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Sample records for information transfer complexity

  1. Thermodynamic aspects of information transfer in complex dynamical systems.

    PubMed

    Cafaro, Carlo; Ali, Sean Alan; Giffin, Adom

    2016-02-01

    From the Horowitz-Esposito stochastic thermodynamical description of information flows in dynamical systems [J. M. Horowitz and M. Esposito, Phys. Rev. X 4, 031015 (2014)], it is known that while the second law of thermodynamics is satisfied by a joint system, the entropic balance for the subsystems is adjusted by a term related to the mutual information exchange rate between the two subsystems. In this article, we present a quantitative discussion of the conceptual link between the Horowitz-Esposito analysis and the Liang-Kleeman work on information transfer between dynamical system components [X. S. Liang and R. Kleeman, Phys. Rev. Lett. 95, 244101 (2005)]. In particular, the entropic balance arguments employed in the two approaches are compared. Notwithstanding all differences between the two formalisms, our work strengthens the Liang-Kleeman heuristic balance reasoning by showing its formal analogy with the recent Horowitz-Esposito thermodynamic balance arguments.

  2. Quantifying information transfer and mediation along causal pathways in complex systems

    NASA Astrophysics Data System (ADS)

    Runge, Jakob

    2015-12-01

    Measures of information transfer have become a popular approach to analyze interactions in complex systems such as the Earth or the human brain from measured time series. Recent work has focused on causal definitions of information transfer aimed at decompositions of predictive information about a target variable, while excluding effects of common drivers and indirect influences. While common drivers clearly constitute a spurious causality, the aim of the present article is to develop measures quantifying different notions of the strength of information transfer along indirect causal paths, based on first reconstructing the multivariate causal network. Another class of novel measures quantifies to what extent different intermediate processes on causal paths contribute to an interaction mechanism to determine pathways of causal information transfer. The proposed framework complements predictive decomposition schemes by focusing more on the interaction mechanism between multiple processes. A rigorous mathematical framework allows for a clear information-theoretic interpretation that can also be related to the underlying dynamics as proven for certain classes of processes. Generally, however, estimates of information transfer remain hard to interpret for nonlinearly intertwined complex systems. But if experiments or mathematical models are not available, then measuring pathways of information transfer within the causal dependency structure allows at least for an abstraction of the dynamics. The measures are illustrated on a climatological example to disentangle pathways of atmospheric flow over Europe.

  3. Communication: Exciton-phonon information flow in the energy transfer process of photosynthetic complexes

    NASA Astrophysics Data System (ADS)

    Rebentrost, Patrick; Aspuru-Guzik, Alán

    2011-03-01

    Non-Markovian and nonequilibrium phonon effects are believed to be key ingredients in the energy transfer in photosynthetic complexes, especially in complexes which exhibit a regime of intermediate exciton-phonon coupling. In this work, we utilize a recently developed measure for non-Markovianity to elucidate the exciton-phonon dynamics in terms of the information flow between electronic and vibrational degrees of freedom. We study the measure in the hierarchical equation of motion approach which captures strong coupling effects and nonequilibrium molecular reorganization. We propose an additional trace distance measure for the information flow that could be extended to other master equations. We find that for a model dimer system and for the Fenna-Matthews-Olson complex the non-Markovianity is significant under physiological conditions.

  4. Symbolic local information transfer

    NASA Astrophysics Data System (ADS)

    Nakajima, K.; Haruna, T.

    2013-06-01

    Recently, the permutation-information theoretic approach has been used in a broad range of research fields. In particular, in the study of high-dimensional dynamical systems, it has been shown that this approach can be effective in characterizing global properties, including the complexity of their spatiotemporal dynamics. Here, we show that this approach can also be applied to reveal local spatiotemporal profiles of distributed computations existing at each spatiotemporal point in the system. J. T. Lizier et al. have recently introduced the concept of local information dynamics, which consists of information storage, transfer, and modification. This concept has been intensively studied with regard to cellular automata, and has provided quantitative evidence of several characteristic behaviors observed in the system. In this paper, by focusing on the local information transfer, we demonstrate that the application of the permutation-information theoretic approach, which introduces natural symbolization methods, makes the concept easily extendible to systems that have continuous states. We propose measures called symbolic local transfer entropies, and apply these measures to two test models, the coupled map lattice (CML) system and the Bak-Sneppen model (BS-model), to show their relevance to spatiotemporal systems that have continuous states. In the CML, we demonstrate that it can be successfully used as a spatiotemporal filter to stress a coherent structure buried in the system. In particular, we show that the approach can clearly stress out defect turbulences or Brownian motion of defects from the background, which gives quantitative evidence suggesting that these moving patterns are the information transfer substrate in the spatiotemporal system. We then show that these measures reveal qualitatively different properties from the conventional approach using the sliding window method, and are also robust against external noise. In the BS-model, we demonstrate that

  5. CAD-ICAD complex structure derived from saturation transfer experiment and simulated annealing without using pairwise NOE information.

    PubMed

    Matsuda, Tomoki; Nakajima, Nobuyuki; Yamazaki, Toshio; Nakamura, Haruki

    2004-01-01

    Saturation transfer experiments were performed for the (2)H- and (15)N-labeled mouse CAD domain of the caspase-activated deoxyribonuclease and the CAD domain of its inhibitor to reveal the protein-protein complexed conformation. Based on the physical model for the spin diffusion, a novel method was developed to reconstruct the complexed structure using the simulated annealing calculation. The complementarity in the molecular surface shape and the electrostatic potential distribution provide a good measure for the assessment of the putative complexed conformation, despite much less experimental information than the conventional distance geometry calculation. Copyright 2004 John Wiley & Sons, Ltd.

  6. Communication complexity and information complexity

    NASA Astrophysics Data System (ADS)

    Pankratov, Denis

    Information complexity enables the use of information-theoretic tools in communication complexity theory. Prior to the results presented in this thesis, information complexity was mainly used for proving lower bounds and direct-sum theorems in the setting of communication complexity. We present three results that demonstrate new connections between information complexity and communication complexity. In the first contribution we thoroughly study the information complexity of the smallest nontrivial two-party function: the AND function. While computing the communication complexity of AND is trivial, computing its exact information complexity presents a major technical challenge. In overcoming this challenge, we reveal that information complexity gives rise to rich geometrical structures. Our analysis of information complexity relies on new analytic techniques and new characterizations of communication protocols. We also uncover a connection of information complexity to the theory of elliptic partial differential equations. Once we compute the exact information complexity of AND, we can compute exact communication complexity of several related functions on n-bit inputs with some additional technical work. Previous combinatorial and algebraic techniques could only prove bounds of the form theta( n). Interestingly, this level of precision is typical in the area of information theory, so our result demonstrates that this meta-property of precise bounds carries over to information complexity and in certain cases even to communication complexity. Our result does not only strengthen the lower bound on communication complexity of disjointness by making it more exact, but it also shows that information complexity provides the exact upper bound on communication complexity. In fact, this result is more general and applies to a whole class of communication problems. In the second contribution, we use self-reduction methods to prove strong lower bounds on the information

  7. Optically active mixed (phthalocyaninato)(porphyrinato) rare earth triple-decker complexes. Synthesis, spectroscopy, and effective chiral information transfer.

    PubMed

    Lu, Jitao; Deng, Yanhua; Zhang, Xiaomei; Kobayashi, Nagao; Jiang, Jianzhuang

    2011-03-21

    With the view to creating novel sandwich-type tetrapyrrole rare earth complexes toward potential applications in material science and chiral catalysis, two new optically active mixed (phthalocyaninato)(porphyrinato) rare earth triple-decker complexes with both (R)- and (S)-enantiomers [M(2)(Pc)(2)(TCBP)] {TCBP = Meso-tetrakis [3,4-(11,12:13,14-di(1',2'-naphtho)-1,4,7,10,15,18-hexaoxacycloeicosa-2,11,13-triene)-phenyl] porphyrinate; M = Eu (1), Y (2)} have been designed and prepared by treating optically active metal free porphyrin (R)-/(S)-H(2)TCBP with M(Pc)(2) in the presence of corresponding M(acac)(3)·nH(2)O (acac = acetylacetonate) in refluxing 1,2,4-trichlorobenzene (TCB). These novel mixed ring rare earth triple-decker compounds were characterized by a wide range of spectroscopic methods including MS, (1)H NMR, IR, electronic absorption, and magnetic circular-dichroism (MCD) spectroscopic measurements in addition to elemental analysis. Perfect mirror image relationship was observed in the Soret and Q absorption regions in the circular-dichroism (CD) spectra of the (R)- and (S)-enantiomers, indicating the optically active nature of these two mixed (phthalocyaninato)(porphyrinato) rare earth triple-decker complexes. This result reveals the effective chiral information transfer from the peripheral chiral binaphthyl units to the porphyrin and phthalocyanine chromophores in the triple-decker molecule because of the intense π-π interaction between porphyrin and phthalocyanine rings. In addition, their electrochemical properties have also been investigated by cyclic voltammetry (CV).

  8. Measuring Information-Transfer Delays

    PubMed Central

    Wibral, Michael; Pampu, Nicolae; Priesemann, Viola; Siebenhühner, Felix; Seiwert, Hannes; Lindner, Michael; Lizier, Joseph T.; Vicente, Raul

    2013-01-01

    In complex networks such as gene networks, traffic systems or brain circuits it is important to understand how long it takes for the different parts of the network to effectively influence one another. In the brain, for example, axonal delays between brain areas can amount to several tens of milliseconds, adding an intrinsic component to any timing-based processing of information. Inferring neural interaction delays is thus needed to interpret the information transfer revealed by any analysis of directed interactions across brain structures. However, a robust estimation of interaction delays from neural activity faces several challenges if modeling assumptions on interaction mechanisms are wrong or cannot be made. Here, we propose a robust estimator for neuronal interaction delays rooted in an information-theoretic framework, which allows a model-free exploration of interactions. In particular, we extend transfer entropy to account for delayed source-target interactions, while crucially retaining the conditioning on the embedded target state at the immediately previous time step. We prove that this particular extension is indeed guaranteed to identify interaction delays between two coupled systems and is the only relevant option in keeping with Wiener’s principle of causality. We demonstrate the performance of our approach in detecting interaction delays on finite data by numerical simulations of stochastic and deterministic processes, as well as on local field potential recordings. We also show the ability of the extended transfer entropy to detect the presence of multiple delays, as well as feedback loops. While evaluated on neuroscience data, we expect the estimator to be useful in other fields dealing with network dynamics. PMID:23468850

  9. New Information Transfer Therapies

    ERIC Educational Resources Information Center

    Lorenzi, Nancy M.; Young, K. Penny

    1974-01-01

    Specific examples of dial access systems, information centers, computer assisted instruction for students, use of media communication, resource centers, and library consortia in the biomedical field. (LS)

  10. The Complex Information Process

    NASA Astrophysics Data System (ADS)

    Taborsky, Edwina

    2000-09-01

    This paper examines the semiosic development of energy to information within a dyadic reality that operates within the contradictions of both classical and quantum physics. These two realities are examined within the three Peircean modal categories of Firstness, Secondness and Thirdness. The paper concludes that our world cannot operate within either of the two physical realities but instead filiates the two to permit a semiosis or information-generation of complex systems.

  11. Information Transfer During Quantum Measurement

    NASA Astrophysics Data System (ADS)

    Lashkari, Nima

    2004-03-01

    ``The progress in quantum measurement theory has increased the need for a physical theory of information transfer during quantum measurement. Using the RPI --Restricted Path Integrals- approach to quantum measurement, we discuss on equivalence of information transfer and measurement. It is possible to understand the nature of measurement process by working on the phenomenon of information transfer. I show that in contrary with today information theory, for a conscious observer the amount of information gained in a measurement is not an absolute amount but related to his or her previous knowledge of the system. The knowledge, the observer has about the history of the system interactions and entanglements with other systems. The more intelligent the observer is, the more information it gains in a measurement. This means that the difficulties in quantum measurement can have roots in consciousness -the intuitive belief of many physicists. And it directs our attention to work on a general theory of consciousness. At the end I will make a model for the amount of transferred information during an observation. ''

  12. Human factors and information transfer

    NASA Technical Reports Server (NTRS)

    Lee, Alfred T.

    1989-01-01

    Key problem areas in the management and transfer of information in the National Airspace System, contributing to human errors are identified. Information-management aspects supporting the user's ability to assess prevailing situations accurately with adequate time to make an informed decision are considered. The relationship between judgment biases and requirements for managing weather information is illustrated by examining such hazardous weather phenomena as microbursts and windshears. The system of air-ground communication relying almost exclusively on voice transmissions is discussed, and recommendations in the areas of communications procedures and technology development are provided.

  13. Heat Transfer in Complex Fluids

    SciTech Connect

    Mehrdad Massoudi

    2012-01-01

    Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these fluids show Newtonian

  14. Information communication on complex networks

    NASA Astrophysics Data System (ADS)

    Igarashi, Akito; Kawamoto, Hiroki; Maruyama, Takahiro; Morioka, Atsushi; Naganuma, Yuki

    2013-02-01

    Since communication networks such as the Internet, which is regarded as a complex network, have recently become a huge scale and a lot of data pass through them, the improvement of packet routing strategies for transport is one of the most significant themes in the study of computer networks. It is especially important to find routing strategies which can bear as many traffic as possible without congestion in complex networks. First, using neural networks, we introduce a strategy for packet routing on complex networks, where path lengths and queue lengths in nodes are taken into account within a framework of statistical physics. Secondly, instead of using shortest paths, we propose efficient paths which avoid hubs, nodes with a great many degrees, on scale-free networks with a weight of each node. We improve the heuristic algorithm proposed by Danila et. al. which optimizes step by step routing properties on congestion by using the information of betweenness, the probability of paths passing through a node in all optimal paths which are defined according to a rule, and mitigates the congestion. We confirm the new heuristic algorithm which balances traffic on networks by achieving minimization of the maximum betweenness in much smaller number of iteration steps. Finally, We model virus spreading and data transfer on peer-to-peer (P2P) networks. Using mean-field approximation, we obtain an analytical formulation and emulate virus spreading on the network and compare the results with those of simulation. Moreover, we investigate the mitigation of information traffic congestion in the P2P networks.

  15. Plasmodesmata: gateways for information transfer.

    PubMed

    Waigmann, E; Cohen, Y; McLean, G; Zambryski, P

    1998-01-01

    Intercellular communication in plants has evolved to occur via elongated cytoplasmic bridges, called plasmodesmata, that traverse the thick cell walls that surround plant cells. Historically, plasmodesmata have been assigned the mostly passive role of creating cytoplasmic continuity between plant cells enabling free transport of the wealth of small plant metabolites and growth hormones under 1 kDa. When it was discovered that plant viruses pirate plasmodesmata for movement of viral genomes during infection, it was proposed that viruses modified plasmodesmata for transport of very large molecules. Now, there is compelling evidence that plasmodesmata are inherently dynamic, rapidly altering their dimensions to increase their transport capabilities, upon contact with viral as well as developmentally important plant proteins. Further, the study of intercellular transport has prompted analyses of intracellular transport pathways, implicating the cytoskeleton as a major tracking system to plasmodesmata. Thus, plasmodesmata form a three-dimensional network of transportation channels and major checkpoints for information transfer. In the following, current knowledge about structure and function of these connective organelles, and about routing of molecules towards plasmodesmata, will be summarized.

  16. Information Complexity and Biology

    NASA Astrophysics Data System (ADS)

    Bagnoli, Franco; Bignone, Franco A.; Cecconi, Fabio; Politi, Antonio

    Kolmogorov contributed directly to Biology in essentially three problems: the analysis of population dynamics (Lotka-Volterra equations), the reaction-diffusion formulation of gene spreading (FKPP equation), and some discussions about Mendel's laws. However, the widely recognized importance of his contribution arises from his work on algorithmic complexity. In fact, the limited direct intervention in Biology reflects the generally slow growth of interest of mathematicians towards biological issues. From the early work of Vito Volterra on species competition, to the slow growth of dynamical systems theory, contributions to the study of matter and the physiology of the nervous system, the first 50-60 years have witnessed important contributions, but as scattered pieces apparently uncorrelated, and in branches often far away from Biology. Up to the 40' it is hard to see the initial loose build up of a convergence, for those theories that will become mainstream research by the end of the century, and connected by the study of biological systems per-se.

  17. Stratospheric Aerosols: The Transfer of Scientific Information.

    ERIC Educational Resources Information Center

    Feidler, Anita; Hurt, C. D.

    1986-01-01

    Examines information transfer in atmospheric physics by tracing one paper through five years of citations and suggesting patterns for highly cited papers. The results are also discussed in terms of information transfer in a popularized environment, as stratospheric aerosols have been prominently discussed in the popular press. (Author/EM)

  18. Stratospheric Aerosols: The Transfer of Scientific Information.

    ERIC Educational Resources Information Center

    Feidler, Anita; Hurt, C. D.

    1986-01-01

    Examines information transfer in atmospheric physics by tracing one paper through five years of citations and suggesting patterns for highly cited papers. The results are also discussed in terms of information transfer in a popularized environment, as stratospheric aerosols have been prominently discussed in the popular press. (Author/EM)

  19. Charge transfer complexes of certain aromatic polyimides

    NASA Technical Reports Server (NTRS)

    Gordina, T. A.; Kotov, B. V.; Kolninov, O. V.; Pravednikov, A. N.

    1985-01-01

    By electron spectroscopy it was shown that aromatic polyimides containing electron-donor residues of diamines -C6H4-X-C6H-(X=NH, NCH3, NC6H5, O, S, and CH2) form charge transfer complexes with low-molecular-weight electron acceptors. Based on the data obtained, the hypothesis was advanced that the coloration of the polyimides per se is due to the formation of charge transfer complexes between the electron-acceptor imide fragments and the electron-donor residues of the diamines.

  20. Dynamic information routing in complex networks

    PubMed Central

    Kirst, Christoph; Timme, Marc; Battaglia, Demian

    2016-01-01

    Flexible information routing fundamentally underlies the function of many biological and artificial networks. Yet, how such systems may specifically communicate and dynamically route information is not well understood. Here we identify a generic mechanism to route information on top of collective dynamical reference states in complex networks. Switching between collective dynamics induces flexible reorganization of information sharing and routing patterns, as quantified by delayed mutual information and transfer entropy measures between activities of a network's units. We demonstrate the power of this mechanism specifically for oscillatory dynamics and analyse how individual unit properties, the network topology and external inputs co-act to systematically organize information routing. For multi-scale, modular architectures, we resolve routing patterns at all levels. Interestingly, local interventions within one sub-network may remotely determine nonlocal network-wide communication. These results help understanding and designing information routing patterns across systems where collective dynamics co-occurs with a communication function. PMID:27067257

  1. Dynamic information routing in complex networks

    NASA Astrophysics Data System (ADS)

    Kirst, Christoph; Timme, Marc; Battaglia, Demian

    2016-04-01

    Flexible information routing fundamentally underlies the function of many biological and artificial networks. Yet, how such systems may specifically communicate and dynamically route information is not well understood. Here we identify a generic mechanism to route information on top of collective dynamical reference states in complex networks. Switching between collective dynamics induces flexible reorganization of information sharing and routing patterns, as quantified by delayed mutual information and transfer entropy measures between activities of a network's units. We demonstrate the power of this mechanism specifically for oscillatory dynamics and analyse how individual unit properties, the network topology and external inputs co-act to systematically organize information routing. For multi-scale, modular architectures, we resolve routing patterns at all levels. Interestingly, local interventions within one sub-network may remotely determine nonlocal network-wide communication. These results help understanding and designing information routing patterns across systems where collective dynamics co-occurs with a communication function.

  2. Promoting Transfer by Grounding Complex Systems Principles

    ERIC Educational Resources Information Center

    Goldstone, Robert L.; Wilensky, Uri

    2008-01-01

    Understanding scientific phenomena in terms of complex systems principles is both scientifically and pedagogically important. Situations from different disciplines of science are often governed by the same principle, and so promoting knowledge transfer across disciplines makes valuable cross-fertilization and scientific unification possible.…

  3. Promoting Transfer by Grounding Complex Systems Principles

    ERIC Educational Resources Information Center

    Goldstone, Robert L.; Wilensky, Uri

    2008-01-01

    Understanding scientific phenomena in terms of complex systems principles is both scientifically and pedagogically important. Situations from different disciplines of science are often governed by the same principle, and so promoting knowledge transfer across disciplines makes valuable cross-fertilization and scientific unification possible.…

  4. Coronene-based charge-transfer complexes

    NASA Astrophysics Data System (ADS)

    Yoshida, Yukihiro; Isomura, Kazuhide; Kumagai, Yoshihide; Maesato, Mitsuhiko; Kishida, Hideo; Mizuno, Motohiro; Saito, Gunzi

    2016-08-01

    Recent developments in the arena of charge-transfer complexes composed of the D 6h-symmetric polycyclic aromatic hydrocarbon, coronene, are highlighted with emphasis on the structural and physical properties of these complexes. Because of the dual electron-donating and -accepting abilities of coronene, this group involves structurally-defined four cation salts and three anion salts. The Jahn-Teller distortions and in-plane motion of coronene molecules in the solids, both of which are closely associated with the high symmetry of coronene molecules, and syntheses of clathrate-type complexes are also presented.

  5. Information transfer in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Lee, Alfred T.

    1988-01-01

    An informal overview is given of the work in progress and the planned work in the area of information transfer that specifically addresses human factors issues in National Airspace System (NAS). The issues of how weather information will be displayed on the flight deck, the development of appropriate decision making technology, and digital datalink transmission are also briefly discussed.

  6. Accessing complexity from genome information

    NASA Astrophysics Data System (ADS)

    Tenreiro Machado, J. A.

    2012-06-01

    This paper studies the information content of the chromosomes of 24 species. In a first phase, a scheme inspired in dynamical system state space representation is developed. For each chromosome the state space dynamical evolution is shed into a two dimensional chart. The plots are then analyzed and characterized in the perspective of fractal dimension. This information is integrated in two measures of the species' complexity addressing its average and variability. The results are in close accordance with phylogenetics pointing quantitative aspects of the species' genomic complexity.

  7. Darwinian demons, evolutionary complexity, and information maximization.

    PubMed

    Krakauer, David C

    2011-09-01

    Natural selection is shown to be an extended instance of a Maxwell's demon device. A demonic selection principle is introduced that states that organisms cannot exceed the complexity of their selective environment. Thermodynamic constraints on error repair impose a fundamental limit to the rate that information can be transferred from the environment (via the selective demon) to the genome. Evolved mechanisms of learning and inference can overcome this limitation, but remain subject to the same fundamental constraint, such that plastic behaviors cannot exceed the complexity of reward signals. A natural measure of evolutionary complexity is provided by mutual information, and niche construction activity--the organismal contribution to the construction of selection pressures--might in principle lead to its increase, bounded by thermodynamic free energy required for error correction.

  8. Information transfer in community structured multiplex networks

    NASA Astrophysics Data System (ADS)

    Solé Ribalta, Albert; Granell, Clara; Gómez, Sergio; Arenas, Alex

    2015-08-01

    The study of complex networks that account for different types of interactions has become a subject of interest in the last few years, specially because its representational power in the description of users interactions in diverse online social platforms (Facebook, Twitter, Instagram, etc.). The mathematical description of these interacting networks has been coined under the name of multilayer networks, where each layer accounts for a type of interaction. It has been shown that diffusive processes on top of these networks present a phenomenology that cannot be explained by the naive superposition of single layer diffusive phenomena but require the whole structure of interconnected layers. Nevertheless, the description of diffusive phenomena on multilayer networks has obviated the fact that social networks have strong mesoscopic structure represented by different communities of individuals driven by common interests, or any other social aspect. In this work, we study the transfer of information in multilayer networks with community structure. The final goal is to understand and quantify, if the existence of well-defined community structure at the level of individual layers, together with the multilayer structure of the whole network, enhances or deteriorates the diffusion of packets of information.

  9. Information aspects of actomyosin complex.

    PubMed

    Matsuno, K; Honda, H

    1991-01-01

    Actomyosin complex as a representative case of cell motility exhibits an intricate interplay between the structure it maintains and the function it realizes. The correspondence between structure and function an actomyosin complex displays is a one-to-many type. Mechanochemical couplings underlying the energy transduction associated with the hydrolysis of ATP in the complex render the correspondence between the displacement of the medium and the force acting there a one-to-many type. Such a one-to-many correspondence between displacement and force makes the dynamic development informational in the sense that the prior indefiniteness turns into the posterior definiteness with the elapse of time. This characteristic exhibits sharp contrast to the time-honored one-to-one correspondence between displacement and force that is most common in mechanics, whether classical or quantal, in which no information is generated because of a forcible intrusion of exogenous detection of nonlocal character claiming an instantaneous bird's eye view of everything involved. Information generation is due intrinsically to the process of endogenous detection of local character, and the process has to be local because any physical signal propagates at a finite velocity. Actomyosin complex serves as a material example witnessing that detection of local character certainly generates information and leaves itself nonprogrammable.

  10. Entropy, complexity, and spatial information

    NASA Astrophysics Data System (ADS)

    Batty, Michael; Morphet, Robin; Masucci, Paolo; Stanilov, Kiril

    2014-10-01

    We pose the central problem of defining a measure of complexity, specifically for spatial systems in general, city systems in particular. The measures we adopt are based on Shannon's (in Bell Syst Tech J 27:379-423, 623-656, 1948) definition of information. We introduce this measure and argue that increasing information is equivalent to increasing complexity, and we show that for spatial distributions, this involves a trade-off between the density of the distribution and the number of events that characterize it; as cities get bigger and are characterized by more events—more places or locations, information increases, all other things being equal. But sometimes the distribution changes at a faster rate than the number of events and thus information can decrease even if a city grows. We develop these ideas using various information measures. We first demonstrate their applicability to various distributions of population in London over the last 100 years, then to a wider region of London which is divided into bands of zones at increasing distances from the core, and finally to the evolution of the street system that characterizes the built-up area of London from 1786 to the present day. We conclude by arguing that we need to relate these measures to other measures of complexity, to choose a wider array of examples, and to extend the analysis to two-dimensional spatial systems.

  11. Information Dissemination and Technology Transfer in Telecommunications.

    ERIC Educational Resources Information Center

    Roderer, Nancy K.; King, Donald W.

    Using a model of scientific and technical information transfer as a framework, this document focuses on four types of activities: the generation or authorship of telecommunications information and its publication, distribution, and use. Different forms of publication are considered in each functional area, though primary emphasis is on the…

  12. Information Transfer as Technical Assistance for Development.

    ERIC Educational Resources Information Center

    Dosa, Marta L.

    1985-01-01

    Outlines trends in assistance strategies and types of international organizations as sources of information transfer for development. Highlights include impact of development policies (modernization theory, basic needs policy, dependency theory, adjustment theory), telematics and technical assistance (transborder data flow, information policies),…

  13. Information Dissemination and Technology Transfer in Telecommunications.

    ERIC Educational Resources Information Center

    Roderer, Nancy K.; King, Donald W.

    Using a model of scientific and technical information transfer as a framework, this document focuses on four types of activities: the generation or authorship of telecommunications information and its publication, distribution, and use. Different forms of publication are considered in each functional area, though primary emphasis is on the…

  14. Organization and transfer of information in risk-related fields

    SciTech Connect

    Kertesz, F.

    1983-01-01

    The two case histories on risk-related information flow illustrate the complexity of the problem and the high level of cooperation between the participants. Unorthodox channels of transfer - CHEMTREX, NUCLEAR NOTEPAD - were developed to satisfy specific needs. As computers are becoming more widely accessible, real-time contact beween participants appears to become a commonplace activity.

  15. Information transfer during a transitive reasoning task.

    PubMed

    Brzezicka, Aneta; Kamiński, Maciej; Kamiński, Jan; Blinowska, Katarzyna

    2011-03-01

    For about two decades now, the localization of the brain regions involved in reasoning processes is being investigated through fMRI studies, and it is known that for a transitive form of reasoning the frontal and parietal regions are most active. In contrast, less is known about the information exchange during the performance of such complex tasks. In this study, the propagation of brain activity during a transitive reasoning task was investigated and compared to the propagation during a simple memory task. We studied EEG transmission patterns obtained for physiological indicators of brain activity and determined whether there are frequency bands specifically related to this type of cognitive operations. The analysis was performed by means of the directed transfer function. The transmission patterns were determined in the theta, alpha and gamma bands. The results show stronger transmissions in theta and alpha bands from frontal to parietal as well as within frontal regions in reasoning trials comparing to memory trials. The increase in theta and alpha transmissions was accompanied by flows in gamma band from right posterior to left posterior and anterior sites. These results are consistent with previous neuroimaging (fMRI) data concerning fronto-parietal regions involvement in reasoning and working memory processes and also provide new evidence for the executive role of frontal theta waves in organizing the cognition.

  16. Thermodynamic Model of Noise Information Transfer

    NASA Astrophysics Data System (ADS)

    Hejna, Bohdan

    2008-10-01

    In this paper we apply a certain unifying physical description of the results of Information Theory. Assuming that heat entropy is a thermodynamic realization of information entropy [2], we construct a cyclical, thermodynamic, average-value model of an information transfer chain [3] as a general heat engine, in particular a Carnot engine, reversible or irreversible. A working medium of the cycle (a thermodynamic system transforming input heat energy) can be considered as a thermodynamic, average-value model or, as such, as a realization of an information transfer channel. We show that in a model realized in this way the extended II. Principle of Thermodynamics is valid [2] and we formulate its information form.

  17. Complex quantum network model of energy transfer in photosynthetic complexes.

    PubMed

    Ai, Bao-Quan; Zhu, Shi-Liang

    2012-12-01

    The quantum network model with real variables is usually used to describe the excitation energy transfer (EET) in the Fenna-Matthews-Olson (FMO) complexes. In this paper we add the quantum phase factors to the hopping terms and find that the quantum phase factors play an important role in the EET. The quantum phase factors allow us to consider the space structure of the pigments. It is found that phase coherence within the complexes would allow quantum interference to affect the dynamics of the EET. There exist some optimal phase regions where the transfer efficiency takes its maxima, which indicates that when the pigments are optimally spaced, the exciton can pass through the FMO with perfect efficiency. Moreover, the optimal phase regions almost do not change with the environments. In addition, we find that the phase factors are useful in the EET just in the case of multiple pathways. Therefore, we demonstrate that the quantum phases may bring the other two factors, the optimal space of the pigments and multiple pathways, together to contribute the EET in photosynthetic complexes with perfect efficiency.

  18. Conscious attention, meditation, and bilateral information transfer.

    PubMed

    Bob, Petr; Zimmerman, Elizabeth M; Hamilton, Elizabeth A; Sheftel, Jenna G; Bajo, Stephanie D; Raboch, Jiri; Golla, Megan; Konopka, Lukasz M

    2013-01-01

    Recent findings indicate that conscious attention is related to large-scale information integration of various brain regions, including both hemispheres, that enables integration of parallel distributed modalities of processed information. There is also evidence that the level of information transference related to integration or splitting among brain regions, and between hemispheres, establishes a certain level of efficiency of the information processing. The level of information transference also may have modulatory influences on attentional capacity that are closely linked to the emotional arousal and autonomic response related to a stimulus. These findings suggest a hypothesis that changes in conscious attention, specifically during meditation could be reflected in the autonomic activity as the left-right information transference calculated from bilateral electrodermal activity (EDA). With the aim to compare conscious attention during meditation with other attentional states (resting state, Stroop task, and memory task), we performed bilateral EDA measurement in 7 healthy persons during resting state, Stroop task, neurofeedback memory test, and meditation. The results indicate that the information transference (ie, transinformation) is able to distinguish those attentional states, and that the highest level of the transinformation has been found during attentional processing related to meditation, indicating higher level of connectivity between left and right sides. Calculations other than pointwise transinformation (PTI) performed on EDA records, such as mean skin conductance level or laterality index, were not able to distinguish attentional states. The results suggest that PTI may present an interesting method useful for the assessment of information flow, related to neural functioning, that in the case of meditation may reflect typical integrative changes in the autonomic nervous system related to brain functions and focused attentional processing.

  19. User Needs and the Information Transfer Process.

    ERIC Educational Resources Information Center

    Morehead, Joe

    1982-01-01

    Identifies problematic points in the transfer of information from government to library to user, and discusses government accountability, survey results concerning publications being cataloged, use studies, the conversion of Government Printing Office publications to microformat, and federal economizing measures. Fourteen references are cited.…

  20. Information Technology in Complex Health Services

    PubMed Central

    Southon, Frank Charles Gray; Sauer, Chris; Dampney, Christopher Noel Grant (Kit)

    1997-01-01

    Abstract Objective: To identify impediments to the successful transfer and implementation of packaged information systems through large, divisionalized health services. Design: A case analysis of the failure of an implementation of a critical application in the Public Health System of the State of New South Wales, Australia, was carried out. This application had been proven in the United States environment. Measurements: Interviews involving over 60 staff at all levels of the service were undertaken by a team of three. The interviews were recorded and analyzed for key themes, and the results were shared and compared to enable a continuing critical assessment. Results: Two components of the transfer of the system were considered: the transfer from a different environment, and the diffusion throughout a large, divisionalized organization. The analyses were based on the Scott-Morton organizational fit framework. In relation to the first, it was found that there was a lack of fit in the business environments and strategies, organizational structures and strategy-structure pairing as well as the management process-roles pairing. The diffusion process experienced problems because of the lack of fit in the strategy-structure, strategy-structure-management processes, and strategy-structure-role relationships. Conclusion: The large-scale developments of integrated health services present great challenges to the efficient and reliable implementation of information technology, especially in large, divisionalized organizations. There is a need to take a more sophisticated approach to understanding the complexities of organizational factors than has traditionally been the case. PMID:9067877

  1. Noise enhances information transfer in hierarchical networks.

    PubMed

    Czaplicka, Agnieszka; Holyst, Janusz A; Sloot, Peter M A

    2013-01-01

    We study the influence of noise on information transmission in the form of packages shipped between nodes of hierarchical networks. Numerical simulations are performed for artificial tree networks, scale-free Ravasz-Barabási networks as well for a real network formed by email addresses of former Enron employees. Two types of noise are considered. One is related to packet dynamics and is responsible for a random part of packets paths. The second one originates from random changes in initial network topology. We find that the information transfer can be enhanced by the noise. The system possesses optimal performance when both kinds of noise are tuned to specific values, this corresponds to the Stochastic Resonance phenomenon. There is a non-trivial synergy present for both noisy components. We found also that hierarchical networks built of nodes of various degrees are more efficient in information transfer than trees with a fixed branching factor.

  2. Noise enhances information transfer in hierarchical networks

    PubMed Central

    Czaplicka, Agnieszka; Holyst, Janusz A.; Sloot, Peter M. A.

    2013-01-01

    We study the influence of noise on information transmission in the form of packages shipped between nodes of hierarchical networks. Numerical simulations are performed for artificial tree networks, scale-free Ravasz-Barabási networks as well for a real network formed by email addresses of former Enron employees. Two types of noise are considered. One is related to packet dynamics and is responsible for a random part of packets paths. The second one originates from random changes in initial network topology. We find that the information transfer can be enhanced by the noise. The system possesses optimal performance when both kinds of noise are tuned to specific values, this corresponds to the Stochastic Resonance phenomenon. There is a non-trivial synergy present for both noisy components. We found also that hierarchical networks built of nodes of various degrees are more efficient in information transfer than trees with a fixed branching factor. PMID:23390574

  3. Quantifying ‘Causality’ in Complex Systems: Understanding Transfer Entropy

    PubMed Central

    Abdul Razak, Fatimah; Jensen, Henrik Jeldtoft

    2014-01-01

    ‘Causal’ direction is of great importance when dealing with complex systems. Often big volumes of data in the form of time series are available and it is important to develop methods that can inform about possible causal connections between the different observables. Here we investigate the ability of the Transfer Entropy measure to identify causal relations embedded in emergent coherent correlations. We do this by firstly applying Transfer Entropy to an amended Ising model. In addition we use a simple Random Transition model to test the reliability of Transfer Entropy as a measure of ‘causal’ direction in the presence of stochastic fluctuations. In particular we systematically study the effect of the finite size of data sets. PMID:24955766

  4. Information transfer network of global market indices

    NASA Astrophysics Data System (ADS)

    Kim, Yup; Kim, Jinho; Yook, Soon-Hyung

    2015-07-01

    We study the topological properties of the information transfer networks (ITN) of the global financial market indices for six different periods. ITN is a directed weighted network, in which the direction and weight are determined by the transfer entropy between market indices. By applying the threshold method, it is found that ITN undergoes a crossover from the complete graph to a small-world (SW) network. SW regime of ITN for a global crisis is found to be much more enhanced than that for ordinary periods. Furthermore, when ITN is in SW regime, the average clustering coefficient is found to be synchronized with average volatility of markets. We also compare the results with the topological properties of correlation networks.

  5. Anesthesia-related changes in information transfer may be caused by reduction in local information generation.

    PubMed

    Wollstadt, Patricia; Sellers, Kristin K; Hutt, Axel; Frohlich, Flavio; Wibral, Michael

    2015-08-01

    In anesthesia research it is an open question how general anesthetics lead to loss of consciousness (LOC). It has been proposed that LOC may be caused by the disruption of cortical information processing, preventing information integration. Therefore, recent studies investigating information processing under anesthesia focused on changes in information transfer, measured by transfer entropy (TE). However, often this complex technique was not applied rigorously, using time series in symbolic representation, or using TE differences without accounting for neural conduction delays, or without accounting for signal history. Here, we used current best-practice in TE estimation to investigate information transfer under anesthesia: We conducted simultaneous recordings in primary visual cortex (V1) and prefrontal cortex (PFC) of head-fixed ferrets in a dark environment under different levels of anesthesia (awake, 0.5% isoflurane, 1.0 % isoflurane). To elucidate reasons for changes in TE, we further quantified information processing within brain areas by estimating active information storage (AIS) as an estimator of predictable information, and Lempel-Ziv complexity (LZC) as an estimator of signal entropy. Under anesthesia, we found a reduction in information transfer (TE) between PFC and V1 with a stronger reduction for the feedback direction (PFC to V1), validating previous results. Furthermore, entropy (LZC) was reduced and activity became more predictable as indicated by higher values of AIS. We conclude that higher anesthesia concentrations indeed lead to reduced inter-areal information transfer, which may be partly caused by decreases in local entropy and increases in local predictability. In revealing a possible reason for reduced TE that is potentially independent of inter-areal coupling, we demonstrate the value of directly quantifying information processing in addition to focusing on dynamic properties such as coupling strength.

  6. Ytterbocene charge-transfer molecular wire complexes.

    PubMed

    Carlson, Christin N; Kuehl, Christopher J; Da Re, Ryan E; Veauthier, Jacqueline M; Schelter, Eric J; Milligan, Ashley E; Scott, Brian L; Bauer, Eric D; Thompson, J D; Morris, David E; John, Kevin D

    2006-06-07

    A systematic study of the novel charge-transfer [(f)14-(pi)0-(f)14 --> (f)13-(pi)2-(f)13] electronic state found in 2:1 metal-to-ligand adducts of the type [(Cp)2Yb](BL)[Yb(Cp)2] [BL = tetra(2-pyridyl)pyrazine (tppz) (1), 6',6' '-bis(2-pyridyl)-2,2':4',4'':2'',2'''-quaterpyridine (qtp) (2), 1,4-di(terpyridyl)-benzene (dtb) (3), Cp = (C5Me5)] has been conducted with the aim of determining the effects of increased Yb-Yb separation on the magnetic and electronic properties of these materials. The neutral [(f)13-(pi)2-(f)13], cationic [(f)13-(pi)1-(f)13] and dicationic [(f)13-(pi)0-(f)13] states of these complexes were studied by cyclic voltammetry, UV-vis-NIR electronic absorption spectroscopy, NMR, X-ray crystallography, and magnetic susceptibility measurements. The spectroscopic and magnetic data for the neutral bimetallic complexes is consistent with an [(f)13(pi)2(f)13] ground-state electronic configuration in which each ytterbocene fragment donates one electron to give a singlet dianionic bridging ligand with two paramagnetic Yb(III) centers. The voltammetric data demonstrate that the electronic interaction in the neutral molecular wires 1-3, as manifested in the separation between successive metal reduction waves, is large compared to analogous transition metal systems. Electronic spectra for the neutral and monocationic bimetallic species are dominated by pi-pi and pi-pi transitions, masking the f-f bands that are expected to best reflect the electronic metal-metal interactions. However, these metal-localized transitions are observed when the electrons are removed from the bridging ligand via chemical oxidation to yield the dicationic species, and they suggest very little electronic interaction between metal centers in the absence of pi electrons on the bridging ligands. Analysis of the magnetic data reveals that the qtp complex displays antiferromagnetic coupling of the type Yb(alpha)(alphabeta)Yb(beta) at approximately 13 K.

  7. Secure information transfer based on computing reservoir

    NASA Astrophysics Data System (ADS)

    Szmoski, R. M.; Ferrari, F. A. S.; de S. Pinto, S. E.; Baptista, M. S.; Viana, R. L.

    2013-04-01

    There is a broad area of research to ensure that information is transmitted securely. Within this scope, chaos-based cryptography takes a prominent role due to its nonlinear properties. Using these properties, we propose a secure mechanism for transmitting data that relies on chaotic networks. We use a nonlinear on-off device to cipher the message, and the transfer entropy to retrieve it. We analyze the system capability for sending messages, and we obtain expressions for the operating time. We demonstrate the system efficiency for a wide range of parameters. We find similarities between our method and the reservoir computing.

  8. Vibrational transfer functions for complex structures

    NASA Technical Reports Server (NTRS)

    Jones, P. A.; Berry, R. L.

    1972-01-01

    Evaluation of effects of vibrational multiple frequency forcing functions is discussed. Computer program for developing vibrational transfer functions is described. Possible applications of computer program are enumerated.

  9. Rich club neurons dominate Information Transfer in local cortical networks

    NASA Astrophysics Data System (ADS)

    Nigam, Sunny; Shimono, Masanori; Sporns, Olaf; Beggs, John

    2015-03-01

    The performance of complex networks depends on how they route their traffic. It is unknown how information is transferred in local cortical networks of hundreds of closely-spaced neurons. To address this, it is necessary to record simultaneously from hundreds of neurons at a spacing that matches typical axonal connection distances, and at a temporal resolution that matches synaptic delays. We used a 512 electrode array (60 μm spacing) to record spontaneous activity at 20 kHz, simultaneously from up to 700 neurons in slice cultures of mouse somatosensory cortex for 1 hr at a time. We used transfer entropy to quantify directed information transfer (IT) between pairs of neurons. We found an approximately lognormal distribution of firing rates as reported in in-vivo. Pairwise information transfer strengths also were nearly lognormally distributed, similar to synaptic strengths. 20% of the neurons accounted for 70% of the total IT coming into, and going out of the network and were defined as rich nodes. These rich nodes were more densely and strongly connected to each other expected by chance, forming a rich club. This highly uneven distribution of IT has implications for the efficiency and robustness of local cortical networks, and gives clues to the plastic processes that shape them. JSPS.

  10. Sources and Information on Transfer Associate Degrees

    ERIC Educational Resources Information Center

    Ayon, Carlos

    2012-01-01

    This chapter provides an annotated bibliography of articles about the effects of transfer associate degrees and related statewide transfer and articulation policies. It also provides links to transfer degree legislation in several states.

  11. Sources and Information on Transfer Associate Degrees

    ERIC Educational Resources Information Center

    Ayon, Carlos

    2012-01-01

    This chapter provides an annotated bibliography of articles about the effects of transfer associate degrees and related statewide transfer and articulation policies. It also provides links to transfer degree legislation in several states.

  12. 28 CFR 22.24 - Information transfer agreement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... STATISTICAL INFORMATION § 22.24 Information transfer agreement. Prior to the transfer of any identifiable... identifiable to a private person will be used only for research and statistical purposes. (b) Information...-know basis for research or statistical purposes, provided that such transfer is approved by the...

  13. 28 CFR 22.24 - Information transfer agreement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... STATISTICAL INFORMATION § 22.24 Information transfer agreement. Prior to the transfer of any identifiable... identifiable to a private person will be used only for research and statistical purposes. (b) Information...-know basis for research or statistical purposes, provided that such transfer is approved by the...

  14. 28 CFR 22.24 - Information transfer agreement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... STATISTICAL INFORMATION § 22.24 Information transfer agreement. Prior to the transfer of any identifiable... identifiable to a private person will be used only for research and statistical purposes. (b) Information...-know basis for research or statistical purposes, provided that such transfer is approved by the...

  15. 28 CFR 22.24 - Information transfer agreement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... STATISTICAL INFORMATION § 22.24 Information transfer agreement. Prior to the transfer of any identifiable... identifiable to a private person will be used only for research and statistical purposes. (b) Information...-know basis for research or statistical purposes, provided that such transfer is approved by the...

  16. 28 CFR 22.24 - Information transfer agreement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... STATISTICAL INFORMATION § 22.24 Information transfer agreement. Prior to the transfer of any identifiable... identifiable to a private person will be used only for research and statistical purposes. (b) Information...-know basis for research or statistical purposes, provided that such transfer is approved by the...

  17. Optically active homoleptic bis(phthalocyaninato) rare earth double-decker complexes bearing peripheral chiral menthol moieties: effect of pi-pi interaction on the chiral information transfer at the molecular level.

    PubMed

    Lv, Wei; Zhu, Peihua; Bian, Yongzhong; Ma, Changqin; Zhang, Xiaomei; Jiang, Jianzhuang

    2010-07-19

    With the view to creating novel sandwich-type phthalocyaninato rare earth complexes toward new applications in material science and catalysis, d- and l-enantiomers of a series of optically active homoleptic bis(phthalocyaninato) rare earth double-deckers with four chiral menthol moieties at the peripheral positions of the phthalocyanine ligand, M(Pc*)(2) [Pc* = 2(3),9(10),16(17),23(24)-tetrakis(2-isopropyl-5-methylcyclohexoxyl)phthalocyanine; M = Eu, Y, Lu] (1-3), have been designed and prepared by treating (d)- or (l)-4-(2-isopropyl-5-methylcyclohexoxyl)-1,2-dicyanobenzene with the corresponding M(acac)(3).nH(2)O (acac = acetylacetonate) in the presence of the organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in refluxing n-pentanol. For the purpose of comparative study, heteroleptic bis(phthalocyaninato) europium analogues (d)- and (l)-Eu(Pc)(Pc*) (4) as well as the unsubstituted homoleptic bis(phthalocyaninato) europium counterpart Eu(Pc)(2) (5) were also prepared. The novel synthesized bis(phthalocyaninato) rare earth double-deckers have been characterized by a wide range of spectroscopic methods including MS, (1)H NMR, IR, and electronic absorption spectroscopic measurements in addition to elemental analysis. In contrast to the CD silent monomeric metal-free 2(3),9(10),16(17),23(24)-tetrakis(2-isopropyl-5-methylcyclohexoxyl)phthalocyanine, observation of the CD signal in the N absorption region of 4 reveals the significant effect of intramolecular pi-pi interaction on intensifying the asymmetrical perturbation of the chiral menthol units onto the phthalocyanine chromophore, which results in successful chiral information transfer from menthol moieties to the phthalocyanine chromophore at a molecular level in the heteroleptic double-decker compound 4 despite the lack of CD signal in the Soret and Q absorption regions of the phthalocyanine ligand. This is further supported by the optical activity of homoleptic bis(phthalocyaninato) rare earth double-deckers M

  18. Dynamic information routing in complex networks

    NASA Astrophysics Data System (ADS)

    Kirst, Christoph; Timme, Marc; Battaglia, Demian

    2015-03-01

    Flexible information routing fundamentally underlies the function of many biological and artificial networks. Yet, how information may be specifically communicated and dynamically routed in these systems is not well understood. Here we demonstrate that collective dynamical states systematically control patterns of information sharing and transfer in networks, as measured by delayed mutual information and transfer entropies between activities of a network's units. For oscillatory networks we analyze how individual unit properties, the connectivity structure and external inputs all provide means to flexibly control information routing. For multi-scale, modular architectures, we resolve communication patterns at all levels and show how local interventions within one sub-network may remotely control the non-local network-wide routing of information. This theory helps understanding information routing patterns across systems where collective dynamics co-occurs with a communication function.

  19. Complexity measurement based on information theory and kolmogorov complexity.

    PubMed

    Lui, Leong Ting; Terrazas, Germán; Zenil, Hector; Alexander, Cameron; Krasnogor, Natalio

    2015-01-01

    In the past decades many definitions of complexity have been proposed. Most of these definitions are based either on Shannon's information theory or on Kolmogorov complexity; these two are often compared, but very few studies integrate the two ideas. In this article we introduce a new measure of complexity that builds on both of these theories. As a demonstration of the concept, the technique is applied to elementary cellular automata and simulations of the self-organization of porphyrin molecules.

  20. Transfer mutual information: A new method for measuring information transfer to the interactions of time series

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaojun; Shang, Pengjian; Lin, Aijing

    2017-02-01

    In this paper, we propose a new method to measure the influence of a third variable on the interactions of two variables. The method called transfer mutual information (TMI) is defined by the difference between the mutual information and the partial mutual information. It is established on the assumption that if the presence or the absence of one variable does make change to the interactions of another two variables, then quantifying this change is supposed to be the influence from this variable to those two variables. Moreover, a normalized TMI and other derivatives of the TMI are introduced as well. The empirical analysis including the simulations as well as real-world applications is investigated to examine this measure and to reveal more information among variables.

  1. 28 CFR 22.26 - Requests for transfer of information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Requests for transfer of information. 22.26 Section 22.26 Judicial Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND STATISTICAL INFORMATION § 22.26 Requests for transfer of information. (a) Requests...

  2. 28 CFR 22.26 - Requests for transfer of information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Requests for transfer of information. 22.26 Section 22.26 Judicial Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND STATISTICAL INFORMATION § 22.26 Requests for transfer of information. (a) Requests...

  3. 28 CFR 22.26 - Requests for transfer of information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Requests for transfer of information. 22.26 Section 22.26 Judicial Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND STATISTICAL INFORMATION § 22.26 Requests for transfer of information. (a) Requests...

  4. 28 CFR 22.26 - Requests for transfer of information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Requests for transfer of information. 22.26 Section 22.26 Judicial Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND STATISTICAL INFORMATION § 22.26 Requests for transfer of information. (a) Requests...

  5. 28 CFR 22.26 - Requests for transfer of information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Requests for transfer of information. 22.26 Section 22.26 Judicial Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND STATISTICAL INFORMATION § 22.26 Requests for transfer of information. (a) Requests...

  6. Size-Independent Energy Transfer in Biomimetic Nanoring Complexes.

    PubMed

    Parkinson, Patrick; Kamonsutthipaijit, Nuntaporn; Anderson, Harry L; Herz, Laura M

    2016-06-28

    Supramolecular antenna-ring complexes are of great interest due to their presence in natural light-harvesting complexes. While such systems are known to provide benefits through robust and efficient energy funneling, the relationship between molecular structure, strain (governed by nuclear coordinates and motion), and energy dynamics (arising from electronic behavior) is highly complex. We present a synthetic antenna-nanoring system based on a series of conjugated porphyrin chromophores ideally suited to explore such effects. By systematically varying the size of the acceptor nanoring, we reveal the interplay between antenna-nanoring binding, local strain, and energy dynamics on the picosecond time scale. Binding of the antenna unit creates a local strain in the nanoring, and this strain was measured as a function of the size of the nanoring, by UV-vis-NIR titration, providing information on the conformational flexibility of the system. Strikingly, the energy-transfer rate is independent of nanoring size, indicating the existence of strain-localized acceptor states, spread over about six porphyrin units, arising from the noncovalent antenna-nanoring association.

  7. Size-Independent Energy Transfer in Biomimetic Nanoring Complexes

    PubMed Central

    2016-01-01

    Supramolecular antenna-ring complexes are of great interest due to their presence in natural light-harvesting complexes. While such systems are known to provide benefits through robust and efficient energy funneling, the relationship between molecular structure, strain (governed by nuclear coordinates and motion), and energy dynamics (arising from electronic behavior) is highly complex. We present a synthetic antenna-nanoring system based on a series of conjugated porphyrin chromophores ideally suited to explore such effects. By systematically varying the size of the acceptor nanoring, we reveal the interplay between antenna-nanoring binding, local strain, and energy dynamics on the picosecond time scale. Binding of the antenna unit creates a local strain in the nanoring, and this strain was measured as a function of the size of the nanoring, by UV–vis-NIR titration, providing information on the conformational flexibility of the system. Strikingly, the energy-transfer rate is independent of nanoring size, indicating the existence of strain-localized acceptor states, spread over about six porphyrin units, arising from the noncovalent antenna-nanoring association. PMID:27176553

  8. WTCS Transfer Information, 1996-97.

    ERIC Educational Resources Information Center

    Wisconsin Technical Coll. System Board, Madison.

    This document presents the annual headcount statistics on students transferring from the University of Wisconsin (UW) to the Wisconsin Technical College System (WTCS) during the academic year 1996-97. It includes a summary narrative description of data, technical colleges accepting UW credits, demographic characteristics of transfer students, and…

  9. Transfer Students: Information Accessibility, Services, and Student Engagement

    ERIC Educational Resources Information Center

    Fugard, Anne Sheridan

    2009-01-01

    The purpose of this study was to explore to what degree Florida public, 4-year universities are supporting transfer students. This included a focus on accessibility of information for transfer students, the transfer services provided by institutions, and student engagement. This mixed-methods study included three parts. Together, the findings from…

  10. Primary cells utilize halogen-organic charge transfer complex

    NASA Technical Reports Server (NTRS)

    Gutmann, F.; Hermann, A. M.; Rembaum, A.

    1966-01-01

    Electrochemical cells with solid state components employ charge transfer complexes or donor-acceptor complexes in which the donor component is an organic compound and the acceptor component is a halogen. A minor proportion of graphite added to these composition helps reduce the resistivity.

  11. Primary cells utilize halogen-organic charge transfer complex

    NASA Technical Reports Server (NTRS)

    Gutmann, F.; Hermann, A. M.; Rembaum, A.

    1966-01-01

    Electrochemical cells with solid state components employ charge transfer complexes or donor-acceptor complexes in which the donor component is an organic compound and the acceptor component is a halogen. A minor proportion of graphite added to these composition helps reduce the resistivity.

  12. Charge-transfer complexation between naphthalene diimides and aromatic solvents.

    PubMed

    Kulkarni, Chidambar; Periyasamy, Ganga; Balasubramanian, S; George, Subi J

    2014-07-28

    Naphthalene diimides (NDIs) form emissive ground-state charge-transfer (CT) complexes with various electron rich aromatic solvents like benzene, o-xylene and mesitylene. TD-DFT calculation of the complexes suggests CT interaction and accounts for the observed ground-state changes.

  13. Transfer entropy coefficient: Quantifying level of information flow between financial time series

    NASA Astrophysics Data System (ADS)

    Teng, Yue; Shang, Pengjian

    2017-03-01

    In this paper, a new coefficient is proposed with the objective of quantifying the level of information flow between financial time series. This transfer entropy coefficient, which provides an assessment on the multiscale information flow between measurements, is defined in terms of the transfer entropy method and the multiscale method. The implementation of this transfer entropy coefficient is illustrated with simulated time series and financial time series. Examples taken from simulated and financial data demonstrate that the dynamic mechanism of a complex system cannot be detected solely on the basis of transfer entropy of single scale.

  14. Dimensions of the information transfer problem. [human performance

    NASA Technical Reports Server (NTRS)

    Billings, C. E.; Reynard, W. D.

    1981-01-01

    Several facets of the information transfer problems in aviation are described. A general analysis of these problem are given and the implications of some proposed solutions discussed. It is concluded that information transfer problems are responsible for many potentially serious human errors in aviation operations.

  15. Year 7 Students, Information Literacy, and Transfer: A Grounded Theory

    ERIC Educational Resources Information Center

    Herring, James E.

    2011-01-01

    This study examined the views of year 7 students, teacher librarians, and teachers in three state secondary schools in rural New South Wales, Australia, on information literacy and transfer. The aims of the study included the development of a grounded theory in relation to information literacy and transfer in these schools. The study's perspective…

  16. Recording information on protein complexes in an information management system.

    PubMed

    Savitsky, Marc; Diprose, Jonathan M; Morris, Chris; Griffiths, Susanne L; Daniel, Edward; Lin, Bill; Daenke, Susan; Bishop, Benjamin; Siebold, Christian; Wilson, Keith S; Blake, Richard; Stuart, David I; Esnouf, Robert M

    2011-08-01

    The Protein Information Management System (PiMS) is a laboratory information management system (LIMS) designed for use with the production of proteins in a research environment. The software is distributed under the CCP4 licence, and so is available free of charge to academic laboratories. Like most LIMS, the underlying PiMS data model originally had no support for protein-protein complexes. To support the SPINE2-Complexes project the developers have extended PiMS to meet these requirements. The modifications to PiMS, described here, include data model changes, additional protocols, some user interface changes and functionality to detect when an experiment may have formed a complex. Example data are shown for the production of a crystal of a protein complex. Integration with SPINE2-Complexes Target Tracker application is also described.

  17. Recording information on protein complexes in an information management system

    PubMed Central

    Savitsky, Marc; Diprose, Jonathan M.; Morris, Chris; Griffiths, Susanne L.; Daniel, Edward; Lin, Bill; Daenke, Susan; Bishop, Benjamin; Siebold, Christian; Wilson, Keith S.; Blake, Richard; Stuart, David I.; Esnouf, Robert M.

    2011-01-01

    The Protein Information Management System (PiMS) is a laboratory information management system (LIMS) designed for use with the production of proteins in a research environment. The software is distributed under the CCP4 licence, and so is available free of charge to academic laboratories. Like most LIMS, the underlying PiMS data model originally had no support for protein–protein complexes. To support the SPINE2-Complexes project the developers have extended PiMS to meet these requirements. The modifications to PiMS, described here, include data model changes, additional protocols, some user interface changes and functionality to detect when an experiment may have formed a complex. Example data are shown for the production of a crystal of a protein complex. Integration with SPINE2-Complexes Target Tracker application is also described. PMID:21605682

  18. Control of complex heat transfer on producing extremal fields

    NASA Astrophysics Data System (ADS)

    Grenkin, G. V.; Chebotarev, A. Yu.

