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Sample records for information transfer complexity

  1. 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).

  2. 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.

  3. 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. ''

  4. 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

  5. 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.

  6. Information Flows? A Critique of Transfer Entropies

    NASA Astrophysics Data System (ADS)

    James, Ryan G.; Barnett, Nix; Crutchfield, James P.

    2016-06-01

    A central task in analyzing complex dynamics is to determine the loci of information storage and the communication topology of information flows within a system. Over the last decade and a half, diagnostics for the latter have come to be dominated by the transfer entropy. Via straightforward examples, we show that it and a derivative quantity, the causation entropy, do not, in fact, quantify the flow of information. At one and the same time they can overestimate flow or underestimate influence. We isolate why this is the case and propose several avenues to alternate measures for information flow. We also address an auxiliary consequence: The proliferation of networks as a now-common theoretical model for large-scale systems, in concert with the use of transferlike entropies, has shoehorned dyadic relationships into our structural interpretation of the organization and behavior of complex systems. This interpretation thus fails to include the effects of polyadic dependencies. The net result is that much of the sophisticated organization of complex systems may go undetected.

  7. 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.

  8. 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)

  9. 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

  10. 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.

  11. 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.…

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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…

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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…

  6. 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.

  7. 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.

  8. 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…

  9. Securing Information with Complex Optical Encryption Networks

    DTIC Science & Technology

    2015-08-11

    encryption networks, and to provide effective and reliable solutions for information security. 15. SUBJECT TERMS Optical Encryption...popularization of networking and internet , much research effort is made in the field of information security. Military communication system makes an...objective is to propose the architectures for a number of complex optical encryption networks so as to provide effective and reliable solutions for

  10. 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…

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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…

  19. 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…

  20. 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…

  1. 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.

  2. 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…

  3. 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…

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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).

  14. 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.

  15. 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.

  16. 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

  17. 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.

  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. 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.

  20. 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.

  1. 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…

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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%.

  13. [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.

  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. 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

  16. Catalytic Transfer of Magnetism using a Neutral Iridium Phenoxide Complex

    PubMed Central

    Ruddlesden, Amy J.; Mewis, Ryan E.; Green, Gary G. R.; Whitwood, Adrian C.; Duckett, Simon B.

    2016-01-01

    A novel neutral iridium carbene complex Ir(κC,O-L1)(COD) (1) [where COD = cyclooctadiene and L1 = 3-(2-methylene-4-nitrophenolate)-1-(2,4,6-trimethylphenyl) imidazolylidene] with a pendant alkoxide ligand has been prepared and characterized. It contains a strong Ir-O bond and X-ray analysis reveals a distorted square planar structure. NMR spectroscopy reveals dynamic solution state behavior commensurate with rapid seven-membered ring flipping. In CD2Cl2 solution, under hydrogen at low temperature, this complex dominates although it exists in equilibrium with a reactive iridium dihydride cyclooctadiene complex. 1 reacts with pyridine and H2 to form neutral Ir(H)2(κC,O-L1)(py)2 which also exists in two conformers that differ according to the orientation of the seven-membered metallocycle and whilst its Ir-O bond remains intact, the complex undergoes both pyridine and H2 exchange. As a consequence, when placed under parahydrogen, efficient polarization transfer catalysis (PTC) is observed via the Signal Amplification By Reversible Exchange (SABRE) approach. Due to the neutral character of this catalyst, good hyperpolarization activity is shown in a wide range of solvents for a number of substrates. These observations reflect a dramatic improvement in solvent tolerance of SABRE over that reported for the best PTC precursor IrCl(IMes)(COD). For THF, the associated 1H NMR signal enhancement for the ortho proton signal of pyridine shows an increase of 600-fold at 298 K. The level of signal enhancement can be increased further through warming or varying the magnetic field experienced by the sample at the point of catalytic magnetization transfer.

  17. 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…

  18. 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)

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

    DTIC Science & Technology

    2012-07-31

    TERMS 15. NUMBER OF PAGES:12 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF...THIS PAGE Unclassified 19. SECURITY CLASSIFICATION OF ABSTRACT Unclassified 20. LIMITATION OF ABSTRACT NSN 7540-01-280-5500...for assurance of information transfer. Proposed and studied the use of Network Coding for secure communication in wireless ad hoc and sensor

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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)

  3. 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.…

  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. 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

  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. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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)

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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....

  10. 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

  11. 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.

  12. 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.

  13. 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…

  14. 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.

  15. 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...

  16. 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)

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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…

  5. 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…

  6. 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.

  7. 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.

  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. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Analysis of charge transfer effects in molecular complexes based on absolutely localized molecular orbitals

    SciTech Connect

    Khaliullin, Rustam Z.; Head-Gordon, Martin; Bell, Alexis T.

    2008-05-14

    A new method based on absolutely localized molecular orbitals (ALMOs) is proposed to measure the degree of intermolecular electron density delocalization (charge transfer) in molecular complexes. ALMO charge transfer analysis (CTA) enables separation of the forward and backward charge transfer components for each pair of molecules in the system. The key feature of ALMO CTA is that all charge transfer terms have corresponding well defined energetic effects that measure the contribution of the given term to the overall energetic stabilization of the system. To simplify analysis of charge transfer effects, the concept of chemically significant complementary occupied-virtual orbital pairs (COVPs) is introduced. COVPs provide a simple description of intermolecular electron transfer effects in terms of just a few localized orbitals. ALMO CTA is applied to understand fundamental aspects of donor-acceptor interactions in borane adducts, synergic bonding in classical and nonclassical metal carbonyls, and multiple intermolecular hydrogen bonds in a complex of isocyanuric acid and melamine. These examples show that the ALMO CTA results are generally consistent with the existing conceptual description of intermolecular bonding. The results also show that charge transfer and the energy lowering due to charge transfer are not proportional to each other, and some interesting differences emerge which are discussed. Additionally, according to ALMO CTA, the amount of electron density transferred between molecules is significantly smaller than charge transfer estimated from various population analysis methods.

  17. Analysis of charge transfer effects in molecular complexes based on absolutely localized molecular orbitals.

    PubMed

    Khaliullin, Rustam Z; Bell, Alexis T; Head-Gordon, Martin

    2008-05-14

    A new method based on absolutely localized molecular orbitals (ALMOs) is proposed to measure the degree of intermolecular electron density delocalization (charge transfer) in molecular complexes. ALMO charge transfer analysis (CTA) enables separation of the forward and backward charge transfer components for each pair of molecules in the system. The key feature of ALMO CTA is that all charge transfer terms have corresponding well defined energetic effects that measure the contribution of the given term to the overall energetic stabilization of the system. To simplify analysis of charge transfer effects, the concept of chemically significant complementary occupied-virtual orbital pairs (COVPs) is introduced. COVPs provide a simple description of intermolecular electron transfer effects in terms of just a few localized orbitals. ALMO CTA is applied to understand fundamental aspects of donor-acceptor interactions in borane adducts, synergic bonding in classical and nonclassical metal carbonyls, and multiple intermolecular hydrogen bonds in a complex of isocyanuric acid and melamine. These examples show that the ALMO CTA results are generally consistent with the existing conceptual description of intermolecular bonding. The results also show that charge transfer and the energy lowering due to charge transfer are not proportional to each other, and some interesting differences emerge which are discussed. Additionally, according to ALMO CTA, the amount of electron density transferred between molecules is significantly smaller than charge transfer estimated from various population analysis methods.

  18. Analysis of charge transfer effects in molecular complexes based on absolutely localized molecular orbitals

    NASA Astrophysics Data System (ADS)

    Khaliullin, Rustam Z.; Bell, Alexis T.; Head-Gordon, Martin

    2008-05-01

    A new method based on absolutely localized molecular orbitals (ALMOs) is proposed to measure the degree of intermolecular electron density delocalization (charge transfer) in molecular complexes. ALMO charge transfer analysis (CTA) enables separation of the forward and backward charge transfer components for each pair of molecules in the system. The key feature of ALMO CTA is that all charge transfer terms have corresponding well defined energetic effects that measure the contribution of the given term to the overall energetic stabilization of the system. To simplify analysis of charge transfer effects, the concept of chemically significant complementary occupied-virtual orbital pairs (COVPs) is introduced. COVPs provide a simple description of intermolecular electron transfer effects in terms of just a few localized orbitals. ALMO CTA is applied to understand fundamental aspects of donor-acceptor interactions in borane adducts, synergic bonding in classical and nonclassical metal carbonyls, and multiple intermolecular hydrogen bonds in a complex of isocyanuric acid and melamine. These examples show that the ALMO CTA results are generally consistent with the existing conceptual description of intermolecular bonding. The results also show that charge transfer and the energy lowering due to charge transfer are not proportional to each other, and some interesting differences emerge which are discussed. Additionally, according to ALMO CTA, the amount of electron density transferred between molecules is significantly smaller than charge transfer estimated from various population analysis methods.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.).

  5. 48 CFR 52.232-38 - Submission of Electronic Funds Transfer Information with Offer.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  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...

  8. 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...

  9. 48 CFR 52.232-38 - Submission of Electronic Funds Transfer Information with Offer.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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...

  17. 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... refer to ``OMB Control No. 2900-0708.'' SUPPLEMENTARY INFORMATION: Title: Evidence for Transfer of... children, or a combination of the spouse and children. VA will accept DOD Form 2366-1 as evidence that...

  18. 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...

  19. 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.

  20. 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.

  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. Information theoretical quantification of cooperativity in signalling complexes

    PubMed Central

    Lenaerts, Tom; Ferkinghoff-Borg, Jesper; Schymkowitz, Joost; Rousseau, Frederic

    2009-01-01

    Background Intra-cellular information exchange, propelled by cascades of interacting signalling proteins, is essential for the proper functioning and survival of cells. Now that the interactome of several organisms is being mapped and several structural mechanisms of cooperativity at the molecular level in proteins have been elucidated, the formalization of this fundamental quantity, i.e. information, in these very diverse biological contexts becomes feasible. Results We show here that Shannon's mutual information quantifies information in biological system and more specifically the cooperativity inherent to the assembly of macromolecular complexes. We show how protein complexes can be considered as particular instances of noisy communication channels. Further we show, using a portion of the p27 regulatory pathway, how classical equilibrium thermodynamic quantities such as binding affinities and chemical potentials can be used to quantify information exchange but also to determine engineering properties such as channel noise and channel capacity. As such, this information measure identifies and quantifies those protein concentrations that render the biochemical system most effective in switching between the active and inactive state of the intracellular process. Conclusion The proposed framework provides a new and original approach to analyse the effects of cooperativity in the assembly of macromolecular complexes. It shows the conditions, provided by the protein concentrations, for which a particular system acts most effectively, i.e. exchanges the most information. As such this framework opens the possibility of grasping biological qualities such as system sensitivity, robustness or plasticity directly in terms of their effect on information exchange. Although these parameters might also be derived using classical thermodynamic parameters, a recasting of biological signalling in terms of information exchange offers an alternative framework for visualising network

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  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. 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.

  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 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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

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

    PubMed

    Ahl, Richard E; Keil, Frank C

    2016-09-26

    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.

  3. 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…

  4. 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.

  5. 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.

  6. 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.

  7. 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....

  8. 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…

  9. 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…

  10. 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

  11. 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.

  12. 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)

  13. 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)

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  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. 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...

  3. 77 FR 36479 - Proposed Information Collection; Comment Request; License Transfer and Duplicate License Services

    Federal Register 2010, 2011, 2012, 2013, 2014

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  4. 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...

  5. 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.

  6. 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

  7. 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

  8. 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.

  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. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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).

  18. [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.

  19. SNP Markers as Additional Information to Resolve Complex Kinship Cases

    PubMed Central

    Pontes, M. Lurdes; Fondevila, Manuel; Laréu, Maria Victoria; Medeiros, Rui

    2015-01-01

    Summary Background DNA profiling with sets of highly polymorphic autosomal short tandem repeat (STR) markers has been applied in various aspects of human identification in forensic casework for nearly 20 years. However, in some cases of complex kinship investigation, the information provided by the conventionally used STR markers is not enough, often resulting in low likelihood ratio (LR) calculations. In these cases, it becomes necessary to increment the number of loci under analysis to reach adequate LRs. Recently, it has been proposed that single nucleotide polymorphisms (SNPs) could be used as a supportive tool to STR typing, eventually even replacing the methods/markers now employed. Methods In this work, we describe the results obtained in 7 revised complex paternity cases when applying a battery of STRs, as well as 52 human identification SNPs (SNPforID 52plex identification panel) using a SNaPshot methodology followed by capillary electrophoresis. Results Our results show that the analysis of SNPs, as complement to STR typing in forensic casework applications, would at least increase by a factor of 4 total PI values and correspondent Essen-Möller's W value. Conclusions We demonstrated that SNP genotyping could be a key complement to STR information in challenging casework of disputed paternity, such as close relative individualization or complex pedigrees subject to endogamous relations. PMID:26733770

  20. 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.

  1. 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.

  2. 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.

  3. 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).

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  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. 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.

  18. 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…

  19. 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…

  20. 49 CFR 8.23 - Classified information transferred to the Department of Transportation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... adopt a system of records management that will facilitate the public release of documents at the time... with the Archivist in efforts to establish a Government-wide database of information that has been... 49 Transportation 1 2013-10-01 2013-10-01 false Classified information transferred to...

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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).

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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).

  19. 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...

  20. 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...

  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. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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…

  17. 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.

  18. 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…

  19. 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.

  20. 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

    ...Under the provisions of the Paperwork Reduction Act, the Regulatory Secretariat will be submitting to the Office of Management and Budget (OMB) a request to review and approve an extension of a previously approved information collection requirement regarding Standard Form (SF) 123, transfer order-surplus personal property and continuation sheet. Public comments are particularly invited on:......

  1. 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…

  2. 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…

  3. 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...

  4. 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…

  5. 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.

  6. 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.

  7. 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-.

  8. 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.

  9. 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.

  10. Energy transfer in complexes of water-soluble quantum dots and chlorin e6 molecules in different environments

    PubMed Central

    Martynenko, Irina V; Maslov, Vladimir G; Baranov, Alexander V; Fedorov, Anatoly V; Artemyev, Mikhail

    2013-01-01

    Summary The photoexcitation energy transfer is found and investigated in complexes of CdSe/ZnS cationic quantum dots and chlorin e6 molecules formed by covalent bonding and electrostatic interaction in aqueous solution and in porous track membranes. The quantum dots and chlorin e6 molecules form stable complexes that exhibit Förster resonance energy transfer (FRET) from quantum dots to chlorin e6 regardless of complex formation conditions. Competitive channels of photoexcitation energy dissipation in the complexes, which hamper the FRET process, were found and discussed. PMID:24367759

  11. Energy transfer in complexes of water-soluble quantum dots and chlorin e6 molecules in different environments.

    PubMed

    Martynenko, Irina V; Orlova, Anna O; Maslov, Vladimir G; Baranov, Alexander V; Fedorov, Anatoly V; Artemyev, Mikhail

    2013-01-01

    The photoexcitation energy transfer is found and investigated in complexes of CdSe/ZnS cationic quantum dots and chlorin e6 molecules formed by covalent bonding and electrostatic interaction in aqueous solution and in porous track membranes. The quantum dots and chlorin e6 molecules form stable complexes that exhibit Förster resonance energy transfer (FRET) from quantum dots to chlorin e6 regardless of complex formation conditions. Competitive channels of photoexcitation energy dissipation in the complexes, which hamper the FRET process, were found and discussed.

  12. A resonance mechanism of efficient energy transfer mediated by Fenna-Matthews-Olson complex

    NASA Astrophysics Data System (ADS)

    Alicki, Robert; Miklaszewski, Wiesław

    2012-04-01

    The Wigner-Weisskopf-type model developed by Alicki and Giraldi [J. Phys. B 44, 154020 (2011)], 10.1088/0953-4075/44/15/154020 is applied to the biological process of energy transfer from a large peripheral light harvesting antenna to the reaction center. This process is mediated by the Fenna-Matthews-Olson (FMO) photosynthetic complex with a remarkably high efficiency. The proposed model provides a simple resonance mechanism of this phenomenon employing exciton coherent motion and is described by analytical formulas. A coupling to the vibrational environment is a necessary component of this mechanism as well as a fine-tuning of the FMO complex Hamiltonian. The role of the relatively strong coupling to the energy sink in achieving the resonance condition and the absence of heating of the vibrational environment are emphasized.

  13. Intramolecular energy- and electron-transfer reactions in polymetallic complexes. Annual report

    SciTech Connect

    Peterson, J.D.

    1991-12-01

    The complexes (tpy)Ru(II)(tpp)Co(III)(PPhEt{sub 2})H{sub 2}{sup 3+}, (NC){sub 3}Fe(II)(tpp)Co(III)(PPhEt{sub 2})H{sub 2} and (NC){sub 3}Fe(II)(tpp)Co(III)(PPh{sub 3})H{sub 2} (where tpp = 2,3,5,6-tetrakis(2{prime}-pyridyl)pyrazine), were prepared and their photochemistry studied. Reasons for the low quantum yields for H{sub 2} production are discussed briefly. A series of FeRuRh complexes is being prepared. Plans for the coming year on intramolecular energy transfer and charge separation are discussed.

  14. Cryo-EM structures and atomic model of the HIV-1 strand transfer complex intasome.

    PubMed

    Passos, Dario Oliveira; Li, Min; Yang, Renbin; Rebensburg, Stephanie V; Ghirlando, Rodolfo; Jeon, Youngmin; Shkriabai, Nikoloz; Kvaratskhelia, Mamuka; Craigie, Robert; Lyumkis, Dmitry

    2017-01-06

    Like all retroviruses, HIV-1 irreversibly inserts a viral DNA (vDNA) copy of its RNA genome into host target DNA (tDNA). The intasome, a higher-order nucleoprotein complex composed of viral integrase (IN) and the ends of linear vDNA, mediates integration. Productive integration into host chromatin results in the formation of the strand transfer complex (STC) containing catalytically joined vDNA and tDNA. HIV-1 intasomes have been refractory to high-resolution structural studies. We used a soluble IN fusion protein to facilitate structural studies, through which we present a high-resolution cryo-electron microscopy (cryo-EM) structure of the core tetrameric HIV-1 STC and a higher-order form that adopts carboxyl-terminal domain rearrangements. The distinct STC structures highlight how HIV-1 can use the common retroviral intasome core architecture to accommodate different IN domain modules for assembly.

  15. Assembly of prototype foamy virus strand transfer complexes on product DNA bypassing catalysis of integration.

    PubMed

    Yin, Zhiqi; Lapkouski, Mikalai; Yang, Wei; Craigie, Robert

    2012-12-01

    Integrase is the key enzyme that mediates integration of retroviral DNA into cellular DNA which is essential for viral replication. Inhibitors of HIV-1 that target integrase recognize the nucleoprotein complexes formed by integrase and viral DNA substrate (intasomes) rather than the free enzyme. Atomic resolution structures of HIV-1 intasomes are therefore required to understand the mechanisms of inhibition and drug resistance. To date, prototype foamy virus (PFV) is the only retrovirus for which such structures have been determined. We show that PFV strand transfer complexes (STC) can be assembled on product DNA without going through the normal forward reaction pathway. The finding that a retroviral STC can be assembled in this way may provide a powerful tool to alleviate the obstacles that impede structural studies of nucleoprotein intermediates in HIV-1 DNA integration.

  16. Charge Transfer Dissociation of Complex Oligosaccharides: Comparison with Collision-Induced Dissociation and Extreme Ultraviolet Dissociative Photoionization

    NASA Astrophysics Data System (ADS)

    Ropartz, David; Li, Pengfei; Fanuel, Mathieu; Giuliani, Alexandre; Rogniaux, Hélène; Jackson, Glen P.

    2016-10-01

    The structural characterization of oligosaccharides still challenges the field of analytical chemistry. Tandem mass spectrometry offers many advantages toward this aim, although the generic fragmentation method (low-energy collision-induced dissociation) shows clear limitations and is often insufficient to retrieve some essential structural information on these molecules. In this work, we present the first application of helium charge transfer dissociation (He-CTD) to characterize the structure of complex oligosaccharides. We compare this method with low-energy collision-induced dissociation and extreme-ultraviolet dissociative photoionization (XUV-DPI), which was shown previously to ensure the successful characterization of complex glycans. Similarly to what could be obtained by XUV-DPI, He-CTD provides a complete description of the investigated structures by producing many informative cross-ring fragments and no ambiguous fragmentation. Unlike XUV-DPI, which is performed at a synchrotron source, He-CTD has the undeniable advantage of being implementable in a conventional benchtop ion trap in a conventional laboratory setting.

  17. New ruthenium nitrosyl pincer complexes bearing an O2 ligand. Mono-oxygen transfer.

    PubMed

    Fogler, Eran; Efremenko, Irena; Gargir, Moti; Leitus, Gregory; Diskin-Posner, Yael; Ben-David, Yehoshoa; Martin, Jan M L; Milstein, David

    2015-03-02

    We report on Ru((II))(μ(2)-O2) nitrosyl pincer complexes that can return to their original Ru(0) state by reaction with mono-oxygen scavengers. Potential intermediates were calculated by density functional theory (DFT) and a mechanism is proposed, revealing a new type of metal-ligand cooperation consisting of activation of the O2 moiety by both the metal center and the NO ligand. Reaction of the Ru(0) nitrosyl complex 1 with O2 quantitatively yielded the crystallographically characterized Ru((II)) (μ(2)-O2) nitrosyl complex 2. Reaction of 2 with the mono-oxygen scavengers phosphines or CO gave the Ru(0) complex 1 and phosphine oxides, or the carbonyl complex 3 (1 trapped by CO) and CO2, respectively. Reaction of 2 with 1 equiv of phosphine at room temperature or -40 °C resulted in immediate formation of half an equivalent of 1 and 1 equiv of phosphine oxide, while half an equivalent of 2 remained unchanged. Overnight reaction at room temperature of 2 with excess CO (≥3 equiv) resulted in 3 and CO2 gas as the only products. Reaction of 1 with 1 equiv of mono-oxygen source (dioxirane) at -78 °C yielded the Ru((II))(μ(2)-O2) complex 2. Similarly, reaction of the Ru(0) dearomatized complex 4 with O2 led to the crystallographicaly characterized Ru((II))(μ(2)-O2) complex 5. Further reaction of 5 with mono-oxygen scavengers (phosphines or CO) led to the Ru(0) complex 4 and phosphine oxides or complex 6 (4 trapped by CO) and CO2. When instead only 1 equiv of 5 was reacted with 1 equiv of phosphine at room temperature, immediate formation of half an equivalent of 4 and 1 equiv of phosphine oxide took place, while half an equivalent of 5 remained unchanged. When 5 reacted with an excess of CO (≥3 equiv), complex 6 and CO2 gas were the only products obtained. DFT studies indicate a new mode of metal-ligand cooperation involving the nitrosyl ligand in the oxygen transfer process.

  18. Stereochemical consequences of oxygen atom transfer and electron transfer in imido/oxido molybdenum(IV, V, VI) complexes with two unsymmetric bidentate ligands.

    PubMed

    Hüttinger, Kristina; Förster, Christoph; Bund, Timo; Hinderberger, Dariush; Heinze, Katja

    2012-04-02

    Two equivalents of the unsymmetrical Schiff base ligand (L(tBu))(-) (4-tert-butyl phenyl(pyrrolato-2-ylmethylene)amine) and MoCl(2)(NtBu)O(dme) (dme = 1,2-dimethoxyethane) gave a single stereoisomer of a mixed imido/oxido Mo(VI) complex 2(tBu). The stereochemistry of 2(tBu) was elucidated using X-ray diffraction, NMR spectroscopy, and DFT calculations. The complex is active in an oxygen atom transfer (OAT) reaction to trimethyl phosphane. The putative intermediate five-coordinate Mo(IV) imido complex coordinates a PMe(3) ligand, giving the six-coordinate imido phosphane Mo(IV) complex 5(tBu). The stereochemistry of 5(tBu) is different from that of 2(tBu) as shown by NMR spectroscopy, DFT calculations, and X-ray diffraction. Single-electron oxidation of 5(tBu) with ferrocenium hexafluorophosphate gave the stable cationic imido phosphane Mo(V) complex [5(tBu)](+) as the PF(6)(-) salt. EPR spectra of [5(tBu)](PF(6)) confirmed the presence of PMe(3) in the coordination sphere. Single-crystal X-ray diffraction analysis of [5(tBu)](PF(6)) revealed that electron transfer occurred under retention of the stereochemical configuration. The rate of OAT, the outcome of the electron transfer reaction, and the stabilities of the imido complexes presented here differ dramatically from those of analogous oxido complexes.

