Quentin Cronk
- Published in print:
- 2009
- Published Online:
- May 2009
- ISBN:
- 9780199550357
- eISBN:
- 9780191720154
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199550357.001.1
- Subject:
- Biology, Plant Sciences and Forestry, Developmental Biology
This book surveys the momentous morphological change in plant evolution that created the terrestrial biosphere as we know it today. It takes as its premise that the study of plant evolution at its ...
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This book surveys the momentous morphological change in plant evolution that created the terrestrial biosphere as we know it today. It takes as its premise that the study of plant evolution at its grandest is the study of how mutations in genes have changed the way the planet functions. The evolution of the leaf, for instance, change terrestrial carbon cycling and primary productivity, so changing the earth's atmosphere and the distribution of carbon. The book charts the rise to complexity of the three many organs systems of complex land plants, the axis or stem, the leaf, and the root. These organs system are surveyed morphologically in the light of empirical morphology, in which organ concepts are considered as hypotheses to be tested in a developmental, molecular, and phylogenetic framework. It also tackles the evolution of the seed (via heterospory and covering of the megasporangium) and the flower (by complex patterning of sporophylls and sterile phyllomes). All this is placed where possible in its molecular context, with the aim of demonstrating how evolving gene networks have given rise to increasing morphological complexity.Less
This book surveys the momentous morphological change in plant evolution that created the terrestrial biosphere as we know it today. It takes as its premise that the study of plant evolution at its grandest is the study of how mutations in genes have changed the way the planet functions. The evolution of the leaf, for instance, change terrestrial carbon cycling and primary productivity, so changing the earth's atmosphere and the distribution of carbon. The book charts the rise to complexity of the three many organs systems of complex land plants, the axis or stem, the leaf, and the root. These organs system are surveyed morphologically in the light of empirical morphology, in which organ concepts are considered as hypotheses to be tested in a developmental, molecular, and phylogenetic framework. It also tackles the evolution of the seed (via heterospory and covering of the megasporangium) and the flower (by complex patterning of sporophylls and sterile phyllomes). All this is placed where possible in its molecular context, with the aim of demonstrating how evolving gene networks have given rise to increasing morphological complexity.
Geoffrey Lloyd
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780199214617
- eISBN:
- 9780191706493
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199214617.001.0001
- Subject:
- Philosophy, Philosophy of Mind
This book presents a study of the problems posed by the unity and diversity of the human mind. On the one hand, as humans we all share broadly the same anatomy, physiology, biochemistry, and certain ...
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This book presents a study of the problems posed by the unity and diversity of the human mind. On the one hand, as humans we all share broadly the same anatomy, physiology, biochemistry, and certain psychological capabilities — the capacity to learn a language, for instance. On the other, different individuals and groups have very different talents, tastes, and beliefs, for instance about how they see themselves, other humans and the world around them. These issues are highly charged, for any denial of psychic unity savours of racism, while many assertions of psychic diversity raise the spectres of arbitrary relativism, the incommensurability of beliefs systems, and their mutual unintelligibility. The book examines where different types of arguments, scientific, philosophical, anthropological and historical, can take us. It discusses colour perception, spatial cognition, animal and plant taxonomy, the emotions, ideas of health and well-being, concepts of the self, agency and causation, varying perceptions of the distinction between nature and culture, and reasoning itself. It pays attention to the multidimensionality of the phenomena to be apprehended and to the diversity of manners, or styles, of apprehending them. The weight to be given to different factors, physical, biological, psychological, cultural, ideological, varies as between different subject areas and sometimes even within a single area. The book uses recent work in social anthropology, linguistics, cognitive science, neurophysiology, and the history of ideas to redefine the problems and clarify how our evident psychic diversity can be reconciled with our shared humanity.Less
This book presents a study of the problems posed by the unity and diversity of the human mind. On the one hand, as humans we all share broadly the same anatomy, physiology, biochemistry, and certain psychological capabilities — the capacity to learn a language, for instance. On the other, different individuals and groups have very different talents, tastes, and beliefs, for instance about how they see themselves, other humans and the world around them. These issues are highly charged, for any denial of psychic unity savours of racism, while many assertions of psychic diversity raise the spectres of arbitrary relativism, the incommensurability of beliefs systems, and their mutual unintelligibility. The book examines where different types of arguments, scientific, philosophical, anthropological and historical, can take us. It discusses colour perception, spatial cognition, animal and plant taxonomy, the emotions, ideas of health and well-being, concepts of the self, agency and causation, varying perceptions of the distinction between nature and culture, and reasoning itself. It pays attention to the multidimensionality of the phenomena to be apprehended and to the diversity of manners, or styles, of apprehending them. The weight to be given to different factors, physical, biological, psychological, cultural, ideological, varies as between different subject areas and sometimes even within a single area. The book uses recent work in social anthropology, linguistics, cognitive science, neurophysiology, and the history of ideas to redefine the problems and clarify how our evident psychic diversity can be reconciled with our shared humanity.
