowerPoint presentations. Many of the PowerPoint slides have been reproduced here, although some copyrighted images have been omitted.Less
This chapter presents three lectures intended as an introduction to locomotion at low Reynolds numbers. It covers swimming, crawling, and burrowing. For those who desire a more in-depth treatment, references throughout the text are included. These notes are written in an informal tone to match the lectures, which included a mix of chalk talks and PowerPoint presentations. Many of the PowerPoint slides have been reproduced here, although some copyrighted images have been omitted.
Christel Hohenegger and Michael J. Shelley
- Published in print:
- 2011
- Published Online:
- September 2011
- ISBN:
- 9780199605835
- eISBN:
- 9780191729522
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199605835.003.0003
- Subject:
- Physics, Soft Matter / Biological Physics
This chapter is organized as follows. Section 2 reviews the basics of non-Newtonian fluid mechanics and then focuses on the two main examples, of rod-shaped and dumbbell-shaped immersed particles. ...
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This chapter is organized as follows. Section 2 reviews the basics of non-Newtonian fluid mechanics and then focuses on the two main examples, of rod-shaped and dumbbell-shaped immersed particles. The latter is a necessary element in the derivation of the Oldroyd-B model and is described in Section 3.3. In order to find the extra stress due to a suspension of rod-like bodies, the Kirkwood formula is recalled in Section 3.2.3 and its application to an actively swimming rod is presented. The last section, Section 3.4, consists of an overview of recent work on two important applications, pumping and swimming. In-depth details are given on the continuum model describing a suspension of active rods and its stability behaviour around a state of uniformity and isotropy.Less
This chapter is organized as follows. Section 2 reviews the basics of non-Newtonian fluid mechanics and then focuses on the two main examples, of rod-shaped and dumbbell-shaped immersed particles. The latter is a necessary element in the derivation of the Oldroyd-B model and is described in Section 3.3. In order to find the extra stress due to a suspension of rod-like bodies, the Kirkwood formula is recalled in Section 3.2.3 and its application to an actively swimming rod is presented. The last section, Section 3.4, consists of an overview of recent work on two important applications, pumping and swimming. In-depth details are given on the continuum model describing a suspension of active rods and its stability behaviour around a state of uniformity and isotropy.
Peter C. Waldmeier and Laurent Maitre
- Published in print:
- 1991
- Published Online:
- March 2012
- ISBN:
- 9780192620118
- eISBN:
- 9780191724725
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780192620118.003.0005
- Subject:
- Neuroscience, Techniques
The enantiomers of the tetracyclic antidepressant oxaprotiline differ in their ability to inhibit noradrenaline (NA) uptake. While (+)-oxaprotiline (CGP 12104 A) is extraordinarily potent in this ...
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The enantiomers of the tetracyclic antidepressant oxaprotiline differ in their ability to inhibit noradrenaline (NA) uptake. While (+)-oxaprotiline (CGP 12104 A) is extraordinarily potent in this respect, the (-)-enantiomer (CGP 12103 A, levoprotiline) is virtually inactive in vitro and in vivo. Levoprotiline was originally tested clinically in depressed patients as it is an ideal way to test the catecholamine hypothesis of affective disorders. Contrary to the prediction by this hypothesis, the compound clearly showed antidepressant effects in patients, which automatically raised the question of the mechanism of action. Levoprotiline has been found active in a number of behavioral tests for antidepressants: it was effective in the Porsolt swim test after chronic application; it enhanced the neurological syndrome induced by 5-hydroxytryptophan (5-HTP) and the stereotypies caused by apomorphine and after repeated treatment it also potentiated the effects of damphetamine and dopamine injected into the rat nucleus accumbens. Levoprotiline has little if any interaction with α2- and β-noradrenergic, cholinergic, serotonergic (5-HTx subtypes, 5-HT2), dopaminergic, GABAA, benzodiazepine, adenosine, and opiate receptors.Less
The enantiomers of the tetracyclic antidepressant oxaprotiline differ in their ability to inhibit noradrenaline (NA) uptake. While (+)-oxaprotiline (CGP 12104 A) is extraordinarily potent in this respect, the (-)-enantiomer (CGP 12103 A, levoprotiline) is virtually inactive in vitro and in vivo. Levoprotiline was originally tested clinically in depressed patients as it is an ideal way to test the catecholamine hypothesis of affective disorders. Contrary to the prediction by this hypothesis, the compound clearly showed antidepressant effects in patients, which automatically raised the question of the mechanism of action. Levoprotiline has been found active in a number of behavioral tests for antidepressants: it was effective in the Porsolt swim test after chronic application; it enhanced the neurological syndrome induced by 5-hydroxytryptophan (5-HTP) and the stereotypies caused by apomorphine and after repeated treatment it also potentiated the effects of damphetamine and dopamine injected into the rat nucleus accumbens. Levoprotiline has little if any interaction with α2- and β-noradrenergic, cholinergic, serotonergic (5-HTx subtypes, 5-HT2), dopaminergic, GABAA, benzodiazepine, adenosine, and opiate receptors.