    2016-10-01

    A time-dependent model of complex heat transfer including the P 1 approximation for the equation of radiative transfer is considered. The problem of finding the coefficient in the boundary condition from a given interval, providing the minimum (maximum) temperature and radiation intensity in the entire domain is formulated. The solvability of the control problem is proven, conditions for optimality are obtained, and an iterative algorithm for finding the optimal control is found.

  19. Entropy Transfer of Quantum Gravity Information Processing

    NASA Astrophysics Data System (ADS)

    Gyongyosi, Laszlo; Imre, Sandor

    2015-05-01

    We introduce the term smooth entanglement entropy transfer, a phenomenon that is a consequence of the causality-cancellation property of the quantum gravity environment. The causality-cancellation of the quantum gravity space removes the causal dependencies of the local systems. We study the physical effects of the causality-cancellation and show that it stimulates entropy transfer between the quantum gravity environment and the independent local systems of the quantum gravity space. The entropy transfer reduces the entropies of the contributing local systems and increases the entropy of the quantum gravity environment. We discuss the space-time geometry structure of the quantum gravity environment and the local quantum systems. We propose the space-time geometry model of the smooth entropy transfer. We reveal on a smooth Cauchy slice that the space-time geometry of the quantum gravity environment dynamically adapts to the vanishing causality. We prove that the Cauchy area expansion, along with the dilation of the Rindler horizon area of the quantum gravity environment, is a corollary of the causality-cancellation of the quantum gravity environment. This work was partially supported by the GOP-1.1.1-11-2012-0092 (Secure quantum key distribution between two units on optical fiber network) project sponsored by the EU and European Structural Fund, and by the COST Action MP1006.

  20. Structure of cytochrome c complexes with phospholipids as revealed by resonance energy transfer.

    PubMed

    Gorbenko, G P

    1999-08-20

    Resonance energy transfer between a series of lipid-bound fluorescent probes as donors and the heme group of cytochrome c as acceptor has been used to obtain structural information on the protein complexes with model membranes, composed of phosphatidylcholine and cardiolipin. Analysis of experimental data in terms of the model of energy transfer in two-dimensional systems provides further evidence for preferential cytochrome c orientation with respect to the lipid bilayer and penetration of the protein into the membrane interior.

  1. Quantum information transfer between topological and spin qubit systems.

    PubMed

    Leijnse, Martin; Flensberg, Karsten

    2011-11-18

    We propose a method to coherently transfer quantum information, and to create entanglement, between topological qubits and conventional spin qubits. Our suggestion uses gated control to transfer an electron (spin qubit) between a quantum dot and edge Majorana modes in adjacent topological superconductors. Because of the spin polarization of the Majorana modes, the electron transfer translates spin superposition states into superposition states of the Majorana system, and vice versa. Furthermore, we show how a topological superconductor can be used to facilitate long-distance quantum information transfer and entanglement between spatially separated spin qubits.

  2. Information transfer satellite concept study. Volume 3: Appendices

    NASA Technical Reports Server (NTRS)

    Bergin, P.; Kincade, C.; Kurpiewski, D.; Leinhaupel, F.; Millican, F.; Onstad, R.

    1971-01-01

    Briefly reviewed are the various documents which supply background information for the information transfer satellite study. The sixteen papers reviewed are evaluated in terms of: (1) the category of service or demand being treated; (2) the extent to which information transfer predictions are quantified; (3) the degree to which the data supplied is adequate for the purposes of system synthesis; (4) some assessment as to the overall utility of the data presented in the paper.

  3. Facilitating information transfer in the EOS era

    NASA Technical Reports Server (NTRS)

    Billingsley, Frederic C.; Johnson, John; Greenberg, Edward; Macmedan, Merv

    1989-01-01

    A simple interactive demonstration program has been written in C to allow a user to input data field descriptions as label format. This program generates a full RECFMT (record format) description and the complete transfer syntax description notation (TSDN) file. It is intended that this program be upgraded to operational quality and be made available to users to simplify the description and TSDN file construction task. The total set of capabilities, from the standard formatted data unit packaging of related files and consistent segment structures, through the type definition techniques and the call server, will constitute a unique tool for the systematic transfer of data. This software on each end may be independent, one end from the other. With it available, local software that will be needed to convert user files to and from the canonical interface will be appreciably simplified.

  4. Mapping energy transfer channels in fucoxanthin-chlorophyll protein complex.

    PubMed

    Gelzinis, Andrius; Butkus, Vytautas; Songaila, Egidijus; Augulis, Ramūnas; Gall, Andrew; Büchel, Claudia; Robert, Bruno; Abramavicius, Darius; Zigmantas, Donatas; Valkunas, Leonas

    2015-02-01

    Fucoxanthin-chlorophyll protein (FCP) is the key molecular complex performing the light-harvesting function in diatoms, which, being a major group of algae, are responsible for up to one quarter of the total primary production on Earth. These photosynthetic organisms contain an unusually large amount of the carotenoid fucoxanthin, which absorbs the light in the blue-green spectral region and transfers the captured excitation energy to the FCP-bound chlorophylls. Due to the large number of fucoxanthins, the excitation energy transfer cascades in these complexes are particularly tangled. In this work we present the two-color two-dimensional electronic spectroscopy experiments on FCP. Analysis of the data using the modified decay associated spectra permits a detailed mapping of the excitation frequency dependent energy transfer flow with a femtosecond time resolution. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Free flap transfer for complex regional pain syndrome type II

    PubMed Central

    Matsuda, Ken; Kikuchi, Mamoru; Murase, Tsuyoshi; Hosokawa, Ko; Shibata, Minoru

    2014-01-01

    Abstract A patient with complex regional pain syndrome type II was successfully treated using free anterolateral thigh flap transfer with digital nerve coaptation to the cutaneous nerve of the flap. Release of the scarred tissue and soft tissue coverage with targeted sensory nerve coaptation were useful in relieving severe pain. PMID:27252946

  6. The Transfer of Abstract Principles Governing Complex Adaptive Systems

    ERIC Educational Resources Information Center

    Goldstone, Robert L.; Sakamoto, Yasuaki

    2003-01-01

    Four experiments explored participants' understanding of the abstract principles governing computer simulations of complex adaptive systems. Experiments 1, 2, and 3 showed better transfer of abstract principles across simulations that were relatively dissimilar, and that this effect was due to participants who performed relatively poorly on the…

  7. Exploiting Complexity Information for Brain Activation Detection

    PubMed Central

    Zhang, Yan; Liang, Jiali; Lin, Qiang; Hu, Zhenghui

    2016-01-01

    We present a complexity-based approach for the analysis of fMRI time series, in which sample entropy (SampEn) is introduced as a quantification of the voxel complexity. Under this hypothesis the voxel complexity could be modulated in pertinent cognitive tasks, and it changes through experimental paradigms. We calculate the complexity of sequential fMRI data for each voxel in two distinct experimental paradigms and use a nonparametric statistical strategy, the Wilcoxon signed rank test, to evaluate the difference in complexity between them. The results are compared with the well known general linear model based Statistical Parametric Mapping package (SPM12), where a decided difference has been observed. This is because SampEn method detects brain complexity changes in two experiments of different conditions and the data-driven method SampEn evaluates just the complexity of specific sequential fMRI data. Also, the larger and smaller SampEn values correspond to different meanings, and the neutral-blank design produces higher predictability than threat-neutral. Complexity information can be considered as a complementary method to the existing fMRI analysis strategies, and it may help improving the understanding of human brain functions from a different perspective. PMID:27045838

  8. Exploiting Complexity Information for Brain Activation Detection.

    PubMed

    Zhang, Yan; Liang, Jiali; Lin, Qiang; Hu, Zhenghui

    2016-01-01

    We present a complexity-based approach for the analysis of fMRI time series, in which sample entropy (SampEn) is introduced as a quantification of the voxel complexity. Under this hypothesis the voxel complexity could be modulated in pertinent cognitive tasks, and it changes through experimental paradigms. We calculate the complexity of sequential fMRI data for each voxel in two distinct experimental paradigms and use a nonparametric statistical strategy, the Wilcoxon signed rank test, to evaluate the difference in complexity between them. The results are compared with the well known general linear model based Statistical Parametric Mapping package (SPM12), where a decided difference has been observed. This is because SampEn method detects brain complexity changes in two experiments of different conditions and the data-driven method SampEn evaluates just the complexity of specific sequential fMRI data. Also, the larger and smaller SampEn values correspond to different meanings, and the neutral-blank design produces higher predictability than threat-neutral. Complexity information can be considered as a complementary method to the existing fMRI analysis strategies, and it may help improving the understanding of human brain functions from a different perspective.

  9. Presentation Media, Information Complexity, and Learning Outcomes

    ERIC Educational Resources Information Center

    Andres, Hayward P.; Petersen, Candice

    2002-01-01

    Cognitive processing limitations restrict the number of complex information items held and processed in human working memory. To overcome such limitations, a verbal working memory channel is used to construct an if-then proposition representation of facts and a visual working memory channel is used to construct a visual imagery of geometric…

  10. Feedback Specificity, Information Processing, and Transfer of Training

    ERIC Educational Resources Information Center

    Goodman, Jodi S.; Wood, Robert E.; Chen, Zheng

    2011-01-01

    This study examines the effects of feedback specificity on transfer of training and the mechanisms through which feedback can enhance or inhibit transfer. We used concurrent verbal protocol methodology to elicit and operationalize the explicit information processing activities used by 48 trainees performing the Furniture Factory computer…

  11. Feedback Specificity, Information Processing, and Transfer of Training

    ERIC Educational Resources Information Center

    Goodman, Jodi S.; Wood, Robert E.; Chen, Zheng

    2011-01-01

    This study examines the effects of feedback specificity on transfer of training and the mechanisms through which feedback can enhance or inhibit transfer. We used concurrent verbal protocol methodology to elicit and operationalize the explicit information processing activities used by 48 trainees performing the Furniture Factory computer…

  12. Information Systems and Networks for Technology Transfer. Final Report.

    ERIC Educational Resources Information Center

    Page, John; Szentivanyi, Tibor

    Results of a survey of the information resources available in industrialized countries which might be used in a United Nations technology transfer program for developing countries are presented. Information systems and networks, organized information collections of a scientific and technical character, and the machinery used to disseminate this…

  13. Information Systems and Networks for Technology Transfer. Final Report.

    ERIC Educational Resources Information Center

    Page, John; Szentivanyi, Tibor

    Results of a survey of the information resources available in industrialized countries which might be used in a United Nations technology transfer program for developing countries are presented. Information systems and networks, organized information collections of a scientific and technical character, and the machinery used to disseminate this…

  14. Transfer in Artificial Grammar Learning: The Role of Repetition Information

    ERIC Educational Resources Information Center

    Lotz, Anja; Kinder, Annette

    2006-01-01

    In this article, the authors report 2 experiments that investigated the sources of information used in transfer and nontransfer tasks in artificial grammar learning. Multiple regression analyses indicated that 2 types of information about repeating elements were crucial for performance in both tasks: information about the repetition of adjacent…

  15. A flight test facility design for examining digital information transfer

    NASA Technical Reports Server (NTRS)

    Knox, Charles E.

    1990-01-01

    Information is given in viewgraph form on a flight test facility design for examining digital information transfer. Information is given on aircraft/ground exchange, data link research activities, data link display format, a data link flight test, and the flight test setup.

  16. Scientific Information Transfer and National Development in Africa.

    ERIC Educational Resources Information Center

    Adimorah, E. N. O.

    1978-01-01

    Examines the potential of scientific information transfer in selected English- and Arab-speaking countries of Africa, as it relates to national development through socio-economic planning, agriculture, medicine, and science and technology. (Author/CWM)

  17. Spectrophotometric determination of moclobemide by charge-transfer complexation.

    PubMed

    Adikwu, M U; Ofokansi, K C

    1997-11-01

    A simple and sensitive spectrophotometric method is described for the assay for the moclobemide. The method is based on the molecular interaction between the drug and chloranilic acid, to form a charge-transfer complex in which the drug acts as n-donor and chloranilic acid as pi-acceptor. Chloranilic acid was found to form a charge-transfer complex in a 1:1 stoichiometry with a maximum absorption band at 526 nm. Conformity with Beer's law was evident over the concentration range 4-36 mg 100 ml-1. A complete, detailed investigation of the complex formed was made with respect to its composition, association constant, molar absorptivity and free energy change. The method has been applied successfully to the analysis of commercially available moclobemide tablets with good recovery and reproducibility.

  18. Proton transfer in methyleneimine complexed with formic acid

    NASA Astrophysics Data System (ADS)

    Peeters, D.

    1994-06-01

    The hydrogen-bonded complexes and the proton transfer process between methyleneimine and formic acid have been investigated from a theoretical viewpoint. The structures are fully optimized at the RHF 6-31G level and the corresponding force constant matrix obtained. Complementary computation at 6-31G* and 6-31G** levels as well as MP2 calculations were performed. The 1 : 1 system presents a single-well potential energy, but a double-well potential energy may be induced by a solvent effect. This solvent-induced effect may be obtained either by adding one extra molecule leading to trimolecular complexes or by immersing the bimolecular complex in the reaction field of a dielectric continuum. This study shows that slightly polar solvents (ɛ ⩾ 2.5) are sufficient to induce the proton transfer.

  19. Forest Resource Information System. Phase 3: System transfer report

    NASA Technical Reports Server (NTRS)

    Mroczynski, R. P. (Principal Investigator)

    1981-01-01

    Transfer of the forest reserve information system (FRIS) from the Laboratory for Applications of Remote Sensing to St. Regis Paper Company is described. Modifications required for the transfer of the LARYS image processing software are discussed. The reformatting, geometric correction, image registration, and documentation performed for preprocessing transfer are described. Data turnaround was improved and geometrically corrected and ground-registered CCT LANDSAT 3 data provided to the user. The technology transfer activities are summarized. An application test performed in order to assess a Florida land acquisition is described. A benefit/cost analysis of FRIS is presented.

  20. Biological Information as Set-Based Complexity

    PubMed Central

    Galas, David J.; Nykter, Matti; Carter, Gregory W.; Price, Nathan D.; Shmulevich, Ilya

    2010-01-01

    Summary It is not obvious what fraction of all the potential information residing in the molecules and structures of living systems is significant or meaningful to the system. Sets of random sequences or identically repeated sequences, for example, would be expected to contribute little or no useful information to a cell. This issue of quantitation of information is important since the ebb and flow of biologically significant information is essential to our quantitative understanding of biological function and evolution. Motivated specifically by these problems of biological information, we propose here a class of measures to quantify the contextual nature of the information in sets of objects, based on Kolmogorov's intrinsic complexity. Such measures discount both random and redundant information and are inherent in that they do not require a defined state space to quantify the information. The maximization of this new measure, which can be formulated in terms of the universal information distance, appears to have several useful and interesting properties, some of which we illustrate with examples. PMID:27857450

  1. Revealing the complex conduction heat transfer mechanism of nanofluids.

    PubMed

    Sergis, A; Hardalupas, Y

    2015-12-01

    Nanofluids are two-phase mixtures consisting of small percentages of nanoparticles (sub 1-10 %vol) inside a carrier fluid. The typical size of nanoparticles is less than 100 nm. These fluids have been exhibiting experimentally a significant increase of thermal performance compared to the corresponding carrier fluids, which cannot be explained using the classical thermodynamic theory. This study deciphers the thermal heat transfer mechanism for the conductive heat transfer mode via a molecular dynamics simulation code. The current findings are the first of their kind and conflict with the proposed theories for heat transfer propagation through micron-sized slurries and pure matter. The authors provide evidence of a complex new type of heat transfer mechanism, which explains the observed abnormal heat transfer augmentation. The new mechanism appears to unite a number of popular speculations for the thermal heat transfer mechanism employed by nanofluids as predicted by the majority of the researchers of the field into a single one. The constituents of the increased diffusivity of the nanoparticle can be attributed to mismatching of the local temperature profiles between parts of the surface of the solid and the fluid resulting in increased local thermophoretic effects. These effects affect the region surrounding the solid manifesting interfacial layer phenomena (Kapitza resistance). In this region, the activity of the fluid and the interactions between the fluid and the nanoparticle are elevated. Isotropic increased nanoparticle mobility is manifested as enhanced Brownian motion and diffusion effects.

  2. Revealing the complex conduction heat transfer mechanism of nanofluids

    NASA Astrophysics Data System (ADS)

    Sergis, A.; Hardalupas, Y.

    2015-06-01

    Nanofluids are two-phase mixtures consisting of small percentages of nanoparticles (sub 1-10 %vol) inside a carrier fluid. The typical size of nanoparticles is less than 100 nm. These fluids have been exhibiting experimentally a significant increase of thermal performance compared to the corresponding carrier fluids, which cannot be explained using the classical thermodynamic theory. This study deciphers the thermal heat transfer mechanism for the conductive heat transfer mode via a molecular dynamics simulation code. The current findings are the first of their kind and conflict with the proposed theories for heat transfer propagation through micron-sized slurries and pure matter. The authors provide evidence of a complex new type of heat transfer mechanism, which explains the observed abnormal heat transfer augmentation. The new mechanism appears to unite a number of popular speculations for the thermal heat transfer mechanism employed by nanofluids as predicted by the majority of the researchers of the field into a single one. The constituents of the increased diffusivity of the nanoparticle can be attributed to mismatching of the local temperature profiles between parts of the surface of the solid and the fluid resulting in increased local thermophoretic effects. These effects affect the region surrounding the solid manifesting interfacial layer phenomena (Kapitza resistance). In this region, the activity of the fluid and the interactions between the fluid and the nanoparticle are elevated. Isotropic increased nanoparticle mobility is manifested as enhanced Brownian motion and diffusion effects

  3. The coordination and atom transfer chemistry of titanium porphyrin complexes

    SciTech Connect

    Hays, James Allen

    1993-11-05

    Preparation, characterization, and reactivity of (η2- alkyne)(meso-tetratolylpoprphrinato)titanium(II) complexes are described, along with inetermetal oxygen atom transfer reactions involving Ti(IV) and Ti(III) porphyrin complexes. The η2- alkyne complexes are prepared by reaction of (TTP)TiCl2 with LiAlH4 in presence of alkyne. Structure of (OEP)Ti(η2-Ph-C≡C-Ph) (OEP=octaethylporphryin) was determined by XRD. The compounds undergo simple substitution to displace the alkyne and produce doubly substituted complexes. Structure of (TTP)Ti(4-picoline)2 was also determined by XRD. Reaction of (TTP)Ti=O with (OEP)Ti-Cl yields intermetal O/Cl exchange, which is a one-electron redox process mediated by O atom transfer. Also a zero-electron redox process mediated by atom transfer is observed when (TTP)TiCl2 is reacted with (OEP)Ti=O.

  4. Simple charge-transfer model for metallic complexes.

    PubMed

    Ramírez-Ramírez, José-Zeferino; Vargas, Rubicelia; Garza, Jorge; Gázquez, José L

    2010-08-05

    In the chemistry of metallic complexes, two important concepts have been used to rationalize the recognition and selectivity of a host by a guest: preorganization and complementarity. Both of these concepts stem from geometrical features. Less explored in the literature has been the interactional complementarity, where mainly the electronic factors in the intermolecular forces are involved. Because the charge transfer between a species rich in electrons (ligand) and another deficient in them (cation) is one of the main intermolecular factors that control the binding energies in metallic complexes, for such systems, we propose a simple model based on density functional theory. We define an interactional energy in which the geometrical energy changes are subtracted from the binding energies and just the electronic factors are taken into account. The model is tested for the complexation between bidentate and cyclic ligands and Ca, Pb, and Hg metal dications. The charge-transfer energy described by our model fits nicely with the interactional energy. Thus, when the geometrical changes do not contribute in a significant way to the complexation energy, the interactional energy is dominated by charge-transfer effects.

  5. Photoinduced energy transfer in transition metal complex oligomers

    SciTech Connect

    1997-04-01

    The work we have done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. We have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed us prepare a variety of other ligands which may have unique applications (vide infra). We have prepared, characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived ( > 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, we have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to make light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.

  6. Photoinduced energy transfer in transition metal complex oligomers

    SciTech Connect

    1997-06-01

    The work done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. The authors have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed them to prepare a variety of other ligands which may have unique applications (vide infra). They have prepared, characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived (> 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, the authors have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to make light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.

  7. Gait information flow indicates complex motor dysfunction.

    PubMed

    Hoyer, Dirk; Kletzin, Ulf; Adler, Daniela; Adler, Steffen; Meissner, Winfried; Blickhan, Reinhard

    2005-08-01

    Gait-related back movements require coordination of multiple extremities including the flexible trunk. Ageing and chronic back pain influence these adjustments. These complex coordinations can advantageously be quantified by information theoretically based communication measures such as the gait information flow (GIF). Nine back pain patients (aged 61+/-10 yr) and 12 controls (aged 38+/-10 yr) were investigated during normal walking across a distance of 300 m. The back movements were measured as distances between characteristic points (cervical spine CS, thoracic spine TS, lumbar spine LS) by the sonoSens Monitor, a system for mobile motion analysis. Gait information flow and regularity indices (RI1: short prediction horizon of 100 ms, RI2: longer prediction horizon of walking period) were assessed as communication characteristics. All indices were non-parametrically tested for group differences. Sensitivity and specificity were assessed by bivariate logistic regression models. We found regularity indices systematically dependent on measurement points, information flow horizon and groups. In the patients RI1 was increased, but RI2 was decreased in comparison to the control group. These results quantitatively characterize the altered complex communication in the patients. We conclude that ageing and/or chronic back pain related dysfunctions of gait can advantageously be monitored by gait information flow characteristics of back movements measured as distances between characteristics points at the back surface.

  8. Information, complexity and efficiency: The automobile model

    SciTech Connect

    Allenby, B. |

    1996-08-08

    The new, rapidly evolving field of industrial ecology - the objective, multidisciplinary study of industrial and economic systems and their linkages with fundamental natural systems - provides strong ground for believing that a more environmentally and economically efficient economy will be more information intensive and complex. Information and intellectual capital will be substituted for the more traditional inputs of materials and energy in producing a desirable, yet sustainable, quality of life. While at this point this remains a strong hypothesis, the evolution of the automobile industry can be used to illustrate how such substitution may, in fact, already be occurring in an environmentally and economically critical sector.

  9. Complex Networks/Foundations of Information Systems

    DTIC Science & Technology

    2013-03-06

    Information Systems 6 March 2013 Robert J. Bonneau, Ph.D. Division Chief AFOSR/RTC Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...if it does not display a currently valid OMB control number. 1. REPORT DATE 06 MAR 2013 2. REPORT TYPE 3. DATES COVERED 00-00-2013 to 00-00...2013 4. TITLE AND SUBTITLE Complex Networks/Foundations of Information Systems 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  10. Quantum information transfer between topological and conventional charge qubits

    NASA Astrophysics Data System (ADS)

    Jun, Li; Yan, Zou

    2016-02-01

    We propose a scheme to realize coherent quantum information transfer between topological and conventional charge qubits. We first consider a hybrid system where a quantum dot (QD) is tunnel-coupled to a semiconductor Majorana-hosted nanowire (MNW) via using gated control as a switch, the information encoded in the superposition state of electron empty and occupied state can be transferred to each other through choosing the proper interaction time to make measurements. Then we consider another system including a double QDs and a pair of parallel MNWs, it is shown that the entanglement information transfer can be realized between the two kinds of systems. We also realize long distance quantum information transfer between two quantum dots separated by an MNW, by making use of the nonlocal fermionic level formed with the pared Majorana feimions (MFs) emerging at the two ends of the MNW. Furthermore, we analyze the teleportationlike electron transfer phenomenon predicted by Tewari et al. [Phys. Rev. Lett. 100, 027001 (2008)] in our considered system. Interestingly, we find that this phenomenon exactly corresponds to the case that the information encoded in one QD just returns back to its original place during the dynamical evolution of the combined system from the perspective of quantum state transfer. Project supported by the National Natural Science Foundation of China (Grant No. 11304031).

  11. Informational analysis involving application of complex information system

    NASA Astrophysics Data System (ADS)

    Ciupak, Clébia; Vanti, Adolfo Alberto; Balloni, Antonio José; Espin, Rafael

    The aim of the present research is performing an informal analysis for internal audit involving the application of complex information system based on fuzzy logic. The same has been applied in internal audit involving the integration of the accounting field into the information systems field. The technological advancements can provide improvements to the work performed by the internal audit. Thus we aim to find, in the complex information systems, priorities for the work of internal audit of a high importance Private Institution of Higher Education. The applied method is quali-quantitative, as from the definition of strategic linguistic variables it was possible to transform them into quantitative with the matrix intersection. By means of a case study, where data were collected via interview with the Administrative Pro-Rector, who takes part at the elaboration of the strategic planning of the institution, it was possible to infer analysis concerning points which must be prioritized at the internal audit work. We emphasize that the priorities were identified when processed in a system (of academic use). From the study we can conclude that, starting from these information systems, audit can identify priorities on its work program. Along with plans and strategic objectives of the enterprise, the internal auditor can define operational procedures to work in favor of the attainment of the objectives of the organization.

  12. Maximizing information exchange between complex networks

    NASA Astrophysics Data System (ADS)

    West, Bruce J.; Geneston, Elvis L.; Grigolini, Paolo

    2008-10-01

    modern research overarching all of the traditional scientific disciplines. The transportation networks of planes, highways and railroads; the economic networks of global finance and stock markets; the social networks of terrorism, governments, businesses and churches; the physical networks of telephones, the Internet, earthquakes and global warming and the biological networks of gene regulation, the human body, clusters of neurons and food webs, share a number of apparently universal properties as the networks become increasingly complex. Ubiquitous aspects of such complex networks are the appearance of non-stationary and non-ergodic statistical processes and inverse power-law statistical distributions. Herein we review the traditional dynamical and phase-space methods for modeling such networks as their complexity increases and focus on the limitations of these procedures in explaining complex networks. Of course we will not be able to review the entire nascent field of network science, so we limit ourselves to a review of how certain complexity barriers have been surmounted using newly applied theoretical concepts such as aging, renewal, non-ergodic statistics and the fractional calculus. One emphasis of this review is information transport between complex networks, which requires a fundamental change in perception that we express as a transition from the familiar stochastic resonance to the new concept of complexity matching.

  13. Production and transfer of energy and information in Hamiltonian systems.

    PubMed

    Antonopoulos, Chris G; Bianco-Martinez, Ezequiel; Baptista, Murilo S

    2014-01-01

    We present novel results that relate energy and information transfer with sensitivity to initial conditions in chaotic multi-dimensional Hamiltonian systems. We show the relation among Kolmogorov-Sinai entropy, Lyapunov exponents, and upper bounds for the Mutual Information Rate calculated in the Hamiltonian phase space and on bi-dimensional subspaces. Our main result is that the net amount of transfer from kinetic to potential energy per unit of time is a power-law of the upper bound for the Mutual Information Rate between kinetic and potential energies, and also a power-law of the Kolmogorov-Sinai entropy. Therefore, transfer of energy is related with both transfer and production of information. However, the power-law nature of this relation means that a small increment of energy transferred leads to a relatively much larger increase of the information exchanged. Then, we propose an "experimental" implementation of a 1-dimensional communication channel based on a Hamiltonian system, and calculate the actual rate with which information is exchanged between the first and last particle of the channel. Finally, a relation between our results and important quantities of thermodynamics is presented.

  14. Production and Transfer of Energy and Information in Hamiltonian Systems

    PubMed Central

    Antonopoulos, Chris G.; Bianco-Martinez, Ezequiel; Baptista, Murilo S.

    2014-01-01

    We present novel results that relate energy and information transfer with sensitivity to initial conditions in chaotic multi-dimensional Hamiltonian systems. We show the relation among Kolmogorov-Sinai entropy, Lyapunov exponents, and upper bounds for the Mutual Information Rate calculated in the Hamiltonian phase space and on bi-dimensional subspaces. Our main result is that the net amount of transfer from kinetic to potential energy per unit of time is a power-law of the upper bound for the Mutual Information Rate between kinetic and potential energies, and also a power-law of the Kolmogorov-Sinai entropy. Therefore, transfer of energy is related with both transfer and production of information. However, the power-law nature of this relation means that a small increment of energy transferred leads to a relatively much larger increase of the information exchanged. Then, we propose an “experimental” implementation of a 1-dimensional communication channel based on a Hamiltonian system, and calculate the actual rate with which information is exchanged between the first and last particle of the channel. Finally, a relation between our results and important quantities of thermodynamics is presented. PMID:24586891

  15. Light induced electron transfer reactions of metal complexes

    SciTech Connect

    Sutin, N; Creutz, C

    1980-01-01

    Properties of the excited states of tris(2,2'-bipyridine) and tris(1,10-phenanthroline) complexes of chromium(III), iron(II), ruthenium(II), osmium(II), rhodium(III), and iridium(III) are described. The electron transfer reactions of the ground and excited states are discussed and interpreted in terms of the driving force for the reaction and the distortions of the excited states relative to the corresponding ground states. General considerations relevant to the conversion of light into chemical energy are presented and progress in the use of polypyridine complexes to effect the light decomposition of water into hydrogen and oxygen is reviewed.

  16. Energy Information Transfer in Virginia. A Planning Conference.

    ERIC Educational Resources Information Center

    Hickin, Patricia

    The Virginia Planning Conference for Solar Technology Information Transfer was held in Richmond in February 1978 to elicit suggestions on how to make Virginians aware of libraries as sources of energy information and how Virginia libraries can keep their energy materials and reference services up to date. A summary of this planning session and a…

  17. Information Literacy and Transfer in Schools: Implications for Teacher Librarians

    ERIC Educational Resources Information Center

    Herring, James E.; Bush, Stephanie J.

    2011-01-01

    This study focuses on the use of the New South Wales (NSW) Department of Education and Training information literacy model in a primary school as the basis for the possible establishment of a culture of transfer of information literacy skills. The study used constructivist grounded analysis to interpret data gathered from teachers and principals.…

  18. Energy Information Transfer in Virginia. A Planning Conference.

    ERIC Educational Resources Information Center

    Hickin, Patricia

    The Virginia Planning Conference for Solar Technology Information Transfer was held in Richmond in February 1978 to elicit suggestions on how to make Virginians aware of libraries as sources of energy information and how Virginia libraries can keep their energy materials and reference services up to date. A summary of this planning session and a…

  19. Positron annihilation studies of some charge transfer molecular complexes

    NASA Astrophysics Data System (ADS)

    El-Sayed, A. M. A.; Mohamed, Hamdy F. M.; Boraei, Anmed A. A.

    2000-06-01

    Positron annihilation lifetimes were measured for some solid charge transfer (CT) molecular complexes of quinoline compounds (2,6-dimethylquinoline, 6-methoxyquinoline, quinoline, 6-methylquinoline, 3-bromoquinoline and 2-chloro-4-methylquinoline) as electron donor and picric acid as an electron acceptor. The infrared spectra (IR) of the solid complexes clearly indicated the formation of the hydrogen-bonding CT-complexes. The annihilation spectra were analyzed into two lifetime components using PATFIT program. The values of the average and bulk lifetimes divide the complexes into two groups according to the non-bonding ionization potential of the donor (electron donating power) and the molecular weight of the complexes. Also, it is found that the ionization potential of the donors and molecular weight of the complexes have a conspicuous effect on the average and bulk lifetime values. The bulk lifetime values of the complexes are consistent with the formation of stable hydrogen-bonding CT-complexes as inferred from the IR-spectral data.

  20. Secondary transfer effects of intergroup contact via social identity complexity.

    PubMed

    Schmid, Katharina; Hewstone, Miles; Tausch, Nicole

    2014-09-01

    Secondary transfer effects (STEs) of intergroup contact refer to the generalization of contact effects from a primary encountered outgroup to attitudes towards secondary outgroups (Pettigrew, 2009). Using two large, cross-sectional data sets from Germany (N = 1,381) and Northern Ireland (N = 1,948), this article examined the extent to which STEs of intergroup contact on attitudes towards a range of secondary outgroups occur via a previously unexplored psychological construct, social identity complexity (operationalized as similarity complexity and overlap complexity). Study 1 found primary outgroup contact to be associated with greater similarity complexity, but no indirect effects on secondary outgroup attitudes via complexity emerged. Study 2, however, revealed indirect positive relationships between primary outgroup contact and secondary outgroup attitudes via increased similarity complexity and overlap complexity. These relationships were obtained while controlling for two previously tested mediating mechanisms, attitude generalization (operationalized as primary outgroup attitude) and deprovincialization (operationalized as ingroup attitude and identification). We discuss the theoretical implications of these findings and the contribution of social identity complexity to understanding processes underlying STEs of contact. © 2013 The British Psychological Society.

  1. Air-ground information transfer in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Lee, Alfred T.; Lozito, Sandra

    1989-01-01

    This paper reviews NASA's Aviation Safety Reporting System incident data for a two-year period in order to identify the frequency of air-ground information transfer errors and the factors associated with their occurrence. Of the more than 14,000 primary reports received during the 1985 and 1986 reporting period, one out of four reports concerned problems of information transfer between aircraft and ATC. Approximately half of these errors were associated directly or indirectly with aircraft deviations from assigned heading or altitude. The majority of incidents cited some human-system problem such as workload, cockpit distractions, etc., as the primary contributing factor. Improvements in air-ground information transfer using existing and future (e.g., data link) technology are proposed centering on the development and application of user-centered information management principles.

  2. Information transfer using wearable thin electrotactile displays with microneedle electrodes

    NASA Astrophysics Data System (ADS)

    Tezuka, Mayuko; Kitamura, Norihide; Miki, Norihisa

    2016-06-01

    Tactile sensation is considered as a promising information transfer tool that can replace or compensate for sight and hearing information. In this study, we developed a sheet-type electrotactile display with microneedle electrodes. This flexible and thin display is suitable for wearable applications. It can present tactile sensation to the skin at a low voltage by penetrating the stratum corneum with microneedles. As a proof-of-concept experiment of transferring information via tactile sensation, we first tried to convey signals of two patterns using a single display. Next, we attempted to use multiple displays and experimentally investigated the spatial resolution of the tactile sensation on the forearm. Finally, 3-bit information was successfully transferred by three devices attached to the forearm.

  3. Efficiency Of Information Transfer In Diagnostic Radiology

    NASA Astrophysics Data System (ADS)

    Brodie, I.; Gutcheck, R. A.

    1981-11-01

    Pictorial information theory is restated in a form that predicts, with fair precision, the minimum radiation required to detect a given feature size in diagnostic radiology. In contrast to conventional approaches, the probability of detection is made a visible variable in the calculation--an aspect of prime importance for diagnostic interpretation. An accurate knowledge of the absorption coefficients of the tissue concerned and the sizes one wishes to detect is required, but the calculation is relatively easy to carry out with a programmable calculator or microcomputer. The concept of "viewing efficiency" is introduced to compare the performance of a real radiographic system with that of a perfect radiographic system. The theory is applied to mammography, where the viewing efficiencies of film, film/ screen combinations, and xeroradiography are compared. It is shown that a more efficient method for detecting the latent charge image in xeroradiography, coupled with digital data storage and appropriate viewing methods, should result in substantial reductions in exposure compared to the present toning methods.

  4. Information to Change the World--Fulfilling the Information Needs of Technology Transfer.

    ERIC Educational Resources Information Center

    Duberman, Josh; Zeller, Martin

    1996-01-01

    Provides an introduction to fulfilling the information needs of technology transfer. Highlights include a definition of technology transfer; government and university involvement; industry's role; publishers; an annotated list of information sources and contacts; technology assessment, including patent searching, competitive intelligence, and…

  5. Photo-Induced Atom-Transfer Radical Reactions Using Charge-Transfer Complex between Iodine and Tertiary Amine.

    PubMed

    Yoshioka, Eito; Kohtani, Shigeru; Hashimoto, Takurou; Takebe, Tomoko; Miyabe, Hideto

    2017-01-01

    In the presence of charge-transfer complexes between iodine and tertiary amines, the aqueous-medium atom-transfer radical reactions proceeded under visible light irradiation without the typical photocatalysts.

  6. Transfer of Complex Skill Learning from Virtual to Real Rowing

    PubMed Central

    Rauter, Georg; Sigrist, Roland; Koch, Claudio; Crivelli, Francesco; van Raai, Mark; Riener, Robert; Wolf, Peter

    2013-01-01

    Simulators are commonly used to train complex tasks. In particular, simulators are applied to train dangerous tasks, to save costs, and to investigate the impact of different factors on task performance. However, in most cases, the transfer of simulator training to the real task has not been investigated. Without a proof for successful skill transfer, simulators might not be helpful at all or even counter-productive for learning the real task. In this paper, the skill transfer of complex technical aspects trained on a scull rowing simulator to sculling on water was investigated. We assume if a simulator provides high fidelity rendering of the interactions with the environment even without augmented feedback, training on such a realistic simulator would allow similar skill gains as training in the real environment. These learned skills were expected to transfer to the real environment. Two groups of four recreational rowers participated. One group trained on water, the other group trained on a simulator. Within two weeks, both groups performed four training sessions with the same licensed rowing trainer. The development in performance was assessed by quantitative biomechanical performance measures and by a qualitative video evaluation of an independent, blinded trainer. In general, both groups could improve their performance on water. The used biomechanical measures seem to allow only a limited insight into the rowers' development, while the independent trainer could also rate the rowers' overall impression. The simulator quality and naturalism was confirmed by the participants in a questionnaire. In conclusion, realistic simulator training fostered skill gains to a similar extent as training in the real environment and enabled skill transfer to the real environment. In combination with augmented feedback, simulator training can be further exploited to foster motor learning even to a higher extent, which is subject to future work. PMID:24376518

  7. Use of Ruthenium Photooxidation Techniques to Study Electron Transfer in the Cytochrome bc1 Complex

    PubMed Central

    Millett, Francis; Durham, Bill

    2009-01-01

    Ruthenium photooxidation methods are presented to study electron transfer between the cytochrome bc1 complex and cytochrome c, and within the cytochrome bc1 complex. Methods are described to prepare a ruthenium cytochrome c derivative, Ruz-39-Cc, by labeling the single sulfhydryl on yeast H39C;C102T iso-1-Cc with the reagent Ru(bpz)2(4-bromomethyl-4′-methylbipyridine). The ruthenium complex attached to Cys-39 on the opposite side of Cc from the heme crevice does not affect the interaction with cyt bc1. Laser excitation of reduced Ruz-39-Cc results in photooxidation of heme c within 1 μs with a yield of 20%. Flash photolysis of a 1:1 complex between reduced yeast cytochrome bc1 and Ruz-39-Cc leads to electron transfer from heme c1 to heme c with a rate constant of 1.4 × 104 s-1. Methods are described for the use of the ruthenium dimer, Ru2D, to photooxidize cyt c1 in the cytochrome bc1 complex within 1 μs with a yield of 20%. Electron transfer from the Rieske iron-sulfur center [2Fe2S] to cyt c1 was detected with a rate constant of 6 × 104 s-1 in R. sphaeroides cyt bc1 using this method. This electron transfer step is rate-limited by the rotation of the Rieske iron-sulfur protein in a conformational gating mechanism. This method provides critical information on the dynamics of rotation of the iron-sulfur protein (ISP) as it transfers electrons from QH2 in the Qo site to cyt c1 These ruthenium photooxidation methods can be used to measure many of the electron transfer reactions in cytochrome bc1 complexes from any source. PMID:19348884

  8. Information transfer in auditoria and room-acoustical quality.

    PubMed

    Summers, Jason E

    2013-04-01

    It is hypothesized that room-acoustical quality correlates with the information-transfer rate. Auditoria are considered as multiple-input multiple-output communication channels and a theory of information-transfer is outlined that accounts for time-variant multipath, spatial hearing, and distributed directional sources. Source diversity and spatial hearing are shown to be the mechanisms through which multipath increases the information-transfer rate by overcoming finite spatial resolution. In addition to predictions that are confirmed by recent and historical findings, the theory provides explanations for the influence of factors such as musical repertoire and ensemble size on subjective preference and the influence of multisource, multichannel auralization on perceived realism.

  9. Transfer in artificial grammar learning: the role of repetition information.

    PubMed

    Lotz, Anja; Kinder, Annette

    2006-07-01

    In this article, the authors report 2 experiments that investigated the sources of information used in transfer and nontransfer tasks in artificial grammar learning. Multiple regression analyses indicated that 2 types of information about repeating elements were crucial for performance in both tasks: information about the repetition of adjacent elements and information about repetition of elements in the whole item. Similarity of test items to specific training items and chunk information influenced participants' judgments only in nontransfer tasks. Copyright 2006 APA, all rights reserved.

  10. Patent information - towards simplicity or complexity?

    NASA Astrophysics Data System (ADS)

    Shenton, Written By Kathleen; Norton, Peter; Onodera, Translated By Natsuo

    Since the advent of online services, the ability to search and find chemical patent information has improved immeasurably. Recently, integration of a multitude of files (through file merging as well as cross-file/simultaneous searches), 'intelligent' interfaces and optical technology for large amounts of data seem to achieve greater simplicity and convenience in the retrieval of patent information. In spite of these progresses, there is more essential problem which increases complexity. It is a tendency to expand indefinitely the range of claim for chemical substances by a ultra-generic description of structure (overuse of optional substituents, variable divalent groups, repeating groups, etc.) and long listing of prophetic examples. Not only does this tendency worry producers and searchers of patent databases but also prevents truly worthy inventions in future.

  11. Electronic Energy transfer in light-harvesting antenna complexes

    NASA Astrophysics Data System (ADS)

    Hossein-Nejad, Hoda

    The studies presented in this thesis explore electronic energy transfer (EET) in light-harvesting antenna complexes and investigate the role of quantum coherence in EET. The dynamics of energy transfer are investigated in three distinct length scales and a different formulation of the exciton transport problem is applied at each scale. These scales include: the scale of a molecular dimer, the scale of a single protein and the scale of a molecular aggregate. The antenna protein phycoerythrin 545 (PE545) isolated from the photosynthetic cryptophyte algae Rhodomonas CS4 is specifically studied in two chapters of this thesis. It is found that formation of small aggregates delocalizes the excitation across chromophores of adjacent proteins, and that this delocalization has a dramatic effect in enhancing the rate of energy transfer between pigments. Furthermore, we investigate EET from a donor to an acceptor via an intermediate site and observe that interference of coherent pathways gives a finite correction to the transfer rate that is sensitively dependent on the nature of the vibrational interactions in the system. The statistical fluctuations of a system exhibiting EET are investigated in the final chapter. The techniques of non-equilibrium statistical mechanics are applied to investigate the steady-state of a typical system exhibiting EET that is perturbed out of equilibrium due to its interaction with a fluctuating bath.

  12. Ultrafast energy transfer within the photosystem II core complex.

    PubMed

    Pan, Jie; Gelzinis, Andrius; Chorošajev, Vladimir; Vengris, Mikas; Senlik, S Seckin; Shen, Jian-Ren; Valkunas, Leonas; Abramavicius, Darius; Ogilvie, Jennifer P

    2017-06-14

    We report 2D electronic spectroscopy on the photosystem II core complex (PSII CC) at 77 K under different polarization conditions. A global analysis of the high time-resolution 2D data shows rapid, sub-100 fs energy transfer within the PSII CC. It also reveals the 2D spectral signatures of slower energy equilibration processes occurring on several to hundreds of picosecond time scales that are consistent with previous work. Using a recent structure-based model of the PSII CC [Y. Shibata, S. Nishi, K. Kawakami, J. R. Shen and T. Renger, J. Am. Chem. Soc., 2013, 135, 6903], we simulate the energy transfer in the PSII CC by calculating auxiliary time-resolved fluorescence spectra. We obtain the observed sub-100 fs evolution, even though the calculated electronic energy shows almost no dynamics at early times. On the other hand, the electronic-vibrational interaction energy increases considerably over the same time period. We conclude that interactions with vibrational degrees of freedom not only induce population transfer between the excitonic states in the PSII CC, but also reshape the energy landscape of the system. We suggest that the experimentally observed ultrafast energy transfer is a signature of excitonic-polaron formation.

  13. Complex Clinical Communication Practices: How Do Information Receivers Assimilate and Act Upon Information for Patient Care?

    PubMed

    Wong, Ming Chao; Yee, Kwang Chien; Turner, Paul

    2017-01-01

    Improving clinical communication is imperative to improving the quality and safety of patient care. Significant efforts have been made to improve clinical communication and patient safety, guided by the mantra of "the right information, to the right person, in the right place, at the right time". The design and implementation of information communication technologies (ICTs) has been considered as one of the major developments in improving patient care. Clinical communication in today's clinical practice is complex and involves multi-disciplinary teams using different types of media for information transfer. This paper argues that traditional communication theories fail to adequately capture and describe contemporary clinical communicative practices or to provide insight into how information transferred is actually assimilated and/or utilised for patient care. This paper argues for the need to more fully consider underlying assumptions about the role of information in clinical communication and to recognise how the attributes of information receivers, especially where ICTs are deployed influence outcomes. The paper presents a discussion regarding the need to consider information receivers as the foundation for clinical communication improvement and future design and development of ICTs to improve patient care.

  14. The architecture of the management system of complex steganographic information

    NASA Astrophysics Data System (ADS)

    Evsutin, O. O.; Meshcheryakov, R. V.; Kozlova, A. S.; Solovyev, T. M.

    2017-01-01

    The aim of the study is to create a wide area information system that allows one to control processes of generation, embedding, extraction, and detection of steganographic information. In this paper, the following problems are considered: the definition of the system scope and the development of its architecture. For creation of algorithmic maintenance of the system, classic methods of steganography are used to embed information. Methods of mathematical statistics and computational intelligence are used to identify the embedded information. The main result of the paper is the development of the architecture of the management system of complex steganographic information. The suggested architecture utilizes cloud technology in order to provide service using the web-service via the Internet. It is meant to provide streams of multimedia data processing that are streams with many sources of different types. The information system, built in accordance with the proposed architecture, will be used in the following areas: hidden transfer of documents protected by medical secrecy in telemedicine systems; copyright protection of online content in public networks; prevention of information leakage caused by insiders.

  15. Modelling excitonic-energy transfer in light-harvesting complexes

    SciTech Connect

    Kramer, Tobias; Kreisbeck, Christoph

    2014-01-08

    The theoretical and experimental study of energy transfer in photosynthesis has revealed an interesting transport regime, which lies at the borderline between classical transport dynamics and quantum-mechanical interference effects. Dissipation is caused by the coupling of electronic degrees of freedom to vibrational modes and leads to a directional energy transfer from the antenna complex to the target reaction-center. The dissipative driving is robust and does not rely on fine-tuning of specific vibrational modes. For the parameter regime encountered in the biological systems new theoretical tools are required to directly compare theoretical results with experimental spectroscopy data. The calculations require to utilize massively parallel graphics processor units (GPUs) for efficient and exact computations.

  16. Modelling excitonic-energy transfer in light-harvesting complexes

    NASA Astrophysics Data System (ADS)

    Kramer, Tobias; Kreisbeck, Christoph

    2014-01-01

    The theoretical and experimental study of energy transfer in photosynthesis has revealed an interesting transport regime, which lies at the borderline between classical transport dynamics and quantum-mechanical interference effects. Dissipation is caused by the coupling of electronic degrees of freedom to vibrational modes and leads to a directional energy transfer from the antenna complex to the target reaction-center. The dissipative driving is robust and does not rely on fine-tuning of specific vibrational modes. For the parameter regime encountered in the biological systems new theoretical tools are required to directly compare theoretical results with experimental spectroscopy data. The calculations require to utilize massively parallel graphics processor units (GPUs) for efficient and exact computations.

  17. Infrared Spectroscopy of Charge Transfer Complexes of Purines and Pyrimidines

    SciTech Connect

    Rathod, Pravinsinh I.; Oza, A. T.

    2011-10-20

    The FTIR spectra of charge transfer complexes of purines and pyrimidines with organic acceptors such as TCNQ, TCNE, DDQ, chloranil and iodine are obtained and studied in the present work. Adenine, guanine, thymine, cytosine and uracil are the purines and pyrimidines which are found as constituent of DNA and RNA. Charge transfer induced hydrogen bonding is concluded on the basis of indirect transitions observed in the infrared range in these CTCs. Some CTCs show gaussian bands revealing delocalization of charge carriers. The CTCs show interband transition in three-dimensions rather than two-dimensions unlike CTCs of amino acids. There is no extended hydrogen bonded network spanning the whole crystal. This leads to indirect transition due to locally deformed lattice furnishing a phonon-assisted transition.

  18. Infrared Spectroscopy of Charge Transfer Complexes of Purines and Pyrimidines

    NASA Astrophysics Data System (ADS)

    Rathod, Pravinsinh I.; Oza, A. T.

    2011-10-01

    The FTIR spectra of charge transfer complexes of purines and pyrimidines with organic acceptors such as TCNQ, TCNE, DDQ, chloranil and iodine are obtained and studied in the present work. Adenine, guanine, thymine, cytosine and uracil are the purines and pyrimidines which are found as constituent of DNA and RNA. Charge transfer induced hydrogen bonding is concluded on the basis of indirect transitions observed in the infrared range in these CTCs. Some CTCs show gaussian bands revealing delocalization of charge carriers. The CTCs show interband transition in three-dimensions rather than two-dimensions unlike CTCs of amino acids. There is no extended hydrogen bonded network spanning the whole crystal. This leads to indirect transition due to locally deformed lattice furnishing a phonon-assisted transition.

  19. Optimal information transfer in enzymatic networks: A field theoretic formulation

    NASA Astrophysics Data System (ADS)

    Samanta, Himadri S.; Hinczewski, Michael; Thirumalai, D.

    2017-07-01

    Signaling in enzymatic networks is typically triggered by environmental fluctuations, resulting in a series of stochastic chemical reactions, leading to corruption of the signal by noise. For example, information flow is initiated by binding of extracellular ligands to receptors, which is transmitted through a cascade involving kinase-phosphatase stochastic chemical reactions. For a class of such networks, we develop a general field-theoretic approach to calculate the error in signal transmission as a function of an appropriate control variable. Application of the theory to a simple push-pull network, a module in the kinase-phosphatase cascade, recovers the exact results for error in signal transmission previously obtained using umbral calculus [Hinczewski and Thirumalai, Phys. Rev. X 4, 041017 (2014), 10.1103/PhysRevX.4.041017]. We illustrate the generality of the theory by studying the minimal errors in noise reduction in a reaction cascade with two connected push-pull modules. Such a cascade behaves as an effective three-species network with a pseudointermediate. In this case, optimal information transfer, resulting in the smallest square of the error between the input and output, occurs with a time delay, which is given by the inverse of the decay rate of the pseudointermediate. Surprisingly, in these examples the minimum error computed using simulations that take nonlinearities and discrete nature of molecules into account coincides with the predictions of a linear theory. In contrast, there are substantial deviations between simulations and predictions of the linear theory in error in signal propagation in an enzymatic push-pull network for a certain range of parameters. Inclusion of second-order perturbative corrections shows that differences between simulations and theoretical predictions are minimized. Our study establishes that a field theoretic formulation of stochastic biological signaling offers a systematic way to understand error propagation in

  20. Vibrational energy transfer dynamics in ruthenium polypyridine transition metal complexes.

    PubMed

    Fedoseeva, Marina; Delor, Milan; Parker, Simon C; Sazanovich, Igor V; Towrie, Michael; Parker, Anthony W; Weinstein, Julia A

    2015-01-21

    Understanding the dynamics of the initial stages of vibrational energy transfer in transition metal complexes is a challenging fundamental question which is also of crucial importance for many applications, such as improving the performance of solar devices or photocatalysis. The present study investigates vibrational energy transport in the ground and the electronic excited state of Ru(4,4'-(COOEt)2-2,2-bpy)2(NCS)2, a close relative of the efficient "N3" dye used in dye-sensitized solar cells. Using the emerging technique of ultrafast two-dimensional infrared spectroscopy, we show that, similarly to other transition-metal complexes, the central Ru heavy atom acts as a "bottleneck" making the energy transfer from small ligands with high energy vibrational stretching frequencies less favorable and thereby affecting the efficiency of vibrational energy flow in the complex. Comparison of the vibrational relaxation times in the electronic ground and excited state of Ru(4,4'-(COOEt)2-2,2-bpy)2(NCS)2 shows that it is dramatically faster in the latter. We propose to explain this observation by the intramolecular electrostatic interactions between the thiocyanate group and partially oxidised Ru metal center, which increase the degree of vibrational coupling between CN and Ru-N modes in the excited state thus reducing structural and thermodynamic barriers that slow down vibrational relaxation and energy transport in the electronic ground state. As a very similar behavior was earlier observed in another transition-metal complex, Re(4,4'-(COOEt)2-2,2'-bpy)(CO)3Cl, we suggest that this effect in vibrational energy dynamics might be common for transition-metal complexes with heavy central atoms.

  1. Hydrophone's sensitivity calibration based on its complex transfer function

    NASA Astrophysics Data System (ADS)

    Oliveira, E. G.; Machado, J. C.; Costa-Felix, R. P. B.

    2015-01-01

    A novel approach to calibrate ultrasonic hydrofone's sensitivity magnitude has been developed. The primary calibration method known as self-reciprocity with an auxiliary transducer was improved with a measurement technique based on the assessment of complex transfer function of the system. The protocol was experimented from 1.0 MHz to 7.0 MHz, and thereafter compared with a previous calibration realized at the National Physical Laboratory (NPL, Teddington, UK). Within the frequency range of interest, the novel calibration results were statistically identical to the previous calibration data. The 95% confidence level uncertainty varied from 6.6% to 7.5%.

  2. [Fluorescent energy transfer study of lysozyme complexes with liposomes].

    PubMed

    Gorbenko, G P

    1999-01-01

    The method of radiationless energy transfer was used to study the structure of lysozyme complexes with liposomes composed of phosphatidylcholine and diphosphatidylglycerol (4:3, mol:mol). 4-(n-Dimethylaminostyryl)-1-methylpyridinium n-toluenesulfonate, 4-(n-dimethylaminostyryl)-1-hexylpyridinium n-toluenesulfonate, 4-(n-dimethylaminostyryl)-1-dodecylpyridinium n-toluenesulfonate, and 3-metoxybenzanthrone were used as donors, and nile blue and rhodamine 6G, as acceptors. An increase in the surface area of model membranes upon binging of the protein to lipid bilayer was found.

  3. Information Transfer Capacity of Articulators in American Sign Language.

    PubMed

    Malaia, Evie; Borneman, Joshua D; Wilbur, Ronnie B

    2017-05-01

    The ability to convey information is a fundamental property of communicative signals. For sign languages, which are overtly produced with multiple, completely visible articulators, the question arises as to how the various channels co-ordinate and interact with each other. We analyze motion capture data of American Sign Language (ASL) narratives, and show that the capacity of information throughput, mathematically defined, is highest on the dominant hand (DH). We further demonstrate that information transfer capacity is also significant for the non-dominant hand (NDH), and the head channel too, as compared to control channels (ankles). We discuss both redundancy and independence in articulator motion in sign language, and argue that the NDH and the head articulators contribute to the overall information transfer capacity, indicating that they are neither completely redundant to, nor completely independent of, the DH.

  4. A Survey on Simultaneous Wireless Information and Power Transfer

    NASA Astrophysics Data System (ADS)

    Perera, T. D. P.; Jayakody, D. N. K.; De, S.; Ivanov, M. A.

    2017-01-01

    This paper presents a comprehensive study related to simultaneous wireless information and power transfer (SWIPT) in different types of wireless communication setups. Harvesting energy using SWIPT is an appealing solution in the context of extending battery life of wireless devices for a fully sustainable communication system. Strong signal power increases power transfer, but also causes more interference in information transfer, causing realization of the SWIPT challenging problem. This article provides an overview of technical evolution of SWIPT. A survey and qualitative comparison of the existing SWIPT schemes is provided to demonstrate their limitations in the current and 5G networks. Open challenges are emphasized and guidelines are provided to adapt the existing schemes in order to overcome these limitations and make them fit for integrating with the modern and emerging next generation communication networks, such as 5G systems.

  5. TIS (Technology Information System) A Focal Point for Technology Transfer

    DTIC Science & Technology

    1982-09-01

    3 2.1 Stevenson-Wydler Technology Inovation Act of 1980 .................................... 3 2.2 Technical Information Centers...passwords is required since none were disclosed. The DIAL command provides an equally powerful , but user-controlled, method for accessing other...a local file from TIS to a remote machine. This has particular importance when downloaded and saved information is to be transferred to more powerful

  6. Information Transfer and the Adoption of Agricultural Innovations.

    ERIC Educational Resources Information Center

    Longo, Rose Mary Juliano

    1990-01-01

    Data collected in the Federal District of Brazil were analyzed in terms of information transfer through mass media and interpersonal communication and how they influence farmers in the Federal District of Brazil in their decisions to adopt agricultural innovations. (42 references) (EAM)

  7. Information Networks: A Probablistic Model for Hierarchical Message Transfer.

    ERIC Educational Resources Information Center

    Bhat, U. Narayan; And Others

    A strictly hierarchical message transfer scheme requires that a message follow a specified referral path unless finally it is either rejected or filled at any one of the information centers of the network. Thus at each node in the network three decisions can be made: satisfy, reject or refer the message to the succeeding node in the hierarchy.…

  8. Information Transfer and the Adoption of Agricultural Innovations.

    ERIC Educational Resources Information Center

    Longo, Rose Mary Juliano

    1990-01-01

    Data collected in the Federal District of Brazil were analyzed in terms of information transfer through mass media and interpersonal communication and how they influence farmers in the Federal District of Brazil in their decisions to adopt agricultural innovations. (42 references) (EAM)

  9. Workshop on Possibilities for Improving Information Transfer. Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    Presented are the proceedings from a workshop held in Rabat, Morocco from May 24-28, 1976. The main objective of the workshop was to evaluate progress made in information transfer and prepare a program of action enabling documentation centers created or assisted by UNESCO to cooperate in such areas as staff training, translation activities, and…

  10. Information transfer during contingency operations: Emergency air-ground communications

    NASA Technical Reports Server (NTRS)

    Porter, R. F.

    1981-01-01

    Safety related problems are reported which occur as a consequence of information transfer deficiencies that arise when air/ground communications are (or should be) used as a resource in inflight emergency situations. The system factors, the human errors, and the associated causes of these problem are defined.

