Author: Jan Bogg
Publisher: Radcliffe Publishing
ISBN: 184619203X
Category : Complexity (Philosophy)
Languages : en
Pages : 188
Book Description
Complexity is a new interdisciplinary approach to science and society that challenges traditional academic divisions, frameworks and paradigms. This book helps the expert, student or policy practitioner have a better understanding of the enormous potential of complexity, and how it relates to their particular area of interest or expertise.
Complexity, Science and Society
Author: Jan Bogg
Publisher: Radcliffe Publishing
ISBN: 184619203X
Category : Complexity (Philosophy)
Languages : en
Pages : 188
Book Description
Complexity is a new interdisciplinary approach to science and society that challenges traditional academic divisions, frameworks and paradigms. This book helps the expert, student or policy practitioner have a better understanding of the enormous potential of complexity, and how it relates to their particular area of interest or expertise.
Publisher: Radcliffe Publishing
ISBN: 184619203X
Category : Complexity (Philosophy)
Languages : en
Pages : 188
Book Description
Complexity is a new interdisciplinary approach to science and society that challenges traditional academic divisions, frameworks and paradigms. This book helps the expert, student or policy practitioner have a better understanding of the enormous potential of complexity, and how it relates to their particular area of interest or expertise.
Complexity Science
Author: Henrik Jeldtoft Jensen
Publisher: Cambridge University Press
ISBN: 1108883168
Category : Science
Languages : en
Pages : 462
Book Description
Ecosystems, the human brain, ant colonies, and economic networks are all complex systems displaying collective behaviour, or emergence, beyond the sum of their parts. Complexity science is the systematic investigation of these emergent phenomena, and stretches across disciplines, from physics and mathematics, to biological and social sciences. This introductory textbook provides detailed coverage of this rapidly growing field, accommodating readers from a variety of backgrounds, and with varying levels of mathematical skill. Part I presents the underlying principles of complexity science, to ensure students have a solid understanding of the conceptual framework. The second part introduces the key mathematical tools central to complexity science, gradually developing the mathematical formalism, with more advanced material provided in boxes. A broad range of end of chapter problems and extended projects offer opportunities for homework assignments and student research projects, with solutions available to instructors online. Key terms are highlighted in bold and listed in a glossary for easy reference, while annotated reading lists offer the option for extended reading and research.
Publisher: Cambridge University Press
ISBN: 1108883168
Category : Science
Languages : en
Pages : 462
Book Description
Ecosystems, the human brain, ant colonies, and economic networks are all complex systems displaying collective behaviour, or emergence, beyond the sum of their parts. Complexity science is the systematic investigation of these emergent phenomena, and stretches across disciplines, from physics and mathematics, to biological and social sciences. This introductory textbook provides detailed coverage of this rapidly growing field, accommodating readers from a variety of backgrounds, and with varying levels of mathematical skill. Part I presents the underlying principles of complexity science, to ensure students have a solid understanding of the conceptual framework. The second part introduces the key mathematical tools central to complexity science, gradually developing the mathematical formalism, with more advanced material provided in boxes. A broad range of end of chapter problems and extended projects offer opportunities for homework assignments and student research projects, with solutions available to instructors online. Key terms are highlighted in bold and listed in a glossary for easy reference, while annotated reading lists offer the option for extended reading and research.
Complexity, Science and Society
Author: Jan Bogg
Publisher: CRC Press
ISBN: 1498791220
Category : Medical
Languages : en
Pages : 189
Book Description
'The following sections are a very good representation of the core developments of complexity thinking in a number of major fields. Our intention is to provide an accessible interdisciplinary introduction to the wonderful intellectual breadth that complexity can offer.' - Jan Bogg and Robert Geyer in the Introduction. Complexity is a new and exciting interdisciplinary approach to science and society that challenges traditional academic divisions, frameworks and paradigms. This book helps the expert, student or policy practitioner have a better understanding of the enormous potential of complexity, and how it relates to their particular area of interest or expertise. It provides excellent representations of the core developments of complexity thinking in a number of major fields. "Complexity, Science and Society" brings together an unrivalled selection of new applications of complexity from leading experts across subjects including medicine and healthcare, education, public policy and social theory, ecology, philosophy, international politics, the arts, modelling and design, and others. Together they offer an unprecedented review of the latest developments. This book is an accessible interdisciplinary introduction to the wonderful intellectual breadth that complexity can offer.