Jeff Wiltse
- Published in print:
- 2007
- Published Online:
- July 2014
- ISBN:
- 9780807831007
- eISBN:
- 9781469604664
- Item type:
- chapter
- Publisher:
- University of North Carolina Press
- DOI:
- 10.5149/9780807888988_wiltse.5
- Subject:
- History, African-American History
This chapter examines the contested early history of municipal swimming pools in the United States. It traces the creation of municipal pools during the last third of the nineteenth century as public ...
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This chapter examines the contested early history of municipal swimming pools in the United States. It traces the creation of municipal pools during the last third of the nineteenth century as public baths located within residential slums to promote cleanliness, refinement, and modesty among the urban poor. The chapter shows how reformers and public officials used municipal pools as a means to counteract the increasing rates of disease, crime, and pauperism that accompanied urban growth from the mid- to late nineteenth century. It also considers the cities' introduction of elaborate rules and anti-swimming ordinances as well as the employment of poolside police officers to control the rowdy behavior of the bathers, particularly that of boys and young men, in the pools. The chapter also discusses the social divisions caused by swimming, notably along gender lines.Less
This chapter examines the contested early history of municipal swimming pools in the United States. It traces the creation of municipal pools during the last third of the nineteenth century as public baths located within residential slums to promote cleanliness, refinement, and modesty among the urban poor. The chapter shows how reformers and public officials used municipal pools as a means to counteract the increasing rates of disease, crime, and pauperism that accompanied urban growth from the mid- to late nineteenth century. It also considers the cities' introduction of elaborate rules and anti-swimming ordinances as well as the employment of poolside police officers to control the rowdy behavior of the bathers, particularly that of boys and young men, in the pools. The chapter also discusses the social divisions caused by swimming, notably along gender lines.
G. N. Orlovsky, T. G. Deliagina, and S. Grillner
- Published in print:
- 1999
- Published Online:
- March 2012
- ISBN:
- 9780198524052
- eISBN:
- 9780191724497
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524052.003.0001
- Subject:
- Neuroscience, Sensory and Motor Systems
This chapter focuses on the sea angel Clione limacina, a marine mollusc and its importance for examining all components of the locomotor control system at the network and cellular levels. An adult ...
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This chapter focuses on the sea angel Clione limacina, a marine mollusc and its importance for examining all components of the locomotor control system at the network and cellular levels. An adult Clione is normally 3–5 cm long and is normally oriented vertically, with its head up, hovering or slowly swimming upward in the water column due to rhythmic movements of its two wings. Since Clione is slightly negatively buoyant, only these continuous wing oscillations prevent it from sinking. The frequency of wing flapping during hovering or slow swimming is 1–2 Hz, but it can increase up to 3–5 Hz in some other forms of behaviour. The flapping cycle consists of two symmetrical parts, the dorsal flexion and the ventral flexion. Due to the specific configuration of the wing profile, with the posterior edge remaining behind the anterior one, propulsive force is generated in both phases of the swim cycle. The central nervous system of Clione has a ganglionic structure that is typical of invertebrates in general. In each ganglion, cell bodies form a layer around the central neuropil area. There are five pairs of central ganglia in Clione with a specific distribution of functions that is characteristic of other gastropod molluscs as well. Swimming in Clione is based on rhythmical flapping of two wings. All components of the locomotor control system in Clione have been extensively examined at the cellular levels, and their organization and function have been understood to a considerable extent.Less
This chapter focuses on the sea angel Clione limacina, a marine mollusc and its importance for examining all components of the locomotor control system at the network and cellular levels. An adult Clione is normally 3–5 cm long and is normally oriented vertically, with its head up, hovering or slowly swimming upward in the water column due to rhythmic movements of its two wings. Since Clione is slightly negatively buoyant, only these continuous wing oscillations prevent it from sinking. The frequency of wing flapping during hovering or slow swimming is 1–2 Hz, but it can increase up to 3–5 Hz in some other forms of behaviour. The flapping cycle consists of two symmetrical parts, the dorsal flexion and the ventral flexion. Due to the specific configuration of the wing profile, with the posterior edge remaining behind the anterior one, propulsive force is generated in both phases of the swim cycle. The central nervous system of Clione has a ganglionic structure that is typical of invertebrates in general. In each ganglion, cell bodies form a layer around the central neuropil area. There are five pairs of central ganglia in Clione with a specific distribution of functions that is characteristic of other gastropod molluscs as well. Swimming in Clione is based on rhythmical flapping of two wings. All components of the locomotor control system in Clione have been extensively examined at the cellular levels, and their organization and function have been understood to a considerable extent.