  19. The Deceptively Simple N170 Reflects Network Information Processing Mechanisms Involving Visual Feature Coding and Transfer Across Hemispheres

    PubMed Central

    Ince, Robin A. A.; Jaworska, Katarzyna; Gross, Joachim; Panzeri, Stefano; van Rijsbergen, Nicola J.; Rousselet, Guillaume A.; Schyns, Philippe G.

    2016-01-01

    A key to understanding visual cognition is to determine “where”, “when”, and “how” brain responses reflect the processing of the specific visual features that modulate categorization behavior—the “what”. The N170 is the earliest Event-Related Potential (ERP) that preferentially responds to faces. Here, we demonstrate that a paradigmatic shift is necessary to interpret the N170 as the product of an information processing network that dynamically codes and transfers face features across hemispheres, rather than as a local stimulus-driven event. Reverse-correlation methods coupled with information-theoretic analyses revealed that visibility of the eyes influences face detection behavior. The N170 initially reflects coding of the behaviorally relevant eye contralateral to the sensor, followed by a causal communication of the other eye from the other hemisphere. These findings demonstrate that the deceptively simple N170 ERP hides a complex network information processing mechanism involving initial coding and subsequent cross-hemispheric transfer of visual features. PMID:27550865

  20. The control of complex finger movements by directional information flow between mesial frontocentral areas and the primary motor cortex.

    PubMed

    Boenstrup, M; Feldheim, J; Heise, K; Gerloff, C; Hummel, F C

    2014-09-01

    Complex movements require the interplay of local activation and interareal communication of sensorimotor brain regions. This is reflected in a decrease of task-related spectral power over the sensorimotor cortices and an increase in functional connectivity predominantly in the upper alpha band in the electroencephalogram (EEG). In the present study, directionality of information flow was investigated using EEG recordings to gain better understanding about the network architecture underlying the performance of complex sequential finger movements. This was assessed by means of Granger causality-derived directed transfer function (DTF). As DTF measures the influence one signal exerts on another based on a time lag between them, it allows implications to be drawn on causal relationships. To reveal causal connections between brain regions that are specifically modulated by task complexity, we contrasted the performance of right-handed sequential finger movements of different complexities (simple, scale, complex) that were either pre-learned (memorized) or novel instructed. A complexity-dependent increase in information flow from mesial frontocentral to the left motor cortex and, less pronounced, also to the right motor cortex specifically in the upper alpha range was found. Effective coupling during sequences of high complexity was larger for memorized sequences compared with novel sequences (P = 0.0037). These findings further support the role of mesial frontocentral areas in directing the primary motor cortex in the process of orchestrating complex movements and in particular learned sequences.

  1. Determining Protein Complex Structures Based on a Bayesian Model of in Vivo Förster Resonance Energy Transfer (FRET) Data*

    PubMed Central

    Bonomi, Massimiliano; Pellarin, Riccardo; Kim, Seung Joong; Russel, Daniel; Sundin, Bryan A.; Riffle, Michael; Jaschob, Daniel; Ramsden, Richard; Davis, Trisha N.; Muller, Eric G. D.; Sali, Andrej

    2014-01-01

    The use of in vivo Förster resonance energy transfer (FRET) data to determine the molecular architecture of a protein complex in living cells is challenging due to data sparseness, sample heterogeneity, signal contributions from multiple donors and acceptors, unequal fluorophore brightness, photobleaching, flexibility of the linker connecting the fluorophore to the tagged protein, and spectral cross-talk. We addressed these challenges by using a Bayesian approach that produces the posterior probability of a model, given the input data. The posterior probability is defined as a function of the dependence of our FRET metric FRETR on a structure (forward model), a model of noise in the data, as well as prior information about the structure, relative populations of distinct states in the sample, forward model parameters, and data noise. The forward model was validated against kinetic Monte Carlo simulations and in vivo experimental data collected on nine systems of known structure. In addition, our Bayesian approach was validated by a benchmark of 16 protein complexes of known structure. Given the structures of each subunit of the complexes, models were computed from synthetic FRETR data with a distance root-mean-squared deviation error of 14 to 17 Å. The approach is implemented in the open-source Integrative Modeling Platform, allowing us to determine macromolecular structures through a combination of in vivo FRETR data and data from other sources, such as electron microscopy and chemical cross-linking. PMID:25139910

  2. Information Transfer Efficiency of X-Ray Image Intensifier-Based Imaging Systems.

    NASA Astrophysics Data System (ADS)

    Fu, Tao-Yi.

    The information transfer efficiency of any quantum detection imaging system can be described by a unique measure: the detective quantum efficiency {DQE(f)}, which is a function of the statistically independent frequency channels. The DQE(f) is a combined descriptor which takes into account the signal transfer as well as noise transfer properties of a complete system. For a complicated multistage imaging system, each system component contributes noise. In this dissertation, physical and mathematical models for noise analysis are developed and verified experimentally with an x-ray image intensifier (XRII)-based imaging system. In such a system, the DQE at low frequency range is primarily determined by the x-ray detection and scintillation processes at the CsI layer of the XRII. The effects of x-ray photon energy and sensor layer thickness on DQE are measured in detail. Numerical calculations based on a physical model of x-ray interactions show a general agreement with the experimental data. At higher frequencies, the DQE behavior becomes more complicated. A mathematical model which combines the micro-image properties and noise statistics is formulated to analyze the noise power spectrum (NPS) of a linear n-stage imaging system. Measurement of NPS components of an XRII system verifies the validity of this analytical prediction. The associated image transfer properties are also measured with emphasis on the effect of signal-induced background on the image information transfer. The low frequency data derived from these image property measurements show further agreement with the numerical calculations based on the physical model. As a result of this predictability of information transfer efficiency, system gain and recording capacity are emphasized in the design consideration of a projected high performance XRII radiographic system.

  3. Thermodynamic cost of computation, algorithmic complexity and the information metric

    NASA Technical Reports Server (NTRS)

    Zurek, W. H.

    1989-01-01

    Algorithmic complexity is discussed as a computational counterpart to the second law of thermodynamics. It is shown that algorithmic complexity, which is a measure of randomness, sets limits on the thermodynamic cost of computations and casts a new light on the limitations of Maxwell's demon. Algorithmic complexity can also be used to define distance between binary strings.

  4. Synthesis and characterization of highly conductive charge-transfer complexes using positron annihilation spectroscopy.

    PubMed

    Adam, Abdel Majid A; Refat, Moamen S; Sharshar, T; Heiba, Z K

    2012-09-01

    Molecular charge-transfer complexes of the tetramethylethylenediamine (TMEDA) with picric acid (Pi-OH), benzene-1,4-diol (QL), tin(IV) tetrachloride (SnCl(4)), iodine, bromine, and zinc chloride (ZnCl(2)) have been synthesized and investigated by elemental and thermal analysis, electronic, infrared, Raman and proton-NMR, energy-dispersive X-ray spectroscopy, X-ray powder diffraction and positron annihilation lifetime spectroscopy, and scanning electron microscopy. In this work, three types of acceptors π-acceptors (Pi-OH and QL), σ-acceptors (iodine and bromine), and vacant orbital acceptors (SnCl(4) and ZnCl(2)) were covered. The results of elemental analysis indicated that the CT complexes were formed with ratios 1:1 and 1:2 for QL, SnCl(4), and ZnCl(2) acceptors and iodine, Pi-OH, and Br(2) acceptors, respectively. The type of chelating between the TMEDA donor and the mentioned acceptors depends upon the behavior of both items. The positron annihilation lifetime parameters were found to be dependent on the structure, electronic configuration, and the power of acceptors. The correlation between these parameters and the molecular weight and biological activities of studied complexes was also observed. Regarding the electrical properties, the AC conductivity and the dielectric coefficients were measured as a function of frequency at room temperature. The TMEDA charge-transfer complexes were screened against antibacterial (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa) and antifungal (Aspergillus flavus and Candida albicans) activities.

  5. NASA technology transfer network communications and information system: TUNS user survey

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Applied Expertise surveyed the users of the deployed Technology Utilization Network System (TUNS) and surveyed prospective new users in order to gather background information for developing the Concept Document of the system that will upgrade and replace TUNS. Survey participants broadly agree that automated mechanisms for acquiring, managing, and disseminating new technology and spinoff benefits information can and should play an important role in meeting NASA technology utilization goals. However, TUNS does not meet this need for most users. The survey describes a number of systematic improvements that will make it easier to use the technology transfer mechanism, and thus expedite the collection and dissemination of technology information. The survey identified 26 suggestions for enhancing the technology transfer system and related processes.

  6. WTCS Transfers to the University of Wisconsin System. Information on: Enrollment, Demographics, Outcomes, Conclusions. Joint Administrative Committee on Academic Programs.

    ERIC Educational Resources Information Center

    Wisconsin Univ. System, Madison.

    This document reports on enrollment, demographics, and outcomes for Wisconsin Technical College System (WTCS) transfers to the University of Wisconsin (UW) System. Enrollment Information presents findings on transfers within and into the UW System by year (1994-95 to 1997-98), illustrates the proportion of transfers within and into the UW System…

  7. Theoretical study of intermolecular proton transfer reaction in isolated 5-hydroxyisoxazole water complexes

    NASA Astrophysics Data System (ADS)

    Yi, Ping G.; Liang, Yong H.; Tang, Zhen Q.

    2006-03-01

    A systematic investigation in isolated 5-hydroxyisoxazole-water complexes (5-HIO · (H 2O) nn = 1-3) is performed at the DFT level, employing B3LYP/6-31G(d, p) basis set. Single-point energy calculations are also performed at the MP2 level using B3LYP/6-31G(d, p) optimized geometries and the 6-311++G(d, p) basis set. The computational results show that the keto tautomer K 2 is the most stable isomer in the gas phase, and the tautomer K 1 to be the next most stable tautomer. Hydrogen bonding between HIO and the water molecule(s) will dramatically lower the barrier by a concerted multiple proton transfer mechanism. The proton transfer process of 3WE cis ↔ 3WK 1 and 2WE trans ↔ 2WK 2 is found to be more efficient in two tautomerization, and the barrier heights are 7.03 and 14.15 kcal/mol at B3LYP/6-31G(d, p) level, respectively. However, the proton transfer reaction between E cis and K 1 cannot happen without solvent-assisted.

  8. Applying complexity theory: a review to inform evaluation design.

    PubMed

    Walton, Mat

    2014-08-01

    Complexity theory has increasingly been discussed and applied within evaluation literature over the past decade. This article reviews the discussion and use of complexity theory within academic journal literature. The aim is to identify the issues to be considered when applying complexity theory to evaluation. Reviewing 46 articles, two groups of themes are identified. The first group considers implications of applying complexity theory concepts for defining evaluation purpose, scope and units of analysis. The second group of themes consider methodology and method. Results provide a starting point for a configuration of an evaluation approach consistent with complexity theory, whilst also identifying a number of design considerations to be resolved within evaluation planning.

  9. Intergenerational transfers and informal care for disabled elderly persons in China: evidence from CHARLS.

    PubMed

    Liu, Xiaoting; Lu, Bei; Feng, Zhixin

    2017-03-09

    Aiming at 'ageing healthier and ageing better', a certain amount of high-quality informal care should be available for elderly persons with physical disability as formal care is barely accessible in China. The demographic transition and family structural changes have dramatically weakened traditional norms of filial piety and the structure of intergenerational transfers. This article employed nationwide representative data from the first wave (2011) of Chinese Health and Retirement Longitudinal Study (CHARLS) in order to identify the duration of informal care provision at home for frail elders (1122 in rural areas and 577 in urban areas, total 1699), measured in monthly hours, before estimating the associations between intergenerational transfers and the received time of informal care with Tobit Model analysis. Results showed that financial support from the younger generation was unexpectedly negatively associated with the monthly hours of care, implying a reduction of caring support along with increasing financial transfers towards older parents. The lack of informal care could not be compensated by having more children, co-residing with children, or increasing the parent-to-child/grandchild transfers. Spouses were shown to replace children as the major caregivers. In addition, the community-based long-term care system needs to be promoted to sustain and develop informal care, as the latter will become increasingly important with changing family dynamics. Finally, the received time of informal care, rather than the severity of physical disability measured by difficulty with ADLs or IADLs, was introduced to identify the actual demand for care by elders. The paper argues that it is important to reconceptualise and re-investigate the duration of care provision in the Chinese context in order to develop standards of payment as part of long-term care policies.

  10. Transferring an optimized TAP-toolbox for the isolation of protein complexes to a portfolio of rice tissues.

    PubMed

    Dedecker, Maarten; Van Leene, Jelle; De Winne, Nancy; Eeckhout, Dominique; Persiau, Geert; Van De Slijke, Eveline; Cannoot, Bernard; Vercruysse, Leen; Dumoulin, Lies; Wojsznis, Nathalie; Gevaert, Kris; Vandenabeele, Steven; De Jaeger, Geert

    2016-06-01

    Proteins are the cell's functional entities. Rather than operating independently, they interact with other proteins. Capturing in vivo protein complexes is therefore crucial to gain understanding of the function of a protein in a cellular context. Affinity purification coupled to mass spectrometry has proven to yield a wealth of information about protein complex constitutions for a broad range of organisms. For Oryza sativa, the technique has been initiated in callus and shoots, but has not been optimized ever since. We translated an optimized tandem affinity purification (TAP) approach from Arabidopsis thaliana toward Oryza sativa, and demonstrate its applicability in a variety of rice tissues. A list of non-specific and false positive interactors is presented, based on re-occurrence over more than 170 independent experiments, to filter bona fide interactors. We demonstrate the sensitivity of our approach by isolating the complexes for the rice ANAPHASE PROMOTING COMPLEX SUBUNIT 10 (APC10) and CYCLIN-DEPENDENT KINASE D (CDKD) proteins from the proliferation zone of the emerging fourth leaf. Next to APC10 and CDKD, we tested several additional baits in the different rice tissues and reproducibly retrieved at least one interactor for 81.4 % of the baits screened for in callus tissue and T1 seedlings. By transferring an optimized TAP tag combined with state-of-the-art mass spectrometry, our TAP protocol enables the discovery of interactors for low abundance proteins in rice and opens the possibility to capture complex dynamics by comparing tissues at different stages of a developing rice organ.

  11. Demonstration of intramolecular energy transfer in asymmetric bimetallic ruthenium(ii) complexes.

    PubMed

    Bar, Manoranjan; Maity, Dinesh; Das, Shyamal; Baitalik, Sujoy

    2016-11-01

    A new family of bimetallic Ru(ii) complexes derived from an asymmetric bridging ligand (tpy-Hbzim-dipy) consisting of both bipyridine and terpyridine chelating sites covalently connected via phenyl-imidazole spacer were designed in this work to demonstrate intramolecular energy transfer from one component to the other in asymmetric dyads. To fine tune the photo-redox properties, both bidentate and tridentate terminal ligands in the complexes were varied systematically. Both steady state and time-resolved luminescence spectral results indicated photo-induced intramolecular energy transfer from the excited MLCT state of the [(bpy/phen)2Ru(II)(dipy-Hbzim-tpy)] component to the MLCT state of the tpy-containing unit [(dipy-Hbzim-tpy)Ru(II)(tpy-PhCH3/H2pbbzim)] in dyads with rate constant values on the order of 10(6)-10(7) s(-1). Temperature-dependent luminescence studies indicated an enhancement in the luminescence intensity and excited state lifetimes upon decreasing the temperature.

  12. Complex and charge transfer between TiO2 and pyrroloquinoline quinone.

    PubMed

    Dimitrijevic, Nada M; Poluektov, Oleg G; Saponjic, Zoran V; Rajh, Tijana

    2006-12-21

    Pyrroloquinoline quinone (PQQ) forms a tridentate complex with coordinatively unsaturated titanium atoms on the surface of approximately 4.5 nm TiO2 particles; an association constant of K = 550 M-1 per Ti(IV)surf has been determined. Low-temperature electron paramagnetic resonance was employed in identification of localized charges and consequently produced radicals and in determination of charge-transfer processes. The photoexcitation of the PQQ-TiO2 complex results in the transfer of conduction band electrons from TiO2 to bound PQQ and the formation of the semiquinone radical. Attaching dopamine (DA) as an electron donor and PQQ as an electron acceptor on the surface of TiO2 results in spatial separation of photogenerated charges; the holes localize on dopamine and electrons on PQQ, with higher yields than for each component separately. In this triad-type assembly (PQQ-TiO2/DA) the PQQ that is bound to the particles acts as a sink for electrons allowing their almost complete scavenging even at temperature as low as 4 K.

  13. Quinone-dependent proton transfer pathways in the photosynthetic cytochrome b6f complex.

    PubMed

    Hasan, S Saif; Yamashita, Eiki; Baniulis, Danas; Cramer, William A

    2013-03-12

    As much as two-thirds of the proton gradient used for transmembrane free energy storage in oxygenic photosynthesis is generated by the cytochrome b6f complex. The proton uptake pathway from the electrochemically negative (n) aqueous phase to the n-side quinone binding site of the complex, and a probable route for proton exit to the positive phase resulting from quinol oxidation, are defined in a 2.70-Å crystal structure and in structures with quinone analog inhibitors at 3.07 Å (tridecyl-stigmatellin) and 3.25-Å (2-nonyl-4-hydroxyquinoline N-oxide) resolution. The simplest n-side proton pathway extends from the aqueous phase via Asp20 and Arg207 (cytochrome b6 subunit) to quinone bound axially to heme c(n). On the positive side, the heme-proximal Glu78 (subunit IV), which accepts protons from plastosemiquinone, defines a route for H(+) transfer to the aqueous phase. These pathways provide a structure-based description of the quinone-mediated proton transfer responsible for generation of the transmembrane electrochemical potential gradient in oxygenic photosynthesis.

  14. Quinone-dependent proton transfer pathways in the photosynthetic cytochrome b6f complex

    PubMed Central

    Hasan, S. Saif; Yamashita, Eiki; Baniulis, Danas; Cramer, William A.

    2013-01-01

    As much as two-thirds of the proton gradient used for transmembrane free energy storage in oxygenic photosynthesis is generated by the cytochrome b6f complex. The proton uptake pathway from the electrochemically negative (n) aqueous phase to the n-side quinone binding site of the complex, and a probable route for proton exit to the positive phase resulting from quinol oxidation, are defined in a 2.70-Å crystal structure and in structures with quinone analog inhibitors at 3.07 Å (tridecyl-stigmatellin) and 3.25-Å (2-nonyl-4-hydroxyquinoline N-oxide) resolution. The simplest n-side proton pathway extends from the aqueous phase via Asp20 and Arg207 (cytochrome b6 subunit) to quinone bound axially to heme cn. On the positive side, the heme-proximal Glu78 (subunit IV), which accepts protons from plastosemiquinone, defines a route for H+ transfer to the aqueous phase. These pathways provide a structure-based description of the quinone-mediated proton transfer responsible for generation of the transmembrane electrochemical potential gradient in oxygenic photosynthesis. PMID:23440205

  15. Efficient Super Energy Transfer Collisions Through Reactive-Complex Formation: H + SO2

    NASA Astrophysics Data System (ADS)

    Smith, Jonathan M.; Wilhelm, Michael J.; Ma, Jianqiang; Dai, HAI-LUNG

    2015-06-01

    Translational-to-vibrational energy transfer (ET) from a hyperthermal H atom to ambient SO2 was characterized using time-resolved Fourier transform infrared emission spectroscopy. Vibrational excitation of SO2, following collisions with H atoms containing 59 kcal/mol of kinetic energy, generated from the 193 nm photolysis of HBr, is detected in two distinct energy distributions: one with excitation predominantly at the fundamental vibrational levels is attributable to classical impulsive collisions, while the other, accounting for 80% of the excited SO2 with vibrational energy as high as 14,000 wn, is proposed to arise from the formation of a transient reactive-complex during the collision. The cross-section for this super ET collision is determined to be 0.53±0.05 Å2, or roughly 2% of all hard sphere collisions. This observation reveals that in collisions between a hyperthermal atom and an ambient molecule, for which a reactive-complex exists on the potential energy surface, a large quantity of translational energy can be transferred to the molecule with high efficiency.

  16. Spectrophotometric and electrical studies of charge-transfer complexes of sodium flucloxacillin with π-acceptors

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; El-Didamony, Akram M.

    2006-11-01

    The present study is interested to develop a simple, rapid and accurate spectrophotometric method for determination of sodium flucloxacillin (fluc) in pure form and pharmaceutical formulations. The charge-transfer (CT) interactions between sodium flucloxacillin as electron donor and chloranilic acid (CLA), dichloroquinone 4-chloroimide (DCQ), 2,3-dichloro-5,6-dicyano- p-benzoquinone (DDQ) and 7,7,8,8 tetracyano- p-quinodimethane (TCNQ), as π-electron acceptors have been investigated spectrophotometrically. Different variables affecting the reaction were studied and optimized. Under the optimum conditions, linear relationships with good correlation coefficients (0.9979-0.9995) were found between the absorbance and the concentration of the drug in the range 16-880 μg ml -1. The proposed methods were applied successfully to the determination of the examined drug either in pure or pharmaceutical dosage forms with good accuracy and precision. The formation of the CT-complexes and the sites of interaction were confirmed by elemental analysis CHN, UV-vis, IR, 1H NMR and mass spectra techniques. Based on Job's method of continuous variation plots, the obtained results indicate the formation of 1:1 charge-transfer complexes with the general formula [(fluc)(acceptor)]. Statistical analysis of the obtained results showed no significant difference between the proposed method and official method.

  17. Association of a novel preribosomal complex in Trypanosoma brucei determined by fluorescence resonance energy transfer.

    PubMed

    Wang, Lei; Ciganda, Martin; Williams, Noreen

    2013-02-01

    We have previously reported that the trypanosome-specific proteins P34 and P37 form a unique preribosomal complex with ribosomal protein L5 and 5S rRNA in the nucleoplasm. We hypothesize that this novel trimolecular complex is necessary for stabilizing 5S rRNA in Trypanosoma brucei and is essential for the survival of the parasite. In vitro quantitative analysis of the association between the proteins L5 and P34 is fundamental to our understanding of this novel complex and thus our ability to exploit its unique characteristics. Here we used in vitro fluorescence resonance energy transfer (FRET) to analyze the association between L5 and P34. First, we demonstrated that FRET can be used to confirm the association between L5 and P34. We then determined that the binding constant for L5 and P34 is 0.60 ± 0.03 μM, which is in the range of protein-protein binding constants for RNA binding proteins. In addition, we used FRET to identify the critical regions of L5 and P34 involved in the protein-protein association. We found that the N-terminal APK-rich domain and RNA recognition motif (RRM) of P34 and the L18 domain of L5 are important for the association of the two proteins with each other. These results provide us with the framework for the discovery of ways to disrupt this essential complex.

  18. Chemical mechanism of surface-enhanced Raman scattering via charge transfer in fluorenone-Ag complex

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Li, Yafei; Wu, Shiwei; Song, Peng; Xia, Lixin

    2016-06-01

    The intermolecular interaction between fluorenone (FN) and silver surfaces was investigated experimentally and theoretically. The structural, electronic and optical properties of the FN-Ag complex indicate that the carbonyl group O atom in FN molecules is the adsorbed position site to attach the silver substrate through the weak bond O…Ag. The analysis of vibrational modes and Raman activity of the largely enhanced Raman peaks using two FN-Ag4-x (x  =  l, s) complex models reveals that only the a1 vibrational modes with C 2v symmetry are selectively enhanced, from the point view of the change of dipole moment and polarizability induced by the interaction between FN and Ag4 substrate. Furthermore, the direct visualized evidence of the surface-enhanced Raman scattering (SERS) chemical enhancement mechanism for the FN-Ag complex is presented. The results reveal that only the intermolecular charge transfer with π-π transition characterization between FN and an Ag4 cluster facilitates the resonance Raman process and is directly responsible for chemical enhancement of Raman scattering of the FN-Ag complex.