Publisher: CRC Press
ISBN: 1498791220
Category : Medical
Languages : en
Pages : 189
Book Description
'The following sections are a very good representation of the core developments of complexity thinking in a number of major fields. Our intention is to provide an accessible interdisciplinary introduction to the wonderful intellectual breadth that complexity can offer.' - Jan Bogg and Robert Geyer in the Introduction. Complexity is a new and exciting interdisciplinary approach to science and society that challenges traditional academic divisions, frameworks and paradigms. This book helps the expert, student or policy practitioner have a better understanding of the enormous potential of complexity, and how it relates to their particular area of interest or expertise. It provides excellent representations of the core developments of complexity thinking in a number of major fields. "Complexity, Science and Society" brings together an unrivalled selection of new applications of complexity from leading experts across subjects including medicine and healthcare, education, public policy and social theory, ecology, philosophy, international politics, the arts, modelling and design, and others. Together they offer an unprecedented review of the latest developments. This book is an accessible interdisciplinary introduction to the wonderful intellectual breadth that complexity can offer.
Complexity
Author: Chris Mowles
Publisher: Routledge
ISBN: 1000505685
Category : Business & Economics
Languages : en
Pages : 209
Book Description
This book interprets insights from the complexity sciences to explore seven types of complexity better to understand the predictable unpredictability of social life. Drawing on the natural and social sciences, it describes how complexity models are helpful but insufficient for our understanding of complex reality. Taking an interdisciplinary approach, the book develops a complex theory of action more consistent with our experience that our plans inevitably lead to unexpected outcomes, explains why we are both individuals and thoroughly social, and gives an account of why, no matter how clear our message, we may still be misunderstood. The book investigates what forms of knowledge are most helpful for thinking about complex experience, reflects on the way we exercise authority (leadership) and thinks through the ethical implications of trying to co-operate in a complex world. Taking complexity seriously poses a radical challenge to more orthodox theories of managing and leading, based as they are on assumptions of predictability, control and universality. The author argues that management is an improvisational practice which takes place in groups in a particular context at a particular time. Managers can influence but never control an uncontrollable world. To become more skilful in complex group dynamics involves taking into account multiple points of view and acknowledging not knowing, ambivalence and doubt. This book will be of interest to researchers, professionals, academics and students in the fields of business and management, especially those interested in how taking complexity seriously can influence the functioning of businesses and organizations and how they manage and lead.
Publisher: Routledge
ISBN: 1000505685
Category : Business & Economics
Languages : en
Pages : 209
Book Description
This book interprets insights from the complexity sciences to explore seven types of complexity better to understand the predictable unpredictability of social life. Drawing on the natural and social sciences, it describes how complexity models are helpful but insufficient for our understanding of complex reality. Taking an interdisciplinary approach, the book develops a complex theory of action more consistent with our experience that our plans inevitably lead to unexpected outcomes, explains why we are both individuals and thoroughly social, and gives an account of why, no matter how clear our message, we may still be misunderstood. The book investigates what forms of knowledge are most helpful for thinking about complex experience, reflects on the way we exercise authority (leadership) and thinks through the ethical implications of trying to co-operate in a complex world. Taking complexity seriously poses a radical challenge to more orthodox theories of managing and leading, based as they are on assumptions of predictability, control and universality. The author argues that management is an improvisational practice which takes place in groups in a particular context at a particular time. Managers can influence but never control an uncontrollable world. To become more skilful in complex group dynamics involves taking into account multiple points of view and acknowledging not knowing, ambivalence and doubt. This book will be of interest to researchers, professionals, academics and students in the fields of business and management, especially those interested in how taking complexity seriously can influence the functioning of businesses and organizations and how they manage and lead.
Complexity Science and World Affairs
Author: Walter C. Clemens Jr.
