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Sample records for cu-catalyzed asymmetric conjugate

  1. Asymmetric synthesis of all-carbon benzylic quaternary stereocenters via Cu-catalyzed conjugate addition of dialkylzinc reagents to 5-(1-arylalkylidene) Meldrum's acids.

    Fillion, Eric; Wilsily, Ashraf

    2006-03-08

    The asymmetric synthesis of all-carbon benzylic quaternary stereocenters has been successfully achieved through copper-catalyzed addition of dialkylzinc reagents to 5-(1-arylalkylidene) and 5-(dihydroindenylidene) Meldrum's acids in the presence of phosphoramidite ligand. The resulting benzyl-substituted Meldrum's acids and 1,1-disubstituted indanes were obtained in good yields and up to 99% ee. The significance of substituting the position para, meta, and ortho to the electrophilic benzylic center was highlighted. A benzyl Meldrum's acid product was further transformed to a 3,3-disubstituted 1-indanone and a beta,beta-disubstituted pentanoic acid.

  2. Total Synthesis of (R, R, R)-gamma-Tocopherol through Cu-Catalyzed Asymmetric 1,2-Addition

    Wu, Zhongtao; Harutyunyan, Syuzanna R.; Minnaard, Adriaan J.

    2014-01-01

    Based on the asymmetric copper-catalyzed 1,2-addition of Grignard reagents to ketones, (R,R,R)--tocopherol has been synthesized in 36% yield over 12 steps (longest linear sequence). The chiral center in the chroman ring was constructed with 73% ee by the 1,2-addition of a phytol-derived Grignard

  3. Exploring asymmetric catalytic transformations

    Guduguntla, Sureshbabu

    2017-01-01

    In Chapter 2, we report a highly enantioselective synthesis of β-alkyl-substituted alcohols through a one-pot Cu- catalyzed asymmetric allylic alkylation with organolithium reagents followed by reductive ozonolysis. The synthesis of γ-alkyl-substituted alcohols was also achieved through Cu-catalyzed

  4. Asymmetric rifting, breakup and magmatism across conjugate margin pairs: insights from Newfoundland to Ireland

    Peace, Alexander L.; Welford, J. Kim; Foulger, Gillian R.; McCaffrey, Ken J. W.

    2017-04-01

    Continental extension, subsequent rifting and eventual breakup result in the development of passive margins with transitional crust between extended continental crust and newly created oceanic crust. Globally, passive margins are typically classified as either magma-rich or magma-poor. Despite this simple classification, magma-poor margins like the West Orphan Basin, offshore Newfoundland, do exhibit some evidence of localized magmatism, as magmatism to some extent invariably accompanies all continental breakup. For example, on the Newfoundland margin, a small volcanic province has been interpreted near the termination of the Charlie Gibbs Fracture Zone, whereas on the conjugate Irish margin within the Rockall Basin, magmatism appears to be more widespread and has been documented both in the north and in the south. The broader region over which volcanism has been identified on the Irish margin is suggestive of magmatic asymmetry across this conjugate margin pair and this may have direct implications for the mechanisms governing the nature of rifting and breakup. Possible causes of the magmatic asymmetry include asymmetric rifting (simple shear), post-breakup thermal anomalies in the mantle, or pre-existing compositional zones in the crust that predispose one of the margins to more melting than its conjugate. A greater understanding of the mechanisms leading to conjugate margin asymmetry will enhance our fundamental understanding of rifting processes and will also reduce hydrocarbon exploration risk by better characterizing the structural and thermal evolution of hydrocarbon bearing basins on magma-poor margins where evidence of localized magmatism exists. Here, the latest results of a conjugate margin study of the Newfoundland-Ireland pair utilizing seismic interpretation integrated with other geological and geophysical datasets are presented. Our analysis has begun to reveal the nature and timing of rift-related magmatism and the degree to which magmatic asymmetry

  5. Enantioselective Intramolecular CH-Insertions upon Cu-Catalyzed Decomposition of Phenyliodonium Ylides

    Christelle Boléa

    2001-02-01

    Full Text Available The Cu-catalyzed intramolecular CH insertion of phenyliodonium ylide 5b has been investigated at 0° C in the presence of several chiral ligands. Enantioselectivities vary in the range of 38–72 %, and are higher than those resulting from reaction of the diazo compound 5c at 65° C. The results are consistent with a carbenoid mechanism for Cu-catalyzed decomposition of phenyliodonium ylides.

  6. Two-Dimensional Lead Halide Perovskites Templated by a Conjugated Asymmetric Diammonium.

    Hautzinger, Matthew P; Dai, Jun; Ji, Yujin; Fu, Yongping; Chen, Jie; Guzei, Ilia A; Wright, John C; Li, Youyong; Jin, Song

    2017-12-18

    We report novel two-dimensional lead halide perovskite structures templated by a unique conjugated aromatic dication, N,N-dimethylphenylene-p-diammonium (DPDA). The asymmetrically substituted primary and tertiary ammoniums in DPDA facilitate the formation of two-dimensional network (2DN) perovskite structures incorporating a conjugated dication between the PbX 4 2- (X = Br, I) layers. These 2DN structures of (DPDA)PbI 4 and (DPDA)PbBr 4 were characterized by single-crystal X-ray diffraction, showing uniquely low distortions in the Pb-X-Pb bond angle for 2D perovskites. The Pb-I-Pb bond angle is very close to ideal (180°) for a 2DN lead iodide perovskite, which can be attributed to the ability of the rigid diammonium DPDA to insert into the PbX 6 2- octahedral pockets. Optical characterization of (DPDA)PbI 4 shows an excitonic absorption peak at 2.29 eV (541 nm), which is red-shifted in comparison to similar 2DN lead iodide structures. Temperature-dependent photoluminescence of both compounds reveals both a self-trapped exciton and free exciton emission feature. The reduced exciton absorption energy and emission properties are attributed to the dication-induced structural order of the inorganic PbX 4 2- layers. DFT calculation results suggest mixing of the conjugated organic orbital component in the valence band of these 2DN perovskites. These results demonstrate a rational new strategy to incorporate conjugated organic dications into hybrid perovskites and will spur spectroscopic investigations of these compounds as well as optoelectronic applications.

  7. Asymmetric diketopyrrolopyrrole conjugated polymers for field-effect transistors and polymer solar cells processed from a non-chlorinated solvent

    Ji, Y.; Xiao, C.; Wang, Q.; Zhang, J.; Li, C.; Wu, Y.; Wei, Z.; Zhan, X.; Hu, W.; Wang, Z.; Janssen, R.A.J.; Li, W.W.

    2016-01-01

    Newly designed asymmetric diketopyrrolopyrrole conjugated polymers with two different aromatic substituents possess a hole mobility of 12.5 cm2 V−1 s−1 in field-effect transistors and a power conversion efficiency of 6.5% in polymer solar cells, when solution processed from a nonchlorinated

  8. Cu-Catalyzed Asymmetric Allylic Alkylation of Phosphonates and Phosphine Oxides with Grignard Reagents

    Hornillos, Valentin; Perez, Manuel; Fananas-Mastral, Martin; Feringa, Ben L.

    An efficient and highly enantioselective copper-catalyzed allylic alkylation of phosphonates and phosphine oxides with Grignard reagents and Taniaphos or phosphoramidites as chiral ligands is reported. Transformation of these products leads to a variety of new phosphorus-containing chiral

  9. Asymmetric Construction of Benzindoloquinolizidine: Application of An Organocatalytic Enantioselective Conjugate Addition-Cyclization Cascade Reaction

    Kim, Cheolwoong; Seo, Seung Woo; Lee, Yona; Kim, Sunggon

    2014-01-01

    We have developed the synthetic methodology of enantioenriched benzindoloquinolizidines based on the organocatalytic enantioselective conjugate addition-cyclization cascade reaction of o-N-(3-indoleacetyl)amino-cinnamaldehydes with malonates followed by an acid-catalyzed intramolecular Pictet-Spengler type cyclization. The asymmetric reaction using diphenylprolinol TMS ether as an organocatalyst produces the desired products with good to excellent yields and high enantioselectivities (up to 98% ee). The evaluation of the applications of this synthetic methodology for generating enantioenriched benzindolo-quinolizidines and studies on the biological activity of these compounds against human prostate cancer in particular are now in progress. Results of these studies will be presented in due course. Many new types of chemical reactions have been developed to facilitate easier synthesis of complex compounds. Among the strategies, domino reactions, which have been utilized for the efficient and stereoselective construction of complex molecules from simple precursors in a single process, are widely used due to their high synthetic efficiency by reducing both the number of synthetic operation required and the quantities of chemicals and solvents used

  10. Asymmetric Synthesis and Evaluation of Danshensu-Cysteine Conjugates as Novel Potential Anti-Apoptotic Drug Candidates

    Pan, Li-Long; Wang, Jie; Jia, Yao-Ling; Zheng, Hong-Ming; Wang, Yang; Zhu, Yi-Zhun

    2014-01-01

    We have previously reported that the danshensu-cysteine conjugate N-((R)-3-benzylthio-1-methoxy-1-oxo-2-propanyl)-2-acetoxy-3-(3,4-diacetoxyphenyl) propanamide (DSC) is a potent anti-oxidative and anti-apoptotic agent. Herein, we further design and asymmetrically synthesize two diastereoisomers of DSC and explore their potential bioactivities. Our results show that DSC and its two diastereoisomers exert similar protective effects in hydrogen peroxide (H2O2)-induced cellular injury in SH-SY5Y cells, as evidenced by the increase of cell viability, superoxide dismutase (SOD), and reduced glutathione (GSH) activity, and glutathione peroxidase (GPx) expression, and the decrease of cellular morphological changes and nuclear condensation, lactate dehydrogenase (LDH) release, and malondialdehyde (MDA) production. In H2O2-stimulated human umbilical vein endothelial cells (HUVEC), DSC concentration-dependently attenuates H2O2-induced cell death, LDH release, mitochondrial membrane potential collapse, and modulates the expression of apoptosis-related proteins (Bcl-2, Bax, caspase-3, and caspase-9). Our results provide strong evidence that DSC and its two diastereoisomers have similar anti-oxidative activity and that DSC exerts significant vascular-protective effects, at least in part, through inhibition of apoptosis and modulation of endogenous antioxidant enzymes. PMID:25551606

  11. Asymmetrically Substituted and π-Conjugated 2,2'-Bipyridine Derivatives: Synthesis, Spectroscopy, Computation, and Crystallography.

    Bodapati, Ramakrishna; Sarma, Monima; Kanakati, Arunkumar; Das, Samar K

    2015-12-18

    A new series of monosubstituted styryl- and bistyryl-2,2'-bipyridine luminophores (compounds 16-23) have been synthesized via Horner-Wadsworth-Emmons reaction involving a monophosphonate and donor aromatic aldehydes. In the title chromophores, the amino donors are varied between acyclic and cyclic while the alkoxy donors are varied in terms of their number and position. The absorption maxima of these chromophores shift predominantly due to intramolecular charge transfer (ICT) between different donor and acceptor moieties. The title donor-acceptor molecules exhibit intense fluorescence in solution at room temperature, and their emissive behavior has been found to be highly sensitive to solvent polarity. The fluorescence spectra and quantum yields of all the chromophores were recorded in four different solvent media, and the chromophores 16, 17, 19, and 21 exhibit fluorescence in the solid state too. The influence of the nature and position of the donor functionalities in the conjugated backbone of the bipyridine moiety on the electronic absorption properties of the title chromophores (16-23) has been demonstrated, which has further been corroborated by DFT and TD-DFT computation both in gas phase and in solution phase. The crystal structure of compound 18 has been described as a representative member of the family (16-23).

  12. Embedding SAS approach into conjugate gradient algorithms for asymmetric 3D elasticity problems

    Chen, Hsin-Chu; Warsi, N.A. [Clark Atlanta Univ., GA (United States); Sameh, A. [Univ. of Minnesota, Minneapolis, MN (United States)

    1996-12-31

    In this paper, we present two strategies to embed the SAS (symmetric-and-antisymmetric) scheme into conjugate gradient (CG) algorithms to make solving 3D elasticity problems, with or without global reflexive symmetry, more efficient. The SAS approach is physically a domain decomposition scheme that takes advantage of reflexive symmetry of discretized physical problems, and algebraically a matrix transformation method that exploits special reflexivity properties of the matrix resulting from discretization. In addition to offering large-grain parallelism, which is valuable in a multiprocessing environment, the SAS scheme also has the potential for reducing arithmetic operations in the numerical solution of a reasonably wide class of scientific and engineering problems. This approach can be applied directly to problems that have global reflexive symmetry, yielding smaller and independent subproblems to solve, or indirectly to problems with partial symmetry, resulting in loosely coupled subproblems. The decomposition is achieved by separating the reflexive subspace from the antireflexive one, possessed by a special class of matrices A, A {element_of} C{sup n x n} that satisfy the relation A = PAP where P is a reflection matrix (symmetric signed permutation matrix).

  13. Cu-catalyzed esterification reaction via aerobic oxygenation and C-C bond cleavage: an approach to α-ketoesters.

    Zhang, Chun; Feng, Peng; Jiao, Ning

    2013-10-09

    The Cu-catalyzed novel aerobic oxidative esterification reaction of 1,3-diones for the synthesis of α-ketoesters has been developed. This method combines C-C σ-bond cleavage, dioxygen activation and oxidative C-H bond functionalization, as well as provides a practical, neutral, and mild synthetic approach to α-ketoesters which are important units in many biologically active compounds and useful precursors in a variety of functional group transformations. A plausible radical process is proposed on the basis of mechanistic studies.

  14. Cu-catalyzed C(sp³)-H bond activation reaction for direct preparation of cycloallyl esters from cycloalkanes and aromatic aldehydes.

    Zhao, Jincan; Fang, Hong; Han, Jianlin; Pan, Yi

    2014-05-02

    Cu-catalyzed dehydrogenation-olefination and esterification of C(sp(3))-H bonds of cycloalkanes with TBHP as an oxidant has been developed. The reaction involves four C-H bond activations and gives cycloallyl ester products directly from cycloalkanes and aromatic aldehydes.

  15. Cyclic aldimines as superior electrophiles for Cu-catalyzed decarboxylative Mannich reaction of β-ketoacids with a broad scope and high enantioselectivity.

    Zhang, Heng-Xia; Nie, Jing; Cai, Hua; Ma, Jun-An

    2014-05-02

    A novel Cu-catalyzed enantioselective decarboxylative Mannich reaction of cyclic aldimines with β-ketoacids is described. The cyclic structure of these aldimines, in which the C═N bond is constrained in the Z geometry, appears to be important, allowing Mannich condensation to proceed in high yields with excellent enantioselectivities. A chiral chroman-4-amine was synthesized from the decarboxylative Mannich product in several steps without loss of enantioselectivity.

  16. (E)-α,β-unsaturated amides from tertiary amines, olefins and CO via Pd/Cu-catalyzed aerobic oxidative N-dealkylation.

    Shi, Renyi; Zhang, Hua; Lu, Lijun; Gan, Pei; Sha, Yuchen; Zhang, Heng; Liu, Qiang; Beller, Matthias; Lei, Aiwen

    2015-02-21

    A novel Pd/Cu-catalyzed chemoselective aerobic oxidative N-dealkylation/carbonylation reaction has been developed. Tertiary amines are utilized as a "reservoir" of "active" secondary amines in this transformation, which inhibits the formation of undesired by-products and the deactivation of the catalysts. This protocol allows for an efficient and straightforward construction of synthetically useful and bioactive (E)-α,β-unsaturated amide derivatives from easily available tertiary amines, olefins and CO.

  17. Asymmetric Conjugated Molecules Based on [1]Benzothieno[3,2-b][1]benzothiophene for High-Mobility Organic Thin-Film Transistors: Influence of Alkyl Chain Length.

    He, Keqiang; Li, Weili; Tian, Hongkun; Zhang, Jidong; Yan, Donghang; Geng, Yanhou; Wang, Fosong

    2017-10-11

    Herein, we report the synthesis and characterization of a series of [1]benzothieno[3,2-b][1]benzothiophene (BTBT)-based asymmetric conjugated molecules, that is, 2-(5-alkylthiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophene (BTBT-Tn, in which T and n represent thiophene and the number of carbons in the alkyl group, respectively). All of the molecules with n ≥ 4 show mesomorphism and display smectic A, smectic B (n = 4), or smectic E (n > 4) phases and then crystalline phases in succession upon cooling from the isotropic state. Alkyl chain length has a noticeable influence on the microstructures of vacuum-deposited films and therefore on the performance of the organic thin-film transistors (OTFTs). All molecules except for 2-(thiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophene and 2-(5-ethylthiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophene showed OTFT mobilities above 5 cm 2 V -1 s -1 . 2-(5-Hexylthiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophene and 2-(5-heptylthiophen-2-yl)[1]benzothieno[3,2-b][1]benzothiophene showed the greatest OTFT performance with reliable hole mobilities (μ) up to 10.5 cm 2 V -1 s -1 because they formed highly ordered and homogeneous films with diminished grain boundaries.

  18. From ketones to esters by a Cu-catalyzed highly selective C(CO)-C(alkyl) bond cleavage: aerobic oxidation and oxygenation with air.

    Huang, Xiaoqiang; Li, Xinyao; Zou, Miancheng; Song, Song; Tang, Conghui; Yuan, Yizhi; Jiao, Ning

    2014-10-22

    The Cu-catalyzed aerobic oxidative esterification of simple ketones via C-C bond cleavage has been developed. Varieties of common ketones, even inactive aryl long-chain alkyl ketones, are selectively converted into esters. The reaction tolerates a wide range of alcohols, including primary and secondary alcohols, chiral alcohols with retention of the configuration, electron-deficient phenols, as well as various natural alcohols. The usage of inexpensive copper catalyst, broad substrate scope, and neutral and open air conditions make this protocol very practical. (18)O labeling experiments reveal that oxygenation occurs during this transformation. Preliminary mechanism studies indicate that two novel pathways are mainly involved in this process.

  19. Synthesis of Bioactive 2-(Arylaminothiazolo[5,4-f]-quinazolin-9-ones via the Hügershoff Reaction or Cu- Catalyzed Intramolecular C-S Bond Formation

    Damien Hédou

    2016-06-01

    Full Text Available A library of thirty eight novel thiazolo[5,4-f]quinazolin-9(8H-one derivatives (series 8, 10, 14 and 17 was prepared via the Hügershoff reaction and a Cu catalyzed intramolecular C-S bond formation, helped by microwave-assisted technology when required. The efficient multistep synthesis of the key 6-amino-3-cyclopropylquinazolin-4(3H-one (3 has been reinvestigated and performed on a multigram scale from the starting 5-nitroanthranilic acid. The inhibitory potency of the final products was evaluated against five kinases involved in Alzheimer’s disease and showed that some molecules of the 17 series described in this paper are particularly promising for the development of novel multi-target inhibitors of kinases.

  20. Vicinal Diboronates in High Enantiomeric Purity through Tandem Site-Selective NHC–Cu-Catalyzed Boron-Copper Additions to Terminal Alkynes

    Lee, Yunmi; Jang, Hwanjong; Hoveyda, Amir H.

    2009-01-01

    A Cu-catalyzed protocol for conversion of terminal alkynes to enantiomerically enriched diboronates is reported. In a single vessel, a site-selective hydroboration of an alkyne leads to the corresponding terminal vinylboronate, which undergoes a second site-selective and enantioselective hydroboration. Reactions proceed in the presence of two equivalents of commercially available bis(pinacolato)diboron [B2(pin)2] and 5–7.5 mol % of a chiral bidentate imidazolinium salt, affording diboronates in 60–93% yield and up to 97.5:2.5 enantiomeric ratio (er). The enantiomerically enriched products can be functionalized to afford an assortment of versatile organic molecules. Enynes are converted to unsaturated diboronates with high chemo- (>98% reaction of alkyne; <2% at alkene) and enantioselectivity (e.g., 94.5:5.5 er). PMID:19968273

  1. 1,2-Ferrocenediylazaphosphinines 3: a new class of planar chiral ligands for Cu-catalyzed cyclopropanation

    Paek, Seung Hwan; Co, Thanh Thien; Lee, Dong Ho; Park, Yu Chul; Kim, Tae Jeong [Kyungpook National Univ., Daegu (Korea, Republic of)

    2002-12-01

    The synthesis and catalytic application of a new class of planar chiral ferrocenes, 1,2-ferrocenediylazaphos-phinines (1 and 2) are described. They are powerful ligands for the copper(I)-catalyzed asymmetric cyclopropanation of a range of alkenes with diazo esters to exhibit an exceptionally high degree of diastereoselectivity ({approx}100%) in favor of trans isomers, regardless the structure of the olefins and the diazo compounds. Comparative studies between 1 and 2 reveal that the former works better in terms of diastereocontrol. In contrast, however, enantioselectivity is low with both 1 and 2 as a whole although, in certain cases with a proper combination of the olefin and the diazo ester, high optical yields (up to 100% ee) can be achieved. Other reaction parameters such as the reaction temperature and the structure of the ligand do exhibit some influence, although infinitesimal, on both chemical and optical yields.

  2. 1,2-Ferrocenediylazaphosphinines 3: a new class of planar chiral ligands for Cu-catalyzed cyclopropanation

    Paek, Seung Hwan; Co, Thanh Thien; Lee, Dong Ho; Park, Yu Chul; Kim, Tae Jeong

    2002-01-01

    The synthesis and catalytic application of a new class of planar chiral ferrocenes, 1,2-ferrocenediylazaphos-phinines (1 and 2) are described. They are powerful ligands for the copper(I)-catalyzed asymmetric cyclopropanation of a range of alkenes with diazo esters to exhibit an exceptionally high degree of diastereoselectivity (∼100%) in favor of trans isomers, regardless the structure of the olefins and the diazo compounds. Comparative studies between 1 and 2 reveal that the former works better in terms of diastereocontrol. In contrast, however, enantioselectivity is low with both 1 and 2 as a whole although, in certain cases with a proper combination of the olefin and the diazo ester, high optical yields (up to 100% ee) can be achieved. Other reaction parameters such as the reaction temperature and the structure of the ligand do exhibit some influence, although infinitesimal, on both chemical and optical yields

  3. Cu-catalyzed aerobic oxidative cyclizations of 3-N-hydroxyamino-1,2-propadienes with alcohols, thiols, and amines to form α-O-, S-, and N-substituted 4-methylquinoline derivatives.

    Sharma, Pankaj; Liu, Rai-Shung

    2015-03-16

    A one-pot, two-step synthesis of α-O-, S-, and N-substituted 4-methylquinoline derivatives through Cu-catalyzed aerobic oxidations of N-hydroxyaminoallenes with alcohols, thiols, and amines is described. This reaction sequence involves an initial oxidation of N-hydroxyaminoallenes with NuH (Nu = OH, OR, NHR, and SR) to form 3-substituted 2-en-1-ones, followed by Brønsted acid catalyzed intramolecular cyclizations of the resulting products. Our mechanistic analysis suggests that the reactions proceed through a radical-type mechanism rather than a typical nitrone-intermediate route. The utility of this new Cu-catalyzed reaction is shown by its applicability to the synthesis of several 2-amino-4-methylquinoline derivatives, which are known to be key precursors to several bioactive molecules. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Role of Nearby Charges on the Electronic Structure of π-Conjugated Molecules: Symmetric versus Asymmetric Charge Distributions in Oligo(p-phenyleneethynylene)

    Kirketerp, Maj-Britt Suhr; Ryhding, Torben; Støchkel, Kristian

    2011-01-01

    Oligo(p-phenyleneethynylene)s (OPEs) are conjugated oligomers of great interest within materials science and molecular electronics on account of their highly applicable electronic and optical properties. Here we use gas-phase action spectroscopy to elucidate how the intrinsic electronic properties...

  5. CPDES2: A preconditioned conjugate gradient solver for linear asymmetric matrix equations arising from coupled partial differential equations in two dimensions

    Anderson, D. V.; Koniges, A. E.; Shumaker, D. E.

    1988-11-01

    Many physical problems require the solution of coupled partial differential equations on two-dimensional domains. When the time scales of interest dictate an implicit discretization of the equations a rather complicated global matrix system needs solution. The exact form of the matrix depends on the choice of spatial grids and on the finite element or finite difference approximations employed. CPDES2 allows each spatial operator to have 5 or 9 point stencils and allows for general couplings between all of the component PDE's and it automatically generates the matrix structures needed to perform the algorithm. The resulting sparse matrix equation is solved by either the preconditioned conjugate gradient (CG) method or by the preconditioned biconjugate gradient (BCG) algorithm. An arbitrary number of component equations are permitted only limited by available memory. In the sub-band representation used, we generate an algorithm that is written compactly in terms of indirect indices which is vectorizable on some of the newer scientific computers.

  6. CPDES3: A preconditioned conjugate gradient solver for linear asymmetric matrix equations arising from coupled partial differential equations in three dimensions

    Anderson, D. V.; Koniges, A. E.; Shumaker, D. E.

    1988-11-01

    Many physical problems require the solution of coupled partial differential equations on three-dimensional domains. When the time scales of interest dictate an implicit discretization of the equations a rather complicated global matrix system needs solution. The exact form of the matrix depends on the choice of spatial grids and on the finite element or finite difference approximations employed. CPDES3 allows each spatial operator to have 7, 15, 19, or 27 point stencils and allows for general couplings between all of the component PDE's and it automatically generates the matrix structures needed to perform the algorithm. The resulting sparse matrix equation is solved by either the preconditioned conjugate gradient (CG) method or by the preconditioned biconjugate gradient (BCG) algorithm. An arbitrary number of component equations are permitted only limited by available memory. In the sub-band representation used, we generate an algorithm that is written compactly in terms of indirect induces which is vectorizable on some of the newer scientific computers.

  7. Catalytic asymmetric synthesis of the alkaloid (+)-myrtine

    Pizzuti, Maria Gabriefla; Minnaard, Adriaan J.; Feringa, Ben L.

    2008-01-01

    A new protocol for the asymmetric synthesis of trans-2,6-disubstituted-4-piperidones has been developed using a catalytic enantioselective conjugate addition reaction in combination with a diastereoselective lithiation-substitution sequence; an efficient synthesis of (+)-myrtine has been achieved

  8. Asymmetric collider

    Bharadwaj, V.; Colestock, P.; Goderre, G.; Johnson, D.; Martin, P.; Holt, J.; Kaplan, D.

    1993-01-01

    The study of CP violation in beauty decay is one of the key challenges facing high energy physics. Much work has not yielded a definitive answer how this study might best be performed. However, one clear conclusion is that new accelerator facilities are needed. Proposals include experiments at asymmetric electron-positron colliders and in fixed-target and collider modes at LHC and SSC. Fixed-target and collider experiments at existing accelerators, while they might succeed in a first observation of the effect, will not be adequate to study it thoroughly. Giomataris has emphasized the potential of a new approach to the study of beauty CP violation: the asymmetric proton collider. Such a collider might be realized by the construction of a small storage ring intersecting an existing or soon-to-exist large synchrotron, or by arranging collisions between a large synchrotron and its injector. An experiment at such a collider can combine the advantages of fixed-target-like spectrometer geometry, facilitating triggering, particle identification and the instrumentation of a large acceptance, while the increased √s can provide a factor > 100 increase in beauty-production cross section compared to Tevatron or HERA fixed-target. Beams crossing at a non-zero angle can provide a small interaction region, permitting a first-level decay-vertex trigger to be implemented. To achieve large √s with a large Lorentz boost and high luminosity, the most favorable venue is the high-energy booster (HEB) at the SSC Laboratory, though the CERN SPS and Fermilab Tevatron are also worth considering

  9. Asymmetric Ashes

    2006-11-01

    that oscillate in certain directions. Reflection or scattering of light favours certain orientations of the electric and magnetic fields over others. This is why polarising sunglasses can filter out the glint of sunlight reflected off a pond. When light scatters through the expanding debris of a supernova, it retains information about the orientation of the scattering layers. If the supernova is spherically symmetric, all orientations will be present equally and will average out, so there will be no net polarisation. If, however, the gas shell is not round, a slight net polarisation will be imprinted on the light. This is what broad-band polarimetry can accomplish. If additional spectral information is available ('spectro-polarimetry'), one can determine whether the asymmetry is in the continuum light or in some spectral lines. In the case of the Type Ia supernovae, the astronomers found that the continuum polarisation is very small so that the overall shape of the explosion is crudely spherical. But the much larger polarization in strongly blue-shifted spectral lines evidences the presence, in the outer regions, of fast moving clumps with peculiar chemical composition. "Our study reveals that explosions of Type Ia supernovae are really three-dimensional phenomena," says Dietrich Baade. "The outer regions of the blast cloud is asymmetric, with different materials found in 'clumps', while the inner regions are smooth." "This study was possible because polarimetry could unfold its full strength thanks to the light-collecting power of the Very Large Telescope and the very precise calibration of the FORS instrument," he adds. The research team first spotted this asymmetry in 2003, as part of the same observational campaign (ESO PR 23/03 and ESO PR Photo 26/05). The new, more extensive results show that the degree of polarisation and, hence, the asphericity, correlates with the intrinsic brightness of the explosion. The brighter the supernova, the smoother, or less clumpy

  10. Asymmetric synthesis of cyclo-archaeol and ß-glucosyl cyclo-archaeol

    Ferrer, C.; Fodran, P.; Barroso, S.; Gibson, R.; Hopmans, E.C.; Sinninghe Damsté, J.S.; Schouten, S.; Minnaard, A.J.

