The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform
Dawn M. Higginson - One of the best experts on this subject based on the ideXlab platform.
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Cycles of External Dependency drive evolution of avian carotenoid networks
Nature communications, 2019Co-Authors: Alexander V. Badyaev, Alexander B. Posner, Erin S. Morrison, Dawn M. HigginsonAbstract:All organisms depend on input of exogenous compounds that cannot be internally produced. Gain and loss of such dependencies structure ecological communities and drive species' evolution, yet the evolution of mechanisms that accommodate these variable dependencies remain elusive. Here, we show that historical cycles of gains and losses of External dependencies in avian carotenoid-producing networks are linked to their evolutionary diversification. This occurs because internalization of metabolic controls-produced when gains in redundancy of dietary inputs coincide with increased branching of their derived products-enables rapid and sustainable exploration of an existing network by shielding it from environmental fluctuations in inputs. Correspondingly, loss of internal controls constrains evolution to the rate of the gains and losses of dietary precursors. Because internalization of a network's controls necessarily bridges diet-specific enzymatic modules within a network, it structurally links local adaptation and continuous evolution even for traits fully dependent on contingent External inputs.
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cycles of External Dependency drive evolution of avian carotenoid networks
Nature Communications, 2019Co-Authors: Alexander V. Badyaev, Alexander B. Posner, Erin S. Morrison, Dawn M. HigginsonAbstract:All organisms depend on input of exogenous compounds that cannot be internally produced. Gain and loss of such dependencies structure ecological communities and drive species’ evolution, yet the evolution of mechanisms that accommodate these variable dependencies remain elusive. Here, we show that historical cycles of gains and losses of External dependencies in avian carotenoid-producing networks are linked to their evolutionary diversification. This occurs because internalization of metabolic controls—produced when gains in redundancy of dietary inputs coincide with increased branching of their derived products—enables rapid and sustainable exploration of an existing network by shielding it from environmental fluctuations in inputs. Correspondingly, loss of internal controls constrains evolution to the rate of the gains and losses of dietary precursors. Because internalization of a network’s controls necessarily bridges diet-specific enzymatic modules within a network, it structurally links local adaptation and continuous evolution even for traits fully dependent on contingent External inputs. The mechanisms that accommodate variable External dependencies in evolution are not clear. Here, the authors show that switches between External and internal metabolic controls of carotenoid-producing networks in birds are linked to shifts in evolutionary rates, with internalization of control resulting in bursts of evolutionary diversification.
Xuemei Bai - One of the best experts on this subject based on the ideXlab platform.
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Eight energy and material flow characteristics of urban ecosystems
Ambio, 2016Co-Authors: Xuemei BaiAbstract:Recent decades have seen an expanding literature exploring urban energy and material flows, loosely branded as urban metabolism analysis. However, this has occurred largely in parallel to the mainstream studies of cities as ecosystems. This paper aims to conceptually bridge these two distinctive fields of research, by (a) identifying the common aspects between them; (b) identifying key characteristics of urban ecosystems that can be derived from energy and material flow analysis, namely energy and material budget and pathways; flow intensity; energy and material efficiency; rate of resource depletion, accumulation and transformation; self-sufficiency or External Dependency; intra-system heterogeneity; intersystem and temporal variation; and regulating mechanism and governing capacity. I argue that significant ecological insight can be, or has the potential to be, drawn from the rich and rapidly growing empirical findings of urban metabolism studies to understand the behaviour of cities as human-dominated, complex systems. A closer intellectual linkage and cross pollination between urban metabolism and urban ecosystem studies will advance our scientific understanding and better inform urban policy and management practices.
Alexander V. Badyaev - One of the best experts on this subject based on the ideXlab platform.
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Cycles of External Dependency drive evolution of avian carotenoid networks
Nature communications, 2019Co-Authors: Alexander V. Badyaev, Alexander B. Posner, Erin S. Morrison, Dawn M. HigginsonAbstract:All organisms depend on input of exogenous compounds that cannot be internally produced. Gain and loss of such dependencies structure ecological communities and drive species' evolution, yet the evolution of mechanisms that accommodate these variable dependencies remain elusive. Here, we show that historical cycles of gains and losses of External dependencies in avian carotenoid-producing networks are linked to their evolutionary diversification. This occurs because internalization of metabolic controls-produced when gains in redundancy of dietary inputs coincide with increased branching of their derived products-enables rapid and sustainable exploration of an existing network by shielding it from environmental fluctuations in inputs. Correspondingly, loss of internal controls constrains evolution to the rate of the gains and losses of dietary precursors. Because internalization of a network's controls necessarily bridges diet-specific enzymatic modules within a network, it structurally links local adaptation and continuous evolution even for traits fully dependent on contingent External inputs.