G. N. Orlovsky, T. G. Deliagina, and S. Grillner
- Published in print:
- 1999
- Published Online:
- March 2012
- ISBN:
- 9780198524052
- eISBN:
- 9780191724497
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524052.003.0003
- Subject:
- Neuroscience, Sensory and Motor Systems
This chapter presents opportunities for examining all components of the locomotor control system at the network and cellular levels in leech. There are two forms of locomotion in the leech – swimming ...
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This chapter presents opportunities for examining all components of the locomotor control system at the network and cellular levels in leech. There are two forms of locomotion in the leech – swimming and crawling – but the neuronal mechanisms of swimming are better understood. At rest, the leech has a tubular shape. At the onset of swimming the body is flattened due to a tonic contraction of dorso-ventral muscles, and during the locomotion waves of dorsal and ventral flexion start to propagate retrogradely along the body. The swimming undulations are caused by contractions of dorsal and ventral longitudinal muscles. In each of the twenty-one body segments, these muscles contract in antiphase. The Analysis of the rhythm-generator network in the leech swim CPG appeared a very difficult task because of the great number of neurons involved in rhythmogenesis. While swimming, the leech is oriented with its dorsal side up. No organs responsible for gravity sensing have been found in the leech central nervous system, however.Less
This chapter presents opportunities for examining all components of the locomotor control system at the network and cellular levels in leech. There are two forms of locomotion in the leech – swimming and crawling – but the neuronal mechanisms of swimming are better understood. At rest, the leech has a tubular shape. At the onset of swimming the body is flattened due to a tonic contraction of dorso-ventral muscles, and during the locomotion waves of dorsal and ventral flexion start to propagate retrogradely along the body. The swimming undulations are caused by contractions of dorsal and ventral longitudinal muscles. In each of the twenty-one body segments, these muscles contract in antiphase. The Analysis of the rhythm-generator network in the leech swim CPG appeared a very difficult task because of the great number of neurons involved in rhythmogenesis. While swimming, the leech is oriented with its dorsal side up. No organs responsible for gravity sensing have been found in the leech central nervous system, however.
G. N. Orlovsky, T. G. Deliagina, and S. Grillner
- Published in print:
- 1999
- Published Online:
- March 2012
- ISBN:
- 9780198524052
- eISBN:
- 9780191724497
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524052.003.0005
- Subject:
- Neuroscience, Sensory and Motor Systems
This chapter gives an account of swim-motor patterns in lobsters and crayfish. The swimmerets of crayfish and lobsters are paired segmental limbs located on the ventral side of the abdomen, and which ...
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This chapter gives an account of swim-motor patterns in lobsters and crayfish. The swimmerets of crayfish and lobsters are paired segmental limbs located on the ventral side of the abdomen, and which normally beat metachronously when the animal swims forward, walks, or ventilates its burrow. Each cycle consists of a posteriorly directed power stroke that alternates with an anteriorly directed return stroke. The frequency of beating is 1–2 Hz. Each of the swimmerets is controlled by a separate nervous mechanism located in the corresponding abdominal hemiganglion. Two groups of motor neurons innervate the muscles generating the power stroke and the return stroke of a swimmeret. Each group contains at least six excitatory neurons and one inhibitory neuron. The power-stroke and return-stroke motor neurons receive a depolarizing drive from the rhythm-generating interneurons in one phase of the swim cycle, and a hyperpolarizing drive in the opposite phase. Activation of the swimmeret system is performed by a few pairs of identified command neurons.Less
This chapter gives an account of swim-motor patterns in lobsters and crayfish. The swimmerets of crayfish and lobsters are paired segmental limbs located on the ventral side of the abdomen, and which normally beat metachronously when the animal swims forward, walks, or ventilates its burrow. Each cycle consists of a posteriorly directed power stroke that alternates with an anteriorly directed return stroke. The frequency of beating is 1–2 Hz. Each of the swimmerets is controlled by a separate nervous mechanism located in the corresponding abdominal hemiganglion. Two groups of motor neurons innervate the muscles generating the power stroke and the return stroke of a swimmeret. Each group contains at least six excitatory neurons and one inhibitory neuron. The power-stroke and return-stroke motor neurons receive a depolarizing drive from the rhythm-generating interneurons in one phase of the swim cycle, and a hyperpolarizing drive in the opposite phase. Activation of the swimmeret system is performed by a few pairs of identified command neurons.