Publisher: SUNY Press
ISBN: 1438449011
Category : Political Science
Languages : en
Pages : 292
Book Description
Applies complexity science to the study of international politics. Why did some countries transition peacefully from communist rule to political freedom and market economies, while others did not? Why did the United States enjoy a brief moment as the sole remaining superpower, and then lose power and influence across the board? What are the prospects for China, the main challenger to American hegemony? In Complexity Science and World Affairs, Walter C. Clemens Jr. demonstrates how the basic concepts of complexity science can broaden and deepen the insights gained by other approaches to the study of world affairs. He argues that societal fitnessthe ability of a social system to cope with complex challenges and opportunitieshinges heavily on the values and way of life of each society, and serves to explain why some societies gain and others lose. Applying theory to several rich case studies, including political developments across postSoviet Eurasia and the United States, Clemens shows that complexity science offers a powerful set of tools for advancing the study of international relations, comparative government, and, more broadly, the social sciences. Clemens has written an outstanding bookthe culmination of a half?centurys experience in and analysis of world affairs [It is] bound to interest not only political and other social scientists but all thoughtful persons concerned with understanding and perhaps improving the human condition. from the Foreword by Stuart A. Kauffman This breakthrough book provides a new, promising general paradigm exploring and explaining the complexity of world politics. For scholars and analysts pushing the boundaries of our field, this is a must-read volume. Jacek Kugler, Claremont Graduate University Complexity can be overwhelming and complexity science can be daunting, and, yet, in Walter Clemenss skilled hands both become accessible, understandable, and useful tools for both scholars and practitioners. Once again, Clemens has shown that sophisticated academic theorizing only benefits from clarity, elegance, and wit. The book is ideal for graduate and undergraduate students as a supplementary text in international relations or comparative politics. Alexander Motyl, Rutgers UniversityNewark Clemens offers a fresh, even startling, paradigm and process for analyzing the seemingly unpredictable relations within and among human societies. With impressive clarity he proposes that the capacity to cope with complexity has become a key determinant of success in our intricately interrelated world. Careful study of this capacity in specific contexts can lead to revealing analyses in comparative politics and international relations. A provocative and stimulating treatise! S. Frederick Starr, Johns Hopkins University Walt Clemenss provocative new book can be appreciated at several levels: as an analytical framework in international relationscomplexity sciencethat offers a compelling alternative to realism and neoliberalism; as an incisive critique of the fitness of the supposedly most developed societies to deal with our complex world; and as a humanistic value-set that provides better standards for assessing governments than do GDP, trade levels, or military spending. Clemens skillfully integrates theory and practice to explore US hyperpower, the two Koreas, China, and other states from new angles, and with consistent objectivity. IR specialists should find this book exciting, while IR and international studies students will be challenged by the new paradigm it presents. Mel Gurtov, Portland State University Clemens proposes a powerful new way of looking at international relations and politics, and offers a productive method for assessing the fitness of societies in the early twenty-first century. Guntis midchens, University of Washington, Seattle You dont have to be a political scientist to wonder why some states succeed and others do not, why some societies flourish while others suffer stagnation and conflict. Employing the relatively new tool of complexity science, Walter Clemens evaluates the fitness of states and societies, i.e. their ability to cope with complex challenges and opportunities. He does so in a way that is eruditehow many studies quote Walt Whitman and Karl Marx in the same chapter?yet clear and accessible. Clemens challenges both existing political science paradigms and policy perspectives. This is a stimulating, rich volume that can be read and re-read with profit and appreciation for its breadth and depth and most of all for its insistence that we see the world, and the states in it, in all their complexity. Ronald H. Linden, University of Pittsburgh
Publisher: SUNY Press
ISBN: 1438449011
Category : Political Science
Languages : en
Pages : 292
Book Description
Applies complexity science to the study of international politics. Why did some countries transition peacefully from communist rule to political freedom and market economies, while others did not? Why did the United States enjoy a brief moment as the sole remaining superpower, and then lose power and influence across the board? What are the prospects for China, the main challenger to American hegemony? In Complexity Science and World Affairs, Walter C. Clemens Jr. demonstrates how the basic concepts of complexity science can broaden and deepen the insights gained by other approaches to the study of world affairs. He argues that societal fitnessthe ability of a social system to cope with complex challenges and opportunitieshinges heavily on the values and way of life of each society, and serves to explain why some societies gain and others lose. Applying theory to several rich case studies, including