The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jeanmarie Lehn - One of the best experts on this subject based on the ideXlab platform.
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supramolecular chemistry from molecular information towards Self Organization and complex matter
Reports on Progress in Physics, 2004Co-Authors: Jeanmarie LehnAbstract:Molecular chemistry has developed a wide range of very powerful procedures for constructing ever more sophisticated molecules from atoms linked by covalent bonds. Beyond molecular chemistry lies supramolecular chemistry, which aims at developing highly complex chemical systems from components interacting via non-covalent intermolecular forces.By the appropriate manipulation of these interactions, supramolecular chemistry became progressively the chemistry of molecular information, involving the storage of information at the molecular level, in the structural features, and its retrieval, transfer, and processing at the supramolecular level, through molecular recognition processes operating via specific interactional algorithms.This has paved the way towards apprehending chemistry also as an information science.Numerous receptors capable of recognizing, i.e. selectively binding, specific substrates have been developed, based on the molecular information stored in the interacting species. Suitably functionalized receptors may perform supramolecular catalysis and selective transport processes. In combination with polymolecular Organization, recognition opens ways towards the design of molecular and supramolecular devices based on functional (photoactive, electroactive, ionoactive, etc) components.A step beyond preOrganization consists in the design of systems undergoing Self-Organization, i.e. systems capable of spontaneously generating well-defined supramolecular architectures by Self-assembly from their components. Self-Organization processes, directed by the molecular information stored in the components and read out at the supramolecular level through specific interactions, represent the operation of programmed chemical systems. They have been implemented for the generation of a variety of discrete functional architectures of either organic or inorganic nature.Self-Organization processes also give access to advanced supramolecular materials, such as supramolecular polymers and liquid crystals, and provide an original approach to nanoscience and nanotechnology. In particular, the spontaneous but controlled generation of well-defined, functional supramolecular architectures of nanometric size through Self-Organization represents a means of performing programmed engineering and processing of nanomaterials.Supramolecular chemistry is intrinsically a dynamic chemistry, in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when a molecular entity contains covalent bonds that may form and break reversibly, so as to make possible a continuous change in constitution and structure by reOrganization and exchange of building blocks. This behaviour defines a constitutional dynamic chemistry that allows Self-Organization by selection as well as by design at both the molecular and supramolecular levels. Whereas Self-Organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, Self-Organization by selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation in a Darwinistic fashion.The merging of the features, information and programmability, dynamics and reversibility, constitution and structural diversity, points towards the emergence of adaptative and evolutionary chemistry. Together with the corresponding fields of physics and biology, it constitutes a science of informed matter, of organized, adaptative complex matter.
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toward complex matter supramolecular chemistry and Self Organization
Proceedings of the National Academy of Sciences of the United States of America, 2002Co-Authors: Jeanmarie LehnAbstract:As the wind of time blows into the sails of space, the unfolding of the universe nurtures the evolution of matter under the pressure of information. From divided to condensed and on to organized, living, and thinking matter, the path is toward an increase in complexity through Self-Organization.
Daiju Kitagawa - One of the best experts on this subject based on the ideXlab platform.
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Self Organization of plk4 regulates symmetry breaking in centriole duplication
Nature Communications, 2019Co-Authors: Shohei Yamamoto, Daiju KitagawaAbstract:During centriole duplication, a single daughter centriole is formed next to the mother centriole. The molecular mechanism that determines a single duplication site remains a long-standing question. Here, we show that intrinsic Self-Organization of Plk4 is implicated in symmetry breaking in the process of centriole duplication. We demonstrate that Plk4 has an ability to phase-separate into condensates via an intrinsically disordered linker and that the condensation properties of Plk4 are regulated by autophosphorylation. Consistently, the dissociation dynamics of centriolar Plk4 are controlled by autophosphorylation. We further found that autophosphorylated Plk4 is already distributed as a single focus around the mother centriole before the initiation of procentriole formation, and is subsequently targeted for STIL-HsSAS6 loading. Perturbation of Plk4 Self-Organization affects the asymmetry of centriolar Plk4 distribution and proper centriole duplication. Overall, we propose that the spatial pattern formation of Plk4 is a determinant of a single duplication site per mother centriole.
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Self Organization of plk4 regulates symmetry breaking in centriole duplication
bioRxiv, 2018Co-Authors: Shohei Yamamoto, Daiju KitagawaAbstract:During centriole duplication, a single daughter centriole is formed near the mother centriole. The mechanism that determines a single duplication site is unknown. Here, we demonstrate that intrinsic Self-Organization of Plk4 underlies symmetry breaking in centriole duplication. We show that in its nonphosphorylated state, Plk4 preferentially Self-assembles via a disordered linker and that this Self-assembly is prevented by autophosphorylation. Consistently, the dissociation dynamics of centriolar Plk4 are controlled by autophosphorylation. We further found that autophophorylated Plk4 is localized as a single focus around the mother centriole before procentriole formation, and is subsequently targeted for STIL-HsSAS6 loading. Perturbing Plk4 Self-Organization affects the asymmetry of centriolar Plk4 distribution and centriole duplication. We propose that the spatial patterning of Plk4 directs a single duplication site per mother centriole.
Peter J Stang - One of the best experts on this subject based on the ideXlab platform.