  11. Transgenerational epigenetic inheritance: focus on soma to germline information transfer.

    PubMed

    Sharma, Abhay

    2013-12-01

    In trangenerational epigenetic inheritance, phenotypic information not encoded in DNA sequence is transmitted across generations. In germline-dependent mode, memory of environmental exposure in parental generation is transmitted through gametes, leading to appearance of phenotypes in the unexposed future generations. The memory is considered to be encoded in epigenetic factors like DNA methylation, histone modifications and regulatory RNAs. Environmental exposure may cause epigenetic modifications in the germline either directly or indirectly through primarily affecting the soma. The latter possibility is most intriguing because it contradicts the established dogma that hereditary information flows only from germline to soma, not in reverse. As such, identification of the factor(s) mediating soma to germline information transfer in transgenerational epigenetic inheritance would be pathbreaking. Regulatory RNAs and hormone have previously been implicated or proposed to play a role in soma to germline communication in epigenetic inheritance. This review examines the recent examples of gametogenic transgenerational inheritance in plants and animals in order to assess if evidence of regulatory RNAs and hormones as mediators of information transfer is supported. Overall, direct evidence for both mobile regulatory RNAs and hormones is found to exist in plants. In animals, although involvement of mobile RNAs seems imminent, direct evidence of RNA-mediated soma to germline information transfer in transgenerational epigenetic inheritance is yet to be obtained. Direct evidence is also lacking for hormones in animals. However, detailed examination of recently reported examples of transgenerational inheritance reveals circumstantial evidence supporting a role of hormones in information transmission.

  12. Adaptive Local Information Transfer in Random Boolean Networks.

    PubMed

    Haruna, Taichi

    2017-01-01

    Living systems such as gene regulatory networks and neuronal networks have been supposed to work close to dynamical criticality, where their information-processing ability is optimal at the whole-system level. We investigate how this global information-processing optimality is related to the local information transfer at each individual-unit level. In particular, we introduce an internal adjustment process of the local information transfer and examine whether the former can emerge from the latter. We propose an adaptive random Boolean network model in which each unit rewires its incoming arcs from other units to balance stability of its information processing based on the measurement of the local information transfer pattern. First, we show numerically that random Boolean networks can self-organize toward near dynamical criticality in our model. Second, the proposed model is analyzed by a mean-field theory. We recognize that the rewiring rule has a bootstrapping feature. The stationary indegree distribution is calculated semi-analytically and is shown to be close to dynamical criticality in a broad range of model parameter values.

  13. Measuring information transfer in a soft robotic arm.

    PubMed

    Nakajima, K; Schmidt, N; Pfeifer, R

    2015-05-13

    Soft robots can exhibit diverse behaviors with simple types of actuation by partially outsourcing control to the morphological and material properties of their soft bodies, which is made possible by the tight coupling between control, body, and environment. In this paper, we present a method that will quantitatively characterize these diverse spatiotemporal dynamics of a soft body based on the information-theoretic approach. In particular, soft bodies have the ability to propagate the effect of actuation through the entire body, with a certain time delay, due to their elasticity. Our goal is to capture this delayed interaction in a quantitative manner based on a measure called momentary information transfer. We extend this measure to soft robotic applications and demonstrate its power using a physical soft robotic platform inspired by the octopus. Our approach is illustrated in two ways. First, we statistically characterize the delayed actuation propagation through the body as a strength of information transfer. Second, we capture this information propagation directly as local information dynamics. As a result, we show that our approach can successfully characterize the spatiotemporal dynamics of the soft robotic platform, explicitly visualizing how information transfers through the entire body with delays. Further extension scenarios of our approach are discussed for soft robotic applications in general.

  14. Resonance energy transfer study of peptide-lipid complexes.

    PubMed

    Gorbenko, G; Saito, H; Molotkovsky, J; Tanaka, M; Egashira, M; Nakano, M; Handa, T

    2001-09-18

    Resonance energy transfer involving tryptophan as a donor and anthrylvinyl-labeled phosphatidylcholine (AV-PC), 3-methoxybenzanthrone (MBA) and 8-anilino-1-naphthalene sulfonic acid (ANS) as acceptors has been examined to obtain information on the structure of peptide-lipid systems consisting of 18A or Ac-18A-NH(2) peptides and large unilamellar phosphatidylcholine vesicles. The lower and upper limits for the tryptophan distance from the bilayer midplane have been assessed in terms of the models of energy transfer in two-dimensional systems, taking into account orientational effects. Evidence for the existence of preferential orientations of Ac-18A-NH(2) with respect to the lipid-water interface has been obtained.

  15. The electronic transfer of information and aerospace knowledge diffusion

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Bishop, Ann P.; Barclay, Rebecca O.; Kennedy, John M.

    1992-01-01

    Increasing reliance on and investment in information technology and electronic networking systems presupposes that computing and information technology will play a motor role in the diffusion of aerospace knowledge. Little is known, however, about actual information technology needs, uses, and problems within the aerospace knowledge diffusion process. The authors state that the potential contributions of information technology to increased productivity and competitiveness will be diminished unless empirically derived knowledge regarding the information-seeking behavior of the members of the social system - those who are producing, transferring, and using scientific and technical information - is incorporated into a new technology policy framework. Research into the use of information technology and electronic networks by U.S. aerospace engineers and scientists, collected as part of a research project designed to study aerospace knowledge diffusion, is presented in support of this assertion.

  16. Information-Theoretical Complexity Analysis of Selected Elementary Chemical Reactions

    NASA Astrophysics Data System (ADS)

    Molina-Espíritu, M.; Esquivel, R. O.; Dehesa, J. S.

    We investigate the complexity of selected elementary chemical reactions (namely, the hydrogenic-abstraction reaction and the identity SN2 exchange reaction) by means of the following single and composite information-theoretic measures: disequilibrium (D), exponential entropy(L), Fisher information (I), power entropy (J), I-D, D-L and I-J planes and Fisher-Shannon (FS) and Lopez-Mancini-Calbet (LMC) shape complexities. These quantities, which are functionals of the one-particle density, are computed in both position (r) and momentum (p) spaces. The analysis revealed that the chemically significant regions of these reactions can be identified through most of the single information-theoretic measures and the two-component planes, not only the ones which are commonly revealed by the energy, such as the reactant/product (R/P) and the transition state (TS), but also those that are not present in the energy profile such as the bond cleavage energy region (BCER), the bond breaking/forming regions (B-B/F) and the charge transfer process (CT). The analysis of the complexities shows that the energy profile of the abstraction reaction bears the same information-theoretical features of the LMC and FS measures, however for the identity SN2 exchange reaction does not hold a simple behavior with respect to the LMC and FS measures. Most of the chemical features of interest (BCER, B-B/F and CT) are only revealed when particular information-theoretic aspects of localizability (L or J), uniformity (D) and disorder (I) are considered.

  17. 76 FR 7559 - Access in Litigation to Confidential Business Information; Transfer of Information Claimed as...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ... AGENCY Access in Litigation to Confidential Business Information; Transfer of Information Claimed as Confidential Business Information to the United States Department of Justice and Parties to Certain Litigation... States Department of Justice (``DOJ'') to disclose, in response to discovery requests received by...

  18. Image transfer through the complex scattering turbid media

    NASA Astrophysics Data System (ADS)

    Meglinski, I. V.; Berrocal, E.; Linne, M. A.; Greenhalgh, D. A.

    2007-05-01

    Seeing through a turbid medium such as fog, mist or clouds is a fascinating idea that would find applications in a large range of fields from research to industry. The main difficulty of this challenging task is related to the complexity of multiple scattering of optical radiation propagated through an ensemble of scattering particles and/or droplets randomly distributed in a medium. To deal with this challenging problem we develop a new Monte Carlo based computational technique able to simulate image transfer through the complex inhomogeneous turbid media. The model is able to identify the contribution of the scattering orders in the detected images for a particular medium. With the presented approach the simulation of laser beam propagation and image transfer of an object hidden within a turbid scattering medium has been performed. The results of simulation demonstrate a good agreement with the experimental results. The validation of the technique has been done by using several modeling samples of water polystyrene spheres solutions.

  19. Hydrated alizarin complexes: hydrogen bonding and proton transfer.

    PubMed

    Huh, Hyun; Cho, Sung Haeng; Heo, Jiyoung; Kim, Nam Joon; Kim, Seong Keun

    2012-07-07

    We investigated the hydrogen bonding structures and proton transfer for the hydration complexes of alizarin (Az) produced in a supersonic jet using fluorescence excitation (FE), dispersed laser induced fluorescence (LIF), visible-visible hole burning (HB), and fluorescence detected infrared (FDIR) spectroscopy. The FDIR spectrum of bare Az with two O-H groups exhibits two vibrational bands at 3092 and 3579 cm(-1), which, respectively, correspond to the stretching vibration of O1-H1 that forms a strong intramolecular hydrogen bond with the C9=O9 carbonyl group and the stretching vibration of O2-H2 that is weakly hydrogen-bonded to O1-H1. For the 1:1 hydration complex Az(H(2)O)(1), we identified three conformers. In the most stable conformer, the water molecule forms hydrogen bonds with the O1-H1 and O2-H2 groups of Az as a proton donor and proton acceptor, respectively. In the other conformers, the water binds to the C10=O10 group in two nearly isoenergetic configurations. In contrast to the sharp vibronic peaks in the FE spectra of Az and Az(H(2)O)(1), only broad, structureless absorption was observed for Az(H(2)O)(n) (n≥ 2), indicating a facile decay process, possibly due to proton transfer in the electronic excited state. The FDIR spectrum with the wavelength of the probe laser fixed at the broad band exhibited a broad vibrational band near the O2-H2 stretching vibration frequency of the most stable conformer of Az(H(2)O)(1). With the help of theoretical calculations, we suggest that the broad vibrational band may represent the occurrence of proton transfer by tunnelling in the electronic ground state of Az(H(2)O)(n) (n≥ 2) upon excitation of the O2-H2 vibration.

  20. Scalable quantum information transfer between nitrogen-vacancy-center ensembles

    SciTech Connect

    Zhang, Feng-yang; Yang, Chui-Ping; Song, He-Shan

    2015-04-15

    We propose an architecture for realizing quantum information transfer (QIT). In this architecture, a LC circuit is used to induce the necessary interaction between flux qubits, each magnetically coupling to a nitrogen-vacancy center ensemble (NVCE). We explicitly show that for resonant interaction and large detuning cases, high-fidelity QIT between two spatially-separated NVCEs can be implemented. Our proposal can be extended to achieve QIT between any two selected NVCEs in a large hybrid system by adjusting system parameters, which is important in large scale quantum information processing. - Highlights: • Quantum information transfer between any two selected NV ensembles is implemented. • This architecture is robust against the dissipation of the system. • We explicitly show that for resonant interaction and large detuning cases.

  1. Compositional genomes: Prebiotic information transfer in mutually catalytic noncovalent assemblies

    PubMed Central

    Segré, Daniel; Ben-Eli, Dafna; Lancet, Doron

    2000-01-01

    Mutually catalytic sets of simple organic molecules have been suggested to be capable of self-replication and rudimentary chemical evolution. Previous models for the behavior of such sets have analyzed the global properties of short biopolymer ensembles by using graph theory and a mean field approach. In parallel, experimental studies with the autocatalytic formation of amphiphilic assemblies (e.g., lipid vesicles or micelles) demonstrated self-replication properties resembling those of living cells. Combining these approaches, we analyze here the kinetic behavior of small heterogeneous assemblies of spontaneously aggregating molecules, of the type that could form readily under prebiotic conditions. A statistical formalism for mutual rate enhancement is used to numerically simulate the detailed chemical kinetics within such assemblies. We demonstrate that a straightforward set of assumptions about kinetically enhanced recruitment of simple amphiphilic molecules, as well as about the spontaneous growth and splitting of assemblies, results in a complex population behavior. The assemblies manifest a significant degree of homeostasis, resembling the previously predicted quasi-stationary states of biopolymer ensembles (Dyson, F. J. (1982) J. Mol. Evol. 18, 344–350). Such emergent catalysis-driven, compositionally biased entities may be viewed as having rudimentary “compositional genomes.” Our analysis addresses the question of how mutually catalytic metabolic networks, devoid of sequence-based biopolymers, could exhibit transfer of chemical information and might undergo selection and evolution. This computed behavior may constitute a demonstration of natural selection in populations of molecules without genetic apparatus, suggesting a pathway from random molecular assemblies to a minimal protocell. PMID:10760281

  2. Conceptual model for transferring information between small watersheds

    USGS Publications Warehouse

    Cleaves, E.T.

    2003-01-01

    Stream and watershed management and restoration can be greatly facilitated through use of physiographic landform classification to organize and communicate natural resource, hazard, and environmental information at a broad scale (1:250,000) as illustrated by the Piedmont and Coastal Plain Provinces in Maryland, or at a small scale (1:24,000) as illustrated using divisions and zones combined with a conceptual model. The conceptual model brings together geology, surficial processes, landforms and land use change information at the small watershed scale and facilitates transfer of information from one small watershed to another with similar geology and landforms. Stream flow, sediment erosion, and water quality illustrate the use of the model.

  3. Serotonergic Psychedelics Temporarily Modify Information Transfer in Humans

    PubMed Central

    Alonso, Joan Francesc; Romero, Sergio; Mañanas, Miquel Àngel

    2015-01-01

    Background: Psychedelics induce intense modifications in the sensorium, the sense of “self,” and the experience of reality. Despite advances in our understanding of the molecular and cellular level mechanisms of these drugs, knowledge of their actions on global brain dynamics is still incomplete. Recent imaging studies have found changes in functional coupling between frontal and parietal brain structures, suggesting a modification in information flow between brain regions during acute effects. Methods: Here we assessed the psychedelic-induced changes in directionality of information flow during the acute effects of a psychedelic in humans. We measured modifications in connectivity of brain oscillations using transfer entropy, a nonlinear measure of directed functional connectivity based on information theory. Ten healthy male volunteers with prior experience with psychedelics participated in 2 experimental sessions. They received a placebo or a dose of ayahuasca, a psychedelic preparation containing the serotonergic 5-HT2A agonist N,N-dimethyltryptamine. Results: The analysis showed significant changes in the coupling of brain oscillations between anterior and posterior recording sites. Transfer entropy analysis showed that frontal sources decreased their influence over central, parietal, and occipital sites. Conversely, sources in posterior locations increased their influence over signals measured at anterior locations. Exploratory correlations found that anterior-to-posterior transfer entropy decreases were correlated with the intensity of subjective effects, while the imbalance between anterior-to-posterior and posterior-to-anterior transfer entropy correlated with the degree of incapacitation experienced. Conclusions: These results suggest that psychedelics induce a temporary disruption of neural hierarchies by reducing top-down control and increasing bottom-up information transfer in the human brain. PMID:25820842

  4. Serotonergic psychedelics temporarily modify information transfer in humans.

    PubMed

    Alonso, Joan Francesc; Romero, Sergio; Mañanas, Miquel Àngel; Riba, Jordi

    2015-03-28

    Psychedelics induce intense modifications in the sensorium, the sense of "self," and the experience of reality. Despite advances in our understanding of the molecular and cellular level mechanisms of these drugs, knowledge of their actions on global brain dynamics is still incomplete. Recent imaging studies have found changes in functional coupling between frontal and parietal brain structures, suggesting a modification in information flow between brain regions during acute effects. Here we assessed the psychedelic-induced changes in directionality of information flow during the acute effects of a psychedelic in humans. We measured modifications in connectivity of brain oscillations using transfer entropy, a nonlinear measure of directed functional connectivity based on information theory. Ten healthy male volunteers with prior experience with psychedelics participated in 2 experimental sessions. They received a placebo or a dose of ayahuasca, a psychedelic preparation containing the serotonergic 5-HT2A agonist N,N-dimethyltryptamine. The analysis showed significant changes in the coupling of brain oscillations between anterior and posterior recording sites. Transfer entropy analysis showed that frontal sources decreased their influence over central, parietal, and occipital sites. Conversely, sources in posterior locations increased their influence over signals measured at anterior locations. Exploratory correlations found that anterior-to-posterior transfer entropy decreases were correlated with the intensity of subjective effects, while the imbalance between anterior-to-posterior and posterior-to-anterior transfer entropy correlated with the degree of incapacitation experienced. These results suggest that psychedelics induce a temporary disruption of neural hierarchies by reducing top-down control and increasing bottom-up information transfer in the human brain. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  5. Synaptic information transfer in computer models of neocortical columns

    PubMed Central

    Jacobs, Kimberle M.; Fenton, André A.; Lytton, William W.

    2010-01-01

    Understanding the direction and quantity of information flowing in neuronal networks is a fundamental problem in neuroscience. Brains and neuronal networks must at the same time store information about the world and react to information in the world. We sought to measure how the activity of the network alters information flow from inputs to output patterns. Using neocortical column neuronal network simulations, we demonstrated that networks with greater internal connectivity reduced input/output correlations from excitatory synapses and decreased negative correlations from inhibitory synapses, measured by Kendall's τ correlation. Both of these changes were associated with reduction in information flow, measured by normalized transfer entropy (nTE). Information handling by the network reflected the degree of internal connectivity. With no internal connectivity, the feedforward network transformed inputs through nonlinear summation and thresholding. With greater connectivity strength, the recurrent network translated activity and information due to contribution of activity from intrinsic network dynamics. This dynamic contribution amounts to added information drawn from that stored in the network. At still higher internal synaptic strength, the network corrupted the external information, producing a state where little external information came through. The association of increased information retrieved from the network with increased gamma power supports the notion of gamma oscillations playing a role in information processing. PMID:20556639

  6. Complexity of genetic sequences modified by horizontal gene transfer and degraded-DNA uptake

    NASA Astrophysics Data System (ADS)

    Tremberger, George; Dehipawala, S.; Nguyen, A.; Cheung, E.; Sullivan, R.; Holden, T.; Lieberman, D.; Cheung, T.

    2015-09-01

    Horizontal gene transfer has been a major vehicle for efficient transfer of genetic materials among living species and could be one of the sources for noncoding DNA incorporation into a genome. Our previous study of lnc- RNA sequence complexity in terms of fractal dimension and information entropy shows a tight regulation among the studied genes in numerous diseases. The role of sequence complexity in horizontal transferred genes was investigated with Mealybug in symbiotic relation with a 139K genome microbe and Deinococcus radiodurans as examples. The fractal dimension and entropy showed correlation R-sq of 0.82 (N = 6) for the studied Deinococcus radiodurans sequences. For comparison the Deinococcus radiodurans oxidative stress tolerant catalase and superoxide dismutase genes under extracellular dGMP growth condition showed R-sq ~ 0.42 (N = 6); and the studied arsenate reductase horizontal transferred genes for toxicity survival in several microorganisms showed no correlation. Simulation results showed that R-sq < 0.4 would be improbable at less than one percent chance, suggestive of additional selection pressure when compared to the R-sq ~ 0.29 (N = 21) in the studied transferred genes in Mealybug. The mild correlation of R-sq ~ 0.5 for fractal dimension versus transcription level in the studied Deinococcus radiodurans sequences upon extracellular dGMP growth condition would suggest that lower fractal dimension with less electron density fluctuation favors higher transcription level.

  7. Rényi’s information transfer between financial time series

    NASA Astrophysics Data System (ADS)

    Jizba, Petr; Kleinert, Hagen; Shefaat, Mohammad

    2012-05-01

    In this paper, we quantify the statistical coherence between financial time series by means of the Rényi entropy. With the help of Campbell’s coding theorem, we show that the Rényi entropy selectively emphasizes only certain sectors of the underlying empirical distribution while strongly suppressing others. This accentuation is controlled with Rényi’s parameter q. To tackle the issue of the information flow between time series, we formulate the concept of Rényi’s transfer entropy as a measure of information that is transferred only between certain parts of underlying distributions. This is particularly pertinent in financial time series, where the knowledge of marginal events such as spikes or sudden jumps is of a crucial importance. We apply the Rényian information flow to stock market time series from 11 world stock indices as sampled at a daily rate in the time period 02.01.1990-31.12.2009. Corresponding heat maps and net information flows are represented graphically. A detailed discussion of the transfer entropy between the DAX and S&P500 indices based on minute tick data gathered in the period 02.04.2008-11.09.2009 is also provided. Our analysis shows that the bivariate information flow between world markets is strongly asymmetric with a distinct information surplus flowing from the Asia-Pacific region to both European and US markets. An important yet less dramatic excess of information also flows from Europe to the US. This is particularly clearly seen from a careful analysis of Rényi information flow between the DAX and S&P500 indices.

  8. Information transfer rate in fMRI experiments measured using mutual information theory.

    PubMed

    Ward, B Douglas; Mazaheri, Yousef

    2008-01-15

    Information theory provides a mathematical framework for analysis of fMRI experiments. By modeling the fMRI experiment as a communication system, various results from information theory can be applied to measure information transfer rate in fMRI experiments. The information transfer rate has important implications for design and analysis of brain-computer interface (BCI) experiments. A key factor in the effective implementation of BCI techniques is to achieve maximum information transfer rate. In this report, mutual information rate (MIR) was used to evaluate the efficiency of alternative experimental designs. The channel capacity, a fundamental physical limit on the rate at which information can be extracted from an fMRI experiment, was estimated and compared with the theoretical limit specified by the Hartley-Shannon Theorem. We present an information theory framework for the analysis of fMRI time-series assuming a known hemodynamic response function. Using MIR to evaluate fMRI experimental designs, we show that block lengths of 3-5s have maximum information transfer rates. For designs with shorter block lengths, the MIR is limited by the channel capacity. For experimental designs with longer block lengths, the MIR is limited by the low source information transmission rate.

  9. Quantum ferroelectricity in charge-transfer complex crystals

    PubMed Central

    Horiuchi, Sachio; Kobayashi, Kensuke; Kumai, Reiji; Minami, Nao; Kagawa, Fumitaka; Tokura, Yoshinori

    2015-01-01

    Quantum phase transition achieved by fine tuning the continuous phase transition down to zero kelvin is a challenge for solid state science. Critical phenomena distinct from the effects of thermal fluctuations can materialize when the electronic, structural or magnetic long-range order is perturbed by quantum fluctuations between degenerate ground states. Here we have developed chemically pure tetrahalo-p-benzoquinones of n iodine and 4–n bromine substituents (QBr4–nIn, n=0–4) to search for ferroelectric charge-transfer complexes with tetrathiafulvalene (TTF). Among them, TTF–QBr2I2 exhibits a ferroelectric neutral–ionic phase transition, which is continuously controlled over a wide temperature range from near-zero kelvin to room temperature under hydrostatic pressure. Quantum critical behaviour is accompanied by a much larger permittivity than those of other neutral–ionic transition compounds, such as well-known ferroelectric complex of TTF–QCl4 and quantum antiferroelectric of dimethyl–TTF–QBr4. By contrast, TTF–QBr3I complex, another member of this compound family, shows complete suppression of the ferroelectric spin-Peierls-type phase transition. PMID:26076656

  10. Diameter dependent electron transfer kinetics in semiconductor-enzyme complexes.

    PubMed

    Brown, Katherine A; Song, Qing; Mulder, David W; King, Paul W

    2014-10-28

    Excited state electron transfer (ET) is a fundamental step for the catalytic conversion of solar energy into chemical energy. To understand the properties controlling ET between photoexcited nanoparticles and catalysts, the ET kinetics were measured for solution-phase complexes of CdTe quantum dots and Clostridium acetobutylicum [FeFe]-hydrogenase I (CaI) using time-resolved photoluminescence spectroscopy. Over a 2.0-3.5 nm diameter range of CdTe nanoparticles, the observed ET rate (kET) was sensitive to CaI concentration. To account for diameter effects on CaI binding, a Langmuir isotherm and two geometric binding models were created to estimate maximal CaI affinities and coverages at saturating concentrations. Normalizing the ET kinetics to CaI surface coverage for each CdTe diameter led to k(ET) values that were insensitive to diameter, despite a decrease in the free energy for photoexcited ET (ΔGET) with increasing diameter. The turnover frequency (TOF) of CaI in CdTe-CaI complexes was measured at several molar ratios. Normalization for diameter-dependent changes in CaI coverage showed an increase in TOF with diameter. These results suggest that k(ET) and H2 production for CdTe-CaI complexes are not strictly controlled by ΔG(ET) and that other factors must be considered.

  11. Quantum ferroelectricity in charge-transfer complex crystals

    NASA Astrophysics Data System (ADS)

    Horiuchi, Sachio; Kobayashi, Kensuke; Kumai, Reiji; Minami, Nao; Kagawa, Fumitaka; Tokura, Yoshinori

    2015-06-01

    Quantum phase transition achieved by fine tuning the continuous phase transition down to zero kelvin is a challenge for solid state science. Critical phenomena distinct from the effects of thermal fluctuations can materialize when the electronic, structural or magnetic long-range order is perturbed by quantum fluctuations between degenerate ground states. Here we have developed chemically pure tetrahalo-p-benzoquinones of n iodine and 4-n bromine substituents (QBr4-nIn, n=0-4) to search for ferroelectric charge-transfer complexes with tetrathiafulvalene (TTF). Among them, TTF-QBr2I2 exhibits a ferroelectric neutral-ionic phase transition, which is continuously controlled over a wide temperature range from near-zero kelvin to room temperature under hydrostatic pressure. Quantum critical behaviour is accompanied by a much larger permittivity than those of other neutral-ionic transition compounds, such as well-known ferroelectric complex of TTF-QCl4 and quantum antiferroelectric of dimethyl-TTF-QBr4. By contrast, TTF-QBr3I complex, another member of this compound family, shows complete suppression of the ferroelectric spin-Peierls-type phase transition.

  12. Quantifying and transferring contextual information in object detection.

    PubMed

    Zheng, Wei-Shi; Gong, Shaogang; Xiang, Tao

    2012-04-01

    Context is critical for reducing the uncertainty in object detection. However, context modeling is challenging because there are often many different types of contextual information coexisting with different degrees of relevance to the detection of target object(s) in different images. It is therefore crucial to devise a context model to automatically quantify and select the most effective contextual information for assisting in detecting the target object. Nevertheless, the diversity of contextual information means that learning a robust context model requires a larger training set than learning the target object appearance model, which may not be available in practice. In this work, a novel context modeling framework is proposed without the need for any prior scene segmentation or context annotation. We formulate a polar geometric context descriptor for representing multiple types of contextual information. In order to quantify context, we propose a new maximum margin context (MMC) model to evaluate and measure the usefulness of contextual information directly and explicitly through a discriminant context inference method. Furthermore, to address the problem of context learning with limited data, we exploit the idea of transfer learning based on the observation that although two categories of objects can have very different visual appearance, there can be similarity in their context and/or the way contextual information helps to distinguish target objects from nontarget objects. To that end, two novel context transfer learning models are proposed which utilize training samples from source object classes to improve the learning of the context model for a target object class based on a joint maximum margin learning framework. Experiments are carried out on PASCAL VOC2005 and VOC2007 data sets, a luggage detection data set extracted from the i-LIDS data set, and a vehicle detection data set extracted from outdoor surveillance footage. Our results validate the

  13. The charge-transfer complex trans-STB-TCNQF4.

    PubMed

    Sato, A; Okada, M; Saito, K; Sorai, M

    2001-05-01

    In the crystal structure of the title charge-transfer complex, namely trans-stilbene-2,2'-(2,3,5,6-tetrafluorobenzene-1,4-diylidene)propanedinitrile (1/1) (trans-STB-TCNQF(4)), C(14)H(12).C(12)F(4)N(4), the planar STB and TCNQF(4) molecules are stacked alternately. The structure is not isostructural with that of STB-TCNQ. No anomaly was found in the displacement parameters of any atoms, while the bond length of the central C=C moiety was shorter than the corresponding bond in ethylene. This suggests that the central C=C moiety of the STB molecule vibrates with a large amplitude, similar to the case in free STB and STB-TCNQ.

  14. Is there an optimal basis to maximise optical information transfer?

    PubMed Central

    Chen, Mingzhou; Dholakia, Kishan; Mazilu, Michael

    2016-01-01

    We establish the concept of the density of the optical degrees of freedom that may be applied to any photonics based system. As a key example of this versatile approach we explore information transfer using optical communication. We demonstrate both experimentally, theoretically and numerically that the use of a basis set with fields containing optical vortices does not increase the telecommunication capacity of an optical system. PMID:26976626

  15. Information transfer satellite concept study. Volume 2: Technical

    NASA Technical Reports Server (NTRS)

    Bergin, P.; Kincade, C.; Kurpiewski, D.; Leinhaupel, F.; Millican, F.; Onstad, R.

    1971-01-01

    The ITS concept study is preceded by two requirements studies whose primary objectives are to identify viable demands and to develop the functional requirements associated with these demands. In addition to continuing this basic activity the ITS concept study objectives are to: (1) develop tools and techniques for planning advanced information transfer satellite communications systems, and to (2) select viable systems for further analysis both in their near-term and in the far-term aspects.

  16. Research Strategy for Modeling the Complexities of Turbine Heat Transfer

    NASA Technical Reports Server (NTRS)

    Simoneau, Robert J.

    1996-01-01

    The subject of this paper is a NASA research program, known as the Coolant Flow Management Program, which focuses on the interaction between the internal coolant channel and the external film cooling of a turbine blade and/or vane in an aircraft gas turbine engine. The turbine gas path is really a very complex flow field. The combination of strong pressure gradients, abrupt geometry changes and intersecting surfaces, viscous forces, rotation, and unsteady blade/vane interactions all combine to offer a formidable challenge. To this, in the high pressure turbine, we add the necessity of film cooling. The ultimate goal of the turbine designer is to maintain or increase the high level of turbine performance and at the same time reduce the amount of coolant flow needed to achieve this end. Simply stated, coolant flow is a penalty on the cycle and reduces engine thermal efficiency. Accordingly, understanding the flow field and heat transfer associated with the coolant flow is a priority goal. It is important to understand both the film cooling and the internal coolant flow, particularly their interaction. Thus, the motivation for the Coolant Flow Management Program. The paper will begin with a brief discussion of the management and research strategy, will then proceed to discuss the current attack from the internal coolant side, and will conclude by looking at the film cooling effort - at all times keeping sight of the primary goal the interaction between the two. One of the themes of this paper is that complex heat transfer problems of this nature cannot be attacked by single researchers or even groups of researchers, each working alone. It truly needs the combined efforts of a well-coordinated team to make an impact. It is important to note that this is a government/industry/university team effort.

  17. Research Strategy for Modeling the Complexities of Turbine Heat Transfer

    SciTech Connect

    Simoneau, R.J.

    1996-03-01

    The subject of this paper is a NASA research program, known as the Coolant Flow Management Program, which focuses on the interaction between the internal coolant channel and the external film cooling of a turbine blade and/or vane in an aircraft gas turbine engine. The turbine gas path is really a very complex flow field. The combination of strong pressure gradients, abrupt geometry changes and intersecting surfaces, viscous forces, rotation, and unsteady blade/vane interactions all combine to offer a formidable challenge. To this, in the high pressure turbine, one adds the necessity of film cooling. The ultimate goal of the turbine designer is to maintain or increase the high level of turbine performance and at the same time reduce the amount of coolant flow needed to achieve this end. Simply stated, coolant flow is a penalty on the cycle and reduces engine thermal efficiency. Accordingly, understanding the flow field and heat transfer associated with the coolant flow is a priority goal. It is important to understand both the film cooling and the internal coolant flow, particularly their interaction. Thus, the motivation for the Coolant Flow Management Program. The paper will begin with a brief discussion of the management and research strategy, will then proceed to discuss the current attack from the internal coolant side, and will conclude by looking at the film cooling effort - at all times keeping sight of the primary goal the interaction between the two. One of the themes of this paper is that complex heat transfer problems of this nature cannot be attacked by single researchers or even groups of researchers, each working alone. It truly needs the combined efforts of a well-coordinated team to make an impact. It is important to note that this is a government/industry/university team effort.

  18. Teacher Modeling Using Complex Informational Texts

    ERIC Educational Resources Information Center

    Fisher, Douglas; Frey, Nancy

    2015-01-01

    Modeling in complex texts requires that teachers analyze the text for factors of qualitative complexity and then design lessons that introduce students to that complexity. In addition, teachers can model the disciplinary nature of content area texts as well as word solving and comprehension strategies. Included is a planning guide for think aloud.

  19. Teacher Modeling Using Complex Informational Texts

    ERIC Educational Resources Information Center

    Fisher, Douglas; Frey, Nancy

    2015-01-01

    Modeling in complex texts requires that teachers analyze the text for factors of qualitative complexity and then design lessons that introduce students to that complexity. In addition, teachers can model the disciplinary nature of content area texts as well as word solving and comprehension strategies. Included is a planning guide for think aloud.

  20. An Information Transfer Model to Define Information Users and Outputs with Specific Application to Environmental Technology.

    ERIC Educational Resources Information Center

    Landau, Herbert B.; And Others

    1982-01-01

    Develops an information transfer model which relates information products to the user's innovation decision-making process and highlights the linkage between specific products and user needs at each decision point. Specific applications to environmental technology are discussed. Three figures, five tables, and a reference list accompany the text.…

  1. International Co-operation and Trends in Social Science Information Transfer.

    ERIC Educational Resources Information Center

    Rozsa, Gyorgy; Foldi, Tamas

    1980-01-01

    Identifies the role and mechanism of information transfer in the social sciences, and surveys selected, significant institutions and organizations (mostly international), which promote such transfer. (RAA)

  2. Information Transfer With Censored Data: Some Large-Sample Results

    NASA Astrophysics Data System (ADS)

    Clarke, Robin T.

    1991-06-01

    This paper presents some new results for the transfer and extension of information at sites with short hydrological records. The results refer particularly to the transfer and extension of annual flood data. The methods described make use of incomplete or "censored" data such as may be supplied by people living near a river or from records collected for nonhydrological purposes, and they constitute extensions to methods already described in the literature. For two specific censoring configurations, the gain in information is assessed analytically; it is shown that, under certain conditions, the gain in information can be substantial, but in general the gain is small, particularly where scale parameters are estimated. For other configurations of censored data, an analytical formulation is not possible, and integrals are given from which information gain may be assessed by numerical calculation. Another result extends the use of flood peaks exceeding some threshold value ("peaks over a threshold," POTs); probabilistic models of flood frequency using POTs are, in effect, fitted using censored data. The value of the results presented in the paper is likely to be restricted by assumptions about the probabilistic structure of flood sequences: in one case that their distribution (at different sites) is bivariate lognormal, and, for the POT model, that floods occur as a Poisson process with POTs exponentially distributed. The results show, in strictly qualitative terms, the circumstances in which information might be gained by the use of censored data at two sites, and how large (or small) the gains might be.

  3. Tech transfer outreach. An informal proceedings of the first technology transfer/communications conference

    SciTech Connect

    Liebetrau, S.

    1992-10-01

    This document provides an informal summary of the conference workshop sessions. ``Tech Transfer Outreach!`` was originally designed as an opportunity for national laboratory communications and technology transfer staff to become better acquainted and to discuss matters of mutual interest. When DOE field office personnel asked if they could attend, and then when one of our keynote speakers became a participant in the discussions, the actual event grew in importance. The conference participants--the laboratories and DOE representatives from across the nation--worked to brainstorm ideas. Their objective: identify ways to cooperate for effective (and cost-effective) technology transfer outreach. Thus, this proceedings is truly a product of ten national laboratories and DOE, working together. It candidly presents the discussion of issues and the ideas generated by each working group. The issues and recommendations are a consensus of their views.

  4. Information transfer and behavioural inertia in starling flocks

    NASA Astrophysics Data System (ADS)

    Attanasi, Alessandro; Cavagna, Andrea; Del Castello, Lorenzo; Giardina, Irene; Grigera, Tomas S.; Jelić, Asja; Melillo, Stefania; Parisi, Leonardo; Pohl, Oliver; Shen, Edward; Viale, Massimiliano

    2014-09-01

    Collective decision-making in biological systems requires all individuals in the group to go through a behavioural change of state. During this transition fast and robust transfer of information is essential to prevent cohesion loss. The mechanism by which natural groups achieve such robustness, however, is not clear. Here we present an experimental study of starling flocks performing collective turns. We find that information about direction changes propagates across the flock with a linear dispersion law and negligible attenuation, hence minimizing group decoherence. These results contrast starkly with present models of collective motion, which predict diffusive transport of information. Building on spontaneous symmetry breaking and conservation-law arguments, we formulate a theory that correctly reproduces linear and undamped propagation. Essential to this framework is the inclusion of the birds' behavioural inertia. The theory not only explains the data, but also predicts that information transfer must be faster the stronger the group's orientational order, a prediction accurately verified by the data. Our results suggest that swift decision-making may be the adaptive drive for the strong behavioural polarization observed in many living groups.

  5. Spatial resolution and information transfer in scanning transmission electron microscopy.

    PubMed

    Peng, Yiping; Oxley, Mark P; Lupini, Andrew R; Chisholm, Matthew F; Pennycook, Stephen J

    2008-02-01

    The relation between image resolution and information transfer is explored. It is shown that the existence of higher frequency transfer in the image is just a necessary but not sufficient condition for the achievement of higher resolution. Adopting a two-point resolution criterion, we suggest that a 10% contrast level between two features in an image should be used as a practical definition of resolution. In the context of scanning transmission electron microscopy, it is shown that the channeling effect does not have a direct connection with image resolution because sharp channeling peaks do not move with the scanning probe. Through a quantitative comparison between experimental image and simulation, a Fourier-space approach is proposed to estimate defocus and sample thickness. The effective atom size in Z-contrast imaging depends on the annular detector's inner angle. Therefore, an optimum angle exists for the highest resolution as a trade-off between reduced atom size and reduced signal with limited information transfer due to noise.

  6. Nonlocal Quantum Information Transfer Without Superluminal Signalling and Communication

    NASA Astrophysics Data System (ADS)

    Walleczek, Jan; Grössing, Gerhard

    2016-09-01

    It is a frequent assumption that—via superluminal information transfers—superluminal signals capable of enabling communication are necessarily exchanged in any quantum theory that posits hidden superluminal influences. However, does the presence of hidden superluminal influences automatically imply superluminal signalling and communication? The non-signalling theorem mediates the apparent conflict between quantum mechanics and the theory of special relativity. However, as a `no-go' theorem there exist two opposing interpretations of the non-signalling constraint: foundational and operational. Concerning Bell's theorem, we argue that Bell employed both interpretations, and that he finally adopted the operational position which is associated often with ontological quantum theory, e.g., de Broglie-Bohm theory. This position we refer to as "effective non-signalling". By contrast, associated with orthodox quantum mechanics is the foundational position referred to here as "axiomatic non-signalling". In search of a decisive communication-theoretic criterion for differentiating between "axiomatic" and "effective" non-signalling, we employ the operational framework offered by Shannon's mathematical theory of communication, whereby we distinguish between Shannon signals and non-Shannon signals. We find that an effective non-signalling theorem represents two sub-theorems: (1) Non-transfer-control (NTC) theorem, and (2) Non-signification-control (NSC) theorem. Employing NTC and NSC theorems, we report that effective, instead of axiomatic, non-signalling is entirely sufficient for prohibiting nonlocal communication. Effective non-signalling prevents the instantaneous, i.e., superluminal, transfer of message-encoded information through the controlled use—by a sender-receiver pair —of informationally-correlated detection events, e.g., in EPR-type experiments. An effective non-signalling theorem allows for nonlocal quantum information transfer yet—at the same time

  7. Information on biotic interactions improves transferability of distribution models.

    PubMed

    Godsoe, William; Murray, Rua; Plank, Michael J

    2015-02-01

    Predicting changes in species' distributions is a crucial problem in ecology, with leading methods relying on information about species' putative climatic requirements. Empirical support for this approach relies on our ability to use observations of a species' distribution in one region to predict its range in other regions (model transferability). On the basis of this observation, ecologists have hypothesized that climate is the strongest determinant of species' distributions at large spatial scales. However, it is difficult to reconcile this claim with the pervasive effects of biotic interactions. Here, we resolve this apparent paradox by demonstrating how biotic interactions can affect species' range margins yet still be compatible with model transferability. We also identify situations where small changes in species' interactions dramatically shift range margins.

  8. Genetic Redundancies Enhance Information Transfer in Noisy Regulatory Circuits

    PubMed Central

    Rodrigo, Guillermo; Poyatos, Juan F.

    2016-01-01

    Cellular decision making is based on regulatory circuits that associate signal thresholds to specific physiological actions. This transmission of information is subjected to molecular noise what can decrease its fidelity. Here, we show instead how such intrinsic noise enhances information transfer in the presence of multiple circuit copies. The result is due to the contribution of noise to the generation of autonomous responses by each copy, which are altogether associated with a common decision. Moreover, factors that correlate the responses of the redundant units (extrinsic noise or regulatory cross-talk) contribute to reduce fidelity, while those that further uncouple them (heterogeneity within the copies) can lead to stronger information gain. Overall, our study emphasizes how the interplay of signal thresholding, redundancy, and noise influences the accuracy of cellular decision making. Understanding this interplay provides a basis to explain collective cell signaling mechanisms, and to engineer robust decisions with noisy genetic circuits. PMID:27741249

  9. Information transfer satellite concept study. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    Bergin, P.; Kincade, C.; Kurpiewski, D.; Leinhaupel, F.; Millican, F.; Onstad, R.

    1971-01-01

    A wide range of information transfer demands were identified and analyzed. They were then combined into an appropriate set of requirements for satellite communication services. In this process the demands were ranked and combined into single and multipurpose satellite systems. A detailed analysis was performed on each satellite system to determine: total system cost, including both ground and space segments; sensitivities of the systems to various system tradeoffs; and forcing functions which control the system variations. A listing of candidate missions for detailed study is presented, along with a description of the conceptual system design and an identification of the technology developments required to bring these systems to fruition.

  10. Controls, Displays, and Information Transfer for General Aviation IFR Operations

    NASA Technical Reports Server (NTRS)

    Bergeron, H. P. (Editor); Shaughnessy, J. D. (Editor)

    1983-01-01

    The purpose of the workshop was to review and evaluate the work performed under the NASA Single Pilot IFR (SPIFR) program, to highlight and disseminate major research findings, and to provide a forum for industry, universities, and government to interact and discuss the future thrust of research in the SPIFR program. The presentations selected represent key elements of the SPIFR program. These elements are classified into five disciplinary areas: program definition, controls, displays, information transfer, and research simulation facilities. Emphasis is also placed on aircraft accident investigation.

  11. Identifying changes in EEG information transfer during drowsy driving by transfer entropy

    PubMed Central

    Huang, Chih-Sheng; Pal, Nikhil R.; Chuang, Chun-Hsiang; Lin, Chin-Teng

    2015-01-01

    Drowsy driving is a major cause of automobile accidents. Previous studies used neuroimaging based approaches such as analysis of electroencephalogram (EEG) activities to understand the brain dynamics of different cortical regions during drowsy driving. However, the coupling between brain regions responding to this vigilance change is still unclear. To have a comprehensive understanding of neural mechanisms underlying drowsy driving, in this study we use transfer entropy, a model-free measure of effective connectivity based on information theory. We investigate the pattern of information transfer between brain regions when the vigilance level, which is derived from the driving performance, changes from alertness to drowsiness. Results show that the couplings between pairs of frontal, central, and parietal areas increased at the intermediate level of vigilance, which suggests that an enhancement of the cortico-cortical interaction is necessary to maintain the task performance and prevent behavioral lapses. Additionally, the occipital-related connectivity magnitudes monotonically decreases as the vigilance level declines, which further supports the cortical gating of sensory stimuli during drowsiness. Neurophysiological evidence of mutual relationships between brain regions measured by transfer entropy might enhance the understanding of cortico-cortical communication during drowsy driving. PMID:26557069

  12. Quantifying the causal strength of multivariate cardiovascular couplings with momentary information transfer.

    PubMed

    Runge, Jakob; Riedl, Maik; Müller, Andreas; Stepan, Holger; Kurths, Jürgen; Wessel, Niels

    2015-04-01

    This article studies a recently introduced information-theoretic approach to detect and quantify the causal couplings in a complex cardiovascular system. In the first step a causal algorithm detects the coupling delays and in the second step the causal strength of each coupling mechanism is quantified using the recently introduced momentary information transfer. As an example, the method is applied to time series of respiration, systolic and diastolic blood pressure, and heart rate of pregnant healthy women and women suffering from pre-eclampsia. A possible explanation for the influence of heart rate on systolic blood pressure is found and some differences between healthy women and patients are discussed.

  13. Coherent Control Protocol for Separating Energy-Transfer Pathways in Photosynthetic Complexes by Chiral Multidimensional Signals†

    PubMed Central

    Abramavicius, Darius; Mukamel, Shaul

    2013-01-01

    Adaptive optimizations performed using a genetic algorithm are employed to construct optimal laser pulse configurations that separate spectroscopic features associated with the two main energy-transfer pathways in the third-order nonlinear optical response simulated for the Fenna–Matthews–Olson (FMO) photosynthetic complex from the green sulfur bacterium Chlorobium tepidum. Superpositions of chirality-induced tensor components in both collinear and noncollinear pulse configurations are analyzed. The optimal signals obtained by manipulating the ratios of various 2D spectral peaks reveal detailed information about the excitation dynamics. PMID:21495702

  14. Electron transfer and catalysis with high-valent metal-oxo complexes.

    PubMed

    Fukuzumi, Shunichi

    2015-04-21

    High-valent metal-oxo complexes are produced by reductive activation of dioxygen via reduction of metal complexes with reductants and dioxygen. Photoinduced electron transfer from substrates to metal complexes with dioxygen also leads to the generation of high-valent metal-oxo complexes that can oxygenate substrates. In such a case metal complexes act as a photocatalyst to oxygenate substrates with dioxygen. High-valent metal-oxo complexes are also produced by proton-coupled electron-transfer oxidation of metal complexes by one-electron oxidants with water, oxygenating substrates to regenerate metal complexes. In such a case metal complexes act as a catalyst for electron-transfer oxygenation of substrates by one-electron oxidants with water that acts as an oxygen source. The one-electron oxidants which can oxidize metal complexes can be replaced by much weaker oxidants by a combination of redox photocatalysts and metal complexes. Thus, photocatalytic oxygenation of substrates proceeds via photoinduced electron transfer from a photocatalyst to reductants followed by proton-coupled electron transfer oxidation of metal complexes with the oxidized photocatalyst to produce high-valent metal-oxo complexes that oxygenate substrates. Thermal and photoinduced electron-transfer catalytic reactions of high-valent metal-oxo complexes for oxygenation of substrates using water or dioxygen as an oxygen source are summarized in this perspective.

  15. Formation of peptide radical ions through dissociative electron transfer in ternary metal-ligand-peptide complexes.

    PubMed

    Chu, Ivan K; Laskin, Julia

    2011-01-01

    The formation and fragmentation of odd-electron ions of peptides and proteins is of interest to applications in biological mass spectrometry. Gas-phase redox chemistry occurring during collision-induced dissociation of ternary metal-ligand-peptide complexes enables the formation of a variety of peptide radicals, including the canonical radical cations, M(+•), radical dications, [M+H](2+•), radical anions, [M-2H](-•) and phosphorylated radical cations. In addition, odd-electron peptide ions with well-defined initial location of the radical site are produced through side-chain losses from the radical ions. Subsequent fragmentation of these species provides information regarding the role of charge and location of the radical site on the competition between radical-induced and proton-driven fragmentation of odd-electron peptide ions. This account summarizes current understanding of the factors that control the efficiency of the intramolecular electron transfer (ET) in ternary metal-ligand-peptide complexes resulting in formation of odd-electron peptide ions. Specifically, we discuss the effect of the metal center, the ligand and the peptide structure on the competition between the ET, proton transfer (PT) and loss of neutral peptide and neutral peptide fragments from the complex. Fundamental studies of the structures, stabilities and the energetics and dynamics of fragmentation of these complexes are also important for detailed molecular-level understanding of photosynthesis and respiration in biological systems.

  16. Cross-modal transfer of statistical information benefits from sleep.

    PubMed

    Durrant, Simon J; Cairney, Scott A; Lewis, Penelope A

    2016-05-01

    Extracting regularities from a sequence of events is essential for understanding our environment. However, there is no consensus regarding the extent to which such regularities can be generalised beyond the modality of learning. One reason for this could be the variation in consolidation intervals used in different paradigms, also including an opportunity to sleep. Using a novel statistical learning paradigm in which structured information is acquired in the auditory domain and tested in the visual domain over either 30 min or 24 h consolidation intervals, we show that cross-modal transfer can occur, but this transfer is only seen in the 24 h group. Importantly, the extent of cross-modal transfer is predicted by the amount of slow wave sleep (SWS) obtained. Additionally, cross-modal transfer is associated with the same pattern of decreasing medial temporal lobe and increasing striatal involvement which has previously been observed to occur across 24 h in unimodal statistical learning. We also observed enhanced functional connectivity after 24 h in a network of areas which have been implicated in cross-modal integration including the precuneus and the middle occipital gyrus. Finally, functional connectivity between the striatum and the precuneus was also enhanced, and this strengthening was predicted by SWS. These results demonstrate that statistical learning can generalise to some extent beyond the modality of acquisition, and together with our previously published unimodal results, support the notion that statistical learning is both domain-general and domain-specific.

  17. Information transfer by exosomes: A new frontier in hematologic malignancies.

    PubMed

    Boyiadzis, Michael; Whiteside, Theresa L

    2015-09-01

    Exosomes are small (30-150 mm) vesicles secreted by all cell types and present in all body fluids. They are emerging as vehicles for delivery of membrane-tethered signaling molecules and membrane enclosed genes to target cells. Exosome-mediated information transfer allows for crosstalk of cells within the hematopoietic system and for interactions between hematopoietic cells and local or distant tissue cells. Exosomes carry physiological signals essential for health and participate in pathological processes, including malignant transformation. In hematologic malignancies, exosomes reprogram the bone marrow microenvironment, creating a niche for abnormal cells and favoring their expansion. The molecular and genetic mechanisms exosomes utilize to shuttle information between cells are currently being examined as are the potential roles exosomes play as biomarkers of disease or future therapeutic targets.

  18. Can complexity science inform physician leadership development?

    PubMed

    Grady, Colleen Marie

    2016-07-04

    Purpose The purpose of this paper is to describe research that examined physician leadership development using complexity science principles. Design/methodology/approach Intensive interviewing of 21 participants and document review provided data regarding physician leadership development in health-care organizations using five principles of complexity science (connectivity, interdependence, feedback, exploration-of-the-space-of-possibilities and co-evolution), which were grouped in three areas of inquiry (relationships between agents, patterns of behaviour and enabling functions). Findings Physician leaders are viewed as critical in the transformation of healthcare and in improving patient outcomes, and yet significant challenges exist that limit their development. Leadership in health care continues to be associated with traditional, linear models, which are incongruent with the behaviour of a complex system, such as health care. Physician leadership development remains a low priority for most health-care organizations, although physicians admit to being limited in their capacity to lead. This research was based on five principles of complexity science and used grounded theory methodology to understand how the behaviours of a complex system can provide data regarding leadership development for physicians. The study demonstrated that there is a strong association between physician leadership and patient outcomes and that organizations play a primary role in supporting the development of physician leaders. Findings indicate that a physician's relationship with their patient and their capacity for innovation can be extended as catalytic behaviours in a complex system. The findings also identified limiting factors that impact physicians who choose to lead, such as reimbursement models that do not place value on leadership and medical education that provides minimal opportunity for leadership skill development. Practical Implications This research provides practical

  19. Securing Information with Complex Optical Encryption Networks

    DTIC Science & Technology

    2015-08-11

    optical setups and principles have been analyzed and sifted for the optical cryptography topology. The combination of different topology types is...feasible to create a new and complex topology type for optical cryptography . (5) A multiple-CCD system has been designed and applied in the...high flexibility and multi- dimensional capabilities. Compared with electronic cryptography , unique characteristics of optical encryption are

  20. Vulnerability Assessment Tools for Complex Information Networks

    DTIC Science & Technology

    2006-11-14

    developed intrusion detection algorithms for two routing protocols: AODV and OLSR . The results showed that our systems can detect most of attacks ...information networks against information-based attack . Accomplishments during the current reporting period are documented in 49 publications and 1 patent...2003. 5. Cassandras, C.G., “Detecting and Reacting to DoS Attacks ”, ARO Grantee Meeting, Cambridge, MA, July 2003. 6. Cassandras, C.G

  1. Intramolecular energy transfer reactions in polymetallic complexes.. Progress report, 1991--1992

    SciTech Connect

    Petersen, J.

    1992-12-01

    (1) Excited-state energy transfer: The major effort was an attempt to sensitize the photoelimination of H{sub 2} from a bimetallic, metal-dihydride complex. These complexes have involved Fe, Ru, and Co complexes. (2) Excited-state electron transfer (charge separation): A series of diad and triad complexes were prepared in order to sustain charge separation in an artificial photosynthetic system.

  2. Complex Dynamics in Information Sharing Networks

    NASA Astrophysics Data System (ADS)

    Cronin, Bruce

    This study examines the roll-out of an electronic knowledge base in a medium-sized professional services firm over a six year period. The efficiency of such implementation is a key business problem in IT systems of this type. Data from usage logs provides the basis for analysis of the dynamic evolution of social networks around the depository during this time. The adoption pattern follows an "s-curve" and usage exhibits something of a power law distribution, both attributable to network effects, and network position is associated with organisational performance on a number of indicators. But periodicity in usage is evident and the usage distribution displays an exponential cut-off. Further analysis provides some evidence of mathematical complexity in the periodicity. Some implications of complex patterns in social network data for research and management are discussed. The study provides a case study demonstrating the utility of the broad methodological approach.

  3. Application of Lattice Boltzmann Methods in Complex Mass Transfer Systems

    NASA Astrophysics Data System (ADS)

    Sun, Ning

    Lattice Boltzmann Method (LBM) is a novel computational fluid dynamics method that can easily handle complex and dynamic boundaries, couple local or interfacial interactions/reactions, and be easily parallelized allowing for simulation of large systems. While most of the current studies in LBM mainly focus on fluid dynamics, however, the inherent power of this method makes it an ideal candidate for the study of mass transfer systems involving complex/dynamic microstructures and local reactions. In this thesis, LBM is introduced to be an alternative computational method for the study of electrochemical energy storage systems (Li-ion batteries (LIBs) and electric double layer capacitors (EDLCs)) and transdermal drug design on mesoscopic scale. Based on traditional LBM, the following in-depth studies have been carried out: (1) For EDLCs, the simulation of diffuse charge dynamics is carried out for both the charge and the discharge processes on 2D systems of complex random electrode geometries (pure random, random spheres and random fibers). Steric effect of concentrated solutions is considered by using modified Poisson-Nernst-Plank (MPNP) equations and compared with regular Poisson-Nernst-Plank (PNP) systems. The effects of electrode microstructures (electrode density, electrode filler morphology, filler size, etc.) on the net charge distribution and charge/discharge time are studied in detail. The influence of applied potential during discharging process is also discussed. (2) For the study of dendrite formation on the anode of LIBs, it is shown that the Lattice Boltzmann model can capture all the experimentally observed features of microstructure evolution at the anode, from smooth to mossy to dendritic. The mechanism of dendrite formation process in mesoscopic scale is discussed in detail and compared with the traditional Sand's time theories. It shows that dendrite formation is closely related to the inhomogeneous reactively at the electrode-electrolyte interface

  4. Information transfer across the scales of climate data variability

    NASA Astrophysics Data System (ADS)

    Palus, Milan; Jajcay, Nikola; Hartman, David; Hlinka, Jaroslav

    2015-04-01

    Multitude of scales characteristic of the climate system variability requires innovative approaches in analysis of instrumental time series. We present a methodology which starts with a wavelet decomposition of a multi-scale signal into quasi-oscillatory modes of a limited band-with, described using their instantaneous phases and amplitudes. Then their statistical associations are tested in order to search for interactions across time scales. In particular, an information-theoretic formulation of the generalized, nonlinear Granger causality is applied together with surrogate data testing methods [1]. The method [2] uncovers causal influence (in the Granger sense) and information transfer from large-scale modes of climate variability with characteristic time scales from years to almost a decade to regional temperature variability on short time scales. In analyses of daily mean surface air temperature from various European locations an information transfer from larger to smaller scales has been observed as the influence of the phase of slow oscillatory phenomena with periods around 7-8 years on amplitudes of the variability characterized by smaller temporal scales from a few months to annual and quasi-biennial scales [3]. In sea surface temperature data from the tropical Pacific area an influence of quasi-oscillatory phenomena with periods around 4-6 years on the variability on and near the annual scale has been observed. This study is supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Program KONTAKT II, Project No. LH14001. [1] M. Palus, M. Vejmelka, Phys. Rev. E 75, 056211 (2007) [2] M. Palus, Entropy 16(10), 5263-5289 (2014) [3] M. Palus, Phys. Rev. Lett. 112, 078702 (2014)

  5. New scaling relation for information transfer in biological networks

    PubMed Central

    Kim, Hyunju; Davies, Paul; Walker, Sara Imari

    2015-01-01

    We quantify characteristics of the informational architecture of two representative biological networks: the Boolean network model for the cell-cycle regulatory network of the fission yeast Schizosaccharomyces pombe (Davidich et al. 2008 PLoS ONE 3, e1672 (doi:10.1371/journal.pone.0001672)) and that of the budding yeast Saccharomyces cerevisiae (Li et al. 2004 Proc. Natl Acad. Sci. USA 101, 4781–4786 (doi:10.1073/pnas.0305937101)). We compare our results for these biological networks with the same analysis performed on ensembles of two different types of random networks: Erdös–Rényi and scale-free. We show that both biological networks share features in common that are not shared by either random network ensemble. In particular, the biological networks in our study process more information than the random networks on average. Both biological networks also exhibit a scaling relation in information transferred between nodes that distinguishes them from random, where the biological networks stand out as distinct even when compared with random networks that share important topological properties, such as degree distribution, with the biological network. We show that the most biologically distinct regime of this scaling relation is associated with a subset of control nodes that regulate the dynamics and function of each respective biological network. Information processing in biological networks is therefore interpreted as an emergent property of topology (causal structure) and dynamics (function). Our results demonstrate quantitatively how the informational architecture of biologically evolved networks can distinguish them from other classes of network architecture that do not share the same informational properties. PMID:26701883

  6. Uses of Color in Complex Information Displays

    DTIC Science & Technology

    1985-02-01

    Information Service database , the Lockheed Dialog System and the Defense File. The principal areas searched were: color perception, color coding, visual...computerized databases were also ident This search was multidisciplinary, covering relevant resea computer graphics, display technologies, human...saturated ones. This is true for all wavelengths, except spectral yellow (Chapanis & Halsey, 1955). While the scientific database remains incomplete

  7. Visual sensory networks and effective information transfer in animal groups.

    PubMed

    Strandburg-Peshkin, Ariana; Twomey, Colin R; Bode, Nikolai W F; Kao, Albert B; Katz, Yael; Ioannou, Christos C; Rosenthal, Sara B; Torney, Colin J; Wu, Hai Shan; Levin, Simon A; Couzin, Iain D

    2013-09-09

    Social transmission of information is vital for many group-living animals, allowing coordination of motion and effective response to complex environments. Revealing the interaction networks underlying information flow within these groups is a central challenge. Previous work has modeled interactions between individuals based directly on their relative spatial positions: each individual is considered to interact with all neighbors within a fixed distance (metric range), a fixed number of nearest neighbors (topological range), a 'shell' of near neighbors (Voronoi range), or some combination (Figure 1A). However, conclusive evidence to support these assumptions is lacking. Here, we employ a novel approach that considers individual movement decisions to be based explicitly on the sensory information available to the organism. In other words, we consider that while spatial relations do inform interactions between individuals, they do so indirectly, through individuals' detection of sensory cues. We reconstruct computationally the visual field of each individual throughout experiments designed to investigate information propagation within fish schools (golden shiners, Notemigonus crysoleucas). Explicitly considering visual sensing allows us to more accurately predict the propagation of behavioral change in these groups during leadership events. Furthermore, we find that structural properties of visual interaction networks differ markedly from those of metric and topological counterparts, suggesting that previous assumptions may not appropriately reflect information flow in animal groups.