political developments across postSoviet Eurasia and the United States, Clemens shows that complexity science offers a powerful set of tools for advancing the study of international relations, comparative government, and, more broadly, the social sciences. Clemens has written an outstanding bookthe culmination of a half?centurys experience in and analysis of world affairs [It is] bound to interest not only political and other social scientists but all thoughtful persons concerned with understanding and perhaps improving the human condition. from the Foreword by Stuart A. Kauffman This breakthrough book provides a new, promising general paradigm exploring and explaining the complexity of world politics. For scholars and analysts pushing the boundaries of our field, this is a must-read volume. Jacek Kugler, Claremont Graduate University Complexity can be overwhelming and complexity science can be daunting, and, yet, in Walter Clemenss skilled hands both become accessible, understandable, and useful tools for both scholars and practitioners. Once again, Clemens has shown that sophisticated academic theorizing only benefits from clarity, elegance, and wit. The book is ideal for graduate and undergraduate students as a supplementary text in international relations or comparative politics. Alexander Motyl, Rutgers UniversityNewark Clemens offers a fresh, even startling, paradigm and process for analyzing the seemingly unpredictable relations within and among human societies. With impressive clarity he proposes that the capacity to cope with complexity has become a key determinant of success in our intricately interrelated world. Careful study of this capacity in specific contexts can lead to revealing analyses in comparative politics and international relations. A provocative and stimulating treatise! S. Frederick Starr, Johns Hopkins University Walt Clemenss provocative new book can be appreciated at several levels: as an analytical framework in international relationscomplexity sciencethat offers a compelling alternative to realism and neoliberalism; as an incisive critique of the fitness of the supposedly most developed societies to deal with our complex world; and as a humanistic value-set that provides better standards for assessing governments than do GDP, trade levels, or military spending. Clemens skillfully integrates theory and practice to explore US hyperpower, the two Koreas, China, and other states from new angles, and with consistent objectivity. IR specialists should find this book exciting, while IR and international studies students will be challenged by the new paradigm it presents. Mel Gurtov, Portland State University Clemens proposes a powerful new way of looking at international relations and politics, and offers a productive method for assessing the fitness of societies in the early twenty-first century. Guntis midchens, University of Washington, Seattle You dont have to be a political scientist to wonder why some states succeed and others do not, why some societies flourish while others suffer stagnation and conflict. Employing the relatively new tool of complexity science, Walter Clemens evaluates the fitness of states and societies, i.e. their ability to cope with complex challenges and opportunities. He does so in a way that is eruditehow many studies quote Walt Whitman and Karl Marx in the same chapter?yet clear and accessible. Clemens challenges both existing political science paradigms and policy perspectives. This is a stimulating, rich volume that can be read and re-read with profit and appreciation for its breadth and depth and most of all for its insistence that we see the world, and the states in it, in all their complexity. Ronald H. Linden, University of Pittsburgh
Complexity Science: An Introduction
Author: Mark A Peletier
Publisher: World Scientific
ISBN: 9813239611
Category : Science
Languages : en
Pages : 428
Book Description
This book on complexity science comprises a collection of chapters on methods and principles from a wide variety of disciplinary fields — from physics and chemistry to biology and the social sciences.In this two-part volume, the first part is a collection of chapters introducing different aspects in a coherent fashion, and providing a common basis and the founding principles of the different complexity science approaches; the next provides deeper discussions of the different methods of use in complexity science, with interesting illustrative applications.The fundamental topics deal with self-organization, pattern formation, forecasting uncertainties, synchronization and revolutionary change, self-adapting and self-correcting systems, and complex networks. Examples are taken from biology, chemistry, engineering, epidemiology, robotics, economics, sociology, and neurology.
Publisher: World Scientific
ISBN: 9813239611
Category : Science
Languages : en
Pages : 428
Book Description
This book on complexity science comprises a collection of chapters on methods and principles from a wide variety of disciplinary fields — from physics and chemistry to biology and the social sciences.In this two-part volume, the first part is a collection of chapters introducing different aspects in a coherent fashion, and providing a common basis and the founding principles of the different complexity science approaches; the next provides deeper discussions of the different methods of use in complexity science, with interesting illustrative applications.The fundamental topics deal with self-organization, pattern formation, forecasting uncertainties, synchronization and revolutionary change, self-adapting and self-correcting systems, and complex networks. Examples are taken from biology, chemistry, engineering, epidemiology, robotics, economics, sociology, and neurology.
