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Sample records for complexes conformational influences

  1. S-Adenosylmethionine conformations in solution and in protein complexes: Conformational influences of the sulfonium group

    DEFF Research Database (Denmark)

    Markham, George D.; Norrby, Per-Ola; Bock, Charles W.

    2002-01-01

    S-Adenosylmethionine (AdoMet) and other sulfonium ions play central roles in the metabolism of all organisms. The conformational preferences of AdoMet and two other biologically important sulfonium ions, S-methylmethionine and dimethylsulfonioproprionic acid, have been investigated by NMR...... and computational studies. Molecular mechanics parameters for the sulfonium center have been developed for the AMBER force field to permit analysis of NMR results and to enable comparison of the relative energies of the different conformations of AdoMet that have been found in crystal structures of complexes...... with proteins. S-Methylmethionine and S-dimethylsulfonioproprionate adopt a variety of conformations in aqueous solution; a conformation with an electrostatic interaction between the sulfonium sulfur and the carboxylate group is not noticeably favored, in contrast to the preferred conformation found by in vacuo...

  2. [Influence of LDAO on the conformation and release of bacteriochlorophyll of peripheral light-harvesting complex (LH2) from Rhodobacter azotoformans].

    Science.gov (United States)

    Zhao, Gen-gui; Dong, Yan-min; Yang, Su-ping; Jiao, Nian-zhi; Qu, Yin-bo

    2010-10-01

    The aim of this study is to reveal the interaction relationships between lauryl dimethylamine N-oxide (LDAO) and peripheral light-harvesting complex (LH2) as well as the influence of LDAO on structure and function of LH2. In the present work, the effects of LDAO on the conformation and release processes of bacteriochlorophyll (BChl) of LH2 when incubated under different temperature and pH in the presence and absence of LDAO were investigated by spectroscopy. The results indicated that (1) the presence of LDAO resulted in alterations in the conformation, alpha-helix content, and spectra of Tyr and B850 band of LH2 at room temperature and pH 8.0. Moreover, energy transfer efficiency of LH2 was enhanced markedly in the presence of LDAO. (2) At 60 degrees C, both the B800 and B850 band of LH2 were released and transited into free BChl at pH 8.0. However, the release rates of bacteriochlorophylls of B800 and B850 band from LH2 were slowed down and the release processes were changed when incubated in the presence of LDAO. Hence, the stability of LH2 was improved in the presence of LDAO. (3) The accelerated release processes of bacteriochlorophylls of B800 and B850 band of LH2 were induced to transform into bacteriopheophytin (BPhe) and free BChl by LDAO in strong acid and strong alkalic solution at room temperature. However, the kinetic patterns of the B800 and B850 band were remarkably different. The release and self-assemble processes of B850 in LH2 were observed in strong acid solution without LDAO. Therefore, the different release behaviors of B800 and B850 of LH2 are induced by LDAO under different extreme environmental conditions.

  3. Conformation driven complexation of two analogous benzimidazole ...

    Indian Academy of Sciences (India)

    metal-organic framework involving Ag(I) and a neutral, semirigid, tripodal ligand, 1 .... tion quality single crystals of the complex, suitable for single crystal diffraction ..... Mohanty J S, Baksi A, Leeb H and Pradeep T 2015 RSC. Adv. 5 48039. 14.

  4. Complex analysis conformal inequalities and the Bieberbach conjecture

    CERN Document Server

    Kythe, Prem K

    2015-01-01

    Complex Analysis: Conformal Inequalities and the Bieberbach Conjecture discusses the mathematical analysis created around the Bieberbach conjecture, which is responsible for the development of many beautiful aspects of complex analysis, especially in the geometric-function theory of univalent functions. Assuming basic knowledge of complex analysis and differential equations, the book is suitable for graduate students engaged in analytical research on the topics and researchers working on related areas of complex analysis in one or more complex variables. The author first reviews the theory of analytic functions, univalent functions, and conformal mapping before covering various theorems related to the area principle and discussing Löwner theory. He then presents Schiffer’s variation method, the bounds for the fourth and higher-order coefficients, various subclasses of univalent functions, generalized convexity and the class of a-convex functions, and numerical estimates of the coefficient problem. The boo...

  5. Informational and Normative Influences in Conformity from a Neurocomputational Perspective.

    Science.gov (United States)

    Toelch, Ulf; Dolan, Raymond J

    2015-10-01

    We consider two distinct influences that drive conformity behaviour. Whereas informational influences facilitate adaptive and accurate responses, normative influences bias decisions to enhance social acceptance. We explore these influences from a perspective of perceptual and value-based decision-making models and apply these models to classical works on conformity. We argue that an informational account predicts a surprising tendency to conform. Moreover, we detail how normative influences fit into this framework and interact with social influences. Finally, we explore potential neuronal substrates for informational and normative influences based on a consideration of the neurobiological literature, highlighting conceptual shortcomings particularly with regard to a failure to segregate informational and normative influences. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Supercharging Protein Complexes from Aqueous Solution Disrupts their Native Conformations

    Science.gov (United States)

    Sterling, Harry J.; Kintzer, Alexander F.; Feld, Geoffrey K.; Cassou, Catherine A.; Krantz, Bryan A.; Williams, Evan R.

    2012-02-01

    The effects of aqueous solution supercharging on the solution- and gas-phase structures of two protein complexes were investigated using traveling-wave ion mobility-mass spectrometry (TWIMS-MS). Low initial concentrations of m-nitrobenzyl alcohol ( m-NBA) in the electrospray ionization (ESI) solution can effectively increase the charge of concanavalin A dimers and tetramers, but at higher m-NBA concentrations, the increases in charge are accompanied by solution-phase dissociation of the dimers and up to a ~22% increase in the collision cross section (CCS) of the tetramers. With just 0.8% m-NBA added to the ESI solution of a ~630 kDa anthrax toxin octamer complex, the average charge is increased by only ~4% compared with the "native" complex, but it is sufficiently destabilized so that extensive gas-phase fragmentation occurs in the relatively high pressure regions of the TWIMS device. Anthrax toxin complexes exist in either a prechannel or a transmembrane channel state. With m-NBA, the prechannel state of the complex has the same CCS/charge ratio in the gas phase as the transmembrane channel state of the same complex formed without m-NBA, yet undergoes extensive dissociation, indicating that destabilization from supercharging occurs in the ESI droplet prior to ion formation and is not a result of Coulombic destabilization in the gas phase as a result of higher charging. These results demonstrate that the supercharging of large protein complexes is the result of conformational changes induced by the reagents in the ESI droplets, where enrichment of the supercharging reagent during droplet evaporation occurs.

  7. Conformational flexibility of avidin: the influence of biotin binding

    International Nuclear Information System (INIS)

    Soledad Celej, M.; Montich, Guillermo G.; Fidelio, Gerardo D.

    2004-01-01

    Ligand binding to proteins is a key process in cell biochemistry. The interaction usually induces modifications in the unfolding thermodynamic parameters of the macromolecule due to the coupling of unfolding and binding equilibria. In addition, these modifications can be attended by changes in protein structure and/or conformational flexibility induced by ligand binding. In this work, we have explored the effect of biotin binding on conformation and dynamic properties of avidin by using infrared spectroscopy including kinetics of hydrogen/deuterium exchange. Our results, along with previously thermodynamic published data, indicate a clear correlation between thermostability and protein compactness. In addition, our results also help to interpret the thermodynamic binding parameters of the exceptionally stable biotin:AVD complex

  8. Sex differences in confidence influence patterns of conformity.

    Science.gov (United States)

    Cross, Catharine P; Brown, Gillian R; Morgan, Thomas J H; Laland, Kevin N

    2017-11-01

    Lack of confidence in one's own ability can increase the likelihood of relying on social information. Sex differences in confidence have been extensively investigated in cognitive tasks, but implications for conformity have not been directly tested. Here, we tested the hypothesis that, in a task that shows sex differences in confidence, an indirect effect of sex on social information use will also be evident. Participants (N = 168) were administered a mental rotation (MR) task or a letter transformation (LT) task. After providing an answer, participants reported their confidence before seeing the responses of demonstrators and being allowed to change their initial answer. In the MR, but not the LT, task, women showed lower levels of confidence than men, and confidence mediated an indirect effect of sex on the likelihood of switching answers. These results provide novel, experimental evidence that confidence is a general explanatory mechanism underpinning susceptibility to social influences. Our results have implications for the interpretation of the wider literature on sex differences in conformity. © 2016 The British Psychological Society.

  9. Peer influence: neural mechanisms underlying in-group conformity.

    Science.gov (United States)

    Stallen, Mirre; Smidts, Ale; Sanfey, Alan G

    2013-01-01

    People often conform to the behavior of others with whom they identify. However, it is unclear what fundamental mechanisms underlie this type of conformity. Here, we investigate the processes mediating in-group conformity by using functional magnetic resonance imaging (fMRI). Participants completed a perceptual decision-making task while undergoing fMRI, during which they were exposed to the judgments of both in-group and out-group members. Our data suggest that conformity to the in-group is mediated by both positive affect as well as the cognitive capacity of perspective taking. Examining the processes that drive in-group conformity by utilizing a basic decision-making paradigm combined with neuroimaging methods provides important insights into the potential mechanisms of conformity. These results may provide an integral step in developing more effective campaigns using group conformity as a tool for behavioral change.

  10. Theoretical investigation into the influence of conformational equilibria on the water-exchange process in magnetic resonance imaging contrast agents

    NARCIS (Netherlands)

    Cosentino, U; Pitea, D; Moro, G; Barone, [No Value; Villa, Alessandra; Muller, RN; Botteman, F

    The conformational behavior in aqueous solution of four complexes of the Eu(III) ion with bis (R-amide) derivatives (R=H, methyl, ethyl, butyl) of diethylentriamine pentacetate ligands has been characterized at the ab initio level to rationalize the experimentally observed influence of alkyl

  11. Major conformations of the ligand skeleton of a tetranuclear dysprosium (3) tartrate complex

    International Nuclear Information System (INIS)

    Chevela, V.V.; Semenov, V.Eh.; Bezryadin, S.G.; Savitskaya, T.V.; Kolesar, I.R.; Matveev, S.N.; Shamov, G.A.

    1999-01-01

    By the molecular mechanics method (MIND program, stoichiometry was studied and basic conformations of ligand frame of dysprosium (3) tetranuclear complex bis-(d-tartrato) bis-(l-tartrato)tetradysprosiate (3) - anion Dy 4 (d-L) 2 (l-L) 2 4- (1) (d-H 4 L = d-tartaric acid, l-H 4 L = l - tartaric acid) were revealed. It is shown that theoretically calculated mP τ constants for so-called compact conformations of 1, where tartratoligands are in gosh conformation, agree with experimentally obtained constant of paramagnetic birefringence (mP e ) of complex 1 [ru

  12. Molecular dynamics of conformation-specific dopamine transporter-inhibitor complexes.

    Science.gov (United States)

    Jean, Bernandie; Surratt, Christopher K; Madura, Jeffry D

    2017-09-01

    The recreational psychostimulant cocaine inhibits dopamine reuptake from the synapse, resulting in excessive stimulation of postsynaptic dopamine receptors in brain areas associated with reward and addiction. Cocaine binds to and stabilizes the outward- (extracellular-) facing conformation of the dopamine transporter (DAT) protein, while the low abuse potential DAT inhibitor benztropine prefers the inward- (cytoplasmic-) facing conformation. A correlation has been previously postulated between psychostimulant abuse potential and preference for the outward-facing DAT conformation. The 3β-aryltropane cocaine analogs LX10 and LX11, however, differ only in stereochemistry and share a preference for the outward-facing DAT, yet are reported to vary widely in abuse potential in an animal model. In search of the molecular basis for DAT conformation preference, complexes of cocaine, benztropine, LX10 or LX11 bound to each DAT conformation were subjected to 100ns of all-atom molecular dynamics simulation. Results were consistent with previous findings from cysteine accessibility assays used to assess an inhibitor's DAT conformation preference. The respective 2β- and 2α-substituted phenyltropanes of LX10 and LX11 interacted with hydrophobic regions of the DAT S1 binding site that were inaccessible to cocaine. Solvent accessibility measurements also revealed subtle differences in inhibitor positioning within a given DAT conformation. This work serves to advance our understanding of the conformational selectivity of DAT inhibitors and suggests that MD may be useful in antipsychostimulant therapeutic design. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Fluorescence spectroscopy of conformational changes of single LH2 complexes

    NARCIS (Netherlands)

    Rutkauskas, D.; Novoderezhkin, V.; Cogdell, R.J.; van Grondelle, R.

    2005-01-01

    We have investigated the energy landscape of the bacterial photosynthetic peripheral light-harvesting complex LH2 of purple bacterium Rhodopseudomonas acidophila by monitoring sequences of fluorescence spectra of single LH2 assemblies, at room temperature, with different excitation intensities as

  14. Pancreatic cancer planning: Complex conformal vs modulated therapies

    International Nuclear Information System (INIS)

    Chapman, Katherine L.; Witek, Matthew E.; Chen, Hongyu; Showalter, Timothy N.; Bar-Ad, Voichita; Harrison, Amy S.

    2016-01-01

    To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT. All volumes were approved by a single observer in accordance with Radiation Therapy Oncology Group (RTOG) Pancreas Contouring Atlas. Plans included tumor/tumor bed and regional lymph nodes to 45 Gy; with tumor/tumor bed boosted to 50.4 Gy, at least 95% of planning target volume (PTV) received the prescription dose. Dose-volume histograms (DVH) for multiple end points, treatment planning, and delivery time were assessed. Complex 3DCRT, IMRT, and VMAT plans significantly (p < 0.05) decreased mean kidney dose, mean liver dose, liver (V 30 , V 35 ), stomach (D 10 %), stomach (V 45 ), mean right kidney dose, and right kidney (V 15 ) as compared with the simple 4-field plans that are most commonly reported in the literature. IMRT plans resulted in decreased mean liver dose, liver (V 35 ), and left kidney (V 15 , V 18 , V 20 ). VMAT plans decreased small bowel (D 10 %, D 15 %), small bowel (V 35 , V 45 ), stomach (D 10 %, D 15 %), stomach (V 35 , V 45 ), mean liver dose, liver (V 35 ), left kidney (V 15 , V 18 , V 20 ), and right kidney (V 18 , V 20 ). VMAT plans significantly decreased small bowel (D 10 %, D 15 %), left kidney (V 20 ), and stomach (V 45 ) as compared with IMRT plans. Treatment planning and delivery times were most efficient for simple 4-field box and VMAT. Excluding patient setup and imaging, average treatment delivery was within 10 minutes for simple and complex 3DCRT, IMRT, and VMAT treatments. This article

  15. Pancreatic cancer planning: Complex conformal vs modulated therapies

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Katherine L. [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Witek, Matthew E. [Department of Radiation Oncology, University of Wisconsin School of Medicine School of Medicine and Public Health, Madison, WI (United States); Chen, Hongyu [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Showalter, Timothy N. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Bar-Ad, Voichita [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Harrison, Amy S., E-mail: amy.harrison@jefferson.edu [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States)

    2016-07-01

    To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT. All volumes were approved by a single observer in accordance with Radiation Therapy Oncology Group (RTOG) Pancreas Contouring Atlas. Plans included tumor/tumor bed and regional lymph nodes to 45 Gy; with tumor/tumor bed boosted to 50.4 Gy, at least 95% of planning target volume (PTV) received the prescription dose. Dose-volume histograms (DVH) for multiple end points, treatment planning, and delivery time were assessed. Complex 3DCRT, IMRT, and VMAT plans significantly (p < 0.05) decreased mean kidney dose, mean liver dose, liver (V{sub 30}, V{sub 35}), stomach (D{sub 10}%), stomach (V{sub 45}), mean right kidney dose, and right kidney (V{sub 15}) as compared with the simple 4-field plans that are most commonly reported in the literature. IMRT plans resulted in decreased mean liver dose, liver (V{sub 35}), and left kidney (V{sub 15}, V{sub 18}, V{sub 20}). VMAT plans decreased small bowel (D{sub 10}%, D{sub 15}%), small bowel (V{sub 35}, V{sub 45}), stomach (D{sub 10}%, D{sub 15}%), stomach (V{sub 35}, V{sub 45}), mean liver dose, liver (V{sub 35}), left kidney (V{sub 15}, V{sub 18}, V{sub 20}), and right kidney (V{sub 18}, V{sub 20}). VMAT plans significantly decreased small bowel (D{sub 10}%, D{sub 15}%), left kidney (V{sub 20}), and stomach (V{sub 45}) as compared with IMRT plans. Treatment planning and delivery times were most efficient for simple 4-field box and VMAT. Excluding patient setup and imaging, average

  16. Conformation-Directed Formation of Self-Healing Diblock Copolypeptide Hydrogels via Polyion Complexation.

    Science.gov (United States)

    Sun, Yintao; Wollenberg, Alexander L; O'Shea, Timothy Mark; Cui, Yanxiang; Zhou, Z Hong; Sofroniew, Michael V; Deming, Timothy J

    2017-10-25

    Synthetic diblock copolypeptides were designed to incorporate oppositely charged ionic segments that form β-sheet-structured hydrogel assemblies via polyion complexation when mixed in aqueous media. The observed chain conformation directed assembly was found to be required for efficient hydrogel formation and provided distinct and useful properties to these hydrogels, including self-healing after deformation, microporous architecture, and stability against dilution in aqueous media. While many promising self-assembled materials have been prepared using disordered or liquid coacervate polyion complex (PIC) assemblies, the use of ordered chain conformations in PIC assemblies to direct formation of new supramolecular morphologies is unprecedented. The promising attributes and unique features of the β-sheet-structured PIC hydrogels described here highlight the potential of harnessing conformational order derived from PIC assembly to create new supramolecular materials.

  17. Constructing Markov State Models to elucidate the functional conformational changes of complex biomolecules

    KAUST Repository

    Wang, Wei

    2017-10-06

    The function of complex biomolecular machines relies heavily on their conformational changes. Investigating these functional conformational changes is therefore essential for understanding the corresponding biological processes and promoting bioengineering applications and rational drug design. Constructing Markov State Models (MSMs) based on large-scale molecular dynamics simulations has emerged as a powerful approach to model functional conformational changes of the biomolecular system with sufficient resolution in both time and space. However, the rapid development of theory and algorithms for constructing MSMs has made it difficult for nonexperts to understand and apply the MSM framework, necessitating a comprehensive guidance toward its theory and practical usage. In this study, we introduce the MSM theory of conformational dynamics based on the projection operator scheme. We further propose a general protocol of constructing MSM to investigate functional conformational changes, which integrates the state-of-the-art techniques for building and optimizing initial pathways, performing adaptive sampling and constructing MSMs. We anticipate this protocol to be widely applied and useful in guiding nonexperts to study the functional conformational changes of large biomolecular systems via the MSM framework. We also discuss the current limitations of MSMs and some alternative methods to alleviate them.

  18. [Technique of complex mammary irradiation: Mono-isocentric 3D conformational radiotherapy and helical tomotherapy].

    Science.gov (United States)

    Vandendorpe, B; Guilbert, P; Champagne, C; Antoni, T; Nguyen, T D; Gaillot-Petit, N; Servagi Vernat, S

    2017-12-01

    To evaluate the dosimetric contribution of helical tomotherapy for breast cancers compared with conformal radiotherapy in mono-isocentric technique. For 23 patients, the dosimetric results in mono-isocentric 3D conformational radiotherapy did not satisfy the constraints either of target volumes nor organs at risk. A prospective dosimetric comparison between mono-isocentric 3D conformational radiotherapy and helical tomotherapy was therefore carried out. The use of helical tomotherapy showed a benefit in these 23 patients, with either an improvement in the conformity index or homogeneity, but with an increase in low doses. Of the 23 patients, two had pectus excavatum, five had past thoracic irradiation and two required bilateral irradiation. The other 14 patients had a combination of morphology and/or indication of lymph node irradiation. For these patients, helical tomotherapy was therefore preferred to mono-isocentric 3D conformational radiotherapy. Tomotherapy appears to provide better homogeneity and tumour coverage. This technique of irradiation may be justified in the case of morphological situations such as pectus exavatum and in complex clinical situations. In other cases, conformal radiotherapy in mono-isocentric technique remains to be favoured. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  19. Conformation transitions of blood proteins under influence of physical factors on microwave dielectric method

    International Nuclear Information System (INIS)

    Gorobchenko, O.A.; Nikolov, O.T.; Gatash, S.V.

    2006-01-01

    In this article, the influence of γ-irradiation and temperature on albumin and fibrinogen conformation and dielectric properties of protein solutions have been studied by the microwave dielectric method. Both the values of the real part ε' (dielectric permittivity) and the imaginary part ε'' (dielectric losses) of the complex dielectric permittivity of the aqueous solution of bovine serum albumin and human fibrinogen as functions of temperature and γ-irradiation dose have been obtained. The time of dielectric relaxation of water molecules in the protein solutions was calculated. The hydration of the albumin and fibrinogen molecules was determined. The temperature dependencies of hydration are non-monotonous and have a number of characteristic features at the temperatures 30-34 and 44-47 deg. C for serum albumin, and 24 and 32 deg. C for fibrinogen

  20. Conformational determinants of phosphotyrosine peptides complexed with the Src SH2 domain.

    Directory of Open Access Journals (Sweden)

    Joseph Nachman

    2010-06-01

    Full Text Available The inhibition of specific SH2 domain mediated protein-protein interactions as an effective chemotherapeutic approach in the treatment of diseases remains a challenge. That different conformations of peptide-ligands are preferred by different SH2 domains is an underappreciated observation from the structural analysis of phosphotyrosine peptide binding to SH2 domains that may aid in future drug design. To explore the nature of ligand binding, we use simulated annealing (SA to sample the conformational space of phosphotyrosine-containing peptides complexed with the Src SH2 domain. While in good agreement with the crystallographic and NMR studies of high-affinity phosphopeptide-SH2 domain complexes, the results suggest that the structural basis for phopsphopeptide- Src SH2 interactions is more complex than the "two-pronged plug two-hole socket" model. A systematic study of peptides of type pYEEX, where pY is phosphotyrosine and X is a hydrophobic residue, indicates that these peptides can assume two conformations, one extended and one helical, representing the balance between the interaction of residue X with the hydrophobic hole on the surface of the Src SH2 domain, and its contribution to the inherent tendency of the two glutamic acids to form an alpha-helix. In contrast, a beta-turn conformation, almost identical to that observed in the crystal structure of pYVNV bound to the Grb2 SH2 domain, predominates for pYXNX peptides, even in the presence of isoleucine at the third position. While peptide binding affinities, as measured by fluorescence polarization, correlate with the relative proportion of extended peptide conformation, these results suggest a model where all three residues C-terminal to the phosphotyrosine determine the conformation of the bound phosphopeptide. The information obtained in this work can be used in the design of specific SH2 domain inhibitors.

  1. Modeling Pedestrian’s Conformity Violation Behavior: A Complex Network Based Approach

    Directory of Open Access Journals (Sweden)

    Zhuping Zhou

    2014-01-01

    Full Text Available Pedestrian injuries and fatalities present a problem all over the world. Pedestrian conformity violation behaviors, which lead to many pedestrian crashes, are common phenomena at the signalized intersections in China. The concepts and metrics of complex networks are applied to analyze the structural characteristics and evolution rules of pedestrian network about the conformity violation crossings. First, a network of pedestrians crossing the street is established, and the network’s degree distributions are analyzed. Then, by using the basic idea of SI model, a spreading model of pedestrian illegal crossing behavior is proposed. Finally, through simulation analysis, pedestrian’s illegal crossing behavior trends are obtained in different network structures and different spreading rates. Some conclusions are drawn: as the waiting time increases, more pedestrians will join in the violation crossing once a pedestrian crosses on red firstly. And pedestrian’s conformity violation behavior will increase as the spreading rate increases.

  2. Conformity-based cooperation in online social networks: The effect of heterogeneous social influence

    International Nuclear Information System (INIS)

    Xu, Bo; Wang, Jianwei; Zhang, Xuejun

    2015-01-01

    This paper extends the conformity model by introducing heterogeneous social influence into the analysis. We associate the influence of a player in the network with its degree centrality assuming that players of higher degree exhibit more social influence on its neighbors. The results show that the equilibrium level of cooperators can be dramatically enhanced if the conformity-driven players are preferentially influenced by neighbors of higher degree. We attribute this finding to two elementary mechanisms in the evolutionary process: (1) degree-based social influence facilitates the formation of strategic clusters around hubs; and (2) payoff-heterogeneity between cooperative clusters and defective clusters contributes to the promotion of cooperation. This research reveals the important role of heterogeneous social influence on the emergence of cooperation in social networks.

  3. Influence of conformity on the wear of total knee replacement: An experimental study.

    Science.gov (United States)

    Brockett, Claire L; Carbone, Silvia; Fisher, John; Jennings, Louise M

    2018-02-01

    Wear of total knee replacement continues to be a significant factor influencing the clinical longevity of implants. Historically, failure due to delamination and fatigue directed design towards more conforming inserts to reduce contact stress. As new generations of more oxidatively stable polyethylene have been developed, more flexibility in bearing design has been introduced. The aim of this study was to investigate the effect of insert conformity on the wear performance of a fixed bearing total knee replacement through experimental simulation. Two geometries of insert were studied under standard gait conditions. There was a significant reduction in wear with reducing implant conformity. This study has demonstrated that bearing conformity has a significant impact on the wear performance of a fixed bearing total knee replacement, providing opportunities to improve clinical performance through enhanced material and design selection.

  4. Small molecules CK-666 and CK-869 inhibit actin-related protein 2/3 complex by blocking an activating conformational change.

    Science.gov (United States)

    Hetrick, Byron; Han, Min Suk; Helgeson, Luke A; Nolen, Brad J

    2013-05-23

    Actin-related protein 2/3 (Arp2/3) complex is a seven-subunit assembly that nucleates branched actin filaments. Small molecule inhibitors CK-666 and CK-869 bind to Arp2/3 complex and inhibit nucleation, but their modes of action are unknown. Here, we use biochemical and structural methods to determine the mechanism of each inhibitor. Our data indicate that CK-666 stabilizes the inactive state of the complex, blocking movement of the Arp2 and Arp3 subunits into the activated filament-like (short pitch) conformation, while CK-869 binds to a serendipitous pocket on Arp3 and allosterically destabilizes the short pitch Arp3-Arp2 interface. These results provide key insights into the relationship between conformation and activity in Arp2/3 complex and will be critical for interpreting the influence of the inhibitors on actin filament networks in vivo. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Study on protein conformation and adsorption behaviors in nanodiamond particle-protein complexes

    International Nuclear Information System (INIS)

    Wang Haidong; Niu, Catherine Hui; Yang Qiaoqin; Badea, Ildiko

    2011-01-01

    In the present research, the conformation of bovine serum albumin (BSA) in the nanodiamond particle (ND)-BSA complex was studied by Fourier transform infrared spectroscopy, fluorescence spectroscopy, UV-vis spectroscopy, and circular dichroism spectroscopy. The spectroscopic study revealed that most BSA structural features could be preserved in the complex though the BSA underwent conformational changes in the complex due to ND-BSA interaction. In addition, BSA adsorption isotherms and zeta-potential measurements were employed to investigate the pH dependence of the ND-BSA interaction. The changes in surface charge of the ND-BSA complex with pH variations indicated that the binding of BSA to ND might lead to not only the adsorption of BSA onto the ND surface but also the partial breakup of ND aggregates into relatively small ND-BSA aggregates because of the strong binding force between ND and BSA. The results show that ND is an excellent platform for protein immobilization with high affinity and holds great potential to be used for biosensor applications.

  6. Study on protein conformation and adsorption behaviors in nanodiamond particle-protein complexes

    Energy Technology Data Exchange (ETDEWEB)

    Wang Haidong [Department of Biomedical Engineering, University of Saskatchewan, Saskatoon, S7N 5A9 (Canada); Niu, Catherine Hui [Department of Chemical Engineering, University of Saskatchewan, Saskatoon, S7N 5A9 (Canada); Yang Qiaoqin [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, S7N 5A9 (Canada); Badea, Ildiko, E-mail: catherine.niu@usask.ca [Drug Design and Discovery Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, S7N 5C9 (Canada)

    2011-04-08

    In the present research, the conformation of bovine serum albumin (BSA) in the nanodiamond particle (ND)-BSA complex was studied by Fourier transform infrared spectroscopy, fluorescence spectroscopy, UV-vis spectroscopy, and circular dichroism spectroscopy. The spectroscopic study revealed that most BSA structural features could be preserved in the complex though the BSA underwent conformational changes in the complex due to ND-BSA interaction. In addition, BSA adsorption isotherms and zeta-potential measurements were employed to investigate the pH dependence of the ND-BSA interaction. The changes in surface charge of the ND-BSA complex with pH variations indicated that the binding of BSA to ND might lead to not only the adsorption of BSA onto the ND surface but also the partial breakup of ND aggregates into relatively small ND-BSA aggregates because of the strong binding force between ND and BSA. The results show that ND is an excellent platform for protein immobilization with high affinity and holds great potential to be used for biosensor applications.

  7. Neural Basis of Two Kinds of Social Influence: Obedience and Conformity

    Directory of Open Access Journals (Sweden)

    Ying eXie

    2016-02-01

    Full Text Available Event-related potentials (ERPs were used in this study to explore the neural mechanism of obedience and conformity on the model of online book purchasing. Participants were asked to decide as quickly as possible whether to buy a book based on limited information including its title, keywords and number of positive and negative reviews. Obedience was induced by forcing participants to buy books which received mostly negative reviews. In contrast, conformity was aroused by majority influence (caused by positive and negative comments. P3 and N2, two kinds of ERP components related to social cognitive process, were measured and recorded with electroencephalogram (EEG test. The results show that compared with conformity decisions, obedience decisions induced greater cognitive conflicts. In ERP measurements, greater amplitudes of N2 component were observed in the context of obedience. However, consistency level did not make a difference on P3 peak latency for both conformity and obedience. This shows that classification process is implicit in both conformity and obedience decision-making. In addition, for both conformity and obedience decisions, augmented P3 was observed when the reviews consistency (either negative or positive was higher.

  8. Neural Basis of Two Kinds of Social Influence: Obedience and Conformity.

    Science.gov (United States)

    Xie, Ying; Chen, Mingliang; Lai, Hongxia; Zhang, Wuke; Zhao, Zhen; Anwar, Ch Mahmood

    2016-01-01

    Event-related potentials (ERPs) were used in this study to explore the neural mechanism of obedience and conformity on the model of online book purchasing. Participants were asked to decide as quickly as possible whether to buy a book based on limited information including its title, keywords and number of positive and negative reviews. Obedience was induced by forcing participants to buy books which received mostly negative reviews. In contrast, conformity was aroused by majority influence (caused by positive and negative comments). P3 and N2, two kinds of ERP components related to social cognitive process, were measured and recorded with electroencephalogram (EEG) test. The results show that compared with conformity decisions, obedience decisions induced greater cognitive conflicts. In ERP measurements, greater amplitudes of N2 component were observed in the context of obedience. However, consistency level did not make a difference on P3 peak latency for both conformity and obedience. This shows that classification process is implicit in both conformity and obedience decision-making. In addition, for both conformity and obedience decisions, augmented P3 was observed when the reviews consistency (either negative or positive) was higher.

  9. Factors influencing conformity index in radiotherapy for non-small cell lung cancer.

    LENUS (Irish Health Repository)

    Brennan, Sinead M

    2010-01-01

    The radiotherapy conformity index (CI) is a useful tool to quantitatively assess the quality of radiotherapy treatment plans, and represents the relationship between isodose distributions and target volume. A conformity index of unity implies high planning target volume (PTV) coverage and minimal unnecessary irradiation of surrounding tissues. We performed this analysis to describe the CI for lung cancer 3-dimensional conformal radiotherapy (3DCRT) and to identify clinical and technical determinants of CI, as it is not known which factors are associated with good quality 3D conformal radiotherapy treatment planning. Radiotherapy treatment plans from a database of 52 patients with inoperable Stage 1 to 3b lung cancer, on a hypofractionated 3DCRT trial were evaluated. A CI was calculated for all plans using the definition of the ICRU 62:CI = (TV\\/PTV), which is the quotient of the treated volume (TV) and the PTV. Data on patient, tumor, and planning variables, which could influence CI, were recorded and analyzed. Mean CI was 2.01 (range = 1.06-3.8). On univariate analysis, PTV (p = 0.023), number of beams (p = 0.036), medial vs. lateral tumor location (p = 0.016), and increasing tumor stage (p = 0.041) were associated with improved conformity. On multiple regression analysis, factors found to be associated with CI included central vs. peripheral tumor location (p = 0.041) and PTV size (p = 0.058). The term 3DCRT is used routinely in the literature, without any indication of the degree of conformality. We recommend routine reporting of conformity indices. Conformity indices may be affected by both planning variables and tumor factors.

  10. Influence of locus of control on conformity to authority in a ...

    African Journals Online (AJOL)

    Influence of locus of control on conformity to authority in a multicultural organisation - A case of IITA Nigeria. John O Ekore. Abstract. No Abstract Available African Journal for the Psychological Study of Social Issues Vol.5(2) 2000: 90-96. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT ...

  11. Subnanomolar Inhibitor of Cytochrome bc1 Complex Designed via Optimizing Interaction with Conformationally Flexible Residues

    Science.gov (United States)

    Zhao, Pei-Liang; Wang, Le; Zhu, Xiao-Lei; Huang, Xiaoqin; Zhan, Chang-Guo; Wu, Jia-Wei; Yang, Guang-Fu

    2009-01-01

    Cytochrome bc1 complex (EC 1.10.2.2, bc1), an essential component of the cellular respiratory chain and the photosynthetic apparatus in photosynthetic bacteria, has been identified as a promising target for new drugs and agricultural fungicides. X-ray diffraction structures of the free bc1 complex and its complexes with various inhibitors revealed that the phenyl group of Phe274 in the binding pocket exhibited significant conformational flexibility upon different inhibitors binding to optimize respective π-π interactions, whereas the side chains of other hydrophobic residues showed conformational stability. Therefore, in the present study, a strategy of optimizing the π-π interaction with conformationally flexible residues was proposed to design and discover new bc1 inhibitors with a higher potency. Eight new compounds were designed and synthesized, among which compound 5c with a Ki value of 570 pM was identified as the most promising drug or fungicide candidate, significantly more potent than the commercially available bc1 inhibitors including azoxystrobin (AZ), kresoxim-methyl (KM), and pyraclostrobin (PY). To our knowledge, this is the first bc1 inhibitor discovered from structure-based design with a potency of subnanomolar Ki value. For all of the compounds synthesized and assayed, the calculated binding free energies correlated reasonably well with the binding free energies derived from the experimental Ki values with a correlation coefficient of r2 = 0.89. The further inhibitory kinetics studies revealed that compound 5c is a non-competitive inhibitor with respect to substrate cytochrome c, but is a competitive inhibitor with respect to substrate ubiquinol. Due to its subnanomolar Ki potency and slow dissociation rate constant (k−0 = 0.00358 s−1), compound 5c could be used as a specific probe for further elucidation of the mechanism of bc1 function and as a new lead compound for future drug discovery. PMID:19928849

  12. Rotational Spectrum of the Methyl Salicylate-Water Complex: the Missing Conformer and the Tunneling Motions

    Science.gov (United States)

    Ghosh, Supriya; Thomas, Javix; Xu, Yunjie; Jäger, Wolfgang

    2015-06-01

    Methyl salicylate is a naturally occurring organic ester produced by wintergreen and other plants. It is also found in many over-the-counter remedies, such as muscle ache creams. The rotational spectrum of the methyl salicylate monomer was reported previously, where the most stable, dominant conformer was identified. The methyl salicylate-water complex was first studied using fluorescence-detected infrared spectroscopy; only one monohydrate conformer was found in that work. In the present study, we employed both broadband chirped and cavity based Fourier transform microwave spectroscopy to examine the competition between intra- and intermolecular hydrogen-bonding interactions and possible large amplitude motions associated with the methyl group and the water subunit. In contrast to the previous infrared study, two monohydrate conformers were identified, with carbonyl O or hydroxyl O as the hydrogen bond acceptors. Detailed analyses of the observed hyperfine structures will be presented, as well as our efforts to extend the study to larger methyl salicylate hydration clusters. S. Melandri, B. M. Giuliano, A. Maris, L. B. Favero, P. Ottaviani, B. Velino, W. Caminati, J. Phys. Chem. A. 2007, 111, 9076. A. Mitsuzuka, A. Fujii, T. Ebata, N. Mikami, J. Phys. Chem. A 1998, 102, 9779.

  13. Conformational Effects in Non-Stoichiometric Complexes of Two Hyperbranched Molecules with a Linear Polyelectrolyte

    Directory of Open Access Journals (Sweden)

    Alexey Lyulin

    2012-01-01

    Full Text Available We report results from Brownian dynamics computer simulations of systems comprised by two terminally charged hyperbranched molecules preferentially branched in the periphery, with an oppositely charged linear chain of varying length. Comparison of the findings from the present study to stoichiometric counterparts and to analogous dendrimer-based complexes, reveal that the presence of the second hyperbranched molecule incurs significant changes in the conformational characteristics of both components of the complex. Instead of step-like changes in the average size and shape of the hyperbranched component that were noted in the previously studied stoichiometric systems, a rather smooth change is observed upon increase of the length of the linear component. In addition, a markedly different behavior is also noticed in the conformational characteristics of the linear chain when compared to that in similar dendrimer-based systems. The above findings are consistent with the higher degree of deformability of the peripherally branched molecules which allow appropriate rearrangements in shape in order to accommodate the favorable Coulombic interactions between the two components of the complex. This behavior offers new insight towards the design of more efficient hyperbranched-based systems which can take advantage of the multifunctionality and the structural properties of the highly branched polymer components.

  14. Can Crystal Symmetry and Packing Influence the Active Site Conformation of Homohexameric Purine Nucleoside Phosphorylases?

    Directory of Open Access Journals (Sweden)

    Marija Luić

    2016-06-01

    Full Text Available It is generaly believed that enzymes retain most of their functionality in the crystal form due to the large solvent content of protein crystals. This is facilitated by the fact that their natural environment in solution is not too far from the one found in the crystal form. Nevertheless, if the nature of the enzyme is such to require conformational changes, overcoming of the crystal packing constraints may prove to be too difficult. Such conformational change is present in one class of enzymes (purine nucleoside phosphorylases, that is the subject of our scientific interest for many years. The influence of crystal symmetry and crystal packing on the conformation of the active sites in the case of homohexameric purine nucleoside phosphorylases is presented and analysed. This work is licensed under a Creative Commons Attribution 4.0 International License.

  15. Influence of brand differential on motivation to conform and manufacturer versus store brand purchase intention

    Directory of Open Access Journals (Sweden)

    Tran, E.

    2014-05-01

    Full Text Available Relationships and characteristics that influence consumers’ purchase decision between store brand and manufacturer brand product offerings have emerged as an interesting and practical area of research. From a management perspective, understanding the process by which consumers make purchase choices between these brand offerings would lead to both theoretical and practical applications. Therefore, this study attempts to enhance understanding about the factors that influence consumers’ manufacturer versus store brand purchase decisions. A conceptual model is developed to integrate the manner by which a consumer’s motivation to conform to the perceived social norm of purchasing manufacturer brand products influences this purchase decision. The model is tested using survey data. Findings indicate the importance of the intensity of perceived differences between store brand and manufacturer brand product offerings in affecting consumers’ purchase intention of these products. The relationship is also mediated by consumers’ motivation to conform to manufacturer brand products in their purchase decision.

  16. Enhanced conformational sampling to visualize a free-energy landscape of protein complex formation.

    Science.gov (United States)

    Iida, Shinji; Nakamura, Haruki; Higo, Junichi

    2016-06-15

    We introduce various, recently developed, generalized ensemble methods, which are useful to sample various molecular configurations emerging in the process of protein-protein or protein-ligand binding. The methods introduced here are those that have been or will be applied to biomolecular binding, where the biomolecules are treated as flexible molecules expressed by an all-atom model in an explicit solvent. Sampling produces an ensemble of conformations (snapshots) that are thermodynamically probable at room temperature. Then, projection of those conformations to an abstract low-dimensional space generates a free-energy landscape. As an example, we show a landscape of homo-dimer formation of an endothelin-1-like molecule computed using a generalized ensemble method. The lowest free-energy cluster at room temperature coincided precisely with the experimentally determined complex structure. Two minor clusters were also found in the landscape, which were largely different from the native complex form. Although those clusters were isolated at room temperature, with rising temperature a pathway emerged linking the lowest and second-lowest free-energy clusters, and a further temperature increment connected all the clusters. This exemplifies that the generalized ensemble method is a powerful tool for computing the free-energy landscape, by which one can discuss the thermodynamic stability of clusters and the temperature dependence of the cluster networks. © 2016 The Author(s).

  17. Conformal gravity, the Einstein equations and spaces of complex null geodesics

    Energy Technology Data Exchange (ETDEWEB)

    Baston, R.J.; Mason, L.J.

    1987-07-01

    The aim of the paper is to give a twistorial characterisation of the field equations of conformal gravity and of Einstein spacetimes. Strong evidence is provided for a particularly concise characterisation of these equations in terms of 'formal neighbourhoods'of the space of complex null geodesics. Second-order perturbations of the metric of complexified Minkowski space are considered. These correspond to certain infinitesimal deformations of its space of complex null geodesics, PN. PN has a natural codimension one embedding into a larger space. It is shown that deformations extend automatically to the fourth-order embedding (that is, the fourth formal neighbourhood). They extend to the fifth formal neighbourhood if and only if the corresponding perturbation in the metric has vanishing Bach tensor. Finally, deformations which extend to the sixth formal neighbourhood correspond to perturbations in the metric that are conformally related to ones satisfying the Einstein equations. The authors present arguments which suggest that the results will also hold when spacetime is fully curved.

  18. Conformal gravity, the Einstein equations and spaces of complex null geodesics

    International Nuclear Information System (INIS)

    Baston, R.J.; Mason, L.J.

    1987-01-01

    The aim of the paper is to give a twistorial characterisation of the field equations of conformal gravity and of Einstein spacetimes. Strong evidence is provided for a particularly concise characterisation of these equations in terms of 'formal neighbourhoods'of the space of complex null geodesics. Second-order perturbations of the metric of complexified Minkowski space are considered. These correspond to certain infinitesimal deformations of its space of complex null geodesics, PN. PN has a natural codimension one embedding into a larger space. It is shown that deformations extend automatically to the fourth-order embedding (that is, the fourth formal neighbourhood). They extend to the fifth formal neighbourhood if and only if the corresponding perturbation in the metric has vanishing Bach tensor. Finally, deformations which extend to the sixth formal neighbourhood correspond to perturbations in the metric that are conformally related to ones satisfying the Einstein equations. The authors present arguments which suggest that the results will also hold when spacetime is fully curved. (author)

  19. Resolving dual binding conformations of cellulosome cohesin-dockerin complexes using single-molecule force spectroscopy.

    Science.gov (United States)

    Jobst, Markus A; Milles, Lukas F; Schoeler, Constantin; Ott, Wolfgang; Fried, Daniel B; Bayer, Edward A; Gaub, Hermann E; Nash, Michael A

    2015-10-31

    Receptor-ligand pairs are ordinarily thought to interact through a lock and key mechanism, where a unique molecular conformation is formed upon binding. Contrary to this paradigm, cellulosomal cohesin-dockerin (Coh-Doc) pairs are believed to interact through redundant dual binding modes consisting of two distinct conformations. Here, we combined site-directed mutagenesis and single-molecule force spectroscopy (SMFS) to study the unbinding of Coh:Doc complexes under force. We designed Doc mutations to knock out each binding mode, and compared their single-molecule unfolding patterns as they were dissociated from Coh using an atomic force microscope (AFM) cantilever. Although average bulk measurements were unable to resolve the differences in Doc binding modes due to the similarity of the interactions, with a single-molecule method we were able to discriminate the two modes based on distinct differences in their mechanical properties. We conclude that under native conditions wild-type Doc from Clostridium thermocellum exocellulase Cel48S populates both binding modes with similar probabilities. Given the vast number of Doc domains with predicted dual binding modes across multiple bacterial species, our approach opens up new possibilities for understanding assembly and catalytic properties of a broad range of multi-enzyme complexes.

  20. Conformational distributions and proximity relationships in the rigor complex of actin and myosin subfragment-1.

    Science.gov (United States)

    Nyitrai, M; Hild, G; Lukács, A; Bódis, E; Somogyi, B

    2000-01-28

    Cyclic conformational changes in the myosin head are considered essential for muscle contraction. We hereby show that the extension of the fluorescence resonance energy transfer method described originally by Taylor et al. (Taylor, D. L., Reidler, J., Spudich, J. A., and Stryer, L. (1981) J. Cell Biol. 89, 362-367) allows determination of the position of a labeled point outside the actin filament in supramolecular complexes and also characterization of the conformational heterogeneity of an actin-binding protein while considering donor-acceptor distance distributions. Using this method we analyzed proximity relationships between two labeled points of S1 and the actin filament in the acto-S1 rigor complex. The donor (N-[[(iodoacetyl)amino]ethyl]-5-naphthylamine-1-sulfonate) was attached to either the catalytic domain (Cys-707) or the essential light chain (Cys-177) of S1, whereas the acceptor (5-(iodoacetamido)fluorescein) was attached to the actin filament (Cys-374). In contrast to the narrow positional distribution (assumed as being Gaussian) of Cys-707 (5 +/- 3 A), the positional distribution of Cys-177 was found to be broad (102 +/- 4 A). Such a broad positional distribution of the label on the essential light chain of S1 may be important in accommodating the helically arranged acto-myosin binding relative to the filament axis.

  1. IgG Fab Fragments Forming Bivalent Complexes by a Conformational Mechanism That Is Reversible by Osmolytes*

    Science.gov (United States)

    Nelson, Alfreda D.; Hoffmann, Michele M.; Parks, Christopher A.; Dasari, Surendra; Schrum, Adam G.; Gil, Diana

    2012-01-01

    Generated by proteolytic cleavage of immunoglobulin, Fab fragments possess great promise as blocking reagents, able to bind receptors or other targets without inducing cross-linking. However, aggregation of Fab preparations is a common occurrence, which generates intrinsic stimulatory capacity and thwarts signal blockade strategies. Using a panel of biochemical approaches, including size exclusion chromatography, SDS-PAGE, mass spectrometry, and cell stimulation followed by flow cytometry, we have measured the oligomerization and acquisition of stimulatory capacity that occurs in four monoclonal IgG Fabs specific for TCR/CD3. Unexpectedly, we observed that all Fabs spontaneously formed complexes that were precisely bivalent, and these bivalent complexes possessed most of the stimulatory activity of each Fab preparation. Fabs composing bivalent complexes were more susceptible to proteolysis than monovalent Fabs, indicating a difference in conformation between the Fabs involved in these two different states of valency. Because osmolytes represent a class of compounds that stabilize protein folding and conformation, we sought to determine the extent to which the amino acid osmolyte l-proline might impact bivalent Fab complexation. We found that l-proline (i) inhibited the adoption of the conformation associated with bivalent complexation, (ii) preserved Fab monovalency, (iii) reversed the conformation of preformed bivalent Fabs to that of monovalent Fabs, and (iv) separated a significant percentage of preformed bivalent complexes into monovalent species. Thus, Fab fragments can adopt a conformation that is compatible with folding or packing of a bivalent complex in a process that can be inhibited by osmolytes. PMID:23109335

  2. A zinc complex of heparan sulfate destabilises lysozyme and alters its conformation

    International Nuclear Information System (INIS)

    Hughes, Ashley J.; Hussain, Rohanah; Cosentino, Cesare; Guerrini, Marco; Siligardi, Giuliano; Yates, Edwin A.; Rudd, Timothy R.

    2012-01-01

    Highlights: ► Zinc–heparan sulfate complex destabilises lysozyme, a model amyloid protein. ► Addition of zinc, without heparan sulfate, stabilises lysozyme. ► Heparan sulfate cation complexes provide alternative protein folding routes. -- Abstract: The naturally occurring anionic cell surface polysaccharide heparan sulfate is involved in key biological activities and is implicated in amyloid formation. Following addition of Zn–heparan sulfate, hen lysozyme, a model amyloid forming protein, resembled β-rich amyloid by far UV circular dichroism (increased β-sheet: +25%), with a significantly reduced melting temperature (from 68 to 58 °C) by fluorescence shift assay. Secondary structure stability of the Zn–heparan sulfate complex with lysozyme was also distinct from that with heparan sulfate, under stronger denaturation conditions using synchrotron radiation circular dichroism. Changing the cation associated with heparan sulfate is sufficient to alter the conformation and stability of complexes formed between heparan sulfate and lysozyme, substantially reducing the stability of the protein. Complexes of heparan sulfate and cations, such as Zn, which are abundant in the brain, may provide alternative folding routes for proteins.

  3. Conformational Complexity in the LH2 Antenna of the Purple Sulfur Bacterium Allochromatium vinosum Revealed by Hole-Burning Spectroscopy.

    Science.gov (United States)

    Kell, Adam; Jassas, Mahboobe; Acharya, Khem; Hacking, Kirsty; Cogdell, Richard J; Jankowiak, Ryszard

    2017-06-15

    This work discusses the protein conformational complexity of the B800-850 LH2 complexes from the purple sulfur bacterium Allochromatium vinosum, focusing on the spectral characteristics of the B850 chromophores. Low-temperature B850 absorption and the split B800 band shift blue and red, respectively, at elevated temperatures, revealing isosbestic points. The latter indicates the presence of two (unresolved) conformations of B850 bacteriochlorophylls (BChls), referred to as conformations 1 and 2, and two conformations of B800 BChls, denoted as B800 R and B800 B . The energy differences between average site energies of conformations 1 and 2, and B800 R and B800 B are similar (∼200 cm -1 ), suggesting weak and strong hydrogen bonds linking two major subpopulations of BChls and the protein scaffolding. Although conformations 1 and 2 of the B850 chromophores, and B800 R and B800 B , exist in the ground state, selective excitation leads to 1 → 2 and B800 R → B800 B phototransformations. Different static inhomogeneous broadening is revealed for the lowest energy exciton states of B850 (fwhm ∼195 cm -1 ) and B800 R (fwhm ∼140 cm -1 ). To describe the 5 K absorption spectrum and the above-mentioned conformations, we employ an exciton model with dichotomous protein conformation disorder. We show that both experimental data and the modeling study support a two-site model with strongly and weakly hydrogen-bonded B850 and B800 BChls, which under illumination undergo conformational changes, most likely caused by proton dynamics.

  4. An Individualized 3-Dimensional Designed and Printed Conformer After Dermis Fat Grafting for Complex Sockets.

    Science.gov (United States)

    Mourits, Daphne L; Remmers, Jelmer S; Tan, Stevie H; Moll, Annette C; Hartong, Dyonne T

    2018-04-03

    To introduce a novel technique to design individually customized conformers for postenucleation sockets with dermis fat implants. We use a 3-dimensional scan of the frontal face/orbit and eyelid contour to design an individualized conformer. This polymethylmetacrylate printed conformer is adapted to patients' socket, palpebral fissures, horizontal eyelid aperture, curvature of the eyelids, and mean diameter of patients' contralateral eye. Sutures through holes in the inferior part of the conformer and in the extension can be placed to fixate the conformer and anchor fornix deepening sutures. A correct fitting conformer can be printed and attached to the socket and eyelids. The shape of this conformer can be used subsequently postsurgically to design the ocular prosthesis. Presurgical planning is important to anticipate for a functional socket to adequately fit an artificial eye. The presented technique using 3-dimensional imaging, designing, and printing promises to prevent conformer extrusion and forniceal shortening.

  5. The effect of conformational transition of gelatin-polysaccharide polyelectrolyte complex on its functional properties

    Directory of Open Access Journals (Sweden)

    Tomáš Valenta

    2017-01-01

    Full Text Available The blends of gelatin and shear-thinning hydrocolloids (guar gum, kappa-carrageenan and xanthan gum were examined to determine the effect of the conformational change on the functional properties of the solutions. The polyelectrolyte complexes of 0.5% gelatin/0.5% polysaccharide in 70 mM KCl or 70 mM NaCl were investigated by the laboratory rheometer and conductivity meter in the temperature range 25 - 45 °C. The rheological data were fitted by the power-law and Herschel-Bulkley model to obtain the flow parameters. The functional properties of the samples were substantially affected by the conformational change of the polysaccharide, as well as by the type of the hydrocolloid and salt solution. There was an evident change of viscosity and conductivity of the solutions upon heating, corresponding to the helix-coil transition of the polysaccharide at temperature about 35 °C. The type of the salt solvent had an effect on the gelation properties of the samples. Gelatin/kappa-carrageenan blend in NaCl provided a gel of high consistency at ambient temperature (20 - 25 °C, whereas the blend in KCl did not gel in the studied temperature range. The potential stability of the blends was determined by zeta-potential analysis. The low values of ζ-potential indicate that the gelatin/polysaccharide blends are electrically unstable systems which tend to coagulate. The mixtures of gelatin/polysaccharide electrostatic complexes may have a great potential in many food applications.

  6. Covalent dye attachment influences the dynamics and conformational properties of flexible peptides.

    Directory of Open Access Journals (Sweden)

    Manuel P Luitz

    Full Text Available Fluorescence spectroscopy techniques like Förster resonance energy transfer (FRET and fluorescence correlation spectroscopy (FCS have become important tools for the in vitro and in vivo investigation of conformational dynamics in biomolecules. These methods rely on the distance-dependent quenching of the fluorescence signal of a donor fluorophore either by a fluorescent acceptor fluorophore (FRET or a non-fluorescent quencher, as used in FCS with photoinduced electron transfer (PET. The attachment of fluorophores to the molecule of interest can potentially alter the molecular properties and may affect the relevant conformational states and dynamics especially of flexible biomolecules like intrinsically disordered proteins (IDP. Using the intrinsically disordered S-peptide as a model system, we investigate the impact of terminal fluorescence labeling on the molecular properties. We perform extensive molecular dynamics simulations on the labeled and unlabeled peptide and compare the results with in vitro PET-FCS measurements. Experimental and simulated timescales of end-to-end fluctuations were found in excellent agreement. Comparison between simulations with and without labels reveal that the π-stacking interaction between the fluorophore labels traps the conformation of S-peptide in a single dominant state, while the unlabeled peptide undergoes continuous conformational rearrangements. Furthermore, we find that the open to closed transition rate of S-peptide is decreased by at least one order of magnitude by the fluorophore attachment. Our approach combining experimental and in silico methods provides a benchmark for the simulations and reveals the significant effect that fluorescence labeling can have on the conformational dynamics of small biomolecules, at least for inherently flexible short peptides. The presented protocol is not only useful for comparing PET-FCS experiments with simulation results but provides a strategy to minimize the

  7. SURFACE FLUID REGISTRATION OF CONFORMAL REPRESENTATION: APPLICATION TO DETECT DISEASE BURDEN AND GENETIC INFLUENCE ON HIPPOCAMPUS

    Science.gov (United States)

    Shi, Jie; Thompson, Paul M.; Gutman, Boris; Wang, Yalin

    2013-01-01

    In this paper, we develop a new automated surface registration system based on surface conformal parameterization by holomorphic 1-forms, inverse consistentsurface fluid registration, and multivariate tensor-based morphometry (mTBM). First, we conformally map a surface onto a planar rectangle space with holomorphic 1-forms. Second, we compute surface conformal representation by combining its local conformal factor and mean curvature and linearly scale the dynamic range of the conformal representation to form the feature image of the surface. Third, we align the feature image with a chosen template image via the fluid image registration algorithm, which has been extended into the curvilinear coordinates to adjust for the distortion introduced by surface parameterization. The inverse consistent image registration algorithm is also incorporated in the system to jointly estimate the forward and inverse transformations between the study and template images. This alignment induces a corresponding deformation on the surface. We tested the system on Alzheimer's Disease Neuroimaging Initiative (ADNI) baseline dataset to study AD symptoms on hippocampus. In our system, by modeling a hippocampus as a 3D parametric surface, we nonlinearly registered each surface with a selected template surface. Then we used mTBM to analyze the morphometrydifference between diagnostic groups. Experimental results show that the new system has better performance than two publically available subcortical surface registration tools: FIRST and SPHARM. We also analyzed the genetic influence of the Apolipoprotein E ε4 allele (ApoE4),which is considered as the most prevalent risk factor for AD.Our work successfully detected statistically significant difference between ApoE4 carriers and non-carriers in both patients of mild cognitive impairment (MCI) and healthy control subjects. The results show evidence that the ApoE genotype may be associated with accelerated brain atrophy so that our workprovides

  8. Conformational isomerism in mixed-ligand complexes of 2,2'-bipyridine and triphenylphosphine with copper(I) halides

    International Nuclear Information System (INIS)

    Barron, P.F.; Engelhardt, L.M.; Healy, P.C.; Kildea, J.D.; White, A.H.

    1988-01-01

    Mixed-ligand complexes of triphenylphosphine and 2,2'-bipyridine and copper(I) halides have been synthesized. The 31 P NMR spectra of the complexes were measured and are reported along with data for complete structural characterization of the complexes. The results indicate a novel dichotomy of conformational isomers to be present in the chloride lattice. The Cu-P bond length was found to not vary with different halides. 8 refs., 4 figs., 6 tabs

  9. Microscopic insight into thermodynamics of conformational changes of SAP-SLAM complex in signal transduction cascade

    Science.gov (United States)

    Samanta, Sudipta; Mukherjee, Sanchita

    2017-04-01

    The signalling lymphocytic activation molecule (SLAM) family of receptors, expressed by an array of immune cells, associate with SLAM-associated protein (SAP)-related molecules, composed of single SH2 domain architecture. SAP activates Src-family kinase Fyn after SLAM ligation, resulting in a SLAM-SAP-Fyn complex, where, SAP binds the Fyn SH3 domain that does not involve canonical SH3 or SH2 interactions. This demands insight into this SAP mediated signalling cascade. Thermodynamics of the conformational changes are extracted from the histograms of dihedral angles obtained from the all-atom molecular dynamics simulations of this structurally well characterized SAP-SLAM complex. The results incorporate the binding induced thermodynamic changes of individual amino acid as well as the secondary structural elements of the protein and the solvent. Stabilization of the peptide partially comes through a strong hydrogen bonding network with the protein, while hydrophobic interactions also play a significant role where the peptide inserts itself into a hydrophobic cavity of the protein. SLAM binding widens SAP's second binding site for Fyn, which is the next step in the signal transduction cascade. The higher stabilization and less fluctuation of specific residues of SAP in the Fyn binding site, induced by SAP-SLAM complexation, emerge as the key structural elements to trigger the recognition of SAP by the SH3 domain of Fyn. The thermodynamic quantification of the protein due to complexation not only throws deeper understanding in the established mode of SAP-SLAM interaction but also assists in the recognition of the relevant residues of the protein responsible for alterations in its activity.

  10. Conformational Plasticity in the Transsynaptic Neurexin-Cerebellin-Glutamate Receptor Adhesion Complex

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Shouqiang; Seven, Alpay B.; Wang, Jing; Skiniotis, Georgios; Özkan, Engin (UC); (Michigan)

    2016-12-01

    Synaptic specificity is a defining property of neural networks. In the cerebellum, synapses between parallel fiber neurons and Purkinje cells are specified by the simultaneous interactions of secreted protein cerebellin with pre-synaptic neurexin and post-synaptic delta-type glutamate receptors (GluD). Here, we determined the crystal structures of the trimeric C1q-like domain of rat cerebellin-1, and the first complete ectodomain of a GluD, rat GluD2. Cerebellin binds to the LNS6 domain of α- and β-neurexin-1 through a high-affinity interaction that involves its highly flexible N-terminal domain. In contrast, we show that the interaction of cerebellin with isolated GluD2 ectodomain is low affinity, which is not simply an outcome of lost avidity when compared with binding with a tetrameric full-length receptor. Rather, high-affinity capture of cerebellin by post-synaptic terminals is likely controlled by long-distance regulation within this transsynaptic complex. Altogether, our results suggest unusual conformational flexibility within all components of the complex.

  11. Conformational co-dependence between Plasmodium berghei LCCL proteins promotes complex formation and stability.

    Science.gov (United States)

    Saeed, Sadia; Tremp, Annie Z; Dessens, Johannes T

    2012-10-01

    Malaria parasites express a conserved family of LCCL-lectin adhesive-like domain proteins (LAPs) that have essential functions in sporozoite transmission. In Plasmodium falciparum all six family members are expressed in gametocytes and form a multi-protein complex. Intriguingly, knockout of P. falciparum LCCL proteins adversely affects expression of other family members at protein, but not at mRNA level, a phenomenon termed co-dependent expression. Here, we investigate this in Plasmodium berghei by crossing a PbLAP1 null mutant parasite with a parasite line expressing GFP-tagged PbLAP3 that displays strong fluorescence in gametocytes. Selected and validated double mutants show normal synthesis and subcellular localization of PbLAP3::GFP. However, GFP-based fluorescence is dramatically reduced without PbLAP1 present, indicating that PbLAP1 and PbLAP3 interact. Moreover, absence of PbLAP1 markedly reduces the half-life of PbLAP3, consistent with a scenario of misfolding. These findings unveil a potential mechanism of conformational interdependence that facilitates assembly and stability of the functional LCCL protein complex. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Influence of multiple well defined conformations on small-angle scattering of proteins in solution.

    Science.gov (United States)

    Heller, William T

    2005-01-01

    A common structural motif for many proteins comprises rigid domains connected by a flexible hinge or linker. The flexibility afforded by these domains is important for proper function and such proteins may be able to adopt more than one conformation in solution under equilibrium conditions. Small-angle scattering of proteins in solution samples all conformations that exist in the sampled volume during the time of the measurement, providing an ensemble-averaged intensity. In this paper, the influence of sampling an ensemble of well defined protein structures on the small-angle solution scattering intensity profile is examined through common analysis methods. Two tests were performed using simulated data: one with the extended and collapsed states of the bilobal calcium-binding protein calmodulin and the second with the catalytic subunit of protein kinase A, which has two globular domains connected by a glycine hinge. In addition to analyzing the simulated data for the radii of gyration Rg, distance distribution function P(r) and particle volume, shape restoration was applied to the simulated data. Rg and P(r) of the ensemble profiles could be easily mistaken for a single intermediate state. The particle volumes and models of the ensemble intensity profiles show that some indication of multiple conformations exists in the case of calmodulin, which manifests an enlarged volume and shapes that are clear superpositions of the conformations used. The effect on the structural parameters and models is much more subtle in the case of the catalytic subunit of protein kinase A. Examples of how noise influences the data and analyses are also presented. These examples demonstrate the loss of the indications of multiple conformations in cases where even broad distributions of structures exist. While the tests using calmodulin show that the ensemble states remain discernible from the other ensembles tested or a single partially collapsed state, the tests performed using the

  13. Complete relaxation and conformational exchange matrix (CORCEMA) analysis of intermolecular saturation transfer effects in reversibly forming ligand-receptor complexes.

    Science.gov (United States)

    Jayalakshmi, V; Krishna, N Rama

    2002-03-01

    A couple of recent applications of intermolecular NOE (INOE) experiments as applied to biomolecular systems involve the (i) saturation transfer difference NMR (STD-NMR) method and (ii) the intermolecular cross-saturation NMR (ICS-NMR) experiment. STD-NMR is a promising tool for rapid screening of a large library of compounds to identify bioactive ligands binding to a target protein. Additionally, it is also useful in mapping the binding epitopes presented by a bioactive ligand to its target protein. In this latter application, the STD-NMR technique is essentially similar to the ICS-NMR experiment, which is used to map protein-protein or protein-nucleic acid contact surfaces in complexes. In this work, we present a complete relaxation and conformational exchange matrix (CORCEMA) theory (H. N. B. Moseley et al., J. Magn. Reson. B 108, 243-261 (1995)) applicable for these two closely related experiments. As in our previous work, we show that when exchange is fast on the relaxation rate scale, a simplified CORCEMA theory can be formulated using a generalized average relaxation rate matrix. Its range of validity is established by comparing its predictions with those of the exact CORCEMA theory which is valid for all exchange rates. Using some ideal model systems we have analyzed the factors that influence the ligand proton intensity changes when the resonances from some protons on the receptor protein are saturated. The results show that the intensity changes in the ligand signals in an intermolecular NOE experiment are very much dependent upon: (1) the saturation time, (2) the location of the saturated receptor protons with respect to the ligand protons, (3) the conformation of the ligand-receptor interface, (4) the rotational correlation times for the molecular species, (5) the kinetics of the reversibly forming complex, and (6) the ligand/receptor ratio. As an example of a typical application of the STD-NMR experiment we have also simulated the STD effects for a

  14. Characterizing highly dynamic conformational states: The transcription bubble in RNAP-promoter open complex as an example

    Science.gov (United States)

    Lerner, Eitan; Ingargiola, Antonino; Weiss, Shimon

    2018-03-01

    Bio-macromolecules carry out complicated functions through structural changes. To understand their mechanism of action, the structure of each step has to be characterized. While classical structural biology techniques allow the characterization of a few "structural snapshots" along the enzymatic cycle (usually of stable conformations), they do not cover all (and often fast interconverting) structures in the ensemble, where each may play an important functional role. Recently, several groups have demonstrated that structures of different conformations in solution could be solved by measuring multiple distances between different pairs of residues using single-molecule Förster resonance energy transfer (smFRET) and using them as constrains for hybrid/integrative structural modeling. However, this approach is limited in cases where the conformational dynamics is faster than the technique's temporal resolution. In this study, we combine existing tools that elucidate sub-millisecond conformational dynamics together with hybrid/integrative structural modeling to study the conformational states of the transcription bubble in the bacterial RNA polymerase-promoter open complex (RPo). We measured microsecond alternating laser excitation-smFRET of differently labeled lacCONS promoter dsDNA constructs. We used a combination of burst variance analysis, photon-by-photon hidden Markov modeling, and the FRET-restrained positioning and screening approach to identify two conformational states for RPo. The experimentally derived distances of one conformational state match the known crystal structure of bacterial RPo. The experimentally derived distances of the other conformational state have characteristics of a scrunched RPo. These findings support the hypothesis that sub-millisecond dynamics in the transcription bubble are responsible for transcription start site selection.

  15. EEG reveals an early influence of social conformity on visual processing in group pressure situations.

    Science.gov (United States)

    Trautmann-Lengsfeld, Sina Alexa; Herrmann, Christoph Siegfried

    2013-01-01

    Humans are social beings and often have to perceive and perform within groups. In conflict situations, this puts them under pressure to either adhere to the group opinion or to risk controversy with the group. Psychological experiments have demonstrated that study participants adapt to erroneous group opinions in visual perception tasks, which they can easily solve correctly when performing on their own. Until this point, however, it is unclear whether this phenomenon of social conformity influences early stages of perception that might not even reach awareness or later stages of conscious decision-making. Using electroencephalography, this study has revealed that social conformity to the wrong group opinion resulted in a decrease of the posterior-lateral P1 in line with a decrease of the later centro-parietal P3. These results suggest that group pressure situations impact early unconscious visual perceptual processing, which results in a later diminished stimulus discrimination and an adaptation even to the wrong group opinion. These findings might have important implications for understanding social behavior in group settings and are discussed within the framework of social influence on eyewitness testimony.

  16. Conformation of an Shc-derived phosphotyrosine-containing peptide complexed with the Grb2 SH2 domain

    International Nuclear Information System (INIS)

    Ogura, Kenji; Tsuchiya, Shigeo; Terasawa, Hiroaki; Yuzawa, Satoru; Hatanaka, Hideki; Mandiyan, Valsan; Schlessinger, Joseph; Inagaki, Fuyuhiko

    1997-01-01

    We have determined the structure of an Shc-derived phosphotyrosine-containing peptide complexed with Grb2 SH2 based on intra-and intermolecular NOE correlations observed by a series of isotope-filtered NMR experiments using a PFG z-filter. In contrast to an extended conformation of phosphotyrosine-containing peptides bound to Src, Syp and PLC γ SH2s, the Shc-derived peptide formed a turn at the +1 and +2 positions next to the phosphotyrosine residue. Trp 121 , located at the EF1 site of Grb2 SH2, blocked the peptide binding in an extended conformation. The present study confirms that each phosphotyrosine-containing peptide binds to the cognate SH2 with a specific conformation, which gives the structural basis for the binding specificity between SH2s and target proteins

  17. Conformational Heterogeneity in Antibody-Protein Antigen Recognition IMPLICATIONS FOR HIGH AFFINITY PROTEIN COMPLEX FORMATION

    Czech Academy of Sciences Publication Activity Database

    Addis, P. W.; Hall, c. J.; Bruton, S.; Veverka, Václav; Wilkinson, I. C.; Muskett, F. W.; Renshaw, P. S.; Prosser, C. E.; Carrington, B.; Lawson, A. D. G.; Griffin, R.; Taylor, R. J.; Waters, L. C.; Henry, A. J.; Carr, M. D.