C. Neal Stewart
- Published in print:
- 2004
- Published Online:
- September 2007
- ISBN:
- 9780195157451
- eISBN:
- 9780199790388
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195157451.001.0001
- Subject:
- Biology, Biotechnology
From years prior to the release of the first commercial transgenic crop in 1995 to the present, many concerned activists, regulators, and scientists have questioned how genetic engineering might ...
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From years prior to the release of the first commercial transgenic crop in 1995 to the present, many concerned activists, regulators, and scientists have questioned how genetic engineering might impact the environment. No measurable negative environmental impacts have been observed for commercial genetically modified crops to date, even though several risks have been identified in experimental releases. Even so, none have approached doomsday scenarios posed by activists. The risks that have been extensively studied are gene flow from crops to weeds or crop landraces; side-effects of insecticidal transgenic proteins, such as accidental killing of monarch butterflies or beneficial insects; viral recombination; and transgene combinations. Close examination has uncovered no negative effects, but plenty of positive environmental impacts from growing crops engineered for insect resistance and herbicide resistance. Insect resistant cotton and corn kill only the insects that attempt to eat the crops and have saved several million gallons of chemical insecticide applications. Herbicide resistant soybean and corn have helped in soil conservation efforts since farmers do not have to use as much tillage to control weeds. In addition to these benefits, scientists are conducting research to produce genetically engineered plants to clean up toxins, produce plastics and biofuels, and perform other ecological services. The responsible use of genetic engineering is part of sustainable agriculture now and in the future.Less
From years prior to the release of the first commercial transgenic crop in 1995 to the present, many concerned activists, regulators, and scientists have questioned how genetic engineering might impact the environment. No measurable negative environmental impacts have been observed for commercial genetically modified crops to date, even though several risks have been identified in experimental releases. Even so, none have approached doomsday scenarios posed by activists. The risks that have been extensively studied are gene flow from crops to weeds or crop landraces; side-effects of insecticidal transgenic proteins, such as accidental killing of monarch butterflies or beneficial insects; viral recombination; and transgene combinations. Close examination has uncovered no negative effects, but plenty of positive environmental impacts from growing crops engineered for insect resistance and herbicide resistance. Insect resistant cotton and corn kill only the insects that attempt to eat the crops and have saved several million gallons of chemical insecticide applications. Herbicide resistant soybean and corn have helped in soil conservation efforts since farmers do not have to use as much tillage to control weeds. In addition to these benefits, scientists are conducting research to produce genetically engineered plants to clean up toxins, produce plastics and biofuels, and perform other ecological services. The responsible use of genetic engineering is part of sustainable agriculture now and in the future.
Nicholas P. Money
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780195189711
- eISBN:
- 9780199790265
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195189711.001.0001
- Subject:
- Biology, Microbiology
This book is concerned with the most devastating fungal diseases in history. These are the plagues of trees and crop plants caused by invisible spores that have reshaped entire landscapes and ...
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This book is concerned with the most devastating fungal diseases in history. These are the plagues of trees and crop plants caused by invisible spores that have reshaped entire landscapes and decimated human populations. Everyone is aware of the Irish potato famine, but while many other fungal diseases are less familiar, they have had similarly disastrous consequences. The book focuses on the fascinating biology of the well- and lesser-known diseases, and tells the stories of the scientists involved in their study and of the people directly impacted by the loss of forest trees like the chestnut, and cash crops such as coffee and cacao. While a book about fungal epidemics is not tailor-made for an intoxicating and uplifting read, the story of the mycologists and plant pathologists engaged in combating these diseases is one of human optimism (often encouraged by desperate eccentricity). In a surprisingly brief time, human knowledge of the fungi that infect plants has evolved from Biblical superstition to the recognition of the true nature of plant disease, and more recently, to a sense of awe for the sophistication of these microbes. The crucial issue of human culpability in these fungal epidemics is addressed in the book’s closing chapter.Less
This book is concerned with the most devastating fungal diseases in history. These are the plagues of trees and crop plants caused by invisible spores that have reshaped entire landscapes and decimated human populations. Everyone is aware of the Irish potato famine, but while many other fungal diseases are less familiar, they have had similarly disastrous consequences. The book focuses on the fascinating biology of the well- and lesser-known diseases, and tells the stories of the scientists involved in their study and of the people directly impacted by the loss of forest trees like the chestnut, and cash crops such as coffee and cacao. While a book about fungal epidemics is not tailor-made for an intoxicating and uplifting read, the story of the mycologists and plant pathologists engaged in combating these diseases is one of human optimism (often encouraged by desperate eccentricity). In a surprisingly brief time, human knowledge of the fungi that infect plants has evolved from Biblical superstition to the recognition of the true nature of plant disease, and more recently, to a sense of awe for the sophistication of these microbes. The crucial issue of human culpability in these fungal epidemics is addressed in the book’s closing chapter.
John Alcock
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780195182743
- eISBN:
- 9780199790005
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195182743.001.0001
- Subject:
- Biology, Evolutionary Biology / Genetics
This book reviews a variety of evolutionary themes and uses the small terrestrial orchids of Australia to introduce and illustrate these themes. Among the topics explored are the competing ideas of ...