  19. Structural dynamics of a noncovalent charge transfer complex from femtosecond stimulated Raman spectroscopy.

    PubMed

    Fujisawa, Tomotsumi; Creelman, Mark; Mathies, Richard A

    2012-09-06

    Femtosecond stimulated Raman spectroscopy is used to examine the structural dynamics of photoinduced charge transfer within a noncovalent electron acceptor/donor complex of pyromellitic dianhydride (PMDA, electron acceptor) and hexamethylbenzene (HMB, electron donor) in ethylacetate and acetonitrile. The evolution of the vibrational spectrum reveals the ultrafast structural changes that occur during the charge separation (Franck-Condon excited state complex → contact ion pair) and the subsequent charge recombination (contact ion pair → ground state complex). The Franck-Condon excited state is shown to have significant charge-separated character because its vibrational spectrum is similar to that of the ion pair. The charge separation rate (2.5 ps in ethylacetate and ∼0.5 ps in acetonitrile) is comparable to solvation dynamics and is unaffected by the perdeuteration of HMB, supporting the dominant role of solvent rearrangement in charge separation. On the other hand, the charge recombination slows by a factor of ∼1.4 when using perdeuterated HMB, indicating that methyl hydrogen motions of HMB mediate the charge recombination process. Resonance Raman enhancement of the HMB vibrations in the complex reveals that the ring stretches of HMB, and especially the C-CH(3) deformations are the primary acceptor modes promoting charge recombination.

  20. Structural and mutational studies of an electron transfer complex of maize sulfite reductase and ferredoxin.

    PubMed

    Kim, Ju Yaen; Nakayama, Masato; Toyota, Hiroshi; Kurisu, Genji; Hase, Toshiharu

    2016-08-01

    The structure of the complex of maize sulfite reductase (SiR) and ferredoxin (Fd) has been determined by X-ray crystallography. Co-crystals of the two proteins prepared under different conditions were subjected to the diffraction analysis and three possible structures of the complex were solved. Although topological relationship of SiR and Fd varied in each of the structures, two characteristics common to all structures were found in the pattern of protein-protein interactions and positional arrangements of redox centres; (i) a few negative residues of Fd contact with a narrow area of SiR with positive electrostatic surface potential and (ii) [2Fe-2S] cluster of Fd and [4Fe-4S] cluster of SiR are in a close proximity with the shortest distance around 12 Å. Mutational analysis of a total of seven basic residues of SiR distributed widely at the interface of the complex showed their importance for supporting an efficient Fd-dependent activity and a strong physical binding to Fd. These combined results suggest that the productive electron transfer complex of SiR and Fd could be formed through multiple processes of the electrostatic intermolecular interaction and this implication is discussed in terms of the multi-functionality of Fd in various redox metabolisms.

  1. Can Förster Theory Describe Stereoselective Energy Transfer Dynamics in a Protein-Ligand Complex?

    PubMed

    Pinheiro, Silvana; Curutchet, Carles

    2017-03-16

    Förster resonance energy transfer (FRET) reactions involving ligands and aromatic amino acids can substantially impact the fluorescence properties of a protein-ligand complex, an impact intimately related to the corresponding binding mode. Structural characterization of such binding events in terms of intermolecular distances can be done through the well-known R(-6) distance-dependent Förster rate expression. However, such an interpretation suffers from uncertainties underlying Förster theory in the description of the electronic coupling that promotes FRET, mostly related to the dipole-dipole orientation factor, dielectric screening effects, and deviations from the ideal dipole approximation. Here, we investigate how Förster approximations impact the prediction of energy transfer dynamics in the complex between flurbiprofen (FBP) and human serum albumin (HSA), as well as a model FBP-Trp dyad, in which recent observation of enantioselective fluorescence quenching has been ascribed to energy transfer from FBP to Trp. To this end, we combine classical molecular dynamics simulations with polarizable quantum mechanics/molecular mechanics calculations that allow overcoming Förster approximations. On the basis of our results, we discuss the potential of structure-based simulations in the characterization of drug-binding events through fluorescence techniques. Overall, we find an excellent agreement between theory and experiment both in terms of enantioselectivity and FRET times, thus strongly supporting the reliability of the binding modes proposed for the (S) and (R) enantiomers of FBP. In particular, we show that the dynamic quenching arises from a small fraction of drug bound to the secondary site of HSA at the interface between subdomains IIA and IIB, whereas the enantioselectivity arises from the larger flexibility of the (S)-FBP enantiomer in the binding pocket.

  2. Asymmetric transfer hydrogenation of ketones catalyzed by enantiopure osmium(II) pybox complexes.

    PubMed

    Vega, Esmeralda; Lastra, E; Gamasa, M Pilar

    2013-05-20

    The complexes trans-[OsCl2(L){(S,S)-(i)Pr-pybox}] ((S,S)-(i)Pr-pybox = 2,6-bis[4'-(S)-isopropyloxazolin-2'-yl]pyridine, L = P(OMe)3 (1a), P(OEt)3 (2a), P(O(i)Pr)3 (3a), P(OPh)3 (4a), and cis-[OsCl2(L){(S,S)-(i)Pr-pybox}] (L = PPh3 (5a), P(i)Pr3 (6a), and PCy3 (7a)) have been synthesized from the complex trans-[OsCl2(η(2)-C2H4){(S,S)-(i)Pr-pybox}] via substitution of ethylene by phosphites and phosphines, respectively, under toluene reflux conditions. On the other hand, the synthesis of the complexes trans-[OsCl2(L){(R,R)-Ph-pybox}] (L = P(OMe)3 (1b) and cis-[OsCl2(L){(R,R)-Ph-pybox}] (L = PPh3 (5b), P(i)Pr3 (6b), and PCy3 (7b)) has been achieved from the complex trans-[OsCl2(η(2)-C2H4){(R,R)-Ph-pybox}] ((R,R)-Ph-pybox = 2,6-bis[4'-(R)-phenyloxazolin-2'-yl]pyridine under microwave irradiation. Complexes 1a-6a, 1b, 5b, and 6b have been assayed as catalysts for the asymmetric transfer hydrogenation (ATH) of ketones. Among the catalysts tested, the (i)Pr-pybox complexes trans-[OsCl2(L){(S,S)-(i)Pr-pybox}] (L = P(OMe)3 (1a), P(OEt)3 (2a), P(O(i)Pr)3 (3a), P(OPh)3 (4a)) have proven to be the most active catalysts for the reduction of a variety of aromatic ketones as nearly complete conversion and high enantioselectivity (up to 94%) are reached.

  3. Telecommunications Information Network: A Model for On-Demand Transfer of Medical Information. Annual Report.

    ERIC Educational Resources Information Center

    Lorenzi, Nancy M.; And Others

    This report describes and evaluates the first year of a demonstration project to develop an on-demand telecommunications network linking four remote hospitals in southwestern Ohio to the University of Cincinnati Medical Center. The Telecommunications Information Network (TIN) is designed to allow health care professionals at those hospitals to…

  4. Telecommunications Information Network: A Model for On-Demand Transfer of Medical Information. Final Report.

    ERIC Educational Resources Information Center

    Lorenzi, Nancy M.; And Others

    This report summarizes the third phase of the Telecommunications Information Network (TIN), which provides a telecommunications link between four remote southwest Ohio hospitals and the University of Cincinnati Medical Center, thereby reducing the isolation of healthcare providers at the remote hospitals. A description of the system explains the…

  5. Energetics and Dynamics of Electron Transfer and Proton Transfer in Dissociation of Metal III (salen)-Peptide Complexes in the Gas Phase

    SciTech Connect

    Laskin, Julia; Yang, Zhibo; Chu, Ivan K.

    2008-03-12

    Time- and collision energy-resolved surface-induced dissociation (SID) of ternary complexes of CoIII(salen)+, FeIII(salen)+, and MnIII(salen)+ with several angiotensin peptide analogs was studied using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially equipped to perform SID experiments. Time-resolved fragmentation efficiency curves (TFECs) were modeled using an RRKM-based approach developed in our laboratory. The approach utilizes a very flexible analytical expression for the internal energy deposition function that is capable of reproducing both single-collision and multiple-collision activation in the gas phase and excitation by collisions with a surface. The energetics and dynamics of competing dissociation pathways obtained from the modeling provides important insight on the competition between proton transfer, electron transfer, loss of neutral peptide ligand, and other processes that determine gas-phase fragmentation of these model systems. Similar fragmentation behavior was obtained for various CoIII(salen)-peptide systems of different angiotensin analogs. In contrast, dissociation pathways and relative stabilities of the complexes changed dramatically when cobalt was replaced with trivalent iron or manganese. We demonstrate that the electron transfer efficiency is correlated with redox properties of the metalIII(salen) complexes (Co > Fe > Mn), while differences in the types of fragments formed from the complexes reflect differences in the modes of binding between the metal-salen complex and the peptide ligand. RRKM modeling of time- and collision energy-resolved SID data suggests that the competition between proton transfer and electron transfer during dissociation of CoIII(salen)-peptide complexes is mainly determined by differences in entropy effects while the energetics of these two pathways are very similar.

  6. Analytical studies on the charge transfer complexes of loperamide hydrochloride and trimebutine drugs. Spectroscopic and thermal characterization of CT complexes

    NASA Astrophysics Data System (ADS)

    Elqudaby, Hoda M.; Mohamed, Gehad G.; El-Din, Ghada M. G.

    2014-08-01

    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 842 nm in case of LOP.HCl and at 455, 414 and 842 nm 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 10.00-100.0 μg mL-1 for LOP.HCl and 37.85-264.9, 38.75-310.0 and 7.75-155.0 μg mL-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, 1H 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.

  7. The dynamics of information-driven coordination phenomena: A transfer entropy analysis

    PubMed Central

    Borge-Holthoefer, Javier; Perra, Nicola; Gonçalves, Bruno; González-Bailón, Sandra; Arenas, Alex; Moreno, Yamir; Vespignani, Alessandro

    2016-01-01

    Data from social media provide unprecedented opportunities to investigate the processes that govern the dynamics of collective social phenomena. We consider an information theoretical approach to define and measure the temporal and structural signatures typical of collective social events as they arise and gain prominence. We use the symbolic transfer entropy analysis of microblogging time series to extract directed networks of influence among geolocalized subunits in social systems. This methodology captures the emergence of system-level dynamics close to the onset of socially relevant collective phenomena. The framework is validated against a detailed empirical analysis of five case studies. In particular, we identify a change in the characteristic time scale of the information transfer that flags the onset of information-driven collective phenomena. Furthermore, our approach identifies an order-disorder transition in the directed network of influence between social subunits. In the absence of clear exogenous driving, social collective phenomena can be represented as endogenously driven structural transitions of the information transfer network. This study provides results that can help define models and predictive algorithms for the analysis of societal events based on open source data. PMID:27051875

  8. Soft versus hard junction formation for α-terthiophene molecular wires and their charge transfer complexes

    NASA Astrophysics Data System (ADS)

    Vezzoli, Andrea; Grace, Iain M.; Brooke, Carly; Nichols, Richard J.; Lambert, Colin J.; Higgins, Simon J.

    2017-03-01

    We used a range of scanning tunnelling microscopy (STM)-based methods to conduct a detailed study of single molecule junction conductance enhancement upon charge transfer complex formation, using bis(thiaalkyl)arene molecular wires as electron donors and tetracyanoethylene (TCNE) as an electron acceptor. Using the "hard" STM break junction (STM-BJ) method, in which a Au STM tip is pushed into a Au substrate and then withdrawn in the presence of molecules, we see a single, very broad, peak in the resulting conductance histogram when all data are used; the conductance enhancement is 25-fold for a terthiophene donor and 15-fold for a phenyl group. After rational data selection, in which only current-distance curves that contain a current plateau >0.2 nm long are used in the conductance histogram, three sharper peaks are resolved in the histograms for the charge transfer complexes; two substantially lower-conductance peaks are resolved for the uncomplexed molecules. Using the "soft" STM I(s) technique, in which initial contact between tip and substrate is avoided and the current limit is about an order of magnitude lower, we were able to resolve two peaks for the uncomplexed molecules depending upon the initial set point current (i.e., tip height), one at the same value as the lower of the two data-selected STM-BJ histogram peaks and an additional peak beyond the low-current limit for the STM-BJ experiment. For the terthiophene, the low, medium, and high conductance peaks for the TCNE complex are, respectively, ca. 70, 70, and 46 times higher in conductance than the corresponding peaks for the free molecule.

  9. Short term synaptic depression imposes a frequency dependent filter on synaptic information transfer.

    PubMed

    Rosenbaum, Robert; Rubin, Jonathan; Doiron, Brent

    2012-01-01

    Depletion of synaptic neurotransmitter vesicles induces a form of short term depression in synapses throughout the nervous system. This plasticity affects how synapses filter presynaptic spike trains. The filtering properties of short term depression are often studied using a deterministic synapse model that predicts the mean synaptic response to a presynaptic spike train, but ignores variability introduced by the probabilistic nature of vesicle release and stochasticity in synaptic recovery time. We show that this additional variability has important consequences for the synaptic filtering of presynaptic information. In particular, a synapse model with stochastic vesicle dynamics suppresses information encoded at lower frequencies more than information encoded at higher frequencies, while a model that ignores this stochasticity transfers information encoded at any frequency equally well. This distinction between the two models persists even when large numbers of synaptic contacts are considered. Our study provides strong evidence that the stochastic nature neurotransmitter vesicle dynamics must be considered when analyzing the information flow across a synapse.

  10. The Testing Effect and Far Transfer: The Role of Exposure to Key Information

    PubMed Central

    van Eersel, Gerdien G.; Verkoeijen, Peter P. J. L.; Povilenaite, Migle; Rikers, Remy

    2016-01-01

    Butler (2010: Experiment 3) showed that retrieval practice enhanced transfer to a new knowledge domain compared to rereading. The first experiment of the present study was a direct replication of Butler’s third experiment. Participants studied text passages and then either reread them three times or went through three cycles of cued recall questions (i.e., retrieval practice) with feedback. As in Butler’s (2010) experiment, an advantage of retrieval practice on the final far transfer test emerged after 1 week. Additionally, we observed an advantage of retrieval practice on the final test administered after 5 min. However, these advantages might have been due to participants in the retrieval practice condition receiving focused exposure to the key information (i.e., the feedback) that was needed to answer the final test questions. We therefore conducted a second experiment in which we included the retrieval practice condition and the reread condition from our first experiment, as well as a new reread-plus-statements condition. In the reread-plus-statements condition, participants received focused exposure to the key information after they had reread a text. As in Experiment 1, we found a large effect on far transfer when retrieval practice was compared to rereading. However, this effect was substantially reduced when retrieval practice was compared to the reread-plus-statements condition. Taken together, the results of the present experiments demonstrate that Butler’s (2010) testing effect in far transfer is robust. Moreover, focused exposure to key information appears to be a significant factor in this far transfer testing effect. PMID:28082930

  11. Report of a Planning Conference for Solar Technology Information Transfer in Georgia (Atlanta, Georgia, July 24-25, 1978).

    ERIC Educational Resources Information Center

    Aldridge, Mark C., Ed.

    A summary of the deliberations of the Georgia planning conference of the Solar Technology Transfer Program is presented in this report. Topic areas include background information on the Georgia conference and a summary of the discussions and recommendations dealing with solar information transfer within state systems and the need for greater…

  12. 48 CFR 52.232-35 - Designation of Office for Government Receipt of Electronic Funds Transfer Information.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Government Receipt of Electronic Funds Transfer Information. 52.232-35 Section 52.232-35 Federal Acquisition... of Office for Government Receipt of Electronic Funds Transfer Information (MAY 1999) (a) As provided... CONTRACT CLAUSES Text of Provisions and Clauses 52.232-35 Designation of Office for Government Receipt...

  13. Contribution of posterior corpus callosum to the interhemispheric transfer of tactile information.

    PubMed

    Fabri, Mara; Del Pesce, Maria; Paggi, Aldo; Polonara, Gabriele; Bartolini, Marco; Salvolini, Ugo; Manzoni, Tullio

    2005-06-01

    Three total and three partial callosotomy patients underwent neuropsychological testing to evaluate interhemispheric transfer of tactile information. Tactile transfer is required to name objects presented to the left hand, to compare objects held in either hand, and to transfer topological information between hands. Tactile Naming, Same-Different Recognition, and Tactile Finger Localization Tests (intra- and intermanual tasks) were administered as specific tools. Results were compared with previous fMRI data from the same subjects and with the performance of a control group (20 age-matched subjects). Total callosotomy patients performed modestly: mean correct responses were 93% and 30% (right and left hand, respectively) in Tactile Naming; 68% in Same-Different Recognition; 84% and 76% (right and left hand stimulation, respectively) in intermanual Tactile Finger Localization, and 100% in the intramanual task. Partial callosotomy patients achieved 93-100% accuracy: all have an intact splenium, and one, and possibly all, also an intact posterior callosal body. Controls scored 99% in Tactile Naming, both hands, and Same-Different Recognition; 100% in intramanual Tactile Finger Localization; and 96% and 95%, with right and left hand stimulation, respectively, in the intermanual task. Differences between the two callosotomy groups were significant, as were those between total callosotomy patients and controls. The partial callosotomy group scored like the control subjects. Neuropsychological data agree with previous functional findings, further demonstrating that interhemispheric tactile transfer requires posterior corpus callosum integrity.

  14. Spectral Transfer Learning Using Information Geometry for a User-Independent Brain-Computer Interface

    PubMed Central

    Waytowich, Nicholas R.; Lawhern, Vernon J.; Bohannon, Addison W.; Ball, Kenneth R.; Lance, Brent J.

    2016-01-01

    Recent advances in signal processing and machine learning techniques have enabled the application of Brain-Computer Interface (BCI) technologies to fields such as medicine, industry, and recreation; however, BCIs still suffer from the requirement of frequent calibration sessions due to the intra- and inter-individual variability of brain-signals, which makes calibration suppression through transfer learning an area of increasing interest for the development of practical BCI systems. In this paper, we present an unsupervised transfer method (spectral transfer using information geometry, STIG), which ranks and combines unlabeled predictions from an ensemble of information geometry classifiers built on data from individual training subjects. The STIG method is validated in both off-line and real-time feedback analysis during a rapid serial visual presentation task (RSVP). For detection of single-trial, event-related potentials (ERPs), the proposed method can significantly outperform existing calibration-free techniques as well as outperform traditional within-subject calibration techniques when limited data is available. This method demonstrates that unsupervised transfer learning for single-trial detection in ERP-based BCIs can be achieved without the requirement of costly training data, representing a step-forward in the overall goal of achieving a practical user-independent BCI system. PMID:27713685

  15. Stochastic information transfer from cochlear implant electrodes to auditory nerve fibers

    NASA Astrophysics Data System (ADS)

    Gao, Xiao; Grayden, David B.; McDonnell, Mark D.

    2014-08-01

    Cochlear implants, also called bionic ears, are implanted neural prostheses that can restore lost human hearing function by direct electrical stimulation of auditory nerve fibers. Previously, an information-theoretic framework for numerically estimating the optimal number of electrodes in cochlear implants has been devised. This approach relies on a model of stochastic action potential generation and a discrete memoryless channel model of the interface between the array of electrodes and the auditory nerve fibers. Using these models, the stochastic information transfer from cochlear implant electrodes to auditory nerve fibers is estimated from the mutual information between channel inputs (the locations of electrodes) and channel outputs (the set of electrode-activated nerve fibers). Here we describe a revised model of the channel output in the framework that avoids the side effects caused by an "ambiguity state" in the original model and also makes fewer assumptions about perceptual processing in the brain. A detailed comparison of how different assumptions on fibers and current spread modes impact on the information transfer in the original model and in the revised model is presented. We also mathematically derive an upper bound on the mutual information in the revised model, which becomes tighter as the number of electrodes increases. We found that the revised model leads to a significantly larger maximum mutual information and corresponding number of electrodes compared with the original model and conclude that the assumptions made in this part of the modeling framework are crucial to the model's overall utility.

  16. PREFACE: Complex Networks: from Biology to Information Technology

    NASA Astrophysics Data System (ADS)

    Barrat, A.; Boccaletti, S.; Caldarelli, G.; Chessa, A.; Latora, V.; Motter, A. E.

    2008-06-01

    The field of complex networks is one of the most active areas in contemporary statistical physics. Ten years after seminal work initiated the modern study of networks, interest in the field is in fact still growing, as indicated by the ever increasing number of publications in network science. The reason for such a resounding success is most likely the simplicity and broad significance of the approach that, through graph theory, allows researchers to address a variety of different complex systems within a common framework. This special issue comprises a selection of contributions presented at the workshop 'Complex Networks: from Biology to Information Technology' held in July 2007 in Pula (Cagliari), Italy as a satellite of the general conference STATPHYS23. The contributions cover a wide range of problems that are currently among the most important questions in the area of complex networks and that are likely to stimulate future research. The issue is organised into four sections. The first two sections describe 'methods' to study the structure and the dynamics of complex networks, respectively. After this methodological part, the issue proceeds with a section on applications to biological systems. The issue closes with a section concentrating on applications to the study of social and technological networks. The first section, entitled Methods: The Structure, consists of six contributions focused on the characterisation and analysis of structural properties of complex networks: The paper Motif-based communities in complex networks by Arenas et al is a study of the occurrence of characteristic small subgraphs in complex networks. These subgraphs, known as motifs, are used to define general classes of nodes and their communities by extending the mathematical expression of the Newman-Girvan modularity. The same line of research, aimed at characterising network structure through the analysis of particular subgraphs, is explored by Bianconi and Gulbahce in Algorithm

  17. Fluorescence energy transfer of complexes of skeletal muscle troponin C and melittin derivatives.

    PubMed

    Sano, H; Takahashi, S; Iio, T

    1998-09-01

    We studied Ca2+-dependent structural change of rabbit skeletal troponin C (TnC)-melittin (ME) complex as a model of TnC-troponin I complex. In previous study, we found that the distance between Met-25 and Cys-98 of TnC in TnC-ME complex increased upon binding of Ca2+ to TnC [H. Sano and T. Iio (1995) J. Biochem. 118, 996-1000]. In this study, we used a fluorescence energy transfer method. As a fluorescent donor, we used the tryptophan residue in four melittin derivatives, in which residue 2, 5, 8, or 13 was replaced with tryptophan. As acceptor, we used dansylaziridine (DANZ) bound to Met-25 of TnC, or N-iodoacetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine (1,5-I-AEDANS) bound to Cys-98 of TnC. For all TnCDANZ-ME complexes, the donor-acceptor distance (11.9-17.7 A) did not remarkably depend on Mg2+ or Ca2+ binding of TnC or on the position of tryptophan in ME derivatives. The same results were obtained for TnCAEDANS-ME complexes in the absence of Ca2+ (distance 15.2-21.7 A). But in the presence of Ca2+, tryptophan residues in the central region of ME were near to Cys-98 of TnC (distance much less than 10.4 A). Based on these results, we conclude that ME is enfolded by the N- and C-lobes of TnC, and the ME rod is almost perpendicular to a line connecting Met-25 and Cys-98 of TnC. The position of the ME rod shifts upon binding of Ca2+ to TnC.

  18. Application of Fisher Information to Complex Dynamic Systems (Tucson)

    EPA Science Inventory

    Fisher information was developed by the statistician Ronald Fisher as a measure of the information obtainable from data being used to fit a related parameter. Starting from the work of Ronald Fisher1 and B. Roy Frieden2, we have developed Fisher information as a measure of order ...

  19. Application of Fisher Information to Complex Dynamic Systems

    EPA Science Inventory

    Fisher information was developed by the statistician Ronald Fisher as a measure of the information obtainable from data being used to fit a related parameter. Starting from the work of Ronald Fisher1 and B. Roy Frieden2, we have developed Fisher information as a measure of order ...

  20. Transfer of molecular recognition information from DNA nanostructures to gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Edwardson, Thomas G. W.; Lau, Kai Lin; Bousmail, Danny; Serpell, Christopher J.; Sleiman, Hanadi F.

    2016-02-01

    DNA nanotechnology offers unparalleled precision and programmability for the bottom-up organization of materials. This approach relies on pre-assembling a DNA scaffold, typically containing hundreds of different strands, and using it to position functional components. A particularly attractive strategy is to employ DNA nanostructures not as permanent scaffolds, but as transient, reusable templates to transfer essential information to other materials. To our knowledge, this approach, akin to top-down lithography, has not been examined. Here we report a molecular printing strategy that chemically transfers a discrete pattern of DNA strands from a three-dimensional DNA structure to a gold nanoparticle. We show that the particles inherit the DNA sequence configuration encoded in the parent template with high fidelity. This provides control over the number of DNA strands and their relative placement, directionality and sequence asymmetry. Importantly, the nanoparticles produced exhibit the site-specific addressability of DNA nanostructures, and are promising components for energy, information and biomedical applications.