  8. Information Access in Complex, Poorly Structured Information Spaces

    DTIC Science & Technology

    1990-02-01

    distributed and made available through News creates a serious information overload. The conceptual framework behind this research effort explores (a...is willing to generate it, whose structure is it?). The innovative system building effort (instantiating the conceptual framework as well as

  9. Energy transfer in photosystem I. Time resolved fluorescence of the native photosystem I complex and its core complex

    NASA Astrophysics Data System (ADS)

    Pålsson, Lars-Olof; Tjus, Staffan E.; Andersson, Bertil; Gillbro, Tomas

    1995-05-01

    Energy transfer within isolated spinach photosystem I (PS I) complexes with different antenna size were studied using time-resolved picosecond and steady-state fluorescence spectroscopy. In both the native PS I complexes and the PS I core complexes lacking the outer chlorophyll a/ b antenna we observed a fast dominating emission component ≈ 35 ps at room temperature which is associated with the trapping process by the reaction centre. In the native PS I complex there also appears a 120 ps component which was not observed in the PS I core complex. This component most likely represents an energy transfer from low energy pigments in the light-harvesting complex I antenna and into the core. Due to a very fast energy equilibration (< 10 ps) it was not possible to resolve the energy transfer at room temperature. At 77 K, however, it was possible to follow the energy transfer from F690 to F720 with a transfer time of ≈ 35 ps within the native PS I complex and slightly longer, 78 ps, in the PS I core complex. The native PS I complex also exhibited in the region 700-740 nm a 102 ps component which originates from F720 and represents energy transfer from F720 to P700 at 77 K. At low temperatures the PS I core complex exhibited a component of 161 ps which is associated with F720 and has the same function as the 102 ps component of the native PS I complex. We conclude that the F720 emission originates from pigments in the core antenna system. This emission also increases at low temperature. In the native PS I complex there is an initial increase in the F720 emission as the temperature is lowered but at 77 K the F735 emission originating from LHC I dominates.

  10. Monitoring interconversion between stereochemical states in single chirality-transfer complexes on a platinum surface

    NASA Astrophysics Data System (ADS)

    Goubert, Guillaume; Dong, Yi; Groves, Michael N.; Lemay, J.-C.; Hammer, Bjørk; McBreen, Peter H.

    2017-06-01

    Elementary steps in enantioselective heterogeneous catalysis take place on the catalyst surface and the targeted synthesis of a desired enantiomer requires the implantation of chiral information at the surface, which can be achieved—for example—by adsorbing chiral molecules. Studies of the structures of complexes formed between adsorbed prochiral reagents and chiral molecules yield information on the forces exerting stereocontrol, but further insight could be gained by studying the dynamics of their interactions. Here, using time-lapsed scanning tunnelling microscopy and density functional theory, we observe coupling between multiple stereochemical states within individual non-covalently bonded chirality-transfer complexes on a metal surface. We identify two modes of transformation between stereochemical states and find that the prochiral reagent can sample several complexation geometries during the lifetime of a complex, switching between states of opposing prochirality in the process. These results provide insight on the contribution of individual stereochemical states to the overall enantioselectivity of reactions occurring on catalyst surfaces.

  11. Information transfer by electromagnetic waves in cortex layers.

    PubMed

    Triffet, T; Green, H S

    1988-03-21

    Coupling coefficients are derived for the transfer of energy from an electromagnetic wave propagating in the extracellular fluid of a cortex layer, using an ion dynamical model developed earlier (Green & Triffet, 1985). With the assistance of a simple computational algorithm, these are used to document the performance of a basic neural circuit (Eccles, 1979) embedded in a columnar structure of the type described by Mountcastle (1979). Results point to a holographic model of memory, in which calcium configurations in the dendrites of cerebellar granular cells, fixed by modulated alpha-waves, constitute the basic information storage mechanism. Event-related potential waves, known to sweep over selective regions of the cortex in advance of any muscular act, are explained as a logical consequence of circuit function.

  12. Conditions for Lorentz-invariant superluminal information transfer without signaling

    NASA Astrophysics Data System (ADS)

    Grössing, G.; Fussy, S.; Mesa Pascasio, J.; Schwabl, H.

    2016-03-01

    We understand emergent quantum mechanics in the sense that quantum mechanics describes processes of physical emergence relating an assumed sub-quantum physics to macroscopic boundary conditions. The latter can be shown to entail top-down causation, in addition to usual bottom-up scenarios. With this example it is demonstrated that definitions of “realism” in the literature are simply too restrictive. A prevailing manner to define realism in quantum mechanics is in terms of pre-determination independent of the measurement. With our counter-example, which actually is ubiquitous in emergent, or self-organizing, systems, we argue for realism without pre-determination. We refer to earlier results of our group showing how the guiding equation of the de Broglie-Bohm interpretation can be derived from a theory with classical ingredients only. Essentially, this corresponds to a “quantum mechanics without wave functions” in ordinary 3-space, albeit with nonlocal correlations. This, then, leads to the central question of how to deal with the nonlocality problem in a relativistic setting. We here show that a basic argument discussing the allegedly paradox time ordering of events in EPR-type two-particle experiments falls short of taking into account the contextuality of the experimental setup. Consequently, we then discuss under which circumstances (i.e. physical premises) superluminal information transfer (but not signaling) may be compatible with a Lorentz-invariant theory. Finally, we argue that the impossibility of superluminal signaling - despite the presence of superluminal information transfer - is not the result of some sort of conspiracy (á la “Nature likes to hide”), but the consequence of the impossibility to exactly reproduce in repeated experimental runs a state's preparation, or of the no-cloning theorem, respectively.

  13. Complex learning and information processing by pigeons: a critical analysis

    PubMed Central

    Carter, David E.; Werner, Thomas J.

    1978-01-01

    Three models of conditional discrimination learning by pigeons are described: stimulus configuration learning, the multiple-rule model, and concept learning. A review of the literature reveals that true concept learning is not characteristic of the behavior of pigeons in matching-to-sample, oddity-from-sample, or symbolic matching studies. Instead, pigeons learn a set of sample-specific SD rules. Transfer of the discrimination to novel stimuli, at least along the hue dimension, is predicted by a “coding hypothesis”, which holds that pigeons make a unique, but usually unobserved response, R1, to each sample, and that the comparison stimulus chosen depends on which R1 was emitted in the presence of the sample. Convincing evidence is found that pigeons do code sample hues, but there is little evidence that allows one to infer that the “coding event” must have behavioral properties. Parameters of the conditional discrimination paradigm are identified, and it is shown that by appropriate parametric manipulation, a variety of analogous tasks may be generated for both human and animal subjects. The tasks make possible the comparative study of complex learning, attention, memory, and information processing, with the added advantage that behavior processes may be compared systematically across tasks. PMID:16812079

  14. Architecture of complex I and its implications for electron transfer and proton pumping.

    PubMed

    Zickermann, Volker; Kerscher, Stefan; Zwicker, Klaus; Tocilescu, Maja A; Radermacher, Michael; Brandt, Ulrich

    2009-06-01

    Proton pumping NADH:ubiquinone oxidoreductase (complex I) is the largest and remains by far the least understood enzyme complex of the respiratory chain. It consists of a peripheral arm harbouring all known redox active prosthetic groups and a membrane arm with a yet unknown number of proton translocation sites. The ubiquinone reduction site close to iron-sulfur cluster N2 at the interface of the 49-kDa and PSST subunits has been mapped by extensive site directed mutagenesis. Independent lines of evidence identified electron transfer events during reduction of ubiquinone to be associated with the potential drop that generates the full driving force for proton translocation with a 4H(+)/2e(-) stoichiometry. Electron microscopic analysis of immuno-labelled native enzyme and of a subcomplex lacking the electron input module indicated a distance of 35-60 A of cluster N2 to the membrane surface. Resolution of the membrane arm into subcomplexes showed that even the distal part harbours subunits that are prime candidates to participate in proton translocation because they are homologous to sodium/proton antiporters and contain conserved charged residues in predicted transmembrane helices. The mechanism of redox linked proton translocation by complex I is largely unknown but has to include steps where energy is transmitted over extremely long distances. In this review we compile the available structural information on complex I and discuss implications for complex I function.

  15. Architecture of complex I and its implications for electron transfer and proton pumping

    PubMed Central

    Zickermann, Volker; Kerscher, Stefan; Zwicker, Klaus; Tocilescu, Maja A.; Radermacher, Michael; Brandt, Ulrich

    2009-01-01

    Proton pumping NADH:ubiquinone oxidoreductase (complex I) is the largest and remains by far the least understood enzyme complex of the respiratory chain. It consists of a peripheral arm harbouring all known redox active prosthetic groups and a membrane arm with a yet unknown number of proton translocation sites. The ubiquinone reduction site close to iron-sulfur cluster N2 at the interface of the 49-kDa and PSST subunits has been mapped by extensive site directed mutagenesis. Independent lines of evidence identified electron transfer events during reduction of ubiquinone to be associated with the potential drop that generates the full driving force for proton translocation with a 4 H+/2e− stoichiometry. Electron microscopic analysis of immuno-labelled native enzyme and of a subcomplex lacking the electron input module indicated a distance of 35–60 Å of cluster N2 to the membrane surface. Resolution of the membrane arm into subcomplexes showed that even the distal part harbours subunits that are prime candidates to participate in proton translocation because they are homologous to sodium/proton antiporters and contain conserved charged residues in predicted transmembrane helices. The mechanism of redox linked proton translocation by complex I is largely unknown but has to include steps where energy is transmitted over extremely long distances. In this review we compile the available structural information on complex I and discuss implications for complex I function. PMID:19366614

  16. Using social media to facilitate knowledge transfer in complex engineering environments: a primer for educators

    NASA Astrophysics Data System (ADS)

    Murphy, Glen; Salomone, Sonia

    2013-03-01

    While highly cohesive groups are potentially advantageous they are also often correlated with the emergence of knowledge and information silos based around those same functional or occupational clusters. Consequently, an essential challenge for engineering organisations wishing to overcome informational silos is to implement mechanisms that facilitate, encourage and sustain interactions between otherwise disconnected groups. This paper acts as a primer for those seeking to gain an understanding of the design, functionality and utility of a suite of software tools generically termed social media technologies in the context of optimising the management of tacit engineering knowledge. Underpinned by knowledge management theory and using detailed case examples, this paper explores how social media technologies achieve such goals, allowing for the transfer of knowledge by tapping into the tacit and explicit knowledge of disparate groups in complex engineering environments.

  17. Electron Transfer Studies of Ruthenium(II) Complexes with Biologically Important Phenolic Acids and Tyrosine.

    PubMed

    Rajeswari, Angusamy; Ramdass, Arumugam; Muthu Mareeswaran, Paulpandian; Rajagopal, Seenivasan

    2016-03-01

    The ruthenium(II) complexes having 2,2'-bipyridine and phenanthroline derivatives are synthesized and characterized. The photophysical properties of these complexes at pH 12.5 are studied. The electron transfer reaction of biologically important phenolic acids and tyrosine are studied using absorption, emission and transient absorption spectral techniques. Semiclassical theory is applied to calculate the rate of electron transfer between ruthenium(II) complexes and biologically important phenolic acids.

  18. The origin and dynamic evolution of chemical information transfer

    PubMed Central

    Steiger, Sandra; Schmitt, Thomas; Schaefer, H. Martin

    2011-01-01

    Although chemical communication is the most widespread form of communication, its evolution and diversity are not well understood. By integrating studies of a wide range of terrestrial plants and animals, we show that many chemicals are emitted, which can unintentionally provide information (cues) and, therefore, act as direct precursors for the evolution of intentional communication (signals). Depending on the content, design and the original function of the cue, there are predictable ways that selection can enhance the communicative function of chemicals. We review recent progress on how efficacy-based selection by receivers leads to distinct evolutionary trajectories of chemical communication. Because the original function of a cue may channel but also constrain the evolution of functional communication, we show that a broad perspective on multiple selective pressures acting upon chemicals provides important insights into the origin and dynamic evolution of chemical information transfer. Finally, we argue that integrating chemical ecology into communication theory may significantly enhance our understanding of the evolution, the design and the content of signals in general. PMID:21177681

  19. 77 FR 12840 - Federal Supply Service; Information Collection; Standard Form (SF) 123, Transfer Order-Surplus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-02

    ... ADMINISTRATION Federal Supply Service; Information Collection; Standard Form (SF) 123, Transfer Order-Surplus... regarding Standard Form (SF) 123, transfer order-surplus personal property and continuation sheet. Public... Information Collection 3090- 0014, Standard Form (SF) 123, Transfer Order--Surplus Personal Property and...

  20. 77 FR 3487 - Agency Information Collection Activities: Transfer of Cargo to a Container Station

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-24

    ... Information Collection Activities: Transfer of Cargo to a Container Station AGENCY: U.S. Customs and Border... information collection requirement concerning Transfer of Cargo to a Container Station. This request for...: Title: Transfer of Cargo to a Container Station. OMB Number: 1651-0096. Form Number: None....

  1. Describing the complexity of systems: multivariable "set complexity" and the information basis of systems biology.

    PubMed

    Galas, David J; Sakhanenko, Nikita A; Skupin, Alexander; Ignac, Tomasz

    2014-02-01

    Context dependence is central to the description of complexity. Keying on the pairwise definition of "set complexity," we use an information theory approach to formulate general measures of systems complexity. We examine the properties of multivariable dependency starting with the concept of interaction information. We then present a new measure for unbiased detection of multivariable dependency, "differential interaction information." This quantity for two variables reduces to the pairwise "set complexity" previously proposed as a context-dependent measure of information in biological systems. We generalize it here to an arbitrary number of variables. Critical limiting properties of the "differential interaction information" are key to the generalization. This measure extends previous ideas about biological information and provides a more sophisticated basis for the study of complexity. The properties of "differential interaction information" also suggest new approaches to data analysis. Given a data set of system measurements, differential interaction information can provide a measure of collective dependence, which can be represented in hypergraphs describing complex system interaction patterns. We investigate this kind of analysis using simulated data sets. The conjoining of a generalized set complexity measure, multivariable dependency analysis, and hypergraphs is our central result. While our focus is on complex biological systems, our results are applicable to any complex system.

  2. Transfer of Declarative Knowledge in Complex Information-Processing Domains.

    ERIC Educational Resources Information Center

    Harvey, Leon; Anderson, John

    1996-01-01

    Two experiments tested the hypothesis that subjects introduced to a first programming language develop a representation of basic programming concepts that help them integrate new declarative knowledge from a second programming language. The effect on reading was greater for pages that were conceptually close across texts and for subjects who had…

  3. Conducting molecular nanostructures assembled from charge-transfer complexes grafted onto silicon surfaces

    NASA Astrophysics Data System (ADS)

    Stires, John C., IV; Kasibhatla, Bala S. T.; Siegel, Dustin S.; Kwong, Jinny C.; Caballero, Jonathan B.; Labonte, Andre P.; Reifenberger, Ronald G.; Datta, Supriyo; Kubiak, Clifford P.

    2003-12-01

    Heterodimeric electon-donor/electron-acceptor charge-transfer complexes chemisorbed onto Au(111) by attachment of the electron-donor to the surface have been characterized by scanning tunneling microscopy and Kelvin probe experiments. Conductance measurements exhibit nearly Ohmic I(V) responses at low bias. The electrical properties of the charge-transfer complex are vastly different than those of the electron-donor alone which exhibits insulating behavior at low bias. In an extension of this work, strategies are being developed for attachment of charge-transfer complexes to semiconducting or insulating surfaces. Fabrication of nanoscale molecular electronic devices is being investigated by attaching one component of a charge-transfer complex to a silicon surface by chemically directed self-assembly. The single component-functionalized surface is then used as a substrate on which the second component of the charge-transfer complex is deposited by the atomic force microscopy method, dip-pen nanolithography (DPN). Derivatives of hexamethylbenze (electron-donor) with terminal olefins attached to crystalline silicon surfaces via hydrosilylation form monolayer-functionalized silicon surfaces that are expected to have insulating properties. Well-defined features can be "drawn" onto the donor-functionalized surfaces by DPN using tetracyanoethylene (electron-acceptor) as the "ink." The resulting charge-transfer complex nanostructures have conducting properties suitable for device function and are flanked by an insulating monolayer, thus creating "wires" made from charge-transfer complexes.

  4. Transfer of Learning: From Physical Models to Understanding Complex Phenomena*

    NASA Astrophysics Data System (ADS)

    Aryal, Bijaya; Zollman, D. A.

    2006-12-01

    This study describes the student associations made in order to understand the application of physics to a medical imaging technology positron emission tomography. We define this association as the transfer of learning. The physical models, which have a functional resemblance to portions of the positron emission tomography (PET) process, were introduced to the students without any mention of PET during a teaching session. After a hiatus of a few days they attended another session where PET was briefly mentioned to them. Immediately after that they were asked questions that involved the application of physics ideas underlying the model to describe the PET process. Results of this study indicate that physical models are useful in this transfer of learning. We also observed facilitation in transferring ideas from the models to the problem through peer interaction. *Supported by the National Science Foundation under grant 04-2675.

  5. Spectrophotometric study of the charge-transfer complexes of iodine with antipyrine in organic solvents

    NASA Astrophysics Data System (ADS)

    Hasani, Masoumeh; Rezaei, Alireza

    2006-12-01

    The charge-transfer complex formation of iodine with antipyrine has been studied spectrophotometrically in chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solutions at 25 °C. The results indicate the formation of 1:1 charge-transfer complexes. The observed time dependence of the charge-transfer band and subsequent formation of I 3- in solution were related to the slow transformation of the initially formed 1:1 antipyrine:I 2 outer complex to an inner electron donor-acceptor (EDA) complex, followed by fast reaction of the inner complex with iodine to form a triiodide ion. The values of the equilibrium constant, K, are calculated for each complex and the influence of the solvent properties on the formation of EDA complexes and the rates of subsequent reaction is evaluated.

  6. Spectrophotometric study of the charge-transfer complexes of iodine with antipyrine in organic solvents.

    PubMed

    Hasani, Masoumeh; Rezaei, Alireza

    2006-12-01

    The charge-transfer complex formation of iodine with antipyrine has been studied spectrophotometrically in chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solutions at 25 degrees C. The results indicate the formation of 1:1 charge-transfer complexes. The observed time dependence of the charge-transfer band and subsequent formation of I(3)(-) in solution were related to the slow transformation of the initially formed 1:1 antipyrine:I(2) outer complex to an inner electron donor-acceptor (EDA) complex, followed by fast reaction of the inner complex with iodine to form a triiodide ion. The values of the equilibrium constant, K, are calculated for each complex and the influence of the solvent properties on the formation of EDA complexes and the rates of subsequent reaction is evaluated.

  7. 78 FR 26113 - Information Collection Renewal; Comment Request; Transfer Agent Registration and Amendment Form

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ... Renewal; Comment Request; Transfer Agent Registration and Amendment Form AGENCIES: Office of the... currently valid Office of Management and Budget (OMB) control number. The OCC and FDIC are soliciting comment concerning renewal of its information collection titled, ``Transfer Agent Registration...

  8. Spectrophotometric study of the charge transfer complex between 2-amino-4-picoline with chloranilic acid

    NASA Astrophysics Data System (ADS)

    Alghanmi, Reem M.; Al-Attas, Amirah S.; Habeeb, Moustafa M.

    2013-02-01

    Charge transfer complex formation between 2-amino-4-picoline (2A4P) as the electron donor with chloranilic acid (CLA) as the electron acceptor has been studied spectrophotometrically in different polar solvents included acetone (AcN), ethanol (EtOH) and acetonitrile (AN). The molecular composition of the formed complex was recognized utilizing Job's, photometric and conductometric titration methods to be 1:1. The formation constants and molecular extinction coefficients were estimated using Benesi-Hildebrand equation; they recorded high values confirming high stability of the formed complex. Moreover, the results showed that the complex is more stable in acetone with lower electric permittivity compared with ethanol or acetonitrile of higher ones. The values of some spectroscopic physical parameters like oscillator strength f, transition dipole moment μ, resonance energy RN, charge transfer energy ECT, dissociation energy W, ionization potential IP and standard free energy ΔGo were determined and evaluated. The solid complex was isolated and its molecular composition was determined by elemental analysis to be 1:1. Furthermore, the solid complex was characterized using FTIR and 1H NMR measurements. They confirmed the presence of proton transfer beside charge transfer in the obtained complex. Molecular orbital calculations utilizing GAMESS computations were carried out to predict infrared spectra. They also confirmed the presence of proton transfer beside charge transfer in the formed complex.

  9. Integrated information storage and transfer with a coherent magnetic device

    PubMed Central

    Jia, Ning; Banchi, Leonardo; Bayat, Abolfazl; Dong, Guangjiong; Bose, Sougato

    2015-01-01

    Quantum systems are inherently dissipation-less, making them excellent candidates even for classical information processing. We propose to use an array of large-spin quantum magnets for realizing a device which has two modes of operation: memory and data-bus. While the weakly interacting low-energy levels are used as memory to store classical information (bits), the high-energy levels strongly interact with neighboring magnets and mediate the spatial movement of information through quantum dynamics. Despite the fact that memory and data-bus require different features, which are usually prerogative of different physical systems – well isolation for the memory cells, and strong interactions for the transmission – our proposal avoids the notorious complexity of hybrid structures. The proposed mechanism can be realized with different setups. We specifically show that molecular magnets, as the most promising technology, can implement hundreds of operations within their coherence time, while adatoms on surfaces probed by a scanning tunneling microscope is a future possibility. PMID:26347152

  10. Cognitive Complexity as a Determinant of Information Processing

    ERIC Educational Resources Information Center

    Stewin, L.; Anderson, C. C.

    1974-01-01

    Relationships between cognitive complexity as defined by the ITI [Interpersonal Topical Inventory (Tuckman, 1966) and the CST [Conceptual Systems Test (Harvey, 1967)] and a number of other information processing variables were examined using 107 grade eleven students. (Editor)

  11. Operational test report for 2706-T complex liquid transfer system

    SciTech Connect

    BENZEL, H.R.

    1999-09-01

    This document is the Operational Test Report (OTR). It enters the Record Copy of the W-259 Operational Test Procedure (HNF-3610) into the document retrieval system. Additionally, the OTR summarizes significant issues associated with testing the 2706-T waste liquid transfer and storage system.

  12. Methods of information theory and algorithmic complexity for network biology.

    PubMed

    Zenil, Hector; Kiani, Narsis A; Tegnér, Jesper

    2016-03-01

    We survey and introduce concepts and tools located at the intersection of information theory and network biology. We show that Shannon's information entropy, compressibility and algorithmic complexity quantify different local and global aspects of synthetic and biological data. We show examples such as the emergence of giant components in Erdös-Rényi random graphs, and the recovery of topological properties from numerical kinetic properties simulating gene expression data. We provide exact theoretical calculations, numerical approximations and error estimations of entropy, algorithmic probability and Kolmogorov complexity for different types of graphs, characterizing their variant and invariant properties. We introduce formal definitions of complexity for both labeled and unlabeled graphs and prove that the Kolmogorov complexity of a labeled graph is a good approximation of its unlabeled Kolmogorov complexity and thus a robust definition of graph complexity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Photochemistry between a ruthenium(II) pyridylimidazole complex and benzoquinone: simple electron transfer versus proton-coupled electron transfer.

    PubMed

    Hönes, Roland; Kuss-Petermann, Martin; Wenger, Oliver S

    2013-02-01

    A ruthenium(II) complex with two 4,4'-bis(trifluoromethyl)-2,2'-bipyridine chelates and a 2-(2'-pyridyl)imidazole ligand was synthesized and characterized by electrochemical and optical spectroscopic means. The respective complex has the potential to act as a combined electron-proton donor when promoted to its long-lived (3)MLCT excited state with visible light. The possibility of proton-coupled electron transfer (PCET) between the ruthenium(II) complex and 1,4-benzoquinone as an electron/proton acceptor was explored by steady-state and time-resolved luminescence spectroscopy, as well as by transient absorption spectroscopy in the nanosecond time regime. Excited-state deactivation is found to occur predominantly via simple oxidative quenching involving no proton motion, but a minor fraction of the photoexcited complex appears to react via PCET since there is spectral evidence for semiquinone as a photoproduct. Presumably, PCET is not kinetically competitive with simple electron transfer because the latter process is sufficiently exergonic and because there is little thermodynamic benefit from coupling proton transfer to the photoinduced electron transfer.

  14. Electron Transfer Reactivity on Novel Dirhenium and Dirhodium Tetraazaannulene Complexes.

    DTIC Science & Technology

    1980-01-01

    cyclic voltammetry and differential pulse polarography. Potentials are reported for the electrochemcial generation of pi cation and pi anion radicals of these complexes in the solvents dichloromethane and dimethylformamide. The potential differences between the pi radical reactions of the metallomacrocyclic complexes were compared to the potential differences of the pi radical reactions of the free macrocycles.

  15. On the complexity and the information content of cosmic structures

    NASA Astrophysics Data System (ADS)

    Vazza, F.

    2017-03-01

    The emergence of cosmic structure is commonly considered one of the most complex phenomena in nature. However, this complexity has never been defined nor measured in a quantitative and objective way. In this work, we propose a method to measure the information content of cosmic structure and to quantify the complexity that emerges from it, based on Information Theory. The emergence of complex evolutionary patterns is studied with a statistical symbolic analysis of the datastream produced by state-of-the-art cosmological simulations of forming galaxy clusters. This powerful approach allows us to measure how many bits of information is necessary to predict the evolution of energy fields in a statistical way, and it offers a simple way to quantify when, where and how the cosmic gas behaves in complex ways. The most complex behaviours are found in the peripheral regions of galaxy clusters, where supersonic flows drive shocks and large energy fluctuations over a few tens of million years. Describing the evolution of magnetic energy requires at least twice as large amount of bits as required for the other energy fields. When radiative cooling and feedback from galaxy formation are considered, the cosmic gas is overall found to double its degree of complexity. In the future, Cosmic Information Theory can significantly increase our understanding of the emergence of cosmic structure as it represents an innovative framework to design and analyse complex simulations of the Universe in a simple, yet powerful way.

  16. From charge transfer to electron transfer in halogen-bonded complexes of electrophilic bromocarbons with halide anions.

    PubMed

    Rosokha, Sergiy V; Traversa, Alfredo

    2015-02-21

    Experimental and computational studies of the halogen-bonded complexes, [R-Br, X(-)], of bromosubstituted electrophiles, R-Br, and halide anions, X(-), revealed that decrease of a gap between the frontier orbitals of interacting species led to reduction of the energy of the optical charge-transfer transition and to increase in the ground-state charge transfer (X(-) → R-Br) in their associates. These variations were accompanied by weakening of the intramolecular, C-Br, and strengthening of the intermolecular, BrX(-), bonds. In the limit of the strongest electron donor-acceptor pairs, formation of the halogen-bonded complexes was followed by the oxidation of iodide to triiodide, which took place despite the fact that the I(-) → R-Br electron-transfer step was highly endergonic and the calculated outer-sphere rate constant was negligibly small. However, the calculated barrier for the inner-sphere electron transfer accompanied by the halogen transfer, R-BrI(-) → R˙Br-I(-)˙, was nearly 24 kcal mol(-1) lower as compared to that calculated for the outer-sphere process and the rate constant of such reaction was consistent with the experimental kinetics. A dramatic decrease of the electron-transfer barriers (leading to 18-orders of magnitude increase of the rate constant) was related to the strong electronic coupling of the donor and acceptor within the halogen-bonded precursor complex, as well as to the lower solvent reorganization energy and the successor-complex stabilization.

  17. Effective transfer of geographic information system (GIS) technology: An overview

    NASA Astrophysics Data System (ADS)

    Wardell, Glenn; Scharfen, Greg

    1993-08-01

    Despite the remarkable growth and dissemination of GIS technology in the past decate, barriers yet remain to the full and effective application of the technology by scientific entities. This paper will broadly survey the literature and comment on issues germane to the transfer of GIS technology within and among governmental agencies, universities, and other research organizations. An intellectual framework established by formal education in geography has aided in identifying potential uses for GIS. More widespread inclusion of geographic principles into higher education curricula, using GIS as a tool for demonstration and experimentation, will be suggested. Seminars and demonstrations are useful to spark interest in GIS, but unless material learned can be directly applied to current work, they are not of lasting value. Graphical user interfaces lift GIS from the realm of programmers and put analysis capabilities into the hands of researchers and decision makers. Factors relating to cost must always be dealt with. We have found that an appropriate pilot project is a means by which risks can be minimized while capabilities of the technology can be proven in an operational setting. Technology is not an end in itself, but a means to engender human productivity and creativity; GIS provides a unified mechanism by which to visualize and manage information on the various processes within the earth's environment. Assimilation of GIS technology by the international earth science community will undoubtedly encourage multidisciplinary cooperation.

  18. Software design to facilitate information transfer at hospital discharge.

    PubMed

    Nace, G Stephen; Graumlich, James F; Aldag, Jean C

    2006-01-01

    Discharge communication between inpatient and outpatient physicians is often an inefficient and error-prone process. Adverse events result from poor communication at the time of discharge. The objective of this study was to describe development of discharge software to overcome communication barriers. The secondary objective was to assess factors that influence the time to complete tasks with the software. Methods were a performance improvement model and database analysis of 336 discharges. Software design specifications included computerised physician order entry, immediate utility, minimal development and deployment costs, acceptability to physician-users, and satisfaction of primary care physicians, patients and pharmacists. Design features included simple 'just-in-time' prompts and point-of-care prescribing resources. The dependent variable for analysis was physician time to complete discharge prescriptions and instructions while using the software. General linear and mixed-effects regression models adjusted for physician effects and other predictors. Results revealed that physician factors significantly affected the time to complete a discharge while using the software. As the number of accesses (log-ins) and free text typing increased, then time to complete the computerised discharge increased. Patient-related factors that increased physician time were discharge diagnoses, prescriptions and length of stay. In conclusion, discharge software can help inpatient physicians transfer timely, complete and legible information to outpatient physicians, pharmacists and patients. Physician and patient factors influence the time to complete discharges using the software.

  19. Evaporative Mass Transfer Behavior of a Complex Immiscible Liquid

    PubMed Central

    McColl, Colleen M.; Johnson, Gwynn R.; Brusseau, Mark L.

    2010-01-01

    A series of laboratory experiments was conducted with a multiple-component immiscible liquid, collected from the Picillo Farm Superfund Site in Rhode Island, to examine liquid-vapor mass-transfer behavior. The immiscible liquid, which comprises solvents, oils, pesticides, PCBs, paint sludges, explosives, and other compounds, was characterized using gas chromatography and gas chromatography/mass spectrometry to determine mole fractions of selected constituents. Batch experiments were conducted to evaluate equilibrium phase-partitioning behavior. Two sets of air-stripping column studies were conducted to examine the mass-transfer dynamics of five selected target compounds present in the immiscible-liquid mixture. One set of column experiments was designed to represent a system with free-phase immiscible liquid present; the other was designed to represent a system with a residual phase of immiscible liquid. Initial elution behavior of all target components generally appeared to be ideal for both systems, as the initial vapor-phase concentrations were similar to vapor-phase concentrations measured for the batch experiment and those estimated using Raoult’s law (incorporating the immiscible-liquid composition data). Later-stage removal of 1,2-dichlorobenzene appeared to be rate limited for the columns containing free-phase immiscible liquid and no porous medium. Conversely, evaporative mass transfer appeared to be ideal throughout the experiment conducted with immiscible liquid distributed relatively uniformly as a residual phase within a sandy porous medium. PMID:18614196

  20. Evaporative mass transfer behavior of a complex immiscible liquid.

    PubMed

    McColl, Colleen M; Johnson, Gwynn R; Brusseau, Mark L

    2008-09-01

    A series of laboratory experiments was conducted with a multiple-component immiscible liquid, collected from the Picillo Farm Superfund Site in Rhode Island, to examine liquid-vapor mass-transfer behavior. The immiscible liquid, which comprises solvents, oils, pesticides, PCBs, paint sludges, explosives, and other compounds, was characterized using gas chromatography and gas chromatography/mass spectrometry to determine mole fractions of selected constituents. Batch experiments were conducted to evaluate equilibrium phase-partitioning behavior. Two sets of air-stripping column studies were conducted to examine the mass-transfer dynamics of five selected target compounds present in the immiscible-liquid mixture. One set of column experiments was designed to represent a system with free-phase immiscible liquid present; the other was designed to represent a system with a residual phase of immiscible liquid. Initial elution behavior of all target components generally appeared to be ideal for both systems, as the initial vapor-phase concentrations were similar to vapor-phase concentrations measured for the batch experiment and those estimated using Raoult's law (incorporating the immiscible-liquid composition data). Later-stage removal of 1,2-dichlorobenzene appeared to be rate limited for the columns containing free-phase immiscible liquid and no porous medium. Conversely, evaporative mass transfer appeared to be ideal throughout the experiment conducted with immiscible liquid distributed relatively uniformly as a residual phase within a sandy porous medium.

  1. Energy and Information Transfer Via Coherent Exciton Wave Packets

    NASA Astrophysics Data System (ADS)

    Zang, Xiaoning

    associated excitations were dubbed twisted excitons. Twisted exciton packets can be manipulated as they travel down molecular chains, and this has applications in quantum information science as well. In each setting considered, exciton dynamics were initially studied using a simple tight-binding formalism. This misses the actual many-body interactions and multiple energy levels associated real systems. To remedy this, I adapted an existing time-domain Density Functional Theory code and applied it to study the dynamics of exciton wave packets on quasi-one-dimensional systems. This required the use of high-performance computing and the construction of a number of key auxiliary codes. Establishing the requisite methodology constituted a substantial part of the entire thesis. Surprisingly, this effort uncovered a computational issue associated with Rabi oscillations that had been incorrectly characterized in the literature. My research elucidated the actual problem and a solution was found. This new methodology was an integral part of the overall computational analysis. The thesis then takes up the a detailed consideration of the prospect for creating systems that support a strong measure of transport coherence. While physical implementations include molecular assemblies, solid-state superlattices, and even optical lattices, I decided to focus on assemblies of nanometer-sized silicon quantum dots. First principles computational analysis was used to quantify reorganization within individual dots and excitonic coupling between dots. Quantum dot functionalizations were identified that make it plausible to maintain a measure of excitonic coherence even at room temperatures. Attention was then turned to the use of covalently bonded bridge material to join quantum dots in a way that facilitates efficient exciton transfer. Both carbon and silicon structures were considered by considering the way in which subunits might be best brought together. This resulted in a set of design criteria

  2. Overcoming the Superprincipal Complex: Shared and Informed Decision Making.

    ERIC Educational Resources Information Center

    Chamley, John D.; And Others

    1992-01-01

    To overcome the superprincipal complex, principals must become expert in processing information and making decisions. To make informed decisions most effectively, principals should employ participatory management, become process consultants, and incorporate the Situation-Target-Proposal (STP) method for resolving problems. Otherwise, change will…

  3. Measurement of Information-Based Complexity in Listening.

    ERIC Educational Resources Information Center

    Bishop, Walton B.

    When people say that what they hear is "over their heads," they are describing a severe information-based complexity (I-BC) problem. They cannot understand what is said because some of the information needed is missing, contaminated, and/or costly to obtain. Students often face these I-BC problems, and teachers often exacerbate them. Yet…

  4. Overcoming the Superprincipal Complex: Shared and Informed Decision Making.

    ERIC Educational Resources Information Center

    Chamley, John D.; And Others

    1992-01-01

    To overcome the superprincipal complex, principals must become expert in processing information and making decisions. To make informed decisions most effectively, principals should employ participatory management, become process consultants, and incorporate the Situation-Target-Proposal (STP) method for resolving problems. Otherwise, change will…

  5. MA-9 ASTRONAUT L. GORDON COOPER LEAVES TRANSFER VAN AT LAUNCH COMPLEX 14

    NASA Technical Reports Server (NTRS)

    1963-01-01

    MA-9 ASTRONAUT L. GORDON COOPER LEAVES TRANSFER VAN AT LAUNCH COMPLEX 14 S-63-6247 P-07136, ARCHIVE-03808 Astronaut L. Gordon Cooper, Jr., leaves the transfer van at Pad #14 for his ride up the gantry elevator to the 11th deck where he will be inserted into the spacecraft for his 22-orbit mission.

  6. Complex dynamics of industrial transferring in a credit-constrained economy

    NASA Astrophysics Data System (ADS)

    Yu, Tongkui; Yu, Jiefei; Li, Honggang; Lin, Hongxi

    2010-08-01

    We present a simple industrial transferring macroeconomic model where credit constrained agents may invest projects of different industries. The feedback effect between agent's net worth and credit composition among industries with different productivity gives rise to complex aggregation dynamics including unique equilibrium, multiple-equilibrium, cycle and chaos. These dynamics replicate many industry transferring patterns and provide economic implications for industry policy.

  7. Trial and Error: California Students Make the Best of an Improving yet Complex Transfer Process

    ERIC Educational Resources Information Center

    Lewis, Jodi; Bracco, Kathy Reeves; Moore, Colleen; Nodine, Thad; Venezia, Andrea

    2016-01-01

    Student transfer processes from the California Community Colleges (CCC) to the California State University (CSU) have been simplified somewhat over the past few years, but they remain complex and confusing for most transfer students, according to students, administrators, and staff at several community colleges and CSU campuses. Transfer…

  8. A novel approach to characterize information radiation in complex networks

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyang; Wang, Ying; Zhu, Lin; Li, Chao

    2016-06-01

    The traditional research of information dissemination is mostly based on the virus spreading model that the information is being spread by probability, which does not match very well to the reality, because the information that we receive is always more or less than what was sent. In order to quantitatively describe variations in the amount of information during the spreading process, this article proposes a safety information radiation model on the basis of communication theory, combining with relevant theories of complex networks. This model comprehensively considers the various influence factors when safety information radiates in the network, and introduces some concepts from the communication theory perspective, such as the radiation gain function, receiving gain function, information retaining capacity and information second reception capacity, to describe the safety information radiation process between nodes and dynamically investigate the states of network nodes. On a micro level, this article analyzes the influence of various initial conditions and parameters on safety information radiation through the new model simulation. The simulation reveals that this novel approach can reflect the variation of safety information quantity of each node in the complex network, and the scale-free network has better ;radiation explosive power;, while the small-world network has better ;radiation staying power;. The results also show that it is efficient to improve the overall performance of network security by selecting nodes with high degrees as the information source, refining and simplifying the information, increasing the information second reception capacity and decreasing the noises. In a word, this article lays the foundation for further research on the interactions of information and energy between internal components within complex systems.

  9. Fluorescence energy transfer in quantum dot/azo dye complexes in polymer track membranes

    NASA Astrophysics Data System (ADS)

    Gromova, Yulia A.; Orlova, Anna O.; Maslov, Vladimir G.; Fedorov, Anatoly V.; Baranov, Alexander V.

    2013-10-01

    Fluorescence resonance energy transfer in complexes of semiconductor CdSe/ZnS quantum dots with molecules of heterocyclic azo dyes, 1-(2-pyridylazo)-2-naphthol and 4-(2-pyridylazo) resorcinol, formed at high quantum dot concentration in the polymer pore track membranes were studied by steady-state and transient PL spectroscopy. The effect of interaction between the complexes and free quantum dots on the efficiency of the fluorescence energy transfer and quantum dot luminescence quenching was found and discussed.

  10. Fluorescence energy transfer in quantum dot/azo dye complexes in polymer track membranes.

    PubMed

    Gromova, Yulia A; Orlova, Anna O; Maslov, Vladimir G; Fedorov, Anatoly V; Baranov, Alexander V

    2013-10-31

    Fluorescence resonance energy transfer in complexes of semiconductor CdSe/ZnS quantum dots with molecules of heterocyclic azo dyes, 1-(2-pyridylazo)-2-naphthol and 4-(2-pyridylazo) resorcinol, formed at high quantum dot concentration in the polymer pore track membranes were studied by steady-state and transient PL spectroscopy. The effect of interaction between the complexes and free quantum dots on the efficiency of the fluorescence energy transfer and quantum dot luminescence quenching was found and discussed.

  11. On the structure of iodine charge-transfer complexes in solution

    NASA Astrophysics Data System (ADS)

    Walker, Larry A., II; Pullen, Stuart; Donovan, Brent; Sension, Roseanne J.

    1995-08-01

    Femtosecond transient absorption studies of charge-transfer complexes of I 2 with hexamethylbenzene have been performed in a series of noncomplexing solvents. Anisotropy measurements of the bleach of the charge-transfer absorption band indicate that the geometry and electronic structure of the complex is dependent upon the solvent environment. The results are interpreted as favoring an oblique, nearly axial, geometry in alkanes and a resting geometry in chlorinated methanes.

  12. Information for Our Partners | NCI Technology Transfer Center | TTC

    Cancer.gov

    CRADA PAYMENT OPTIONS: Electronic Payments by Wire Transfer via Fedwire, Mail a check to the Institute or Center, or Automated Clearing House (ACH)/Electronic Funds Transfer (ETF) payments via Pay.gov (NCI ONLY). | [google6f4cd5334ac394ab.html

  13. Information Center Complex publications and presentations, 1971-1980

    SciTech Connect

    Gill, A.B.; Hawthorne, S.W.

    1981-08-01

    This indexed bibliography lists publications and presentations of the Information Center Complex, Information Division, Oak Ridge National Laboratory, from 1971 through 1980. The 659 entries cover such topics as toxicology, air and water pollution, management and transportation of hazardous wastes, energy resources and conservation, and information science. Publications range in length from 1 page to 3502 pages and include topical reports, books, journal articles, fact sheets, and newsletters. Author, title, and group indexes are provided. Annual updates are planned.

  14. Information Center Complex publications and presentations, 1971-1982

    SciTech Connect

    Hawthorne, S.W.; Johnson, A.B.

    1984-02-01

    This indexed bibliography lists publications and presentations of the staff of the Information Center Complex, Information Division, Oak Ridge National Laboratory, from 1971 through 1982. Entries cover such topics as toxicology, air and water pollution, management and transportation of hazardous wastes, energy resources and conservation, and information science. Publications range in length from 1 page to nearly 4000 pages and include topical reports, books, journal articles, fact sheets, and newsletters. Author, title, and group indexes are provided. Annual supplements are planned.

  15. Social complexity can drive vocal complexity: group size influences vocal information in Carolina chickadees.

    PubMed

    Freeberg, Todd M

    2006-07-01

    One hypothesis to explain variation in vocal communication in animal species is that the complexity of the social group influences the group's vocal complexity. This social-complexity hypothesis for communication is also central to recent arguments regarding the origins of human language, but experimental tests of the hypothesis are lacking. This study investigated whether group size, a fundamental component of social complexity, influences the complexity of a call functioning in the social organization of Carolina chickadees, Poecile carolinensis. In unmanipulated field settings, calls of individuals in larger groups had greater complexity (more information) than calls of individuals in smaller groups. In aviary settings manipulating group size, individuals in larger groups used calls with greater complexity than individuals in smaller groups. These results indicate that social complexity can influence communicative complexity in this species.

  16. Structural Allostery and Binding of the Transferring Receptor Complex

    SciTech Connect

    Xu,G.; Liu, R.; Zak, O.; Aisen, P.; Chance, M.

    2005-01-01

    The structural allostery and binding interface for the human serum transferrin (Tf){center_dot}transferrin receptor (TfR) complex were identified using radiolytic footprinting and mass spectrometry. We have determined previously that the transferrin C-lobe binds to the receptor helical domain. In this study we examined the binding interactions of full-length transferrin with receptor and compared these data with a model of the complex derived from cryoelectron microscopy (cryo-EM) reconstructions. The footprinting results provide the following novel conclusions. First, we report characteristic oxidations of acidic residues in the C-lobe of native Tf and basic residues in the helical domain of TfR that were suppressed as a function of complex formation; this confirms ionic interactions between these protein segments as predicted by cryo-EM data and demonstrates a novel method for detecting ion pair interactions in the formation of macromolecular complexes. Second, the specific side-chain interactions between the C-lobe and N-lobe of transferrin and the corresponding interactions sites on the transferrin receptor predicted from cryo-EM were confirmed in solution. Last, the footprinting data revealed allosteric movements of the iron binding C- and N-lobes of Tf that sequester iron as a function of complex formation; these structural changes promote tighter binding of the metal ion and facilitate efficient ion transport during endocytosis.

  17. Spectrophotometric determination of lamotrigine in pharmaceutical preparations and urine by charge-transfer complexation.

    PubMed

    Alizadeh, N; Khakinahad, R; Jabbari, A

    2008-11-01

    Rapid and sensitive spectrophotometric methods are developed for the determination of lamotrigine (LTG) in pharmaceutical dosage forms and urine samples, based on the formation of the charge-transfer (CT) complexes between LTG as an n-donor and the acceptors: bromocresol green (BCG), bromocresol purple (BCP), and chlorophenol red (CPR). These complexes are studied spectrophotometrically in chloroform solution in order to obtain some information about their stoichiometry and stability of complexation. The analytical parameters and their effects on the extraction of drug from urine samples are investigated. The reactions were extremely rapid at room temperature, and the absorbance values remained unchanged after 24 h for all reactions. Beer's law was obeyed in the concentration ranges 0.15-19.8, 0.15-19.8 and 0.05-34.1 microg x ml(-1) for CPR, BCP and BCG, respectively. The proposed methods were applied successfully for the determination of LTG in pharmaceutical formulations, and human urine samples in the presence of other antiepileptic drugs such as carbamazepine, oxcarbazepine and phenobarbital, with good accuracy and precision.

  18. Quantum scattering model of energy transfer in photosynthetic complexes

    NASA Astrophysics Data System (ADS)

    Ai, Bao-quan; Zhu, Shi-Liang

    2015-12-01

    We develop a quantum scattering model to describe the exciton transport through the Fenna-Matthews-Olson (FMO) complex. It is found that the exciton transport involving the optimal quantum coherence is more efficient than that involving classical behaviour alone. Furthermore, we also find that the quantum resonance condition is easier to be fulfilled in multiple pathways than that in one pathway. We then definitely demonstrate that the optimal distribution of the pigments, the multitude of energy delivery pathways and the quantum effects are combined together to contribute to the perfect energy transport in the FMO complex.

  19. Using multiple perspectives to suppress information and complexity

    SciTech Connect

    Kelsey, R.L. |; Webster, R.B.; Hartley, R.T.

    1998-09-01

    Dissemination of battlespace information involves getting information to particular warfighters that is both useful and in a form that facilitates the tasks of those particular warfighters. There are two issues which motivate this problem of dissemination. The first issue deals with disseminating pertinent information to a particular warfighter. This can be thought of as information suppression. The second issue deals with facilitating the use of the information by tailoring the computer interface to the specific tasks of an individual warfighter. This can be thought of as interface complexity suppression. This paper presents a framework for suppressing information using an object-based knowledge representation methodology. This methodology has the ability to represent knowledge and information in multiple perspectives. Information can be suppressed by creating a perspective specific to an individual warfighter. In this way, only the information pertinent and useful to a warfighter is made available to that warfighter. Information is not removed, lost, or changed, but spread among multiple perspectives. Interface complexity is managed in a similar manner. Rather than have one generalized computer interface to access all information, the computer interface can be divided into interface elements. Interface elements can then be selected and arranged into a perspective-specific interface. This is done in a manner to facilitate completion of tasks contained in that perspective. A basic battlespace domain containing ground and air elements and associated warfighters is used to exercise the methodology.

  20. Low-temperature reflectance spectrum of the benzidine-TCNQ charge-transfer complex

    NASA Astrophysics Data System (ADS)

    Yakushi, Kyuya; Kuroda, Haruo

    1984-10-01

    Reflectance spectra of a single crystal of the charge-transfer complex between benzidine and 7,7,8,8-tetracyano- p-quino-dimethane (TCNQ) were measured at 30 K. The vibrational structure of the first charge-transfer band was found to be associated mainly with the intramolecular vibration of TCNQ. From its oscillator strength, the degree of charge transfer was estimated to be 0.28 at room temperature and 0.43 at 30 K. It is concluded that the charge-transfer exciton in this crystal is of localized nature.

  1. Hardware-software complex of informing passengers of forecasted route transport arrival at stop

    NASA Astrophysics Data System (ADS)

    Pogrebnoy, V. Yu; Pushkarev, M. I.; Fadeev, A. S.

    2017-02-01

    The paper presents the hardware-software complex of informing the passengers of the forecasted route transport arrival. A client-server architecture of the forecasting information system is represented and an electronic information board prototype is described. The scheme of information transfer and processing, starting with receiving navigating telemetric data from a transport vehicle and up to the time of passenger public transport arrival at the stop, as well as representation of the information on the electronic board is illustrated and described. Methods and algorithms of determination of the transport vehicle current location in the city route network are considered in detail. The description of the proposed forecasting model of transport vehicle arrival time at the stop is given. The obtained result is applied in Tomsk for forecasting and displaying the arrival time information at the stops.

  2. Photochemistry and electron-transfer mechanism of transition metal oxalato complexes excited in the charge transfer band

    PubMed Central

    Chen, Jie; Zhang, Hua; Tomov, Ivan V.; Ding, Xunliang; Rentzepis, Peter M.

    2008-01-01

    The photoredox reaction of trisoxalato cobaltate (III) has been studied by means of ultrafast extended x-ray absorption fine structure and optical transient spectroscopy after excitation in the charge-transfer band with 267-nm femtosecond pulses. The Co–O transient bond length changes and the optical spectra and kinetics have been measured and compared with those of ferrioxalate. Data presented here strongly suggest that both of these metal oxalato complexes operate under similar photoredox reaction mechanisms where the primary reaction involves the dissociation of a metal–oxygen bond. These results also indicate that excitation in the charge-transfer band is not a sufficient condition for the intramolecular electron transfer to be the dominant photochemistry reaction mechanism. PMID:18832175

  3. Photoinduced electron transfer reactions of ruthenium(II)-complexes containing amino acid with quinones.

    PubMed

    Eswaran, Rajkumar; Kalayar, Swarnalatha; Paulpandian, Muthu Mareeswaran; Seenivasan, Rajagopal

    2014-05-01

    With the aim of mimicking, at basic level the photoinduced electron transfer process in the reaction center of photosystem II, ruthenium(II)-polypyridyl complexes, carrying amino acids were synthesized and studied their photoinduced electron transfer reactions with quinones by steady state and time resolved measurements. The reaction of quinones with excited state of ruthenium(II)-complexes, I-V in acetonitrile has been studied by luminescence quenching technique and the rate constant, k(q), values are close to the diffusion controlled rate. The detection of the semiquinone anion radical in this system using time-resolved transient absorption spectroscopy confirms the electron transfer nature of the reaction. The semiclassical theory of electron transfer has been successfully applied to the photoluminescence quenching of Ru(II)-complexes with quinones.

  4. Excitation energy transfer in photosynthetic protein-pigment complexes

    NASA Astrophysics Data System (ADS)

    Yeh, Shu-Hao

    Quantum biology is a relatively new research area which investigates the rules that quantum mechanics plays in biology. One of the most intriguing systems in this field is the coherent excitation energy transport (EET) in photosynthesis. In this document I will discuss the theories that are suitable for describing the photosynthetic EET process and the corresponding numerical results on several photosynthetic protein-pigment complexes (PPCs). In some photosynthetic EET processes, because of the electronic coupling between the chromophores within the system is about the same order of magnitude as system-bath coupling (electron-phonon coupling), a non-perturbative method called hierarchy equation of motion (HEOM) is applied to study the EET dynamics. The first part of this thesis includes brief introduction and derivation to the HEOM approach. The second part of this thesis the HEOM method will be applied to investigate the EET process within the B850 ring of the light harvesting complex 2 (LH2) from purple bacteria, Rhodopseudomonas acidophila. The dynamics of the exciton population and coherence will be analyzed under different initial excitation configurations and temperatures. Finally, how HEOM can be implemented to simulate the two-dimensional electronic spectra of photosynthetic PPCs will be discussed. Two-dimensional electronic spectroscopy is a crucial experimental technique to probe EET dynamics in multi-chromophoric systems. The system we are interested in is the 7-chromophore Fenna-Matthews-Olson (FMO) complex from green sulfur bacteria, Prosthecochloris aestuarii. Recent crystallographic studies report the existence of an additional (eighth) chromophore in some of the FMO monomers. By applying HEOM we are able to calculate the two-dimensional electronic spectra of the 7-site and 8-site FMO complexes and investigate the functionality of the eighth chromophore.

  5. Quantum complexity: Quantum mutual information, complex networks, and emergent phenomena in quantum cellular automata

    NASA Astrophysics Data System (ADS)

    Vargas, David L.

    Emerging quantum simulator technologies provide a new challenge to quantum many body theory. Quantifying the emergent order in and predicting the dynamics of such complex quantum systems requires a new approach. We develop such an approach based on complex network analysis of quantum mutual information. First, we establish the usefulness of quantum mutual information complex networks by reproducing the phase diagrams of transverse Ising and Bose-Hubbard models. By quantifying the complexity of quantum cellular automata we then demonstrate the applicability of complex network theory to non-equilibrium quantum dynamics. We conclude with a study of student collaboration networks, correlating a student's role in a collaboration network with their grades. This work thus initiates a quantitative theory of quantum complexity and provides a new tool for physics education research. (Abstract shortened by ProQuest.).

  6. 48 CFR 52.232-38 - Submission of Electronic Funds Transfer Information with Offer.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... information that is required to make payment by electronic funds transfer (EFT) under any contract that results from this solicitation. This submission satisfies the requirement to provide EFT information under...

  7. 48 CFR 52.232-38 - Submission of Electronic Funds Transfer Information with Offer.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... information that is required to make payment by electronic funds transfer (EFT) under any contract that results from this solicitation. This submission satisfies the requirement to provide EFT information under...

  8. Redox induced electron transfer in doublet azo-anion diradical rhenium(II) complexes. Characterization of complete electron transfer series.

    PubMed

    Paul, Nandadulal; Samanta, Subhas; Goswami, Sreebrata

    2010-03-15

    Reactions of dirhenium decacarbonyl with the two azoaromatic ligands, L(a) = (2-phenylazo)pyridine and L(b) = (4-chloro-2-phenylazo)pyridine (general abbreviation of the ligands is L) afford paramagnetic rhenium(II) complexes, [Re(II)(L(*-))(2)(CO)(2)] (1) (S = 1/2 ground state) with two one-electron reduced azo-anion radical ligands in an octahedral geometrical arrangement. At room temperature (300 K) the complexes 1a-b, showed magnetic moments (mu(eff)) close to 1.94 mu(B), which is suggestive of the existence of strong antiferromagnetic interactions in the complexes. The results of magnetic measurements on one of the complexes, 1b, in the temperature range 2-300 K are reported. The above complexes showed two cathodic and two anodic responses in cyclic voltammetry where one-electron oxidation leads to an unusual redox event involving simultaneous reduction of the rhenium(II) and oxidation of the second ligand via intramolecular electron transfer. The oxidized complexes 1a(+) and 1b(+) are air stable and were isolated as crystalline solids as their tri-iodide (I(3)(-)) salts. The structures of the two representative complexes, 1b and [1b]I(3), as determined by X-ray crystallography, are compared. The anionic complexes, [1](-) and [1](2-) were characterized in solution by their spectral properties.

  9. Hydrogen bonding in proton-transfer complexes of cytosine with trimesic and pyromellitic acids

    NASA Astrophysics Data System (ADS)

    Thomas, Reji; Kulkarni, G. U.

    2008-02-01

    Protons-transfer complexes (1:1) of cytosine with trimesic and pyromellitic acids have been crystallized and single crystal structures have been solved by X-ray crystallography. Both cocrystals exhibit layered structures, each layer containing a plethora of N-H⋯O and O-H⋯O hydrogen bonds between the proton-transfer duplets. The cytosine-trimesic acid complex exhibits a bilayered structure (2.87 Å) in contrast to the commonly observed layered structure seen in the cytosine-pyromellitic acid complex (3.98 Å). Another layered system, an adduct of pyromellitic acid and 1,4-dihydroxy benzene, has also been studied.

  10. 78 FR 59772 - Proposed Information Collection (Evidence for Transfer of Entitlement of Education Benefits...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-27

    ... AFFAIRS Proposed Information Collection (Evidence for Transfer of Entitlement of Education Benefits... through the use of automated collection techniques or the use of other forms of information technology. Title: Evidence for Transfer of Entitlement of Education Benefits (38 CFR 21.7080). OMB Control...

  11. 49 CFR 8.23 - Classified information transferred to the Department of Transportation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Classified information transferred to the Department of Transportation. 8.23 Section 8.23 Transportation Office of the Secretary of Transportation... § 8.23 Classified information transferred to the Department of Transportation. (a) Classified...