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This book reviews a variety of evolutionary themes and uses the small terrestrial orchids of Australia to introduce and illustrate these themes. Among the topics explored are the competing ideas of biologists who use the theory of natural selection when examining possible adaptations (such as the ability of orchid flowers to attract special pollinators) and those who reject this approach, including creationists as well as the late Stephen Jay Gould. Darwin’s own ideas on the topic are reviewed as his work on adaptive plant behavior, given that orchids provide examples of flowers with moving parts. In addition, the book outlines the ability of evolutionary biologists to trace the origin and subsequent modification of complex traits like the extraordinarily unusual flowers of certain orchids. The book also employs Australian orchids to demonstrate the challenges of determining what a species is and how to preserve the biodiversity that still exists in the world.Less
This book reviews a variety of evolutionary themes and uses the small terrestrial orchids of Australia to introduce and illustrate these themes. Among the topics explored are the competing ideas of biologists who use the theory of natural selection when examining possible adaptations (such as the ability of orchid flowers to attract special pollinators) and those who reject this approach, including creationists as well as the late Stephen Jay Gould. Darwin’s own ideas on the topic are reviewed as his work on adaptive plant behavior, given that orchids provide examples of flowers with moving parts. In addition, the book outlines the ability of evolutionary biologists to trace the origin and subsequent modification of complex traits like the extraordinarily unusual flowers of certain orchids. The book also employs Australian orchids to demonstrate the challenges of determining what a species is and how to preserve the biodiversity that still exists in the world.
Paul Weirich (ed.)
- Published in print:
- 2008
- Published Online:
- January 2008
- ISBN:
- 9780195326864
- eISBN:
- 9780199870325
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195326864.001.0001
- Subject:
- Philosophy, Moral Philosophy
Many countries, such as countries in the European Union, require that food labels announce genetically modified (GM) ingredients. The United States does not require such labeling. Which labeling ...
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Many countries, such as countries in the European Union, require that food labels announce genetically modified (GM) ingredients. The United States does not require such labeling. Which labeling policy is best? An answer must explore a complex web of topics including the science of genetic modification, the benefits of agbiotechnology, and labeling's effects on commerce. This book surveys various labeling policies and the cases for them. It is the first comprehensive, interdisciplinary treatment of the debate about labeling genetically modified food.When polled, consumers say that they want to know whether their food contains GM ingredients, just as many want to know whether their food is natural or organic. Informing consumers is a major motivation for labeling. Consumers who want GM-free products will pay a premium to support voluntary labeling. Labeling need not be mandatory.GM foods are tested to ensure safety and have been on the market for more than a decade. Still, many consumers, including some with food allergies, want to be cautious. Also, despite tests for environmental impact, some consumers may worry that GM crops will adversely effect the environment.GM food currently on the market comes primarily from plants. Meat and dairy products from GM animals are under development. These new foods make the welfare of animals an issue relevant to the debate about labeling. Labeling gives consumers an important voice concerning biotechnology's application to food production.Less
Many countries, such as countries in the European Union, require that food labels announce genetically modified (GM) ingredients. The United States does not require such labeling. Which labeling policy is best? An answer must explore a complex web of topics including the science of genetic modification, the benefits of agbiotechnology, and labeling's effects on commerce. This book surveys various labeling policies and the cases for them. It is the first comprehensive, interdisciplinary treatment of the debate about labeling genetically modified food.
When polled, consumers say that they want to know whether their food contains GM ingredients, just as many want to know whether their food is natural or organic. Informing consumers is a major motivation for labeling. Consumers who want GM-free products will pay a premium to support voluntary labeling. Labeling need not be mandatory.
GM foods are tested to ensure safety and have been on the market for more than a decade. Still, many consumers, including some with food allergies, want to be cautious. Also, despite tests for environmental impact, some consumers may worry that GM crops will adversely effect the environment.
GM food currently on the market comes primarily from plants. Meat and dairy products from GM animals are under development. These new foods make the welfare of animals an issue relevant to the debate about labeling. Labeling gives consumers an important voice concerning biotechnology's application to food production.
Roger Cousens, Calvin Dytham, and Richard Law
- Published in print:
- 2008
- Published Online:
- May 2008
- ISBN:
- 9780199299126
- eISBN:
- 9780191715006
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199299126.001.0001
- Subject:
- Biology, Ecology, Plant Sciences and Forestry
Ecologists, both practical and theoretical, now appreciate that to understand biological systems they must consider the spatial dimension. Consequently, dispersal has become one of the hottest topics ...