  1. Quantum effects in energy and charge transfer in an artificial photosynthetic complex

    NASA Astrophysics Data System (ADS)

    Ghosh, Pulak Kumar; Smirnov, Anatoly Yu.; Nori, Franco

    2011-06-01

    We investigate the quantum dynamics of energy and charge transfer in a wheel-shaped artificial photosynthetic antenna-reaction center complex. This complex consists of six light-harvesting chromophores and an electron-acceptor fullerene. To describe quantum effects on a femtosecond time scale, we derive the set of exact non-Markovian equations for the Heisenberg operators of this photosynthetic complex in contact with a Gaussian heat bath. With these equations we can analyze the regime of strong system-bath interactions, where reorganization energies are of the order of the intersite exciton couplings. We show that the energy of the initially excited antenna chromophores is efficiently funneled to the porphyrin-fullerene reaction center, where a charge-separated state is set up in a few picoseconds, with a quantum yield of the order of 95%. In the single-exciton regime, with one antenna chromophore being initially excited, we observe quantum beatings of energy between two resonant antenna chromophores with a decoherence time of ˜100 fs. We also analyze the double-exciton regime, when two porphyrin molecules involved in the reaction center are initially excited. In this regime we obtain pronounced quantum oscillations of the charge on the fullerene molecule with a decoherence time of about 20 fs (at liquid nitrogen temperatures). These results show a way to directly detect quantum effects in artificial photosynthetic systems.

  2. A charge transfer complex nematic liquid crystalline gel with high electrical conductivity

    SciTech Connect

    Bhargavi, R.; Nair, Geetha G. E-mail: skpras@gmail.com; Krishna Prasad, S. E-mail: skpras@gmail.com; Majumdar, R.; Bag, Braja G.

    2014-10-21

    We describe the rheological, dielectric and elastic properties of a nematic liquid crystal gel created using an anthrylidene derivative of arjunolic acid, a chiral triterpenoid, obtained from the extracts of the wood of Terminalia arjuna. In this novel gel, having the electron-donor and acceptor components as minority constituents, the gelation and strengthening of charge-transfer complex (CTC) formation are seen to be occurring concomitantly. In addition to being mechanically strong with a large storage modulus, the gel with the maximized CTC exhibits Frank bend elastic constant values that approach nanonewton levels. The highlight of the study is the observation of 4–5 orders of magnitude increase in electrical conductivity for this gel, a value that is higher than even in the CT complexes of 2-d ordered columnar structures. A further important advantage of the present system over the columnar complex is that the high conductivity is seen for ac probing also, and owing to the nematic nature can be switched between its anisotropic limits. Some of these features are ascribed to a specific molecular packing architecture, which reduces the trapping of the charge carriers.

  3. Public service communications satellite. [health, education, safety and information transfer applications

    NASA Technical Reports Server (NTRS)

    Wolff, E. A.

    1978-01-01

    Health, education, public safety, and information transfer applications of public service communications satellites are discussed with particular attention to the use of communications satellites to improve rural health delivery. Health-care communications requirements are summarized. The communications system concept involves small inexpensive stationary, portable, and moving ground terminals which will provide communications between any two points in the U.S. with both fixed and moving terminals on a continuous 24-hour basis. User requirements, wavebands, and privacy techniques are surveyed.

  4. 100% Classification Accuracy Considered Harmful: The Normalized Information Transfer Factor Explains the Accuracy Paradox

    PubMed Central

    Valverde-Albacete, Francisco J.; Peláez-Moreno, Carmen

    2014-01-01

    The most widely spread measure of performance, accuracy, suffers from a paradox: predictive models with a given level of accuracy may have greater predictive power than models with higher accuracy. Despite optimizing classification error rate, high accuracy models may fail to capture crucial information transfer in the classification task. We present evidence of this behavior by means of a combinatorial analysis where every possible contingency matrix of 2, 3 and 4 classes classifiers are depicted on the entropy triangle, a more reliable information-theoretic tool for classification assessment. Motivated by this, we develop from first principles a measure of classification performance that takes into consideration the information learned by classifiers. We are then able to obtain the entropy-modulated accuracy (EMA), a pessimistic estimate of the expected accuracy with the influence of the input distribution factored out, and the normalized information transfer factor (NIT), a measure of how efficient is the transmission of information from the input to the output set of classes. The EMA is a more natural measure of classification performance than accuracy when the heuristic to maximize is the transfer of information through the classifier instead of classification error count. The NIT factor measures the effectiveness of the learning process in classifiers and also makes it harder for them to “cheat” using techniques like specialization, while also promoting the interpretability of results. Their use is demonstrated in a mind reading task competition that aims at decoding the identity of a video stimulus based on magnetoencephalography recordings. We show how the EMA and the NIT factor reject rankings based in accuracy, choosing more meaningful and interpretable classifiers. PMID:24427282

  5. 100% classification accuracy considered harmful: the normalized information transfer factor explains the accuracy paradox.

    PubMed

    Valverde-Albacete, Francisco J; Peláez-Moreno, Carmen

    2014-01-01

    The most widely spread measure of performance, accuracy, suffers from a paradox: predictive models with a given level of accuracy may have greater predictive power than models with higher accuracy. Despite optimizing classification error rate, high accuracy models may fail to capture crucial information transfer in the classification task. We present evidence of this behavior by means of a combinatorial analysis where every possible contingency matrix of 2, 3 and 4 classes classifiers are depicted on the entropy triangle, a more reliable information-theoretic tool for classification assessment. Motivated by this, we develop from first principles a measure of classification performance that takes into consideration the information learned by classifiers. We are then able to obtain the entropy-modulated accuracy (EMA), a pessimistic estimate of the expected accuracy with the influence of the input distribution factored out, and the normalized information transfer factor (NIT), a measure of how efficient is the transmission of information from the input to the output set of classes. The EMA is a more natural measure of classification performance than accuracy when the heuristic to maximize is the transfer of information through the classifier instead of classification error count. The NIT factor measures the effectiveness of the learning process in classifiers and also makes it harder for them to "cheat" using techniques like specialization, while also promoting the interpretability of results. Their use is demonstrated in a mind reading task competition that aims at decoding the identity of a video stimulus based on magnetoencephalography recordings. We show how the EMA and the NIT factor reject rankings based in accuracy, choosing more meaningful and interpretable classifiers.

  6. A NEW FRAMEWORK FOR URBAN SUSTAINABILITY ASSESSMENTS: LINKING COMPLEXITY, INFORMATION AND POLICY

    EPA Science Inventory

    Urban systems emerge as distinct entities from the complex interactions among social, economic and cultural attributes, and information, energy and material stocks and flows that operate on different temporal and spatial scales. Such complexity poses a challenge to identify the...

  7. On the evaluation of information flow in multivariate systems by the directed transfer function.

    PubMed

    Eichler, Michael

    2006-06-01

    The directed transfer function (DTF) has been proposed as a measure of information flow between the components of multivariate time series. In this paper, we discuss the interpretation of the DTF and compare it with other measures for directed relationships. In particular, we show that the DTF does not indicate multivariate or bivariate Granger causality, but that it is closely related to the concept of impulse response function and can be viewed as a spectral measure for the total causal influence from one component to another. Furthermore, we investigate the statistical properties of the DTF and establish a simple significance level for testing for the null hypothesis of no information flow.

  8. NOAA's Honua: Visualizations of Complex Environmental Information in Formal and Informal Education

    NASA Astrophysics Data System (ADS)

    McBride, M. A.; Stovall, W. K.; Lewinski, S.; Bennett, S.

    2010-12-01

    The National Oceanic and Atmospheric Administration (NOAA) Pacific Services Center supports a data visualization program, called NOAA's Honua, for the presentation of geophysical processes and environmental data in both formal and informal education settings using 3-D technology. Many display systems are available for the virtual representation of global environmental data, including Google Earth, NASA World Wind, and ESRI's ArcGIS Explorer. All present global data on virtual 3-D platforms using industry standard vector and raster data sources. Other products project earth system data on 3-D spherical platforms: NOAA's Science on a Sphere, Global Imagination's Magic Planet, and the OmniGlobe spherical display system. The NOAA Pacific Services Center provides resources for formal education in the form of lesson plans that cover ocean, climate, and hazards science. Components of NOAA's Honua also utilize spherical display systems for public outreach in a variety of venues, including conferences, community events, and science learning centers. In these settings, NOAA's Honua combines written narratives and accompanying audio in an interactive kiosk. Web-based 3-D interactive components are available and complement both the formal and informal education components. The strength of this program is that complex geophysical processes are presented in intuitive and compelling formats that are readily accessible via the Internet and can be viewed at science centers and museums.

  9. Probing energy transfer events in the light harvesting complex 2 (LH2) of Rhodobacter sphaeroides with two-dimensional spectroscopy

    SciTech Connect

    Fidler, Andrew F.; Singh, Ved P.; Engel, Gregory S.; Long, Phillip D.; Dahlberg, Peter D.

    2013-10-21

    Excitation energy transfer events in the photosynthetic light harvesting complex 2 (LH2) of Rhodobacter sphaeroides are investigated with polarization controlled two-dimensional electronic spectroscopy. A spectrally broadened pulse allows simultaneous measurement of the energy transfer within and between the two absorption bands at 800 nm and 850 nm. The phased all-parallel polarization two-dimensional spectra resolve the initial events of energy transfer by separating the intra-band and inter-band relaxation processes across the two-dimensional map. The internal dynamics of the 800 nm region of the spectra are resolved as a cross peak that grows in on an ultrafast time scale, reflecting energy transfer between higher lying excitations of the B850 chromophores into the B800 states. We utilize a polarization sequence designed to highlight the initial excited state dynamics which uncovers an ultrafast transfer component between the two bands that was not observed in the all-parallel polarization data. We attribute the ultrafast transfer component to energy transfer from higher energy exciton states to lower energy states of the strongly coupled B850 chromophores. Connecting the spectroscopic signature to the molecular structure, we reveal multiple relaxation pathways including a cyclic transfer of energy between the two rings of the complex.

  10. Probing energy transfer events in the light harvesting complex 2 (LH2) of Rhodobacter sphaeroides with two-dimensional spectroscopy.

    PubMed

    Fidler, Andrew F; Singh, Ved P; Long, Phillip D; Dahlberg, Peter D; Engel, Gregory S

    2013-10-21

    Excitation energy transfer events in the photosynthetic light harvesting complex 2 (LH2) of Rhodobacter sphaeroides are investigated with polarization controlled two-dimensional electronic spectroscopy. A spectrally broadened pulse allows simultaneous measurement of the energy transfer within and between the two absorption bands at 800 nm and 850 nm. The phased all-parallel polarization two-dimensional spectra resolve the initial events of energy transfer by separating the intra-band and inter-band relaxation processes across the two-dimensional map. The internal dynamics of the 800 nm region of the spectra are resolved as a cross peak that grows in on an ultrafast time scale, reflecting energy transfer between higher lying excitations of the B850 chromophores into the B800 states. We utilize a polarization sequence designed to highlight the initial excited state dynamics which uncovers an ultrafast transfer component between the two bands that was not observed in the all-parallel polarization data. We attribute the ultrafast transfer component to energy transfer from higher energy exciton states to lower energy states of the strongly coupled B850 chromophores. Connecting the spectroscopic signature to the molecular structure, we reveal multiple relaxation pathways including a cyclic transfer of energy between the two rings of the complex.

  11. Faster Interprotein Electron Transfer in a [Myoglobin, b5] Complex with a Redesigned Interface

    PubMed Central

    Xiong, Peng; Nocek, Judith M.; Vura-Weis, Josh; Lockard, Jenny V.; Wasielewski, Michael R.; Hoffman, Brian M.

    2014-01-01

    Direct measurements of electron transfer (ET) within a protein-protein complex with a redesigned interface formed by physiological partner proteins myoglobin (Mb) and cytochrome b5 (b5) reveal interprotein ET rates comparable to those observed within the photosynthetic reaction center. Brownian dynamics simulations show that Mb in which three surface acid residues are mutated to lysine binds b5 in an ensemble of configurations distributed around a reactive most-probable structure. Correspondingly, charge-separation ET from a photoexcited singlet zinc porphyrin incorporated within Mb to the heme of b5 and the follow-up charge-recombination exhibit distributed kinetics, with median rate constants, kfs=2.1×109second−1 and kbs=4.3×1010second−1, respectively. The latter approaches that for the initial step in photosynthetic charge separation, k = 3.3 × 1011 second−1. PMID:21097931

  12. Faster interprotein electron transfer in a [myoglobin, b⁵] complex with a redesigned interface.

    PubMed

    Xiong, Peng; Nocek, Judith M; Vura-Weis, Josh; Lockard, Jenny V; Wasielewski, Michael R; Hoffman, Brian M

    2010-11-19

    Direct measurements of electron transfer (ET) within a protein-protein complex with a redesigned interface formed by physiological partner proteins myoglobin (Mb) and cytochrome b(5) (b(5)) reveal interprotein ET rates comparable to those observed within the photosynthetic reaction center. Brownian dynamics simulations show that Mb in which three surface acid residues are mutated to lysine binds b(5) in an ensemble of configurations distributed around a reactive most-probable structure. Correspondingly, charge-separation ET from a photoexcited singlet zinc porphyrin incorporated within Mb to the heme of b(5) and the follow-up charge-recombination exhibit distributed kinetics, with median rate constants, k(f)(s) = 2.1 × 10(9) second(-1) and k(b)(s) = 4.3 × 10(10) second(-1), respectively. The latter approaches that for the initial step in photosynthetic charge separation, k = 3.3 × 10(11) second(-1).

  13. Modeling Electronic-Nuclear Interactions for Excitation Energy Transfer Processes in Light-Harvesting Complexes.

    PubMed

    Lee, Mi Kyung; Coker, David F

    2016-08-18

    An accurate approach for computing intermolecular and intrachromophore contributions to spectral densities to describe the electronic-nuclear interactions relevant for modeling excitation energy transfer processes in light harvesting systems is presented. The approach is based on molecular dynamics (MD) calculations of classical correlation functions of long-range contributions to excitation energy fluctuations and a separate harmonic analysis and single-point gradient quantum calculations for electron-intrachromophore vibrational couplings. A simple model is also presented that enables detailed analysis of the shortcomings of standard MD-based excitation energy fluctuation correlation function approaches. The method introduced here avoids these problems, and its reliability is demonstrated in accurate predictions for bacteriochlorophyll molecules in the Fenna-Matthews-Olson pigment-protein complex, where excellent agreement with experimental spectral densities is found. This efficient approach can provide instantaneous spectral densities for treating the influence of fluctuations in environmental dissipation on fast electronic relaxation.

  14. Spectrophotometric determination of clobetasol propionate, halobetasol propionate, quinagolide hydrochloride, through charge transfer complexation.

    PubMed

    Mostafa, Azza A; Bebawy, Lories I; Refaat, Heba H

    2002-03-01

    Two spectrophotometric procedures are described for the determination of clobetasol propionate(I), halobetasol propionate(II) (corticosteroids) and quinagolide hydrochloride(III) (prolactin inhibitor). For corticosteroid drugs, the procedures are based on the formation of phenyl hydrazones of the corticosteroids which are subsequently subjected to charge transfer complexation reaction with either 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) as pi-acceptor or with iodine as sigma-acceptor. Prolactin inhibitor was reacted directly with the previous reagents. The molar ratios of the reactants were established and the experimental conditions were studied giving maximum absorption at 588 and 290 nm with DDQ and iodine methods, respectively for the three drugs. The concentration ranges were 20-150,50-300, and 20-80 microg ml(-1) in DDQ method for (I), (II), and (III), respectively and 13-20,15-40, and 8-32 microg ml(-1) in iodine method for (I), (II) and (III), respectively.

  15. Complex Förster energy transfer interactions between semiconductor quantum dots and a redox-active osmium assembly.

    PubMed

    Stewart, Michael H; Huston, Alan L; Scott, Amy M; Efros, Alexander L; Melinger, Joseph S; Gemmill, Kelly Boeneman; Trammell, Scott A; Blanco-Canosa, Juan B; Dawson, Philip E; Medintz, Igor L

    2012-06-26

    The ability of luminescent semiconductor quantum dots (QDs) to engage in diverse energy transfer processes with organic dyes, light-harvesting proteins, metal complexes, and redox-active labels continues to stimulate interest in developing them for biosensing and light-harvesting applications. Within biosensing configurations, changes in the rate of energy transfer between the QD and the proximal donor, or acceptor, based upon some external (biological) event form the principle basis for signal transduction. However, designing QD sensors to function optimally is predicated on a full understanding of all relevant energy transfer mechanisms. In this report, we examine energy transfer between a range of CdSe-ZnS core-shell QDs and a redox-active osmium(II) polypyridyl complex. To facilitate this, the Os complex was synthesized as a reactive isothiocyanate and used to label a hexahistidine-terminated peptide. The Os-labeled peptide was ratiometrically self-assembled to the QDs via metal affinity coordination, bringing the Os complex into close proximity of the nanocrystal surface. QDs displaying different emission maxima were assembled with increasing ratios of Os-peptide complex and subjected to detailed steady-state, ultrafast transient absorption, and luminescence lifetime decay analyses. Although the possibility exists for charge transfer quenching interactions, we find that the QD donors engage in relatively efficient Förster resonance energy transfer with the Os complex acceptor despite relatively low overall spectral overlap. These results are in contrast to other similar QD donor-redox-active acceptor systems with similar separation distances, but displaying far higher spectral overlap, where charge transfer processes were reported to be the dominant QD quenching mechanism.

  16. Electron transfer reactions in the alkene mono-oxygenase complex from Nocardia corallina B-276.

    PubMed Central

    Gallagher, S C; Cammack, R; Dalton, H

    1999-01-01

    Nocardia corallina B-276 possesses a multi-component enzyme, alkene mono-oxygenase (AMO), that catalyses the stereoselective epoxygenation of alkenes. The reductase component of this system has been shown by EPR and fluorescence spectroscopy to contain two prosthetic groups, an FAD centre and a [2Fe-2S] cluster. The role of these centres in the epoxygenation reaction was determined by midpoint potential measurements and electron transfer kinetics. The order of potentials of the prosthetic groups of the reductase were FAD/FAD.=-216 mV, [2Fe-2S]/[2Fe-2S].=-160 mV and FAD./FAD.=-134 mV. Combined, these data implied that the reductase component supplied the energy required for the epoxygenation reaction and allowed a prediction of the mechanism of electron transfer within the AMO complex. The FAD moiety was reduced by bound NADH in a two-electron reaction. The electrons were then transported to the [2Fe-2S] centre one at a time, which in turn reduced the di-iron centre of the epoxygenase. Reduction of the di-iron centre is required for oxygen binding and substrate oxidation. PMID:10085230

  17. Coordination Sphere Tuning of the Electron Transfer Dissociation Behavior of Cu(II)-Peptide Complexes

    NASA Astrophysics Data System (ADS)

    Dong, Jia; Vachet, Richard W.

    2012-02-01

    In contrast to previous electron capture dissociation (ECD) studies, we find that electron transfer dissociation (ETD) of Cu(II)-peptide complexes can generate c- and z-type product ions when the peptide has a sufficient number of strongly coordinating residues. Double-resonance experiments, ion-molecule reactions, and collision-induced dissociation (CID) prove that the c and z product ions are formed via typical radical pathways without the associated reduction of Cu(II), despite the high second ionization energy of Cu. A positive correlation between the number of Cu(II) binding groups in the peptide sequence and the extent of c and z ion formation was also observed. This trend is rationalized by considering that the recombination energy of Cu(II) can be lowered by strong binding ligands to an extent that enables electron transfer to non-Cu sites (e.g., protonation sites) to compete with Cu(II) reduction, thereby generating c/z ions in a manner similar to that observed for protonated (i.e., nonmetalated) peptides.

  18. Solvent influence on the thermodynamics for hydride transfer from bis(diphosphine) complexes of nickel.

    PubMed

    Connelly Robinson, Samantha J; Zall, Christopher M; Miller, Deanna L; Linehan, John C; Appel, Aaron M

    2016-06-14

    The thermodynamic hydricity of a metal hydride can vary considerably between solvents. This parameter can be used to determine the favourability of a hydride-transfer reaction, such as the reaction between a metal hydride and CO2 to produce formate. Because the hydricities of these species do not vary consistently between solvents, reactions that are thermodynamically unfavourable in one solvent can be favourable in others. The hydricity of a water-soluble, bis-phosphine nickel hydride complex was compared to the hydricity of formate in water and in acetonitrile. Formate is a better hydride donor than [HNi(dmpe)2](+) by 7 kcal mol(-1) in acetonitrile, and no hydride transfer from [HNi(dmpe)2](+) to CO2 occurs in this solvent. The hydricity of [HNi(dmpe)2](+) is greatly improved in water relative to acetonitrile, in that reduction of CO2 to formate by [HNi(dmpe)2](+) was found to be thermodynamically downhill by 8 kcal mol(-1). Catalysis for the hydrogenation of CO2 was pursued, but the regeneration of [HNi(dmpe)2] under catalytic conditions was unfavourable. However, the present results demonstrate that the solvent dependence of thermodynamic parameters such as hydricity and acidity can be exploited in order to produce systems with balanced or favourable overall thermodynamics. This approach should be advantageous for the design of future water-soluble catalysts.

  19. Synthesis and hydride transfer reactions of cobalt and nickel hydride complexes to BX3 compounds.

    PubMed

    Mock, Michael T; Potter, Robert G; O'Hagan, Molly J; Camaioni, Donald M; Dougherty, William G; Kassel, W Scott; DuBois, Daniel L

    2011-12-05

    Hydrides of numerous transition metal complexes can be generated by the heterolytic cleavage of H(2) gas such that they offer alternatives to using main group hydrides in the regeneration of ammonia borane, a compound that has been intensely studied for hydrogen storage applications. Previously, we reported that HRh(dmpe)(2) (dmpe = 1,2-bis(dimethylphosphinoethane)) was capable of reducing a variety of BX(3) compounds having a hydride affinity (HA) greater than or equal to the HA of BEt(3). This study examines the reactivity of less expensive cobalt and nickel hydride complexes, HCo(dmpe)(2) and [HNi(dmpe)(2)](+), to form B-H bonds. The hydride donor abilities (ΔG(H(-))°) of HCo(dmpe)(2) and [HNi(dmpe)(2)](+) were positioned on a previously established scale in acetonitrile that is cross-referenced with calculated HAs of BX(3) compounds. The collective data guided our selection of BX(3) compounds to investigate and aided our analysis of factors that determine favorability of hydride transfer. HCo(dmpe)(2) was observed to transfer H(-) to BX(3) compounds with X = H, OC(6)F(5), and SPh. The reaction with B(SPh)(3) is accompanied by the formation of dmpe-(BH(3))(2) and dmpe-(BH(2)(SPh))(2) products that follow from a reduction of multiple B-SPh bonds and a loss of dmpe ligands from cobalt. Reactions between HCo(dmpe)(2) and B(SPh)(3) in the presence of triethylamine result in the formation of Et(3)N-BH(2)SPh and Et(3)N-BH(3) with no loss of a dmpe ligand. Reactions of the cationic complex [HNi(dmpe)(2)](+) with B(SPh)(3) under analogous conditions give Et(3)N-BH(2)SPh as the final product along with the nickel-thiolate complex [Ni(dmpe)(2)(SPh)](+). The synthesis and characterization of HCo(dedpe)(2) (dedpe = Et(2)PCH(2)CH(2)PPh(2)) from H(2) and a base is also discussed, including the formation of an uncommon trans dihydride species, trans-[(H)(2)Co(dedpe)(2)][BF(4)].

  20. Synthesis and Hydride Transfer Reactions of Cobalt and Nickel Hydride Complexes to BX₃ Compounds

    SciTech Connect

    Mock, Michael T.; Potter, Robert G.; O'Hagan, Molly; Camaioni, Donald M.; Dougherty, William G.; Kassel, W. Scott; DuBois, Daniel L.