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Self Organization in coordination driven Self assembly
ChemInform, 2010Co-Authors: Brian H Northrop, Yao Rong Zheng, Kiwhan Chi, Peter J StangAbstract:Self-assembly allows for the preparation of highly complex molecular and supramolecular systems from relatively simple starting materials. Typically, Self-assembled supramolecules are constructed by combining complementary pairs of two highly symmetric molecular components, thus limiting the chances of forming unwanted side products. Combining asymmetric molecular components or multiple complementary sets of molecules in one complex mixture can produce myriad different ordered and disordered supramolecular assemblies. Alternatively, spontaneous Self-Organization phenomena can promote the formation of specific product(s) out of a collection of multiple possibilities. Self-Organization processes are common throughout much of nature and are especially common in biological systems. Recently, researchers have studied Self-organized Self-assembly in purely synthetic systems. This Account describes our investigations of Self-Organization in the coordination-driven Self-assembly of platinum(II)-based metallosupra...
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multicomponent supramolecular systems Self Organization in coordination driven Self assembly
Chemistry: A European Journal, 2009Co-Authors: Yao Rong Zheng, Haibo Yang, Koushik Ghosh, Liang Zhao, Peter J StangAbstract:The Self-Organization of multicomponent supramolecular systems involving a variety of two-dimensional (2-D) polygons and three-dimensional (3-D) cages is presented. Nine Self-organizing systems, SS1–SS9, have been studied. Each involving the simultaneous mixing of organoplatinum acceptors and pyridyl donors of varying geometry and their selective Self-assembly into three to four specific 2-D (rectangular, triangular, and rhomboid) and/or 3-D (triangular prism and distorted and nondistorted trigonal bipyramidal) supramolecules. The formation of these discrete structures is characterized using NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). In all cases, the Self-Organization process is directed by: (1) the geometric information encoded within the molecular subunits and (2) a thermodynamically driven dynamic Self-correction process. The result is the selective Self-assembly of multiple discrete products from a randomly formed complex. The influence of key experimental variables – temperature and solvent – on the Self-correction process and the fidelity of the resulting Self-Organization systems is also described.
G Beni - One of the best experts on this subject based on the ideXlab platform.
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Self Organization of sensors for swarm intelligence
International Conference on Robotics and Automation, 1992Co-Authors: S Hackwood, G BeniAbstract:The realization of sensing swarms composed of value-specific sensing elements requires distributed cooperation among the members of the swarm. The number of value-specific sensing elements must change under changing external conditions. The recalculations of the optimal distribution of sensing elements can be carried out from the knowledge of the (changed) average value of the sensed feature. Mathematically this can be done by using the maximum-entropy principle. However, distribution operation requires solving two additional problems: the new average value must be known to each sensing element, and a new configuration must be achieved autonomously (i.e. under distributed control). For the solution to these problems the authors introduce a circulating swarm model in which the elements of the swarm circulate in a ring while performing the sensing operations and the Self-Organization. They show which elementary operations can be used in an algorithm for Self-Organization of the swarm in a new configuration optimized for sensing. >
Damien Trentesaux - One of the best experts on this subject based on the ideXlab platform.
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dynamic Self Organization in holonic multi agent manufacturing systems
Computers in Industry, 2015Co-Authors: Jose Barbosa, Paulo Leitao, Emmanuel Adam, Damien TrentesauxAbstract:Holonic multi-agent system evolution of the well-known ADACOR architecture.Behavioural and structural Self-Organization proposed.Nervousness control mechanism.Results show an improvement of the previous version of ADACOR. Nowadays, systems are becoming increasingly complex, mainly due to an exponential increase in the number of entities and their interconnections. Examples of these complex systems can be found in manufacturing, smart-grids, traffic control, logistics, economics and biology, among others. Due to this complexity, particularly in manufacturing, a lack of responsiveness in coping with demand for higher quality products, the drastic reduction in product lifecycles and the increasing need for product customization are being observed. Traditional solutions, based on central monolithic control structures, are becoming obsolete as they are not suitable for reacting and adapting to these perturbations. The decentralization of the complexity problem through simple, intelligent and autonomous entities, such as those found in multi-agent systems, is seen as a suitable methodology for tackling this challenge in industrial scenarios. Additionally, the use of biologically inspired Self-Organization concepts has proved to be suitable for being embedded in these approaches enabling better performances to be achieved. According to these principals, several approaches have been proposed but none can be truly embedded and extract all the potential of Self-Organization mechanisms. This paper proposes an evolution to the ADACOR holonic control architecture inspired by biological and evolutionary theories. In particular, a two-dimensional Self-Organization mechanism was designed taking the behavioural and structural vectors into consideration, thus allowing truly evolutionary and reconfigurable systems to be achieved that can cope with emergent requirements. The approach proposed is validated with two simulation use cases.
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Self Organization in distributed manufacturing control state of the art and future trends
Systems Man and Cybernetics, 2002Co-Authors: S Bousbia, Damien TrentesauxAbstract:Facing new and varied customer's needs, strategies of production have radically changed during these list three decades leading to a need for agile and, as a consequence, Self-organized manufacturing control systems. One possible way to integrate Self-Organization capability is to move from rigid centralized architectures towards distributed architectures. In this paper, we present a state-of-the-art of Self-Organization models in distributed manufacturing control, according to the bionic, holonic, multi-agent and heterarchical design approaches. We show the potential capabilities offered by these approaches to integrate Self-Organization mechanisms. Meanwhile, we also point out the insufficiencies of existing contributions, which lead us to highlight some future trends in the design of effective Self-organized manufacturing control systems.