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Ecologists, both practical and theoretical, now appreciate that to understand biological systems they must consider the spatial dimension. Consequently, dispersal has become one of the hottest topics in plant ecology. However, in the midst of so much research output on dispersal, there is a need for a stock-take to determine the needs of future research: what has been achieved to date, where do current studies fit in, and what still needs to be determined? What are the implications of dispersal for those engaged in managing plant populations and communities? This is the first book for many years to present a synthesis of research on dispersal and its implications for plant population dynamics. The book consists of three sections: Section A reviews information on the biological and environmental processes that determine the path of an individual dispersing propagule, usually a seed, and the theory that has been developed to predict these trajectories; Section B discusses the distributions of seeds resulting from dispersal from an entire plant, theoretical research predicting the shapes of these distributions and design issues for future dispersal studies; Section C explores the implications of dispersal for expansion of populations, structure within existing populations and communities, and the evolution of dispersal traits.Less
Ecologists, both practical and theoretical, now appreciate that to understand biological systems they must consider the spatial dimension. Consequently, dispersal has become one of the hottest topics in plant ecology. However, in the midst of so much research output on dispersal, there is a need for a stock-take to determine the needs of future research: what has been achieved to date, where do current studies fit in, and what still needs to be determined? What are the implications of dispersal for those engaged in managing plant populations and communities? This is the first book for many years to present a synthesis of research on dispersal and its implications for plant population dynamics. The book consists of three sections: Section A reviews information on the biological and environmental processes that determine the path of an individual dispersing propagule, usually a seed, and the theory that has been developed to predict these trajectories; Section B discusses the distributions of seeds resulting from dispersal from an entire plant, theoretical research predicting the shapes of these distributions and design issues for future dispersal studies; Section C explores the implications of dispersal for expansion of populations, structure within existing populations and communities, and the evolution of dispersal traits.
Pat Willmer
- Published in print:
- 2011
- Published Online:
- October 2017
- ISBN:
- 9780691128610
- eISBN:
- 9781400838943
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691128610.003.0003
- Subject:
- Biology, Ecology
This chapter examines pollination, mating, and reproduction in plants. Plant reproduction can be either sexual or asexual, but the generation of new variants (which is the underlying necessity for ...
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This chapter examines pollination, mating, and reproduction in plants. Plant reproduction can be either sexual or asexual, but the generation of new variants (which is the underlying necessity for adaptation to new or changing conditions and for evolutionary change) requires that at some point in the life cycle sexual reproduction occurs. In the case of angiosperms, the pollen grain is the male gamete, the equivalent of a spore in simpler plants. The ovule (egg) contains the female gamete. The chapter first provides an overview of plant fertilization before discussing plant sex and plant mating systems. It then considers the benefits of cross-fertilization and self-fertilization in plants, along with methods for avoiding selfing within a flower. It also describes methods for avoiding selfing between flowers within a plant and concludes with an analysis of methods for ensuring selfing.Less
This chapter examines pollination, mating, and reproduction in plants. Plant reproduction can be either sexual or asexual, but the generation of new variants (which is the underlying necessity for adaptation to new or changing conditions and for evolutionary change) requires that at some point in the life cycle sexual reproduction occurs. In the case of angiosperms, the pollen grain is the male gamete, the equivalent of a spore in simpler plants. The ovule (egg) contains the female gamete. The chapter first provides an overview of plant fertilization before discussing plant sex and plant mating systems. It then considers the benefits of cross-fertilization and self-fertilization in plants, along with methods for avoiding selfing within a flower. It also describes methods for avoiding selfing between flowers within a plant and concludes with an analysis of methods for ensuring selfing.
Gerardo Patriotta
- Published in print:
- 2004
- Published Online:
- September 2007
- ISBN:
- 9780199275243
- eISBN:
- 9780191719684
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199275243.003.0007
- Subject:
- Business and Management, Strategy
This chapter looks at the sense-making processes through which narratives in the workplace lead to the creation and institutionalization of organizational knowledge. The setting is the stamping shop ...
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This chapter looks at the sense-making processes through which narratives in the workplace lead to the creation and institutionalization of organizational knowledge. The setting is the stamping shop of an automotive plant. The focus of the inquiry is on how a best performing team deals with disruption on the shop floor. In contrast to Melfi, the Mirafiori Pressing plant incarnates a highly institutionalized context, characterized by an experienced workforce, consolidated and often opaque work practices, and distinctive cultural tradition.Less
This chapter looks at the sense-making processes through which narratives in the workplace lead to the creation and institutionalization of organizational knowledge. The setting is the stamping shop of an automotive plant. The focus of the inquiry is on how a best performing team deals with disruption on the shop floor. In contrast to Melfi, the Mirafiori Pressing plant incarnates a highly institutionalized context, characterized by an experienced workforce, consolidated and often opaque work practices, and distinctive cultural tradition.
Beverley Glover
- Published in print:
- 2007
- Published Online:
- January 2008
- ISBN:
- 9780198565970
- eISBN:
- 9780191714009
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198565970.001.0001
- Subject:
- Biology, Plant Sciences and Forestry
Flowers are the beautiful and complex reproductive structures of the angiosperms, one of the most diverse and successful groups of living organisms. The underlying thesis of this book is that to ...