  12. 75 FR 68035 - Proposed Information Collection (Evidence for Transfer of Entitlement of Education Benefits...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-04

    ... Information Collection (Evidence for Transfer of Entitlement of Education Benefits) Activity: Comment Request... techniques or the use of other forms of information technology. Title: Evidence for Transfer of Entitlement... children, or a combination of the spouse and children. VA will accept DOD Form 2366-1 as evidence that...

  13. Quantum coherent energy transfer over varying pathways in single light-harvesting complexes.

    PubMed

    Hildner, Richard; Brinks, Daan; Nieder, Jana B; Cogdell, Richard J; van Hulst, Niek F

    2013-06-21

    The initial steps of photosynthesis comprise the absorption of sunlight by pigment-protein antenna complexes followed by rapid and highly efficient funneling of excitation energy to a reaction center. In these transport processes, signatures of unexpectedly long-lived coherences have emerged in two-dimensional ensemble spectra of various light-harvesting complexes. Here, we demonstrate ultrafast quantum coherent energy transfer within individual antenna complexes of a purple bacterium under physiological conditions. We find that quantum coherences between electronically coupled energy eigenstates persist at least 400 femtoseconds and that distinct energy-transfer pathways that change with time can be identified in each complex. Our data suggest that long-lived quantum coherence renders energy transfer in photosynthetic systems robust in the presence of disorder, which is a prerequisite for efficient light harvesting.

  14. Semantic Predications for Complex Information Needs in Biomedical Literature

    PubMed Central

    Cameron, Delroy; Kavuluru, Ramakanth; Bodenreider, Olivier; Mendes, Pablo N.; Sheth, Amit P.; Thirunarayan, Krishnaprasad

    2015-01-01

    Many complex information needs that arise in biomedical disciplines require exploring multiple documents in order to obtain information. While traditional information retrieval techniques that return a single ranked list of documents are quite common for such tasks, they may not always be adequate. The main issue is that ranked lists typically impose a significant burden on users to filter out irrelevant documents. Additionally, users must intuitively reformulate their search query when relevant documents have not been not highly ranked. Furthermore, even after interesting documents have been selected, very few mechanisms exist that enable document-to-document transitions. In this paper, we demonstrate the utility of assertions extracted from biomedical text (called semantic predications) to facilitate retrieving relevant documents for complex information needs. Our approach offers an alternative to query reformulation by establishing a framework for transitioning from one document to another. We evaluate this novel knowledge-driven approach using precision and recall metrics on the 2006 TREC Genomics Track. PMID:25699291

  15. Analysis of complex physiological systems by information flow: a time scale-specific complexity assessment.

    PubMed

    Hoyer, Dirk; Frank, Birgit; Pompe, Bernd; Schmidt, Hendrik; Werdan, Karl; Müller-Werdan, Ursula; Baranowski, Rafal; Zebrowski, Jan J; Meissner, Winfried; Kletzin, Ulf; Adler, Daniela; Adler, Steffen; Blickhan, Reinhard

    2006-07-01

    In the last two decades conventional linear methods for biosignal analysis have been substantially extended by non-stationary, non-linear, and complexity approaches. So far, complexity is usually assessed with regard to one single time scale, disregarding complex physiology organised on different time scales. This shortcoming was overcome and medically evaluated by information flow functions developed in our research group in collaboration with several theoretical, experimental, and clinical partners. In the present work, the information flow is introduced and typical information flow characteristics are demonstrated. The prognostic value of autonomic information flow (AIF), which reflects communication in the cardiovascular system, was shown in patients with multiple organ dysfunction syndrome and in patients with heart failure. Gait information flow (GIF), which reflects communication in the motor control system during walking, was introduced to discriminate between controls and elderly patients suffering from low back pain. The applications presented for the theoretically based approach of information flow confirm its value for the identification of complex physiological systems. The medical relevance has to be confirmed by comprehensive clinical studies. These information flow measures substantially extend the established linear and complexity measures in biosignal analysis.

  16. Spectrophotometric and some thermodynamic parameters of the charge transfer complexation between chloranilic acid and chlorpheniramine.

    PubMed

    Ofoefule, S I; Ajali, U

    2001-01-01

    The principle of charge transfer complexation involving a pi-acceptor (chloranilic acid) and an n-donor (chlorpheniramine) was utilized in the assay of the later in its pure form and in its tablet dosage forms. Some thermodynamic parameters of the complex such as association constant (Kc), molar absorptivity (epsilon c), free energy change (delta G degree), enthalpy (delta H degree) and entropy (delta S degree) changes were determined to establish the stability of the complex and the optimum conditions for the complex formation. The values obtained for these thermodynamic parameters indicated that the complex formed between this two chemical entities is highly stable. Assay of chlorpheniramine in its pure form and in its tablet dosage forms gave high percentage recoveries. The principle of charge transfer complexation could therefore be employed in the colorimetric assay of chlorpheniramine in its tablet dosage forms.

  17. Small-Volume Effect Enables Robust, Sensitive, and Efficient Information Transfer in the Spine

    NASA Astrophysics Data System (ADS)

    Fujii, Masashi; Ohashi, Kaoru; Karasawa, Yasuaki; Hikichi, Minori; Kuroda, Shinya

    2017-02-01

    Why is the spine of a neuron so small that only small numbers of molecules can exist and reactions inevitably become stochastic? Despite such noisy conditions, we previously showed that the spine exhibits robust, sensitive and efficient features of information transfer using probability of Ca$^{2+}$ increase; however, their mechanisms remains unknown. Here we show that the small-volume effect enables robust, sensitive and efficient information transfer in the spine volume, but not in the cell volume. In the spine volume, intrinsic noise in reactions becomes larger than extrinsic noise of input, making robust information transfer against input fluctuation. Stochastic facilitation of Ca$^{2+}$ increase occurs in the spine volume, making higher sensitivity to lower intensity of input. Volume-dependency of information transfer enables efficient information transfer per input in the spine volume. Thus, we propose that the small-volume effect is the functional reasons why the spine has to be so small.

  18. Metal complex-based electron-transfer mediators in dye-sensitized solar cells

    DOEpatents

    Elliott, C. Michael; Sapp, Shawn A.; Bignozzi, Carlo Alberto; Contado, Cristiano; Caramori, Stefano

    2006-03-28

    This present invention provides a metal-ligand complex and methods for using and preparing the same. In particular, the metal-ligand complex of the present invention is of the formula: L.sub.a-M-X.sub.b where L, M, X, a, and b are those define herein. The metal-ligand complexes of the present invention are useful in a variety of applications including as electron-transfer mediators in dye-sensitized solar cells and related photoelectrochromic devices.

  19. Charge Transfer Dynamics in Complexes of Light-Absorbing CdS Nanorods and Redox Catalysts

    NASA Astrophysics Data System (ADS)

    Wilker, Molly Bea

    The use of photoexcited electrons and holes in semiconductor nanocrystals as reduction and oxidation reagents is an intriguing way of harvesting photon energy to drive chemical reactions. This dissertation describes research efforts to understand the photoexcited charge transfer kinetics in complexes of colloidal CdS nanorods coupled with either a water oxidation or reduction catalyst. The first project focuses on the charge transfer interactions between photoexcited CdS nanorods and a mononuclear water oxidation catalyst derived from the [Ru(bpy)(tpy)Cl]+ parent structure. The second project details the electron transfer kinetics in complexes of CdS nanorods coupled with [FeFe]-hydrogenase, which catalyzes H+ reduction. These complexes photochemically produce H2 with quantum yields of up to 20%. Kinetics of electron transfer from CdS nanorods to hydrogenase play a critical role in the overall photochemical reactivity, as the quantum efficiency of electron transfer defines the upper limit on the quantum yield of H 2 generation. Insights from these time-resolved spectroscopic studies are used to discuss the intricate kinetic pathways involved in photochemical H2 generation and the mechanism for electron transfer from photoexcited nanorods to hydrogenase in photocatalytic complexes.

  20. Why are the Interaction Energies of Charge-Transfer Complexes Challenging for DFT?

    PubMed

    Steinmann, Stephan N; Piemontesi, Cyril; Delachat, Aurore; Corminboeuf, Clemence

    2012-05-08

    The description of ground state charge-transfer complexes is highly challenging. Illustrative examples include large overestimations of charge-transfer by local and semilocal density functional approximations as well as inaccurate binding energies. It is demonstrated here that standard density functionals fail to accurately describe interaction energies of charge-transfer complexes not only because of the missing long-range exchange as generally assumed but also as a result of the neglect of weak interactions. Thus, accounting for the missing van der Waals interactions is of key importance. These assertions, based on the evaluation of the extent of stabilization due to dispersion using both DFT coupled with our recent density-dependent dispersion correction (dDsC) and high-level ab initio computations, reflect the imperfect error-cancellation between the overestimation of charge-transfer and the missing long-range interactions. An in-depth energy decomposition analysis of an illustrative series of four small ambidentate molecules (HCN, HNC, HF, and ClF) bound together with NF3 provides the main conclusions, which are validated on a prototypical organic charge-transfer complex (i.e., tetrathiafulvalene-tetracyanoquinodimethane, TTF-TCNQ). We establish that the interaction energies for charge-transfer complexes can only be properly described when using well-balanced functionals such as PBE0-dDsC, M06-2X, and LC-BOP-LRD.

  1. Cholesteryl ester transfer between lipoproteins does not require a ternary tunnel complex with CETP.

    PubMed

    Lauer, Matthias E; Graff-Meyer, Alexandra; Rufer, Arne C; Maugeais, Cyrille; von der Mark, Elisabeth; Matile, Hugues; D'Arcy, Brigitte; Magg, Christine; Ringler, Philippe; Müller, Shirley A; Scherer, Sebastian; Dernick, Gregor; Thoma, Ralf; Hennig, Michael; Niesor, Eric J; Stahlberg, Henning

    2016-05-01

    The cholesteryl ester transfer protein (CETP) enables the transfer of cholesteryl ester (CE) from high-density lipoproteins (HDL) to low-density lipoproteins (LDL) in the plasma compartment. CETP inhibition raises plasma levels of HDL cholesterol; a ternary tunnel complex with CETP bridging HDL and LDL was suggested as a mechanism. Here, we test whether the inhibition of CETP tunnel complex formation is a promising approach to suppress CE transfer from HDL to LDL, for potential treatment of cardio-vascular disease (CVD). Three monoclonal antibodies against different epitopes of CETP are assayed for their potential to interfere with CE transfer between HDL and/or LDL. Surprisingly, antibodies that target the tips of the elongated CETP molecule, interaction sites sterically required to form the suggested transfer complexes, do not interfere with CETP activity, but an antibody binding to the central region does. We show that CETP interacts with HDL, but not with LDL. Our findings demonstrate that a ternary tunnel complex is not the mechanistic prerequisite to transfer CE among lipoproteins.

  2. Transient weak protein-protein complexes transfer heme across the cell wall of Staphylococcus aureus.

    PubMed

    Villareal, Valerie A; Spirig, Thomas; Robson, Scott A; Liu, Mengyao; Lei, Benfang; Clubb, Robert T

    2011-09-14

    Iron is an essential nutrient for the bacterial pathogen Staphylococcus aureus . Heme in hemoglobin (Hb) is the most abundant source of iron in the human body and during infections is captured by S. aureus using iron-regulated surface determinant (Isd) proteins. A central step in this process is the transfer of heme between the cell wall associated IsdA and IsdC hemoproteins. Biochemical evidence indicates that heme is transferred via an activated IsdA:heme:IsdC heme complex. Transfer is rapid and occurs up to 70,000 times faster than indirect mechanisms in which heme is released into the solvent. To gain insight into the mechanism of transfer, we modeled the structure of the complex using NMR paramagnetic relaxation enhancement (PRE) methods. Our results indicate that IsdA and IsdC transfer heme via an ultraweak affinity "handclasp" complex that juxtaposes their respective 3(10) helices and β7/β8 loops. Interestingly, PRE also identified a set of transient complexes that could represent high-energy pre-equilibrium encounter species that form prior to the stereospecific handclasp complex. Targeted amino acid mutagenesis and stopped-flow measurements substantiate the functional relevance of a PRE-derived model, as mutation of interfacial side chains significantly slows the rate of transfer. IsdA and IsdC bind heme using NEAr Transporter (NEAT) domains that are conserved in many species of pathogenic Gram-positive bacteria. Heme transfer in these microbes may also occur through structurally similar transient stereospecific complexes.

  3. (Comparison of group transfer, inner sphere and outer sphere electron transfer mechanisms of organometallic complexes)

    SciTech Connect

    Atwood, J.

    1990-01-01

    During the course of Grant ER13775 we have constructed an infrared stopped-flow spectrophotometer and initiated a study of the mechanisms of reactions that involve a change in the oxidation state of organometallic complexes. The spectrometer combined conventional stopped-flow techniques with an infrared optical system comprised of a carbon monoxide laser, an IRTRAN flow-through cell and a mercury-cadium-telluride detector. In this summary we will highlight our results on reactions: (1) that formally involve exchange of a charged species between two metal carbonyl anions, (2) that involve additional of an electron to, or removal of an electron from organometallic complexes that contain a metal-metal bond, and (3) between coordination complexes and metal carbonyl anions. 12 refs.

  4. Energy transfer between antenna complexes in the purple sulfur bacteria Chromatium tepidum and Chromatium vinosum

    NASA Astrophysics Data System (ADS)

    Kennis, John T. M.; Aartsma, Thijs J.; Amesz, Jan

    1995-05-01

    Energy transfer between antenna complexes was studied by means of time resolved absorption spectroscopy in the purple sulfur bacteria Chromatium tepidum and C. vinosum. The first species contains only one peripheral antenna complex, B800-B50, the other one has two, B800-850 and B800-820. Results obtained with chromatophores of C. tepidum indicated two time constants for energy transfer from B800-850 to the core complex, of 10 ps and a smaller one of 30 ps, suggesting non-uniform distances between the peripheral and core complexes. Similar results were obtained with C. vinosum, where time constants of 7 and 30 ps were found. Energy transfer from B800-820 to B800-850 was significantly faster. These results show that the rates of energy transfer from bacteriochlorophyll 850 to the core complex in the purple sulfur bacteria studied are quite similar to those found in purple non-sulfur bacteria. This may seem remarkable in view of the fact that the core antenna in C. tepidum absorbs at the unusually long wavelength of 918 nm, but a calculation indicates that the overlap integral for energy transfer to the core is not dramatically less than in C. vinosum.

  5. Integration of Complex Objects and Transitive Relationships for Information Retrieval.

    ERIC Educational Resources Information Center

    Jarvelin, Kalervo; Niemi, Timo

    1999-01-01

    Shows that in advanced information-retrieval applications capabilities for data aggregation, transitive computation and non-first normal-form relational computation are often necessary at the same time. Topics include complex objects; advanced data models; query languages; query formulation; knowledge representation; and query-language syntax.…

  6. Recent aspects of the proton transfer reaction in H-bonded complexes

    NASA Astrophysics Data System (ADS)

    Szafran, Mirosław

    1996-07-01

    Proton transfer processes cover a very wide range of situations and time scales and they are of great interest from the viewpoint of chemical reactions in solution. These processes can occur via thermally activated crossing or tunneling. This review considers various aspects of this many-faceted field. Spectroscopic, dielectric, colligative and energetic properties and structures of various species with H-bonds are examined. Proton transfer reactions in water and organic solvents, and the contribution of various H-bonded species and ions to these processes are discussed. Among other topics, this survey includes the effects of solvent, acid-base stoichiometry, concentration, temperature and impurity on proton transfer reactions in complexes of phenols and carboxylic acids with amines, pyridines and pyridine N-oxides. The contribution of the nonstoichiometric acid-base complexes and ionic species to the reversible proton transfer mechanism is discussed.

  7. Complex Geometry Creation and Turbulent Conjugate Heat Transfer Modeling

    SciTech Connect

    Bodey, Isaac T; Arimilli, Rao V; Freels, James D

    2011-01-01

    The multiphysics capabilities of COMSOL provide the necessary tools to simulate the turbulent thermal-fluid aspects of the High Flux Isotope Reactor (HFIR). Version 4.1, and later, of COMSOL provides three different turbulence models: the standard k-{var_epsilon} closure model, the low Reynolds number (LRN) k-{var_epsilon} model, and the Spalart-Allmaras model. The LRN meets the needs of the nominal HFIR thermal-hydraulic requirements for 2D and 3D simulations. COMSOL also has the capability to create complex geometries. The circular involute fuel plates used in the HFIR require the use of algebraic equations to generate an accurate geometrical representation in the simulation environment. The best-estimate simulation results show that the maximum fuel plate clad surface temperatures are lower than those predicted by the legacy thermal safety code used at HFIR by approximately 17 K. The best-estimate temperature distribution determined by COMSOL was then used to determine the necessary increase in the magnitude of the power density profile (PDP) to produce a similar clad surface temperature as compared to the legacy thermal safety code. It was determined and verified that a 19% power increase was sufficient to bring the two temperature profiles to relatively good agreement.

  8. Information, Cooperation, and the Blurring of Boundaries--Technology Transfer in German and American Discourses

    ERIC Educational Resources Information Center

    Krucken, Georg; Meier, Frank; Muller, Andre

    2007-01-01

    The aim of this paper is to examine changing discursive conceptualizations of technology transfer mechanisms for speeding up innovation in Germany and the US since World War II with particular emphasis on universities. According to our analysis, the concepts of technology transfer are getting more and more complex, taking off from a linear model…

  9. Teaching for Transfer: Reconciling the Framework with Disciplinary Information Literacy

    ERIC Educational Resources Information Center

    Kuglitsch, Rebecca Z.

    2015-01-01

    This article explores the tension between information literacy as a generalizable skill and as a skill within the disciplines. The new ACRL Framework for Information Literacy for Higher Education addresses many challenges facing the previous ACRL Information Literacy Competency Standards for Higher Education, but the tension between disciplinary…

  10. Teaching for Transfer: Reconciling the Framework with Disciplinary Information Literacy

    ERIC Educational Resources Information Center

    Kuglitsch, Rebecca Z.

    2015-01-01

    This article explores the tension between information literacy as a generalizable skill and as a skill within the disciplines. The new ACRL Framework for Information Literacy for Higher Education addresses many challenges facing the previous ACRL Information Literacy Competency Standards for Higher Education, but the tension between disciplinary…

  11. Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

    SciTech Connect

    Matsuzaki, Satoshi

    2001-01-01

    This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for understanding the energy transfer process associated within three lowest energy Qy-states of the complex. The results are compared with those obtained earlier on the FMO complex from Chlorobium tepidum. In Chapter 4, the energy transfer dynamics of the B800 molecules of intact LH2 and B800-deficient LH2 complexes of the purple bacterium Rhodopseudomonas acidophila are compared. New insights on the additional decay channel of the B800 ring of bacteriochlorophyll a (BChl a) molecules are provided. General conclusions are given in Chapter 5.

  12. Biological Information Transfer Beyond the Genetic Code: The Sugar Code

    NASA Astrophysics Data System (ADS)

    Gabius, H.-J.

    In the era of genetic engineering, cloning, and genome sequencing the focus of research on the genetic code has received an even further accentuation in the public eye. In attempting, however, to understand intra- and intercellular recognition processes comprehensively, the two biochemical dimensions established by nucleic acids and proteins are not sufficient to satisfactorily explain all molecular events in, for example, cell adhesion or routing. The consideration of further code systems is essential to bridge this gap. A third biochemical alphabet forming code words with an information storage capacity second to no other substance class in rather small units (words, sentences) is established by monosaccharides (letters). As hardware oligosaccharides surpass peptides by more than seven orders of magnitude in the theoretical ability to build isomers, when the total of conceivable hexamers is calculated. In addition to the sequence complexity, the use of magnetic resonance spectroscopy and molecular modeling has been instrumental in discovering that even small glycans can often reside in not only one but several distinct low-energy conformations (keys). Intriguingly, conformers can display notably different capacities to fit snugly into the binding site of nonhomologous receptors (locks). This process, experimentally verified for two classes of lectins, is termed "differential conformer selection." It adds potential for shifts of the conformer equilibrium to modulate ligand properties dynamically and reversibly to the well-known changes in sequence (including anomeric positioning and linkage points) and in pattern of substitution, for example, by sulfation. In the intimate interplay with sugar receptors (lectins, enzymes, and antibodies) the message of coding units of the sugar code is deciphered. Their recognition will trigger postbinding signaling and the intended biological response. Knowledge about the driving forces for the molecular rendezvous, i

  13. Numerical modeling of conjugate heat transfer on complex geometries with diagonal Cartesian method. Part 1: Methods

    SciTech Connect

    Lin, W.L.; Carlson, K.D.; Chen, C.J. |

    1999-05-01

    In this study, a diagonal Cartesian method for thermal analysis is developed for simulation of conjugate heat transfer over complex boundaries. This method uses diagonal line segments in addition to Cartesian coordinates. The velocity fields are also modeled using the diagonal Cartesian method. The transport equations are discretized with the finite analytic (FA) method. The current work is validated by simulating a rotated lid-driven cavity flow with conjugate heat transfer, and accurate results are obtained.

  14. Concerted proton-coupled electron transfer from a metal-hydride complex.

    PubMed

    Bourrez, Marc; Steinmetz, Romain; Ott, Sascha; Gloaguen, Frederic; Hammarström, Leif

    2014-02-01

    Metal hydrides are key intermediates in the catalytic reduction of protons and CO2 as well as in the oxidation of H2. In these reactions, electrons and protons are transferred to or from separate acceptors or donors in bidirectional protoncoupled electron transfer (PCET) steps. The mechanistic interpretation of PCET reactions of metal hydrides has focused on the stepwise transfer of electrons and protons. A concerted transfer may, however, occur with a lower reaction barrier and therefore proceed at higher catalytic rates. Here we investigate the feasibility of such a reaction by studying the oxidation–deprotonation reactions of a tungsten hydride complex. The rate dependence on the driving force for both electron transfer and proton transfer—employing different combinations of oxidants and bases—was used to establish experimentally the concerted, bidirectional PCET of a metal-hydride species. Consideration of the findings presented here in future catalyst designs may lead to more-efficient catalysts.

  15. Numerical modeling of conjugate heat transfer on complex geometries with diagonal Cartesian method. Part 2: Applications

    SciTech Connect

    Carlson, K.D.; Lin, W.L.; Chen, C.J. |

    1999-05-01

    Part 1 of this study discusses the diagonal Cartesian method for temperature analysis. The application of this method to the analysis of flow and conjugate heat transfer in a compact heat exchanger is given in Part 2. In addition to a regular (i.e., Cartesian-oriented) fin arrangement, two complex fin arrangements are modeled using the diagonal Cartesian method. The pressure drop and heat transfer characteristics of the different configurations are compared. It is found that enhanced heat transfer and reduced pressure drop can be obtained with the modified fin arrangements for this compact heat exchanger.

  16. Tuning energy transfer in the peridinin-chlorophyll complex by reconstitution with different chlorophylls.

    PubMed

    Polívka, Tomás; Pascher, Torbjörn; Sundström, Villy; Hiller, Roger G

    2005-11-01

    In vitro studies of the carotenoid peridinin, which is the primary pigment from the peridinin chlorophyll-a protein (PCP) light harvesting complex, showed a strong dependence on the lifetime of the peridinin lowest singlet excited state on solvent polarity. This dependence was attributed to the presence of an intramolecular charge transfer (ICT) state in the peridinin excited state manifold. The ICT state was also suggested to be a crucial factor in efficient peridinin to Chl-a energy transfer in the PCP complex. Here we extend our studies of peridinin dynamics to reconstituted PCP complexes, in which Chl-a was replaced by different chlorophyll species (Chl-b, acetyl Chl-a, Chl-d and BChl-a). Reconstitution of PCP with different Chl species maintains the energy transfer pathways within the complex, but the efficiency depends on the chlorophyll species. In the native PCP complex, the peridinin S1/ICT state has a lifetime of 2.7 ps, whereas in reconstituted PCP complexes it is 5.9 ps (Chl-b) 2.9 ps (Chl-a), 2.2 ps (acetyl Chl-a), 1.9 ps (Chl-d), and 0.45 ps (BChl-a). Calculation of energy transfer rates using the Förster equation explains the differences in energy transfer efficiency in terms of changing spectral overlap between the peridinin emission and the absorption spectrum of the acceptor. It is proposed that the lowest excited state of peridinin is a strongly coupled S1/ICT state, which is the energy donor for the major energy transfer channel. The significant ICT character of the S1/ICT state in PCP enhances the transition dipole moment of the S1/ICT state, facilitating energy transfer to chlorophyll via the Förster mechanism. In addition to energy transfer via the S1/ICT, there is also energy transfer via the S2 and hot S1/ICT states to chlorophyll in all reconstituted PCP complexes.

  17. Photoinduced electron transfer in a protein-surfactant complex: probing the interaction of SDS with BSA.

    PubMed

    Chakraborty, Anjan; Seth, Debabrata; Setua, Palash; Sarkar, Nilmoni

    2006-08-24

    Photoinduced fluorescence quenching electron transfer from N,N-dimethyl aniline to different 7-amino coumarin dyes has been investigated in sodium dodecyl sulfate (SDS) micelles and in bovine serum albumin (BSA)-SDS protein-surfactant complexes using steady state and picosecond time resolved fluorescence spectroscopy. The electron transfer rate has been found to be slower in BSA-SDS protein-surfactant complexes compared to that in SDS micelles. This observation has been explained with the help of the "necklace-and-bead" structure formed by the protein-surfactant complex due to coiling of protein molecules around the micelles. In the correlation of free energy change to the fluorescence quenching electron transfer rate, we have observed that coumarin 151 deviates from the normal Marcus region, showing retardation in the electron transfer rate at higher negative free energy region. We endeavored to establish that the retardation in the fluorescence quenching electron transfer rate for coumarin 151 at higher free energy region is a result of slower rotational relaxation and slower translational diffusion of coumarin 151 (C-151) compared to its analogues coumarin 152 and coumarin 481 in micelles and in protein-surfactant complexes. The slower rotational relaxation and translational diffusion of C-151 are supposed to be arising from the different location of coumarin 151 compared to coumarin 152 and coumarin 481.

  18. Fluorescence energy transfer in quantum dot/azo dye complexes in polymer track membranes

    PubMed Central

    2013-01-01

    Fluorescence resonance energy transfer in complexes of semiconductor CdSe/ZnS quantum dots with molecules of heterocyclic azo dyes, 1-(2-pyridylazo)-2-naphthol and 4-(2-pyridylazo) resorcinol, formed at high quantum dot concentration in the polymer pore track membranes were studied by steady-state and transient PL spectroscopy. The effect of interaction between the complexes and free quantum dots on the efficiency of the fluorescence energy transfer and quantum dot luminescence quenching was found and discussed. PMID:24172215

  19. Informational Complexity and Functional Activity of RNA Structures

    PubMed Central

    Carothers, James M.; Oestreich, Stephanie C.; Davis, Jonathan H.

    2004-01-01

    Very little is known about the distribution of functional DNA, RNA, and protein molecules in sequence space. The question of how the number and complexity of distinct solutions to a particular biochemical problem varies with activity is an important aspect of this general problem. Here we present a comparison of the structures and activities of eleven distinct GTP-binding RNAs (aptamers). By experimentally measuring the amount of information required to specify each optimal binding structure, we show that defining a structure capable of 10-fold tighter binding requires approximately 10 additional bits of information. This increase in information content is equivalent to specifying the identity of five additional nucleotide positions and corresponds to an ∼1000-fold decrease in abundance in a sample of random sequences. We observe a similar relationship between structural complexity and activity in a comparison of two catalytic RNAs (ribozyme ligases), raising the possibility of a general relationship between the complexity of RNA structures and their functional activity. Describing how information varies with activity in other heteropolymers, both biological and synthetic, may lead to an objective means of comparing their functional properties. This approach could be useful in predicting the functional utility of novel heteropolymers. PMID:15099096

  20. Proton-coupled electron transfer and multielectron oxidations in complexes of ruthenium and osmium

    SciTech Connect

    Dovletoglou, A.

    1992-01-01

    This doctoral research concerns the mechanism of proton-coupled electron transfer over an extended pH range. These processes between ruthenium and osmium complexes and hydroquinones have been studied using spectrophotometric methods and cyclic voltammetry. Elucidation of the mechanistic details has been attempted by using isotopic labelling, kinetic analysis, and numerical simulation of complex kinetic schemes. The coordination and redox chemistry of polypyridyl-acetylacetonato and -oxalato complexes of ruthenium and the role of ancillary ligands in defining the properties of Ru[sup IV]O complexes were explored. These studies represent the first attempt to probe possible 2e[sup [minus

  1. Charge-transfer complexes of 4-nitrocatechol with some amino alcohols

    NASA Astrophysics Data System (ADS)

    Baniyaghoob, Sahar; Najafpour, Mohammad Mahdi; Boghaei, Davar M.

    2010-03-01

    Charge-transfer (CT) complexes formed from the reactions of 4-nitropyrocatechol (4-nCat) as an electron acceptor with four amino alcohols: 2-aminoethanol, 1-amino-2-propanol, 4-aminobutanol and N-(2-hydroxyethyl)-1,3-diaminopropane (NHEDAP) as electron donors, have been studied spectrophotometrically in H 2O and H 2O/EtOH at 20, 25, 30, 35 and 40 °C. The calculated values of the oscillator strength and transition moment confirm the formation of CT-complexes. The thermodynamic and spectroscopic parameters were also evaluated for the formation of CT-complexes. The equilibrium constants ranged from 9.00 to 2.20 l mol -1 (M -1). These interactions are exothermic and have relatively large standard enthalpy and entropy changes (Δ H values ranged from -15.58 to -3.10 kJ mol -1; Δ S ranged from 26.81 to -3.25 J K -1 mol -1). The solid CT-complexes have been synthesized and characterized by IR, NMR, mass spectrometry and thermal analysis. The photometric titration curves and other spectrometric data for the reactions indicated that the data obtained refer to the formation of 1:1 charge-transfer complex of [(4-nCat) (NHEDAP)] and 1:2 charge-transfer complexes of other amino alcohols [(4-nCat) (amino alcohol) 2]. The effect of alkali and alkaline earth metals on increasing the equilibrium constant of the CT-complexation was also investigated.

  2. Crystal structure of an electron transfer complex between aromatic amine dehydrogenase and azurin from Alcaligenes faecalis.

    PubMed

    Sukumar, Narayanasami; Chen, Zhi-wei; Ferrari, Davide; Merli, Angelo; Rossi, Gian Luigi; Bellamy, Henry D; Chistoserdov, Andrei; Davidson, Victor L; Mathews, F Scott

    2006-11-14

    The crystal structure of an electron transfer complex of aromatic amine dehydrogenase (AADH) and azurin is presented. Electrons are transferred from the tryptophan tryptophylquinone (TTQ) cofactor of AADH to the type I copper of the cupredoxin azurin. This structure is compared with the complex of the TTQ-containing methylamine dehydrogenase (MADH) and the cupredoxin amicyanin. Despite significant similarities between the two quinoproteins and the two cupredoxins, each is specific for its respective partner and the ionic strength dependence and magnitude of the binding constant for each complex are quite different. The AADH-azurin interface is largely hydrophobic, covering approximately 500 A(2) of surface on each molecule, with one direct hydrogen bond linking them. The closest distance from TTQ to copper is 12.6 A compared with a distance of 9.3 A in the MADH-amicyanin complex. When the MADH-amicyanin complex is aligned with the AADH-azurin complex, the amicyanin lies on top of the azurin but is oriented quite differently. Although the copper atoms differ in position by approximately 4.7 A, the amicyanin bound to MADH appears to be rotated approximately 90 degrees from its aligned position with azurin. Comparison of the structures of the two complexes identifies features of the interface that dictate the specificity of the protein-protein interaction and determine the rate of interprotein electron transfer.

  3. Full-electron ligand-to-ligand charge transfer in a compact Re(I) complex.

    PubMed

    Yue, Yuankai; Grusenmeyer, Tod; Ma, Zheng; Zhang, Peng; Schmehl, Russell H; Beratan, David N; Rubtsov, Igor V

    2014-11-13

    Ligand-to-ligand charge transfer (LLCT) states in transition metal complexes are often characterized by fractional electron transfer due to coupling of the LLCT state with many other states via the metal. We designed and characterized a compact Re(I) complex that displays essentially full-electron charge transfer in the LLCT excited state. The complex, [Re(DCEB)(CO)3(L)](+) (DCEB = 4,4'-dicarboxyethyl-2,2'-bipyridine), referred to as ReEBA, features two redox active ligands with strong electron accepting (DCEB) and electron donating (L is 3-dimethylaminobenzonitrile (3DMABN)) properties. The lowest energy excited state formed with a ca. 10 ps time constant and was characterized as the full-electron 3DMABN → DCEB LLCT state using time-resolved infrared spectroscopy (TRIR), transient absorption spectroscopy, and DFT computations. Analysis of a range of vibrational modes helped to assign the charge transfer characteristics of the complex. The LLCT state lifetime in ReEBA shows a strong dependence on the solvent polarity and features solvent dependent frequency shifts for several vibrational reporters. The formation of a full-electron LLCT state (∼92%) was enabled by tuning the redox properties of the electron accepting ligand (DCEB) and simultaneously decoupling the redox active group of the electron donating ligand (3DMABN) from the metal center. This strategy is generally applicable for designing compact transition metal complexes that have full-electron LLCT states.

  4. Workshop on Possibilities for Improving Information Transfer. Discussion Guide.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    The following topics are discussed to show various forms for cooperative ventures in the information field which countries within a region might consider: (1) building up basic resources, collections, and stores; (2) collective retrieval tools to the combined resources of the region; (3) regional information service activities; (4) communication…

  5. Information processing using a single dynamical node as complex system

    PubMed Central

    Appeltant, L.; Soriano, M.C.; Van der Sande, G.; Danckaert, J.; Massar, S.; Dambre, J.; Schrauwen, B.; Mirasso, C.R.; Fischer, I.

    2011-01-01

    Novel methods for information processing are highly desired in our information-driven society. Inspired by the brain's ability to process information, the recently introduced paradigm known as 'reservoir computing' shows that complex networks can efficiently perform computation. Here we introduce a novel architecture that reduces the usually required large number of elements to a single nonlinear node with delayed feedback. Through an electronic implementation, we experimentally and numerically demonstrate excellent performance in a speech recognition benchmark. Complementary numerical studies also show excellent performance for a time series prediction benchmark. These results prove that delay-dynamical systems, even in their simplest manifestation, can perform efficient information processing. This finding paves the way to feasible and resource-efficient technological implementations of reservoir computing. PMID:21915110

  6. Map of isotachs - statistical approach and meteorological information transfer

    SciTech Connect

    Menezes, A.A.; da Silva, J.I.; Coutinho, C.E.O.

    1985-09-01

    This report gives a statistical treatment of available wind data from airports in Brazil and provides a map of isotachs for extreme yearly wind velocities. A comparison between the statistical models of Frechet and Gumbel is carried out, leading to the adoption of the latter. The low density of meteorological stations used in this approach restricts the knowledge of wind activity. This fact was accounted for in the analytical method for spatial transfer of climatic data. Recommendations are given on how to enlarge the amount of available data.

  7. Informal Care and Inter-vivos Transfers: Results from the National Longitudinal Survey of Mature Women

    PubMed Central

    Norton, Edward C.; Nicholas, Lauren H.; Huang, Sean Sheng-Hsiu

    2013-01-01

    Informal care is the largest source of long-term care for elderly, surpassing home health care and nursing home care. By definition, informal care is unpaid. It remains a puzzle why so many adult children give freely of their time. Transfers of time to the older generation may be balanced by financial transfers going to the younger generation. This leads to the question of whether informal care and inter-vivos transfers are causally related. We analyze data from the 1999 and 2003 waves of National Longitudinal Survey of Mature Women. We examine whether the elderly parents give more inter-vivos monetary transfers to adult children who provide informal care, by examining both the extensive and intensive margins of financial transfers and of informal care. We find statistically significant results that a child who provides informal care is more likely to receive inter-vivos transfers than a sibling who does not. If a child does provide care, there is no statistically significant effect on the amount of the transfer. PMID:25285181

  8. Informal Care and Inter-vivos Transfers: Results from the National Longitudinal Survey of Mature Women.

    PubMed

    Norton, Edward C; Nicholas, Lauren H; Huang, Sean Sheng-Hsiu

    2013-05-01

    Informal care is the largest source of long-term care for elderly, surpassing home health care and nursing home care. By definition, informal care is unpaid. It remains a puzzle why so many adult children give freely of their time. Transfers of time to the older generation may be balanced by financial transfers going to the younger generation. This leads to the question of whether informal care and inter-vivos transfers are causally related. We analyze data from the 1999 and 2003 waves of National Longitudinal Survey of Mature Women. We examine whether the elderly parents give more inter-vivos monetary transfers to adult children who provide informal care, by examining both the extensive and intensive margins of financial transfers and of informal care. We find statistically significant results that a child who provides informal care is more likely to receive inter-vivos transfers than a sibling who does not. If a child does provide care, there is no statistically significant effect on the amount of the transfer.

  9. Do complexity-informed health interventions work? A scoping review.

    PubMed

    Brainard, Julii; Hunter, Paul R

    2016-09-20

    The lens of complexity theory is widely advocated to improve health care delivery. However, empirical evidence that this lens has been useful in designing health care remains elusive. This review assesses whether it is possible to reliably capture evidence for efficacy in results or process within interventions that were informed by complexity science and closely related conceptual frameworks. Systematic searches of scientific and grey literature were undertaken in late 2015/early 2016. Titles and abstracts were screened for interventions (A) delivered by the health services, (B) that explicitly stated that complexity science provided theoretical underpinning, and (C) also reported specific outcomes. Outcomes had to relate to changes in actual practice, service delivery or patient clinical indicators. Data extraction and detailed analysis was undertaken for studies in three developed countries: Canada, UK and USA. Data were extracted for intervention format, barriers encountered and quality aspects (thoroughness or possible biases) of evaluation and reporting. From 5067 initial finds in scientific literature and 171 items in grey literature, 22 interventions described in 29 articles were selected. Most interventions relied on facilitating collaboration to find solutions to specific or general problems. Many outcomes were very positive. However, some outcomes were measured only subjectively, one intervention was designed with complexity theory in mind but did not reiterate this in subsequent evaluation and other interventions were credited as compatible with complexity science but reported no relevant theoretical underpinning. Articles often omitted discussion on implementation barriers or unintended consequences, which suggests that complexity theory was not widely used in evaluation. It is hard to establish cause and effect when attempting to leverage complex adaptive systems and perhaps even harder to reliably find evidence that confirms whether complexity-informed

  10. Diverse Effects, Complex Causes: Children Use Information About Machines' Functional Diversity to Infer Internal Complexity.

    PubMed

    Ahl, Richard E; Keil, Frank C

    2017-05-01

    Four studies explored the abilities of 80 adults and 180 children (4-9 years), from predominantly middle-class families in the Northeastern United States, to use information about machines' observable functional capacities to infer their internal, "hidden" mechanistic complexity. Children as young as 4 and 5 years old used machines' numbers of functions as indications of complexity and matched machines performing more functions with more complex "insides" (Study 1). However, only older children (6 and older) and adults used machines' functional diversity alone as an indication of complexity (Studies 2-4). The ability to use functional diversity as a complexity cue therefore emerges during the early school years, well before the use of diversity in most categorical induction tasks. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

  11. Surface complexation reaction for phase transfer of hydrophobic quantum dot from nonpolar to polar medium.

    PubMed

    Bhandari, Satyapriya; Roy, Shilaj; Pramanik, Sabyasachi; Chattopadhyay, Arun

    2014-09-09

    Chemical reaction between oleate-capped Zn(x)Cd(1-x)S quantum dots (Qdots) and 8-hydroxyquinoline (HQ) led to formation of a surface complex, which was accompanied by transfer of hydrophobic Qdots from nonpolar (hexane) to polar (water) medium with high efficiency. The stability of the complex on the surface was achieved via involvement of dangling sulfide bonds. Moreover, the transferred hydrophilic Qdots--herein called as quantum dot complex (QDC)--exhibited new and superior optical properties in comparison to bare inorganic complexes with retention of the dimension and core structure of the Qdots. Finally, the new and superior optical properties of water-soluble QDC make them potentially useful for biological--in addition to light emitting device (LED)--applications.

  12. Nitrene Metathesis and Catalytic Nitrene Transfer Promoted by Niobium Bis(imido) Complexes.

    PubMed

    Kriegel, Benjamin M; Bergman, Robert G; Arnold, John

    2016-01-13

    We report a metathesis reaction in which a nitrene fragment from an isocyanide ligand is exchanged with a nitrene fragment of an imido ligand in a series of niobium bis(imido) complexes. One of these bis(imido) complexes also promotes nitrene transfer to catalytically generate asymmetric dialkylcarbodiimides from azides and isocyanides in a process involving the Nb(V)/Nb(III) redox couple.

  13. Synchronized Inhibition Boosts Information Transfer in Entrained Neurons

    NASA Astrophysics Data System (ADS)

    Tiesinga, Paul; Fellous, Jean-Marc; Jose, Jorge; Sejnowski, Terrence

    2001-03-01

    We investigated the ability of a single neuron to transduce the information content of a synchronized inhibitory synaptic drive, generated by an interneuron network, into an information-rich output of neuron spike times. The neuron was entrained to the periodic network drive when the jitter in the input spike times is sufficiently small (i.e. high precision), and the number of presynaptic spikes during one drive cycle is sufficiently large. The Shannon entropy of the output of spike times was reduced sharply during entrainment. Surprisingly, however, the amount of transduced information as measured by the mutual information was significantly increased during entrainment. This increase was due to the reduced contribution of the internal correlations to the output variability. These theoretical predictions were confirmed in experimental recordings from the rat neocortex and hippocampus.

  14. Computer Center: BASIC String Models of Genetic Information Transfer.

    ERIC Educational Resources Information Center

    Spain, James D., Ed.

    1984-01-01

    Discusses some of the major genetic information processes which may be modeled by computer program string manipulation, focusing on replication and transcription. Also discusses instructional applications of using string models. (JN)

  15. Computer Center: BASIC String Models of Genetic Information Transfer.

    ERIC Educational Resources Information Center

    Spain, James D., Ed.

    1984-01-01

    Discusses some of the major genetic information processes which may be modeled by computer program string manipulation, focusing on replication and transcription. Also discusses instructional applications of using string models. (JN)

  16. Information Transfer--A Look into the Future.

    ERIC Educational Resources Information Center

    Fournier, Martin

    1987-01-01

    Describes predicted trends in telecommunications, including integrated service digital networks and fast packet switching networks. The possible effects on the worldwide exchange of scientific information, the need for international standards, and preliminary planning activities are discussed. (CLB)

  17. Receiving Providers' Perceptions on Information Transmission During Interfacility Transfers to General Pediatric Floors.

    PubMed

    Rosenthal, Jennifer L; Romano, Patrick S; Kokroko, Jolene; Gu, Wendi; Okumura, Megumi J

    2017-06-01

    Pediatric patients can present to a medical facility and subsequently be transferred to a different hospital for definitive care. Interfacility transfers require a provider handoff across facilities, posing risks that may affect patient outcomes. The goal of this study was to describe the thoroughness of information transmission between providers during interfacility transfers, to describe perceived errors in care at the posttransfer facility, and to identify potential associations between thoroughness of information transmission and perceived errors in care. We performed an exploratory prospective cohort study on communication practices and patient outcomes during interfacility transfers to general pediatric floors. Data were collected from provider surveys and chart review. Descriptive statistics were used to summarize survey responses. Logistic regression was used to analyze the association of communication deficits with odds of having a perceived error in care. A total of 633 patient transfers were reviewed; 218 transport command physician surveys and 217 frontline provider surveys were completed. Transport command physicians reported higher proportions of key elements being included in the verbal handoff compared with frontline providers. The written key element transmitted with the lowest frequency was a summary document (65.2%), and 13% of transfers had at least 1 perceived error in care. Transfers with many deficits were associated with higher odds of having a perceived error in care. Information transmission during pediatric transfers is perceived to be inconsistently complete. Deficits in the verbal and written information transmission are associated with odds of having a perceived error in care. Copyright © 2017 by the American Academy of Pediatrics.

  18. 77 FR 57105 - Notice of Proposed Information Collection: Comment Request; Application for the Transfer of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-17

    ... Transfer of Physical Assets AGENCY: Office of the Assistant Secretary for Housing, HUD. ACTION: Notice... Physical Assets. OMB Control Number, if applicable: 2502-0275. Description of the need for the information... not placed in physical, financial, or managerial jeopardy during a transfer of physical assets. Agency...

  19. Assessing the Suitability of Process and Information Technology in Supporting Tacit Knowledge Transfer

    ERIC Educational Resources Information Center

    Wu, Chien-Hsing; Kao, Shu-Chen; Shih, Lan-Hsin

    2010-01-01

    The transfer of tacit knowledge, one of the most important issues in the knowledge sharing context, needs a multi-dimensional perception in its process. Information technology's (IT) supporting role has already been addressed in the process of tacit knowledge transfer. However, IT has its own characteristics, and in turn, may have dissimilar…

  20. Assessing the Suitability of Process and Information Technology in Supporting Tacit Knowledge Transfer

    ERIC Educational Resources Information Center

    Wu, Chien-Hsing; Kao, Shu-Chen; Shih, Lan-Hsin

    2010-01-01

    The transfer of tacit knowledge, one of the most important issues in the knowledge sharing context, needs a multi-dimensional perception in its process. Information technology's (IT) supporting role has already been addressed in the process of tacit knowledge transfer. However, IT has its own characteristics, and in turn, may have dissimilar…

  1. 77 FR 21579 - Agency Information Collection Activities: Transfer of Cargo to a Container Station

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ... a Container Station AGENCY: U.S. Customs and Border Protection, Department of Homeland Security... and approval in accordance with the Paperwork Reduction Act: Transfer of Cargo to a Container Station... forms of information. Title: Transfer of Cargo to a Container Station. OMB Number: 1651-0096....

  2. Charge transfer in the electron donor-acceptor complex BH3NH3.

    PubMed

    Mo, Yirong; Song, Lingchun; Wu, Wei; Zhang, Qianer

    2004-03-31

    As a simple yet strongly binding electron donor-acceptor (EDA) complex, BH(3)NH(3) serves as a good example to study the electron pair donor-acceptor complexes. We employed both the ab initio valence bond (VB) and block-localized wave function (BLW) methods to explore the electron transfer from NH(3) to BH(3). Conventionally, EDA complexes have been described by two diabatic states: one neutral state and one ionic charge-transferred state. Ab initio VB self-consistent field (VBSCF) computations generate the energy profiles of the two diabatic states together with the adiabatic (ground) state. Our calculations evidently demonstrated that the electron transfer between NH(3) and BH(3) falls in the abnormal regime where the reorganization energy is less than the exoergicity of the reaction. The nature of the NH(3)-BH(3) interaction is probed by an energy decomposition scheme based on the BLW method. We found that the variation of the charge-transfer energy with the donor-acceptor distance is insensitive to the computation levels and basis sets, but the estimation of the amount of electron transferred heavily depends on the population analysis procedures. The recent resurgence of interest in the nature of the rotation barrier in ethane prompted us to analyze the conformational change of BH(3)NH(3), which is an isoelectronic system with ethane. We found that the preference of the staggered structure over the eclipsed structure of BH(3)NH(3) is dominated by the Pauli exchange repulsion.

  3. Information gathering, management and transfering for geospacial intelligence

    NASA Astrophysics Data System (ADS)

    Nunes, Paulo; Correia, Anacleto; Teodoro, M. Filomena

    2017-07-01

    Information is a key subject in modern organization operations. The success of joint and combined operations with organizations partners depends on the accurate information and knowledge flow concerning the operations theatre: provision of resources, environment evolution, markets location, where and when an event occurred. As in the past and nowadays we cannot conceive modern operations without maps and geo-spatial information (GI). Information and knowledge management is fundamental to the success of organizational decisions in an uncertainty environment. The georeferenced information management is a process of knowledge management, it begins in the raw data and ends on generating knowledge. GI and intelligence systems allow us to integrate all other forms of intelligence and can be a main platform to process and display geo-spatial-time referenced events. Combining explicit knowledge with peoples know-how to generate a continuous learning cycle that supports real time decisions mitigates the influences of fog of everyday competition and provides the knowledge supremacy. Extending the preliminary analysis done in [1], this work applies the exploratory factor analysis to a questionnaire about the GI and intelligence management in an organization company allowing to identify future lines of action to improve information process sharing and exploration of all the potential of this important resource.

  4. Energy-Efficient Information Transfer by Visual Pathway Synapses.

    PubMed

    Harris, Julia J; Jolivet, Renaud; Engl, Elisabeth; Attwell, David

    2015-12-21

    The architecture of computational devices is shaped by their energy consumption. Energetic constraints are used to design silicon-based computers but are poorly understood for neural computation. In the brain, most energy is used to reverse ion influxes generating excitatory postsynaptic currents (EPSCs) and action potentials. Thus, EPSCs should be small to minimize energy use, but not so small as to impair information transmission. We quantified information flow through the retinothalamic synapse in the visual pathway in brain slices, with cortical and inhibitory input to the postsynaptic cell blocked. Altering EPSC size with dynamic clamp, we found that a larger-than-normal EPSC increased information flow through the synapse. Thus, the evolutionarily selected EPSC size does not maximize retinal information flow to the cortex. By assessing the energy used on postsynaptic ion pumping and action potentials, we show that, instead, the EPSC size optimizes the ratio of retinal information transmitted to energy consumed. These data suggest maximization of information transmission per energy used as a synaptic design principle.

  5. Energy-Efficient Information Transfer by Visual Pathway Synapses

    PubMed Central

    Harris, Julia J.; Jolivet, Renaud; Engl, Elisabeth; Attwell, David

    2015-01-01

    Summary The architecture of computational devices is shaped by their energy consumption. Energetic constraints are used to design silicon-based computers but are poorly understood for neural computation. In the brain, most energy is used to reverse ion influxes generating excitatory postsynaptic currents (EPSCs) and action potentials. Thus, EPSCs should be small to minimize energy use, but not so small as to impair information transmission. We quantified information flow through the retinothalamic synapse in the visual pathway in brain slices, with cortical and inhibitory input to the postsynaptic cell blocked. Altering EPSC size with dynamic clamp, we found that a larger-than-normal EPSC increased information flow through the synapse. Thus, the evolutionarily selected EPSC size does not maximize retinal information flow to the cortex. By assessing the energy used on postsynaptic ion pumping and action potentials, we show that, instead, the EPSC size optimizes the ratio of retinal information transmitted to energy consumed. These data suggest maximization of information transmission per energy used as a synaptic design principle. PMID:26671670

  6. The NATO Response Force: Facilitating Coalition Warfare through Technology Transfer and Information Sharing

    DTIC Science & Technology

    2005-09-01

    information concerning network architectures, interfaces, protocols, and file structures needed to allow the seamless transfer of information between...planning and agreement on the sharing of network and database architectural and structural information. Network-centric warfare, which is in...gained steam in Europe to move toward a separate “European” security identify, defense capability, and supporting industrial structure . The

  7. Analysis of Technological Information Transfer among Japanese Computer Scientists at a Research Front.

    ERIC Educational Resources Information Center

    Takayama, Masaya

    1986-01-01

    Describes the methodology and results of a study that examined information flow at the technological research front by analyzing a Japanese national project in computer technology. Various formats of information dissemination are identified, and a classification of researchers and engineers by information transfer activities is presented. (4…

  8. Combined mining: discovering informative knowledge in complex data.

    PubMed

    Cao, Longbing; Zhang, Huaifeng; Zhao, Yanchang; Luo, Dan; Zhang, Chengqi

    2011-06-01

    Enterprise data mining applications often involve complex data such as multiple large heterogeneous data sources, user preferences, and business impact. In such situations, a single method or one-step mining is often limited in discovering informative knowledge. It would also be very time and space consuming, if not impossible, to join relevant large data sources for mining patterns consisting of multiple aspects of information. It is crucial to develop effective approaches for mining patterns combining necessary information from multiple relevant business lines, catering for real business settings and decision-making actions rather than just providing a single line of patterns. The recent years have seen increasing efforts on mining more informative patterns, e.g., integrating frequent pattern mining with classifications to generate frequent pattern-based classifiers. Rather than presenting a specific algorithm, this paper builds on our existing works and proposes combined mining as a general approach to mining for informative patterns combining components from either multiple data sets or multiple features or by multiple methods on demand. We summarize general frameworks, paradigms, and basic processes for multifeature combined mining, multisource combined mining, and multimethod combined mining. Novel types of combined patterns, such as incremental cluster patterns, can result from such frameworks, which cannot be directly produced by the existing methods. A set of real-world case studies has been conducted to test the frameworks, with some of them briefed in this paper. They identify combined patterns for informing government debt prevention and improving government service objectives, which show the flexibility and instantiation capability of combined mining in discovering informative knowledge in complex data.

  9. Inter-facility transfer of patient information before and after HIPAA privacy measures.

    PubMed

    Boockvar, Kenneth S; Fridman, Bella

    2005-01-01

    The study objectives were (1) to test whether interfacility communication of health information at the time of patient transfer changed as a result of implementation of US privacy protection measures (HIPAA) in April 2003, and (2) to examine patient, transfer, and illness characteristics correlated with interfacility transfer document completion. Observational study. Individuals transferred between a 514-bed urban nursing home and a 1171-bed academic hospital in New York City. Research staff reviewed medical records of patients transferred both ways between nursing home and hospital, examining interfacility transfer documents for 12 items important for continuity of care. Transfer document completeness equaled the percentage of items recorded and legible in transfer documents. Transfers were classified by direction (nursing home-to-hospital [NH-to-H] or hospital-to-nursing home [H-to-NH]), urgency (urgent or not), timing (weekday 9 am to 6 pm or other), and by whether they occurred before 12 am April 14, 2003 (pre-HIPAA), or after (post-HIPAA). Seventy-eight nursing home residents experienced 100 hospital admissions. NH-to-H transfer documents were more complete than H-to-NH documents (86.7% vs 69.0%; P = .002). There were no significant differences between content of transfer documents between pre- and post-HIPAA transfers in either direction of transfer, with and without controlling for patient and illness characteristics. Older age, female gender, dementia diagnosis, shorter duration of nursing home residence, and off-hours hospital transfer were associated with less complete NH-to-H transfer documents, and shorter hospital length of stay was associated with less complete H-to-NH transfer documents. There was no change in written health information communicated during patient transfer between an urban nursing home and an academic hospital before and after HIPAA privacy protection measures were implemented. This suggests that the rule's intent to not restrict the

  10. 77 FR 71035 - Financial Management Service; Proposed Collection of Information: Electronic Funds Transfer (EFT...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-28

    ... Fiscal Service Financial Management Service; Proposed Collection of Information: Electronic Funds Transfer (EFT) Market Research Study AGENCY: Financial Management Service, Fiscal Service, Treasury. ACTION: Notice and Request for comments. SUMMARY: The Financial Management Service, as part of its...

  11. 77 FR 36479 - Proposed Information Collection; Comment Request; License Transfer and Duplicate License Services

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Bureau of Industry and Security Proposed Information Collection; Comment Request; License Transfer and Duplicate License Services AGENCY: Bureau of Industry and Security, Commerce. ACTION: Notice. SUMMARY:...

  12. 77 FR 34127 - Financial Management Service; Proposed Collection of Information: Electronic Transfer Account...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ... Fiscal Service Financial Management Service; Proposed Collection of Information: Electronic Transfer Account (ETA) Financial Agency Agreement AGENCY: Financial Management Service, Fiscal Service, Treasury. ACTION: Notice and Request for comments. SUMMARY: The Financial Management Service, as part of...

  13. Second law of information thermodynamics with entanglement transfer.

    PubMed

    Tajima, Hiroyasu

    2013-10-01

    We present an inequality which holds in the thermodynamical processes with measurement and feedback controls and uses only the Helmholtz free energy and the entanglement of formation: W(ext)≤-ΔF-k(B)TΔE(F). The quantity -ΔE(F), which is positive, expresses the amount of entanglement transfer from system S to probe P through the interaction U(SP) during the measurement. It is easier to achieve the upper bound in this inequality than in the Sagawa-Ueda inequality [Phys. Rev. Lett. 100, 080403 (2008)]. Our inequality has clear physical meaning: in the above thermodynamical processes, the work which we can extract from the thermodynamic system is greater than the upper bound in the conventional thermodynamics by the amount of the entanglement extracted by the measurement.

  14. Information transfer in verbal presentations at scientific meetings

    NASA Astrophysics Data System (ADS)

    Flinn, Edward A.

    The purpose of this note is to suggest a quantitative approach to deciding how much time to give a speaker at a scientific meeting. The elementary procedure is to use the preacher's rule of thumb that no souls are saved after the first 20 minutes. This is in qualitative agreement with the proverb that one cannot listen to a single voice for more than an hour without going to sleep. A refinement of this crude approach can be made by considering the situation from the point of view of a linear physical system with an input, a transfer function, and an output. We attempt here to derive an optimum speaking time through these considerations.

  15. Ab initio Green-function formulation of the transfer matrix: Application to complex band structures

    NASA Astrophysics Data System (ADS)

    Wortmann, D.; Ishida, H.; Blügel, S.

    2002-04-01

    A method for the first-principles calculation of the transfer matrix is presented. The method is based on a Green-function formulation and allows one to relate the wave functions and their derivatives on boundaries at opposite sides of a film or junction of finite thickness. Both the underlying theory and an actual implementation in the full-potential linearized augmented plane wave method are described. Currently the embedding method is used to evaluate the Green-function matrix elements and in turn we show that the transfer matrix can be used to construct the embedding potential. Some possible applications of the transfer-matrix method such as the calculations of the complex band structure or the calculation of the transmission and reflection coefficients for ballistic transport are discussed. As a first example, complex band structures of Cu, Fe, and Si are presented.