    2014-01-01

    Roč. 289, č. 10 (2014), s. 7200-7210 ISSN 0021-9258 Institutional support: RVO:61388963 Keywords : NMR * antibody * protein-protein interaction * protein conformation Subject RIV: CE - Biochemistry Impact factor: 4.573, year: 2014

  18. Increased Conformational Flexibility of a Macrocycle–Receptor Complex Contributes to Reduced Dissociation Rates

    NARCIS (Netherlands)

    Glas, Adrian; Wamhoff, Eike Christian; Krüger, Dennis M.; Rademacher, Christoph; Grossmann, Tom N.

    2017-01-01

    Constraining a peptide in its bioactive conformation by macrocyclization represents a powerful strategy to design modulators of challenging biomolecular targets. This holds particularly true for the development of inhibitors of protein-protein interactions which often involve interfaces lacking

  19. Constructing Markov State Models to elucidate the functional conformational changes of complex biomolecules

    KAUST Repository

    Wang, Wei; Cao, Siqin; Zhu, Lizhe; Huang, Xuhui

    2017-01-01

    bioengineering applications and rational drug design. Constructing Markov State Models (MSMs) based on large-scale molecular dynamics simulations has emerged as a powerful approach to model functional conformational changes of the biomolecular system

  20. Polymorphisms at Amino Acid Residues 141 and 154 Influence Conformational Variation in Ovine PrP

    Science.gov (United States)

    Yang, Sujeong; Thackray, Alana M.; Hopkins, Lee; Monie, Tom P.; Burke, David F.; Bujdoso, Raymond

    2014-01-01

    Polymorphisms in ovine PrP at amino acid residues 141 and 154 are associated with susceptibility to ovine prion disease: Leu141Arg154 with classical scrapie and Phe141Arg154 and Leu141His154 with atypical scrapie. Classical scrapie is naturally transmissible between sheep, whereas this may not be the case with atypical scrapie. Critical amino acid residues will determine the range or stability of structural changes within the ovine prion protein or its functional interaction with potential cofactors, during conversion of PrPC to PrPSc in these different forms of scrapie disease. Here we computationally identified that regions of ovine PrP, including those near amino acid residues 141 and 154, displayed more conservation than expected based on local structural environment. Molecular dynamics simulations showed these conserved regions of ovine PrP displayed genotypic differences in conformational repertoire and amino acid side-chain interactions. Significantly, Leu141Arg154 PrP adopted an extended beta sheet arrangement in the N-terminal palindromic region more frequently than the Phe141Arg154 and Leu141His154 variants. We supported these computational observations experimentally using circular dichroism spectroscopy and immunobiochemical studies on ovine recombinant PrP. Collectively, our observations show amino acid residues 141 and 154 influence secondary structure and conformational change in ovine PrP that may correlate with different forms of scrapie. PMID:25126555

  1. Factors influencing incidence of acute grade 2 morbidity in conformal and standard radiation treatment of prostate cancer

    International Nuclear Information System (INIS)

    Hanks, Gerald E.; Schultheiss, Timothy E.; Hunt, Margie A.; Epstein, Barry

    1995-01-01

    Purpose: The fundament hypothesis of conformal radiation therapy is that tumor control can be increased by using conformal treatment techniques that allow a higher tumor dose while maintaining an acceptable level of complications. To test this hypothesis, it is necessary first to estimate the incidence of morbidity for both standard and conformal fields. In this study, we examine factors that influence the incidence of acute grade 2 morbidity in patients treated with conformal and standard radiation treatment for prostate cancer. Methods and Materials: Two hundred and forty-seven consecutive patients treated with conformal technique are combined with and compared to 162 consecutive patients treated with standard techniques. The conformal technique includes special immobilization by a cast, careful identification of the target volume in three dimensions, localization of the inferior border of the prostate using the retrograde urethrogram, and individually shaped portals that conform to the Planning Target Volume (PTV). Univariate analysis compares differences in the incidence of RTOG-EORTC grade two acute morbidity by technique, T stage, age, irradiated volume, and dose. Multivariate logistic regression includes these same variables. Results: In nearly all categories, the conformal treatment group experienced significantly fewer acute grade 2 complications than the standard treatment group. Only volume (prostate ± whole pelvis) and technique (conformal vs. standard) were significantly related to incidence of morbidity on multivariate analysis. When dose is treated as a continuous variable (rather than being dichotomized into two levels), a trend is observed on multivariate analysis, but it does not reach significant levels. The incidence of acute grade 2 morbidity in patients 65 years or older is significantly reduced by use of the conformal technique. Conclusion: The conformal technique is associated with fewer grade 2 acute toxicities for all patients. This

  2. A global conformance quality model. A new strategic tool for minimizing defects caused by variation, error, and complexity

    Energy Technology Data Exchange (ETDEWEB)

    Hinckley, C. Martin [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    1994-01-01

    The performance of Japanese products in the marketplace points to the dominant role of quality in product competition. Our focus is motivated by the tremendous pressure to improve conformance quality by reducing defects to previously unimaginable limits in the range of 1 to 10 parts per million. Toward this end, we have developed a new model of conformance quality that addresses each of the three principle defect sources: (1) Variation, (2) Human Error, and (3) Complexity. Although the role of variation in conformance quality is well documented, errors occur so infrequently that their significance is not well known. We have shown that statistical methods are not useful in characterizing and controlling errors, the most common source of defects. Excessive complexity is also a root source of defects, since it increases errors and variation defects. A missing link in the defining a global model has been the lack of a sound correlation between complexity and defects. We have used Design for Assembly (DFA) methods to quantify assembly complexity and have shown that assembly times can be described in terms of the Pareto distribution in a clear exception to the Central Limit Theorem. Within individual companies we have found defects to be highly correlated with DFA measures of complexity in broad studies covering tens of millions of assembly operations. Applying the global concepts, we predicted that Motorola`s Six Sigma method would only reduce defects by roughly a factor of two rather than orders of magnitude, a prediction confirmed by Motorola`s data. We have also shown that the potential defects rates of product concepts can be compared in the earliest stages of development. The global Conformance Quality Model has demonstrated that the best strategy for improvement depends upon the quality control strengths and weaknesses.

  3. The influence of conformational fluctuations on enzymatic activity: modelling the functional motion of β-secretase

    International Nuclear Information System (INIS)

    Neri, M; Cascella, M; Micheletti, C

    2005-01-01

    Considerable insight into the functional activity of proteins and enzymes can be obtained by studying the low energy conformational distortions that the biopolymer can sustain. We carry out the characterization of these large scale structural changes for a protein of considerable pharmaceutical interest, the human β-secretase. Starting from the crystallographic structure of the protein, we use the recently introduced β-Gaussian model to identify, with negligible computational expenditure, the most significant distortions occurring in thermal equilibrium and the associated timescales. The application of this strategy helps us to gain considerable insight into the putative functional movements and, furthermore, allows us to identify a handful of key regions in the protein which have an important mechanical influence on the enzymatic activity despite being spatially distant from the active site. The results obtained within the Gaussian model are validated through an extensive comparison against an all-atom molecular dynamics simulation

  4. NMR studies of differences in the conformations and dynamics of ligand complexes formed with mutant dihydrofolate reductases

    International Nuclear Information System (INIS)

    Birdsall, B.; Andrews, J.; Ostler, G.; Tendler, S.J.B.; Feeney, J.; Roberts, G.C.K.; Davies, R.W.; Cheung, H.T.A.

    1989-01-01

    Two mutants of Lactobacillus casei dihydrofolate reductase, Trp 21 → Leu and Asp 26 → Glu, have been prepared by using site-directed mutagenesis methods, and their ligand binding and structural properties have been compared with those of the wild-type enzyme. 1 H, 13 C, and 31 P NMR studies have been carried out to characterize the structural changes in the complexes of the mutant and wild-type enzymes. Replacement of the conserved Trp 21 by a Leu residue causes a decrease in activity of the enzyme and reduces the NADPH binding constant by a factor of 400. The binding of substrates and substrate analogues is only slightly affected. 1 H NMR studies of the Trp 21 → Leu enzyme complexes have confirmed the original resonance assignments for Trp 21. In complexes formed with methotrexate and the mutant enzyme, the results indicate some small changes in conformation occurring as much as 14 angstrom away from the site of substitution. For the enzyme-NADPH complexes, the chemical shifts of nuclei in the bound coenzyme indicate that the nicotinamide ring binds differently in complexes with the mutant and the wild-type enzyme. There are complexes where the wild-type enzyme has been shown to exist in solution as a mixture of conformations, and studies on the corresponding complexes with the Trp 21 → Leu mutant indicate that the delicately poised equilibria can be perturbed. Some conformational adjustments are required to allow the carboxylate of Glu 26 to bind effectively to the N1 proton of inhibitors such as methotrexate and trimethoprim

  5. Food as a way to convey masculinities: How conformity to hegemonic masculinity norms influences men's and women's food consumption.

    Science.gov (United States)

    Campos, Lúcia; Bernardes, Sónia; Godinho, Cristina

    2018-05-01

    This study investigated how conformity to hegemonic masculinity norms affects men's and women's food consumption and whether such influence was contextually modulated. A total of 519 individuals (65% women; M = 44 years old) participated in a 2 (gender salience: low vs high) × 2 (participants' sex: male vs female) quasi-experimental between-subjects design, completing the Conformity to Masculinity Norms Inventory (Portuguese version) and reporting their past week's food consumption. Gender salience moderated the relation between men's conformity to masculinity norms and food consumption; sex-related differences in food consumption were partially mediated by conformity to masculinity norms. Implications for food consumption interventions are discussed.

  6. Conformational explosion: Understanding the complexity of short chain para-dialkylbenzene potential energy surfaces

    Science.gov (United States)

    Mishra, Piyush; Hewett, Daniel M.; Zwier, Timothy S.

    2018-05-01

    The single-conformation ultraviolet and infrared spectroscopy of three short-chain para-dialkylbenzenes (para-diethylbenzene, para-dipropylbenzene, and para-dibutylbenzene) is reported for the jet-cooled, isolated molecules. The present study builds off previous work on single-chain n-alkylbenzenes, where an anharmonic local mode Hamiltonian method was developed to account for stretch-bend Fermi resonance in the alkyl CH stretch region [D. P. Tabor et al., J. Chem. Phys. 144, 224310 (2016)]. The jet-cooled molecules are interrogated using laser-induced fluorescence (LIF) excitation, fluorescence dip infrared spectroscopy, and dispersed fluorescence. The LIF spectra in the S1 ← S0 origin region show a dramatic increase in the number of resolved transitions with increasing length of the alkyl chains, reflecting an explosion in the number of unique low-energy conformations formed when two independent alkyl chains are present. Since the barriers to isomerization of the alkyl chain are similar in size, this results in an "egg carton" shaped potential energy surface. A combination of electronic frequency shift and alkyl CH stretch infrared spectra is used to generate a consistent set of conformational assignments. Using these experimental techniques in conjunction with computational methods, subsets of origin transitions in the LIF excitation spectrum can be classified into different conformational families. Two conformations are resolved in para-diethylbenzene, seven in para-dipropylbenzene, and about nineteen in para-dibutylbenzene. These chains are largely independent of each other as there are no new single-chain conformations induced by the presence of a second chain. A cursory LIF excitation scan of para-dioctylbenzene shows a broad congested spectrum at frequencies consistent with interactions of alkyl chains with the phenyl π cloud.

  7. The influence of N-terminal acetylation on micelle-induced conformational changes and aggregation of α-Synuclein.

    Directory of Open Access Journals (Sweden)

    David Ruzafa

    Full Text Available The biological function of α-Synuclein has been related to binding to lipids and membranes but these interactions can also mediate α-Synuclein aggregation, which is associated to Parkinson's disease and other neuropathologies. In brain tissue α-Synuclein is constitutively N-acetylated, a modification that plays an important role in its conformational propensity, lipid and membrane binding, and aggregation propensity. We studied the interactions of the lipid-mimetic SDS with N-acetylated and non-acetylated α-Synuclein, as well as their early-onset Parkinson's disease variants A30P, E46K and A53T. At low SDS/protein ratios α-Synuclein forms oligomeric complexes with SDS micelles with relatively low α-helical structure. These micellar oligomers can efficiently nucleate aggregation of monomeric α-Synuclein, with successive formation of oligomers, protofibrils, curly fibrils and mature amyloid fibrils. N-acetylation reduces considerably the rate of aggregation of WT α-Synuclein. However, in presence of any of the early-onset Parkinson's disease mutations the protective effect of N-acetylation against micelle-induced aggregation becomes impaired. At higher SDS/protein ratios, N-acetylation favors another conformational transition, in which a second type of α-helix-rich, non-aggregating oligomers become stabilized. Once again, the Parkinson's disease mutations disconnect the influence of N-acetylation in promoting this transition. These results suggest a cooperative link between the N-terminus and the region of the mutations that may be important for α-Synuclein function.

  8. Myosin isoform determines the conformational dynamics and cooperativity of actin filaments in the strongly bound actomyosin complex

    Science.gov (United States)

    Prochniewicz, Ewa; Chin, Harvey F.; Henn, Arnon; Hannemann, Diane E.; Olivares, Adrian O.; Thomas, David D.; De La Cruz, Enrique M.

    2010-01-01

    SUMMARY We have used transient phosphorescence anisotropy (TPA) to detect the microsecond rotational dynamics of erythrosin iodoacetamide (ErIA)-labeled actin strongly bound to single-headed fragments of muscle myosin (muscle S1) and non-muscle myosin V (MV). The conformational dynamics of actin filaments in solution are markedly influenced by the isoform of bound myosin. Both myosins increase the final anisotropy of actin at sub-stoichiometric binding densities, indicating long-range, non-nearest neighbor cooperative restriction of filament rotational dynamics amplitude, but the cooperative unit is larger with MV than muscle S1. Both myosin isoforms also cooperatively affect the actin filament rotational correlation time, but with opposite effects; muscle S1 decreases rates of intrafilament torsional motion, while binding of MV increases the rates of motion. The cooperative effects on the rates of intrafilament motions correlate with the kinetics of myosin binding to actin filaments such that MV binds more rapidly, and muscle myosin more slowly, to partially decorated filaments than to bare filaments. The two isoforms also differ in their effects on the phosphorescence lifetime of the actin-bound ErIA; while muscle S1 increases the lifetime, suggesting decreased aqueous exposure of the probe, MV does not induce a significant change. We conclude that the dynamics and structure of actin in the strongly bound actomyosin complex is determined by the isoform of the bound myosin, in a manner likely to accommodate the diverse functional roles of actomyosin in muscle and non-muscle cells. PMID:19962990

  9. A chimera grid scheme. [multiple overset body-conforming mesh system for finite difference adaptation to complex aircraft configurations

    Science.gov (United States)

    Steger, J. L.; Dougherty, F. C.; Benek, J. A.

    1983-01-01

    A mesh system composed of multiple overset body-conforming grids is described for adapting finite-difference procedures to complex aircraft configurations. In this so-called 'chimera mesh,' a major grid is generated about a main component of the configuration and overset minor grids are used to resolve all other features. Methods for connecting overset multiple grids and modifications of flow-simulation algorithms are discussed. Computational tests in two dimensions indicate that the use of multiple overset grids can simplify the task of grid generation without an adverse effect on flow-field algorithms and computer code complexity.

  10. Conformational Explosion: Understanding the Complexity of the Para-Dialkylbenzene Potential Energy Surfaces

    Science.gov (United States)

    Mishra, Piyush; Hewett, Daniel M.; Zwier, Timothy S.

    2017-06-01

    This talk focuses on the single-conformation spectroscopy of small-chain para-dialkylbenzenes. This work builds on previous studies from our group on long-chain n-alkylbenzenes that identified the first folded structure in octylbenzene. The dialkylbenzenes are representative of a class of molecules that are common components of coal and aviation fuel and are known to be present in vehicle exhaust. We bring the molecules para-diethylbenzene, para-dipropylbenzene and para-dibutylbenzene into the gas phase and cool the molecules in a supersonic expansion. The jet-cooled molecules are then interrogated using laser-induced fluorescence excitation, fluorescence dip IR spectroscopy (FDIRS) and dispersed fluorescence. The LIF spectra in the S_{0}-S_{1} origin region show dramatic increases in the number of resolved transitions with increasing length of alkyl chains, reflecting an explosion in the number of unique low-energy conformations formed when two independent alkyl chains are present. Since the barriers to isomerization of the alkyl chain are similar in size, this results in an 'egg carton' shape to the potential energy surface. We use a combination of electronic frequency shift and alkyl CH stretch infrared spectra to generate a consistent set of conformational assignments.

  11. Effect of double-tailed surfactant architecture on the conformation, self-assembly, and processing in polypeptide-surfactant complexes.

    Science.gov (United States)

    Junnila, Susanna; Hanski, Sirkku; Oakley, Richard J; Nummelin, Sami; Ruokolainen, Janne; Faul, Charl F J; Ikkala, Olli

    2009-10-12

    This work describes the solid-state conformational and structural properties of self-assembled polypeptide-surfactant complexes with double-tailed surfactants. Poly(L-lysine) was complexed with three dialkyl esters of phosphoric acid (i.e., phosphodiester surfactants), where the surfactant tail branching and length was varied to tune the supramolecular architecture in a facile way. After complexation with the branched surfactant bis(2-ethylhexyl) phosphate in an aqueous solution, the polypeptide chains adopted an alpha-helical conformation. These rod-like helices self-assembled into cylindrical phases with the amorphous alkyl tails pointing outward. In complexes with dioctyl phosphate and didodecyl phosphate, which have two linear n-octyl or n-dodecyl tails, respectively, the polypeptide formed antiparallel beta-sheets separated by alkyl layers, resulting in well-ordered lamellar self-assemblies. By heating, it was possible to trigger a partial opening of the beta-sheets and disruption of the lamellar phase. After repeated heating/cooling, all of these complexes also showed a glass transition between 37 and 50 degrees C. Organic solvent treatment and plasticization by overstoichiometric amount of surfactant led to structure modification in poly(L-lysine)-dioctyl phosphate complexes, PLL(diC8)(x) (x = 1.0-3.0). Here, the alpha-helical PLL is surrounded by the surfactants and these bottle-brush-like chains self-assemble in a hexagonal cylindrical morphology. As x is increased, the materials are clearly plasticized and the degree of ordering is improved: The stiff alpha-helical backbones in a softened surfactant matrix give rise to thermotropic liquid-crystalline phases. The complexes were examined by Fourier transform infrared spectroscopy, small- and wide-angle X-ray scattering, transmission electron microscopy, differential scanning calorimetry, polarized optical microscopy, and circular dichroism.

  12. Influences of conformations of peptides on stereoinversions and/or isomerizations of aspartic acid residues.

    Science.gov (United States)

    Oda, Akifumi; Nakayoshi, Tomoki; Fukuyoshi, Shuichi; Kurimoto, Eiji; Takahashi, Ohgi

    2018-07-01

    Recently, non-enzymatic stereoinversions of aspartic acid (Asp) residues in proteins and peptides have been reported. Here, we performed replica exchange molecular dynamics (REMD) simulations of model peptides (exon 6, 26A-1, and 26A-2) extracted from elastin to investigate their structural features, thereby revealing the factor that influences stereoinversions. For REMD trajectories, we calculated distances between carboxyl carbon in Asp and amide nitrogen in the (n + 1) residue (CN distances). Because bond formation between carbon and nitrogen is indispensable to the formation of a succinimide intermediate the distance between them seems to play an important role in stereoinversion. Moreover, we calculated polar surface areas (PSAs) for the trajectories, finding that CN distances and PSA were different for each peptide, with the longest CN distance and smallest PSA observed for exon 6 peptide, where stereoinversion of Asp is the slowest. Although the average CN distance was shorter for exon 26A-1 peptide than for exon 26A-2 peptide, the number of conformations with CN distances acids: biology in the mirror, edited by Dr. Loredano Pollegioni, Dr. Jean-Pierre Mothet and Dr. Molla Gianluca. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Role and structural mechanism of WASP-triggered conformational changes in branched actin filament nucleation by Arp2/3 complex.

    Science.gov (United States)

    Rodnick-Smith, Max; Luan, Qing; Liu, Su-Ling; Nolen, Brad J

    2016-07-05

    The Arp2/3 (Actin-related proteins 2/3) complex is activated by WASP (Wiskott-Aldrich syndrome protein) family proteins to nucleate branched actin filaments that are important for cellular motility. WASP recruits actin monomers to the complex and stimulates movement of Arp2 and Arp3 into a "short-pitch" conformation that mimics the arrangement of actin subunits within filaments. The relative contribution of these functions in Arp2/3 complex activation and the mechanism by which WASP stimulates the conformational change have been unknown. We purified budding yeast Arp2/3 complex held in or near the short-pitch conformation by an engineered covalent cross-link to determine if the WASP-induced conformational change is sufficient for activity. Remarkably, cross-linked Arp2/3 complex bypasses the need for WASP in activation and is more active than WASP-activated Arp2/3 complex. These data indicate that stimulation of the short-pitch conformation is the critical activating function of WASP and that monomer delivery is not a fundamental requirement for nucleation but is a specific requirement for WASP-mediated activation. During activation, WASP limits nucleation rates by releasing slowly from nascent branches. The cross-linked complex is inhibited by WASP's CA region, even though CA potently stimulates cross-linking, suggesting that slow WASP detachment masks the activating potential of the short-pitch conformational switch. We use structure-based mutations and WASP-Arp fusion chimeras to determine how WASP stimulates movement toward the short-pitch conformation. Our data indicate that WASP displaces the autoinhibitory Arp3 C-terminal tail from a hydrophobic groove at Arp3's barbed end to destabilize the inactive state, providing a mechanism by which WASP stimulates the short-pitch conformation and activates Arp2/3 complex.

  14. On the conformational stability of the smallest RNA kissing complexes maintained through two G·C base pairs

    International Nuclear Information System (INIS)

    Chu, Wally; Weerasekera, Akila; Kim, Chul-Hyun

    2017-01-01

    Two identical 5′GACG3′ tetra-loop motifs with different stem sequences (called H2 and H3) are found in the 5′ end region of Moloney Murine Leukemia Virus (MMLV) genomic RNA. They play important roles in RNA dimerization and encapsidation through two identical tetra-loops (5′GACG3′) forming a loop-to-loop kissing complex, the smallest RNA kissing complex ever found in nature. We examined the effects of a loop-closing base pair as well as a stem sequence on the conformational stability of the kissing complex. UV melting analysis and gel electrophoresis were performed on eight RNA sequences mimicking the H2 and H3 hairpin tetra-loops with variation in loop-closing base pairs. Our results show that changing the loop-closing base pair from the wildtype (5′A·U3′ for H3, 5′U·A3′ for H2) to 5′G·C3’/5′C·G3′ has significant effect on the stability of the kissing complexes: the substitution to 5′C·G3′ significantly decreases both thermal and mechanical stability, while switching to the 5′G·C3′ significantly increases the mechanical stability only. The kissing complexes with the wildtype loop-closing base pairs (5′A·U3′ for H3 and 5′U·A3′ for H2) show different stability when attached to a different stem sequence (H2 stem vs. H3 stem). This suggests that not only the loop-closing base pair itself, but also the stem sequence, affects the conformational stability of the RNA kissing complex. - Highlights: • Thermodynamic parameters of the smallest RNA kissing interactions were measured. • The effects of loop-closing base pairs on the RNA kissing complex was investigated. • Changing the base pair to 5′CG3′ decreases the stability of the kissing complex. • Changing it to 5′GC3′ increases the mechanical resilience of the kissing complex. • Difference in its stem sequence also affects the stability of the kissing complex.

  15. Influence of Hydrophobicity on Polyelectrolyte Complexation

    Energy Technology Data Exchange (ETDEWEB)

    Sadman, Kazi [Department; amp, Engineering, Northwestern University, Evanston, Illinois 60208, United States; Wang, Qifeng [Department; amp, Engineering, Northwestern University, Evanston, Illinois 60208, United States; Chen, Yaoyao [Department; amp, Engineering, Northwestern University, Evanston, Illinois 60208, United States; Keshavarz, Bavand [Department; Jiang, Zhang [X-ray; Shull, Kenneth R. [Department; amp, Engineering, Northwestern University, Evanston, Illinois 60208, United States

    2017-11-16

    Polyelectrolyte complexes are a fascinating class of soft materials that can span the full spectrum of mechanical properties from low viscosity fluids to glassy solids. This spectrum can be accessed by modulating the extent of electrostatic association in these complexes. However, to realize the full potential of polyelectrolyte complexes as functional materials their molecular level details need to be clearly correlated with their mechanical response. The present work demonstrates that by making simple amendments to the chain architecture it is possible to affect the salt responsiveness of polyelectrolyte complexes in a systematic manner. This is achieved by quaternizing poly(4-vinylpyridine) (QVP) with methyl, ethyl and propyl substituents– thereby increasing the hydrophobicity with increasing side chain length– and complexing them with a common anionic polyelectrolyte, poly(styrene sulfonate). The mechanical 1 ACS Paragon Plus Environment behavior of these complexes is compared to the more hydrophilic system of poly(styrene sulfonate) and poly(diallyldimethylammonium) by quantifying the swelling behavior in response to salt stimuli. More hydrophobic complexes are found to be more resistant to doping by salt, yet the mechanical properties of the complex remain contingent on the overall swelling ratio of the complex itself, following near universal swelling-modulus master curves that are quantified in this work. The rheological behavior of QVP complex coacervates are found to be approximately the same, only requiring higher salt concentrations to overcome strong hydrophobic interactions, demonstrating that hydrophobicity can be used as an important parameter for tuning the stability of polyelectrolyte complexes in general, while still preserving the ability to be processed “saloplastically”.

  16. Alternative Conformations of the Tau Repeat Domain in Complex with an Engineered Binding Protein*

    Science.gov (United States)

    Grüning, Clara S. R.; Mirecka, Ewa A.; Klein, Antonia N.; Mandelkow, Eckhard; Willbold, Dieter; Marino, Stephen F.; Stoldt, Matthias; Hoyer, Wolfgang

    2014-01-01

    The aggregation of Tau into paired helical filaments is involved in the pathogenesis of several neurodegenerative diseases, including Alzheimer disease. The aggregation reaction is characterized by conformational conversion of the repeat domain, which partially adopts a cross-β-structure in the resulting amyloid-like fibrils. Here, we report the selection and characterization of an engineered binding protein, β-wrapin TP4, targeting the Tau repeat domain. TP4 was obtained by phage display using the four-repeat Tau construct K18ΔK280 as a target. TP4 binds K18ΔK280 as well as the longest isoform of human Tau, hTau40, with nanomolar affinity. NMR spectroscopy identified two alternative TP4-binding sites in the four-repeat domain, with each including two hexapeptide motifs with high β-sheet propensity. Both binding sites contain the aggregation-determining PHF6 hexapeptide within repeat 3. In addition, one binding site includes the PHF6* hexapeptide within repeat 2, whereas the other includes the corresponding hexapeptide Tau(337–342) within repeat 4, denoted PHF6**. Comparison of TP4-binding with Tau aggregation reveals that the same regions of Tau are involved in both processes. TP4 inhibits Tau aggregation at substoichiometric concentration, demonstrating that it interferes with aggregation nucleation. This study provides residue-level insight into the interaction of Tau with an aggregation inhibitor and highlights the structural flexibility of Tau. PMID:24966331

  17. A saponification-triggered gelation of ester-based Zn(II) complex through conformational transformations.

    Science.gov (United States)

    Kumar, Ashish; Dubey, Mrigendra; Kumar, Amit; Pandey, Daya Shankar

    2014-09-11

    Novel saponification-triggered gelation in an ester-based bis-salen Zn(II) complex (1) is described. Strategic structural modifications induced by NaOH in 1 tune the dipolar-/π-interactions leading to J-aggregation and the creation of an inorganic gel material (IGM), which has been established by photophysical, DFT and rheological studies.

  18. Conformational analysis of the partially disordered measles virus N(TAIL)-XD complex by SDSL EPR spectroscopy.

    Science.gov (United States)

    Kavalenka, Aleh; Urbancic, Iztok; Belle, Valérie; Rouger, Sabrina; Costanzo, Stéphanie; Kure, Sandra; Fournel, André; Longhi, Sonia; Guigliarelli, Bruno; Strancar, Janez

    2010-03-17

    To characterize the structure of dynamic protein systems, such as partly disordered protein complexes, we propose a novel approach that relies on a combination of site-directed spin-labeled electron paramagnetic resonance spectroscopy and modeling of local rotation conformational spaces. We applied this approach to the intrinsically disordered C-terminal domain of the measles virus nucleoprotein (N(TAIL)) both free and in complex with the X domain (XD, aa 459-507) of the viral phosphoprotein. By comparing measured and modeled temperature-dependent restrictions of the side-chain conformational spaces of 12 SL cysteine-substituted N(TAIL) variants, we showed that the 490-500 region of N(TAIL) is prestructured in the absence of the partner, and were able to quantitatively estimate, for the first time to our knowledge, the extent of the alpha-helical sampling of the free form. In addition, we showed that the 505-525 region of N(TAIL) conserves a significant degree of freedom even in the bound form. The latter two findings provide a mechanistic explanation for the reported rather high affinity of the N(TAIL)-XD binding reaction. Due to the nanosecond timescale of X-band EPR spectroscopy, we were also able to monitor the disordering in the 488-525 region of N(TAIL), in particular the unfolding of the alpha-helical region when the temperature was increased from 281 K to 310 K. Copyright 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  19. Conformational changes in the AAA ATPase p97–p47 adaptor complex

    Science.gov (United States)

    Beuron, Fabienne; Dreveny, Ingrid; Yuan, Xuemei; Pye, Valerie E; Mckeown, Ciaran; Briggs, Louise C; Cliff, Matthew J; Kaneko, Yayoi; Wallis, Russell; Isaacson, Rivka L; Ladbury, John E; Matthews, Steve J; Kondo, Hisao; Zhang, Xiaodong; Freemont, Paul S

    2006-01-01

    The AAA+ATPase p97/VCP, helped by adaptor proteins, exerts its essential role in cellular events such as endoplasmic reticulum-associated protein degradation or the reassembly of Golgi, ER and the nuclear envelope after mitosis. Here, we report the three-dimensional cryo-electron microscopy structures at ∼20 Å resolution in two nucleotide states of the endogenous hexameric p97 in complex with a recombinant p47 trimer, one of the major p97 adaptor proteins involved in membrane fusion. Depending on the nucleotide state, we observe the p47 trimer to be in two distinct arrangements on top of the p97 hexamer. By combining the EM data with NMR and other biophysical measurements, we propose a model of ATP-dependent p97(N) domain motions that lead to a rearrangement of p47 domains, which could result in the disassembly of target protein complexes. PMID:16601695

  20. Conformal complex singlet extension of the Standard Model: scenario for dark matter and a second Higgs boson

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhi-Wei; Steele, T.G. [Department of Physics and Engineering Physics, University of Saskatchewan,116 Science Place, Saskatoon, SK, S7N 5E2 (Canada); Hanif, T. [Department of Theoretical Physics, University of Dhaka,Dhaka-1000 (Bangladesh); Mann, R.B. [Department of Physics, University of Waterloo,Waterloo, ON, N2L 3G1 (Canada)

    2016-08-09

    We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. The global U(1) symmetry of the complex singlet can be either broken or unbroken and we study each scenario. In the unbroken case, the global U(1) symmetry protects the complex singlet from decaying, leading to an ideal cold dark matter candidate with approximately 100 GeV mass along with a significant proportion of thermal relic dark matter abundance. In the broken case, we have developed a renormalization-scale optimization technique to significantly narrow the parameter space and in some situations, provide unique predictions for all the model’s couplings and masses. We have found there exists a second Higgs boson with a mass of approximately 550 GeV that mixes with the known 125 GeV Higgs with a large mixing angle sin θ≈0.47 consistent with current experimental limits. The imaginary part of the complex singlet in the broken case could provide axion dark matter for a wide range of models. Upon including interactions of the complex scalar with an additional vector-like fermion, we explore the possibility of a diphoton excess in both the unbroken and the broken cases. In the unbroken case, the model can provide a natural explanation for diphoton excess if extra terms are introduced providing extra contributions to the singlet mass. In the broken case, we find a set of coupling solutions that yield a second Higgs boson of mass 720 GeV and an 830 GeV extra vector-like fermion F, which is able to address the 750 GeV LHC diphoton excess. We also provide criteria to determine the symmetry breaking pattern in both the Higgs and hidden sectors.

  1. Conformal complex singlet extension of the Standard Model: scenario for dark matter and a second Higgs boson

    Science.gov (United States)

    Wang, Zhi-Wei; Steele, T. G.; Hanif, T.; Mann, R. B.

    2016-08-01

    We consider a conformal complex singlet extension of the Standard Model with a Higgs portal interaction. The global U(1) symmetry of the complex singlet can be either broken or unbroken and we study each scenario. In the unbroken case, the global U(1) symmetry protects the complex singlet from decaying, leading to an ideal cold dark matter candidate with approximately 100 GeV mass along with a significant proportion of thermal relic dark matter abundance. In the broken case, we have developed a renormalization-scale optimization technique to significantly narrow the parameter space and in some situations, provide unique predictions for all the model's couplings and masses. We have found there exists a second Higgs boson with a mass of approximately 550 GeV that mixes with the known 125 GeV Higgs with a large mixing angle sin θ ≈ 0.47 consistent with current experimental limits. The imaginary part of the complex singlet in the broken case could provide axion dark matter for a wide range of models. Upon including interactions of the complex scalar with an additional vector-like fermion, we explore the possibility of a diphoton excess in both the unbroken and the broken cases. In the unbroken case, the model can provide a natural explanation for diphoton excess if extra terms are introduced providing extra contributions to the singlet mass. In the broken case, we find a set of coupling solutions that yield a second Higgs boson of mass 720 GeV and an 830 GeV extra vector-like fermion F , which is able to address the 750 GeV LHC diphoton excess. We also provide criteria to determine the symmetry breaking pattern in both the Higgs and hidden sectors.

  2. Influence of Tableting on the Conformation and Thermal Stability of Trypsin as a Model Protein

    DEFF Research Database (Denmark)

    Klukkert, Marten; Van De Weert, Marco; Fanø, Mathias

    2015-01-01

    was performed to determine the Tm as well as the folding reversibility after thermal denaturation of the reconstituted samples. It was found that compacted samples showed reduced activity accompanied by an altered secondary structure. Conformational changes that occur in the solid state were partially...... reversible upon tablet reconstitution. Aqueous-state IR spectroscopy combined with partial least squares was shown to be a powerful tool to follow irreversible structural changes and evaluate sample bioactivity. Besides its conformation, the thermal stability of trypsin was altered as a result of the applied...... compaction pressure, indicated by a reduced folding reversibility. In conclusion, this study reveals that tableting can have a negative impact on the biological quality of protein APIs....

  3. Influence of DNA conformation on radiation-induced single-strand breaks

    International Nuclear Information System (INIS)

    Barone, F.; Belli, M.; Mazzei, F.

    1994-01-01

    We performed experiments on two DNA fragments of about 300 bp having different conformation to test whether radiation-induced single-strand breakage is dependent on DNA conformation. Breakage analysis was carried out by denaturing polyacrylamide gel electrophoresis, which allows determination of the broken site at single nucleotide resolution. We found uniform cutting patterns in B-form regions. On the contrary, X- or γ-irradiation of curved fragments of kinetoplast DNA showed that the distribution of single-strand breaks was not uniform along the fragment, as the cleavage pattern was modulated in phase with the runs of A-T pairs. This modulation likely reflected the reduced accessibility of the sites which on hydroxyl-radical attack give rise to strand breaks. The cleavage pattern was phased with the runs of A-T pairs. Moreover, the overall yield of strand breaks was considerably lower in curved DNA fragments than in those with extended straight regions. The conformation effect found here indicates that the cleavage pattern reflects the fine structural features of DNA. (orig./MG)

  4. Ecotoxicology of waters under the influence of a petrochemical complex

    Energy Technology Data Exchange (ETDEWEB)

    Noll, R.; Zandonai, V.; Ries, M.A. [CORSAN-SITEL, Triunfo, RS (Brazil). Polo Petrquimico do Sul

    1993-12-31

    This work summarizes the regular monitoring and studies conducted by SITEL - The Integrated Wastewater Treatment System of South Petrochemical Complex (South Brazil) - in order to evaluate the full environmental impact on waters in the area of influence of the effluents of the above mentioned Complex. 8 refs., 1 fig., 5 tabs.

  5. Ecotoxicology of waters under the influence of a petrochemical complex

    Energy Technology Data Exchange (ETDEWEB)

    Noll, R; Zandonai, V; Ries, M A [CORSAN-SITEL, Triunfo, RS (Brazil). Polo Petrquimico do Sul

    1994-12-31

    This work summarizes the regular monitoring and studies conducted by SITEL - The Integrated Wastewater Treatment System of South Petrochemical Complex (South Brazil) - in order to evaluate the full environmental impact on waters in the area of influence of the effluents of the above mentioned Complex. 8 refs., 1 fig., 5 tabs.

  6. Conformational changes in the bilirubin-human serum albumin complex at extreme alkaline pH

    DEFF Research Database (Denmark)

    Honoré, B; Frandsen, P C

    1986-01-01

    Light-absorption, c.d. and fluorescence of the bilirubin-albumin complex were investigated at extreme alkaline pH. Above pH 11.1 albumin binds the bilirubin molecule, twisted oppositely to the configuration at more neutral pH. On the basis of light-absorption it is shown that two alkaline...... transitions occur. The first alkaline transition takes place at pH between 11.3 and 11.8, co-operatively dissociating at least six protons. The second alkaline transition takes place at pH between 11.8 and 12.0. It probably implies a reversible unfolding of the albumin molecule, increasing the distance...

  7. Dose prescription complexity versus tumor control probability in biologically conformal radiotherapy

    International Nuclear Information System (INIS)

    South, C. P.; Evans, P. M.; Partridge, M.

    2009-01-01

    The technical feasibility and potential benefits of voxel-based nonuniform dose prescriptions for biologically heterogeneous tumors have been widely demonstrated. In some cases, an ''ideal'' dose prescription has been generated by individualizing the dose to every voxel within the target, but often this voxel-based prescription has been discretized into a small number of compartments. The number of dose levels utilized and the methods used for prescribing doses and assigning tumor voxels to different dose compartments have varied significantly. The authors present an investigation into the relationship between the complexity of the dose prescription and the tumor control probability (TCP) for a number of these methods. The linear quadratic model of cell killing was used in conjunction with a number of modeled tumors heterogeneous in clonogen density, oxygenation, or proliferation. Models based on simple mathematical functions, published biological data, and biological image data were investigated. Target voxels were assigned to dose compartments using (i) simple rules based on the initial biological distribution, (ii) iterative methods designed to maximize the achievable TCP, or (iii) methods based on an ideal dose prescription. The relative performance of the simple rules was found to depend on the form of heterogeneity of the tumor, while the iterative and ideal dose methods performed comparably for all models investigated. In all cases the maximum achievable TCP was approached within the first few (typically two to five) compartments. Results suggest that irrespective of the pattern of heterogeneity, the optimal dose prescription can be well approximated using only a few dose levels but only if both the compartment boundaries and prescribed dose levels are well chosen.

  8. Roles of Bridging Ligand Topology and Conformation in Controlling Exchange Interactions between Paramagnetic Molybdenum Fragments in Dinuclear and Trinuclear Complexes.

    Science.gov (United States)

    Ung VÂ, V&acaron;n Ân; Cargill Thompson, Alexander M. W.; Bardwell, David A.; Gatteschi, Dante; Jeffery, John C.; McCleverty, Jon A.; Totti, Federico; Ward, Michael D.

    1997-07-30

    The magnetic properties of two series of dinuclear complexes, and one trinuclear complex, have been examined as a function of the bridging pathway between the metal centers. The first series of dinuclear complexes is [{Mo(V)(O)(Tp)Cl}(2)(&mgr;-OO)], where "OO" is [1,4-O(C(6)H(4))(n)O](2)(-) (n = 1, 1; n = 2, 3), [4,4'-O(C(6)H(3)-2-Me)(2)O](2)(-) (4), or [1,3-OC(6)H(4)O](2)(-) (2) [Tp = tris(3,5-dimethylpyrazolyl)hydroborate]. The second series of dinuclear complexes is [{Mo(I)(NO)(Tp)Cl}(2)(&mgr;-NN)], where "NN" is 4,4'-bipyridyl (5), 3,3'-dimethyl-4,4'-bipyridine (6), 3,8-phenanthroline (7), or 2,7-diazapyrene (8). The trinuclear complex is [{Mo(V)(O)(Tp)Cl}(3)(1,3,5-C(6)H(3)O(3))] (9), whose crystal structure was determined [9.5CH(2)Cl(2): C(56)H(81)B(3)Cl(13)Mo(3)N(18)O(6); monoclinic, P2(1)/n; a = 13.443, b = 41.46(2), c = 14.314(6) Å; beta = 93.21(3) degrees; V = 7995(5) Å(3); Z = 4; R(1) = 0.106]. In these complexes, the sign and magnitude of the exchange coupling constant J is clearly related to both the topology and the conformation of the bridging ligand [where J is derived from H = -JS(1)().S(2)() for 1-8 and H = -J(S(1)().S(2)() + S(2)().S(3)() + S(1)().S(3)()) for 9]. The values are as follows: 1, -80 cm(-)(1); 2, +9.8 cm(-)(1); 3, -13.2 cm(-)(1); 4, -2.8 cm(-)(1); 5, -33 cm(-)(1); 6, -3.5 cm(-)(1); 7, -35.6 cm(-)(1); 8, -35.0 cm(-)(1); 9, +14.4 cm(-)(1). In particular the following holds: (1) J is negative (antiferromagnetic exchange) across the para-substituted bridges ligands of 1 and 3-8 but positive (ferromagnetic exchange) across the meta-substituted bridging ligands of 2 and 9. (2) J decreases in magnitude dramatically as the bridging ligand conformation changes from planar to twisted (compare 3 and 4, or 6 and 8). These observations are consistent with a spin-polarization mechanism for the exchange interaction, propagated across the pi-system of the bridging ligand by via overlap of bridging ligand p(pi) orbitals with the d(pi) magnetic

  9. How osmolytes influence hydrophobic polymer conformations: A unified view from experiment and theory.

    Science.gov (United States)

    Mondal, Jagannath; Halverson, Duncan; Li, Isaac T S; Stirnemann, Guillaume; Walker, Gilbert C; Berne, Bruce J

    2015-07-28

    It is currently the consensus belief that protective osmolytes such as trimethylamine N-oxide (TMAO) favor protein folding by being excluded from the vicinity of a protein, whereas denaturing osmolytes such as urea lead to protein unfolding by strongly binding to the surface. Despite there being consensus on how TMAO and urea affect proteins as a whole, very little is known as to their effects on the individual mechanisms responsible for protein structure formation, especially hydrophobic association. In the present study, we use single-molecule atomic force microscopy and molecular dynamics simulations to investigate the effects of TMAO and urea on the unfolding of the hydrophobic homopolymer polystyrene. Incorporated with interfacial energy measurements, our results show that TMAO and urea act on polystyrene as a protectant and a denaturant, respectively, while complying with Tanford-Wyman preferential binding theory. We provide a molecular explanation suggesting that TMAO molecules have a greater thermodynamic binding affinity with the collapsed conformation of polystyrene than with the extended conformation, while the reverse is true for urea molecules. Results presented here from both experiment and simulation are in line with earlier predictions on a model Lennard-Jones polymer while also demonstrating the distinction in the mechanism of osmolyte action between protein and hydrophobic polymer. This marks, to our knowledge, the first experimental observation of TMAO-induced hydrophobic collapse in a ternary aqueous system.

  10. Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

    Directory of Open Access Journals (Sweden)

    Ioan Botiz

    2014-03-01

    Full Text Available It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties.

  11. Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

    KAUST Repository

    Botiz, Ioan; Stingelin, Natalie

    2014-01-01

    It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties. © 2014 by the authors.

  12. Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers

    KAUST Repository

    Botiz, Ioan

    2014-03-19

    It is increasingly obvious that the molecular conformations and the long-range arrangement that conjugated polymers can adopt under various experimental conditions in bulk, solutions or thin films, significantly impact their resulting optoelectronic properties. As a consequence, the functionalities and efficiencies of resulting organic devices, such as field-effect transistors, light-emitting diodes, or photovoltaic cells, also dramatically change due to the close structure/property relationship. A range of structure/optoelectronic properties relationships have been investigated over the last few years using various experimental and theoretical methods, and, further, interesting correlations are continuously revealed by the scientific community. In this review, we discuss the latest findings related to the structure/optoelectronic properties interrelationships that exist in organic devices fabricated with conjugated polymers in terms of charge mobility, absorption, photoluminescence, as well as photovoltaic properties. © 2014 by the authors.

  13. INFLUENCE OF COMPLEXITY ON THE MARGINAL LOGISTICAL COSTS

    Directory of Open Access Journals (Sweden)

    Juraj DUBOVEC

    2013-12-01

    Full Text Available In the article is described the influence of complexity on the logistical operations. Ideal example is the exchange of storage in the system "kanban", which has complexity equal one. Clients directed production increases the consumption of time in logistics within manipulation with critical parts, when the ratio isn't equal to multiple capacity relevant storage. Economical consequence is the increase of costs.

  14. Factors influencing efficient structure of fuel and energy complex

    Science.gov (United States)

    Sidorova, N. G.; Novikova, S. A.

    2017-10-01

    The development of the Russian fuel-energy complex is a priority for the national economic policy, and the Far East is a link between Russia and the Asia-Pacific region. Large-scale engineering of numerous resources of the Far East will force industrial development, increase living standard and strengthen Russia’s position in the global energy market. So, revealing the factors which influence rational structure of the fuel-energy complex is very urgent nowadays. With the use of depth analysis of development tendencies of the complex and its problems the authors show ways of its efficiency improvement.

  15. Structure of Mycobacterium tuberculosis phosphopantetheine adenylyltransferase in complex with the feedback inhibitor CoA reveals only one active-site conformation

    Energy Technology Data Exchange (ETDEWEB)

    Wubben, T.; Mesecar, A.D. (Purdue); (UIC)

    2014-10-02

    Phosphopantetheine adenylyltransferase (PPAT) catalyzes the penultimate step in the coenzyme A (CoA) biosynthetic pathway, reversibly transferring an adenylyl group from ATP to 4'-phosphopantetheine to form dephosphocoenzyme A (dPCoA). To complement recent biochemical and structural studies on Mycobacterium tuberculosis PPAT (MtPPAT) and to provide further insight into the feedback regulation of MtPPAT by CoA, the X-ray crystal structure of the MtPPAT enzyme in complex with CoA was determined to 2.11 {angstrom} resolution. Unlike previous X-ray crystal structures of PPAT-CoA complexes from other bacteria, which showed two distinct CoA conformations bound to the active site, only one conformation of CoA is observed in the MtPPAT-CoA complex.

  16. The influence of junction conformation on RNA cleavage by the hairpin ribozyme in its natural junction form.

    Science.gov (United States)

    Thomson, J B; Lilley, D M

    1999-01-01

    In the natural form of the hairpin ribozyme the two loop-carrying duplexes that comprise the majority of essential bases for activity form two adjacent helical arms of a four-way RNA junction. In the present work we have manipulated the sequence around the junction in a way known to perturb the global folding properties. We find that replacement of the junction by a different sequence that has the same conformational properties as the natural sequence gives closely similar reaction rate and Arrhenius activation energy for the substrate cleavage reaction. By comparison, rotation of the natural sequence in order to alter the three-dimensional folding of the ribozyme leads to a tenfold reduction in the kinetics of cleavage. Replacement with the U1 four-way junction that is resistant to rotation into the antiparallel structure required to allow interaction between the loops also gives a tenfold reduction in cleavage rate. The results indicate that the conformation of the junction has a major influence on the catalytic activity of the ribozyme. The results are all consistent with a role for the junction in the provision of a framework by which the loops are presented for interaction in order to create the active form of the ribozyme. PMID:10024170

  17. Structural-conformational aspects of tRNA complexation with chloroethyl nitrosourea derivatives: A molecular modeling and spectroscopic investigation.

    Science.gov (United States)

    Agarwal, Shweta; Tyagi, Gunjan; Chadha, Deepti; Mehrotra, Ranjana

    2017-01-01

    Chloroethyl nitrosourea derivatives (CENUs) represent an important family of anticancer chemotherapeutic agents, which are used in the treatment of different types of cancer such as brain tumors, resistant or relapsed Hodgkin's disease, small cell lung cancer and malignant melanoma. This work focuses towards understanding the interaction of chloroethyl nitrosourea derivatives; lomustine, nimustine and semustine with tRNA using spectroscopic approach in order to elucidate their auxiliary anticancer action mechanism inside the cell. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), Fourier transform infrared difference spectroscopy, circular dichroism spectroscopy and UV-visible spectroscopy were employed to investigate the binding parameters of tRNA-CENUs complexation. Results of present study demonstrate that all CENUs, studied here, interact with tRNA through guanine nitrogenous base residues and possibly further crosslink cytosine residues in paired region of tRNA. Moreover, spectral data collected for nimustine-tRNA and semustine-tRNA complex formation indicates towards the groove-directed-alkylation as their anti-malignant action, which involves the participation of uracil moiety located in major groove of tRNA. Besides this, tRNA-CENUs adduct formation did not alter the native conformation of biopolymer and tRNA remains in A-form after its interaction with all three nitrosourea derivatives studied. The binding constants (K a ) estimated for tRNA complexation with lomustine, nimustine and semustine are 2.55×10 2 M -1 , 4.923×10 2 M -1 and 4.223×10 2 M -1 respectively, which specify weak type of CENU's binding with tRNA. Moreover, molecular modeling simulations were also performed to predict preferential binding orientation of CENUs with tRNA that corroborates well with spectral outcomes. The findings, presented here, recognize tRNA binding properties of CENUs that can further help in rational designing of more specific and

  18. Conformality lost

    International Nuclear Information System (INIS)

    Kaplan, David B.; Lee, Jong-Wan; Son, Dam T.; Stephanov, Mikhail A.

    2009-01-01

    We consider zero-temperature transitions from conformal to nonconformal phases in quantum theories. We argue that there are three generic mechanisms for the loss of conformality in any number of dimensions: (i) fixed point goes to zero coupling, (ii) fixed point runs off to infinite coupling, or (iii) an IR fixed point annihilates with a UV fixed point and they both disappear into the complex plane. We give both relativistic and nonrelativistic examples of the last case in various dimensions and show that the critical behavior of the mass gap behaves similarly to the correlation length in the finite temperature Berezinskii-Kosterlitz-Thouless (BKT) phase transition in two dimensions, ξ∼exp(c/|T-T c | 1/2 ). We speculate that the chiral phase transition in QCD at large number of fermion flavors belongs to this universality class, and attempt to identify the UV fixed point that annihilates with the Banks-Zaks fixed point at the lower end of the conformal window.

  19. Route complexity and simulated physical ageing negatively influence wayfinding

    NARCIS (Netherlands)

    Zijlstra, Emma; Hagedoorn, Mariet; Krijnen, Wim P.; Schans, van der Cornelis; Mobach, Mark P.

    The aim of this age-simulation field experiment was to assess the influence of route complexity and physical ageing on wayfinding. Seventy-five people (aged 18-28) performed a total of 108 wayfinding tasks (i.e., 42 participants performed two wayfinding tasks and 33 performed one wayfinding task),

  20. Enzymatic monoesterification of symmetric diols: restriction of molecular conformations influences selectivity.

    Science.gov (United States)

    Tomer, Sanjiv O; Soni, Hemant P

    2017-10-31

    We have experimentally demonstrated that by 'locking' the molecular conformation through the introduction of a double or triple bond in the center of a symmetric diol, enzymatic monoesterification can be achieved selectively. The enzyme Candida antarctica lipase B, generally used for the transesterification of diols, can be effectively used for the monoesterification of symmetrical diols in an unbuffered system also. By varying the chain length of a carboxylic acid moiety, we have established that optimum selectivity and efficiency can be achieved in the range of 4.8 to 5.0 pK a values. Selectivity can be improved up to 98.75% for a monoester in an overall 73% yield (mixture of a monoester and a diester) when but-2-yne-1,4-diol reacted with hexanoic acid. Water, a by-product, provides an interfacial environment for the enzyme to work in the organic reaction medium. The uniqueness of the reported monoesterification protocol is that it involves only the mechanical stirring of the reaction mixture at room temperature in the presence of the enzyme for 24 h. High percentage yield with selectivity for a monoester, easier product isolation and overall, environmental sustainability are added advantages. The synthesized monoesters are characterized by using HNMR and high resolution mass spectrometry (HRMS).

  1. Influence of hydroxylamine conformation on stereocontrol in Pd-catalyzed isoxazolidine-forming reactions.

    Science.gov (United States)

    Lemen, Georgia S; Giampietro, Natalie C; Hay, Michael B; Wolfe, John P

    2009-03-20

    Palladium-catalyzed carboamination reactions between N-Boc-O-(but-3-enyl)hydroxylamine derivatives and aryl or alkenyl bromides afford cis-3,5- and trans-4,5-disubstituted isoxazolidines in good yield with up to >20:1 dr. The diastereoselectivity observed in the formation of cis-3,5-disubstituted isoxazolidines is superior to selectivities typically obtained in other transformations, such as 1,3-dipolar cycloaddition reactions, that provide these products. In addition, the stereocontrol in the C-N bond-forming Pd-catalyzed carboamination reactions of N-Boc-O-(but-3-enyl)hydroxylamines is significantly higher than that of related C-O bond-forming carboetherification reactions of N-benzyl-N-(but-3-enyl)hydroxylamine derivatives. This is likely due to a stereoelectronic preference for cyclization via transition states in which the Boc group is placed in a perpendicular orientation relative to the plane of the developing ring, which derives from the conformational equilibria of substituted hydroxylamines.

  2. Two conformational states of the membrane-associated Bacillus thuringiensis Cry4Ba δ-endotoxin complex revealed by electron crystallography: Implications for toxin-pore formation

    International Nuclear Information System (INIS)

    Ounjai, Puey; Unger, Vinzenz M.; Sigworth, Fred J.; Angsuthanasombat, Chanan

    2007-01-01

    The insecticidal nature of Cry δ-endotoxins produced by Bacillus thuringiensis is generally believed to be caused by their ability to form lytic pores in the midgut cell membrane of susceptible insect larvae. Here we have analyzed membrane-associated structures of the 65-kDa dipteran-active Cry4Ba toxin by electron crystallography. The membrane-associated toxin complex was crystallized in the presence of DMPC via detergent dialysis. Depending upon the charge of the adsorbed surface, 2D crystals of the oligomeric toxin complex have been captured in two distinct conformations. The projection maps of those crystals have been generated at 17 A resolution. Both complexes appeared to be trimeric; as in one crystal form, its projection structure revealed a symmetrical pinwheel-like shape with virtually no depression in the middle of the complex. The other form revealed a propeller-like conformation displaying an obvious hole in the center region, presumably representing the toxin-induced pore. These crystallographic data thus demonstrate for the first time that the 65-kDa activated Cry4Ba toxin in association with lipid membranes could exist in at least two different trimeric conformations, conceivably implying the closed and open states of the pore

  3. Acute stress influences the discrimination of complex scenes and complex faces in young healthy men.

    Science.gov (United States)

    Paul, M; Lech, R K; Scheil, J; Dierolf, A M; Suchan, B; Wolf, O T

    2016-04-01

    The stress-induced release of glucocorticoids has been demonstrated to influence hippocampal functions via the modulation of specific receptors. At the behavioral level stress is known to influence hippocampus dependent long-term memory. In recent years, studies have consistently associated the hippocampus with the non-mnemonic perception of scenes, while adjacent regions in the medial temporal lobe were associated with the perception of objects, and faces. So far it is not known whether and how stress influences non-mnemonic perceptual processes. In a behavioral study, fifty male participants were subjected either to the stressful socially evaluated cold-pressor test or to a non-stressful control procedure, before they completed a visual discrimination task, comprising scenes and faces. The complexity of the face and scene stimuli was manipulated in easy and difficult conditions. A significant three way interaction between stress, stimulus type and complexity was found. Stressed participants tended to commit more errors in the complex scenes condition. For complex faces a descriptive tendency in the opposite direction (fewer errors under stress) was observed. As a result the difference between the number of errors for scenes and errors for faces was significantly larger in the stress group. These results indicate that, beyond the effects of stress on long-term memory, stress influences the discrimination of spatial information, especially when the perception is characterized by a high complexity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Laser desorption single-conformation UV and IR spectroscopy of the sulfonamide drug sulfanilamide, the sulfanilamide-water complex, and the sulfanilamide dimer.

    Science.gov (United States)

    Uhlemann, Thomas; Seidel, Sebastian; Müller, Christian W

    2017-06-07

    We have studied the conformational preferences of the sulfonamide drug sulfanilamide, its dimer, and its monohydrated complex through laser desorption single-conformation UV and IR spectroscopy in a molecular beam. Based on potential energy curves for the inversion of the anilinic and the sulfonamide NH 2 groups calculated at DFT level, we suggest that the zero-point level wave function of the sulfanilamide monomer is appreciably delocalized over all four conformer wells. The sulfanilamide dimer, and the monohydrated complex each exhibit a single isomer in the molecular beam. The isomeric structures of the sulfanilamide dimer and the monohydrated sulfanilamide complex were assigned based on their conformer-specific IR spectra in the NH and OH stretch region. Quantum Theory of Atoms in Molecules (QTAIM) analysis of the calculated electron density in the water complex suggests that the water molecule is bound side-on in a hydrogen bonding pocket, donating one O-HO[double bond, length as m-dash]S hydrogen bond and accepting two hydrogen bonds, a NHO and a CHO hydrogen bond. QTAIM analysis of the dimer electron density suggests that the C i symmetry dimer structure exhibits two dominating N-HO[double bond, length as m-dash]S hydrogen bonds, and three weaker types of interactions: two CHO bonds, two CHN bonds, and a chalcogen OO interaction. Most interestingly, the molecular beam dimer structure closely resembles the R dimer unit - the dimer unit with the greatest interaction energy - of the α, γ, and δ crystal polymorphs. Interacting Quantum Atoms analysis provides evidence that the total intermolecular interaction in the dimer is dominated by the short-range exchange-correlation contribution.

  5. Influence of the nematic order on the rheology and conformation of stretched comb-like liquid crystalline polymers

    Science.gov (United States)

    Fourmaux-Demange, V.; Brûlet, A.; Boué, F.; Davidson, P.; Keller, P.; Cotton, J. P.

    2000-04-01

    We have studied the rheology and the conformation of stretched comb-like liquid-crystalline polymers. Both the influence of the comb-like structure and the specific effect of the nematic interaction on the dynamics are investigated. For this purpose, two isomers of a comb-like polymetacrylate polymer, of well-defined molecular weights, were synthesized: one displays a nematic phase over a wide range of temperature, the other one has only an isotropic phase. Even with high degrees of polymerization N, between 40 and 1000, the polymer chains studied were not entangled. The stress-strain curves during the stretching and relaxation processes show differences between the isotropic and nematic comb-like polymers. They suggest that, in the nematic phase, the chain dynamics is more cooperative than for a usual linear polymer. Small-angle neutron scattering has been used in order to determine the evolution of the chain conformation after stretching, as a function of the duration of relaxation t_r. The conformation can be described with two parameters only: λ_p, the global deformation of the polymer chain, and p, the number of statistical units of locally relaxed sub-chains. For the comb-like polymer, the chain deformation is pseudo-affine: λ_p is always smaller than λ (the deformation ratio of the whole sample). In the isotropic phase, λ_p has a constant value, while p increases as t_r. This latter behavior is not that expected for non-entangled chains, in which p varies as {t_r}^{1/2} (Rouse model). In the nematic phase, λ_p decreases as a stretched exponential function of t_r, while p remains constant. The dynamics of the comb-like polymers is discussed in terms of living clusters from which junctions are produced by interactions between side chains. The nematic interaction increases the lifetime of these junctions and, strikingly, the relaxation is the same at all scales of the whole polymer chain.

  6. Thickenings and conformal gravity

    Science.gov (United States)

    Lebrun, Claude

    1991-07-01

    A twistor correspondence is given for complex conformal space-times with vanishing Bach and Eastwood-Dighton tensors; when the Weyl curvature is algebraically general, these equations are precisely the conformal version of Einstein's vacuum equations with cosmological constant. This gives a fully curved version of the linearized correspondence of Baston and Mason [B-M].

  7. Thickenings and conformal gravity

    Energy Technology Data Exchange (ETDEWEB)

    LeBrun, C. (State Univ. of New York, Stony Brook, NY (USA). Dept. of Mathematics)

    1991-07-01

    A twistor correspondence is given for complex conformal space-times with vanishing Bach and Eastwood-Dighton tensors; when the Weyl curvature is algebraically general, these equations are precisely the conformal version of Einstein's vacuum equations with cosmological constant. This gives a fully curved version of the linearized correspondence of Baston and Mason (B-M). (orig.).

  8. Thickenings and conformal gravity

    International Nuclear Information System (INIS)

    LeBrun, C.

    1991-01-01

    A twistor correspondence is given for complex conformal space-times with vanishing Bach and Eastwood-Dighton tensors; when the Weyl curvature is algebraically general, these equations are precisely the conformal version of Einstein's vacuum equations with cosmological constant. This gives a fully curved version of the linearized correspondence of Baston and Mason [B-M]. (orig.)

  9. [The conformational dynamics of the tetramer hemoglobin molecule as revealed by hydrogen exchange. III. Influence of the heme removal].

    Science.gov (United States)

    Abaturov, L V; Nosova, N G; Shliapnikova, S V

    2006-01-01

    Two main types of conformational fluctuations--local and global are characteristic of the native protein structure and revealed by hydrogen exchange. The probability of those fluctuations changes to a different extent upon hemoglobin oxygenation, changing of pH, splitting of the intersubunit contacts. To compare with the influence of the heme removal the rate of the H-D exchange of the peptide NH atoms of the human apoHb was studied at the pH range 5.5-9.0 and temperature 10-38 degrees C by the IR spectroscopy. The removal of the heme increases the rate of the H-D exchange of the 80% peptide NH atoms with the factor retardation of the exchange rate (P) in the range approximately 10(2)-10(8). For the most of the peptide NH atoms the probability of the local fluctuations weakly depends on the temperature, the enthalpy changes upon all such local conformational transitions deltaH(op) degrees are 0-15 kcal/M. Characterized by the stronger temperature dependence the global fluctuations are not arised upon the temperature increases up to 38 degrees C at pH 7.0 inspite of in these conditions the slow denaturation and aggregation of apoHb begin to occur. Upon the destabilization of the apoHb structure by the simultaneous decreasing of pH to 5.5 and temperature to 10 degrees C the global fluctuations of the apoHb native structure described by deltaH(op)o < 0 begin to intensify. The mechanism of the overall intensification of the local fluctuations upon the heme removal, the peculiarity of the heat denaturation of apoHb in conditions, close to that existing upon the selfassembly of Hb in vivo, and analogy between low temperature global fluctuations and cold denaturation of globular proteins are discussed.

  10. Role of DNA conformation & energetic insights in Msx-1-DNA recognition as revealed by molecular dynamics studies on specific and nonspecific complexes.

    Science.gov (United States)

    Kachhap, Sangita; Singh, Balvinder

    2015-01-01

    In most of homeodomain-DNA complexes, glutamine or lysine is present at 50th position and interacts with 5th and 6th nucleotide of core recognition region. Molecular dynamics simulations of Msx-1-DNA complex (Q50-TG) and its variant complexes, that is specific (Q50K-CC), nonspecific (Q50-CC) having mutation in DNA and (Q50K-TG) in protein, have been carried out. Analysis of protein-DNA interactions and structure of DNA in specific and nonspecific complexes show that amino acid residues use sequence-dependent shape of DNA to interact. The binding free energies of all four complexes were analysed to define role of amino acid residue at 50th position in terms of binding strength considering the variation in DNA on stability of protein-DNA complexes. The order of stability of protein-DNA complexes shows that specific complexes are more stable than nonspecific ones. Decomposition analysis shows that N-terminal amino acid residues have been found to contribute maximally in binding free energy of protein-DNA complexes. Among specific protein-DNA complexes, K50 contributes more as compared to Q50 towards binding free energy in respective complexes. The sequence dependence of local conformation of DNA enables Q50/Q50K to make hydrogen bond with nucleotide(s) of DNA. The changes in amino acid sequence of protein are accommodated and stabilized around TAAT core region of DNA having variation in nucleotides.

  11. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  12. The influence of the side-chain sequence on the structure-activity correlations of immunomodulatory branched polypeptides. Synthesis and conformational analysis of new model polypeptides.

    Science.gov (United States)

    Mezö, G; Hudecz, F; Kajtár, J; Szókán, G; Szekerke, M

    1989-10-01

    New branched polypeptides were synthesized for a detailed study of the influence of the side-chain structure on the conformation and biological properties. The first subset of polypeptides were prepared by coupling of tetrapeptides to poly[L-Lys]. These polymers contain either DL-Ala3-X [poly[Lys-(X-DL-Ala3)n

  13. Fundamental insights into conformational stability and orbital interactions of antioxidant (+)-catechin species and complexation of (+)-catechin with zinc(II) and oxovanadium(IV)

    Science.gov (United States)

    Yasarawan, Nuttawisit; Thipyapong, Khajadpai; Sirichai, Somsak; Ruangpornvisuti, Vithaya

    2013-09-01

    Conformational stability of (+)-catechin species in water has been examined with density functional theory, associated with the polarizable continuum model (PCM) of solvation. Factors such as electron delocalization, lone-pair electron donation and intramolecular hydrogen bonding substantially contribute to the conformational stabilization. Upon deprotonation, the HOMO and LUMO energies for (+)-catechin are both elevated; the energy gaps for the deprotonated species are narrower than the energy gap for the neutral species. The preferential deprotonation occurs at the C3'-, C5-, C7- and C4'-OH groups successively. The pKa value at 9.3 predicted for the most acidic OH group agrees well with previous experimental data; however the values are overestimated for the less acidic OH groups due to limitations of the PCM for charged solutes and/or complex nature of true deprotonation pathways. Formation of hydrogen radicals should be promoted at high pH values following the bond dissociation enthalpies. Complexation of (+)-catechin with either zinc(II) or oxovanadium(IV) is favored at the 1:1 metal-to-ligand (M:L) mole ratio, with the oxovanadium(IV) complex showing higher reaction preference. At M:L = 1:2, formation of two isomeric complexes are plausible for each type of metal ion. Effects of stoichiometry and isomerism on the computational spectral features of the possibly formed metal complexes have been described.