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Flowers are the beautiful and complex reproductive structures of the angiosperms, one of the most diverse and successful groups of living organisms. The underlying thesis of this book is that to understand fully plant development (and why flowers differ in shape, structure, and colour), it is necessary to understand why it is advantageous for them to look like they do. Conversely, in order to fully understand plant ecology, it is necessary to appreciate how floral structures have adapted and evolved. Uniquely, this book addresses flowers and flowering from both a molecular genetic perspective (considering flower induction, development, and self-incompatibility) and an ecological perspective (looking at the selective pressures placed on plants by pollinators, and the consequences for animal-plant co-evolution). This book first considers the evolution of flowers and the history of research into their development. This is followed by a detailed description of the processes which lead to flower production in model plants. The book then examines how flowers differ in shape, structure, and colour, and how these differences are generated. Finally, it assesses the role of these various aspects of floral biology in attracting pollinators and ensuring successful reproduction. In so doing, it provides the first truly integrated study of the topic — one that discusses both the how and why of flowering plant reproductive biology.Less
Flowers are the beautiful and complex reproductive structures of the angiosperms, one of the most diverse and successful groups of living organisms. The underlying thesis of this book is that to understand fully plant development (and why flowers differ in shape, structure, and colour), it is necessary to understand why it is advantageous for them to look like they do. Conversely, in order to fully understand plant ecology, it is necessary to appreciate how floral structures have adapted and evolved. Uniquely, this book addresses flowers and flowering from both a molecular genetic perspective (considering flower induction, development, and self-incompatibility) and an ecological perspective (looking at the selective pressures placed on plants by pollinators, and the consequences for animal-plant co-evolution). This book first considers the evolution of flowers and the history of research into their development. This is followed by a detailed description of the processes which lead to flower production in model plants. The book then examines how flowers differ in shape, structure, and colour, and how these differences are generated. Finally, it assesses the role of these various aspects of floral biology in attracting pollinators and ensuring successful reproduction. In so doing, it provides the first truly integrated study of the topic — one that discusses both the how and why of flowering plant reproductive biology.
Peer Hull Kristensen and Jonathan Zeitlin
- Published in print:
- 2004
- Published Online:
- September 2007
- ISBN:
- 9780199275625
- eISBN:
- 9780191705809
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199275625.003.0004
- Subject:
- Business and Management, International Business
The strength of Lake Mills' plant-community identity, its historic vertical integration, and its domestic market orientation all combined to inhibit cooperation with other plants within APV to ...
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The strength of Lake Mills' plant-community identity, its historic vertical integration, and its domestic market orientation all combined to inhibit cooperation with other plants within APV to improve the effectiveness of the parent company as a multinational association. There was, in short, no American equivalent to the Danish Mafia, nor could such a network be easily imagined from the perspective of Lake Mills. Without the institutional resources and external allies to support a more expansive vision of the plant's future, local unionists and managers understandably fell back on a slew of defensive carrot-and-stick strategies for maintaining its position within APV. On the positive side, they sought to reinforce Lake Mills' indispensability to the multinational by providing a quick turnaround service to the company's large US customer base, and by developing new products tailored to US technical standards.Less
The strength of Lake Mills' plant-community identity, its historic vertical integration, and its domestic market orientation all combined to inhibit cooperation with other plants within APV to improve the effectiveness of the parent company as a multinational association. There was, in short, no American equivalent to the Danish Mafia, nor could such a network be easily imagined from the perspective of Lake Mills. Without the institutional resources and external allies to support a more expansive vision of the plant's future, local unionists and managers understandably fell back on a slew of defensive carrot-and-stick strategies for maintaining its position within APV. On the positive side, they sought to reinforce Lake Mills' indispensability to the multinational by providing a quick turnaround service to the company's large US customer base, and by developing new products tailored to US technical standards.
Gregory P. Cheplick and Stanley H. Faeth
- Published in print:
- 2009
- Published Online:
- January 2009
- ISBN:
- 9780195308082
- eISBN:
- 9780199867462
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195308082.003.0003
- Subject:
- Biology, Ecology
Perhaps the most well-studied attribute of endophyte-infected grasses is their ability to produce alkaloids. These endophytic alkaloids fall into four general classes: 1) pyrrolopyrazine alkaloids; ...
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Perhaps the most well-studied attribute of endophyte-infected grasses is their ability to produce alkaloids. These endophytic alkaloids fall into four general classes: 1) pyrrolopyrazine alkaloids; 2) lolines or pyrrolizidine alkaloids; 3) ergot alkaloids; and 4) lolitrems or indole dipterpene alkaloids. These alkaloids have been shown to have deterrent and toxic effects on invertebrate and vertebrate herbivores, as well as anti-pathogen effects, depending on the type and level of alkaloid produced. Hence, protection of grass against herbivores has been viewed as the major mechanism of mutualistic benefit to the host and endophytes have been known as defensive mutualists. However, this chapter shows that there is not a simple relationship between endophytes, alkaloids, and resistance to herbivores. Whereas bioassays and tests with generalized agronomic pests show that alkaloids may indeed increase herbivore resistance, this is not always the case, or may not even be typical in natural grass communities. In more complex communities, alkaloids may have more negative effects on natural enemies of herbivores than the herbivores themselves, thus increasing rather than decreasing herbivory. Endophyte infection can change tolerance rather than resistance to herbivores. In the case of increasing tolerance, infected grasses may compensate for increased herbivory without concomitant loss, or even with increases, in fitness. Finally, recent evidence suggests that asexual endophytes promote herbivory during early host ontogeny which, in turn, increases seed transmission. Because most hosts of systemic endophytes are perennial grasses, resistance and tolerance to herbivores may not be an all-or-none phenomenon, but instead change with host ontogeny.Less
Perhaps the most well-studied attribute of endophyte-infected grasses is their ability to produce alkaloids. These endophytic alkaloids fall into four general classes: 1) pyrrolopyrazine alkaloids; 2) lolines or pyrrolizidine alkaloids; 3) ergot alkaloids; and 4) lolitrems or indole dipterpene alkaloids. These alkaloids have been shown to have deterrent and toxic effects on invertebrate and vertebrate herbivores, as well as anti-pathogen effects, depending on the type and level of alkaloid produced. Hence, protection of grass against herbivores has been viewed as the major mechanism of mutualistic benefit to the host and endophytes have been known as defensive mutualists. However, this chapter shows that there is not a simple relationship between endophytes, alkaloids, and resistance to herbivores. Whereas bioassays and tests with generalized agronomic pests show that alkaloids may indeed increase herbivore resistance, this is not always the case, or may not even be typical in natural grass communities. In more complex communities, alkaloids may have more negative effects on natural enemies of herbivores than the herbivores themselves, thus increasing rather than decreasing herbivory. Endophyte infection can change tolerance rather than resistance to herbivores. In the case of increasing tolerance, infected grasses may compensate for increased herbivory without concomitant loss, or even with increases, in fitness. Finally, recent evidence suggests that asexual endophytes promote herbivory during early host ontogeny which, in turn, increases seed transmission. Because most hosts of systemic endophytes are perennial grasses, resistance and tolerance to herbivores may not be an all-or-none phenomenon, but instead change with host ontogeny.