  16. Efficient estimation of energy transfer efficiency in light-harvesting complexes.

    PubMed

    Shabani, A; Mohseni, M; Rabitz, H; Lloyd, S

    2012-07-01

    The fundamental physical mechanisms of energy transfer in photosynthetic complexes is not yet fully understood. In particular, the degree of efficiency or sensitivity of these systems for energy transfer is not known given their realistic with surrounding photonic and phononic environments. One major problem in studying light-harvesting complexes has been the lack of an efficient method for simulation of their dynamics in biological environments. To this end, here we revisit the second order time-convolution (TC2) master equation and examine its reliability beyond extreme Markovian and perturbative limits. In particular, we present a derivation of TC2 without making the usual weak system-bath coupling assumption. Using this equation, we explore the long-time behavior of exciton dynamics of Fenna-Matthews-Olson (FMO) portein complex. Moreover, we introduce a constructive error analysis to estimate the accuracy of TC2 equation in calculating energy transfer efficiency, exhibiting reliable performance for system-bath interactions with weak and intermediate memory and strength. Furthermore, we numerically show that energy transfer efficiency is optimal and robust for the FMO protein complex of green sulfur bacteria with respect to variations in reorganization energy and bath correlation time scales.

  17. Simplifying the model of a complex heat-transfer system for solving the relay control problem

    NASA Astrophysics Data System (ADS)

    Shilin, A. A.; Bukreev, V. G.

    2014-09-01

    A method for approximating the high-dimensionality model of a complex heat-transfer system with time delay by a nonlinear second-order differential equation is proposed. The modeling results confirming adequacy of the nonlinear properties of the reduced and initial models and their correspondence to the controlled plant actual data are presented.

  18. A Conserved Endoplasmic Reticulum Membrane Protein Complex (EMC) Facilitates Phospholipid Transfer from the ER to Mitochondria

    PubMed Central

    Tavassoli, Shabnam; Wong, Andrew K. O.; Choudhary, Vineet; Young, Barry P.; Loewen, Christopher J. R.; Prinz, William A.

    2014-01-01

    Mitochondrial membrane biogenesis and lipid metabolism require phospholipid transfer from the endoplasmic reticulum (ER) to mitochondria. Transfer is thought to occur at regions of close contact of these organelles and to be nonvesicular, but the mechanism is not known. Here we used a novel genetic screen in S. cerevisiae to identify mutants with defects in lipid exchange between the ER and mitochondria. We show that a strain missing multiple components of the conserved ER membrane protein complex (EMC) has decreased phosphatidylserine (PS) transfer from the ER to mitochondria. Mitochondria from this strain have significantly reduced levels of PS and its derivative phosphatidylethanolamine (PE). Cells lacking EMC proteins and the ER–mitochondria tethering complex called ERMES (the ER–mitochondria encounter structure) are inviable, suggesting that the EMC also functions as a tether. These defects are corrected by expression of an engineered ER–mitochondrial tethering protein that artificially tethers the ER to mitochondria. EMC mutants have a significant reduction in the amount of ER tethered to mitochondria even though ERMES remained intact in these mutants, suggesting that the EMC performs an additional tethering function to ERMES. We find that all Emc proteins interact with the mitochondrial translocase of the outer membrane (TOM) complex protein Tom5 and this interaction is important for PS transfer and cell growth, suggesting that the EMC forms a tether by associating with the TOM complex. Together, our findings support that the EMC tethers ER to mitochondria, which is required for phospholipid synthesis and cell growth. PMID:25313861

  19. The free-energy barrier to hydride transfer across a dipalladium complex.

    PubMed

    Vanston, C R; Kearley, G J; Edwards, A J; Darwish, T A; de Souza, N R; Ramirez-Cuesta, A J; Gardiner, M G

    2015-01-01

    We use density-functional theory molecular dynamics (DFT-MD) simulations to determine the hydride transfer coordinate between palladium centres of the crystallographically observed terminal hydride locations, Pd-Pd-H, originally postulated for the solution dynamics of the complex bis-NHC dipalladium hydride [{(MesIm)2CH2}2Pd2H][PF6], and then calculate the free-energy along this coordinate. We estimate the transfer barrier-height to be about 20 kcal mol(-1) with a hydride transfer rate in the order of seconds at room temperature. We validate our DFT-MD modelling using inelastic neutron scattering which reveals anharmonicity of the hydride environment that is so pronounced that there is complete failure of the harmonic model for the hydride ligand. The simulations are extended to high temperature to bring the H-transfer to a rate that is accessible to the simulation technique.

  20. The free-energy barrier to hydride transfer across a dipalladium complex

    SciTech Connect

    Ramirez-Cuesta, Anibal J.

    2015-01-01

    We use density-functional theory molecular dynamics (DFT-MD) simulations to determine the hydride transfer coordinate between palladium centres of the crystallographically observed terminal hydride locations, Pd-Pd-H, originally postulated for the solution dynamics of the complex bis-NHC dipalladium hydride [{(MesIm)(2)CH2}(2)Pd2H][PF6], and then calculate the free-energy along this coordinate. We estimate the transfer barrier-height to be about 20 kcal mol(-1) with a hydride transfer rate in the order of seconds at room temperature. We validate our DFT-MD modelling using inelastic neutron scattering which reveals anharmonicity of the hydride environment that is so pronounced that there is complete failure of the harmonic model for the hydride ligand. The simulations are extended to high temperature to bring the H-transfer to a rate that is accessible to the simulation technique.

  1. The free-energy barrier to hydride transfer across a dipalladium complex

    DOE PAGES

    Ramirez-Cuesta, Anibal J.

    2015-01-01

    We use density-functional theory molecular dynamics (DFT-MD) simulations to determine the hydride transfer coordinate between palladium centres of the crystallographically observed terminal hydride locations, Pd-Pd-H, originally postulated for the solution dynamics of the complex bis-NHC dipalladium hydride [{(MesIm)(2)CH2}(2)Pd2H][PF6], and then calculate the free-energy along this coordinate. We estimate the transfer barrier-height to be about 20 kcal mol(-1) with a hydride transfer rate in the order of seconds at room temperature. We validate our DFT-MD modelling using inelastic neutron scattering which reveals anharmonicity of the hydride environment that is so pronounced that there is complete failure of the harmonic model formore » the hydride ligand. The simulations are extended to high temperature to bring the H-transfer to a rate that is accessible to the simulation technique.« less

  2. Information driven self-organization of complex robotic behaviors.

    PubMed

    Martius, Georg; Der, Ralf; Ay, Nihat

    2013-01-01

    Information theory is a powerful tool to express principles to drive autonomous systems because it is domain invariant and allows for an intuitive interpretation. This paper studies the use of the predictive information (PI), also called excess entropy or effective measure complexity, of the sensorimotor process as a driving force to generate behavior. We study nonlinear and nonstationary systems and introduce the time-local predicting information (TiPI) which allows us to derive exact results together with explicit update rules for the parameters of the controller in the dynamical systems framework. In this way the information principle, formulated at the level of behavior, is translated to the dynamics of the synapses. We underpin our results with a number of case studies with high-dimensional robotic systems. We show the spontaneous cooperativity in a complex physical system with decentralized control. Moreover, a jointly controlled humanoid robot develops a high behavioral variety depending on its physics and the environment it is dynamically embedded into. The behavior can be decomposed into a succession of low-dimensional modes that increasingly explore the behavior space. This is a promising way to avoid the curse of dimensionality which hinders learning systems to scale well.

  3. Information Driven Self-Organization of Complex Robotic Behaviors

    PubMed Central

    Martius, Georg; Der, Ralf; Ay, Nihat

    2013-01-01

    Information theory is a powerful tool to express principles to drive autonomous systems because it is domain invariant and allows for an intuitive interpretation. This paper studies the use of the predictive information (PI), also called excess entropy or effective measure complexity, of the sensorimotor process as a driving force to generate behavior. We study nonlinear and nonstationary systems and introduce the time-local predicting information (TiPI) which allows us to derive exact results together with explicit update rules for the parameters of the controller in the dynamical systems framework. In this way the information principle, formulated at the level of behavior, is translated to the dynamics of the synapses. We underpin our results with a number of case studies with high-dimensional robotic systems. We show the spontaneous cooperativity in a complex physical system with decentralized control. Moreover, a jointly controlled humanoid robot develops a high behavioral variety depending on its physics and the environment it is dynamically embedded into. The behavior can be decomposed into a succession of low-dimensional modes that increasingly explore the behavior space. This is a promising way to avoid the curse of dimensionality which hinders learning systems to scale well. PMID:23723979

  4. Mutual information model for link prediction in heterogeneous complex networks

    PubMed Central

    Shakibian, Hadi; Moghadam Charkari, Nasrollah

    2017-01-01

    Recently, a number of meta-path based similarity indices like PathSim, HeteSim, and random walk have been proposed for link prediction in heterogeneous complex networks. However, these indices suffer from two major drawbacks. Firstly, they are primarily dependent on the connectivity degrees of node pairs without considering the further information provided by the given meta-path. Secondly, most of them are required to use a single and usually symmetric meta-path in advance. Hence, employing a set of different meta-paths is not straightforward. To tackle with these problems, we propose a mutual information model for link prediction in heterogeneous complex networks. The proposed model, called as Meta-path based Mutual Information Index (MMI), introduces meta-path based link entropy to estimate the link likelihood and could be carried on a set of available meta-paths. This estimation measures the amount of information through the paths instead of measuring the amount of connectivity between the node pairs. The experimental results on a Bibliography network show that the MMI obtains high prediction accuracy compared with other popular similarity indices. PMID:28344326

  5. Diverse Effects, Complex Causes: Children Use Information about Machines' Functional Diversity to Infer Internal Complexity

    ERIC Educational Resources Information Center

    Ahl, Richard E.; Keil, Frank C.

    2017-01-01

    Four studies explored the abilities of 80 adults and 180 children (4-9 years), from predominantly middle-class families in the Northeastern United States, to use information about machines' observable functional capacities to infer their internal, "hidden" mechanistic complexity. Children as young as 4 and 5 years old used machines'…

  6. Efficient host-guest energy transfer in polycationic cyclophane-perylene diimide complexes in water.

    PubMed

    Ryan, Seán T J; Del Barrio, Jesús; Ghosh, Indrajit; Biedermann, Frank; Lazar, Alexandra I; Lan, Yang; Coulston, Roger J; Nau, Werner M; Scherman, Oren A

    2014-06-25

    We report the self-assembly of a series of highly charged supramolecular complexes in aqueous media composed of cyclobis(4,4'-(1,4-phenylene)bispyridine-p-phenylene)tetrakis(chloride) (ExBox) and three dicationic perylene diimides (PDIs). Efficient energy transfer (ET) is observed between the host and guests. Additionally, we show that our hexacationic complexes are capable of further complexation with neutral cucurbit[7]uril (CB[7]), producing a 3-polypseudorotaxane via the self-assembly of orthogonal recognition moieties. ExBox serves as the central ring, complexing to the PDI core, while two CB[7]s behave as supramolecular stoppers, binding to the two outer quaternary ammonium motifs. The formation of the 3-polypseudorotaxane results in far superior photophysical properties of the central PDI unit relative to the binary complexes at stoichiometric ratios. Lastly, we also demonstrate the ability of our binary complexes to act as a highly selective chemosensing ensemble for the neurotransmitter melatonin.

  7. Information systems and technology transfer programs on geothermal energy and other renewable sources of energy

    SciTech Connect

    Lippmann, Marcelo J.; Antunez, Emilio u.

    1996-01-24

    In order to remain competitive it is necessary to stay informed and use the most advanced technologies available. Recent developments in communication, like the Internet and the World Wide Web, enormously facilitate worldwide data and technology transfer. A compilation of the most important sources of data on renewable energies, especially geothermal, as well as lists of relevant technology transfer programs are presented. Information on how to gain access to, and learn more about them is also given.

  8. Information systems and technology transfer programs on geothermal energy and other renewable sources of energy

    SciTech Connect

    Lippmann, M.J.; Antunez, E.

    1996-01-01

    In order to remain competitive, it is necessary to stay informed and use the most advanced technologies available. Recent developments in communication, like the Internet and the World Wide Web, enormously facilitate worldwide data and technology transfer. A compilation of the most important sources of data on renewable energies, especially geothermal, as well as lists of relevant technology transfer programs are presented. Information on how to gain access to, and learn more about them, is also given.

  9. Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

    SciTech Connect

    Matsuzaki, Satoshi

    2001-01-01

    This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for understanding the energy transfer process associated within three lowest energy Qy-states of the complex. The results are compared with those obtained earlier on the FMO complex from Chlorobium tepidum. In Chapter 4, the energy transfer dynamics of the B800 molecules of intact LH2 and B800-deficient LH2 complexes of the purple bacterium Rhodopseudomonas acidophila are compared. New insights on the additional decay channel of the B800 ring of bacteriochlorophylla (BChla) molecules are provided. General conclusions are given in Chapter 5. A version of the hole spectrum simulation program written by the candidate for the FMO complex study (Chapter 3) is included as an appendix. The references for each chapter are given at the end of each chapter.

  10. Encoding techniques for complex information structures in connectionist systems

    NASA Technical Reports Server (NTRS)

    Barnden, John; Srinivas, Kankanahalli

    1990-01-01

    Two general information encoding techniques called relative position encoding and pattern similarity association are presented. They are claimed to be a convenient basis for the connectionist implementation of complex, short term information processing of the sort needed in common sense reasoning, semantic/pragmatic interpretation of natural language utterances, and other types of high level cognitive processing. The relationships of the techniques to other connectionist information-structuring methods, and also to methods used in computers, are discussed in detail. The rich inter-relationships of these other connectionist and computer methods are also clarified. The particular, simple forms are discussed that the relative position encoding and pattern similarity association techniques take in the author's own connectionist system, called Conposit, in order to clarify some issues and to provide evidence that the techniques are indeed useful in practice.

  11. Bayesian Case-deletion Model Complexity and Information Criterion

    PubMed Central

    Zhu, Hongtu; Ibrahim, Joseph G.; Chen, Qingxia

    2015-01-01

    We establish a connection between Bayesian case influence measures for assessing the influence of individual observations and Bayesian predictive methods for evaluating the predictive performance of a model and comparing different models fitted to the same dataset. Based on such a connection, we formally propose a new set of Bayesian case-deletion model complexity (BCMC) measures for quantifying the effective number of parameters in a given statistical model. Its properties in linear models are explored. Adding some functions of BCMC to a conditional deviance function leads to a Bayesian case-deletion information criterion (BCIC) for comparing models. We systematically investigate some properties of BCIC and its connection with other information criteria, such as the Deviance Information Criterion (DIC). We illustrate the proposed methodology on linear mixed models with simulations and a real data example. PMID:26180578

  12. Integrated computational and conceptual solutions for complex environmental information management

    NASA Astrophysics Data System (ADS)

    Rückemann, Claus-Peter

    2016-06-01

    This paper presents the recent results of the integration of computational and conceptual solutions for the complex case of environmental information management. The solution for the major goal of creating and developing long-term multi-disciplinary knowledge resources and conceptual and computational support was achieved by implementing and integrating key components. The key components are long-term knowledge resources providing required structures for universal knowledge creation, documentation, and preservation, universal multi-disciplinary and multi-lingual conceptual knowledge and classification, especially, references to Universal Decimal Classification (UDC), sustainable workflows for environmental information management, and computational support for dynamical use, processing, and advanced scientific computing with Integrated Information and Computing System (IICS) components and High End Computing (HEC) resources.

  13. Bayesian Case-deletion Model Complexity and Information Criterion.

    PubMed

    Zhu, Hongtu; Ibrahim, Joseph G; Chen, Qingxia

    2014-10-01

    We establish a connection between Bayesian case influence measures for assessing the influence of individual observations and Bayesian predictive methods for evaluating the predictive performance of a model and comparing different models fitted to the same dataset. Based on such a connection, we formally propose a new set of Bayesian case-deletion model complexity (BCMC) measures for quantifying the effective number of parameters in a given statistical model. Its properties in linear models are explored. Adding some functions of BCMC to a conditional deviance function leads to a Bayesian case-deletion information criterion (BCIC) for comparing models. We systematically investigate some properties of BCIC and its connection with other information criteria, such as the Deviance Information Criterion (DIC). We illustrate the proposed methodology on linear mixed models with simulations and a real data example.

  14. Review: Formation of Peptide Radical Ions Through Dissociative Electron Transfer in Ternary Metal-Ligand-Peptide Complexes

    SciTech Connect

    Chu, Ivan K.; Laskin, Julia

    2011-12-31

    The formation and fragmentation of odd-electron ions of peptides and proteins is of interest to applications in biological mass spectrometry. Gas-phase redox chemistry occurring during collision-induced dissociation of ternary metal-ligand-peptide complexes enables the formation of a variety of peptide radicals including the canonical radical cations, M{sup +{sm_bullet}}, radical dications, [M{sup +}H]{sup 2+{sm_bullet}}, radical anions, [M-2H]{sup -{sm_bullet}}. In addition, odd-electron peptide ions with well-defined initial location of the radical site are produced through side chain losses from the radical ions. Subsequent fragmentation of these species provides information on the role of charge and the location of the radical site on the competition between radical-induced and proton-driven fragmentation of odd-electron peptide ions. This account summarizes current understanding of the factors that control the efficiency of the intramolecular electron transfer (ET) in ternary metal-ligand-peptide complexes resulting in formation of odd-electron peptide ions. Specifically, we discuss the effect of the metal center, the ligand and the peptide structure on the competition between the ET, proton transfer (PT), and loss of neutral peptide and neutral peptide fragments from the complex. Fundamental studies of the structures, stabilities, and the energetics and dynamics of fragmentation of such complexes are also important for detailed molecular-level understanding of photosynthesis and respiration in biological systems.

  15. A case report in health information exchange for inter-organizational patient transfers.

    PubMed

    Richardson, J E; Malhotra, S; Kaushal, R

    2014-01-01

    To provide a case report of barriers and promoters to implementing a health information exchange (HIE) tool that supports patient transfers between hospitals and skilled nursing facilities. A multi-disciplinary team conducted semi-structured telephone and in-person interviews in a purposive sample of HIE organizational informants and providers in New York City who implemented HIE to share patient transfer information. The researchers conducted grounded theory analysis to identify themes of barriers and promoters and took steps to improve the trustworthiness of the results including vetting from a knowledgeable study participant. Between May and October 2011, researchers recruited 18 participants: informaticians, healthcare administrators, software engineers, and providers from a skilled nursing facility. Subjects perceived the HIE tool's development a success in that it brought together stakeholders who had traditionally not partnered for informatics work, and that they could successfully share patient transfer information between a hospital and a skilled nursing facility. Perceived barriers included lack of hospital stakeholder buy-in and misalignment with clinical workflows that inhibited use of HIE-based patient transfer data. Participants described barriers and promoters in themes related to organizational, technical, and user-oriented issues. The investigation revealed that stakeholders could develop and implement health information technology that technically enables clinicians in both hospitals and skilled nursing facilities to exchange real-time information in support of patient transfers. User level barriers, particularly in the emergency department, should give pause to developers and implementers who plan to use HIE in support of patient transfers. Participants' experiences demonstrate how stakeholders may succeed in developing and piloting an electronic transfer form that relies on HIE to aggregate, communicate, and display relevant patient transfer

  16. [Palliative care at home, transferring information to emergency medical teams].

    PubMed

    Ribeaucoup, Luc; Roche, Blandine

    2015-11-01

    Many people wish to die at home. However, the end-of-life period can be marked by the occurrence of numerous symptoms causing situations of crisis. Emergency medical teams are therefore frequently called upon. In order to be able to make the right decisions in a short space of time, they must have quick access to all the relevant information.

  17. The cost of concreteness: the effect of nonessential information on analogical transfer.

    PubMed

    Kaminski, Jennifer A; Sloutsky, Vladimir M; Heckler, Andrew F

    2013-03-01

    Most theories of analogical transfer focus on similarities between the learning and transfer domains, where transfer is more likely between domains that share common surface features, similar elements, or common interpretations of structure. We suggest that characteristics of the learning instantiation alone can give rise to different levels of transfer. We propose that concreteness of the learning instantiation can hinder analogical transfer of well-defined structured concepts, such as mathematical concepts. We operationalize the term concreteness as the amount of information communicated through a specific instantiation of a concept. The 5 reported experiments with undergraduate students tested the hypothesis by presenting participants with the concept of a commutative mathematical group of order 3. The experiments varied the level of concreteness of the training instantiation and measured transfer of learning to a new instantiation. The results support the hypothesis, demonstrating better transfer from more generic instantiations (i.e., ones that communicate minimal extraneous information) than from more concrete instantiations. Specifically, concreteness was found to create an obstacle to successful structural alignment across domains, whereas generic instantiations led to spontaneous structural alignment. These findings have important implications for the theory of learning and transfer and practical implications for the design of educational material. Although some concreteness may activate prior knowledge and perhaps offer a leg up in the learning process, this benefit may come at the cost of transfer.

  18. Energy transfer and aggregate size effects in the inhomogeneously broadened core light-harvesting complex of Rhodobacter sphaeroides

    NASA Astrophysics Data System (ADS)

    van Mourik, F.; Visschers, R. W.; van Grondelle, R.

    1992-05-01

    The 4 K fluorescence emission spectrum of the core light-harvesting complex of the photosynthetic purple bacterium Rhodobacter sphaeroides is shown to depend strongly on the wavelength of excitation. It is concluded that the dominant factor determining the absorption spectrum is inhomogeneous broadening. The site-selected emission spectra are interpreted in terms of energy transfer in a cluster of weakly coupled pigments. Each individual cluster is supposed to be a random sample from the total inhomogeneously broadened pigment pool. For small clusters, with efficient energy transfer leading to fast thermalization, the effects of site-selection depend on the cluster-size only. It is shown that site-selective excitation can yield information about the number of coupled pigments in such a cluster. For the purified LH-1 of Rb. sphaeroides the cluster size was estimated to be 16 pigments.

  19. Charge-transfer complexes of bromine atoms with haloalkanes and alkanes

    SciTech Connect

    Alfassi, Z.B.; Huie, R.E.; Neta, P. ); Mittal, J.P.; Shoute, L.C.T. )

    1993-09-09

    Charge-transfer complexes of bromine atoms with haloalkanes and alkanes were produced by pulse radiolysis and by laser-flash photolysis in various organic solvents. Br atoms were produced by photolysis of Br[sub 2] (at 351 or 248 nm), by photolysis of bromoalkanes (at 248 nm), or by radiolysis of bromoalkanes (either in liquid form or in cyclohexane solutions). The transient spectra, monitored within microseconds after the pulse, had absorption maxima that varied between 300 and 500 nm and are ascribed to complexes of Br atoms with the various solvents or other solutes present. The absorption maxima for Br atom complexes with alkanes and chloroalkanes correlate with the ionization potential of these molecules, suggesting the existence of charge-transfer complexes. The correlation for the bromoalkanes was more complex. CBr[sub 4]Br and CHBr[sub 3][center dot]Br were observed to react rapidly (k = 10[sup 8]-10[sup 9] L mol[sup [minus]1] s[sup [minus]1]) with Br[sub 2] and with HBr to transfer their Br atom to these latter molecules. 16 refs., 5 figs., 2 tabs.

  20. Defining information need in health – assimilating complex theories derived from information science

    PubMed Central

    Ormandy, Paula

    2010-01-01

    Abstract Background  Key policy drivers worldwide include optimizing patients’ roles in managing their care; focusing services around patients’ needs and preferences; and providing information to support patients’ contributions and choices. The term information need penetrates many policy documents. Information need is espoused as the foundation from which to develop patient‐centred or patient‐led services. Yet there is no clear definition as to what the term means or how patients’ information needs inform and shape information provision and patient care. Theoretical synthesis  The assimilation of complex theories originating from information science has much to offer considerations of patient information need within the context of health care. Health‐related research often focuses on the content of information patients prefer, not why they need information. This paper extends and applies knowledge of information behaviour to considerations of information need in health, exposing a working definition for patient information need that reiterates the importance of considering the patient’s goals and understanding the patient’s context/situation. A patient information need is defined as ‘recognition that their knowledge is inadequate to satisfy a goal, within the context/situation that they find themselves at a specific point in the time’. This typifies the key concepts of national/international health policy, the centrality and importance of the patient. Conclusions  The proposed definition of patient information need provides a conceptual framework to guide health‐care practitioners on what to consider and why when meeting the information needs of patients in practice. This creates a solid foundation from which to inform future research. PMID:20550592

  1. Defining information need in health - assimilating complex theories derived from information science.

    PubMed

    Ormandy, Paula

    2011-03-01

    Key policy drivers worldwide include optimizing patients' roles in managing their care; focusing services around patients' needs and preferences; and providing information to support patients' contributions and choices. The term information need penetrates many policy documents. Information need is espoused as the foundation from which to develop patient-centred or patient-led services. Yet there is no clear definition as to what the term means or how patients' information needs inform and shape information provision and patient care. The assimilation of complex theories originating from information science has much to offer considerations of patient information need within the context of health care. Health-related research often focuses on the content of information patients prefer, not why they need information. This paper extends and applies knowledge of information behaviour to considerations of information need in health, exposing a working definition for patient information need that reiterates the importance of considering the patient's goals and understanding the patient's context/situation. A patient information need is defined as 'recognition that their knowledge is inadequate to satisfy a goal, within the context/situation that they find themselves at a specific point in the time'. This typifies the key concepts of national/international health policy, the centrality and importance of the patient. The proposed definition of patient information need provides a conceptual framework to guide health-care practitioners on what to consider and why when meeting the information needs of patients in practice. This creates a solid foundation from which to inform future research. © 2010 The Author. Health Expectations © 2010 Blackwell Publishing Ltd.

  2. A novel spectrophotometric determination of trace copper based on charge transfer complex

    NASA Astrophysics Data System (ADS)

    Di, Junwei; Wu, Ying; Ma, Yun

    2005-03-01

    A new type of colored complex, the charge transfer complex, was used to develop the spectrophotometric determination of copper. The method was based on the formation of a colored product, the charge transfer complex of copper substituted tungstophosphate with 3,3',5,5'-tetramethybenzidine (TMB), which was stabilized and sensitized by the addition of polyvinyl alcohol (PVA) in aqueous solution. The structure of copper substituted tungstophosphate was Keggin-type according to the results of infrared (IR) spectra. The optimum reaction conditions and other important analytic parameters had been investigated. Beer's law was obeyed in the copper(II) concentration range of 0.003-0.1 μg mL -1, and the molar absorptivity at 660 nm is 2.54×10 5 L mol -1 cm -1. The proposed method was simple, selective, and sensitive. It was applied to the analytic samples with satisfactory results.

  3. Electron transfer reactions of osmium(II) complexes with phenols and phenolic acids

    NASA Astrophysics Data System (ADS)

    Rajeswari, Angusamy; Ramdass, Arumugam; Muthu Mareeswaran, Paulpandian; Velayudham, Murugesan; Rajagopal, Seenivasan

    2016-07-01

    Three [Os(NN)3]2+ complexes (NN = polypyridine) with ligands of varying hydrophobicity were synthesized and characterized by NMR spectral techniques. The geometry of the molecules are optimized by DFT calculations. The interaction between [Os(NN)3]2+ complexes and phenolate ion in ground state is confirmed by absorption spectral study and the binding constant values are in the range of 3-740 M-1. The photoinduced electron transfer reaction of these [Os(NN)3]2+ complexes with phenols and phenolic acids at pH 12.5 leads to the formation of phenoxyl radical confirmed through transient absorption spectral study. Binding constants and electron transfer rate constants within the [Os(NN)3]2+-phenolate ion adduct account for the change for the overall quenching constant with the change of structure of reactants.

  4. Quantifying and Assuring Information Transfer in Dynamic Heterogeneous Wireless Networks

    DTIC Science & Technology

    2012-07-31

    Control and Information Sciences, Number 406, Springer-Verlag, Berlin, 2011. Cornell University 1. F. Losilla, A.-J. Garcia- Sanchez , F. Garcia... Sanchez , J. Garcia-Haro, and Z.J. Haas, A Comprehensive Approach to WSN-based ITS Applications: A Survey, Sensors 2011, 11, 10220-10265, October 28...Z.J. Haas, Network-Coding-based Security for Ad Hoc Networks, under journal consideration, 2011 4. C. Garcia-Costa, E. Egea- Lopez , J. Tomas-Gabarron

  5. Stimulus Size Dependence of Information Transfer from Retina to Thalamus

    PubMed Central

    Uglesich, Robert; Casti, Alex; Hayot, Fernand; Kaplan, Ehud

    2009-01-01

    Relay cells in the mammalian lateral geniculate nucleus (LGN) are driven primarily by single retinal ganglion cells (RGCs). However, an LGN cell responds typically to less than half of the spikes it receives from the RGC that drives it, and without retinal drive the LGN is silent (Kaplan and Shapley, 1984). Recent studies, which used stimuli restricted to the receptive field (RF) center, show that despite the great loss of spikes, more than half of the information carried by the RGC discharge is typically preserved in the LGN discharge (Sincich et al., 2009), suggesting that the retinal spikes that are deleted by the LGN carry less information than those that are transmitted to the cortex. To determine how LGN relay neurons decide which retinal spikes to respond to, we recorded extracellularly from the cat LGN relay cell spikes together with the slow synaptic (‘S’) potentials that signal the firing of retinal spikes. We investigated the influence of the inhibitory surround of the LGN RF by stimulating the eyes with spots of various sizes, the largest of which covered the center and surround of the LGN relay cell's RF. We found that for stimuli that activated mostly the RF center, each LGN spike delivered more information than the retinal spike, but this difference was reduced as stimulus size increased to cover the RF surround. To evaluate the optimality of the LGN editing of retinal spikes, we created artificial spike trains from the retinal ones by various deletion schemes. We found that single LGN cells transmitted less information than an optimal detector could. PMID:19838326

  6. Quantum storage and information transfer with superconducting qubits

    NASA Astrophysics Data System (ADS)

    Wang, Y. D.; Wang, Z. D.; Sun, C. P.

    2005-11-01

    We theoretically design a rather simple device to realize the general quantum storage based on dc superconducting quantum interference device charge qubits. The distinct advantages of our scheme are analyzed in comparison with existing storage scenarios. More arrestingly, an easily controllable XY interaction has been realized in superconducting qubits, which may have more potential applications in addition to those in quantum information processing. The experimental feasibility is also elaborated.

  7. Transferring information through a mixed-five-spin chain channel

    NASA Astrophysics Data System (ADS)

    Arian Zad, Hamid; Movahhedian, Hossein

    2016-08-01

    We initially introduce one-dimensional mixed-five-spin chain with Ising-XY model which includes mixture of spins-1/2 and spins-1. Here, it is considered that nearest spins (1,1/2) have Ising-type interaction and nearest spins (1/2,1/2) have both XY-type and Dzyaloshinskii-Moriya (DM) interactions together. Nearest spins (1,1) have XX Heisenberg interaction. This system is in the vicinity of an external homogeneous magnetic field B in thermal equilibrium state. We promote the quantum information transmitting protocol verified for a normal spin chain with simple model (refer to Rossini D, Giovannetti V and Fazio R 2007 Int. J. Quantum Infor. 5 439) (widely in reference: Giovannetti V and Fazio R 2005 Phys. Rev. A 71 032314) by means of considering the suggested mixed-five-spin chain as a quantum communication channel for transmitting both qubits and qutrits ideally. Hence, we investigate some useful quantities such as quantum capacity and quantum information transmission rate for the system. Finally, we conclude that, when the DM interaction between spins (1/2,1/2) increases the system is a more ideal channel for transmitting information.

  8. Spectroscopic evidence for charge-transfer complexation in monoclonal antibodies that bind opiates.

    PubMed

    Droupadi, P R; Meyers, E A; Linthicum, D S

    1994-04-01

    Molecular complexes of four monoclonal anti-morphine antibodies (mAb) with the opiate ligands morphine, oxymorphone, and naloxone were studied using UV-VIS absorption spectroscopy. Although strong overlaps in the absorption spectra of the antibodies, ligands, and complexes were observed, a curve-fitting method was developed to correlate the absorbance with the concentration of the ligand-antibody complex. Using this technique, we determined the intrinsic association constants for the mAb with morphine to be in the nanomolar range, while association constants for oxymorphone and naloxone were in the micromolar range. These values were found to be in agreement with previous radioimmunoassay determinations. We also observed different changes in the absorbancy of the mAb upon complexation with different ligands and such changes were found to be different for all four mAb examined. Upon complexation with the ligand morphine, two of the mAb (clone numbers MOR368-21 and MOR10.5) displayed distinct charge-transfer spectral bands in the 320-nm region. These observations suggest that mAb binding site tryptophans may participate in the formation of the antibody-ligand complex and such complexation involves a charge-transfer interaction.

  9. CISAPS: Complex Informational Spectrum for the Analysis of Protein Sequences.

    PubMed

    Chrysostomou, Charalambos; Seker, Huseyin; Aydin, Nizamettin

    2015-01-01

    Complex informational spectrum analysis for protein sequences (CISAPS) and its web-based server are developed and presented. As recent studies show, only the use of the absolute spectrum in the analysis of protein sequences using the informational spectrum analysis is proven to be insufficient. Therefore, CISAPS is developed to consider and provide results in three forms including absolute, real, and imaginary spectrum. Biologically related features to the analysis of influenza A subtypes as presented as a case study in this study can also appear individually either in the real or imaginary spectrum. As the results presented, protein classes can present similarities or differences according to the features extracted from CISAPS web server. These associations are probable to be related with the protein feature that the specific amino acid index represents. In addition, various technical issues such as zero-padding and windowing that may affect the analysis are also addressed. CISAPS uses an expanded list of 611 unique amino acid indices where each one represents a different property to perform the analysis. This web-based server enables researchers with little knowledge of signal processing methods to apply and include complex informational spectrum analysis to their work.

  10. CISAPS: Complex Informational Spectrum for the Analysis of Protein Sequences

    PubMed Central

    Seker, Huseyin; Aydin, Nizamettin

    2015-01-01

    Complex informational spectrum analysis for protein sequences (CISAPS) and its web-based server are developed and presented. As recent studies show, only the use of the absolute spectrum in the analysis of protein sequences using the informational spectrum analysis is proven to be insufficient. Therefore, CISAPS is developed to consider and provide results in three forms including absolute, real, and imaginary spectrum. Biologically related features to the analysis of influenza A subtypes as presented as a case study in this study can also appear individually either in the real or imaginary spectrum. As the results presented, protein classes can present similarities or differences according to the features extracted from CISAPS web server. These associations are probable to be related with the protein feature that the specific amino acid index represents. In addition, various technical issues such as zero-padding and windowing that may affect the analysis are also addressed. CISAPS uses an expanded list of 611 unique amino acid indices where each one represents a different property to perform the analysis. This web-based server enables researchers with little knowledge of signal processing methods to apply and include complex informational spectrum analysis to their work. PMID:25632276

  11. Reinforcing Visual Grouping Cues to Communicate Complex Informational Structure.

    PubMed

    Bae, Juhee; Watson, Benjamin

    2014-12-01

    In his book Multimedia Learning [7], Richard Mayer asserts that viewers learn best from imagery that provides them with cues to help them organize new information into the correct knowledge structures. Designers have long been exploiting the Gestalt laws of visual grouping to deliver viewers those cues using visual hierarchy, often communicating structures much more complex than the simple organizations studied in psychological research. Unfortunately, designers are largely practical in their work, and have not paused to build a complex theory of structural communication. If we are to build a tool to help novices create effective and well structured visuals, we need a better understanding of how to create them. Our work takes a first step toward addressing this lack, studying how five of the many grouping cues (proximity, color similarity, common region, connectivity, and alignment) can be effectively combined to communicate structured text and imagery from real world examples. To measure the effectiveness of this structural communication, we applied a digital version of card sorting, a method widely used in anthropology and cognitive science to extract cognitive structures. We then used tree edit distance to measure the difference between perceived and communicated structures. Our most significant findings are: 1) with careful design, complex structure can be communicated clearly; 2) communicating complex structure is best done with multiple reinforcing grouping cues; 3) common region (use of containers such as boxes) is particularly effective at communicating structure; and 4) alignment is a weak structural communicator.

  12. Image information transfer via electromagnetically induced transparency-based slow light

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Xiao; Sun, Jia-Xiang; Sun, Yuan-Hang; Li, Ai-Jun; Chen, Yi; Zhang, Xiao-Jun; Kang, Zhi-Hui; Wang, Lei; Wang, Hai-Hua; Gao, Jin-Yue

    2015-07-01

    In this work, we experimentally demonstrate an image information transfer between two channels by using slow light based on electromagnetically induced transparency (EIT) in a solid. The probe optical image is slowed due to steep dispersion induced by EIT. By applying an additional control field to an EIT-driven medium, the slowed image is transferred into two information channels. Image intensities between two information channels can be controlled by adjusting the intensities of the control fields. The similarity of output images is further analyzed. This image information transfer allows for manipulating images in a controlled fashion, and will be important in further information processing. Project supported by the National Basic Research Program of China (Grant No. 2011CB921603), the National Natural Science Foundation of China (Grant Nos. 11374126, 11347137, 11204103, 11404336, and 11204029), and the Fund for Fostering Talents in Basic Science of the National Natural Science Foundation of China (Grant No. J1103202).

  13. Excitation-Energy Transfer Dynamics of Higher Plant Photosystem I Light-Harvesting Complexes

    PubMed Central

    Wientjes, Emilie; van Stokkum, Ivo H.M.; van Amerongen, Herbert; Croce, Roberta

    2011-01-01

    Photosystem I (PSI) plays a major role in the light reactions of photosynthesis. In higher plants, PSI is composed of a core complex and four outer antennas that are assembled as two dimers, Lhca1/4 and Lhca2/3. Time-resolved fluorescence measurements on the isolated dimers show very similar kinetics. The intermonomer transfer processes are resolved using target analysis. They occur at rates similar to those observed in transfer to the PSI core, suggesting competition between the two transfer pathways. It appears that each dimer is adopting various conformations that correspond to different lifetimes and emission spectra. A special feature of the Lhca complexes is the presence of an absorption band at low energy, originating from an excitonic state of a chlorophyll dimer, mixed with a charge-transfer state. These low-energy bands have high oscillator strengths and they are superradiant in both Lhca1/4 and Lhca2/3. This challenges the view that the low-energy charge-transfer state always functions as a quencher in plant Lhc's and it also challenges previous interpretations of PSI kinetics. The very similar properties of the low-energy states of both dimers indicate that the organization of the involved chlorophylls should also be similar, in disagreement with the available structural data. PMID:21354411

  14. Proton transfer in phenol-amine complexes: phenol electronic effects on free energy profile in solution.

    PubMed

    Aono, Shinji; Kato, Shigeki

    2010-12-01

    Free energy profiles for the proton transfer reactions in hydrogen-bonded complex of phenol with trimethylamine in methyl chloride solvent are studied with the reference interaction site model self-consistent field method. The reactions in both the electronic ground and excited states are considered. The second-order Møller-Plesset perturbation (MP) theory or the second-order multireference MP theory is used to evaluate the effect of the dynamical electron correlation on the free energy profiles. The free energy surface in the ground state shows a discrepancy with the experimental results for the related hydrogen-bonded complexes. To resolve this discrepancy, the effects of chloro-substitutions in phenol are examined, and its importance in stabilizing the ionic form is discussed. The temperature effect is also studied. In contrast to the ground state, the ππ* excited state of phenol-trimethylamine complex exhibits the proton transfer reaction with a low barrier. The reaction is almost thermoneutral. This is attributed to the reduction of proton affinity of phenol by the ππ* electronic excitation. We further examine the possibility of the electron-proton-coupled transfer in the ππ* state through the surface crossing with the charge transfer type πσ* state.

  15. Synthesis and electrochemical studies of charge-transfer complexes of thiazolidine-2,4-dione with σ and π acceptors

    NASA Astrophysics Data System (ADS)

    Singh, Prashant; Kumar, Pradeep; Katyal, Anju; Kalra, Rashmi; Dass, Sujata K.; Prakash, Satya; Chandra, Ramesh

    2010-03-01

    In the present work, we report the synthesis and characterization of novel charge-transfer complexes of thiazolidine-2,4-dione (TZD) with sigma acceptor (iodine) and pi acceptors (chloranil, dichlorodicyanoquinone, picric acid and duraquinone). We also evaluated their thermal and electrochemical properties and we conclude that these complexes are frequency dependent. Charge-transfer complex between thiazolidine-2,4-dione and iodine give best conductivity. In conclusion, complex with sigma acceptors are more conducting than with pi acceptors.

  16. Minimal classical communication and measurement complexity for quantum information splitting

    NASA Astrophysics Data System (ADS)

    Zhang, Zhan-jun; Cheung, Chi-Yee

    2008-01-01

    We present two quantum information splitting schemes using respectively tripartite GHZ and asymmetric W states as quantum channels. We show that if the secret state is chosen from a special ensemble and known to the sender (Alice), then she can split and distribute it to the receivers Bob and Charlie by performing only a single-qubit measurement and broadcasting a one-cbit message. It is clear that no other schemes could possibly achieve the same goal with simpler measurement and less classical communication. In comparison, existing schemes work for arbitrary quantum states which need not be known to Alice; however she is required to perform a two-qubit Bell measurement and communicate a two-cbit message. Hence there is a trade-off between flexibility and measurement complexity plus classical resource. In situations where our schemes are applicable, they will greatly reduce the measurement complexity and at the same time cut the communication overhead by one half.

  17. Assessing information transfer in full mission flight simulations

    NASA Technical Reports Server (NTRS)

    Lee, Alfred T.

    1990-01-01

    Considerable attention must be given to the important topic of aircrew situation awareness in any discussion of aviation safety and flight deck design. Reliable means of assessing this important aspect of crew behavior without simultaneously interfering with the behavior are difficult to develop. Unobtrusive measurement of crew situation awareness is particularly important in the conduct of full mission simulations where considerable effort and cost is expended to achieve a high degree of operational fidelity. An unobtrusive method of assessing situational awareness is described here which employs a topical analysis of intra-crew communications. The communications were taken from videotapes of crew behavior prior to, during, and following an encounter with a microburst/windshear event. The simulation scenario re-created an actual encounter with an event during an approach into Denver Stapleton Airport. The analyses were conducted on twelve experienced airline crews with the objective of determining the effect on situation awareness of uplinking ground-based information of the crew during the approach. The topical analysis of crew communication was conducted on all references to weather or weather-related topics. The general weather topic was further divided into weather subtopical references such as surface winds, windshear, precipitation, etc., thereby allowing for an assessment of the relative frequency of subtopic reference during the scenario. Reliable differences were found between the relative frequency of subtopic references when comparing the communications of crews receiving a cockpit display of ground-based information to the communications of a control group. The findings support the utility of this method of assessing situation awareness and information value in full mission simulations. A limiting factor in the use of this measure is that crews vary in the amount of intra-crew communications that may take place due to individual differences and other

  18. Nonadiabatic dynamics of photoinduced proton-coupled electron transfer in a solvated phenol-amine complex.

    PubMed

    Goyal, Puja; Schwerdtfeger, Christine A; Soudackov, Alexander V; Hammes-Schiffer, Sharon

    2015-02-12

    Photoinduced concerted electron-proton transfer (EPT), denoted photo-EPT, is important for a wide range of energy conversion processes. Transient absorption and Raman spectroscopy experiments on the hydrogen-bonded p-nitrophenylphenol-t-butylamine complex, solvated in 1,2-dichloroethane, suggested that this complex may undergo photo-EPT. The experiments probed two excited electronic states that were interpreted as an intramolecular charge transfer (ICT) state and an EPT state. Herein mixed quantum mechanical/molecular mechanical nonadiabatic surface hopping dynamics is used to investigate the relaxation pathways following photoexcitation. The potential energy surface is generated on the fly with a semiempirical floating occupation molecular orbital complete active space configuration interaction method for the solute molecule and a molecular mechanical force field for the explicit solvent molecules. The free energy curves along the proton transfer coordinate illustrate that proton transfer is thermodynamically and kinetically favorable on the lower-energy excited state but not on the higher-energy excited state, supporting the characterization of these states as EPT and ICT, respectively. The nonadiabatic dynamics simulations indicate that the population decays from the ICT state to the EPT state in ∼100 fs and from the EPT state to the ground state on the slower time scale of ∼1 ps, qualitatively consistent with the experimental measurements. For ∼54% of the trajectories, the proton transfers from the phenol to the amine in ∼400 fs on the EPT state and then transfers back to the phenol rapidly upon decay to the ground state. Thus, these calculations augment the original interpretation of the experimental data by providing evidence of proton transfer on the EPT state prior to decay to the ground state. The fundamental insights obtained from these simulations are also relevant to other photo-EPT processes.

  19. Modeling electron transfer thermodynamics in protein complexes: interaction between two cytochromes c(3).

    PubMed

    Teixeira, Vitor H; Baptista, António M; Soares, Cláudio M

    2004-05-01

    Redox protein complexes between type I and type II tetraheme cytochromes c(3) from Desulfovibrio vulgaris Hildenborough are here analyzed using theoretical methodologies. Various complexes were generated using rigid-body docking techniques, and the two lowest energy complexes (1 and 2) were relaxed using molecular dynamics simulations with explicit solvent and subjected to further characterization. Complex 1 corresponds to an interaction between hemes I from both cytochromes c(3). Complex 2 corresponds to an interaction between the heme IV from type I and the heme I from type II cytochrome c(3). Binding free energy calculations using molecular mechanics, Poisson-Boltzmann, and surface accessibility methods show that complex 2 is more stable than complex 1. Thermodynamic calculations on complex 2 show that complex formation induces changes in the reduction potential of both cytochromes c(3), but the changes are larger in the type I cytochrome c(3) (the largest one occurring on heme IV, of approximately 80 mV). These changes are sufficient to invert the global titration curves of both cytochromes, generating directionally in electron transfer from type I to type II cytochrome c(3), a phenomenon of obvious thermodynamic origin and consequences, but also with kinetic implications. The existence of processes like this occurring at complex formation may constitute a natural design of efficient redox chains.

  20. Transferring the Concept of Multinuclearity to Ruthenium Complexes for Improvement of Anticancer Activity

    PubMed Central

    Mendoza-Ferri, Maria G.; Hartinger, Christian G.; Mendoza, Marco A.; Groessl, Michael; Egger, Alexander E.; Eichinger, Rene E.; Mangrum, John B.; Farrell, Nicholas P.; Maruszak, Magdalena; Bednarski, Patrick J.; Klein, Franz; Jakupec, Michael A.; Nazarov, Alexey A.; Severin, Kay; Keppler, Bernhard K.

    2010-01-01

    Multinuclear platinum anticancer complexes are a proven option to overcome resistance of established anticancer compounds. Transferring this concept to ruthenium complexes led to the synthesis of dinuclear Ru(II)–arene compounds containing a bis(pyridinone)alkane ligand linker. A pronounced influence of the spacer length on the in vitro anticancer activity was found, which is correlated to the lipophilicity of the complexes. IC50 values in the same dimension as for established platinum drugs were found in human tumor cell lines. No cross-resistance to oxoplatin, a cisplatin prodrug, was observed for the most active complex in three resistant cell lines; in fact, a 10-fold reversal of sensitivity in two of the oxoplatin-resistant lines was found. (Bio)analytical characterization of the representative examples showed that the ruthenium complexes hydrolyze rapidly, forming predominantly diaqua species that exhibit affinity toward transferrin and DNA, indicating that both proteins and nucleobases are potential targets. PMID:19170599

  1. Transferring the concept of multinuclearity to ruthenium complexes for improvement of anticancer activity.

    PubMed

    Mendoza-Ferri, Maria G; Hartinger, Christian G; Mendoza, Marco A; Groessl, Michael; Egger, Alexander E; Eichinger, Rene E; Mangrum, John B; Farrell, Nicholas P; Maruszak, Magdalena; Bednarski, Patrick J; Klein, Franz; Jakupec, Michael A; Nazarov, Alexey A; Severin, Kay; Keppler, Bernhard K

    2009-02-26

    Multinuclear platinum anticancer complexes are a proven option to overcome resistance of established anticancer compounds. Transferring this concept to ruthenium complexes led to the synthesis of dinuclear Ru(II)-arene compounds containing a bis(pyridinone)alkane ligand linker. A pronounced influence of the spacer length on the in vitro anticancer activity was found, which is correlated to the lipophilicity of the complexes. IC(50) values in the same dimension as for established platinum drugs were found in human tumor cell lines. No cross-resistance to oxoplatin, a cisplatin prodrug, was observed for the most active complex in three resistant cell lines; in fact, a 10-fold reversal of sensitivity in two of the oxoplatin-resistant lines was found. (Bio)analytical characterization of the representative examples showed that the ruthenium complexes hydrolyze rapidly, forming predominantly diaqua species that exhibit affinity toward transferrin and DNA, indicating that both proteins and nucleobases are potential targets.

  2. Electrostatic effects on proton coupled electron transfer in oxomanganese complexes inspired by the oxygen-evolving complex of photosystem II.

    PubMed

    Amin, Muhamed; Vogt, Leslie; Vassiliev, Serguei; Rivalta, Ivan; Sultan, Mohammad M; Bruce, Doug; Brudvig, Gary W; Batista, Victor S; Gunner, M R

    2013-05-23

    The influence of electrostatic interactions on the free energy of proton coupled electron transfer in biomimetic oxomanganese complexes inspired by the oxygen-evolving complex (OEC) of photosystem II (PSII) are investigated. The reported study introduces an enhanced multiconformer continuum electrostatics (MCCE) model, parametrized at the density functional theory (DFT) level with a classical valence model for the oxomanganese core. The calculated pKa's and oxidation midpoint potentials (E(m)'s) match experimental values for eight complexes, indicating that purely electrostatic contributions account for most of the observed couplings between deprotonation and oxidation state transitions. We focus on pKa's of terminal water ligands in [Mn(II/III)(H2O)6](2+/3+) (1), [Mn(III)(P)(H2O)2](3-) (2, P = 5,10,15,20-tetrakis(2,6-dichloro-3-sulfonatophenyl)porphyrinato), [Mn2(IV,IV)(μ-O)2(terpy)2(H2O)2](4+) (3, terpy = 2,2':6',2″-terpyridine), and [Mn3(IV,IV,IV)(μ-O)4(phen)4(H2O)2](4+) (4, phen = 1,10-phenanthroline) and the pKa's of μ-oxo bridges and Mn E(m)'s in [Mn2(μ-O)2(bpy)4] (5, bpy = 2,2'-bipyridyl), [Mn2(μ-O)2(salpn)2] (6, salpn = N,N'-bis(salicylidene)-1,3-propanediamine), [Mn2(μ-O)2(3,5-di(Cl)-salpn)2] (7), and [Mn2(μ-O)2(3,5-di(NO2)-salpn)2] (8). The analysis of complexes 6-8 highlights the strong coupling between electron and proton transfers, with any Mn oxidation lowering the pKa of an oxo bridge by 10.5 ± 0.9 pH units. The model also accounts for changes in the E(m)'s by ligand substituents, such as found in complexes 6-8, due to the electron withdrawing Cl (7) and NO2 (8). The reported study provides the foundation for analysis of electrostatic effects in other oxomanganese complexes and metalloenzymes, where proton coupled electron transfer plays a fundamental role in redox-leveling mechanisms.

  3. The mechanism of coupling between electron transfer and proton translocation in respiratory complex I.

    PubMed

    Sazanov, Leonid A

    2014-08-01

    NADH-ubiquinone oxidoreductase (complex I) is the first and largest enzyme in the respiratory chain of mitochondria and many bacteria. It couples the transfer of two electrons between NADH and ubiquinone to the translocation of four protons across the membrane. Complex I is an L-shaped assembly formed by the hydrophilic (peripheral) arm, containing all the redox centres performing electron transfer and the membrane arm, containing proton-translocating machinery. Mitochondrial complex I consists of 44 subunits of about 1 MDa in total, whilst the prokaryotic enzyme is simpler and generally consists of 14 conserved "core" subunits. Recently we have determined the first atomic structure of the entire complex I, using the enzyme from Thermus thermophilus (536 kDa, 16 subunits, 9 Fe-S clusters, 64 TM helices). Structure suggests a unique coupling mechanism, with redox energy of electron transfer driving proton translocation via long-range (up to ~200 Å) conformational changes. It resembles a steam engine, with coupling elements (akin to coupling rods) linking parts of this molecular machine.

  4. Theoretical Investigation of OCN(-) Charge Transfer Complexes in Condensed Phase Media: Spectroscopic Properties in Amorphous Ice

    NASA Technical Reports Server (NTRS)

    Park, Jin-Young; Woon, David E.

    2004-01-01

    Density functional theory (DFT) calculations of cyanate (OCN(-)) charge-transfer complexes were performed to model the "XCN" feature observed in interstellar icy grain mantles. OCN(-) charge-transfer complexes were formed from precursor combinations of HNCO or HOCN with either NH3 or H2O. Three different solvation strategies for realistically modeling the ice matrix environment were explored, including (1) continuum solvation, (2) pure DFT cluster calculations, and (3) an ONIOM DFT/PM3 cluster calculation. The model complexes were evaluated by their ability to reproduce seven spectroscopic measurements associated with XCN: the band origin of the OCN(-) asymmetric stretching mode, shifts in that frequency due to isotopic substitutions of C, N, O, and H, plus two weak features. The continuum solvent field method produced results consistent with some of the experimental data but failed to account for other behavior due to its limited capacity to describe molecular interactions with solvent. DFT cluster calculations successfully reproduced the available spectroscopic measurements very well. In particular, the deuterium shift showed excellent agreement in complexes where OCN(-) was fully solvated. Detailed studies of representative complexes including from two to twelve water molecules allowed the exploration of various possible solvation structures and provided insights into solvation trends. Moreover, complexes arising from cyanic or isocyanic acid in pure water suggested an alternative mechanism for the formation of OCN(-) charge-transfer complexes without the need for a strong base such as NH3 to be present. An extended ONIOM (B3LYP/PM3) cluster calculation was also performed to assess the impact of a more realistic environment on HNCO dissociation in pure water.

  5. Theoretical Investigation of OCN(-) Charge Transfer Complexes in Condensed Phase Media: Spectroscopic Properties in Amorphous Ice

    NASA Technical Reports Server (NTRS)

    Park, Jin-Young; Woon, David E.

    2004-01-01

    Density functional theory (DFT) calculations of cyanate (OCN(-)) charge-transfer complexes were performed to model the "XCN" feature observed in interstellar icy grain mantles. OCN(-) charge-transfer complexes were formed from precursor combinations of HNCO or HOCN with either NH3 or H2O. Three different solvation strategies for realistically modeling the ice matrix environment were explored, including (1) continuum solvation, (2) pure DFT cluster calculations, and (3) an ONIOM DFT/PM3 cluster calculation. The model complexes were evaluated by their ability to reproduce seven spectroscopic measurements associated with XCN: the band origin of the OCN(-) asymmetric stretching mode, shifts in that frequency due to isotopic substitutions of C, N, O, and H, plus two weak features. The continuum solvent field method produced results consistent with some of the experimental data but failed to account for other behavior due to its limited capacity to describe molecular interactions with solvent. DFT cluster calculations successfully reproduced the available spectroscopic measurements very well. In particular, the deuterium shift showed excellent agreement in complexes where OCN(-) was fully solvated. Detailed studies of representative complexes including from two to twelve water molecules allowed the exploration of various possible solvation structures and provided insights into solvation trends. Moreover, complexes arising from cyanic or isocyanic acid in pure water suggested an alternative mechanism for the formation of OCN(-) charge-transfer complexes without the need for a strong base such as NH3 to be present. An extended ONIOM (B3LYP/PM3) cluster calculation was also performed to assess the impact of a more realistic environment on HNCO dissociation in pure water.

  6. Formycin triphosphate-terbium complex: a novel spectroscopic probe for phosphoryl transfer enzymes.

    PubMed

    Kirk, W R; Amzel, L M

    1987-12-18

    The conditions under which the fluorescent pyrazolopyrimidine nucleotide formycin A triphosphate (7-amino-3-(beta-D-(5'- tripolyphosphate)ribofuranosyl)pyrazolo[4,3-d]pyrimidine, FTP) forms a 1:1 complex in solution with Tb3+ have been characterized. The complex has a dissociation constant of approx. 10(-7) M. Within the complex, the luminescence of Tb3+ is dramatically sensitized by energy transfer from formycin. The value for 50% transfer efficiency, Förster's R0 (Förster, T. (1964) in Modern Quantum Chemistry (Sinanoglu, O., ed.), pp. 93-137, Academic Press, New York) was determined to be 3.34 +/- 0.4 A, and the effective distance between the donor and acceptor transition dipoles, R, in the complex was estimated to be 6.6 +/- 1.0 A. The quantum yield of Tb3+ in the complex is sensitive to the number of O-H oscillators bound to the Tb3+, which allows determination of the number of waters bound to it (approx. 4). Preliminary results show that the complex binds to the phosphoryl transfer enzyme hexokinase in the presence of the glucose analogs N-acetylglucosamine, frucose and xylose, which are not phosphorylated by the enzyme. The binding occurs with a loss of energy efficiency consistent with a new distance from the effective transition dipole of formycin to that of terbium of approx. 9.6 A. The FTP-terbium complex can be used as both a spectroscopic and an X-ray diffraction probe. Studies with this compound should be most valuable for correlating solution and crystallographic data.

  7. Efficient transfer of weather information to the pilot in flight

    NASA Technical Reports Server (NTRS)

    Mcfarland, R. H.

    1982-01-01

    Efficient methods for providing weather information to the pilot in flight are summarized. Use of discrete communications channels in the aeronautical, VHF band or subcarriers in the VOR navigation band are considered the best possibilities. Data rates can be provided such that inputs to the ground based transmitters from 2400 band telephone lines are easily accommodated together with additional data. The crucial weather data considered for uplinking are identified as radar reflectivity patterns relating to precipitation, spherics data, hourly sequences, nowcasts, forecasts, cloud top heights with freezing and icing conditions, the critical weather map and satellite maps. NEXRAD, the ground based, Doppler weather radar which will produce an improved weather product also encourages use of an uplink to fully utilize its capability to improve air safety.

  8. Information transfer dynamics in fixed-pathways networks

    NASA Astrophysics Data System (ADS)

    Moyano, Luis G.; Cárdenas, Juan P.; Salcedo, Jorge; Mouronte, Mary Luz; Benito, Rosa M.