    2013-01-01

    An efficient asymmetric synthesis of cyclo-archaeol and beta-glucosyl cyclo-archaeol is presented employing catalytic asymmetric conjugate addition and catalytic epoxide ring opening as the key steps. Their occurrence in deep sea hydrothermal vents has been confirmed by chromatographic comparison

  11. Principles of asymmetric synthesis

    Gawley, Robert E; Aube, Jeffrey

    2012-01-01

    The world is chiral. Most of the molecules in it are chiral, and asymmetric synthesis is an important means by which enantiopure chiral molecules may be obtained for study and sale. Using examples from the literature of asymmetric synthesis, this book presents a detailed analysis of the factors that govern stereoselectivity in organic reactions. After an explanation of the basic physical-organic principles governing stereoselective reactions, the authors provide a detailed, annotated glossary of stereochemical terms. A chapter on "Practical Aspects of Asymmetric Synthesis" provides a critical overview of the most common methods for the preparation of enantiomerically pure compounds, techniques for analysis of stereoisomers using chromatographic, spectroscopic, and chiroptical methods. The authors then present an overview of the most important methods in contemporary asymmetric synthesis organized by reaction type. Thus, there are four chapters on carbon-carbon bond forming reactions, one chapter on reductions...

  12. Synthesis of Mikto-Arm Star Peptide Conjugates.

    Koo, Jin Mo; Su, Hao; Lin, Yi-An; Cui, Honggang

    2018-01-01

    Mikto-arm star peptide conjugates are an emerging class of self-assembling peptide-based structural units that contain three or more auxiliary segments of different chemical compositions and/or functionalities. This group of molecules exhibit interesting self-assembly behavior in solution due to their chemically asymmetric topology. Here we describe the detailed procedure for synthesis of an ABC Mikto-arm star peptide conjugate in which two immiscible entities (a saturated hydrocarbon and a hydrophobic and lipophobic fluorocarbon) are conjugated onto a short β-sheet forming peptide sequence, GNNQQNY, derived from the Sup35 prion, through a lysine junction. Automated and manual Fmoc-solid phase synthesis techniques are used to synthesize the Mikto-arm star peptide conjugates, followed by HPLC purification. We envision that this set of protocols can afford a versatile platform to synthesize a new class of peptidic building units for diverse applications.

  13. Quantifying social asymmetric structures.

    Solanas, Antonio; Salafranca, Lluís; Riba, Carles; Sierra, Vicenta; Leiva, David

    2006-08-01

    Many social phenomena involve a set of dyadic relations among agents whose actions may be dependent. Although individualistic approaches have frequently been applied to analyze social processes, these are not generally concerned with dyadic relations, nor do they deal with dependency. This article describes a mathematical procedure for analyzing dyadic interactions in a social system. The proposed method consists mainly of decomposing asymmetric data into their symmetric and skew-symmetric parts. A quantification of skew symmetry for a social system can be obtained by dividing the norm of the skew-symmetric matrix by the norm of the asymmetric matrix. This calculation makes available to researchers a quantity related to the amount of dyadic reciprocity. With regard to agents, the procedure enables researchers to identify those whose behavior is asymmetric with respect to all agents. It is also possible to derive symmetric measurements among agents and to use multivariate statistical techniques.

  14. Asymmetrical field emitter

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  15. Asymmetric ion trap

    Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

    1997-01-01

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

  16. Optical phase conjugation

    Fisher, Robert A

    1983-01-01

    This book appears at a time of intense activity in optical phase conjugation. We chose not to await the maturation of the field, but instead to provide this material in time to be useful in its development. We have tried very hard to elucidate and interrelate the various nonlinear phenomena which can be used for optical phase conjugation.

  17. How Is Nature Asymmetric?

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 6. How Is Nature Asymmetric? - Discrete Symmetries in Particle Physics and their Violation ... Indian Institute of Technology, Chennai. Aligarh Muslim University. University of Rajasthan, Jaipur. Indian Institute of Science, Bangalore 560012, India.

  18. Calcium(ii)-catalyzed enantioselective conjugate additions of amines.

    Uno, Brice E; Dicken, Rachel D; Redfern, Louis R; Stern, Charlotte M; Krzywicki, Greg G; Scheidt, Karl A

    2018-02-14

    The direct enantioselective chiral calcium(ii)·phosphate complex (Ca[CPA] 2 )-catalyzed conjugate addition of unprotected alkyl amines to maleimides was developed. This mild catalytic system represents a significant advance towards the general convergent asymmetric amination of α,β-unsaturated electrophiles, providing medicinally relevant chiral aminosuccinimide products in high yields and enantioselectivities. Furthermore, the catalyst can be reused directly from a previously chromatographed reaction and still maintain both high yield and selectivity.

  19. Multipartite asymmetric quantum cloning

    Iblisdir, S.; Gisin, N.; Acin, A.; Cerf, N.J.; Filip, R.; Fiurasek, J.

    2005-01-01

    We investigate the optimal distribution of quantum information over multipartite systems in asymmetric settings. We introduce cloning transformations that take N identical replicas of a pure state in any dimension as input and yield a collection of clones with nonidentical fidelities. As an example, if the clones are partitioned into a set of M A clones with fidelity F A and another set of M B clones with fidelity F B , the trade-off between these fidelities is analyzed, and particular cases of optimal N→M A +M B cloning machines are exhibited. We also present an optimal 1→1+1+1 cloning machine, which is an example of a tripartite fully asymmetric cloner. Finally, it is shown how these cloning machines can be optically realized

  20. Qualidade conjugal: mapeando conceitos

    Clarisse Mosmann

    2006-12-01

    Full Text Available Apesar da ampla utilização do conceito de qualidade conjugal, identifica-se falta de clareza conceitual acerca das variáveis que o compõem. Esse artigo apresenta revisão da literatura na área com o objetivo de mapear o conceito de qualidade conjugal. Foram analisadas sete principais teorias sobre o tema: Troca Social, Comportamental, Apego, Teoria da Crise, Interacionismo Simbólico. Pelos postulados propostos nas diferentes teorias, podem-se identificar três grupos de variáveis fundamentais na definição da qualidade conjugal: recursos pessoais dos cônjuges, contexto de inserção do casal e processos adaptativos. Neste sentido, a qualidade conjugal é resultado do processo dinâmico e interativo do casal, razão deste caráter multidimensional.

  1. Conjugate Gaze Palsies

    ... version Home Brain, Spinal Cord, and Nerve Disorders Cranial Nerve Disorders Conjugate Gaze Palsies Horizontal gaze palsy Vertical ... Version. DOCTORS: Click here for the Professional Version Cranial Nerve Disorders Overview of the Cranial Nerves Internuclear Ophthalmoplegia ...

  2. Conjugated Polymer Solar Cells

    Paraschuk, Dmitry Y

    2006-01-01

    This report results from a contract tasking Moscow State University as follows: Conjugated polymers are promising materials for many photonics applications, in particular, for photovoltaic and solar cell devices...

  3. Polymers for Protein Conjugation

    Gianfranco Pasut

    2014-01-01

    Full Text Available Polyethylene glycol (PEG at the moment is considered the leading polymer for protein conjugation in view of its unique properties, as well as to its low toxicity in humans, qualities which have been confirmed by its extensive use in clinical practice. Other polymers that are safe, biodegradable and custom-designed have, nevertheless, also been investigated as potential candidates for protein conjugation. This review will focus on natural polymers and synthetic linear polymers that have been used for protein delivery and the results associated with their use. Genetic fusion approaches for the preparation of protein-polypeptide conjugates will be also reviewed and compared with the best known chemical conjugation ones.

  4. Asymmetric information and economics

    Frieden, B. Roy; Hawkins, Raymond J.

    2010-01-01

    We present an expression of the economic concept of asymmetric information with which it is possible to derive the dynamical laws of an economy. To illustrate the utility of this approach we show how the assumption of optimal information flow leads to a general class of investment strategies including the well-known Q theory of Tobin. Novel consequences of this formalism include a natural definition of market efficiency and an uncertainty principle relating capital stock and investment flow.

  5. Asymmetric Evolutionary Games

    McAvoy, Alex; Hauert, Christoph

    2015-01-01

    Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner’s Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games. PMID:26308326

  6. Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

    Katherine M. Byrd

    2015-04-01

    Full Text Available The conjugate addition reaction has been a useful tool in the formation of carbon–carbon bonds. The utility of this reaction has been demonstrated in the synthesis of many natural products, materials, and pharmacological agents. In the last three decades, there has been a significant increase in the development of asymmetric variants of this reaction. Unfortunately, conjugate addition reactions using α,β-unsaturated amides and lactams remain underdeveloped due to their inherently low reactivity. This review highlights the work that has been done on both diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams.

  7. Asymmetric quantum cloning machines

    Cerf, N.J.

    1998-01-01

    A family of asymmetric cloning machines for quantum bits and N-dimensional quantum states is introduced. These machines produce two approximate copies of a single quantum state that emerge from two distinct channels. In particular, an asymmetric Pauli cloning machine is defined that makes two imperfect copies of a quantum bit, while the overall input-to-output operation for each copy is a Pauli channel. A no-cloning inequality is derived, characterizing the impossibility of copying imposed by quantum mechanics. If p and p ' are the probabilities of the depolarizing channels associated with the two outputs, the domain in (√p,√p ' )-space located inside a particular ellipse representing close-to-perfect cloning is forbidden. This ellipse tends to a circle when copying an N-dimensional state with N→∞, which has a simple semi-classical interpretation. The symmetric Pauli cloning machines are then used to provide an upper bound on the quantum capacity of the Pauli channel of probabilities p x , p y and p z . The capacity is proven to be vanishing if (√p x , √p y , √p z ) lies outside an ellipsoid whose pole coincides with the depolarizing channel that underlies the universal cloning machine. Finally, the tradeoff between the quality of the two copies is shown to result from a complementarity akin to Heisenberg uncertainty principle. (author)

  8. Metal-Free Catalytic Enantioselective C–B Bond Formation: (Pinacolato)boron Conjugate Additions to α,β-Unsaturated Ketones, Esters, Weinreb Amides and Aldehydes Promoted by Chiral N-Heterocyclic Carbenes

    Wu, Hao; Radomkit, Suttipol; O’Brien, Jeannette M.; Hoveyda, Amir H.

    2012-01-01

    The first broadly applicable metal-free enantioselective method for boron conjugate addition (BCA) to α,β-unsaturated carbonyls is presented. The C–B bond forming reactions are promoted in the presence of 2.5–7.5 mol % of a readily accessible C1-symmetric chiral imidazolinium salt, which is converted, in situ, to the catalytically active diastereo- and enantiomerically pure N-heterocyclic carbene (NHC) by the common organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (dbu). In addition to the commercially available bis(pinacolato)diboron [B2(pin)2], and in contrast to reactions with the less sterically demanding achiral NHCs, the presence of MeOH is required for high efficiency. Acyclic and cyclic α,β-unsaturated ketones, as well as acyclic esters, Weinreb amides and aldehydes can serve as suitable substrates; the desired β-boryl carbonyls are isolated in up to 94% yield and >98:2 enantiomer ratio (er). Transformations are often carried out at ambient temperature. In certain cases, such as when the relatively less reactive unsaturated amides are used, elevated temperatures are required (50–66 °C); nonetheless, reactions remain highly enantioselective. The utility of the NHC-catalyzed method is demonstrated through comparison with the alternative Cu-catalyzed protocols; in cases involving a polyfunctional substrate, unique profiles in chemoselectivity are exhibited by the metal-free approach (e.g., conjugate addition vs reaction with an alkyne, allene or aldehyde). PMID:22559866

  9. Cinchona alkaloids in asymmetric organocatalysis

    Marcelli, T.; Hiemstra, H.

    2010-01-01

    This article reviews the applications of cinchona alkaloids as asymmetric catalysts. In the last few years, characterized by the resurgence of interest in asymmetric organocatalysis, cinchona derivatives have been shown to catalyze an outstanding array of chemical reactions, often with remarkable

  10. Alternative Asymmetric Stochastic Volatility Models

    M. Asai (Manabu); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is

  11. Peptide-Carrier Conjugation

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  12. Photoluminescence in conjugated polymers

    Furst, J.E.; Laugesen, R.; Dastoor, P.; McNeill, C.

    2002-01-01

    Full text: Conjugated polymers combine the electronic and optical properties of semiconductors with the processability of polymers. They contain a sequence of alternate single and double carbon bonds so that the overlap of unhybridised p z orbitals creates a delocalised ρ system which gives semiconducting properties with p-bonding (valence) and p* -antibonding (conduction) bands. Photoluminesence (PL) in conjugated polymers results from the radiative decay of singlet excitons confined to a single chain. The present work is the first in a series of studies in our laboratory that will characterize the optical properties of conjugated polymers. The experiment involves the illumination of thin films of conjugated polymer with UV light (I=360 nm) and observing the subsequent fluorescence using a custom-built, fluorescence spectrometer. Photoluminesence spectra provide basic information about the structure of the polymer film. A typical spectrum is shown in the accompanying figure. The position of the first peak is related to the polymer chain length and resolved multiple vibronic peaks are an indication of film structure and morphology. We will also present results related to the optical degradation of these materials when exposed to air and UV light

  13. DNA-cell conjugates

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2018-05-15

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  14. DNA-cell conjugates

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  15. Asymmetric Realized Volatility Risk

    David E. Allen

    2014-06-01

    Full Text Available In this paper, we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive. Even though returns standardized by ex post quadratic variation measures are nearly Gaussian, this unpredictability brings considerably more uncertainty to the empirically relevant ex ante distribution of returns. Explicitly modeling this volatility risk is fundamental. We propose a dually asymmetric realized volatility model, which incorporates the fact that realized volatility series are systematically more volatile in high volatility periods. Returns in this framework display time varying volatility, skewness and kurtosis. We provide a detailed account of the empirical advantages of the model using data on the S&P 500 index and eight other indexes and stocks.

  16. Asymmetric Higgsino dark matter.

    Blum, Kfir; Efrati, Aielet; Grossman, Yuval; Nir, Yosef; Riotto, Antonio

    2012-08-03

    In the supersymmetric framework, prior to the electroweak phase transition, the existence of a baryon asymmetry implies the existence of a Higgsino asymmetry. We investigate whether the Higgsino could be a viable asymmetric dark matter candidate. We find that this is indeed possible. Thus, supersymmetry can provide the observed dark matter abundance and, furthermore, relate it with the baryon asymmetry, in which case the puzzle of why the baryonic and dark matter mass densities are similar would be explained. To accomplish this task, two conditions are required. First, the gauginos, squarks, and sleptons must all be very heavy, such that the only electroweak-scale superpartners are the Higgsinos. With this spectrum, supersymmetry does not solve the fine-tuning problem. Second, the temperature of the electroweak phase transition must be low, in the (1-10) GeV range. This condition requires an extension of the minimal supersymmetric standard model.

  17. Asymmetric Organocatalytic Cycloadditions

    Mose, Rasmus

    2016-01-01

    has gained broad recognition as it has found several applications in academia and industry. The [4+2] cycloaddition has also been performed in an enantioselective aminocatalytic fashion which allows the generation of optically active products. In this thesis it is demonstrated how trienamines can......Since the onset of the new millennium the field of organocatalysis has undergone a great expansion led by investigations in the field of aminocatalysis. This thesis will address some recent developments in aminocatalyzed cycloadditions and provide a theoretical background hereto. Cycloadditions...... undergo cascade reactions with different electron deficient dienophiles in Diels Alder – nucleophilic ring closing reactions. This methodology opens up for the direct asymmetric formation of hydroisochromenes and hydroisoquinolines which may possess interesting biological activities. It is also...

  18. Force on an Asymmetric Capacitor

    Bahder, Thomas

    2003-01-01

    .... At present, the physical basis for the Biefeld-Brown effect is not understood. The order of magnitude of the net force on the asymmetric capacitor is estimated assuming two different mechanisms of charge conduction between its electrodes...

  19. Asymmetric cation-binding catalysis

    Oliveira, Maria Teresa; Lee, Jiwoong

    2017-01-01

    The employment of metal salts is quite limited in asymmetric catalysis, although it would provide an additional arsenal of safe and inexpensive reagents to create molecular functions with high optical purity. Cation chelation by polyethers increases the salts' solubility in conventional organic...... solvents, thus increasing their applicability in synthesis. The expansion of this concept to chiral polyethers led to the emergence of asymmetric cation-binding catalysis, where chiral counter anions are generated from metal salts, particularly using BINOL-based polyethers. Alkali metal salts, namely KF...... highly enantioselective silylation reactions in polyether-generated chiral environments, and leading to a record-high turnover in asymmetric organocatalysis. This can lead to further applications by the asymmetric use of other inorganic salts in various organic transformations....

  20. Multicatalyst system in asymmetric catalysis

    Zhou, Jian

    2014-01-01

    This book introduces multi-catalyst systems by describing their mechanism and advantages in asymmetric catalysis.  Helps organic chemists perform more efficient catalysis with step-by-step methods  Overviews new concepts and progress for greener and economic catalytic reactions  Covers topics of interest in asymmetric catalysis including bifunctional catalysis, cooperative catalysis, multimetallic catalysis, and novel tandem reactions   Has applications for pharmaceuticals, agrochemicals, materials, and flavour and fragrance

  1. Asymmetric Gepner models (revisited)

    Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain)] [IMAPP, Radboud Universiteit, Nijmegen (Netherlands)

    2010-12-11

    We reconsider a class of heterotic string theories studied in 1989, based on tensor products of N=2 minimal models with asymmetric simple current invariants. We extend this analysis from (2,2) and (1,2) spectra to (0,2) spectra with SO(10) broken to the Standard Model. In the latter case the spectrum must contain fractionally charged particles. We find that in nearly all cases at least some of them are massless. However, we identify a large subclass where the fractional charges are at worst half-integer, and often vector-like. The number of families is very often reduced in comparison to the 1989 results, but there are no new tensor combinations yielding three families. All tensor combinations turn out to fall into two classes: those where the number of families is always divisible by three, and those where it is never divisible by three. We find an empirical rule to determine the class, which appears to extend beyond minimal N=2 tensor products. We observe that distributions of physical quantities such as the number of families, singlets and mirrors have an interesting tendency towards smaller values as the gauge groups approaches the Standard Model. We compare our results with an analogous class of free fermionic models. This displays similar features, but with less resolution. Finally we present a complete scan of the three family models based on the triply-exceptional combination (1,16{sup *},16{sup *},16{sup *}) identified originally by Gepner. We find 1220 distinct three family spectra in this case, forming 610 mirror pairs. About half of them have the gauge group SU(3)xSU(2){sub L}xSU(2){sub R}xU(1){sup 5}, the theoretical minimum, and many others are trinification models.

  2. Organometallic B12-DNA conjugate

    Hunger, Miriam; Mutti, Elena; Rieder, Alexander

    2014-01-01

    Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in hum...

  3. Does asymmetric correlation affect portfolio optimization?

    Fryd, Lukas

    2017-07-01

    The classical portfolio optimization problem does not assume asymmetric behavior of relationship among asset returns. The existence of asymmetric response in correlation on the bad news could be important information in portfolio optimization. The paper applies Dynamic conditional correlation model (DCC) and his asymmetric version (ADCC) to propose asymmetric behavior of conditional correlation. We analyse asymmetric correlation among S&P index, bonds index and spot gold price before mortgage crisis in 2008. We evaluate forecast ability of the models during and after mortgage crisis and demonstrate the impact of asymmetric correlation on the reduction of portfolio variance.

  4. Asymmetric Synthesis via Chiral Aziridines

    Tanner, David Ackland; Harden, Adrian; Wyatt, Paul

    1996-01-01

    A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines)]. In the b......A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines...

  5. Ideal 3D asymmetric concentrator

    Garcia-Botella, Angel [Departamento Fisica Aplicada a los Recursos Naturales, Universidad Politecnica de Madrid, E.T.S.I. de Montes, Ciudad Universitaria s/n, 28040 Madrid (Spain); Fernandez-Balbuena, Antonio Alvarez; Vazquez, Daniel; Bernabeu, Eusebio [Departamento de Optica, Universidad Complutense de Madrid, Fac. CC. Fisicas, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2009-01-15

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)

  6. Conjugation in Escherichia coli

    Boyer, Herbert

    1966-01-01

    Boyer, Herbert (Yale University, New Haven, Conn.). Conjugation in Escherichia coli. J. Bacteriol. 91:1767–1772. 1966.—The sex factor of Escherichia coli K-12 was introduced into an E. coli B/r strain by circumventing the host-controlled modification and restriction incompatibilities known to exist between these closely related strains. The sexual properties of the constructed F+ B strain and its Hfr derivatives were examined. These studies showed that the E. coli strain B/r F+ and Hfr derivatives are similar to the E. coli strain K-12 F+ and Hfr derivatives. However, the site of sex factor integration was found to be dependent on the host genome. PMID:5327905

  7. Electrochromic in conjugated polymers

    Picado Valenzuela, Alfredo

    2007-01-01

    This revision considered object the description of one of the materials with the greatest potential in the field of electrochromic (mainly in the visible region): the conjugated polymers (CP), area of enormous potential both now and in a short time ahead. The CP are insulating materials and organic semiconductors in a state not doped. They can be doped positively or negatively being observed a significant increase in the conductivity and being generated a color change in these materials. The understanding of how optical properties vary based on the chemical structure of the polymer or its mixtures and more precisely of the alternatives that can be entered into the conjugated system or π system to obtain a material that besides to be flexible, environmentally stable, presents the colored states. The revision was centred chiefly in the polypyrrole (Ppy), the polythiophene (PTh) and their derivatives such as poly (3.4-ethylenedioxythiophene) (PEDOT). The advantage of using monomers with variable structure, to adjust the composition of the copolymer, or to blend with the PC, allows to obtain a variety of colored states that can be modulated through the visible spectrum and even with applications to wavelengths outside of this region. Because the PC presented at least two different colored states can be varied continuously as a function of the voltage applied. In some cases, they may submit multicoloured statements, which offers a range of possibilities for their application in flexible electronic devices type screens and windows. Applications include smart windows, camouflage clothing and data screens. This type of material is emerging as one of the substitutes of the traditional inorganic semiconductor, with the advantage of its low cost, high flexibility and the possibility to generate multiple colors through the handling of the monomers in the structure and control of energy of his band gap. (author) [es

  8. Asymmetric Penning trap coherent states

    Contreras-Astorga, Alonso; Fernandez, David J.

    2010-01-01

    By using a matrix technique, which allows to identify directly the ladder operators, the coherent states of the asymmetric Penning trap are derived as eigenstates of the appropriate annihilation operators. They are compared with those obtained through the displacement operator method.

  9. JET and COMPASS asymmetrical disruptions

    Gerasimov, S.N.; Abreu, P.; Baruzzo, M.; Drozdov, V.; Dvornova, A.; Havlíček, Josef; Hender, T.C.; Hronová-Bilyková, Olena; Kruezi, U.; Li, X.; Markovič, Tomáš; Pánek, Radomír; Rubinacci, G.; Tsalas, M.; Ventre, S.; Villone, F.; Zakharov, L.E.

    2015-01-01

    Roč. 55, č. 11 (2015), s. 113006-113006 ISSN 0029-5515 R&D Projects: GA MŠk(CZ) LM2011021 Institutional support: RVO:61389021 Keywords : tokamak * asymmetrical disruption * JET * COMPASS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.040, year: 2015

  10. Stereoselective conjugate radical additions: application of a fluorous oxazolidinone chiral auxiliary for efficient tin removal.

    Hein, Jason E; Zimmerman, Jake; Sibi, Mukund P; Hultin, Philip G

    2005-06-23

    [reaction: see text] A series of asymmetric free-radical-mediated intermolecular conjugate additions using a fluorous oxazolidinone chiral auxiliary has been completed. The fluorous auxiliary facilitated product isolation using fluorous solid phase extractions (FSPE), effectively removing excess organic and organometallic reagents. Parallel reactions carried out with a similar but nonfluorous norephedrine-derived oxazolidinone demonstrated the superior stereoselectivity and purification obtainable with the fluorous chiral auxiliary.

  11. Highly enantio- and diastereoselective reactions of γ-substituted butenolides through direct vinylogous conjugate additions

    Zhang, Wen; Tan, Davin; Lee, Richmond; Tong, Guanghu; Chen, Wenchao; Qi, Baojian; Huang, Kuo-Wei; Tan, Choonhong; Jiang, Zhiyong

    2012-01-01

    The strength of the weak: An L-tert-leucine-derived amine-thiourea catalyst (see scheme, green box) promotes the asymmetric vinylogous conjugate addition reaction between γ-aryl- and alkyl-substituted butenolides with the butenamides and enoates shown. Computational studies show the preference for the observed stereochemistry is a result of favourable weak non-bonding interactions, which stabilize the transition state. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Highly enantio- and diastereoselective reactions of γ-substituted butenolides through direct vinylogous conjugate additions

    Zhang, Wen

    2012-09-05

    The strength of the weak: An L-tert-leucine-derived amine-thiourea catalyst (see scheme, green box) promotes the asymmetric vinylogous conjugate addition reaction between γ-aryl- and alkyl-substituted butenolides with the butenamides and enoates shown. Computational studies show the preference for the observed stereochemistry is a result of favourable weak non-bonding interactions, which stabilize the transition state. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Block-conjugate-gradient method

    McCarthy, J.F.

    1989-01-01

    It is shown that by using the block-conjugate-gradient method several, say s, columns of the inverse Kogut-Susskind fermion matrix can be found simultaneously, in less time than it would take to run the standard conjugate-gradient algorithm s times. The method improves in efficiency relative to the standard conjugate-gradient algorithm as the fermion mass is decreased and as the value of the coupling is pushed to its limit before the finite-size effects become important. Thus it is potentially useful for measuring propagators in large lattice-gauge-theory calculations of the particle spectrum

  14. Asymmetrically doped one-dimensional trans-polymers

    Caldas, Heron

    2009-01-01

    More than 30 years ago [H. Shirakawa, E.J. Louis, A.G. MacDiarmid, C.K. Chiang, A.J. Heeger, J. Chem. Soc. Chem. Comm. 578 (1977); S. Etemad, A.J. Heeger, Ann. Rev. Phys. Chem. 33 (1982) 443] it was discovered that doped trans-polyacetylene (CH) x , a one-dimensional (1D) conjugated polymer, exhibits electrical conductivity. In this work we show that an asymmetrically doped 1D trans-polymer has non-conventional properties, as compared to symmetrically doped systems. Depending on the level of asymmetry between the chemical potentials of the two involved fermionic species, the polymer can be in a partially or fully spin polarized state. Some possible experimental consequences of doped 1D trans-polymers used as 1D organic polarized conductors are discussed.

  15. Cyclodextrins in Asymmetric and Stereospecific Synthesis

    Fliur Macaev

    2015-09-01

    Full Text Available Since their discovery, cyclodextrins have widely been used as green and easily available alternatives to promoters or catalysts of different chemical reactions in water. This review covers the research and application of cyclodextrins and their derivatives in asymmetric and stereospecific syntheses, with their division into three main groups: (1 cyclodextrins promoting asymmetric and stereospecific catalysis in water; (2 cyclodextrins’ complexes with transition metals as asymmetric and stereospecific catalysts; and (3 cyclodextrins’ non-metallic derivatives as asymmetric and stereospecific catalysts. The scope of this review is to systematize existing information on the contribution of cyclodextrins to asymmetric and stereospecific synthesis and, thus, to facilitate further development in this direction.

  16. Entanglements in Conjugated Polymers

    Xie, Renxuan; Lee, Youngmin; Aplan, Melissa; Caggiano, Nick; Gomez, Enrique; Colby, Ralph

    Conjugated polymers, such as poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly-((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(thiophen-5-yl)-2,1,3-benzothiadiazole]-2',2''-diyl) (PFTBT), are widely used as hole and electron transport materials in a variety of electronic devices. However, fundamental knowledge regarding chain entanglements and nematic-to-isotropic transition is still lacking and are crucial to maximize charge transport properties. A systematic melt rheology study on P3HT with various molecular weights and regio regularities was performed. We find that the entanglement molecular weight Me is 5.0 kg/mol for regiorandom P3HT, but the apparent Me for regioregular P3HT is significantly higher. The difference is postulated to arise from the presence of a nematic phase only in regioregular P3HT. Analogously, PFTBT shows a clear rheological signature of the nematic-to-isotropic transition as a reversible sharp transition at 278 C. Shearing of this nematic phase leads to anisotropic crystalline order in PFTBT. We postulate that aligning the microstructure will impact charge transport and thereby advance the field of conducting polymers. National Science Foundation.

  17. Protein carriers of conjugate vaccines

    Pichichero, Michael E

    2013-01-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products. PMID:23955057

  18. Electron Jet of Asymmetric Reconnection

    Khotyaintsev, Yu. V.; Graham, D. B.; Norgren, C.; Eriksson, E.; Li, W.; Johlander, A.; Vaivads, A.; Andre, M.; Pritchett, P. L.; Retino, A.; hide

    2016-01-01

    We present Magnetospheric Multiscale observations of an electron-scale current sheet and electron outflow jet for asymmetric reconnection with guide field at the subsolar magnetopause. The electron jet observed within the reconnection region has an electron Mach number of 0.35 and is associated with electron agyrotropy. The jet is unstable to an electrostatic instability which generates intense waves with E(sub parallel lines) amplitudes reaching up to 300 mV/m and potentials up to 20% of the electron thermal energy. We see evidence of interaction between the waves and the electron beam, leading to quick thermalization of the beam and stabilization of the instability. The wave phase speed is comparable to the ion thermal speed, suggesting that the instability is of Buneman type, and therefore introduces electron-ion drag and leads to braking of the electron flow. Our observations demonstrate that electrostatic turbulence plays an important role in the electron-scale physics of asymmetric reconnection.