Beverley J. Glover
- Published in print:
- 2007
- Published Online:
- January 2008
- ISBN:
- 9780198565970
- eISBN:
- 9780191714009
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198565970.003.0005
- Subject:
- Biology, Plant Sciences and Forestry
Long day plants and short day plants experience photoperiodic induction of flowering, and so flower in certain daylengths. This chapter considers the photoperiodic regulation of flowering in ...
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Long day plants and short day plants experience photoperiodic induction of flowering, and so flower in certain daylengths. This chapter considers the photoperiodic regulation of flowering in Arabidopsis, which is a facultative long day plant (that is, one whose flowering is brought forward by long days, rather than one with an absolute requirement for them). Understanding the photoperiodic induction pathway requires an analysis of how light is perceived, how time is measured, and how the two signals are integrated to activate responses. Phytochromes and cryptochromes are necessary for light perception, an endogenous circadian clock measures time, and several proteins interact to integrate these signals.Less
Long day plants and short day plants experience photoperiodic induction of flowering, and so flower in certain daylengths. This chapter considers the photoperiodic regulation of flowering in Arabidopsis, which is a facultative long day plant (that is, one whose flowering is brought forward by long days, rather than one with an absolute requirement for them). Understanding the photoperiodic induction pathway requires an analysis of how light is perceived, how time is measured, and how the two signals are integrated to activate responses. Phytochromes and cryptochromes are necessary for light perception, an endogenous circadian clock measures time, and several proteins interact to integrate these signals.
Karen Goodell
- Published in print:
- 2008
- Published Online:
- September 2008
- ISBN:
- 9780195316957
- eISBN:
- 9780199871575
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195316957.003.0010
- Subject:
- Biology, Animal Biology, Plant Sciences and Forestry
This chapter examines the interactions between exotic invasive plants focusing on the following questions: How do bees contribute to invasive plant establishment and spread? How do resident bee ...
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This chapter examines the interactions between exotic invasive plants focusing on the following questions: How do bees contribute to invasive plant establishment and spread? How do resident bee communities respond to the invasion? What are the indirect effects of the invasion mediated by pollinator communities? New data on the frequency of insect pollinator-dependent invasive plant species in US natural areas confirm that pollinator interactions are likely to play a role in the outcome of many invasions. Generalizations are sought regarding which invasive plant–bee interactions likely contribute most to reproduction of invasive plants and negative indirect effects on native plant communities. Finally, mechanisms behind pollinator-mediated indirect effects of invasive plants on native plants are examined by considering invasive plants as resources that contribute to bee population abundance and community structure.Less
This chapter examines the interactions between exotic invasive plants focusing on the following questions: How do bees contribute to invasive plant establishment and spread? How do resident bee communities respond to the invasion? What are the indirect effects of the invasion mediated by pollinator communities? New data on the frequency of insect pollinator-dependent invasive plant species in US natural areas confirm that pollinator interactions are likely to play a role in the outcome of many invasions. Generalizations are sought regarding which invasive plant–bee interactions likely contribute most to reproduction of invasive plants and negative indirect effects on native plant communities. Finally, mechanisms behind pollinator-mediated indirect effects of invasive plants on native plants are examined by considering invasive plants as resources that contribute to bee population abundance and community structure.
Thomas J. Stohlgren
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780195172331
- eISBN:
- 9780199790395
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195172331.003.0012
- Subject:
- Biology, Plant Sciences and Forestry
In arid environments, the patterns of native and non-native plant diversity may be affected by cryptobiotic crusts. This chapter is a detailed case study designed to: (1) quantify patterns of native ...