    2011-10-31

    Hydrides of numerous transition metal complexes can be generated by the heterolytic cleavage of H₂ gas such that they offer alternatives to using main group hydrides in the regeneration of ammonia borane, a compound that has been intensely studied for hydrogen storage applications. Previously, we reported that HRh(dmpe)₂ (dmpe = 1,2-bis(dimethylphosphinoethane)) was capable of reducing a variety of BX₃ compounds having a hydride affinity (HA) greater than or equal to the HA of BEt₃. This study examines the reactivity of less expensive cobalt and nickel hydride complexes, HCo(dmpe)₂ and [HNi(dmpe)₂]+, to form B–H bonds. The hydride donor abilities (ΔGH °) of HCo(dmpe)₂ and [HNi(dmpe)₂]+ were positioned on a previously established scale in acetonitrile that is cross-referenced with calculated HAs of BX₃ compounds. The collective data guided our selection of BX₃ compounds to investigate and aided our analysis of factors that determine favorability of hydride transfer. HCo(dmpe)₂ was observed to transfer H to BX₃ compounds with X = H, OC₆F₅, and SPh. The reaction with B(SPh)₃ is accompanied by the formation of dmpe-(BH₃)₂ and dmpe-(BH₂(SPh))₂ products that follow from a reduction of multiple B–SPh bonds and a loss of dmpe ligands from cobalt. Reactions between HCo(dmpe)₂ and B(SPh)₃ in the presence of triethylamine result in the formation of Et₃N–BH₂SPh and Et₃N–BH₃ with no loss of a dmpe ligand. Reactions of the cationic complex [HNi(dmpe)₂]+ with B(SPh)₃ under analogous conditions give Et₃N–BH₂SPh as the final product along with the nickel–thiolate complex [Ni(dmpe)₂(SPh)]+. The synthesis and characterization of HCo(dedpe)₂ (dedpe = Et₂PCH₂CH₂PPh₂) from H₂ and a base is also discussed, including the formation of an uncommon trans dihydride species, trans-[(H)₂Co(dedpe)₂][BF₄].

  1. Synthesis and Hydride Transfer Reactions of Cobalt and Nickel Hydride Complexes to BX3 Compounds

    SciTech Connect

    Mock, Michael T.; Potter, Robert G.; O'Hagan, Molly J.; Camaioni, Donald M.; Dougherty, William G.; Kassel, W. S.; DuBois, Daniel L.

    2011-12-05

    Hydrides of numerous transition metal complexes can be generated by the heterolytic cleavage of H{sub 2} gas such that they offer alternatives to using main group hydrides in the regeneration of ammonia borane, a compound that has been intensely studied for hydrogen storage applications. Previously, we reported that HRh(dmpe){sub 2}, dmpe = 1,2-bis(dimethylphosphinoethane) was capable of reducing a variety of BX{sub 3} compounds having hydride affinity (HA) greater than or equal to HA of BEt{sub 3}. This study examines the reactivity of less expensive cobalt and nickel hydride complexes, (HCo(dmpe){sub 2} and [HNi(dmpe){sub 2}]{sup +}), to form B-H bonds. The hydride donor abilities ({Delta}G{sub H{sup -}}{sup o}) of HCo(dmpe){sub 2} and [HNi(dmpe){sub 2}]{sup +} were positioned on a previously established scale in acetonitrile that is cross-referenced with calculated HAs of BX{sub 3} compounds. The collective data guided our selection of BX{sub 3} compounds to investigate and aided our analysis of factors that determine favorability of hydride transfer. HCo(dmpe){sub 2} was observed to transfer H{sup -} to BX{sub 3} compounds with X = H, OC{sub 6}F{sub 5} and SPh. The reaction with B(SPh){sub 3} is accompanied by formation of (BH{sub 3}){sub 2}-dmpe and (BH{sub 2}SPh){sub 2}-dmpe products that follow from reduction of multiple BSPh bonds and loss of a dmpe ligand from Co. Reactions between HCo(dmpe){sub 2} and B(SPh){sub 3} in the presence of triethylamine result in formation of Et{sub 3}N-BH{sub 2}SPh and Et{sub 3}N-BH{sub 3} with no loss of dmpe ligand. Reactions of the cationic complex [HNi(dmpe){sub 2}]{sup +} with B(SPh){sub 3} under analogous conditions give Et{sub 3}N-BH{sub 2}SPh as the final product along with the nickel-thiolate complex [Ni(dmpe){sub 2}(SPh)]{sup +}. The synthesis and characterization of HCo(dedpe){sub 2} (dedpe = diethyldiphenyl(phosphino)ethane) from H{sub 2} and a base is also discussed; including the formation of an uncommon trans

  2. Spectrophotometric study of the charge transfer complexation of some porphyrin derivatives as electron donors with tetracyanoethylene.

    PubMed

    El-Zaria, Mohamed E

    2008-01-01

    Charge transfer complexes (CTC) of 5,10,15,20-tetraphenylporphyrin (TPP), 5,10,15,20-tetra(4-tolyl)porphyrin (TTP), 5,10,15,20-tetra(4-methoxyphenyl)porphyrin (TMP), Zn-5,10,15,20-tetraphenylporphyrin (Zn-TPP), and Zn-5,10,15,20-tetra(4-tolyl)porphyrin (Zn-TTP) with tetracyanoethylene (TCNE) have been studied at various temperatures in CH(2)Cl(2) and CCl(4). The data are discussed in terms of equilibrium constant (K(CT)), molar extinction coefficient (epsilon(CT)), thermodynamic standard reaction quantities (DeltaG degrees , DeltaH degrees and DeltaS degrees ), oscillator strength (f), and transition dipole moment (mu). The spectrum obtained for TPP/TCNE, TTP/TCNE, and TMP/TCNE systems shows two main absorption bands at 475 and 690nm, which are not due to the absorption of any of the reactants. These bands are characteristic of an intermolecular charge transfer involving the overlap of the lowest unoccupied molecular orbital (LUMO) of the acceptor with the highest occupied molecular orbital (HOMO) of the donor. The results reveal that the interaction between the donors and acceptor is due to pi-pi(*) transitions by the formation of radical ion pairs. The stoichiometry of the complexes was found to be 1:1 ratio by the Job and straight line methods between donors and acceptor with the maximum absorption bands at wavelengths of 475 and 690nm. The observed data show salvation effects on the spectral and thermodynamics properties of CTC. The ionization potential of the donors and the dissociation energy of the CTC were also determined and are found to be constant.

  3. Spectrophotometric study of the charge transfer complexation of some porphyrin derivatives as electron donors with tetracyanoethylene

    NASA Astrophysics Data System (ADS)

    El-Zaria, Mohamed E.

    2008-01-01

    Charge transfer complexes (CTC) of 5,10,15,20-tetraphenylporphyrin (TPP), 5,10,15,20-tetra(4-tolyl)porphyrin (TTP), 5,10,15,20-tetra(4-methoxyphenyl)porphyrin (TMP), Zn-5,10,15,20-tetraphenylporphyrin (Zn-TPP), and Zn-5,10,15,20-tetra(4-tolyl)porphyrin (Zn-TTP) with tetracyanoethylene (TCNE) have been studied at various temperatures in CH 2Cl 2 and CCl 4. The data are discussed in terms of equilibrium constant ( KCT), molar extinction coefficient ( ɛCT), thermodynamic standard reaction quantities (Δ G°, Δ H° and Δ S°), oscillator strength ( f), and transition dipole moment ( μ). The spectrum obtained for TPP/TCNE, TTP/TCNE, and TMP/TCNE systems shows two main absorption bands at 475 and 690 nm, which are not due to the absorption of any of the reactants. These bands are characteristic of an intermolecular charge transfer involving the overlap of the lowest unoccupied molecular orbital (LUMO) of the acceptor with the highest occupied molecular orbital (HOMO) of the donor. The results reveal that the interaction between the donors and acceptor is due to π-π * transitions by the formation of radical ion pairs. The stoichiometry of the complexes was found to be 1:1 ratio by the Job and straight line methods between donors and acceptor with the maximum absorption bands at wavelengths of 475 and 690 nm. The observed data show salvation effects on the spectral and thermodynamics properties of CTC. The ionization potential of the donors and the dissociation energy of the CTC were also determined and are found to be constant.

  4. Thermodynamic studies and hydride transfer reactions from a rhodium complex to BX3 compounds.

    PubMed

    Mock, Michael T; Potter, Robert G; Camaioni, Donald M; Li, Jun; Dougherty, William G; Kassel, W Scott; Twamley, Brendan; DuBois, Daniel L

    2009-10-14

    This study examines the use of transition-metal hydride complexes that can be generated by the heterolytic cleavage of H(2) gas to form B-H bonds. Specifically, these studies are focused on providing a reliable and quantitative method for determining when hydride transfer from transition-metal hydrides to three-coordinate BX(3) (X = OR, SPh, F, H; R = Ph, p-C(6)H(4)OMe, C(6)F(5), (t)Bu, Si(Me)(3)) compounds will be favorable. This involves both experimental and theoretical determinations of hydride transfer abilities. Thermodynamic hydride donor abilities (DeltaG(o)(H(-))) were determined for HRh(dmpe)(2) and HRh(depe)(2), where dmpe = 1,2-bis(dimethylphosphinoethane) and depe = 1,2-bis(diethylphosphinoethane), on a previously established scale in acetonitrile. This hydride donor ability was used to determine the hydride donor ability of [HBEt(3)](-) on this scale. Isodesmic reactions between [HBEt(3)](-) and selected BX(3) compounds to form BEt(3) and [HBX(3)](-) were examined computationally to determine their relative hydride affinities. The use of these scales of hydride donor abilities and hydride affinities for transition-metal hydrides and BX(3) compounds is illustrated with a few selected reactions relevant to the regeneration of ammonia borane. Our findings indicate that it is possible to form B-H bonds from B-X bonds, and the extent to which BX(3) compounds are reduced by transition-metal hydride complexes forming species containing multiple B-H bonds depends on the heterolytic B-X bond energy. An example is the reduction of B(SPh)(3) using HRh(dmpe)(2) in the presence of triethylamine to form Et(3)N-BH(3) in high yields.

  5. Public Information Influences Sperm Transfer to Females in Sailfin Molly Males

    PubMed Central

    Nöbel, Sabine; Witte, Klaudia

    2013-01-01

    In animals, including humans, the social environment can serve as a public information network in which individuals can gather public information about the quality of potential mates by observing conspecifics during sexual interactions. The observing individual itself is also a part of this information network. When recognized by the observed conspecifics as an audience, his/her presence could influence the sexual interaction between those individuals, because the observer might be considered as a potential mate or competitor. One of the most challenging questions in sexual selection to date is how the use of public information in the context of mate choice is linked to the fitness of individuals. Here, we could show that public information influences mate-choice behaviour in sailfin molly males, Poecilia latipinna, and influences the amount of sperm males transfer to a female partner. In the presence of an audience male, males spent less time with the previously preferred, larger of two females and significantly more time with the previously non-preferred, smaller female. When males could physically interact with a female and were faced with an audience male, three audience females or no audience, males transferred significantly more sperm to a female partner in the presence of an audience male than with female audience or no audience and spent less time courting his female partner. This is the first study showing that public information use turns into fitness investment, which is the crucial factor to understand the role of public information in the dynamic processes in sexual selection. PMID:23342021

  6. Shifts of Gamma Phase across Primary Visual Cortical Sites Reflect Dynamic Stimulus-Modulated Information Transfer

    PubMed Central

    Besserve, Michel; Lowe, Scott C.; Logothetis, Nikos K.; Schölkopf, Bernhard; Panzeri, Stefano

    2015-01-01

    Distributed neural processing likely entails the capability of networks to reconfigure dynamically the directionality and strength of their functional connections. Yet, the neural mechanisms that may allow such dynamic routing of the information flow are not yet fully understood. We investigated the role of gamma band (50–80 Hz) oscillations in transient modulations of communication among neural populations by using measures of direction-specific causal information transfer. We found that the local phase of gamma-band rhythmic activity exerted a stimulus-modulated and spatially-asymmetric directed effect on the firing rate of spatially separated populations within the primary visual cortex. The relationships between gamma phases at different sites (phase shifts) could be described as a stimulus-modulated gamma-band wave propagating along the spatial directions with the largest information transfer. We observed transient stimulus-related changes in the spatial configuration of phases (compatible with changes in direction of gamma wave propagation) accompanied by a relative increase of the amount of information flowing along the instantaneous direction of the gamma wave. These effects were specific to the gamma-band and suggest that the time-varying relationships between gamma phases at different locations mark, and possibly causally mediate, the dynamic reconfiguration of functional connections. PMID:26394205

  7. Phase Difference between Model Cortical Areas Determines Level of Information Transfer

    PubMed Central

    ter Wal, Marije; Tiesinga, Paul H.

    2017-01-01

    Communication between cortical sites is mediated by long-range synaptic connections. However, these connections are relatively static, while everyday cognitive tasks demand a fast and flexible routing of information in the brain. Synchronization of activity between distant cortical sites has been proposed as the mechanism underlying such a dynamic communication structure. Here, we study how oscillatory activity affects the excitability and input-output relation of local cortical circuits and how it alters the transmission of information between cortical circuits. To this end, we develop model circuits showing fast oscillations by the PING mechanism, of which the oscillatory characteristics can be altered. We identify conditions for synchronization between two brain circuits and show that the level of intercircuit coherence and the phase difference is set by the frequency difference between the intrinsic oscillations. We show that the susceptibility of the circuits to inputs, i.e., the degree of change in circuit output following input pulses, is not uniform throughout the oscillation period and that both firing rate, frequency and power are differentially modulated by inputs arriving at different phases. As a result, an appropriate phase difference between the circuits is critical for the susceptibility windows of the circuits in the network to align and for information to be efficiently transferred. We demonstrate that changes in synchrony and phase difference can be used to set up or abolish information transfer in a network of cortical circuits. PMID:28232796

  8. Work-Facilitating Information Visualization Techniques for Complex Wastewater Systems

    NASA Astrophysics Data System (ADS)

    Ebert, Achim; Einsfeld, Katja

    The design and the operation of urban drainage systems and wastewater treatment plants (WWTP) have become increasingly complex. This complexity is due to increased requirements concerning process technology, technical, environmental, economical, and occupational safety aspects. The plant operator has access not only to some timeworn filers and measured parameters but also to numerous on-line and off-line parameters that characterize the current state of the plant in detail. Moreover, expert databases and specific support pages of plant manufactures are accessible through the World Wide Web. Thus, the operator is overwhelmed with predominantly unstructured data.

  9. Analysing the information flow between financial time series . An improved estimator for transfer entropy

    NASA Astrophysics Data System (ADS)

    Marschinski, R.; Kantz, H.

    2002-11-01

    Following the recently introduced concept of transfer entropy, we attempt to measure the information flow between two financial time series, the Dow Jones and DAX stock index. Being based on Shannon entropies, this model-free approach in principle allows us to detect statistical dependencies of all types, i.e. linear and nonlinear temporal correlations. However, when available data is limited and the expected effect is rather small, a straightforward implementation suffers badly from misestimation due to finite sample effects, making it basically impossible to assess the significance of the obtained values. We therefore introduce a modified estimator, called effective transfer entropy, which leads to improved results in such conditions. In the application, we then manage to confirm an information transfer on a time scale of one minute between the two financial time series. The different economic impact of the two indices is also recovered from the data. Numerical results are then interpreted on one hand as capability of one index to explain future observations of the other, and on the other hand within terms of coupling strengths in the framework of a bivariate autoregressive stochastic model. Evidence is given for a nonlinear character of the coupling between Dow Jones and DAX.

  10. Rotordynamic analysis using the Complex Transfer Matrix: An application to elastomer supports using the viscoelastic correspondence principle

    NASA Astrophysics Data System (ADS)

    Varney, Philip; Green, Itzhak

    2014-11-01

    Numerous methods are available to calculate rotordynamic whirl frequencies, including analytic methods, finite element analysis, and the transfer matrix method. The typical real-valued transfer matrix (RTM) suffers from several deficiencies, including lengthy computation times and the inability to distinguish forward and backward whirl. Though application of complex coordinates in rotordynamic analysis is not novel per se, specific advantages gained from using such coordinates in a transfer matrix analysis have yet to be elucidated. The present work employs a complex coordinate redefinition of the transfer matrix to obtain reduced forms of the elemental transfer matrices in inertial and rotating reference frames, including external stiffness and damping. Application of the complex-valued state variable redefinition results in a reduction of the 8×8 RTM to the 4×4 Complex Transfer Matrix (CTM). The CTM is advantageous in that it intrinsically separates forward and backward whirl, eases symbolic manipulation by halving the transfer matrices’ dimension, and provides significant improvement in computation time. A symbolic analysis is performed on a simple overhung rotor to demonstrate the mathematical motivation for whirl frequency separation. The CTM's utility is further shown by analyzing a rotordynamic system supported by viscoelastic elastomer rings. Viscoelastic elastomer ring supports can provide significant damping while reducing the cost and complexity associated with conventional components such as squeeze film dampers. The stiffness and damping of a viscoelastic damper ring are determined herein as a function of whirl frequency using the viscoelastic correspondence principle and a constitutive fractional calculus viscoelasticity model. The CTM is then employed to obtain the characteristic equation, where the whirl frequency dependent stiffness and damping of the elastomer supports are included. The Campbell diagram is shown, demonstrating the CTM

  11. Effect of oxygen transfer rate on the composition of the pectolytic enzyme complex of Aspergillus niger

    SciTech Connect

    Zetelaki-Horvath, K.; Vas, K.

    1981-01-01

    Optimal agitation and aeration conditions (assuring O/sub 2/ transfer rates (OTR) of 12-179 mmol/L-h) were determined for pectin lyase (PL) synthesis of an Aspergillus niger strain. Components of the pectolytic enzyme complex were also investigated in order to determine whether their O/sub 2/ demand is identical with or different from that of pectin lyase. Should the latter be the case, a possibility would be given to produce enzyme complexes of different agitation and aeration conditions. The mycelium yield of Aspergillus niger was maximum at an OTR of 100 mmol/L-h. The yields of the various pectolytic enzymes reached maximum at different OTRs. PL production was highest (0.555 mumol/min-mL) at an OTR of 60 mmol/L-h. Endopolygalacturonase (PG) production has a maximum at OTR 49 mmol/L-h, with a 2nd peak at 100-135 mmol O2/L-h. Pectin esterase (PE) synthesis showed a maximum at an OTR of 12-14 mmol/L-h, while both apple juice clarifying and macerating activities gave 2 maximum at 14 and 60 mmol/L-h due to the optima of PE and endo-PG. Macerating activity showed a high value at OTR optimal for PL production as well.

  12. GAM-HEAT: A computer code to compute heat transfer in complex enclosures. Revision 2

    SciTech Connect

    Cooper, R.E.; Taylor, J.R.

    1992-12-01

    This report discusses the GAM{underscore}HEAT code which was developed for heat transfer analyses associated with postulated Double Ended Guilliotine Break Loss Of Coolant Accidents (DEGB LOCA) resulting in a drained reactor vessel. In these analyses the gamma radiation resulting from fission product decay constitutes the primary source of energy as a function of time. This energy is deposited into the various reactor components and is re-radiated as thermal energy. The code accounts for all radiant heat exchanges within and leaving the reactor enclosure. The SRS reactors constitute complex radiant exchange enclosures since there are many assemblies of various types within the primary enclosure and most of the assemblies themselves constitute enclosures. GAM-HEAT accounts for this complexity by processing externally generated view factors and connectivity matrices as discussed below, and also accounts for convective, conductive, and advective heat exchanges. The code is structured such that it is applicable for many situations involving heat exchange between surfaces within a radiatively passive medium.

  13. GAM-HEAT: A computer code to compute heat transfer in complex enclosures

    SciTech Connect

    Cooper, R.E.; Taylor, J.R.

    1992-12-01

    This report discusses the GAM[underscore]HEAT code which was developed for heat transfer analyses associated with postulated Double Ended Guilliotine Break Loss Of Coolant Accidents (DEGB LOCA) resulting in a drained reactor vessel. In these analyses the gamma radiation resulting from fission product decay constitutes the primary source of energy as a function of time. This energy is deposited into the various reactor components and is re-radiated as thermal energy. The code accounts for all radiant heat exchanges within and leaving the reactor enclosure. The SRS reactors constitute complex radiant exchange enclosures since there are many assemblies of various types within the primary enclosure and most of the assemblies themselves constitute enclosures. GAM-HEAT accounts for this complexity by processing externally generated view factors and connectivity matrices as discussed below, and also accounts for convective, conductive, and advective heat exchanges. The code is structured such that it is applicable for many situations involving heat exchange between surfaces within a radiatively passive medium.

  14. Eu(III) complexes as anion-responsive luminescent sensors and paramagnetic chemical exchange saturation transfer agents.

    PubMed

    Hammell, Jacob; Buttarazzi, Leandro; Huang, Ching-Hui; Morrow, Janet R

    2011-06-06

    The Eu(III) complex of (1S,4S,7S,10S)-1,4,7,10-tetrakis(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane (S-THP) is studied as a sensor for biologically relevant anions. Anion interactions produce changes in the luminescence emission spectrum of the Eu(III) complex, in the (1)H NMR spectrum, and correspondingly, in the PARACEST spectrum of the complex (PARACEST = paramagnetic chemical exchange saturation transfer). Direct excitation spectroscopy and luminescence lifetime studies of Eu(S-THP) give information about the speciation and nature of anion interactions including carbonate, acetate, lactate, citrate, phosphate, and methylphosphate at pH 7.2. Data is consistent with the formation of both innersphere and outersphere complexes of Eu(S-THP) with acetate, lactate, and carbonate. These anions have weak dissociation constants that range from 19 to 38 mM. Citrate binding to Eu(S-THP) is predominantly innersphere with a dissociation constant of 17 μM. Luminescence emission peak changes upon addition of anion to Eu(S-THP) show that there are two distinct binding events for phosphate and methylphosphate with dissociation constants of 0.3 mM and 3.0 mM for phosphate and 0.6 mM and 9.8 mM for methyl phosphate. Eu(THPC) contains an appended carbostyril derivative as an antenna to sensitize Eu(III) luminescence. Eu(THPC) binds phosphate and citrate with dissociation constants that are 10-fold less than that of the Eu(S-THP) parent, suggesting that functionalization through a pendent group disrupts the anion binding site. Eu(S-THP) functions as an anion responsive PARACEST agent through exchange of the alcohol protons with bulk water. The alcohol proton resonances of Eu(S-THP) shift downfield in the presence of acetate, lactate, citrate, and methylphosphate, giving rise to distinct PARACEST peaks. In contrast, phosphate binds to Eu(S-THP) to suppress the PARACEST alcohol OH peak and carbonate does not markedly change the alcohol peak at 5 mM Eu(S-THP), 15 mM carbonate at p

  15. Dynamics of information diffusion and its applications on complex networks

    NASA Astrophysics Data System (ADS)

    Zhang, Zi-Ke; Liu, Chuang; Zhan, Xiu-Xiu; Lu, Xin; Zhang, Chu-Xu; Zhang, Yi-Cheng

    2016-09-01

    The ongoing rapid expansion of the Word Wide Web (WWW) greatly increases the information of effective transmission from heterogeneous individuals to various systems. Extensive research for information diffusion is introduced by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and empirical studies, unification and comparison of different theories and approaches are lacking, which impedes further advances. In this article, we review recent developments in information diffusion and discuss the major challenges. We compare and evaluate available models and algorithms to respectively investigate their physical roles and optimization designs. Potential impacts and future directions are discussed. We emphasize that information diffusion has great scientific depth and combines diverse research fields which makes it interesting for physicists as well as interdisciplinary researchers.

  16. Scale effects on information content and complexity of streamflows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding temporal and spatial variations of streamflows is important for flood forecasting, water resources management, and revealing interactions between hydrologic processes (e.g., precipitation, evapotranspiration, and soil water and groundwater flows.) The information theory has been used i...

  17. Complexity and information flow analysis for multi-threaded programs

    NASA Astrophysics Data System (ADS)

    Ngo, Tri Minh; Huisman, Marieke

    2017-01-01

    This paper studies the security of multi-threaded programs. We combine two methods, i.e., qualitative and quantitative security analysis, to check whether a multi-threaded program is secure or not. In this paper, besides reviewing classical analysis models, we present a novel model of quantitative analysis where the attacker is able to select the scheduling policy. This model does not follow the traditional information-theoretic channel setting. Our analysis first studies what extra information an attacker can get if he knows the scheduler's choices, and then integrates this information into the transition system modeling the program execution. Via a case study, we compare this approach with the traditional information-theoretic models, and show that this approach gives more intuitive-matching results.