  19. Stable walking with asymmetric legs

    Merker, Andreas; Rummel, Juergen; Seyfarth, Andre

    2011-01-01

    Asymmetric leg function is often an undesired side-effect in artificial legged systems and may reflect functional deficits or variations in the mechanical construction. It can also be found in legged locomotion in humans and animals such as after an accident or in specific gait patterns. So far, it is not clear to what extent differences in the leg function of contralateral limbs can be tolerated during walking or running. Here, we address this issue using a bipedal spring-mass model for simulating walking with compliant legs. With the help of the model, we show that considerable differences between contralateral legs can be tolerated and may even provide advantages to the robustness of the system dynamics. A better understanding of the mechanisms and potential benefits of asymmetric leg operation may help to guide the development of artificial limbs or the design novel therapeutic concepts and rehabilitation strategies.

  20. Variable angle asymmetric cut monochromator

    Smither, R.K.; Fernandez, P.B.

    1993-09-01

    A variable incident angle, asymmetric cut, double crystal monochromator was tested for use on beamlines at the Advanced Photon Source (APS). For both undulator and wiggler beams the monochromator can expand area of footprint of beam on surface of the crystals to 50 times the area of incident beam; this will reduce the slope errors by a factor of 2500. The asymmetric cut allows one to increase the acceptance angle for incident radiation and obtain a better match to the opening angle of the incident beam. This can increase intensity of the diffracted beam by a factor of 2 to 5 and can make the beam more monochromatic, as well. The monochromator consists of two matched, asymmetric cut (18 degrees), silicon crystals mounted so that they can be rotated about three independent axes. Rotation around the first axis controls the Bragg angle. The second rotation axis is perpendicular to the diffraction planes and controls the increase of the area of the footprint of the beam on the crystal surface. Rotation around the third axis controls the angle between the surface of the crystal and the wider, horizontal axis for the beam and can make the footprint a rectangle with a minimum. length for this area. The asymmetric cut is 18 degrees for the matched pair of crystals, which allows one to expand the footprint area by a factor of 50 for Bragg angles up to 19.15 degrees (6 keV for Si[111] planes). This monochromator, with proper cooling, will be useful for analyzing the high intensity x-ray beams produced by both undulators and wigglers at the APS

  1. Asymmetric information and bank runs

    Gu, Chao

    2007-01-01

    It is known that sunspots can trigger panic-based bank runs and that the optimal banking contract can tolerate panic-based runs. The existing literature assumes that these sunspots are based on a publicly observed extrinsic randomizing device. In this paper, I extend the analysis of panic-based runs to include an asymmetric-information, extrinsic randomizing device. Depositors observe different, but correlated, signals on the stability of the bank. I find that if the signals that depositors o...

  2. Asymmetric information and macroeconomic dynamics

    Hawkins, Raymond J.; Aoki, Masanao; Roy Frieden, B.

    2010-09-01

    We show how macroeconomic dynamics can be derived from asymmetric information. As an illustration of the utility of this approach we derive the equilibrium density, non-equilibrium densities and the equation of motion for the response to a demand shock for productivity in a simple economy. Novel consequences of this approach include a natural incorporation of time dependence into macroeconomics and a common information-theoretic basis for economics and other fields seeking to link micro-dynamics and macro-observables.

  3. Asymmetric Synthesis of Apratoxin E.

    Mao, Zhuo-Ya; Si, Chang-Mei; Liu, Yi-Wen; Dong, Han-Qing; Wei, Bang-Guo; Lin, Guo-Qiang

    2016-10-21

    An efficient method for asymmetric synthesis of apratoxin E 2 is described in this report. The chiral lactone 8, recycled from the degradation of saponin glycosides, was utilized to prepare the non-peptide fragment 6. In addition to this "from nature to nature" strategy, olefin cross-metathesis (CM) was applied as an alternative approach for the formation of the double bond. Moreover, pentafluorophenyl diphenylphosphinate was found to be an efficient condensation reagent for the macrocyclization.

  4. Comprehensive asymmetric dark matter model

    Lonsdale, Stephen J.; Volkas, Raymond R.

    2018-01-01

    Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical...

  5. Conjugated Fatty Acid Synthesis

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-01-01

    Conjugated linolenic acids (CLNs), 18:3 Δ9,11,13, lack the methylene groups found between the double bonds of linolenic acid (18:3 Δ9,12,15). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 Δ9cis,11trans,13cis) or α-eleostearic acid (18:3 Δ9cis,11trans,13trans). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly α-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of α-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation. PMID:22451660

  6. Research study of conjugate materials; Conjugate material no chosa kenkyu

    NONE

    1998-03-01

    The paper reported an introductory research on possibilities of new glass `conjugate materials.` The report took up the structure and synthetic process of conjugate materials to be researched/developed, classified them according to structural elements on molecular, nanometer and cluster levels, and introduced the structures and functions. Further, as glasses with new functions to be proposed, the paper introduced transparent and high-strength glass used for houses and vehicles, light modulation glass which realizes energy saving and optical data processing, and environmentally functional glass which realizes environmental cleaning or high performance biosensor. An initial survey was also conducted on rights of intellectual property to be taken notice of in Japan and abroad in the present situation. Reports were summed up and introduced of Osaka National Research Institute, Electrotechnical Laboratory, and National Industrial Research Institute of Nagoya which are all carrying out leading studies of conjugate materials. 235 refs., 135 figs., 6 tabs.

  7. Conjugated polymer nanoparticles, methods of using, and methods of making

    Habuchi, Satoshi

    2017-03-16

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  8. Conjugated polymer nanoparticles, methods of using, and methods of making

    Habuchi, Satoshi; Piwonski, Hubert Marek; Michinobu, Tsuyoshi

    2017-01-01

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  9. Construction of axial chirality by rhodium-catalyzed asymmetric dehydrogenative Heck coupling of biaryl compounds with alkenes.

    Zheng, Jun; You, Shu-Li

    2014-11-24

    Enantioselective construction of axially chiral biaryls by direct C-H bond functionalization reactions has been realized. Novel axially chiral biaryls were synthesized by the direct C-H bond olefination of biaryl compounds, using a chiral [Cp*Rh(III)] catalyst, in good to excellent yields and enantioselectivities. The obtained axially chiral biaryls were found as suitable ligands for rhodium-catalyzed asymmetric conjugate additions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Conjugated polymer zwitterions and solar cells comprising conjugated polymer zwitterions

    Emrick, Todd; Russell, Thomas; Page, Zachariah; Liu, Yao

    2018-06-05

    A conjugated polymer zwitterion includes repeating units having structure (I), (II), or a combination thereof ##STR00001## wherein Ar is independently at each occurrence a divalent substituted or unsubstituted C3-30 arylene or heteroarylene group; L is independently at each occurrence a divalent C1-16 alkylene group, C6-30arylene or heteroarylene group, or alkylene oxide group; and R1 is independently at each occurrence a zwitterion. A polymer solar cell including the conjugated polymer zwitterion is also disclosed.

  11. Synthesis method of asymmetric gold particles.

    Jun, Bong-Hyun; Murata, Michael; Hahm, Eunil; Lee, Luke P

    2017-06-07

    Asymmetric particles can exhibit unique properties. However, reported synthesis methods for asymmetric particles hinder their application because these methods have a limited scale and lack the ability to afford particles of varied shapes. Herein, we report a novel synthetic method which has the potential to produce large quantities of asymmetric particles. Asymmetric rose-shaped gold particles were fabricated as a proof of concept experiment. First, silica nanoparticles (NPs) were bound to a hydrophobic micro-sized polymer containing 2-chlorotritylchloride linkers (2-CTC resin). Then, half-planar gold particles with rose-shaped and polyhedral structures were prepared on the silica particles on the 2-CTC resin. Particle size was controlled by the concentration of the gold source. The asymmetric particles were easily cleaved from the resin without aggregation. We confirmed that gold was grown on the silica NPs. This facile method for synthesizing asymmetric particles has great potential for materials science.

  12. LG tools for asymmetric wargaming

    Stilman, Boris; Yakhnis, Alex; Yakhnis, Vladimir

    2002-07-01

    Asymmetric operations represent conflict where one of the sides would apply military power to influence the political and civil environment, to facilitate diplomacy, and to interrupt specified illegal activities. This is a special type of conflict where the participants do not initiate full-scale war. Instead, the sides may be engaged in a limited open conflict or one or several sides may covertly engage another side using unconventional or less conventional methods of engagement. They may include peace operations, combating terrorism, counterdrug operations, arms control, support of insurgencies or counterinsurgencies, show of force. An asymmetric conflict can be represented as several concurrent interlinked games of various kinds: military, transportation, economic, political, etc. Thus, various actions of peace violators, terrorists, drug traffickers, etc., can be expressed via moves in different interlinked games. LG tools allow us to fully capture the specificity of asymmetric conflicts employing the major LG concept of hypergame. Hypergame allows modeling concurrent interlinked processes taking place in geographically remote locations at different levels of resolution and time scale. For example, it allows us to model an antiterrorist operation taking place simultaneously in a number of countries around the globe and involving wide range of entities from individuals to combat units to governments. Additionally, LG allows us to model all sides of the conflict at their level of sophistication. Intelligent stakeholders are represented by means of LG generated intelligent strategies. TO generate those strategies, in addition to its own mathematical intelligence, the LG algorithm may incorporate the intelligence of the top-level experts in the respective problem domains. LG models the individual differences between intelligent stakeholders. The LG tools make it possible to incorporate most of the known traits of a stakeholder, i.e., real personalities involved in

  13. Incompressibility of asymmetric nuclear matter

    Chen, Liewen; Cai, Baojun; Shen, Chun; Ko, Cheming; Xu, Jun; Li, Baoan

    2010-01-01

    Using an isospin- and momentum-dependent modified Gogny (MDI) interaction, the Skyrme-Hartree-Fock (SHF) approach, and a phenomenological modified Skyrme-like (MSL) model, we have studied the incompressibility K sat (δ) of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of K sat (δ) in powers of isospin asymmetry δ, i.e., K sat (δ) = K 0 + K sat,2 δ 2 + K sat,4 δ 4 + O(δ 6 ), the magnitude of the 4th-order K sat,4 parameter is generally small. The 2nd-order K sat,2 parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matter at saturation density. Furthermore, the K sat,2 can be expressed as K sat,2 = K sym – 6L – J 0 /K 0 L in terms of the slope parameter L and the curvature parameter K sym of the symmetry energy and the third-order derivative parameter J 0 of the energy of symmetric nuclear matter at saturation density, and we find the higher order J 0 contribution to K sat,2 generally cannot be neglected. Also, we have found a linear correlation between K sym and L as well as between J 0 /K 0 and K 0 . Using these correlations together with the empirical constraints on K 0 and L, the nuclear symmetry energy E sym (ρ0) at normal nuclear density, and the nucleon effective mass, we have obtained an estimated value of K sat,2 = -370 ± 120 MeV for the 2nd-order parameter in the isospin asymmetry expansion of the incompressibility of asymmetric nuclear matter at its saturation density. (author)

  14. Parts of Speech in Non-typical Function: (Asymmetrical Encoding of Non-verbal Predicates in Erzya

    Rigina Turunen

    2011-01-01

    Full Text Available Erzya non-verbal conjugation refers to symmetric paradigms in which non-verbal predicates behave morphosyntactically in a similar way to verbal predicates. Notably, though, non-verbal conjugational paradigms are asymmetric, which is seen as an outcome of paradigmatic neutralisation in less frequent/less typical contexts. For non-verbal predicates it is not obligatory to display the same amount of behavioural potential as it is for verbal predicates, and the lexical class of non-verbal predicate operates in such a way that adjectival predicates are more likely to be conjugated than nominals. Further, besides symmetric paradigms and constructions, in Erzya there are non-verbal predicate constructions which display a more overt structural encoding than do verbal ones, namely, copula constructions. Complexity in the domain of non-verbal predication in Erzya decreases the symmetry of the paradigms. Complexity increases in asymmetric constructions, as well as in paradigmatic neutralisation when non-verbal predicates cannot be inflected in all the tenses and moods occurring in verbal predication. The results would be the reverse if we were to measure complexity in terms of the morphological structure. The asymmetric features in non-verbal predication are motivated language-externally, because non-verbal predicates refer to states and occur less frequently as predicates than verbal categories. The symmetry of the paradigms and constructions is motivated language-internally: a grammatical system with fewer rules is economical.

  15. Asymmetric effects in customer satisfaction

    Füller, Johann; Matzler, Kurt; Faullant, Rita

    2006-01-01

    The results of this study on customer satisfaction in snowboard areas show that the relationship between an attribute and overall satisfaction can indeed be asymmetric. A 30-item self-administered survey was completed by snowboarders (n=2526) in 51 areas in Austria, Germany, Switzerland and Italy....... Results show that waiting time is a dissatisfier; it has a significant impact on overall customer satisfaction in the low satisfaction condition and becomes insignificant in the high satisfaction situation. Restaurants and bars are hybrids, i.e. importance does not depend on performance. Slopes, fun...

  16. Asymmetric Formal Synthesis of Azadirachtin.

    Mori, Naoki; Kitahara, Takeshi; Mori, Kenji; Watanabe, Hidenori

    2015-12-01

    An asymmetric formal synthesis of azadirachtin, a potent insect antifeedant, was accomplished in 30 steps to Ley's synthetic intermediate (longest linear sequence). The synthesis features: 1) rapid access to the optically active right-hand segment starting from the known 5-hydroxymethyl-2-cyclopentenone scaffold; 2) construction of the B and E rings by a key intramolecular tandem radical cyclization; 3) formation of the hemiacetal moiety in the C ring through the α-oxidation of the six-membered lactone followed by methanolysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Spontaneous baryogenesis from asymmetric inflaton

    Takahashi, Fuminobu

    2015-10-01

    We propose a variant scenario of spontaneous baryogenesis from asymmetric inflaton based on current-current interactions between the inflaton and matter fields with a non-zero B-L charge. When the inflaton starts to oscillate around the minimum after inflation, it may lead to excitation of a CP-odd component, which induces an effective chemical potential for the B-L number through the current-current interactions. We study concrete inflation models and show that the spontaneous baryogenesis scenario can be naturally implemented in the chaotic inflation in supergravity.

  18. Field factors for asymmetric collimators

    Turner, J.R.; Butler, A.P.H.

    1996-01-01

    In recent years manufacturers have been supplying linear accelerators with either a single pair or a dual pair of collimators. The use of a model to relate off-axis field factors to on-axis field factors obviates the need for repeat measurements whenever the asymmetric collimators are employed. We have investigated the variation of collimator scatter Sc, with distance of the central ray x from the central axis for a variety of non square field sizes. Collimator scatter was measured by in-air measurements with a build-up cap. The Primaty-Off-Centre-Ratio (POCR) was measured in-air by scanning orthogonally across the beam with an ionization chamber. The result of the investigation is the useful prediction of off-axis field factors for a range of rectangular asymmetric fields using the simple product of the on-axis field factor and the POCR in air. The effect of asymmetry on the quality of the beam and hence the percent depth dose will be discussed. (author)

  19. Conjugal Pairing in Escherichia Coli

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

  20. Persistence Mechanisms of Conjugative Plasmids

    Bahl, Martin Iain; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    Are plasmids selfish parasitic DNA molecules or an integrated part of the bacterial genome? This chapter reviews the current understanding of the persistence mechanisms of conjugative plasmids harbored by bacterial cells and populations. The diversity and intricacy of mechanisms affecting the suc...

  1. Orderings for conjugate gradient preconditionings

    Ortega, James M.

    1991-01-01

    The effect of orderings on the rate of convergence of the conjugate gradient method with SSOR or incomplete Cholesky preconditioning is examined. Some results also are presented that help to explain why red/black ordering gives an inferior rate of convergence.

  2. Bacteriophytochromes control conjugation in Agrobacterium fabrum.

    Bai, Yingnan; Rottwinkel, Gregor; Feng, Juan; Liu, Yiyao; Lamparter, Tilman

    2016-08-01

    Bacterial conjugation, the transfer of single stranded plasmid DNA from donor to recipient cell, is mediated through the type IV secretion system. We performed conjugation assays using a transmissible artificial plasmid as reporter. With this assay, conjugation in Agrobacterium fabrum was modulated by the phytochromes Agp1 and Agp2, photoreceptors that are most sensitive in the red region of visible light. In conjugation studies with wild-type donor cells carrying a pBIN-GUSINT plasmid as reporter that lacked the Ti (tumor inducing) plasmid, no conjugation was observed. When either agp1(-) or agp2(-) knockout donor strains were used, plasmid DNA was delivered to the recipient, indicating that both phytochromes suppress conjugation in the wild type donor. In the recipient strains, the loss of Agp1 or Agp2 led to diminished conjugation. When wild type cells with Ti plasmid and pBIN-GUS reporter plasmid were used as donor, a high rate of conjugation was observed. The DNA transfer was down regulated by red or far-red light by a factor of 3.5. With agp1(-) or agp2(-) knockout donor cells, conjugation in the dark was about 10 times lower than with the wild type donor, and with the double knockout donor no conjugation was observed. These results imply that the phytochrome system has evolved to inhibit conjugation in the light. The decrease of conjugation under different temperature correlated with the decrease of phytochrome autophosphorylation. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy ...

    REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy. AOK Johnson. Abstract. Conjugated hyperbilirubinaemia exists when the conjugated serum bilirubin level is more than 2 mg/dl or more than 20 per cent of the total serum bilirubin. It is always pathological in early infancy. The causes are many and diverse ...

  4. Purification of SUMO conjugating enzymes and kinetic analysis of substrate conjugation

    Yunus, Ali A.; Lima, Christopher D.

    2009-01-01

    SUMO conjugation to protein substrates requires the concerted action of a dedicated E2 ubiquitin conjugation enzyme (Ubc9) and associated E3 ligases. Although Ubc9 can directly recognize and modify substrate lysine residues that occur within a consensus site for SUMO modification, E3 ligases can redirect specificity and enhance conjugation rates during SUMO conjugation in vitro and in vivo. In this chapter, we will describe methods utilized to purify SUMO conjugating enzymes and model substrates which can be used for analysis of SUMO conjugation in vitro. We will also describe methods to extract kinetic parameters during E3-dependent or E3-independent substrate conjugation. PMID:19107417

  5. Asymmetric Frontal Brain Activity and Parental Rejection

    Huffmeijer, R.; Alink, L.R.A.; Tops, M.; Bakermans-Kranenburg, M.J.; van IJzendoorn, M.H.

    2013-01-01

    Asymmetric frontal brain activity has been widely implicated in reactions to emotional stimuli and is thought to reflect individual differences in approach-withdrawal motivation. Here, we investigate whether asymmetric frontal activity, as a measure of approach-withdrawal motivation, also predicts

  6. Worst Asymmetrical Short-Circuit Current

    Arana Aristi, Iván; Holmstrøm, O; Grastrup, L

    2010-01-01

    In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...

  7. Mechanochemistry assisted asymmetric organocatalysis: A sustainable approach

    Pankaj Chauhan

    2012-12-01

    Full Text Available Ball-milling and pestle and mortar grinding have emerged as powerful methods for the development of environmentally benign chemical transformations. Recently, the use of these mechanochemical techniques in asymmetric organocatalysis has increased. This review highlights the progress in asymmetric organocatalytic reactions assisted by mechanochemical techniques.

  8. Designing asymmetric multiferroics with strong magnetoelectric coupling

    Lu, Xuezeng; Xiang, Hongjun; Rondinelli, James; Materials Theory; Design Group Team

    2015-03-01

    Multiferroics offer exciting opportunities for electric-field control of magnetism. Single-phase multiferroics suitable for such applications at room temperature need much more study. Here, we propose the concept of an alternative type of multiferroics, namely, the ``asymmetric multiferroic.'' In asymmetric multiferroics, two locally stable ferroelectric states are not symmetrically equivalent, leading to different magnetic properties between these two states. Furthermore, we predict from first principles that a Fe-Cr-Mo superlattice with the LiNbO3-type structure is such an asymmetric multiferroic. The strong ferrimagnetism, high ferroelectric polarization, and significant dependence of the magnetic transition temperature on polarization make this asymmetric multiferroic an ideal candidate for realizing electric-field control of magnetism at room temperature. Our study suggests that the asymmetric multiferroic may provide an alternative playground for voltage control of magnetism and find its applications in spintronics and quantum computing.

  9. A case of asymmetrical arthrogryposis

    Hageman, G.; Vette, J.K.; Willemse, J.

    1983-01-01

    Following the introduction of the conception that arthrogryposis is a symptom and not a clinical entity, a case of the very rare asymmetric form of neurogenic arthrogryposis is presented. The asymmetry of congenital contractures and weakness is associated with hemihypotrophy. The value of muscular CT-scanning prior to muscle biopsy is demonstrated. Muscular CT-scanning shows the extension of adipose tissue, which has replaced damaged muscles and therby indicates the exact site for muscle biopsy. Since orthopaedic treatment in arthrogryposis can be unrewarding due to severe muscular degeneration, preoperative scanning may provide additional important information on muscular function and thus be of benefit for surgery. The advantage of muscular CT-scanning in other forms of arthrogryposis requires further determination. The differential diagnosis with Werdnig-Hoffmann disease is discussed. (author)

  10. Comprehensive asymmetric dark matter model

    Lonsdale, Stephen J.; Volkas, Raymond R.

    2018-05-01

    Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical constraints. Importantly, it incorporates a deep reason for why the dark matter mass scale is related to the proton mass, a key consideration in ADM models. Our starting point is the idea of mirror matter, which offers an explanation for dark matter by duplicating the standard model with a dark sector related by a Z2 parity symmetry. However, the dark sector need not manifest as a symmetric copy of the standard model in the present day. By utilizing the mechanism of "asymmetric symmetry breaking" with two Higgs doublets in each sector, we develop a model of ADM where the mirror symmetry is spontaneously broken, leading to an electroweak scale in the dark sector that is significantly larger than that of the visible sector. The weak sensitivity of the ordinary and dark QCD confinement scales to their respective electroweak scales leads to the necessary connection between the dark matter and proton masses. The dark matter is composed of either dark neutrons or a mixture of dark neutrons and metastable dark hydrogen atoms. Lepton asymmetries are generated by the C P -violating decays of heavy Majorana neutrinos in both sectors. These are then converted by sphaleron processes to produce the observed ratio of visible to dark matter in the universe. The dynamics responsible for the kinetic decoupling of the two sectors emerges as an important issue that we only partially solve.

  11. Chaos of several typical asymmetric systems

    Feng Jingjing; Zhang Qichang; Wang Wei

    2012-01-01

    The threshold for the onset of chaos in asymmetric nonlinear dynamic systems can be determined using an extended Padé method. In this paper, a double-well asymmetric potential system with damping under external periodic excitation is investigated, as well as an asymmetric triple-well potential system under external and parametric excitation. The integrals of Melnikov functions are established to demonstrate that the motion is chaotic. Threshold values are acquired when homoclinic and heteroclinic bifurcations occur. The results of analytical and numerical integration are compared to verify the effectiveness and feasibility of the analytical method.

  12. Modelling asymmetric growth in crowded plant communities

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size......-asymmetric growth part, where growth is assumed to be proportional to a power function of the size of the individual, and a term that reduces the relative growth rate as a decreasing function of the individual plant size and the competitive interactions from other plants in the neighbourhood....

  13. Modeling of asymmetrical boost converters

    Eliana Isabel Arango Zuluaga

    2014-01-01

    Full Text Available The asymmetrical interleaved dual boost (AIDB is a fifth-order DC/DC converter designed to interface photovoltaic (PV panels. The AIDB produces small current harmonics to the PV panels, reducing the power losses caused by the converter operation. Moreover, the AIDB provides a large voltage conversion ratio, which is required to step-up the PV voltage to the large dc-link voltage used in grid-connected inverters. To reject irradiance and load disturbances, the AIDB must be operated in a closed-loop and a dynamic model is required. Given that the AIDB converter operates in Discontinuous Conduction Mode (DCM, classical modeling approaches based on Continuous Conduction Mode (CCM are not valid. Moreover, classical DCM modeling techniques are not suitable for the AIDB converter. Therefore, this paper develops a novel mathematical model for the AIDB converter, which is suitable for control-pur-poses. The proposed model is based on the calculation of a diode current that is typically disregarded. Moreover, because the traditional correction to the second duty cycle reported in literature is not effective, a new equation is designed. The model accuracy is contrasted with circuital simulations in time and frequency domains, obtaining satisfactory results. Finally, the usefulness of the model in control applications is illustrated with an application example.

  14. Asymmetric Supercapacitor Electrodes and Devices.

    Choudhary, Nitin; Li, Chao; Moore, Julian; Nagaiah, Narasimha; Zhai, Lei; Jung, Yeonwoong; Thomas, Jayan

    2017-06-01

    The world is recently witnessing an explosive development of novel electronic and optoelectronic devices that demand more-reliable power sources that combine higher energy density and longer-term durability. Supercapacitors have become one of the most promising energy-storage systems, as they present multifold advantages of high power density, fast charging-discharging, and long cyclic stability. However, the intrinsically low energy density inherent to traditional supercapacitors severely limits their widespread applications, triggering researchers to explore new types of supercapacitors with improved performance. Asymmetric supercapacitors (ASCs) assembled using two dissimilar electrode materials offer a distinct advantage of wide operational voltage window, and thereby significantly enhance the energy density. Recent progress made in the field of ASCs is critically reviewed, with the main focus on an extensive survey of the materials developed for ASC electrodes, as well as covering the progress made in the fabrication of ASC devices over the last few decades. Current challenges and a future outlook of the field of ASCs are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Bioinspired smart asymmetric nanochannel membranes.

    Zhang, Zhen; Wen, Liping; Jiang, Lei

    2018-01-22

    Bioinspired smart asymmetric nanochannel membranes (BSANM) have been explored extensively to achieve the delicate ionic transport functions comparable to those of living organisms. The abiotic system exhibits superior stability and robustness, allowing for promising applications in many fields. In view of the abundance of research concerning BSANM in the past decade, herein, we present a systematic overview of the development of the state-of-the-art BSANM system. The discussion is focused on the construction methodologies based on raw materials with diverse dimensions (i.e. 0D, 1D, 2D, and bulk). A generic strategy for the design and construction of the BSANM system is proposed first and put into context with recent developments from homogeneous to heterogeneous nanochannel membranes. Then, the basic properties of the BSANM are introduced including selectivity, gating, and rectification, which are associated with the particular chemical and physical structures. Moreover, we summarized the practical applications of BSANM in energy conversion, biochemical sensing and other areas. In the end, some personal opinions on the future development of the BSANM are briefly illustrated. This review covers most of the related literature reported since 2010 and is intended to build up a broad and deep knowledge base that can provide a solid information source for the scientific community.

  16. Reflection asymmetric shapes in nuclei

    Ahmad, I.; Carpenter, M.P.; Emling, H.

    1989-01-01

    Experimental data show that there is no even-even nucleus with a reflection asymmetric shape in its ground state. Maximum octupole- octupole correlations occur in nuclei in the mass 224 (N∼134, Z∼88) region. Parity doublets, which are the characteristic signature of octupole deformation, have been observed in several odd mass Ra, Ac and Pa nuclei. Intertwined negative and positive parity levels have been observed in several even-even Ra and Th nuclei above spin ∼8ℎ. In both cases, the opposite parity states are connected by fast El transitions. In some medium-mass nuclei intertwined negative and positive parity levels have also been observed above spin ∼7ℎ. The nuclei which exhibit octupole deformation in this mass region are 144 Ba, 146 Ba and 146 Ce; 142 Ba, 148 Ce, 150 Ce and 142 Xe do not show these characteristics. No case of parity doublet has been observed in the mass 144 region. 32 refs., 16 figs., 1 tab

  17. Twin Higgs Asymmetric Dark Matter.

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

  18. Lift production through asymmetric flapping

    Jalikop, Shreyas; Sreenivas, K. R.

    2009-11-01

    At present, there is a strong interest in developing Micro Air Vehicles (MAV) for applications like disaster management and aerial surveys. At these small length scales, the flight of insects and small birds suggests that unsteady aerodynamics of flapping wings can offer many advantages over fixed wing flight, such as hovering-flight, high maneuverability and high lift at large angles of attack. Various lift generating mechanims such as delayed stall, wake capture and wing rotation contribute towards our understanding of insect flight. We address the effect of asymmetric flapping of wings on lift production. By visualising the flow around a pair of rectangular wings flapping in a water tank and numerically computing the flow using a discrete vortex method, we demonstrate that net lift can be produced by introducing an asymmetry in the upstroke-to-downstroke velocity profile of the flapping wings. The competition between generation of upstroke and downstroke tip vortices appears to hold the key to understanding this lift generation mechanism.