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In arid environments, the patterns of native and non-native plant diversity may be affected by cryptobiotic crusts. This chapter is a detailed case study designed to: (1) quantify patterns of native and non-native plant species, cryptobiotic crust habitats, rare/unique habitats, and soil characteristics at landscape scales; and (2) determine which habitats in the southeast portion of the Grand Staircase-Escalante Monument, Utah, were more invaded by exotic plant species. It provides an opportunity to evaluate the interactions between various components of vascular plant diversity, with non-vascular plants (crusts) in complex arid soil environments.Less
In arid environments, the patterns of native and non-native plant diversity may be affected by cryptobiotic crusts. This chapter is a detailed case study designed to: (1) quantify patterns of native and non-native plant species, cryptobiotic crust habitats, rare/unique habitats, and soil characteristics at landscape scales; and (2) determine which habitats in the southeast portion of the Grand Staircase-Escalante Monument, Utah, were more invaded by exotic plant species. It provides an opportunity to evaluate the interactions between various components of vascular plant diversity, with non-vascular plants (crusts) in complex arid soil environments.
Andrei A. Znamenski
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780195172317
- eISBN:
- 9780199785759
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195172317.003.0004
- Subject:
- Religion, Religion and Society
This chapter looks at the relationship between shamanism and psychedelic culture, focusing on the experience of investment banker R. Gordon Wasson and his Russian-born wife, Valentina, with ...
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This chapter looks at the relationship between shamanism and psychedelic culture, focusing on the experience of investment banker R. Gordon Wasson and his Russian-born wife, Valentina, with mushrooms. Valentina and Gordon eventually embarked on their lifelong quest to explore the role of mushrooms in the histories and folklore of different cultures. When Valentina died of cancer in 1958, Gordon continued this quest alone. Eventually, his explorations evolved into research on possible links between hallucinogenic mushrooms and early religion. What came out of this research was a small community of scholarship that brought together people who believed that plant hallucinogens gave rise to human spirituality in archaic times; essentially, Wasson and his colleagues added a new hallucinogenic dimension to shamanism studies. That “psychedelic scholarship,” which was closely linked to the counterculture of the 1960s, not only informed the debates about shamanism among academics but also aroused and fed public interest in shamanism.Less
This chapter looks at the relationship between shamanism and psychedelic culture, focusing on the experience of investment banker R. Gordon Wasson and his Russian-born wife, Valentina, with mushrooms. Valentina and Gordon eventually embarked on their lifelong quest to explore the role of mushrooms in the histories and folklore of different cultures. When Valentina died of cancer in 1958, Gordon continued this quest alone. Eventually, his explorations evolved into research on possible links between hallucinogenic mushrooms and early religion. What came out of this research was a small community of scholarship that brought together people who believed that plant hallucinogens gave rise to human spirituality in archaic times; essentially, Wasson and his colleagues added a new hallucinogenic dimension to shamanism studies. That “psychedelic scholarship,” which was closely linked to the counterculture of the 1960s, not only informed the debates about shamanism among academics but also aroused and fed public interest in shamanism.
R. Ford Denison
- Published in print:
- 2012
- Published Online:
- October 2017
- ISBN:
- 9780691139500
- eISBN:
- 9781400842810
- Item type:
- book
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691139500.001.0001
- Subject:
- Biology, Evolutionary Biology / Genetics
As human populations grow and resources are depleted, agriculture will need to use land, water, and other resources more efficiently and without sacrificing long-term sustainability. This book ...
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As human populations grow and resources are depleted, agriculture will need to use land, water, and other resources more efficiently and without sacrificing long-term sustainability. This book presents an entirely new approach to these challenges, one that draws on the principles of evolution and natural selection. It shows how both biotechnology and traditional plant breeding can use Darwinian insights to identify promising routes for crop genetic improvement and avoid costly dead ends. It explains why plant traits that have been genetically optimized by individual selection—such as photosynthesis and drought tolerance—are bad candidates for genetic improvement. Traits like plant height and leaf angle, which determine the collective performance of plant communities, offer more room for improvement. Agriculturalists can also benefit from more sophisticated comparisons among natural communities and from the study of wild species in the landscapes where they evolved. The book reveals why it is sometimes better to slow or even reverse evolutionary trends when they are inconsistent with our present goals, and how we can glean new ideas from natural selection's marvelous innovations in wild species.Less
As human populations grow and resources are depleted, agriculture will need to use land, water, and other resources more efficiently and without sacrificing long-term sustainability. This book presents an entirely new approach to these challenges, one that draws on the principles of evolution and natural selection. It shows how both biotechnology and traditional plant breeding can use Darwinian insights to identify promising routes for crop genetic improvement and avoid costly dead ends. It explains why plant traits that have been genetically optimized by individual selection—such as photosynthesis and drought tolerance—are bad candidates for genetic improvement. Traits like plant height and leaf angle, which determine the collective performance of plant communities, offer more room for improvement. Agriculturalists can also benefit from more sophisticated comparisons among natural communities and from the study of wild species in the landscapes where they evolved. The book reveals why it is sometimes better to slow or even reverse evolutionary trends when they are inconsistent with our present goals, and how we can glean new ideas from natural selection's marvelous innovations in wild species.