    2011-03-01

    Most complex technological networks are defined in such a way that their global properties are manifested at a dynamical level. An example of this is when internal dynamical processes are constrained to predefined pathways, without the possibility of alternate routes. For instance, large corporation software networks, where several flow processes take place, are typically routed along specific paths. In this work, we propose a model to describe the global characteristics of this kind of processes, where the dynamics depends on the state of the nodes, represented by two possibilities: responsive or blocked. We present numerical simulations that show rich global behavior with unexpected emerging properties. In particular, we show that two different regimes appear as a function of the total network load. Each regime is characterized by developing either a unimodal or a bimodal distribution for the density of responsive nodes, directly related to global efficiency. We provide a detailed explanation for the main characteristics of our results as well as an analysis of the implications for real technological systems.

  9. Influence of Humic Acid Complexation with Metal Ions on Extracellular Electron Transfer Activity

    NASA Astrophysics Data System (ADS)

    Zhou, Shungui; Chen, Shanshan; Yuan, Yong; Lu, Qin

    2015-11-01

    Humic acids (HAs) can act as electron shuttles and mediate biogeochemical cycles, thereby influencing the transformation of nutrients and environmental pollutants. HAs commonly complex with metals in the environment, but few studies have focused on how these metals affect the roles of HAs in extracellular electron transfer (EET). In this study, HA-metal (HA-M) complexes (HA-Fe, HA-Cu, and HA-Al) were prepared and characterized. The electron shuttle capacities of HA-M complexes were experimentally evaluated through microbial Fe(III) reduction, biocurrent generation, and microbial azoreduction. The results show that the electron shuttle capacities of HAs were enhanced after complexation with Fe but were weakened when using Cu or Al. Density functional theory calculations were performed to explore the structural geometry of the HA-M complexes and revealed the best binding sites of the HAs to metals and the varied charge transfer rate constants (k). The EET activity of the HA-M complexes were in the order HA-Fe > HA-Cu > HA-Al. These findings have important implications for biogeochemical redox processes given the ubiquitous nature of both HAs and various metals in the environment.

  10. Influence of Humic Acid Complexation with Metal Ions on Extracellular Electron Transfer Activity

    PubMed Central

    Zhou, Shungui; Chen, Shanshan; Yuan, Yong; Lu, Qin

    2015-01-01

    Humic acids (HAs) can act as electron shuttles and mediate biogeochemical cycles, thereby influencing the transformation of nutrients and environmental pollutants. HAs commonly complex with metals in the environment, but few studies have focused on how these metals affect the roles of HAs in extracellular electron transfer (EET). In this study, HA-metal (HA-M) complexes (HA-Fe, HA-Cu, and HA-Al) were prepared and characterized. The electron shuttle capacities of HA-M complexes were experimentally evaluated through microbial Fe(III) reduction, biocurrent generation, and microbial azoreduction. The results show that the electron shuttle capacities of HAs were enhanced after complexation with Fe but were weakened when using Cu or Al. Density functional theory calculations were performed to explore the structural geometry of the HA-M complexes and revealed the best binding sites of the HAs to metals and the varied charge transfer rate constants (k). The EET activity of the HA-M complexes were in the order HA-Fe > HA-Cu > HA-Al. These findings have important implications for biogeochemical redox processes given the ubiquitous nature of both HAs and various metals in the environment. PMID:26593782

  11. Influence of Humic Acid Complexation with Metal Ions on Extracellular Electron Transfer Activity.

    PubMed

    Zhou, Shungui; Chen, Shanshan; Yuan, Yong; Lu, Qin

    2015-11-23

    Humic acids (HAs) can act as electron shuttles and mediate biogeochemical cycles, thereby influencing the transformation of nutrients and environmental pollutants. HAs commonly complex with metals in the environment, but few studies have focused on how these metals affect the roles of HAs in extracellular electron transfer (EET). In this study, HA-metal (HA-M) complexes (HA-Fe, HA-Cu, and HA-Al) were prepared and characterized. The electron shuttle capacities of HA-M complexes were experimentally evaluated through microbial Fe(III) reduction, biocurrent generation, and microbial azoreduction. The results show that the electron shuttle capacities of HAs were enhanced after complexation with Fe but were weakened when using Cu or Al. Density functional theory calculations were performed to explore the structural geometry of the HA-M complexes and revealed the best binding sites of the HAs to metals and the varied charge transfer rate constants (k). The EET activity of the HA-M complexes were in the order HA-Fe > HA-Cu > HA-Al. These findings have important implications for biogeochemical redox processes given the ubiquitous nature of both HAs and various metals in the environment.

  12. Complexity vs. simplicity: groundwater model ranking using information criteria.

    PubMed

    Engelhardt, I; De Aguinaga, J G; Mikat, H; Schüth, C; Liedl, R

    2014-01-01

    A groundwater model characterized by a lack of field data about hydraulic model parameters and boundary conditions combined with many observation data sets for calibration purpose was investigated concerning model uncertainty. Seven different conceptual models with a stepwise increase from 0 to 30 adjustable parameters were calibrated using PEST. Residuals, sensitivities, the Akaike information criterion (AIC and AICc), Bayesian information criterion (BIC), and Kashyap's information criterion (KIC) were calculated for a set of seven inverse calibrated models with increasing complexity. Finally, the likelihood of each model was computed. Comparing only residuals of the different conceptual models leads to an overparameterization and certainty loss in the conceptual model approach. The model employing only uncalibrated hydraulic parameters, estimated from sedimentological information, obtained the worst AIC, BIC, and KIC values. Using only sedimentological data to derive hydraulic parameters introduces a systematic error into the simulation results and cannot be recommended for generating a valuable model. For numerical investigations with high numbers of calibration data the BIC and KIC select as optimal a simpler model than the AIC. The model with 15 adjusted parameters was evaluated by AIC as the best option and obtained a likelihood of 98%. The AIC disregards the potential model structure error and the selection of the KIC is, therefore, more appropriate. Sensitivities to piezometric heads were highest for the model with only five adjustable parameters and sensitivity coefficients were directly influenced by the changes in extracted groundwater volumes.

  13. Students Seeking Access to Four-Year Institutions: Community College Transfers [Background Information].

    ERIC Educational Resources Information Center

    Moore, Jamillah

    This publication provides background information for a hearing by the California Senate Select Committee on Higher Education and Outreach on December 3, 1997. The Introduction presents the Committee announcement, press release, agenda, information about transfer efforts in California, facts and figures about the community colleges, and the text of…

  14. Scientific and Technical Information Transfer for Education (STITE). Research Report No. 4.

    ERIC Educational Resources Information Center

    Zunde, Pranas

    Emphasizing the design of a data base management system for the experimental STITE (Scientific and Technical Information Transfer for Education) project, this progress report details the emerging features of this projected facility. Compiled by four STITE researchers, the report examines: science information communication, learning, dissemination,…

  15. Invited Reaction: Informal Learning and the Transfer of Learning--How Managers Develop Proficiency

    ERIC Educational Resources Information Center

    Marsick, Victoria J.

    2003-01-01

    Enos, Kehrhahn, and Bell have made an important contribution to measuring informal learning and its transfer as proficiency in a set of company-identified managerial skills. Measurement of informal learning is at the crux of research that seeks to link learning outcomes to other indicators of effective performance. The ability to show how informal…

  16. Super resolution nano-information recording in a new hydrazone metal complex material

    NASA Astrophysics Data System (ADS)

    Zhang, Kui; Wei, Jingsong; Chen, Zhimin; Wei, Tao; Geng, Yongyou; Wang, Yang; Wu, Yiqun

    2016-10-01

    Laser thermal lithography has been proposed for a few years, which has the advantages of breaking through the optical diffraction limit, operation in far-field and in air, and low production cost. In this paper, a new hydrazone metal complex is used as the laser thermal lithography material due to its feature of the one-step fabrication of micro/nano structure without mask and wet-etching process. Based on the laser thermal lithography method, super resolution nano-information pits are directly written on the surface of hydrazone metal complex thin films. Pits with a minimum feature size of about 79 nm are successfully obtained, which is only about 1/7 of the writing spot size. Moreover, the reactive ion etching method can be applied to transfer the pits onto a silica substrate. These results suggest the potential applications of the new material in high density optical data storage and semiconductor industries.

  17. Information transfer through stochastic transmission of a linear combination of rates.

    PubMed

    Smyrnakis, Ioannis; Smirnakis, Stelios

    2013-09-01

    In this work, the Shannon information transfer rate due to the transmission of a linear combination of the firing rates of a number of afferent neurons is examined. The transmission of this linear combination (transfer statistic) takes place through a stochastic firing process, while a rate code is assumed. Constraints are imposed on the transmission process by the requirement that the coefficient of variation for the transfer statistic is small and by the relative variance of the individual terms in the calculation of the statistic. In the regime of no noise or signal correlations among the input neurons, simulations suggest that information transfer for fixed overall input is favored when there are few high-firing neurons, as opposed to more lower-firing neurons. Signal correlations among low-firing neurons can result in aggregates of high firing rates, improving in this way information transfer and calculational robustness. Under reasonable rate code assumptions, information transfer rates obtained are of the order 3 to 10 bit/sec.

  18. Information management, today and tomorrow. [acquisition, manipulation, transfer, and display of information

    NASA Technical Reports Server (NTRS)

    Pryor, H. E.

    1975-01-01

    Current problems and future trends in information management are briefly summarized in relation to scientific and technical information management systems and management of management information (planning, marketing, and operations).

  19. Role of protein fluctuation correlations in electron transfer in photosynthetic complexes.

    PubMed

    Nesterov, Alexander I; Berman, Gennady P

    2015-04-01

    We consider the dependence of the electron transfer in photosynthetic complexes on correlation properties of random fluctuations of the protein environment. The electron subsystem is modeled by a finite network of connected electron (exciton) sites. The fluctuations of the protein environment are modeled by random telegraph processes, which act either collectively (correlated) or independently (uncorrelated) on the electron sites. We derived an exact closed system of first-order linear differential equations with constant coefficients, for the average density matrix elements and for their first moments. Under some conditions, we obtained analytic expressions for the electron transfer rates and found the range of parameters for their applicability by comparing with the exact numerical simulations. We also compared the correlated and uncorrelated regimes and demonstrated numerically that the uncorrelated fluctuations of the protein environment can, under some conditions, either increase or decrease the electron transfer rates.

  20. Structural insight into the TRIAP1/PRELI-like domain family of mitochondrial phospholipid transfer complexes.

    PubMed

    Miliara, Xeni; Garnett, James A; Tatsuta, Takashi; Abid Ali, Ferdos; Baldie, Heather; Pérez-Dorado, Inmaculada; Simpson, Peter; Yague, Ernesto; Langer, Thomas; Matthews, Stephen

    2015-07-01

    The composition of the mitochondrial membrane is important for its architecture and proper function. Mitochondria depend on a tightly regulated supply of phospholipid via intra-mitochondrial synthesis and by direct import from the endoplasmic reticulum. The Ups1/PRELI-like family together with its mitochondrial chaperones (TRIAP1/Mdm35) represent a unique heterodimeric lipid transfer system that is evolutionary conserved from yeast to man. Work presented here provides new atomic resolution insight into the function of a human member of this system. Crystal structures of free TRIAP1 and the TRIAP1-SLMO1 complex reveal how the PRELI domain is chaperoned during import into the intermembrane mitochondrial space. The structural resemblance of PRELI-like domain of SLMO1 with that of mammalian phoshatidylinositol transfer proteins (PITPs) suggest that they share similar lipid transfer mechanisms, in which access to a buried phospholipid-binding cavity is regulated by conformationally adaptable loops.

  1. Structural insight into the TRIAP1/PRELI-like domain family of mitochondrial phospholipid transfer complexes

    PubMed Central

    Miliara, Xeni; Garnett, James A; Tatsuta, Takashi; Abid Ali, Ferdos; Baldie, Heather; Pérez-Dorado, Inmaculada; Simpson, Peter; Yague, Ernesto; Langer, Thomas; Matthews, Stephen

    2015-01-01

    The composition of the mitochondrial membrane is important for its architecture and proper function. Mitochondria depend on a tightly regulated supply of phospholipid via intra-mitochondrial synthesis and by direct import from the endoplasmic reticulum. The Ups1/PRELI-like family together with its mitochondrial chaperones (TRIAP1/Mdm35) represent a unique heterodimeric lipid transfer system that is evolutionary conserved from yeast to man. Work presented here provides new atomic resolution insight into the function of a human member of this system. Crystal structures of free TRIAP1 and the TRIAP1–SLMO1 complex reveal how the PRELI domain is chaperoned during import into the intermembrane mitochondrial space. The structural resemblance of PRELI-like domain of SLMO1 with that of mammalian phoshatidylinositol transfer proteins (PITPs) suggest that they share similar lipid transfer mechanisms, in which access to a buried phospholipid-binding cavity is regulated by conformationally adaptable loops. PMID:26071602

  2. Excitation energy transfer in natural photosynthetic complexes and chlorophyll trefoils: hole-burning and single complex/trefoil spectroscopic studies

    SciTech Connect

    Ryszard Jankowiak, Kansas State University, Department of Chemistry, CBC Bldg., Manhattan KS, 66505; Phone: 532-6785

    2012-09-12

    In this project we studied both natural photosynthetic antenna complexes and various artificial systems (e.g. chlorophyll (Chl) trefoils) using high resolution hole-burning (HB) spectroscopy and excitonic calculations. Results obtained provided more insight into the electronic (excitonic) structure, inhomogeneity, electron-phonon coupling strength, vibrational frequencies, and excitation energy (or electron) transfer (EET) processes in several antennas and reaction centers. For example, our recent work provided important constraints and parameters for more advanced excitonic calculations of CP43, CP47, and PSII core complexes. Improved theoretical description of HB spectra for various model systems offers new insight into the excitonic structure and composition of low-energy absorption traps in very several antenna protein complexes and reaction centers. We anticipate that better understanding of HB spectra obtained for various photosynthetic complexes and their simultaneous fits with other optical spectra (i.e. absorption, emission, and circular dichroism spectra) provides more insight into the underlying electronic structures of these important biological systems. Our recent progress provides a necessary framework for probing the electronic structure of these systems via Hole Burning Spectroscopy. For example, we have shown that the theoretical description of non-resonant holes is more restrictive (in terms of possible site energies) than those of absorption and emission spectra. We have demonstrated that simultaneous description of linear optical spectra along with HB spectra provides more realistic site energies. We have also developed new algorithms to describe both nonresonant and resonant hole-burn spectra using more advanced Redfield theory. Simultaneous description of various optical spectra for complex biological system, e.g. artificial antenna systems, FMO protein complexes, water soluble protein complexes, and various mutants of reaction centers

  3. Resonance energy transfer study of hemoglobin and cytochrome c complexes with lipids.

    PubMed

    Gorbenko, G P

    1998-11-02

    The complexes of hemoglobin and cytochrome c with liposomes composed of phosphatidylcholine and its mixtures with cardiolipin and cholesterol have been studied by monitoring resonance energy transfer between fluorescent probe 3-methoxybenzanthrone as donor and heme groups of the proteins as acceptors. By analyzing experimental data within the framework of the model of energy transfer in two-dimensional systems, the limits of the range of possible heme positions with respect to lipid bilayer have been assessed. The distance of heme group of hemoglobin from the membrane center was found to increase in the presence of cardiolipin or cholesterol. The results obtained for cytochrome c complexes with cardiolipin-containing model membranes suggest the existence of preferential protein orientation relative to the lipid bilayer, and provide evidence for the protein penetration in the membrane interior.

  4. Distant ultrafast energy transfer in a trimetallic {Ru-Ru-Cr} complex facilitated by hole delocalization.

    PubMed

    Cadranel, Alejandro; Tate, Jaired E; Oviedo, Paola S; Yamazaki, Shiori; Hodak, José H; Baraldo, Luis M; Kleiman, Valeria D

    2017-01-25

    Multi-metallic complexes based on {Ru-Cr}, {Ru-Ru} and {Ru-Ru-Cr} fragments are investigated for their light-harvesting and long-range energy transfer properties. We report the synthesis and characterization of [Ru(tpy)(bpy)(μ-CN)Ru(py)4Cl](2+) and [Ru(tpy)(bpy)(μ-CN)Ru(py)4(μ-NC)Cr(CN)5]. The intercalation of {Ru(II)(py)4} linked by cyanide bridges between {Ru(tpy)(bpy)} and {Cr(CN)5} results in efficient, distant energy transfer followed by emission from the Cr moiety. Characterization of the energy transfer process based on photophysical and ultrafast time-resolved absorption suggests the delocalization of holes in the excited state, providing a pathway for energy transfer between the end moieties. The proposed mechanism opens the door to utilize this family of complexes as an appealing platform for the design of antenna compounds as the properties of the fragments could be tuned independently.

  5. Spectroscopic studies of charge transfer complexes between colchicine and some π acceptors

    NASA Astrophysics Data System (ADS)

    Arslan, Mustafa; Duymus, Hulya

    2007-07-01

    Charge transfer complexes between colchicine as donor and π acceptors such as tetracyanoethylene (TCNE), 2,3-dichloro-5,6-dicyano- p-benzoquinone (DDQ), p-chloranil ( p-CHL) have been studied spectrophotometrically in dichloromethane at 21 °C. The stoichiometry of the complexes was found to be 1:1 ratio by the Job method between donor and acceptors with the maximum absorption band at a wavelength of 535, 585 and 515 nm. The equilibrium constant and thermodynamic parameters of the complexes were determined by Benesi-Hildebrand and van't Hoff equations. Colchicine in pure form and in dosage form was applied in this study. The formation constants for the complexes were shown to be dependent on the structure of the electron acceptors used.

  6. A general exit strategy of monoheme cytochromes c and c2 in electron transfer complexes?

    PubMed

    De March, Matteo; Brancatelli, Giovanna; Demitri, Nicola; De Zorzi, Rita; Hickey, Neal; Geremia, Silvano

    2015-09-01

    Using our previously reported maps of the electrostatic surface of horse heart ferri- and ferro-cyt c, comparisons were made between the complementary electrostatic surfaces of three cyt c peroxidase-cyt c complexes and the photosynthetic reaction center-cyt c complex, considering both iron oxidation states. The results obtained were consistent with a sliding mechanism for the electron shuttle on the surface of the protein complexes, promoted by the change in iron oxidation state. This mechanism was found to be in agreement with theoretical and NMR studies reported in the literature. Importantly, the analysis also provided a rationale for recognition of nonproductive associations. As we have previously reported the same conclusion on examination of redox partners of cyt c in the mitochondrial respiratory pathway, our hypothesis is that the proposed mechanism could represent a general exit strategy of monoheme cyts c and c2 in electron transfer complexes. © 2015 International Union of Biochemistry and Molecular Biology.

  7. Backward transfer entropy: Informational measure for detecting hidden Markov models and its interpretations in thermodynamics, gambling and causality

    NASA Astrophysics Data System (ADS)

    Ito, Sosuke

    2016-11-01

    The transfer entropy is a well-established measure of information flow, which quantifies directed influence between two stochastic time series and has been shown to be useful in a variety fields of science. Here we introduce the transfer entropy of the backward time series called the backward transfer entropy, and show that the backward transfer entropy quantifies how far it is from dynamics to a hidden Markov model. Furthermore, we discuss physical interpretations of the backward transfer entropy in completely different settings of thermodynamics for information processing and the gambling with side information. In both settings of thermodynamics and the gambling, the backward transfer entropy characterizes a possible loss of some benefit, where the conventional transfer entropy characterizes a possible benefit. Our result implies the deep connection between thermodynamics and the gambling in the presence of information flow, and that the backward transfer entropy would be useful as a novel measure of information flow in nonequilibrium thermodynamics, biochemical sciences, economics and statistics.

  8. Realistic 3D coherent transfer function inverse filtering of complex fields.

    PubMed

    Cotte, Yann; Toy, Fatih M; Arfire, Cristian; Kou, Shan Shan; Boss, Daniel; Bergoënd, Isabelle; Depeursinge, Christian

    2011-08-01

    We present a novel technique for three-dimensional (3D) image processing of complex fields. It consists in inverting the coherent image formation by filtering the complex spectrum with a realistic 3D coherent transfer function (CTF) of a high-NA digital holographic microscope. By combining scattering theory and signal processing, the method is demonstrated to yield the reconstruction of a scattering object field. Experimental reconstructions in phase and amplitude are presented under non-design imaging conditions. The suggested technique is best suited for an implementation in high-resolution diffraction tomography based on sample or illumination rotation.

  9. Realistic 3D coherent transfer function inverse filtering of complex fields

    PubMed Central

    Cotte, Yann; Toy, Fatih M.; Arfire, Cristian; Kou, Shan Shan; Boss, Daniel; Bergoënd, Isabelle; Depeursinge, Christian

    2011-01-01

    We present a novel technique for three-dimensional (3D) image processing of complex fields. It consists in inverting the coherent image formation by filtering the complex spectrum with a realistic 3D coherent transfer function (CTF) of a high-NA digital holographic microscope. By combining scattering theory and signal processing, the method is demonstrated to yield the reconstruction of a scattering object field. Experimental reconstructions in phase and amplitude are presented under non-design imaging conditions. The suggested technique is best suited for an implementation in high-resolution diffraction tomography based on sample or illumination rotation. PMID:21833359

  10. Molecularly Defined Manganese Pincer Complexes for Selective Transfer Hydrogenation of Ketones.

    PubMed

    Perez, Marc; Elangovan, Saravanakumar; Spannenberg, Anke; Junge, Kathrin; Beller, Matthias

    2017-01-10

    For the first time an easily accessible and well-defined manganese N,N,N-pincer complex catalyzes the transfer hydrogenation of a broad range of ketones with good to excellent yields. This cheap earth abundant-metal based catalyst provides access to useful secondary alcohols without the need of hydrogen gas. Preliminary investigations to explore the mechanism of this transformation are also reported. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. The analytical transfer matrix method for PT-symmetric complex potential

    NASA Astrophysics Data System (ADS)

    Naceri, Leila; Hammou, Amine B.

    2017-07-01

    We have extended the analytical transfer matrix (ATM) method to solve quantum mechanical bound state problems with complex PT-symmetric potentials. Our work focuses on a class of models studied by Bender and Jones, we calculate the energy eigenvalues, discuss the critical values of g and compare the results with those obtained from other methods such as exact numerical computation and WKB approximation method.

  12. Spectrophotometric study of the charge-transfer and ion-pair complexation of methamphetamine with some acceptors

    NASA Astrophysics Data System (ADS)

    Shahdousti, Parvin; Aghamohammadi, Mohammad; Alizadeh, Naader

    2008-04-01

    The charge-transfer (CT) complexes of methamphetamine (MPA) as a n-donor with several acceptors including bromocresolgreen (BCG), bromocresolpurple (BCP), chlorophenolred (CPR), picric acid (PIC), and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) have been studied spectrophotometrically in chloroform solutions in order to obtain some information about their stoichiometry and stability of complexation. The oscillator strengths, transition dipole moments and resonance energy of the complex in the ground state for all complexes have been calculated. Vertical ionization potential of MPA and electron affinity of acceptors were determined by ab initio calculation. The acceptors were also used to utilize a simple and sensitive extraction-spectrophotometric method for the determination of MPA. The method is based on the formation of 1:1 ion-pair association complexes of MPA with BCG, BCP and PIC in chloroform medium. Beer's plots were obeyed in a general concentration range of 0.24-22 μg ml -1 for the investigated drug with different acceptors. The proposed methods were applied successfully for the determination of MAP in pure and abuse drug with good accuracy and precision.

  13. Spectrophotometric study of the charge-transfer and ion-pair complexation of methamphetamine with some acceptors.

    PubMed

    Shahdousti, Parvin; Aghamohammadi, Mohammad; Alizadeh, Naader

    2008-04-01

    The charge-transfer (CT) complexes of methamphetamine (MPA) as a n-donor with several acceptors including bromocresolgreen (BCG), bromocresolpurple (BCP), chlorophenolred (CPR), picric acid (PIC), and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) have been studied spectrophotometrically in chloroform solutions in order to obtain some information about their stoichiometry and stability of complexation. The oscillator strengths, transition dipole moments and resonance energy of the complex in the ground state for all complexes have been calculated. Vertical ionization potential of MPA and electron affinity of acceptors were determined by ab initio calculation. The acceptors were also used to utilize a simple and sensitive extraction-spectrophotometric method for the determination of MPA. The method is based on the formation of 1:1 ion-pair association complexes of MPA with BCG, BCP and PIC in chloroform medium. Beer's plots were obeyed in a general concentration range of 0.24-22 microg ml(-1) for the investigated drug with different acceptors. The proposed methods were applied successfully for the determination of MAP in pure and abuse drug with good accuracy and precision.

  14. Structural Information Inference from Lanthanoid Complexing Systems: Photoluminescence Studies on Isolated Ions

    NASA Astrophysics Data System (ADS)

    Greisch, Jean Francois; Harding, Michael E.; Chmela, Jiri; Klopper, Willem M.; Schooss, Detlef; Kappes, Manfred M.

    2016-06-01

    The application of lanthanoid complexes ranges from photovoltaics and light-emitting diodes to quantum memories and biological assays. Rationalization of their design requires a thorough understanding of intramolecular processes such as energy transfer, charge transfer, and non-radiative decay involving their subunits. Characterization of the excited states of such complexes considerably benefits from mass spectrometric methods since the associated optical transitions and processes are strongly affected by stoichiometry, symmetry, and overall charge state. We report herein spectroscopic measurements on ensembles of ions trapped in the gas phase and soft-landed in neon matrices. Their interpretation is considerably facilitated by direct comparison with computations. The combination of energy- and time-resolved measurements on isolated species with density functional as well as ligand-field and Franck-Condon computations enables us to infer structural as well as dynamical information about the species studied. The approach is first illustrated for sets of model lanthanoid complexes whose structure and electronic properties are systematically varied via the substitution of one component (lanthanoid or alkali,alkali-earth ion): (i) systematic dependence of ligand-centered phosphorescence on the lanthanoid(III) promotion energy and its impact on sensitization, and (ii) structural changes induced by the substitution of alkali or alkali-earth ions in relation with structures inferred using ion mobility spectroscopy. The temperature dependence of sensitization is briefly discussed. The focus is then shifted to measurements involving europium complexes with doxycycline an antibiotic of the tetracycline family. Besides discussing the complexes' structural and electronic features, we report on their use to monitor enzymatic processes involving hydrogen peroxide or biologically relevant molecules such as adenosine triphosphate (ATP).

  15. Design of Photoactive Ruthenium Complexes to Study Electron Transfer and Proton Pumping in Cytochrome Oxidase

    PubMed Central

    Durham, Bill; Millett, Francis

    2011-01-01

    This review describes the development and application of photoactive ruthenium complexes to study electron transfer and proton pumping reactions in cytochrome c oxidase (CcO). CcO uses four electrons from Cc to reduce O2 to two waters, and pumps four protons across the membrane. The electron transfer reactions in cytochrome oxidase are very rapid, and cannot be resolved by stopped-flow mixing techniques. Methods have been developed to covalently attach a photoactive tris(bipyridine)ruthenium group [Ru(II)] to Cc to form Ru-39-Cc. Photoexcitation of Ru(II) to the excited state Ru(II*), a strong reductant, leads to rapid electron transfer to the ferric heme group in Cc, followed by electron transfer to CuA in CcO with a rate constant of 60,000 s−1. Ruthenium kinetics and mutagenesis studies have been used to define the domain for the interaction between Cc and CcO. New ruthenium dimers have also been developed to rapidly inject electrons into CuA of CcO with yields as high as 60%, allowing measurement of the kinetics of electron transfer and proton release at each step in the oxygen reduction mechanism. PMID:21939635

  16. Design of photoactive ruthenium complexes to study electron transfer and proton pumping in cytochrome oxidase.

    PubMed

    Durham, Bill; Millett, Francis

    2012-04-01

    This review describes the development and application of photoactive ruthenium complexes to study electron transfer and proton pumping reactions in cytochrome c oxidase (CcO). CcO uses four electrons from Cc to reduce O(2) to two waters, and pumps four protons across the membrane. The electron transfer reactions in cytochrome oxidase are very rapid, and cannot be resolved by stopped-flow mixing techniques. Methods have been developed to covalently attach a photoactive tris(bipyridine)ruthenium group [Ru(II)] to Cc to form Ru-39-Cc. Photoexcitation of Ru(II) to the excited state Ru(II*), a strong reductant, leads to rapid electron transfer to the ferric heme group in Cc, followed by electron transfer to Cu(A) in CcO with a rate constant of 60,000s(-1). Ruthenium kinetics and mutagenesis studies have been used to define the domain for the interaction between Cc and CcO. New ruthenium dimers have also been developed to rapidly inject electrons into Cu(A) of CcO with yields as high as 60%, allowing measurement of the kinetics of electron transfer and proton release at each step in the oxygen reduction mechanism.

  17. Conjugated polymer/porphyrin complexes for efficient energy transfer and improving light-activated antibacterial activity.

    PubMed

    Xing, Chengfen; Xu, Qingling; Tang, Hongwei; Liu, Libing; Wang, Shu

    2009-09-16

    With the increasing antibiotic resistance of microorganisms, there is a growing interest in the design and development of new materials that are effective in killing bacteria to replace conventional antibiotics. Herein, a new anionic water-soluble polythiophene (PTP) and a cationic porphyrin (TPPN) are synthesized and characterized. They can form a complex through electrostatic interactions, and efficient energy transfer from PTP to TPPN occurs upon irradiation under white light (400-800 nm). The energy of TPPN transfers to triplet by intersystem crossing, followed by sensitization of oxygen molecule to enhance the efficiency of singlet oxygen generation related to TPPN itself. The positive charges of PTP/TPPN complex promote its adsorption to the negatively charged bacteria membranes of gram-negative Escherichia coli and gram-positive Bacillus subtilis through electrostatic interactions, and the singlet oxygen effectively kills the bacteria. The photosensitized inactivation of bacteria for the PTP/TPPN complex is efficient, and about 70% reduction of bacterial viability is observed after only 5 min of irradiation with white light at a fluence rate of 90 mW x cm(-2) (27 J x cm(-2)). The technique provides a promising application in photodynamic inactivation of bacteria on the basis of enhanced energy transfer offered by light-harvesting conjugated polymers.

  18. Proton coupled electron transfer from the excited state of a ruthenium(II) pyridylimidazole complex.

    PubMed

    Pannwitz, Andrea; Wenger, Oliver S

    2016-04-28

    Proton coupled electron transfer (PCET) from the excited state of [Ru(bpy)2pyimH](2+) (bpy = 2,2'-bipyridine; pyimH = 2-(2'-pyridyl)imidazole) to N-methyl-4,4'-bipyridinium (monoquat, MQ(+)) was studied. While this complex has been investigated previously, our study is the first to show that the formal bond dissociation free energy (BDFE) of the imidazole-N-H bond decreases from (91 ± 1) kcal mol(-1) in the electronic ground state to (43 ± 5) kcal mol(-1) in the lowest-energetic (3)MLCT excited state. This makes the [Ru(bpy)2pyimH](2+) complex a very strong (formal) hydrogen atom donor even when compared to metal hydride complexes, and this is interesting for light-driven (formal) hydrogen atom transfer (HAT) reactions with a variety of different substrates. Mechanistically, formal HAT between (3)MLCT excited [Ru(bpy)2pyimH](2+) and monoquat in buffered 1 : 1 (v : v) CH3CN/H2O was found to occur via a sequence of reaction steps involving electron transfer from Ru(ii) to MQ(+) coupled to release of the N-H proton to buffer base, followed by protonation of reduced MQ(+) by buffer acid. Our study is relevant in the larger contexts of photoredox catalysis and light-to-chemical energy conversion.

  19. Information transfer and synchronization among the scales of climate variability: clues for understanding anomalies and extreme events?

    NASA Astrophysics Data System (ADS)

    Palus, Milan

    2017-04-01

    Deeper understanding of complex dynamics of the Earth atmosphere and climate is inevitable for sustainable development, mitigation and adaptation strategies for global change and for prediction of and resilience against extreme events. Traditional (linear) approaches cannot explain or even detect nonlinear interactions of dynamical processes evolving on multiple spatial and temporal scales. Combination of nonlinear dynamics and information theory explains synchronization as a process of adjustment of information rates [1] and causal relations (à la Granger) as information transfer [2]. Information born in dynamical complexity or information transferred among systems on a way to synchronization might appear as an abstract quantity, however, information transfer is tied to a transfer of mass and energy, as demonstrated in a recent study using directed (causal) climate networks [2]. Recently, an information transfer across scales of atmospheric dynamics has been observed [3]. In particular, a climate oscillation with the period around 7-8 years has been identified as a factor influencing variability of surface air temperature (SAT) on shorter time scales. Its influence on the amplitude of the SAT annual cycle was estimated in the range 0.7-1.4 °C and the effect on the overall variability of the SAT anomalies (SATA) leads to the changes 1.5-1.7 °C in the annual SATA means. The strongest effect of the 7-8 year cycle was observed in the winter SATA means where it reaches 4-5 °C in central European station and reanalysis data [4]. In the dynamics of El Niño-Southern Oscillation, three principal time scales have been identified: the annual cycle (AC), the quasibiennial (QB) mode(s) and the low-frequency (LF) variability. An intricate causal network of information flows among these modes helps to understand the occurrence of extreme El Niño events, characterized by synchronization of the QB modes and AC, and modulation of the QB amplitude by the LF mode. The latter

  20. Rare Earth Complex as Electron Trapper and Energy Transfer Ladder for Efficient Red Iridium Complex Based Electroluminescent Devices.

    PubMed

    Zhou, Liang; Li, Leijiao; Jiang, Yunlong; Cui, Rongzhen; Li, Yanan; Zhao, Xuesen; Zhang, Hongjie

    2015-07-29

    In this work, we experimentally demonstrated the new functions of trivalent rare earth complex in improving the electroluminescent (EL) performances of iridium complex by codoping trace Eu(TTA)3phen (TTA = thenoyltrifluoroacetone, phen = 1,10-phenanthroline) into a light-emitting layer based on PQ2Ir(dpm) (iridium(III)bis(2-phenylquinoly-N,C(2'))dipivaloylmethane). Compared with a reference device, the codoped devices displayed higher efficiencies, slower efficiency roll-off, higher brightness, and even better color purity. Experimental results demonstrated that Eu(TTA)3phen molecules function as electron trappers due to its low-lying energy levels, which are helpful in balancing holes and electrons and in broadening recombination zone. In addition, the matched triplet energy of Eu(TTA)3phen is instrumental in facilitating energy transfer from host to emitter. Finally, highly efficient red EL devices with the highest current efficiency, power efficiency and brightness up to 58.98 cd A(-1) (external quantum efficiency (EQE) of 21%), 61.73 lm W(-1) and 100870 cd m(-2), respectively, were obtained by appropriately decreasing the doping concentration of iridium complex. At certain brightness of 1000 cd m(-2), EL current efficiency up to 51.94 cd A(-1) (EQE = 18.5%) was retained. Our investigation extends the application of rare earth complexes in EL devices and provides a chance to improve the device performances.

  1. Exosomes and microvesicles: extracellular vesicles for genetic information transfer and gene therapy.

    PubMed

    Lee, Yi; El Andaloussi, Samir; Wood, Matthew J A

    2012-10-15

    Exosomes and microvesicles are extracellular nanovesicles released by most but not all cells. They are specifically equipped to mediate intercellular communication via the transfer of genetic information, including the transfer of both coding and non-coding RNAs, to recipient cells. As a result, both exosomes and microvesicles play a fundamental biological role in the regulation of normal physiological as well as aberrant pathological processes, via altered gene regulatory networks and/or via epigenetic programming. For example, microvesicle-mediated genetic transfer can regulate the maintenance of stem cell plasticity and induce beneficial cell phenotype modulation. Alternatively, such vesicles play a role in tumor pathogenesis and the spread of neurodegenerative diseases via the transfer of specific microRNAs and pathogenic proteins. Given this natural property for genetic information transfer, the possibility of exploiting these vesicles for therapeutic purposes is now being investigated. Stem cell-derived microvesicles appear to be naturally equipped to mediate tissue regeneration under certain conditions, while recent evidence suggests that exosomes might be harnessed for the targeted delivery of human genetic therapies via the introduction of exogenous genetic cargoes such as siRNA. Thus, extracellular vesicles are emerging as potent genetic information transfer agents underpinning a range of biological processes and with therapeutic potential.

  2. 26 CFR 1.6045A-1 - Statements of information required in connection with transfers of securities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... connection with transfers of securities. 1.6045A-1 Section 1.6045A-1 Internal Revenue INTERNAL REVENUE...) Information Returns § 1.6045A-1 Statements of information required in connection with transfers of securities... described in paragraph (a)(4) of this section) that transfers custody of a specified security to a...

  3. 26 CFR 1.6045A-1 - Statements of information required in connection with transfers of securities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... connection with transfers of securities. 1.6045A-1 Section 1.6045A-1 Internal Revenue INTERNAL REVENUE...) Information Returns § 1.6045A-1 Statements of information required in connection with transfers of securities... described in paragraph (a)(4) of this section) that transfers custody of a specified security to a...

  4. The physics of complex systems in information and biology

    NASA Astrophysics Data System (ADS)

    Walker, Dylan

    Citation networks have re-emerged as a topic intense interest in the complex networks community with the recent availability of large-scale data sets. The ranking of citation networks is a necessary practice as a means to improve information navigability and search. Unlike many information networks, the aging characteristics of citation networks require the development of new ranking methods. To account for strong aging characteristics of citation networks, we modify the PageRank algorithm by initially distributing random surfers exponentially with age, in favor of more recent publications. The output of this algorithm, which we call CiteRank, is interpreted as approximate traffic to individual publications in a simple model of how researchers find new information. We optimize parameters of our algorithm to achieve the best performance. The results are compared for two rather different citation networks: all American Physical Society publications between 1893-2003 and the set of high-energy physics theory (hep-th) preprints. Despite major differences between these two networks, we find that their optimal parameters for the CiteRank algorithm are remarkably similar. The advantages and performance of CiteRank over more conventional methods of ranking publications are discussed. Collaborative voting systems have emerged as an abundant form of real-world, complex information systems that exist in a variety of online applications. These systems are comprised of large populations of users that collectively submit and vote on objects. While the specific properties of these systems vary widely, many of them share a core set of features and dynamical behaviors that govern their evolution. We study a subset of these systems that involve material of a time-critical nature as in the popular example of news items. We consider a general model system in which articles are introduced, voted on by a population of users, and subsequently expire after a proscribed period of time. To

  5. Transfer of Phase Information between Microwave and Optical Fields via an Electron Spin.

    PubMed

    Lekavicius, Ignas; Golter, D Andrew; Oo, Thein; Wang, Hailin

    2017-08-11

    We demonstrate the coherent coupling and the resulting transfer of phase information between microwave and optical fields in a single nitrogen vacancy center in diamond. The relative phase of two microwave fields is encoded in a coherent superposition spin state. This phase information is then retrieved with a pair of optical fields. A related process is also used for the transfer of phase information from optical to microwave fields. These studies show the essential role of dark states, including optical pumping into the dark states, in the coherent microwave-optical coupling and open the door to the full quantum state transfer between microwave and optical fields in a solid-state spin ensemble.

  6. Study of charge transfer complexes of [70]fullerene with phenol and substituted phenols.

    PubMed

    Bhattacharya, Sumanta; Banerjee, Shrabanti; Banerjee, Manas

    2005-07-01

    To improve the understanding of the charge transfer (CT) interaction of [70]fullerene with electron donors, interaction of [70]fullerene with a series of phenols, e.g., phenol, resorcinol and p-quinol were studied in 1,4-dioxan medium using absorption spectroscopy. An absorption band due to CT transition was observed in the visible region. The experimental CT transition energies (h nuCT) are well correlated (through Mulliken's equation) with the vertical ionisation potentials (I(D)v) of the series of phenols studied. From an analysis of this correlation degrees of charge transfer for the [70]fullerene-phenol complexes were estimated. The degrees of charge transfer in the ground state of the complexes have been found to be very low (<2%). The h nuCT values change systematically as the number and position of the -OH groups change on the aromatic ring of the phenol moiety. From the trends in the h nuCT values, the Hückel parameters (h(O) and k(C-O)) for the -OH group were obtained in a straightforward way and the values so obtained, viz., 1.91 and 1.0, respectively, are close to the ones (1.8 and 0.8) recommended by Streitwieser on the basis of other evidence. Oscillator strengths, transition dipole strengths and resonance energies of the [70]fullerene-phenol complexes were determined. Formation constants of the CT complexes were determined at four different temperatures from which enthalpies and entropies of formation of the complexes were estimated.

  7. An application protocol for CAD to CAD transfer of electronic information

    NASA Technical Reports Server (NTRS)

    Azu, Charles C., Jr.

    1993-01-01

    The exchange of Computer Aided Design (CAD) information between dissimilar CAD systems is a problem. This is especially true for transferring electronics CAD information such as multi-chip module (MCM), hybrid microcircuit assembly (HMA), and printed circuit board (PCB) designs. Currently, there exists several neutral data formats for transferring electronics CAD information. These include IGES, EDIF, and DXF formats. All these formats have limitations for use in exchanging electronic data. In an attempt to overcome these limitations, the Navy's MicroCIM program implemented a project to transfer hybrid microcircuit design information between dissimilar CAD systems. The IGES (Initial Graphics Exchange Specification) format is used since it is well established within the CAD industry. The goal of the project is to have a complete transfer of microelectronic CAD information, using IGES, without any data loss. An Application Protocol (AP) is being developed to specify how hybrid microcircuit CAD information will be represented by IGES entity constructs. The AP defines which IGES data items are appropriate for describing HMA geometry, connectivity, and processing as well as HMA material characteristics.

  8. Transfer and distortion of atmospheric information in the satellite temperature retrieval problem

    NASA Technical Reports Server (NTRS)

    Thompson, O. E.

    1981-01-01

    A systematic approach to investigating the transfer of basic ambient temperature information and its distortion by satellite systems and subsequent analysis algorithms is discussed. The retrieval analysis cycle is derived, the variance spectrum of information is examined as it takes different forms in that process, and the quality and quantity of information existing at each stop is compared with the initial ambient temperature information. Temperature retrieval algorithms can smooth, add, or further distort information, depending on how stable the algorithm is, and how heavily influenced by a priori data.

  9. Interfacial Hydration, Dynamics and Electron Transfer: Multi-Scale ET Modeling of the Transient [Myoglobin, Cytochrome b5] Complex

    PubMed Central

    Keinan, Shahar; Nocek, Judith M.; Beratan, David N.; Hoffman, Brian M.

    2012-01-01

    Formation of a transient [myoglobin (Mb), cytochrome b5 (cyt b5)] complex is required for the reductive repair of inactive ferri-Mb to its functional ferro-Mb state. The [Mb, cyt b5] complex exhibits dynamic docking (DD), with its cyt b5 partner in rapid exchange at multiple sites on the Mb surface. A triple mutant (Mb(3M)) was designed as part of efforts to shift the electron-transfer process to the simple docking (SD) regime, in which reactive binding occurs at a restricted, reactive region on the Mb surface that dominates the docked ensemble.1 An electrostatically-guided Brownian dynamics (BD) docking protocol was used to generate an initial ensemble of reactive configurations of the complex between unrelaxed partners. This ensemble samples a broad and diverse array of heme-heme distances and orientations. These configurations seeded all-atom constrained molecular dynamics simulations (MD) to generate relaxed complexes for the calculation of electron tunneling matrix elements (TDA) through tunneling-pathway analysis. This procedure for generating an ensemble of relaxed complexes combines the ability of BD calculations to sample the large variety of available conformations and interprotein distances, with the ability of MD to generate the atomic level information, especially regarding the structure of water molecules at the protein-protein interface, that defines electron-tunneling pathways. We used the calculated TDA values to compute ET rates for the [Mb(wt), cyt b5] complex and for the complex with a mutant that has a binding free energy strengthened by three D/E → K charge-reversal mutations, [Mb(3M), cyt b5]. The calculated rate constants are in agreement with the measured values, and the mutant complex ensemble has many more geometries with higher TDA values than does the wild-type Mb complex. Interestingly, water plays a double role in this electron-transfer system, lowering the tunneling barrier as well as inducing protein interface remodeling that

  10. Methods of Information Geometry to model complex shapes

    NASA Astrophysics Data System (ADS)

    De Sanctis, A.; Gattone, S. A.

    2016-09-01

    In this paper, a new statistical method to model patterns emerging in complex systems is proposed. A framework for shape analysis of 2- dimensional landmark data is introduced, in which each landmark is represented by a bivariate Gaussian distribution. From Information Geometry we know that Fisher-Rao metric endows the statistical manifold of parameters of a family of probability distributions with a Riemannian metric. Thus this approach allows to reconstruct the intermediate steps in the evolution between observed shapes by computing the geodesic, with respect to the Fisher-Rao metric, between the corresponding distributions. Furthermore, the geodesic path can be used for shape predictions. As application, we study the evolution of the rat skull shape. A future application in Ophthalmology is introduced.

  11. Dependence of (35)Cl NQR on hydrogen bonding and temperature in dichlorophenol-aniline charge transfer complexes.

    PubMed

    Ramananda, D; Ramesh, K P; Uchil, J

    2007-10-01

    The hydrogen-bonded charge transfer complexes of aniline with pi-acceptors (or proton donors) such as 2,5-, 2,6-, 3,4- and 3,5-dichlorophenol were prepared. The (35)Cl nuclear quadrupole resonance (NQR) frequencies of these charge transfer complexes in the temperature range 77-300 K were measured to ascertain the existence or otherwise of a phase transition upon complex formation. Further, the NQR frequency and asymmetry parameter of the electric field gradient at the site of quadrupole nucleus were used to estimate the chemical bond parameters, namely ionic bond, double bond character of the carbon-chlorine(C--Cl) bond and the percentage charge transfer between the donor-acceptor components in charge transfer complexes. The effect of hydrogen bonding and temperature on the charge transfer process is analysed. (c) 2007 John Wiley & Sons, Ltd.

  12. Spontaneous trait inference and spontaneous trait transference are both unaffected by prior evaluations of informants.

    PubMed

    Zengel, Bettina; Ambler, James K; McCarthy, Randy J; Skowronski, John J

    2017-01-01

    This article reports results from a study in which participants encountered either (a) previously known informants who were positive (e.g. Abraham Lincoln), neutral (e.g., Jay Leno), or negative (e.g., Adolf Hitler), or (b) previously unknown informants. The informants ostensibly described either a trait-implicative positive behavior, a trait-implicative negative behavior, or a neutral behavior. These descriptions were framed as either the behavior of the informant or the behavior of another person. Results yielded evidence of informant-trait linkages for both self-informants and for informants who described another person. These effects were not moderated by informant type, behavior valence, or the congruency or incongruency between the prior knowledge of the informant and the behavior valence. Results are discussed in terms of theories of Spontaneous Trait Inference and Spontaneous Trait Transference.

  13. Impact of delayed information in sub-second complex systems

    NASA Astrophysics Data System (ADS)

    Manrique, Pedro D.; Zheng, Minzhang; Johnson Restrepo, D. Dylan; Hui, Pak Ming; Johnson, Neil F.

    What happens when you slow down the delivery of information in large-scale complex systems that operate faster than the blink of an eye? This question just adopted immediate commercial, legal and political importance following U.S. regulators' decision to allow an intentional 350 microsecond delay to be added in the ultrafast network of financial exchanges. However there is still no scientific understanding available to policymakers of the potential system-wide impact of such delays. Here we take a first step in addressing this question using a minimal model of a population of competing, heterogeneous, adaptive agents which has previously been shown to produce similar statistical features to real markets. We find that while certain extreme system-level behaviors can be prevented by such delays, the duration of others is increased. This leads to a highly non-trivial relationship between delays and system-wide instabilities which warrants deeper empirical investigation. The generic nature of our model suggests there should be a fairly wide class of complex systems where such delay-driven extreme behaviors can arise, e.g. sub-second delays in brain function possibly impacting individuals' behavior, and sub-second delays in navigational systems potentially impacting the safety of driverless vehicles.

  14. Making decisions in a complex information environment: evidential preference and information we trust.

    PubMed

    Sanders Thompson, Vetta L

    2013-01-01

    Informed decision making requires that those individuals making health and health-care decisions understand the advantages and disadvantages associated with particular health options. Research and theory suggest factors that contribute to the decision-making process: data on the likelihood of risks and benefits, level of certainty about outcomes, familiarity with the health issue, characteristics of information sources and presentation, and patient values and beliefs. As the health information environment increases in complexity, it becomes important to understand how interactions among information sources, family, and friends may affect the processing of health information and choices and their alignment with available evidence. This paper discusses the potential interactions among social networks, information sources and evidential preferences for health information as they influence health decisions. The role of family and friends who increasingly search for health information for others and the potential for information filtering influenced by second- or third-party attitudes and preferences is explored. Evidential preferences suggestive of the potential value of social math (creatively presented statistics) strategies for presenting data, the information-processing factors that may make personal experiences, anecdotes and testimonials that are often shared within social networks and may exert powerful influences on health decisions are examined in this article. The paper concludes with recommendations for revised health-communication practices, health professional training to improve patient understanding in the clinical encounter, and directions for future research. Simple, direct, and socially relevant communications that avoid conflicts with the values and beliefs of the individual, as well as those of the family and social network, are recommended.

  15. Long-distance quantum information transfer with strong coupling hybrid solid system

    NASA Astrophysics Data System (ADS)

    Zhang, Feng-Yang; Chen, Xin-Yu; Li, Chong; Song, He-Shan

    2015-11-01

    In this paper, we demonstrate how information can be transferred among the long-distance memory units in a hybrid solid architecture, which consists the nitrogen-vacancy (NV) ensemble acting as the memory unit, the LC circuit acting as the transmitter (receiver), and the flux qubit acting as the interface. Numerical simulation demonstrates that the high-fidelity quantum information transfer between memory unit and transmitter (receiver) can be implemented, and this process is robust to both the LC circuit decay and NV ensemble spontaneous emission.

  16. Do we have a knowledge transfer and translation plan at Teratogen Information Services?

    PubMed

    Einarson, Adrienne; Lockett, Donna

    2006-10-01

    Recently, a new field in science is emerging, which addresses the issue of ensuring that information that is generated from research, reaches the right people in the right format. This has been coined as knowledge transfer and translation and public health leaders worldwide are finding out ways to carry this out effectively. Ultimately, this should ensure greater investment in knowledge syntheses and transfer initiatives, that involve potential users of research to improve the quality of health for everyone. In this brief review/comment, an attempt will be made to help the readers understand the meaning of this new terminology and how it impacts Teratogen Information Services.

  17. Quantum Oblivious Transfer Based on a Quantum Symmetrically Private Information Retrieval Protocol

    NASA Astrophysics Data System (ADS)

    Yang, Yu-Guang; Sun, Si-Jia; Wang, Yan

    2015-03-01

    Private information retrieval implies oblivious transfer in classical cryptography. Following this clue, we present a novel quantum one-out-of-two OT protocol based on a practical quantum symmetrically private information retrieval protocol Jakobi et al. (Phys. Rev. A 83, 022301 2011), with changes only in the classical postprocessing of the key. While unconditionally secure oblivious transfer is known to be impossible, we argue that an interesting degree of security can be achieved by means of quantum physical principles instead of unproven security assumptions in order to protect both the sender and the receiver. The proposed OT protocol is loss tolerant, practical and robust against quantum memory attack.

  18. Oxygen atom transfer to a half-sandwich iridium complex: clean oxidation yielding a molecular product.

    PubMed

    Turlington, Christopher R; White, Peter S; Brookhart, Maurice; Templeton, Joseph L

    2014-03-12

    The oxidation of [Ir(Cp*)(phpy)(NCAr(F))][B(Ar(F))4] (1; Cp* = η(5)-pentamethylcyclopentadienyl, phpy = 2-phenylene-κC(1')-pyridine-κN, NCAr(F) = 3,5-bis(trifluoromethyl)benzonitrile, B(Ar(F))4 = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) with the oxygen atom transfer (OAT) reagent 2-tert-butylsulfonyliodosobenzene (sPhIO) yielded a single, molecular product at -40 °C. New Ir(Cp*) complexes with bidentate ligands derived by oxidation of phpy were synthesized to model possible products resulting from oxygen atom insertion into the iridium-carbon and/or iridium-nitrogen bonds of phpy. These new ligands were either cleaved from iridium by water or formed unreactive, phenoxide-bridged iridium dimers. The reactivity of these molecules suggested possible decomposition pathways of Ir(Cp*)-based water oxidation catalysts with bidentate ligands that are susceptible to oxidation. Monitoring the [Ir(Cp*)(phpy)(NCAr(F))](+) oxidation reaction by low-temperature NMR techniques revealed that the reaction involved two separate OAT events. An intermediate was detected, synthesized independently with trapping ligands, and characterized. The first oxidation step involves direct attack of the sPhIO oxidant on the carbon of the coordinated nitrile ligand. Oxygen atom transfer to carbon, followed by insertion into the iridium-carbon bond of phpy, formed a coordinated organic amide. A second oxygen atom transfer generated an unidentified iridium species (the "oxidized complex"). In the presence of triphenylphosphine, the "oxidized complex" proved capable of transferring one oxygen atom to phosphine, generating phosphine oxide and forming an Ir-PPh3 adduct in 92% yield. The final Ir-PPh3 product was fully characterized.

  19. Electrostatics, hydration, and proton transfer dynamics in the membrane domain of respiratory complex I.

    PubMed

    Kaila, Ville R I; Wikström, Mårten; Hummer, Gerhard

    2014-05-13

    Complex I serves as the primary electron entry point into the mitochondrial and bacterial respiratory chains. It catalyzes the reduction of quinones by electron transfer from NADH, and couples this exergonic reaction to the translocation of protons against an electrochemical proton gradient. The membrane domain of the enzyme extends ∼180 Å from the site of quinone reduction to the most distant proton pathway. To elucidate possible mechanisms of the long-range proton-coupled electron transfer process, we perform large-scale atomistic molecular dynamics simulations of the membrane domain of complex I from Escherichia coli. We observe spontaneous hydration of a putative proton entry channel at the NuoN/K interface, which is sensitive to the protonation state of buried glutamic acid residues. In hybrid quantum mechanics/classical mechanics simulations, we find that the observed water wires support rapid proton transfer from the protein surface to the center of the membrane domain. To explore the functional relevance of the pseudosymmetric inverted-repeat structures of the antiporter-like subunits NuoL/M/N, we constructed a symmetry-related structure of a possible alternate-access state. In molecular dynamics simulations, we find the resulting structural changes to be metastable and reversible at the protein backbone level. However, the increased hydration induced by the conformational change persists, with water molecules establishing enhanced lateral connectivity and pathways for proton transfer between conserved ionizable residues along the center of the membrane domain. Overall, the observed water-gated transitions establish conduits for the unidirectional proton translocation processes, and provide a possible coupling mechanism for the energy transduction in complex I.

  20. Charge-transfer optical absorption mechanism of DNA:Ag-nanocluster complexes

    NASA Astrophysics Data System (ADS)

    Longuinhos, R.; Lúcio, A. D.; Chacham, H.; Alexandre, S. S.

    2016-05-01

    Optical properties of DNA:Ag-nanoclusters complexes have been successfully applied experimentally in Chemistry, Physics, and Biology. Nevertheless, the mechanisms behind their optical activity remain unresolved. In this work, we present a time-dependent density functional study of optical absorption in DNA:Ag4. In all 23 different complexes investigated, we obtain new absorption peaks in the visible region that are not found in either the isolated Ag4 or isolated DNA base pairs. Absorption from red to green are predominantly of charge-transfer character, from the Ag4 to the DNA fragment, while absorption in the blue-violet range are mostly associated to electronic transitions of a mixed character, involving either DNA-Ag4 hybrid orbitals or intracluster orbitals. We also investigate the role of exchange-correlation functionals in the calculated optical spectra. Significant differences are observed between the calculations using the PBE functional (without exact exchange) and the CAM-B3LYP functional (which partly includes exact exchange). Specifically, we observe a tendency of charge-transfer excitations to involve purines bases, and the PBE spectra error is more pronounced in the complexes where the Ag cluster is bound to the purines. Finally, our results also highlight the importance of adding both the complementary base pair and the sugar-phosphate backbone in order to properly characterize the absorption spectrum of DNA:Ag complexes.

  1. Computational Confirmation of the Carrier for the "XCN" Interstellar Ice Bank: OCN(-) Charge Transfer Complexes

    NASA Technical Reports Server (NTRS)

    Park, J.-Y.; Woon, D. E.

    2004-01-01

    Recent experimental studies provide evidence that carrier for the so-called XCN feature at 2165 cm(exp -1) (4.62 micron) in young stellar objects is an OCN(-)/NH4(+) charge transfer (CT) complex that forms in energetically processed interstellar icy grain mantles. Although other RCN nitriles and RCN iosonitriles have been considered, Greenberg's conjecture that OCN(-) is associated with the XCN feature has persisted for over 15 years. In this work we report a computational investigation that thoroughly confirms the hypothesis that the XCN feature observed in laboratory studies can result from OCN(-)/NH4(+) CT complexes arising from HNCO and NH3, in a water ice environment. Density functional theory calculations with theory calculations with HNCO, NH3, and up to 12 waters reproduce seven spectroscopic measurements associated with XCN: the band origin of the asymmetric stretching mode of OCN(-), shifts due to isotopic substitutions of C, N, O, and H, and two weak features. However, very similar values are also found for the OCN(-)/NH4(+) CT complex arising from HOCN and NH3. In both cases, the complex forms by barrierless proton transfer from HNCO or HOCN to NH3 during the optimization of the solvated system. Scaled B3LYP/6-31+G** harmonic frequencies for HNCO and HOCN cases are 2181 and 2202 cm(exp -1), respectively.

  2. Transferability of empirical crystal-field parameters of Ni(II) complexes of different symmetries

    NASA Astrophysics Data System (ADS)

    Beltrán, F. Gómez; Sordo, J. A.; Pueyo, L.

    1982-10-01

    A method of systematic linearization of the crystal-field matrices appropriate for obtaining empirical parameters of transition metal complexes of any symmetry is presented and applied to forty complexes of Ni 2+ of Oh and D4 h symmetries. The method is a generalization of that proposed by L. Pueyo, M. Bermejo, and J. W. Richardson ( J. Solid State Chem.31, 217 (1980)) for complexes of Oh symmetry and incorporates the spin-orbit coupling in a very simple manner. Using this method, classical parameters, such as 10 Dq, and punctual quantities, such as the ligand perturbing charges qi, were obtained for these complexes. The former are transferable within 10% if (a) there are not big changes in the metal-ligand distances and (b) the chemical environments of the ligand atoms are comparable. However, the punctual parameters show variations of 20% or more. Electronic repulsion integrals seem to be nicely transferable by means of addition rules based on the hypothesis of isotropic repulsion in the low-symmetry field. Since one of the fitting parameters is a scaling factor of the Rnl( r) metal function, the process of optimization generates an empirical representation, Rnl( λr), of the locally perturbed metallic state.