  19. An efficient catalyst for asymmetric Reformatsky reaction

    rate enantioselectivity using N,N-dialkylnorephedrines as chiral ligands. ..... temperatures also, there was no product conversion. ... Optimization of reaction conditions for asymmetric Reformatsky reaction between benzaldehyde and α-.

  20. Asymmetric cryptography based on wavefront sensing.

    Peng, Xiang; Wei, Hengzheng; Zhang, Peng

    2006-12-15

    A system of asymmetric cryptography based on wavefront sensing (ACWS) is proposed for the first time to our knowledge. One of the most significant features of the asymmetric cryptography is that a trapdoor one-way function is required and constructed by analogy to wavefront sensing, in which the public key may be derived from optical parameters, such as the wavelength or the focal length, while the private key may be obtained from a kind of regular point array. The ciphertext is generated by the encoded wavefront and represented with an irregular array. In such an ACWS system, the encryption key is not identical to the decryption key, which is another important feature of an asymmetric cryptographic system. The processes of asymmetric encryption and decryption are formulized mathematically and demonstrated with a set of numerical experiments.

  1. Asymmetrical Representation of Gender in Amharic1

    Administrator

    in its grammar. Gender representation in this language is asymmetrical heavily ..... In dictionaries where. Amharic appears either as the target or the source language, verbs are entered ...... The Dialects of Amharic Revisited. Semitica et.

  2. Beam-beam issues in asymmetric colliders

    Furman, M.A.

    1992-07-01

    We discuss generic beam-beam issues for proposed asymmetric e + - e - colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II)

  3. Congenital asymmetric crying face: a case report

    Semra Kara

    2011-12-01

    Full Text Available Congenital asymmetric crying face is an anomalia caused by unilateral absence or weakness of depressor anguli oris muscle The major finding of the disease is the absence or weakness in the outer and lower movement of the commissure during crying. The other expression muscles are normal and the face is symmetric at rest. The asymmetry in congenital asymmetric crying face is most evident during infancy but decreases by age. Congenital asymmetric crying face can be associated with cervicofacial, musclebone, respiratory, genitourinary and central nervous system anomalia. It is diagnosed by physical examination. This paper presents a six days old infant with Congenital asymmetric crying face and discusses the case in terms of diagnosis and disease features.

  4. Asymmetric total synthesis of cladosporin and isocladosporin.

    Zheng, Huaiji; Zhao, Changgui; Fang, Bowen; Jing, Peng; Yang, Juan; Xie, Xingang; She, Xuegong

    2012-07-06

    The first asymmetric total syntheses of cladosporin and isocladosporin were accomplished in 8 steps with 8% overall yield and 10 steps with 26% overall yield, respectively. The relative configuration of isocladosporin was determined via this total synthesis.

  5. Magnetically Modified Asymmetric Supercapacitors, Phase I

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is for the development of an asymmetric supercapacitor that will have improved energy density and cycle life....

  6. Impact of Secondary Interactions in Asymmetric Catalysis

    Frölander, Anders

    2007-01-01

    This thesis deals with secondary interactions in asymmetric catalysis and their impact on the outcome of catalytic reactions. The first part revolves around the metal-catalyzed asymmetric allylic alkylation reaction and how interactions within the catalyst affect the stereochemistry. An OH–Pd hydrogen bond in Pd(0)–π-olefin complexes of hydroxy-containing oxazoline ligands was identified by density functional theory computations and helped to rationalize the contrasting results obtained emplo...

  7. Engineered Asymmetric Composite Membranes with Rectifying Properties.

    Wen, Liping; Xiao, Kai; Sainath, Annadanam V Sesha; Komura, Motonori; Kong, Xiang-Yu; Xie, Ganhua; Zhang, Zhen; Tian, Ye; Iyoda, Tomokazu; Jiang, Lei

    2016-01-27

    Asymmetric composite membranes with rectifying properties are developed by grafting pH-stimulus-responsive materials onto the top layer of the composite structure, which is prepared by two novel block copolymers using a phase-separation technique. This engineered asymmetric composite membrane shows potential applications in sensors, filtration, and nanofluidic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Structure Property Relationships in Organic Conjugated Systems

    O'Neill, Luke

    2008-01-01

    A series of pi(п) conjugated oligomers containing 1 to 6 monomer units were studied by absorption and photoluminescence spectroscopies. The results are discussed and examined with regard to the variation of the optical properties with the increase of effective conjugation length. It was found that there was a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length. The relationships are in good agreement with the si...

  9. Conjugated Polymers for Energy Production

    Livi, Francesco

    This dissertation is aimed at developing materials for flexible, large area, ITO-free polymer solar cells (PSCs) fully printed under ambient conditions. A large screening of conjugated polymers, both novel and well-known materials, has been carried out in order to find suitable candidates...... polymerization method for industrial production of polymers. Several DArP protocols have been employed for the synthesis of PPDTBT leading to polymers with high structural regularity and photovoltaic performances comparable with the same materials synthesized via Stille cross-coupling polymerization...

  10. Novel ?-cyclodextrin?eosin conjugates

    Benkovics, G?bor; Afonso, Damien; Darcsi, Andr?s; B?ni, Szabolcs; Conoci, Sabrina; Fenyvesi, ?va; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy an...

  11. Test of charge conjugation invariance

    Nefkens, B.M.K.; Prakhov, S.; Gaardestig, A.; Clajus, M.; Marusic, A.; McDonald, S.; Phaisangittisakul, N.; Price, J.W.; Starostin, A.; Tippens, W.B.; Allgower, C.E.; Spinka, H.; Bekrenev, V.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Lopatin, I.; Briscoe, W.J.; Shafi, A.; Comfort, J.R.

    2005-01-01

    We report on the first determination of upper limits on the branching ratio (BR) of η decay to π 0 π 0 γ and to π 0 π 0 π 0 γ. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(η→π 0 π 0 γ) -4 at the 90% confidence level, in support of C invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured BR(η→π 0 π 0 π 0 γ) -5 at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions

  12. Inclined asymmetric librations in exterior resonances

    Voyatzis, G.; Tsiganis, K.; Antoniadou, K. I.

    2018-04-01

    Librational motion in Celestial Mechanics is generally associated with the existence of stable resonant configurations and signified by the existence of stable periodic solutions and oscillation of critical (resonant) angles. When such an oscillation takes place around a value different than 0 or π , the libration is called asymmetric. In the context of the planar circular restricted three-body problem, asymmetric librations have been identified for the exterior mean motion resonances (MMRs) 1:2, 1:3, etc., as well as for co-orbital motion (1:1). In exterior MMRs the massless body is the outer one. In this paper, we study asymmetric librations in the three-dimensional space. We employ the computational approach of Markellos (Mon Not R Astron Soc 184:273-281, https://doi.org/10.1093/mnras/184.2.273, 1978) and compute families of asymmetric periodic orbits and their stability. Stable asymmetric periodic orbits are surrounded in phase space by domains of initial conditions which correspond to stable evolution and librating resonant angles. Our computations were focused on the spatial circular restricted three-body model of the Sun-Neptune-TNO system (TNO = trans-Neptunian object). We compare our results with numerical integrations of observed TNOs, which reveal that some of them perform 1:2 resonant, inclined asymmetric librations. For the stable 1:2 TNO librators, we find that their libration seems to be related to the vertically stable planar asymmetric orbits of our model, rather than the three-dimensional ones found in the present study.

  13. Conjugated polymers developed from alkynes

    Yajing Liu; Jacky W.Y.Lam; Ben Zhong Tang

    2015-01-01

    The numerous merits of conjugated polymers(CPs) have encouraged scientists to develop a variety of synthetic routes to CPs with diverse structures and functionalities. Among the large scope of substrates,alkyne plays an important role in constructing polymers with conjugated backbones. In addition to some well-developed reactions including Glaser–Hay and Sonogashira coupling, azide/thiol-yne click reaction and cyclotrimerization, some novel alkyne-based reactions have also been explored such as oxidative polycoupling, decarbonylative polycoupling and multicomponent tandem polymerizations. his review focuses on the recent progress on the synthetic methodology of CPs in the last ive years using monomers with two or more triple bonds and some of their high-technological applications. Selected examples of materials properties of these CPs are given in this review, such as luorescence response to chemical or physical stimuli, magnetism, white light emission, cell imaging and bioprobing. Finally, a short perspective is raised in regard to the outlook of the preparation methodologies, functionalities as well as potential applications of CPs in the future.

  14. Subgap Absorption in Conjugated Polymers

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  15. Subgap absorption in conjugated polymers

    Sinclair, M.; Seager, C.H. (Sandia National Labs., Albuquerque, NM (USA)); McBranch, D.; Heeger, A.J. (California Univ., Santa Barbara, CA (USA)); Baker, G.L. (Bell Communications Research, Inc., Red Bank, NJ (USA))

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination. 11 refs., 4 figs.

  16. Preconditioning the modified conjugate gradient method ...

    In this paper, the convergence analysis of the conventional conjugate Gradient method was reviewed. And the convergence analysis of the modified conjugate Gradient method was analysed with our extension on preconditioning the algorithm. Convergence of the algorithm is a function of the condition number of M-1A.

  17. DENDRIMER CONJUGATES FOR SELECTIVE OF PROTEIN AGGREGATES

    2004-01-01

    Dendrimer conjugates are presented, which are formed between a dendrimer and a protein solubilising substance. Such dendrimer conjugates are effective in the treatment of protein aggregate-related diseases (e.g. prion-related diseases). The protein solubilising substance and the dendrimer together...

  18. Tetrafullerene conjugates for all-organic photovoltaics

    Fernández, G.; Sánchez, L.; Veldman, D.; Wienk, M.M.; Atienza, C.M.; Guldi, D.M.; Janssen, R.A.J.; Martin, N.

    2008-01-01

    The synthesis of two new tetrafullerene nanoconjugates in which four C60 units are covalently connected through different -conjugated oligomers (oligo(p-phenylene ethynylene) and oligo(p-phenylene vinylene)) is described. The photovoltaic (PV) response of these C60-based conjugates was evaluated by

  19. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  20. The Conjugate Acid-Base Chart.

    Treptow, Richard S.

    1986-01-01

    Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

  1. Bio-Conjugates for Nanoscale Applications

    Villadsen, Klaus

    Bio-conjugates for Nanoscale Applications is the title of this thesis, which covers three different projects in chemical bio-conjugation research, namely synthesis and applications of: Lipidated fluorescent peptides, carbohydrate oxime-azide linkers and N-aryl O-R2 oxyamine derivatives. Lipidated...

  2. Class, Kinship Density, and Conjugal Role Segregation.

    Hill, Malcolm D.

    1988-01-01

    Studied conjugal role segregation in 150 married women from intact families in working-class community. Found that, although involvement in dense kinship networks was associated with conjugal role segregation, respondents' attitudes toward marital roles and phase of family cycle when young children were present were more powerful predictors of…

  3. Reversal modes in asymmetric Ni nanowires

    Leighton, B.; Pereira, A. [Departamento de Fisica, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Escrig, J., E-mail: jescrigm@gmail.com [Departamento de Fisica, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avda. Ecuador 3493, 917-0124 Santiago (Chile)

    2012-11-15

    We have investigated the evolution of the magnetization reversal mechanism in asymmetric Ni nanowires as a function of their geometry. Circular nanowires are found to reverse their magnetization by the propagation of a vortex domain wall, while in very asymmetric nanowires the reversal is driven by the propagation of a transverse domain wall. The effect of shape asymmetry of the wire on coercivity and remanence is also studied. Angular dependence of the remanence and coercivity is also addressed. Tailoring the magnetization reversal mechanism in asymmetric nanowires can be useful for magnetic logic and race-track memory, both of which are based on the displacement of magnetic domain walls. Finally, an alternative method to detect the presence of magnetic drops is proposed. - Highlights: Black-Right-Pointing-Pointer Asymmetry strongly modifies the magnetic behavior of a wire. Black-Right-Pointing-Pointer Very asymmetric nanowires reverse their magnetization by a transverse domain wall. Black-Right-Pointing-Pointer An alternative method to detect the presence of magnetic drops is proposed. Black-Right-Pointing-Pointer Tailoring the reversal mode in asymmetric nanowires can be useful for potential applications.

  4. Misonidazole-glutathione conjugates in CHO cells

    Varghese, A.J.; Whitmore, G.F.

    1984-01-01

    Misonidazole, after reduction to the hydroxylamine derivative, reacts with glutathione (GSH) under physiological conditions. The reaction product has been identified as a mixture of two isomeric conjugates. When water soluble extracts of CHO cells exposed to misonidazole under hypoxic conditions are subjected to HPLC analysis, misonidazole derivatives, having the same chromatographic properties as the GSH-MISO conjugates, were detected. When CHO cells were incubated with misonidazole in the presence of added GSH, a substantial increase in the amount of the conjugate was detected. When extracts of CHO cells exposed to misonidazole under hypoxia were subsequently exposed to GSH, an increased formation of the conjugate was observed. A rearrangement product of the hydroxylamine derivative of misonidazole is postulated as the reactive intermediate responsible for the formation of the conjugate

  5. Approximate error conjugation gradient minimization methods

    Kallman, Jeffrey S

    2013-05-21

    In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

  6. Modelling conjugation with stochastic differential equations

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Hasman, Henrik

    2010-01-01

    Enterococcus faecium strains in a rich exhaustible media. The model contains a new expression for a substrate dependent conjugation rate. A maximum likelihood based method is used to estimate the model parameters. Different models including different noise structure for the system and observations are compared......Conjugation is an important mechanism involved in the transfer of resistance between bacteria. In this article a stochastic differential equation based model consisting of a continuous time state equation and a discrete time measurement equation is introduced to model growth and conjugation of two...... using a likelihood-ratio test and Akaike's information criterion. Experiments indicating conjugation on the agar plates selecting for transconjugants motivates the introduction of an extended model, for which conjugation on the agar plate is described in the measurement equation. This model is compared...

  7. Renewable resource management under asymmetric information

    Jensen, Frank; Andersen, Peder; Nielsen, Max

    2013-01-01

    Asymmetric information between fishermen and the regulator is important within fisheries. The regulator may have less information about stock sizes, prices, costs, effort, productivity and catches than fishermen. With asymmetric information, a strong analytical tool is principal-agent analysis....... In this paper, we study asymmetric information about productivity within a principal-agent framework and a tax on fishing effort is considered. It is shown that a second best optimum can be achieved if the effort tax is designed such that low-productivity agents rent is exhausted, while high-productivity agents...... receive an information rent. The information rent is equivalent to the total incentive cost. The incentive costs arise as we want to reveal the agent's type....

  8. Asymmetric synthesis II more methods and applications

    Christmann, Mathias

    2012-01-01

    After the overwhelming success of 'Asymmetric Synthesis - The Essentials', narrating the colorful history of asymmetric synthesis, this is the second edition with latest subjects and authors. While the aim of the first edition was mainly to honor the achievements of the pioneers in asymmetric syntheses, the aim of this new edition was bringing the current developments, especially from younger colleagues, to the attention of students. The format of the book remained unchanged, i.e. short conceptual overviews by young leaders in their field including a short biography of the authors. The growing multidisciplinary research within chemistry is reflected in the selection of topics including metal catalysis, organocatalysis, physical organic chemistry, analytical chemistry, and its applications in total synthesis. The prospective reader of this book is a graduate or undergraduate student of advanced organic chemistry as well as the industrial chemist who wants to get a brief update on the current developments in th...

  9. Asymmetric acoustic transmission in multiple frequency bands

    Sun, Hong-xiang, E-mail: jsdxshx@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China); Yuan, Shou-qi, E-mail: Shouqiy@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Zhang, Shu-yi [Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-11-23

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices.

  10. Asymmetric acoustic transmission in multiple frequency bands

    Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi

    2015-01-01

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices

  11. Novel Aflatoxin Derivatives and Protein Conjugates

    Reinhard Niessner

    2007-03-01

    Full Text Available Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a reliable and fast synthesis of novel aflatoxin derivatives, purification by preparative HPLC and characterisation by ESI-MS and one- and two-dimensional NMR. Novel aflatoxin bovine serum albumin conjugates were prepared and characterised by UV absorption and MALDI-MS. These aflatoxin protein conjugates are potentially interesting as immunogens for the generation of aflatoxin selective antibodies with novel specificities.

  12. Standards vs. labels with imperfect competition and asymmetric information

    Baltzer, Kenneth Thomas

    2012-01-01

    I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical differentiation model I show that a Minimum Quality Standard, which retains asymmetric information...

  13. Standards vs. labels with imperfect competition and asymmetric information

    Baltzer, Kenneth Thomas

    I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical dierentiation model I show that a Minimum Quality Standard, which retains asymmetric information...

  14. Vortex Dynamics of Asymmetric Heave Plates

    Rusch, Curtis; Maurer, Benjamin; Polagye, Brian

    2017-11-01

    Heave plates can be used to provide reaction forces for wave energy converters, which harness the power in ocean surface waves to produce electricity. Heave plate inertia includes both the static mass of the heave plate, as well as the ``added mass'' of surrounding water accelerated with the object. Heave plate geometries may be symmetric or asymmetric, with interest in asymmetric designs driven by the resulting hydrodynamic asymmetry. Limited flow visualization has been previously conducted on symmetric heave plates, but flow visualization of asymmetric designs is needed to understand the origin of observed hydrodynamic asymmetries and their dependence on the Keulegan-Carpenter number. For example, it is hypothesized that the time-varying added mass of asymmetric heave plates is caused by vortex shedding, which is related to oscillation amplitude. Here, using direct flow visualization, we explore the relationship between vortex dynamics and time-varying added mass and drag. These results suggest potential pathways for more advanced heave plate designs that can exploit vortex formation and shedding to achieve more favorable hydrodynamic properties for wave energy converters.

  15. Asymmetric hindwing foldings in rove beetles.

    Saito, Kazuya; Yamamoto, Shuhei; Maruyama, Munetoshi; Okabe, Yoji

    2014-11-18

    Foldable wings of insects are the ultimate deployable structures and have attracted the interest of aerospace engineering scientists as well as entomologists. Rove beetles are known to fold their wings in the most sophisticated ways that have right-left asymmetric patterns. However, the specific folding process and the reason for this asymmetry remain unclear. This study reveals how these asymmetric patterns emerge as a result of the folding process of rove beetles. A high-speed camera was used to reveal the details of the wing-folding movement. The results show that these characteristic asymmetrical patterns emerge as a result of simultaneous folding of overlapped wings. The revealed folding mechanisms can achieve not only highly compact wing storage but also immediate deployment. In addition, the right and left crease patterns are interchangeable, and thus each wing internalizes two crease patterns and can be folded in two different ways. This two-way folding gives freedom of choice for the folding direction to a rove beetle. The use of asymmetric patterns and the capability of two-way folding are unique features not found in artificial structures. These features have great potential to extend the design possibilities for all deployable structures, from space structures to articles of daily use.

  16. Mixed gas plasticization phenomena in asymmetric membranes

    Visser, Tymen

    2006-01-01

    This thesis describes the thorough investigation of mixed gas transport behavior of asymmetric membranes in the separation of feed streams containing plasticizing gases in order to gain more insights into the complicated behavior of plasticization. To successfully employ gas separation membranes in

  17. Asymmetric conditional volatility in international stock markets

    Ferreira, Nuno B.; Menezes, Rui; Mendes, Diana A.

    2007-08-01

    Recent studies show that a negative shock in stock prices will generate more volatility than a positive shock of similar magnitude. The aim of this paper is to appraise the hypothesis under which the conditional mean and the conditional variance of stock returns are asymmetric functions of past information. We compare the results for the Portuguese Stock Market Index PSI 20 with six other Stock Market Indices, namely the SP 500, FTSE 100, DAX 30, CAC 40, ASE 20, and IBEX 35. In order to assess asymmetric volatility we use autoregressive conditional heteroskedasticity specifications known as TARCH and EGARCH. We also test for asymmetry after controlling for the effect of macroeconomic factors on stock market returns using TAR and M-TAR specifications within a VAR framework. Our results show that the conditional variance is an asymmetric function of past innovations raising proportionately more during market declines, a phenomenon known as the leverage effect. However, when we control for the effect of changes in macroeconomic variables, we find no significant evidence of asymmetric behaviour of the stock market returns. There are some signs that the Portuguese Stock Market tends to show somewhat less market efficiency than other markets since the effect of the shocks appear to take a longer time to dissipate.

  18. MHD stability of vertically asymmetric tokamak equilibria

    Dalhed, H.E.; Grimm, R.C.; Johnson, J.L.

    1981-03-01

    The ideal MHD stability properties of a special class of vertically asymmetric tokamak equilibria are examined. The calculations confirm that no major new physical effects are introduced and the modifications can be understood by conventional arguments. The results indicate that significant departures from up-down symmetry can be tolerated before the reduction in β becomes important for reactor operation

  19. Asymmetric Aminalization via Cation-Binding Catalysis

    Park, Sang Yeon; Liu, Yidong; Oh, Joong Suk

    2018-01-01

    Asymmetric cation-binding catalysis, in principle, can generate "chiral" anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen-nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope of the...

  20. Volume inequalities for asymmetric Wulff shapes

    Schuster, Franz E.; Weberndorfer, Manuel

    2012-01-01

    Sharp reverse affine isoperimetric inequalities for asymmetric Wulff shapes and their polars are established, along with the characterization of all extremals. These new inequalities have as special cases previously obtained simplex inequalities by Ball, Barthe and Lutwak, Yang, and Zhang. In particular, they provide the solution to a problem by Zhang.

  1. Quantum optics of lossy asymmetric beam splitters

    Uppu, Ravitej; Wolterink, Tom; Tentrup, Tristan Bernhard Horst; Pinkse, Pepijn Willemszoon Harry

    2016-01-01

    We theoretically investigate quantum interference of two single photons at a lossy asymmetric beam splitter, the most general passive 2×2 optical circuit. The losses in the circuit result in a non-unitary scattering matrix with a non-trivial set of constraints on the elements of the scattering

  2. Motion in an Asymmetric Double Well

    Brizard, Alain J.; Westland, Melissa C.

    2016-01-01

    The problem of the motion of a particle in an asymmetric double well is solved explicitly in terms of the Weierstrass and Jacobi elliptic functions. While the solution of the orbital motion is expressed simply in terms of the Weierstrass elliptic function, the period of oscillation is more directly expressed in terms of periods of the Jacobi elliptic functions.

  3. Asymmetric output profile of Xe Laser

    Blok, F.J.; Rubin, P.L.; Verschuur, Jeroen W.J.; Witteman, W.J.

    2001-01-01

    A new set of asymmetric modes was recently revealed in a Xe slab laser with pronounced lens effects originating from gas heating in the discharge. The appearance of these modes is a threshold effect. Their domain of existence in the Xe laser is discussed. It is shown that mode competition can result

  4. Computing modal dispersion characteristics of radially Asymmetric ...

    We developed a matrix theory that applies to with non-circular/circular but concentric layers fibers. And we compute the dispersion characteristics of radially unconventional fiber, known as Asymmetric Bragg fiber. An attempt has been made to determine how the modal characteristics change as circular Bragg fiber is ...

  5. Seasonally asymmetric enhancement of northern vegetation productivity

    Park, T.; Myneni, R.

    2017-12-01

    Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

  6. HARD X-RAY ASYMMETRY LIMITS IN SOLAR FLARE CONJUGATE FOOTPOINTS

    Daou, Antoun G.; Alexander, David, E-mail: agdaou@rice.edu, E-mail: dalex@rice.edu [Department of Physics and Astronomy, Rice University, 6100 Main Street, MS 108, Houston, TX, 77005 (United States)

    2016-11-20

    The transport of energetic electrons in a solar flare is modeled using a time-dependent one-dimensional Fokker–Planck code that incorporates asymmetric magnetic convergence. We derive the temporal and spectral evolution of the resulting hard X-ray (HXR) emission in the conjugate chromospheric footpoints, assuming thick target photon production, and characterize the time evolution of the numerically simulated footpoint asymmetry and its relationship to the photospheric magnetic configuration. The thick target HXR asymmetry in the conjugate footpoints is found to increase with magnetic field ratio as expected. However, we find that the footpoint HXR asymmetry saturates for conjugate footpoint magnetic field ratios ≥4. This result is borne out in a direct comparison with observations of 44 double-footpoint flares. The presence of such a limit has not been reported before, and may serve as both a theoretical and observational benchmark for testing a range of particle transport and flare morphology constraints, particularly as a means to differentiate between isotropic and anisotropic particle injection.

  7. Charge Asymmetric Cosmic Rays as a probe of Flavor Violating Asymmetric Dark Matter

    Masina, Isabella; Sannino, Francesco

    2011-01-01

    The recently introduced cosmic sum rules combine the data from PAMELA and Fermi-LAT cosmic ray experiments in a way that permits to neatly investigate whether the experimentally observed lepton excesses violate charge symmetry. One can in a simple way determine universal properties of the unknown...... component of the cosmic rays. Here we attribute a potential charge asymmetry to the dark sector. In particular we provide models of asymmetric dark matter able to produce charge asymmetric cosmic rays. We consider spin zero, spin one and spin one-half decaying dark matter candidates. We show that lepton...... flavor violation and asymmetric dark matter are both required to have a charge asymmetry in the cosmic ray lepton excesses. Therefore, an experimental evidence of charge asymmetry in the cosmic ray lepton excesses implies that dark matter is asymmetric....

  8. Palladium-Catalyzed Asymmetric Quaternary Stereocenter Formation

    Gottumukkala, Aditya L.; Matcha, Kiran; Lutz, Martin; de Vries, Johannes G.; Minnaard, Adriaan J.

    2012-01-01

    An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of beta,beta-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and

  9. Palladium-catalyzed asymmetric quaternary stereocenter formation

    Gottumukkala, A.L.; Matcha, K.; Lutz, M.; de Vries, J.G.; Minnaard, A.J.

    2012-01-01

    An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of β,β-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and provides

  10. Evaluation of iodovinyl antibody conjugates: Comparison with a p-iodobenzoyl conjugate and direct radioiodination

    Hadley, S.W.; Wilbur, D.S.

    1990-01-01

    The preparations and conjugations of 2,3,5,6-tetrafluorophenyl 5-[125I/131I]iodo-4-pentenoate (7a) and 2,3,5,6-tetrafluorophenyl 3,3-dimethyl-5-[125I/131I]iodo-4-pentenoate (7b) to monoclonal antibodies are reported. Reagents 7a and 7b were prepared in high radiochemical yield by iododestannylation of their corresponding 5-tri-n-butylstannyl precursors. Radioiodinated antibody conjugates were prepared by reaction of 7a or 7b with the protein at basic pH. Evaluation of these conjugates by several in vitro procedures demonstrated that the radiolabel was attached to the antibody in a stable manner and that the conjugates maintained immunoreactivity. Comparative dual-isotope biodistribution studies of a monoclonal antibody Fab fragment conjugate of 7a and 7b with the same Fab fragment labeled with N-succinimidyl p-[131I]iodobenzoate (PIB, p-iodobenzoate, 2) or directly radioiodinated have been carried out in tumor-bearing nude mice. Coinjection of the Fab conjugate of 7a with the Fab conjugate of 2 demonstrated that the biodistributions were similar in most organs, except the neck tissue (thyroid-containing) and the stomach, which contained substantially increased levels of the 7a label. Coinjection of the Fab conjugate of 7a with the Fab fragment radioiodinated by using the chloramine-T method demonstrated that the biodistributions were remarkably similar, suggesting roughly equivalent in vivo deiodination of these labeled antibody fragments. Coinjection of the Fab conjugate of 7a with the Fab conjugate of 7b indicated that there was ∼ a 2-fold reduction in the amount of in vivo deiodination of the 7b conjugate as compared to the 7a conjugate

  11. Conjugate descent formulation of backpropagation error in ...

    nique of backpropagation was popularized in a paper by Rumelhart, et al. ... the training of a multilayer neural network using a gradient descent approach applied to a .... superior convergence of the conjugate descent method over a standard ...

  12. Soluble polymer conjugates for drug delivery.

    Minko, Tamara

    2005-01-01

    The use of water-soluble polymeric conjugates as drug carriers offers several possible advantages. These advantages include: (1) improved drug pharmacokinetics; (2) decreased toxicity to healthy organs; (3) possible facilitation of accumulation and preferential uptake by targeted cells; (4) programmed profile of drug release. In this review, we will consider the main types of useful polymeric conjugates and their role and effectiveness as carriers in drug delivery systems.: © 2005 Elsevier Ltd . All rights reserved.

  13. Structure Property Relationships in Organic Conjugated Systems

    O'Neill, Luke; Lynch, Patrick; McNamara, Mary

    2005-01-01

    A series of π conjugated oligomers were studied by absorption and photoluminescence spectroscopy. A linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Sto...

  14. Diffeomorphisms Holder conjugate to Anosov diffeomorphisms

    Gogolev, Andrey

    2008-01-01

    We show by means of a counterexample that a $C^{1+Lip}$ diffeomorphism Holder conjugate to an Anosov diffeomorphism is not necessarily Anosov. The counterexample can bear higher smoothness up to $C^3$. Also we include a result from the 2006 Ph.D. thesis of T. Fisher: a $C^{1+Lip}$ diffeomorphism Holder conjugate to an Anosov diffeomorphism is Anosov itself provided that Holder exponents of the conjugacy and its inverse are sufficiently large.