  18. Scalability, Complexity and Reliability in Quantum Information Processing

    DTIC Science & Technology

    2007-03-01

    Information and Quantum Computation, Abdus Salam International Centre for Theoretical Physics, Trieste, Italy, “Quantum algorithm for the hidden shift...Future (and Past) of Quantum Lower Bounds by Polynomials,” October 17, 2002 W. van Dam, Workshop on Quantum Information and Quantum Computation, Abdus ... Salam International Centre for Theoretical Physics, Trieste, Italy, “Quantum algorithms: Fourier transforms and group theory,” October 21, 2002 K

  19. Quantifying impacts of short-term plasticity on neuronal information transfer

    NASA Astrophysics Data System (ADS)

    Scott, Pat; Cowan, Anna I.; Stricker, Christian

    2012-04-01

    Short-term changes in efficacy have been postulated to enhance the ability of synapses to transmit information between neurons, and within neuronal networks. Even at the level of connections between single neurons, direct confirmation of this simple conjecture has proven elusive. By combining paired-cell recordings, realistic synaptic modeling, and information theory, we provide evidence that short-term plasticity can not only improve, but also reduce information transfer between neurons. We focus on a concrete example in rat neocortex, but our results may generalize to other systems. When information is contained in the timings of individual spikes, we find that facilitation, depression, and recovery affect information transmission in proportion to their impacts upon the probability of neurotransmitter release. When information is instead conveyed by mean spike rate only, the influences of short-term plasticity critically depend on the range of spike frequencies that the target network can distinguish (its effective dynamic range). Our results suggest that to efficiently transmit information, the brain must match synaptic type, coding strategy, and network connectivity during development and behavior.

  20. Phenylketonuria and Complex Spatial Visualization: An Analysis of Information Processing.

    ERIC Educational Resources Information Center

    Brunner, Robert L.; And Others

    1987-01-01

    The study of the ability of 16 early treated phenylketonuric (PKU) patients (ages 6-23 years) to solve complex spatial problems suggested that choice of problem-solving strategy, attention span, and accuracy of mental representation may be affected in PKU patients, despite efforts to maintain well-controlled phenylalanine concentrations in the…

  1. Energy transfer between surface-immobilized light-harvesting chlorophyll a/b complex (LHCII) studied by surface plasmon field-enhanced fluorescence spectroscopy (SPFS).

    PubMed

    Lauterbach, Rolf; Liu, Jing; Knoll, Wolfgang; Paulsen, Harald

    2010-11-16

    The major light-harvesting chlorophyll a/b complex (LHCII) of the photosynthetic apparatus in green plants can be viewed as a protein scaffold binding and positioning a large number of pigment molecules that combines rapid and efficient excitation energy transfer with effective protection of its pigments from photobleaching. These properties make LHCII potentially interesting as a light harvester (or a model thereof) in photoelectronic applications. Most of such applications would require the LHCII to be immobilized on a solid surface. In a previous study we showed the immobilization of recombinant LHCII on functionalized gold surfaces via a 6-histidine tag (His tag) in the protein moiety. In this work the occurrence and efficiency of Förster energy transfer between immobilized LHCII on a functionalized surface have been analyzed by surface plasmon field-enhanced fluorescence spectroscopy (SPFS). A near-infrared dye was attached to some but not all of the LHC complexes, serving as an energy acceptor to chlorophylls. Analysis of the energy transfer from chlorophylls to this acceptor dye yielded information about the extent of intercomplex energy transfer between immobilized LHCII.

  2. ELAS - A geobased information system that is transferable to several computers. [Earth resources Laboratory Applications Software

    NASA Technical Reports Server (NTRS)

    Whitley, S. L.; Pearson, R. W.; Seyfarth, B. R.; Graham, M. H.

    1981-01-01

    In the early years of remote sensing, emphasis was placed on the processing and analysis of data from a single multispectral sensor, such as the Landsat Multispectral Scanner System (MSS). However, in connection with attempts to use the data for resource management, it was realized that many deficiencies existed in single data sets. A need was established to geographically reference the MSS data and to register with it data from disparate sources. Technological transfer activities have required systems concepts that can be easily transferred to computers of different types in other organizations. ELAS (Earth Resources Laboratory Applications Software), a geographically based information system, was developed to meet the considered needs. ELAS accepts data from a variety of sources. It contains programs to geographically reference the data to the Universal Transverse Mercator grid. One of the primary functions of ELAS is to produce a surface cover map.

  3. Manipulating charge transfer excited state relaxation and spin crossover in iron coordination complexes with ligand substitution

    DOE PAGES

    Zhang, Wenkai; Kjaer, Kasper S.; Alonso-Mori, Roberto; ...

    2016-08-25

    Developing light-harvesting and photocatalytic molecules made with iron could provide a cost effective, scalable, and environmentally benign path for solar energy conversion. To date these developments have been limited by the sub-picosecond metal-to-ligand charge transfer (MLCT) electronic excited state lifetime of iron based complexes due to spin crossover – the extremely fast intersystem crossing and internal conversion to high spin metal-centered excited states. We revitalize a 30 year old synthetic strategy for extending the MLCT excited state lifetimes of iron complexes by making mixed ligand iron complexes with four cyanide (CN–) ligands and one 2,2'-bipyridine (bpy) ligand. This enables MLCTmore » excited state and metal-centered excited state energies to be manipulated with partial independence and provides a path to suppressing spin crossover. We have combined X-ray Free-Electron Laser (XFEL) Kβ hard X-ray fluorescence spectroscopy with femtosecond time-resolved UV-visible absorption spectroscopy to characterize the electronic excited state dynamics initiated by MLCT excitation of [Fe(CN)4(bpy)]2–. The two experimental techniques are highly complementary; the time-resolved UV-visible measurement probes allowed electronic transitions between valence states making it sensitive to ligand-centered electronic states such as MLCT states, whereas the Kβ fluorescence spectroscopy provides a sensitive measure of changes in the Fe spin state characteristic of metal-centered excited states. Here, we conclude that the MLCT excited state of [Fe(CN)4(bpy)]2– decays with roughly a 20 ps lifetime without undergoing spin crossover, exceeding the MLCT excited state lifetime of [Fe(2,2'-bipyridine)3]2+ by more than two orders of magnitude.« less

  4. Bonding and charge transfer in nitrogen-donor uranyl complexes: insights from NEXAFS spectra.

    PubMed

    Pemmaraju, C D; Copping, Roy; Wang, Shuao; Janousch, Markus; Teat, Simon J; Tyliszcak, Tolek; Canning, Andrew; Shuh, David K; Prendergast, David

    2014-11-03

    We investigate the electronic structure of three newly synthesized nitrogen-donor uranyl complexes [(UO2)(H2bbp)Cl2], [(UO)2(Hbbp)(Py)Cl], and [(UO2)(bbp)(Py)2] using a combination of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy experiments and simulations. The complexes studied feature derivatives of the tunable tridentate N-donor ligand 2,6-bis(2-benzimidazyl)pyridine (bbp) and exhibit discrete chemical differences in uranyl coordination. The sensitivity of the N K-edge X-ray absorption spectrum to local bonding and charge transfer is exploited to systematically investigate the evolution of structural as well as electronic properties across the three complexes. A thorough interpretation of the measured experimental spectra is achieved via ab initio NEXAFS simulations based on the eXcited electron and Core-Hole (XCH) approach and enables the assignment of spectral features to electronic transitions on specific absorbing sites. We find that ligand-uranyl bonding leads to a signature blue shift in the N K-edge absorption onset, resulting from charge displacement toward the uranyl, while changes in the equatorial coordination shell of the uranyl lead to more subtle modulations in the spectral features. Theoretical simulations show that the flexible local chemistry at the nonbinding imidazole-N sites of the bbp ligand is also reflected in the NEXAFS spectra and highlights potential synthesis strategies to improve selectivity. In particular, we find that interactions of the bbp ligand with solvent molecules can lead to changes in ligand-uranyl binding geometry while also modulating the K-edge absorption. Our results suggest that NEXAFS spectroscopy combined with first-principles interpretation can offer insights into the coordination chemistry of analogous functionalized conjugated ligands.

  5. Manipulating charge transfer excited state relaxation and spin crossover in iron coordination complexes with ligand substitution

    SciTech Connect

    Zhang, Wenkai; Kjaer, Kasper S.; Alonso-Mori, Roberto; Bergmann, Uwe; Chollet, Matthieu; Fredin, Lisa A.; Hadt, Ryan G.; Hartsock, Robert W.; Harlang, Tobias; Kroll, Thomas; Kubicek, Katharina; Lemke, Henrik T.; Liang, Huiyang W.; Liu, Yizhu; Nielsen, Martin M.; Persson, Petter; Robinson, Joseph S.; Solomon, Edward I.; Sun, Zheng; Sokaras, Dimosthenis; van Driel, Tim B.; Weng, Tsu -Chien; Zhu, Diling; Warnmark, Kenneth; Sundstrom, Villy; Gaffney, Kelly J.

    2016-08-25

    Developing light-harvesting and photocatalytic molecules made with iron could provide a cost effective, scalable, and environmentally benign path for solar energy conversion. To date these developments have been limited by the sub-picosecond metal-to-ligand charge transfer (MLCT) electronic excited state lifetime of iron based complexes due to spin crossover – the extremely fast intersystem crossing and internal conversion to high spin metal-centered excited states. We revitalize a 30 year old synthetic strategy for extending the MLCT excited state lifetimes of iron complexes by making mixed ligand iron complexes with four cyanide (CN) ligands and one 2,2'-bipyridine (bpy) ligand. This enables MLCT excited state and metal-centered excited state energies to be manipulated with partial independence and provides a path to suppressing spin crossover. We have combined X-ray Free-Electron Laser (XFEL) Kβ hard X-ray fluorescence spectroscopy with femtosecond time-resolved UV-visible absorption spectroscopy to characterize the electronic excited state dynamics initiated by MLCT excitation of [Fe(CN)4(bpy)]2–. The two experimental techniques are highly complementary; the time-resolved UV-visible measurement probes allowed electronic transitions between valence states making it sensitive to ligand-centered electronic states such as MLCT states, whereas the Kβ fluorescence spectroscopy provides a sensitive measure of changes in the Fe spin state characteristic of metal-centered excited states. Here, we conclude that the MLCT excited state of [Fe(CN)4(bpy)]2– decays with roughly a 20 ps lifetime without undergoing spin crossover, exceeding the MLCT excited state lifetime of [Fe(2,2'-bipyridine)3]2+ by more than two orders of magnitude.

  6. Validated spectrophotometric methods for determination of sodium valproate based on charge transfer complexation reactions

    NASA Astrophysics Data System (ADS)

    Belal, Tarek S.; El-Kafrawy, Dina S.; Mahrous, Mohamed S.; Abdel-Khalek, Magdi M.; Abo-Gharam, Amira H.

    2016-02-01

    This work presents the development, validation and application of four simple and direct spectrophotometric methods for determination of sodium valproate (VP) through charge transfer complexation reactions. The first method is based on the reaction of the drug with p-chloranilic acid (p-CA) in acetone to give a purple colored product with maximum absorbance at 524 nm. The second method depends on the reaction of VP with dichlone (DC) in dimethylformamide forming a reddish orange product measured at 490 nm. The third method is based upon the interaction of VP and picric acid (PA) in chloroform resulting in the formation of a yellow complex measured at 415 nm. The fourth method involves the formation of a yellow complex peaking at 361 nm upon the reaction of the drug with iodine in chloroform. Experimental conditions affecting the color development were studied and optimized. Stoichiometry of the reactions was determined. The proposed spectrophotometric procedures were effectively validated with respect to linearity, ranges, precision, accuracy, specificity, robustness, detection and quantification limits. Calibration curves of the formed color products with p-CA, DC, PA and iodine showed good linear relationships over the concentration ranges 24-144, 40-200, 2-20 and 1-8 μg/mL respectively. The proposed methods were successfully applied to the assay of sodium valproate in tablets and oral solution dosage forms with good accuracy and precision. Assay results were statistically compared to a reference pharmacopoeial HPLC method where no significant differences were observed between the proposed methods and reference method.

  7. Validated spectrophotometric methods for determination of sodium valproate based on charge transfer complexation reactions.

    PubMed

    Belal, Tarek S; El-Kafrawy, Dina S; Mahrous, Mohamed S; Abdel-Khalek, Magdi M; Abo-Gharam, Amira H

    2016-02-15

    This work presents the development, validation and application of four simple and direct spectrophotometric methods for determination of sodium valproate (VP) through charge transfer complexation reactions. The first method is based on the reaction of the drug with p-chloranilic acid (p-CA) in acetone to give a purple colored product with maximum absorbance at 524nm. The second method depends on the reaction of VP with dichlone (DC) in dimethylformamide forming a reddish orange product measured at 490nm. The third method is based upon the interaction of VP and picric acid (PA) in chloroform resulting in the formation of a yellow complex measured at 415nm. The fourth method involves the formation of a yellow complex peaking at 361nm upon the reaction of the drug with iodine in chloroform. Experimental conditions affecting the color development were studied and optimized. Stoichiometry of the reactions was determined. The proposed spectrophotometric procedures were effectively validated with respect to linearity, ranges, precision, accuracy, specificity, robustness, detection and quantification limits. Calibration curves of the formed color products with p-CA, DC, PA and iodine showed good linear relationships over the concentration ranges 24-144, 40-200, 2-20 and 1-8μg/mL respectively. The proposed methods were successfully applied to the assay of sodium valproate in tablets and oral solution dosage forms with good accuracy and precision. Assay results were statistically compared to a reference pharmacopoeial HPLC method where no significant differences were observed between the proposed methods and reference method.

  8. Backward transfer entropy: Informational measure for detecting hidden Markov models and its interpretations in thermodynamics, gambling and causality

    PubMed Central

    Ito, Sosuke

    2016-01-01

    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. PMID:27833120

  9. (Comparison of group transfer, inner sphere and outer sphere electron transfer mechanisms of organometallic complexes: Progress report)

    SciTech Connect

    Atwood, J.

    1990-01-01

    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. In this summary we highlight our results on reactions (1) that formally involve exchange of a charged species between two metal carbonyl anions, (2) that involve addition 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.

  10. [Comparison of group transfer, inner sphere and outer sphere electron transfer mechanisms of organometallic complexes: Progress report

    SciTech Connect

    Atwood, J.

    1990-12-31

    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. In this summary we highlight our results on reactions (1) that formally involve exchange of a charged species between two metal carbonyl anions, (2) that involve addition 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.

  11. Energy transfer ultraviolet photodetector with 8-hydroxyquinoline derivative-metal complexes as acceptors

    NASA Astrophysics Data System (ADS)

    Wu, Shuang-Hong; Li, Wen-Lian; Chen, Zhi; Li, Shi-Bin; Wang, Xiao-Hui; Wei, Xiong-Bang

    2015-02-01

    We choose 8-hydroxyquinoline derivative-metal complexes (Beq, Mgq, and Znq) as the acceptors (A) and 4,4',4”-tri-(2-methylphenyl phenylamino) triphenylaine (m-MTDATA) as the donor (D) respectively to study the existing energy transfer process in the organic ultraviolet (UV) photodetector (PD), which has an important influence on the sensitivity of PDs. The energy transfer process from D to A without exciplex formation is discussed, differing from the working mechanism of previous PDs with Gaq [Zisheng Su, Wenlian Li, Bei Chu, Tianle Li, Jianzhuo Zhu, Guang Zhang, Fei Yan, Xiao Li, Yiren Chen and Chun-Sing Lee 2008 Appl. Phys. Lett. 93 103309)] and REq [J. B. Wang, W. L. Li, B. Chu, L. L. Chen, G. Zhang, Z. S. Su, Y. R. Chen, D. F. Yang, J. Z. Zhu, S. H. Wu, F. Yan, H. H. Liu, C. S. Lee 2010 Org. Electron. 11 1301] used as an A material. Under 365-nm UV irradiation with an intensity of 1.2 mW/cm2, the m-MTDATA:Beq blend device with a weight ratio of 1:1 shows a response of 192 mA/W with a detectivity of 6.5× 1011 Jones, which exceeds those of PDs based on Mgq (146 mA/W) and Znq (182 mA/W) due to better energy level alignment between m-MTDATA/Beq and lower radiative decay. More photophysics processes of the PDs involved are discussed in detail. Project supported by the National Natural Science Foundation of China (Grant Nos. 61371046, 61405026, 61474016, and 61421002) and China Postdoctoral Science Foundation (Grant No. 2014M552330).

  12. Interfacial electron transfer in TiO(2) surfaces sensitized with Ru(II)-polypyridine complexes.

    PubMed

    Jakubikova, Elena; Snoeberger, Robert C; Batista, Victor S; Martin, Richard L; Batista, Enrique R

    2009-11-12

    Studies of interfacial electron transfer (IET) in TiO(2) surfaces functionalized with (1) pyridine-4-phosphonic acid, (2) [Ru(tpy)(tpy(PO(3)H(2)))](2+), and (3) [Ru(tpy)(bpy)(H(2)O)-Ru(tpy)(tpy(PO(3)H(2)))](4+) (tpy = 2,2':6,2''-terpyridine; bpy = 2,2'-bipyridine) are reported. We characterize the electronic excitations, electron injection time scales, and interfacial electron transfer (IET) mechanisms through phosphonate anchoring groups. These are promising alternatives to the classic carboxylates of conventional dye-sensitized solar cells since they bind more strongly to TiO(2) surfaces and form stable covalent bonds that are unaffected by humidity. Density functional theory calculations and quantum dynamics simulations of IET indicate that electron injection in 1-TiO(2) can be up to 1 order of magnitude faster when 1 is attached to TiO(2) in a bidentate mode (tau approximately 60 fs) than when attached in a monodentate motif (tau approximately 460 fs). The IET time scale also depends strongly on the properties of the sensitizer as well as on the nature of the electronic excitation initially localized in the adsorbate molecule. We show that IET triggered by the visible light excitation of 2-TiO(2) takes 1-10 ps when 2 is attached in a bidentate mode, a time comparable to the lifetime of the excited electronic state. IET due to visible-light photoexcitation of 3-TiO(2) is slower, since the resulting electronic excitation remains localized in the tpy-tpy bridge that is weakly coupled to the electronic states of the conduction band of TiO(2). These results are particularly valuable to elucidate the possible origin of IET efficiency drops during photoconversion in solar cells based on Ru(II)-polypyridine complexes covalently attached to TiO(2) thin films with phosphonate linkers.

  13. Interfacial Electron Transfer in TiO2 Surfaces Sensitized with Ru(II)-Polypyridine Complexes

    NASA Astrophysics Data System (ADS)

    Jakubikova, Elena; Snoeberger, Robert C., III; Batista, Victor S.; Martin, Richard L.; Batista, Enrique R.

    2009-07-01

    Studies of interfacial electron transfer (IET) in TiO2 surfaces functionalized with (1) pyridine-4-phosphonic acid, (2) [Ru(tpy)(tpy(PO3H2))]2+, and (3) [Ru(tpy)(bpy)(H2O)-Ru(tpy)(tpy(PO3H2))]4+ (tpy = 2,2':6,2''-terpyridine; bpy = 2,2'-bipyridine) are reported. We characterize the electronic excitations, electron injection time scales, and interfacial electron transfer (IET) mechanisms through phosphonate anchoring groups. These are promising alternatives to the classic carboxylates of conventional dye-sensitized solar cells since they bind more strongly to TiO2 surfaces and form stable covalent bonds that are unaffected by humidity. Density functional theory calculations and quantum dynamics simulations of IET indicate that electron injection in 1-TiO2 can be up to 1 order of magnitude faster when 1 is attached to TiO2 in a bidentate mode (τ ˜ 60 fs) than when attached in a monodentate motif (τ ˜ 460 fs). The IET time scale also depends strongly on the properties of the sensitizer as well as on the nature of the electronic excitation initially localized in the adsorbate molecule. We show that IET triggered by the visible light excitation of 2-TiO2 takes 1-10 ps when 2 is attached in a bidentate mode, a time comparable to the lifetime of the excited electronic state. IET due to visible-light photoexcitation of 3-TiO2 is slower, since the resulting electronic excitation remains localized in the tpy-tpy bridge that is weakly coupled to the electronic states of the conduction band of TiO2. These results are particularly valuable to elucidate the possible origin of IET efficiency drops during photoconversion in solar cells based on Ru(II)-polypyridine complexes covalently attached to TiO2 thin films with phosphonate linkers.

  14. Seeking Information Online: The Influence of Menu Type, Navigation Path Complexity and Spatial Ability on Information Gathering Tasks

    ERIC Educational Resources Information Center

    Puerta Melguizo, Mari Carmen; Vidya, Uti; van Oostendorp, Herre

    2012-01-01

    We studied the effects of menu type, navigation path complexity and spatial ability on information retrieval performance and web disorientation or lostness. Two innovative aspects were included: (a) navigation path relevance and (b) information gathering tasks. As expected we found that, when measuring aspects directly related to navigation…

  15. Validating Information Complexity Questionnaires Using Travel Web Sites

    DTIC Science & Technology

    2009-07-01

    from Dallas, TX, to Yellowstone Natonal Park on partcular dates; 2) buy an arlne tcket for one person from Okla- homa Cty, OK, to Chcago, IL, on...22060; and the National Technical Information Service, Springfield, VA 22161 19. Security Classif. (of this report) 20. Security Classif. (of

  16. Synthesis and spectrophotometric studies of charge transfer complexes of p-nitroaniline with benzoic acid in different polar solvents

    NASA Astrophysics Data System (ADS)

    Singh, Neeti; Ahmad, Afaq

    2014-09-01

    The charge transfer complexes of the donor p-nitroaniline (PNA) with the π-acceptor benzoic acid (BEA) have been studied spectrophotometrically in various solvents such as acetone, ethanol, and methanol at room temperature using an absorption spectrophotometer. The outcome suggests that the formation of the CT-complex is comparatively high in less polar solvent. The stoichiometry of the CT-complex was found to be 1:1. The physical parameters of the CT-complex were evaluated by the Benesi-Hildebrand equation. The data are discussed in terms of the formation constant (KCT), molar extinction coefficient (ɛCT), Standard Gibbs free energy (ΔG0), oscillator strength (f), transition dipole moment (μEN), resonance energy (RN) and ionization potential (ID). The formation constant (KCT) of the complex was depends upon the nature of electron acceptor, donor, and polarity of solvents used. It is also observed that a charge transfer molecular complex is stabilized by hydrogen bonding. The formation of the complex has been confirmed by UV-visible, FT-IR, 1H NMR and TGA/DTA. The structure of the CT-complex is [(PNA)+ (BEA)-]. A general mechanism for its formation of the complex has also been proposed.

  17. The study on knowledge transferring incentive for information system requirement development

    SciTech Connect

    Li, Yang

    2015-03-10

    Information system requirement development is a process of users’ knowledge sharing and transferring. However the tacit requirements developing is a main problem during requirement development process, for the reason of difficult to encoding, express, and communicate. Knowledge fusion and corporate effort is needed to finding tacit requirements. Under this background, our paper try to find out the rule of effort dynamic evolutionary of software developer and user by building an evolutionary game model on the condition of incentive system. And in addition this paper provides an in depth discussion at the end of this paper.

  18. Protein film voltammetry and co-factor electron transfer dynamics in spinach photosystem II core complex.

    PubMed

    Zhang, Yun; Magdaong, Nikki; Frank, Harry A; Rusling, James F

    2014-05-01

    Direct protein film voltammetry (PFV) was used to investigate the redox properties of the photosystem II (PSII) core complex from spinach. The complex was isolated using an improved protocol not used previously for PFV. The PSII core complex had high oxygen-evolving capacity and was incorporated into thin lipid and polyion films. Three well-defined reversible pairs of reduction and oxidation voltammetry peaks were observed at 4 °C in the dark. Results were similar in both types of films, indicating that the environment of the PSII-bound cofactors was not influenced by film type. Based on comparison with various control samples including Mn-depleted PSII, peaks were assigned to chlorophyll a (Chl a) (Em = -0.47 V, all vs. NHE, at pH 6), quinones (-0.12 V), and the manganese (Mn) cluster (Em = 0.18 V). PFV of purified iron heme protein cytochrome b-559 (Cyt b-559), a component of PSII, gave a partly reversible peak pair at 0.004 V that did not have a potential similar to any peaks observed from the intact PSII core complex. The closest peak in PSII to 0.004 V is the 0.18 V peak that was found to be associated with a two-electron process, and thus is inconsistent with iron heme protein voltammetry. The -0.47 V peak had a peak potential and peak potential-pH dependence similar to that found for purified Chl a incorporated into DMPC films. The midpoint potentials reported here may differ to various extents from previously reported redox titration data due to the influence of electrode double-layer effects. Heterogeneous electron transfer (hET) rate constants were estimated by theoretical fitting and digital simulations for the -0.47 and 0.18 V peaks. Data for the Chl a peaks were best fit to a one-electron model, while the peak assigned to the Mn cluster was best fit by a two-electron/one-proton model.

  19. 22 CFR 706.44 - What happens to business information contained in OPIC records transferred to the National...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Rights of Submitters of Confidential Business Information § 706.44 What happens to business information... 22 Foreign Relations 2 2010-04-01 2010-04-01 true What happens to business information contained in OPIC records transferred to the National Archives of the United States? 706.44 Section...