  3. Preparation of metal-TCNQ charge-transfer complexes on conducting and insulating surfaces by photocrystallization.

    PubMed

    O'Mullane, Anthony P; Fay, Nigel; Nafady, Ayman; Bond, Alan M

    2007-02-21

    A generic method for the synthesis of metal-7,7,8,8-tetracyanoquinodimethane (TCNQ) charge-transfer complexes on both conducting and nonconducting substrates is achieved by photoexcitation of TCNQ in acetonitrile in the presence of a sacrificial electron donor and the relevant metal cation. The photochemical reaction leads to reduction of TCNQ to the TCNQ(-) monoanion. In the presence of M(x+)(MeCN), reaction with TCNQ(-)(MeCN) leads to deposition of M(x+)[TCNQ]x crystals onto a solid substrate with morphologies that are dependent on the metal cation. Thus, CuTCNQ phase I photocrystallizes as uniform microrods, KTCNQ as microrods with a random size distribution, AgTCNQ as very long nanowires up to 30 mum in length and with diameters of less than 180 nm, and Co[TCNQ](2)(H(2)O)(2) as nanorods and wires. The described charge-transfer complexes have been characterized by optical and scanning electron microscopy and IR and Raman spectroscopy. The CuTCNQ and AgTCNQ complexes are of particular interest for use in memory storage and switching devices. In principle, this simple technique can be employed to generate all classes of metal-TCNQ complexes and opens up the possibility to pattern them in a controlled manner on any type of substrate.

  4. Atomic dipole polarization in charge-transfer complexes with halogen bonding.

    PubMed

    Bartashevich, E V; Tsirelson, V G

    2013-02-21

    The polarization effects associated with halogen bonding for the series of charge-transfer complexes D(m)···X-Y, where donor molecules D(m) = NH(3), H(2)O, H(2)S, C(2)H(4), CO and X-Y = Cl(2), ClF, Br(2), BrCl, ICl, I(2), are characterized in terms of the quantum theory of atoms in molecules using the B3LYP/6-311** Kohn-Sham wave functions. We study the electrostatic potential features of separate donor and acceptor molecules, the change in atomic charges as well as the atomic electric dipole moments and their components, and the intra-atomic electron density dipole polarization and the bonding dipole moments resulting from the electron density redistribution between the molecules in the charge-transfer complexes. The equation linking the most negative electrostatic potential values in the donor molecules and the most positive values in dihalogen molecules with the stretching force constants was found using two-factor regression. It is demonstrated that the dipole polarization of the acceptor atom mirrors the strength of halogen bonding in complexes in a series of different donors and acceptors. An exponential relationship between the magnitude of the total atomic electric dipole moment of the acceptor atom and the intermolecular stretching force constant is established for weakly bounded complexes.

  5. Ferrocene-o-benzosemiquinonato tin(IV) electron-transfer complexes.

    PubMed

    Ilyakina, Ekaterina V; Poddel'sky, Andrey I; Fukin, Georgy K; Bogomyakov, Artem S; Cherkasov, Vladimir K; Abakumov, Gleb A

    2013-05-06

    The interaction of ferrocene with tin(IV) o-benzosemiquinonato complexes in acetonitrile results in a reversible electron transfer (ET) from ferrocene to the redox-active ligand with the formation of electron-transfer complexes [(3,6-Cat)SnBr3](-)[Cp2Fe](+) (1) and [(3,6-Cat)(3,6-SQ)SnCl2](-)[Cp2Fe](+) (2), where 3,6-Cat is the 3,6-di-tert-butyl-catecholate dianion and 3,6-SQ is the 3,6-di-tert-butyl-o-benzosemiquinonato radical anion. The ET process and the solvent effect in the system "ferrocene-o-benzosemiquinonato tin(IV) complexes" were investigated on the basis of a combination of spectroscopic and X-ray diffraction methods. The molecular structures of 1 and 2 were confirmed by X-ray analysis. Complex 2 demonstrates the ferromagnetic coupling in the linear chain alternating ···D(+•)A(-•)D(+•)A(-•)··· motif.

  6. Entropy-based analysis and bioinformatics-inspired integration of global economic information transfer.

    PubMed

    Kim, Jinkyu; Kim, Gunn; An, Sungbae; Kwon, Young-Kyun; Yoon, Sungroh

    2013-01-01

    The assessment of information transfer in the global economic network helps to understand the current environment and the outlook of an economy. Most approaches on global networks extract information transfer based mainly on a single variable. This paper establishes an entirely new bioinformatics-inspired approach to integrating information transfer derived from multiple variables and develops an international economic network accordingly. In the proposed methodology, we first construct the transfer entropies (TEs) between various intra- and inter-country pairs of economic time series variables, test their significances, and then use a weighted sum approach to aggregate information captured in each TE. Through a simulation study, the new method is shown to deliver better information integration compared to existing integration methods in that it can be applied even when intra-country variables are correlated. Empirical investigation with the real world data reveals that Western countries are more influential in the global economic network and that Japan has become less influential following the Asian currency crisis.

  7. Entropy-Based Analysis and Bioinformatics-Inspired Integration of Global Economic Information Transfer

    PubMed Central

    An, Sungbae; Kwon, Young-Kyun; Yoon, Sungroh

    2013-01-01

    The assessment of information transfer in the global economic network helps to understand the current environment and the outlook of an economy. Most approaches on global networks extract information transfer based mainly on a single variable. This paper establishes an entirely new bioinformatics-inspired approach to integrating information transfer derived from multiple variables and develops an international economic network accordingly. In the proposed methodology, we first construct the transfer entropies (TEs) between various intra- and inter-country pairs of economic time series variables, test their significances, and then use a weighted sum approach to aggregate information captured in each TE. Through a simulation study, the new method is shown to deliver better information integration compared to existing integration methods in that it can be applied even when intra-country variables are correlated. Empirical investigation with the real world data reveals that Western countries are more influential in the global economic network and that Japan has become less influential following the Asian currency crisis. PMID:23300959

  8. Identifying the magnetoconductance responses by the induced charge transfer complex states in pentacene-based diodes

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Shun; Lee, Tsung-Hsun; Guo, Tzung-Fang; Huang, J. C. A.; Wen, Ten-Chin

    2012-07-01

    We investigate the magnetoconductance (MC) responses in photocurrent, unipolar injection, and bipolar injection regimes in pentacene-based diodes. Both photocurrent and bipolar injection contributed MC responses show large difference in MC line shape, which are attributed to triplet-polaron interaction modulated by the magnetic field dependent singlet fission and the intersystem crossing of the polaron pair, respectively. By blending 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane into pentacene, all the MC responses are suppressed but the MC response at unipolar injection regime is enhanced, which is attributed to the induced charge transfer complex states (CT complex states). This work identify the MC responses between single carrier contributed MC and exciton related MC by the induced CT complex states.

  9. Spectroscopic and thermodynamic study of charge transfer complexes of cloxacillin sodium in aqueous ethanol medium

    NASA Astrophysics Data System (ADS)

    Roy, Dalim Kumar; Saha, Avijit; Mukherjee, Asok K.

    2005-07-01

    Cloxacillin sodium has been shown to form charge transfer (CT) complexes of 1:1 stoichiometry with a number of electron acceptors in 50% (v/v) aqueous ethanol medium. From the trends in the CT absorption bands, the vertical ionization potential of the drug molecule (cloxacillin sodium) has been estimated to be 7.89 eV. The enthalpies and entropies of formation of two such complexes have been determined by estimating the formation constants spectrophotometrically at five different temperatures. The oscillator strengths and transition dipole moments of these complexes have been determined. It has further been noted that the reduction of o-chloranil by aqueous ethanol is completely inhibited by cloxacillin sodium, a phenomenon that makes the present study of formation equilibrium possible.

  10. Volatile anesthetics disrupt frontal-posterior recurrent information transfer at gamma frequencies in rat.

    PubMed

    Imas, Olga A; Ropella, Kristina M; Ward, B Douglas; Wood, James D; Hudetz, Anthony G

    2005-10-28

    We seek to understand neural correlates of anesthetic-induced unconsciousness. We hypothesize that cortical integration of sensory information may underlie conscious perception and may be disrupted by anesthetics. A critical role in frontal-posterior interactions has been proposed, and gamma (20-60 Hz) oscillations have also been assigned an essential role in consciousness. Here we investigated whether general anesthetics may interfere with the exchange of information encoded in gamma oscillations between frontal and posterior cortices. Bipolar electrodes for recording of event-related potentials (ERP) were chronically implanted in the primary visual cortex, parietal association and frontal association cortices of six rats. Sixty light flashes were presented every 5s, and ERPs were recorded at increasing concentrations of halothane or isoflurane (0-2%). Information exchange was estimated by transfer entropy, a novel measure of directional information transfer. Transfer entropy was calculated from 1-s wavelet-transformed ERPs. We found that (1) feedforward transfer entropy (FF-TE) and feedback transfer entropy (FB-TE) were balanced in conscious-sedated state; (2) anesthetics at concentrations producing unconsciousness augmented both FF-TE and FB-TE at 30 Hz but reduced them at 50 Hz; (3) reduction at 50 Hz was more pronounced for FB-TE, especially between frontal and posterior regions; (4) at high concentrations, both FF-TE and FB-TE at all frequencies were at or below conscious-sedated baseline. Our findings suggest that inhalational anesthetics preferentially impair frontal-posterior FB information transfer at high gamma frequencies consistent with the postulated role of frontal-posterior interactions in consciousness.

  11. Power laws of complex systems from extreme physical information.

    PubMed

    Frieden, B Roy; Gatenby, Robert A

    2005-09-01

    Many complex systems obey allometric, or power, laws y=Y x(a) . Here y > or = 0 is the measured value of some system attribute a , Y> or =0 is a constant, and x is a stochastic variable. Remarkably, for many living systems the exponent a is limited to values n/4 , n=0, +/-1, +/-2.... Here x is the mass of a randomly selected creature in the population. These quarter-power laws hold for many attributes, such as pulse rate (n=-1) . Allometry has, in the past, been theoretically justified on a case-by-case basis. An ultimate goal is to find a common cause for allometry of all types and for both living and nonliving systems. The principle I-J=extremum of extreme physical information is found to provide such a cause. It describes the flow of Fisher information J-->I from an attribute value a on the cell level to its exterior observation y . Data y are formed via a system channel function y identical to f (x,a) , with f (x,a) to be found. Extremizing the difference I-J through variation of f (x,a) results in a general allometric law f (x,a) identical to y=Y x(a) . Darwinian evolution is presumed to cause a second extremization of I-J , now with respect to the choice of a . The solution is a=n/4 , n=0,+/-1,+/-2..., defining the particular powers of biological allometry. Under special circumstances, the model predicts that such biological systems are controlled by only two distinct intracellular information sources. These sources are conjectured to be cellular DNA and cellular transmembrane ion gradients.

  12. A Statistical Framework to Infer Delay and Direction of Information Flow from Measurements of Complex Systems.

    PubMed

    Schumacher, Johannes; Wunderle, Thomas; Fries, Pascal; Jäkel, Frank; Pipa, Gordon

    2015-08-01

    In neuroscience, data are typically generated from neural network activity. The resulting time series represent measurements from spatially distributed subsystems with complex interactions, weakly coupled to a high-dimensional global system. We present a statistical framework to estimate the direction of information flow and its delay in measurements from systems of this type. Informed by differential topology, gaussian process regression is employed to reconstruct measurements of putative driving systems from measurements of the driven systems. These reconstructions serve to estimate the delay of the interaction by means of an analytical criterion developed for this purpose. The model accounts for a range of possible sources of uncertainty, including temporally evolving intrinsic noise, while assuming complex nonlinear dependencies. Furthermore, we show that if information flow is delayed, this approach also allows for inference in strong coupling scenarios of systems exhibiting synchronization phenomena. The validity of the method is demonstrated with a variety of delay-coupled chaotic oscillators. In addition, we show that these results seamlessly transfer to local field potentials in cat visual cortex.

  13. Structure and Bonding in Nickel-Thiolate-Iodine Charge-Transfer Complexes.

    PubMed

    Beyer, Norman; Steinfeld, Gunther; Lozan, Vasile; Naumov, Sergej; Flyunt, Roman; Abel, Bernd; Kersting, Berthold

    2017-02-16

    The dinuclear nickel complexes [Ni2 L(μ-O2 CR)](ClO4 ) [R=Me (4), R=OMe (6)], where L(2-) is a 24-membered macrocyclic N6 S2 ligand, react readily with excess I2 in MeCN solution at 4 °C to form stable mono-(I2 ) and bis-(I2 ) charge-transfer (CT) adducts of the type [Ni2 L(μ-O2 CR)(I2 )n ](+) (n=1 or 2) containing linear RS-I-I linkages. Three new CT compounds, namely, [Ni2 L(OAc)(I2 )](I2 )(I3 ) (5), [Ni2 L(O2 COMe)(I2 )](I5 )⋅MeCN (7⋅MeCN), and [Ni2 L(O2 COMe)(I2 )2 ](I5 )⋅MeCN (8⋅MeCN) as well as the triiodide salt [Ni2 L(OAc)](I3 ) (9) were synthesized and fully characterized. A common feature of the CT adducts is a polyiodide matrix, which surrounds the individual complex molecules, stabilized by secondary I⋅⋅⋅I interactions with the CT linkages. The scatter in both the RS-I (2.6 to 3.0 Å) and the I-I bond lengths (2.7 to 3.0 Å) is indicative of both a variable strength of the RS(-) →I2 bond and a varying degree of charge transfer. An analysis of the structural parameters was undertaken accompanied by DFT calculations to quantify the donating ability of the bridging thiolate functions and to shed more light on the bonding in this rare sort of charge-transfer complexes. The stability of the CT complexes and the results of preliminary transport measurements are also reported.

  14. Diffusion or advection? Mass transfer and complex boundary layer landscapes of the brown alga Fucus vesiculosus.

    PubMed

    Lichtenberg, Mads; Nørregaard, Rasmus Dyrmose; Kühl, Michael

    2017-03-01

    The role of hyaline hairs on the thallus of brown algae in the genus Fucus is long debated and several functions have been proposed. We used a novel motorized set-up for two-dimensional and three-dimensional mapping with O2 microsensors to investigate the spatial heterogeneity of the diffusive boundary layer (DBL) and O2 flux around single and multiple tufts of hyaline hairs on the thallus of Fucus vesiculosus. Flow was a major determinant of DBL thickness, where higher flow decreased DBL thickness and increased O2 flux between the algal thallus and the surrounding seawater. However, the topography of the DBL varied and did not directly follow the contour of the underlying thallus. Areas around single tufts of hyaline hairs exhibited a more complex mass-transfer boundary layer, showing both increased and decreased thickness when compared with areas over smooth thallus surfaces. Over thallus areas with several hyaline hair tufts, the overall effect was an apparent increase in the boundary layer thickness. We also found indications for advective O2 transport driven by pressure gradients or vortex shedding downstream from dense tufts of hyaline hairs that could alleviate local mass-transfer resistances. Mass-transfer dynamics around hyaline hair tufts are thus more complex than hitherto assumed and may have important implications for algal physiology and plant-microbe interactions. © 2017 The Author(s).

  15. Light Absorption and Energy Transfer in the Antenna Complexes of Photosynthetic Organisms.

    PubMed

    Mirkovic, Tihana; Ostroumov, Evgeny E; Anna, Jessica M; van Grondelle, Rienk; Govindjee; Scholes, Gregory D

    2017-01-25

    The process of photosynthesis is initiated by the capture of sunlight by a network of light-absorbing molecules (chromophores), which are also responsible for the subsequent funneling of the excitation energy to the reaction centers. Through evolution, genetic drift, and speciation, photosynthetic organisms have discovered many solutions for light harvesting. In this review, we describe the underlying photophysical principles by which this energy is absorbed, as well as the mechanisms of electronic excitation energy transfer (EET). First, optical properties of the individual pigment chromophores present in light-harvesting antenna complexes are introduced, and then we examine the collective behavior of pigment-pigment and pigment-protein interactions. The description of energy transfer, in particular multichromophoric antenna structures, is shown to vary depending on the spatial and energetic landscape, which dictates the relative coupling strength between constituent pigment molecules. In the latter half of the article, we focus on the light-harvesting complexes of purple bacteria as a model to illustrate the present understanding of the synergetic effects leading to EET optimization of light-harvesting antenna systems while exploring the structure and function of the integral chromophores. We end this review with a brief overview of the energy-transfer dynamics and pathways in the light-harvesting antennas of various photosynthetic organisms.

  16. Knowledge transfer on complex social interventions in public health: a scoping study.

    PubMed

    Dagenais, Christian; Malo, Marie; Robert, Émilie; Ouimet, Mathieu; Berthelette, Diane; Ridde, Valéry

    2013-01-01

    Scientific knowledge can help develop interventions that improve public health. The objectives of this review are (1) to describe the status of research on knowledge transfer strategies in the field of complex social interventions in public health and (2) to identify priorities for future research in this field. A scoping study is an exploratory study. After searching databases of bibliographic references and specialized periodicals, we summarized the relevant studies using a predetermined assessment framework. In-depth analysis focused on the following items: types of knowledge transfer strategies, fields of public health, types of publics, types of utilization, and types of research specifications. From the 1,374 references identified, we selected 26 studies. The strategies targeted mostly administrators of organizations and practitioners. The articles generally dealt with instrumental utilization and most often used qualitative methods. In general, the bias risk for the studies is high. Researchers need to consider the methodological challenges in this field of research in order to improve assessment of more complex knowledge transfer strategies (when they exist), not just diffusion/dissemination strategies and conceptual and persuasive utilization.

  17. Polarized radiative transfer in two-dimensional scattering medium with complex geometries by natural element method

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Kim, Yong-Jun; Yi, Hong-Liang; Xie, Ming; Tan, He-Ping

    2016-08-01

    The natural element method (NEM) is extended to solve the polarized radiative transfer problem in a two-dimensional scattering medium with complex geometries, in which the angular space is discretized by the discrete-ordinates approach, and the spatial discretization is conducted by the Galerkin weighted residuals approach. The Laplace interpolation scheme is adopted to obtain the shape functions used in the Galerkin weighted residuals approach. The NEM solution to the vector radiative transfer in a square enclosure filled with a Mie scattering medium is first examined to validate our program. We then study the polarized radiative transfer in two kinds of geometries filled with scattering medium which is equivalent to a suspension of latex spheres in water. Three sizes of spheres are considered. The results for non-dimensional polarized radiative flux along the boundaries and the angular distributions of the Stokes vector at specific positions are presented and discussed. For the complex geometry bounded by the square and circular object, numerical solutions are presented for the cases both with Lambertian (diffuse) reflection and with Fresnel reflection. Some interesting phenomenon are found and analyzed.

  18. Effective field theory models for nonviolent information transfer from black holes

    NASA Astrophysics Data System (ADS)

    Giddings, Steven B.; Shi, Yinbo

    2014-06-01

    Transfer of quantum information from the interior of a black hole to its atmosphere is described, in models based on effective field theory. This description illustrates that such transfer need not be violent to the semiclassical geometry or to infalling observers, and in particular can avoid producing a singular horizon or "firewall". One can specifically quantify the rate of information transfer and show that a rate necessary to unitarize black hole evaporation produces a relatively mild modification to the stress tensor near the horizon. In an exterior description of the transfer, the new interactions responsible for it are approximated by "effective sources" acting on fields in the black hole atmosphere. If the necessary interactions couple to general modes in the black hole atmosphere, one also finds a straightforward mechanism for information transfer rates to increase when a black hole is mined, avoiding paradoxical behavior. Correspondence limits are discussed, in the presence of such new interactions, for both small black holes and large ones; the near-horizon description of the latter is approximately that of Rindler space.

  19. Investigation of ground state charge transfer complex between paracetamol and p-chloranil through DFT and UV-visible studies

    NASA Astrophysics Data System (ADS)

    Shukla, Madhulata; Srivastava, Nitin; Saha, Satyen

    2012-08-01

    The present report deals with the theoretical investigation on ground state structure and charge transfer (CT) transitions in paracetamol (PA)/p-chloranil (CA) complex using Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TD-DFT) method. It is found that Cdbnd O bond length of p-chloranil increases on complexation with paracetamol along with considerable amount of charge transfer from PA to CA. TD-DFT calculations have been performed to analyse the observed UV-visible spectrum of PA-CA charge transferred complex. Interestingly, in addition to expected CT transition, a weak symmetry relieved π-π* transition in the chloranil is also observed.

  20. The thermochromic behavior of aromatic amine-SO2 charge transfer complexes

    NASA Astrophysics Data System (ADS)

    Monezi, Natália M.; Borin, Antonio C.; Santos, Paulo S.; Ando, Rômulo A.

    2017-02-01

    The distinct thermochromism observed in solutions containing N,N-dimethylaniline (DMA) and N,N-diethylaniline (DEA) and SO2 was investigated by resonance Raman spectroscopy in a wide range of temperatures. The results indicate in addition to the charge transfer (CT) complexes DMA-SO2 and DEA-SO2, the presence of collision complexes involving the CT complexes and excess DMA and DEA molecules. The latter in fact is the chromophore responsible for the long wavelength absorption originating the color. The Raman signature of the collision complex was attributed to the distinct enhancement of a band at 1140 cm- 1 assigned to νs(SO2), in contrast to the same mode in the 1:1 complex at 1115 cm- 1. The intensity of such band, assigned to the collision complex is favored at high temperatures and depends on the steric hindrance associated to amines, as well as the SO2 molar fraction. Quantum chemical calculations based on time-dependent density functional theory (TDDFT) support the proposed interpretation.

  1. The thermochromic behavior of aromatic amine-SO2 charge transfer complexes.

    PubMed

    Monezi, Natália M; Borin, Antonio C; Santos, Paulo S; Ando, Rômulo A

    2017-02-15

    The distinct thermochromism observed in solutions containing N,N-dimethylaniline (DMA) and N,N-diethylaniline (DEA) and SO2 was investigated by resonance Raman spectroscopy in a wide range of temperatures. The results indicate in addition to the charge transfer (CT) complexes DMA-SO2 and DEA-SO2, the presence of collision complexes involving the CT complexes and excess DMA and DEA molecules. The latter in fact is the chromophore responsible for the long wavelength absorption originating the color. The Raman signature of the collision complex was attributed to the distinct enhancement of a band at 1140cm(-1) assigned to νs(SO2), in contrast to the same mode in the 1:1 complex at 1115cm(-1). The intensity of such band, assigned to the collision complex is favored at high temperatures and depends on the steric hindrance associated to amines, as well as the SO2 molar fraction. Quantum chemical calculations based on time-dependent density functional theory (TDDFT) support the proposed interpretation.

  2. Information concerning multidrug-resistant bacterial colonization or infection in the medical transfer letter.

    PubMed

    Lefebvre, A; Laporte, S; Faure, S; Tiv, M; Chavanet, P; Belpois-Duchamp, C; Astruc, K; Aho-Glélé, L S

    2015-07-01

    The aim of this study was to evaluate the proportion of transfer letters that contained information relative to infection or colonization by multidrug-resistant (MDR) bacteria and factors associated with the presence of that information. Patients for whom at least one of these selected MDR bacteria (methicillin-resistant Staphylococcus aureus, extended-spectrum β-lactamase-producing Enterobacteriaceae, or MDR Pseudomonas aeruginosa) was isolated during their hospitalization and who were transferred to another health care facility between 2009 and 2012 were included. Information of the MDR bacterium and the mention of isolation precautions were evaluated in the electronic medical record. Information (mention of MDR bacterium or isolation precaution) was present in 57% [52; 65] of records. Full information (genus and species, concept of MDR bacterium and mention of isolation precaution) was found in 20% [16; 25]. The presence of a dedicated item in the standard medical discharge letter was associated with more frequent information. Less information was retrieved with P. aeruginosa cases than with the other 2 MDR bacteria. The presence of the information has improved, but it is still insufficiently reported. Measures to improve information are needed. Indeed, information on MDR bacterial colonization or infection is the first step for isolation precautions. An item could be added to all standard medical discharge letters. An item could also be added to the indicators used to assess quality and safety in healthcare facilities. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  3. Information Transfer in the Illinois Swine Industry: How Producers Are Informed of New Technologies.

    ERIC Educational Resources Information Center

    Brashear, Genefer L.; Hollis, Gilbert; Wheeler, Matthew B.

    2000-01-01

    A survey of 127 (of 300) Illinois swine producers found that 114 owned computers; the majority used industry magazines as sources of information about new technologies; extension newsletters were used much less by corporate farm enterprises; very small numbers used electronic mail; only about half used university specialists for information; and…

  4. Information Transfer in the Illinois Swine Industry: How Producers Are Informed of New Technologies.

    ERIC Educational Resources Information Center

    Brashear, Genefer L.; Hollis, Gilbert; Wheeler, Matthew B.

    2000-01-01

    A survey of 127 (of 300) Illinois swine producers found that 114 owned computers; the majority used industry magazines as sources of information about new technologies; extension newsletters were used much less by corporate farm enterprises; very small numbers used electronic mail; only about half used university specialists for information; and…

  5. From School to Work and from Work to School: Information Environments and Transferring Information Literacy Practices

    ERIC Educational Resources Information Center

    Herring, James E.

    2011-01-01

    Introduction: This study, based in a Scottish secondary school, aimed to examine the views of students who were completing work experience, on their information literacy practices, and the differences they found between the school and workplace information environments while on work experience. The views of guidance teachers were also explored.…

  6. Charge-transfer complexes of Cu(II)/HD analogue in sol gel sensors

    NASA Astrophysics Data System (ADS)

    Brinkley, J. F.; Kirkey, M. L.; Marques, A. D. S.; Lin, C. T.

    2003-01-01

    An optically transparent xerogel encapsulating Cu(II) acetate is fabricated to detect mustard gas (HD) analogues via a charge-transfer mechanism. A fast response (color change from sky blue to canary yellow) is observed for the chlorinated sulfide, and is accompanied by an absorption band at 370-420 nm. MO calculations revealed that the chlorinated HD analogue displays a charge-transfer transition extended from sulfur to chlorine atom. A 1:1 complex of Cu(II)/HD analogue is preferred. For a colorimetric sol-gel detector prepared at pH 3, the detection limit of HD analogue is calibrated at 0.03 μl per 1.5 ml sensor volume.

  7. Multilayer-MCTDH approach to the energy transfer dynamics in the LH2 antenna complex

    NASA Astrophysics Data System (ADS)

    Shibl, Mohamed F.; Schulze, Jan; Al-Marri, Mohammed J.; Kühn, Oliver

    2017-09-01

    The multilayer multiconfiguration time-dependent Hartree method is used to study the coupled exciton-vibrational dynamics in a high-dimensional nonameric model of the LH2 antenna complex of purple bacteria. The exciton-vibrational coupling is parametrized within the Huang-Rhys model according to phonon and intramolecular vibrational modes derived from an experimental bacteriochlorophyll spectral density. In contrast to reduced density matrix approaches, the Schrödinger equation is solved explicitly, giving access to the full wave function. This facilitates an unbiased analysis in terms of the coupled dynamics of excitonic and vibrational degrees of freedom. For the present system, we identify spectator modes for the B800 to B800 transfer and we find a non-additive effect of phonon and intramolecular vibrational modes on the B800 to B850 exciton transfer.

  8. Role of coherent vibrations in energy transfer and conversion in photosynthetic pigment-protein complexes.

    PubMed

    Abramavicius, Darius; Valkunas, Leonas

    2016-01-01

    Oscillatory features of two-dimensional spectra of photosynthetic pigment-protein complexes during few picoseconds after electronic excitations of chlorophylls in various pigment-proteins were recently related to the coherent nuclear vibrations. It has been also speculated that the vibrations may assist the excitonic energy transfer and charge separation, hence contributing to energy transport and energy conversion efficiency. Here, we consider three theoretical approaches usually used for characterization of the excitation dynamics and charge separation, namely Redfield, Förster, and Marcus model descriptions, regarding this question. We show that two out of the three mechanisms require explicit resonances of excitonic splittings and the nuclear vibration frequencies. However, the third one related to the electron transfer is in principle off resonant.

  9. A diabatic state model for double proton transfer in hydrogen bonded complexes.

    PubMed

    McKenzie, Ross H

    2014-09-14

    Four diabatic states are used to construct a simple model for double proton transfer in hydrogen bonded complexes. Key parameters in the model are the proton donor-acceptor separation R and the ratio, D1/D2, between the proton affinity of a donor with one and two protons. Depending on the values of these two parameters the model describes four qualitatively different ground state potential energy surfaces, having zero, one, two, or four saddle points. Only for the latter are there four stable tautomers. In the limit D2 = D1 the model reduces to two decoupled hydrogen bonds. As R decreases a transition can occur from a synchronous concerted to an asynchronous concerted to a sequential mechanism for double proton transfer.

  10. The structure of control and data transfer management system for the GAMMA-400 scientific complex

    NASA Astrophysics Data System (ADS)

    Arkhangelskiy, A. I.; Bobkov, S. G.; Serdin, O. V.; Gorbunov, M. S.; Topchiev, N. P.

    2016-02-01

    A description of the control and data transfer management system for scientific instrumentation involved in the GAMMA-400 space project is given. The technical capabilities of all specialized equipment to provide the functioning of the scientific instrumentation and satellite support systems are unified in a single structure. Control of the scientific instruments is maintained using one-time pulse radio commands, as well as program commands in the form of 16-bit code words, which are transmitted via onboard control system and scientific data acquisition system. Up to 100 GByte of data per day can be transferred to the ground segment of the project. The correctness of the proposed and implemented structure, engineering solutions and electronic elemental base selection has been verified by the experimental working-off of the prototype of the GAMMA-400 scientific complex in laboratory conditions.

  11. Resonance energy transfer study of hemoglobin complexes with model phospholipid membranes.

    PubMed

    Gorbenko, G P

    1999-10-04

    By examining the resonance energy transfer between fluorescent probes, embedded in the lipid bilayer (4-(dimethylaminostyryl)-1-methylpiridine, 4-(dimethylaminostyryl)-1-dodecylpiridine, N,N'-bishexamethylenrhodamine, rhodamine 6G) as donors, and the heme group of hemoglobin as acceptor, the structure of the protein complexes with the model membranes composed of phosphatidylcholine and cardiolipin was characterized. Quantitative interpretation of the experimental data was performed in terms of the model of energy transfer in two-dimensional systems, using a set of parameters including the distance of closest approach between donor and acceptor, the vertical separation of donor planes, the acceptor distance from the donor plane and the orientation factor. The limits for the heme distance from the lipid bilayer center and the depth of the protein penetration in the membrane interior were estimated. The results obtained suggest that the depth of hemoglobin insertion into liposomal membranes decreases upon increasing CL content in the lipid bilayer.

  12. Direct detection of photoinduced charge transfer complexes in polymer fullerene blends

    NASA Astrophysics Data System (ADS)

    Behrends, Jan; Sperlich, Andreas; Schnegg, Alexander; Biskup, Till; Teutloff, Christian; Lips, Klaus; Dyakonov, Vladimir; Bittl, Robert

    2012-03-01

    We report transient electron paramagnetic resonance (trEPR) measurements with submicrosecond time resolution performed on a polymer:fullerene blend consisting of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) at low temperatures. The trEPR spectrum immediately following photoexcitation reveals signatures of spin-correlated polaron pairs. The pair partners (positive polarons in P3HT and negative polarons in PCBM) can be identified by their characteristic g values. The fact that the polaron pair states exhibit strong non-Boltzmann population unambiguously shows that the constituents of each pair are geminate, i.e., originate from one exciton. We demonstrate that coupled polaron pairs are present even several microseconds after charge transfer and suggest that they embody the intermediate charge transfer complexes that form at the donor/acceptor interface and mediate the conversion from excitons into free charge carriers.

  13. Method and apparatus for transfer function simulator for testing complex systems

    NASA Technical Reports Server (NTRS)

    Kavaya, M. J. (Inventor)

    1985-01-01

    A method and apparatus for testing the operation of a complex stabilization circuit in a closed loop system is presented. The method is comprised of a programmed analog or digital computing system for implementing the transfer function of a load thereby providing a predictable load. The digital computing system employs a table stored in a microprocessor in which precomputed values of the load transfer function are stored for values of input signal from the stabilization circuit over the range of interest. This technique may be used not only for isolating faults in the stabilization circuit, but also for analyzing a fault in a faulty load by so varying parameters of the computing system as to simulate operation of the actual load with the fault.

  14. Analytical studies on the charge transfer complexes of loperamide hydrochloride and trimebutine drugs. Spectroscopic and thermal characterization of CT complexes.

    PubMed

    Elqudaby, Hoda M; Mohamed, Gehad G; El-Din, Ghada M G

    2014-08-14

    Charge transfer complexes of loperamide hydrochloride (LOP.HCl) and trimebutine (TB) drugs as electron donor with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), tetracyanoethylene (TCNE) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π-acceptors in acetonitrile were investigated spectrophotometrically to determine the cited drugs in pure and dosage forms. The reaction gives highly coloured complex species which are measured spectrophotometrically at 460, 415 and 842nm in case of LOP.HCl and at 455, 414 and 842nm in case of TB using DDQ, TCNE and TCNQ reagents, respectively. The optimum experimental conditions have been studied carefully and optimized. Beer's law was obeyed over the concentration ranges of 47.70-381.6, 21.50-150.5 and 10.00-100.0μgmL(-1) for LOP.HCl and 37.85-264.9, 38.75-310.0 and 7.75-155.0μgmL(-1) for TB using DDQ, TCNE and TCNQ reagents, respectively. Sandell sensitivity, standard deviation, relative standard deviation, limit of detection and quantification were calculated. The obtained data refer to high accuracy and precision of the proposed method. These results are also confirmed by inter and intra-day precision with percent recovery of 99.18-101.1% and 99.32-101.4% in case of LOP.HCl and 98.00-102.0% and 97.50-101.4% in case of TB using DDQ, TCNE and TCNQ reagents for intra- and inter-day, respectively. These data were compared with those obtained using official methods for the determination of the cited drugs. The stability constants of the CT complexes were determined. The final products of the reaction were isolated and characterized using FT-IR, (1)H NMR, elemental analysis and thermogravimetric analysis (TG). The stoichiometry and apparent formation constant of the complexes formed were determined by applying the conventional spectrophotometric molar ratio method.

  15. Informational Entropy and Bridge Scour Estimation under Complex Hydraulic Scenarios

    NASA Astrophysics Data System (ADS)

    Pizarro, Alonso; Link, Oscar; Fiorentino, Mauro; Samela, Caterina; Manfreda, Salvatore

    2017-04-01

    Bridges are important for society because they allow social, cultural and economic connectivity. Flood events can compromise the safety of bridge piers up to the complete collapse. The Bridge Scour phenomena has been described by empirical formulae deduced from hydraulic laboratory experiments. The range of applicability of such models is restricted by the specific hydraulic conditions or flume geometry used for their derivation (e.g., water depth, mean flow velocity, pier diameter and sediment properties). We seek to identify a general formulation able to capture the main dynamic of the process in order to cover a wide range of hydraulic and geometric configuration, allowing to extend our analysis in different contexts. Therefore, exploiting the Principle of Maximum Entropy (POME) and applying it on the recently proposed dimensionless Effective flow work, W*, we derived a simple model characterized by only one parameter. The proposed Bridge Scour Entropic (BRISENT) model shows good performances under complex hydraulic conditions as well as under steady-state flow. Moreover, the model was able to capture the evolution of scour in several hydraulic configurations even if the model contains only one parameter. Furthermore, results show that the model parameter is controlled by the geometric configurations of the experiment. This offers a possible strategy to obtain a priori model parameter calibration. The BRISENT model represents a good candidate for estimating the time-dependent scour depth under complex hydraulic scenarios. The authors are keen to apply this idea for describing the scour behavior during a real flood event. Keywords: Informational entropy, Sediment transport, Bridge pier scour, Effective flow work.

  16. [Incidence of the standardization of scientific journals in the transfer and evaluation of scientific information].

    PubMed

    Delgado López-Cózar, E

    1997-12-01

    I analyze the repercussions of standardization of scientific publications in general, and of journals in particular, on the processes of scientific information transfer, diffusion and evaluation. Standardization facilitates the work of all agents in the primary (authors, publishers and readers) and secondary communication systems (librarians, information scientifics). Compliance with standards influences the presence of journal in bibliographic databases and de quality of bibliometric studies. Standardization thus has repercussions in the evaluation of science.

  17. Report of a Planning Conference for Solar Technology Information Transfer. Austin, Texas, 12-13 June 1979).

    ERIC Educational Resources Information Center

    Southwestern Library Association, Stillwater, OK.

    Charged with the responsibility of determining the best way to plan for solar technology information transfer within the state of Texas, participants in the Planning Conference for Solar Technology Information Transfer met to discuss the many ongoing activities related to energy information dissemination, to analyze the resources available in…

  18. 75 FR 43536 - Agency Information Collection Activities: Permit To Transfer Containers to a Container Station

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-26

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Permit To Transfer Containers to a Container Station AGENCY: U.S. Customs and Border Protection, Department of Homeland Security...-0049. SUMMARY: U.S. Customs and Border Protection (CBP) of the Department of Homeland Security will...

  19. Information Transfer Problems of the Partially Sighted: Recent Results and Project Summary.

    ERIC Educational Resources Information Center

    Genensky, S. M.; And Others

    The fourth in a series of Rand reports on information transfer problems of the partially sighted reviews earlier reports and describes an experimental secretarial closed circuit TV (CCTV) system which enables the partially sighted to type from a printed or handwritten manuscript. Discussed are experiments using a pseudocolor system to determine…

  20. 76 FR 2758 - Agency Information Collection (Evidence for Transfer of Entitlement of Education Benefits (CFR 21...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ... AFFAIRS Agency Information Collection (Evidence for Transfer of Entitlement of Education Benefits (CFR 21.7080)) Activity Under OMB Review AGENCY: Veterans Benefits Administration, Department of Veterans.... 3501-3521), this notice announces that the Veterans Benefits Administration (VBA), Department of...

  1. Efficient transfer of information from hexitol nucleic acids to RNA during nonenzymatic oligomerization

    NASA Technical Reports Server (NTRS)

    Kozlov, I. A.; De Bouvere, B.; Van Aerschot, A.; Herdewijn, P.; Orgel, L. E.

    1999-01-01

    Hexitol nucleic acids (HNAs) are DNA analogues that contain the standard nucleoside bases attached to a phosphorylated 1,5-anhydrohexitol backbone. We find that HNAs support efficient information transfer in nonensymatic template-directed reactions. HNA heterosequences appeared to be superior to the corresponding DNA heterosequences in facilitating synthesis of complementary oligonucleotides from nucleoside-5'-phosphoro-2-methyl imidazolides.

  2. Collaboration for Student Success: A System for Providing Transfer Student Performance Information to Feeder Institutions.

    ERIC Educational Resources Information Center

    Thompson, Susan

    Southwest Texas State (SWT) University has developed a system of communication with two-year community colleges that aims to provide information about new student performance and identify student needs. About 60% of the 7,000 new undergraduate students first enrolling in SWT each year are transfer students. In 1992, about 60% of new students at…

  3. Efficient transfer of information from hexitol nucleic acids to RNA during nonenzymatic oligomerization

    NASA Technical Reports Server (NTRS)

    Kozlov, I. A.; De Bouvere, B.; Van Aerschot, A.; Herdewijn, P.; Orgel, L. E.

    1999-01-01

    Hexitol nucleic acids (HNAs) are DNA analogues that contain the standard nucleoside bases attached to a phosphorylated 1,5-anhydrohexitol backbone. We find that HNAs support efficient information transfer in nonensymatic template-directed reactions. HNA heterosequences appeared to be superior to the corresponding DNA heterosequences in facilitating synthesis of complementary oligonucleotides from nucleoside-5'-phosphoro-2-methyl imidazolides.

  4. Parental Modeling, Reinforcement, and Information Transfer: Risk Factors in the Development of Child Anxiety?

    ERIC Educational Resources Information Center

    Fisak, Brian, Jr.; Grills-Taquechel, Amie E.

    2007-01-01

    The purpose of this article is to provide a comprehensive review and a conceptual integration of research examining the potential role of learning from parents in the development of child anxiety. Specifically, research in this area is discussed within the framework of three specific mechanisms: parental modeling, information transfer, and…

  5. Information Transfer and Cognitive Mismatch: A Popperian Model for Studies of Public Understanding.

    ERIC Educational Resources Information Center

    Abbott, R.

    1997-01-01

    The deficiencies and distortions revealed in studies of public understanding of science, intuitive physics, nutritional myths and misunderstandings, and mental mapping of geographical space are defects in information transfer from the physical and intellectual realms to the subjective realms of individuals (Popper's three "Worlds").…

  6. Anatomy of a Technology Transfer: The National Commission on Libraries and Information Science Literacy Project.

    ERIC Educational Resources Information Center

    Young, Christina Carr

    1986-01-01

    Discusses a demonstration project conducted by the National Commission on Libraries and Information Science to transfer reading development technology developed by the military to adult literacy education. The development and testing of a computer-assisted instruction program for language skills in two library sites and plans for expanded testing…

  7. Interhemispheric Information Transfer: A New Diagnostic Method for Mild Traumatic Brain Injury

    DTIC Science & Technology

    2011-10-01

    brain tumors, meningitis, cerebral palsy , encephalitis, brain abscesses, vascular malformations, cerebrovascular disease, Alzheimer’s disease...transfer information between the two cerebral hemispheres. The functioning of these white matter regions can be assessed using neuropsychological... cerebral hemispheres [2]. The normal functioning of the corpus callosum and other white matter regions can be assessed easily and rapidly using

  8. Supercurrents in Unidirectional Channels Originate from Information Transfer in the Opposite Direction: A Theoretical Prediction.

    PubMed

    Huang, Xiao-Li; Nazarov, Yuli V

    2017-04-28

    It has been thought that the long chiral edge channels cannot support any supercurrent between the superconducting electrodes. We show theoretically that the supercurrent can be mediated by a nonlocal interaction that facilitates a long-distance information transfer in the direction opposite of electron flow. We compute the supercurrent for several interaction models, including that of an external circuit.

  9. The Alternative complex III: properties and possible mechanisms for electron transfer and energy conservation.

    PubMed

    Refojo, Patrícia N; Teixeira, Miguel; Pereira, Manuela M

    2012-10-01

    Alternative complexes III (ACIII) are recently identified membrane-bound enzymes that replace functionally the cytochrome bc(1/)b(6)f complexes. In general, ACIII are composed of four transmembrane proteins and three peripheral subunits that contain iron-sulfur centers and C-type hemes. ACIII are built by a combination of modules present in different enzyme families, namely the complex iron-sulfur molybdenum containing enzymes. In this article a historical perspective on the investigation of ACIII is presented, followed by an overview of the present knowledge on these enzymes. Electron transfer pathways within the protein are discussed taking into account possible different locations (cytoplasmatic or periplasmatic) of the iron-sulfur containing protein and their contribution to energy conservation. In this way several hypotheses for energy conservation modes are raised including linear and bifurcating electron transfer pathways. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012). Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Transferability of a Three-Dimensional Air Quality Model between Two Different Sites in Complex Terrain.

    NASA Astrophysics Data System (ADS)

    Lange, Rolf

    1989-07-01

    The three-dimensional, diagnostic, particle-in-cell transport and diffusion model MATHEW/ADPIC is used to test its transferability from one site in complex terrain to another with different characteristics, under stable nighttime drainage flow conditions. The two sites were subject to extensive drainage flow tracer experiments under the multilaboratory Atmospheric Studies in Complex Terrain (ASCOT) program: the first being a valley in the Geysers geothermal region of northern California, and the second a canyon in western Colorado. The domain in each case is approximately 10 × 10 km. The 1980 Geysers model evaluation is only quoted. The 1984 Brush Creek model evaluation is described in detail.Results from comparing computed with measured concentrations from a variety of tracer releases indicate that 52% of the 4531 samples from five experiments in Brush Creek and 50% of the 831 samples from four experiments in the Geysers agreed within a factor of 5. When an angular 10° uncertainty, consistent with anemometer reliability limits in complex terrain, was allowed to be applied to the model results, model performance improved such that 78% of samples compared within a factor of 5 for Brush Creek and 77% for the Geysers. Looking at the range of other factors of concentration ratios, results indicate that the model is satisfactorily transferable without tuning it to a specific site.

  11. Training on a new, portable, simple simulator transfers to performance of complex bronchoscopy procedures.

    PubMed

    Krogh, Charlotte Loumann; Konge, Lars; Bjurström, Johanna; Ringsted, Charlotte

    2013-07-01

    Virtual-reality (VR) simulation provides a safe and effective learning environment prior to practicing on patients. However, existing bronchoscopy simulators are expensive and not easily portable. The aim of this study was to assess the effect of self-directed training on a new, portable, simple simulator measured by transfer of skills to performance of more complex bronchoscopy procedures on an advanced VR simulator. Twenty medical students participated in the study. After a general introduction to bronchoscopy, they were randomised into two groups, receiving either self-directed bronchoscopy training using a portable, simple simulator or no manual training. Subsequently, all participants were tested on complex scenarios in an advanced VR simulator using a validated bronchoscopy quality test. Bronchoscopy quality scores were compared using independent samples t-test and correlated with a previously established pass-fail standard. The intervention group spent an average of 71-min training on the new simulator. The intervention group performed significantly better than the control group, mean bronchoscopy quality score 0.55 [standard deviation (SD) 0.16] vs 0.36 (SD 0.10), P = 0.005, effect size = 1.47. Eight out of 10 participants in the intervention group passed the test compared with only 1 out of 10 in the control group. The effect of a brief, self-directed training session using a portable, simple simulator was substantial and transferred to performance of more complex skills. © 2012 John Wiley & Sons Ltd.

  12. Minimal Model of Quantum Kinetic Clusters for the Energy-Transfer Network of a Light-Harvesting Protein Complex.

    PubMed

    Wu, Jianlan; Tang, Zhoufei; Gong, Zhihao; Cao, Jianshu; Mukamel, Shaul

    2015-04-02

    The energy absorbed in a light-harvesting protein complex is often transferred collectively through aggregated chromophore clusters. For population evolution of chromophores, the time-integrated effective rate matrix allows us to construct quantum kinetic clusters quantitatively and determine the reduced cluster-cluster transfer rates systematically, thus defining a minimal model of energy-transfer kinetics. For Fenna-Matthews-Olson (FMO) and light-havrvesting complex II (LCHII) monomers, quantum Markovian kinetics of clusters can accurately reproduce the overall energy-transfer process in the long-time scale. The dominant energy-transfer pathways are identified in the picture of aggregated clusters. The chromophores distributed extensively in various clusters can assist a fast and long-range energy transfer.

  13. Faster oxygen atom transfer catalysis with a tungsten dioxo complex than with its molybdenum analog.

    PubMed

    Arumuganathan, T; Mayilmurugan, Ramasamy; Volpe, Manuel; Mösch-Zanetti, Nadia C

    2011-08-21

    The synthesis and characterization of a series of molybdenum ([MoO(2)Cl(L(n))]; L(1) (1), L(2) (3)) and tungsten ([WO(2)Cl(L(n))]; L(1) (2), L(2) (4)) dioxo complexes (L(1) = 1-methyl-4-(2-hydroxybenzyl)-1,4-diazepane and L(2) = 1-methyl-4-(2-hydroxy-3,5-di-tert-butylbenzyl)-1,4-diazepane) of tridentate aminomonophenolate ligands HL(1) and HL(2) are reported. The ligands were obtained by reductive amination of 1-methyl-1,4-diazepane with the corresponding aldehyde. Complexes 3 and 4 were obtained by the reaction of [MO(2)Cl(2)(dme)(n)] (M = Mo, n = 0; W, n = 1) with the corresponding ligand in presence of a base, whereas for the preparation of 1 and 2 the ligands were deprotonated by KH prior to the addition to the metal. They were characterized by NMR and IR spectroscopy, by cyclic voltammetry, mass spectrometry, elemental analysis and by single-crystal X-ray diffraction analysis. Solid-state structures of the molybdenum and tungsten cis-dioxo complexes reveal hexa-coordinate metal centers surrounded by two oxo groups, a chloride ligand and by the tridentate monophenolate ligand which coordinates meridionally through its [ONN] donor set. In the series of compounds 1-4, complexes 3 and 4 have been used as catalysts for the oxygen atom transfer reaction between dimethyl sulfoxide (DMSO) and trimethyl phosphine (PMe(3)). Surprisingly, faster oxygen atom transfer (OAT) reactivity has been observed for the tungsten complex [WO(2)Cl(L(2))] (4) in comparison to its molybdenum analog [MoO(2)Cl(L(2))] (3) at room temperature. The kinetic results are discussed and compared in terms of their reactivity. This journal is © The Royal Society of Chemistry 2011

  14. Electronic and vibronic properties of a discotic liquid-crystal and its charge transfer complex.

    PubMed

    Haverkate, Lucas A; Zbiri, Mohamed; Johnson, Mark R; Carter, Elizabeth; Kotlewski, Arek; Picken, S; Mulder, Fokko M; Kearley, Gordon J

    2014-01-07

    Discotic liquid crystalline (DLC) charge transfer (CT) complexes combine visible light absorption and rapid charge transfer characteristics, being favorable properties for photovoltaic (PV) applications. We present a detailed study of the electronic and vibrational properties of the prototypic 1:1 mixture of discotic 2,3,6,7,10,11-hexakishexyloxytriphenylene (HAT6) and 2,4,7-trinitro-9-fluorenone (TNF). It is shown that intermolecular charge transfer occurs in the ground state of the complex: a charge delocalization of about 10(-2) electron from the HAT6 core to TNF is deduced from both Raman and our previous NMR measurements [L. A. Haverkate, M. Zbiri, M. R. Johnson, B. Deme, H. J. M. de Groot, F. Lefeber, A. Kotlewski, S. J. Picken, F. M. Mulder, and G. J. Kearley, J. Phys. Chem. B 116, 13098 (2012)], implying the presence of permanent dipoles at the donor-acceptor interface. A combined analysis of density functional theory calculations, resonant Raman and UV-VIS absorption measurements indicate that fast relaxation occurs in the UV region due to intramolecular vibronic coupling of HAT6 quinoidal modes with lower lying electronic states. Relatively slower relaxation in the visible region the excited CT-band of the complex is also indicated, which likely involves motions of the TNF nitro groups. The fast quinoidal relaxation process in the hot UV band of HAT6 relates to pseudo-Jahn-Teller interactions in a single benzene unit, suggesting that the underlying vibronic coupling mechanism can be generic for polyaromatic hydrocarbons. Both the presence of ground state CT dipoles and relatively slow relaxation processes in the excited CT band can be relevant concerning the design of DLC based organic PV systems.

  15. Complex internal rearrangement processes triggered by electron transfer to acetic acid

    NASA Astrophysics Data System (ADS)

    Limão-Vieira, P.; Meneses, G.; Cunha, T.; Gil, A.; Calhorda, M. J.; García, G.; Ferreira da Silva, F.

    2015-09-01

    We present negative ion formation from collisions of 100 eV neutral potassium atoms with acetic acid (CH3COOH) and its deuterated analogue molecules (CH3COOD, CD3COOH). From the negative ion time-of-flight (TOF) mass spectra, OH- is the main fragment detected accounting on average for more than 25% of the total anion yield. The complex internal rearrangement processes triggered by electron transfer to acetic acid have been evaluated with the help of theoretical calculations at the DFT levels explaining the fragmentation channel yielding OH-.

  16. Charge separation and energy transfer in the photosystem II core complex studied by femtosecond midinfrared spectroscopy.

    PubMed

    Pawlowicz, N P; Groot, M-L; van Stokkum, I H M; Breton, J; van Grondelle, R

    2007-10-15

    The core of photosystem II (PSII) of green plants contains the reaction center (RC) proteins D1D2-cytb559 and two core antennas CP43 and CP47. We have used time-resolved visible pump/midinfrared probe spectroscopy in the region between 1600 and 1800 cm(-1) to study the energy transfer and charge separation events within PSII cores. The absorption difference spectra in the region of the keto and ester chlorophyll modes show spectral evolution with time constants of 3 ps, 27 ps, 200 ps, and 2 ns. Comparison of infrared (IR) difference spectra obtained for the isolated antennas CP43 and CP47 and the D1D2-RC with those measured for the PSII core allowed us to identify the features specific for each of the PSII core components. From the presence of the CP43 and CP47 specific features in the spectra up to time delays of 20-30 ps, we conclude that the main part of the energy transfer from the antennas to the RC occurs on this timescale. Direct excitation of the pigments in the RC evolution associated difference spectra to radical pair formation of PD1+PheoD1- on the same timescale as multi-excitation annihilation and excited state equilibration within the antennas CP43 and CP47, which occur within approximately 1-3 ps. The formation of the earlier radical pair ChlD1+PheoD1-, as identified in isolated D1D2 complexes with time-resolved mid-IR spectroscopy is not observed in the current data, probably because of its relatively low concentration. Relaxation of the state PD1+PheoD1-, caused by a drop in free energy, occurs in 200 ps in closed cores. We conclude that the kinetic model proposed earlier for the energy and electron transfer dynamics within the D1D2-RC, plus two slowly energy-transferring antennas C43 and CP47 explain the complex excited state and charge separation dynamics in the PSII core very well. We further show that the time-resolved IR-difference spectrum of PD1+PheoD1- as observed in PSII cores is virtually identical to that observed in the isolated D1D2-RC

  17. Potential Energy Surfaces and Charge Transfer of PAH-Sodium-PAH Complexes.

    PubMed

    Hjertenaes, Eirik; Andersson, Stefan; Koch, Henrik

    2016-09-19

    To further understanding of the role of sodium in carbon cathode degradation in Hall-Héroult cells, potential-energy surfaces and charge-transfer curves are presented for finite-size complexes of sodium intercalated between various polycyclic aromatic hydrocarbons. Calculations for lithium and potassium are included to highlight the disparate intercalation behaviour of the alkali metals in graphite intercalation compounds. Static energy barriers from DFT are used to compute macroscopic diffusion coefficients according to transition-state theory. Comparing the calculated diffusion coefficient to experimental values from the literature sheds light on the role of lattice diffusion of sodium-graphite intercalation compounds in sodium intrusion in graphitic carbon cathodes.

  18. Formation of charge-transfer-complex in organic:metal oxides systems

    NASA Astrophysics Data System (ADS)

    Wu, S. P.; Kang, Y.; Liu, T. L.; Jin, Z. H.; Jiang, N.; Lu, Z. H.

    2013-04-01

    It is found that composite systems consisting of 4,4'-bis(carbazol-9-yl)biphenyl (CBP) and molybdenum trioxide (MoO3) form an IR absorption band around 847 nm. It is also found that the vibrational modes of the CBP, as measured by Fourier Transform Infrared Spectroscopy, are quenched upon the formation of charge-transfer-complex (CTC) between CBP and MoO3. By examining several sets of organic:metal oxides systems, we discovered that the IR absorption band of the CTCs follow two distinct mechanisms depending on the nature and location of the HOMOs in the organic molecules.

  19. Charge-transfer complexation as a general phenomenon in the copigmentation of anthocyanins.

    PubMed

    Ferreira da Silva, Palmira; Lima, João C; Freitas, Adilson A; Shimizu, Karina; Maçanita, Antonio L; Quina, Frank H

    2005-08-18

    Color intensification of anthocyanin solutions in the presence of natural polyphenols (copigmentation) is re-interpreted in terms of charge transfer from the copigment to the anthocyanin. Flavylium cations are shown to be excellent electron acceptors (E(red) approximately -0.3 V vs SCE). It is also demonstrated, for a large series of anthocyanin-copigment pairs, that the standard Gibbs free energy of complex formation decreases linearly with EA(Anthoc) - IP(Cop), the difference between the electron affinity of the anthocyanin, EA(Anthoc), and the ionization potential of the copigment, IP(Cop). Based on this correlation, copigmentation strengths of potential candidates for copigments can be predicted.

  20. Bis(pentamethylcyclopentadienyl) ytterbium: Electron-transfer reactions with organotransition metal complexes

    SciTech Connect

    Matsunaga, P.T.

    1991-11-01

    The divalent lanthanide complex, (Me{sub 5}C{sub 5}){sub 2}Yb, reacts with methylcopper to produce the base-free, ytterbium-methyl complex, (Me{sub 5}C{sub 5}){sub 2}YbMe. This product forms a asymmetric, methyl-bridged dimer in the solid state. The bulky alkyl complex, (Me{sub 5}C{sub 5}){sub 2}YbCH(SiMe{sub 3}){sub 2}, displays similar chemistry to (Me{sub 5}C{sub 5}){sub 2}YbMe, but at a reduced reaction rate due to the limited accessibility of the metal in (Me{sub 5}C{sub 5}){sub 2}YbCH(SiMe{sub 3}){sub 2}. Copper and silver halide salts react with (Me{sub 5}C{sub 5}){sub 2}V to produce the trivalent halide derivatives, (Me{sub 5}C{sub 5}){sub 2}VX (X + F, Cl, Br, I). The chloride complex, (Me{sub 5}C{sub 5}){sub 2}VCl, reacts with lithium reagents to form the phenyl and borohydride species. Nitrous oxide transfers an oxygen atom to (Me{sub 5}C{sub 5}){sub 2}V producing the vanadium-oxo complex, (Me{sub 5}Ce{sub 5}){sub 2}VO. The trivalent titanium species, (Me{sub 5}C{sub 5}){sub 2}TiX (X = Cl, Br, Me, BH{sub 4}), form bimetallic coordination complexes with (Me{sub 5}C{sub 5}){sub 2}Yb. The magnetic behavior of the products indicates that electron transfer has not occurred. The solid state structures of the chloride and bromide complexes show unusual bend angles for the halide bridges between ytterbium and titanium. A model based on frontier orbital theory has been proposed to account for the bending behavior in these species. The bimetallic methyl complex contains a linear methyl bridge between ytterbium and titanium.