  15. Rapid modification of retroviruses using lipid conjugates

    Mukherjee, Nimisha G; Le Doux, Joseph M; Andrew Lyon, L

    2009-01-01

    Methods are needed to manipulate natural nanoparticles. Viruses are particularly interesting because they can act as therapeutic cellular delivery agents. Here we examine a new method for rapidly modifying retroviruses that uses lipid conjugates composed of a lipid anchor (1,2-distearoyl-sn-glycero-3-phosphoethanolamine), a polyethylene glycol chain, and biotin. The conjugates rapidly and stably modified retroviruses and enabled them to bind streptavidin. The implication of this work for modifying viruses for gene therapy and vaccination protocols is discussed.

  16. Energy exchange and transition to localization in the asymmetric Fermi-Pasta-Ulam oscillatory chain

    Smirnov, Valeri V.; Shepelev, Denis S.; Manevitch, Leonid I.

    2013-01-01

    A finite (periodic) FPU chain is chosen as a convenient model for investigating the energy exchange phenomenon in nonlinear oscillatory systems. As we have recently shown, this phenomenon may occur as a consequence of the resonant interaction between high-frequency nonlinear normal modes. This interaction determines both the complete energy exchange between different parts of the chain and the transition to energy localization in an excited group of particles. In the paper, we demonstrate that this mechanism can exist in realistic (asymmetric) models of atomic or molecular oscillatory chains. Also, we study the resonant interaction of conjugated nonlinear normal modes and prove a possibility of linearization of the equations of motion. The theoretical constructions developed in this paper are based on the concepts of "effective particles" and Limiting Phase Trajectories. In particular, an analytical description of energy exchange between the "effective particles" in the terms of non-smooth functions is presented. The analytical results are confirmed with numerical simulations.

  17. Direct catalytic asymmetric aldol-Tishchenko reaction.

    Gnanadesikan, Vijay; Horiuchi, Yoshihiro; Ohshima, Takashi; Shibasaki, Masakatsu

    2004-06-30

    A direct catalytic asymmetric aldol reaction of propionate equivalent was achieved via the aldol-Tishchenko reaction. Coupling an irreversible Tishchenko reaction to a reversible aldol reaction overcame the retro-aldol reaction problem and thereby afforded the products in high enantio and diastereoselectivity using 10 mol % of the asymmetric catalyst. A variety of ketones and aldehydes, including propyl and butyl ketones, were coupled efficiently, yielding the corresponding aldol-Tishchenko products in up to 96% yield and 95% ee. Diastereoselectivity was generally below the detection limit of 1H NMR (>98:2). Preliminary studies performed to clarify the mechanism revealed that the aldol products were racemic with no diastereoselectivity. On the other hand, the Tishchenko products were obtained in a highly enantiocontrolled manner.

  18. Brownian Motion of Asymmetric Boomerang Colloidal Particles

    Chakrabarty, Ayan; Konya, Andrew; Wang, Feng; Selinger, Jonathan; Sun, Kai; Wei, Qi-Huo

    2014-03-01

    We used video microscopy and single particle tracking to study the diffusion and local behaviors of asymmetric boomerang particles in a quasi-two dimensional geometry. The motion is biased towards the center of hydrodynamic stress (CoH) and the mean square displacements of the particles are linear at short and long times with different diffusion coefficients and in the crossover regime it is sub-diffusive. Our model based on Langevin theory shows that these behaviors arise from the non-coincidence of the CoH with the center of the body. Since asymmetric boomerangs represent a class of rigid bodies of more generals shape, therefore our findings are generic and true for any non-skewed particle in two dimensions. Both experimental and theoretical results will be discussed.

  19. Dynamics of asymmetric kinetic Ising systems revisited

    Huang, Haiping; Kabashima, Yoshiyuki

    2014-01-01

    The dynamics of an asymmetric kinetic Ising model is studied. Two schemes for improving the existing mean-field description are proposed. In the first scheme, we derive the formulas for instantaneous magnetization, equal-time correlation, and time-delayed correlation, considering the correlation between different local fields. To derive the time-delayed correlation, we emphasize that the small-correlation assumption adopted in previous work (Mézard and Sakellariou, 2011 J. Stat. Mech. L07001) is in fact not required. To confirm the prediction efficiency of our method, we perform extensive simulations on single instances with either temporally constant external driving fields or sinusoidal external fields. In the second scheme, we develop an improved mean-field theory for instantaneous magnetization prediction utilizing the notion of the cavity system in conjunction with a perturbative expansion approach. Its efficiency is numerically confirmed by comparison with the existing mean-field theory when partially asymmetric couplings are present. (paper)

  20. Bianisotropic metamaterials based on twisted asymmetric crosses

    Reyes-Avendaño, J A; Sampedro, M P; Juárez-Ruiz, E; Pérez-Rodríguez, F

    2014-01-01

    The effective bianisotropic response of 3D periodic metal-dielectric structures, composed of crosses with asymmetrically-cut wires, is investigated within a general homogenization theory using the Fourier formalism and the form-factor division approach. It is found that the frequency dependence of the effective permittivity for a system of periodically-repeated layers of metal crosses exhibits two strong resonances, whose separation is due to the cross asymmetry. Besides, bianisotropic metamaterials, having a base of four twisted asymmetric crosses, are proposed. The designed metamaterials possess negative refractive index at frequencies determined by the cross asymmetry, the gap between the arms of adjacent crosses lying on the same plane, and the type of Bravais lattice. (papers)

  1. Improved DFIG Capability during Asymmetrical Grid Faults

    Zhou, Dao; Blaabjerg, Frede

    2015-01-01

    In the wind power application, different asymmetrical types of the grid fault can be categorized after the Y/d transformer, and the positive and negative components of a single-phase fault, phase-to-phase fault, and two-phase fault can be summarized. Due to the newly introduced negative and even...... the natural component of the Doubly-Fed Induction Generator (DFIG) stator flux during the fault period, their effects on the rotor voltage can be investigated. It is concluded that the phase-to-phase fault has the worst scenario due to its highest introduction of the negative stator flux. Afterwards......, the capability of a 2 MW DFIG to ride through asymmetrical grid faults can be estimated at the existing design of the power electronics converter. Finally, a control scheme aimed to improve the DFIG capability is proposed and the simulation results validate its feasibility....

  2. Asymmetric volatility connectedness on the forex market

    Baruník, Jozef; Kočenda, Evžen; Vácha, Lukáš

    2017-01-01

    Roč. 77, č. 1 (2017), s. 39-56 ISSN 0261-5606 R&D Projects: GA ČR(CZ) GA16-14179S Institutional support: RVO:67985556 Keywords : volatility * connectedness * asymmetric effects Subject RIV: AH - Economics OBOR OECD: Finance Impact factor: 1.853, year: 2016 http://library.utia.cas.cz/separaty/2017/E/barunik-0478477.pdf

  3. Magnetic properties of strongly asymmetric nuclear matter

    Kutschera, M.; Wojcik, W.

    1988-01-01

    We investigate stability of neutron matter containing a small proton admixture with respect to spin fluctuations. We establish conditions under which strongly asymmetric nuclear matter could acquire a permanent magnetization. It is shown that if the protons are localized, the system becomes unstable to spin fluctuations for arbitrarily weak proton-neutron spin interactions. For non-localized protons there exists a threshold value of the spin interaction above which the system can develop a spontaneous polarization. 12 refs., 2 figs. (author)

  4. Isospin dependent properties of asymmetric nuclear matter

    Chowdhury, P. Roy; Basu, D. N.; Samanta, C.

    2009-01-01

    The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and the isovector components of density dependent M3Y interaction. The incompressibility $K_\\infty$ for the symmetric nuclear matter, the isospin dependent part $K_{asy}$ of the isobaric incompressibility and the slope $L$ are all in excellent agreement with the constraints recently extracted from measured isotopic de...

  5. Asymmetric flow events in a VEER 1000

    Horak, W.C.; Kennett, R.J.; Shier, W.; Guppy, J.G.

    1992-07-01

    This paper describes the simulation of asymmetric loss of flow events in Russian designed VVER-1000 reactors using the RETRAN-02 Mod4 computer code. VVER-1000 reactors have significant differences from United States pressurized water reactors including multi-level emergency response systems and plant operation at reduced power levels with one or more main circulation pumps inoperable. The results of these simulations are compared to similar analyses done by the designers for the Rovno plant

  6. Two particle states in an asymmetric box

    Li, Xin; Liu, Chuan

    2004-01-01

    The exact two-particle energy eigenstates in an asymmetric rectangular box with periodic boundary conditions in all three directions are studied. Their relation with the elastic scattering phases of the two particles in the continuum are obtained. These results can be viewed as a generalization of the corresponding formulae in a cubic box obtained by L\\"uscher before. In particular, the s-wave scattering length is related to the energy shift in the finite box. Possible applications of these f...

  7. Symmetric vs. asymmetric punishment regimes for bribery

    Engel, Christoph; Goerg, Sebastian J.; Yu, Gaoneng

    2012-01-01

    In major legal orders such as UK, the U.S., Germany, and France, bribers and recipients face equally severe criminal sanctions. In contrast, countries like China, Russia, and Japan treat the briber more mildly. Given these differences between symmetric and asymmetric punishment regimes for bribery, one may wonder which punishment strategy is more effective in curbing corruption. For this purpose, we designed and ran a lab experiment in Bonn (Germany) and Shanghai (China) with exactly the same...

  8. Predicting tensorial electrophoretic effects in asymmetric colloids

    Mowitz, Aaron J.; Witten, T. A.

    2017-12-01

    We formulate a numerical method for predicting the tensorial linear response of a rigid, asymmetrically charged body to an applied electric field. This prediction requires calculating the response of the fluid to the Stokes drag forces on the moving body and on the countercharges near its surface. To determine the fluid's motion, we represent both the body and the countercharges using many point sources of drag known as Stokeslets. Finding the correct flow field amounts to finding the set of drag forces on the Stokeslets that is consistent with the relative velocities experienced by each Stokeslet. The method rigorously satisfies the condition that the object moves with no transfer of momentum to the fluid. We demonstrate that a sphere represented by 1999 well-separated Stokeslets on its surface produces flow and drag force like a solid sphere to 1% accuracy. We show that a uniformly charged sphere with 3998 body and countercharge Stokeslets obeys the Smoluchowski prediction [F. Morrison, J. Colloid Interface Sci. 34, 210 (1970), 10.1016/0021-9797(70)90171-2] for electrophoretic mobility when the countercharges lie close to the sphere. Spheres with dipolar and quadrupolar charge distributions rotate and translate as predicted analytically to 4% accuracy or better. We describe how the method can treat general asymmetric shapes and charge distributions. This method offers promise as a way to characterize and manipulate asymmetrically charged colloid-scale objects from biology (e.g., viruses) and technology (e.g., self-assembled clusters).

  9. Asymmetric threat data mining and knowledge discovery

    Gilmore, John F.; Pagels, Michael A.; Palk, Justin

    2001-03-01

    Asymmetric threats differ from the conventional force-on- force military encounters that the Defense Department has historically been trained to engage. Terrorism by its nature is now an operational activity that is neither easily detected or countered as its very existence depends on small covert attacks exploiting the element of surprise. But terrorism does have defined forms, motivations, tactics and organizational structure. Exploiting a terrorism taxonomy provides the opportunity to discover and assess knowledge of terrorist operations. This paper describes the Asymmetric Threat Terrorist Assessment, Countering, and Knowledge (ATTACK) system. ATTACK has been developed to (a) data mine open source intelligence (OSINT) information from web-based newspaper sources, video news web casts, and actual terrorist web sites, (b) evaluate this information against a terrorism taxonomy, (c) exploit country/region specific social, economic, political, and religious knowledge, and (d) discover and predict potential terrorist activities and association links. Details of the asymmetric threat structure and the ATTACK system architecture are presented with results of an actual terrorist data mining and knowledge discovery test case shown.

  10. Diagnostic implications of asymmetrical mammographic patterns

    Asenjo, M.; Ania, B.J.

    1997-01-01

    To analyze the effect of asymmetrical mammographic patterns of the diagnosis of breast cancer. In a series of 6, 476 patients referred to a Breast Imaging Diagnosis Unit, we excluded males, women with previous breast surgery, and cases in which mammography was not performed, which left 5,203 women included. Each breast was classified according to one of four patterns of mammographic parenchymal density. Asymmetry was considered to exist when a patient's breasts had different patterns. Breast cancer was confirmed histologically in 282 (5.4%) women. The mammographic pattern was asymmetrical in 8% of the women with cancer and in 2% of the women without cancer (p<0.001). Fine-needle aspiration biopsy was performed in 78% and 96% (p=0.04), respectively, of the women with and without mammographic asymmetry who had neoplasms, and in 33% and 22% (p=0.02), respectively, of the women with and without mammographic asymmetry who did not have neoplasms. Asymmetrical mammographic pattern was four times more frequent in the women with breast cancer. This asymmetry decreased the frequency of needle biopsy in women with cancer, but increased the frequency of needle biopsy in women without cancer. (Author) 11 refs

  11. Hadron scattering in an asymmetric box

    Li Xin; Chen Ying; Meng Guozhan; Feng Xu; Gong Ming; He Song; Li Gang; Liu Chuan; Liu Yubin; Ma Jianping; Meng Xiangfei; Shen Yan; Zhang Jianbo

    2007-01-01

    We propose to study hadron-hadron scattering using lattice QCD in an asymmetric box which allows one to access more non-degenerate low-momentum modes for a given volume. The conventional Luescher's formula applicable in a symmetric box is modified accordingly. To illustrate the feasibility of this approach, pion-pion elastic scattering phase shifts in the I = 2, J = 0 channel are calculated within quenched approximation using improved gauge and Wilson fermion actions on anisotropic lattices in an asymmetric box. After the chiral and continuum extrapolation, we find that our quenched results for the scattering phase shifts in this channel are consistent with the experimental data when the three-momentum of the pion is below 300MeV. Agreement is also found when compared with previous theoretical results from lattice and other means. Moreover, with the usage of asymmetric volume, we are able to compute the scattering phases in the low-momentum range (pion three momentum less than about 350MeV in the center of mass frame) for over a dozen values of the pion three-momenta, much more than using the conventional symmetric box with comparable volume

  12. Simulation of Phenix EOL Asymmetric Test

    Ha, Kwi Seok; Lee, Kwi Lim; Choi, Chi Woong; Kang, Seok Hun; Chang, Won Pyo; Jeong, Hae Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The asymmetric test of End-Of-Life (EOL) tests on the Phenix plant was used for the evaluation of the MARS-LMR in the Generation IV frame as a part of the code validation. The purpose of the test is to evaluate the ability of the system code to describe asymmetric situations and to identify important phenomena during asymmetrical transient such as a three dimensional effect, buoyancy influence, and thermal stratification in the hot and cold pools. 3-dimensional sodium coolant mixing in the pools has different characteristics from the one dimensional full instantaneous mixing. The velocities and temperatures at the core outlet level differ at each sub-assembly and the temperature in the center of the hot pool may be high because the driver fuels are located at the center region. The temperatures in the hot pool are not the same in the radial and axial locations due to the buoyancy effect. The temperatures in the cold pool also differ along with the elevations and azimuthal directions due to the outlet location of IHX and the thermal stratification

  13. Flatfish: an asymmetric perspective on metamorphosis.

    Schreiber, Alexander M

    2013-01-01

    The most asymmetrically shaped and behaviorally lateralized of all the vertebrates, the flatfishes are an endless source of fascination to all fortunate enough to study them. Although all vertebrates undergo left-right asymmetric internal organ placement during embryogenesis, flatfish are unusual in that they experience an additional period of postembryonic asymmetric remodeling during metamorphosis, and thus deviate from a bilaterally symmetrical body plan more than other vertebrates. As with amphibian metamorphosis, all the developmental programs of flatfish metamorphosis are ultimately under the control of thyroid hormone. At least one gene pathway involved in embryonic organ lateralization (nodal-lefty-pitx2) is re-expressed in the larval stage during flatfish metamorphosis. Aspects of modern flatfish ontogeny, such as the gradual translocation of one eye to the opposite side of the head and the appearance of key neurocranial elements during metamorphosis, seem to elegantly recapitulate flatfish phylogeny. This chapter highlights the current state of knowledge of the developmental biology of flatfish metamorphosis with emphases on the genetic, morphological, behavioral, and evolutionary origins of flatfish asymmetry. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Novel asymmetrical pyrene derivatives as light emitting materials: Synthesis and photophysics

    Li Yang; Wang Dong; Wang Lei; Li Zhengqiang; Cui Qing; Zhang Haiquan; Yang Huai

    2012-01-01

    A series of novel substituted pyrene derivatives with asymmetrical groups have been successfully synthesized in excellent yield. Structures of the asymmetrical compound were fully characterized by 1 H-NMR, IR spectroscopy and mass spectrometry. By introducing ethynyl functions to pyrene, we obtained highly efficient blue and green light emitting materials. It has been demonstrated that the emission characteristics of pyrene derivatives have been bathochromatically tuned in the visible region by extending the π-conjugation. The photophysical properties of these compounds were carefully examined in different organic solvents and different concentrations. The electrochemical properties and geometrical electronic structures of the new pyrene derivatives have been investigated by cyclic voltammograms and density functional theory (DFT) calculations. - Highlights: ► It is the first research about asymmetrial pyrene derivatives as highly efficient light emitting materials. ► The solvatochromism and concentration effect of the new compounds have been discussed. ► Furthermore, the electrochemical properties and geometrical electronic structures were also investigated in this paper.

  15. Cu-catalyzed aerobic oxidative esterification of acetophenones with alcohols to α-ketoesters.

    Xu, Xuezhao; Ding, Wen; Lin, Yuanguang; Song, Qiuling

    2015-02-06

    Copper-catalyzed aerobic oxidative esterification of acetophenones with alcohols using molecular oxygen has been developed to form a broad range of α-ketoesters in good yields. In addition to reporting scope and limitations of our new method, mechanism studies are reported that reveal that the carbonyl oxygen in the ester mainly originated from dioxygen.

  16. Organocatalytic Asymmetric Michael Addition of 4-Hydroxycoumarin to β,γ-Unsaturated α-Keto Esters

    Suh, Chang Won; Han, Tae Hyun; Kim, Dae Young [Soonchunhyang Univ., Asan (Korea, Republic of)

    2013-06-15

    In conclusion, we have developed organocatalytic enantioselective conjugate addition reaction of 4-hydroxycoumarin (1) to β,γ-unsaturated α-keto esters 2 to afford biologically valuable warfarin derivatives 3. The process is efficiently catalyzed by a binaphthyl-modified thiourea organocatalyst. The coumarin core is present as a characteristic structural motif in a large number of natural products and biologically active molecules.1 Particularly, many of these naturally occurring 4-hydroxycoumarin and their synthetic analogues are important precursors for the synthesis of natural products and pharmaceuticals. Enantioselective organocatalytic conjugate addition of 4-hydroxycoumarin to α,β-unsaturated ketones is a straightforward method to access warfarin which is an effective anticoagulants. Although a number of reactions of α,β-unsaturated ketones as Michael acceptors have been reported, the corresponding β,γ-unsaturated α-keto esters have received relatively little attention as Michael acceptors. Recently, several groups have reported the asymmetric Michael addition of 4-hydroxycoumarin to β,γ-unsaturated α-keto esters catalyzed by Cu(II)-bisoxazoline, N,N'-dioxide-Ni(II) complexes, thiourea catalysts. Although several efficient methods have been achieved by these systems, an effective method for the synthesis of warfarin analogues is still a challenge.

  17. Organocatalytic Asymmetric Michael Addition of 4-Hydroxycoumarin to β,γ-Unsaturated α-Keto Esters

    Suh, Chang Won; Han, Tae Hyun; Kim, Dae Young

    2013-01-01

    In conclusion, we have developed organocatalytic enantioselective conjugate addition reaction of 4-hydroxycoumarin (1) to β,γ-unsaturated α-keto esters 2 to afford biologically valuable warfarin derivatives 3. The process is efficiently catalyzed by a binaphthyl-modified thiourea organocatalyst. The coumarin core is present as a characteristic structural motif in a large number of natural products and biologically active molecules.1 Particularly, many of these naturally occurring 4-hydroxycoumarin and their synthetic analogues are important precursors for the synthesis of natural products and pharmaceuticals. Enantioselective organocatalytic conjugate addition of 4-hydroxycoumarin to α,β-unsaturated ketones is a straightforward method to access warfarin which is an effective anticoagulants. Although a number of reactions of α,β-unsaturated ketones as Michael acceptors have been reported, the corresponding β,γ-unsaturated α-keto esters have received relatively little attention as Michael acceptors. Recently, several groups have reported the asymmetric Michael addition of 4-hydroxycoumarin to β,γ-unsaturated α-keto esters catalyzed by Cu(II)-bisoxazoline, N,N'-dioxide-Ni(II) complexes, thiourea catalysts. Although several efficient methods have been achieved by these systems, an effective method for the synthesis of warfarin analogues is still a challenge

  18. Cretaceous to Recent Asymetrical Subsidence of South American and West African Conjugate Margins

    Kenning, J.; Mann, P.

    2017-12-01

    Two divergent interpretations have been proposed for South American rifted-passive margins: the "mirror hypothesis" proposes that the rifted margins form symmetrically from pure shear of the lithosphere while upper-plate-lower plate models propose that the rifted margins form asymmetrically by simple shear. Models based on seismic reflection and refraction imaging and comparison of conjugate, rifted margins generally invoke a hybrid stretching process involving elements of both end member processes along with the effects of mantle plumes active during the rift and passive margin phases. We use subsidence histories of 14, 1-7 km-deep exploration wells located on South American and West African conjugate pairs now separated by the South Atlantic Ocean, applying long-term subsidence to reveal the symmetry or asymmetry of the underlying, conjugate, rift processes. Conjugate pairs characterize the rifted margin over a distance of 3500 km and include: Colorado-South Orange, Punta Del Este-North Orange, South Pelotas-Lüderitz and the North Pelotas-Walvis Basins. Of the four conjugate pairs, more rapid subsidence on the South American plate is consistently observed with greater initial rift and syn-rift subsidence rates of >60m/Ma (compared to 100 m/Ma are observed offshore South Africa between approximately 120-80 Ma, compatible with onset of the post-rift thermal sag phase. During this period the majority of burial is completed and rates remain low at Argentina/Uruguay displays more gradual subsidence throughout the Cretaceous, consistently averaging a moderate 15-30m/Ma. By the end of this stage there is a subsequent increase to 25-60 m/Ma within the last 20 Ma, interpreted to reflect lithospheric loading due to increased sedimentation rates during the Cenozoic. This increase in subsidence rate is not seen in the African conjugate section where the majority of sediments bypassed the highly aggraded Cretaceous shelf. Initially greater on the Brazilian margin compared to

  19. Analytical characterization of polymer-drug conjugates

    Rizzo, V.; Gigli, M.; Pinciroli, V.

    1998-01-01

    A few polymeric conjugates of antitumor drugs have been recently developed in view of possible therapeutic advantages: solubilization of sparingly soluble drugs in water, improvement of therapeutic index, organ targeting through a second chemical species bound to the same polymeric chain. In this article it's described the analytical approach used in the characterization of the conjugates for chemical identity, purity and strength of the contained active ingredient. The techniques are: high field NMR and size exclusion chromatography with non-aqueous mobile phase for identity; selective hydrolysis and HPLC for strength and purity. A complete and reliable picture is thus obtained both for qualitative and for quantitative aspects. This is an important step forward in the direction of further development and marketing of polymer-drug conjugates [it

  20. Nonlinear conjugate gradient methods in micromagnetics

    J. Fischbacher

    2017-04-01

    Full Text Available Conjugate gradient methods for energy minimization in micromagnetics are compared. The comparison of analytic results with numerical simulation shows that standard conjugate gradient method may fail to produce correct results. A method that restricts the step length in the line search is introduced, in order to avoid this problem. When the step length in the line search is controlled, conjugate gradient techniques are a fast and reliable way to compute the hysteresis properties of permanent magnets. The method is applied to investigate demagnetizing effects in NdFe12 based permanent magnets. The reduction of the coercive field by demagnetizing effects is μ0ΔH = 1.4 T at 450 K.

  1. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Miller, Jacqueline M.; Mesaros, Narcisa; Van Der Wielen, Marie; Baine, Yaela

    2011-01-01

    Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT) designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles. PMID:21991444

  2. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Jacqueline M. Miller

    2011-01-01

    Full Text Available Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles.

  3. 125I Radioimmunoassay of serum ursodeoxycholyl conjugates

    Hill, A.; Ross, P.E.; Bouchier, I.A.D.

    1983-01-01

    A radioimmunoassay for serum ursodeoxycholic conjugates using an iodine-125 ligand has been developed. The bile acid was present in normal fasting serum (0.19 +- SD 0.19 μmol/l, n=24) and 2-hour post-prandial serum (0.8 +- SD 0.8 μmol/l, n=16). Gallstone patients undergoing oral ursodeoxycholic acid therapy had significantly higher post-prandial serum levels (21.5 +- SD 14.0 μmol/l, n=15) by radioimmunoassay. Gas liquid chromatography analysis indicated that in normal serum ursodeoxycholic acid was totally conjugated, whereas sera from gallstone patients contained a proportion as the free bile acid (10.2 +- SD 8.1 μmol/l, n=15). Following an oral dose of ursodeoxycholic acid, both unconjugated and conjugated forms of the bile acid appeared in the serum of healthy individuals. (Auth.)

  4. Novel β-cyclodextrin–eosin conjugates

    Gábor Benkovics

    2017-03-01

    Full Text Available Eosin B (EoB and eosin Y (EoY, two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

  5. Novel β-cyclodextrin-eosin conjugates.

    Benkovics, Gábor; Afonso, Damien; Darcsi, András; Béni, Szabolcs; Conoci, Sabrina; Fenyvesi, Éva; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin-EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

  6. Deciphering conjugative plasmid permissiveness in wastewater microbiomes

    Jacquiod, Samuel Jehan Auguste; Brejnrod, Asker Daniel; Milani, Stefan Morberg

    2017-01-01

    Wastewater treatment plants (WWTPs) are designed to robustly treat polluted water. They are characterized by ceaseless flows of organic, chemical and microbial matter, followed by treatment steps before environmental release. WWTPs are hotspots of horizontal gene transfer between bacteria via...... still remains largely uncharted. Furthermore, current in vitro methods used to assess conjugation in complex microbiomes do not include in situ behaviours of recipient cells, resulting in partial understanding of transfers. We investigated the in vitro conjugation capacities of WWTP microbiomes from...... inlet sewage and outlet treated water using the broad-host range IncP-1 conjugative plasmid, pKJK5. A thorough molecular approach coupling metagenomes to 16S rRNA DNA/cDNA amplicon sequencing was established to characterize microbiomes using the ecological concept of functional response groups. A broad...

  7. Conjugate gradient algorithms using multiple recursions

    Barth, T.; Manteuffel, T.

    1996-12-31

    Much is already known about when a conjugate gradient method can be implemented with short recursions for the direction vectors. The work done in 1984 by Faber and Manteuffel gave necessary and sufficient conditions on the iteration matrix A, in order for a conjugate gradient method to be implemented with a single recursion of a certain form. However, this form does not take into account all possible recursions. This became evident when Jagels and Reichel used an algorithm of Gragg for unitary matrices to demonstrate that the class of matrices for which a practical conjugate gradient algorithm exists can be extended to include unitary and shifted unitary matrices. The implementation uses short double recursions for the direction vectors. This motivates the study of multiple recursion algorithms.

  8. Opening of the Central Atlantic Ocean: Implications for Geometric Rifting and Asymmetric Initial Seafloor Spreading after Continental Breakup

    Klingelhoefer, F.; Biari, Y.; Sahabi, M.; Funck, T.; Benabdellouahed, M.; Schnabel, M.; Reichert, C. J.; Gutscher, M. A.; Bronner, A.; Austin, J. A., Jr.

    2017-12-01

    The structure of conjugate passive margins provides information about rifting styles, the initial phases of the opening of an ocean and the formation of its associated sedimentary basins. The study of the deep structure of conjugate passive continental margins combined with precise plate kinematic reconstructions can provide constraints on the mechanisms of rifting and formation of initial oceanic crust. In this study the Central Atlantic conjugate margins are compared, based on compilation of wide-angle seismic profiles from the NW-Africa Nova Scotian and US passive margins. Plate cinematic reconstructions were used to place the profiles in the position at opening and at the M25 magnetic anomaly. The patterns of volcanism, crustal thickness, geometry, and seismic velocities in the transition zone. suggest symmetric rifting followed by asymmetric oceanic crustal accretion. Conjugate profiles in the southern Central Atlantic image differences in the continental crustal thickness. While profiles on the eastern US margin are characterized by thick layers of magmatic underplating, no such underplate was imaged along the NW-African continental margin. It has been proposed that these volcanic products form part of the CAMP (Central Atlantic Magmatic Province). In the north, two wide-angle seismic profiles acquired in exactly conjugate positions show that the crustal geometry of the unthinned continental crust and the necking zone are nearly symmetric. A region including seismic velocities too high to be explained by either continental or oceanic crust is imaged along the Nova Scotia margin off Eastern Canada, corresponding on the African side to an oceanic crust with slightly elevated velocities. These might result from asymmetric spreading creating seafloor by faulting the existing lithosphere on the Canadian side and the emplacement of magmatic oceanic crust including pockets of serpentinite on the Moroccan margin. A slightly elevated crustal thickness along the

  9. An N-Linked Bidentate Phosphoramidite Ligand (N-Me-BIPAM for Rhodium-Catalyzed Asymmetric 1,4-Addition of Arylboronic Acids to α,β-Unsaturated Ketones

    Norio Miyaura

    2012-12-01

    Full Text Available A new bidentate phosphoramidite (N-Me-BIPAM based on Shibasaki’s N-linked BINOL was synthesized. This ligand appears to be highly effective for rhodium-catalyzed asymmetric conjugated addition of arylboronic acids to α,β-unsaturated enones. The reaction of ortho-substituted arylboronic acid with acyclic and cyclic enones provides the corresponding products in good yields and enantioselectivities.