  20. 48 CFR 52.232-35 - Designation of Office for Government Receipt of Electronic Funds Transfer Information.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the office to receive the Contractor's electronic funds transfer (EFT) information, in lieu of the payment office of this contract. (b) The Contractor shall send all EFT information, and any changes to EFT information to the office designated in paragraph (c) of this clause. The Contractor shall not send...

  1. 48 CFR 52.232-35 - Designation of Office for Government Receipt of Electronic Funds Transfer Information.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... as the office to receive the Contractor's electronic funds transfer (EFT) information, in lieu of the payment office of this contract. (b) The Contractor shall send all EFT information, and any changes to EFT information to the office designated in paragraph (c) of this clause. The Contractor shall not send...

  2. 48 CFR 52.232-35 - Designation of Office for Government Receipt of Electronic Funds Transfer Information.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... as the office to receive the Contractor's electronic funds transfer (EFT) information, in lieu of the payment office of this contract. (b) The Contractor shall send all EFT information, and any changes to EFT information to the office designated in paragraph (c) of this clause. The Contractor shall not send...

  3. 48 CFR 52.232-35 - Designation of Office for Government Receipt of Electronic Funds Transfer Information.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the office to receive the Contractor's electronic funds transfer (EFT) information, in lieu of the payment office of this contract. (b) The Contractor shall send all EFT information, and any changes to EFT information to the office designated in paragraph (c) of this clause. The Contractor shall not send...

  4. Statistical physics of networks, information and complex systems

    SciTech Connect

    Ecke, Robert E

    2009-01-01

    In this project we explore the mathematical methods and concepts of statistical physics that are fmding abundant applications across the scientific and technological spectrum from soft condensed matter systems and bio-infonnatics to economic and social systems. Our approach exploits the considerable similarity of concepts between statistical physics and computer science, allowing for a powerful multi-disciplinary approach that draws its strength from cross-fertilization and mUltiple interactions of researchers with different backgrounds. The work on this project takes advantage of the newly appreciated connection between computer science and statistics and addresses important problems in data storage, decoding, optimization, the infonnation processing properties of the brain, the interface between quantum and classical infonnation science, the verification of large software programs, modeling of complex systems including disease epidemiology, resource distribution issues, and the nature of highly fluctuating complex systems. Common themes that the project has been emphasizing are (i) neural computation, (ii) network theory and its applications, and (iii) a statistical physics approach to infonnation theory. The project's efforts focus on the general problem of optimization and variational techniques, algorithm development and infonnation theoretic approaches to quantum systems. These efforts are responsible for fruitful collaborations and the nucleation of science efforts that span multiple divisions such as EES, CCS, 0 , T, ISR and P. This project supports the DOE mission in Energy Security and Nuclear Non-Proliferation by developing novel infonnation science tools for communication, sensing, and interacting complex networks such as the internet or energy distribution system. The work also supports programs in Threat Reduction and Homeland Security.

  5. Measures of Information Complexity and the Implications for Automation Design

    DTIC Science & Technology

    2004-10-01

    Miller, & Lane, 1998). Morçöl and Asche (1993) used this index to measure the creativity of persons in several social groups. The results indicated...Langton C (1991). Life at the edge of chaos. In: Langton C, Taylor C, Farmer J, Rasmussen S, eds. Proceed- ings Artifi cial Life II; Redwood City...California: Addison-Wesley; 41–91. McCabe (1976). A complexity measure. IEEE Transac- tions on Software Engineering; SE-2:308-20. Morçöl G, Asche M (1993

  6. Molecular basis of coupled protein and electron transfer dynamics of cytochrome c in biomimetic complexes.

    PubMed

    Alvarez-Paggi, Damián; Martín, Diego F; DeBiase, Pablo M; Hildebrandt, Peter; Martí, Marcelo A; Murgida, Daniel H

    2010-04-28

    Direct electron transfer (ET) of redox proteins immobilized on biomimetic or biocompatible electrodes represents an active field of fundamental and applied research. In this context, several groups have reported for a variety of proteins unexpected distance dependencies of the ET rate, whose origin remains largely speculative and controversial, but appears to be a quite general phenomenon. Here we have employed molecular dynamics (MD) simulations and electron pathway analyses to study the ET properties of cytochrome c (Cyt) electrostatically immobilized on Au coated by carboxyl-terminated alkylthiols. The MD simulations and concomitant binding energy calculations allow identification of preferred binding configurations of the oxidized and reduced Cyt which are established via different lysine residues and, thus, correspond to different orientations and dipole moments. Calculations of the electronic coupling matrices for the various Cyt/self-assembled monolayer (SAM) complexes indicate that the thermodynamically preferred protein orientations do not coincide with the orientations of optimum coupling. These findings demonstrate that the ET of the immobilized Cyt is controlled by an interplay between protein dynamics and tunneling probabilities. Protein dynamics exerts two level of tuning on the electronic coupling via reorientation (coarse) and low amplitude thermal fluctuations (fine). Upon operating the Au support as an electrode, electric-field-dependent alignment of the protein dipole moment becomes an additional determinant for the protein dynamics and thus for the overall ET rate. The present results provide a consistent molecular description of previous (spectro)electrochemical data and allow conclusions concerning the coupling of protein dynamics and ET of Cyt in physiological complexes.

  7. GAM-HEAT -- a computer code to compute heat transfer in complex enclosures. Revision 1

    SciTech Connect

    Cooper, R.E.; Taylor, J.R.; Kielpinski, A.L.; Steimke, J.L.

    1991-02-01

    The GAM-HEAT code was developed for heat transfer analyses associated with postulated Double Ended Guillotine Break Loss Of Coolant Accidents (DEGB LOCA) resulting in a drained reactor vessel. In these analyses the gamma radiation resulting from fission product decay constitutes the primary source of energy as a function of time. This energy is deposited into the various reactor components and is re- radiated as thermal energy. The code accounts for all radiant heat exchanges within and leaving the reactor enclosure. The SRS reactors constitute complex radiant exchange enclosures since there are many assemblies of various types within the primary enclosure and most of the assemblies themselves constitute enclosures. GAM-HEAT accounts for this complexity by processing externally generated view factors and connectivity matrices, and also accounts for convective, conductive, and advective heat exchanges. The code is applicable for many situations involving heat exchange between surfaces within a radiatively passive medium. The GAM-HEAT code has been exercised extensively for computing transient temperatures in SRS reactors with specific charges and control components. Results from these computations have been used to establish the need for and to evaluate hardware modifications designed to mitigate results of postulated accident scenarios, and to assist in the specification of safe reactor operating power limits. The code utilizes temperature dependence on material properties. The efficiency of the code has been enhanced by the use of an iterative equation solver. Verification of the code to date consists of comparisons with parallel efforts at Los Alamos National Laboratory and with similar efforts at Westinghouse Science and Technology Center in Pittsburgh, PA, and benchmarked using problems with known analytical or iterated solutions. All comparisons and tests yield results that indicate the GAM-HEAT code performs as intended.

  8. The effects of spontaneous activity, background noise, and the stimulus ensemble on information transfer in neurons.

    PubMed

    Chacron, Maurice J; Longtin, André; Maler, Leonard

    2003-11-01

    trial-to-trial variability of the neural response to repeated presentations of a stimulus. However, the same background noise can also increase the variability of the spike train and hence can lead to increased information transfer in the presence of background noise. Our study emphasizes how different assumptions can lead to different predictions for the information transmission of a neuron. Assumptions about the computations being performed by the system under study as well as the stimulus ensemble and background noise should therefore be carefully considered when applying information theory.

  9. Charge Transfer as a Probe for the Interfacial Properties of Quantum Dot-Ligand Complexes

    NASA Astrophysics Data System (ADS)

    Weinberg, David Joseph

    well as using quantum dots to catalyze reactions between coadsorbed molecules. The research described in this dissertation furthers the study of charge transfer as a means to more completely understand QD-molecule hybrid systems and will inform design parameters for incorporating quantum dots into light harvesting and light emitting platforms.

  10. Information transfer and criticality in the Ising model on the human connectome.

    PubMed

    Marinazzo, Daniele; Pellicoro, Mario; Wu, Guorong; Angelini, Leonardo; Cortés, Jesús M; Stramaglia, Sebastiano

    2014-01-01

    We implement the Ising model on a structural connectivity matrix describing the brain at two different resolutions. Tuning the model temperature to its critical value, i.e. at the susceptibility peak, we find a maximal amount of total information transfer between the spin variables. At this point the amount of information that can be redistributed by some nodes reaches a limit and the net dynamics exhibits signature of the law of diminishing marginal returns, a fundamental principle connected to saturated levels of production. Our results extend the recent analysis of dynamical oscillators models on the connectome structure, taking into account lagged and directional influences, focusing only on the nodes that are more prone to became bottlenecks of information. The ratio between the outgoing and the incoming information at each node is related to the the sum of the weights to that node and to the average time between consecutive time flips of spins. The results for the connectome of 66 nodes and for that of 998 nodes are similar, thus suggesting that these properties are scale-independent. Finally, we also find that the brain dynamics at criticality is organized maximally to a rich-club w.r.t. the network of information flows.

  11. Information transfer from peptide nucleic acids to RNA by template-directed syntheses

    NASA Technical Reports Server (NTRS)

    Schmidt, J. G.; Nielsen, P. E.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1997-01-01

    Peptide nucleic acids (PNAs) are uncharged analogs of DNA and RNA in which the ribose-phosphate backbone is substituted by a backbone held together by amide bonds. PNAs are interesting as models of alternative genetic systems because they form potentially informational base paired helical structures. A PNA C10 oligomer has been shown to act as template for efficient formation of oligoguanylates from activated guanosine ribonucleotides. In a previous paper we used heterosequences of DNA as templates in sequence-dependent polymerization of PNA dimers. In this paper we show that information can be transferred from PNA to RNA. We describe the reactions of activated mononucleotides on heterosequences of PNA. Adenylic, cytidylic and guanylic acids were incorporated into the products opposite their complement on PNA, although less efficiently than on DNA templates.

  12. Study of information hiding algorithm based on GHM and color transfer theory

    NASA Astrophysics Data System (ADS)

    Ren, Shuai; Mu, De-Jun; Zhang, Tao; Hu, Wei

    2009-11-01

    Taking the feature that the energy of the image would gather and spread on four components ( LL 2, LH 2, HL 2 and HH 2) in the sub-image after first-order GHM multi-wavelet-transform. And by using the color control ability of lαβ color space in color transfer theory (CTT), an information hiding algorithm based on GHM-CTT is proposed. In this way, the robust parameters are embedded in the LL 2, the hidden information is set in LH 2 and HL 2 with RAID4, and fragile sign is set in HH 2. The consistence between the embedded data bits’ order and the embedded code of the sub-image is improved by using the chaotic mapping and the genetic algorithm. Experimental results indicate that the GHM-CTT can increase the imperceptibility by 15.72% averagely and robustness by 18.89% at least.

  13. Potential energy curves crossing and low-energy charge transfer dynamics in (BeH2O)2+ complex

    NASA Astrophysics Data System (ADS)

    Sun, QiXiang; Yan, Bing

    2012-07-01

    The singlet rigid Be—O dissociation potential energy curves correlating to the first four molecular limits of (BeH2O)2+ complex were calculated using the multi-reference single and double excitation configuration interaction theory. The radial couplings of three low-lying 1A1 states were calculated and combined with adiabatic potential energy curves to investigate and charge-transfer collision dynamics by using quantum-mechanical molecular orbital close-coupling methods. It is found that the total charge-transfer cross sections are dominated by the Be+(2S)+H2O+(Ã2A1) channel. The rate coefficients in the range of 10-17-10-12 cm3/s are very sensitive to temperature below 1000 K. The complexation energy without charge-transfer was determined to be 143.6 kcal/mol, including zero-point vibration energy corrections. This is in good agreement with the previous results.

  14. Nonlinear network model analysis of vibrational energy transfer and localisation in the Fenna-Matthews-Olson complex

    PubMed Central

    Morgan, Sarah E.; Cole, Daniel J.; Chin, Alex W.

    2016-01-01

    Collective protein modes are expected to be important for facilitating energy transfer in the Fenna-Matthews-Olson (FMO) complex of photosynthetic green sulphur bacteria, however to date little work has focussed on the microscopic details of these vibrations. The nonlinear network model (NNM) provides a computationally inexpensive approach to studying vibrational modes at the microscopic level in large protein structures, whilst incorporating anharmonicity in the inter-residue interactions which can influence protein dynamics. We apply the NNM to the entire trimeric FMO complex and find evidence for the existence of nonlinear discrete breather modes. These modes tend to transfer energy to the highly connected core pigments, potentially opening up alternative excitation energy transfer routes through their influence on pigment properties. Incorporating localised modes based on these discrete breathers in the optical spectra calculations for FMO using ab initio site energies and excitonic couplings can substantially improve their agreement with experimental results. PMID:27827409

  15. Nonlinear network model analysis of vibrational energy transfer and localisation in the Fenna-Matthews-Olson complex

    NASA Astrophysics Data System (ADS)

    Morgan, Sarah E.; Cole, Daniel J.; Chin, Alex W.

    2016-11-01

    Collective protein modes are expected to be important for facilitating energy transfer in the Fenna-Matthews-Olson (FMO) complex of photosynthetic green sulphur bacteria, however to date little work has focussed on the microscopic details of these vibrations. The nonlinear network model (NNM) provides a computationally inexpensive approach to studying vibrational modes at the microscopic level in large protein structures, whilst incorporating anharmonicity in the inter-residue interactions which can influence protein dynamics. We apply the NNM to the entire trimeric FMO complex and find evidence for the existence of nonlinear discrete breather modes. These modes tend to transfer energy to the highly connected core pigments, potentially opening up alternative excitation energy transfer routes through their influence on pigment properties. Incorporating localised modes based on these discrete breathers in the optical spectra calculations for FMO using ab initio site energies and excitonic couplings can substantially improve their agreement with experimental results.

  16. Faster Interprotein Electron Transfer in a [Myoglobin, b(5)] Complex with a Redesigned Interface

    SciTech Connect

    Xiong, P.; Nocek, J.M.; Vura-Weis, Josh; Lockard, Jenny V.; Wasielewski, Michael R; Hoffman, Brian M.

    2010-11-18

    Direct measurements of electron transfer (ET) within a protein-protein complex with a redesigned interface formed by physiological partner proteins myoglobin (Mb) and cytochrome b5 (b5) reveal interprotein ET rates comparable to those observed within the photosynthetic reaction center. Brownian dynamics simulations show that Mb in which three surface acid residues are mutated to lysine binds b5 in an ensemble of configurations distributed around a reactive most-probable structure. Correspondingly, charge-separation ET from a photoexcited singlet zinc porphyrin incorporated within Mb to the heme of b5 and the follow-up charge-recombination exhibit distributed kinetics, with median rate constants, ksf = 2.1 × 109 second-1 and ksb = 4.3 × 1010 second-1, respectively. The latter approaches that for the initial step in photosynthetic charge separation, k = 3.3 × 1011 second-1.

  17. Influence of tailored MLI for complex surface geometries on heat transfer

    NASA Astrophysics Data System (ADS)

    Neumann, H.; Mayrhofer, R.; Richter, T.

    2015-12-01

    Complex, non-developable surfaces require a tailored multi-layer insulation (MLI) for lowest heat load. The most experiments showing the heat transfer through MLI are performed under quasi-ideal conditions determining the principle insulation quality. But the surface to be insulated in real cryostats implies feed-throughs and other non-developable surface parts. The thermal performance of MLI is degraded significantly at cutting points. To investigate this degrading effect a LN2-filled cylinder with a diameter of 219 mm and a length of 1820 mm was insulated with MLI and the heat load was measured by means of calorimetry. In addition the heat load to an insulated cylinder with eighteen branches was measured. Both cylinders have the same surface of 1.37 m2 for a comparison of the results. This article describes the experiments with different ways of tailoring the MLI for the cylinder with branches and discusses their results. It was shown that the cutting points at the branches have a significant degrading influence on the thermal performance of MLI.

  18. Resonant transfer of one- and two-photon excitations in quantum dot-bacteriorhodopsin complexes

    NASA Astrophysics Data System (ADS)

    Krivenkov, V. A.; Samokhvalov, P. S.; Bilan, R. S.; Chistyakov, A. A.; Nabiev, I. R.

    2017-01-01

    Light-sensitive protein bacteriorhodopsin (BR), which is capable of electrical response upon exposure to light, is a promising material for photovoltaics and optoelectronics. However, the rather narrow absorption spectrum of BR does not allow achieving efficient conversion of the light energy in the blue and infrared spectral regions. This paper summarizes the results of studies showing the possibility of extending the spectral region of the BR function by means of the Förster resonance energy transfer (FRET) from CdSe/ZnS quantum dots (QDs), which have a broad spectrum of one-photon absorption and a large twophoton absorption cross section (TPACS), to BR upon one- and two-photon excitation. In particular, it is shown that, on the basis of QDs and BR-containing purple membranes, it is possible to create electrostatically associated bio-nano hybrid systems in which FRET is implemented. In addition, the large TPACS of QDs, which is two orders of magnitude larger than those of BR and organic dyes, opens up a means for selective two-photon excitation of synthesized bio-nano hybrid complexes. On the basis of the results of this work, the spectral region in which BR converts the light energy into electrical energy can be extended from the UV to near-IR region, creating new opportunities for the use of this material in photovoltaics and optoelectronics.

  19. Oxygen atom transfer reactions from Mimoun complexes to sulfides and sulfoxides. A bonding evolution theory analysis.

    PubMed

    González-Navarrete, Patricio; Sensato, Fabricio R; Andrés, Juan; Longo, Elson

    2014-08-07

    In this research, a comprehensive theoretical investigation has been conducted on oxygen atom transfer (OAT) reactions from Mimoun complexes to sulfides and sulfoxides. The joint use of the electron localization function (ELF) and Thom's catastrophe theory (CT) provides a powerful tool to analyze the evolution of chemical events along a reaction pathway. The progress of the reaction has been monitored by structural stability domains from ELF topology while the changes between them are controlled by turning points derived from CT which reveal that the reaction mechanism can be separated in several steps: first, a rupture of the peroxo O1-O2 bond, then a rearrangement of lone pairs of the sulfur atom occurs and subsequently the formation of S-O1 bond. The OAT process involving the oxidation of sulfides and sulfoxides is found to be an asynchronous process where O1-O2 bond breaking and S-O1 bond formation processes do not occur simultaneously. Nucleophilic/electrophilic characters of both dimethyl sulfide and dimethyl sulfoxide, respectively, are sufficiently described by our results, which hold the key to unprecedented insight into the mapping of electrons that compose the bonds while the bonds change.

  20. Competition between covalent bonding and charge transfer tendencies at complex-oxides interfaces

    NASA Astrophysics Data System (ADS)

    Salafranca, J.; Tornos, J.; García-Barriocanal, J.; León, C.; Santamaria, J.; Rincón, J.; Álvarez, G.; Pennycook, S. J.; Dagotto, E.; Varela, M.

    2013-03-01

    Interfaces alter the subtle balance among different degrees of freedom responsible for exotic phenomena in complex oxides, such as cuprate-manganite interfaces. We study these interfaces by means of scanning transmission electron microscopy and theoretical calculations. Microscopy and EEL spectroscopy indicate that the interfaces are sharp, and the chemical profile is symmetric with two equivalent interfaces. Spectroscopy also allows us to establish an oxidation state profile with sub-nanometer resolution. We find an anomalous charge redistribution: a non-monotonic behavior of the occupancy of d orbitals in the manganite layers as a function of distance to the interface. Relying on model calculations, we establish that this profile is a result of the competition between standard charge transfer tendencies involving materials with different chemical potentials and strong bonding effects across the interface. The competition can be tuned by different factors (temperature, doping, magnetic fields...). As examples, we report different charge distributions as a function of doping of the manganite layers. ACKNOWLEDGEMENTS ORNL:U.S. DOE-BES, Material Sciences and Engineering Division & ORNL's ShaRE. UCM:Juan de la Cierva, Ramon y Cajal, & ERC Starting Investigator Award programs.

  1. Transference of Traditional Versus Complex Strength and Power Training to Sprint Performance

    PubMed Central

    Loturco, Irineu; Tricoli, Valmor; Roschel, Hamilton; Nakamura, Fabio Yuzo; Cal Abad, Cesar Cavinato; Kobal, Ronaldo; Gil, Saulo; González-Badillo, Juan José

    2014-01-01

    The purpose of this study was to determine the effects of two different strength-power training models on sprint performance. Forty-eight soldiers of the Brazilian brigade of special operations with at least one year of army training experience were divided into a control group (CG: n = 15, age: 20.2 ± 0.7 years, body height: 1.74 ± 0.06 m, and body mass: 66.7 ± 9.8 kg), a traditional training group (TT: n = 18, age: 20.1 ± 0.7 years, body height: 1.71 ± 0.05 m, and body mass: 64.2 ± 4.7 kg), and a complex training group (CT: n = 15, age: 20.3 ± 0.8 years, body height: 1.71 ± 0.07 m; and body mass: 64.0 ± 8.8 kg). Maximum strength (25% and 26%), CMJ height (36% and 39%), mean power (30% and 35%) and mean propulsive power (22% and 28%) in the loaded jump squat exercise, and 20-m sprint speed (16% and 14%) increased significantly (p≤0.05) following the TT and CT, respectively. However, the transfer effect coefficients (TEC) of strength and power performances to 20-m sprint performance following the TT were greater than the CT throughout the 9-week training period. Our data suggest that TT is more effective than CT to improve sprint performance in moderately trained subjects. PMID:25114753

  2. Side chain effects in reactions of the potassium-tyrosine charge transfer complex

    NASA Astrophysics Data System (ADS)

    da Silva, F. Ferreira; Meneses, G.; Ingólfsson, O.; Limão-Vieira, P.

    2016-10-01

    Fragmentation of transient negative ions of tyrosine formed through electron transfer in collisions with neutral potassium atoms is presented in the collision energy range from 30 to 75 eV. At low collision energies the dominating side chain channel observed corresponds to the cleavage of the bond from the para-position of the phenyl ring to the β-C of the remaining moiety, but cleavage of the Cαsbnd Cβ bond is also observed. Further fragments are formed through cleavage of the Cα bond to the carbonyl group, through decomposition of the carboxyl group or through significant decomposition of the backbone. The dehydrogenated molecular anion is also observed with appreciable intensity. These results are discussed in the context of earlier studies on dissociative electron attachment to tyrosine and other amino acids, as well as within the role of the side chain in electron induced decomposition of this aromatic amino acid. Stabilization of the temporary molecular anion in the transient collision complex is discussed and we argue that this may have significant influence on the branching ratios observed.

  3. Frequency dependent magneto-transport in charge transfer Co(II) complex

    NASA Astrophysics Data System (ADS)

    Shaw, Bikash Kumar; Saha, Shyamal K.

    2014-09-01

    A charge transfer chelated system containing ferromagnetic metal centers is the ideal system to investigate the magneto-transport and magneto-dielectric effects due to the presence of both electronic as well as magnetic properties and their coupling. Magneto-transport properties in materials are usually studied through dc charge transport under magnetic field. As frequency dependent conductivity is an essential tool to understand the nature of carrier wave, its spatial extension and their mutual interaction, in the present work, we have investigated frequency dependent magneto-transport along with magnetization behavior in [Co2(II)-(5-(4-PhMe)-1,3,4-oxadiazole-H+-2-thiolate)5](OAc)4 metal complex to elucidate the nature of above quantities and their response under magnetic field in the transport property. We have used the existing model for ac conduction incorporating the field dependence to explain the frequency dependent magneto-transport. It is seen that the frequency dependent magneto-transport could be well explained using the existing model for ac conduction.

  4. The reaction of an iridium PNP complex with parahydrogen facilitates polarisation transfer without chemical change.

    PubMed

    Holmes, Arthur J; Rayner, Peter J; Cowley, Michael J; Green, Gary G R; Whitwood, Adrian C; Duckett, Simon B

    2015-01-21

    The short lived pincer complex [(C5H3N(CH2P((t)Bu)2)2)Ir(H)2(py)]BF4 is shown to be active for signal amplification by reversible exchange. This catalyst formulation enables the efficient transfer of polarization from parahydrogen to be placed into just a single molecule of the hyperpolarisation target, pyridine. When the catalysts (1)H nuclei are replaced by (2)H, increased levels of substrate hyperpolarization result and when the reverse situation is examined the catalyst itself is clearly visible through hyperpolarised signals. The ligand exchange pathways of [(C5H3N(CH2P((t)Bu)2)2)Ir(H)2(py)]BF4 that are associated with this process are shown to involve the formation of 16-electron [(C5H3N(CH2P((t)Bu)2)2)Ir(H)2]BF4 and the 18-electron H2 addition product [(C5H3N(CH2P((t)Bu)2)2)Ir(H)2(H2)]BF4.