G. N. Orlovsky, T. G. Deliagina, and S. Grillner
- Published in print:
- 1999
- Published Online:
- March 2012
- ISBN:
- 9780198524052
- eISBN:
- 9780191724497
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524052.003.0008
- Subject:
- Neuroscience, Sensory and Motor Systems
This chapter discusses swimming in insects and animals such as lamprey. Swimming by means of undulatory movements of the trunk is the main form of locomotion in most aquatic vertebrate species. Most ...
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This chapter discusses swimming in insects and animals such as lamprey. Swimming by means of undulatory movements of the trunk is the main form of locomotion in most aquatic vertebrate species. Most information available on the nervous control of swimming has been obtained from the lamprey. The lamprey originates from a group of animals that diverged from the main evolutionary line of the vertebrates around 450 million years ago. The anatomical structure of the lamprey brainstem, spinal cord, sensory organs, and motor apparatus is in many respects similar to that in higher vertebrates. The functional and cellular organizations of the locomotor control mechanisms are also similar. The lamprey presents good opportunities for analytical studies of the neural networks controlling different motor functions. This is because it has fewer nerve cells of each type than higher vertebrates. An in vitro preparation of the brainstem and spinal cord has been developed that can remain in good condition for several days. The motor pattern underlying locomotion can be elicited in this isolated nervous system. The lamprey swims by producing alternating lateral undulating movements of the body, usually with a frequency range of 1–8 Hz. These caudally directed undulatory waves push the animal forward through the water. The higher the speed of propagation of the locomotor waves, the faster the lamprey will swim.Less
This chapter discusses swimming in insects and animals such as lamprey. Swimming by means of undulatory movements of the trunk is the main form of locomotion in most aquatic vertebrate species. Most information available on the nervous control of swimming has been obtained from the lamprey. The lamprey originates from a group of animals that diverged from the main evolutionary line of the vertebrates around 450 million years ago. The anatomical structure of the lamprey brainstem, spinal cord, sensory organs, and motor apparatus is in many respects similar to that in higher vertebrates. The functional and cellular organizations of the locomotor control mechanisms are also similar. The lamprey presents good opportunities for analytical studies of the neural networks controlling different motor functions. This is because it has fewer nerve cells of each type than higher vertebrates. An in vitro preparation of the brainstem and spinal cord has been developed that can remain in good condition for several days. The motor pattern underlying locomotion can be elicited in this isolated nervous system. The lamprey swims by producing alternating lateral undulating movements of the body, usually with a frequency range of 1–8 Hz. These caudally directed undulatory waves push the animal forward through the water. The higher the speed of propagation of the locomotor waves, the faster the lamprey will swim.
G. N. Orlovsky, T. G. Deliagina, and S. Grillner
- Published in print:
- 1999
- Published Online:
- March 2012
- ISBN:
- 9780198524052
- eISBN:
- 9780191724497
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198524052.003.0009
- Subject:
- Neuroscience, Sensory and Motor Systems
This chapter focuses on the swimming characteristics of toads. The toad tadpole presents a unique vertebrate animal model for studying the nervous control of locomotion, and has been used extensively ...