Tony Elger and Chris Smith
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780199241514
- eISBN:
- 9780191714405
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199241514.001.0001
- Subject:
- Business and Management, International Business
This book uses research on Japanese firms in the UK to contribute to broader debate about the role of international firms in reconstructing contemporary work and employment relations. Japanese ...
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This book uses research on Japanese firms in the UK to contribute to broader debate about the role of international firms in reconstructing contemporary work and employment relations. Japanese manufacturing subsidiaries in Britain have often been portrayed as carriers of Japanese best practice models of work organization and employment relations. This research challenges this view on the basis of intensive comparative workplace case studies of several Japanese manufacturing plants in Britain. It develops an analysis of system, society, and dominance effects to identify the competing pressures upon such firms, and argues that factory managers have to negotiate the implications of these cross pressures. Thus, the analysis focuses on the ways in which Japanese and British managers have sought to construct distinctive production and employment regimes in the light of their particular branch plant mandates and competencies, the evolving character of management-worker relations within factories, and the varied product and labour market conditions they face. It also explores the scope and bases of consent and dissent among employees working in these modern workplaces. On this basis, it highlights the constraints as well as the opportunities facing managers of such greenfield workplaces, the uncertainties that arise from intractable features of capitalist employment relations, and the ways in which employment and production regimes are adapted and remade in specific corporate and local contexts. Finally, it assesses the strengths and weaknesses of three competing contemporary images of international subsidiaries, as transplants, as hybrids, and as branch plants.Less
This book uses research on Japanese firms in the UK to contribute to broader debate about the role of international firms in reconstructing contemporary work and employment relations. Japanese manufacturing subsidiaries in Britain have often been portrayed as carriers of Japanese best practice models of work organization and employment relations. This research challenges this view on the basis of intensive comparative workplace case studies of several Japanese manufacturing plants in Britain. It develops an analysis of system, society, and dominance effects to identify the competing pressures upon such firms, and argues that factory managers have to negotiate the implications of these cross pressures. Thus, the analysis focuses on the ways in which Japanese and British managers have sought to construct distinctive production and employment regimes in the light of their particular branch plant mandates and competencies, the evolving character of management-worker relations within factories, and the varied product and labour market conditions they face. It also explores the scope and bases of consent and dissent among employees working in these modern workplaces. On this basis, it highlights the constraints as well as the opportunities facing managers of such greenfield workplaces, the uncertainties that arise from intractable features of capitalist employment relations, and the ways in which employment and production regimes are adapted and remade in specific corporate and local contexts. Finally, it assesses the strengths and weaknesses of three competing contemporary images of international subsidiaries, as transplants, as hybrids, and as branch plants.
Thomas J. Stohlgren
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780195172331
- eISBN:
- 9780199790395
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195172331.003.0001
- Subject:
- Biology, Plant Sciences and Forestry
This chapter reviews why standard methods for plant diversity studies have been slow to develop. It provides specific examples why plant diversity studies are inherently difficult due to issues of ...
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This chapter reviews why standard methods for plant diversity studies have been slow to develop. It provides specific examples why plant diversity studies are inherently difficult due to issues of taxonomy, phonology, and species rarity. In addition, it shows that designing plant diversity studies also is hampered by plant-to-plant neighborhood scale variability, landscape-to-regional scale variability, and long-term changes in plant diversity brought about by immigration, particularly plant species invasions from other countries.Less
This chapter reviews why standard methods for plant diversity studies have been slow to develop. It provides specific examples why plant diversity studies are inherently difficult due to issues of taxonomy, phonology, and species rarity. In addition, it shows that designing plant diversity studies also is hampered by plant-to-plant neighborhood scale variability, landscape-to-regional scale variability, and long-term changes in plant diversity brought about by immigration, particularly plant species invasions from other countries.
Thomas J. Stohlgren
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780195172331
- eISBN:
- 9780199790395
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195172331.003.0002
- Subject:
- Biology, Plant Sciences and Forestry
This chapter provides a very brief history of plant ecology, and historical figures in the field, focusing on how previous ecologists have influenced the ways ecologists typically measure plant ...
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This chapter provides a very brief history of plant ecology, and historical figures in the field, focusing on how previous ecologists have influenced the ways ecologists typically measure plant diversity today. It draws additional attention to the authors of two textbooks, Rexford Daubenmire, and Dieter Mueller-Dombois and Heinz Ellenberg, because they seem to reflect best the development of many current plant diversity field methods. Lastly, the chapter discusses the general direction provided by past plant ecologists, and the “baggage” of older ideas — how inertia developed and persists in modern plant ecology regarding measuring plant diversity.Less
This chapter provides a very brief history of plant ecology, and historical figures in the field, focusing on how previous ecologists have influenced the ways ecologists typically measure plant diversity today. It draws additional attention to the authors of two textbooks, Rexford Daubenmire, and Dieter Mueller-Dombois and Heinz Ellenberg, because they seem to reflect best the development of many current plant diversity field methods. Lastly, the chapter discusses the general direction provided by past plant ecologists, and the “baggage” of older ideas — how inertia developed and persists in modern plant ecology regarding measuring plant diversity.