  14. Influence of structural features of carrageenan on the formation of polyelectrolyte complexes with chitosan.

    Science.gov (United States)

    Volod'ko, A V; Davydova, V N; Glazunov, V P; Likhatskaya, G N; Yermak, I M

    2016-03-01

    The polyelectrolyte complexes (PEC) of carrageenans (CG)-κ-, κ/β-, λ-and x-CG with chitosan were obtained. The formation of PEC was detected by Fourier-transform infrared (FTIR) spectroscopy and by centrifugation in a Percoll gradient. The influence of the structural peculiarities of CG on its interaction with chitosan was studied. The results of centrifugation showed that x-CG with a high degree of sulphation (SD) was completely bound to chitosan, unlike low SD κ-CG and κ/β-CG. Binding constant values showed there was a high affinity of CG for chitosan. CG with flexible macromolecule conformation and high SD exhibited the greatest binding affinity for chitosan. The full-atomic 3D-structures of the PEC κ-CG: chitosan in solution have been obtained by the experiments in silico for the first time. The amino groups of chitosan make the largest contribution to the energy of the complex formation by means of hydrogen and ionic bonds. The most probable complexes have stoichiometries of 1:1 and 1:1.5. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Environmental influences on neural systems of relational complexity

    Directory of Open Access Journals (Sweden)

    Layne eKalbfleisch

    2013-09-01

    Full Text Available Constructivist learning theory contends that we construct knowledge by experience and that environmental context influences learning. To explore this principle, we examined the cognitive process relational complexity (RC, defined as the number of visual dimensions considered during problem solving on a matrix reasoning task and a well-documented measure of mature reasoning capacity. We sought to determine how the visual environment influences RC by examining the influence of color and visual contrast on RC in a neuroimaging task. To specify the contributions of sensory demand and relational integration to reasoning, our participants performed a non-verbal matrix task comprised of color, no-color line, or black-white visual contrast conditions parametrically varied by complexity (relations 0, 1, 2. The use of matrix reasoning is ecologically valid for its psychometric relevance and for its potential to link the processing of psychophysically specific visual properties with various levels of relational complexity during reasoning. The role of these elements is important because matrix tests assess intellectual aptitude based on these seemingly context-less exercises. This experiment is a first step toward examining the psychophysical underpinnings of performance on these types of problems. The importance of this is increased in light of recent evidence that intelligence can be linked to visual discrimination. We submit three main findings. First, color and black-white visual contrast add demand at a basic sensory level, but contributions from color and from black-white visual contrast are dissociable in cortex such that color engages a reasoning heuristic and black-white visual contrast engages a sensory heuristic. Second, color supports contextual sense-making by boosting salience resulting in faster problem solving. Lastly, when visual complexity reaches 2-relations, color and visual contrast relinquish salience to other dimensions of problem

  16. Implementing complex innovations: factors influencing middle manager support.

    Science.gov (United States)

    Chuang, Emmeline; Jason, Kendra; Morgan, Jennifer Craft

    2011-01-01

    Middle manager resistance is often described as a major challenge for upper-level administrators seeking to implement complex innovations such as evidence-based protocols or new skills training. However, factors influencing middle manager support for innovation implementation are currently understudied in the U.S. health care literature. This article examined the factors that influence middle managers' support for and participation in the implementation of work-based learning, a complex innovation adopted by health care organizations to improve the jobs, educational pathways, skills, and/or credentials of their frontline workers. We conducted semistructured interviews and focus groups with 92 middle managers in 17 health care organizations. Questions focused on understanding middle managers' support for work-based learning as a complex innovation, facilitators and barriers to the implementation process, and the systems changes needed to support the implementation of this innovation. Factors that emerged as influential to middle manager support were similar to those found in broader models of innovation implementation within the health care literature. However, our findings extend previous research by developing an understanding about how middle managers perceived these constructs and by identifying specific strategies for how to influence middle manager support for the innovation implementation process. These findings were generally consistent across different types of health care organizations. Study findings suggest that middle manager support was highest when managers felt the innovation fit their workplace needs and priorities and when they had more discretion and control over how it was implemented. Leaders seeking to implement innovations should consider the interplay between middle managers' control and discretion, their narrow focus on the performance of their own departments or units, and the dedication of staff and other resources for empowering their

  17. Solid state conformational classification of eight-membered rings

    DEFF Research Database (Denmark)

    Pérez, J.; García, L.; Kessler, M.

    2005-01-01

    A statistical classification of the solid state conformation in the title complexes using data retrieved from the Cambridge Structural Database (CSD) has been made. Phosphate and phosphinate complexes show a chair conformation preferably. In phosphonate complexes, the most frequent conformations...

  18. Influence of planning time and treatment complexity on radiation therapy errors.

    Science.gov (United States)

    Gensheimer, Michael F; Zeng, Jing; Carlson, Joshua; Spady, Phil; Jordan, Loucille; Kane, Gabrielle; Ford, Eric C

    2016-01-01

    Radiation treatment planning is a complex process with potential for error. We hypothesized that shorter time from simulation to treatment would result in rushed work and higher incidence of errors. We examined treatment planning factors predictive for near-miss events. Treatments delivered from March 2012 through October 2014 were analyzed. Near-miss events were prospectively recorded and coded for severity on a 0 to 4 scale; only grade 3-4 (potentially severe/critical) events were studied in this report. For 4 treatment types (3-dimensional conformal, intensity modulated radiation therapy, stereotactic body radiation therapy [SBRT], neutron), logistic regression was performed to test influence of treatment planning time and clinical variables on near-miss events. There were 2257 treatment courses during the study period, with 322 grade 3-4 near-miss events. SBRT treatments had more frequent events than the other 3 treatment types (18% vs 11%, P = .04). For the 3-dimensional conformal group (1354 treatments), univariate analysis showed several factors predictive of near-miss events: longer time from simulation to first treatment (P = .01), treatment of primary site versus metastasis (P < .001), longer treatment course (P < .001), and pediatric versus adult patient (P = .002). However, on multivariate regression only pediatric versus adult patient remained predictive of events (P = 0.02). For the intensity modulated radiation therapy, SBRT, and neutron groups, time between simulation and first treatment was not found to be predictive of near-miss events on univariate or multivariate regression. When controlling for treatment technique and other clinical factors, there was no relationship between time spent in radiation treatment planning and near-miss events. SBRT and pediatric treatments were more error-prone, indicating that clinical and technical complexity of treatments should be taken into account when targeting safety interventions. Copyright © 2015 American

  19. Influence maximization in complex networks through optimal percolation

    Science.gov (United States)

    Morone, Flaviano; Makse, Hernán A.

    2015-08-01

    The whole frame of interconnections in complex networks hinges on a specific set of structural nodes, much smaller than the total size, which, if activated, would cause the spread of information to the whole network, or, if immunized, would prevent the diffusion of a large scale epidemic. Localizing this optimal, that is, minimal, set of structural nodes, called influencers, is one of the most important problems in network science. Despite the vast use of heuristic strategies to identify influential spreaders, the problem remains unsolved. Here we map the problem onto optimal percolation in random networks to identify the minimal set of influencers, which arises by minimizing the energy of a many-body system, where the form of the interactions is fixed by the non-backtracking matrix of the network. Big data analyses reveal that the set of optimal influencers is much smaller than the one predicted by previous heuristic centralities. Remarkably, a large number of previously neglected weakly connected nodes emerges among the optimal influencers. These are topologically tagged as low-degree nodes surrounded by hierarchical coronas of hubs, and are uncovered only through the optimal collective interplay of all the influencers in the network. The present theoretical framework may hold a larger degree of universality, being applicable to other hard optimization problems exhibiting a continuous transition from a known phase.

  20. Complexation of triptycene-derived macrotricyclic polyether with paraquat derivatives, diquat, and a 2,7-diazapyrenium salt: guest-induced conformational changes of the host.

    Science.gov (United States)

    Han, Ying; Cao, Jing; Li, Peng-Fei; Zong, Qian-Shou; Zhao, Jian-Min; Guo, Jia-Bin; Xiang, Jun-Feng; Chen, Chuan-Feng

    2013-04-05

    Complexation between a triptycene-derived macrotricyclic polyether containing two dibenzo-[30]-crown-10 cavities and different functionalized paraquat derivatives, diquat, and a 2,7-diazapyrenium salt in both solution and solid state was investigated in detail. It was found that depending on the guests with different terminal functional groups and structures, the macrotricyclic polyether could form 1:1 or 1:2 complexes with the guests in different complexation modes in solution and also in the solid state. Especially, the conformation of the macrotricyclic polyether was efficiently adjusted by the encapsulated guests, which was to some extent similar to substrate-induced fit of enzymes. Moreover, the binding and releasing of the guests in the complexes could be controlled by potassium ions.

  1. Influence of the nucleobase on the physicochemical characteristics and biological activities of Sb{sup V}-ribonucleoside complexes

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Claudio S.; Demicheli, Cynthia, E-mail: demichel@netuno.lcc.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica; Rocha, Iara C.M. da; Melo, Maria N. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Parasitologia; Monte Neto, Rubens L.; Frezard, Frederic [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Fisiologia e Biofisica

    2010-07-01

    The influence of the nucleobase (uracyl, U; cytosine, C; adenine, A; guanine, G) on the physicochemical characteristics and in vitro biological activities of Sb{sup V}-ribonucleoside complexes has been investigated. The 1:1 Sb-U and Sb-C complexes were characterized by NMR and ESI-MS spectroscopies and elemental analysis. The stability constant and the apparent association and dissociation rate constants of 1:1 Sb{sup V}-U, Sb{sup V}-C and Sb{sup V}-A complexes were determined. Although Sb{sup V} most probably binds via oxygen atoms to the same 2' and 3' positions in the different nucleosides, the ribose conformational changes and the physicochemical characteristics of the complex depend on the nucleobase. The nucleobase had a strong influence on the cytotoxicity against macrophages and the antileishmanial activity of the Sb{sup V}-ribonucleoside complexes. The Sb{sup V}-purine complexes were more cytotoxic and more effective against Leishmania chagasi than the Sb{sup V}-pyrimidine complexes, supporting the model that the interaction of Sb{sup V} with purine nucleosides may mediate the antileishmanial activity of pentavalent antimonial drugs. (author)

  2. Pharmacophore Modelling and 4D-QSAR Study of Ruthenium(II) Arene Complexes as Anticancer Agents (Inhibitors) by Electron Conformational- Genetic Algorithm Method.

    Science.gov (United States)

    Yavuz, Sevtap Caglar; Sabanci, Nazmiye; Saripinar, Emin

    2018-01-01

    The EC-GA method was employed in this study as a 4D-QSAR method, for the identification of the pharmacophore (Pha) of ruthenium(II) arene complex derivatives and quantitative prediction of activity. The arrangement of the computed geometric and electronic parameters for atoms and bonds of each compound occurring in a matrix is known as the electron-conformational matrix of congruity (ECMC). It contains the data from HF/3-21G level calculations. Compounds were represented by a group of conformers for each compound rather than a single conformation, known as fourth dimension to generate the model. ECMCs were compared within a certain range of tolerance values by using the EMRE program and the responsible pharmacophore group for ruthenium(II) arene complex derivatives was found. For selecting the sub-parameter which had the most effect on activity in the series and the calculation of theoretical activity values, the non-linear least square method and genetic algorithm which are included in the EMRE program were used. In addition, compounds were classified as the training and test set and the accuracy of the models was tested by cross-validation statistically. The model for training and test sets attained by the optimum 10 parameters gave highly satisfactory results with R2 training= 0.817, q 2=0.718 and SEtraining=0.066, q2 ext1 = 0.867, q2 ext2 = 0.849, q2 ext3 =0.895, ccctr = 0.895, ccctest = 0.930 and cccall = 0.905. Since there is no 4D-QSAR research on metal based organic complexes in the literature, this study is original and gives a powerful tool to the design of novel and selective ruthenium(II) arene complexes. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Conformal house

    DEFF Research Database (Denmark)

    Ryttov, Thomas Aaby; Sannino, Francesco

    2010-01-01

    fixed point. As a consistency check we recover the previously investigated bounds of the conformal windows when restricting to a single matter representation. The earlier conformal windows can be imagined to be part now of the new conformal house. We predict the nonperturbative anomalous dimensions...... at the infrared fixed points. We further investigate the effects of adding mass terms to the condensates on the conformal house chiral dynamics and construct the simplest instanton induced effective Lagrangian terms...

  4. Accessibility of nucleic acid-complexed biomolecules to hydroxyl radicals correlates with their conformation: a fluorescence polarization spectroscopy study

    International Nuclear Information System (INIS)

    Makrigiorgos, G.M.; Bump, E.; Huang, C.; Kassis, A.I.; Baranowska-Kortylewicz, J.

    1994-01-01

    A fluorescence methodology has been developed to examine the relationship between the conformational state of specific biomolecules in simple chromatin models and their accessibility to hydroxyl radicals ( . OH). Polylysine and histone H1 were labelled with SECCA, the succinimidyl ester of coumarin-3-carboxylic acid, which generates the fluorescent derivative 7-OH-SECCA following its interaction with radiation-induced . OH in aqueous solution. The fluorescence induced per unit γ-ray dose reflecting the accessibility of . OH to such SECCA-conjugated biomolecules was recorded. The biomolecules were also labelled with the fluorescent derivative 7-OH-SECCA in trace amounts to study their conformation under identical conditions via fluorescence polarization spectroscopy. (author)

  5. Influence maximization in complex networks through optimal percolation

    Science.gov (United States)

    Morone, Flaviano; Makse, Hernan; CUNY Collaboration; CUNY Collaboration

    The whole frame of interconnections in complex networks hinges on a specific set of structural nodes, much smaller than the total size, which, if activated, would cause the spread of information to the whole network, or, if immunized, would prevent the diffusion of a large scale epidemic. Localizing this optimal, that is, minimal, set of structural nodes, called influencers, is one of the most important problems in network science. Here we map the problem onto optimal percolation in random networks to identify the minimal set of influencers, which arises by minimizing the energy of a many-body system, where the form of the interactions is fixed by the non-backtracking matrix of the network. Big data analyses reveal that the set of optimal influencers is much smaller than the one predicted by previous heuristic centralities. Remarkably, a large number of previously neglected weakly connected nodes emerges among the optimal influencers. Reference: F. Morone, H. A. Makse, Nature 524,65-68 (2015)

  6. Complex terrain influences ecosystem carbon responses to temperature and precipitation

    Science.gov (United States)

    Reyes, W. M.; Epstein, H. E.; Li, X.; McGlynn, B. L.; Riveros-Iregui, D. A.; Emanuel, R. E.

    2017-08-01

    Terrestrial ecosystem responses to temperature and precipitation have major implications for the global carbon cycle. Case studies demonstrate that complex terrain, which accounts for more than 50% of Earth's land surface, can affect ecological processes associated with land-atmosphere carbon fluxes. However, no studies have addressed the role of complex terrain in mediating ecophysiological responses of land-atmosphere carbon fluxes to climate variables. We synthesized data from AmeriFlux towers and found that for sites in complex terrain, responses of ecosystem CO2 fluxes to temperature and precipitation are organized according to terrain slope and drainage area, variables associated with water and energy availability. Specifically, we found that for tower sites in complex terrain, mean topographic slope and drainage area surrounding the tower explained between 51% and 78% of site-to-site variation in the response of CO2 fluxes to temperature and precipitation depending on the time scale. We found no such organization among sites in flat terrain, even though their flux responses exhibited similar ranges. These results challenge prevailing conceptual framework in terrestrial ecosystem modeling that assumes that CO2 fluxes derive from vertical soil-plant-climate interactions. We conclude that the terrain in which ecosystems are situated can also have important influences on CO2 responses to temperature and precipitation. This work has implications for about 14% of the total land area of the conterminous U.S. This area is considered topographically complex and contributes to approximately 15% of gross ecosystem carbon production in the conterminous U.S.

  7. Beyond Contagion: Reality Mining Reveals Complex Patterns of Social Influence.

    Science.gov (United States)

    Alshamsi, Aamena; Pianesi, Fabio; Lepri, Bruno; Pentland, Alex; Rahwan, Iyad

    2015-01-01

    Contagion, a concept from epidemiology, has long been used to characterize social influence on people's behavior and affective (emotional) states. While it has revealed many useful insights, it is not clear whether the contagion metaphor is sufficient to fully characterize the complex dynamics of psychological states in a social context. Using wearable sensors that capture daily face-to-face interaction, combined with three daily experience sampling surveys, we collected the most comprehensive data set of personality and emotion dynamics of an entire community of work. From this high-resolution data about actual (rather than self-reported) face-to-face interaction, a complex picture emerges where contagion (that can be seen as adaptation of behavioral responses to the behavior of other people) cannot fully capture the dynamics of transitory states. We found that social influence has two opposing effects on states: adaptation effects that go beyond mere contagion, and complementarity effects whereby individuals' behaviors tend to complement the behaviors of others. Surprisingly, these effects can exhibit completely different directions depending on the stable personality or emotional dispositions (stable traits) of target individuals. Our findings provide a foundation for richer models of social dynamics, and have implications on organizational engineering and workplace well-being.

  8. Beyond Contagion: Reality Mining Reveals Complex Patterns of Social Influence.

    Directory of Open Access Journals (Sweden)

    Aamena Alshamsi

    Full Text Available Contagion, a concept from epidemiology, has long been used to characterize social influence on people's behavior and affective (emotional states. While it has revealed many useful insights, it is not clear whether the contagion metaphor is sufficient to fully characterize the complex dynamics of psychological states in a social context. Using wearable sensors that capture daily face-to-face interaction, combined with three daily experience sampling surveys, we collected the most comprehensive data set of personality and emotion dynamics of an entire community of work. From this high-resolution data about actual (rather than self-reported face-to-face interaction, a complex picture emerges where contagion (that can be seen as adaptation of behavioral responses to the behavior of other people cannot fully capture the dynamics of transitory states. We found that social influence has two opposing effects on states: adaptation effects that go beyond mere contagion, and complementarity effects whereby individuals' behaviors tend to complement the behaviors of others. Surprisingly, these effects can exhibit completely different directions depending on the stable personality or emotional dispositions (stable traits of target individuals. Our findings provide a foundation for richer models of social dynamics, and have implications on organizational engineering and workplace well-being.

  9. Complex Relationships Among Masculine Norms and Health/Well-Being Outcomes: Correlation Patterns of the Conformity to Masculine Norms Inventory Subscales.

    Science.gov (United States)

    Gerdes, Zachary T; Levant, Ronald F

    2018-03-01

    The Conformity to Masculine Norms Inventory (CMNI) is a widely used multidimensional scale. Studies using the CMNI most often report only total scale scores, which are predominantly associated with negative outcomes. Various studies since the CMNI's inception in 2003 using subscales have reported both positive and negative outcomes. The current content analysis examined studies ( N = 17) correlating the 11 subscales with 63 criterion variables across 7 categories. Most findings were consistent with past research using total scale scores that reported negative outcomes. For example, conformity to masculine norms has been inversely related to help-seeking and positively correlated with concerning health variables, such as substance use. Nonetheless, past reliance on total scores has obscured the complexity of associations with the CMNI in that 30% of the findings in the present study reflected positive outcomes, particularly for health promotion. Subscales differed in their relationships with various outcomes: for one subscale they were predominantly positive, but six others were mostly negative. The situational and contextual implications of conformity to masculine norms and their relationships to positive and negative outcomes are discussed.

  10. Synthesis, structure and DFT conformation analysis of CpNiX(NHC) and NiX2(NHC)2 (X = SPh or Br) complexes

    Science.gov (United States)

    Malan, Frederick P.; Singleton, Eric; van Rooyen, Petrus H.; Conradie, Jeanet; Landman, Marilé

    2017-11-01

    The synthesis, density functional theory (DFT) conformational study and structure analysis of novel two-legged piano stool Ni N-heterocyclic carbene (NHC) complexes and square planar Ni bis-N-heterocyclic carbene complexes, all containing either bromido- or thiophenolato ligands, are described. [CpNi(SPh)(NHC)] complexes were obtained from the neutral 18-electron [CpNiBr(NHC)] complexes by substitution of a bromido ligand with SPh, using NEt3 as a base to abstract the proton of HSPh. The 16-electron biscarbene complexes [Ni(SPh)2{NHC}2] were isolated when an excess of HSPh was added to the reaction mixture. Biscarbene complexes of the type [NiBr2(NHC)2] were obtained in the reaction of NiCp2 with a slight excess of the specific imidazolium bromide salt. The molecular and electronic structures of the mono- and bis-N-heterocyclic carbene complexes have been analysed using single crystal diffraction and density functional theory (DFT) calculations, to give insight into their structural properties.

  11. Transportation Conformity

    Science.gov (United States)

    This section provides information on: current laws, regulations and guidance, policy and technical guidance, project-level conformity, general information, contacts and training, adequacy review of SIP submissions

  12. IRMPD Action Spectroscopy of Alkali Metal Cation-Cytosine Complexes: Effects of Alkali Metal Cation Size on Gas Phase Conformation

    NARCIS (Netherlands)

    Yang, B.; Wu, R.R.; Polfer, N.C.; Berden, G.; Oomens, J.; Rodgers, M.T.

    2013-01-01

    The gas-phase structures of alkali metal cation-cytosine complexes generated by electrospray ionization are probed via infrared multiple photon dissociation (IRMPD) action spectroscopy and theoretical calculations. IRMPD action spectra of five alkali metal cation-cytosine complexes exhibit both

  13. DNA minor groove electrostatic potential: influence of sequence-specific transitions of the torsion angle gamma and deoxyribose conformations.

    Science.gov (United States)

    Zhitnikova, M Y; Shestopalova, A V

    2017-11-01

    The structural adjustments of the sugar-phosphate DNA backbone (switching of the γ angle (O5'-C5'-C4'-C3') from canonical to alternative conformations and/or C2'-endo → C3'-endo transition of deoxyribose) lead to the sequence-specific changes in accessible surface area of both polar and non-polar atoms of the grooves and the polar/hydrophobic profile of the latter ones. The distribution of the minor groove electrostatic potential is likely to be changing as a result of such conformational rearrangements in sugar-phosphate DNA backbone. Our analysis of the crystal structures of the short free DNA fragments and calculation of their electrostatic potentials allowed us to determine: (1) the number of classical and alternative γ angle conformations in the free B-DNA; (2) changes in the minor groove electrostatic potential, depending on the conformation of the sugar-phosphate DNA backbone; (3) the effect of the DNA sequence on the minor groove electrostatic potential. We have demonstrated that the structural adjustments of the DNA double helix (the conformations of the sugar-phosphate backbone and the minor groove dimensions) induce changes in the distribution of the minor groove electrostatic potential and are sequence-specific. Therefore, these features of the minor groove sizes and distribution of minor groove electrostatic potential can be used as a signal for recognition of the target DNA sequence by protein in the implementation of the indirect readout mechanism.

  14. Contribution to the development and the modelling of an ultrasonic conformable phased array transducer for the contact inspection of 3D complex geometry components

    International Nuclear Information System (INIS)

    Guedes, O.

    2005-04-01

    With the difficulties encountered for the exploration of complex shape surfaces, particularly in nuclear industry, the ultrasonic conformable phased array transducer allows a non destructive evaluation of parts with 3D complex parts. For this, one can use the Smart Contact Transducer principle to generate an ultrasonic field by adaptive dynamic focalisation, with a matrix array composed of independent elements moulded in a soft resin. This work deals with the electro-acoustic conception, with the realization of such a prototype and with the study of it's mechanical and acoustic behaviour. The array design is defined using a radiation model adapted to the simulation of contact sources on a free surface. Once one have defined the shape of the radiating elements, a vibratory analysis using finite elements method allows the determination of the emitting structure with 1-3 piezocomposite, witch leads to the realization of emitting-receiving elements. With the measurement of the field transmitted by such elements, we deduced new hypothesis to change the model of radiation. Thus one can take into account normal and tangential stresses calculated with finite element modelling at the interface between the element and the propagation medium, to use it with the semi-analytical model. Some vibratory phenomena dealing with fluid coupling of contact transducers have been studied, and the prediction of the transverse wave radiation profile have been improved. The last part of this work deals with the realization of the first prototype of the conformable phased array transducer. For this a deformation measuring system have been developed, to determine the position of each element on real time with the displacement of the transducer on complex shape surfaces. With those positions, one can perform the calculation of the a delay law intended for the adaptive dynamic focusing of the desired ultrasonic field. The conformable phased array transducer have been characterized in

  15. Workers’ Conformism

    Directory of Open Access Journals (Sweden)

    Nikolay Ivantchev

    2013-10-01

    Full Text Available Conformism was studied among 46 workers with different kinds of occupations by means of two modified scales measuring conformity by Santor, Messervey, and Kusumakar (2000 – scale for perceived peer pressure and scale for conformism in antisocial situations. The hypothesis of the study that workers’ conformism is expressed in a medium degree was confirmed partly. More than a half of the workers conform in a medium degree for taking risk, and for the use of alcohol and drugs, and for sexual relationships. More than a half of the respondents conform in a small degree for anti-social activities (like a theft. The workers were more inclined to conform for risk taking (10.9%, then – for the use of alcohol, drugs and for sexual relationships (8.7%, and in the lowest degree – for anti-social activities (6.5%. The workers who were inclined for the use of alcohol and drugs tended also to conform for anti-social activities.

  16. The complex influence of ENSO on droughts in Ecuador

    KAUST Repository

    Vicente-Serrano, S. M.

    2016-03-26

    In this study, we analyzed the influence of El Niño–Southern Oscillation (ENSO) on the spatio-temporal variability of droughts in Ecuador for a 48-year period (1965–2012). Droughts were quantified from 22 high-quality and homogenized time series of precipitation and air temperature by means of the Standardized Precipitation Evapotranspiration Index. In addition, the propagation of two different ENSO indices (El Niño 3.4 and El Niño 1 + 2 indices) and other atmospheric circulation processes (e.g., vertical velocity) on different time-scales of drought severity were investigated. The results showed a very complex influence of ENSO on drought behavior across Ecuador, with two regional patterns in the evolution of droughts: (1) the Andean chain with no changes in drought severity, and (2) the Western plains with less severe and frequent droughts. We also detected that drought variability in the Andes mountains is explained by the El Niño 3.4 index [sea surface temperature (SST) anomalies in the central Pacific], whereas the Western plains are much more driven by El Niño 1 + 2 index (SST anomalies in the eastern Pacific). Moreover, it was also observed that El Niño and La Niña phases enhance droughts in the Andes and Western plains regions, respectively. The results of this work could be crucial for predicting and monitoring drought variability and intensity in Ecuador. © 2016 Springer-Verlag Berlin Heidelberg

  17. On the social influence of emotions in groups: Interpersonal effects of anger and happiness on conformity versus deviance

    NARCIS (Netherlands)

    Heerdink, M.W.; van Kleef, G.A.; Homan, A.C.; Fischer, A.H.

    2013-01-01

    How do emotional expressions of group members shape conformity versus deviance in groups? We hypothesized that angry and happy responses to a group member’s deviating opinion are interpreted as signals of imminent rejection versus acceptance. In 5 studies, the majority’s expressions of anger led the

  18. Conformity to Parental Rules : Asymmetric Influences of Father’s and Mother’s Levels of Education

    NARCIS (Netherlands)

    Slik, Frans W.P. van der; Graaf, Nan Dirk de; Gerris, Jan R.M.

    2002-01-01

    The relative e¡ects of both parents’educational levels on their child-rearing values were examined by analysing data froma sample of Dutch families (N¼589).This research focuses upon dominance of fathers overmothers with respect to the value placed on children’s conformity to parental rules.We argue

  19. Conformational stability of the epidermal growth factor (EGF) receptor as influenced by glycosylation, dimerization and EGF hormone binding.

    Science.gov (United States)

    Taylor, Eric S; Pol-Fachin, Laercio; Lins, Roberto D; Lower, Steven K

    2017-04-01

    The epidermal growth factor receptor (EGFR) is an important transmembrane glycoprotein kinase involved the initiation or perpetuation of signal transduction cascades within cells. These processes occur after EGFR binds to a ligand [epidermal growth factor (EGF)], thus inducing its dimerization and tyrosine autophosphorylation. Previous publications have highlighted the importance of glycosylation and dimerization for promoting proper function of the receptor and conformation in membranes; however, the effects of these associations on the protein conformational stability have not yet been described. Molecular dynamics simulations were performed to characterize the conformational preferences of the monomeric and dimeric forms of the EGFR extracellular domain upon binding to EGF in the presence and absence of N-glycan moieties. Structural stability analyses revealed that EGF provides the most conformational stability to EGFR, followed by glycosylation and dimerization, respectively. The findings also support that EGF-EGFR binding takes place through a large-scale induced-fitting mechanism. Proteins 2017; 85:561-570. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. The cytosolic DNA sensor cGAS forms an oligomeric complex with DNA and undergoes switch-like conformational changes in the activation loop.

    Science.gov (United States)

    Zhang, Xu; Wu, Jiaxi; Du, Fenghe; Xu, Hui; Sun, Lijun; Chen, Zhe; Brautigam, Chad A; Zhang, Xuewu; Chen, Zhijian J

    2014-02-13

    The presence of DNA in the cytoplasm is a danger signal that triggers immune and inflammatory responses. Cytosolic DNA binds to and activates cyclic GMP-AMP (cGAMP) synthase (cGAS), which produces the second messenger cGAMP. cGAMP binds to the adaptor protein STING and activates a signaling cascade that leads to the production of type I interferons and other cytokines. Here, we report the crystal structures of human cGAS in its apo form, representing its autoinhibited conformation as well as in its cGAMP- and sulfate-bound forms. These structures reveal switch-like conformational changes of an activation loop that result in the rearrangement of the catalytic site. The structure of DNA-bound cGAS reveals a complex composed of dimeric cGAS bound to two molecules of DNA. Functional analyses of cGAS mutants demonstrate that both the protein-protein interface and the two DNA binding surfaces are critical for cGAS activation. These results provide insights into the mechanism of DNA sensing by cGAS. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  1. The Cytosolic DNA Sensor cGAS Forms an Oligomeric Complex with DNA and Undergoes Switch-like Conformational Changes in the Activation Loop

    Directory of Open Access Journals (Sweden)

    Xu Zhang

    2014-02-01

    Full Text Available The presence of DNA in the cytoplasm is a danger signal that triggers immune and inflammatory responses. Cytosolic DNA binds to and activates cyclic GMP-AMP (cGAMP synthase (cGAS, which produces the second messenger cGAMP. cGAMP binds to the adaptor protein STING and activates a signaling cascade that leads to the production of type I interferons and other cytokines. Here, we report the crystal structures of human cGAS in its apo form, representing its autoinhibited conformation as well as in its cGAMP- and sulfate-bound forms. These structures reveal switch-like conformational changes of an activation loop that result in the rearrangement of the catalytic site. The structure of DNA-bound cGAS reveals a complex composed of dimeric cGAS bound to two molecules of DNA. Functional analyses of cGAS mutants demonstrate that both the protein-protein interface and the two DNA binding surfaces are critical for cGAS activation. These results provide insights into the mechanism of DNA sensing by cGAS.

  2. INFLUENCE OF NATURAL ADDITIVES ON PROTEIN COMPLEX OF BREAD

    Directory of Open Access Journals (Sweden)

    Dana Urminská

    2010-11-01

    Full Text Available The study focuses on researching the influence of natural additives on certain technological characteristics of mixtures used for bread production, more particularly the influence of N substances in used raw material on selected qualitative parameters of bread. The blends for bread production to be analysed were prepared by mixing wheat flour with an addition of oat, buckwheat, lentil and chickpea wholegrain flour in different portions (10, 20, 30, 40 and 50 %. The experiment showed that the addition of natural additives worsened the protein complex of the blends used in bread production (worsening also qualitative parameters known as product volume. The loaves prepared with an addition of buckwheat, oat, lentil and chickpea were evaluated to be of a lesser quality from a technological viewpoint when compared with pure wheat loaves. The lower content of gluten forming proteins and the generally changed protein composition of blends due to additives caused a lower percentage of wet gluten content, its lower extensibility and swelling capacity. The sedimentation value (Zeleny index decreased proportionally with the increase of addition until the level was unsatisfactory for raw material intended for bakery purposes. The N content in experimental loaves was higher than in the reference loaves and it increased according to the selected additive and its portion in the blend (more with the addition of lentil and chickpea, less in case of buckwheat and oat which is considered as positive from a nutritional point of view. But from the technological point of view the additives did not show any positive influence and caused a lower loaf bread volume. The most significant decrease of the loaf bread volume was found with the addition of 50 % of buckwheat (- 45.6 %. Better results were obtained with a lower portion of the additive: loaf with an addition of 30 % of chickpea (volume decreased by 12.8 % > loaf with an addition of 30 % of lentil (volume

  3. Structural characterization of POM6 Fab and mouse prion protein complex identifies key regions for prions conformational conversion.

    Science.gov (United States)

    Baral, Pravas Kumar; Swayampakula, Mridula; Aguzzi, Adriano; James, Michael N G

    2018-05-01

    Conversion of the cellular prion protein PrP C into its pathogenic isoform PrP S c is the hallmark of prion diseases, fatal neurodegenerative diseases affecting many mammalian species including humans. Anti-prion monoclonal antibodies can arrest the progression of prion diseases by stabilizing the cellular form of the prion protein. Here, we present the crystal structure of the POM6 Fab fragment, in complex with the mouse prion protein (moPrP). The prion epitope of POM6 is in close proximity to the epitope recognized by the purportedly toxic antibody fragment, POM1 Fab also complexed with moPrP. The POM6 Fab recognizes a larger binding interface indicating a likely stronger binding compared to POM1. POM6 and POM1 exhibit distinct biological responses. Structural comparisons of the bound mouse prion proteins from the POM6 Fab:moPrP and POM1 Fab:moPrP complexes reveal several key regions of the prion protein that might be involved in initiating mis-folding events. The structural data of moPrP:POM6 Fab complex are available in the PDB under the accession number www.rcsb.org/pdb/search/structidSearch.do?structureId=6AQ7. © 2018 Federation of European Biochemical Societies.

  4. Human insulin analogues modified at the B26 site reveal a hormone conformation that is undetected in the receptor complex

    Czech Academy of Sciences Publication Activity Database

    Žáková, Lenka; Kletvíková, Emília; Lepšík, Martin; Collinsová, Michaela; Watson, C. J.; Turkenburg, J. P.; Jiráček, Jiří; Brzozowski, A. M.

    2014-01-01

    Roč. 70, č. 10 (2014), s. 2765-2774 ISSN 0907-4449 R&D Projects: GA ČR GPP207/11/P430; GA ČR GBP208/12/G016 Institutional support: RVO:61388963 Keywords : insulin * insulin receptor * complex * active form * analog * structure Subject RIV: CE - Biochemistry Impact factor: 7.232, year: 2013

  5. Conformal Infinity

    Directory of Open Access Journals (Sweden)

    Frauendiener Jörg

    2000-08-01

    Full Text Available The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, ``conformal infinity'' is related with almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved out of physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation and how it lends itself very naturally to solve radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.

  6. Conformal Infinity.

    Science.gov (United States)

    Frauendiener, Jörg

    2004-01-01

    The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, "conformal infinity" is related to almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved from physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation, and how it lends itself very naturally to the solution of radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.

  7. Conformal Infinity

    Directory of Open Access Journals (Sweden)

    Frauendiener Jörg

    2004-01-01

    Full Text Available The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, 'conformal infinity' is related to almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved from physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation, and how it lends itself very naturally to the solution of radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.

  8. General Conformity

    Science.gov (United States)

    The General Conformity requirements ensure that the actions taken by federal agencies in nonattainment and maintenance areas do not interfere with a state’s plans to meet national standards for air quality.

  9. Conformal Infinity

    OpenAIRE

    Frauendiener, J?rg

    2000-01-01

    The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, 'conformal infinity' is related to almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved from physical issues, namely the need to understand gravitational radiation and isolated systems within the theory...

  10. Conformation Control of a Conjugated Polymer through Complexation with Bile Acids Generates Its Novel Spectral and Morphological Properties.

    Science.gov (United States)

    Tsuchiya, Youichi; Noguchi, Takao; Yoshihara, Daisuke; Roy, Bappaditya; Yamamoto, Tatsuhiro; Shinkai, Seiji

    2016-11-29

    Control of higher-order polymer structures attracts a great deal of interest for many researchers when they lead to the development of materials having various advanced functions. Among them, conjugated polymers that are useful as starting materials in the design of molecular wires are particularly attractive. However, an equilibrium existing between isolated chains and bundled aggregates is inevitable and has made their physical properties very complicated. As an attempt to simplify this situation, we previously reported that a polymer chain of a water-soluble polythiophene could be isolated through complexation with a helix-forming polysaccharide. More recently, a covalently self-threading polythiophene was reported, the main chain of which was physically protected from self-folding and chain-chain π-stacking. In this report, we wish to report a new strategy to isolate a water-soluble polythiophene and to control its higher-order structure by a supramolecular approach: that is, among a few bile acids, lithocholate can form stoichiometric complexes with cationic polythiophene to isolate the polymer chain, and the higher-order structure is changeable by the molar ratio. The optical and morphological studies have been thoroughly performed, and the resultant complex has been applied to the selective recognition of two AMP structural isomers.

  11. Conformational coupling between receptor and kinase binding sites through a conserved salt bridge in a signaling complex scaffold protein.

    Directory of Open Access Journals (Sweden)

    Davi R Ortega

    Full Text Available Bacterial chemotaxis is one of the best studied signal transduction pathways. CheW is a scaffold protein that mediates the association of the chemoreceptors and the CheA kinase in a ternary signaling complex. The effects of replacing conserved Arg62 of CheW with other residues suggested that the scaffold protein plays a more complex role than simply binding its partner proteins. Although R62A CheW had essentially the same affinity for chemoreceptors and CheA, cells expressing the mutant protein are impaired in chemotaxis. Using a combination of molecular dynamics simulations (MD, NMR spectroscopy, and circular dichroism (CD, we addressed the role of Arg62. Here we show that Arg62 forms a salt bridge with another highly conserved residue, Glu38. Although this interaction is unimportant for overall protein stability, it is essential to maintain the correct alignment of the chemoreceptor and kinase binding sites of CheW. Computational and experimental data suggest that the role of the salt bridge in maintaining the alignment of the two partner binding sites is fundamental to the function of the signaling complex but not to its assembly. We conclude that a key feature of CheW is to maintain the specific geometry between the two interaction sites required for its function as a scaffold.

  12. Follow (or don't follow) the crowd: Young children's conformity is influenced by norm domain and age.

    Science.gov (United States)

    Flynn, Emma; Turner, Cameron; Giraldeau, Luc-Alain

    2018-03-01

    This study investigated whether young children's conformity to a consensus varies across the normative domain and age. A total of 168 3- and 5-year-olds participated. Each child was presented with a puzzle box that had two transparent compartments. In a reward preference condition, one of the compartments contained 1 sticker, whereas the other compartment contained 12 stickers. In perceptual judgment and arbitrary preference conditions, one compartment contained a short plank, whereas one contained a perceptually longer plank. Each child was shown a video of four female adults, each of whom was asked the same question within condition: "Which one's the biggest?" (perceptual task; each model retrieved the smaller block), "Which one do you want?" (reward preference; each model retrieved the smaller reward), and "Which one do you want?" (arbitrary preference; each model retrieved the smaller plank). Children were then asked the same question by condition and were allowed to retrieve the item. Notably, more children conformed in the arbitrary preference condition than in the reward preference and perceptual judgment conditions, with 3-year-olds conforming significantly more than 5-year-olds. The 5-year-olds were more successful and imitated with greater fidelity, including demonstrating overimitation. However, less overimitation was observed in the arbitrary preference condition. Together, these findings show that children are sensitive to the contextual cues of the domain in which they are witnessing norms and vary their own conformity based on such cues. Furthermore, children can navigate which information to copy to fulfil their own ends. Copyright © 2017. Published by Elsevier Inc.

  13. Ligand complex structures of l-amino acid oxidase/monooxygenase from Pseudomonas sp. AIU 813 and its conformational change.

    Science.gov (United States)

    Im, Dohyun; Matsui, Daisuke; Arakawa, Takatoshi; Isobe, Kimiyasu; Asano, Yasuhisa; Fushinobu, Shinya

    2018-03-01

    l-Amino acid oxidase/monooxygenase from Pseudomonas sp. AIU 813 (l-AAO/MOG) catalyzes both the oxidative deamination and oxidative decarboxylation of the α-group of l-Lys to produce a keto acid and amide, respectively. l-AAO/MOG exhibits limited specificity for l-amino acid substrates with a basic side chain. We previously determined its ligand-free crystal structure and identified a key residue for maintaining the dual activities. Here, we determined the structures of l-AAO/MOG complexed with l-Lys, l-ornithine, and l-Arg and revealed its substrate recognition. Asp238 is located at the ceiling of a long hydrophobic pocket and forms a strong interaction with the terminal, positively charged group of the substrates. A mutational analysis on the D238A mutant indicated that the interaction is critical for substrate binding but not for catalytic control between the oxidase/monooxygenase activities. The catalytic activities of the D238E mutant unexpectedly increased, while the D238F mutant exhibited altered substrate specificity to long hydrophobic substrates. In the ligand-free structure, there are two channels connecting the active site and solvent, and a short region located at the dimer interface is disordered. In the l-Lys complex structure, a loop region is displaced to plug the channels. Moreover, the disordered region in the ligand-free structure forms a short helix in the substrate complex structures and creates the second binding site for the substrate. It is assumed that the amino acid substrate enters the active site of l-AAO/MOG through this route. The atomic coordinates and structure factors (codes 5YB6, 5YB7, and 5YB8) have been deposited in the Protein Data Bank (http://wwpdb.org/). 1.4.3.2 (l-amino acid oxidase), 1.13.12.2 (lysine 2-monooxygenase).

  14. Conformation radiotherapy and conformal radiotherapy

    International Nuclear Information System (INIS)

    Morita, Kozo

    1999-01-01

    In order to coincide the high dose region to the target volume, the 'Conformation Radiotherapy Technique' using the multileaf collimator and the device for 'hollow-out technique' was developed by Prof. S. Takahashi in 1960. This technique can be classified a type of 2D-dynamic conformal RT techniques. By the clinical application of this technique, the late complications of the lens, the intestine and the urinary bladder after radiotherapy for the maxillary cancer and the cervical cancer decreased. Since 1980's the exact position and shape of the tumor and the surrounding normal tissues can be easily obtained by the tremendous development of the CT/MRI imaging technique. As a result, various kinds of new conformal techniques such as the 3D-CRT, the dose intensity modulation, the tomotherapy have been developed since the beginning of 1990'. Several 'dose escalation study with 2D-/3D conformal RT' is now under way to improve the treatment results. (author)

  15. Conformal Gravity

    International Nuclear Information System (INIS)

    Hooft, G.

    2012-01-01

    The dynamical degree of freedom for the gravitational force is the metric tensor, having 10 locally independent degrees of freedom (of which 4 can be used to fix the coordinate choice). In conformal gravity, we split this field into an overall scalar factor and a nine-component remainder. All unrenormalizable infinities are in this remainder, while the scalar component can be handled like any other scalar field such as the Higgs field. In this formalism, conformal symmetry is spontaneously broken. An imperative demand on any healthy quantum gravity theory is that black holes should be described as quantum systems with micro-states as dictated by the Hawking-Bekenstein theory. This requires conformal symmetry that may be broken spontaneously but not explicitly, and this means that all conformal anomalies must cancel out. Cancellation of conformal anomalies yields constraints on the matter sector as described by some universal field theory. Thus black hole physics may eventually be of help in the construction of unified field theories. (author)

  16. Influence of vitamin b-12 complex injection (eldervit-12) on ...

    African Journals Online (AJOL)

    Objectives: To assess the effect of vitamin B-12 complex injection on the nephrotoxicity of gentamicin. Design: Experimental study using a pre-validated model. Subject: Adult Swiss albino rats weighing 140-214g, Generic gentamicin sulphate injection and Vitamin B-12complex injection containing 2500mcg ...

  17. Crystal structures of PRK1 in complex with the clinical compounds lestaurtinib and tofacitinib reveal ligand induced conformational changes.

    Directory of Open Access Journals (Sweden)

    Philip Chamberlain

    Full Text Available Protein kinase C related kinase 1 (PRK1 is a component of Rho-GTPase, androgen receptor, histone demethylase and histone deacetylase signaling pathways implicated in prostate and ovarian cancer. Herein we describe the crystal structure of PRK1 in apo form, and also in complex with a panel of literature inhibitors including the clinical candidates lestaurtinib and tofacitinib, as well as the staurosporine analog Ro-31-8220. PRK1 is a member of the AGC-kinase class, and as such exhibits the characteristic regulatory sequence at the C-terminus of the catalytic domain--the 'C-tail'. The C-tail fully encircles the catalytic domain placing a phenylalanine in the ATP-binding site. Our inhibitor structures include examples of molecules which both interact with, and displace the C-tail from the active site. This information may assist in the design of inhibitors targeting both PRK and other members of the AGC kinase family.

  18. Influence of the electronic distribution of polymers in the spatial conformation of polymer grafted carbon nanotube composites

    Energy Technology Data Exchange (ETDEWEB)

    Garate, H. [Universidad de Buenos Aires, FCEyN, Depto. de Fisica IFIBA-CONICET LPyMC, Pabellon I, Buenos Aires 1428 (Argentina); Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, (CIHIDECAR-CONICET) Buenos Aires 1428 (Argentina); De Falco, A. [Universidad de Buenos Aires, FCEyN, Depto. de Fisica IFIBA-CONICET LPyMC, Pabellon I, Buenos Aires 1428 (Argentina); Moreno, M.S. [Centro Atomico Bariloche, 8400 S.C. de Bariloche (Argentina); Fascio, M.L. [Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, (CIHIDECAR-CONICET) Buenos Aires 1428 (Argentina); Goyanes, S. [Universidad de Buenos Aires, FCEyN, Depto. de Fisica IFIBA-CONICET LPyMC, Pabellon I, Buenos Aires 1428 (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); D' Accorso, N.B., E-mail: norma@qo.fcen.uba.ar [Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, (CIHIDECAR-CONICET) Buenos Aires 1428 (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)

    2012-08-15

    In this work we report the covalent functionalization of multiwalled carbon nanotubes (MWCNTs) with polyacrylonitrile (PAN) and polyvinylpyridine (PVP) by the graft from method. Differences in the electronic distribution of both polymers resulted in different interaction between polymers and the nanotubes. It was found that PVP chains wrapped the nanotubes while nanotubes functionalized with PAN presented PAN chains forming amorphous entanglements on the nanoscale linked to the MWCNTs. Differences in the conformation between both polymers and the MWCNTs can be attributed to interactions between the aromatic groups in PVP and the MWCNTs through {pi}-{pi} stacking. The absence of aromatic groups in the case of the PAN chains favours the interaction between them. The functionalization efficiency was characterized using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and UV-vis spectroscopy, while morphological changes were characterized by high resolution transmission electron microscopy.

  19. Contribution to the development and the modelling of an ultrasonic conformable phased array transducer for the contact inspection of 3D complex geometry components; Contribution au developpement et a la modelisation d'un traducteur ultrasonore multielements conformable pour l'inspection au contact de composants a geometrie complexe 3D

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, O

    2005-04-15

    With the difficulties encountered for the exploration of complex shape surfaces, particularly in nuclear industry, the ultrasonic conformable phased array transducer allows a non destructive evaluation of parts with 3D complex parts. For this, one can use the Smart Contact Transducer principle to generate an ultrasonic field by adaptive dynamic focalisation, with a matrix array composed of independent elements moulded in a soft resin. This work deals with the electro-acoustic conception, with the realization of such a prototype and with the study of it's mechanical and acoustic behaviour. The array design is defined using a radiation model adapted to the simulation of contact sources on a free surface. Once one have defined the shape of the radiating elements, a vibratory analysis using finite elements method allows the determination of the emitting structure with 1-3 piezocomposite, witch leads to the realization of emitting-receiving elements. With the measurement of the field transmitted by such elements, we deduced new hypothesis to change the model of radiation. Thus one can take into account normal and tangential stresses calculated with finite element modelling at the interface between the element and the propagation medium, to use it with the semi-analytical model. Some vibratory phenomena dealing with fluid coupling of contact transducers have been studied, and the prediction of the transverse wave radiation profile have been improved. The last part of this work deals with the realization of the first prototype of the conformable phased array transducer. For this a deformation measuring system have been developed, to determine the position of each element on real time with the displacement of the transducer on complex shape surfaces. With those positions, one can perform the calculation of the a delay law intended for the adaptive dynamic focusing of the desired ultrasonic field. The conformable phased array transducer have been characterized in

  20. Contribution to the development and the modelling of an ultrasonic conformable phased array transducer for the contact inspection of 3D complex geometry components; Contribution au developpement et a la modelisation d'un traducteur ultrasonore multielements conformable pour l'inspection au contact de composants a geometrie complexe 3D

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, O

    2005-04-15

    With the difficulties encountered for the exploration of complex shape surfaces, particularly in nuclear industry, the ultrasonic conformable phased array transducer allows a non destructive evaluation of parts with 3D complex parts. For this, one can use the Smart Contact Transducer principle to generate an ultrasonic field by adaptive dynamic focalisation, with a matrix array composed of independent elements moulded in a soft resin. This work deals with the electro-acoustic conception, with the realization of such a prototype and with the study of it's mechanical and acoustic behaviour. The array design is defined using a radiation model adapted to the simulation of contact sources on a free surface. Once one have defined the shape of the radiating elements, a vibratory analysis using finite elements method allows the determination of the emitting structure with 1-3 piezocomposite, witch leads to the realization of emitting-receiving elements. With the measurement of the field transmitted by such elements, we deduced new hypothesis to change the model of radiation. Thus one can take into account normal and tangential stresses calculated with finite element modelling at the interface between the element and the propagation medium, to use it with the semi-analytical model. Some vibratory phenomena dealing with fluid coupling of contact transducers have been studied, and the prediction of the transverse wave radiation profile have been improved. The last part of this work deals with the realization of the first prototype of the conformable phased array transducer. For this a deformation measuring system have been developed, to determine the position of each element on real time with the displacement of the transducer on complex shape surfaces. With those positions, one can perform the calculation of the a delay law intended for the adaptive dynamic focusing of the desired ultrasonic field. The conformable phased array transducer have been characterized in

  1. Rheological properties of wheat starch influenced by amylose-lysophosphatidylcholine complexation at different gelation phases

    NARCIS (Netherlands)

    Ahmadiabhari, Salomeh; Woortman, Albert; Hamer, Rob; Loos, Katja

    2015-01-01

    Amylose is able to form helical inclusion complexes with lysophosphatidylcholine (LPC). This complexation influences the functional and rheological properties of wheat starch; however it is well known that the formation of these complexes lead the starchy systems to a slower enzymatic hydrolysis.

  2. Rheological properties of wheat starch influenced by amylose-lysophosphatidylcholine complexation at different gelation phases

    NARCIS (Netherlands)

    Ahmadi-Abhari, S.; Woortman, A.J.J.; Hamer, R.J.; Loos, K.

    2015-01-01

    Amylose is able to form helical inclusion complexes with lysophosphatidylcholine (LPC). This complexation influences the functional and rheological properties of wheat starch; however it is well known that the formation of these complexes lead the starchy systems to a slower enzymatic hydrolysis.

  3. Conformity and statistical tolerancing

    Science.gov (United States)

    Leblond, Laurent; Pillet, Maurice

    2018-02-01

    Statistical tolerancing was first proposed by Shewhart (Economic Control of Quality of Manufactured Product, (1931) reprinted 1980 by ASQC), in spite of this long history, its use remains moderate. One of the probable reasons for this low utilization is undoubtedly the difficulty for designers to anticipate the risks of this approach. The arithmetic tolerance (worst case) allows a simple interpretation: conformity is defined by the presence of the characteristic in an interval. Statistical tolerancing is more complex in its definition. An interval is not sufficient to define the conformance. To justify the statistical tolerancing formula used by designers, a tolerance interval should be interpreted as the interval where most of the parts produced should probably be located. This tolerance is justified by considering a conformity criterion of the parts guaranteeing low offsets on the latter characteristics. Unlike traditional arithmetic tolerancing, statistical tolerancing requires a sustained exchange of information between design and manufacture to be used safely. This paper proposes a formal definition of the conformity, which we apply successively to the quadratic and arithmetic tolerancing. We introduce a concept of concavity, which helps us to demonstrate the link between tolerancing approach and conformity. We use this concept to demonstrate the various acceptable propositions of statistical tolerancing (in the space decentring, dispersion).

  4. Axiomatic conformal field theory

    International Nuclear Information System (INIS)

    Gaberdiel, M.R.; Goddard, P.

    2000-01-01

    A new rigourous approach to conformal field theory is presented. The basic objects are families of complex-valued amplitudes, which define a meromorphic conformal field theory (or chiral algebra) and which lead naturally to the definition of topological vector spaces, between which vertex operators act as continuous operators. In fact, in order to develop the theory, Moebius invariance rather than full conformal invariance is required but it is shown that every Moebius theory can be extended to a conformal theory by the construction of a Virasoro field. In this approach, a representation of a conformal field theory is naturally defined in terms of a family of amplitudes with appropriate analytic properties. It is shown that these amplitudes can also be derived from a suitable collection of states in the meromorphic theory. Zhu's algebra then appears naturally as the algebra of conditions which states defining highest weight representations must satisfy. The relationship of the representations of Zhu's algebra to the classification of highest weight representations is explained. (orig.)

  5. Ring-to-chain conformation may be a determining factor in the ability of xanthophylls to bind to the bulk light-harvesting complex of plants

    Science.gov (United States)

    Young, Andrew J.; Phillip, Denise M.; Hashimoto, Hideki

    2002-12-01

    The binding of xanthophylls to the main light-harvesting complex (LHC) of higher plants has been studied using the technique of in vitro reconstitution. This demonstrated that the carotenoid diol lactucaxanthin (native to many LHC) would not support the assembly of LHC whilst other diols, notably zeaxanthin and lutein would. Analysis of the most stable forms of the carotenoid end-groups found in xanthophylls native to higher plant LHC (as determined by theoretical calculations) revealed profound differences in the adiabatic potential energy curves for the C5-C6-C7-C8-torsion angle for the ɛ end-groups in lactucaxanthin (6-s- trans), in comparison to carotenoids possessing a 3-hydroxy β end-group (zeaxanthin; 6-s- cis), 3-hydroxy-4-keto β end-group (astaxanthin, 6-s- cis) or a 3-hydroxy-5,6-epoxy end-group (violaxanthin, distorted 6-s- cis). The (ɛ end-groups of other carotenoids studied were 6-s- trans. We examine the possible relationship between carotenoid ring-to-chain conformation and binding to LHC.

  6. The influence of complexing pharmaceutical compositions on alkaline phosphatase

    Science.gov (United States)

    Atyaksheva, L. F.; Chukhrai, E. S.; Stepina, N. D.; Novikova, N. N.; Yur'eva, E. A.

    2011-06-01

    It is established that the pharmaceutical compositions xydiphon, medifon, succimer, and EDTA, which are used as complexing agents for accelerating the excretion of heavy metals from human organism, at certain concentrations inhibit enzyme alkaline phosphatase (AP). It is concluded that xydiphon and EDTA have a noticeable effect on AP activity at concentrations over 0.01 mM; medifon and succimer, at concentrations of over 0.3-0.5 mM. The enzyme's inhibition constants and type of inhibition are determined. Xydiphon is found to manifest the highest affinity to AP ( K I = 0.35 mM). It is shown by kinetic analysis that dissociative chemoinactivation of the enzyme takes place under the action of complexing agents. The corresponding kinetic parameters are calculated.

  7. Research of complex briquetted modifiers influence on cast iron properties

    Directory of Open Access Journals (Sweden)

    Наталя Валеріївна Сусло

    2016-07-01

    Full Text Available Such properties of cast iron as hardness and shock resistance are relevant and have been investigated. Some possible ways to improve these properties have been studied and solutions to the assigned tasks in accordance with modern trends have been found. The use of nano-dispersed modifiers is most promising in modification. The compositions of experimental complex briquetted modifiers have been developed. The technology of cast iron processing with complex briquetted modifiers has been developed. A series of experiments on the effect of a complex briquetted modifier introduced into cast iron on its properties were carried out. The rational content of components in the briquette that makes maximum use of the modifying effect and improves such service characteristics of cast iron as hardness, impact - and wear-resistance has been defined. Ways of a briquette destruction in metal have been explored. The effect of an organic binder amount on the destruction of a briquette and its dissolution in the melt has been investigated. Rational composition of the briquetted modifier that makes it possible to increase hardness and impact resistance of cast iron has been developed

  8. Complexities and constraints influencing learner performance in physical science

    Directory of Open Access Journals (Sweden)

    Mavhungu Abel Mafukata

    2016-01-01

    Full Text Available This paper explores complexities and constraints affecting performance and output of physical science learners in Vhembe District, Limpopo Province, South Africa. The study was motivated by the desire of the researcher to establish, profile and characterise the complexities and constraints reminiscence of poor performance of learners in physical science as measured through end-of-year Grade 12 (final year of high school education examination results. Twenty six schools (n=26 were purposively selected from three circuits of education (n=3. From these schools, two learners were randomly selected (n=52 for interviews. In addition, two circuit managers (n=2 were conveniently selected as part of Key Informant Interviews (KII. For the Focus Group Discussions (FGDs, twelve (n=12 parents were randomly selected to form two groups of six members each. Multi-factor complexities and constraints impeding performance of learners were discovered. Intensive teacher in-service programme is recommended. Community engagement should be encouraged to educate parents on the value of involvement in the education of their children. Free access learner support structures such as Homework and Extra-lessons Assistance Centre (H&EACs should be established.

  9. Does hormonal therapy influence sexual function in men receiving 3D conformal radiation therapy for prostate cancer?

    International Nuclear Information System (INIS)

    Chen, Christopher T.; Valicenti, Richard K.; Lu Jiandong; Derose, Troy; Dicker, Adam P.; Strup, Stephen E.; Mulholland, S. Grant; Hirsch, Irvin H.; McGinnis, David E.; Gomella, Leonard G.

    2001-01-01

    Purpose: We evaluated the effect of three-dimensional conformal radiation therapy (3D-CRT) with or without hormonal therapy (HT) on sexual function (SF) in prostate cancer patients whose SF was known before all treatment. Methods and Materials: Between March 1996 and March 1999, 144 patients received 3D-CRT (median dose = 70.2 Gy, range 66.6-79.2 Gy) for prostate cancer and had pre- and post-therapy SF data. All SF data were obtained with the O'Leary Brief SF Inventory, a self-administered, multidimensional, validated instrument. We defined total sexual potency as erections firm enough for penetration during intercourse. Mean follow-up time was 21 months (SD ± 11 months). The Wilcoxon signed-rank test was used to test for significance of the change from baseline. Results: Before 3D-CRT, 87 (60%) of 144 men were totally potent as compared to only 47 (47%) of 101 at 1-year follow-up. Of the 60 men totally potent at baseline and followed for at least 1 year, 35 (58%) remained totally potent. These changes corresponded to a significant reduction in SF (p<0.05). Patients who had 3D-CRT alone were more likely to be totally potent at 1 year than those receiving 3D-CRT with HT (56% vs. 31%, p=0.012); however, they were also more likely to be potent at baseline (71% vs. 44%, p=0.001). Although these two groups had a significant reduction in SF from baseline, their change was not significantly different from each other. Conclusion: These data indicate that 3D-CRT causes a significant reduction in total sexual potency as compared to pretreatment baseline. The addition of HT does not appear to increase the risk of sexual dysfunction

  10. Factors Influencing Neurocognitive Outcomes in Young Patients With Benign and Low-Grade Brain Tumors Treated With Stereotactic Conformal Radiotherapy

    International Nuclear Information System (INIS)

    Jalali, Rakesh; Mallick, Indranil; Dutta, Debnarayan

    2010-01-01

    Purpose: To present the effect of radiotherapy doses to different volumes of normal structures on neurocognitive outcomes in young patients with benign and low-grade brain tumors treated prospectively with stereotactic conformal radiotherapy (SCRT). Methods and Materials: Twenty-eight patients (median age, 13 years) with residual/progressive brain tumors (10 craniopharyngioma, 8 cerebellar astrocytoma, 6 optic pathway glioma and 4 cerebral low-grade glioma) were treated with SCRT to a dose of 54 Gy in 30 fractions over 6 weeks. Prospective neuropsychological assessments were done at baseline before RT and at subsequent follow-up examinations. The change in intelligence quotient (IQ) scores was correlated with various factors, including dose-volume to normal structures. Results: Although the overall mean full-scale IQ (FSIQ) at baseline before RT remained unchanged at 2-year follow-up after SCRT, one third of patients did show a >10% decline in FSIQ as compared with baseline. Logistic regression analysis demonstrated that patients aged 10% drop in FSIQ than older patients (53% vs. 10%, p = 0.03). Dosimetric comparison in patients showing a >10% decline vs. patients showing a 43.2 Gy to >13% of volume of the left temporal lobe were the ones to show a significant drop in FSIQ (p = 0.048). Radiotherapy doses to other normal structures, including supratentorial brain, right temporal lobe, and frontal lobes, did not reveal any significant correlation. Conclusion: Our prospectively collected dosimetric data show younger age and radiotherapy doses to left temporal lobe to be predictors of neurocognitive decline, and may well be used as possible dose constraints for high-precision radiotherapy planning.

  11. Information technologies in exposure of conformities to the law of influence of biorhythms on individual effectiveness in sporting tourism

    Directory of Open Access Journals (Sweden)

    Tregub V.V.

    2010-06-01

    Full Text Available The question of influence of biorhythms is considered in the multilevel system of psychophysiological properties of individuality of young sportsmen. Research was conducted in a sporting command on pedestrian tourism. In research 12 sportsmen of the first digit took part in age 13-14 years. Possibility of prognostication of connections is rotined between the features of ритмики and level of individuality. Preliminary conclusions are done about influence of biorhythms on the dynamics of individual sporting results of sportsman.

  12. AN INVESTIGATION OF CONTEXTUAL INFLUENCES ON INNOVATION IN COMPLEX PROJECTS

    DEFF Research Database (Denmark)

    Kavin, Lone; Narasimhan, Ram

    2018-01-01

    There is paucity of literature on supplier-enabled-innovation in complex project-contexts. Based on literature from repetitive-manufacturing-contexts, this conceptual chapter identifies innovation-fostering-practices and develops a conceptual-framework relating them to innovation-performance. The......There is paucity of literature on supplier-enabled-innovation in complex project-contexts. Based on literature from repetitive-manufacturing-contexts, this conceptual chapter identifies innovation-fostering-practices and develops a conceptual-framework relating them to innovation......-performance. The framework suggests that new knowledge is the basis of innovation and leveraging knowledge from the supply-network is a key element along with absorptive-capacity and R&D-investment in creating new knowledge. New knowledge, however, must be exploited to create innovative new products and successfully...... commercialized. Suppliers can play an important role in ensuring successful exploitation of new knowledge. We posit that innovation-fostering-practices mediate the exploitation of new knowledge into superior innovation-performance. Thus, the proposed conceptual-framework incorporates the exploration...

  13. Influence of metacide - surfactant complexes on agricultural crops

    Directory of Open Access Journals (Sweden)

    Orynkul Esimova

    2014-12-01

    Full Text Available The complexes based on surfactants and polyhexamethyleneguanidine hydrochloride (metacide are important for agriculture. This paper considers compositions of known bactericidal metacide with different surfactants: anionic surfactant sodium dodecylsulphate (DDSNa and nonionic surfactant Tween 80 (monooleate of oxyethylenated anhydrosorbitols. The effect of individual components and associates of metacide and surfactants on productivity and infection of cereals was studied. According to the study, the highest productivity and infection rate were shown by the associate of metacide and Tween-80. At concentration of Tween-80 in aqueous solution equal to 0.001% in combination with metacide, efficiency was 98% at 0% infection. The surface tension and the wetting of metacide, DDSNa, Tween-80, and associates of metacide with surfactants were studied. In comparison with individual components, metacide-DDSNa and metacide-Tween-80 associates have higher surface activity.

  14. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  15. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers.

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  16. Influence of neutrophil defects on Burkholderia cepacia complex pathogenesis

    Directory of Open Access Journals (Sweden)

    Laura A. Porter

    2011-11-01

    Full Text Available The Burkholderia cepacia complex (Bcc is a group of Gram-negative bacteria that are ubiquitous in the environment and have emerged as opportunistic pathogens in immunocompromised patients. The primary patient populations infected with Bcc include individuals with cystic fibrosis (CF, as well as those with chronic granulomatous disease (CGD. While Bcc infection in CF is better characterized than in CGD, these two genetic diseases are not obviously similar and it is currently unknown if there is any commonality in host immune defects that is responsible for the susceptibility to Bcc. CF is caused by mutations in the CF transmembrane conductance regulator, resulting in manifestations in various organ systems, however the major cause of morbidity and mortality is currently due to bacterial respiratory infections. CGD, on the other hand, is a genetic disorder that is caused by defects in phagocyte NADPH oxidase. Because of the defect in CGD, phagocytes in these patients are unable to produce reactive oxygen species, which results in increased susceptibility to bacterial and fungal infections. Despite this significant defect in microbial clearance, the spectrum of pathogens frequently implicated in infections in CGD is relatively narrow and includes some bacterial species that are considered almost pathognomonic for this disorder. Very little is known about the cause of the specific susceptibility to Bcc over other potential pathogens more prevalent in the environment, and a better understanding of specific mechanisms required for bacterial virulence has become a high priority. This review will summarize both the current knowledge and future directions related to Bcc virulence in immunocompromised individuals with a focus on the roles of bacterial factors and neutrophil defects in pathogenesis.

  17. Two dimensional infinite conformal symmetry

    International Nuclear Information System (INIS)

    Mohanta, N.N.; Tripathy, K.C.

    1993-01-01

    The invariant discontinuous (discrete) conformal transformation groups, namely the Kleinian and Fuchsian groups Gamma (with an arbitrary signature) of H (the Poincare upper half-plane l) and the unit disc Delta are explicitly constructed from the fundamental domain D. The Riemann surface with signatures of Gamma and conformally invariant automorphic forms (functions) with Peterson scalar product are discussed. The functor, where the category of complex Hilbert spaces spanned by the space of cusp forms constitutes the two dimensional conformal field theory. (Author) 7 refs

  18. ELECTRIC FACTORS INFLUENCING THE COMPLEX EROSION PROCESSING BY INTRODUCING THE ELECTROLYTE THROUGH THE TRANSFER OBJECT

    Directory of Open Access Journals (Sweden)

    Alin Nioata

    2014-05-01

    Full Text Available The electric and electrochemical complex erosion processing is influenced by a great number of factors acting in tight interdependence and mutually influencing one another for achieving the stability of the processing process and achieving the final technological characteristics.The values taking part in developing the fundamental phenomena of the mechanism of complex erosion prevailing and contributes to the definition of technological characteristics, are factors.The paper presents the U potential difference and electric strength I as determining factors of the complex erosion process as well as other factors deriving from them: the current density, the power of the supply source.

  19. Gold nanoparticles as a factor of influence on doxorubicin-bovine serum albumin complex

    Science.gov (United States)

    Goncharenko, N. A.; Pavlenko, O. L.; Dmytrenko, O. P.; Kulish, M. P.; Lopatynskyi, A. M.; Chegel, V. I.

    2018-04-01

    The interaction between doxorubicin (Dox) and bovine serum albumin (BSA) complex with gold nanoparticles (AuNPs) was investigated by optical spectroscopy. The optical absorption of Dox and BSA solutions was studied. The formation of Dox-BSA complexes with a binding constant K = 7.56 × 106 M-2 and the number of binding sites n = 2 was found out. With pH 6.9, the concentration of complexes is an order of magnitude lower than the concentration of unbound antibiotic molecules. Optical absorption in solutions of Dox-BSA conjugates in the presence of AuNPs undergoes a significant rearrangement, which manifests the changes in the magnitude of the hydrophobic interaction of BSA with Dox, changes in the conformational state of antibiotic, and, as a consequence, a plasmon-induced change in the mechanism of complex formation. The aggregation of the Dox-AuNPs conjugate depends on the presence and concentration of BSA and in the case of formation of the Dox-BSA complex is minimal.

  20. Conformational equilibrium in supramolecular chemistry: Dibutyltriuret case.

    Science.gov (United States)

    Mroczyńska, Karina; Kaczorowska, Małgorzata; Kolehmainen, Erkki; Grubecki, Ireneusz; Pietrzak, Marek; Ośmiałowski, Borys

    2015-01-01

    The association of substituted benzoates and naphthyridine dianions was used to study the complexation of dibutyltriuret. The title molecule is the simplest molecule able to form two intramolecular hydrogen bonds. The naphthyridine salt was used to break two intramolecular hydrogen bonds at a time while with the use of substituted benzoates the systematic approach to study association was achieved. Both, titrations and variable temperature measurements shed the light on the importance of conformational equilibrium and its influence on association in solution. Moreover, the associates were observed by mass spectrometry. The DFT-based computations for complexes and single bond rotational barriers supports experimental data and helps understanding the properties of multiply hydrogen bonded complexes.