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cycles of External Dependency drive evolution of avian carotenoid networks
Nature Communications, 2019Co-Authors: Alexander V. Badyaev, Alexander B. Posner, Erin S. Morrison, Dawn M. HigginsonAbstract:All organisms depend on input of exogenous compounds that cannot be internally produced. Gain and loss of such dependencies structure ecological communities and drive species’ evolution, yet the evolution of mechanisms that accommodate these variable dependencies remain elusive. Here, we show that historical cycles of gains and losses of External dependencies in avian carotenoid-producing networks are linked to their evolutionary diversification. This occurs because internalization of metabolic controls—produced when gains in redundancy of dietary inputs coincide with increased branching of their derived products—enables rapid and sustainable exploration of an existing network by shielding it from environmental fluctuations in inputs. Correspondingly, loss of internal controls constrains evolution to the rate of the gains and losses of dietary precursors. Because internalization of a network’s controls necessarily bridges diet-specific enzymatic modules within a network, it structurally links local adaptation and continuous evolution even for traits fully dependent on contingent External inputs. The mechanisms that accommodate variable External dependencies in evolution are not clear. Here, the authors show that switches between External and internal metabolic controls of carotenoid-producing networks in birds are linked to shifts in evolutionary rates, with internalization of control resulting in bursts of evolutionary diversification.
Steve Wood - One of the best experts on this subject based on the ideXlab platform.
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Europe's Energy Politics
Journal of Contemporary European Studies, 2010Co-Authors: Steve WoodAbstract:A cluster of interconnected energy-related challenges confronts the European Union (EU), individual member states, and their populations. GHG emissions, economic-industrial restructuring, rising costs, developing and implementing new technologies, and External Dependency, are prominent. Existential imperatives and political constraints imposed by energy needs have affected environmental and foreign policy ambitions. Some EU states are compelled to renew their nuclear industries.16 page(s
Gianfranco Chicco - One of the best experts on this subject based on the ideXlab platform.
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Uncertainty characterization of carrier-based demand response in smart multi-energy systems
2015 IEEE 5th International Conference on Power Engineering Energy and Electrical Drives (POWERENG), 2015Co-Authors: Nilufar Neyestani, Maziar Yazdani Damavandi, Miadreza Shafie-khah, Joao P. S. Catalao, Gianfranco ChiccoAbstract:The concept of Carrier-Based Demand Response (CBDR) programs in Smart Multi-Energy Systems (MES) is proposed in this paper. It is discussed that by establishing the bi-directional relation between multi-energy demand and MES through the penetration of multi-carrier device technologies, the opportunity of demand-side participation in system operation can be activated. In this paper, the External Dependency caused by multi-carrier devices is employed as a demand response. The CBDR is introduced as the flexibility of end-use to change the conversion pattern of input carriers into required demand. As the CBDR program is influenced by energy carrier prices, upstream network obligations and also the customer's behavior, its uncertainty is effectively modeled in this paper. The results compare the difference between the stochastic and deterministic approaches to the problem and show the improved accuracy through the stochastic modeling. The role of those customers that are not taking part in CBDR program is also investigated.
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Modeling the carrier dependencies on demand-side in a smart multi-energy local network
2014 Smart Grid Conference (SGC), 2014Co-Authors: Nilufar Neyestani, Maziar Yazdani Damavandi, Miadreza Shafie-khah, Joao P. S. Catalao, Gianfranco ChiccoAbstract:Smart local energy networks represent a key option for more penetration of sustainably developed facilities. These facilities can cause an extended Dependency in both time and carrier domains which should be considered through a comprehensive model. This paper introduces a new concept of internal and External dependencies. The concept is related to penetration of energy converters on demand side and the effects they bring to the system. Being achieved by implementation of smart grid, dependencies release operational flexibility and subsequently enhance the system efficiency. The model contains, carrier based demand response which preserves consumers satisfaction by utilizing the flexibility in exchanging the input energy carrier instead of changing end-usage pattern. The paper develops the coupling matrix model for smart multi-energy systems considering the External Dependency as an added module to the overall model