  10. METHOD OF CONJUGATED CIRCULAR ARCS TRACING

    N. Ageyev Vladimir

    2017-01-01

    Full Text Available The geometric properties of conjugated circular arcs connecting two points on the plane with set directions of tan- gent vectors are studied in the work. It is shown that pairs of conjugated circular arcs with the same conditions in frontier points create one-parameter set of smooth curves tightly filling all the plane. One of the basic properties of this set is the fact that all coupling points of circular arcs are on the circular curve going through the initially given points. The circle radius depends on the direction of tangent vectors. Any point of the circle curve, named auxiliary in this work, determines a pair of conjugated arcs with given boundary conditions. One more condition of the auxiliary circle curve is that it divides the plane into two parts. The arcs going from the initial point are out of the circle limited by this circle curve and the arcs coming to the final point are inside it. These properties are the basis for the method of conjugated circular arcs tracing pro- posed in this article. The algorithm is rather simple and allows to fulfill all the needed plottings using only the divider and ruler. Two concrete examples are considered. The first one is related to the problem of tracing of a pair of conjugated arcs with the minimal curve jump when going through the coupling point. The second one demonstrates the possibility of trac- ing of the smooth curve going through any three points on the plane under condition that in the initial and final points the directions of tangent vectors are given. The proposed methods of conjugated circular arcs tracing can be applied in solving of a wide variety of problems connected with the tracing of cam contours, for example pattern curves in textile industry or in computer-aided-design systems when programming of looms with numeric control.

  11. Conjugated Polymers as Actuators: Modes of Actuation

    Skaarup, Steen

    2004-01-01

    The physical and chemical properties of conjugated polymers often depend very strongly on the degree of doping with anions or cations. The movement of ions in and out of the polymer matrix as it is redox cycled is also accompanied by mechanical changes. Both the volume and the stiffness can exhibit...... significant differences between the oxidized and reduced states. These effects form the basis of the use of conjugated polymers as actuators (or “artificial muscles”) controllable by a small (1-10 V) voltage. Three basic modes of actuation (bending, linear extension and stiffness change) have been proposed...

  12. Conjugated polymers as actuators: modes of actuation

    Skaarup, Steen

    2007-01-01

    The physical and chemical properties of conjugated polymers often depend very strongly on the degree of doping with anions or cations. The movement of ions in and out of the polymer matrix as it is redox cycled is also accompanied by mechanical changes. Both the volume and the stiffness can exhibit...... significant differences between the oxidized and reduced states. These effects form the basis of the use of conjugated polymers as actuators (or “artificial muscles”) controllable by a small (1-10 V) voltage. Three basic modes of actuation (bending, linear extension and stiffness change) have been proposed...

  13. Functionalized conjugated polyelectrolytes design and biomedical applications

    Wang, Shu

    2014-01-01

    Functionalized Conjugated Polyelectrolytes presents a comprehensive review of these polyelectrolytes and their biomedical applications. Basic aspects like molecular design and optoelectronic properties are covered in the first chapter. Emphasis is placed on the various applications including sensing (chemical and biological), disease diagnosis, cell imaging, drug/gene delivery and disease treatment. This book explores a multi-disciplinary topic of interest to researchers working in the fields of chemistry, materials, biology and medicine. It also offers an integrated perspective on both basic research and application issues. Functionalized conjugated polyelectrolyte materials, which have already drawn considerable interest, will become a major new direction for biomedicine development.

  14. Conjugation of silica nanoparticles with cellulose acetate/polyethylene glycol 300 membrane for reverse osmosis using MgSO4 solution.

    Sabir, Aneela; Shafiq, Muhammad; Islam, Atif; Jabeen, Faiza; Shafeeq, Amir; Ahmad, Adnan; Zahid Butt, Muhammad Taqi; Jacob, Karl I; Jamil, Tahir

    2016-01-20

    Thermally-induced phase separation (TIPS) method was used to synthesize polymer matrix (PM) membranes for reverse osmosis from cellulose acetate/polyethylene glycol (CA/PEG300) conjugated with silica nanoparticles (SNPs). Experimental data showed that the conjugation of SNPs changed the surface properties as dense and asymmetric composite structure. The results were explicitly determined by the permeability flux and salt rejection efficiency of the PM-SNPs membranes. The effect of SNPs conjugation on MgSO4 salt rejection was more significant in magnitude than on permeation flux i.e. 2.38 L/m(2)h. FTIR verified that SNPs were successfully conjugated on the surface of PM membrane. DSC of PM-SNPs shows an improved Tg from 76.2 to 101.8 °C for PM and PM-S4 respectively. Thermal stability of the PM-SNPs membranes was observed by TGA which was significantly enhanced with the conjugation of SNPs. The micrographs of SEM and AFM showed the morphological changes and increase in the valley and ridges on membrane surface. Experimental data showed that the PM-S4 (0.4 wt% SNPs) membrane has maximum salt rejection capacity and was selected as an optimal membrane. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Observation of asymmetric electromagnetic field profiles in chiral metamaterials

    Hisamoto, Nobuyuki; Ueda, Tetsuya; Sawada, Kei; Tomita, Satoshi

    2018-02-01

    We experimentally observe asymmetric electromagnetic field profiles along two-dimensional chiral metamaterials. The asymmetric field profiles depending on the chirality and the operation frequency have been reproduced well by the numerical simulation. Around a chiral meta-atom, distribution of a Poynting vector is found to be shifted asymmetrically. These results are explained in terms of an analogy with the side-jump mechanism in the electronic anomalous Hall systems.

  16. Asymmetric forecasting and commitment policy in a robust control problem

    Taro Ikeda

    2013-01-01

    This paper provides a piece of results regarding asymmetric forecasting and commitment monetary policy with a robust control algorithm. Previous studies provide no clarification of the connection between asymmetric preference and robust commitment policy. Three results emerge from general equilibrium modeling with asymmetric preference: (i) the condition for system stability implies an average inflation bias with respect to asymmetry (ii) the effect of asymmetry can be mitigated if policy mak...

  17. Asymmetric acoustic transmission in graded beam

    Jing, Li, E-mail: lj94172350@hotmail.com [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Wu, Jiu Hui, E-mail: ejhwu@mail.xjtu.edu.cn [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Guan, Dong; Lu, Kuan [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Gao, Nansha [School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China); Songhua, Cao [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China)

    2016-12-01

    We demonstrate the dynamic effective material parameters and vibration performance of a graded beam. The structure of the beam was composed of several unit cells with different fill factors. The dispersion relations and energy band structures of each unit cell were calculated using the finite element method (FEM). The dynamic effective material parameters in each unit cell of the graded beam were determined by the dispersion relations and energy band structures. Longitudinal wave propagation was investigated using a numerical method and FEM. The results show that the graded beam allows asymmetric acoustic transmission over a wide range of frequencies.

  18. OFFICER AND COMMANDER IN ASYMMETRIC WARFARE OPERATIONS

    Giuseppe CAFORIO

    2013-01-01

    Full Text Available Starting from the data of a field research conducted among soldiers with asymmetric warfare experiences from nine different countries, the author seeks to identify and shed light on the various problems that officers with command responsibilities had to face during their missions. A picture emerges of feelings and experiences relating to their first impression upon arriving in the theatre, relations with local armed forces, relations with the local population and local authorities, relations with NGOs, relations with other armies, the impact of the rules of engagement (ROEs, training and education, and operational experiences. The paper ends with a discussion of the lessons learned.

  19. Nanotribology of Symmetric and Asymmetric Liquid Lubricants

    Shinji Yamada

    2010-03-01

    Full Text Available When liquid molecules are confined in a narrow gap between smooth surfaces, their dynamic properties are completely different from those of the bulk. The molecular motions are highly restricted and the system exhibits solid-like responses when sheared slowly. This solidification behavior is very dependent on the molecular geometry (shape of liquids because the solidification is induced by the packing of molecules into ordered structures in confinement. This paper reviews the measurements of confined structures and friction of symmetric and asymmetric liquid lubricants using the surface forces apparatus. The results show subtle and complex friction mechanisms at the molecular scale.

  20. Asymmetric Total Synthesis of Ieodomycin B

    Shuangjie Lin

    2017-01-01

    Full Text Available Ieodomycin B, which shows in vitro antimicrobial activity, was isolated from a marine Bacillus species. A novel asymmetric total synthetic approach to ieodomycin B using commercially available geraniol was achieved. The approach involves the generation of 1,3-trans-dihydroxyl at C-3 and C-5 positions via a Crimmins-modified Evans aldol reaction and a chelation-controlled Mukaiyama aldol reaction of a p-methoxybenzyl-protected aldehyde, as well as the generation of a lactone ring in a deprotection–lactonization one-pot reaction.

  1. The Asymmetric Effects of Investor Sentiment

    Lutz, Chandler

    2016-01-01

    We use the returns on lottery-like stocks and a dynamic factor model to construct a novel index of investor sentiment. This new measure is highly correlated with other behavioral indicators, but more closely tracks speculative episodes. Our main new finding is that the effects of sentiment...... are asymmetric: During peak-to-trough periods of investor sentiment (sentiment contractions), high sentiment predicts low future returns for the cross section of speculative stocks and for the market overall, whereas the relationship between sentiment and future returns is positive but relatively weak during...... trough-to-peak episodes (sentiment expansions). Overall, these results match theories and anecdotal accounts of investor sentiment....

  2. On asymmetric causal relationships in Petropolitics

    Balan Feyza

    2016-01-01

    Full Text Available The aim of this paper is to examine whether the First Law of Petropolitics denominated by Friedman in 2006 is valid for OPEC countries. To do this, this paper analyses the relationship between political risk and oil supply by applying the asymmetric panel causality test suggested by Hatemi-J (2011 to these countries for the period 1984-2014. The results show that the First Law of Petropolitics is valid for Angola, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, and the UAE, given that positive oil supply shocks significantly lead to negative political stability shocks, and negative oil supply shocks significantly lead to positive shocks in political stability.

  3. Asymmetric nuclear matter and neutron star properties

    Engvik, L.; Hjorth-Jensen, M.; Osnes, E.; Bao, G.; Oestgaard, E.

    1994-06-01

    Properties of neutron stars such as mass and radius, using a relativistic Dirac-Brueckner-Hartree-Fock approach, are calculated. Modern meson-exchange potential models are used to evaluate the G-matrix for asymmetric nuclear matter. For pure neutron matter the maximum mass is found to be M max ∼ 2.4M for a radius R ∼ 12 km. With a proton fraction of 30% the result is M max ∼ 2.1M for a radius R ∼ 10.5 km, close to the experimental values. The implications are discussed. 20 refs., 3 figs

  4. Two particle states in an asymmetric box

    Li Xin; Liu Chuan

    2004-01-01

    The exact two-particle energy eigenstates in an asymmetric rectangular box with periodic boundary conditions in all three directions are studied. Their relation with the elastic scattering phases of the two particles in the continuum are obtained. These results can be viewed as a generalization of the corresponding formulae in a cubic box obtained by Luescher before. In particular, the s-wave scattering length is related to the energy shift in the finite box. Possible applications of these formulae are also discussed

  5. Asymmetrical Capacitors for Propulsion and the ISR Asymmetrical Capacitator Thruster, Experimental Results and Improved Designs

    Canning, Francis; Winet, Ed; Ice, Bob; Melcher, Cory; Pesavento, Phil; Holmes, Alan; Butler, Carey; Cole, John; Campbell, Jonathan

    2004-01-01

    The outline of this viewgraph presentation on asymmetrical capacitor thruster development includes: 1) Test apparatus; 2) Devices tested; 3) Circuits used; 4) Data collected (Time averaged, Time resolved); 5) Patterns observed; 6) Force calculation; 7) Electrostatic modeling; 8) Understand it all.

  6. Chiral ferrocenes in asymmetric catalysis: synthesis and applications

    Dai, Li-Xin; Hou, Xue-Long

    2010-01-01

    .... It provides a thorough overview of the synthesis and characterization of different types of chiral ferrocene ligands, their application to various catalytic asymmetric reactions, and versatile chiral...

  7. Deep seismic studies of conjugate profiles from the Nova Scotia - Moroccan and the Liguro-Provencal margin pairs

    Klingelhoefer, F.; Biari, Y.; Sahabi, M.; Aslanian, D.; Philippe, S.; Schnabel, M.; Moulin, M.; Louden, K. E.; Funck, T.; Reichert, C. J.

    2014-12-01

    The structure of conjugate passive margins provides information about rifting styles, opening of an ocean and formation of it's associated sedimentary basins. In order to distinguish between tectonic inheritance and structures directly related to rifting of passive margins conjugate profiles have to be acquired on margins on diverse locations and different ages. In this study we use new and existing reflection and wide-angle seismic data from two margin pairs, the 200 Ma year old Nova-Scotia - Morocco margin pair and the only 20 Ma Gulf of Lions - Sardinia margin pair. On both margin pairs wide-angle seismic data combined with reflection seismic data were acquired on conjugate profiles on sea and extended on land. Forward modelling of the deep crustal structure along the four transects indicates that a high velocity zone (HVZ) (> 7.2 km/s) is present at the base of the lower crust on all four margins along the ocean-continental transition zone (OCT). This may represent either exhumed upper mantle material or injection of upper mantle material into proto-oceanic crust at the onset of sea-floor spreading. However the width of the HVZ might strongly differ between conjugates, which may be the result of tectonic inheritance, for example the presence of ancient subduction zones or orogens. Both margin pairs show a similar unthinned continental crustal thickness. Crustal thinning and upper-to-lower crustal thickness vary between margin pairs, but remain nearly symmetric on conjugate profiles and might therefore depend on the structure and mechanical properties of the original continental crust. For the Mediterranean margin pair, the oceanic crust is similar on both sides, with a thickness of only 4-5 km. For the Atlantic margin pair, oceanic crustal thickness is higher on the Moroccan Margin, a fact that can be explained by either asymmetric spreading or by the volcanic underplating, possibly originating from the Canary Hot Spot.

  8. Plasmid transfer by conjugation in Xylella fastidiosa.

    Recombination and horizontal gene transfer have been implicated in the adaption of Xylella fastidiosa (Xf) to infect a wide variety of different plant species. There is evidence that certain strains of Xf carry native plasmids equipped with transfer and mobilization genes, suggesting conjugation as ...

  9. Theory of periodic conjugate heat transfer

    Zudin, Yuri B

    2016-01-01

    This book presents the theory of periodic conjugate heat transfer in detail. It offers a simplified description of the interaction between a solid body and a fluid as a boundary value problem of the heat conduction equation for the solid body.

  10. Conjugate Problems in Convective Heat Transfer: Review

    Abram Dorfman

    2009-01-01

    Full Text Available A review of conjugate convective heat transfer problems solved during the early and current time of development of this modern approach is presented. The discussion is based on analytical solutions of selected typical relatively simple conjugate problems including steady-state and transient processes, thermal material treatment, and heat and mass transfer in drying. This brief survey is accompanied by the list of almost two hundred publications considering application of different more and less complex analytical and numerical conjugate models for simulating technology processes and industrial devices from aerospace systems to food production. The references are combined in the groups of works studying similar problems so that each of the groups corresponds to one of selected analytical solutions considered in detail. Such structure of review gives the reader the understanding of early and current situation in conjugate convective heat transfer modeling and makes possible to use the information presented as an introduction to this area on the one hand, and to find more complicated publications of interest on the other hand.

  11. Stochastic differential equations used to model conjugation

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo

    Stochastic differential equations (SDEs) are used to model horizontal transfer of antibiotic resis- tance by conjugation. The model describes the concentration of donor, recipient, transconjugants and substrate. The strength of the SDE model over the traditional ODE models is that the noise can...

  12. Immunogenicity of novel sulfadimethoxide conjugates | Chen ...

    Immunogenicity of novel sulfadimethoxide conjugates. L Chen, J Su, X Zhang, L Li, X He. Abstract. Sulfadimethoxine (SDM) is an antibiotic commonly added to animal feeds. Anti-SDM antibodies are useful for the detection of residual SDM in foods, feeds and biological fluids by ELISA. In this study, we show that SDM is ...

  13. Women experiencing the intergenerationality of conjugal violence

    Gilvânia Patrícia do Nascimento Paixão

    2015-10-01

    Full Text Available Objective: to analyze the family relationship, in childhood and adolescence, of women who experience conjugal violence.Method: qualitative study. Interviews were held with 19 women, who were experiencing conjugal violence, and who were resident in a community in Salvador, Bahia, Brazil. The project was approved by the Research Ethics Committee (N. 42/2011.Results: the data was organized using the Discourse of the Collective Subject, identifying the summary central ideas: they witnessed violence between their parents; they suffered repercussions from the violence between their parents: they were angry about the mother's submission to her partner; and they reproduced the conjugal violence. The discourse showed that the women witnessed, in childhood and adolescence, violence between their parents, and were injured both physically and psychologically. As a result of the mother's submission, feelings of anger arose in the children. However, in the adult phase of their own lives, they noticed that their conjugal life resembled that of their parents, reproducing the violence.Conclusion: investment is necessary in strategies designed to break inter-generational violence, and the health professionals are important in this process, as it is a phenomenon with repercussions in health. Because they work in the Family Health Strategy, which focuses on the prevention of harm and illness, health promotion and interdepartmentality, the nurses are essential in the process of preventing and confronting this phenomenon.

  14. Integrated circuits based on conjugated polymer monolayer.

    Li, Mengmeng; Mangalore, Deepthi Kamath; Zhao, Jingbo; Carpenter, Joshua H; Yan, Hongping; Ade, Harald; Yan, He; Müllen, Klaus; Blom, Paul W M; Pisula, Wojciech; de Leeuw, Dago M; Asadi, Kamal

    2018-01-31

    It is still a great challenge to fabricate conjugated polymer monolayer field-effect transistors (PoM-FETs) due to intricate crystallization and film formation of conjugated polymers. Here we demonstrate PoM-FETs based on a single monolayer of a conjugated polymer. The resulting PoM-FETs are highly reproducible and exhibit charge carrier mobilities reaching 3 cm 2  V -1  s -1 . The high performance is attributed to the strong interactions of the polymer chains present already in solution leading to pronounced edge-on packing and well-defined microstructure in the monolayer. The high reproducibility enables the integration of discrete unipolar PoM-FETs into inverters and ring oscillators. Real logic functionality has been demonstrated by constructing a 15-bit code generator in which hundreds of self-assembled PoM-FETs are addressed simultaneously. Our results provide the state-of-the-art example of integrated circuits based on a conjugated polymer monolayer, opening prospective pathways for bottom-up organic electronics.

  15. Conjugate problems in convective heat transfer

    Dorfman, Abram S

    2009-01-01

    The conjugate heat transfer (CHT) problem takes into account the thermal interaction between a body and fluid flowing over or through it, a key consideration in both mechanical and aerospace engineering. Presenting more than 100 solutions of non-isothermal and CHT problems, this title considers the approximate solutions of CHT problems.

  16. Compositions for directed alignment of conjugated polymers

    Kim, Jinsang; Kim, Bong-Gi; Jeong, Eun Jeong

    2016-04-19

    Conjugated polymers (CPs) achieve directed alignment along an applied flow field and a dichroic ratio of as high as 16.67 in emission from well-aligned thin films and fully realized anisotropic optoelectronic properties of CPs in field-effect transistor (FET).

  17. Conjugate Gradient Algorithms For Manipulator Simulation

    Fijany, Amir; Scheid, Robert E.

    1991-01-01

    Report discusses applicability of conjugate-gradient algorithms to computation of forward dynamics of robotic manipulators. Rapid computation of forward dynamics essential to teleoperation and other advanced robotic applications. Part of continuing effort to find algorithms meeting requirements for increased computational efficiency and speed. Method used for iterative solution of systems of linear equations.

  18. Conjugated Polymer Actuators: Prospects and Limitations

    Skaarup, Steen

    2007-01-01

    Actuators constructed with a conjugated polymer as the active part have been predicted to have a number of highly desirable properties: Large mechanical strength, high power density, i.e. high actuation speeds possible, sufficient maximum strain values, high reversibility and safe, low voltages (1...

  19. Some aspects of geomagnetically conjugate phenomena

    Rycroft, M.J.

    1987-12-01

    Both charged particles and waves convey information about the thermosphere, ionosphere and magnetosphere from the Northern to the Southern Hemisphere and vice versa, along geomagnetic flux tubes.The interhemispheric travel time of electrons or ions, being dependent upon L-value , pitch angle and energy (which may lie between less than or equal to 1 eV and greater than or equal to 1 MeV) may be many hours, ranging down to less than or equal to 1 s. However, the one-hop propagation time for magnetohydrodynamic or whistler mode waves generally lies between 10/sup 2/s and 1 s. Such times, therefore, give the time scales of transient phenomena that are geomagnetically conjugate and of changes in steady-state plasma processes occurring in geomagnetically conjugate regions. Contrasting examples are presented of conjugate physical phenomena, obtained using satellite, rocket, aircraft and ground-based observations; the latter capitalise upon the rather rare disposition of land - rather than ocean - at each end of a geophysically interesting flux tube. Particular attention is paid to the interactions between whistler mode waves and energetic electrons. Geomagnetic, radio, optical and plasma observations, taken together with model computations, provide a wealth of knowledge on conjugate phenomena and their dependence on conditions in the solar wind, substorms, L-value, etc... Finally, some suggestions are made for future lines of research.

  20. Cross-Conjugated n-Dopable Aromatic Polyketone

    Voortman, Thomas P.; Bartesaghi, Davide; Koster, L. Jan Anton; Chiechi, Ryan C.

    2015-01-01

    This paper describes the synthesis and characterization of a high molecular weight cross-conjugated polyketone synthesized via scalable Friedel Crafts chemistry. Cross-conjugated polyketones are precursors to conjugated polyions; they become orders of magnitude more conductive after a two-electron

  1. Bis-polymer lipid-peptide conjugates and nanoparticles thereof

    Xu, Ting; Dong, He; Shu, Jessica; Dube, Nikhil

    2018-04-24

    The present invention provides bis-polymer lipid-peptide conjugates containing a hydrophobic block and headgroup containing a helical peptide and two polymer blocks. The conjugates can self-assemble to form helix bundle subunits, which in turn assemble to provide micellar nanocarriers for drug cargos and other agents. Particles containing the conjugates and methods for forming the particles are also disclosed.

  2. [Asymmetric hypertrophy of the masticatory muscles].

    Arzul, L; Corre, P; Khonsari, R H; Mercier, J-M; Piot, B

    2012-06-01

    Hypertrophy of the masticatory muscles most commonly affects the masseter. Less common cases of isolated or associated temporalis hypertrophy are also reported. Parafunctional habits, and more precisely bruxism, can favor the onset of the hypertrophy. This condition is generally idiopathic and can require both medical and/or surgical management. A 29-year-old patient was referred to our department for an asymmetric swelling of the masticatory muscles. Physical examination revealed a bilateral hypertrophy of the masticatory muscles, predominantly affecting the right temporalis and the left masseter. Major bruxism was assessed by premature dental wearing. The additional examinations confirmed the isolated muscle hypertrophy. Benign asymmetric hypertrophy of the masticatory muscles promoted by bruxism was diagnosed. Treatment with injections of type A botulinum toxin was conducted in association with a splint and relaxation. Its effectiveness has been observed at six months. Few cases of unilateral or bilateral temporalis hypertrophy have been reported, added to the more common isolated masseter muscles hypertrophy. The diagnosis requires to rule out secondary hypertrophies and tumors using Magnetic Resonance Imaging. The condition is thought to be favoured by parafunctional habits such as bruxism. The conservative treatment consists in reducing the volume of the masticatory muscles using intramuscular injections of type A botulinum toxin. Other potential conservative treatments are wearing splints and muscle relaxant drugs. Surgical procedures aiming to reduce the muscle volume and/or the bone volume (mandibular gonioplasty) can be proposed. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  3. Asymmetric Uncertainty Expression for High Gradient Aerodynamics

    Pinier, Jeremy T

    2012-01-01

    When the physics of the flow around an aircraft changes very abruptly either in time or space (e.g., flow separation/reattachment, boundary layer transition, unsteadiness, shocks, etc), the measurements that are performed in a simulated environment like a wind tunnel test or a computational simulation will most likely incorrectly predict the exact location of where (or when) the change in physics happens. There are many reasons for this, includ- ing the error introduced by simulating a real system at a smaller scale and at non-ideal conditions, or the error due to turbulence models in a computational simulation. The un- certainty analysis principles that have been developed and are being implemented today do not fully account for uncertainty in the knowledge of the location of abrupt physics changes or sharp gradients, leading to a potentially underestimated uncertainty in those areas. To address this problem, a new asymmetric aerodynamic uncertainty expression containing an extra term to account for a phase-uncertainty, the magnitude of which is emphasized in the high-gradient aerodynamic regions is proposed in this paper. Additionally, based on previous work, a method for dispersing aerodynamic data within asymmetric uncer- tainty bounds in a more realistic way has been developed for use within Monte Carlo-type analyses.

  4. D mesons in asymmetric nuclear matter

    Mishra, Amruta; Mazumdar, Arindam

    2009-01-01

    We calculate the in-medium D and D meson masses in isospin-asymmetric nuclear matter in an effective chiral model. The D and D mass modifications arising from their interactions with the nucleons and the scalar mesons in the effective hadronic model are seen to be appreciable at high densities and have a strong isospin dependence. These mass modifications can open the channels of the decay of the charmonium states (Ψ ' ,χ c ,J/Ψ) to DD pairs in dense hadronic matter. The isospin asymmetry in the doublet D=(D 0 ,D + ) is seen to be particularly appreciable at high densities and should show in observables such as their production and flow in asymmetric heavy-ion collisions in the compressed baryonic matter experiments in the future facility of FAIR, GSI. The results of the present work are compared to calculations of the D(D) in-medium masses in the literature using the QCD sum rule approach, quark meson coupling model, and coupled channel approach as well as to those from studies of quarkonium dissociation using heavy-quark potentials from lattice QCD at finite temperatures

  5. On the Collisionless Asymmetric Magnetic Reconnection Rate

    Liu, Yi-Hsin; Hesse, M.; Cassak, P. A.; Shay, M. A.; Wang, S.; Chen, L.-J.

    2018-04-01

    A prediction of the steady state reconnection electric field in asymmetric reconnection is obtained by maximizing the reconnection rate as a function of the opening angle made by the upstream magnetic field on the weak magnetic field (magnetosheath) side. The prediction is within a factor of 2 of the widely examined asymmetric reconnection model (Cassak & Shay, 2007, https://doi.org/10.1063/1.2795630) in the collisionless limit, and they scale the same over a wide parameter regime. The previous model had the effective aspect ratio of the diffusion region as a free parameter, which simulations and observations suggest is on the order of 0.1, but the present model has no free parameters. In conjunction with the symmetric case (Liu et al., 2017, https://doi.org/10.1103/PhysRevLett.118.085101), this work further suggests that this nearly universal number 0.1, essentially the normalized fast-reconnection rate, is a geometrical factor arising from maximizing the reconnection rate within magnetohydrodynamic-scale constraints.

  6. Evolutionary stability in the asymmetric volunteer's dilemma.

    Jun-Zhou He

    Full Text Available It is often assumed that in public goods games, contributors are either strong or weak players and each individual has an equal probability of exhibiting cooperation. It is difficult to explain why the public good is produced by strong individuals in some cooperation systems, and by weak individuals in others. Viewing the asymmetric volunteer's dilemma game as an evolutionary game, we find that whether the strong or the weak players produce the public good depends on the initial condition (i.e., phenotype or initial strategy of individuals. These different evolutionarily stable strategies (ESS associated with different initial conditions, can be interpreted as the production modes of public goods of different cooperation systems. A further analysis revealed that the strong player adopts a pure strategy but mixed strategies for the weak players to produce the public good, and that the probability of volunteering by weak players decreases with increasing group size or decreasing cost-benefit ratio. Our model shows that the defection probability of a "strong" player is greater than the "weak" players in the model of Diekmann (1993. This contradicts Selten's (1980 model that public goods can only be produced by a strong player, is not an evolutionarily stable strategy, and will therefore disappear over evolutionary time. Our public good model with ESS has thus extended previous interpretations that the public good can only be produced by strong players in an asymmetric game.