  1. Conformal Tachyons

    CERN Document Server

    Tomaschitz, R

    2000-01-01

    We study tachyons conformally coupled to the background geometry of a Milne universe. The causality of superluminal signal transfer is scrutinized in this context. The cosmic time of the comoving frame determines a distinguished time order for events connected by superluminal signals. An observer can relate his rest frame to the galaxy frame, and compare so the time order of events in his proper time to the cosmic time order. All observers can in this way arrive at identical conclusions on the causality of events connected by superluminal signals. An unambiguous energy concept for tachyonic rays is defined by means of the cosmic time of the comoving reference frame, without resorting to an antiparticle interpretation. On that basis we give an explicit proof that no signals can be sent into the past of observers. Causality violating signals are energetically forbidden, as they would have negative energy in the rest frame of the emitting observer. If an observer emits a superluminal signal, the tachyonic respon...

  2. Influence of the Hydrophobicity of Polyelectrolytes on Polyelectrolyte Complex Formation and Complex Particle Structure and Shape

    Directory of Open Access Journals (Sweden)

    Gudrun Petzold

    2011-08-01

    Full Text Available Polyelectrolyte complexes (PECs were prepared by structural uniform and strongly charged cationic and anionic modified alternating maleic anhydride copolymers. The hydrophobicity of the polyelectrolytes was changed by the comonomers (ethylene, isobutylene and styrene. Additionally, the n−/n+ ratio of the molar charges of the polyelectrolytes and the procedure of formation were varied. The colloidal stability of the systems and the size, shape, and structure of the PEC particles were investigated by turbidimetry, dynamic light scattering (DLS and atomic force microscopy (AFM. Dynamic light scattering indicates that beside large PEC particle aggregates distinct smaller particles were formed by the copolymers which have the highest hydrophobicity (styrene. These findings could be proved by AFM. Fractal dimension (D, root mean square (RMS roughness and the surface profiles of the PEC particles adsorbed on mica allow the following conclusions: the higher the hydrophobicity of the polyelectrolytes, the broader is the particle size distribution and the minor is the swelling of the PEC particles. Hence, the most compact particles are formed with the very hydrophobic copolymer.

  3. The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes

    Science.gov (United States)

    Gregson, Matthew; Lu, Erli; Mills, David P.; Tuna, Floriana; McInnes, Eric J. L.; Hennig, Christoph; Scheinost, Andreas C.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Kerridge, Andrew; Liddle, Stephen T.

    2017-02-01

    Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal-ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inverse-trans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle.

  4. Social dimension and complexity differentially influence brain responses during feedback processing.

    Science.gov (United States)

    Pfabigan, Daniela M; Gittenberger, Marianne; Lamm, Claus

    2017-10-30

    Recent research emphasizes the importance of social factors during performance monitoring. Thus, the current study investigated the impact of social stimuli -such as communicative gestures- on feedback processing. Moreover, it addressed a shortcoming of previous studies, which failed to consider stimulus complexity as potential confounding factor. Twenty-four volunteers performed a time estimation task while their electroencephalogram was recorded. Either social complex, social non-complex, non-social complex, or non-social non-complex stimuli were used to provide performance feedback. No effects of social dimension or complexity were found for task performance. In contrast, Feedback-Related Negativity (FRN) and P300 amplitudes were sensitive to both factors, with larger FRN and P300 amplitudes after social compared to non-social stimuli, and larger FRN amplitudes after complex positive than non-complex positive stimuli. P2 amplitudes were solely sensitive to feedback valence and social dimension. Subjectively, social complex stimuli were rated as more motivating than non-social complex ones. Independently of each other, social dimension and visual complexity influenced amplitude variation during performance monitoring. Social stimuli seem to be perceived as more salient, which is corroborated by P2, FRN and P300 results, as well as by subjective ratings. This could be explained due to their given relevance during every day social interactions.

  5. Conformal field theory in conformal space

    International Nuclear Information System (INIS)

    Preitschopf, C.R.; Vasiliev, M.A.

    1999-01-01

    We present a new framework for a Lagrangian description of conformal field theories in various dimensions based on a local version of d + 2-dimensional conformal space. The results include a true gauge theory of conformal gravity in d = (1, 3) and any standard matter coupled to it. An important feature is the automatic derivation of the conformal gravity constraints, which are necessary for the analysis of the matter systems

  6. Geometrical formulation of the conformal Ward identity

    International Nuclear Information System (INIS)

    Kachkachi, M.

    2002-08-01

    In this paper we use deep ideas in complex geometry that proved to be very powerful in unveiling the Polyakov measure on the moduli space of Riemann surfaces and lead to obtain the partition function of perturbative string theory for 2, 3, 4 loops. Indeed, a geometrical interpretation of the conformal Ward identity in two dimensional conformal field theory is proposed: the conformal anomaly is interpreted as a deformation of the complex structure of the basic Riemann surface. This point of view is in line with the modern trend of geometric quantizations that are based on deformations of classical structures. Then, we solve the conformal Ward identity by using this geometrical formalism. (author)

  7. Analysis of Conformational B-Cell Epitopes in the Antibody-Antigen Complex Using the Depth Function and the Convex Hull.

    Directory of Open Access Journals (Sweden)

    Wei Zheng

    Full Text Available The prediction of conformational b-cell epitopes plays an important role in immunoinformatics. Several computational methods are proposed on the basis of discrimination determined by the solvent-accessible surface between epitopes and non-epitopes, but the performance of existing methods is far from satisfying. In this paper, depth functions and the k-th surface convex hull are used to analyze epitopes and exposed non-epitopes. On each layer of the protein, we compute relative solvent accessibility and four different types of depth functions, i.e., Chakravarty depth, DPX, half-sphere exposure and half space depth, to analyze the location of epitopes on different layers of the proteins. We found that conformational b-cell epitopes are rich in charged residues Asp, Glu, Lys, Arg, His; aliphatic residues Gly, Pro; non-charged residues Asn, Gln; and aromatic residue Tyr. Conformational b-cell epitopes are rich in coils. Conservation of epitopes is not significantly lower than that of exposed non-epitopes. The average depths (obtained by four methods for epitopes are significantly lower than that of non-epitopes on the surface using the Wilcoxon rank sum test. Epitopes are more likely to be located in the outer layer of the convex hull of a protein. On the benchmark dataset, the cumulate 10th convex hull covers 84.6% of exposed residues on the protein surface area, and nearly 95% of epitope sites. These findings may be helpful in building a predictor for epitopes.

  8. Influence of complexing on physicochemical properties of polymer-salt solutions

    International Nuclear Information System (INIS)

    Ostroushko, A.A.; Yushkova, S.M.; Koridze, N.V.; Skobkoreva, N.V.; Zhuravleva, L.I.; Palitskaya, T.A.; Antropova, S.V.; Ostroushko, I.P.; AN SSSR, Moscow

    1993-01-01

    Using the methods of spectrophotometry, viscosimetry, conductometry the influence of salt-polymer complexing processes on physicochemical prperties of aqueous solutions of yttrium, barium, copper nitrates and formates with polyvinyl alcohol was studied. Change of dynamic viscosity, specific electric conductivity of solutions in the process of complexing was shown. Thermal effects of salt-polymer interaction were measured. It is shown that decrease of transition temperature of polymer to plastic state in films, temperature and effective activation energy of salt decomposition is also connected with complexing. Effective values of surface tension on the boundary with air are measured. Coefficients of cation diffusion in polymer-salt solutions are estimated

  9. Influence of a solvent on thermodynamics of electrolytic dissociation of simple and complex rare earth salts

    Energy Technology Data Exchange (ETDEWEB)

    Gorodyskij, A.V.; Fialkov, Yu.Ya.; Chernyj, D.B. (AN Ukrainskoj SSR, Kiev. Inst. Obshchej i Neorganicheskoj Khimii; Kievskij Politekhnicheskij Inst. (Ukrainian SSR))

    1982-03-01

    Influence of the double mixed solvent on thermodynamic characteristics of ionic migration of lanthanum, neodymium, europium and dysprosium chlorides as well as their phenanthroline complexes is considered. Decrease of lambdasub(c) of simple and complex rare earth salts in the lanthanum, neodymium-europium-dysprosium series as explained by increase of solvation degree, associated with lanthanum compression. It is shown that increase of methanol or propanol content results in exothermicity decrease of the ionic migration process. The temperature constituents of enthalpy and entropy of dissociation of the simple and complex rare earth salts are presented.

  10. Influence of Introduced Substituents on the Anion-selectivity of [14]Tetraazaannulene Complexes.

    Science.gov (United States)

    Moriuchi-Kawakami, Takayo; Obita, Minako; Tsujinaka, Toshiki; Shibutani, Yasuhiko

    2015-01-01

    Nickel(II) complexes of [14]tetraazaannulene derivatives incorporating aromatic rings into their azaannulene framework were synthesized, and the anion-selectivity of the [14]tetraazaannulene nickel complexes 1 - 4 was evaluated by potentiometric measurements with solvent polymeric membrane electrodes. All of the [14]Tetraazaannulene nickel complexes, except 3, were found to exhibit high selectivity for the I(-) ion over the SCN(-) ion, although considerable interference of the ClO4(-) ion was observed in all 1 - 4 complexes. Concerning the anion-selectivities of 1 and 4, the incorporation of naphthalene rings into the azaannulene framework decreased not only the interference of the ClO4(-) ion but also the I(-) ion-selectivity over the SCN(-) ion. Comparison studies between the dibenzotetraaza[14]annulene nickel complexes 1 - 3 indicated that differences in the attached substituents of the [14]tetraazaannulene nickel complexes greatly influenced the ion-selectivity as ionophores. According to our computational results, the ionophoric properties of [14]tetraazaannulene nickel complexes 1 - 4 were influenced by their electrostatic properties rather than their topological properties.

  11. Factors of influence on acute skin toxicity of breast cancer patients treated with standard three-dimensional conformal radiotherapy (3D-CRT) after breast conserving surgery (BCS)

    International Nuclear Information System (INIS)

    Kraus-Tiefenbacher, Uta; Sfintizky, Andreas; Welzel, Grit; Simeonova, Anna; Sperk, Elena; Siebenlist, Kerstin; Mai, Sabine; Wenz, Frederik

    2012-01-01

    Standard 3D-CRT after BCS may cause skin toxicity with a wide range of intensity including acute effects like erythema or late effects. In order to reduce these side effects it is mandatory to identify potential factors of influence in breast cancer patients undergoing standard three-dimensional conformal radiation therapy (3D-CRT) of the breast and modern systemic therapy. Between 2006 and 2010 a total of 211 breast cancer patients (median age 52,4 years, range 24–77) after BCS consecutively treated in our institution with 3D-CRT (50 Gy whole breast photon radiotherapy followed by 16 Gy electron boost to the tumorbed) were evaluated with special focus on documented skin toxicity at the end of the 50 Gy-course. Standardized photodocumentation of the treated breast was done in each patient lying on the linac table with arms elevated. Skin toxicity was documented according to the common toxicity criteria (CTC)-score. Potential influencing factors were classified in three groups: patient-specific (smoking, age, breast size, body mass index = BMI, allergies), tumor-specific (tumorsize) and treatment-specific factors (antihormonal therapy with tamoxifen or aromatase inhibitors, chemotherapy). Uni- and multivariate statistical analyses were done using IBM SPSS version 19. After 50 Gy 3D-CRT to the whole breast 28.9% of all 211 patients had no erythema, 62.2% showed erythema grade 1 (G1) and 8.5% erythema grade 2. None of the patients had grade 3/4 (G3/4) erythema. In univariate analyses a significant influence or trend on the development of acute skin toxicities (erythema G0 versus G1 versus G2) was observed for larger breast volumes (p=0,004), smoking during radiation therapy (p=0,064) and absence of allergies (p=0,014) as well as larger tumorsize (p=0,009) and antihormonal therapy (p=0.005). Neither patient age, BMI nor choice of chemotherapy showed any significant effect on higher grade toxicity. In the multivariate analysis, factors associated with higher grade

  12. Complex Network Structure Influences Processing in Long-Term and Short-Term Memory

    Science.gov (United States)

    Vitevitch, Michael S.; Chan, Kit Ying; Roodenrys, Steven

    2012-01-01

    Complex networks describe how entities in systems interact; the structure of such networks is argued to influence processing. One measure of network structure, clustering coefficient, C, measures the extent to which neighbors of a node are also neighbors of each other. Previous psycholinguistic experiments found that the C of phonological…

  13. Force and complexity of tongue task training influences behavioral measures of motor learning

    DEFF Research Database (Denmark)

    Kothari, Mohit; Svensson, Peter; Huo, Xueliang

    2012-01-01

    Relearning of motor skills is important in neurorehabilitation. We investigated the improvement of training success during simple tongue protrusion (two force levels) and a more complex tongue-training paradigm using the Tongue Drive System (TDS). We also compared subject-based reports of fun, pain...... training influences behavioral aspects of tongue motor learning....

  14. The Influence of Time Pressure and Case Complexity on Physicians׳ Diagnostic Performance

    Directory of Open Access Journals (Sweden)

    Dalal A. ALQahtani

    2016-12-01

    Conclusions: Time pressure did not impact the diagnostic performance, whereas the complexity of the clinical case negatively influenced the diagnostic accuracy. Further studies with the enhanced experimental manipulation of time pressure are needed to reveal the effect of time pressure, if any, on a physician׳s diagnostic performance.

  15. Influence of step complexity and presentation style on step performance of computerized emergency operating procedures

    Energy Technology Data Exchange (ETDEWEB)

    Xu Song [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China); Li Zhizhong [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China)], E-mail: zzli@tsinghua.edu.cn; Song Fei; Luo Wei; Zhao Qianyi; Salvendy, Gavriel [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China)

    2009-02-15

    With the development of information technology, computerized emergency operating procedures (EOPs) are taking the place of paper-based ones. However, ergonomics issues of computerized EOPs have not been studied adequately since the industrial practice is quite limited yet. This study examined the influence of step complexity and presentation style of EOPs on step performance. A simulated computerized EOP system was developed in two presentation styles: Style A: one- and two-dimensional flowcharts combination; Style B: two-dimensional flowchart and success logic tree combination. Step complexity was quantified by a complexity measure model based on an entropy concept. Forty subjects participated in the experiment of EOP execution using the simulated system. The results of data analysis on the experiment data indicate that step complexity and presentation style could significantly influence step performance (both step error rate and operation time). Regression models were also developed. The regression analysis results imply that operation time of a step could be well predicted by step complexity while step error rate could only partly predicted by it. The result of a questionnaire investigation implies that step error rate was influenced not only by the operation task itself but also by other human factors. These findings may be useful for the design and assessment of computerized EOPs.

  16. Influence of Herbal Complexes Containing Licorice on Potassium Levels: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    WooSang Jung

    2014-01-01

    Full Text Available To observe the influence of these complexes on potassium levels in a clinical setting, we investigated the influence of herbal complexes containing licorice on potassium levels. We retrospectively examined the medical records of patients treated with herbal complexes containing licorice from January 1, 2010, to December 31, 2010. We recorded the changes in the levels of potassium, creatinine, and blood urea nitrogen and examined the differences between before and after herbal complexes intake using a paired t-test. In addition, we investigated the prevalence of hypokalemia among these patients and reviewed such patients. We identified 360 patients who did not show significant changes in the levels of potassium and creatinine (P=0.815, 0.289. We observed hypokalemia in 6 patients. However, in 5 patients, the hypokalemia did not appear to be related to the licorice. Thus, we could suggest that herbal complexes containing licorice do not significantly influence the potassium levels in routine clinical herbal therapies. However, we propose that follow-up examination for potassium levels is required to prevent any unpredictable side effects of administration of licorice in routine herbal medicine care.

  17. Atropisomerism about aryl-Csp(3) bonds: the electronic and steric influence of ortho-substituents on conformational exchange in cannabidiol and linderatin derivatives.

    Science.gov (United States)

    Berber, Hatice; Lameiras, Pedro; Denhez, Clément; Antheaume, Cyril; Clayden, Jonathan

    2014-07-03

    Terpenylation reactions of substituted phenols were used to prepare cannabidiol and linderatin derivatives, and their structure and conformational behavior in solution were investigated by NMR and, for some representative examples, by DFT. VT-NMR spectra and DFT calculations were used to determine the activation energies of the conformational change arising from restricted rotation about the aryl-Csp(3) bond that lead to two unequally populated rotameric epimers. The NBO calculation was applied to explain the electronic stabilization of one conformer over another by donor-acceptor charge transfer interactions. Conformational control arises from a combination of stereoelectronic and steric effects between substituents in close contact with each other on the two rings of the endocyclic epoxide atropisomers. This study represents the first exploration of the stereoelectronic origins of atropisomerism around C(sp(2))-C(sp(3)) single bonds through theoretical calculations.

  18. PMMA-g-OEtOx Graft Copolymers: Influence of Grafting Degree and Side Chain Length on the Conformation in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Irina Muljajew

    2018-03-01

    Full Text Available Depending on the degree of grafting (DG and the side chain degree of polymerization (DP, graft copolymers may feature properties similar to statistical copolymers or to block copolymers. This issue is approached by studying aqueous solutions of PMMA-g-OEtOx graft copolymers comprising a hydrophobic poly(methyl methacrylate (PMMA backbone and hydrophilic oligo(2-ethyl-2-oxazoline (OEtOx side chains. The graft copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT copolymerization of methyl methacrylate (MMA and OEtOx-methacrylate macromonomers of varying DP. All aqueous solutions of PMMA-g-OEtOx (9% ≤ DG ≤ 34%; 5 ≤ side chain DP ≤ 24 revealed lower critical solution temperature behavior. The graft copolymer architecture significantly influenced the aggregation behavior, the conformation in aqueous solution and the coil to globule transition, as verified by means of turbidimetry, dynamic light scattering, nuclear magnetic resonance spectroscopy, and analytical ultracentrifugation. The aggregation behavior of graft copolymers with a side chain DP of 5 was significantly affected by small variations of the DG, occasionally forming mesoglobules above the cloud point temperature (Tcp, which was around human body temperature. On the other hand, PMMA-g-OEtOx with elongated side chains assembled into well-defined structures below the Tcp (apparent aggregation number (Nagg = 10 that were able to solubilize Disperse Orange 3. The thermoresponsive behavior of aqueous solutions thus resembled that of micelles comprising a poly(2-ethyl-2-oxazoline (PEtOx shell (Tcp > 60 °C.

  19. Comparison of rectal volume definition techniques and their influence on rectal toxicity in patients with prostate cancer treated with 3D conformal radiotherapy: a dose-volume analysis

    International Nuclear Information System (INIS)

    Onal, Cem; Topkan, Erkan; Efe, Esma; Yavuz, Melek; Sonmez, Serhat; Yavuz, Aydin

    2009-01-01

    To evaluate the impact of four different rectum contouring techniques and rectal toxicities in patients with treated with 3D conformal radiotherapy (3DCRT). Clinical and dosimetric data were evaluated for 94 patients who received a total dose 3DCRT of 70 Gy, and rectal doses were compared in four different rectal contouring techniques: the prostate-containing CT sections (method 1); 1 cm above and below the planning target volume (PTV) (method 2); 110 mm starting from the anal verge (method 3); and from the anal verge to the sigmoid flexure (method 4). The percentage of rectal volume receiving RT doses (30–70 Gy) and minimum, mean rectal doses were assessed. Median age was 69 years. Percentage of rectal volume receiving high doses (≥ 70 Gy) were higher with the techniques that contoured smaller rectal volumes. In methods 2 and 3, the percentage of rectal volume receiving ≥ 70 Gy was significantly higher in patients with than without rectal bleeding (method 2: 30.8% vs. 22.5%, respectively (p = 0.03); method 3: 26.9% vs. 18.1%, respectively (p = 0.006)). Mean rectal dose was significant predictor of rectal bleeding only in method 3 (48.8 Gy in patients with bleeding vs. 44.4 Gy in patients without bleeding; p = 0.02). Different techniques of rectal contouring significantly influence the calculation of radiation doses to the rectum and the prediction of rectal toxicity. Rectal volume receiving higher doses (≥ 70 Gy) and mean rectal doses may significantly predict rectal bleeding for techniques contouring larger rectal volumes, as was in method 3

  20. Stability and properties of quasi-stable conformational states in the LH2 light-harvesting complex of Rbl. acidophilus bacteria formed by hexacoordination of bacteriochlorophyll a magnesium atom

    Science.gov (United States)

    Belov, Aleksandr S.; Khokhlov, Daniil V.; Glebov, Ilya O.; Poddubnyy, Vladimir V.; Eremin, Vadim V.

    2017-06-01

    Single-molecule spectroscopic experiments on several light-harvesting complexes revealed the existence of a set of metastable conformational states with different spectroscopic properties and lifetimes spanning from milliseconds to tens of seconds. In the absence of explicit structural data, a number of probable structural changes underlying the observed spectroscopic shifts were proposed. We examine the donor-acceptor interaction between the magnesium atom and the acetyl group of the adjacent bacteriochlorophylls a as a possible origin of metastable conformational states in the LH2 light-harvesting complex of Rbl. acidophilus bacteria. The results of QM/MM and molecular dynamics simulations show that such ligation can occur at room temperature and leads to one metastable coordination bond per pair of bacteriochlorophylls in the B850 ring. According to the results of Poisson-TrESP modeling, such coordination lowers the energies of the excited states of the complex by up to 163 cm-1 which causes red spectral shift of the B850 band.

  1. 2D parallel interpenetration of [M2(bpp)4X4] [M, Fe(II)/Co(II); bpp, 4,4'-trimethylenedipyridine; X, SCN-, SeCN- and N3-] complexes: Pseudohalide-dependent conformation of bpp

    International Nuclear Information System (INIS)

    Manna, Subal Chandra; Jana, Atish Dipankar; Rosair, Georgina M.; Drew, Michael G.B.; Mostafa, Golam; Ray Chaudhuri, Nirmalendu

    2008-01-01

    Three coordination complexes of Co(II)/Fe(II) with 4,4'-trimethylenedipyridine (bpp) and pseudohalides (SCN - , SeCN - and N 3 - ) have been synthesized. The complexes have been characterized by X-ray single crystal structure determination. They are isomorphous having 2D layers in which two independent wavy nets display parallel interwoven structures. Pseudohalide binds metal centers through N terminal and occupies the trans axial positions of the octahedral metal coordination environment. Pseudohalide remains pendant on both sides of the polymeric layer and help the stacking through hydrogen bonding. The conformation of bpp in the interpenetrated nets is observed to be dependent on the choice of pseudohalide. - Graphical abstract: Complexes of [M 2 (bpp) 4 X 4 ] [M, Fe(II)/Co(II); bpp, 4,4'-trimethylenedipyridine; X, SCN - , SeCN - and N3 - ] have been synthesized. The structural analysis reveals undulated 2D network with (4,4) net topology adopting two different conformations of bpp alternately. Two such networks undergo parallel interpenetration. Pseudohalides are observed to help in stacking the interpenetrated nets through hydrogen bonding

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

    Science.gov (United States)

    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.

  3. Conformational changes in glycine tri- and hexapeptide

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2006-01-01

    conformations and calculated the energy barriers for transitions between them. Using a thermodynamic approach, we have estimated the times of the characteristic transitions between these conformations. The results of our calculations have been compared with those obtained by other theoretical methods...... also investigated the influence of the secondary structure of polypeptide chains on the formation of the potential energy landscape. This analysis has been performed for the sheet and the helix conformations of chains of six amino acids....

  4. Plastic influence functions for calculating J-integral of complex-cracks in pipe

    International Nuclear Information System (INIS)

    Jeong, Jae-Uk; Choi, Jae-Boong; Kim, Moon-Ki; Huh, Nam-Su; Kim, Yun-Jae

    2016-01-01

    In this study, the plastic influence functions, h_1, for estimates of J-integral of a pipe with a complex crack were newly proposed based on the systematic 3-dimensional (3-D) elastic-plastic finite element (FE) analyses by using Ramberg-Osgood (R-O) relation, in which global bending moment, axial tension and internal pressure were considered as loading conditions. Based on the present plastic influence functions, the GE/EPRI-type J-estimation scheme for complex-cracked pipes was suggested, and the results from the proposed J-estimation were compared with the FE results using both R-O fit parameters and actual tensile data of SA376 TP304 stainless steel. The comparison results demonstrate that although the proposed scheme provided sensitive J estimations according to fitting ranges of R-O parameters, it showed overall good agreements with the FE results using R-O relation. Thus, the proposed engineering J prediction method can be utilized to assess instability of a complex crack in pipes for R-O material. - Highlights: • New h_1values of GE/EPRI method for complex-cracked pipes are proposed. • The plastic limit loads of complex-cracked pipes using Mises yield criterion are provided. • The new J estimates of complex-cracked pipes are proposed based on GE/EPRI concept. • The proposed estimates for J are validated against 3-D finite element results.

  5. Determination of molecular structure of succinic acid in a very complex conformational landscape: Gas-phase electron diffraction (GED) and ab initio studies

    Science.gov (United States)

    Vogt, Natalja; Abaev, Maxim A.; Rykov, Anatolii N.; Shishkov, Igor F.

    2011-06-01

    The molecular structure of succinic acid has been investigated by the gas-phase electron diffraction (GED) method for the first time. According to predictions of MP2/cc-pVTZ calculations, the molecule has 18 stable conformers with the C sbnd C sbnd C sbnd C chain in the gauche ( G) or anti ( A) configuration, and four of them, I ( G), II ( A), III ( G) and IV ( A) belonging to the C 2, C 2h, C 1 and C 1 point groups, respectively, with relative energies ΔE ZPE within 2.2 kcal/mol can be present at the experimental temperature of 445 K in noticeable amounts. The ratio of the conformers I:II:III:IV = 45(15):20(15):10(assumed):25(15) (in %) has been determined in the GED analysis guided by theoretical predictions. To take into account vibrational effects, the corrections Δ( r e - r a) to the experimental r a bond lengths were calculated from the MP2/cc-pVTZ quadratic and cubic force constants. The obtained equilibrium structural parameters of the dominant conformer I are the following (bond lengths in Å, angles in degrees): r e(C sp3sbnd C sp3) = 1.508(3), r e(C sp3sbnd C sp2) = 1.499(2), r e(C sbnd O) = 1.343(2), r e(C dbnd O) = 1.202(1), e(C sbnd C sbnd C) = 111.8(4), e(C sbnd C sbnd O) = 112.0(4), e(O sbnd C dbnd O) = 123.0(1), τ(C sbnd C sbnd C sbnd C) = 69.9(11). Yielding the best agreement with the GED structure, the MP2/cc-pVQZ approximation overestimates the C sbnd O and C dbnd O bond lengths by ca. 0.005(2) Å.

  6. Conformation analysis of oligomeric flavanoids

    Science.gov (United States)

    Jan P. Steynberg; E. Vincent Brandt; Daneel Ferreira; Carin A. Helfer; Wayne L. Mattice; Dominika Gornik; Richard W. Hemingway

    1995-01-01

    The profisetinidins are the most important polyflavanoids of commerce, making up the major constituents of wattle and quebracho tannins. Within the dimeric profisetinidins, substantial complexity exists because of stereo-, regio, rotational and conformational isomers. Definition of the stereochemistry of the upper and lower flavan units, the location of the...

  7. Conformational analysis of oligomeric flavanoids

    Science.gov (United States)

    Jan P. Steynberg; E. Vincent Brandt; Daneel Ferreira; Carin A. Helfer; Wayne L. Mattice; Dominika Gornik; Richard W. Hemingway

    1995-01-01

    The profisetinidins are the most important polyflavanoids of commerce, making up the major constituents of wattle and quebracho tannins. Even within the dimeric profisetinidins, substantial complexity exists because of stereo-, regio-, rotational and conformational isomers. Definition of the stereochemistry of the upper and lower flavan units, the location of the...

  8. Influence of cueing on the preparation and execution of untrained and trained complex motor responses

    Directory of Open Access Journals (Sweden)

    S.R. Alouche

    2012-05-01

    Full Text Available This study investigated the influence of cueing on the performance of untrained and trained complex motor responses. Healthy adults responded to a visual target by performing four sequential movements (complex response or a single movement (simple response of their middle finger. A visual cue preceded the target by an interval of 300, 1000, or 2000 ms. In Experiment 1, the complex and simple responses were not previously trained. During the testing session, the complex response pattern varied on a trial-by-trial basis following the indication provided by the visual cue. In Experiment 2, the complex response and the simple response were extensively trained beforehand. During the testing session, the trained complex response pattern was performed in all trials. The latency of the untrained and trained complex responses decreased from the short to the medium and long cue-target intervals. The latency of the complex response was longer than that of the simple response, except in the case of the trained responses and the long cue-target interval. These results suggest that the preparation of untrained complex responses cannot be completed in advance, this being possible, however, for trained complex responses when enough time is available. The duration of the 1st submovement, 1st pause and 2nd submovement of the untrained and the trained complex responses increased from the short to the long cue-target interval, suggesting that there is an increase of online programming of the response possibly related to the degree of certainty about the moment of target appearance.

  9. Conformational analysis of oligosaccharides and polysaccharides using molecular dynamics simulations.

    Science.gov (United States)

    Frank, Martin

    2015-01-01

    Complex carbohydrates usually have a large number of rotatable bonds and consequently a large number of theoretically possible conformations can be generated (combinatorial explosion). The application of systematic search methods for conformational analysis of carbohydrates is therefore limited to disaccharides and trisaccharides in a routine analysis. An alternative approach is to use Monte-Carlo methods or (high-temperature) molecular dynamics (MD) simulations to explore the conformational space of complex carbohydrates. This chapter describes how to use MD simulation data to perform a conformational analysis (conformational maps, hydrogen bonds) of oligosaccharides and how to build realistic 3D structures of large polysaccharides using Conformational Analysis Tools (CAT).

  10. Conformal deformation of Riemann space and torsion

    International Nuclear Information System (INIS)

    Pyzh, V.M.

    1981-01-01

    Method for investigating conformal deformations of Riemann spaces using torsion tensor, which permits to reduce the second ' order equations for Killing vectors to the system of the first order equations, is presented. The method is illustrated using conformal deformations of dimer sphere as an example. A possibility of its use when studying more complex deformations is discussed [ru

  11. Ligand influences on properties of uranium coordination complexes. Structure, reactivity, and spectroscopy

    International Nuclear Information System (INIS)

    Kosog, Boris

    2012-01-01

    In this thesis several different aspects of uranium chemistry are presented. It was shown that terminal uranium(V) oxo and imido complexes [(( R ArO) 3 tacn)U V (O)] and [(( R ArO) 3 tacn)U V (NSiMe 3 )] (R = t Bu, Ad) can be oxidized by silver(I) hexafluoro-antimonate to the uranium(VI) oxo and imido complexes [(( R ArO) 3 tacn)U VI (O)]SbF 6 and [(( R ArO) 3 tacn)U VI (NSiMe 3 )]SbF 6 . While for the t Bu-derivative of the oxo complex an equatorial coordination is observed due to stabilization by the inverse trans-influence, normal axial coordination is observed for the Ad-derivative and both imido complexes. The inverse trans-influence was thus proven to be a key factor for the coordination mode of a terminal ligand on high valent uranium complexes. L III XANES was shown to be a great tool for the determination of oxidation states of uranium complexes. Therefore, a series of uranium complexes in all stable oxidation states for uranium, +III to +VI was prepared, and their spectra analyzed. All compounds bear only O-donor ligands in addition to the chlating trisaryloxide-tacn-ligand. A separation of 1.5 to 3 eV in the white line energy is observed between the different oxidation states. This series can be used as reference for compounds, where oxidation state assignment is not obvious, such as a ketyl radical complex [(( t-Bu Ar)O 3 tacn)U(O-C( t-Bu Ph) 2 .- )]. For this complex, the oxidation state of +IV could be assigned. Moreover, a series of isostructural uranium(IV) complexes was prepared. The influence of different ligands according to the spectrochemical series on the electronic and magnetic properties could be shown using UV/vis/NIR spectroscopy and variable temperature SQUID measurements. Calculations of uranium L III XANES spectra show a variation in the shape of the spectra and thus high resolution PFY-XANES would be a great tool to determine the electronic influence of these different axial ligands. Using the single N-anchored ligand system, the first

  12. Polycation-sodium lauryl ether sulfate-type surfactant complexes: influence of ethylene oxide length.

    Science.gov (United States)

    Vleugels, Leo F W; Pollet, Jennifer; Tuinier, Remco

    2015-05-21

    Polyelectrolyte-surfactant complexes (PESC) are a class of materials which form spontaneously by self-assembly driven by electrostatic and hydrophobic interactions. PESC containing sodium lauryl ether sulfates (SLES) have found wide application in hair care products like shampoo. Typically, SLES with only one or two ethylene oxide (EO) groups are used for this application. We have studied the influence of the size of the EO block (ranging from 0 to 30 EO groups) on complexation with two model polycations: linear polyDADMAC and branched PEI. PESC size and electrostatic properties were determined during stepwise titration of buffered polycation solutions. The critical aggregation concentration (CAC) of PESC was determined by surface tension measurements and fluorescence spectroscopy. For polyDADMAC, there is no influence of the size of the EO block on the complexation behavior; the stiff polycation governs the structure formation. For PEI, it was seen that the EO block size does affect the structure of the complexes. The CAC value of the investigated complexes turns out to be rather independent of the EO block size; however, the CMC/CAC ratio decreases with increasing size of the EO block. This latter observation explains why the Lochhead-Goddard effect is most effective for small EO blocks.

  13. Stereochemistry of Complex Marine Natural Products by Quantum Mechanical Calculations of NMR Chemical Shifts: Solvent and Conformational Effects on Okadaic Acid

    Directory of Open Access Journals (Sweden)

    Humberto J. Domínguez

    2014-01-01

    Full Text Available Marine organisms are an increasingly important source of novel metabolites, some of which have already inspired or become new drugs. In addition, many of these molecules show a high degree of novelty from a structural and/or pharmacological point of view. Structure determination is generally achieved by the use of a variety of spectroscopic methods, among which NMR (nuclear magnetic resonance plays a major role and determination of the stereochemical relationships within every new molecule is generally the most challenging part in structural determination. In this communication, we have chosen okadaic acid as a model compound to perform a computational chemistry study to predict 1H and 13C NMR chemical shifts. The effect of two different solvents and conformation on the ability of DFT (density functional theory calculations to predict the correct stereoisomer has been studied.

  14. Infrared multiple photon dissociation action spectroscopy of alkali metal cation-cyclen complexes: Effects of alkali metal cation size on gas-phase conformation

    NARCIS (Netherlands)

    Austin, C.A.; Chen, Y.; Kaczan, C.M.; Berden, G.; Oomens, J.; Rodgers, M.T.

    2013-01-01

    The gas-phase structures of alkali metal cationized complexes of cyclen (1,4,7,10-tetraazacyclododecane) are examined via infrared multiple photon dissociation (IRMPD) action spectroscopy and electronic structure theory calculations. The measured IRMPD action spectra of four M+(cyclen) complexes are

  15. The influence of the physical environment on simulations of complex aquatic ecosystem dynamics

    DEFF Research Database (Denmark)

    Hu, Fenjuan

    hydrodynamics. To test the hypothesis that the physical environment may induce strong influence on ecosystem processes, we applied and compared PCLake applications, with the same standard ecosystem model parameterization, for three different physical environment representations of the same volume of water body......The field of aquatic ecosystem modelling has been active since the late 1970s, and in recent decades the models have grown in complexity in terms of ecosystem components and included processes. However, the complexity in ecosystem conceptualizations generally comes at the expense of simple...... or no hydrodynamic representation, in particular for ecosystem models where higher trophic levels, such as fish, are included. On the other hand, physically resolved hydrodynamic models often include none or only simple representations of ecosystem dynamics. To overcome this discrepancy in complexity between...

  16. Influence of Beaver Dams on Channel Complexity, Hydrology, and Temperature Regime in a Mountainous Stream

    Science.gov (United States)

    Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

    2013-12-01

    Beaver dams and beaver activity affect hydrologic processes, sediment transport, channel complexity and water quality of streams. Beaver ponds, which form behind beaver dams, increase in-channel water storage affecting the timing and volume of flow and resulting in the attenuation and flattening of the hydrograph. Channel complexity also increases the potential for transient storage (both surface and subsurface) and influences stream temperature. Impacts of beaver dams and beaver activity on stream responses are difficult to quantify because responses are dynamic and spatially variable. Few studies have focused on the reach scale temporal influences on stream responses and further research is needed particularly in quantifying the influence of beaver dams and their role in shaping the stream habitat. This study explores the changing hydrology and temperature regime of Curtis Creek, a mountainous stream located in Northern Utah, in a 560 m long reach where groundwater exchanges and temperature differences were observed over a three-year period. We have collected continuous stream discharge, stream temperature data and performed tracer experiments. During the first year, we were able to capture the pre-beaver activity. In the second year, we captured the impacts of some beaver activity with only a few dams built in the reach, while the third year included the effects of an entire active beaver colony. By the end of the study period, a single thread channel had been transformed into a channel with side channels and backwaters at multiple locations therefore increasing channel complexity. The cumulative influence of beaver dams on reach scale discharge resulted in a slightly losing reach that developed into a gaining reach. At the smaller sub-reach scale, both losing to gaining and gaining to losing transformations were observed. Temperature differences showed a warming effect of beaver dams at the reach scale. The reach stream temperature difference increased on

  17. Influences of the propyl group on the van der Waals structures of 4-propylaniline complexes with one and two argon atoms studied by electronic and cationic spectroscopy

    International Nuclear Information System (INIS)

    Yang, Zhijun; Gu, Quanli; Trindle, Carl O.; Knee, J. L.

    2015-01-01

    4-propylaniline complexes with one and two argon atoms formed in the molecular beam were studied in the first excited electronic state, S 1 , using resonance enhanced two-photon ionization spectroscopy and in the cation ground state, D 0 , using mass analyzed threshold ionization spectroscopy. The combination of electronic and cationic spectra of the clusters allows two conformations to be identified in both aniline-Ar 1 and aniline-Ar 2 , which are assigned to either the gauche configuration or anti-configuration of 4-propylaniline. The gauche isomer exhibits complex bands shifted 29 cm −1 and 89 cm −1 from the S 1 origin bands and 83 cm −1 and 148 cm −1 from the ionization potential assigned to the Ar 1 and Ar 2 complexes, respectively. For the anti-rotamer, the corresponding shifts actually become nearly additive, 53 cm −1 and 109 cm −1 for the S 1 origin bands, and 61 cm −1 and 125 cm −1 for the ionization potentials. Ab initio calculations provide insights into the influences of the propyl and amino groups on the positions of the argon atoms within the clusters. In addition, the binding energy of one argon with the gauche isomer of 4-propylaniline has been measured to be 550 ± 5 cm −1 in the D 0 state, 496 ± 5 cm −1 in the S 1 state, and 467 ± 5 cm −1 in the neutral ground state, S 0

  18. Viscous conformal gauge theories

    DEFF Research Database (Denmark)

    Toniato, Arianna; Sannino, Francesco; Rischke, Dirk H.

    2017-01-01

    We present the conformal behavior of the shear viscosity-to-entropy density ratio and the fermion-number diffusion coefficient within the perturbative regime of the conformal window for gauge-fermion theories.......We present the conformal behavior of the shear viscosity-to-entropy density ratio and the fermion-number diffusion coefficient within the perturbative regime of the conformal window for gauge-fermion theories....

  19. Conformal Einstein spaces

    International Nuclear Information System (INIS)

    Kozameh, C.N.; Newman, E.T.; Tod, K.P.

    1985-01-01

    Conformal transformations in four-dimensional. In particular, a new set of two necessary and sufficient conditions for a space to be conformal to an Einstein space is presented. The first condition defines the class of spaces conformal to C spaces, whereas the last one (the vanishing of the Bach tensor) gives the particular subclass of C spaces which are conformally related to Einstein spaces. (author)

  20. Superspace conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Quella, Thomas [Koeln Univ. (Germany). Inst. fuer Theoretische Physik; Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-07-15

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  1. Superspace conformal field theory

    International Nuclear Information System (INIS)

    Quella, Thomas

    2013-07-01

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  2. The influence of atomic number on the complex formation constants by visible spectrophotometric method

    International Nuclear Information System (INIS)

    Samin; Kris-Tri-Basuki; Farida-Ernawati

    1996-01-01

    The influence of atomic number on the complex formation constants and it's application by visible spectrophotometric method has been carried out. The complex compound have been made of Y, Nd, Sm and Gd with alizarin red sulfonic in the mole fraction range of 0.20 - 0.53 and pH range of 3.5 - 5. The optimum condition of complex formation was found in the mole fraction range of 0.30 - 0.53, range of pH 3.75 - 5, and the total concentration was 0.00030 M. It was found that the formation constant (β) of alizarin red S. complex by continued variation and matrix disintegration techniques were β : (7.00 ± 0.64).10 9 of complex 3 9γ,β : (4.09±0.34).10 8 of 6 0Nd, β : (7.26 ± 0.42).10 8 of 62 S m and β : (8.38 ± 0.70).10 8 of 64 G d. It can be concluded that the atomic number of Nd is bigger than Sm which is bigger than Gd. The atomic number of Y is the smallest. (39) and the complex formation constant is a biggest. The complex compound can be used for sample analysis with limit detection of Y : 2.2 .10 -5 M, Nd : 2.9 .10 -5 M, Sm : 2.6 .10 -5 M and Gd : 2.4 .10 -5 M. The sensitivity of analysis are Y>Gd>Sm>Nd. The Y 2 O 3 sample of product result from xenotime sand contains Y 2 O 3 : 98.96 ± 1.40 % and in the filtrate (product of monazite sand) contains Nd : 0.27 ± 0.002 M

  3. Plasmon waveguide resonance spectroscopic evidence for differential binding of oxidized and reduced rhodobacter capsulatus cytochrome c(2) to the cytochrome bc(1) complex mediated by the conformation of the rieske iron-sulfur protein

    International Nuclear Information System (INIS)

    Devanathan, S.; Salamon, Z.; Tollin, G.; Fitch, J.C.; Meyer, T.E.; Berry, E.A.; Cusanovich, M.A.

    2007-01-01

    The dissociation constants for the binding of Rhodobacter capsulatus cytochrome c2 and its K93P mutant to the cytochrome bc1 complex embedded in a phospholipid bilayer were measured by plasmon waveguide resonance spectroscopy in the presence and absence of the inhibitor stigmatellin. The reduced form of cytochrome c2 strongly binds to reduced cytochrome bc1 (Kd = 0.02 M) but binds much more weakly to the oxidized form (Kd = 3.1 M). In contrast, oxidized cytochrome c2 binds to oxidized cytochrome bc1 in a biphasic fashion with Kd values of 0.11 and 0.58 M. Such a biphasic interaction is consistent with binding to two separate sites or conformations of oxidized cytochrome c2 and/or cytochrome bc1. However, in the presence of stigmatellin, we find that oxidized cytochrome c2 binds to oxidized cytochrome bc1 in a monophasic fashion with high affinity (Kd = 0.06 M) and reduced cytochrome c2 binds less strongly (Kd = 0.11 M) but ∼30-fold more tightly than in the absence of stigmatellin. Structural studies with cytochrome bc1, with and without the inhibitor stigmatellin, have led to the proposal that the Rieske protein is mobile, moving between the cytochrome b and cytochrome c1 components during turnover. In one conformation, the Rieske protein binds near the heme of cytochrome c1, while the cytochrome c2 binding site is also near the cytochrome c1 heme but on the opposite side from the Rieske site, where cytochrome c2 cannot directly interact with Rieske. However, the inhibitor, stigmatellin, freezes the Rieske protein iron-sulfur cluster in a conformation proximal to cytochrome b and distal to cytochrome c1. We conclude from this that the dual conformation of the Rieske protein is primarily responsible for biphasic binding of oxidized cytochrome c2 to cytochrome c1. This optimizes turnover by maximizing binding of the substrate, oxidized cytochrome c2, when the iron-sulfur cluster is proximal to cytochrome b and minimizing binding of the product, reduced cytochrome c

  4. Fabrication challenges associated with conformal optics

    Science.gov (United States)

    Schaefer, John; Eichholtz, Richard A.; Sulzbach, Frank C.

    2001-09-01

    A conformal optic is typically an optical window that conforms smoothly to the external shape of a system platform to improve aerodynamics. Conformal optics can be on-axis, such as an ogive missile dome, or off-axis, such as in a free form airplane wing. A common example of conformal optics is the automotive head light window that conforms to the body of the car aerodynamics and aesthetics. The unusual shape of conformal optics creates tremendous challenges for design, manufacturing, and testing. This paper will discuss fabrication methods that have been successfully demonstrated to produce conformal missile domes and associated wavefront corrector elements. It will identify challenges foreseen with more complex free-form configurations. Work presented in this paper was directed by the Precision Conformal Optics Consortium (PCOT). PCOT is comprised of both industrial and academic members who teamed to develop and demonstrate conformal optical systems suitable for insertion into future military programs. The consortium was funded under DARPA agreement number MDA972-96-9-08000.

  5. Standing in the Hallway Improves Students' Understanding of Conformity

    Science.gov (United States)

    Lawson, Timothy J.; Haubner, Richard R.; Bodle, James H.

    2013-01-01

    To help beginning psychology students understand how they are influenced by social pressures to conform, we developed a demonstration designed to elicit their conformity to a small group of students standing in the hallway before class. Results showed the demonstration increased students' recognition of their own tendency to conform, knowledge of…

  6. The Transcription Bubble of the RNA Polymerase-Promoter Open Complex Exhibits Conformational Heterogeneity and Millisecond-Scale Dynamics : Implications for Transcription Start-Site Selection

    NARCIS (Netherlands)

    Robb, Nicole C.; Cordes, Thorben; Hwang, Ling Chin; Gryte, Kristofer; Duchi, Diego; Craggs, Timothy D.; Santoso, Yusdi; Weiss, Shimon; Ebright, Richard H.; Kapanidis, Achillefs N.

    2013-01-01

    Bacterial transcription is initiated after RNA polymerase (RNAP) binds to promoter DNA, melts similar to 14 bp around the transcription start site and forms a single-stranded "transcription bubble" within a catalytically active RNAP-DNA open complex (RPo). There is significant flexibility in the

  7. Non-conformable, partial and conformable transposition

    DEFF Research Database (Denmark)

    König, Thomas; Mäder, Lars Kai

    2013-01-01

    and the Commission regarding a directive’s outcome, play a much more strategic role than has to date acknowledged in the transposition literature. Whereas disagreement of a member state delays conformable transposition, it speeds up non-conformable transposition. Disagreement of the Commission only prolongs...... the transposition process. We therefore conclude that a stronger focus on an effective sanctioning mechanism is warranted for safeguarding compliance with directives....

  8. Influence of the complexity of radiation-induced DNA damage on enzyme recognition

    International Nuclear Information System (INIS)

    Palmer, Philip

    2002-01-01

    Ionising radiation is unique in inducing DNA clustered damage together with the simple isolated lesions. Understanding how these complex lesions are recognised and repaired by the cell is key to understanding the health risks associated with radiation exposure. This study focuses on whether ionising radiation-induced complex single-strand breaks (SSB) are recognised by DNA-PK and PARP, and whether the complexity of DSB influence their ligation by either DNA ligase lV/XRCC4 (LX) complex or T4 DNA ligase. Plasmid DNA, irradiated in aqueous solution using sparsely ionising γ-rays and densely ionising α-particles produce different yields of complex DNA damages, used as substrates for in vitro DNA-PK and PARP activity assays. The activity of DNA-PK to phosphorylate a peptide was determined using HF19 cell nuclear extracts as a source of DNA-PK. PARP ADP-ribosylation activity was determined using purified PARP enzyme. The activation of DNA-PK and PARP by irradiated DNA is due to SSB and not the low yield of DSB (linear plasmid DNA <10%). A ∼2 fold increase in DNA-PK activation and a ∼3-fold reduction in PARP activity seen on increasing the ionising density of the radiation (proportion of complex damage) are proposed to reflect changes in the complexity of SSB and may relate to damage signalling. Complex DSB synthesised as double-stranded oligonucleotides, with a 2 bp 5'-overhang, and containing modified lesions, 8-oxoguanine and abasic sites, at known positions relative to the termini were used as substrates for in vitro ligation by DNA ligase IV/XRCC4 or T4 ligase. The presence of a modified lesion 2 or 3 bp but not 4 bp from the 3'-termini and 2 or 6 bp from the 5'-termini caused a drastic reduction in the extent of ligation. Therefore, the presence of modified lesions near to the termini of a DSB may compromise their rejoining by non-homologous end-joining (NHEJ) involving the LX complex. (author)

  9. Influence of the Investor's Behavior on the Complexity of the Stock Market

    Science.gov (United States)

    Atman, A. P. F.; Gonçalves, Bruna Amin

    2012-04-01

    One of the pillars of the finance theory is the efficient-market hypothesis, which is used to analyze the stock market. However, in recent years, this hypothesis has been questioned by a number of studies showing evidence of unusual behaviors in the returns of financial assets ("anomalies") caused by behavioral aspects of the economic agents. Therefore, it is time to initiate a debate about the efficient-market hypothesis and the "behavioral finances." We here introduce a cellular automaton model to study the stock market complexity, considering different behaviors of the economical agents. From the analysis of the stationary standard of investment observed in the simulations and the Hurst exponents obtained for the term series of stock index, we draw conclusions concerning the complexity of the model compared to real markets. We also investigate which conditions of the investors are able to influence the efficient market hypothesis statements.

  10. Influence of Superplasticizer-Microsilica Complex on Cement Hydration, Structure and Properties of Cement Stone

    Science.gov (United States)

    Ivanov, I. M.; Kramar, L. Ya; Orlov, A. A.

    2017-11-01

    According to the study results, the influence of complex additives based on microsilica and superplasticizers on the processes of the heat release, hydration, hardening, formation of the structure and properties of cement stone was determined. Calorimetry, derivatography, X-ray phase analysis, electronic microscopy and physical-mechanical methods for analyzing the properties of cement stone were used for the studies. It was established that plasticizing additives, in addition to the main water-reducing and rheological functions, regulate cement solidification and hardening while polycarboxylate superplasticizers even contribute to the formation of a special, amorphized microstructure of cement stone. In a complex containing microsilica and a polycarboxylate superplasticizer the strength increases sharply with a sharp drop in the capillary porosity responsible for the density, permeability, durability, and hence, the longevity of concrete. All this is a weighty argument in favor of the use of microsilica jointly with a polycarboxylate superplasticizer in road concretes operated under aggressive conditions.

  11. Factors Influencing Adaptation and Performance at Physical Exercise in Complex Congenital Heart Diseases after Surgical Repair

    Directory of Open Access Journals (Sweden)

    P. P. Bassareo

    2014-01-01

    Full Text Available In the last thirty years, steady progress in the diagnostic tools and care of subjects affected by congenital heart diseases (CHD has resulted in a significant increase in their survival to adulthood, even for those affected by complex CHD. Based on these premises, a number of teenagers and adults affected by corrected (surgically or through interventional techniques CHD ask to be allowed to undertake sporting activities, both at a recreational and competitive level. The purpose of this review is to examine the mechanisms influencing the adaption at physical exercise of patients suffering from complex CHD. The conclusion is that even if there are some modest risks with exercise, they should be seen in perspective, and the life-long benefits of regular exercise on general health, mood, and well-being should be emphasized.

  12. Factors influencing Complexity in Financial Report preparation - Evidence from the Banking Sector in Kenya

    Directory of Open Access Journals (Sweden)

    A.Mutiso

    2013-06-01

    Full Text Available The current developments in the business environment as well as in the accountancy profession have significantly affected the way the financial reports are prepared. This study sought to assess the factors influencing complexity of preparing financial reports in the banking sector in Kenya. The objectives included assessing whether disclosures, adoption of International financial Reporting Standard, regulations and lack of competence by the preparers have contributed to the complexity of preparing financial statements. Using a descriptive study design, data was collected from ten banks registered in the Nairobi Capital Market. The study found out that the identified variables positively contributed to complications in the preparation of financial reports. Management interference, lack of guidance on interpretations and frequent updates of the standards were identified as the main challenges in preparing financial reports. Several recommendations were given to help simplify the process of preparing financial statements.

  13. Governing Influence of Thermodynamic and Chemical Equilibria on the Interfacial Properties in Complex Fluids.

    Science.gov (United States)

    Harikrishnan, A R; Dhar, Purbarun; Gedupudi, Sateesh; Das, Sarit K

    2018-04-12

    We propose a comprehensive analysis and a quasi-analytical mathematical formalism to predict the surface tension and contact angles of complex surfactant-infused nanocolloids. The model rests on the foundations of the interaction potentials for the interfacial adsorption-desorption dynamics in complex multicomponent colloids. Surfactant-infused nanoparticle-laden interface problems are difficult to deal with because of the many-body interactions and interfaces involved at the meso-nanoscales. The model is based on the governing role of thermodynamic and chemical equilibrium parameters in modulating the interfacial energies. The influence of parameters such as the presence of surfactants, nanoparticles, and surfactant-capped nanoparticles on interfacial dynamics is revealed by the analysis. Solely based on the knowledge of interfacial properties of independent surfactant solutions and nanocolloids, the same can be deduced for complex surfactant-based nanocolloids through the proposed approach. The model accurately predicts the equilibrium surface tension and contact angle of complex nanocolloids available in the existing literature and present experimental findings.

  14. Triple-resonance multidimensional NMR study of calmodulin complexed with the binding domain of skeletal muscle myosin light-chain kinase: Indication of a conformational change in the central helix

    International Nuclear Information System (INIS)

    Ikura, Mitsuhiko; Kay, L.E.; Bax, A.; Krinks, M.

    1991-01-01

    Heteronuclear 3D and 4D NMR experiments have been used to obtain 1 H, 13 C, and 15 N backbone chemical shift assignments in Ca 2+ -loaded clamodulin complexed with a 26-residue synthetic peptide (M13) corresponding to the calmodulin-bionding domain (residues 577-602) of rabbit skeletal muscle muosin light-chain kinase. Comparison of the chemical shift values with those observed in peptide-free calmodulin shows that binding of M13 peptide induces substantial chemical shift changes that are not localized in one particular region of the protein. The largest changes are found in the first helix of the Ca 2+ -binding site 1 (E11-E14), the N-terminal portion of the central helix (M72-D78), and the second helix of the Ca 2+ -binding site 4 (F141-M145). Analysis of backbone NOE connectivities indicates a change from α-helical to an extended conformation for residues 75-77 upon complexation with M13. Upon complexation with M13, a significant decrease in the amide exchange rate is observed for residues T110, L112, G113, and E114 at the end of the second helix of site 3

  15. INVESTIGATION OF INFLUENCE OF ENCODING FUNCTION COMPLEXITY ON DISTRIBUTION OF ERROR MASKING PROBABILITY

    Directory of Open Access Journals (Sweden)

    A. B. Levina

    2016-03-01

    Full Text Available Error detection codes are mechanisms that enable robust delivery of data in unreliable communication channels and devices. Unreliable channels and devices are error-prone objects. Respectively, error detection codes allow detecting such errors. There are two classes of error detecting codes - classical codes and security-oriented codes. The classical codes have high percentage of detected errors; however, they have a high probability to miss an error in algebraic manipulation. In order, security-oriented codes are codes with a small Hamming distance and high protection to algebraic manipulation. The probability of error masking is a fundamental parameter of security-oriented codes. A detailed study of this parameter allows analyzing the behavior of the error-correcting code in the case of error injection in the encoding device. In order, the complexity of the encoding function plays an important role in the security-oriented codes. Encoding functions with less computational complexity and a low probability of masking are the best protection of encoding device against malicious acts. This paper investigates the influence of encoding function complexity on the error masking probability distribution. It will be shownthat the more complex encoding function reduces the maximum of error masking probability. It is also shown in the paper that increasing of the function complexity changes the error masking probability distribution. In particular, increasing of computational complexity decreases the difference between the maximum and average value of the error masking probability. Our resultshave shown that functions with greater complexity have smoothed maximums of error masking probability, which significantly complicates the analysis of error-correcting code by attacker. As a result, in case of complex encoding function the probability of the algebraic manipulation is reduced. The paper discusses an approach how to measure the error masking

  16. Electronic and steric influences of pendant amine groups on the protonation of molybdenum bis (dinitrogen) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Labios, Liezel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heiden, Zachariah M. [Washington State Univ., Pullman, WA (United States); Mock, Michael T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-05-04

    The synthesis of a series of PEtPNRR' (PEtPNRR' = Et₂PCH₂CH₂P(CH₂NRR')₂, R = H, R' = Ph or 2,4-difluorophenyl; R = R' = Ph or iPr) diphosphine ligands containing mono- and disubstituted pendant amine groups, and the preparation of their corresponding molybdenum bis(dinitrogen) complexes trans-Mo(N₂)₂(PMePh₂)₂(PEtPNRR') is described. In situ IR and multinuclear NMR spectroscopic studies monitoring the stepwise addition of (HOTf) to trans-Mo(N₂)₂(PMePh₂)₂(PEtPNRR') complexes in THF at -40 °C show that the electronic and steric properties of the R and R' groups of the pendant amines influence whether the complexes are protonated at Mo, a pendant amine, a coordinated N2 ligand, or a combination of these sites. For example, complexes containing mono-aryl substituted pendant amines are protonated at Mo and pendant amine to generate mono- and dicationic Mo–H species. Protonation of the complex containing less basic diphenyl-substituted pendant amines exclusively generates a monocationic hydrazido (Mo(NNH₂)) product, indicating preferential protonation of an N₂ ligand. Addition of HOTf to the complex featuring more basic diisopropyl amines primarily produces a monocationic product protonated at a pendant amine site, as well as a trace amount of dicationic Mo(NNH₂) product that contain protonated pendant amines. In addition, trans-Mo(N₂)₂(PMePh₂)₂(depe) (depe = Et₂PCH₂CH₂PEt₂) without a pendant amine was synthesized and treated with HOTf, generating a monocationic Mo(NNH₂) product. Protonolysis experiments conducted on select complexes in the series afforded trace amounts of NH₄⁺. Computational analysis of the series of trans-Mo(N₂)₂(PMePh₂)₂(PEtPNRR') complexes provides further insight into the proton affinity values of the metal center, N

  17. The influence of carboxilate, phosphinate and seleninate groups on luminescent properties of lanthanides complexes

    International Nuclear Information System (INIS)

    Monteiro, Jorge H.S.K.; Formiga, André L.B.; Sigoli, Fernando A.

    2014-01-01

    The lanthanides(III) complexes [Ln(bza) 3 (H 2 O) n ]·mH 2 O, [Ln(ppa) 3 (H 2 O) n ]·mH 2 O and [Ln(abse) 3 (H 2 O) n ]·mH 2 O where Ln=Eu 3+ , Gd 3+ or Tb 3+ were synthesized using sodium benzoate (Nabza), sodium phenylseleninate (Naabse) and sodium phenylphosphinate (Nappa) in order to verify the influence on coordination modes and the luminescence parameters when the carbon is exchanged by phosphorus or selenium in those ligands. The complexes' stoichiometries were determined by lanthanide(III) titration, microanalysis and TGA. The coordination modes were determined as bidentate bridging and chelate by the FT-IR. The triplet state energies of the ligands were obtained by two different approaches giving a difference of about ∼2000 cm −1 between them. The [Eu(abse) 3 (H 2 O)] complex shows the higher degree of covalence which was verified by the centroid of 5 D 0 → 7 F 0 transition (17,248 cm −1 ). On the other hand the [Ln(abse) 3 (H 2 O) n ]·mH 2 O complexes have an inefficient antenna effect verified by the low values of absolute emission quantum yields. The [Ln(ppa) 3 (H 2 O) n ]·mH 2 O complexes have higher emission decay lifetime values among the complexes which is a result of the ability of this ligand to form coordination polymers avoiding water molecules in the first coordination sphere. The [Eu(ppa) 3 ] complex has the highest point symmetry around europium(III) among the synthesized complexes, followed by the [Eu(bza) 3 (H 2 O) 2 ]·3/2(H 2 O) and [Eu(abse) 3 (H 2 O)] complexes where europium(III) show similar point symmetries. As one may expect, the triplet state energy position would change the transfer and/or back energy transfer rates from ligand to metal. The calculation of these rates show that the back energy transfer rates are more affected than the transfer ones by changing the triplet state energy in the range of ∼2000 cm −1 . The changes in the energy transfer rates from triplet state to europium(III) levels are not

  18. A novel germ cell protein, SPIF (sperm PKA interacting factor), is essential for the formation of a PKA/TCP11 complex that undergoes conformational and phosphorylation changes upon capacitation.

    Science.gov (United States)

    Stanger, Simone J; Law, Estelle A; Jamsai, Duangporn; O'Bryan, Moira K; Nixon, Brett; McLaughlin, Eileen A; Aitken, R John; Roman, Shaun D

    2016-08-01

    Spermatozoa require the process of capacitation to enable them to fertilize an egg. PKA is crucial to capacitation and the development of hyperactivated motility. Sperm PKA is activated by cAMP generated by the germ cell-enriched adenylyl cyclase encoded by Adcy10 Male mice lacking Adcy10 are sterile, because their spermatozoa are immotile. The current study was designed to identify binding partners of the sperm-specific (Cα2) catalytic subunit of PKA (PRKACA) by using it as the "bait" in a yeast 2-hybrid system. This approach was used to identify a novel germ cell-enriched protein, sperm PKA interacting factor (SPIF), in 25% of the positive clones. Homozygous Spif-null mice were embryonically lethal. SPIF was coexpressed and coregulated with PRKACA and with t-complex protein (TCP)-11, a protein associated with PKA signaling. We established that these 3 proteins form part of a novel complex in mouse spermatozoa. Upon capacitation, the SPIF protein becomes tyrosine phosphorylated in >95% of sperm. An apparent molecular rearrangement in the complex occurs, bringing PRKACA and TCP11 into proximity. Taken together, these results suggest a role for the novel complex of SPIF, PRKACA, and TCP11 during sperm capacitation, fertilization, and embryogenesis.-Stanger, S. J., Law, E. A., Jamsai, D., O'Bryan, M. K., Nixon, B., McLaughlin, E. A., Aitken, R. J., Roman, S. D. A novel germ cell protein, SPIF (sperm PKA interacting factor), is essential for the formation of a PKA/TCP11 complex that undergoes conformational and phosphorylation changes upon capacitation. © FASEB.

  19. Influence of intensive light exposure on the complex impedance of polymer light-emitting diodes

    Directory of Open Access Journals (Sweden)

    Fábio Rogério Cury

    2008-06-01

    Full Text Available In this work we investigated the effect of visible radiation on the electrical properties of poly[(2-methoxy-5-hexyloxy-p-phenylenevinylene]- MH-PPV films and light emitting diodes. Complex impedance measurements of (Au or ITO/MH-PPV/(Au or Al samples were carried out at room temperature and exposed to white light. Over the frequency range from 100 mHz to 2 MHz, the electrical results of Au/MH-PPV/Au was dominated by the Cole-Cole approach, where the electrode influence is negligible. However, some additional influence of the interface was observed to occur when Al was used as electrode. These effects were observed under both dark and visible-light illumination conditions. A simple model based on resistor-capacitor parallel circuits was developed to represent the complex impedance of the samples, thereby separating bulk and interface contributions. We observed that the polymer electrical resistivity decreased while the dielectric constant of the polymer and the thickness of the Al/MH-PPV layer were almost constant with increasing light intensity. The decrease of the polymer layer resistance comes from a better charge injection due to a light induced dissociation of positive charge carriers at the electrode.

  20. Epigenetic dominance of prion conformers.

    Directory of Open Access Journals (Sweden)

    Eri Saijo

    2013-10-01

    Full Text Available Although they share certain biological properties with nucleic acid based infectious agents, prions, the causative agents of invariably fatal, transmissible neurodegenerative disorders such as bovine spongiform encephalopathy, sheep scrapie, and human Creutzfeldt Jakob disease, propagate by conformational templating of host encoded proteins. Once thought to be unique to these diseases, this mechanism is now recognized as a ubiquitous means of information transfer in biological systems, including other protein misfolding disorders such as those causing Alzheimer's and Parkinson's diseases. To address the poorly understood mechanism by which host prion protein (PrP primary structures interact with distinct prion conformations to influence pathogenesis, we produced transgenic (Tg mice expressing different sheep scrapie susceptibility alleles, varying only at a single amino acid at PrP residue 136. Tg mice expressing ovine PrP with alanine (A at (OvPrP-A136 infected with SSBP/1 scrapie prions propagated a relatively stable (S prion conformation, which accumulated as punctate aggregates in the brain, and produced prolonged incubation times. In contrast, Tg mice expressing OvPrP with valine (V at 136 (OvPrP-V136 infected with the same prions developed disease rapidly, and the converted prion was comprised of an unstable (U, diffusely distributed conformer. Infected Tg mice co-expressing both alleles manifested properties consistent with the U conformer, suggesting a dominant effect resulting from exclusive conversion of OvPrP-V136 but not OvPrP-A136. Surprisingly, however, studies with monoclonal antibody (mAb PRC5, which discriminates OvPrP-A136 from OvPrP-V136, revealed substantial conversion of OvPrP-A136. Moreover, the resulting OvPrP-A136 prion acquired the characteristics of the U conformer. These results, substantiated by in vitro analyses, indicated that co-expression of OvPrP-V136 altered the conversion potential of OvPrP-A136 from the S to

  1. Inversion theory and conformal mapping

    CERN Document Server

    Blair, David E

    2000-01-01

    It is rarely taught in an undergraduate or even graduate curriculum that the only conformal maps in Euclidean space of dimension greater than two are those generated by similarities and inversions in spheres. This is in stark contrast to the wealth of conformal maps in the plane. The principal aim of this text is to give a treatment of this paucity of conformal maps in higher dimensions. The exposition includes both an analytic proof in general dimension and a differential-geometric proof in dimension three. For completeness, enough complex analysis is developed to prove the abundance of conformal maps in the plane. In addition, the book develops inversion theory as a subject, along with the auxiliary theme of circle-preserving maps. A particular feature is the inclusion of a paper by Carath�odory with the remarkable result that any circle-preserving transformation is necessarily a M�bius transformation, not even the continuity of the transformation is assumed. The text is at the level of advanced undergr...

  2. Influence of complexing agents on the mechanical performances of the cement conditioning matrix

    International Nuclear Information System (INIS)

    Nicu, M.; Mihai, F.; Turcanu, C.

    1998-01-01

    The safety of the radioactive waste disposal is a priority demand concerning the protection of the environment and population. For this reason, an engineering multi-barrier system is studied in order to be improved. This study aims to establish the influence of the complexing agents on the mechanical performances of the cement conditioning matrix. Radioactive effluents which contain agents as oxalic and citric acids are generated during the radioactive decontamination operation using chemical methods. The conditioning of these wastes by cementing process imposed the experimental determination of the mechanical performances of the matrix and the upper permissible level of complexing agent concentration. To determine the influence of complexing agents on the mechanical performances of cement conditioning matrix, cubic samples (20 mm x 20 mm x 20 mm) were prepared using commercial Portland cement and solutions of organic complexing acids or salts (citric acid, oxalic acid, tartaric acid, sodium citrate and ammonium oxalate). The complexation concentration varied between 0.25% and 1% in distilled and drinking water, respectively. The selected cement/water ratio was 0.5. The experiments were focused on: - establishing the firmness of the Pa 35 cement pastes and mortars in dependence on the water/cement ratio, by classical methods (Tetmeyer probe for pastes and standard cone for mortars) and by triclinic time through a funnel with 15 mm aperture; - studying the influence of the tartaric, oxalic, citric acids, ammonium oxalate and sodium citrate solution concentrations on water quantities used to obtain pastes with normal firmness and on Pa 35 cement setting; - the influence of oxalic acid, tartaric acid and ammonium oxalate solution concentrations on the strength of compression of the pastes with normal firmness; - for testing, standard test bar cubes with 20 mm sides were used and the strength of compression was tested at 28 days; - establishing the behaviour in time of

  3. Small-angle scattering studies show distinct conformations of calmodulin in its complexes with two peptides based on the regulatory domain of the catalytic subunit of phosphorylase kinase

    International Nuclear Information System (INIS)

    Trewhella, J.; Blumenthal, D.K.; Rokop, S.E.; Seeger, P.A.