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This chapter focuses on the swimming characteristics of toads. The toad tadpole presents a unique vertebrate animal model for studying the nervous control of locomotion, and has been used extensively to investigate the spinal mechanisms of undulatory swimming. The main object for studies of the cellular and network mechanisms of undulatory swimming is the embryo of the toad Xenopus laevis. The embryos can swim if released from their egg membrane shortly before they normally hatch. Swimming is due to the waves of lateral body flexion that propagate periodically, at a frequency of 10–25 Hz, from the head towards the tail. Swimming can be evoked as an escape reaction to different sensory stimuli. Swimming in the tadpole is based on caudally propagating periodical waves of lateral body flexions controlled by the spinal cord. In the escape reaction, the spinal central patter generator is activated by sensory input.Less
This chapter focuses on the swimming characteristics of toads. The toad tadpole presents a unique vertebrate animal model for studying the nervous control of locomotion, and has been used extensively to investigate the spinal mechanisms of undulatory swimming. The main object for studies of the cellular and network mechanisms of undulatory swimming is the embryo of the toad Xenopus laevis. The embryos can swim if released from their egg membrane shortly before they normally hatch. Swimming is due to the waves of lateral body flexion that propagate periodically, at a frequency of 10–25 Hz, from the head towards the tail. Swimming can be evoked as an escape reaction to different sensory stimuli. Swimming in the tadpole is based on caudally propagating periodical waves of lateral body flexions controlled by the spinal cord. In the escape reaction, the spinal central patter generator is activated by sensory input.
Simon Lewis
- Published in print:
- 2011
- Published Online:
- September 2011
- ISBN:
- 9780813036021
- eISBN:
- 9780813038636
- Item type:
- chapter
- Publisher:
- University Press of Florida
- DOI:
- 10.5744/florida/9780813036021.003.0005
- Subject:
- Literature, World Literature
This chapter analyzes Alan Hollinghurst's book The Swimming-Pool Library. In contract, Boyd's book An Ice-Cream War is an exclusive male construction which is based on a combination of public school ...
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This chapter analyzes Alan Hollinghurst's book The Swimming-Pool Library. In contract, Boyd's book An Ice-Cream War is an exclusive male construction which is based on a combination of public school attitudes towards others while the otherness is defined in terms of race, gender, class, and nation. Furthermore, The Swimming-Pool Library takes on the otherness of homosexuality. Indeed, it is generally read as a “gay novel” eulogizing the brief period of relative permissiveness between the 1967 decriminalization of homosexuality in Great Britain and the explosive spread of AIDS in the early 1980s. Hollinghurst's linking of two generally unrecorded histories—of black London and of gay London—makes The Swimming-Pool Library a perfect example of what Christopher Lane identifies as the paradoxical nature of homosexual desire in “British colonial allegory.”Less
This chapter analyzes Alan Hollinghurst's book The Swimming-Pool Library. In contract, Boyd's book An Ice-Cream War is an exclusive male construction which is based on a combination of public school attitudes towards others while the otherness is defined in terms of race, gender, class, and nation. Furthermore, The Swimming-Pool Library takes on the otherness of homosexuality. Indeed, it is generally read as a “gay novel” eulogizing the brief period of relative permissiveness between the 1967 decriminalization of homosexuality in Great Britain and the explosive spread of AIDS in the early 1980s. Hollinghurst's linking of two generally unrecorded histories—of black London and of gay London—makes The Swimming-Pool Library a perfect example of what Christopher Lane identifies as the paradoxical nature of homosexual desire in “British colonial allegory.”
Neil Cornwell
- Published in print:
- 2006
- Published Online:
- July 2012
- ISBN:
- 9780719074097
- eISBN:
- 9781781700969
- Item type:
- chapter
- Publisher:
- Manchester University Press
- DOI:
- 10.7228/manchester/9780719074097.003.0009
- Subject:
- Literature, European Literature
This chapter takes a look at Brian O'Nolan, who was also known as Flann O'Brien and Myles na Gopaleen in the literary world, introducing each of O'Nolan's literary personas, from the novelist and ...
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This chapter takes a look at Brian O'Nolan, who was also known as Flann O'Brien and Myles na Gopaleen in the literary world, introducing each of O'Nolan's literary personas, from the novelist and short-story writer (O'Brien), to the author of the funniest newspaper feature (na Gopaleen). From there the discussion focuses his two main novels, At Swim-Two-Birds and The Third Policeman. It notes that At Swim-Two-Birds was written through the second half of the 1930s and that it follows from the early writings of that decade. The Third Policeman, on the other hand, has lesser elements than the other novels, but is considered as more concentrated and serious.Less
This chapter takes a look at Brian O'Nolan, who was also known as Flann O'Brien and Myles na Gopaleen in the literary world, introducing each of O'Nolan's literary personas, from the novelist and short-story writer (O'Brien), to the author of the funniest newspaper feature (na Gopaleen). From there the discussion focuses his two main novels, At Swim-Two-Birds and The Third Policeman. It notes that At Swim-Two-Birds was written through the second half of the 1930s and that it follows from the early writings of that decade. The Third Policeman, on the other hand, has lesser elements than the other novels, but is considered as more concentrated and serious.