  5. Triplet-triplet energy transfer from chlorophylls to carotenoids in two antenna complexes from dinoflagellate Amphidinium carterae.

    PubMed

    Kvíčalová, Zuzana; Alster, Jan; Hofmann, Eckhard; Khoroshyy, Petro; Litvín, Radek; Bína, David; Polívka, Tomáš; Pšenčík, Jakub

    2016-04-01

    Room temperature transient absorption spectroscopy with nanosecond resolution was used to study quenching of the chlorophyll triplet states by carotenoids in two light-harvesting complexes of the dinoflagellate Amphidinium carterae: the water soluble peridinin-chlorophyll protein complex and intrinsic, membrane chlorophyll a-chlorophyll c2-peridinin protein complex. The combined study of the two complexes facilitated interpretation of a rather complicated relaxation observed in the intrinsic complex. While a single carotenoid triplet state was resolved in the peridinin-chlorophyll protein complex, evidence of at least two different carotenoid triplets was obtained for the intrinsic light-harvesting complex. Most probably, each of these carotenoids protects different chlorophylls. In both complexes the quenching of the chlorophyll triplet states by carotenoids occurs with a very high efficiency (~100%), and with transfer times estimated to be in the order of 0.1ns or even faster. The triplet-triplet energy transfer is thus much faster than formation of the chlorophyll triplet states by intersystem crossing. Since the triplet states of chlorophylls are formed during the whole lifetime of their singlet states, the apparent lifetimes of both states are the same, and observed to be equal to the carotenoid triplet state rise time (~5ns).

  6. Spectroscopic studies and molecular orbital calculations of charge transfer complexation between 3,5-dimethylpyrazole with DDQ in acetonitrile.

    PubMed

    Habeeb, Moustafa M; Al-Attas, Amirah S; Al-Raimi, Doaa S

    2015-05-05

    Charge transfer (CT) interaction between 3,5-dimethylpyrazole (DMP) with the π-acceptor 2,3-dichloro-5,6-dicyano-p-benzoquinon (DDQ) has been investigated spectrophotometrically in acetonitrile (AN). Simultaneous reddish brown color has been observed upon mixing donor with acceptor solutions attributing to CT complex formation. The electronic spectra of the formed complex exhibited multi-charge transfer bands at 429, 447, 506, 542 and 589nm, respectively. Job(')s method of continuous variations and spectrophotometric titration methods confirmed the formation of the studied complex in 1:2 ratio between DMP and DDQ. Benesi-Hildebrand equation has been applied to calculate the stability constant of the formed complex where it recorded high value supporting formation of stable complex. Molecular orbital calculations using MM2 method and GAMESS (General Atomic and Molecular Electronic Structure System) interface computations as a package of ChemBio3D Ultra12 software were carried out for more analysis of the formed complex in the gas phase. The computational analysis included energy minimisation, stabilisation energy, molecular geometry, Mullikan charges, molecular electrostatic potential (MEP) surfaces of reactants and complex as well as characterization of the higher occupied molecular orbitals (HOMO) and lower unoccupied molecular orbitals (LUMO) surfaces of the complex. A good consistency between experimental and theoretical results has been recorded.

  7. Highly efficient energy transfer from a carbonyl carotenoid to chlorophyll a in the main light harvesting complex of Chromera velia.

    PubMed

    Durchan, Milan; Keşan, Gürkan; Slouf, Václav; Fuciman, Marcel; Staleva, Hristina; Tichý, Josef; Litvín, Radek; Bína, David; Vácha, František; Polívka, Tomáš

    2014-10-01

    We report on energy transfer pathways in the main light-harvesting complex of photosynthetic relative of apicomplexan parasites, Chromera velia. This complex, denoted CLH, belongs to the family of FCP proteins and contains chlorophyll (Chl) a, violaxanthin, and the so far unidentified carbonyl carotenoid related to isofucoxanthin. The overall carotenoid-to-Chl-a energy transfer exhibits efficiency over 90% which is the largest among the FCP-like proteins studied so far. Three spectroscopically different isofucoxanthin-like molecules were identified in CLH, each having slightly different energy transfer efficiency that increases from isofucoxanthin-like molecules absorbing in the blue part of the spectrum to those absorbing in the reddest part of spectrum. Part of the energy transfer from carotenoids proceeds via the ultrafast S2 channel of both the violaxanthin and isofucoxanthin-like carotenoid, but major energy transfer pathway proceeds via the S1/ICT state of the isofucoxanthin-like carotenoid. Two S1/ICT-mediated channels characterized by time constants of ~0.5 and ~4ps were found. For the isofucoxanthin-like carotenoid excited at 480nm the slower channel dominates, while those excited at 540nm employs predominantly the fast 0.5ps channel. Comparing these data with the excited-state properties of the isofucoxanthin-like carotenoid in solution we conclude that, contrary to other members of the FCP family employing carbonyl carotenoids, CLH complex suppresses the charge transfer character of the S1/ICT state of the isofucoxanthin-like carotenoid to achieve the high carotenoid-to-Chl-a energy transfer efficiency.

  8. Making sense in a complex landscape: how the Cynefin Framework from Complex Adaptive Systems Theory can inform health promotion practice.

    PubMed

    Van Beurden, Eric K; Kia, Annie M; Zask, Avigdor; Dietrich, Uta; Rose, Lauren

    2013-03-01

    Health promotion addresses issues from the simple (with well-known cause/effect links) to the highly complex (webs and loops of cause/effect with unpredictable, emergent properties). Yet there is no conceptual framework within its theory base to help identify approaches appropriate to the level of complexity. The default approach favours reductionism--the assumption that reducing a system to its parts will inform whole system behaviour. Such an approach can yield useful knowledge, yet is inadequate where issues have multiple interacting causes, such as social determinants of health. To address complex issues, there is a need for a conceptual framework that helps choose action that is appropriate to context. This paper presents the Cynefin Framework, informed by complexity science--the study of Complex Adaptive Systems (CAS). It introduces key CAS concepts and reviews the emergence and implications of 'complex' approaches within health promotion. It explains the framework and its use with examples from contemporary practice, and sets it within the context of related bodies of health promotion theory. The Cynefin Framework, especially when used as a sense-making tool, can help practitioners understand the complexity of issues, identify appropriate strategies and avoid the pitfalls of applying reductionist approaches to complex situations. The urgency to address critical issues such as climate change and the social determinants of health calls for us to engage with complexity science. The Cynefin Framework helps practitioners make the shift, and enables those already engaged in complex approaches to communicate the value and meaning of their work in a system that privileges reductionist approaches.

  9. Vesicles derived via AP-3 dependent recycling contribute to asynchronous release and influence information transfer

    PubMed Central

    Evstratova, Alesya; Chamberland, Simon; Faundez, Victor; Tóth, Katalin

    2014-01-01

    Summary Action potentials trigger synchronous and asynchronous neurotransmitter release. Temporal properties of both types of release could be altered in an activity-dependent manner. While the effects of activity-dependent changes in synchronous release on postsynaptic signal integration have been studied, the contribution of asynchronous release to information transfer during natural stimulus patterns is unknown. Here we find that during trains of stimulations, asynchronous release contributes to the precision of action potential firing. Our data show that this form of release is selectively diminished in AP-3b2 KO animals, which lack functional neuronal AP-3, an adaptor protein regulating vesicle formation from endosomes generated during bulk endocytosis. We find that in the absence of neuronal AP-3, asynchronous release is attenuated and the activity-dependent increase in the precision of action potential timing is compromised. Lack of asynchronous release decreases the capacity of synaptic information transfer and renders synaptic communication less reliable in response to natural stimulus patterns. PMID:25410111

  10. Synthesis, characterization, and application of vanadium-salan complexes in oxygen transfer reactions.

    PubMed

    Adão, Pedro; Costa Pessoa, João; Henriques, Rui T; Kuznetsov, Maxim L; Avecilla, Fernando; Maurya, Mannar R; Kumar, Umesh; Correia, Isabel

    2009-04-20

    We report the synthesis and characterization of several chiral salen- and salan-type ligands and their vanadium complexes, which are derived from salicylaldehyde or salicylaldehyde derivatives and chiral diamines (1R,2R-diaminocyclohexane, 1S,2S-diaminocyclohexane, and 1S,2S-diphenylethylenediamine). The structures of H(2)sal(R,R-chan)(2+) x 2 Cl(-) x (CH(3))(2)CHOH x H(2)O (1c; H(2)sal(R,R-chan) = N,N'-salicyl-R,R-cyclohexanediaminium), Etvan(S,S-chen) (3c; Etvan(S,S-chen) = N,N'-3-ethoxy-salicylidene-S,S-cyclohexanediiminato), and naph(R,R-chen) (6c; naph(R,R-chen) = N,N'-naphthylidene-R,R-cyclohexanediiminato) were determined by single-crystal X-ray diffraction. The corresponding vanadium(IV) complexes and several other new complexes involving different salicylaldehyde-type precursors were prepared and characterized in the solid state and in solution by spectroscopic techniques: UV-vis, circular dichroism, electron paramagnetic resonance, and (51)V NMR, which provide information on the coordination geometry. The salan complexes oxidize in organic solvents to V(V) species, and this process was also studied using spectroscopic techniques. Single crystals suitable for X-ray diffraction were obtained for [{V(V)O[sal(S,S-dpan)]}(2)(mu-O)] x H(2)O x 2(CH(3))(2)CHOH (14c; sal(S,S-dpan) = N,N'-salicyl-S,S-diphenylethylenediaminato) and [{V(V)O[t-Busal(R,R-chan)]}(2)(mu-O)] x 2 (CH(3))(2)CHOH (15c), both containing an OV(V)(mu-O)V(V)O moiety (V(2)O(3)(4+) core) with tetradentate ligands and one mu-oxo bridge. Both structures are the first examples of dinuclear vanadium complexes involving the V(V)(2)O(3)(4+) core with tetradentate ligands, the configuration of the V(2)O(3) unit being twist-angular. The V-salen and V-salan complexes are tested as catalysts in the oxidation of styrene, cyclohexene, cumene, and methyl phenyl sulfide with H(2)O(2) and t-BuOOH as oxidants. Overall, the V-salan complexes show higher activity and normally better selectivity in alkene oxidation

  11. Quantifying information transfer by protein domains: Analysis of the Fyn SH2 domain structure

    PubMed Central

    Lenaerts, Tom; Ferkinghoff-Borg, Jesper; Stricher, Francois; Serrano, Luis; Schymkowitz, Joost WH; Rousseau, Frederic

    2008-01-01

    Background Efficient communication between distant sites within a protein is essential for cooperative biological response. Although often associated with large allosteric movements, more subtle changes in protein dynamics can also induce long-range correlations. However, an appropriate formalism that directly relates protein structural dynamics to information exchange between functional sites is still lacking. Results Here we introduce a method to analyze protein dynamics within the framework of information theory and show that signal transduction within proteins can be considered as a particular instance of communication over a noisy channel. In particular, we analyze the conformational correlations between protein residues and apply the concept of mutual information to quantify information exchange. Mapping out changes of mutual information on the protein structure then allows visualizing how distal communication is achieved. We illustrate the approach by analyzing information transfer by the SH2 domain of Fyn tyrosine kinase, obtained from Monte Carlo dynamics simulations. Our analysis reveals that the Fyn SH2 domain forms a noisy communication channel that couples residues located in the phosphopeptide and specificity binding sites and a number of residues at the other side of the domain near the linkers that connect the SH2 domain to the SH3 and kinase domains. We find that for this particular domain, communication is affected by a series of contiguous residues that connect distal sites by crossing the core of the SH2 domain. Conclusion As a result, our method provides a means to directly map the exchange of biological information on the structure of protein domains, making it clear how binding triggers conformational changes in the protein structure. As such it provides a structural road, next to the existing attempts at sequence level, to predict long-range interactions within protein structures. PMID:18842137

  12. Maximum likelihood: Extracting unbiased information from complex networks

    NASA Astrophysics Data System (ADS)

    Garlaschelli, Diego; Loffredo, Maria I.

    2008-07-01

    The choice of free parameters in network models is subjective, since it depends on what topological properties are being monitored. However, we show that the maximum likelihood (ML) principle indicates a unique, statistically rigorous parameter choice, associated with a well-defined topological feature. We then find that, if the ML condition is incompatible with the built-in parameter choice, network models turn out to be intrinsically ill defined or biased. To overcome this problem, we construct a class of safely unbiased models. We also propose an extension of these results that leads to the fascinating possibility to extract, only from topological data, the “hidden variables” underlying network organization, making them “no longer hidden.” We test our method on World Trade Web data, where we recover the empirical gross domestic product using only topological information.

  13. Mechanistic studies of photoinduced spin crossover and electron transfer in inorganic complexes.

    PubMed

    Zhang, Wenkai; Gaffney, Kelly J

    2015-04-21

    Electronic excited-state phenomena provide a compelling intersection of fundamental and applied research interests in the chemical sciences. This holds true for coordination chemistry, where harnessing the strong optical absorption and photocatalytic activity of compounds depends on our ability to control fundamental physical and chemical phenomena associated with the nonadiabatic dynamics of electronic excited states. The central events of excited-state chemistry can critically influence the dynamics of electronic excited states, including internal conversion (transitions between distinct electronic states) and intersystem crossing (transitions between electronic states with different spin multiplicities), events governed by nonadiabatic interactions between electronic states in close proximity to conical intersections, as well as solvation and electron transfer. The diversity of electronic and nuclear dynamics also makes the robust interpretation of experimental measurements challenging. Developments in theory, simulation, and experiment can all help address the interpretation and understanding of chemical dynamics in organometallic and coordination chemistry. Synthesis presents the opportunity to chemically engineer the strength and symmetry of the metal-ligand interactions. This chemical control can be exploited to understand the influence of electronic ground state properties on electronic excited-state dynamics. New time-resolved experimental methods and the insightful exploitation of established methods have an important role in understanding, and ideally controlling, the photophysics and photochemistry of transition metal complexes. Techniques that can disentangle the coupled motion of electrons and nuclear dynamics warrant emphasis. We present a review of electron localization dynamics in charge transfer excited states and the dynamics of photoinitiated spin crossover dynamics. Both electron localization and spin crossover have been investigated by

  14. IR, 1H NMR, mass, XRD and TGA/DTA investigations on the ciprofloxacin/iodine charge-transfer complex

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; El-Hawary, W. F.; Moussa, Mohamed A. A.

    2011-05-01

    The charge-transfer complex (CTC) of ciprofloxacin drug (CIP) as a donor with iodine (I 2) as a sigma acceptor has been studied spectrophotometrically in CHCl 3. At maximum absorption bands, the stoichiometry of CIP:iodine system was found to be 1:1 ratio according to molar ratio method. The essential spectroscopic data like formation constant ( KCT), molar extinction coefficient ( ɛCT), standard free energy (Δ G°), oscillator strength ( f), transition dipole moment ( μ), resonance energy ( RN) and ionization potential ( ID) were estimated. The spectroscopic techniques such as IR, 1H NMR, mass and UV-vis spectra and elemental analyses (CHN) as well as TG-DTG and DTA investigations were used to characterize the chelating behavior of CIP/iodine charge-transfer complex. The iodine CT interaction was associated with a presence of intermolecular hydrogen bond. The X-ray investigation was carried out to investigate the iodine doping in the synthetic CT complex.

  15. Human machine interaction via the transfer of power and information signals

    NASA Technical Reports Server (NTRS)

    Kazerooni, H.; Foslien, W. K.; Anderson, B. J.; Hessburg, T. M.

    1989-01-01

    Robot manipulators are designed to perform tasks which would otherwise be executed by a human operator. No manipulator can even approach the speed and accuracy with which humans execute these tasks. But manipulators have the capability to exceed human ability in one particular area: strength. Through any reasonable observation and experience, the human's ability to perform a variety of physical tasks is limited not by his intelligence, but by his physical strength. If, in the appropriate environment, we can more closely integrate the mechanical power of a machine with intellectually driven human hand under the supervisory control of the human's intellect, we will then have a system which is superior to a loosely-integrated combination of a human and his fully automated robot as in the present day robotic systems. We must therefore develop a fundamental approach to the problem of this extending human mechanical power in certain environments. Extenders will be a class of robots worn by humans to increase human mechanical ability, while the wearer's intellect remains the central intelligent control system for manipulating the extender. The human body, in physical contact with the extender, exchanges information signals and power with the extender. Commands are transferred to the extender via the contact forces between the wearer and the extender as opposed to use of joystick (master arm), push-button or key-board to execute such commands that were used in previous man amplifiers. Instead, the operator becomes an integral part of the extender while executing the task. In this unique configuration the mechanical power transfer between the human and extender occurs in addition to information signal transfer. When the wearer uses the extender to touch and manipulate an object, the extender transfers to the wearer's hand, in feedback fashion, a scaled-down value of the actual external load which the extender is manipulating. This natural feedback force on the wearer's hand

  16. Supramolecular chemistry: from molecular information towards self-organization and complex matter

    NASA Astrophysics Data System (ADS)

    Lehn, Jean-Marie

    2004-03-01

    Molecular chemistry has developed a wide range of very powerful procedures for constructing ever more sophisticated molecules from atoms linked by covalent bonds. Beyond molecular chemistry lies supramolecular chemistry, which aims at developing highly complex chemical systems from components interacting via non-covalent intermolecular forces. By the appropriate manipulation of these interactions, supramolecular chemistry became progressively the chemistry of molecular information, involving the storage of information at the molecular level, in the structural features, and its retrieval, transfer, and processing at the supramolecular level, through molecular recognition processes operating via specific interactional algorithms. This has paved the way towards apprehending chemistry also as an information science. Numerous receptors capable of recognizing, i.e. selectively binding, specific substrates have been developed, based on the molecular information stored in the interacting species. Suitably functionalized receptors may perform supramolecular catalysis and selective transport processes. In combination with polymolecular organization, recognition opens ways towards the design of molecular and supramolecular devices based on functional (photoactive, electroactive, ionoactive, etc) components. A step beyond preorganization consists in the design of systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined supramolecular architectures by self-assembly from their components. Self-organization processes, directed by the molecular information stored in the components and read out at the supramolecular level through specific interactions, represent the operation of programmed chemical systems. They have been implemented for the generation of a variety of discrete functional architectures of either organic or inorganic nature. Self-organization processes also give access to advanced supramolecular materials, such as

  17. The Influence of Information Acquisition on the Complex Dynamics of Market Competition

    NASA Astrophysics Data System (ADS)

    Guo, Zhanbing; Ma, Junhai

    In this paper, we build a dynamical game model with three bounded rational players (firms) to study the influence of information on the complex dynamics of market competition, where useful information is about rival’s real decision. In this dynamical game model, one information-sharing team is composed of two firms, they acquire and share the information about their common competitor, however, they make their own decisions separately, where the amount of information acquired by this information-sharing team will determine the estimation accuracy about the rival’s real decision. Based on this dynamical game model and some creative 3D diagrams, the influence of the amount of information on the complex dynamics of market competition such as local dynamics, global dynamics and profits is studied. These results have significant theoretical and practical values to realize the influence of information.

  18. Fresh look at electron-transfer mechanisms via the donor/acceptor bindings in the critical encounter complex.

    PubMed

    Rosokha, Sergiy V; Kochi, Jay K

    2008-05-01

    Seminal insights provided by the iconic R. S. Mulliken and his "charge-transfer" theory, H. Taube and his "outer/inner-sphere" mechanisms, R. A. Marcus and his "two-state non-adiabatic" theory, and N. S. Hush and his "intervalence" theory are each separately woven into the rich panoramic tapestry constituting chemical research into electron-transfer dynamics, and its mechanistic dominance for the past half century and more. In this Account, we illustrate how the simultaneous melding of all four key concepts allows sharp focus on the charge-transfer character of the critical encounter complex to evoke the latent facet of traditional electron-transfer mechanisms. To this end, we exploit the intervalence (electronic) transition that invariably accompanies the diffusive encounter of electron-rich organic donors (D) with electron-poor acceptors (A) as the experimental harbinger of the collision complex, which is then actually isolated and X-ray crystallographically established as loosely bound pi-stacked pairs of various aromatic and olefinic donor/acceptor dyads with uniform interplanar separations of r(DA) = 3.1 +/- 0.2 A. These X-ray structures, together with the spectral measurements of their intervalence transitions, lead to the pair of important electron-transfer parameters, H(DA) (electronic coupling element) versus lambdaT (reorganization energy), the ratio of which generally defines the odd-electron mobility within such an encounter complex in terms of the resonance stabilization of the donor/acceptor assembly [D, A] as opposed to the reorganization-energy penalty required for its interconversion to the electron-transfer state [D(+*), A(-*)]. We recognize the resonance-stabilization energy relative to the intrinsic activation barrier as the mechanistic binding factor, Q = 2H(DA)/lambdaT, to represent the quantitative measure of the highly variable continuum of inner-sphere/outer-sphere interactions that are possible within various types of precursor complexes

  19. Sequential energy and charge transfer processes in mixed host-guest complexes of subphthalocyanine, porphyrin and phthalocyanine chromophores.

    PubMed

    Menting, Roel; Ng, Dennis K P; Röder, Beate; Ermilov, Eugeny A

    2012-11-14

    Porphyrins, phthalocyanines and subphthalocyanines are three attractive classes of chromophores with intriguing properties making them suitable for the design of artificial photosynthetic systems. The assembly of these components by a supramolecular approach is of particular interest as it provides a facile means to build multi-chromophoric arrays with various architectures and tuneable photophysical properties. In this paper, we show the formation of mixed host-guest supramolecular complexes that consist of a β-cyclodextrin-conjugated subphthalocyanine, a tetrasulfonated porphyrin and a series of silicon(IV) phthalocyanines substituted axially with two β-cyclodextrins via different spacers. We found that the three components form supramolecular complexes held by host-guest interactions in aqueous solution. Upon excitation of the subphthalocyanine part of the complex, the excitation energy is delivered to the phthalocyanine unit via excitation energy transfer and the porphyrin chromophore acts as an energy transfer bridge enabling this process. It was shown that photo-induced charge transfer also takes place. A sequential electron transfer process from the porphyrin unit to the phthalocyanine moiety and subsequently from the subphthalocyanine moiety to the porphyrin unit takes place, and the probability of this process is controlled by the linker between β-cyclodextrin and phthalocyanine. The lifetime of the charge-separated state was found to be 1.7 ns by transient absorption spectroscopy.

  20. Efficient light-harvesting using non-carbonyl carotenoids: Energy transfer dynamics in the VCP complex from Nannochloropsis oceanica.

    PubMed

    Keşan, Gürkan; Litvín, Radek; Bína, David; Durchan, Milan; Šlouf, Václav; Polívka, Tomáš

    2016-04-01

    Violaxanthin-chlorophyll a protein (VCP) from Nannochloropsis oceanica is a Chl a-only member of the LHC family of light-harvesting proteins. VCP binds carotenoids violaxanthin (Vio), vaucheriaxanthin (Vau), and vaucheriaxanthin-ester (Vau-ester). Here we report on energy transfer pathways in the VCP complex. The overall carotenoid-to-Chla energy transfer has efficiency over 90%. Based on their energy transfer properties, the carotenoids in VCP can be divided into two groups; blue carotenoids with the lowest energy absorption band around 480nm and red carotenoids with absorption extended up to 530nm. Both carotenoid groups transfer energy efficiently from their S2 states, reaching efficiencies of ~70% (blue) and ~60% (red). The S1 pathway, however, is efficient only for the red carotenoid pool for which two S1 routes characterized by 0.33 and 2.4ps time constants were identified. For the blue carotenoids the S1-mediated pathway is represented only by a minor route likely involving a hot S1 state. The relaxed S1 state of blue carotenoids decays to the ground state within 21ps. Presence of a fraction of non-transferring red carotenoids with the S1 lifetime of 13ps indicates some specific carotenoid-protein interaction that must shorten the intrinsic S1 lifetime of Vio and/or Vau whose S1 lifetimes in methanol are 26 and 29ps, respectively. The VCP complex from N. oceanica is the first example of a light-harvesting complex binding only non-carbonyl carotenoids with carotenoid-to-chlorophyll energy transfer efficiency over 90%.