    1990-01-01

    Small-angle X-ray and neutron scattering have been used to study the solution structures of calmodulin complexed with synthetic peptides corresponding to residues 342-366 and 301-326, designated PhK5 and PhK13, respectively, in the regulatory domain of the catalytic subunit of skeletal muscle phosphorylase kinase. The scattering data show that binding of PhK5 to calmodulin induces a dramatic contraction of calmodulin, similar to that previously observed when calmodulin is complexed with the calmodulin-binding domain peptide from rabbit skeletal muscle myosin light chain kinase. In contrast, calmodulin remains extended upon binding PhK13. In the presence of both peptides, calmodulin also remains extended. Apparently, the presence of PhK13 inhibits calmodulin from undergoing the PhK5-induced contraction. These data indicate that there is a fundamentally different type of calmodulin-target enzyme interaction in the case of the catalytic subunit of phosphorylase kinase compared with that for myosin light chain kinase

  4. Study of conformational and acid-base properties of norbadione A and pulvinic derivatives: Consequences on their complexation properties of alkaline and alkaline earth cations

    International Nuclear Information System (INIS)

    Kuad, P.

    2006-01-01

    This work deals with the study of norbadione A, a pigment extracted from mushrooms and known to complex cesium cations. The study of the acid-base properties of norbadione A has allowed to determine the relative acidity of the seven protonable functions of the molecule and to reveal a reversible isomerization of the double exocyclic bond of the pulvinic moieties. The observed change of configuration is induced by a hydrogen bond of the H-O-H type and by electrostatic interactions. Moreover, the microscopic protonation mechanism of the norbadione A has been analyzed, considering three different study media where the acid-base properties of the norbadione A are compared. In the presence of 0.15 mol.l -1 of NaCl, it has been observed a remarkable cooperativity in the protonation of the enol groups. At last, the use of different analytical methods (NMR, potentiometry and calorimetry) has allowed to study the complexing properties of the norbadione A towards cesium and other alkaline and rare earth cations. (O.M.)

  5. Organizational Influences on Interdisciplinary Interactions during Research and Design of Large-Scale Complex Engineered Systems

    Science.gov (United States)

    McGowan, Anna-Maria R.; Seifert, Colleen M.; Papalambros, Panos Y.

    2012-01-01

    The design of large-scale complex engineered systems (LaCES) such as an aircraft is inherently interdisciplinary. Multiple engineering disciplines, drawing from a team of hundreds to thousands of engineers and scientists, are woven together throughout the research, development, and systems engineering processes to realize one system. Though research and development (R&D) is typically focused in single disciplines, the interdependencies involved in LaCES require interdisciplinary R&D efforts. This study investigates the interdisciplinary interactions that take place during the R&D and early conceptual design phases in the design of LaCES. Our theoretical framework is informed by both engineering practices and social science research on complex organizations. This paper provides preliminary perspective on some of the organizational influences on interdisciplinary interactions based on organization theory (specifically sensemaking), data from a survey of LaCES experts, and the authors experience in the research and design. The analysis reveals couplings between the engineered system and the organization that creates it. Survey respondents noted the importance of interdisciplinary interactions and their significant benefit to the engineered system, such as innovation and problem mitigation. Substantial obstacles to interdisciplinarity are uncovered beyond engineering that include communication and organizational challenges. Addressing these challenges may ultimately foster greater efficiencies in the design and development of LaCES and improved system performance by assisting with the collective integration of interdependent knowledge bases early in the R&D effort. This research suggests that organizational and human dynamics heavily influence and even constrain the engineering effort for large-scale complex systems.

  6. Molecular modeling and molecular dynamics simulation study of archaeal leucyl-tRNA synthetase in complex with different mischarged tRNA in editing conformation.

    Science.gov (United States)

    Rayevsky, A V; Sharifi, M; Tukalo, M A

    2017-09-01

    Aminoacyl-tRNA synthetases (aaRSs) play important roles in maintaining the accuracy of protein synthesis. Some aaRSs accomplish this via editing mechanisms, among which leucyl-tRNA synthetase (LeuRS) edits non-cognate amino acid norvaline mainly by post-transfer editing. However, the molecular basis for this pathway for eukaryotic and archaeal LeuRS remain unclear. In this study, a complex of archaeal P. horikoshii LeuRS (PhLeuRS) with misacylated tRNA Leu was modeled wherever tRNA's acceptor stem was oriented directly into the editing site. To understand the distinctive features of organization we reconstructed a complex of PhLeuRS with tRNA and visualize post-transfer editing interactions mode by performing molecular dynamics (MD) simulation studies. To study molecular basis for substrate selectivity by PhLeuRS's editing site we utilized MD simulation of the entire LeuRS complexes using a diverse charged form of tRNAs, namely norvalyl-tRNA Leu and isoleucyl-tRNA Leu . In general, the editing site organization of LeuRS from P.horikoshii has much in common with bacterial LeuRS. The MD simulation results revealed that the post-transfer editing substrate norvalyl-A76, binds more strongly than isoleucyl-A76. Moreover, the branched side chain of isoleucine prevents water molecules from being closer and hence the hydrolysis reaction slows significantly. To investigate a possible mechanism of the post-transfer editing reaction, by PhLeuRS we have determined that two water molecules (the attacking and assisting water molecules) are localized near the carbonyl group of the amino acid to be cleaved off. These water molecules approach the substrate from the opposite side to that observed for Thermus thermophilus LeuRS (TtLeuRS). Based on the results obtained, it was suggested that the post-transfer editing mechanism of PhLeuRS differs from that of prokaryotic TtLeuRS. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. A remote palm domain residue of RB69 DNA polymerase is critical for enzyme activity and influences the conformation of the active site.

    Directory of Open Access Journals (Sweden)

    Agata Jacewicz

    Full Text Available Non-conserved amino acids that are far removed from the active site can sometimes have an unexpected effect on enzyme catalysis. We have investigated the effects of alanine replacement of residues distant from the active site of the replicative RB69 DNA polymerase, and identified a substitution in a weakly conserved palm residue (D714A, that renders the enzyme incapable of sustaining phage replication in vivo. D714, located several angstroms away from the active site, does not contact the DNA or the incoming dNTP, and our apoenzyme and ternary crystal structures of the Pol(D714A mutant demonstrate that D714A does not affect the overall structure of the protein. The structures reveal a conformational change of several amino acid side chains, which cascade out from the site of the substitution towards the catalytic center, substantially perturbing the geometry of the active site. Consistent with these structural observations, the mutant has a significantly reduced k pol for correct incorporation. We propose that the observed structural changes underlie the severe polymerization defect and thus D714 is a remote, non-catalytic residue that is nevertheless critical for maintaining an optimal active site conformation. This represents a striking example of an action-at-a-distance interaction.

  8. Dynamics of Clinical and Biochemical Parameters in Patients with Liver Cirrhosis Under the Influence of Complex Therapy with Ursodeoxycholic Acid

    Directory of Open Access Journals (Sweden)

    M.I. Shved

    2013-11-01

    Full Text Available It was studied dynamics of clinical and biochemical parameters in patients with liver cirrhosis under the influence of complex treatment using ursosan. It is found that the inclusion of ursosan in complex treatment improves clinical and laboratory parameters, significantly reduces the manifestations of general inflammatory liver syndrome, which prevents the progression of the disease.

  9. Influence of complex impurity centres on radiation damage in wide-gap metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Lushchik, A., E-mail: aleksandr.lushchik@ut.ee [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Lushchik, Ch. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Popov, A.I. [Institute of Solid State Physics, University of Latvia, Kengaraga 8, Riga LV-1063 (Latvia); Schwartz, K. [GSI Helmholtzzentrum für Schwerionenforschung (GSI), Planckstr. 1, 64291 Darmstadt (Germany); Shablonin, E.; Vasil’chenko, E. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia)

    2016-05-01

    Different mechanisms of radiation damage of wide-gap metal oxides as well as a dual influence of impurity ions on the efficiency of radiation damage have been considered on the example of binary ionic MgO and complex ionic–covalent Lu{sub 3}Al{sub 5}O{sub 12} single crystals. Particular emphasis has been placed on irradiation with ∼2 GeV heavy ions ({sup 197}Au, {sup 209}Bi, {sup 238}U, fluence of 10{sup 12} ions/cm{sup 2}) providing extremely high density of electronic excitations within ion tracks. Besides knock-out mechanism for Frenkel pair formation, the additional mechanism through the collapse of mobile discrete breathers at certain lattice places (e.g., complex impurity centres) leads to the creation of complex defects that involve a large number of host atoms. The experimental manifestations of the radiation creation of intrinsic and impurity antisite defects (Lu|{sub Al} or Ce|{sub Al} – a heavy ion in a wrong cation site) have been detected in LuAG and LuAG:Ce{sup 3+} single crystals. Light doping of LuAG causes a small enhancement of radiation resistance, while pair impurity centres (for instance, Ce|{sub Lu}–Ce|{sub Al} or Cr{sup 3+}–Cr{sup 3+} in MgO) are formed with a rise of impurity concentration. These complex impurity centres as well as radiation-induced intrinsic antisite defects (Lu|{sub Al} strongly interacting with Lu in a regular site) tentatively serve as the places for breathers collapse, thus decreasing the material resistance against dense irradiation.

  10. 94: Treatment plan optimization for conformal therapy

    International Nuclear Information System (INIS)

    Rosen, I.I.; Lane, R.G.

    1987-01-01

    Computer-controlled conformal radiation therapy techniques can deliver complex treatments utilizing large numbers of beams, gantry angles and beam shapes. Linear programming is well-suited for planning conformal treatments. Given a list of available treatment beams, linear programming calculates the relative weights of the beams such that the objective function is optimized and doses to constraint points are within the prescribed limits. 5 refs.; 3 figs

  11. Conformation sensitive charge transport in conjugated polymers

    International Nuclear Information System (INIS)

    Mattias Andersson, L.; Hedström, Svante; Persson, Petter

    2013-01-01

    Temperature dependent charge carrier mobility measurements using field effect transistors and density functional theory calculations are combined to show how the conformation dependent frontier orbital delocalization influences the hole- and electron mobilities in a donor-acceptor based polymer. A conformationally sensitive lowest unoccupied molecular orbital results in an electron mobility that decreases with increasing temperature above room temperature, while a conformationally stable highest occupied molecular orbital is consistent with a conventional hole mobility behavior and also proposed to be one of the reasons for why the material works well as a hole transporter in amorphous bulk heterojunction solar cells

  12. Influence of competition and age on tree growth in structurally complex old-growth forests in northern Minnesota, USA

    Science.gov (United States)

    Tuomas Aakala; Shawn Fraver; Anthony W. D' Amato; Brian J. Palik

    2013-01-01

    Factors influencing tree growth in structurally complex forests remain poorly understood. Here we assessed the influence of competition on Pinus resinosa (n = 224) and Pinus strobus (n = 90) growth in four old-growth stands in Minnesota, using mixed effects models. A subset of trees, with...

  13. The degree of microbiome complexity influences the epithelial response to infection

    Directory of Open Access Journals (Sweden)

    Baker Henry V

    2009-08-01

    Full Text Available Abstract Background The human microflora is known to be extremely complex, yet most pathogenesis research is conducted in mono-species models of infection. Consequently, it remains unclear whether the level of complexity of a host's indigenous flora can affect the virulence potential of pathogenic species. Furthermore, it remains unclear whether the colonization by commensal species affects a host cell's response to pathogenic species beyond the direct physical saturation of surface receptors, the sequestration of nutrients, the modulation of the physico-chemical environment in the oral cavity, or the production of bacteriocins. Using oral epithelial cells as a model, we hypothesized that the virulence of pathogenic species may vary depending on the complexity of the flora that interacts with host cells. Results This is the first report that determines the global epithelial transcriptional response to co-culture with defined complex microbiota. In our model, human immortalized gingival keratinocytes (HIGK were infected with mono- and mixed cultures of commensal and pathogenic species. The global transcriptional response of infected cells was validated and confirmed phenotypically. In our model, commensal species were able to modulate the expression of host genes with a broad diversity of physiological functions and antagonize the effect of pathogenic species at the cellular level. Unexpectedly, the inhibitory effect of commensal species was not correlated with its ability to inhibit adhesion or invasion by pathogenic species. Conclusion Studying the global transcriptome of epithelial cells to single and complex microbial challenges offers clues towards a better understanding of how bacteria-bacteria interactions and bacteria-host interactions impact the overall host response. This work provides evidence that the degree of complexity of a mixed microbiota does influence the transcriptional response to infection of host epithelial cells, and

  14. Temperature and ionic strength influences on actinide(VI)/(V) redox potentials for carbonate limiting complexes

    International Nuclear Information System (INIS)

    Capdevila, H.; Vitorge, P.

    1998-01-01

    Actinide behaviour was studied in two limiting aqueous solutions: acidic and carbonate. Cyclic voltametry was validated with well-known U redox system. SIT was used to account for I influence. Taylor's series expansions to the second order were used to account for T influence. Redox potentials of actinide couples had previously been measured in non complexing media. The above data treatments give standard values for redox potential E 0 , for the corresponding entropy ΔS 0 , enthalpy ΔH 0 and heat capacity ΔC p 0 changes, and also for the corresponding excess values (i.e. the variation of these thermodynamic constants with ionic strength). This methodology was here used in carbonate media to measure the potential of the redox couple PuO 2 (CO 3 ) 3 4- /PuO 2 (CO 3 ) 3 5- from 5 to 70 degC and from I = 0.5 to 4.5 M in Na 2 CO 3 , NaClO 4 media. Experimental details and full results are given for Pu. Only final results are given for Np. Previous and/or published data for U and Am are discussed. E and ΔS variations with T or I were enough to be measured. The values obtained for the fitted SIT coefficients Δε, and for ΔS and ΔCp are similar for U, Np and Pu redox reactions. Using this analogy for Am missing data is discussed. β 3 V /β 3 VI formation constant ratio of the carbonate limiting complexes were deduced from the potential shift from complexing to non complexing media for the Actinide(VI)/Actinide(V) redox couples. β 3 V (U and Pu) and β 3 VI (Np) were finally proposed using published β3 VI (U and Pu) and β 3 V (Np). For Am, this data treatment was used to discuss the AmO 2 2+ / AmO 2 + redox potential

  15. Gel dosimetry for conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Gambarini, G [Department of Physics of the University and INFN, Milan (Italy)

    2005-07-01

    With the continuum development of conformal radio therapies, aimed at delivering high dose to tumor tissue and low dose to the healthy tissue around, the necessities has appeared of suitable improvement of dosimetry techniques giving the possibility of obtaining dose images to be compared with diagnostic images. Also if wide software has been developed for calculating dose distributions in the fields of various radiotherapy units, experimental verifications are necessary, in particular in the case of complex geometries in conformal radiotherapy. Gel dosimetry is a promising method for imaging the absorbed dose in tissue-equivalent phantoms, with the possibility of 3D reconstruction of the spatial dose distribution, with milli metric resolution. Optical imaging of gel dosimeters, based on visible light absorbance analysis, has shown to be a reliable technique for achieving dose distributions. (Author)

  16. Swedish women's perceptions of and conformity to feminine norms.

    Science.gov (United States)

    Kling, Johanna; Holmqvist Gattario, Kristina; Frisén, Ann

    2017-06-01

    The relatively high gender equality in the Swedish society is likely to exert an influence on gender role construction. Hence, the present research aimed to investigate Swedish women's perceptions of and conformity to feminine norms. A mixed methods approach with two studies was used. In Study 1, young Swedish women's gender role conformity, as measured by the Conformity to Feminine Norms Inventory 45 (CFNI-45), was compared to the results from previously published studies in Canada, the United States, and Slovakia. Overall, Swedish women displayed less conformity than their foreign counterparts, with the largest difference on the subscale Sexual fidelity. In Study 2, focus group interviews with young Swedish women added a more complex picture of feminine norms in the Swedish society. For instance the results indicated that Swedish women, while living in a society with a strong gender equality discourse, are torn between the perceived need to invest in their appearances and the risk of being viewed as non-equal when doing so. In sum, despite the fact that traditional gender roles are less pronounced in Sweden, gender role conformity is still a pressing issue. Since attending to the potential roles of feminine norms in women's lives previously has been proposed to be useful in counseling and therapeutic work, the present research also offers valuable information for both researchers and practitioners. [Correction added on 5 May 2017, after first online publication in April 2017: An incorrect Abstract was inadvertently captured in the published article and has been corrected in this current version.]. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  17. REGULARITIES OF THE INFLUENCE OF ORGANIZATIONAL AND TECHNOLOGICAL FACTORS ON THE DURATION OF CONSTRUCTION OF HIGH-RISE MULTIFUNCTIONAL COMPLEXES

    Directory of Open Access Journals (Sweden)

    ZAIATS Yi. I.

    2015-10-01

    Full Text Available Problem statement. Technical and economic indexes of projects of construction of high-rise multifunctional complexes, namely: the duration of construction works and the cost of building products depends on the technology of construction works and method of construction organization, and on their choice influence the architectural and design, constructional and engineering made decisions. Purpose. To reveal the regularity of influence of organizational and technological factors on the duration of construction of high-rise multifunctional complexes in the conditions of dense city building. Conclusion. To reveal the regularity of the influence of organizational and technological factors (the height, the factor complexity of design of project and and estimate documentation, factor of complexity of construction works, the factor of complexity of control of investment and construction project, economy factor, comfort factor, factor of technology of projected solutions for the duration of the construction of high-rise multifunctional complexes (depending on their height: from 73,5 m to 100 m inclusively; from 100 m to 200 m inclusively allow us to quantitatively assess their influence and can be used in the development of the methodology of substantiation of the expediency and effectiveness of the realization of projects of high-rise construction in condition of compacted urban development, based on the consideration of the influence of organizational and technological aspects.

  18. Induced quantum conformal gravity

    International Nuclear Information System (INIS)

    Novozhilov, Y.V.; Vassilevich, D.V.

    1988-11-01

    Quantum gravity is considered as induced by matter degrees of freedom and related to the symmetry breakdown in the low energy region of a non-Abelian gauge theory of fundamental fields. An effective action for quantum conformal gravity is derived where both the gravitational constant and conformal kinetic term are positive. Relation with induced classical gravity is established. (author). 15 refs

  19. Conformal transformations in superspace

    International Nuclear Information System (INIS)

    Dao Vong Duc

    1977-01-01

    The spinor extension of the conformal algebra is investigated. The transformation law of superfields under the conformal coordinate inversion R defined in the superspace is derived. Using R-technique, the superconformally covariant two-point and three-point correlation functions are found

  20. Conformational stability of calreticulin

    DEFF Research Database (Denmark)

    Jørgensen, C.S.; Trandum, C.; Larsen, N.

    2005-01-01

    The conformational stability of calreticulin was investigated. Apparent unfolding temperatures (T-m) increased from 31 degrees C at pH 5 to 51 degrees C at pH 9, but electrophoretic analysis revealed that calreticulin oligomerized instead of unfolding. Structural analyses showed that the single C......-terminal a-helix was of major importance to the conformational stability of calreticulin....

  1. Influence of conformal radiotherapy technique on survival after chemoradiotherapy for patients with stage III non-small cell lung cancer in the National Cancer Data Base.

    Science.gov (United States)

    Sher, David J; Koshy, Matthew; Liptay, Michael J; Fidler, Mary Jo

    2014-07-01

    Definitive chemoradiotherapy is a core treatment modality for patients with stage III non-small cell lung cancer (NSCLC). Although radiotherapy (RT) technologies have advanced dramatically, to the authors' knowledge relatively little is known regarding the importance of irradiation technique on outcome, particularly given the competing risk of distant metastasis. The National Cancer Data Base was used to determine predictors of overall survival (OS) in patients with AJCC stage III NSCLC who were treated with chemoradiotherapy, focusing on the importance of conformal RT (CRT). Patients with stage III NSCLC who were treated with chemoradiotherapy between 2003 and 2005 in the National Cancer Data Base were included. RT technique was defined as conventional, 3-dimensional-conformal, or intensity-modulated RT (IMRT), the latter 2 combined as CRT. Cox proportional hazards regression was performed for univariable and multivariable analyses of OS. The median, 3-year, and 5-year survival outcomes for the 13,292 patients were 12.9 months, 19%, and 11%, respectively. The 3-year and 5-year survival probabilities of patients receiving CRT versus no CRT were 22% versus 19% and 14% versus 11%, respectively (P < .0001). On multivariable analysis, CRT was found to be significantly associated with improved OS (hazards ratio, 0.89). This effect was confirmed on sensitivity analyses, including restricting the cohort to minimum 6-month survivors, young patients with stage IIIA disease, and propensity score-matching. Institutional academic status and patient volume were not found to be associated with OS. CRT was found to be independently associated with a survival advantage. These results reflect the importance of optimal locoregional therapy in patients with stage III NSCLC and provide motivation for further study of advanced RT technologies in patients with NSCLC. © 2014 American Cancer Society.

  2. Conformity index: A review

    International Nuclear Information System (INIS)

    Feuvret, Loic; Noel, Georges; Mazeron, Jean-Jacques; Bey, Pierre

    2006-01-01

    We present a critical analysis of the conformity indices described in the literature and an evaluation of their field of application. Three-dimensional conformal radiotherapy, with or without intensity modulation, is based on medical imaging techniques, three-dimensional dosimetry software, compression accessories, and verification procedures. It consists of delineating target volumes and critical healthy tissues to select the best combination of beams. This approach allows better adaptation of the isodose to the tumor volume, while limiting irradiation of healthy tissues. Tools must be developed to evaluate the quality of proposed treatment plans. Dosimetry software provides the dose distribution in each CT section and dose-volume histograms without really indicating the degree of conformity. The conformity index is a complementary tool that attributes a score to a treatment plan or that can compare several treatment plans for the same patient. The future of conformal index in everyday practice therefore remains unclear

  3. FORECAST OF INFLUENCING THE UNDERGROUND COMPLEX CONSTRUCTION ON A CONTEXT AREA

    Directory of Open Access Journals (Sweden)

    Orekhov Vyacheslav Valentinovich

    2017-08-01

    Full Text Available The present paper is concerned with the method, research objective and the results of numerical simulation of change of stress-strain behaviour of soil masses when constructing underground complex. In order to get consistent results of forecast, all major factors affecting the results of design studies have been taken into account, including spatial performance of soil mass, enclosure structure and an adjacent context area, phasing of construction, site investigation, initial stress-strain behaviour of soil mass and elasto-plastic strain of soils. The authors give assessment of influence of pit excavation and subsequent construction on a context adjacent area and construction of an underground railroad. Results of the studies show that the proposed construction of an underground complex on the Tverskaya Zastava square would not have a significant impact on the surrounding buildings and subway structures. The spreading of the subsidence crater around the excavating pit is projected by 30...80 m. The ground lift directly below the bottom of the excavation pit in the places of metro stations and transport tunnels will be about 0.1 cm.

  4. Spatial complexity of carcass location influences vertebrate scavenger efficiency and species composition.

    Science.gov (United States)

    Smith, Joshua B; Laatsch, Lauren J; Beasley, James C

    2017-08-31

    Scavenging plays an important role in shaping communities through inter- and intra-specific interactions. Although vertebrate scavenger efficiency and species composition is likely influenced by the spatial complexity of environments, heterogeneity in carrion distribution has largely been disregarded in scavenging studies. We tested this hypothesis by experimentally placing juvenile bird carcasses on the ground and in nests in trees to simulate scenarios of nestling bird carrion availability. We used cameras to record scavengers removing carcasses and elapsed time to removal. Carrion placed on the ground was scavenged by a greater diversity of vertebrates and at > 2 times the rate of arboreal carcasses, suggesting arboreal carrion may represent an important resource to invertebrate scavengers, particularly in landscapes with efficient vertebrate scavenging communities. Nonetheless, six vertebrate species scavenged arboreal carcasses. Rat snakes (Elaphe obsolete), which exclusively scavenged from trees, and turkey vultures (Cathartes aura) were the primary scavengers of arboreal carrion, suggesting such resources are potentially an important pathway of nutrient acquisition for some volant and scansorial vertebrates. Our results highlight the intricacy of carrion-derived food web linkages, and how consideration of spatial complexity in carcass distribution (i.e., arboreal) may reveal important pathways of nutrient acquisition by invertebrate and vertebrate scavenging guilds.

  5. Influence of Microclimate on Semi-Arid Montane Conifer Forest Sapflux Velocity in Complex Terrain

    Science.gov (United States)

    Thirouin, K. R.; Barnard, D. M.; Barnard, H. R.

    2016-12-01

    Microclimate variation in complex terrain is key to our understanding of large-scale climate change effects on montane ecosystems. Modern climate models forecast that semi-arid montane ecosystems in the western United States are to experience increases in temperature, number of extreme drought events, and decreases in annual snowpack, all of which will potentially influence ecosystem water, carbon, and energy balances. In this study, we developed response curves that describe the relationships between stem sapflux velocity, air temperature (Tair), incoming solar radiation (SWin), soil temperature (Tsoil), and soil moisture content (VWC) in sites of Pinus contorta and Pinus ponderosa distributed along an elevation and aspect gradient in the montane zone of the Central Rocky Mountains, Colorado, USA. Among sites we found sapflux velocity to be significantly correlated with all four environmental factors (p physiological differences, the highest elevation south-facing P. contorta site behaved similarly to the south-facing P. ponderosa, suggesting that environmental drivers may dominate the response. In response to Tair, peak sapflux velocity occurred at 12-13 degrees C at all sites except the mid-slope north-facing P. contorta site, which also had the lowest Tsoil. The responses of stem sapflux velocity to climate drivers indicate that forest transpiration is regulated by microclimate gradients across small spatial scales in complex terrain, which need to be characterized in order to understand broader ecosystem dynamics and the role that large-scale climate change will play in these systems.

  6. Influence of Plastic Deformation on Martensitic Transformation During Hot Stamping of Complex Structure Auto Parts

    Science.gov (United States)

    Shen, Yuhan; Song, Yanli; Hua, Lin; Lu, Jue

    2017-04-01

    The ultra-high strength steel auto parts manufactured by hot stamping are widely applied for weight reduction and safety improvement. During the hot stamping process, hot forming and quenching are performed in one step wherein plastic deformation and phase transformation simultaneously take place and affect each other. Thereinto, the influence of deformation on martensitic transformation is of great importance. In the present paper, the influence of plastic deformation on martensitic transformation during hot stamping of complex structure auto parts was investigated. For this purpose, a B-pillar reinforced panel in B1500HS steel was manufactured by hot stamping, and the process was simulated by finite element software based on a thermo-mechanical-metallurgical coupled model. Considering various deformation degrees, the microstructures and mechanical properties at four typical locations of the hot stamped B-pillar reinforced panel were detected. The results show that the martensitic content and the microhardness increase with the increase in the deformation amount. There are two reasons causing this phenomenon: (1) the increase in mechanical driving force and (2) the increased probability of the martensitic nucleation at crystal defects. The x-ray diffraction analysis indicates the carbon enrichment in retained austenite which results from the carbon diffusion during the low-carbon martensite formation. Furthermore, the carbon content decreases with the increase in the deformation amount, because the deformation of austenite suppresses the carbon diffusion.

  7. Conformal invariance in supergravity

    International Nuclear Information System (INIS)

    Bergshoeff, E.A.

    1983-01-01

    In this thesis the author explains the role of conformal invariance in supergravity. He presents the complete structure of extended conformal supergravity for N <= 4. The outline of this work is as follows. In chapter 2 he briefly summarizes the essential properties of supersymmetry and supergravity and indicates the use of conformal invariance in supergravity. The idea that the introduction of additional symmetry transformations can make clear the structure of a field theory is not reserved to supergravity only. By means of some simple examples it is shown in chapter 3 how one can always introduce additional gauge transformations in a theory of massive vector fields. Moreover it is shown how the gauge invariant formulation sometimes explains the quantum mechanical properties of the theory. In chapter 4 the author defines the conformal transformations and summarizes their main properties. He explains how these conformal transformations can be used to analyse the structure of gravity. The supersymmetric extension of these results is discussed in chapter 5. Here he describes as an example how N=1 supergravity can be reformulated in a conformally-invariant way. He also shows that beyond N=1 the gauge fields of the superconformal symmetries do not constitute an off-shell field representation of extended conformal supergravity. Therefore, in chapter 6, a systematic method to construct the off-shell formulation of all extended conformal supergravity theories with N <= 4 is developed. As an example he uses this method to construct N=1 conformal supergravity. Finally, in chapter 7 N=4 conformal supergravity is discussed. (Auth.)

  8. Influence of dose rate on the induction of simple and complex chromosome exchanges by gamma rays.

    Science.gov (United States)

    Loucas, Bradford D; Eberle, Richard; Bailey, Susan M; Cornforth, Michael N

    2004-10-01

    Single-color painting of whole chromosomes, or protocols in which only a few chromosomes are distinctively painted, will always fail to detect a proportion of complex exchanges because they frequently produce pseudosimple painting patterns that are indistinguishable from those produced by bona fide simple exchanges. When 24-color multi-fluor FISH (mFISH) was employed for the purpose of distinguishing (truly) simple from pseudosimple exchanges, it was confirmed that the acute low-LET radiation dose-response relationship for simple exchanges lacked significant upward curvature. This result has been interpreted to indicate that the formation of simple exchanges requires only one chromosome locus be damaged (e.g. broken) by radiation to initiate an exchange-not two, as classical cytogenetic theory maintains. Because a one-lesion mechanism implies single-track action, it follows that the production of simple exchanges should not be influenced by changes in dose rate. To examine this prediction, we irradiated noncycling primary human fibroblasts with graded doses of (137)Cs gamma rays at an acute dose rate of 1.10 Gy/min and compared, using mFISH, the yield of simple exchanges to that observed after exposure to the same radiation delivered at a chronic dose rate of 0.08 cGy/min. The shape of the dose response was found to be quasi-linear for both dose rates, but, counter to providing support for a one-lesion mechanism, the yield of simple aberrations was greatly reduced by protracted exposure. Although chronic doses were delivered at rates low enough to produce damage exclusively by single-track action, this did not altogether eliminate the formation of complex aberrations, an analysis of which leads to the conclusion that a single track of low-LET radiation is capable of inducing complex exchanges requiring up to four proximate breaks for their formation. For acute exposures, the ratio of simple reciprocal translocations to simple dicentrics was near unity.

  9. Popularity, likeability, and peer conformity: Four field experiments

    NARCIS (Netherlands)

    Gommans, R.; Sandstrom, M.J.; Stevens, G.W.J.M.; Bogt, T.F.M. ter; Cillessen, A.H.N.

    2017-01-01

    Adolescents tend to alter their attitudes and behaviors to match those of others; a peer influence process named peer conformity. This study investigated to what extent peer conformity depended on the status (popularity and likeability) of the influencer and the influencee. The study consisted of

  10. Influence of a soil enzyme on iron-cyanide complex speciation and mineral adsorption.

    Science.gov (United States)

    Zimmerman, Andrew R; Kang, Dong-Hee; Ahn, Mi-Youn; Hyun, Seunghun; Banks, M Katherine

    2008-01-01

    Cyanide is commonly found as ferrocyanide [Fe(II)(CN)(6)](-4) and in the more mobile form, ferricyanide [Fe(III)(CN)(6)](-3) in contaminated soils and sediments. Although soil minerals may influence ferrocyanide speciation, and thus mobility, the possible influence of soil enzymes has not been examined. In a series of experiments conducted under a range of soil-like conditions, laccase, a phenoloxidase enzyme derived from the fungi Trametes versicolor, was found to exert a large influence on iron-cyanide speciation and mobility. In the presence of laccase, up to 93% of ferrocyanide (36-362ppm) was oxidized to ferricyanide within 4h. No significant effect of pH (3.6 and 6.2) or initial ferrocyanide concentration on the extent or rate of oxidation was found and ferrocyanide oxidation did not occur in the absence of laccase. Relative to iron-cyanide-mineral systems without laccase, ferrocyanide adsorption to aluminum hydroxide and montmorillonite decreased in the presence of laccase and was similar to or somewhat greater than that of ferricyanide without laccase. Laccase-catalyzed conversion of ferrocyanide to ferricyanide was extensive though up to 33% of the enzyme was mineral-bound. These results demonstrate that soil enzymes can play a major role in ferrocyanide speciation and mobility. Biotic soil components must be considered as highly effective oxidation catalysts that may alter the mobility of metals and metal complexes in soil. Immobilized enzymes should also be considered for use in soil metal remediation efforts.

  11. Influences of the propyl group on the van der Waals structures of 4-propylaniline complexes with one and two argon atoms studied by electronic and cationic spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhijun [School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan 453003 (China); Gu, Quanli [School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan 453003 (China); Department of Chemistry, University of Oklahoma, Norman, Oklahoma 73019 (United States); Trindle, Carl O., E-mail: cot@virginia.edu [Chemistry Department, University of Virginia, Charlottesville, Virginia 22904 (United States); Knee, J. L., E-mail: jknee@wesleyan.edu [Chemistry Department, Wesleyan University, Middletown, Connecticut 06459 (United States)

    2015-07-21

    4-propylaniline complexes with one and two argon atoms formed in the molecular beam were studied in the first excited electronic state, S{sub 1}, using resonance enhanced two-photon ionization spectroscopy and in the cation ground state, D{sub 0}, using mass analyzed threshold ionization spectroscopy. The combination of electronic and cationic spectra of the clusters allows two conformations to be identified in both aniline-Ar{sub 1} and aniline-Ar{sub 2}, which are assigned to either the gauche configuration or anti-configuration of 4-propylaniline. The gauche isomer exhibits complex bands shifted 29 cm{sup −1} and 89 cm{sup −1} from the S{sub 1} origin bands and 83 cm{sup −1} and 148 cm{sup −1} from the ionization potential assigned to the Ar{sub 1} and Ar{sub 2} complexes, respectively. For the anti-rotamer, the corresponding shifts actually become nearly additive, 53 cm{sup −1} and 109 cm{sup −1} for the S{sub 1} origin bands, and 61 cm{sup −1} and 125 cm{sup −1} for the ionization potentials. Ab initio calculations provide insights into the influences of the propyl and amino groups on the positions of the argon atoms within the clusters. In addition, the binding energy of one argon with the gauche isomer of 4-propylaniline has been measured to be 550 ± 5 cm{sup −1} in the D{sub 0} state, 496 ± 5 cm{sup −1} in the S{sub 1} state, and 467 ± 5 cm{sup −1} in the neutral ground state, S{sub 0}.

  12. Understanding modern magnets through conformal mapping

    International Nuclear Information System (INIS)

    Halbach, K.

    1989-10-01

    I want to show with the help of a number of examples that conformal mapping is a unique and enormously powerful tool for thinking about, and solving, problems. Usually one has to write down only a few equations, and sometimes none at all exclamation point When I started getting involved in work for which conformal mapping seemed to be a powerful tool, I did not think that I would ever be able to use that technique successfully because it seemed to require a nearly encyclopedic memory, an impression that was strengthened when I saw K. Kober's Dictionary of Conformal Representations. This attitude changed when I started to realize that beyond the basics of the theory of a function of a complex variable, I needed to know only about a handful of conformal maps and procedures. Consequently, my second goal for this talk is to show that in most cases conformal mapping functions can be obtained by formulating the underlying physics appropriately. This means particularly that encyclopedic knowledge of conformal maps is not necessary for successful use of conformal mapping techniques. To demonstrate these facts I have chosen examples from an area of physics/engineering in which I am active, namely accelerator physics. In order to do that successfully I start with a brief introduction into high energy charged particle storage ring technology, even though not all examples used in this paper to elucidate my points come directly from this particular field of accelerator technology

  13. Conformal expansions and renormalons

    Energy Technology Data Exchange (ETDEWEB)

    Rathsman, J.

    2000-02-07

    The coefficients in perturbative expansions in gauge theories are factorially increasing, predominantly due to renormalons. This type of factorial increase is not expected in conformal theories. In QCD conformal relations between observables can be defined in the presence of a perturbative infrared fixed-point. Using the Banks-Zaks expansion the authors study the effect of the large-order behavior of the perturbative series on the conformal coefficients. The authors find that in general these coefficients become factorially increasing. However, when the factorial behavior genuinely originates in a renormalon integral, as implied by a postulated skeleton expansion, it does not affect the conformal coefficients. As a consequence, the conformal coefficients will indeed be free of renormalon divergence, in accordance with previous observations concerning the smallness of these coefficients for specific observables. The authors further show that the correspondence of the BLM method with the skeleton expansion implies a unique scale-setting procedure. The BLM coefficients can be interpreted as the conformal coefficients in the series relating the fixed-point value of the observable with that of the skeleton effective charge. Through the skeleton expansion the relevance of renormalon-free conformal coefficients extends to real-world QCD.

  14. Conformal and Nearly Conformal Theories at Large N

    Science.gov (United States)

    Tarnoplskiy, Grigory M.

    In this thesis we present new results in conformal and nearly conformal field theories in various dimensions. In chapter two, we study different properties of the conformal Quantum Electrodynamics (QED) in continuous dimension d. At first we study conformal QED using large Nf methods, where Nf is the number of massless fermions. We compute its sphere free energy as a function of d, ignoring the terms of order 1/Nf and higher. For finite Nf we use the epsilon-expansion. Next we use a large Nf diagrammatic approach to calculate the leading corrections to CT, the coefficient of the two-point function of the stress-energy tensor, and CJ, the coefficient of the two-point function of the global symmetry current. We present explicit formulae as a function of d and check them versus the expectations in 2 and 4 - epsilon dimensions. In chapter three, we discuss vacuum stability in 1 + 1 dimensional conformal field theories with external background fields. We show that the vacuum decay rate is given by a non-local two-form. This two-form is a boundary term that must be added to the effective in/out Lagrangian. The two-form is expressed in terms of a Riemann-Hilbert decomposition for background gauge fields, and is given by its novel "functional'' version in the gravitational case. In chapter four, we explore Tensor models. Such models possess the large N limit dominated by the melon diagrams. The quantum mechanics of a real anti-commuting rank-3 tensor has a large N limit similar to the Sachdev-Ye-Kitaev (SYK) model. We also discuss the quantum mechanics of a complex 3-index anti-commuting tensor and argue that it is equivalent in the large N limit to a version of SYK model with complex fermions. Finally, we discuss models of a commuting tensor in dimension d. We study the spectrum of the large N quantum field theory of bosonic rank-3 tensors using the Schwinger-Dyson equations. We compare some of these results with the 4 - epsilon expansion, finding perfect agreement. We

  15. Conformal sequestering simplified

    International Nuclear Information System (INIS)

    Schmaltz, Martin; Sundrum, Raman

    2006-01-01

    Sequestering is important for obtaining flavor-universal soft masses in models where supersymmetry breaking is mediated at high scales. We construct a simple and robust class of hidden sector models which sequester themselves from the visible sector due to strong and conformally invariant hidden dynamics. Masses for hidden matter eventually break the conformal symmetry and lead to supersymmetry breaking by the mechanism recently discovered by Intriligator, Seiberg and Shih. We give a unified treatment of subtleties due to global symmetries of the CFT. There is enough review for the paper to constitute a self-contained account of conformal sequestering

  16. Conformally connected universes

    International Nuclear Information System (INIS)

    Cantor, M.; Piran, T.

    1983-01-01

    A well-known difficulty associated with the conformal method for the solution of the general relativistic Hamiltonian constraint is the appearance of an aphysical ''bag of gold'' singularity at the nodal surface of the conformal factor. This happens whenever the background Ricci scalar is too large. Using a simple model, it is demonstrated that some of these singular solutions do have a physical meaning, and that these can be considered as initial data for Universe containing black holes, which are connected, in a conformally nonsingular way with each other. The relation between the ADM mass and the horizon area in this solution supports the cosmic censorship conjecture. (author)

  17. Radioactive contaminants in the subsurface: the influence of complexing ligands on trace metal speciation

    International Nuclear Information System (INIS)

    Hummel, W.

    2007-01-01

    in Swiss radioactive waste disposal projects. Within the scope of this TDB project I reviewed extensively thermodynamic data for Th, Pd, Al, and solubility and metal complexation of silicates, the review considering not only U, Np, Pu, Am, Tc, Ni, Se and Zr, but also the major constituents of ground and surface waters, i.e. H, Na, K, Mg and Ca. The decision to evaluate the organic ligands oxalate, citrate, ethylenediaminetetraacetate (edta) and α-isosaccharinate (isa) was based on two aspects, namely the importance of the ligands in radioactive waste problems, and the availability of experimental data. (ii) In many case studies involving inorganic and simple organic ligands a serious lack of reliable thermodynamic data is encountered. There, a new modeling approach to estimate the effects of these missing data was applied. This so called 'backdoor approach' begins with the question: 'What total concentration of a ligand is necessary to significantly influence the speciation, and hence the solubility, of a given trace metal?' Radioactive waste contains substantial amounts of ion-exchange resins from decontamination procedures. Degradation of these organic waste forms by radiolysis in a repository is a source of concern in radioactive waste management. Radiolytic degradation experiments with strong acidic ion exchange resins resulted in the formation of the complexing ligands oxalate and ligand X, whose structure could not be identified. In the case of anion exchange resins, ammonia and methylamines were detected. I assessed the influence of these ligands on radionuclide speciation in groundwater and cement pore water of a repository using the 'backdoor approach'. Prussian Blue, Fe III 4 [Fe II (CN) 6 ] 3 , and structurally related transition metal compounds like Ni 2 [Fe(CN) 6 ] are used as cesium ion exchangers in decontamination procedures of liquid radioactive waste. The used ion exchangers are conditioned as cementitious waste form for interim storage and finally

  18. Reciprocity Outperforms Conformity to Promote Cooperation.

    Science.gov (United States)

    Romano, Angelo; Balliet, Daniel

    2017-10-01

    Evolutionary psychologists have proposed two processes that could give rise to the pervasiveness of human cooperation observed among individuals who are not genetically related: reciprocity and conformity. We tested whether reciprocity outperformed conformity in promoting cooperation, especially when these psychological processes would promote a different cooperative or noncooperative response. To do so, across three studies, we observed participants' cooperation with a partner after learning (a) that their partner had behaved cooperatively (or not) on several previous trials and (b) that their group members had behaved cooperatively (or not) on several previous trials with that same partner. Although we found that people both reciprocate and conform, reciprocity has a stronger influence on cooperation. Moreover, we found that conformity can be partly explained by a concern about one's reputation-a finding that supports a reciprocity framework.

  19. Electrophysiological precursors of social conformity

    Science.gov (United States)

    Rieskamp, Jörg; Tugin, Sergey; Ossadtchi, Alexey; Krutitskaya, Janina; Klucharev, Vasily

    2013-01-01

    Humans often change their beliefs or behavior due to the behavior or opinions of others. This study explored, with the use of human event-related potentials (ERPs), whether social conformity is based on a general performance-monitoring mechanism. We tested the hypothesis that conflicts with a normative group opinion evoke a feedback-related negativity (FRN) often associated with performance monitoring and subsequent adjustment of behavior. The experimental results show that individual judgments of facial attractiveness were adjusted in line with a normative group opinion. A mismatch between individual and group opinions triggered a frontocentral negative deflection with the maximum at 200 ms, similar to FRN. Overall, a conflict with a normative group opinion triggered a cascade of neuronal responses: from an earlier FRN response reflecting a conflict with the normative opinion to a later ERP component (peaking at 380 ms) reflecting a conforming behavioral adjustment. These results add to the growing literature on neuronal mechanisms of social influence by disentangling the conflict-monitoring signal in response to the perceived violation of social norms and the neural signal of a conforming behavioral adjustment. PMID:22683703

  20. The influence of vertical disparity gradient and cue conflict on EEG omega complexity in Panum's limiting case.

    Science.gov (United States)

    Li, Huayun; Jia, Huibin; Yu, Dongchuan

    2018-03-01

    Using behavioral measures and ERP technique, researchers discovered at least two factors could influence the final perception of depth in Panum's limiting case, which are the vertical disparity gradient and the degree of cue conflict between two- and three-dimensional shapes. Although certain event-related potential components have been proved to be sensitive to the different levels of these two factors, some methodological limitations existed in this technique. In this study, we proposed that the omega complexity of EEG signal may serve as an important supplement of the traditional event-related potential technique. We found that the trials with lower vertical gradient disparity have lower omega complexity (i.e., higher global functional connectivity) of the occipital region, especially that of the right-occipital hemisphere. Moreover, for occipital omega complexity, the trials with low-cue conflict have significantly larger omega complexity than those with medium- and high-cue conflict. It is also found that the electrodes located in the middle line of the occipital region (i.e., POz and Oz) are more crucial to the impact of different levels of cue conflict on omega complexity than the other electrodes located in the left- and right-occipital hemispheres. These evidences demonstrated that the EEG omega complexity could reflect distinct neural activities evoked by Panum's limiting case configurations, with different levels of vertical disparity gradient and cue conflict. Besides, the influence of vertical disparity gradient and cue conflict on omega complexity may be regional dependent. NEW & NOTEWORTHY The EEG omega complexity could reflect distinct neural activities evoked by Panum's limiting case configurations with different levels of vertical disparity gradient and cue conflict. The influence of vertical disparity gradient and cue conflict on omega complexity is regional dependent. The omega complexity of EEG signal can serve as an important supplement of the

  1. Conformable variational iteration method

    Directory of Open Access Journals (Sweden)

    Omer Acan

    2017-02-01

    Full Text Available In this study, we introduce the conformable variational iteration method based on new defined fractional derivative called conformable fractional derivative. This new method is applied two fractional order ordinary differential equations. To see how the solutions of this method, linear homogeneous and non-linear non-homogeneous fractional ordinary differential equations are selected. Obtained results are compared the exact solutions and their graphics are plotted to demonstrate efficiency and accuracy of the method.

  2. Delineating the conformal window

    DEFF Research Database (Denmark)

    Frandsen, Mads Toudal; Pickup, Thomas; Teper, Michael

    2011-01-01

    We identify and characterise the conformal window in gauge theories relevant for beyond the standard model building, e.g. Technicolour, using the criteria of metric confinement and causal analytic couplings, which are known to be consistent with the phase diagram of supersymmetric QCD from Seiberg...... duality. Using these criteria we find perturbation theory to be consistent throughout the predicted conformal window for several of these gauge theories and we discuss recent lattice results in the light of our findings....

  3. conformational complexity of complement component C3

    NARCIS (Netherlands)

    Janssen, B.J.C.

    2007-01-01

    The complement system is an important part of the immune system and critical for the elimination of pathogens. In mammals the complement system consists of an intricate set of about 35 soluble and cell-surface plasma proteins. Central to complement is component C3, a large protein of 1,641 residues.

  4. The conforming brain and deontological resolve.

    Science.gov (United States)

    Pincus, Melanie; LaViers, Lisa; Prietula, Michael J; Berns, Gregory

    2014-01-01

    Our personal values are subject to forces of social influence. Deontological resolve captures how strongly one relies on absolute rules of right and wrong in the representation of one's personal values and may predict willingness to modify one's values in the presence of social influence. Using fMRI, we found that a neurobiological metric for deontological resolve based on relative activity in the ventrolateral prefrontal cortex (VLPFC) during the passive processing of sacred values predicted individual differences in conformity. Individuals with stronger deontological resolve, as measured by greater VLPFC activity, displayed lower levels of conformity. We also tested whether responsiveness to social reward, as measured by ventral striatal activity during social feedback, predicted variability in conformist behavior across individuals but found no significant relationship. From these results we conclude that unwillingness to conform to others' values is associated with a strong neurobiological representation of social rules.

  5. The conforming brain and deontological resolve.

    Directory of Open Access Journals (Sweden)

    Melanie Pincus

    Full Text Available Our personal values are subject to forces of social influence. Deontological resolve captures how strongly one relies on absolute rules of right and wrong in the representation of one's personal values and may predict willingness to modify one's values in the presence of social influence. Using fMRI, we found that a neurobiological metric for deontological resolve based on relative activity in the ventrolateral prefrontal cortex (VLPFC during the passive processing of sacred values predicted individual differences in conformity. Individuals with stronger deontological resolve, as measured by greater VLPFC activity, displayed lower levels of conformity. We also tested whether responsiveness to social reward, as measured by ventral striatal activity during social feedback, predicted variability in conformist behavior across individuals but found no significant relationship. From these results we conclude that unwillingness to conform to others' values is associated with a strong neurobiological representation of social rules.

  6. Radio metal (169Yb) uptake in normal and tumour cells in vitro. Influence of metabolic cell activity and complex structure

    International Nuclear Information System (INIS)

    Franke, W.G.; Kampf, G.

    1996-01-01

    Trivalent radio metal tracers have been used for tumour imaging and metastatic pain palliation. For better understanding their tumour accumulation, basic model studies of uptake of different 169 Yb complexes into cultured normal and tumour cells were performed. Whereas the uptake of 169 Yb citrate is strongly dependent on the metabolic activity and is not tumour-cell pacific, the uptake of 169 Yb complexed with amino carbonic acid (NTA, EDTA, DTPA) does not correlate to the metabolic activities. These complexes are taken up to a greater amount by the tumour cells (by a factor of about 2). Uptake of both complex types leads to a stable association to cellular compounds, 169 Yb is not releasable by the strong complexing agent DTPA. Protein binding of the 169 Yb complexes shows great influence on their cellular uptake. The bound proportion is no more available,for cellular uptake. The results indicate that i 0 uptake of 169 Yb citrate is an active cellular transport process which i not tumor-specific, ii) the 169 Yb amino carbonic acid complexes show a weak favouring by the tumour cells, iii) different from earlier acceptions the Yb complexes studied are not taken up by the cells in protein-bound form. The structure of the Yb complex is decisive for its protein binding and cellular uptake. (author). 13 refs., 6 figs

  7. Non-neural Muscle Weakness Has Limited Influence on Complexity of Motor Control during Gait

    Directory of Open Access Journals (Sweden)

    Marije Goudriaan

    2018-01-01

    Full Text Available Cerebral palsy (CP and Duchenne muscular dystrophy (DMD are neuromuscular disorders characterized by muscle weakness. Weakness in CP has neural and non-neural components, whereas in DMD, weakness can be considered as a predominantly non-neural problem. Despite the different underlying causes, weakness is a constraint for the central nervous system when controlling gait. CP demonstrates decreased complexity of motor control during gait from muscle synergy analysis, which is reflected by a higher total variance accounted for by one synergy (tVAF1. However, it remains unclear if weakness directly contributes to higher tVAF1 in CP, or whether altered tVAF1 reflects mainly neural impairments. If muscle weakness directly contributes to higher tVAF1, then tVAF1 should also be increased in DMD. To examine the etiology of increased tVAF1, muscle activity data of gluteus medius, rectus femoris, medial hamstrings, medial gastrocnemius, and tibialis anterior were measured at self-selected walking speed, and strength data from knee extensors, knee flexors, dorsiflexors and plantar flexors, were analyzed in 15 children with CP [median (IQR age: 8.9 (2.2], 15 boys with DMD [8.7 (3.1], and 15 typical developing (TD children [8.6 (2.7]. We computed tVAF1 from 10 concatenated steps with non-negative matrix factorization, and compared tVAF1 between the three groups with a Mann-Whiney U-test. Spearman's rank correlation coefficients were used to determine if weakness in specific muscle groups contributed to altered tVAF1. No significant differences in tVAF1 were found between DMD [tVAF1: 0.60 (0.07] and TD children [0.65 (0.07], while tVAF1 was significantly higher in CP [(0.74 (0.09] than in the other groups (both p < 0.005. In CP, weakness in the plantar flexors was related to higher tVAF1 (r = −0.72. In DMD, knee extensor weakness related to increased tVAF1 (r = −0.50. These results suggest that the non-neural weakness in DMD had limited influence on

  8. Radioactive contaminants in the subsurface: the influence of complexing ligands on trace metal speciation

    International Nuclear Information System (INIS)

    Hummel, W. . Author

    2006-01-01

    Equilibrium thermodynamics is one of the pillars which support safety analyzes of repositories for radioactive waste. The research summarized in this review deals with approaches to resolve the problems related to thermodynamic equilibrium constants and solubility of solid phases in the field of radioactive waste management. The results have been obtained at the Paul Scherrer Institut between 1995 and 2005 and comprise the scientific basis of the author's habilitation thesis in the field of nuclear environmental chemistry. The topics are grouped according to three different levels of problem solving strategies: critical and comprehensive reviews of the available literature, which are necessary in order to establish a reliable chemical thermodynamic database that fulfils the requirements for rigorous modeling of the behavior of the actinides and fission products in the environment. In many case studies involving inorganic and simple organic ligands a serious lack of reliable thermodynamic data is encountered. There, a new modeling approach to estimate the effects of these missing data was applied. This so called 'backdoor approach' begins with the question, 'What total concentration of a ligand is necessary to significantly influence the speciation, and hence the solubility, of a given trace metal?' In the field of natural organics, mainly humic and fulvic acids, we face an ill-defined problem concerning the molecular structure of the ligands. There, a pragmatic approach for performance assessment purposes was applied, the 'conservative roof' approach, which does not aim to accurately model all experimental data, but allows estimates of maximum effects on metal complexation by humic substances to be calculated. (author)

  9. Ecological interactions in dinosaur communities: influences of small offspring and complex ontogenetic life histories.

    Directory of Open Access Journals (Sweden)

    Daryl Codron

    Full Text Available Because egg-laying meant that even the largest dinosaurs gave birth to very small offspring, they had to pass through multiple ontogenetic life stages to adulthood. Dinosaurs' successors as the dominant terrestrial vertebrate life form, the mammals, give birth to live young, and have much larger offspring and less complex ontogenetic histories. The larger number of juveniles in dinosaur as compared to mammal ecosystems represents both a greater diversity of food available to predators, and competitors for similar-sized individuals of sympatric species. Models of population abundances across different-sized species of dinosaurs and mammals, based on simulated ecological life tables, are employed to investigate how differences in predation and competition pressure influenced dinosaur communities. Higher small- to medium-sized prey availability leads to a normal body mass-species richness (M-S distribution of carnivorous dinosaurs (as found in the theropod fossil record, in contrast to the right-skewed M-S distribution of carnivorous mammals (as found living members of the order Carnivora. Higher levels of interspecific competition leads to a left-skewed M-S distribution in herbivorous dinosaurs (as found in sauropods and ornithopods, in contrast to the normal M-S distribution of large herbivorous mammals. Thus, our models suggest that differences in reproductive strategy, and consequently ontogeny, explain observed differences in community structure between dinosaur and mammal faunas. Models also show that the largest dinosaurian predators could have subsisted on similar-sized prey by including younger life stages of the largest herbivore species, but that large predators likely avoided prey much smaller than themselves because, despite predicted higher abundances of smaller than larger-bodied prey, contributions of small prey to biomass intake would be insufficient to satisfy meat requirements. A lack of large carnivores feeding on small prey

  10. Ecological interactions in dinosaur communities: influences of small offspring and complex ontogenetic life histories.

    Science.gov (United States)

    Codron, Daryl; Carbone, Chris; Clauss, Marcus

    2013-01-01

    Because egg-laying meant that even the largest dinosaurs gave birth to very small offspring, they had to pass through multiple ontogenetic life stages to adulthood. Dinosaurs' successors as the dominant terrestrial vertebrate life form, the mammals, give birth to live young, and have much larger offspring and less complex ontogenetic histories. The larger number of juveniles in dinosaur as compared to mammal ecosystems represents both a greater diversity of food available to predators, and competitors for similar-sized individuals of sympatric species. Models of population abundances across different-sized species of dinosaurs and mammals, based on simulated ecological life tables, are employed to investigate how differences in predation and competition pressure influenced dinosaur communities. Higher small- to medium-sized prey availability leads to a normal body mass-species richness (M-S) distribution of carnivorous dinosaurs (as found in the theropod fossil record), in contrast to the right-skewed M-S distribution of carnivorous mammals (as found living members of the order Carnivora). Higher levels of interspecific competition leads to a left-skewed M-S distribution in herbivorous dinosaurs (as found in sauropods and ornithopods), in contrast to the normal M-S distribution of large herbivorous mammals. Thus, our models suggest that differences in reproductive strategy, and consequently ontogeny, explain observed differences in community structure between dinosaur and mammal faunas. Models also show that the largest dinosaurian predators could have subsisted on similar-sized prey by including younger life stages of the largest herbivore species, but that large predators likely avoided prey much smaller than themselves because, despite predicted higher abundances of smaller than larger-bodied prey, contributions of small prey to biomass intake would be insufficient to satisfy meat requirements. A lack of large carnivores feeding on small prey exists in mammals

  11. Virtual and solution conformations of oligosaccharides

    International Nuclear Information System (INIS)

    Cumming, D.A.; Carver, J.P.

    1987-01-01

    The possibility that observed nuclear Overhauser enhancements and bulk longitudinal relaxation times, parameters measured by 1 H NMR and often employed in determining the preferred solution conformation of biologically important molecules, are the result of averaging over many conformational states is quantitatively evaluated. Of particular interest was to ascertain whether certain 1 H NMR determined conformations are virtual in nature; i.e., the fraction of the population of molecules actually found at any time within the subset of conformational space defined as the solution conformation is vanishingly small. A statistical mechanics approach was utilized to calculate an ensemble average relaxation matrix from which (NOE)'s and (T 1 )'s are calculated. Model glycosidic linkages in four oligosaccharides were studied. The nature of the resultant population distributions is such that 50% of the molecular population is found within 1% of available microstates, while 99% of the molecular population occupies about 10% of the ensemble microstates, a number roughly equal to that sterically allowed. From this analysis the authors conclude that in many cases quantitative interpretation of NMR relaxation data, which attempts to define a single set of allowable torsion angle values consistent with the observed data, will lead to solution conformations that are either virtual or reflect torsion angle values possessed by a minority of the molecular population. Observed values of NMR relaxation data are the result of the complex interdependence of the population distribution and NOE (or T 1 ) surfaces in conformational space. In conformational analyses, NMR data can therefore be used to test different population distributions calculated from empirical potential energy functions

  12. Complex formation of blueberry (Vaccinium angustifolium) anthocyanins during freeze-drying and its influence on their biological activity.

    Science.gov (United States)

    Correa-Betanzo, Julieta; Padmanabhan, Priya; Corredig, Milena; Subramanian, Jayasankar; Paliyath, Gopinadhan

    2015-03-25

    Biological activity of polyphenols is influenced by their uptake and is highly influenced by their interactions with the food matrix. This study evaluated the complex formation of blueberry polyphenols with fruit matrixes such as pectin and cellulose and their effect on the biological and antiproliferative properties of human colon cell lines HT-29 and CRL 1790. Free or complexed polyphenols were isolated by dialyzing aqueous or methanolic blueberry homogenates. Seven phenolic compounds and thirteen anthocyanins were identified in blueberry extracts. Blueberry extracts showed varying degrees of antioxidant and antiproliferative activities, as well as α-glucosidase activity. Fruit matrix containing cellulose and pectin, or purified polygalacturonic acid and cellulose, did not retain polyphenols and showed very low antioxidant or antiproliferative activities. These findings suggest that interactions between polyphenols and the food matrix may be more complex than a simple association and may play an important role in the bioefficacy of blueberry polyphenols.

  13. Conformational alterations in the CD4 binding cavity of HIV-1 gp120 influencing gp120-CD4 interactions and fusogenicity of HIV-1 envelopes derived from brain and other tissues

    Directory of Open Access Journals (Sweden)

    Ramsland Paul A

    2011-06-01

    Full Text Available Abstract Background CD4-binding site (CD4bs alterations in gp120 contribute to HIV-1 envelope (Env mediated fusogenicity and the ability of gp120 to utilize low levels of cell-surface CD4. In a recent study, we constructed three-dimensional models of gp120 to illustrate CD4bs conformations associated with enhanced fusogenicity and enhanced CD4-usage of a modestly-sized panel of blood-derived HIV-1 Envs (n = 16. These conformations were characterized by a wider aperture of the CD4bs cavity, as constrained by the inner-most atoms at the gp120 V1V2 stem and the V5 loop. Here, we sought to provide further validation of the utility of these models for understanding mechanisms that influence Env function, by characterizing the structure-function relationships of a larger panel of Envs derived from brain and other tissues (n = 81. Findings Three-dimensional models of gp120 were generated by our recently validated homology modelling protocol. Analysis of predicted CD4bs structures showed correlations between the aperture width of the CD4bs cavity and ability of the Envs to mediate cell-cell fusion, scavenge low-levels of cell-surface CD4, bind directly to soluble CD4, and bind to the Env mAb IgG1b12 whose epitope overlaps the gp120 CD4bs. These structural alterations in the CD4bs cavity were associated with repositioning of the V5 loop. Conclusions Using a large, independent panel of Envs, we can confirm the utility of three-dimensional gp120 structural models for illustrating CD4bs alterations that can affect Env function. Furthermore, we now provide new evidence that these CD4bs alterations augment the ability of gp120 to interact with CD4 by increasing the exposure of the CD4bs.

  14. REDOR NMR Reveals Multiple Conformers for a Protein Kinase C Ligand in a Membrane Environment

    Directory of Open Access Journals (Sweden)

    Hao Yang

    2018-01-01

    Full Text Available Bryostatin 1 (henceforth bryostatin is in clinical trials for the treatment of Alzheimer’s disease and for HIV/AIDS eradication. It is also a preclinical lead for cancer immunotherapy and other therapeutic indications. Yet nothing is known about the conformation of bryostatin bound to its protein kinase C (PKC target in a membrane microenvironment. As a result, efforts to design more efficacious, better tolerated, or more synthetically accessible ligands have been limited to structures that do not include PKC or membrane effects known to influence PKC–ligand binding. This problem extends more generally to many membrane-associated proteins in the human proteome. Here, we use rotational-echo double-resonance (REDOR solid-state NMR to determine the conformations of PKC modulators bound to the PKCδ-C1b domain in the presence of phospholipid vesicles. The conformationally limited PKC modulator phorbol diacetate (PDAc is used as an initial test substrate. While unanticipated partitioning of PDAc between an immobilized protein-bound state and a mobile state in the phospholipid assembly was observed, a single conformation in the bound state was identified. In striking contrast, a bryostatin analogue (bryolog was found to exist exclusively in a protein-bound state, but adopts a distribution of conformations as defined by three independent distance measurements. The detection of multiple PKCδ-C1b-bound bryolog conformers in a functionally relevant phospholipid complex reveals the inherent dynamic nature of cellular systems that is not captured with single-conformation static structures. These results indicate that binding, selectivity, and function of PKC modulators, as well as the design of new modulators, are best addressed using a dynamic multistate model, an analysis potentially applicable to other membrane-associated proteins.

  15. Perspectives on electrostatics and conformational motions in enzyme catalysis.

    Science.gov (United States)

    Hanoian, Philip; Liu, C Tony; Hammes-Schiffer, Sharon; Benkovic, Stephen

    2015-02-17

    CONSPECTUS: Enzymes are essential for all living organisms, and their effectiveness as chemical catalysts has driven more than a half century of research seeking to understand the enormous rate enhancements they provide. Nevertheless, a complete understanding of the factors that govern the rate enhancements and selectivities of enzymes remains elusive, due to the extraordinary complexity and cooperativity that are the hallmarks of these biomolecules. We have used a combination of site-directed mutagenesis, pre-steady-state kinetics, X-ray crystallography, nuclear magnetic resonance (NMR), vibrational and fluorescence spectroscopies, resonance energy transfer, and computer simulations to study the implications of conformational motions and electrostatic interactions on enzyme catalysis in the enzyme dihydrofolate reductase (DHFR). We have demonstrated that modest equilibrium conformational changes are functionally related to the hydride transfer reaction. Results obtained for mutant DHFRs illustrated that reductions in hydride transfer rates are correlated with altered conformational motions, and analysis of the evolutionary history of DHFR indicated that mutations appear to have occurred to preserve both the hydride transfer rate and the associated conformational changes. More recent results suggested that differences in local electrostatic environments contribute to finely tuning the substrate pKa in the initial protonation step. Using a combination of primary and solvent kinetic isotope effects, we demonstrated that the reaction mechanism is consistent across a broad pH range, and computer simulations suggested that deprotonation of the active site Tyr100 may play a crucial role in substrate protonation at high pH. Site-specific incorporation of vibrational thiocyanate probes into the ecDHFR active site provided an experimental tool for interrogating these microenvironments and for investigating changes in electrostatics along the DHFR catalytic cycle

  16. Extended conformal algebras

    International Nuclear Information System (INIS)

    Goddard, Peter

    1990-01-01

    The algebra of the group of conformal transformations in two dimensions consists of two commuting copies of the Virasoro algebra. In many mathematical and physical contexts, the representations of ν which are relevant satisfy two conditions: they are unitary and they have the ''positive energy'' property that L o is bounded below. In an irreducible unitary representation the central element c takes a fixed real value. In physical contexts, the value of c is a characteristic of a theory. If c < 1, it turns out that the conformal algebra is sufficient to ''solve'' the theory, in the sense of relating the calculation of the infinite set of physically interesting quantities to a finite subset which can be handled in principle. For c ≥ 1, this is no longer the case for the algebra alone and one needs some sort of extended conformal algebra, such as the superconformal algebra. It is these algebras that this paper aims at addressing. (author)

  17. Algebraic conformal field theory

    International Nuclear Information System (INIS)

    Fuchs, J.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica

    1991-11-01

    Many conformal field theory features are special versions of structures which are present in arbitrary 2-dimensional quantum field theories. So it makes sense to describe 2-dimensional conformal field theories in context of algebraic theory of superselection sectors. While most of the results of the algebraic theory are rather abstract, conformal field theories offer the possibility to work out many formulae explicitly. In particular, one can construct the full algebra A-bar of global observables and the endomorphisms of A-bar which represent the superselection sectors. Some explicit results are presented for the level 1 so(N) WZW theories; the algebra A-bar is found to be the enveloping algebra of a Lie algebra L-bar which is an extension of the chiral symmetry algebra of the WZW theory. (author). 21 refs., 6 figs

  18. Influencing of resorption and side-effects of salicylic acid by complexing with β-cyclodextrin

    International Nuclear Information System (INIS)

    Szejtli, J.; Gerloczy, A.; Sebestyen, G.; Fonagy, A.

    1981-01-01

    After oral administration of 14 C-labelled salicylic acid and its β-cyclodextrin complex to rats, the radioactivity level of the blood reached its maximum during the first 2 h. The blood level obtained with the complex is somewhat but not significantly lower than with free acid. Since the resorption of cyclodextrin is a considerably slower process, it is very likely that the resorption of salicylic acid takes place in the form of free acid after dissociation of the complex. The urinary excretion cumulative curves showed that the free salicylic acid was completely excreted, while about 10% of the salicylic acid administered in the form of complex is lost. The cyclodextrin complex formation increased the pK values of all hydroxybenzoic acids. Direct observations revealed that complex formation decreased the stomach-irritating effect of salicylic acid. The ratio of radioactivity was nearly the same in the organs of animals treated by both free salicylic and cyclodextrin complex. (author)

  19. Killing tensors and conformal Killing tensors from conformal Killing vectors

    International Nuclear Information System (INIS)

    Rani, Raffaele; Edgar, S Brian; Barnes, Alan

    2003-01-01

    Koutras has proposed some methods to construct reducible proper conformal Killing tensors and Killing tensors (which are, in general, irreducible) when a pair of orthogonal conformal Killing vectors exist in a given space. We give the completely general result demonstrating that this severe restriction of orthogonality is unnecessary. In addition, we correct and extend some results concerning Killing tensors constructed from a single conformal Killing vector. A number of examples demonstrate that it is possible to construct a much larger class of reducible proper conformal Killing tensors and Killing tensors than permitted by the Koutras algorithms. In particular, by showing that all conformal Killing tensors are reducible in conformally flat spaces, we have a method of constructing all conformal Killing tensors, and hence all the Killing tensors (which will in general be irreducible) of conformally flat spaces using their conformal Killing vectors

  20. Influence of the absorptive part of the complex potential on the S-Matrix poles

    International Nuclear Information System (INIS)

    Grama, C.; Grama, N.; Zamfirescu, I

    2001-01-01

    Although the polology of the S-matrix has been extensively studied, it occurred that some aspects remained disputable in the case of complex central potential V(r)=gV(r), g in C . These aspects are related to the origin of the observed narrow Σ-hypernuclear states that have been interpreted by Gal, Toker and Alexander as states which correspond to S-matrix poles situated in the second k-plane quadrant. From the analytical properties of the S-matrix for a real potential it results that there is no pole in the first and second k-plane quadrants, except for the imaginary k-axis. By switching on the absorption the S-matrix poles for real potential can evolve into the second quadrant of the k-plane. A critical study of the Σ-hypernuclear states needs the analysis of the motion of the S-matrix poles in the k-plane for variable complex coupling strength g. Recently contradictory opinions relative to the S-matrix poles trajectories in the complex k-plane for a complex square potential occurred. According to some authors the poles in the second quadrant can occur either from bound state poles moving anticlockwise, or from virtual state poles and capture resonant state poles moving clockwise as the absorption is switched on. Dabrowski argues that the statement made by Gal et al, Bonetti et al and Oset et al concerning the movement of the virtual poles with increasing absorptive potential is in general not correct. Dabrowski relates the direction in which the pole moves when the potential absorption increases to the direction in which the pole moves with increasing the real part of the potential, without clarifying this last question. For example, two poles moving in opposite directions along the imaginary k-axis are associated by Dabrowski to the same state. This is a wrong result, because one should associate a single pole to each quantum state. The aim of our work is to study the influence of the absorptive part of the potential on the S-matrix poles for the non

  1. Influence of radiographic techniques on the measurement of femoral anteversion angles and a conformation score of pelvic limbs in Labrador retrievers.

