The Experts below are selected from a list of 481470 Experts worldwide ranked by ideXlab platform
Min Zhou - One of the best experts on this subject based on the ideXlab platform.
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Multidimensionality and Gravity in Global Trade, 1950–2000
Social Forces, 2010Co-Authors: Min ZhouAbstract:The expansion of global trade in the post-war period is subject to various interpretations. Some stress the trade-promoting role of the novel features in the world economy; some insist on the role of traditional factors, such as geographic distance, political difference and cultural dissimilarity, in continuously depressing trade flows; others even argue that the importance of these traditional factors has been on the rise. To adjudicate the divergence, this article applies the gravity model to a large data set on global bilateral trade from 1950 through 2000. Although the global institutional factor does promote bilateral trade and global economic activity indeed becomes more trade-generating, the trade-depressing effects of geographic distance, political difference and cultural dissimilarity remain strong. Moreover, geographic and cultural proximity actually generates greater gravity over time that draws countries together, which may trigger fragmentation in global trade along geo-cultural lines.
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Multidimensionality and gravity in global trade 1950 2000
Social Forces, 2010Co-Authors: Min ZhouAbstract:The expansion of global trade in the post-war period is subject to various interpretations. Some stress the trade-promoting role of the novel features in the world economy; some insist on the role of traditional factors, such as geographic distance, political difference and cultural dissimilarity, in continuously depressing trade flows; others even argue that the importance of these traditional factors has been on the rise. To adjudicate the divergence, this article applies the gravity model to a large data set on global bilateral trade from 1950 through 2000. Although the global institutional factor does promote bilateral trade and global economic activity indeed becomes more trade-generating, the trade-depressing effects of geographic distance, political difference and cultural dissimilarity remain strong. Moreover, geographic and cultural proximity actually generates greater gravity over time that draws countries together, which may trigger fragmentation in global trade along geo-cultural lines.
Marie-jeanne Perrot-minnot - One of the best experts on this subject based on the ideXlab platform.
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Multidimensionality in host manipulation mimicked by serotonin injection.
Proceedings of the Royal Society B: Biological Sciences, 2014Co-Authors: Marie-jeanne Perrot-minnot, Kevin Sanchez-thirion, Frank CézillyAbstract:Manipulative parasites often alter the phenotype of their hosts along multiple dimensions. 'Multidimensionality' in host manipulation could consist in the simultaneous alteration of several physiological pathways independently of one another, or proceed from the disruption of some key physiological parameter, followed by a cascade of effects. We compared Multidimensionality in 'host manipulation' between two closely related amphipods, Gammarus fossarum and Gammarus pulex, naturally and experimentally infected with Pomphorhynchus laevis (Acanthocephala), respectively. To that end, we calculated in each host-parasite association the effect size of the difference between infected and uninfected individuals for six different traits (activity, phototaxis, geotaxis, attraction to conspecifics, refuge use and metabolic rate). The effects sizes were highly correlated between host-parasite associations, providing evidence for a relatively constant 'infection syndrome'. Using the same methodology, we compared the extent of phenotypic alterations induced by an experimental injection of serotonin (5-HT) in uninfected G. pulex to that induced by experimental or natural infection with P. laevis. We observed a significant correlation between effect sizes across the six traits, indicating that injection with 5-HT can faithfully mimic the 'infection syndrome'. This is, to our knowledge, the first experimental evidence that Multidimensionality in host manipulation can proceed, at least partly, from the disruption of some major physiological mechanism.
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Multidimensionality in parasite-induced phenotypic alterations: ultimate versus proximate aspects.
Journal of Experimental Biology, 2013Co-Authors: Frank Cézilly, Adrien Favrat, Marie-jeanne Perrot-minnotAbstract:In most cases, parasites alter more than one dimension in their host phenotype. Although Multidimensionality in parasite-induced phenotypic alterations (PIPAs) seems to be the rule, it has started to be addressed only recently. Here, we critically review some of the problems associated with the definition, quantification and interpretation of Multidimensionality in PIPAs. In particular, we confront ultimate and proximate accounts, and evaluate their own limitations. We end up by introducing several suggestions for the development of future research, including some practical guidelines for the quantitative analysis of Multidimensionality in PIPAs.
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Interpreting Multidimensionality in parasite-induced phenotypic alterations: panselectionism versus parsimony.