  7. An asymmetric B factory based on PEP

    1991-02-01

    In this report we describe a design for a high-luminosity Asymmetric B Factory to be built in the PEP tunnel on the SLAC site. This proposal, a collaborative effort SLAC, LBL, and LLNL, is the culmination of more than two years of effort aimed at the design and construction of an asymmetric e{sup +}e{sup {minus}} collider capable of achieving a luminosity of L = 3 {times} 10{sup 33} cm{sup {minus}2} s{sup {minus}1}. The configuration adopted utilizes two storage rings, and electron ring operating at 9 GeV and a positron ring at 3.1 GeV, each with a circumference of 2200 m. The high-energy ring is an upgrade of the PEP storage ring at SLAC; all PEP magnets and most power supplies will be reused. The upgrade consists primarily of replacing the PEP vacuum chamber and RF system with newly designed versions optimized for the high-current environment of the B Factory. The low-energy ring will be newly constructed and will be situated atop the high-energy ring in the PEP tunnel. Utilities already installed in the PEP tunnel are largely sufficient to operate the two B Factory storage rings.

  8. An asymmetric B factory based on PEP

    1991-02-01

    In this report we describe a design for a high-luminosity Asymmetric B Factory to be built in the PEP tunnel on the SLAC site. This proposal, a collaborative effort SLAC, LBL, and LLNL, is the culmination of more than two years of effort aimed at the design and construction of an asymmetric e + e - collider capable of achieving a luminosity of L = 3 x 10 33 cm -2 s -1 . The configuration adopted utilizes two storage rings, and electron ring operating at 9 GeV and a positron ring at 3.1 GeV, each with a circumference of 2200 m. The high-energy ring is an upgrade of the PEP storage ring at SLAC; all PEP magnets and most power supplies will be reused. The upgrade consists primarily of replacing the PEP vacuum chamber and RF system with newly designed versions optimized for the high-current environment of the B Factory. The low-energy ring will be newly constructed and will be situated atop the high-energy ring in the PEP tunnel. Utilities already installed in the PEP tunnel are largely sufficient to operate the two B Factory storage rings

  9. Particle identification at an asymmetric B Factory

    Coyle, P.; Eigen, G.; Hitlin, D.; Oddone, P.; Ratcliff, B.; Roe, N.; Va'vra, J.; Ypsilantis, T.

    1991-09-01

    Particle identification systems are an important component of any detector at a high-luminosity, asymmetric B Factory. In particular, excellent hadron identification is required to probe CP violation in B 0 decays to CP eigenstates. The particle identification systems discussed below also provide help in separating leptons from hadrons at low momenta. We begin this chapter with a discussion of the physics motivation for providing particle identification, the inherent limitations due to interactions and decays in flight, and the requirements for hermiticity and angular coverage. A special feature of an asymmetric B Factory is the resulting asymmetry in the momentum distribution as a function of polar angle; this will also be quantified and discussed. In the next section the three primary candidates, time-of-flight (TOF), energy loss (dE/dx), and Cerenkov counters, both ring-imaging and threshold, will be briefly described and evaluated. Following this, one of the candidates, a long-drift Cerenkov ring-imaging device, is described in detail to provide a reference design. Design considerations for a fast RICH are then described. A detailed discussion of aerogel threshold counter designs and associated R ampersand D conclude the chapter. 56 refs., 64 figs., 13 tabs

  10. Efficient Supercapacitor Energy Storage Using Conjugated Microporous Polymer Networks Synthesized from Buchwald-Hartwig Coupling.

    Liao, Yaozu; Wang, Haige; Zhu, Meifang; Thomas, Arne

    2018-03-01

    Supercapacitors have received increasing interest as energy storage devices due to their rapid charge-discharge rates, high power densities, and high durability. In this work, novel conjugated microporous polymer (CMP) networks are presented for supercapacitor energy storage, namely 3D polyaminoanthraquinone (PAQ) networks synthesized via Buchwald-Hartwig coupling between 2,6-diaminoanthraquinone and aryl bromides. PAQs exhibit surface areas up to 600 m 2 g -1 , good dispersibility in polar solvents, and can be processed to flexible electrodes. The PAQs exhibit a three-electrode specific capacitance of 576 F g -1 in 0.5 m H 2 SO 4 at a current of 1 A g -1 retaining 80-85% capacitances and nearly 100% Coulombic efficiencies (95-98%) upon 6000 cycles at a current density of 2 A g -1 . Asymmetric two-electrode supercapacitors assembled by PAQs show a capacitance of 168 F g -1 of total electrode materials, an energy density of 60 Wh kg -1 at a power density of 1300 W kg -1 , and a wide working potential window (0-1.6 V). The asymmetric supercapacitors show Coulombic efficiencies up to 97% and can retain 95.5% of initial capacitance undergo 2000 cycles. This work thus presents novel promising CMP networks for charge energy storage. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Ultrathin-skinned asymmetric membranes by immiscible solvents treatment

    Friesen, Dwayne T.; Babcock, Walter C.

    1989-01-01

    Improved semipermeable asymmetric fluid separation membranes useful in gas, vapor and liquid separations are disclosed. The membranes are prepared by substantially filling the pores of asymmetric cellulosic semipermeable membranes having a finely porous layer on one side thereof with a water immiscible organic liquid, followed by contacting the finely porous layer with water.

  12. A new convenient asymmetric approach to herbarumin Ⅲ

    Xue Song Chen; Shi Jun Da; Li Hong Yang; Bo Yan Xu; Zhi Xiang Xie; Ying Li

    2007-01-01

    The asymmetric total synthesis of herbarumin Ⅲ 3, a naturally occurred phytotoxin, along with 8-epi-herbarumin Ⅲ 22, was succeeded in 12 steps from n-butyraldehyde based on Brown's asymmetric allylation, taking modified Julia olefination and Yamaguchi's macro-lactonization as key steps.

  13. Appropriate quantization of asymmetric games with continuous strategies

    Qin Gan; Chen Xi; Sun Min; Zhou Xianyi; Du Jiangfeng

    2005-01-01

    We establish a new quantization scheme to study the asymmetric Bertrand duopoly with differentiated products. This scheme is more efficient than the previous symmetric one because it can exactly make the optimal cooperative payoffs at quantum Nash equilibrium. It is also a necessary condition for general asymmetric games with continuous strategies to reach such payoffs

  14. An Evolving Asymmetric Game for Modeling Interdictor-Smuggler Problems

    2016-06-01

    ASYMMETRIC GAME FOR MODELING INTERDICTOR-SMUGGLER PROBLEMS by Richard J. Allain June 2016 Thesis Advisor: David L. Alderson Second Reader: W...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE AN EVOLVING ASYMMETRIC GAME FOR MODELING INTERDICTOR- SMUGGLER PROBLEMS 5. FUNDING NUMBERS 6...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited AN EVOLVING

  15. Decrease in back strength in asymmetric trunk postures

    Vink, P.; Daanen, H. A M; Meijst, W. J.; Ligteringen, J.

    1992-01-01

    The extension force against resistance was recorded in 23 postures for 12 subjects to find explanations for the decrease in back strength in asymmetric postures. A reduction in muscle force in asymmetric postures was found up to 40%, but was strongly dependent on the plane in which asymmetry

  16. Application of optical phase conjugation to plasma diagnostics (invited)

    Jahoda, F.C.; Anderson, B.T.; Forman, P.R.; Weber, P.G.

    1985-01-01

    Several possibilities for plasma diagnostics provided by optical phase conjugation and, in particular, self-pumped phase conjugation in barium titanate (BaTiO 3 ) are discussed. These include placing a plasma within a dye laser cavity equipped with a phase conjugate mirror for intracavity absorption measurements, time differential refractometry with high spatial resolution, and simplified real-time holographic interferometry. The principles of phase conjugation with particular reference to photorefractive media and the special advantages of self-pumped phase conjugation are reviewed prior to the discussion of the applications. Distinctions are made in the applications between those for which photorefractive conjugators are essential and those for which they only offer experimental simplification relative to other types of phase conjugators

  17. Subcopula-based measure of asymmetric association for contingency tables.

    Wei, Zheng; Kim, Daeyoung

    2017-10-30

    For the analysis of a two-way contingency table, a new asymmetric association measure is developed. The proposed method uses the subcopula-based regression between the discrete variables to measure the asymmetric predictive powers of the variables of interest. Unlike the existing measures of asymmetric association, the subcopula-based measure is insensitive to the number of categories in a variable, and thus, the magnitude of the proposed measure can be interpreted as the degree of asymmetric association in the contingency table. The theoretical properties of the proposed subcopula-based asymmetric association measure are investigated. We illustrate the performance and advantages of the proposed measure using simulation studies and real data examples. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Asymmetric double Langmuir probe: Small signal application

    Uckan, T.

    1987-11-01

    We discuss the asymmetric double Langmuir probe (ADLP) and demonstrate the possibility of using it to measure plasma temperature T/sub e/ and density n when it is operated in the region of small signal response. The area of one of the ADLP collectors is considerably larger than the other. This probe can be operated at a relatively low applied voltage, eV/sub a/T/sub e/ < 1, and still provides sufficient information to determine the plasma T/sub e/ and n. There is no need for a direct measurement of the ion saturation current, which can be on the order of a few amperes in large fusion devices. This reduces the requirements on the probe power supply. 6 refs., 6 figs

  19. Do Daily Retail Gasoline Prices adjust Asymmetrically?

    Bettendorf, L. [Tinbergen Instituut, Amsterdam/Rotterdam (Netherlands); Van der Geest, S. [Erasmus Universiteit, Rotterdam (Netherlands); Kuper, G. [University of Groningen, Groningen (Netherlands)

    2005-04-15

    This paper analyzes adjustments in the Dutch retail gasoline prices. We estimate an error correction model on changes in the daily retail price for gasoline (taxes excluded) for the period 1996-2004 taking care of volatility clustering by estimating an EGARCH model. It turns out the volatility process is asymmetrical: an unexpected increase in the producer price has a larger effect on the variance of the producer price than an unexpected decrease. We do not find strong evidence for amount asymmetry. However, there is a faster reaction to upward changes in spot prices than to downward changes in spot prices. This implies timing or pattern asymmetry. This asymmetry starts three days after the change in the spot price and lasts for four days.

  20. Isospin dependent properties of asymmetric nuclear matter

    Chowdhury, P. Roy; Basu, D. N.; Samanta, C.

    2009-07-01

    The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and isovector components of the density dependent M3Y interaction. The incompressibility K∞ for the symmetric nuclear matter, the isospin dependent part Kasy of the isobaric incompressibility, and the slope L are all in excellent agreement with the constraints recently extracted from measured isotopic dependence of the giant monopole resonances in even-A Sn isotopes, from the neutron skin thickness of nuclei, and from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions. This work provides a fundamental basis for the understanding of nuclear matter under extreme conditions and validates the important empirical constraints obtained from recent experimental data.

  1. Asymmetric Spatial Processing Under Cognitive Load.

    Naert, Lien; Bonato, Mario; Fias, Wim

    2018-01-01

    Spatial attention allows us to selectively process information within a certain location in space. Despite the vast literature on spatial attention, the effect of cognitive load on spatial processing is still not fully understood. In this study we added cognitive load to a spatial processing task, so as to see whether it would differentially impact upon the processing of visual information in the left versus the right hemispace. The main paradigm consisted of a detection task that was performed during the maintenance interval of a verbal working memory task. We found that increasing cognitive working memory load had a more negative impact on detecting targets presented on the left side compared to those on the right side. The strength of the load effect correlated with the strength of the interaction on an individual level. The implications of an asymmetric attentional bias with a relative disadvantage for the left (vs the right) hemispace under high verbal working memory (WM) load are discussed.

  2. Baryon destruction by asymmetric dark matter

    Davoudiasl, Hooman; Morrissey, David E.; Tulin, Sean; Sigurdson, Kris

    2011-01-01

    We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause induced nucleon decay by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10 29 -10 32 yrs in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter-induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.

  3. Asymmetric Dark Matter and Dark Radiation

    Blennow, Mattias; Mena, Olga; Redondo, Javier; Serra, Paolo

    2012-01-01

    Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry, similar to the one observed in the Baryon sector, to account for the Dark Matter (DM) abundance. Both asymmetries are usually generated by the same mechanism and generally related, thus predicting DM masses around 5 GeV in order to obtain the correct density. The main challenge for successful models is to ensure efficient annihilation of the thermally produced symmetric component of such a light DM candidate without violating constraints from collider or direct searches. A common way to overcome this involves a light mediator, into which DM can efficiently annihilate and which subsequently decays into Standard Model particles. Here we explore the scenario where the light mediator decays instead into lighter degrees of freedom in the dark sector that act as radiation in the early Universe. While this assumption makes indirect DM searches challenging, it leads to signals of extra radiation at BBN and CMB. Under certain conditions, pre...

  4. PEP-II: An asymmetric B factory

    1993-06-01

    In this report, the authors have described an updated conceptual design for the high-luminosity Asymmetric B Factory (PEP-II) to be built in the PEP tunnel culmination of more than four years of effort aimed at the design and construction of an asymmetric e + e - collider capable of achieving a luminosity of L = 3 x 10 33 cm -2 s -1 . All aspects of the conceptual design were scrutinized in March 1991 by a DOE technical review committee chaired by Dr. L. Edward Temple. The design was deemed feasible and capable of achieving its physics goals. Furthermore, the cost estimate, schedule, and management plan for the project were fully endorsed by the committee. This updated conceptual design report captures the technical progress since the March 1991 review and reflects the lower cost estimate corresponding to the improved design. Although the PEP-II design has continued to evolve, no technical scope changes have been made that invalidate the conclusion of the DOE review. The configuration adopted utilizes two storage rings, an electron ring operating at 9 GeV and a positron ring at 3.1 GeV, each with a circumference of 2200 m. The high-energy ring is an upgrade of the PEP storage ring at SLAC; all PEP magnets and most power supplies will be reused. The upgrade consists primarily of replacing the PEP vacuum chamber and RF system with newly designed versions optimized for the high-current environment of PEP-II. The low-energy ring will be newly constructed and will be situated atop the high-energy ring in the PEP tunnel. Utilities already installed in the PEP tunnel are largely sufficient to operate the two PEP-II storage rings

  5. The asymmetric total synthesis of (+)- and (-)-trypargine via Noyori asymmetric transfer hydrogenation

    Pilli, Ronaldo A.; Rodrigues Junior, Manoel Trindade

    2009-01-01

    A concise and efficient total synthesis of (+)- and (-)-trypargine (6 steps and 38% overall yield), a 1-substituted β-carboline guanidine alkaloid isolated from the skin of the African frog K. senegalensis, was developed based on the construction of the b-carboline moiety via Bischler-Napieralski reaction and the enantioselective reduction of the dihydro-β-carboline intermediate via an asymmetric transfer hydrogenation reaction using Noyori's protocol. (author)

  6. Asymmetric dominance and asymmetric mate choice oppose premating isolation after allopatric divergence.

    Sefc, Kristina M; Hermann, Caroline M; Steinwender, Bernd; Brindl, Hanna; Zimmermann, Holger; Mattersdorfer, Karin; Postl, Lisbeth; Makasa, Lawrence; Sturmbauer, Christian; Koblmüller, Stephan

    2015-04-01

    Assortative mating promotes reproductive isolation and allows allopatric speciation processes to continue in secondary contact. As mating patterns are determined by mate preferences and intrasexual competition, we investigated male-male competition and behavioral isolation in simulated secondary contact among allopatric populations. Three allopatric color morphs of the cichlid fish Tropheus were tested against each other. Dyadic male-male contests revealed dominance of red males over bluish and yellow-blotch males. Reproductive isolation in the presence of male-male competition was assessed from genetic parentage in experimental ponds and was highly asymmetric among pairs of color morphs. Red females mated only with red males, whereas the other females performed variable degrees of heteromorphic mating. Discrepancies between mating patterns in ponds and female preferences in a competition-free, two-way choice paradigm suggested that the dominance of red males interfered with positive assortative mating of females of the subordinate morphs and provoked asymmetric hybridization. Between the nonred morphs, a significant excess of negative assortative mating by yellow-blotch females with bluish males did not coincide with asymmetric dominance among males. Hence, both negative assortative mating preferences and interference of male-male competition with positive assortative preferences forestall premating isolation, the latter especially in environments unsupportive of competition-driven spatial segregation.

  7. Stochastic Spectral and Conjugate Descent Methods

    Kovalev, Dmitry

    2018-02-11

    The state-of-the-art methods for solving optimization problems in big dimensions are variants of randomized coordinate descent (RCD). In this paper we introduce a fundamentally new type of acceleration strategy for RCD based on the augmentation of the set of coordinate directions by a few spectral or conjugate directions. As we increase the number of extra directions to be sampled from, the rate of the method improves, and interpolates between the linear rate of RCD and a linear rate independent of the condition number. We develop and analyze also inexact variants of these methods where the spectral and conjugate directions are allowed to be approximate only. We motivate the above development by proving several negative results which highlight the limitations of RCD with importance sampling.

  8. Stochastic Spectral and Conjugate Descent Methods

    Kovalev, Dmitry; Gorbunov, Eduard; Gasanov, Elnur; Richtarik, Peter

    2018-01-01

    The state-of-the-art methods for solving optimization problems in big dimensions are variants of randomized coordinate descent (RCD). In this paper we introduce a fundamentally new type of acceleration strategy for RCD based on the augmentation of the set of coordinate directions by a few spectral or conjugate directions. As we increase the number of extra directions to be sampled from, the rate of the method improves, and interpolates between the linear rate of RCD and a linear rate independent of the condition number. We develop and analyze also inexact variants of these methods where the spectral and conjugate directions are allowed to be approximate only. We motivate the above development by proving several negative results which highlight the limitations of RCD with importance sampling.

  9. Phase-conjugate optical coherence tomography

    Erkmen, Baris I.; Shapiro, Jeffrey H.

    2006-01-01

    Quantum optical coherence tomography (Q-OCT) offers a factor-of-2 improvement in axial resolution and the advantage of even-order dispersion cancellation when it is compared to conventional OCT (C-OCT). These features have been ascribed to the nonclassical nature of the biphoton state employed in the former, as opposed to the classical state used in the latter. Phase-conjugate OCT (PC-OCT) shows that nonclassical light is not necessary to reap Q-OCT's advantages. PC-OCT uses classical-state signal and reference beams, which have a phase-sensitive cross correlation, together with phase conjugation to achieve the axial resolution and even-order dispersion cancellation of Q-OCT with a signal-to-noise ratio that can be comparable to that of C-OCT

  10. Antibody conjugate radioimmunotherapy of superficial bladder cancer

    Perkins, Alan; Hopper, Melanie; Murray, Andrea; Frier, Malcolm; Bishop, Mike

    2002-01-01

    The administration of antibody conjugates for cancer therapy is now proving to be of clinical value. We are currently undertaking a programme of clinical studies using the monoclonal antibody C 595 (gG3) which reacts with the MUC1 glycoprotein antigen that is aberrantly expressed in a high proportion of bladder tumours. Radio immuno conjugates of the C 595 antibody have been produced with high radiolabelling efficiency and immuno reactivity using Tc-99 m and In-111 for diagnostic imaging, and disease staging and the cytotoxic radionuclides Cu-67 and Re-188 for therapy of superficial bladder cancer. A Phase I/II therapeutic trail involving the intravesical administration of antibody directly into the bladder has now begun. (author)

  11. Charge conjugation invariance of the spectator equations

    Gross, F.

    1999-01-01

    In response to recent criticism, the authors show how to define the spectator equations for negative energies so that charge conjugation invariance is preserved. The result, which emerges naturally from the application of spectator principles to systems of particles with negative energies, is to replace all factors of the external energies W iota by √ W 2 iota , insuring that the amplitudes are independent of the sign of the energies W iota

  12. Conjugated Linoleic Acid: good or bad nutrient

    Gonçalves Daniela C

    2010-10-01

    Full Text Available Abstract Conjugated linoleic acid (CLA is a class of 28 positional and geometric isomers of linoleic acid octadecadienoic.Currently, it has been described many benefits related to the supplementation of CLA in animals and humans, as in the treatment of cancer, oxidative stress, in atherosclerosis, in bone formation and composition in obesity, in diabetes and the immune system. However, our results show that, CLA appears to be not a good supplement in patients with cachexia.

  13. Error Estimation in Preconditioned Conjugate Gradients

    Strakoš, Zdeněk; Tichý, Petr

    2005-01-01

    Roč. 45, - (2005), s. 789-817 ISSN 0006-3835 R&D Projects: GA AV ČR 1ET400300415; GA AV ČR KJB1030306 Institutional research plan: CEZ:AV0Z10300504 Keywords : preconditioned conjugate gradient method * error bounds * stopping criteria * evaluation of convergence * numerical stability * finite precision arithmetic * rounding errors Subject RIV: BA - General Mathematics Impact factor: 0.509, year: 2005

  14. Conjugate gradient optimization programs for shuttle reentry

    Powers, W. F.; Jacobson, R. A.; Leonard, D. A.

    1972-01-01

    Two computer programs for shuttle reentry trajectory optimization are listed and described. Both programs use the conjugate gradient method as the optimization procedure. The Phase 1 Program is developed in cartesian coordinates for a rotating spherical earth, and crossrange, downrange, maximum deceleration, total heating, and terminal speed, altitude, and flight path angle are included in the performance index. The programs make extensive use of subroutines so that they may be easily adapted to other atmospheric trajectory optimization problems.

  15. M-step preconditioned conjugate gradient methods

    Adams, L.

    1983-01-01

    Preconditioned conjugate gradient methods for solving sparse symmetric and positive finite systems of linear equations are described. Necessary and sufficient conditions are given for when these preconditioners can be used and an analysis of their effectiveness is given. Efficient computer implementations of these methods are discussed and results on the CYBER 203 and the Finite Element Machine under construction at NASA Langley Research Center are included.

  16. [Relationship between family variables and conjugal adjustment].

    Jiménez-Picón, Nerea; Lima-Rodríguez, Joaquín-Salvador; Lima-Serrano, Marta

    2018-04-01

    To determine whether family variables, such as type of relationship, years of marriage, existence of offspring, number of members of family, stage of family life cycle, transition between stages, perceived social support, and/or stressful life events are related to conjugal adjustment. A cross-sectional and correlational study using questionnaires. Primary care and hospital units of selected centres in the province of Seville, Spain. Consecutive stratified sampling by quotas of 369 heterosexual couples over 18years of age, who maintained a relationship, with or without children, living in Seville. A self-report questionnaire for the sociodemographic variables, and the abbreviated version of the Dyadic Adjustment Scale, Questionnaire MOS Perceived Social Support, and Social Readjustment Rating Scale, were used. Descriptive and inferential statistics were performed with correlation analysis and multivariate regression. Statistically significant associations were found between conjugal adjustment and marriage years (r=-10: Pfamily life cycle (F=2.65; Pfamily life cycle stage (mature-aged stage) on conjugal adjustment (R2=.21; F=9.9; df=356; Prelationship. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  17. Cancer Chemopreventive Ability of Conjugated Linolenic Acids

    Kazuo Miyashita

    2011-11-01

    Full Text Available Conjugated fatty acids (CFA have received increased interest because of their beneficial effects on human health, including preventing cancer development. Conjugated linoleic acids (CLA are such CFA, and have been reviewed extensively for their multiple biological activities. In contrast to other types of CFAs including CLA that are found at low concentrations (less than 1% in natural products, conjugated linolenic acids (CLN are the only CFAs that occur in higher quantities in natural products. Some plant seeds contain a considerably high concentration of CLN (30 to 70 wt% lipid. Our research group has screened CLN from different plant seed oils to determine their cancer chemopreventive ability. This review describes the physiological functions of CLN isomers that occur in certain plant seeds. CLN are able to induce apoptosis through decrease of Bcl-2 protein in certain human cancer cell lines, increase expression of peroxisome proliferator-activated receptor (PPAR-γ, and up-regulate gene expression of p53. Findings in our preclinical animal studies have indicated that feeding with CLN resulted in inhibition of colorectal tumorigenesis through modulation of apoptosis and expression of PPARγ and p53. In this review, we summarize chemopreventive efficacy of CLN against cancer development, especially colorectal cancer.

  18. Survey of beta-particle interaction experiments with asymmetric matter

    Van Horn, J. David; Wu, Fei

    2018-05-01

    Asymmetry is a basic property found at multiple scales in the universe. Asymmetric molecular interactions are fundamental to the operation of biological systems in both signaling and structural roles. Other aspects of asymmetry are observed and useful in many areas of science and engineering, and have been studied since the discovery of chirality in tartrate salts. The observation of parity violation in beta decay provided some impetus for later experiments using asymmetric particles. Here we survey historical work and experiments related to electron (e-) or positron (e+) polarimetry and their interactions with asymmetric materials in gas, liquid and solid forms. Asymmetric interactions may be classified as: 1) stereorecognition, 2) stereoselection and 3) stereoinduction. These three facets of physical stereochemistry are unique but interrelated; and examples from chemistry and materials science illustrate these aspects. Experimental positron and electron interactions with asymmetric materials may be classified in like manner. Thus, a qualitative assessment of helical and polarized positron experiments with different forms of asymmetric matter from the past 40 years is presented, as well as recent experiments with left-hand and right-hand single crystal quartz and organic compounds. The purpose of this classification and review is to evaluate the field for potential new experiments and directions for positron (or electron) studies with asymmetric materials.

  19. SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER

    Lopes, Ilidio [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Silk, Joseph, E-mail: ilidio.lopes@ist.utl.pt, E-mail: silk@astro.ox.ac.uk [Institut d' Astrophysique de Paris, F-75014 Paris (France)

    2012-10-01

    The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these {eta}-parameterized asymmetric dark matter ({eta}ADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry {eta} close to the baryon asymmetry {eta}{sub B}. Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain {eta}ADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an {eta}-asymmetry with a value in the interval 10{sup -12}-10{sup -10}, would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological {eta}ADM scenarios that we discuss have a relic dark matter density {Omega}h {sup 2} and baryon asymmetry {eta}{sub B} in agreement with

  20. SOLAR CONSTRAINTS ON ASYMMETRIC DARK MATTER

    Lopes, Ilídio; Silk, Joseph

    2012-01-01

    The dark matter content of the universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the universe, the dark matter particles are produced in a process similar to baryogenesis, and dark matter freezeout depends on the dark matter asymmetry and the annihilation cross section (s-wave and p-wave annihilation channels) of particles and antiparticles. In these η-parameterized asymmetric dark matter (ηADM) models, the dark matter particles have an annihilation cross section close to the weak interaction cross section, and a value of dark matter asymmetry η close to the baryon asymmetry η B . Furthermore, we assume that dark matter scattering of baryons, namely, the spin-independent scattering cross section, is of the same order as the range of values suggested by several theoretical particle physics models used to explain the current unexplained events reported in the DAMA/LIBRA, CoGeNT, and CRESST experiments. Here, we constrain ηADM by investigating the impact of such a type of dark matter on the evolution of the Sun, namely, the flux of solar neutrinos and helioseismology. We find that dark matter particles with a mass smaller than 15 GeV, a spin-independent scattering cross section on baryons of the order of a picobarn, and an η-asymmetry with a value in the interval 10 –12 -10 –10 , would induce a change in solar neutrino fluxes in disagreement with current neutrino flux measurements. This result is also confirmed by helioseismology data. A natural consequence of this model is suppressed annihilation, thereby reducing the tension between indirect and direct dark matter detection experiments, but the model also allows a greatly enhanced annihilation cross section. All the cosmological ηADM scenarios that we discuss have a relic dark matter density Ωh 2 and baryon asymmetry η B in agreement with the current WMAP measured values, Ω DM h 2 = 0

  1. Dye linked conjugated homopolymers: using conjugated polymer electroluminescence to optically pump porphyrin-dye emission

    Nielsen, K.T.; Spanggaard, H.; Krebs, Frederik C

    2004-01-01

    . Electroluminescent devices of the homopolymer itself and of the zinc-porphyrin containing polymer were prepared and the nature of the electroluminescence was characterized. The homopolymer segments were found to optically pump the emission of the zinc-porphyrin dye moities. The homopolymer exhibits blue......Zinc-porphyrin dye molecules were incorporated into the backbone of a conjugated polymer material by a method, which allowed for the incorporation of only one zinc-porphyrin dye molecule into the backbone of each conjugated polymer molecule. The electronic properties of the homopolymer were...

  2. Co-conjugation vis-à-vis individual conjugation of α-amylase and glucoamylase for hydrolysis of starch.

    Jadhav, Swati B; Singhal, Rekha S

    2013-10-15

    Two enzymes, α-amylase and glucoamylase have been individually and co-conjugated to pectin by covalent binding. Both the enzyme systems showed better thermal and pH stability over the free enzyme system with the complete retention of original activities. Mixture of individually conjugated enzymes showed lower inactivation rate constant with longer half life than the co-conjugated enzyme system. Individually conjugated enzymes showed an increase of 56.48 kJ/mole and 38.22 kJ/mole in activation energy for denaturation than the free enzymes and co-conjugated enzymes, respectively. Km as well as Vmax of individually and co-conjugated enzymes was found to be higher than the free enzymes. SDS-polyacrylamide gel electrophoresis confirmed the formation of conjugate and co-conjugate as evident by increased molecular weight. Both the enzyme systems were used for starch hydrolysis where individually conjugated enzymes showed highest release of glucose at 60 °C and pH 5.0 as compared to free and co-conjugated enzyme. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Comparison of the rift and post-rift architecture of conjugated salt and salt-free basins offshore Brazil and Angola/Namibia, South Atlantic

    Strozyk, Frank; Back, Stefan; Kukla, Peter A.