    Science.gov (United States)

    Mostafa, Ayman A; Cunningham, Devin P; Boudrieau, Randy J; Kowaleski, Michael P; Griffon, Dominique J

    2018-04-01

    To determine repeatability of and correlation between 2 radiographic measurements of femoral anteversion angles (FAA) and to determine their influence on a score derived from tibial plateau angle (TPA) and FAA to predict the risk of cranial cruciate ligament disease (CCLD). Prospective clinical study. Forty-eight Labrador retrievers with or without CCLD. FAA and CCLD scores were calculated for each limb from extended pelvic radiographs (t-FAA) or angled (a-FAA) projections of the femur by 3 investigators. One investigator repeated measurements twice. Data were analyzed for repeatability, correlation between t-FAA and a-FAA, and their influence on CCLD scores. FAA correlated most strongly with the distance between the femoral head and the femoral axis on mediolateral radiographs, a measurement with excellent repeatability. t-FAA and a-FAA correlated with each other (r > 0.79, P FAA were about 1° greater than a-FAA (P = .01). Intrainvestigator and interinvestigator repeatability of the CCLD score was fair when derived from t-FAA and good to excellent when derived from a-FAA. CCLD scores differed between radiographic techniques but led to different predictions in only 9 (10%) limbs, all with lower TPA and CCLD scores than the rest of the population. a-FAA correlated strongly with t-FAA and improved the repeatability of CCLD scores within and between investigators. A craniocaudal angled beam projection of the femur is a suitable alternative to a ventrodorsal pelvic radiograph when measuring FAA and may improve the repeatability and positive predictive value of CCLD scores. © 2018 The American College of Veterinary Surgeons.

  2. A Framework for Online Conformance Checking

    DEFF Research Database (Denmark)

    Burattin, Andrea; Carmona, Josep

    2017-01-01

    is quantified after the completion of the process instance. In this paper we propose a framework for online conformance checking: not only do we quantify (non-)conformant behavior as the execution is running, we also restrict the computation to constant time complexity per event analyzed, thus enabling...... the online analysis of a stream of events. The framework is instantiated with ideas coming from the theory of regions, and state similarity. An implementation is available in ProM and promising results have been obtained....

  3. Studing the Influence of Six Main Industrial Losses on Overall Equipment Effectiveness in Cold Rolling Unit of Mobarakeh Steel Complex

    Directory of Open Access Journals (Sweden)

    seyed Akbar Nilipour Tabatabaei

    2011-03-01

    Full Text Available Overall Equipment Effectiveness (OEE is a key indicator and a basis for evaluating the effectiveness of equipments as well as assessing the effectiveness of the Total Productive Maintenance (TPM system. This indicator together with overall equipment performance can be used in production lines such as steel production. The aim of this article is to study the influence of six main industrial losses on the OEE indicator . For this purpose, the OEE has been calculated in the cold rolling production lines of Mobarakeh Steel Complex the gap between production lines and the global industrial standards has been studied the causes of production system inefficiency has been investigated and the effectiveness of TPM system, equipments' bottlenecks and the influence of the main industry losses on OEE have been studied. The findings imply that the influence of the variation of availability and performance rates on OEE is high, while the influence of the variation of quality rate on OEE is not considerable.

  4. Influence of Vegetations' Metabolites on the Composition and Functioning of Soil Microbial Complex

    Science.gov (United States)

    Biryukov, Mikhail

    2013-04-01

    Microbiota is one of the major factors of soils fertility. It transforms organic substances in soil and, therefore, serves as the main component in the cycles of carbon and nitrogen. Microbial communities (MC) are characterized as highly diverse and extremely complex structures. This allows them to adapt to any affection and provide all the necessary biospheric functions. Hence, the study of their functional diversity and adaptivity of microbiota provides the key to the understanding of the ecosystems' functioning and their adaptivity to the human impact. The formation of MC at the initial stage is regulated by the fluxes of substrates and biologically active substances (BAS), which vary greatly in soils under different vegetations. These fluxes are presented by: low molecular weights organic substances (LMWOS), which can be directly included in metabolism of microbes; polymers, that can be decomposed to LMWOS by exoenzymes; and more complex compounds, having different "drug effects" (e.g. different types of phenolic acids) and regulating growth and enzymatic properties of microbiota. Therefore, the main hypothesis of the research was formulated as follows: penetration of different types of substrates and BAS into soil leads to the emergence of MC varying in enzymatic properties and structure. As a soil matrix we used the soil from the untreated variant of the lysimeter model experiment taking place in the faculty of Soil Science of the MSU for over the last 40 years. It was sieved with a 2mm sieves, humidified and incubated at 25C during one week. Subsequently, the samples were air-dried with occasional stirring for one more week. Thereafter, aliquots of the prepared soil were taken for the different experimental variants. The samples were rewetted with solutions of various substrates (glucose, cellulose, starch, etc.) and thoroughly mixed. The control variant was established with addition of deionised water. The samples were incubated at the 25C. During the

  5. The Biological Bases of Conformity

    Science.gov (United States)

    Morgan, T. J. H.; Laland, K. N.

    2012-01-01

    Humans are characterized by an extreme dependence on culturally transmitted information and recent formal theory predicts that natural selection should favor adaptive learning strategies that facilitate effective copying and decision making. One strategy that has attracted particular attention is conformist transmission, defined as the disproportionately likely adoption of the most common variant. Conformity has historically been emphasized as significant in the social psychology literature, and recently there have also been reports of conformist behavior in non-human animals. However, mathematical analyses differ in how important and widespread they expect conformity to be, and relevant experimental work is scarce, and generates findings that are both mutually contradictory and inconsistent with the predictions of the models. We review the relevant literature considering the causation, function, history, and ontogeny of conformity, and describe a computer-based experiment on human subjects that we carried out in order to resolve ambiguities. We found that only when many demonstrators were available and subjects were uncertain was subject behavior conformist. A further analysis found that the underlying response to social information alone was generally conformist. Thus, our data are consistent with a conformist use of social information, but as subjects’ behavior is the result of both social and asocial influences, the resultant behavior may not be conformist. We end by relating these findings to an embryonic cognitive neuroscience literature that has recently begun to explore the neural bases of social learning. Here conformist transmission may be a particularly useful case study, not only because there are well-defined and tractable opportunities to characterize the biological underpinnings of this form of social learning, but also because early findings imply that humans may possess specific cognitive adaptations for effective social learning. PMID:22712006

  6. The Biological Bases of Conformity

    Directory of Open Access Journals (Sweden)

    Thomas Joshau Henry Morgan

    2012-06-01

    Full Text Available Humans are characterized by an extreme dependence on culturally transmitted information and recent formal theory predicts that natural selection should favour adaptive learning strategies that facilitate effective use of social information in decision making. One strategy that has attracted particular attention is conformist transmission, defined as the disproportionately likely adoption of the most common variant. Conformity has historically been emphasized as significant in the social psychology literature, and recently there have also been reports of conformist behaviour in nonhuman animals. However, mathematical analyses differ in how important and widespread they expect conformity to be, and relevant experimental work is scarce, and generates findings that are both mutually contradictory and inconsistent with the predictions of the models. We review the relevant literature considering the causation, function, history and ontogeny of conformity and describe a computer-based experiment on human subjects that we carried out in order to resolve ambiguities. We found that only when many demonstrators were available and subjects were uncertain was subject behaviour conformist. A further analysis found that the underlying response to social information alone was generally conformist. Thus, our data are consistent with a conformist use of social information, but as subject’s behaviour is the result of both social and asocial influences, the resultant behaviour may not be conformist. We end by relating these findings to an embryonic cognitive neuroscience literature that has recently begun to explore the neural bases of social learning. Here conformist transmission may be a particularly useful case study, not only because there are well-defined and tractable opportunities to characterize the biological underpinnings of this form of social learning, but also because early findings imply that humans may possess specific cognitive adaptations for

  7. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Akihisa, E-mail: ayamamoto@icems.kyoto-u.ac.jp, E-mail: tanaka@uni-heidelberg.de; Tanaka, Motomu, E-mail: ayamamoto@icems.kyoto-u.ac.jp, E-mail: tanaka@uni-heidelberg.de [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501 (Japan); Abuillan, Wasim; Körner, Alexander [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Burk, Alexandra S. [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Ries, Annika [Institute of Organic and Biomolecular Chemistry, University of Göttingen, 37077 Göttingen (Germany); Werz, Daniel B. [Institute of Organic Chemistry, Technische Universität Braunschweig, 38106 Braunschweig (Germany); Demé, Bruno [Institut Laue-Langevin, 38042 Grenoble Cedex 9, Grenoble (France)

    2015-04-21

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier “bent” Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter “bent” disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3.

  8. Massive Conformal Gravity

    International Nuclear Information System (INIS)

    Faria, F. F.

    2014-01-01

    We construct a massive theory of gravity that is invariant under conformal transformations. The massive action of the theory depends on the metric tensor and a scalar field, which are considered the only field variables. We find the vacuum field equations of the theory and analyze its weak-field approximation and Newtonian limit.

  9. Taming the conformal zoo

    International Nuclear Information System (INIS)

    Moore, G.; Seiberg, N.

    1989-01-01

    All known rational conformal field theories may be obtained from (2+1)-dimensional Chern-Simons gauge theories by appropriate choice of gauge group. We conjecture that all rational field theories are classified by groups via (2+1)-dimensional Chern-Simons gauge theories. (orig.)

  10. Conformal special relativity

    International Nuclear Information System (INIS)

    Maia, M.D.

    2006-01-01

    It is shown that the information loss/recovery theorem based on the ADS/CFT correspondence is not consistent with the stability of the Schwarzschild or Reissner-Nordstrom black holes. Nonetheless, the conformal invariance of Yang-Mills theory points to new relativity principle compatible with quantum unitarity near those black holes

  11. Animal culture: chimpanzee conformity?

    Science.gov (United States)

    van Schaik, Carel P

    2012-05-22

    Culture-like phenomena in wild animals have received much attention, but how good is the evidence and how similar are they to human culture? New data on chimpanzees suggest their culture may even have an element of conformity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Parafermionic conformal field theory

    International Nuclear Information System (INIS)

    Kurak, V.

    1989-09-01

    Conformal parafermionic field theories are reviewed with emphasis on the computation of their OPE estructure constants. It is presented a simple computational of these for the Z(N) parafermions, unveilling their Lie algebra content. (A.C.A.S.) [pt

  13. Quantifying polypeptide conformational space: sensitivity to conformation and ensemble definition.

    Science.gov (United States)

    Sullivan, David C; Lim, Carmay

    2006-08-24

    Quantifying the density of conformations over phase space (the conformational distribution) is needed to model important macromolecular processes such as protein folding. In this work, we quantify the conformational distribution for a simple polypeptide (N-mer polyalanine) using the cumulative distribution function (CDF), which gives the probability that two randomly selected conformations are separated by less than a "conformational" distance and whose inverse gives conformation counts as a function of conformational radius. An important finding is that the conformation counts obtained by the CDF inverse depend critically on the assignment of a conformation's distance span and the ensemble (e.g., unfolded state model): varying ensemble and conformation definition (1 --> 2 A) varies the CDF-based conformation counts for Ala(50) from 10(11) to 10(69). In particular, relatively short molecular dynamics (MD) relaxation of Ala(50)'s random-walk ensemble reduces the number of conformers from 10(55) to 10(14) (using a 1 A root-mean-square-deviation radius conformation definition) pointing to potential disconnections in comparing the results from simplified models of unfolded proteins with those from all-atom MD simulations. Explicit waters are found to roughen the landscape considerably. Under some common conformation definitions, the results herein provide (i) an upper limit to the number of accessible conformations that compose unfolded states of proteins, (ii) the optimal clustering radius/conformation radius for counting conformations for a given energy and solvent model, (iii) a means of comparing various studies, and (iv) an assessment of the applicability of random search in protein folding.

  14. Spatial Patterns in Herbivory on a Coral Reef Are Influenced by Structural Complexity but Not by Algal Traits

    Science.gov (United States)

    Vergés, Adriana; Vanderklift, Mathew A.; Doropoulos, Christopher; Hyndes, Glenn A.

    2011-01-01

    Background Patterns of herbivory can alter the spatial structure of ecosystems, with important consequences for ecosystem functions and biodiversity. While the factors that drive spatial patterns in herbivory in terrestrial systems are well established, comparatively less is known about what influences the distribution of herbivory in coral reefs. Methodology and Principal Findings We quantified spatial patterns of macroalgal consumption in a cross-section of Ningaloo Reef (Western Australia). We used a combination of descriptive and experimental approaches to assess the influence of multiple macroalgal traits and structural complexity in establishing the observed spatial patterns in macroalgal herbivory, and to identify potential feedback mechanisms between herbivory and macroalgal nutritional quality. Spatial patterns in macroalgal consumption were best explained by differences in structural complexity among habitats. The biomass of herbivorous fish, and rates of herbivory were always greater in the structurally-complex coral-dominated outer reef and reef flat habitats, which were also characterised by high biomass of herbivorous fish, low cover and biomass of macroalgae and the presence of unpalatable algae species. Macroalgal consumption decreased to undetectable levels within 75 m of structurally-complex reef habitat, and algae were most abundant in the structurally-simple lagoon habitats, which were also characterised by the presence of the most palatable algae species. In contrast to terrestrial ecosystems, herbivory patterns were not influenced by the distribution, productivity or nutritional quality of resources (macroalgae), and we found no evidence of a positive feedback between macroalgal consumption and the nitrogen content of algae. Significance This study highlights the importance of seascape-scale patterns in structural complexity in determining spatial patterns of macroalgal consumption by fish. Given the importance of herbivory in maintaining the

  15. Spatial patterns in herbivory on a coral reef are influenced by structural complexity but not by algal traits.

    Directory of Open Access Journals (Sweden)

    Adriana Vergés

    2011-02-01

    Full Text Available Patterns of herbivory can alter the spatial structure of ecosystems, with important consequences for ecosystem functions and biodiversity. While the factors that drive spatial patterns in herbivory in terrestrial systems are well established, comparatively less is known about what influences the distribution of herbivory in coral reefs.We quantified spatial patterns of macroalgal consumption in a cross-section of Ningaloo Reef (Western Australia. We used a combination of descriptive and experimental approaches to assess the influence of multiple macroalgal traits and structural complexity in establishing the observed spatial patterns in macroalgal herbivory, and to identify potential feedback mechanisms between herbivory and macroalgal nutritional quality. Spatial patterns in macroalgal consumption were best explained by differences in structural complexity among habitats. The biomass of herbivorous fish, and rates of herbivory were always greater in the structurally-complex coral-dominated outer reef and reef flat habitats, which were also characterised by high biomass of herbivorous fish, low cover and biomass of macroalgae and the presence of unpalatable algae species. Macroalgal consumption decreased to undetectable levels within 75 m of structurally-complex reef habitat, and algae were most abundant in the structurally-simple lagoon habitats, which were also characterised by the presence of the most palatable algae species. In contrast to terrestrial ecosystems, herbivory patterns were not influenced by the distribution, productivity or nutritional quality of resources (macroalgae, and we found no evidence of a positive feedback between macroalgal consumption and the nitrogen content of algae.This study highlights the importance of seascape-scale patterns in structural complexity in determining spatial patterns of macroalgal consumption by fish. Given the importance of herbivory in maintaining the ability of coral reefs to reorganise and

  16. Scene complexity: influence on perception, memory, and development in the medial temporal lobe

    Directory of Open Access Journals (Sweden)

    Xiaoqian J Chai

    2010-03-01

    Full Text Available Regions in the medial temporal lobe (MTL and prefrontal cortex (PFC are involved in memory formation for scenes in both children and adults. The development in children and adolescents of successful memory encoding for scenes has been associated with increased activation in PFC, but not MTL, regions. However, evidence suggests that a functional subregion of the MTL that supports scene perception, located in the parahippocampal gyrus (PHG, goes through a prolonged maturation process. Here we tested the hypothesis that maturation of scene perception supports the development of memory for complex scenes. Scenes were characterized by their levels of complexity defined by the number of unique object categories depicted in the scene. Recognition memory improved with age, in participants ages 8-24, for high, but not low, complexity scenes. High-complexity compared to low-complexity scenes activated a network of regions including the posterior PHG. The difference in activations for high- versus low- complexity scenes increased with age in the right posterior PHG. Finally, activations in right posterior PHG were associated with age-related increases in successful memory formation for high-, but not low-, complexity scenes. These results suggest that functional maturation of the right posterior PHG plays a critical role in the development of enduring long-term recollection for high-complexity scenes.

  17. Influence of lysozyme complexation with purified Aldrich humic acid on lysozyme activity

    NARCIS (Netherlands)

    Li, Y.; Tan, W.F.; Wang, M.X.; Liu, F.; Weng, L.P.; Norde, W.; Koopal, L.K.

    2012-01-01

    Humic acid is an important component of dissolved organic matter and in two previous papers it has been shown that purified Aldrich humic acid (PAHA) forms strong complexes with the oppositely charged protein lysozyme (LSZ). The complexation and aggregation of enzymes with humic acids may lead to

  18. Generative Models of Conformational Dynamics

    Science.gov (United States)

    Langmead, Christopher James

    2014-01-01

    Atomistic simulations of the conformational dynamics of proteins can be performed using either Molecular Dynamics or Monte Carlo procedures. The ensembles of three-dimensional structures produced during simulation can be analyzed in a number of ways to elucidate the thermodynamic and kinetic properties of the system. The goal of this chapter is to review both traditional and emerging methods for learning generative models from atomistic simulation data. Here, the term ‘generative’ refers to a model of the joint probability distribution over the behaviors of the constituent atoms. In the context of molecular modeling, generative models reveal the correlation structure between the atoms, and may be used to predict how the system will respond to structural perturbations. We begin by discussing traditional methods, which produce multivariate Gaussian models. We then discuss GAMELAN (GrAphical Models of Energy LANdscapes), which produces generative models of complex, non-Gaussian conformational dynamics (e.g., allostery, binding, folding, etc) from long timescale simulation data. PMID:24446358

  19. On bidimensional Lagrangian conformal models

    International Nuclear Information System (INIS)

    Lazzarini, S.

    1990-04-01

    The main topic of this thesis is the study of Conformal Field Theories defined on an arbitrary compact Riemann surface without boundary. The Beltrami parametrization of complexe structures endowing such a surface provides a local bidimensional diffeomorphism invariance of the theory and the holomorphic factorization. The perturbative quantization a la Feynman is then constrained by local factorized Ward identities. The renormalization is analysed in the Esptein-Glaser scheme. A first part deals with the simplest free field models where one checks the interesting conjecture that renormalized perturbative expansions could be resumed by a Polyakov's formula which is a Wess-Zumino action for the diffeomorphism anomaly. For a higher genus surface, only a differential version is proposed. The second part of this thesis is devoted to the characterization of some observables of the free bosonic string in the corresponding gauge theory with the aid of the nilpotent Slavnov s-operator. It is conjectured that part of the observables of this theory is labelled by the local cohomology of s modulo d and corresponds to the vertex operators, as it is verified for the tachyon vertex in the conformal gauge [fr

  20. Influence of coral cover and structural complexity on the accuracy of visual surveys of coral-reef fish communities

    KAUST Repository

    Coker, Darren James

    2017-04-20

    Using manipulated patch reefs with combinations of varying live-coral cover (low, medium and high) and structural complexity (low and high), common community metrics (abundance, diversity, richness and community composition) collected through standard underwater visual census techniques were compared with exhaustive collections using a fish anaesthetic (clove oil). This study showed that reef condition did not influence underwater visual census estimates at a community level, but reef condition can influence the detectability of some small and cryptic species and this may be exacerbated if surveys are conducted on a larger scale.

  1. Influence of coral cover and structural complexity on the accuracy of visual surveys of coral-reef fish communities

    KAUST Repository

    Coker, Darren James; Nowicki, J. P.; Graham, N. A. J.

    2017-01-01

    Using manipulated patch reefs with combinations of varying live-coral cover (low, medium and high) and structural complexity (low and high), common community metrics (abundance, diversity, richness and community composition) collected through standard underwater visual census techniques were compared with exhaustive collections using a fish anaesthetic (clove oil). This study showed that reef condition did not influence underwater visual census estimates at a community level, but reef condition can influence the detectability of some small and cryptic species and this may be exacerbated if surveys are conducted on a larger scale.

  2. Comparison of Structurally–Related Alkoxide, Amine, and Thiolate–Ligated MII (M= Fe, Co) Complexes: the Influence of Thiolates on the Properties of Biologically Relevant Metal Complexes

    Science.gov (United States)

    Brines, Lisa M.; Villar-Acevedo, Gloria; Kitagawa, Terutaka; Swartz, Rodney D.; Lugo-Mas, Priscilla; Kaminsky, Werner; Benedict, Jason B.; Kovacs, Julie A.

    2009-01-01

    Mechanistic pathways of metalloenzymes are controlled by the metal ion’s electronic and magnetic properties, which are tuned by the coordinated ligands. The functional advantage gained by incorporating cysteinates into the active site of non-heme iron enzymes such as superoxide reductase (SOR) is not entirely understood. Herein we compare the structural and redox properties of a series of structurally–related thiolate, alkoxide, and amine–ligated Fe(II) complexes in order to determine how the thiolate influences properties critical to function. Thiolates are shown to reduce metal ion Lewis acidity relative to alkoxides and amines, and have a strong trans influence thereby helping to maintain an open coordination site. Comparison of the redox potentials of the structurally analogous compounds described herein indicates that alkoxide ligands favor the higher-valent Fe3+ oxidation state, amine ligands favor the reduced Fe2+ oxidation state, and thiolates fall somewhere in between. These properties provide a functional advantange for substrate reducing enzymes in that they provide a site at the metal ion for substrate to bind, and a moderate potential that facilitates both substrate reduction, and regeneration of the catalytically active reduced state. Redox potentials for structurally–related Co(II) complexes are shown to be cathodically–shifted relative to their Fe(II) analogues, making them ineffective reducing agents for substrates such as superoxide. PMID:21731109

  3. Pleiotropy constrains the evolution of protein but not regulatory sequences in a transcription regulatory network influencing complex social behaviours

    Directory of Open Access Journals (Sweden)

    Daria eMolodtsova

    2014-12-01

    Full Text Available It is increasingly apparent that genes and networks that influence complex behaviour are evolutionary conserved, which is paradoxical considering that behaviour is labile over evolutionary timescales. How does adaptive change in behaviour arise if behaviour is controlled by conserved, pleiotropic, and likely evolutionary constrained genes? Pleiotropy and connectedness are known to constrain the general rate of protein evolution, prompting some to suggest that the evolution of complex traits, including behaviour, is fuelled by regulatory sequence evolution. However, we seldom have data on the strength of selection on mutations in coding and regulatory sequences, and this hinders our ability to study how pleiotropy influences coding and regulatory sequence evolution. Here we use population genomics to estimate the strength of selection on coding and regulatory mutations for a transcriptional regulatory network that influences complex behaviour of honey bees. We found that replacement mutations in highly connected transcription factors and target genes experience significantly stronger negative selection relative to weakly connected transcription factors and targets. Adaptively evolving proteins were significantly more likely to reside at the periphery of the regulatory network, while proteins with signs of negative selection were near the core of the network. Interestingly, connectedness and network structure had minimal influence on the strength of selection on putative regulatory sequences for both transcription factors and their targets. Our study indicates that adaptive evolution of complex behaviour can arise because of positive selection on protein-coding mutations in peripheral genes, and on regulatory sequence mutations in both transcription factors and their targets throughout the network.

  4. CLINICAL, HISTOLOGICAL AND RADIOLOGICAL ASPECTS REGARDING THE INFLUENCE OF SOME EXTERNAL FACTORS ON THE PULP-DENTIN COMPLEX

    OpenAIRE

    C. Giuroiu; Maria Vataman; Liana Aminov; Mihaela Sălceanu; S. Andrian

    2012-01-01

    The present study aimed at assesssing – by clinical, histological and radiological investigations – the influence of some external factors on the pulp-dentin complex, and at providing a causal interpretation of the structural changes observed. Materials and methods. Clinical and radiological exams were performed on 65 old patients with ages between 60-75, and also on 40 young patients with ages between 20-35, presenting different dental-periodontal pathologies. The ...

  5. Seed conformal blocks in 4D CFT

    Energy Technology Data Exchange (ETDEWEB)

    Echeverri, Alejandro Castedo; Elkhidir, Emtinan; Karateev, Denis [SISSA and INFN,Via Bonomea 265, I-34136 Trieste (Italy); Serone, Marco [SISSA and INFN,Via Bonomea 265, I-34136 Trieste (Italy); ICTP,Strada Costiera 11, I-34151 Trieste (Italy)

    2016-02-29

    We compute in closed analytical form the minimal set of “seed' conformal blocks associated to the exchange of generic mixed symmetry spinor/tensor operators in an arbitrary representation (ℓ,ℓ̄) of the Lorentz group in four dimensional conformal field theories. These blocks arise from 4-point functions involving two scalars, one (0,|ℓ−ℓ̄|) and one (|ℓ−ℓ̄|,0) spinors or tensors. We directly solve the set of Casimir equations, that can elegantly be written in a compact form for any (ℓ,ℓ̄), by using an educated ansatz and reducing the problem to an algebraic linear system. Various details on the form of the ansatz have been deduced by using the so called shadow formalism. The complexity of the conformal blocks depends on the value of p=|ℓ−ℓ̄| and grows with p, in analogy to what happens to scalar conformal blocks in d even space-time dimensions as d increases. These results open the way to bootstrap 4-point functions involving arbitrary spinor/tensor operators in four dimensional conformal field theories.

  6. Preparation of three terbium complexes with p-aminobenzoic acid and investigation of crystal structure influence on luminescence property

    International Nuclear Information System (INIS)

    Ye Chaohong; Sun Haoling; Wang Xinyi; Li Junran; Nie Daobo; Fu Wenfu; Gao Song

    2004-01-01

    Three new rare earth p-aminobenzoic acid complexes, [Tb 2 L 6 (H 2 O) 2 ] n (1), [Tb 2 L 6 (H 2 O) 4 ].2H 2 O (2) and [Tb(phen) 2 L 2 (H 2 O) 2 ](phen)L·4H 2 O (3) (HL: p-aminobenzoic acid; phen: 1, 10-phenanthroline), with different structural forms are reported in this paper. Complex 1 is a polymolecule with a two-dimensional plane structure. Compound 2 is a binuclear molecule, and 3 appears to be a mononuclear complex. The fluorescence intensity, the fluorescence life-time and emission quantum yield of 2, which has two coordination water molecules, is better than those of 1, which has only one coordination water molecule. This is an unusual phenomenon for general fluorescent rare earth complexes. The fluorescence performance of 3 is the most unsatisfactory among the three complexes. Their crystal structures show that the coordination mode of the ligand is an important factor influencing the luminescence properties of a fluorescent rare earth complex

  7. Influence of complex particle emission on properties of giant dipole resonance of hot nuclei

    International Nuclear Information System (INIS)

    Wen Wanxin; Jin Genming

    2003-01-01

    The possible reasons for the discrepancy between calculation results based on the statistical evaporation model and experimental data of giant dipole resonance of very hot nuclei are discussed. Both of simulations with the standard CASCADE code and the code coupling complex particle emission are carried out. It is shown that the complex particle emission affects the properties of giant dipole resonance of very hot nuclei

  8. Logarithmic conformal field theory

    Science.gov (United States)

    Gainutdinov, Azat; Ridout, David; Runkel, Ingo

    2013-12-01

    Conformal field theory (CFT) has proven to be one of the richest and deepest subjects of modern theoretical and mathematical physics research, especially as regards statistical mechanics and string theory. It has also stimulated an enormous amount of activity in mathematics, shaping and building bridges between seemingly disparate fields through the study of vertex operator algebras, a (partial) axiomatisation of a chiral CFT. One can add to this that the successes of CFT, particularly when applied to statistical lattice models, have also served as an inspiration for mathematicians to develop entirely new fields: the Schramm-Loewner evolution and Smirnov's discrete complex analysis being notable examples. When the energy operator fails to be diagonalisable on the quantum state space, the CFT is said to be logarithmic. Consequently, a logarithmic CFT is one whose quantum space of states is constructed from a collection of representations which includes reducible but indecomposable ones. This qualifier arises because of the consequence that certain correlation functions will possess logarithmic singularities, something that contrasts with the familiar case of power law singularities. While such logarithmic singularities and reducible representations were noted by Rozansky and Saleur in their study of the U (1|1) Wess-Zumino-Witten model in 1992, the link between the non-diagonalisability of the energy operator and logarithmic singularities in correlators is usually ascribed to Gurarie's 1993 article (his paper also contains the first usage of the term 'logarithmic conformal field theory'). The class of CFTs that were under control at this time was quite small. In particular, an enormous amount of work from the statistical mechanics and string theory communities had produced a fairly detailed understanding of the (so-called) rational CFTs. However, physicists from both camps were well aware that applications from many diverse fields required significantly more

  9. Transportation Conformity Training and Presentations

    Science.gov (United States)

    EPA's OTAQ has provided multiple conformity training sessions in the past to assist state and local governments in implementing conformity requirements. As training information is prepared for other venues, it will be posted on this page.

  10. Hot Conformal Gauge Theories

    DEFF Research Database (Denmark)

    Mojaza, Matin; Pica, Claudio; Sannino, Francesco

    2010-01-01

    of flavors. Surprisingly this number, if computed to the order g^2, agrees with previous predictions for the lower boundary of the conformal window for nonsupersymmetric gauge theories. The higher order results tend to predict a higher number of critical flavors. These are universal properties, i......We compute the nonzero temperature free energy up to the order g^6 \\ln(1/g) in the coupling constant for vector like SU(N) gauge theories featuring matter transforming according to different representations of the underlying gauge group. The number of matter fields, i.e. flavors, is arranged...... in such a way that the theory develops a perturbative stable infrared fixed point at zero temperature. Due to large distance conformality we trade the coupling constant with its fixed point value and define a reduced free energy which depends only on the number of flavors, colors and matter representation. We...

  11. Conformational flexibility of aspartame.

    Science.gov (United States)

    Toniolo, Claudio; Temussi, Pierandrea

    2016-05-01

    L-Aspartyl-L-phenylalanine methyl ester, better known as aspartame, is not only one of the most used artificial sweeteners, but also a very interesting molecule with respect to the correlation between molecular structure and taste. The extreme conformational flexibility of this dipeptide posed a huge difficulty when researchers tried to use it as a lead compound to design new sweeteners. In particular, it was difficult to take advantage of its molecular model as a mold to infer the shape of the, then unknown, active site of the sweet taste receptor. Here, we follow the story of the 3D structural aspects of aspartame from early conformational studies to recent docking into homology models of the receptor. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 376-384, 2016. © 2016 Wiley Periodicals, Inc.

  12. Conformal description of spinning particles

    International Nuclear Information System (INIS)

    Todorov, I.T.

    1986-01-01

    This book is an introduction to the application of the conformal group to quantum field theory of particles with spin. After an introduction to the twistor representations of the conformal group of a conformally flat space-time and twistor flag manifolds with Su(2,2) orbits the classical phase space of conformal spinning particles is described. Thereafter the twistor description of classical zero mass fields is considered together with the quantization. (HSI)

  13. Conformal boundaries of warped products

    DEFF Research Database (Denmark)

    Kokkendorff, Simon Lyngby

    2006-01-01

    In this note we prove a result on how to determine the conformal boundary of a type of warped product of two length spaces in terms of the individual conformal boundaries. In the situation, that we treat, the warping and conformal distortion functions are functions of distance to a base point....... The result is applied to produce examples of CAT(0)-spaces, where the conformal and ideal boundaries differ in interesting ways....

  14. Conformal radiotherapy: a glossary

    International Nuclear Information System (INIS)

    Dubray, B.; Giraud, P.; Beaudre, A.

    1999-01-01

    Most of the concepts and terms related to conformal radiotherapy were produced by English-speaking authors and eventually validated by international groups of experts, whose working language was also English. Therefore, a significant part of this literature is poorly accessible to the French-speaking radiation oncology community. The present paper gathers the 'official' definitions already published in French, along with propositions for the remaining terms which should be submitted to a more formal and representative validation process. (author)

  15. [Influence of the earthworm Lumbricus terrestris on soil solution complexation capacity].

    Science.gov (United States)

    el Gharmali, A; Rada, A; el Meray, M; Nejmeddine, A

    2001-04-01

    Four soil samples highly contaminated with metals of urban and mine origin (SE1, SE2, SM1, SM2) and having different physico-chemical proprieties were selected to study copper complexation capacity (LT) of soil solution. The effect of Lumbricus terrestris on copper complexation capacity of soil solution was investigated on SE1 and SE2. The complexation capacity was estimated by amperometric titration of soil solution by copper. Free hydrated cation and labile complexes of copper were determined by DPASV. The results show that the copper complexation capacity variation depends on the physico-chemical characteristics of soils, particularly pH. Thus, the values of copper complexation capacity are 0; 0.6 x 10(-7); 1.8 x 10(-7) and 5.5 x 10(-7) mol l-1 respectively for SM2; SM1; SE1 and SE2 which are pH 5; 5.4; 6.5 and 7.4. Based on these results, the bioavailability levels of heavy metals show the following pool ranking: SM2 > SM1 > SE1 > SE2. The copper complexation capacity of soil solution increases with the soil disturbance by Lumbricus terrestris. This is more obvious when the time of disturbance by lumbrics is longer. Indeed, average values determined for 1 month and 3 months are 3.8 x 10(-7) and 7.8 x 10(-7) mol l-1 for SE1; 7.7 x 10(-7) and 15.2 x 10(-7) mol l-1 for SE2 respectively. It seems that the action of earthworm on soil can contribute to the decrease of bioavailability of heavy metals, particularly copper.

  16. Conformational analysis investigation into the influence of nano-porosity of ultra-permeable ultra-selective polyimides on its diffusivity as potential membranes for use in the ''green'' separation of natural gases

    International Nuclear Information System (INIS)

    Madkour, Tarek M

    2013-01-01

    Nano-porous polymers of intrinsic microporosity, PIM, have exhibited excellent permeability and selectivity characteristics that could be utilized in an environmentally friendly gas separation process. A full understanding of the mechanism through which these membranes effectively and selectively allow for the permeation of specific gases will lead to further development of these membranes. Three factors obviously influenced the conformational behavior of these polymers, which are the presence of electronegative atoms, the presence of non-linearity in the polymeric backbones (backbone kinks) and the presence of bulky side groups on the polymeric chains. The dipole moment increased sharply with the presence of backbone kinks more than any other factor. Replacing the fluorine atoms with bulky alkyl groups didn't influence the dipole moment greatly indicating that the size of the side chains had much less dramatic influence on the dipole moment than having a bent backbone. Similarly, the presence of the backbone kinks in the polymeric chains influenced the polymeric chains to assume less extended configuration causing the torsional angles around the interconnecting bonds unable to cross the high potential energy barriers. The presence of the bulky side groups also caused the energy barriers of the cis-configurations to increase dramatically, which prevented the polymeric segments from experiencing full rotation about the connecting bonds. For these polymers, it was clear that the fully extended configurations are the preferred configurations in the absence of strong electronegative atoms, backbones kinks or bulky side groups. The addition of any of these factors to the polymeric structures resulted in the polymeric chains being forced to assume less extended configurations. Rather interestingly, the length or bulkiness of the side groups didn't affect the end-to-end distance distribution to a great deal since the presence of quite large bulky side chain such as the

  17. The Influence of Fluorination on Structure of the Trifluoroacetonitrile Water Complex

    Science.gov (United States)

    Lin, Wei; Wu, Anan; Lu, Xin; Obenchain, Daniel A.; Novick, Stewart E.

    2015-06-01

    Acetonitrile, CH_3CN, and trifluoroacetonitrile, CF_3CN, are symmetric tops. In a recent study of the rotational spectrum of the acetonitrile and water complex, it was observed that the structure was also an effective symmetric top, with the external hydrogen freely rotating about the O-H bond aligned towards the nitrogen of the cyanide of CH_3CN. Unlike the CH_3CN-H_2O complex, the CH_3CN-Ar and CF_3CN-Ar complexes were observed to be asymmetric tops. Having a series of symmetric and asymmetric top complexes of acetonitrile and trifluoracetonitrile for comparison, we report the rotational spectrum of the weakly bound complex between trifluoroacetonitrile and water. Rotational constants and quadrupole coupling constants will be presented, and the structure of CF_3CN-H_2O will be revealed. Lovas, F.J.; Sobhanadri, J. Microwave rotational spectral study of CH_3CN-H_2O and Ar-CH_3CN. J. Mol. Spetrosc. 2015, 307, 59-64. SPOILER ALERT: It's an asymmetric top.

  18. Structural influence in the interaction of cysteine with five coordinated copper complexes: Theoretical and experimental studies

    Science.gov (United States)

    Huerta-Aguilar, Carlos Alberto; Thangarasu, Pandiyan; Mora, Jesús Gracia

    2018-04-01

    Copper complexes of N,N,N‧,N‧-tetrakis(pyridyl-2-ylmethyl)-1,2-diaminoethane (L1) and N,N,N‧,N‧-tetrakis(pyridyl-2-ylmethyl)-1,3-diaminopropane (L2) prepared were characterized completely by different analytical methods. The X-structure of the complexes shows that Cu(II) presents in trigonal bi-pyramidal (TBP) geometry, consisting with the electronic spectra where two visible bands corresponding to five coordinated structure were observed. Thus TD-DFT was used to analyze the orbital contribution to the electronic transitions for the visible bands. Furthermore, the interaction of cysteine with the complexes was spectrally studied, and the results were explained through DFT analysis, observing that the geometrical parameters and oxidation state of metal ions play a vital role in the binding of cysteine with copper ion. It appears that the TBP structure is being changed into octahedral geometry during the addition of cysteine to the complexes as two bands (from complex) is turned to a broad band in visible region, signifying the occupation of cysteine molecule at sixth position of octahedral geometry. In the molecular orbital analysis, the existence of a strong overlapping of HOMOs (from cysteine) with LUMOs of Cu ion was observed. The total energy of the systems calculated by DFT shows that cysteine binds favorably with copper (I) than that with Cu(II).

  19. Complexes of natural carbohydrates with metal cations

    International Nuclear Information System (INIS)

    Alekseev, Yurii E; Garnovskii, Alexander D; Zhdanov, Yu A

    1998-01-01

    Data on the interaction of natural carbohydrates (mono-, oligo-, and poly-saccharides, amino sugars, and natural organic acids of carbohydrate origin) with metal cations are surveyed and described systematically. The structural diversity of carbohydrate metal complexes, caused by some specific features of carbohydrates as ligands, is demonstrated. The influence of complex formation on the chemical properties of carbohydrates is discussed. It is shown that the formation of metal complexes plays an important role in the configurational and conformational analysis of carbohydrates. The practical significance of the coordination interaction in the series of carbohydrate ligands is demonstrated. The bibliography includes 571 references.

  20. Studies on the complexation of diclofenac sodium with β-cyclodextrin: Influence of method of preparation

    Science.gov (United States)

    Das, Subhraseema; Subuddhi, Usharani

    2015-11-01

    Inclusion complexes of diclofenac sodium (DS) with β-cyclodextrin (β-CD) were prepared in order to improve the solubility, dissolution and oral bioavailability of the poorly water soluble drug. The effect of method of preparation of the DS/β-CD inclusion complexes (ICs) was investigated. The ICs were prepared by microwave irradiation and also by the conventional methods of kneading, co-precipitation and freeze drying. Though freeze drying method is usually referred to as the gold standard among all the conventional methods, its long processing time limits the utility. Microwave irradiation accomplishes the process in a very short span of time and is a more environmentally benign method. Better efficacy of the microwaved inclusion product (MW) was observed in terms of dissolution, antimicrobial activity and antibiofilm properties of the drug. Thus microwave irradiation can be utilized as an improved, time-saving and cost-effective method for the generation of DS/β-CD inclusion complexes.

  1. Ligand Influences on Properties of Uranium Coordination Complexes - Structure, Reactivity, and Spectroscopy

    OpenAIRE

    Kosog, Boris

    2012-01-01

    In this thesis several different aspects of uranium chemistry are presented. It was shown that terminal uranium(V) oxo and imido complexes [((RArO)3tacn)UV(O)] and [((RArO)3tacn)UV(NSiMe3)] (R = t Bu, Ad) can be oxidized by silver(I) hexafluoro-antimonate to the uranium(VI) oxo and imido complexes [((RArO)3tacn)UVI(O)]SbF6 and [((RArO)3tacn)UVI(NSiMe3)]SbF6. While for the t Bu-derivative of the oxo complex an equatorial coordination is observed due to stabilization by the inverse trans-influe...

  2. Influence of complexes of iron on genetic changes at gamma-irradiated wheat

    International Nuclear Information System (INIS)

    Shamilov, E. N.; Rzayev, A.A.; Huseynova, Z.H; Mamedli, S.A; Azizov, I.V.

    2006-01-01

    Full text: At the result of research action of salts of some metals on living organisms their preventive and therapeutic action is revealed. It was revealed, that metals in structure of organic complex connections are less toxic, than as inorganic salts. Presence of organic ligand gives metallic-complexes lipophilically, will neutralize electrostatistical charges of metals therefore their transport through cellular membranes is strongly facilitated. In this connection rather expedient study of radioprotector properties of trivalent metals and their complexes is represented. Use of iron as a radioprotector is caused with its ability to steady complexing biogenic character. As objects of researches are taken seeds drought-resistant firm of wheat Triticum L. Seeds subjected to the general uniform scale of irradiation-from a source 60 Co and gamma to installation R khund a t average capacity of a doze of radiation dose rate (D R=0,024 Gy/s). Before the irradiation seeds have been processed pyrocatechol, iron pyrocatechol, thiocarbamide, iron-thiocarbamide, rutin and iron rutin at concentration 10 2 M. For synthesis of complexes used chloride of iron (III), thiocarbamide, pyrocatechol marks a .p.a. . Routines (3- ramnoglycoside-3,5,7,3,4-penta-oksi-flavone, chartreuse fine-grained a powder) have received from (Sophora japonica L.): Synthesis complexes of iron carried out by the following technique: stoichiometric quantity of thiocarbamide, pyrocatechol and routine dissolved separately in 50 ml isopropyl alcohol. A solution of chloride of iron (III) deposits dropped out, separated, dried up to constant weight was added to the received solutions in the portions at hashing.

  3. Does reef architectural complexity influence resource availability for a large reef-dwelling invertebrate?

    Science.gov (United States)

    Lozano-Álvarez, Enrique; Luviano-Aparicio, Nelia; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia; Aguíñiga-García, Sergio; Morillo-Velarde, Piedad S.; Álvarez-Filip, Lorenzo; Briones-Fourzán, Patricia

    2017-10-01

    In coral reefs, loss of architectural complexity and its associated habitat degradation is expected to affect reef specialists in particular due to changes in resource availability. We explored whether these features could potentially affect populations of a large invertebrate, the spotted spiny lobster Panulirus guttatus, which is an obligate Caribbean coral reef-dweller with a limited home range. We selected two separate large coral reef patches in Puerto Morelos (Mexico) that differed significantly in structural complexity and level of degradation, as assessed via the rugosity index, habitat assessment score, and percent cover of various benthic components. On each reef, we estimated density of P. guttatus and sampled lobsters to analyze their stomach contents, three different condition indices, and stable isotopes (δ15N and δ13C) in muscle. Lobster density did not vary with reef, suggesting that available crevices in the less complex patch still provided adequate refuge to these lobsters. Lobsters consumed many food types, dominated by mollusks and crustaceans, but proportionally more crustaceans (herbivore crabs) in the less complex patch, which had more calcareous macroalgae and algal turf. Lobsters from both reefs had a similar condition (all three indices) and mean δ15N, suggesting a similar quality of diet between reefs related to their opportunistic feeding, but differed in mean δ13C values, reflecting the different carbon sources between reefs and providing indirect evidence of individuals of P. guttatus foraging exclusively over their home reef. Overall, we found no apparent effects of architectural complexity, at least to the degree observed in our less complex patch, on density, condition, or trophic level of P. guttatus.

  4. Conformation-independent structural comparison of macromolecules with ProSMART

    International Nuclear Information System (INIS)

    Nicholls, Robert A.; Fischer, Marcus; McNicholas, Stuart; Murshudov, Garib N.

    2014-01-01

    The Procrustes Structural Matching Alignment and Restraints Tool (ProSMART) has been developed to allow local comparative structural analyses independent of the global conformations and sequence homology of the compared macromolecules. This allows quick and intuitive visualization of the conservation of backbone and side-chain conformations, providing complementary information to existing methods. The identification and exploration of (dis)similarities between macromolecular structures can help to gain biological insight, for instance when visualizing or quantifying the response of a protein to ligand binding. Obtaining a residue alignment between compared structures is often a prerequisite for such comparative analysis. If the conformational change of the protein is dramatic, conventional alignment methods may struggle to provide an intuitive solution for straightforward analysis. To make such analyses more accessible, the Procrustes Structural Matching Alignment and Restraints Tool (ProSMART) has been developed, which achieves a conformation-independent structural alignment, as well as providing such additional functionalities as the generation of restraints for use in the refinement of macromolecular models. Sensible comparison of protein (or DNA/RNA) structures in the presence of conformational changes is achieved by enforcing neither chain nor domain rigidity. The visualization of results is facilitated by popular molecular-graphics software such as CCP4mg and PyMOL, providing intuitive feedback regarding structural conservation and subtle dissimilarities between close homologues that can otherwise be hard to identify. Automatically generated colour schemes corresponding to various residue-based scores are provided, which allow the assessment of the conservation of backbone and side-chain conformations relative to the local coordinate frame. Structural comparison tools such as ProSMART can help to break the complexity that accompanies the constantly growing

  5. Conformation-independent structural comparison of macromolecules with ProSMART

    Energy Technology Data Exchange (ETDEWEB)

    Nicholls, Robert A., E-mail: nicholls@mrc-lmb.cam.ac.uk [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH (United Kingdom); Fischer, Marcus [University of California San Francisco, San Francisco, CA 94158 (United States); McNicholas, Stuart [University of York, Heslington, York YO10 5DD (United Kingdom); Murshudov, Garib N. [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH (United Kingdom)

    2014-09-01

    The Procrustes Structural Matching Alignment and Restraints Tool (ProSMART) has been developed to allow local comparative structural analyses independent of the global conformations and sequence homology of the compared macromolecules. This allows quick and intuitive visualization of the conservation of backbone and side-chain conformations, providing complementary information to existing methods. The identification and exploration of (dis)similarities between macromolecular structures can help to gain biological insight, for instance when visualizing or quantifying the response of a protein to ligand binding. Obtaining a residue alignment between compared structures is often a prerequisite for such comparative analysis. If the conformational change of the protein is dramatic, conventional alignment methods may struggle to provide an intuitive solution for straightforward analysis. To make such analyses more accessible, the Procrustes Structural Matching Alignment and Restraints Tool (ProSMART) has been developed, which achieves a conformation-independent structural alignment, as well as providing such additional functionalities as the generation of restraints for use in the refinement of macromolecular models. Sensible comparison of protein (or DNA/RNA) structures in the presence of conformational changes is achieved by enforcing neither chain nor domain rigidity. The visualization of results is facilitated by popular molecular-graphics software such as CCP4mg and PyMOL, providing intuitive feedback regarding structural conservation and subtle dissimilarities between close homologues that can otherwise be hard to identify. Automatically generated colour schemes corresponding to various residue-based scores are provided, which allow the assessment of the conservation of backbone and side-chain conformations relative to the local coordinate frame. Structural comparison tools such as ProSMART can help to break the complexity that accompanies the constantly growing

  6. Toluidine blue-sodium lauryl ether sulfate complexes : Influence of ethylene oxide length

    NARCIS (Netherlands)

    Vleugels, L.F.W.; Féat, A.; Voets, I.K.; Tuinier, R.

    2017-01-01

    Sodium Lauryl Ether Sulfates (SLES) are an increasingly important and versatile type of surfactants. The complexation between ortho-Toluidine blue (TBO) and a homologous series of SLES, including Sodium Lauryl Sulfate (SDS) without Ethylene Oxide (EO), has been investigated using visible

  7. Polycation–sodium lauryl ether sulfate-type surfactant complexes : influence of ethylene oxide length

    NARCIS (Netherlands)

    Vleugels, L.F.W.; Pollet, J.; Tuinier, R.

    2015-01-01

    Polyelectrolyte-surfactant complexes (PESC) are a class of materials which form spontaneously by self-assembly driven by electrostatic and hydrophobic interactions. PESC containing sodium lauryl ether sulfates (SLES) have found wide application in hair care products like shampoo. Typically, SLES

  8. Polycation-Sodium Lauryl Ether Sulfate-Type Surfactant Complexes : Influence of Ethylene Oxide Length

    NARCIS (Netherlands)

    Vleugels, Leo F. W.; Pollet, Jennifer; Tuinier, Remco

    2015-01-01

    Poiyelectrolyte-surfactant complexes (PESC) are a class of materials which form spontaneously by self-assembly driven by electrostatic and hydrophobic interactions. PESC containing sodium lauryl ether Sulfates (SLES) have found wide application in hair care products like shampoo. Typically, SLES

  9. CONSIDERATIONS ON THE INFLUENCE OF COMPLEXATION IN THE COPPER UPTAKE AND TRANSLOCATION

    Directory of Open Access Journals (Sweden)

    SEMAGHIUL BIRGHILA

    2014-07-01

    Full Text Available The actual knowledge about food and the environment underlines the fact that agricultural and environmental sciences must solve various problems regarding copper uptake from soil to plants and its bioaccumulation, being important issues for copper concentration in crops and also for phytoremediation of polluted soils. We studied the relation between the form in which copper is applied to soil and the consequential copper bioavailability, uptake and translocation, using as examples simple and complex copper compounds. The copper concentration in basil plants harvested from soils treated with copper compounds and the calculated values of transfer coefficient, translocation factor, bioaccumulation factor, and uptake coefficient demonstrated that the ionic copper (from simple salts is not necessarily easier to uptake than complex ions, but is easier translocated in plants, while the copper given as complex ions is most likely to be retained by roots. The results indicated that the involvement of copper complexes in agricultural treatments is a solution for soils phytoremediation, concerning the phytostabilization technology.

  10. Study of factors that influence complex-formation of n-alkanes with crystal carbamide

    Energy Technology Data Exchange (ETDEWEB)

    Dorodnova, V.S.; Korzhov, Yu.A.; Martynenko, A.G.

    1982-01-01

    Studies effect of temperature, solid phase content in the suspension and amount of MeOH on extent of n-alkane extraction during carbamide deparaffinization. A most thorough extraction of n-alkanes is achieved with a graduated temperature regimen of complex-formation.

  11. The influence of molecular complexity on expanding flows of ideal and dense gases

    NARCIS (Netherlands)

    Harinck, J.; Guardone, A.; Colonna, P.

    2009-01-01

    This paper presents an investigation about the effect of the complexity of a fluid molecule on the fluid dynamic quantities sound speed, velocity, and Mach number in isentropic expansions. Ideal-gas and dense-gas expansions are analyzed, using the polytropic ideal gas and Van der Waals thermodynamic

  12. Improving Young Children's Writing: The Influence of Story Structure on Kindergartners' Writing Complexity

    Science.gov (United States)

    Watanabe, Lynne M.; Hall-Kenyon, Kendra M.

    2011-01-01

    This study examined the change in complexity of kindergarteners' writing after implementing writing instruction based on story elements. Writing samples from six students of three ability levels were collected over a 6-week period. Writing samples included students' oral language, pictures, and written text and were analyzed using two rubrics…

  13. Determination of stability constants of pyrophosphate complexes. 2. Influence of divalent cations: the magnesium

    International Nuclear Information System (INIS)

    Courriere, P.; Guillemart, A.; Besnard, J.-C.

    1978-01-01

    The stability constants of the complexes of pyrophosphate with magnesium have been determined directly from the titration curves of sodium pyrophosphate in presence of Mg 2+ with hydrochloric acid by a least-square iterative method at the temperature of 25 0 C and at a ionic strength adjusted to unity [fr

  14. Explaining Student Behavior at Scale : The Influence of Video Complexity on Student Dwelling Time

    NARCIS (Netherlands)

    Sluis, van der F.; Ginn, J.H.; Zee, van der T.; Haywood, J.; Aleven, V.; Kay, J.; Roll, I.

    2016-01-01

    Understanding why and how students interact with educational videos is essential to further improve the quality of MOOCs. In this paper, we look at the complexity of videos to explain two related aspects of student behavior: the dwelling time (how much time students spend watching a video) and the

  15. Theoretical analysis of the influence of chelate-ring size and vicinal effects on electronic circular dichroism spectra of cobalt(III) EDDA-type complexes.

    Science.gov (United States)

    Wang, Ai; Wang, Yuekui; Jia, Jie; Feng, Lixia; Zhang, Chunxia; Liu, Linlin

    2013-06-20

    To assess the contributions of configurational and vicinal effects as well as chelate-ring size to rotational strengths, the geometries of a series of cobalt(III) complexes [Co(EDDA-type)(L)](±) with the tetradentate EDDA-type ligands, EDDA (ethylenediamine-N,N'-diacetate), DMEDDA (N,N'-dimethylethylenediamine-N,N'-diacetate), DEEDDA (N,N'-diethylethylenediamine-N,N'-diacetate), and a bidentate ancillary ligand L (L = ethylenediamine, oxalate, carbonate, (S)-alanine, and malonate) in aqueous solution have been optimized at the DFT/B3LYP/6-311++G(2d,p) level of theory. Based on the optimized geometries, the excitation energies and oscillator and rotational strengths have been calculated using the time-dependent density functional theory (TDDFT) method with the same functional and basis set. The calculated circular dichroism (CD) curves are in excellent agreement with the observed ones except for some small red or blue shifts in peak wavelengths. For the influence of chelate-ring size of the bidentate ligands on the CD intensities, a qualitative analysis together with the quantitative TDDFT calculation reveal that it depends on the symmetry of the cobalt-EDDA backbone. For the s-cis-isomers, the influence is negligible due to the perturbation is symmetric. For the uns-cis-isomers, the perturbation is unsymmetric. Since a small ring size means a large perturbation, this leads to the integral CD intensities decreasing with increasing the chelate ring size. The vicinal effects of asymmetric nitrogens incorporate both the substitutent effects and conformational relaxation effects, with the former being dominant. By analyzing the contributions of chiral arrays to rotational strengths, we found that the part of contributions dominated by the S-type chiral nitrogens could be considered as a good measure for the vicinal effects of chiral nitrogens. In addition, we found that the twist form (δ/λ) of the backbone ethylenediamine ring (E-ring) of the coordinated EDDA

  16. Connections and curvatures on complex Riemannian manifolds

    International Nuclear Information System (INIS)

    Ganchev, G.; Ivanov, S.

    1991-05-01

    Characteristic connection and characteristic holomorphic sectional curvatures are introduced on a complex Riemannian manifold (not necessarily with holomorphic metric). For the class of complex Riemannian manifolds with holomorphic characteristic connection a classification of the manifolds with (pointwise) constant holomorphic characteristic curvature is given. It is shown that the conformal geometry of complex analytic Riemannian manifolds can be naturally developed on the class of locally conformal holomorphic Riemannian manifolds. Complex Riemannian manifolds locally conformal to the complex Euclidean space are characterized with zero conformal fundamental tensor and zero conformal characteristic tensor. (author). 12 refs

  17. The Complexity in Defining Leadership: How Gifted Students' Backgrounds Influence Their Understanding of Effective Leadership

    Science.gov (United States)

    Jackson, Shawon; Sakuma, Satoe; DeVol, Purva

    2015-01-01

    There is no universally accepted definition of what it means to be an effective leader. Individuals understand leadership differently based on their own identities and lived experiences. The purpose of this investigation is to determine how one's ethnicity, class, and gender identities influence their understanding of effective leadership,…

  18. Does Early Environmental Complexity Influence Tyrosine Hydroxylase in the Chicken Hippocampus and "Prefrontal" Caudolateral Nidopallium?

    NARCIS (Netherlands)

    Tahamtani, Fernanda M; Nordgreen, Janicke; Brantsæter, Margrethe; Østby, Gunn C; Nordquist, Rebecca E; Janczak, Andrew M

    2016-01-01

    In adult chickens, the housing system influences hippocampal morphology and neurochemistry. However, no work has been done investigating the effects of the early life environment on chicken brain development. In the present study, we reared 67 commercial laying hens (Gallus gallus domesticus) in two

  19. Conformational analysis by intersection: CONAN.

    Science.gov (United States)

    Smellie, Andrew; Stanton, Robert; Henne, Randy; Teig, Steve

    2003-01-15

    As high throughput techniques in chemical synthesis and screening improve, more demands are placed on computer assisted design and virtual screening. Many of these computational methods require one or more three-dimensional conformations for molecules, creating a demand for a conformational analysis tool that can rapidly and robustly cover the low-energy conformational spaces of small molecules. A new algorithm of intersection is presented here, which quickly generates (on average heuristics are applied after intersection to generate a small representative collection of conformations that span the conformational space. In a study of approximately 97,000 randomly selected molecules from the MDDR, results are presented that explore these conformations and their ability to cover low-energy conformational space. Copyright 2002 Wiley Periodicals, Inc. J Comput Chem 24: 10-20, 2003

  20. Conformal superalgebras via tractor calculus

    Science.gov (United States)

    Lischewski, Andree

    2015-01-01

    We use the manifestly conformally invariant description of a Lorentzian conformal structure in terms of a parabolic Cartan geometry in order to introduce a superalgebra structure on the space of twistor spinors and normal conformal vector fields formulated in purely algebraic terms on parallel sections in tractor bundles. Via a fixed metric in the conformal class, one reproduces a conformal superalgebra structure that has been considered in the literature before. The tractor approach, however, makes clear that the failure of this object to be a Lie superalgebra in certain cases is due to purely algebraic identities on the spinor module and to special properties of the conformal holonomy representation. Moreover, it naturally generalizes to higher signatures. This yields new formulas for constructing new twistor spinors and higher order normal conformal Killing forms out of existing ones, generalizing the well-known spinorial Lie derivative. Moreover, we derive restrictions on the possible dimension of the space of twistor spinors in any metric signature.

  1. Emergent nested systems a theory of understanding and influencing complex systems as well as case studies in urban systems

    CERN Document Server

    Walloth, Christian

    2016-01-01

    This book presents a theory as well as methods to understand and to purposively influence complex systems. It suggests a theory of complex systems as nested systems, i. e. systems that enclose other systems and that are simultaneously enclosed by even other systems. According to the theory presented, each enclosing system emerges through time from the generative activities of the systems they enclose. Systems are nested and often emerge unplanned, and every system of high dynamics is enclosed by a system of slower dynamics. An understanding of systems with faster dynamics, which are always guided by systems of slower dynamics, opens up not only new ways to understanding systems, but also to effectively influence them. The aim and subject of this book is to lay out these thoughts and explain their relevance to the purposive development of complex systems, which are exemplified in case studies from an urban system. The interested reader, who is not required to be familiar with system-theoretical concepts or wit...

  2. Dynamic and Progressive Control of DNA Origami Conformation by Modulating DNA Helicity with Chemical Adducts.

    Science.gov (United States)

    Chen, Haorong; Zhang, Hanyu; Pan, Jing; Cha, Tae-Gon; Li, Shiming; Andréasson, Joakim; Choi, Jong Hyun

    2016-05-24

    DNA origami has received enormous attention for its ability to program complex nanostructures with a few nanometer precision. Dynamic origami structures that change conformation in response to environmental cues or external signals hold great promises in sensing and actuation at the nanoscale. The reconfiguration mechanism of existing dynamic origami structures is mostly limited to single-stranded hinges and relies almost exclusively on DNA hybridization or strand displacement. Here, we show an alternative approach by demonstrating on-demand conformation changes with DNA-binding molecules, which intercalate between base pairs and unwind DNA double helices. The unwinding effect modulates the helicity mismatch in DNA origami, which significantly influences the internal stress and the global conformation of the origami structure. We demonstrate the switching of a polymerized origami nanoribbon between different twisting states and a well-constrained torsional deformation in a monomeric origami shaft. The structural transformation is shown to be reversible, and binding isotherms confirm the reconfiguration mechanism. This approach provides a rapid and reversible means to change DNA origami conformation, which can be used for dynamic and progressive control at the nanoscale.

  3. Microstructure of Pharmaceutical Semicrystalline Dispersions: The Significance of Polymer Conformation.

    Science.gov (United States)

    Van Duong, Tu; Goderis, Bart; Van Humbeeck, Jan; Van den Mooter, Guy

    2018-02-05

    The microstructure of pharmaceutical semicrystalline solid dispersions has attracted extensive attention due to its complexity that might result in the diversity in physical stability, dissolution behavior, and pharmaceutical performance of the systems. Numerous factors have been reported that dictate the microstructure of semicrystalline dispersions. Nevertheless, the importance of the complicated conformation of the polymer has never been elucidated. In this study, we investigate the microstructure of dispersions of polyethylene glycol and active pharmaceutical ingredients by small-angle X-ray scattering and high performance differential scanning calorimetry. Polyethylene glycol with molecular weight of 2000 g/mol (PEG2000) and 6000 g/mol (PEG6000) exhibited remarkable discrepancy in the lamellar periodicity in dispersions with APIs which was attributed to the differences in their folding behavior. The long period of PEG2000 always decreased upon aging-induced exclusion of APIs from the interlamellar region of extended chain crystals whereas the periodicity of PEG6000 may decrease or increase during storage as a consequence of the competition between the drug segregation and the lamellar thickening from nonintegral-folded into integral-folded chain crystals. These processes were in turn significantly influenced by the crystallization tendency of the pharmaceutical compounds, drug-polymer interactions, as well as the dispersion composition and crystallization temperature. This study highlights the significance of the polymer conformation on the microstructure of semicrystalline systems that is critical for the preparation of solid dispersions with consistent and reproducible quality.

  4. FORECAST OF INFLUENCING THE UNDERGROUND COMPLEX CONSTRUCTION ON A CONTEXT AREA

    OpenAIRE

    Orekhov Vyacheslav Valentinovich; Alekseev German Valer’evich

    2017-01-01

    The present paper is concerned with the method, research objective and the results of numerical simulation of change of stress-strain behaviour of soil masses when constructing underground complex. In order to get consistent results of forecast, all major factors affecting the results of design studies have been taken into account, including spatial performance of soil mass, enclosure structure and an adjacent context area, phasing of construction, site investigation, initial stress-strain be...

  5. Host Genome Influence on Gut Microbial Composition and Microbial Prediction of Complex Traits in Pigs.

    Science.gov (United States)

    Camarinha-Silva, Amelia; Maushammer, Maria; Wellmann, Robin; Vital, Marius; Preuss, Siegfried; Bennewitz, Jörn

    2017-07-01

    The aim of the present study was to analyze the interplay between gastrointestinal tract (GIT) microbiota, host genetics, and complex traits in pigs using extended quantitative-genetic methods. The study design consisted of 207 pigs that were housed and slaughtered under standardized conditions, and phenotyped for daily gain, feed intake, and feed conversion rate. The pigs were genotyped with a standard 60 K SNP chip. The GIT microbiota composition was analyzed by 16S rRNA gene amplicon sequencing technology. Eight from 49 investigated bacteria genera showed a significant narrow sense host heritability, ranging from 0.32 to 0.57. Microbial mixed linear models were applied to estimate the microbiota variance for each complex trait. The fraction of phenotypic variance explained by the microbial variance was 0.28, 0.21, and 0.16 for daily gain, feed conversion, and feed intake, respectively. The SNP data and the microbiota composition were used to predict the complex traits using genomic best linear unbiased prediction (G-BLUP) and microbial best linear unbiased prediction (M-BLUP) methods, respectively. The prediction accuracies of G-BLUP were 0.35, 0.23, and 0.20 for daily gain, feed conversion, and feed intake, respectively. The corresponding prediction accuracies of M-BLUP were 0.41, 0.33, and 0.33. Thus, in addition to SNP data, microbiota abundances are an informative source of complex trait predictions. Since the pig is a well-suited animal for modeling the human digestive tract, M-BLUP, in addition to G-BLUP, might be beneficial for predicting human predispositions to some diseases, and, consequently, for preventative and personalized medicine. Copyright © 2017 by the Genetics Society of America.

  6. Classical extended conformal symmetries

    International Nuclear Information System (INIS)

    Viswanathan, R.

    1990-02-01

    Extensions of the Virasoro algebra are constructed as Poisson brackets of higher spin fields which appear as coefficient fields in certain covariant derivative operators of order N. These differential operators are constructed so as to be covariant under reparametrizations on fields of definite conformal dimension. Factorization of such an N-th order operator in terms of first order operators, together with the inclusion of a spin one U(1) current, is shown to lead to a two-parameter W-algebra. One of these parameters plays the role of interpolating between W-algebras based on different Lie algebras of the same rank. (author). 11 refs

  7. Influence of Arbuscular Mycorrhizal Fungus (AMF) on degradation of iron-cyanide complexes

    Science.gov (United States)

    Sut, Magdalena; Boldt-Burisch, Katja; Raab, Thomas

    2015-04-01

    Soil contamination in the vicinities of former Manufactured Gas Plant (MGP) sites is a worldwide known environmental issue. The pollutants, in form of iron-cyanide complexes, originating from the gas purification process, create a risk for human health due to potential release of toxic free cyanide, CN(aq) and HCN(g), (aq).The management and remediation of cyanide contaminated soil can be very challenging due to the complex chemistry and toxicity of CN compounds. The employment of phytoremediation to remove or stabilize contaminants at a former MGP site is an inexpensive process, but can be limited through shallow rotting, decreased biomass, poor growing and the risk of secondary accumulation. However, this adaptation may be enhanced via arbuscular mycorrhizal fungi (AMF) activity, which may cooperate on the degradation, transformation or uptake of the contaminants. We would like to present our preliminary results from the ongoing project concerning toxic substrate-AMF-plant relation, based on studying the site of a former MGP site. In situ experiments contributed to identifying those fungi that are likely to persist in extremely acidic and toxic conditions. Subsequently, commercially available Rhizophagus irregularis was grown in sterilized, un-spiked soil with the roots of the host plant Calamagrostis epigejos. Extracted roots and AMF hyphae were used in the batch experiment, were the potential of this association on degradation of iron-cyanide complexes, in form of potassium ferrocyanide solution, was assessed.