Oikos, 2010Co-Authors: Frank Cézilly, Marie-jeanne Perrot-minnotAbstract:The purpose of this note is to provide an alternative to the interpretation of Multidimensionality in parasite-induced phenotypic alterations as a set of effectively-independent traits produced by adaptive evolution. We propose here that infection with so-called ‘ manipulative parasites ' typically results in an ‘ infection syndrome ' , characterized by several distinctive symptoms corresponding to the alteration of particular phenotypic traits in infected hosts. Based on the available physiological evidence, we argue that symptoms might actually be the consequence of the dysregulation of some key neuromodulator, arising as a byproduct of the subversion of the host's immune system by the parasite. In that respect, it might be inadequate, from a functional point of view, to separate phenotypic effects that appear to increase trophic transmission from those that do not. We suggest that future research should test the validity of the ‘ infection syndrome ' hypothesis through focusing on the mechanisms involved in Multidimensionality at the intraspecific level, and through looking for the existence of nonrandom associations between symptoms at the interspecific level, across host-parasite associations.
Van Den Robert Bosch - One of the best experts on this subject based on the ideXlab platform.
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The Multidimensionality of Schizotypy
Schizophrenia bulletin, 1995Co-Authors: Vollema, Van Den Robert BoschAbstract:We present an overview of self-report scales for measuring schizotypy and a review of factor-analytical studies of these scales. These studies show that schizotypy is a multidimensional construct consisting of three or four factors. Positive Schizotypy, Negative Schizotypy, Nonconformity, and possibly Social Anxiety/Cognitive Disorganization. Clinical and external validation studies provide support for the construct validity of the Positive Schizotypy and Negative Schizotypy factors, but as yet fail to support the Nonconformity and Social Anxiety/Cognitive Disorganization factors. In accordance with this multidimensional structure, the scales for measuring schizotypy can be classified as factor-specific scales. We consider the striking similarities between the Multidimensionality of schizotypal traits and the Multidimensionality of schizophrenic symptoms. We also look at the similarities and differences between schizotypy and normal personality traits. Some practical and theoretical implications of these relationships are discussed.
Frank Cézilly - One of the best experts on this subject based on the ideXlab platform.
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Stage-dependent behavioural changes but early castration induced by the acanthocephalan parasite Polymorphus minutus in its Gammarus pulex intermediate host.
Parasitology, 2018Co-Authors: Yann Bailly, Frank Cézilly, Thierry RigaudAbstract:Multidimensionality in parasite-induced phenotypic alterations (PIPA) has been observed in a large number of host-parasite associations, particularly in parasites with complex life cycles. However, it is still unclear whether such a syndrome is due to the successive activation of independent PIPAs, or results from the synchronous disruption of a single mechanism. The aim of the present study was to investigate the onset and progression of two PIPAs (a behavioural alteration: reversion of geotaxis, and castration) occurring in the crustacean amphipod Gammarus pulex infected with the acanthocephalan Polymorphus minutus, at different parasite developmental stages. Modifications of geotaxis in hosts differed according to the parasite developmental stage. Whereas the cystacanth stage induced a negative geotaxis (exposing the gammarid to predation by birds, the definitive hosts), the acanthella stage, not yet infective for the definitive host, induced a stronger positive geotaxis (presumably protecting gammarids from bird predation). In contrast, castration was almost total at the acanthella stage, with no significant variation in the intensity according to parasite maturation. Finally, no significant correlation was found between the intensity of behavioural changes and the intensity of castration. We discuss our results in relation with current views on the evolution of Multidimensionality in PIPA.
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Multidimensionality in host manipulation mimicked by serotonin injection.
Proceedings of the Royal Society B: Biological Sciences, 2014Co-Authors: Marie-jeanne Perrot-minnot, Kevin Sanchez-thirion, Frank CézillyAbstract:Manipulative parasites often alter the phenotype of their hosts along multiple dimensions. 'Multidimensionality' in host manipulation could consist in the simultaneous alteration of several physiological pathways independently of one another, or proceed from the disruption of some key physiological parameter, followed by a cascade of effects. We compared Multidimensionality in 'host manipulation' between two closely related amphipods, Gammarus fossarum and Gammarus pulex, naturally and experimentally infected with Pomphorhynchus laevis (Acanthocephala), respectively. To that end, we calculated in each host-parasite association the effect size of the difference between infected and uninfected individuals for six different traits (activity, phototaxis, geotaxis, attraction to conspecifics, refuge use and metabolic rate). The effects sizes were highly correlated between host-parasite associations, providing evidence for a relatively constant 'infection syndrome'. Using the same methodology, we compared the extent of phenotypic alterations induced by an experimental injection of serotonin (5-HT) in uninfected G. pulex to that induced by experimental or natural infection with P. laevis. We observed a significant correlation between effect sizes across the six traits, indicating that injection with 5-HT can faithfully mimic the 'infection syndrome'. This is, to our knowledge, the first experimental evidence that Multidimensionality in host manipulation can proceed, at least partly, from the disruption of some major physiological mechanism.