A Crude Look at the Whole
Author: John H. Miller
Publisher: Hachette UK
ISBN: 0465073867
Category : Science
Languages : en
Pages : 218
Book Description
A top expert explains why a social and economic understanding of complex systems will help society to anticipate and confront our biggest challenges Imagine trying to understand a stained glass window by breaking it into pieces and examining it one shard at a time. While you could probably learn a lot about each piece, you would have no idea about what the entire picture looks like. This is reductionism -- the idea that to understand the world we only need to study its pieces -- and it is how most social scientists approach their work. In A Crude Look at the Whole, social scientist and economist John H. Miller shows why we need to start looking at whole pictures. For one thing, whether we are talking about stock markets, computer networks, or biological organisms, individual parts only make sense when we remember that they are part of larger wholes. And perhaps more importantly, those wholes can take on behaviors that are strikingly different from that of their pieces. Miller, a leading expert in the computational study of complex adaptive systems, reveals astounding global patterns linking the organization of otherwise radically different structures: It might seem crude, but a beehive's temperature control system can help predict market fluctuations and a mammal's heartbeat can help us understand the "heartbeat" of a city and adapt urban planning accordingly. From enduring racial segregation to sudden stock market disasters, once we start drawing links between complex systems, we can start solving what otherwise might be totally intractable problems. Thanks to this revolutionary perspective, we can finally transcend the limits of reductionism and discover crucial new ideas. Scientifically founded and beautifully written, A Crude Look at the Whole is a powerful exploration of the challenges that we face as a society. As it reveals, taking the crude look might be the only way to truly see.
Publisher: Hachette UK
ISBN: 0465073867
Category : Science
Languages : en
Pages : 218
Book Description
A top expert explains why a social and economic understanding of complex systems will help society to anticipate and confront our biggest challenges Imagine trying to understand a stained glass window by breaking it into pieces and examining it one shard at a time. While you could probably learn a lot about each piece, you would have no idea about what the entire picture looks like. This is reductionism -- the idea that to understand the world we only need to study its pieces -- and it is how most social scientists approach their work. In A Crude Look at the Whole, social scientist and economist John H. Miller shows why we need to start looking at whole pictures. For one thing, whether we are talking about stock markets, computer networks, or biological organisms, individual parts only make sense when we remember that they are part of larger wholes. And perhaps more importantly, those wholes can take on behaviors that are strikingly different from that of their pieces. Miller, a leading expert in the computational study of complex adaptive systems, reveals astounding global patterns linking the organization of otherwise radically different structures: It might seem crude, but a beehive's temperature control system can help predict market fluctuations and a mammal's heartbeat can help us understand the "heartbeat" of a city and adapt urban planning accordingly. From enduring racial segregation to sudden stock market disasters, once we start drawing links between complex systems, we can start solving what otherwise might be totally intractable problems. Thanks to this revolutionary perspective, we can finally transcend the limits of reductionism and discover crucial new ideas. Scientifically founded and beautifully written, A Crude Look at the Whole is a powerful exploration of the challenges that we face as a society. As it reveals, taking the crude look might be the only way to truly see.
Sociology and Complexity Science
Author: Brian Castellani
Publisher: Springer Science & Business Media
ISBN: 3540884629
Category : Science
Languages : en
Pages : 292
Book Description
By now, most academics have heard something about the new science of complexity. In a manner reminiscent of Einstein and the last hundred years of physics, complexity science has captured the public imagination. ® One can go to Amazon. com and purchase books on complexification (Casti 1994), emergence (Holland 1998), small worlds (Barabási 2003), the web of life (Capra 1996), fuzzy thinking (Kosko 1993), global c- plexity (Urry 2003) and the business of long-tails (Anderson 2006). Even television has incorporated the topics of complexity science. Crime shows ® ® such as 24 or CSI typically feature investigators using the latest advances in computational modeling to “simulate scenarios” or “data mine” all p- sible suspects—all of which is done before the crime takes place. The ® World Wide Web is another example. A simple search on Google. Com using the phrase “complexity science” gets close to a million hits! C- plexity science is ubiquitous. What most scholars do not realize, however, is the remarkable role sociologists are playing in this new science. C- sider the following examples. 0. 1 Sociologists in Complexity Science The first example comes from the new science of networks (Barabási 2003). By now, most readers are familiar with the phenomena known as six-degrees of separation—the idea that, because most large networks are comprised of a significant number of non-random weak-ties, the nodes (e. g. , people, companies, etc.