  8. Using value-based analysis to influence outcomes in complex surgical systems.

    Science.gov (United States)

    Kirkpatrick, John R; Marks, Stanley; Slane, Michele; Kim, Donald; Cohen, Lance; Cortelli, Michael; Plate, Juan; Perryman, Richard; Zapas, John

    2015-04-01

    Value-based analysis (VBA) is a management strategy used to determine changes in value (quality/cost) when a usual practice (UP) is replaced by a best practice (BP). Previously validated in clinical initiatives, its usefulness in complex systems is unknown. To answer this question, we used VBA to correct deficiencies in cardiac surgery at Memorial Healthcare System. Cardiac surgery is a complex surgical system that lends itself to VBA because outcomes metrics provided by the Society of Thoracic Surgeons provide an estimate of quality; cost is available from Centers for Medicare and Medicaid Services and other contemporary sources; the UP can be determined; and the best practice can be established. Analysis of the UP at Memorial Healthcare System revealed considerable deficiencies in selection of patients for surgery; the surgery itself, including choice of procedure and outcomes; after care; follow-up; and control of expenditures. To correct these deficiencies, each UP was replaced with a BP. Changes included replacement of most of the cardiac surgeons; conversion to an employed physician model; restructuring of a heart surgery unit; recruitment of cardiac anesthesiologists; introduction of an interactive educational program; eliminating unsafe practices; and reducing cost. There was a significant (p value (quality/cost) in a complex surgical system. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Influence of the large-small split effect on strategy choice in complex subtraction.

    Science.gov (United States)

    Xiang, Yan Hui; Wu, Hao; Shang, Rui Hong; Chao, Xiaomei; Ren, Ting Ting; Zheng, Li Ling; Mo, Lei

    2018-04-01

    Two main theories have been used to explain the arithmetic split effect: decision-making process theory and strategy choice theory. Using the inequality paradigm, previous studies have confirmed that individuals tend to adopt a plausibility-checking strategy and a whole-calculation strategy to solve large and small split problems in complex addition arithmetic, respectively. This supports strategy choice theory, but it is unknown whether this theory also explains performance in solving different split problems in complex subtraction arithmetic. This study used small, intermediate and large split sizes, with each split condition being further divided into problems requiring and not requiring borrowing. The reaction times (RTs) for large and intermediate splits were significantly shorter than those for small splits, while accuracy was significantly higher for large and middle splits than for small splits, reflecting no speed-accuracy trade-off. Further, RTs and accuracy differed significantly between the borrow and no-borrow conditions only for small splits. This study indicates that strategy choice theory is suitable to explain the split effect in complex subtraction arithmetic. That is, individuals tend to choose the plausibility-checking strategy or the whole-calculation strategy according to the split size. © 2016 International Union of Psychological Science.

  10. System Integration and Its Influence on the Quality of Life of Children with Complex Needs

    Directory of Open Access Journals (Sweden)

    Sandy Thurston

    2010-01-01

    Full Text Available Purpose. To explore the interactions between child and parents psychosocial factors and team integration variables that may explain improvements in physical dimensions of the PEDS QL quality of life of children with complex needs after 2 years. Methods. In this 2-year study, parents were identified by the Children's Treatment Network. Families were eligible if the child was aged 0–19 years, had physical limitations, resided in either Simcoe County or the Region of York, Ontario, and there were multiple other family needs. Regression analysis used to explore associations and interactions; n=110. Results. A child's physical quality of life was affected by interacting factors including child's behavior, parenting, and integrated care. Statistically significant interactions between team integration, processes of care, and child/parent variables highlight the complexity of the rehabilitation approach in real-life situations. Conclusions. Rehabilitation providers working with children with complex needs and their families should also address child and parent problematic behaviors. When this was the case in high integrated teams, the child's physical quality of life improved after two years.

  11. Influence of absorption on the time of flight of the light going through a complex medium

    Directory of Open Access Journals (Sweden)

    M. Kervella

    2011-09-01

    Full Text Available The aim of this work is to evaluate the influence of absorption processes on the time of flight of light going through an absorbing and scattering thick medium (clouds, paints, gas cell, etc. In order to study statistical scattering and absorbing processes, we use a Monte-Carlo simulation code with temporal phase function and Debye modes. The main result is that absorption inside particles induces a decrease of the global time delay.

  12. Influences on the implementation of TQM in health care organizations: professional bureaucracies, ownership and complexity.

    Science.gov (United States)

    Badrick, T; Preston, A

    2001-01-01

    TQM is introduced into many organisations in an attempt to improve productivity and quality. There are a number of organisational variables that have been recognised as influencing the success of TQM implementation including leadership, teamwork, and suppliers. This paper presents findings of a study of the implementation of TQM in Australian health care organisations. Structural factors were observed to affect the progress of TQM. Professional bureaucracies were less successful than machine bureaucracies. Private organisations were more successful than their public counterparts.

  13. Complexity of the influence of gangliosides on histamine release from human basophils and rat mast cells

    DEFF Research Database (Denmark)

    Jensen, C; Svendsen, U G; Thastrup, Ole

    1987-01-01

    The influence of exogenous addition of gangliosides on histamine release from human basophils and rat mast cells was examined in vitro. Gangliosides dose-dependently inhibited histamine release, and this inhibition was dependent on the ganglioside sialic acid content, since GT1b, having 3 sialic...... was reflected in the sensitivity of the cells to extracellular calcium, since inhibition of the release could be counteracted by increasing the extracellular concentration of calcium....

  14. Conformally symmetric traversable wormholes

    International Nuclear Information System (INIS)

    Boehmer, Christian G.; Harko, Tiberiu; Lobo, Francisco S. N.

    2007-01-01

    Exact solutions of traversable wormholes are found under the assumption of spherical symmetry and the existence of a nonstatic conformal symmetry, which presents a more systematic approach in searching for exact wormhole solutions. In this work, a wide variety of solutions are deduced by considering choices for the form function, a specific linear equation of state relating the energy density and the pressure anisotropy, and various phantom wormhole geometries are explored. A large class of solutions impose that the spatial distribution of the exotic matter is restricted to the throat neighborhood, with a cutoff of the stress-energy tensor at a finite junction interface, although asymptotically flat exact solutions are also found. Using the 'volume integral quantifier', it is found that the conformally symmetric phantom wormhole geometries may, in principle, be constructed by infinitesimally small amounts of averaged null energy condition violating matter. Considering the tidal acceleration traversability conditions for the phantom wormhole geometry, specific wormhole dimensions and the traversal velocity are also deduced

  15. Supergravitational conformal Galileons

    Science.gov (United States)

    Deen, Rehan; Ovrut, Burt

    2017-08-01

    The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated, play an essential role in cosmological theories of the early universe. These include Galileon Genesis and "bouncing" cosmology, where a pre-Big Bang contracting phase bounces smoothly to the presently observed expanding universe. Perhaps the most natural arena for such branes to arise is within the context of superstring and M -theory vacua. Here, not only are branes required for the consistency of the theory, but, in many cases, the exact spectrum of particle physics occurs at low energy. However, such theories have the additional constraint that they must be N = 1 supersymmetric. This motivates us to compute the worldvolume actions of N = 1 supersymmetric three-branes, first in flat superspace and then to generalize them to N = 1 supergravitation. In this paper, for simplicity, we begin the process, not within the context of a superstring vacuum but, rather, for the conformal Galileons arising on a co-dimension one brane embedded in a maximally symmetric AdS 5 bulk space. We proceed to N = 1 supersymmetrize the associated worldvolume theory and then generalize the results to N = 1 supergravity, opening the door to possible new cosmological scenarios

  16. Quantification of Runoff as Influenced by Morphometric Characteristics in a Rural Complex Catchment

    Science.gov (United States)

    Abdulkareem, Jabir Haruna; Pradhan, Biswajeet; Sulaiman, Wan Nor Azmin; Jamil, Nor Rohaizah

    2018-03-01

    This study addresses the critical scientific question of assessing the relationship between morphometric features and the hydrological factors that increase the risk of flooding in Kelantan River basin, Malaysia. Two hypotheses were developed to achieve this aim, namely: the alternate hypothesis (runoff, is influenced by morphometric characteristics in the study watershed) and the null hypothesis (runoff is not influenced by morphometric characteristics). First, the watershed was delineated into four major catchments, namely: Galas, Pergau, Lebir, and Nenggiri. Next, quantitative morphometric characters such as linear aspects, areal aspects, and relief aspects were determined on each of these catchments. Furthermore, HEC-HMS and flood response analyses were employed to simulate the hydrological response of the catchments. From the results of morphometric analysis, profound spatial changes were observed between runoff features of Kelantan River and the morphometric characteristics. The length of overflow that was related to drainage density and constant channel maintenance was found to be 0.12 in Pergau, 0.04 in both Nenggiri and Lebir, and 0.03 in Galas. Drainage density as influenced by geology and vegetation density was found to be low in all the catchments (0.07-0.24). Results of hydrological response indicated that Lebir, Nenggiri, Galas, and Pergau recorded a flood response factor of 0.75, 0.63, 0.40, and 0.05, respectively. Therefore, Lebir and Nenggiri are more likely to be flooded during a rainstorm. There was no clear indication with regard to the catchment that emerged as the most prevailing in all the morphological features. Hence, the alternate hypothesis was affirmed. This study can be replicated in other catchments with different hydrologic setup.

  17. CARBON DIOXIDE INFLUENCE ON THE THERMAL FORMATION OF COMPLEX ORGANIC MOLECULES IN INTERSTELLAR ICE ANALOGS

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradoff, V.; Fray, N.; Bouilloud, M.; Cottin, H. [LISA Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR CNRS 7583, Université Paris Est Créteil (UPEC), Université Paris Diderot (UPD), Institut Pierre Simon Laplace, Labex ESEP, Paris (France); Duvernay, F.; Chiavassa, T., E-mail: vvinogradoff@mnhn.fr [PIIM, Laboratoire de Physique des Interactions Ioniques et Moléculaires, Université Aix-Marseille, UMR CNRS 7345, Marseille (France)

    2015-08-20

    Interstellar ices are submitted to energetic processes (thermal, UV, and cosmic-ray radiations) producing complex organic molecules. Laboratory experiments aim to reproduce the evolution of interstellar ices to better understand the chemical changes leading to the reaction, formation, and desorption of molecules. In this context, the thermal evolution of an interstellar ice analogue composed of water, carbon dioxide, ammonia, and formaldehyde is investigated. The ice evolution during the warming has been monitored by IR spectroscopy. The formation of hexamethylenetetramine (HMT) and polymethylenimine (PMI) are observed in the organic refractory residue left after ice sublimation. A better understanding of this result is realized with the study of another ice mixture containing methylenimine (a precursor of HMT) with carbon dioxide and ammonia. It appears that carbamic acid, a reaction product of carbon dioxide and ammonia, plays the role of catalyst, allowing the reactions toward HMT and PMI formation. This is the first time that such complex organic molecules (HMT, PMI) are produced from the warming (without VUV photolysis or irradiation with energetic particles) of abundant molecules observed in interstellar ices (H{sub 2}O, NH{sub 3}, CO{sub 2}, H{sub 2}CO). This result strengthens the importance of thermal reactions in the ices’ evolution. HMT and PMI, likely components of interstellar ices, should be searched for in the pristine objects of our solar system, such as comets and carbonaceous chondrites.

  18. CARBON DIOXIDE INFLUENCE ON THE THERMAL FORMATION OF COMPLEX ORGANIC MOLECULES IN INTERSTELLAR ICE ANALOGS

    International Nuclear Information System (INIS)

    Vinogradoff, V.; Fray, N.; Bouilloud, M.; Cottin, H.; Duvernay, F.; Chiavassa, T.

    2015-01-01

    Interstellar ices are submitted to energetic processes (thermal, UV, and cosmic-ray radiations) producing complex organic molecules. Laboratory experiments aim to reproduce the evolution of interstellar ices to better understand the chemical changes leading to the reaction, formation, and desorption of molecules. In this context, the thermal evolution of an interstellar ice analogue composed of water, carbon dioxide, ammonia, and formaldehyde is investigated. The ice evolution during the warming has been monitored by IR spectroscopy. The formation of hexamethylenetetramine (HMT) and polymethylenimine (PMI) are observed in the organic refractory residue left after ice sublimation. A better understanding of this result is realized with the study of another ice mixture containing methylenimine (a precursor of HMT) with carbon dioxide and ammonia. It appears that carbamic acid, a reaction product of carbon dioxide and ammonia, plays the role of catalyst, allowing the reactions toward HMT and PMI formation. This is the first time that such complex organic molecules (HMT, PMI) are produced from the warming (without VUV photolysis or irradiation with energetic particles) of abundant molecules observed in interstellar ices (H 2 O, NH 3 , CO 2 , H 2 CO). This result strengthens the importance of thermal reactions in the ices’ evolution. HMT and PMI, likely components of interstellar ices, should be searched for in the pristine objects of our solar system, such as comets and carbonaceous chondrites

  19. Influence of RNA Strand Rigidity on Polyion Complex Formation with Block Catiomers.

    Science.gov (United States)

    Hayashi, Kotaro; Chaya, Hiroyuki; Fukushima, Shigeto; Watanabe, Sumiyo; Takemoto, Hiroyasu; Osada, Kensuke; Nishiyama, Nobuhiro; Miyata, Kanjiro; Kataoka, Kazunori

    2016-03-01

    Polyion complexes (b-PICs) are prepared by mixing single- or double-stranded oligo RNA (aniomer) with poly(ethylene glycol)-b-poly(L-lysine) (PEG-PLL) (block catiomer) to clarify the effect of aniomer chain rigidity on association behaviors at varying concentrations. Here, a 21-mer single-stranded RNA (ssRNA) (persistence length: 1.0 nm) and a 21-mer double-stranded RNA (small interfering RNA, siRNA) (persistence length: 62 nm) are compared. Both oligo RNAs form a minimal charge-neutralized ionomer pair with a single PEG-PLL chain, termed unit b-PIC (uPIC), at low concentrations (<≈ 0.01 mg mL(-1)). Above the critical association concentration (≈ 0.01 mg mL(-1)), ssRNA b-PICs form secondary associates, PIC micelles, with sizes up to 30-70 nm, while no such multimolecular assembly is observed for siRNA b-PICs. The entropy gain associated with the formation of a segregated PIC phase in the multimolecular PIC micelles may not be large enough for rigid siRNA strands to compensate with appreciably high steric repulsion derived from PEG chains. Chain rigidity appears to be a critical parameter in polyion complex association. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. The influence of different cyclometalated ligand substituents and ancillary ligand on the phosphorescent properties of iridium(III) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qing; Li, Yuanyuan; Wang, Xin; Wang, Li, E-mail: chemwangl@henu.edu.cn; Zhang, Jinglai, E-mail: zhangjinglai@henu.edu.cn

    2016-07-01

    Four iridium(III) complexes, (dfpmpy){sub 2}Ir(pic), (1), (dfpmpy){sub 2}Ir(EO{sub 2}-pic) (2), (dfpmpy){sub 2}Ir(pic-N-O) (3), and (dfpmpy){sub 2}Ir(EO{sub 2}-pic-N-O) (4) (dfpmpy = 2-(2,4-difluorophenyl)-4-methylpyridine, pic = picolinic acid, EO{sub 2}-pic = 4-(2-ethoxyethoxy) picolinic acid, pic-N-O = picolinic acid N-oxide, and EO{sub 2}-pic-N-O = 4-(2-ethoxyethoxy) picolinic acid N-oxide) are investigated by means of the density functional theory/time-dependent density functional theory (DFT/TD-DFT) to explore the influence of the ancillary ligand on the electronic structures, phosphorescent properties, and organic light-emitting diode (OLED) performance. Employing pic-N-O and EO{sub 2}-pic-N-O as the ancillary ligands would decrease the vertical energy and result in the red-shifted wavelength. Then, other four iridium(III) complexes (2a-2d) (See Scheme 1) are designed by introduction of the phenyl and −CHO substituents on the pyridine ring and phenyl ring of complex 2, respectively. As compared with complex 2, theoretical results show that newly designed complexes 2a-2c might be potential candidates for blue-emitting phosphors with better/comparable quantum yield and Δλ. Moreover, the performance of complexes 2a and 2c, i.e., introducing phenyl on the para-position of pyridine ring and phenyl ring in dfpmpy ligand, are better than that of 2b. - Highlights: • The structure-property relationship of Ir(III) complexes are investigated. • The effect of different substituents/positions on properties is explored. • Do the emissions follow the Kasha or non-Kasha scenario? • Newly possible blue-emitting Ir(III) complexes are theoretically designed.

  1. Relating c 0 conformal field theories

    International Nuclear Information System (INIS)

    Guruswamy, S.; Ludwig, A.W.W.

    1998-03-01

    A 'canonical mapping' is established between the c = -1 system of bosonic ghosts at the c = 2 complex scalar theory and, a similar mapping between the c = -2 system of fermionic ghosts and the c = 1 Dirac theory. The existence of this mapping is suggested by the identity of the characters of the respective theories. The respective c 0 theories share the same space of states, whereas the spaces of conformal fields are different. Upon this mapping from their c 0) complex scalar and the Dirac theories inherit hidden nonlocal sl(2) symmetries. (author)

  2. Ward identities for conformal models

    International Nuclear Information System (INIS)

    Lazzarini, S.; Stora, R.

    1988-01-01

    Ward identities which express the symmetry of conformal models are treated. Diffeomorphism invariance or locally holomorphic coordinate transformations are used. Diffeomorphism invariance is then understood in terms of Riemannian geometry. Two different sets of Ward identities expressing diffeomorphism invariance in a conformally invariant way are found for the free bosonic string. Using a geometrical argument, the correct invariance for a large class of conformal models is given

  3. Conformational analysis of lignin models

    International Nuclear Information System (INIS)

    Santos, Helio F. dos

    2001-01-01

    The conformational equilibrium for two 5,5' biphenyl lignin models have been analyzed using a quantum mechanical semiempirical method. The gas phase and solution structures are discussed based on the NMR and X-ray experimental data. The results obtained showed that the observed conformations are solvent-dependent, being the geometries and the thermodynamic properties correlated with the experimental information. This study shows how a systematic theoretical conformational analysis can help to understand chemical processes at a molecular level. (author)

  4. On the linear conformal gravitation

    International Nuclear Information System (INIS)

    Pal'chik, M.Ya.; Fradkin, E.S.

    1984-01-01

    Conformal gravitation is analyzed under the assumption that its solution possesses the property of conformal symmetry. This assumption has sense in the case of small distances and only for definite types of matter fields, namely: at special choice of matter fields and their interactions, providing a lack of conformal anomalies; or at definite magnitudes of binding constants, coinciding with the zeroes of the Gell-Mann-Low function. The field equations, of the group-theoretical natura are obtained

  5. Fermion-scalar conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Iliesiu, Luca [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States); Kos, Filip [Department of Physics, Yale University,217 Prospect Street, New Haven, CT 06520 (United States); Poland, David [Department of Physics, Yale University,217 Prospect Street, New Haven, CT 06520 (United States); School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, New Jersey 08540 (United States); Pufu, Silviu S. [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States); Simmons-Duffin, David [School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, New Jersey 08540 (United States); Yacoby, Ran [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States)

    2016-04-13

    We compute the conformal blocks associated with scalar-scalar-fermion-fermion 4-point functions in 3D CFTs. Together with the known scalar conformal blocks, our result completes the task of determining the so-called ‘seed blocks’ in three dimensions. Conformal blocks associated with 4-point functions of operators with arbitrary spins can now be determined from these seed blocks by using known differential operators.

  6. Stress influences decisions to break a safety rule in a complex simulation task in females.

    Science.gov (United States)

    Starcke, Katrin; Brand, Matthias; Kluge, Annette

    2016-07-01

    The current study examines the effects of acutely induced laboratory stress on a complex decision-making task, the Waste Water Treatment Simulation. Participants are instructed to follow a certain decision rule according to safety guidelines. Violations of this rule are associated with potential high rewards (working faster and earning more money) but also with the risk of a catastrophe (an explosion). Stress was induced with the Trier Social Stress Test while control participants underwent a non-stress condition. In the simulation task, stressed females broke the safety rule more often than unstressed females: χ(2) (1, N=24)=10.36, pbreak the safety rule because stressed female participants focused on the potential high gains while they neglected the risk of potential negative consequences. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Influence of temperature and light intensity on Ru(II) complex based organic-inorganic device

    International Nuclear Information System (INIS)

    Asubay, Sezai; Durap, Feyyaz; Aydemir, Murat; Baysal, Akin; Ocak, Yusuf Selim; Tombak, Ahmet

    2016-01-01

    An organic-inorganic junction was fabricated by forming [Ru(Cy_2PNHCH_2-C_4H_3O)(η"6-p-cymene)Cl_2] complex thin film using spin coating technique on n-Si and evaporating Au metal on the film. It was seen that the structure had perfect rectification property. Current-voltage (I-V) measurements were carried out in dark and under various illumination conditions (between 50-100 mW/cm"2) and with the temperature range from 303 to 380 K. The structure showed unusually forward and reverse bias temperature and light sensing behaviors. It was seen that the current both in forward and reverse bias increased with the increase in light intensity and temperature.

  8. Influence of Poroelasticity on the 3D Seismic Response of Complex Geological Media

    Directory of Open Access Journals (Sweden)

    Wuttke Frank

    2017-06-01

    Full Text Available Elastic wave propagation in 3D poroelastic geological media with localized heterogeneities, such as an elastic inclusion and a canyon is investigated to visualize the modification of local site responses under consideration of water saturated geomaterial. The extended computational environment herein developed is a direct Boundary Integral Equation Method (BIEM, based on the frequency-dependent fundamental solution of the governing equation in poro-visco elastodynamics. Bardet’s model is introduced in the analysis as the computationally efficient viscoelastic isomorphism to Biot’s equations of dynamic poroelasticity, thus replacing the two-phase material by a complex valued single-phase one. The potential of Bardet’s analogue is illustrated for low frequency vibrations and all simulation results demonstrate the dependency of wave field developed along the free surface on the properties of the soil material.

  9. On Influence of Neutrals on Dust Particle Charging in Complex Plasmas in the Presence of Electromagnetic Radiation

    International Nuclear Information System (INIS)

    Kopnin, S. I.; Morzhakova, A. A.; Popel, S. I.; Shukla, P. K.

    2011-01-01

    Effects associated with neutral component of complex (dusty) ionospheric plasmas which affect dust particle charging are studied. Microscopic ion currents on dust particles with taking into account ion-neutral interaction are presented. Calculations are performed both for the case of negative charges of dust particles, when the influence of Solar radiation on dust particle charging processes is negligible, and for the case of positive charges which is realized in the presence of sufficiently intensive UV or X-ray radiation. We also carry out investigation of the electron heating due to the photoelectric effect. We show that the efficiency of electron heating depends on the density of neutral component of the plasma. As result, we determine altitudes where the influence of the neutral plasma component on dust particle charging processes as well as the electron heating effect are significant and should be taken into account under consideration of the ionospheric complex plasmas. In particular, we show that the effects considered could be important for the description of noctilucent clouds, polar mesosphere summer echoes, and some other physical phenomena associated with dust particles in the ionosphere.

  10. Untangling the Influences of Voluntary Running, Environmental Complexity, Social Housing and Stress on Adult Hippocampal Neurogenesis

    Science.gov (United States)

    Grégoire, Catherine-Alexandra; Bonenfant, David; Le Nguyen, Adalie; Aumont, Anne; Fernandes, Karl J. L.

    2014-01-01

    Environmental enrichment (EE) exerts powerful effects on brain physiology, and is widely used as an experimental and therapeutic tool. Typical EE paradigms are multifactorial, incorporating elements of physical exercise, environmental complexity, social interactions and stress, however the specific contributions of these variables have not been separable using conventional housing paradigms. Here, we evaluated the impacts of these individual variables on adult hippocampal neurogenesis by using a novel “Alternating EE” paradigm. For 4 weeks, adult male CD1 mice were alternated daily between two enriched environments; by comparing groups that differed in one of their two environments, the individual and combinatorial effects of EE variables could be resolved. The Alternating EE paradigm revealed that (1) voluntary running for 3 days/week was sufficient to increase both mitotic and post-mitotic stages of hippocampal neurogenesis, confirming the central importance of exercise; (2) a complex environment (comprised of both social interactions and rotated inanimate objects) had no effect on neurogenesis itself, but enhanced depolarization-induced c-Fos expression (attributable to social interactions) and buffered stress-induced plasma corticosterone levels (attributable to inanimate objects); and (3) neither social isolation, group housing, nor chronically increased levels of plasma corticosterone had a prolonged impact on neurogenesis. Mouse strain, handling and type of running apparatus were tested and excluded as potential confounding factors. These findings provide valuable insights into the relative effects of key EE variables on adult neurogenesis, and this “Alternating EE” paradigm represents a useful tool for exploring the contributions of individual EE variables to mechanisms of neural plasticity. PMID:24465980

  11. Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size

    Directory of Open Access Journals (Sweden)

    Sara M. Rodríguez

    2017-08-01

    Full Text Available Background Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood. Methods Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts’ exposure to the parasite’s dispersive stages. Results Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm than large molecrabs (<15 mm. Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs. Conclusions These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation—a characteristic of indirect host

  12. Complexing agents and pH influence on chemical durability of type I moulded glass containers.

    Science.gov (United States)

    Biavati, Alberto; Poncini, Michele; Ferrarini, Arianna; Favaro, Nicola; Scarpa, Martina; Vallotto, Marta

    2017-06-16

    Among the factors that affect the glass surface chemical durability, pH and complexing agents presence in aqueous solution have the main role (1). Glass surface attack can be also related to the delamination issue with glass particles appearance in the pharmaceutical preparation. A few methods to check for glass containers delamination propensity and some control guidelines have been proposed (2,3). The present study emphasizes the possible synergy between a few complexing agents with pH on the borosilicate glass chemical durability. Hydrolytic attack was performed in small volume 23 ml type I glass containers autoclaved according to EP or USP for 1 hour at 121°C, in order to enhance the chemical attack due to time, temperature and the unfavourable surface/volume ratio. 0,048 M or 0.024 M (moles/liter) solutions of the acids citric, glutaric, acetic, EDTA (ethylenediaminetetraacetic acid) and sodium phosphate with water for comparison, were used for the trials. The pH was adjusted ± 0,05 units at fixed values 5,5-6,6-7-7,4-8-9 by LiOH diluted solution. Since silicon is the main glass network former, silicon release into the attack solutions was chosen as the main index of the glass surface attack and analysed by ICPAES. The work was completed by the analysis of the silicon release in the worst attack conditions, of moulded glass, soda lime type II and tubing borosilicate glass vials to compare different glass compositions and forming technologies. Surface analysis by SEM was finally performed to check for the surface status after the worst chemical attack condition by citric acid. Copyright © 2017, Parenteral Drug Association.

  13. Untangling the influences of voluntary running, environmental complexity, social housing and stress on adult hippocampal neurogenesis.

    Directory of Open Access Journals (Sweden)

    Catherine-Alexandra Grégoire

    Full Text Available Environmental enrichment (EE exerts powerful effects on brain physiology, and is widely used as an experimental and therapeutic tool. Typical EE paradigms are multifactorial, incorporating elements of physical exercise, environmental complexity, social interactions and stress, however the specific contributions of these variables have not been separable using conventional housing paradigms. Here, we evaluated the impacts of these individual variables on adult hippocampal neurogenesis by using a novel "Alternating EE" paradigm. For 4 weeks, adult male CD1 mice were alternated daily between two enriched environments; by comparing groups that differed in one of their two environments, the individual and combinatorial effects of EE variables could be resolved. The Alternating EE paradigm revealed that (1 voluntary running for 3 days/week was sufficient to increase both mitotic and post-mitotic stages of hippocampal neurogenesis, confirming the central importance of exercise; (2 a complex environment (comprised of both social interactions and rotated inanimate objects had no effect on neurogenesis itself, but enhanced depolarization-induced c-Fos expression (attributable to social interactions and buffered stress-induced plasma corticosterone levels (attributable to inanimate objects; and (3 neither social isolation, group housing, nor chronically increased levels of plasma corticosterone had a prolonged impact on neurogenesis. Mouse strain, handling and type of running apparatus were tested and excluded as potential confounding factors. These findings provide valuable insights into the relative effects of key EE variables on adult neurogenesis, and this "Alternating EE" paradigm represents a useful tool for exploring the contributions of individual EE variables to mechanisms of neural plasticity.

  14. THE INFLUENCE OF COMPLEX THERAPY ON THE INFLAMMATORY MARKERS OF PATIENTS WITH SECONDARY OSTEOARTHRITIS

    Directory of Open Access Journals (Sweden)

    I. A. Starodubtseva

    2015-01-01

    Full Text Available The aim of the study is to evaluate the efficacy of complex therapy of secondary osteoarthritis in patients with rheumatoid arthritis with the use of inhibitor of interleukin-1, including the dynamics of inflammatory markers.Materials and methods: 248 patients with secondary osteoarthritis in rheumatoid arthritis were involved in the trial. The participants were divided into 4 groups: patients of group I took inhibitor of interleukin-1 (diacerein in combination with laser therapy and methotrexate; inhibitor of interleukin-1 in complex with methotrexate took patients from group II; group 3 — laser therapy + methotrexate and patients of group IV took only methotrexate. The efficacy of therapy we estimated in 6 months.Results: The constructed model surfaces indicated the decreased levels of IL-1, COMP and DAS 28 in group 1 till 6,68±0,37 pg/ml (p<0,001, 16,92±0,8 ng/ml х 10² (p<0,001 и 2,06±1,19 (p<0,05 accordingly in comparison with groups III and IV. Also the model surfaces revealed the interdependency of all these indicators. The control group (IV reacted to the treatment by decreasing the indicators as well. However, the dynamics of the changes was significantly less. In patients of groups I and II the levels of ESR and CRP decreased to 13,95±0,52* (*p<0,001 and 10,97±0,43* (*p<0,001; 16,53±0,63* (*p<0,001 and 12,81±0,77* (*p<0,001 accordingly.Conclusions: In comparison analysis we noted statistical significant advantages (p<0,01 of the use of diacerein with methotrexate regarding the dynamic of IL-1 and COMP, ESR, CRP in patient’s serum, which is accompanied by the reduction of basic disease activity on DAS 28.

  15. Simulation of complex fracture networks influenced by natural fractures in shale gas reservoir

    Directory of Open Access Journals (Sweden)

    Zhao Jinzhou

    2014-10-01

    Full Text Available When hydraulic fractures intersect with natural fractures, the geometry and complexity of a fracture network are determined by the initiation and propagation pattern which is affected by a number of factors. Based on the fracture mechanics, the criterion for initiation and propagation of a fracture was introduced to analyze the tendency of a propagating angle and factors affecting propagating pressure. On this basis, a mathematic model with a complex fracture network was established to investigate how the fracture network form changes with different parameters, including rock mechanics, in-situ stress distribution, fracture properties, and frac treatment parameters. The solving process of this model was accelerated by classifying the calculation nodes on the extending direction of the fracture by equal pressure gradients, and solving the geometrical parameters prior to the iteration fitting flow distribution. With the initiation and propagation criterion as the bases for the propagation of branch fractures, this method decreased the iteration times through eliminating the fitting of the fracture length in conventional 3D fracture simulation. The simulation results indicated that the formation with abundant natural fractures and smaller in-situ stress difference is sufficient conditions for fracture network development. If the pressure in the hydraulic fractures can be kept at a high level by temporary sealing or diversion, the branch fractures will propagate further with minor curvature radius, thus enlarging the reservoir stimulation area. The simulated shape of fracture network can be well matched with the field microseismic mapping in data point range and distribution density, validating the accuracy of this model.

  16. Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size.

    Science.gov (United States)

    Rodríguez, Sara M; Valdivia, Nelson

    2017-01-01

    Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood. Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence) and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts' exposure to the parasite's dispersive stages. Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm) than large molecrabs (analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs. These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation-a characteristic of indirect host-parasite interactions-and subsequent increasing mortality rates over ontogeny underpin size-dependent host-parasite dynamics.

  17. Influence of multi-microphone signal enhancement algorithms on auditory movement detection in acoustically complex situations

    DEFF Research Database (Denmark)

    Lundbeck, Micha; Hartog, Laura; Grimm, Giso

    2017-01-01

    The influence of hearing aid (HA) signal processing on the perception of spatially dynamic sounds has not been systematically investigated so far. Previously, we observed that interfering sounds impaired the detectability of left-right source movements and reverberation that of near-far source...... movements for elderly hearing-impaired (EHI) listeners (Lundbeck et al., 2017). Here, we explored potential ways of improving these deficits with HAs. To that end, we carried out acoustic analyses to examine the impact of two beamforming algorithms and a binaural coherence-based noise reduction scheme...... on the cues underlying movement perception. While binaural cues remained mostly unchanged, there were greater monaural spectral changes and increases in signal-to-noise ratio and direct-to-reverberant sound ratio as a result of the applied processing. Based on these findings, we conducted a listening test...

  18. Instantons in conformal gravity

    International Nuclear Information System (INIS)

    Strominger, A.; Horowitz, G.T.; Perry, M.J.

    1984-01-01

    Fe study extrema of the general conformally invariant action: Ssub(c)=∫1/sub(α) 2 Csup(abcd)Csub(abcd)+γRsup(abcd*)Rsup(*)sub(abcd)+iTHETARsup(abcd)*Rsub(abcd). We find the first examples in four dimensions of asymptotically euclidean gravitational instantons. These have arbitrary Euler number and Hirzebruch signature. Some of these instantons represent tunneling between zero-curvature vacua that are not related by small gauge transformations. Others represent tunneling between flat space and topologically non-trivial zero-energy initial data. A general formula for the one-loop determinant is derived in terms of the renormalization group invariant masses, the volume of space-time, the Euler number and the Hirzebruch signature. (orig.)

  19. Conformance and Deviance

    DEFF Research Database (Denmark)

    Gjerdrum Pedersen, Esben Rahbek; Neergaard, Peter; Thusgaard Pedersen, Janni

    2013-01-01

    This paper analyses how large Danish companies are responding to new governmental regulation which requires them to report on corporate social responsibility (CSR). The paper is based on an analysis of 142 company annual reports required by the new Danish regulation regarding CSR reporting, plus 10...... interviews with first-time reporting companies and six interviews with companies that failed to comply with the new law. It is concluded that coercive pressures from government have an impact on CSR reporting practices. Further, the analysis finds traces of mimetic isomorphism which inspires a homogenisation...... in CSR reporting practices. Finally, it is argued that non-conformance with the new regulatory requirements is not solely about conscious resistance but may also be caused by, for example, lack of awareness, resource limitations, misinterpretations, and practical difficulties....

  20. Reflections on Conformal Spectra

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    We use modular invariance and crossing symmetry of conformal field theory to reveal approximate reflection symmetries in the spectral decompositions of the partition function in two dimensions in the limit of large central charge and of the four-point function in any dimension in the limit of large scaling dimensions Δ0 of external operators. We use these symmetries to motivate universal upper bounds on the spectrum and the operator product expansion coefficients, which we then derive by independent techniques. Some of the bounds for four-point functions are valid for finite Δ0 as well as for large Δ0. We discuss a similar symmetry in a large spacetime dimension limit. Finally, we comment on the analogue of the Cardy formula and sparse light spectrum condition for the four-point function. (based on 1510.08772 with Kim & Ooguri). This seminar will be given via videolink

  1. Conformal boundary loop models

    International Nuclear Information System (INIS)

    Jacobsen, Jesper Lykke; Saleur, Hubert

    2008-01-01

    We study a model of densely packed self-avoiding loops on the annulus, related to the Temperley-Lieb algebra with an extra idempotent boundary generator. Four different weights are given to the loops, depending on their homotopy class and whether they touch the outer rim of the annulus. When the weight of a contractible bulk loop x≡q+q -1 element of (-2,2], this model is conformally invariant for any real weight of the remaining three parameters. We classify the conformal boundary conditions and give exact expressions for the corresponding boundary scaling dimensions. The amplitudes with which the sectors with any prescribed number and types of non-contractible loops appear in the full partition function Z are computed rigorously. Based on this, we write a number of identities involving Z which hold true for any finite size. When the weight of a contractible boundary loop y takes certain discrete values, y r ≡([r+1] q )/([r] q ) with r integer, other identities involving the standard characters K r,s of the Virasoro algebra are established. The connection with Dirichlet and Neumann boundary conditions in the O(n) model is discussed in detail, and new scaling dimensions are derived. When q is a root of unity and y=y r , exact connections with the A m type RSOS model are made. These involve precise relations between the spectra of the loop and RSOS model transfer matrices, valid in finite size. Finally, the results where y=y r are related to the theory of Temperley-Lieb cabling

  2. Conformal Aspects of QCD

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S

    2003-11-19

    Theoretical and phenomenological evidence is now accumulating that the QCD coupling becomes constant at small virtuality; i.e., {alpha}{sub s}(Q{sup 2}) develops an infrared fixed point in contradiction to the usual assumption of singular growth in the infrared. For example, the hadronic decays of the {tau} lepton can be used to determine the effective charge {alpha}{sub {tau}}(m{sub {tau}{prime}}{sup 2}) for a hypothetical {tau}-lepton with mass in the range 0 < m{sub {tau}{prime}} < m{sub {tau}}. The {tau} decay data at low mass scales indicates that the effective charge freezes at a value of s = m{sub {tau}{prime}}{sup 2} of order 1 GeV{sup 2} with a magnitude {alpha}{sub {tau}} {approx} 0.9 {+-} 0.1. The near-constant behavior of effective couplings suggests that QCD can be approximated as a conformal theory even at relatively small momentum transfer and why there are no significant running coupling corrections to quark counting rules for exclusive processes. The AdS/CFT correspondence of large N{sub c} supergravity theory in higher-dimensional anti-de Sitter space with supersymmetric QCD in 4-dimensional space-time also has interesting implications for hadron phenomenology in the conformal limit, including an all-orders demonstration of counting rules for exclusive processes and light-front wavefunctions. The utility of light-front quantization and light-front Fock wavefunctions for analyzing nonperturbative QCD and representing the dynamics of QCD bound states is also discussed.

  3. Electromagnetic field and the theory of conformal and biholomorphic invariants

    International Nuclear Information System (INIS)

    Lawrynowicz, J.

    1976-01-01

    This paper contains sections on: 1. Conformal invariance and variational principles in electrodynamics. 2. The principles of Dirichlet and Thomson as a physical motivation for the methods of conformal capacities and extremal lengths. 3. Extension to pseudoriemannian manifolds. 4. Extension to hermitian manifolds. 5. An extension of Schwarz's lemma for hermitian manifolds and its physical significance. 6. Variation of ''complex'' capacities within the admissible class of plurisubharmonic functions. The author concentrates on motivations and interpretations connected with the electromagnetic field. (author)

  4. Factors influencing transfection efficiency of pIDUA/nanoemulsion complexes in a mucopolysaccharidosis type I murine model

    Directory of Open Access Journals (Sweden)

    Fraga M

    2017-03-01

    Full Text Available Michelle Fraga,1,2 Talita Giacomet de Carvalho,2,3 Juliana Bidone,1 Roselena Silvestri Schuh,1,2 Ursula Matte,2,3 Helder Ferreira Teixeira1 1Pharmaceutical Sciences Graduate Program, Universidade Federal do Rio Grande do Sul, 2Gene Therapy Center, Experimental Research Center, Hospital de Clínicas de Porto Alegre, 3Genetics and Molecular Biology Graduate Program, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil Abstract: Mucopolysaccharidosis type I (MPS I is an autosomal disease caused by alpha-L-iduronidase (IDUA deficiency. This study used IDUA knockout mice as a model to evaluate whether parameters such as dose of plasmid and time of treatment could influence the transfection efficiency of complexes formed with PEGylated cationic nanoemulsions and plasmid (pIDUA, which contains the gene that encodes for IDUA. Formulations were composed of medium chain triglycerides, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-(amino[polyethylene glycol]-2000, 1,2-dioleoyl-sn-glycero-3-trimethylammonium propane (DOTAP, glycerol, and water and were prepared by the adsorption or encapsulation of preformed pIDUA–DOTAP complexes by high-pressure homogenization. A progressive increase in IDUA expression was observed with an increase in the dose and time of transfection for mice treated with both complexes (adsorbed and encapsulated, especially in the liver. Regardless of the complex administered, a significant increase in IDUA activity was detected in lungs and liver compared with nontreated MPS I when a dose of 60 µg was administered and IDUA activity was measured 7 days postadministration. Tissue sections of major organs showed no presence of cell necrosis, inflammatory infiltrate, or an increase in apoptosis. Furthermore, immunohistochemistry for CD68 showed no difference in the number of macrophage cells in treated and nontreated animals, indicating the absence of inflammatory reaction

  5. Influence of Proton Acceptors on the Proton-Coupled Electron Transfer Reaction Kinetics of a Ruthenium-Tyrosine Complex.

    Science.gov (United States)

    Lennox, J Christian; Dempsey, Jillian L

    2017-11-22

    A polypyridyl ruthenium complex with fluorinated bipyridine ligands and a covalently bound tyrosine moiety was synthesized, and its photo-induced proton-coupled electron transfer (PCET) reactivity in acetonitrile was investigated with transient absorption spectroscopy. Using flash-quench methodology with methyl viologen as an oxidative quencher, a Ru 3+ species is generated that is capable of initiating the intramolecular PCET oxidation of the tyrosine moiety. Using a series of substituted pyridine bases, the reaction kinetics were found to vary as a function of proton acceptor concentration and identity, with no significant H/D kinetic isotope effect. Through analysis of the kinetics traces and comparison to a control complex without the tyrosine moiety, PCET reactivity was found to proceed through an equilibrium electron transfer followed by proton transfer (ET-PT) pathway in which irreversible deprotonation of the tyrosine radical cation shifts the ET equilibrium, conferring a base dependence on the reaction. Comprehensive kinetics modeling allowed for deconvolution of complex kinetics and determination of rate constants for each elementary step. Across the five pyridine bases explored, spanning a range of 4.2 pK a units, a linear free-energy relationship was found for the proton transfer rate constant with a slope of 0.32. These findings highlight the influence that proton transfer driving force exerts on PCET reaction kinetics.

  6. Complexing Agents and pH Influence on Chemical Durability of Type I Molded Glass Containers.

    Science.gov (United States)

    Biavati, Alberto; Poncini, Michele; Ferrarini, Arianna; Favaro, Nicola; Scarpa, Martina; Vallotto, Marta

    2017-01-01

    Among the factors that affect the glass surface chemical durability, pH and complexing agents present in aqueous solution have the main role. Glass surface attack can be also related to the delamination issue causing glass particles' appearance in the pharmaceutical preparation. A few methods to check for glass containers delamination propensity and some control guidelines have been proposed. The present study emphasizes the possible synergy between a few complexing agents with pH on borosilicate glass chemical durability.Hydrolytic attack was performed in small-volume 23 mL type I glass containers autoclaved according to the European Pharmacopoeia or United States Pharmacopeia for 1 h at 121 °C, in order to enhance the chemical attack due to time, temperature, and the unfavorable surface/volume ratio. Solutions of 0.048 M or 0.024 M (M/L) of the acids citric, glutaric, acetic, EDTA (ethylenediaminetetraacetic acid), together with sodium phosphate with water for comparison, were used for the trials. The pH was adjusted ±0.05 units at fixed values 5.5, 6.6, 7, 7.4, 8, and 9 by LiOH diluted solution.Because silicon is the main glass network former, silicon release into the attack solutions was chosen as the main index of the glass surface attack and analysed by inductively coupled plasma atomic emission spectrophotometry. The work was completed by the analysis of the silicon release in the worst attack conditions of molded glass, soda lime type II glass, and tubing borosilicate glass vials to compare different glass compositions and forming technologies. Surface analysis by scanning electron microscopy was finally performed to check for the surface status after the worst chemical attack condition by citric acid. LAY ABSTRACT: Glass, like every packaging material, can have some usage limits, mainly in basic pH solutions. The issue of glass surface degradation particles that appear in vials (delamination) has forced a number of drug product recalls in recent years

  7. Logarithmic conformal field theory through nilpotent conformal dimensions

    International Nuclear Information System (INIS)

    Moghimi-Araghi, S.; Rouhani, S.; Saadat, M.

    2001-01-01

    We study logarithmic conformal field theories (LCFTs) through the introduction of nilpotent conformal weights. Using this device, we derive the properties of LCFTs such as the transformation laws, singular vectors and the structure of correlation functions. We discuss the emergence of an extra energy momentum tensor, which is the logarithmic partner of the energy momentum tensor

  8. Influence of humic-acid complexing on the mobility of Americium in the soil aquatic environment

    International Nuclear Information System (INIS)

    Sheppard, J.C.; Campbell, M.J.; Kittrick, J.A.

    1982-03-01

    Diffusion data indicate the Am, Cm and Np migrate 1.2, 0.8, and 26 centimeters, respectively, in a thousand years. Thus, excluding mass transport by moving water or wind, actinide elements, such as Cm, Am, and Np that find their way to the soil-aquatic environment are relatively immobile. Measured diffusion coefficients, corrected for distribution between the aqueous and soil phases, tortuosity, negative absorption, and relative fluidity are in reasonable agreement with aqueous diffusion coefficients. However, agreement depends strongly on measurement method used to determine distribution ratios. Two sets of experiments with 241 Am and 152 Eu tracers have been done to measure distribution ratios as a function of the aqueous humic acid concentration. In the first experiments the solid phase was kaolinite and in the second series of distribution ratios were measured with Burbank sandy loam. Both of these experiments indicated that Am(III) and Eu(III) form very strong humic acid complexes with formation constants of approximately 10 5 . Additional experiments are being done to establish the average number of Am(III)s or Eu(III)s bound to the humic acid polymer

  9. The influence of the formation pitching angle on the area for employing the KM-103 complex

    Energy Technology Data Exchange (ETDEWEB)

    Shulga, A I; Teryanik, V I

    1982-01-01

    Mining sections in which the KM-103 powered complexes are used should be selected and planned on the basis of the actual pitching angle of the formation, and the anticipated vertical and lateral rock displacement in the workings. With the shapes and dimensions characteristic of galley cross-sections which are reinforced by arched 3 and 5-arm supports, and with the anticipated values of rock displacement, a maximum pitching angle exists, above which it is difficult to facilitate the drives of stope face conveyors. For arch-shaped galleys, which are reinforced by an arched 5-arm support, the maximum pitching angle of the formation is greater than in galleys which are reinforced by arched three-arm supports, with equal cross-sections even with large rock displacements. An increase in the cross-section of upwards of 13 square meters does not result in an increase in the maximum pitching angle of the formation due to the extension of the support roof timber. In the trapezoidal workings which are supported by the KPS-3 supports and are worked without employing roof blasting, the maximum pitching angle of the formation is 12 degrees. The thickness of the formation worked must be less than 1.1 meter.

  10. Low-Mode Conformational Search Method with Semiempirical Quantum Mechanical Calculations: Application to Enantioselective Organocatalysis.

    Science.gov (United States)

    Kamachi, Takashi; Yoshizawa, Kazunari

    2016-02-22

    A conformational search program for finding low-energy conformations of large noncovalent complexes has been developed. A quantitatively reliable semiempirical quantum mechanical PM6-DH+ method, which is able to accurately describe noncovalent interactions at a low computational cost, was employed in contrast to conventional conformational search programs in which molecular mechanical methods are usually adopted. Our approach is based on the low-mode method whereby an initial structure is perturbed along one of its low-mode eigenvectors to generate new conformations. This method was applied to determine the most stable conformation of transition state for enantioselective alkylation by the Maruoka and cinchona alkaloid catalysts and Hantzsch ester hydrogenation of imines by chiral phosphoric acid. Besides successfully reproducing the previously reported most stable DFT conformations, the conformational search with the semiempirical quantum mechanical calculations newly discovered a more stable conformation at a low computational cost.

  11. Resistance and conformity

    NARCIS (Netherlands)

    Sumter, S.R.; Bokhorst, C.L.; Westenberg, P.M.; Levesque, R.J.R.

    2011-01-01

    Resistance to peer influence, or the ability to resist making choices or adopting views under the implicit or explicit influence of your peers, is expected to undergo changes during adolescence. Two developmental trajectories have emerged from the field. On the one hand, adolescents show a temporary

  12. Replacement between conformity and counter-conformity in consumption decisions.

    Science.gov (United States)

    Chou, Ting-Jui; Chang, En-Chung; Dai, Qi; Wong, Veronica

    2013-02-01

    This study assessed, in a Chinese context, how self-esteem interacts with perceived similarity and uniqueness to yield cognitive dissonance, and whether the dissonance leads to self-reported conformity or counter-conformity behavior. Participants were 408 respondents from 4 major Chinese cities (M age = 33.0 yr., SD = 4.3; 48% men). Self-perceptions of uniqueness, similarity, cognitive dissonance, self-esteem and need to behave in conformity or counter-conformity were measured. A theoretical model was assessed in four situations, relating the ratings of self-esteem and perceived similarity/uniqueness to the way other people at a wedding were dressed, and the resultant cognitive dissonance and conformity/ counter-conformity behavior. Regardless of high or low self-esteem, all participants reported cognitive dissonance when they were told that they were dressed extremely similarly to or extremely differently from the other people attending the wedding. However, the conforming/counter-conforming strategies used by participants to resolve the cognitive dissonance differed. When encountering dissonance induced by the perceived extreme uniqueness of dress, participants with low self-esteem tended to say they would dress next time so as to conform with the way others were dressed, while those with high self-esteem indicated they would continue their counter-conformity in attire. When encountering dissonance induced by the perceived extreme similarity to others, both those with high and low self-esteem tended to say they would dress in an unorthodox manner to surprise other people in the future.

  13. On Associative Conformal Algebras of Linear Growth

    OpenAIRE

    Retakh, Alexander

    2000-01-01

    Lie conformal algebras appear in the theory of vertex algebras. Their relation is similar to that of Lie algebras and their universal enveloping algebras. Associative conformal algebras play a role in conformal representation theory. We introduce the notions of conformal identity and unital associative conformal algebras and classify finitely generated simple unital associative conformal algebras of linear growth. These are precisely the complete algebras of conformal endomorphisms of finite ...

  14. Influence of learning strategy on response time during complex value-based learning and choice.

    Directory of Open Access Journals (Sweden)

    Shiva Farashahi

    Full Text Available Measurements of response time (RT have long been used to infer neural processes underlying various cognitive functions such as working memory, attention, and decision making. However, it is currently unknown if RT is also informative about various stages of value-based choice, particularly how reward values are constructed. To investigate these questions, we analyzed the pattern of RT during a set of multi-dimensional learning and decision-making tasks that can prompt subjects to adopt different learning strategies. In our experiments, subjects could use reward feedback to directly learn reward values associated with possible choice options (object-based learning. Alternatively, they could learn reward values of options' features (e.g. color, shape and combine these values to estimate reward values for individual options (feature-based learning. We found that RT was slower when the difference between subjects' estimates of reward probabilities for the two alternative objects on a given trial was smaller. Moreover, RT was overall faster when the preceding trial was rewarded or when the previously selected object was present. These effects, however, were mediated by an interaction between these factors such that subjects were faster when the previously selected object was present rather than absent but only after unrewarded trials. Finally, RT reflected the learning strategy (i.e. object-based or feature-based approach adopted by the subject on a trial-by-trial basis, indicating an overall faster construction of reward value and/or value comparison during object-based learning. Altogether, these results demonstrate that the pattern of RT can be informative about how reward values are learned and constructed during complex value-based learning and decision making.

  15. What makes a rhythm complex? The influence of musical training and accent type on beat perception.

    Science.gov (United States)

    Bouwer, Fleur L; Burgoyne, J Ashley; Odijk, Daan; Honing, Henkjan; Grahn, Jessica A

    2018-01-01

    Perception of a regular beat in music is inferred from different types of accents. For example, increases in loudness cause intensity accents, and the grouping of time intervals in a rhythm creates temporal accents. Accents are expected to occur on the beat: when accents are "missing" on the beat, the beat is more difficult to find. However, it is unclear whether accents occurring off the beat alter beat perception similarly to missing accents on the beat. Moreover, no one has examined whether intensity accents influence beat perception more or less strongly than temporal accents, nor how musical expertise affects sensitivity to each type of accent. In two experiments, we obtained ratings of difficulty in finding the beat in rhythms with either temporal or intensity accents, and which varied in the number of accents on the beat as well as the number of accents off the beat. In both experiments, the occurrence of accents on the beat facilitated beat detection more in musical experts than in musical novices. In addition, the number of accents on the beat affected beat finding more in rhythms with temporal accents than in rhythms with intensity accents. The effect of accents off the beat was much weaker than the effect of accents on the beat and appeared to depend on musical expertise, as well as on the number of accents on the beat: when many accents on the beat are missing, beat perception is quite difficult, and adding accents off the beat may not reduce beat perception further. Overall, the different types of accents were processed qualitatively differently, depending on musical expertise. Therefore, these findings indicate the importance of designing ecologically valid stimuli when testing beat perception in musical novices, who may need different types of accent information than musical experts to be able to find a beat. Furthermore, our findings stress the importance of carefully designing rhythms for social and clinical applications of beat perception, as not

  16. Recent advancements in conformal gravity

    International Nuclear Information System (INIS)

    O’Brien, James G.; Chaykov, Spasen S.; Moss, Robert J.; Dentico, Jeremy; Stulge, Modestas; Stefanski, Brian

    2017-01-01

    In recent years, due to the lack of direct observed evidence of cold dark matter, coupled with the shrinking parameter space to search for new dark matter particles, there has been increased interest in Alternative Gravitational theories. This paper, addresses three recent advances in conformal gravity, a fourth order renormalizable metric theory of gravitation originally formulated by Weyl, and later advanced by Mannheim and Kazanas. The first section of the paper applies conformal gravity to the rotation curves of the LITTLE THINGS survey, extending the total number of rotation curves successfully fit by conformal gravity to well over 200 individual data sets without the need for additional dark matter. Further, in this rotation curve study, we show how MOND and conformal gravity compare for each galaxy in the sample. Second, we look at the original Zwicky problem of applying the virial theorem to the Coma cluster in order to get an estimate for the cluster mass. However, instead of using the standard Newtonian potential, here we use the weak field approximation of conformal gravity. We show that in the conformal case we can get a much smaller mass estimate and thus there is no apparent need to include dark matter. We then show that this calculation is in agreement with the observational data from other well studied clusters. Last, we explore the calculation of the deflection of starlight through conformal gravity, as a first step towards applying conformal gravity to gravitaitonal lensing. (paper)

  17. Conformal invariance in harmonic superspace

    International Nuclear Information System (INIS)

    Galperin, A.; Ivanov, E.; Ogievetsky, V.; Sokatchev, E.

    1985-01-01

    N=2 conformal supersymmetry is realized in harmonic superspace, its peculiarities are analyzed. The coordinate group and analytical prepotentials for N=2 conformal supergravity are found. A new version of the N=2 Einstein supergravity with infinite number of auxiliary fields is suggested. A hypermultiplet without central charges and constraints is used as a compensator

  18. Counselor Identity: Conformity or Distinction?

    Science.gov (United States)

    McLaughlin, Jerry E.; Boettcher, Kathryn

    2009-01-01

    The authors explore 3 debates in other disciplines similar to counseling's identity debate in order to learn about common themes and outcomes. Conformity, distinction, and cohesion emerged as common themes. They conclude that counselors should retain their distinctive, humanistic approach rather than conforming to the dominant, medical approach.

  19. A new fundamental type of conformational isomerism

    Science.gov (United States)

    Canfield, Peter J.; Blake, Iain M.; Cai, Zheng-Li; Luck, Ian J.; Krausz, Elmars; Kobayashi, Rika; Reimers, Jeffrey R.; Crossley, Maxwell J.

    2018-06-01

    Isomerism is a fundamental chemical concept, reflecting the fact that the arrangement of atoms in a molecular entity has a profound influence on its chemical and physical properties. Here we describe a previously unclassified fundamental form of conformational isomerism through four resolved stereoisomers of a transoid (BF)O(BF)-quinoxalinoporphyrin. These comprise two pairs of enantiomers that manifest structural relationships not describable within existing IUPAC nomenclature and terminology. They undergo thermal diastereomeric interconversion over a barrier of 104 ± 2 kJ mol-1, which we term `akamptisomerization'. Feasible interconversion processes between conceivable synthesis products and reaction intermediates were mapped out by density functional theory calculations, identifying bond-angle inversion (BAI) at a singly bonded atom as the reaction mechanism. We also introduce the necessary BAI stereodescriptors parvo and amplo. Based on an extended polytope formalism of molecular structure and stereoisomerization, BAI-driven akamptisomerization is shown to be the final fundamental type of conformational isomerization.

  20. Recursion Relations for Conformal Blocks

    CERN Document Server

    Penedones, João; Yamazaki, Masahito

    2016-09-12

    In the context of conformal field theories in general space-time dimension, we find all the possible singularities of the conformal blocks as functions of the scaling dimension $\\Delta$ of the exchanged operator. In particular, we argue, using representation theory of parabolic Verma modules, that in odd spacetime dimension the singularities are only simple poles. We discuss how to use this information to write recursion relations that determine the conformal blocks. We first recover the recursion relation introduced in 1307.6856 for conformal blocks of external scalar operators. We then generalize this recursion relation for the conformal blocks associated to the four point function of three scalar and one vector operator. Finally we specialize to the case in which the vector operator is a conserved current.

  1. Conformal algebra of Riemann surfaces

    International Nuclear Information System (INIS)

    Vafa, C.

    1988-01-01

    It has become clear over the last few years that 2-dimensional conformal field theories are a crucial ingredient of string theory. Conformal field theories correspond to vacuum solutions of strings; or more precisely we know how to compute string spectrum and scattering amplitudes by starting from a formal theory (with a proper value of central charge of the Virasoro algebra). Certain non-linear sigma models do give rise to conformal theories. A lot of progress has been made in the understanding of conformal theories. The author discusses a different view of conformal theories which was motivated by the development of operator formalism on Riemann surfaces. The author discusses an interesting recent work from this point of view

  2. The logarithmic conformal field theories

    International Nuclear Information System (INIS)

    Rahimi Tabar, M.R.; Aghamohammadi, A.; Khorrami, M.

    1997-01-01

    We study the correlation functions of logarithmic conformal field theories. First, assuming conformal invariance, we explicitly calculate two- and three-point functions. This calculation is done for the general case of more than one logarithmic field in a block, and more than one set of logarithmic fields. Then we show that one can regard the logarithmic field as a formal derivative of the ordinary field with respect to its conformal weight. This enables one to calculate any n-point function containing the logarithmic field in terms of ordinary n-point functions. Finally, we calculate the operator product expansion (OPE) coefficients of a logarithmic conformal field theory, and show that these can be obtained from the corresponding coefficients of ordinary conformal theory by a simple derivation. (orig.)

  3. Molecular Orbital and Density Functional Study of the Formation, Charge Transfer, Bonding and the Conformational Isomerism of the Boron Trifluoride (BF3 and Ammonia (NH3 Donor-Acceptor Complex

    Directory of Open Access Journals (Sweden)

    Dulal C. Ghosh

    2004-09-01

    Full Text Available The formation of the F3B–NH3 supermolecule by chemical interaction of its fragment parts, BF3 and NH3, and the dynamics of internal rotation about the ‘B–N’ bond have been studied in terms of parameters provided by the molecular orbital and density functional theories. It is found that the pairs of frontier orbitals of the interacting fragments have matching symmetry and are involved in the charge transfer interaction. The donation process stems from the HOMO of the donor into the LUMO of the acceptor and simultaneously, back donation stems from the HOMO of acceptor into the LUMO of the donor. The density functional computation of chemical activation in the donor and acceptor fragments, associated with the physical process of structural reorganization just prior to the event of chemical reaction, indicates that BF3 becomes more acidic and NH3 becomes more basic, compared to their separate equilibrium states. Theoretically it is observed that the chemical reaction event of the formation of the supermolecule from its fragment parts is in accordance with the chemical potential equalization principle of the density functional theory and the electronegativity equalization principle of Sanderson. The energetics of the chemical reaction, the magnitude of the net charge transfer and the energy of the newly formed bond are quite consistent, both internally and with the principle of maximum hardness, PMH. The dynamics of the internal rotation of one part with respect to the other part of the supermolecule about the ‘B–N’ bond mimics the pattern of the conformational isomerism of the isostructural ethane molecule. It is also observed that the dynamics and evolution of molecular conformations as a function of dihedral angles is also in accordance with the principle of maximum hardness, PMH. Quite consistent with spectroscopic predictions, the height of the molecule

  4. The influence of open fracture anisotropy on CO2 movement within geological storage complexes

    Science.gov (United States)

    Bond, C. E.; Wightman, R.; Ringrose, P. S.

    2012-12-01

    Carbon mitigation through the geological storage of carbon dioxide is dependent on the ability of geological formations to store CO2 trapping it within a geological storage complex. Secure long-term containment needs to be demonstrated, due to both political and social drivers, meaning that this containment must be verifiable over periods of 100-105 years. The effectiveness of sub-surface geological storage systems is dependent on trapping CO2 within a volume of rock and is reliant on the integrity of the surrounding rocks, including their chemical and physical properties, to inhibit migration to the surface. Oil and gas reservoir production data, and field evidence show that fracture networks have the potential to act as focused pathways for fluid movement. Fracture networks can allow large volumes of fluid to migrate to the surface within the time scales of interest. In this paper we demonstrate the importance of predicting the effects of fracture networks in storage, using a case study from the In Salah CO2 storage site, and show how the fracture permeability is closely controlled by the stress regime that determines the open fracture network. Our workflow combines well data of imaged fractures, with a discrete fracture network (DFN) model of tectonically induced fractures, within the horizon of interest. The modelled and observed fractures have been compared and combined with present day stress data to predict the open fracture network and its implications for anisotropic movement of CO2 in the sub-surface. The created fracture network model has been used to calculate the 2D permeability tensor for the reservoir for two scenarios: 1) a model in which all fractures are permeable, based on the whole DFN model and 2) those fractures determined to be in dilatational failure under the present day stress regime, a sub-set of the DFN. The resulting permeability anisotropy tensors show distinct anisotropies for the predicted CO2 movement within the reservoir. These

  5. How does ulnar shortening osteotomy influence morphologic changes in the triangular fibrocartilage complex?

    Science.gov (United States)

    Yamanaka, Yoshiaki; Nakamura, Toshiyasu; Sato, Kazuki; Toyama, Yoshiaki

    2014-11-01

    Ulnar shortening osteotomy often is indicated for treatment of injuries to the triangular fibrocartilage complex (TFCC). However, the effect of ulnar shortening osteotomy on the changes in shape of the TFCC is unclear. In our study, quantitative evaluations were performed using MRI to clarify the effect of ulnar shortening on triangular fibrocartilage (TFC) thickness attributable to disc regeneration of the TFC and TFC angle attributable to the suspension effect of ulnar shortening on the TFC. The purposes of this study were (1) to compare preoperative and postoperative TFC thickness and TFC angle on MR images to quantitatively evaluate the effect of ulnar shortening osteotomy on disc regeneration and the suspension effect on the TFC; and (2) to assess whether changes in TFC thickness and TFC angle correlated with the Mayo wrist score. Between 1995 and 2008, 256 patients underwent ulnar shortening osteotomy for TFCC injuries. The minimum followup was 24 months (mean, 51 months; range, 24-210 months). A total of 79 patients (31%) with complete followup including preoperative and postoperative MR images and the Mayo wrist score was included in this retrospective study. Evaluation of the postoperative MR images and the Mayo wrist score were performed at the final followup. The remaining 177 patients did not undergo postoperative MRI, or they had a previous fracture, large tears of the disc proper, or were lost to followup. Two orthopaedists, one of whom performed the surgeries, measured the TFC thickness and the TFC angle on coronal MR images before and after surgery for each patient. Correlations of the percent change in the TFC thickness and the magnitude of TFC angle change with age, sex, postoperative MR images, extent of ulnar shortening, preoperative ulnar variance, and postoperative Mayo wrist score were assessed. Stepwise regression analysis showed a correlation between the percent change in TFC thickness and preoperative ulnar variance (R2=0.21; β=-0.33; 95

  6. Popularity, likeability, and peer conformity : Four field experiments. Journal of Experimental Social Psychology

    NARCIS (Netherlands)

    Gommans, R.; Sandstrom, Marlene J.; Stevens, G.W.J.M.; ter Bogt, T.F.M.; Cillessen, Toon

    2017-01-01

    Adolescents tend to alter their attitudes and behaviors to match those of others; a peer influence process named peer conformity. This study investigated to what extent peer conformity depended on the status (popularity and likeability) of the influencer and the influencee. The study consisted of

  7. The influence of complex compost on the aggregate composition and water and air properties of an ordinary chernozem

    Science.gov (United States)

    Belyuchenko, I. S.; Antonenko, D. A.

    2015-07-01

    The influence of complex compost composed of the waste products of the agriculture (semi-rotted cattle manure and plant residues) and chemical industries (phosphogypsum) on the agrophysical properties of an ordinary chernozem (Haplic Chernozem) was studied in the western Ciscaucasian region. In the field experiment, the compost was applied to the plow layer (0-20 cm) in 2007. In five years, the content of agronomically valuable aggregates increased by 7-9%, and their water stability became higher. This resulted in a better aggregation of the plow layer; its bulk density decreased by about 0.1 g/cm3 in comparison with the control plot treated with mineral fertilizers according to traditional technology. The water and air properties of the soil were optimized, which was seen from an increase in the field and total water capacity, total porosity, and soil water storage.

  8. The combination of major histocompatibility complex (MHC) and non-MHC genes influences murine lymphocytic choriomeningitis virus pathogenesis

    DEFF Research Database (Denmark)

    Eyler, Y L; Pfau, C J; Broomhall, K S

    1989-01-01

    with the recessive disease phenotype. In all cases, susceptibility was dominant. In backcross progeny obtained from matings of parental strains differing in both major histocompatibility complex (MHC) and non-MHC (SWR; C3H), 90% of the challenged mice died, indicating that at least three loci controlled...... susceptibility to the disease. When the parental strains carried similar MHC haplotypes but dissimilar background genes (B10.BR; CBA), 78% of the backcross mice succumbed, indicating that at least two non-MHC loci influenced disease susceptibility. It is unlikely, however, that the same two non-MHC loci...... are critical in all genetic combinations, since F1 produced from two H-2 identical, resistant strains (B10.BR; C3H) were found to be fully susceptible. When congenic mice, differing only in the D-end of the MHC region, were analysed, 50% of the backcross animals died, indicating that one gene in the MHC region...

  9. Influence of the π-coordinated arene on the anticancer activity of ruthenium(II carbohydrate organometallic complexes

    Directory of Open Access Journals (Sweden)

    Muhammad eHanif

    2013-10-01

    Full Text Available The synthesis and in vitro cytotoxicity of a series of RuII(arene complexes with carbohydrate-derived phosphite ligands and various arene co-ligands is described. The arene ligand has a strong influence on the in vitro anticancer activity of this series of compounds, which correlates fairly well with cellular accumulation. The most lipophilic compound bearing a biphenyl moiety and a cyclohexylidene-protected carbohydrate is the most cytotoxic with unprecedented IC50 values for the compound class in three human cancer cell lines. This compound shows reactivity to the DNA model nucleobase 9-ethylguanine, but does not alter the secondary structure of plasmid DNA indicating that other biological targets are responsible for its cytotoxic effect.

  10. Conformal solids and holography

    Science.gov (United States)

    Esposito, A.; Garcia-Saenz, S.; Nicolis, A.; Penco, R.

    2017-12-01

    We argue that a SO( d) magnetic monopole in an asymptotically AdS space-time is dual to a d-dimensional strongly coupled system in a solid state. In light of this, it would be remiss of us not to dub such a field configuration solidon. In the presence of mixed boundary conditions, a solidon spontaneously breaks translations (among many other symmetries) and gives rise to Goldstone excitations on the boundary — the phonons of the solid. We derive the quadratic action for the boundary phonons in the probe limit and show that, when the mixed boundary conditions preserve conformal symmetry, the longitudinal and transverse sound speeds are related to each other as expected from effective field theory arguments. We then include backreaction and calculate the free energy of the solidon for a particular choice of mixed boundary conditions, corresponding to a relevant multi-trace deformation of the boundary theory. We find such free energy to be lower than that of thermal AdS. This suggests that our solidon undergoes a solid-to-liquid first order phase transition by melting into a Schwarzschild-AdS black hole as the temperature is raised.