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Multidimensionality in parasite-induced phenotypic alterations: ultimate versus proximate aspects.
Journal of Experimental Biology, 2013Co-Authors: Frank Cézilly, Adrien Favrat, Marie-jeanne Perrot-minnotAbstract:In most cases, parasites alter more than one dimension in their host phenotype. Although Multidimensionality in parasite-induced phenotypic alterations (PIPAs) seems to be the rule, it has started to be addressed only recently. Here, we critically review some of the problems associated with the definition, quantification and interpretation of Multidimensionality in PIPAs. In particular, we confront ultimate and proximate accounts, and evaluate their own limitations. We end up by introducing several suggestions for the development of future research, including some practical guidelines for the quantitative analysis of Multidimensionality in PIPAs.
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Interpreting Multidimensionality in parasite-induced phenotypic alterations: panselectionism versus parsimony.
Oikos, 2010Co-Authors: Frank Cézilly, Marie-jeanne Perrot-minnotAbstract:The purpose of this note is to provide an alternative to the interpretation of Multidimensionality in parasite-induced phenotypic alterations as a set of effectively-independent traits produced by adaptive evolution. We propose here that infection with so-called ‘ manipulative parasites ' typically results in an ‘ infection syndrome ' , characterized by several distinctive symptoms corresponding to the alteration of particular phenotypic traits in infected hosts. Based on the available physiological evidence, we argue that symptoms might actually be the consequence of the dysregulation of some key neuromodulator, arising as a byproduct of the subversion of the host's immune system by the parasite. In that respect, it might be inadequate, from a functional point of view, to separate phenotypic effects that appear to increase trophic transmission from those that do not. We suggest that future research should test the validity of the ‘ infection syndrome ' hypothesis through focusing on the mechanisms involved in Multidimensionality at the intraspecific level, and through looking for the existence of nonrandom associations between symptoms at the interspecific level, across host-parasite associations.
Deepak Sharma - One of the best experts on this subject based on the ideXlab platform.
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the Multidimensionality of electricity reform an australian perspective
Energy Policy, 2003Co-Authors: Deepak SharmaAbstract:The electricity industry in Australia has over the last decade undergone fundamental and profound change. The industry has been functionally unbundled. The generation and retail segments of the industry have been exposed to competition. The transmission and distribution monopolies have been reoriented to foster competition. The customers are being offered increasing choice in the selection of their energy providers. The ownership of the industry is generally moving away from the public domain to the private domain. The rules for the governance of the industry have been developed in the form of a variety of market codes and regulation. Much of the debate about industry reform is being conducted exclusively in the economic domain. There is a general lack of any serious analysis and debate on the political, social, environmental and other dimensions of reform despite a wide consensus on the criticality of such dimensions. This is clearly unhelpful and could lead to obfuscation of the real challenges confronting the industry and preclude the development of responsible policy prescriptions to meet such challenges. There is an obvious need to devote some direct attention to these neglected dimensions of reform. This paper is one such attempt. It draws together the various dimensions of reform and provides a firmer basis for meaningful analyses and concrete debate on the issues. While the discussion focuses on Australian experience, the messages are relevant for other countries engaged in electricity reform.
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The Multidimensionality of electricity reform—an Australian perspective
Energy Policy, 2003Co-Authors: Deepak SharmaAbstract:The electricity industry in Australia has over the last decade undergone fundamental and profound change. The industry has been functionally unbundled. The generation and retail segments of the industry have been exposed to competition. The transmission and distribution monopolies have been reoriented to foster competition. The customers are being offered increasing choice in the selection of their energy providers. The ownership of the industry is generally moving away from the public domain to the private domain. The rules for the governance of the industry have been developed in the form of a variety of market codes and regulation. Much of the debate about industry reform is being conducted exclusively in the economic domain. There is a general lack of any serious analysis and debate on the political, social, environmental and other dimensions of reform despite a wide consensus on the criticality of such dimensions. This is clearly unhelpful and could lead to obfuscation of the real challenges confronting the industry and preclude the development of responsible policy prescriptions to meet such challenges. There is an obvious need to devote some direct attention to these neglected dimensions of reform. This paper is one such attempt. It draws together the various dimensions of reform and provides a firmer basis for meaningful analyses and concrete debate on the issues. While the discussion focuses on Australian experience, the messages are relevant for other countries engaged in electricity reform.