Publisher: Springer Science & Business Media
ISBN: 3540884629
Category : Science
Languages : en
Pages : 292
Book Description
By now, most academics have heard something about the new science of complexity. In a manner reminiscent of Einstein and the last hundred years of physics, complexity science has captured the public imagination. ® One can go to Amazon. com and purchase books on complexification (Casti 1994), emergence (Holland 1998), small worlds (Barabási 2003), the web of life (Capra 1996), fuzzy thinking (Kosko 1993), global c- plexity (Urry 2003) and the business of long-tails (Anderson 2006). Even television has incorporated the topics of complexity science. Crime shows ® ® such as 24 or CSI typically feature investigators using the latest advances in computational modeling to “simulate scenarios” or “data mine” all p- sible suspects—all of which is done before the crime takes place. The ® World Wide Web is another example. A simple search on Google. Com using the phrase “complexity science” gets close to a million hits! C- plexity science is ubiquitous. What most scholars do not realize, however, is the remarkable role sociologists are playing in this new science. C- sider the following examples. 0. 1 Sociologists in Complexity Science The first example comes from the new science of networks (Barabási 2003). By now, most readers are familiar with the phenomena known as six-degrees of separation—the idea that, because most large networks are comprised of a significant number of non-random weak-ties, the nodes (e. g. , people, companies, etc.
Complexity Theory and the Social Sciences
Author: David Byrne
Publisher: Routledge
ISBN: 1134714742
Category : Social Science
Languages : en
Pages : 215
Book Description
Chaos and complexity are the new buzz words in both science and contemporary society. The ideas they represent have enormous implications for the way we understand and engage with the world. Complexity Theory and the Social Sciences introduces students to the central ideas which surround the chaos/complexity theories. It discusses key concepts before using them as a way of investigating the nature of social research. By applying them to such familiar topics as urban studies, education and health, David Byrne allows readers new to the subject to appreciate the contribution which complexity theory can make to social research and to illuminating the crucial social issues of our day.
Publisher: Routledge
ISBN: 1134714742
Category : Social Science
Languages : en
Pages : 215
Book Description
Chaos and complexity are the new buzz words in both science and contemporary society. The ideas they represent have enormous implications for the way we understand and engage with the world. Complexity Theory and the Social Sciences introduces students to the central ideas which surround the chaos/complexity theories. It discusses key concepts before using them as a way of investigating the nature of social research. By applying them to such familiar topics as urban studies, education and health, David Byrne allows readers new to the subject to appreciate the contribution which complexity theory can make to social research and to illuminating the crucial social issues of our day.
Complexity and Public Policy
Author: Robert Geyer
Publisher: Routledge
ISBN: 1135153485
Category : Political Science
Languages : en
Pages : 230
Book Description
This book provides a clear, concise and readable introduction to complexity thinking, its application to the social sciences and public policy, and the relevance of some of its various tools to those fields of politics, health, the international realm, development, planning and terrorism. The authors argue that the foundation for many of the current crises in these areas can be traced to the attempt by social scientists and policy-makers to treat these systems and processes as fundamentally orderly, predictable and controllable. By providing an overview of complex systems, a practical introduction to basic concepts and tools of these systems, and examples for understanding and managing them in real life policy situations they provide an exciting new perspective for rethinking our basic approaches to the social sciences and for understanding and managing the increasingly interdependent world of public policy. The book is vital reading for students and scholars of the social sciences and public policy, and also policymakers and the policy actor audience.
Publisher: Routledge
ISBN: 1135153485
Category : Political Science
Languages : en
Pages : 230
Book Description
This book provides a clear, concise and readable introduction to complexity thinking, its application to the social sciences and public policy, and the relevance of some of its various tools to those fields of politics, health, the international realm, development, planning and terrorism. The authors argue that the foundation for many of the current crises in these areas can be traced to the attempt by social scientists and policy-makers to treat these systems and processes as fundamentally orderly, predictable and controllable. By providing an overview of complex systems, a practical introduction to basic concepts and tools of these systems, and examples for understanding and managing them in real life policy situations they provide an exciting new perspective for rethinking our basic approaches to the social sciences and for understanding and managing the increasingly interdependent world of public policy. The book is vital reading for students and scholars of the social sciences and public policy, and also policymakers and the policy actor audience.