  11. Intensity modulated conformal radiotherapy

    International Nuclear Information System (INIS)

    Noel, Georges; Moty-Monnereau, Celine; Meyer, Aurelia; David, Pauline; Pages, Frederique; Muller, Felix; Lee-Robin, Sun Hae; David, Denis Jean

    2006-12-01

    This publication reports the assessment of intensity-modulated conformal radiotherapy (IMCR). This assessment is based on a literature survey which focussed on indications, efficiency and safety on the short term, on the risk of radio-induced cancer on the long term, on the role in the therapeutic strategy, on the conditions of execution, on the impact on morbidity-mortality and life quality, on the impact on the health system and on public health policies and program. This assessment is also based on the opinion of a group of experts regarding the technical benefit of IMCR, its indications depending on the cancer type, safety in terms of radio-induced cancers, and conditions of execution. Before this assessment, the report thus indicates indications for which the use of IMCR can be considered as sufficient or not determined. It also proposes a technical description of IMCR and helical tomo-therapy, discusses the use of this technique for various pathologies or tumours, analyses the present situation of care in France, and comments the identification of this technique in foreign classifications

  12. 6d Conformal matter

    International Nuclear Information System (INIS)

    Zotto, Michele Del; Heckman, Jonathan J.; Tomasiello, Alessandro; Vafa, Cumrun

    2015-01-01

    A single M5-brane probing G, an ADE-type singularity, leads to a system which has G×G global symmetry and can be viewed as “bifundamental” (G,G) matter. For the A N series, this leads to the usual notion of bifundamental matter. For the other cases it corresponds to a strongly interacting (1,0) superconformal system in six dimensions. Similarly, an ADE singularity intersecting the Hořava-Witten wall leads to a superconformal matter system with E 8 ×G global symmetry. Using the F-theory realization of these theories, we elucidate the Coulomb/tensor branch of (G,G ′ ) conformal matter. This leads to the notion of fractionalization of an M5-brane on an ADE singularity as well as fractionalization of the intersection point of the ADE singularity with the Hořava-Witten wall. Partial Higgsing of these theories leads to new 6d SCFTs in the infrared, which we also characterize. This generalizes the class of (1,0) theories which can be perturbatively realized by suspended branes in IIA string theory. By reducing on a circle, we arrive at novel duals for 5d affine quiver theories. Introducing many M5-branes leads to large N gravity duals.

  13. Quantifying the Physiological Stress Response to Simulated Maritime Pilotage Tasks: The Influence of Task Complexity and Pilot Experience.

    Science.gov (United States)

    Main, Luana C; Wolkow, Alexander; Chambers, Timothy P

    2017-11-01

    The aim of this study was to quantify the stress associated with performing maritime pilotage tasks in a high-fidelity simulator. Eight trainee and 13 maritime pilots completed two simulated pilotage tasks of varying complexity. Salivary cortisol samples were collected pre- and post-simulation for both trials. Heart rate was measured continuously throughout the study. Significant changes in salivary cortisol (P = 0.000, η = 0.139), average (P = 0.006, η = 0.087), and peak heart rate (P = 0.013, η = 0.077) from pre- to postsimulation were found. Varying task complexity did partially influence stress response; average (P = 0.016, η = 0.026) and peak heart rate (P = 0.034, η = 0.020) were higher in the experimental condition. Trainees also recorded higher average (P = 0.000, η = 0.054) and peak heart rates (P = 0.027, η = 0.022). Performing simulated pilotage tasks evoked a measurable stress response in both trainee and expert maritime pilots.

  14. An evaluation of factors influencing pore pressure in accretionary complexes: Implications for taper angle and wedge mechanics

    Science.gov (United States)

    Saffer, D.M.; Bekins, B.A.

    2006-01-01

    At many subduction zones, accretionary complexes form as sediment is off-scraped from the subducting plate. Mechanical models that treat accretionary complexes as critically tapered wedges of sediment demonstrate that pore pressure controls their taper angle by modifying basal and internal shear strength. Here, we combine a numerical model of groundwater flow with critical taper theory to quantify the effects of sediment and de??collement permeability, sediment thickness, sediment partitioning between accretion and underthrusting, and plate convergence rate on steady state pore pressure. Our results show that pore pressure in accretionary wedges can be viewed as a dynamically maintained response to factors which drive pore pressure (source terms) and those that limit flow (permeability and drainage path length). We find that sediment permeability and incoming sediment thickness are the most important factors, whereas fault permeability and the partitioning of sediment have a small effect. For our base case model scenario, as sediment permeability is increased, pore pressure decreases from near-lithostatic to hydrostatic values and allows stable taper angles to increase from ??? 2.5?? to 8??-12.5??. With increased sediment thickness in our models (from 100 to 8000 m), increased pore pressure drives a decrease in stable taper angle from 8.4??-12.5?? to 15?? to <4??) with increased sediment thickness (from <1 to 7 km). One key implication is that hydrologic properties may strongly influence the strength of the crust in a wide range of geologic settings. Copyright 2006 by the American Geophysical Union.

  15. The influence of venous blood flow on the retinal ganglion cell complex in patients with primary open angle glaucoma

    Directory of Open Access Journals (Sweden)

    N. I. Kurysheva

    2014-07-01

    Full Text Available Purpose: To study the influence of venous blood flow on the ganglion cell complex (GCC in patients with preperimetric and perimetric open angle glaucoma.Methods: 74 patients were included in the research. 59 eyes and 62 eyes were diagnosed with preperimetric and perimetric open angle glaucoma respectively. The mean age was 56.5±10.5 years. 22 (12 female and 10 male healthy individuals constituted the control group. The ganglion cell complex and retinal nerve fibre layer were evaluated with the help of optical coherence tomography (RTVue-100 OCT, Optovue, Inc., Fremont, CA. Ocular blood flow was measured by Color Doppler Imaging (multifunctional VOLUSON 730 ProSystem. The statistical analysis included correlation between GCC and RNFL thickness in both glaucoma groups.Results: The results showed a statistically significant reduction of venous blood flow velocity in both glaucoma groups compared to the control group. No difference in venous blood flow parameters between two glaucoma groups was found, except resistance index, which was higher in perimetric group in comparison to preperimetric group. A correlation was also obtained between venous blood flow parameters and GCC and RNFL thickness in both glaucoma groups.Conclusion: Early GCC damage in glaucoma might occur due to venous blood flow reduction. This fact may be of great value in understanding glaucoma pathogenesis and search for novel treatment options.

  16. Influence of processing parameters on pore structure of 3D porous chitosan-alginate polyelectrolyte complex scaffolds.

    Science.gov (United States)

    Florczyk, Stephen J; Kim, Dae-Joon; Wood, David L; Zhang, Miqin

    2011-09-15

    Fabrication of porous polymeric scaffolds with controlled structure can be challenging. In this study, we investigated the influence of key experimental parameters on the structures and mechanical properties of resultant porous chitosan-alginate (CA) polyelectrolyte complex (PEC) scaffolds, and on proliferation of MG-63 osteoblast-like cells, targeted at bone tissue engineering. We demonstrated that the porous structure is largely affected by the solution viscosity, which can be regulated by the acetic acid and alginate concentrations. We found that the CA PEC solutions with viscosity below 300 Pa.s yielded scaffolds of uniform pore structure and that more neutral pH promoted more complete complexation of chitosan and alginate, yielding stiffer scaffolds. CA PEC scaffolds produced from solutions with viscosities below 300 Pa.s also showed enhanced cell proliferation compared with other samples. By controlling the key experimental parameters identified in this study, CA PEC scaffolds of different structures can be made to suit various tissue engineering applications. Copyright © 2011 Wiley Periodicals, Inc.

  17. Towards conformal loop quantum gravity

    International Nuclear Information System (INIS)

    Wang, Charles H-T

    2006-01-01

    A discussion is given of recent developments in canonical gravity that assimilates the conformal analysis of gravitational degrees of freedom. The work is motivated by the problem of time in quantum gravity and is carried out at the metric and the triad levels. At the metric level, it is shown that by extending the Arnowitt-Deser-Misner (ADM) phase space of general relativity (GR), a conformal form of geometrodynamics can be constructed. In addition to the Hamiltonian and Diffeomorphism constraints, an extra first class constraint is introduced to generate conformal transformations. This phase space consists of York's mean extrinsic curvature time, conformal three-metric and their momenta. At the triad level, the phase space of GR is further enlarged by incorporating spin-gauge as well as conformal symmetries. This leads to a canonical formulation of GR using a new set of real spin connection variables. The resulting gravitational constraints are first class, consisting of the Hamiltonian constraint and the canonical generators for spin-gauge and conformorphism transformations. The formulation has a remarkable feature of being parameter-free. Indeed, it is shown that a conformal parameter of the Barbero-Immirzi type can be absorbed by the conformal symmetry of the extended phase space. This gives rise to an alternative approach to loop quantum gravity that addresses both the conceptual problem of time and the technical problem of functional calculus in quantum gravity

  18. Benchmarking Commercial Conformer Ensemble Generators.

    Science.gov (United States)

    Friedrich, Nils-Ole; de Bruyn Kops, Christina; Flachsenberg, Florian; Sommer, Kai; Rarey, Matthias; Kirchmair, Johannes

    2017-11-27

    We assess and compare the performance of eight commercial conformer ensemble generators (ConfGen, ConfGenX, cxcalc, iCon, MOE LowModeMD, MOE Stochastic, MOE Conformation Import, and OMEGA) and one leading free algorithm, the distance geometry algorithm implemented in RDKit. The comparative study is based on a new version of the Platinum Diverse Dataset, a high-quality benchmarking dataset of 2859 protein-bound ligand conformations extracted from the PDB. Differences in the performance of commercial algorithms are much smaller than those observed for free algorithms in our previous study (J. Chem. Inf. 2017, 57, 529-539). For commercial algorithms, the median minimum root-mean-square deviations measured between protein-bound ligand conformations and ensembles of a maximum of 250 conformers are between 0.46 and 0.61 Å. Commercial conformer ensemble generators are characterized by their high robustness, with at least 99% of all input molecules successfully processed and few or even no substantial geometrical errors detectable in their output conformations. The RDKit distance geometry algorithm (with minimization enabled) appears to be a good free alternative since its performance is comparable to that of the midranked commercial algorithms. Based on a statistical analysis, we elaborate on which algorithms to use and how to parametrize them for best performance in different application scenarios.

  19. Dynamic conformational change regulates the protein-DNA recognition: an investigation on binding of a Y-family polymerase to its target DNA.

    Directory of Open Access Journals (Sweden)

    Xiakun Chu

    2014-09-01

    Full Text Available Protein-DNA recognition is a central biological process that governs the life of cells. A protein will often undergo a conformational transition to form the functional complex with its target DNA. The protein conformational dynamics are expected to contribute to the stability and specificity of DNA recognition and therefore may control the functional activity of the protein-DNA complex. Understanding how the conformational dynamics influences the protein-DNA recognition is still challenging. Here, we developed a two-basin structure-based model to explore functional dynamics in Sulfolobus solfataricus DNA Y-family polymerase IV (DPO4 during its binding to DNA. With explicit consideration of non-specific and specific interactions between DPO4 and DNA, we found that DPO4-DNA recognition is comprised of first 3D diffusion, then a short-range adjustment sliding on DNA and finally specific binding. Interestingly, we found that DPO4 is under a conformational equilibrium between multiple states during the binding process and the distributions of the conformations vary at different binding stages. By modulating the strength of the electrostatic interactions, the flexibility of the linker, and the conformational dynamics in DPO4, we drew a clear picture on how DPO4 dynamically regulates the DNA recognition. We argue that the unique features of flexibility and conformational dynamics in DPO4-DNA recognition have direct implications for low-fidelity translesion DNA synthesis, most of which is found to be accomplished by the Y-family DNA polymerases. Our results help complete the description of the DNA synthesis process for the Y-family polymerases. Furthermore, the methods developed here can be widely applied for future investigations on how various proteins recognize and bind specific DNA substrates.

  20. Conformal invariance in harmonic superspace

    International Nuclear Information System (INIS)

    Galperin, A.; Ivanov, E.; Ogievetsky, V.; Sokatchev, E.

    1987-01-01

    In the present paper we show how the N = 2 superconformal group is realised in harmonic superspace and examine conformal invariance of N = 2 off-shell theories. We believe that the example of N = O self-dual Yang-Mills equations can serve as an instructive introduction to the subject of harmonic superspace and this is examined. The rigid N = 2 conformal supersymmetry and its local version, i.e. N = 2 conformal supergravity is also discussed. The paper is a contribution to the book commemorating the sixtieth birthday of E.S. Fradkin. (author)

  1. Harmony of spinning conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Sobko, Evgeny [Stockholm Univ. (Sweden); Nordita, Stockholm (Sweden); Isachenkov, Mikhail [Weizmann Institute of Science, Rehovoth (Israel). Dept. of Particle Physics and Astrophysics

    2016-12-07

    Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

  2. Harmony of spinning conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Volker [DESY Hamburg, Theory Group,Notkestraße 85, 22607 Hamburg (Germany); Sobko, Evgeny [Nordita and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Isachenkov, Mikhail [Department of Particle Physics and Astrophysics, Weizmann Institute of Science,Rehovot 7610001 (Israel)

    2017-03-15

    Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

  3. Mass generation within conformal invariant theories

    International Nuclear Information System (INIS)

    Flato, M.; Guenin, M.

    1981-01-01

    The massless Yang-Mills theory is strongly conformally invariant and renormalizable; however, when masses are introduced the theory becomes nonrenormalizable and weakly conformally invariant. Conditions which recover strong conformal invariance are discussed in the letter. (author)

  4. Moduli spaces of unitary conformal field theories

    International Nuclear Information System (INIS)

    Wendland, K.

    2000-08-01

    We investigate various features of moduli spaces of unitary conformal field theories. A geometric characterization of rational toroidal conformal field theories in arbitrary dimensions is presented and discussed in relation to singular tori and those with complex multiplication. We study the moduli space M 2 of unitary two-dimensional conformal field theories with central charge c = 2. All the 26 non-exceptional non-isolated irreducible components of M 2 are constructed that may be obtained by an orbifold procedure from toroidal theories. The parameter spaces and partition functions are calculated explicitly. All multicritical points and lines are determined, such that all but three of these 26 components are directly or indirectly connected to the space of toroidal theories in M 2 . Relating our results to those by Dixon, Ginsparg, Harvey on the classification of c = 3/2 superconformal field theories, we give geometric interpretations to all non-isolated orbifolds discussed by them and correct their statements on multicritical points within the moduli space of c = 3/2 superconformal field theories. In the main part of this work, we investigate the moduli space M of N = (4, 4) superconformal field theories with central charge c = 6. After a slight emendation of its global description we give generic partition functions for models contained in M. We explicitly determine the locations of various known models in the component of M associated to K3 surfaces

  5. Conformal geometry and invariants of 3-strand Brownian braids

    International Nuclear Information System (INIS)

    Nechaev, Sergei; Voituriez, Raphael

    2005-01-01

    We propose a simple geometrical construction of topological invariants of 3-strand Brownian braids viewed as world lines of 3 particles performing independent Brownian motions in the complex plane z. Our construction is based on the properties of conformal maps of doubly-punctured plane z to the universal covering surface. The special attention is paid to the case of indistinguishable particles. Our method of conformal maps allows us to investigate the statistical properties of the topological complexity of a bunch of 3-strand Brownian braids and to compute the expectation value of the irreducible braid length in the non-Abelian case

  6. The Influence of Business Environmental Dynamism, Complexity and Munificence on Performance of Small and Medium Enterprises in Kenya

    Directory of Open Access Journals (Sweden)

    Washington Oduor Okeyo

    2014-08-01

    Full Text Available The main purpose of this article is to examine how business environment affects small and medium enterprises. The paper is motivated by the important contributions small and medium enterprises have in many countries, especially Kenya towards job creation, poverty reduction and economic development. Literature however argues that effectiveness of the contributions is conditioned by the state of business environmental factors such as politics, economy, socio-culture, technology, ecology and laws/regulations. Dynamism, complexity and munificence of these factors are therefore vital to achievement of organizational objectives and overall performance. Even so, a review of literature reveals contradictory views regarding the effect of these factors on performance of organizations. Furthermore, studies focusing on these factors in the Kenyan context, particularly with regard to their effect on performance of small and medium firms, are scarce. This article bridges this gap based on a study focusing on 800 manufacturing organizations in Nairobi – Kenya. A sample of 150 enterprises was selected through stratification by business sector followed by simple random sampling. The research design was cross sectional survey where data was collected using a structured questionnaire over a period of one month at the end of which 95 organizations responded giving a response rate of 64%. Reliability and validity of the instrument were determined through Cronbach’s alpha tests and expert reviews. Statistical Package for Social Sciences was used to determine normality through descriptive statistics and study hypotheses tested using inferential statistics. The study established that business environment had an overall impact on organizational performance. Specifically, dynamism, complexity and munificence each had a direct influence on the enterprises in the study. Furthermore the combined effect on performance was found to be greater than that of dynamism and

  7. Study by similarity of wind influence on mass transfers in complex buildings; Etude par similitude de l'influence du vent sur les transferts de masse dans les batiments complexes

    Energy Technology Data Exchange (ETDEWEB)

    Le Roux, Nicolas

    2011-12-05

    Residential and industrial buildings equipped with a ventilation system are complex facilities, where various heat and mass transfers could occur according to the operating conditions. In order to study these mass transfers, a methodology has been developed so as to carry out reduced-scale experiments for the study of isothermal flows, in steady or transient state. This methodology has been numerically and experimentally validated on simple configurations, and then applied to two standard configurations, representing nuclear facilities. The wind influence on mass transfers inside these configurations, in normal, damaged (stopping ventilation) or accidental (internal overpressure) situations, has been studied in the Jules Verne climatic wind tunnel of the CSTB. The wind effects, coupled or not with an internal overpressure, can lead to a partial or a total loss of the pollutant's containment inside buildings. Moreover, the wind turbulence can bring about instantaneous reversal leakage flow-rates, which cannot be identified in steady state. In addition, the study of transient phenomena has highlighted the low influence of the branch inertia on transient flows, for typical values of real facilities. Finally, tracer tests have been carried out in order to study the pollutant dispersion inside a standard configuration subjected to wind, mechanical ventilation and internal overpressure effects. The reliability of the zonal code SYLVIA, used notably to support safety assessment in nuclear buildings, has been analyzed from these experimental results. The modelling of the physical phenomena experimentally observed has been validated, in steady and transient states. However, limitations have been identified for the study of pollutant dispersion, due to hypothesis used in SYLVIA code, as in all zonal codes (homogenous concentration inside rooms, instantaneous propagation inside branches and rooms). (author)

  8. Energy of knots and conformal geometry

    CERN Document Server

    O'Hara, Jun

    2003-01-01

    Energy of knots is a theory that was introduced to create a "canonical configuration" of a knot - a beautiful knot which represents its knot type. This book introduces several kinds of energies, and studies the problem of whether or not there is a "canonical configuration" of a knot in each knot type. It also considers this problems in the context of conformal geometry. The energies presented in the book are defined geometrically. They measure the complexity of embeddings and have applications to physical knotting and unknotting through numerical experiments. Contents: In Search of the "Optima

  9. Higher-derivative generalization of conformal mechanics

    Science.gov (United States)

    Baranovsky, Oleg

    2017-08-01

    Higher-derivative analogs of multidimensional conformal particle and many-body conformal mechanics are constructed. Their Newton-Hooke counterparts are derived by applying appropriate coordinate transformations.

  10. Naturality in conformal field theory

    International Nuclear Information System (INIS)

    Moore, G.; Seiberg, N.

    1989-01-01

    We discuss constraints on the operator product coefficients in diagonal and nondiagonal rational conformal field theories. Nondiagonal modular invariants always arise from automorphisms of the fusion rule algebra or from extensions of the chiral algebra. Moreover, when the chiral algebra has been maximally extended a strong form of the naturality principle of field theory can be proven for rational conformal field theory: operator product coefficients vanish if and only if the corresponding fusion rules vanish; that is, if and only if the vanishing can be understood in terms of a symmetry. We illustrate these ideas with several examples. We also generalize our ideas about rational conformal field theories to a larger class of theories: 'quasi-rational conformal field theories' and we explore some of their properties. (orig.)

  11. Steady states in conformal theories

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    A novel conjecture regarding the steady state behavior of conformal field theories placed between two heat baths will be presented. Some verification of the conjecture will be provided in the context of fluid dynamics and holography.

  12. National Automated Conformity Inspection Process -

    Data.gov (United States)

    Department of Transportation — The National Automated Conformity Inspection Process (NACIP) Application is intended to expedite the workflow process as it pertains to the FAA Form 81 0-10 Request...

  13. Aspect of the conformal invariance

    International Nuclear Information System (INIS)

    Bauer, M.

    1990-11-01

    This thesis is about the study of several physical and mathematical aspects of critical phenomena at two dimensions. These phenomena have remarkable symmetry properties in the coordonnates changes keeping the angles. They are named conformal theories

  14. Some Progress in Conformal Geometry

    Directory of Open Access Journals (Sweden)

    Sun-Yung A. Chang

    2007-12-01

    Full Text Available This is a survey paper of our current research on the theory of partial differential equations in conformal geometry. Our intention is to describe some of our current works in a rather brief and expository fashion. We are not giving a comprehensive survey on the subject and references cited here are not intended to be complete. We introduce a bubble tree structure to study the degeneration of a class of Yamabe metrics on Bach flat manifolds satisfying some global conformal bounds on compact manifolds of dimension 4. As applications, we establish a gap theorem, a finiteness theorem for diffeomorphism type for this class, and diameter bound of the $sigma_2$-metrics in a class of conformal 4-manifolds. For conformally compact Einstein metrics we introduce an eigenfunction compactification. As a consequence we obtain some topological constraints in terms of renormalized volumes.

  15. Conformity Adequacy Review: Region 5

    Science.gov (United States)

    Resources are for air quality and transportation government and community leaders. Information on the conformity SIP adequacy/inadequacy of state implementation plans (SIPs) in EPA Region 5 (IL, IN, MI, OH, WI) is provided here.

  16. Inverse bootstrapping conformal field theories

    Science.gov (United States)

    Li, Wenliang

    2018-01-01

    We propose a novel approach to study conformal field theories (CFTs) in general dimensions. In the conformal bootstrap program, one usually searches for consistent CFT data that satisfy crossing symmetry. In the new method, we reverse the logic and interpret manifestly crossing-symmetric functions as generating functions of conformal data. Physical CFTs can be obtained by scanning the space of crossing-symmetric functions. By truncating the fusion rules, we are able to concentrate on the low-lying operators and derive some approximate relations for their conformal data. It turns out that the free scalar theory, the 2d minimal model CFTs, the ϕ 4 Wilson-Fisher CFT, the Lee-Yang CFTs and the Ising CFTs are consistent with the universal relations from the minimal fusion rule ϕ 1 × ϕ 1 = I + ϕ 2 + T , where ϕ 1 , ϕ 2 are scalar operators, I is the identity operator and T is the stress tensor.

  17. Conformal radiotherapy: principles and classification

    International Nuclear Information System (INIS)

    Rosenwald, J.C.; Gaboriaud, G.; Pontvert, D.

    1999-01-01

    'Conformal radiotherapy' is the name fixed by usage and given to a new form of radiotherapy resulting from the technological improvements observed during the last ten years. While this terminology is now widely used, no precise definition can be found in the literature. Conformal radiotherapy refers to an approach in which the dose distribution is more closely 'conformed' or adapted to the actual shape of the target volume. However, the achievement of a consensus on a more specific definition is hampered by various difficulties, namely in characterizing the degree of 'conformality'. We have therefore suggested a classification scheme be established on the basis of the tools and the procedures actually used for all steps of the process, i.e., from prescription to treatment completion. Our classification consists of four levels: schematically, at level 0, there is no conformation (rectangular fields); at level 1, a simple conformation takes place, on the basis of conventional 2D imaging; at level 2, a 3D reconstruction of the structures is used for a more accurate conformation; and level 3 includes research and advanced dynamic techniques. We have used our personal experience, contacts with colleagues and data from the literature to analyze all the steps of the planning process, and to define the tools and procedures relevant to a given level. The corresponding tables have been discussed and approved at the European level within the Dynarad concerted action. It is proposed that the term 'conformal radiotherapy' be restricted to procedures where all steps are at least at level 2. (author)

  18. Conformal Cosmology and Supernova Data

    OpenAIRE

    Behnke, Danilo; Blaschke, David; Pervushin, Victor; Proskurin, Denis

    2000-01-01

    We define the cosmological parameters $H_{c,0}$, $\\Omega_{m,c}$ and $\\Omega_{\\Lambda, c}$ within the Conformal Cosmology as obtained by the homogeneous approximation to the conformal-invariant generalization of Einstein's General Relativity theory. We present the definitions of the age of the universe and of the luminosity distance in the context of this approach. A possible explanation of the recent data from distant supernovae Ia without a cosmological constant is presented.

  19. Scalar perturbations and conformal transformation

    International Nuclear Information System (INIS)

    Fabris, J.C.; Tossa, J.

    1995-11-01

    The non-minimal coupling of gravity to a scalar field can be transformed into a minimal coupling through a conformal transformation. We show how to connect the results of a perturbation calculation, performed around a Friedman-Robertson-Walker background solution, before and after the conformal transformation. We work in the synchronous gauge, but we discuss the implications of employing other frames. (author). 16 refs

  20. Interrogating the activities of conformational deformed enzyme by single-molecule fluorescence-magnetic tweezers microscopy

    Science.gov (United States)

    Guo, Qing; He, Yufan; Lu, H. Peter

    2015-01-01

    Characterizing the impact of fluctuating enzyme conformation on enzymatic activity is critical in understanding the structure–function relationship and enzymatic reaction dynamics. Different from studying enzyme conformations under a denaturing condition, it is highly informative to manipulate the conformation of an enzyme under an enzymatic reaction condition while monitoring the real-time enzymatic activity changes simultaneously. By perturbing conformation of horseradish peroxidase (HRP) molecules using our home-developed single-molecule total internal reflection magnetic tweezers, we successfully manipulated the enzymatic conformation and probed the enzymatic activity changes of HRP in a catalyzed H2O2–amplex red reaction. We also observed a significant tolerance of the enzyme activity to the enzyme conformational perturbation. Our results provide a further understanding of the relation between enzyme behavior and enzymatic conformational fluctuation, enzyme–substrate interactions, enzyme–substrate active complex formation, and protein folding–binding interactions. PMID:26512103

  1. Habitat selection of two gobies (Microgobius gulosus, Gobiosoma robustum): influence of structural complexity, competitive interactions and presence of a predator

    Science.gov (United States)

    Schofield, P.J.

    2003-01-01

    Herein I compare the relative importance of preference for structurally complex habitat against avoidance of competitors and predators in two benthic fishes common in the Gulf of Mexico. The code goby Gobiosoma robustum Ginsburg and clown goby Microgobius gulosus (Girard) are common, ecologically similar fishes found throughout the Gulf of Mexico and in the southeastern Atlantic Ocean. In Florida Bay, these fishes exhibit habitat partitioning: G. robustum is most abundant in seagrass-dominated areas while M. gulosus is most abundant in sparsely vegetated habitats. In a small-scale field survey, I documented the microhabitat use of these species where their distributions overlap. In a series of laboratory experiments, I presented each species with structured (artificial seagrass) versus nonstructured (bare sand) habitats and measured their frequency of choosing either habitat type. I then examined the use of structured versus nonstructured habitats when the two species were placed together in a mixed group. Finally, I placed a predator (Opsanus beta) in the experimental aquaria to determine how its presence influenced habitat selection. In the field, G. robustum was more abundant in seagrass and M. gulosus was more abundant in bare mud. In the laboratory, both species selected grass over sand in allopatry. However, in sympatry, M. gulosus occupied sand more often when paired with G. robustum than when alone. G. robustum appears to directly influence the habitat choice of M. gulosus: It seems that M. gulosus is pushed out of the structured habitat that is the preferred habitat of G. robustum. Thus, competition appears to modify the habitat selection of these species when they occur in sympatry. Additionally, the presence of the toadfish was a sufficient stimulus to provoke both M. gulosus and G. robustum to increase their selection for sand (compared to single-species treatments). Distribution patterns of M. gulosus and G. robustum

  2. Influence of Beaver-Induced Complexity on Storage of Organic Carbon and Sediment in Colorado Mountain Streams

    Science.gov (United States)

    Laurel, D.; Wohl, E.

    2016-12-01

    Beaver meadows (complexes of multiple different aged beaver dams and ponds) influence the storage of water, sediment, and nutrients. Although beaver meadows compose only a small fraction of catchment area, they provide a potentially large role in retaining these fluxes in mountain watersheds. Multiple dams and ponds in beaver meadows increase overbank flows leading to an anastomosing stream channel planform, and deposition of fine sediment along with particulate organic carbon. An earlier study estimated a range of cumulative carbon stored in 27 beaver meadows east of the continental divide in Rocky Mountain National Park. Storage ranged from 735,800 to 2.8 x 106 Mg carbon, with the high value estimating storage if all the meadows had active beaver (historic conditions pre-European settlement) and the lower value estimating current conditions where many of the meadows are abandoned. We combined geomorphic surveys, soil depth probing by rebar, and soil cores analyzed for carbon content to investigate the influence of beaver activity, meadow size, and meadow placement within the drainage on catchment-scale fluxes of fine sediment and organic carbon. We found carbon storage in floodplain soils to be highly variable across both active and abandoned meadows; however, active beaver meadows store more carbon on average than abandoned meadows. In addition, active meadows with high levels of beaver activity (multiple colonies) stored greater volumes of fine sediment behind dams and in ponds. These results have implications for the restoration potential of abandoned beaver meadows in mountain environments to store greater volumes of sediment and more organic carbon if beaver are successfully reintroduced.

  3. Klotho: a humeral mediator in CSF and plasma that influences longevity and susceptibility to multiple complex disorders, including depression.

    Science.gov (United States)

    Pavlatou, M G; Remaley, A T; Gold, P W

    2016-08-30

    Klotho is a hormone secreted into human cerebrospinal fluid (CSF), plasma and urine that promotes longevity and influences the onset of several premature senescent phenotypes in mice and humans, including atherosclerosis, cardiovascular disease, stroke and osteoporosis. Preliminary studies also suggest that Klotho possesses tumor suppressor properties. Klotho's roles in these phenomena were first suggested by studies demonstrating that a defect in the Klotho gene in mice results in a significant decrease in lifespan. The Klotho-deficient mouse dies prematurely at 8-9 weeks of age. At 4-5 weeks of age, a syndrome resembling human ageing emerges consisting of atherosclerosis, osteoporosis, cognitive disturbances and alterations of hippocampal architecture. Several deficits in Klotho-deficient mice are likely to contribute to these phenomena. These include an inability to defend against oxidative stress in the central nervous system and periphery, decreased capacity to generate nitric oxide to sustain normal endothelial reactivity, defective Klotho-related mediation of glycosylation and ion channel regulation, increased insulin/insulin-like growth factor signaling and a disturbed calcium and phosphate homeostasis accompanied by altered vitamin D levels and ectopic calcification. Identifying the mechanisms by which Klotho influences multiple important pathways is an emerging field in human biology that will contribute significantly to understanding basic physiologic processes and targets for the treatment of complex diseases. Because many of the phenomena seen in Klotho-deficient mice occur in depressive illness, major depression and bipolar disorder represent illnesses potentially associated with Klotho dysregulation. Klotho's presence in CSF, blood and urine should facilitate its study in clinical populations.

  4. Conformational changes in matrix-isolated 6-methoxyindole: Effects of the thermal and infrared light excitations

    Energy Technology Data Exchange (ETDEWEB)

    Lopes Jesus, A. J. [CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); CQC, Faculty of Pharmacy, University of Coimbra, 3004-295 Coimbra (Portugal); Reva, I., E-mail: reva@qui.uc.pt; Fausto, R. [CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Araujo-Andrade, C. [CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Unidad Académica de Física de la Universidad Autónoma de Zacatecas, Zacatecas (Mexico); ICFO–The Institute of Photonic Sciences, 08860 Castelldefels (Barcelona) (Spain)

    2016-03-28

    Conformational changes induced thermally or upon infrared excitation of matrix-isolated 6-methoxyindole were investigated. Narrowband near-infrared excitation of the first overtone of the N–H stretching vibration of each one of the two identified conformers is found to induce a selective large-scale conversion of the pumped conformer into the other one. This easily controllable bidirectional process consists in the intramolecular reorientation of the methoxy group and allowed a full assignment of the infrared spectra of the two conformers. Matrices with different conformational compositions prepared by narrow-band irradiations were subsequently used to investigate the effects of both thermal and broadband infrared excitations on the conformational mixtures. Particular attention is given to the influence of the matrix medium (Ar vs. Xe) and conformational effects of exposition of the sample to the spectrometer light source during the measurements.

  5. CLINICAL, HISTOLOGICAL AND RADIOLOGICAL ASPECTS REGARDING THE INFLUENCE OF SOME EXTERNAL FACTORS ON THE PULP-DENTIN COMPLEX

    Directory of Open Access Journals (Sweden)

    C. Giuroiu

    2012-12-01

    Full Text Available The present study aimed at assesssing – by clinical, histological and radiological investigations – the influence of some external factors on the pulp-dentin complex, and at providing a causal interpretation of the structural changes observed. Materials and methods. Clinical and radiological exams were performed on 65 old patients with ages between 60-75, and also on 40 young patients with ages between 20-35, presenting different dental-periodontal pathologies. The pulp-dentin complex was submitted to a morphopathological examination, to highlight the structural changes observed at microscopic level. Fragments of dental pulp were imersed in a 4% formaldehyde solution with phosphate buffer 0.1 M., pH 7.2, for 12 -14 hours, at a temperature of 4ºC, and 3-5 µm thick slices were prepared. The slices were coloured with hematoxylin-eosine (HE, by the trichromic technique – Masson. Photographies were taken with a Zeiss microscope, with Kodak 200 ASA. Results. Significant differences were observed, between the two groups of patients, as to the external factors that produce structural changes on pulp-dentin organ. In the group of young patients dental caries and coronal fillings prevailed, while the group of old patients was mostly associated with atrition and chronic marginal periodontitis. Out of the 40 young patients, 30 presented chronic dental caries (75%, while, among the 65 old patients, only 24 presented dental caries (36.9%. The percentages of coronary fillings between the two study groups were close, which could be considered as one of the causes producing changes in the pulp-dentin organ, following aggresive preparation of cavities, the action of materials used for the protection of pulp-dentin complex or of the materials used for coronry fillings. Conclusions. Dental pulp has a remarkable ability to counteract the action of harmful factors, producing a mineral barrier and stimulating the reparatory processes. Changes in the endodontic

  6. Influence of substituents of nickel(II) complexes of Schiff bases of substituted (S)-2-N-(benzylpropyl)aminobenzophenones and amino-acids on their asymmetric induction

    International Nuclear Information System (INIS)

    Nadvornik, M.; Lycka, A.; Gee, A.; Popkov, A.

    1999-01-01

    The aim of this work was to study of influence of substituents on benzophenone substituent on thermodynamic controlled induction of complexes as well as influence of substituents on benzyl group and on benzophenone on kinetically controlled asymmetric induction of complexes. [ 13 C]methyl iodide was used in the synthesis. Replace of benzyl group by 2,4,6-trimethylbenzyl group increase kinetically controlled asymmetric induction of synthesis of (S)-α-[ 13 C]methylalanine from 43% d.e. to 66% d.e

  7. Quantum Conformal Algebras and Closed Conformal Field Theory

    CERN Document Server

    Anselmi, D

    1999-01-01

    We investigate the quantum conformal algebras of N=2 and N=1 supersymmetric gauge theories. Phenomena occurring at strong coupling are analysed using the Nachtmann theorem and very general, model-independent, arguments. The results lead us to introduce a novel class of conformal field theories, identified by a closed quantum conformal algebra. We conjecture that they are the exact solution to the strongly coupled large-N_c limit of the open conformal field theories. We study the basic properties of closed conformal field theory and work out the operator product expansion of the conserved current multiplet T. The OPE structure is uniquely determined by two central charges, c and a. The multiplet T does not contain just the stress-tensor, but also R-currents and finite mass operators. For this reason, the ratio c/a is different from 1. On the other hand, an open algebra contains an infinite tower of non-conserved currents, organized in pairs and singlets with respect to renormalization mixing. T mixes with a se...

  8. Influence of FGR complexity modelling on the practical results in gas pressure calculation of selected fuel elements from Dukovany NPP

    International Nuclear Information System (INIS)

    Lahodova, M.

    2001-01-01

    A modernization fuel system and advanced fuel for operation up to the high burnup are used in present time in Dukovany NPP. Reloading of the cores are evaluated using computer codes for thermomechanical behavior of the most loaded fuel rods. The paper presents results of parametric calculations performed by the NRI Rez integral code PIN, version 2000 (PIN2k) to assess influence of fission gas release modelling complexity on achieved results. The representative Dukovany NPP fuel rod irradiation history data are used and two cases of fuel parameter variables (soft and hard) are chosen for the comparison. Involved FGR models where the GASREL diffusion model developed in the NRI Rez plc and standard Weisman model that is recommended in the previous version of the PIN integral code. FGR calculation by PIN2k with GASREL model represents more realistic results than standard Weisman's model. Results for linear power, fuel centre temperature, FGR and gas pressure versus burnup are given for two fuel rods

  9. Influence of complexing agent (Na2EDTA on chemical bath deposited Cu4SnS4 thin films

    Directory of Open Access Journals (Sweden)

    Anuar Kassim

    2010-08-01

    Full Text Available The quality of thin film is influenced by the presence of complexing agents such as Na2EDTA. The Cu4SnS4 thin films were deposited onto indium tin oxide glass substrate by chemical bath deposition method. The structural, morphological and optical properties of the deposited films have been studied using X-ray diffraction, atomic force microscopy and UV-Vis spectrophotometer, respectively. The XRD data showed that the films have a polycrystalline and orthorhombic structure. It also indicated that the most intense peak at 2 θ = 30.2° which belongs to (221 plane of Cu4 SnS4. The film deposited with 0.05 M Na2 EDTA showed good uniformity, good surface coverage with bigger grains and produced higher absorbance value. The band gap energy varies with the variation of Na2EDTA concentration which ranging from 1.56-1.60 eV. Deposition at concentration of 0.05 M Na2EDTA proved to offer a reasonably good Cu4SnS4 thin film.

  10. Bronchial Mucus as a Complex Fluid: Molecular Interactions and Influence of Nanostructured Particles on Rheological and Transport Properties

    Directory of Open Access Journals (Sweden)

    Odziomek Marcin

    2017-06-01

    Full Text Available Transport properties of bronchial mucus are investigated by two-stage experimental approach focused on: (a rheological properties and (b mass transfer rate through the stagnant layer of solutions of mucus components (mucine, DNA, proteins and simulated multi-component mucus. Studies were done using thermostated horizontal diffusion cells with sodium cromoglycate and carminic acid as transferred solutes. Rheological properties of tested liquids was studied by a rotational viscometer and a cone-plate rheometer (dynamic method. First part of the studies demonstrated that inter-molecular interactions in these complex liquids influence both rheological and permeability characteristics. Transfer rate is governed not only by mucus composition and concentration but also by hydrophobic/hydrophilic properties of transported molecules. Second part was focused on the properties of such a layer in presence of selected nanostructured particles (different nanoclays and graphene oxide which may be present in lungs after inhalation. It was shown that most of such particles increase visco-elasticity of the mucus and reduce the rate of mass transfer of model drugs. Measured effects may have adverse impact on health, since they will reduce mucociliary clearance in vivo and slow down drug penetration to the bronchial epithelium during inhalation therapy.

  11. Influence of the neural tube/notochord complex on MyoD expression and cellular proliferation in chicken embryos

    Directory of Open Access Journals (Sweden)

    H.J. Alves

    2003-02-01

    Full Text Available Important advances have been made in understanding the genetic processes that control skeletal muscle formation. Studies conducted on quails detected a delay in the myogenic program of animals selected for high growth rates. These studies have led to the hypothesis that a delay in myogenesis would allow somitic cells to proliferate longer and consequently increase the number of embryonic myoblasts. To test this hypothesis, recently segmented somites and part of the unsegmented paraxial mesoderm were separated from the neural tube/notochord complex in HH12 chicken embryos. In situ hybridization and competitive RT-PCR revealed that MyoD transcripts, which are responsible for myoblast determination, were absent in somites separated from neural tube/notochord (1.06 and 0.06 10-3 attomol MyoD/1 attomol ß-actin for control and separated somites, respectively; P<0.01. However, reapproximation of these structures allowed MyoD to be expressed in somites. Cellular proliferation was analyzed by immunohistochemical detection of incorporated BrdU, a thymidine analogue. A smaller but not significant (P = 0.27 number of proliferating cells was observed in somites that had been separated from neural tube/notochord (27 and 18 for control and separated somites, respectively. These results confirm the influence of the axial structures on MyoD activation but do not support the hypothesis that in the absence of MyoD transcripts the cellular proliferation would be maintained for a longer period of time.

  12. Dynamic differentiation of GABAA-sensitive influences on orientation selectivity of complex cells in the cat striate cortex.

    Science.gov (United States)

    Pfleger, B; Bonds, A B

    1995-01-01

    The influence of GABAA receptors on orientation selectivity of cat complex cells was tested by iontophoresis of the GABAA receptor blockers bicuculline and N-methyl-bicuculline while stimulating with drifting sinusoidal gratings. Reduction of orientation tuning was markedly less than reported in previous studies that used drifting bars as visual stimuli. Only 3/31 cells lost orientation selectivity, with an average increase in bandwidth of 33%, as opposed to half the cells losing selectivity and a bandwidth increase for the remainder of 47% as reported previously. Infusion of GABAA blockers revealed a prominent stimulus onset transient response, lasting about 120 ms, that showed a broadening of orientation selectivity comparable to that found using drifting bars under similar circumstances. We believe that drifting gratings emphasize a steady-state response component that retains, in the presence of GABAA blockers, significant orientation selectivity. Because the onset transient is initially unselective for orientation, we suggest that the steady-state, orientation-selective response component develops from an alternate inhibitory mechanism, possibly mediated by GABAB receptors.

  13. How computational methods and relativistic effects influence the study of chemical reactions involving Ru-NO complexes?

    Science.gov (United States)

    Orenha, Renato Pereira; Santiago, Régis Tadeu; Haiduke, Roberto Luiz Andrade; Galembeck, Sérgio Emanuel

    2017-05-05

    Two treatments of relativistic effects, namely effective core potentials (ECP) and all-electron scalar relativistic effects (DKH2), are used to obtain geometries and chemical reaction energies for a series of ruthenium complexes in B3LYP/def2-TZVP calculations. Specifically, the reaction energies of reduction (A-F), isomerization (G-I), and Cl - negative trans influence in relation to NH 3 (J-L) are considered. The ECP and DKH2 approaches provided geometric parameters close to experimental data and the same ordering for energy changes of reactions A-L. From geometries optimized with ECP, the electronic energies are also determined by means of the same ECP and basis set combined with the computational methods: MP2, M06, BP86, and its derivatives, so as B2PLYP, LC-wPBE, and CCSD(T) (reference method). For reactions A-I, B2PLYP provides the best agreement with CCSD(T) results. Additionally, B3LYP gave the smallest error for the energies of reactions J-L. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Influence of complexing on physicochemical properties of polymer-salt solutions. Vliyanie kompleksoobrazovaniya na fiziko-khimicheskie svojstva polimerno-solevykh rastvorov

    Energy Technology Data Exchange (ETDEWEB)

    Ostroushko, A A; Yushkova, S M; Koridze, N V; Skobkoreva, N V; Zhuravleva, L I; Palitskaya, T A; Antropova, S V; Ostroushko, I P [Ural' skij Gosudarstvennyj Univ., Sverdlovsk (Russian Federation) AN SSSR, Moscow (Russian Federation). Inst. Obshchej i Neorganicheskoj Khimii

    1993-06-01

    Using the methods of spectrophotometry, viscosimetry, conductometry the influence of salt-polymer complexing processes on physicochemical prperties of aqueous solutions of yttrium, barium, copper nitrates and formates with polyvinyl alcohol was studied. Change of dynamic viscosity, specific electric conductivity of solutions in the process of complexing was shown. Thermal effects of salt-polymer interaction were measured. It is shown that decrease of transition temperature of polymer to plastic state in films, temperature and effective activation energy of salt decomposition is also connected with complexing. Effective values of surface tension on the boundary with air are measured. Coefficients of cation diffusion in polymer-salt solutions are estimated.

  15. Gauge fixing problem in the conformal QED

    International Nuclear Information System (INIS)

    Ichinose, Shoichi

    1986-01-01

    The gauge fixing problem in the conformal (spinor and scalar) QED is examined. For the analysis, we generalize Dirac's manifestly conformal-covariant formalism. It is shown that the (vector and matter) fields must obey a certain mixed (conformal and gauge) type of transformation law in order to fix the local gauge symmetry preserving the conformal invariance in the Lagrangian. (orig.)

  16. 40 CFR 93.154 - Conformity analysis.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Conformity analysis. 93.154 Section 93...) DETERMINING CONFORMITY OF FEDERAL ACTIONS TO STATE OR FEDERAL IMPLEMENTATION PLANS Determining Conformity of General Federal Actions to State or Federal Implementation Plans § 93.154 Conformity analysis. Any Federal...

  17. Structural studies of conformational changes of proteins upon phosphorylation: Structures of activated CheY, CheY-N16-FliM complex, and AAA + ATPase domain of NtrC1 in both inactive and active states

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seok-Yong [Univ. of California, Berkeley, CA (United States)

    2003-04-10

    Protein phosphorylation is a general mechanism for signal transduction as well as regulation of cellular function. Unlike phosphorylation in eukaryotic systems that uses Ser/Thr for the sites of modification, two-component signal transduction systems, which are prevalent in bacteria, archea, and lower eukaryotes, use an aspartate as the site of phosphorylation. Two-component systems comprise a histidine kinase and a receiver domain. The conformational change of the receiver domain upon phosphorylation leads to signal transfer to the downstream target, a process that had not been understood well at the molecular level. The transient nature of the phospho-Asp bond had made structural studies difficult. The discovery of an excellent analogue for acylphosphate, BeF3-, enabled structural study of activated receiver domains. The structure of activated Chemotaxis protein Y (CheY) was determined both by NMR spectroscopy and X-ray crystallography. These structures revealed the molecular basis of the conformational change that is coupled to phosphorylation. Phosphorylation of the conserved Asp residue in the active site allows hydrogen bonding of the T87 Oγ to phospho-aspartate, which in turn leads to the rotation of Y106 into the ''in'' position (termed Y-T coupling). The structure of activated CheY complexed with the 16 N-terminal residues of FliM (N16-FliM), its target, was also determined by X-ray crystallography and confirmed the proposed mechanism of activation (Y-T coupling). First, N16-FliM binds to the region on CheY that undergoes a significant conformational change. Second, the ''in'' position of Y106 presents a better binding surface for FliM because the sidechain of Y106 in the inactive form of CheY (''out'' position) sterically interferes with binding of N16-FliM. In addition to confirmation of Y-T coupling, the structure of the activated CheY-N16-FliM complex suggested that the

  18. Conformational changes in hemoglobin triggered by changing the iron charge

    International Nuclear Information System (INIS)

    Croci, S.; Achterhold, K.; Ortalli, I.; Parak, F. G.

    2008-01-01

    In this work the hemoglobin conformational changes induced by changing the iron charge have been studied and compared with Myoglobin. Moessbauer spectroscopy was used to follow the change of the iron conformation. In order to compare the conformational relaxation of hemoglobin and myoglobin, and to study a possible influence of the quaternary structure, an intermediate metastable state of hemoglobin has been created by low temperature X-ray irradiation of methemoglobin. The irradiation reduces the Fe(III) of the heme groups to Fe(II) Low Spin, where the water is still bound on the sixth coordination. Heating cycles performed at temperatures from 140 K to 200 K allow the molecules to overcome an activation energy barrier and to relax into a stable conformation such as deoxy-hemoglobin or carboxy-hemoglobin, if CO is present. Slightly different structures (conformational substates) reveal themselves as a distribution of energy barriers (ΔG). The distribution of the activation energy, for the decay of the Fe(II) Low Spin intermediate, has been fitted with a Gaussian. For comparison, published myoglobin data were re-analysed in the same way. The average energy value at characteristic temperature is very similar in case of myoglobin and hemoglobin. The larger Gaussian energy distribution for myoglobin with respect to hemoglobin shows that more conformational substates are available. This may be caused by a larger area exposed to water. In hemoglobin, part of the surface of the chains is not water accessible due to the quaternary structure.

  19. Conformational Clusters of Phosphorylated Tyrosine.

    Science.gov (United States)

    Abdelrasoul, Maha; Ponniah, Komala; Mao, Alice; Warden, Meghan S; Elhefnawy, Wessam; Li, Yaohang; Pascal, Steven M

    2017-12-06

    Tyrosine phosphorylation plays an important role in many cellular and intercellular processes including signal transduction, subcellular localization, and regulation of enzymatic activity. In 1999, Blom et al., using the limited number of protein data bank (PDB) structures available at that time, reported that the side chain structures of phosphorylated tyrosine (pY) are partitioned into two conserved conformational clusters ( Blom, N.; Gammeltoft, S.; Brunak, S. J. Mol. Biol. 1999 , 294 , 1351 - 1362 ). We have used the spectral clustering algorithm to cluster the increasingly growing number of protein structures with pY sites, and have found that the pY residues cluster into three distinct side chain conformations. Two of these pY conformational clusters associate strongly with a narrow range of tyrosine backbone conformation. The novel cluster also highly correlates with the identity of the n + 1 residue, and is strongly associated with a sequential pYpY conformation which places two adjacent pY side chains in a specific relative orientation. Further analysis shows that the three pY clusters are associated with distinct distributions of cognate protein kinases.

  20. Conformation and activity alteration of horseradish peroxidase induced by the interaction with gene carrier polyethyleneimines

    Science.gov (United States)

    Huang, Aimin; Wei, Bangzhi; Mo, Junyong; Wang, Yajing; Ma, Lin

    2018-01-01

    Polyethyleneimine (PEI) has long been considered as "golden standard" for polymeric gene delivery carriers. However the molecular basis of the cytotoxicity of PEI is poorly understood. Little is known about the effects of PEI on the structure and functions of biomacromolecules. In this work, fluorescence, UV-vis absorption, circular dichroism spectroscopy were conducted to investigate the influence of PEI of average molecular weight 25, 10 and 1.8 kDa (denoted as PEI25k, PEI10k and PEI1.8k) on the conformation of horseradish peroxidase (HRP) and its catalytic efficiency. Zeta-potential measurement and isothermal titration calorimetry were used to reveal the mechanism of the interaction between PEIs and HRP. PEIs were found to bind onto the surface of HRP predominantly via hydrophobic interaction and hydrogen bond or van der Waals interaction. The complex formation between HRP and PEI induced a more compact conformation of the enzyme and an increased hydrophobicity of the microenvironment surrounding heme pocket. The conformational change of HRP had little impact on the affinity towards H2O2 and phenol. However, the increase in the non-planarity of porphyrin ring in the heme group led to an increase in the exposure degree of the active center and thus an enhancement of catalytic efficiency of HRP in the presence of high molecular weight PEIs (PEI25k and PEI10k). The polymer size played an important role in PEI-HRP interaction. PEI of low molecular weight (PEI1.8k) was less efficient to alter the conformation and catalytic activity of HRP in aqueous solutions.

  1. A surprising role for conformational entropy in protein function

    Science.gov (United States)

    Wand, A. Joshua; Moorman, Veronica R.; Harpole, Kyle W.

    2014-01-01

    Formation of high-affinity complexes is critical for the majority of enzymatic reactions involving proteins. The creation of the family of Michaelis and other intermediate complexes during catalysis clearly involves a complicated manifold of interactions that are diverse and complex. Indeed, computing the energetics of interactions between proteins and small molecule ligands using molecular structure alone remains a grand challenge. One of the most difficult contributions to the free energy of protein-ligand complexes to experimentally access is that due to changes in protein conformational entropy. Fortunately, recent advances in solution nuclear magnetic resonance (NMR) relaxation methods have enabled the use of measures-of-motion between conformational states of a protein as a proxy for conformational entropy. This review briefly summarizes the experimental approaches currently employed to characterize fast internal motion in proteins, how this information is used to gain insight into conformational entropy, what has been learned and what the future may hold for this emerging view of protein function. PMID:23478875

  2. Distraction of attention with the use of virtual reality. Influence of the level of game complexity on the level of experienced pain

    Directory of Open Access Journals (Sweden)

    Piskorz Joanna

    2014-12-01

    Full Text Available : Research done in recent years shows that Virtual Reality (VR can be an effective tool for distracting attention from pain. The purpose of this study was to test how the complexity of Virtual Environment (VE influences the experienced intensity of thermal pain stimuli.

  3. How does complex terrain influence responses of carbon and water cycle processes to climate variability and climate change? (Invited)

    Science.gov (United States)

    Bond, B. J.; Peterson, K.; McKane, R.; Lajtha, K.; Quandt, D. J.; Allen, S. T.; Sell, S.; Daly, C.; Harmon, M. E.; Johnson, S. L.; Spies, T.; Sollins, P.; Abdelnour, A. G.; Stieglitz, M.

    2010-12-01

    We are pursuing the ambitious goal of understanding how complex terrain influences the responses of carbon and water cycle processes to climate variability and climate change. Our studies take place in H.J. Andrews Experimental Forest, an LTER (Long Term Ecological Research) site situated in Oregon’s central-western Cascade Range. Decades of long-term measurements and intensive research have revealed influences of topography on vegetation patterns, disturbance history, and hydrology. More recent research has shown surprising interactions between microclimates and synoptic weather patterns due to cold air drainage and pooling in mountain valleys. Using these data and insights, in addition to a recent LiDAR (Light Detection and Ranging) reconnaissance and a small sensor network, we are employing process-based models, including “SPA” (Soil-Plant-Atmosphere, developed by Mathew Williams of the University of Edinburgh), and “VELMA” (Visualizing Ecosystems for Land Management Alternatives, developed by Marc Stieglitz and colleagues of the Georgia Institute of Technology) to focus on two important features of mountainous landscapes: heterogeneity (both spatial and temporal) and connectivity (atmosphere-canopy-hillslope-stream). Our research questions include: 1) Do fine-scale spatial and temporal heterogeneity result in emergent properties at the basin scale, and if so, what are they? 2) How does connectivity across ecosystem components affect system responses to climate variability and change? Initial results show that for environmental drivers that elicit non-linear ecosystem responses on the plot scale, such as solar radiation, soil depth and soil water content, fine-scale spatial heterogeneity may produce unexpected emergent properties at larger scales. The results from such modeling experiments are necessarily a function of the supporting algorithms. However, comparisons based on models such as SPA and VELMA that operate at much different spatial scales

  4. Renyi entropy and conformal defects

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, Lorenzo [Humboldt-Univ. Berlin (Germany). Inst. fuer Physik; Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Meineri, Marco [Scuola Normale Superiore, Pisa (Italy); Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada); Istituto Nazionale di Fisica Nucleare, Pisa (Italy); Myers, Robert C. [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada); Smolkin, Michael [California Univ., Berkely, CA (United States). Center for Theoretical Physics and Department of Physics

    2016-04-18

    We propose a field theoretic framework for calculating the dependence of Renyi entropies on the shape of the entangling surface in a conformal field theory. Our approach rests on regarding the corresponding twist operator as a conformal defect and in particular, we define the displacement operator which implements small local deformations of the entangling surface. We identify a simple constraint between the coefficient defining the two-point function of the displacement operator and the conformal weight of the twist operator, which consolidates a number of distinct conjectures on the shape dependence of the Renyi entropy. As an example, using this approach, we examine a conjecture regarding the universal coefficient associated with a conical singularity in the entangling surface for CFTs in any number of spacetime dimensions. We also provide a general formula for the second order variation of the Renyi entropy arising from small deformations of a spherical entangling surface, extending Mezei's results for the entanglement entropy.

  5. Conformal dimension theory and application

    CERN Document Server

    Mackay, John M

    2010-01-01

    Conformal dimension measures the extent to which the Hausdorff dimension of a metric space can be lowered by quasisymmetric deformations. Introduced by Pansu in 1989, this concept has proved extremely fruitful in a diverse range of areas, including geometric function theory, conformal dynamics, and geometric group theory. This survey leads the reader from the definitions and basic theory through to active research applications in geometric function theory, Gromov hyperbolic geometry, and the dynamics of rational maps, amongst other areas. It reviews the theory of dimension in metric spaces and of deformations of metric spaces. It summarizes the basic tools for estimating conformal dimension and illustrates their application to concrete problems of independent interest. Numerous examples and proofs are provided. Working from basic definitions through to current research areas, this book can be used as a guide for graduate students interested in this field, or as a helpful survey for experts. Background needed ...

  6. Elementary introduction to conformal invariance

    International Nuclear Information System (INIS)

    Grandati, Y.

    1992-01-01

    These notes constitute an elementary introduction to the concept of conformal invariance and its applications to the study of bidimensional critical phenomena. The aim is to give an access as pedestrian as possible to this vast subject. After a brief account of the general properties of conformal transformation in D dimensions, we study more specifically the case D = 2. The center of the discussion is then the consequences of the action of this symmetry group on bidimensional field theories, and in particular the links between the representations of the Virasoro algebra and the structure of the correlation functions of conformal field theories. Finally after showing how the Ising model reduces to a Majorana fermionic field theory, we see how the general formalism previously discussed can be applied to the Ising case at the critical point. (orig.)

  7. Conformal geometry and quasiregular mappings

    CERN Document Server

    Vuorinen, Matti

    1988-01-01

    This book is an introduction to the theory of spatial quasiregular mappings intended for the uninitiated reader. At the same time the book also addresses specialists in classical analysis and, in particular, geometric function theory. The text leads the reader to the frontier of current research and covers some most recent developments in the subject, previously scatterd through the literature. A major role in this monograph is played by certain conformal invariants which are solutions of extremal problems related to extremal lengths of curve families. These invariants are then applied to prove sharp distortion theorems for quasiregular mappings. One of these extremal problems of conformal geometry generalizes a classical two-dimensional problem of O. Teichmüller. The novel feature of the exposition is the way in which conformal invariants are applied and the sharp results obtained should be of considerable interest even in the two-dimensional particular case. This book combines the features of a textbook an...

  8. Renyi entropy and conformal defects

    International Nuclear Information System (INIS)

    Bianchi, Lorenzo; Myers, Robert C.; Smolkin, Michael

    2016-01-01

    We propose a field theoretic framework for calculating the dependence of Renyi entropies on the shape of the entangling surface in a conformal field theory. Our approach rests on regarding the corresponding twist operator as a conformal defect and in particular, we define the displacement operator which implements small local deformations of the entangling surface. We identify a simple constraint between the coefficient defining the two-point function of the displacement operator and the conformal weight of the twist operator, which consolidates a number of distinct conjectures on the shape dependence of the Renyi entropy. As an example, using this approach, we examine a conjecture regarding the universal coefficient associated with a conical singularity in the entangling surface for CFTs in any number of spacetime dimensions. We also provide a general formula for the second order variation of the Renyi entropy arising from small deformations of a spherical entangling surface, extending Mezei's results for the entanglement entropy.

  9. Conformation of the azo bond and its influence on the molecular and crystal structures, IR and Raman spectra, and electron properties of 6-methyl-3,5-dinitro-2-[(E)-phenyldiazenyl]pyridine - Quantum chemical DFT calculations

    Science.gov (United States)

    Michalski, J.; Bryndal, I.; Lorenc, J.; Hermanowicz, K.; Janczak, J.; Hanuza, J.

    2018-02-01

    The crystal and molecular structures of 6-methyl-3,5-dinitro-2-[(E)-phenyldiazenyl]pyridine have been determined by X-ray diffraction and quantum chemical DFT calculations. The crystal is monoclinic, space group Cc (No. 9) with Z = 4 with the unit cell parameters: a = 12.083(7), b = 12.881(6), c = 8.134(3) Å and β = 97.09(5)°. The azo-bridge appears in the trans conformation in which C2-N2-N2‧-C1‧ torsion angle takes a value - 178.6(3)°, whereas the dihedral angle between the planes of the phenyl and pyridine rings is 3.5(2)°. The IR and Raman spectra measured in the temperature range 80-350 K and quantum chemical calculations with the use of B3LYP/6-311G(2d,2p) approach confirmed the trans configuration of the azo-bridge as the most stable energetically and allowed determination of the energy other virtual structures. The observed effects were used in the discussion of vibrational dynamics of the studied compound. The energy gap between cis and trans conformers equals to 1.054 eV (0.03873 Hartree). The electron absorption and emission spectra have been measured and analyzed on the basis of DFT calculations. The life time of the excited state is 12 μs and the Stokes shift is close to 5470 cm- 1.

  10. Acetylcholinesterase in motion : Visualizing conformational changes in crystal structures by a morphing procedure

    NARCIS (Netherlands)

    Zeev-Ben-Mordehai, T; Silman, I.; Sussman, J.L.

    In order to visualize and appreciate conformational changes between homologous three-dimensional (3D) protein structures or protein/inhibitor complexes, we have developed a user-friendly morphing procedure. It enabled us to detect coordinated conformational changes not easily discernible by analytic

  11. CONFORMATIONAL SEARCH BY POTENTIAL-ENERGY ANNEALING - ALGORITHM AND APPLICATION TO CYCLOSPORINE-A

    NARCIS (Netherlands)

    VANSCHAIK, RC; VANGUNSTEREN, WF; BERENDSEN, HJC

    A major problem in modelling (biological) macromolecules is the search for low-energy conformations. The complexity of a conformational search problem increases exponentially with the number of degrees of freedom which means that a systematic search can only be performed for very small structures.

  12. SUSY Unparticle and Conformal Sequestering

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Yu; Nakayama, Yu

    2007-07-17

    We investigate unparticle physics with supersymmetry (SUSY). The SUSY breaking effects due to the gravity mediation induce soft masses for the SUSY unparticles and hence break the conformal invariance. The unparticle physics observable in near future experiments is only consistent if the SUSY breakingeffects from the hidden sector to the standard model sector are dominated by the gauge mediation, or if the SUSY breaking effects to the unparticle sector are sufficiently sequestered. We argue that the natural realization of the latter possibility is the conformal sequestering scenario.

  13. Topics in conformal field theory

    International Nuclear Information System (INIS)

    Kiritsis, E.B.

    1988-01-01

    In this work two major topics in Conformal Field Theory are discussed. First a detailed investigation of N = 2 Superconformal theories is presented. The structure of the representations of the N = 2 superconformal algebras is investigated and the character formulae are calculated. The general structure of N = 2 superconformal theories is elucidated and the operator algebra of the minimal models is derived. The first minimal system is discussed in more detail. Second, applications of the conformal techniques are studied in the Ashkin-Teller model. The c = 1 as well as the c = 1/2 critical lines are discussed in detail

  14. Complex analysis

    CERN Document Server

    Freitag, Eberhard

    2005-01-01

    The guiding principle of this presentation of ``Classical Complex Analysis'' is to proceed as quickly as possible to the central results while using a small number of notions and concepts from other fields. Thus the prerequisites for understanding this book are minimal; only elementary facts of calculus and algebra are required. The first four chapters cover the essential core of complex analysis: - differentiation in C (including elementary facts about conformal mappings) - integration in C (including complex line integrals, Cauchy's Integral Theorem, and the Integral Formulas) - sequences and series of analytic functions, (isolated) singularities, Laurent series, calculus of residues - construction of analytic functions: the gamma function, Weierstrass' Factorization Theorem, Mittag-Leffler Partial Fraction Decomposition, and -as a particular highlight- the Riemann Mapping Theorem, which characterizes the simply connected domains in C. Further topics included are: - the theory of elliptic functions based on...

  15. Assessment of the influence of amylose-LPC complexation on the extent of wheat starch digestibility by size-exclusion chromatography.

    Science.gov (United States)

    Ahmadi-Abhari, S; Woortman, A J J; Hamer, R J; Loos, K

    2013-12-15

    Amylose forms inclusion complexes with lysophosphatidylcholine (LPC), that decrease the susceptibility of amylose to amylase degradation. This study on the influence of complexation on starch susceptibility to amylase explains the nature of this protective effect. Wheat starch suspensions (9% w/w) containing 0.5-5% LPC were subjected to hydrolysis by porcine pancreatic α-amylase at 37 °C for several digestion times. The digesta were analysed by size-exclusion chromatography (SEC). The molar mass distribution was closely dependent on the digestion time and amount of LPC. This study precisely demonstrates the alteration of the digestion profile of starch on a molecular level, influenced by amylose-LPC complexation; however the effect depends on the digestion time. During 15 and 30 min digestion, inclusion complexes not only protect amylopectin in the initial hydrolysis stage, but also demonstrate lower susceptibility of the molecular amylose complexes to amylase hydrolysis. Digestion for 240 min resulted in a lower oligosaccharide peak concentration, in the presence of a high LPC concentration, which is related to less degradation of complexed amylose fraction. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. The influence of phthalocyanine aggregation in complexes with CdSe/ZnS quantum dots on the photophysical properties of the complexes

    Directory of Open Access Journals (Sweden)

    Irina V. Martynenko

    2016-07-01

    Full Text Available The formation of nonluminescent aggregates of aluminium sulfonated phthalocyanine in complexes with CdSe/ZnS quantum dots causes a decrease of the intracomplex energy transfer efficiency with increasing phthalocyanine concentration. This was confirmed by steady-state absorption and photoluminescent spectroscopy. A corresponding physical model was developed that describes well the experimental data. The results can be used at designing of QD/molecule systems with the desired spatial arrangement for photodynamic therapy.

  17. Spin-4 extended conformal algebras

    International Nuclear Information System (INIS)

    Kakas, A.C.

    1988-01-01

    We construct spin-4 extended conformal algebras using the second hamiltonian structure of the KdV hierarchy. In the presence of a U(1) current a family of spin-4 algebras exists but the additional requirement that the spin-1 and spin-4 currents commute fixes the algebra uniquely. (orig.)

  18. Defects in conformal field theory

    International Nuclear Information System (INIS)

    Billò, Marco; Gonçalves, Vasco; Lauria, Edoardo; Meineri, Marco

    2016-01-01

    We discuss consequences of the breaking of conformal symmetry by a flat or spherical extended operator. We adapt the embedding formalism to the study of correlation functions of symmetric traceless tensors in the presence of the defect. Two-point functions of a bulk and a defect primary are fixed by conformal invariance up to a set of OPE coefficients, and we identify the allowed tensor structures. A correlator of two bulk primaries depends on two cross-ratios, and we study its conformal block decomposition in the case of external scalars. The Casimir equation in the defect channel reduces to a hypergeometric equation, while the bulk channel blocks are recursively determined in the light-cone limit. In the special case of a defect of codimension two, we map the Casimir equation in the bulk channel to the one of a four-point function without defect. Finally, we analyze the contact terms of the stress-tensor with the extended operator, and we deduce constraints on the CFT data. In two dimensions, we relate the displacement operator, which appears among the contact terms, to the reflection coefficient of a conformal interface, and we find unitarity bounds for the latter.

  19. Conformal symmetry and holographic cosmology

    NARCIS (Netherlands)

    Bzowski, A.W.

    2013-01-01

    This thesis presents a novel approach to cosmology using gauge/gravity duality. Analysis of the implications of conformal invariance in field theories leads to quantitative cosmological predictions which are in agreement with current data. Furthermore, holographic cosmology extends the theory of

  20. Checking behavioral conformance of artifacts

    NARCIS (Netherlands)

    Fahland, D.; Leoni, de M.; Dongen, van B.F.; Aalst, van der W.M.P.

    2011-01-01

    The usefulness of process models (e.g., for analysis, improvement, or execution) strongly depends on their ability to describe reality. Conformance checking is a technique to validate how good a given process model describes recorded executions of the actual process. Recently, artifacts have been