    2017-10-01

    This study presents a regional comparison between selected 2D seismic transects from large, conjugated salt and salt-free basins offshore southern Brazil (Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Kwanza Basin, northern and southern Namibe Basin, Walvis Basin). Tectonic-stratigraphic interpretation of the main rift and post-rift units, free-air gravity data and flexural isostatic backstripping were used for a comprehensive basin-to-basin documentation of key mechanisms controlling the present-day differences in conjugated and neighbouring South Atlantic basins. A significant variation in the tectonic-sedimentary architecture along-strike at each margin and between the conjugated basins across the South Atlantic reflects major differences in (1) the structural configuration of each margin segment at transitional phase between rifting and breakup, as emphasized in the highly asymmetric settings of the large Santos salt basin and the conjugated, salt-free southern Namibe Basin, (2) the post-breakup subsidence and uplift history of the respective margin segment, which caused major differences for example between the Campos and Espirito Santo basins and the conjugated northern Namibe and Kwanza basins, (3) variations in the quantity and distribution of post-breakup margin sediments, which led to major differences in the subsidence history and the related present-day basin architecture, for example in the initially rather symmetric, siliciclastic Pelotas and Walvis basins, and (4) the deposition of Aptian evaporites in the large rift and sag basin provinces north of the Rio Grande Rise and Walvis Ridge, highly contrasting the siliciclastic basins along the margin segments south of the ridges. The resulting present-day architecture of the basins can be generally classified as (i) moderately symmetric, salt-free, and magma-rich in the northern part of the southern segment, (i) highly asymmetric, salt-bearing and magma-poor vs. salt-free and magma

  4. An Asymmetric Furan/Thieno[3,2-b]Thiophene Diketopyrrolopyrrole Building Block for Annealing-Free Green-Solvent Processable Organic Thin-Film Transistors.

    Ding, Shang; Ni, Zhenjie; Hu, Mengxiao; Qiu, Gege; Li, Jie; Ye, Jun; Zhang, Xiaotao; Liu, Feng; Dong, Huanli; Hu, Wenping

    2018-06-21

    A new asymmetric furan and thieno[3,2-b]thiophene flanked diketopyrrolopyrrole (TTFDPP) building block for conjugated polymers is designed and used to generate a donor-acceptor semiconducting polymer, poly[3-(furan-2-yl)-2,5-bis(2-octyldodecyl)-6-(thieno[3,2-b]thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-thieno[3,2-b]thiophene] (abbreviated to PTTFDPP-TT), consisting of TTFDPP unit copolymerized with thieno[3,2-b]thiophene comonomer (TT), which is further synthesized. Results demonstrate that PTTFDPP-TT-based thin-film transistors in a bottom-gate bottom-contact device configuration exhibit typical hole-transporting property, with weak temperature dependence for charge carrier mobility from room temperature to 200 °C. In addition, the good solubility of PTTFDPP-TT due to the incorporation of a polar furan unit and an asymmetric conjugated structure makes it able to be solution processed with a less toxic nonchlorinated solvent such as toluene, demonstrating comparable performance with that prepared from chlorinated solution. These results suggest PTTFDPP-TT as a promising organic semiconductor candidate for annealing-free, environmentally benign, and less energy-consuming applications in large-area flexible organic electronic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Minimizing inner product data dependencies in conjugate gradient iteration

    Vanrosendale, J.

    1983-01-01

    The amount of concurrency available in conjugate gradient iteration is limited by the summations required in the inner product computations. The inner product of two vectors of length N requires time c log(N), if N or more processors are available. This paper describes an algebraic restructuring of the conjugate gradient algorithm which minimizes data dependencies due to inner product calculations. After an initial start up, the new algorithm can perform a conjugate gradient iteration in time c*log(log(N)).

  6. Asymmetric quantum well broadband thyristor laser

    Liu, Zhen; Wang, Jiaqi; Yu, Hongyan; Zhou, Xuliang; Chen, Weixi; Li, Zhaosong; Wang, Wei; Ding, Ying; Pan, Jiaoqing

    2017-11-01

    A broadband thyristor laser based on InGaAs/GaAs asymmetric quantum well (AQW) is fabricated by metal organic chemical vapor deposition (MOCVD). The 3-μm-wide Fabry-Perot (FP) ridge-waveguide laser shows an S-shape I-V characteristic and exhibits a flat-topped broadband optical spectrum coverage of ~27 nm (Δ-10 dB) at a center wavelength of ~1090 nm with a total output power of 137 mW under pulsed operation. The AQW structure was carefully designed to establish multiple energy states within, in order to broaden the gain spectrum. An obvious blue shift emission, which is not generally acquired in QW laser diodes, is observed in the broadening process of the optical spectrum as the injection current increases. This blue shift spectrum broadening is considered to result from the prominent band-filling effect enhanced by the multiple energy states of the AQW structure, as well as the optical feedback effect contributed by the thyristor laser structure. Project supported by the National Natural Science Foundation of China (Nos. 61604144, 61504137). Zhen Liu and Jiaqi Wang contributed equally to this work.

  7. Asymmetric Cherenkov acoustic reverse in topological insulators

    Smirnov, Sergey

    2014-09-01

    A general phenomenon of the Cherenkov radiation known in optics or acoustics of conventional materials is a formation of a forward cone of, respectively, photons or phonons emitted by a particle accelerated above the speed of light or sound in those materials. Here we suggest three-dimensional topological insulators as a unique platform to fundamentally explore and practically exploit the acoustic aspect of the Cherenkov effect. We demonstrate that by applying an in-plane magnetic field to a surface of a three-dimensional topological insulator one may suppress the forward Cherenkov sound up to zero at a critical magnetic field. Above the critical field the Cherenkov sound acquires pure backward nature with the polar distribution differing from the forward one generated below the critical field. Potential applications of this asymmetric Cherenkov reverse are in the design of low energy electronic devices such as acoustic ratchets or, in general, in low power design of electronic circuits with a magnetic field control of the direction and magnitude of the Cherenkov dissipation.

  8. Asymmetric Spatial Processing Under Cognitive Load

    Lien Naert

    2018-04-01

    Full Text Available Spatial attention allows us to selectively process information within a certain location in space. Despite the vast literature on spatial attention, the effect of cognitive load on spatial processing is still not fully understood. In this study we added cognitive load to a spatial processing task, so as to see whether it would differentially impact upon the processing of visual information in the left versus the right hemispace. The main paradigm consisted of a detection task that was performed during the maintenance interval of a verbal working memory task. We found that increasing cognitive working memory load had a more negative impact on detecting targets presented on the left side compared to those on the right side. The strength of the load effect correlated with the strength of the interaction on an individual level. The implications of an asymmetric attentional bias with a relative disadvantage for the left (vs the right hemispace under high verbal working memory (WM load are discussed.

  9. Collaborative hierarchy maintains cooperation in asymmetric games.

    Antonioni, Alberto; Pereda, María; Cronin, Katherine A; Tomassini, Marco; Sánchez, Angel

    2018-03-29

    The interplay of social structure and cooperative behavior is under much scrutiny lately as behavior in social contexts becomes increasingly relevant for everyday life. Earlier experimental work showed that the existence of a social hierarchy, earned through competition, was detrimental for the evolution of cooperative behaviors. Here, we study the case in which individuals are ranked in a hierarchical structure based on their performance in a collective effort by having them play a Public Goods Game. In the first treatment, participants are ranked according to group earnings while, in the second treatment, their rankings are based on individual earnings. Subsequently, participants play asymmetric Prisoner's Dilemma games where higher-ranked players gain more than lower ones. Our experiments show that there are no detrimental effects of the hierarchy formed based on group performance, yet when ranking is assigned individually we observe a decrease in cooperation. Our results show that different levels of cooperation arise from the fact that subjects are interpreting rankings as a reputation which carries information about which subjects were cooperators in the previous phase. Our results demonstrate that noting the manner in which a hierarchy is established is essential for understanding its effects on cooperation.

  10. Climate policy, asymmetric information and firm survival

    Hagem, C.

    2001-02-01

    The purpose of this paper is to compare the effect of different domestic climate policy instruments under asymmetric information when the regulator wants to secure the survival of a specific firm. It is a well-known result from economic theory that emission taxes lead to a cost-effective distribution of abatement across polluters. However, if the regulator wants to ensure the survival of a specific firm, it may need to design policy instruments that reduce the firm's cost of complying with an emission tax regime. The climate policy instruments considered in this paper are tradable emission permits with distribution of free permits, emission taxes in combination with a fixed subsidy, and two types of voluntary agreements. It demonstrates first that if distributing free tradable permits shall have a preventing effect, the allocation of permits has to be made contingent on production. It further shows that a voluntary agreement where a specific abatement target is set by the regulator can prevent a shutdown but leads to lower welfare than the use of emission taxes in combination with a fixed subsidy. And finally it illustrates that a voluntary agreement designed as a menu of abatement contracts increases social welfare compared to an emission tax regime

  11. Performance of an AGATA asymmetric detector

    Boston, A.J. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)], E-mail: ajboston@liv.ac.uk; Dimmock, M.R.; Unsworth, C.; Boston, H.C.; Cooper, R.J.; Grint, A.N.; Harkness, L.J. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lazarus, I.H. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Jones, M.; Nolan, P.J.; Oxley, D.C. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Slee, M. [Department of Physics, University of Liverpool, Liverpool L69 7ZE (United Kingdom)

    2009-06-01

    High-resolution gamma-ray detectors based on high-purity germanium crystals (HPGe) are one of the key workhorses of experimental nuclear science. The technical development of such detector technology has been dramatic in recent years. Large volume, high-granularity, electrically segmented HPGe detectors have been realised and a methodology to improve position sensitivity using pulse-shape analysis coupled with the novel technique of gamma-ray tracking has been developed. Collaborations have been established in Europe (Advanced GAmma Tracking Array (AGATA)) [J. Simpson, Acta Phys. Pol. B 36 (2005) 1383] and the USA (GRETA/GRETINA) [C.W. Beausang, Nucl. Instr. and Meth. B 204 (2003)] to build gamma-ray tracking spectrometers. This paper discusses the performance of the first AGATA asymmetric detector that has been tested at the University of Liverpool. The use of a fully digital data acquisition system has allowed detector charge pulse shapes from a selection of well-defined photon interaction positions to be analysed, yielding important information on the position sensitivity of the detector.

  12. Asymmetric Dark Matter and Dark Radiation

    Blennow, Mattias; Martinez, Enrique Fernandez; Mena, Olga; Redondo, Javier; Serra, Paolo

    2012-01-01

    Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry, similar to the one observed in the Baryon sector, to account for the Dark Matter (DM) abundance. Both asymmetries are usually generated by the same mechanism and generally related, thus predicting DM masses around 5 GeV in order to obtain the correct density. The main challenge for successful models is to ensure efficient annihilation of the thermally produced symmetric component of such a light DM candidate without violating constraints from collider or direct searches. A common way to overcome this involves a light mediator, into which DM can efficiently annihilate and which subsequently decays into Standard Model particles. Here we explore the scenario where the light mediator decays instead into lighter degrees of freedom in the dark sector that act as radiation in the early Universe. While this assumption makes indirect DM searches challenging, it leads to signals of extra radiation at BBN and CMB. Under certain conditions, precise measurements of the number of relativistic species, such as those expected from the Planck satellite, can provide information on the structure of the dark sector. We also discuss the constraints of the interactions between DM and Dark Radiation from their imprint in the matter power spectrum

  13. Asymmetric adaptations to energy price changes

    Kuper, G.H.; Van Soest, D.P.

    1999-01-01

    The effectiveness of policies to reduce the use of energy depend on the elasticity of substitution between the various inputs and on the rate of technological progress. This paper presents a theoretical model emphasising energy investment characteristics of uncertainty and irreversibility that result in testable hypotheses concerning the relative values of substitution parameters and rates of technological change in periods of high and increasing energy prices and in periods of low prices. Estimation results for a panel of sectors of the Dutch economy show that the elasticity of substitution between energy and other inputs is low in periods of low energy prices, whereas it is significantly higher in the preceding period of high and increasing energy prices. Furthermore, energy-saving technological progress in periods of high and increasing energy prices is also significantly higher than if energy prices are low and falling. The regression results suggest that, due this asymmetric response of firms to changes in energy prices, taxing energy in the current period of low energy prices will not yield substantial reductions in energy use of Dutch industry. 21 refs

  14. Trade Credit Insurance and Asymmetric Information Problem

    Sokolovska Olena

    2017-03-01

    Full Text Available The presence of different risk factors in international trade gives evidence of the necessity of support in gaps that may affect exporters’ activity. To maximize the trade volumes and in the same time to minimize the exporters’ risks the stakeholders use trade credit insurance. The paper provides analysis of conceptual background of the trade credit insurance in the world. We analyzed briefly the problems, arising in insurance markets due to asymmetric information, such as adverse selection and moral hazard. Also we discuss the main stages of development of trade credit insurance in countries worldwide. Using comparative and graphical analysis we provide a brief evaluation of the dynamics of claims and recoveries for different forms of trade credit insurance. We found that the claims related to the commercial risk for medium and long trade credits in recent years exceed the recoveries, while with the political risk the reverse trend holds. And we originally consider these findings in terms of information asymmetry in the trade credit insurance differentiated by type of risk.

  15. Asymmetric sensory reweighting in human upright stance.

    David Logan

    Full Text Available To investigate sensory reweighting as a fundamental property of sensor fusion during standing, we probed postural control with simultaneous rotations of the visual scene and surface of support. Nineteen subjects were presented with pseudo-random pitch rotations of visual scene and platform at the ankle to test for amplitude dependencies in the following conditions: low amplitude vision: high amplitude platform, low amplitude vision: low amplitude platform, and high amplitude vision: low amplitude platform. Gain and phase of frequency response functions (FRFs to each stimulus were computed for two body sway angles and a single weighted EMG signal recorded from seven muscles. When platform stimulus amplitude was increased while visual stimulus amplitude remained constant, gain to vision increased, providing strong evidence for inter-modal reweighting between vision and somatosensation during standing. Intra-modal reweighting of vision was also observed as gains to vision decreased as visual stimulus amplitude increased. Such intra-modal and inter-modal amplitude dependent changes in gain were also observed in muscular activity. Gains of leg segment angle and muscular activity relative to the platform, on the other hand, showed only intra-modal reweighting. That is, changing platform motion amplitude altered the responses to both visual and support surface motion whereas changing visual scene motion amplitude did not significantly affect responses to support surface motion, indicating that the sensory integration scheme between somatosensation (at the support surface and vision is asymmetric.

  16. Micromagnetic simulation of Fe asymmetric nanorings

    Palma, J.L.; Morales-Concha, C.; Leighton, B.; Altbir, D.; Escrig, J.

    2012-01-01

    During the last decade several methods to control the vortex chirality in nanodots have been proposed. One of them, the introduction of asymmetry in the geometry of the dots, originates interesting effects on the magnetic behavior of the particle. However, asymmetry in core-free structures is also interesting to investigate because of the reproducibility of their magnetic properties. In this work we report systematic changes in the coercivity and remanence in asymmetric nanorings. The angular dependence is also addressed. For specific geometries and magnetic field direction newly reversal modes appear associated with important changes in the coercivity and remanence of the rings. - Highlights: → We report that the existence of asymmetry strongly influences the coercivity and the remanence. → Magnetization reversal is driven by the nucleation of a C state and propagation of a vortex state. → We also conclude that the lack of a core contributes to the stability of the vortex state. → Asymmetry can be useful for tailoring specific magnetic characteristics of these systems.

  17. Optimal multicopy asymmetric Gaussian cloning of coherent states

    Fiurášek, Jaromír; Cerf, Nicolas J.

    2007-05-01

    We investigate the asymmetric Gaussian cloning of coherent states which produces M copies from N input replicas in such a way that the fidelity of each copy may be different. We show that the optimal asymmetric Gaussian cloning can be performed with a single phase-insensitive amplifier and an array of beam splitters. We obtain a simple analytical expression characterizing the set of optimal asymmetric Gaussian cloning machines and prove the optimality of these cloners using the formalism of Gaussian completely positive maps and semidefinite programming techniques. We also present an alternative implementation of the asymmetric cloning machine where the phase-insensitive amplifier is replaced with a beam splitter, heterodyne detector, and feedforward.

  18. Asymmetrical Polymer Vesicles for Drug delivery and Other Applications

    Yi Zhao

    2017-06-01

    Full Text Available Scientists have been attracted by polymersomes as versatile drug delivery systems since the last two decades. Polymersomes have the potential to be versatile drug delivery systems because of their tunable membrane formulations, stabilities in vivo, various physicochemical properties, controlled release mechanisms, targeting abilities, and capacities to encapsulate a wide range of drugs and other molecules. Asymmetrical polymersomes are nano- to micro-sized polymeric capsules with asymmetrical membranes, which means, they have different outer and inner coronas so that they can exhibit better endocytosis rate and endosomal escape ability than other polymeric systems with symmetrical membranes. Hence, asymmetrical polymersomes are highly promising as self-assembled nano-delivery systems in the future for in vivo therapeutics delivery and diagnostic imaging applications. In this review, we prepared a summary about recent research progresses of asymmetrical polymersomes in the following aspects: synthesis, preparation, applications in drug delivery and others.

  19. All conducting polymer electrodes for asymmetric solid-state supercapacitors

    Kurra, Narendra; Wang, Ruiqi; Alshareef, Husam N.

    2015-01-01

    electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid

  20. Outage Analysis of Asymmetric RF-FSO Systems

    Ansari, Imran Shafique; Abdallah, Mohamed M.; Alouini, Mohamed-Slim; Qaraqe, Khalid A.

    2017-01-01

    In this work, the outage performance analysis of a dual-hop transmission system composed of asymmetric radio frequency (RF) channels cascaded with free-space optical (FSO) links is presented. The RF links are modeled by the Rayleigh fading

  1. Asymmetric H-D exchange reactions of fluorinated aromatic ketones

    Zhao, Yujun; Lim, XiaoZhi; Pan, Yuanhang; Zong, Lili; Feng, Wei; Tan, Choonhong; Huang, Kuo-Wei

    2012-01-01

    Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction's stereoselectivity. © 2012 The Royal Society of Chemistry.

  2. Polarization dependent switching of asymmetric nanorings with a circular field

    Nihar R. Pradhan

    2016-01-01

    Full Text Available We experimentally investigated the switching from onion to vortex states in asymmetric cobalt nanorings by an applied circular field. An in-plane field is applied along the symmetric or asymmetric axis of the ring to establish domain walls (DWs with symmetric or asymmetric polarization. A circular field is then applied to switch from the onion state to the vortex state, moving the DWs in the process. The asymmetry of the ring leads to different switching fields depending on the location of the DWs and direction of applied field. For polarization along the asymmetric axis, the field required to move the DWs to the narrow side of the ring is smaller than the field required to move the DWs to the larger side of the ring. For polarization along the symmetric axis, establishing one DW in the narrow side and one on the wide side, the field required to switch to the vortex state is an intermediate value.

  3. Optimal multicopy asymmetric Gaussian cloning of coherent states

    Fiurasek, Jaromir; Cerf, Nicolas J.

    2007-01-01

    We investigate the asymmetric Gaussian cloning of coherent states which produces M copies from N input replicas in such a way that the fidelity of each copy may be different. We show that the optimal asymmetric Gaussian cloning can be performed with a single phase-insensitive amplifier and an array of beam splitters. We obtain a simple analytical expression characterizing the set of optimal asymmetric Gaussian cloning machines and prove the optimality of these cloners using the formalism of Gaussian completely positive maps and semidefinite programming techniques. We also present an alternative implementation of the asymmetric cloning machine where the phase-insensitive amplifier is replaced with a beam splitter, heterodyne detector, and feedforward

  4. Asymmetric continuum extreme processes in solids and fluids

    Teisseyre, Roman

    2014-01-01

    This book deals with a class of basic deformations in asymmetric continuum theory. It describes molecular deformations and transport velocities in fluids, strain deformations in solids as well as the molecular transport, important in fracture processes.

  5. Asymmetric H-D exchange reactions of fluorinated aromatic ketones

    Zhao, Yujun

    2012-01-01

    Chiral bicyclic guanidine catalyzes the asymmetric H-D exchange reactions. Up to 30% ee was achieved. DFT calculations were employed to elucidate and explain the origin of the reaction\\'s stereoselectivity. © 2012 The Royal Society of Chemistry.

  6. Index profile measurement of asymmetrical elliptical preforms or fibers

    Blitterswijk, van W.; Smit, M.K.

    1987-01-01

    An extension of the beam-deflection method to the case of elliptical preforms with eccentric core (asymmetrical elliptical preforms) is presented, which can be easily implemented on automatic measurement equipment

  7. Pseudo-Goldstone modes in isospin-asymmetric nuclear matter

    Cohen, T.D.; Broniowski, W.

    1995-01-01

    The authors analyze the chiral limit in dense isospin-asymmetric nuclear matter. It is shown that the pseudo-Goldstone modes in this system are qualitatively different from the case of isospin-symmetric matter

  8. Subglottic cysts and asymmetrical subglottic narrowing on neck radiograph

    Holinger, L.D.; Torium, D.M.; Anandappa, E.C.

    1988-01-01

    The congenital subglottic hemangioma typically appears as an asymmetric subglottic narrowing or mass on frontal neck radiograph. Therefore, soft tissue neck radiography has been advocated as a definitive non-operative approach for diagnosing these lesions. However, we have noted similar asymmetric subglottic narrowing in patients with acquired subglottic cysts. These retention cysts occur following long-term intubation in the neonate. The mechanism probably involves subglottic fibrosis which obstructs glands with subsequent cyst formation. Acquired subglottic cysts typically appear as an asymmetric narrowing on frontal or lateral soft tissue neck radiographs. These lesions may produce airway compromise but are effectively treated by forceps or laser removal. Acquired subglottic cysts must be included in the differential diagnosis of asymmetric subglottic narrowing. The definitive diagnosis is made by direct laryngoscopy, not soft tissue neck radiograph. (orig.)

  9. Asymmetric periflexural exanthema: A report in an adult patient

    Zawar V

    2003-11-01

    Full Text Available Asymmetric periflexural exanthem (APE is a distinctive exanthem, probably viral in origin. It is largely a disease of childhood and is uncommon in adults. We report an adult man presenting with the typical clinical findings of APE.

  10. Fourier synthesis of asymmetrical optical potentials for atoms

    Ritt, G.

    2007-01-01

    In this work a dissipationless asymmetrical optical potential for cold atoms was produced. In a first step a new type of optical lattice was generated, whose spatial periodicity only corresponds to a quarter of the wavelength of the light used for the generation. This corresponds to the half of the periodicity of a conventional optical lattice, which is formed by the light of the same wavelength. The generation of this new type of optical lattice was reached by the use of two degenerated raman transitions. Virtual processes occur, in which four photons are involved. In conventional optical lattices however virtual two-photon processes occur. By spatially superimposing this optical lattice with a conventional optical lattice an asymmetrical optical potential could be formed. By diffraction of a Bose Einstein condensate of rubidium atoms at the transient activated asymmetrical potential the asymmetrical structure was proven. (orig.)

  11. Kinematics and Dynamics of an Asymmetrical Parallel Robotic Wrist

    Wu, Guanglei

    2014-01-01

    This paper introduces an asymmetrical parallel robotic wrist, which can generate a decoupled unlimited-torsion motion and achieve high positioning accuracy. The kinematics, dexterity, and singularities of the manipulator are investigated to visualize the performance contours of the manipulator...

  12. Salt supply to and significance of asymmetric salt diapirs

    Koyi, H.; Burliga, S.; Chemia, Zurab

    2012-01-01

    Salt diapirs can be asymmetric both internally and externally reflecting their evolution history. As such, this asymmetry bear a significant amount of information about the differential loading (± lateral forces) and in turn the salt supply that have shaped the diapir. In two dimensions......, In this study we compare results of analogue and numerical models of diapirs with two natural salt diapris (Klodawa and Gorleben diapirs) to explain their salt supply and asymmetric evolution. In a NW-SE section, the Gorleben salt diapir possesses an asymmetric external geometry represented by a large...... southeastern overhang due to salt extrusion during Middle Cretaceous followed by its burial in Tertiary. This external asymmetry is also reflected in the internal configuration of the diapir which shows different rates of salt flow on the two halves of the structure. The asymmetric external and internal...

  13. Vertical Control and Parallel Trade under Asymmetric Information

    Alessandro Avenali

    2015-05-01

    profits from the manufacturer to the wholesaler. Therefore, in R&D-intensive industries, such as pharmaceuticals, policy makers should anticipate the likely consequences of PT under asymmetric information on the long-run incentives to innovate.

  14. Methotrexate and epirubicin conjugates as potential antitumor drugs

    Szymon Wojciech Kmiecik

    2017-07-01

    Full Text Available Introduction: The use of hybrid molecules has become one of the most significant approaches in new cytotoxic drug design. This study describes synthesis and characterization of conjugates consisting of two well-known and characterized chemotherapeutic agents: methotrexate (MTX and epirubicin (EPR. The synthesized conjugates combine two significant anticancer strategies: combinatory therapy and targeted therapy. These two drugs were chosen because they have different mechanisms of action, which can increase the anticancer effect of the obtained conjugates. MTX, which is a folic acid analog, has high cytotoxic properties and can serve as a targeting moiety that can reach folate receptors (FRs overexpresing tumor cells. Combination of nonselective drugs such as EPR with MTX can increase the selectivity of the obtained conjugates, while maintaining the high cytotoxic properties.Materials and methods: Conjugates were purified by RP-HPLC and the structure was investigated by MS and MS/MS methods. The effect of the conjugates on proliferation of LoVo, LoVo/Dx, MCF-7 and MV-4-11 human cancer cell lines was determined by SRB or MTT assay.Results: The conjugation reaction results in the formation of monosubstituted (α, γ and disubstituted MTX derivatives. In vitro proliferation data demonstrate that the conjugates synthesized in our study show lower cytotoxic properties than both chemotherapeutics used alone.Discussion: Epirubicin cytotoxicity was not observed in obtained conjugates. Effective drugs release after internalization needs further investigation.

  15. Poly(2-oxazoline)-Antibiotic Conjugates with Penicillins.

    Schmidt, Martin; Bast, Livia K; Lanfer, Franziska; Richter, Lena; Hennes, Elisabeth; Seymen, Rana; Krumm, Christian; Tiller, Joerg C

    2017-09-20

    The conjugation of antibiotics with polymers is rarely done, but it might be a promising alternative to low-molecular-weight derivatization. The two penicillins penicillin G (PenG) and penicillin V (PenV) were attached to the end groups of different water-soluble poly(2-oxazoline)s (POx) via their carboxylic acid function. This ester group was shown to be more stable against hydrolysis than the β-lactam ring of the penicillins. The conjugates are still antimicrobially active and up to 20 times more stable against penicillinase catalyzed hydrolysis. The antibiotic activity of the conjugates against Staphylococcus aureus in the presence of penicillinase is up to 350 times higher compared with the free antibiotics. Conjugates with a second antimicrobial function, a dodecyltrimethylammonium group (DDA-X), at the starting end of the PenG and PenV POx conjugates are more antimicrobially active than the conjugates without DDA-X and show high activity in the presence of penicillinase. For example, the conjugates DDA-X-PEtOx-PenG and DDA-X-PEtOx-PenV are 200 to 350 times more active against S. aureus in the presence of penicillinase and almost as effective as the penicillinase stable cloxacollin (Clox) under these conditions. These conjugates show even greater activity compared to cloxacollin without this enzyme present. Further, both conjugates kill Escherichia coli more effectively than PenG and Clox.

  16. Sources and Bioactive Properties of Conjugated Dietary Fatty Acids.

    Hennessy, Alan A; Ross, Paul R; Fitzgerald, Gerald F; Stanton, Catherine

    2016-04-01

    The group of conjugated fatty acids known as conjugated linoleic acid (CLA) isomers have been extensively studied with regard to their bioactive potential in treating some of the most prominent human health malignancies. However, CLA isomers are not the only group of potentially bioactive conjugated fatty acids currently undergoing study. In this regard, isomers of conjugated α-linolenic acid, conjugated nonadecadienoic acid and conjugated eicosapentaenoic acid, to name but a few, have undergone experimental assessment. These studies have indicated many of these conjugated fatty acid isomers commonly possess anti-carcinogenic, anti-adipogenic, anti-inflammatory and immune modulating properties, a number of which will be discussed in this review. The mechanisms through which these bioactivities are mediated have not yet been fully elucidated. However, existing evidence indicates that these fatty acids may play a role in modulating the expression of several oncogenes, cell cycle regulators, and genes associated with energy metabolism. Despite such bioactive potential, interest in these conjugated fatty acids has remained low relative to the CLA isomers. This may be partly attributed to the relatively recent emergence of these fatty acids as bioactives, but also due to a lack of awareness regarding sources from which they can be produced. In this review, we will also highlight the common sources of these conjugated fatty acids, including plants, algae, microbes and chemosynthesis.

  17. Quantitative clinical uptake measurements using conjugate counting

    Lathrop, K.A.; Bartlett, R.D.; Chen, C.T.; Chou, J.S.; Faulhaber, P.F.; Harper, P.V.; Stark, V.J.

    1986-01-01

    While the use of conjugate counting for determination of organ uptake in human subjects has been extensively described, in the present study the determination of the organ uptake of ortho-iodohippurate presented several opportunities for validation of the in vivo counting data. Ortho-iodohippurate is distributed in the extracellular space, is largely extracted on each pass through the kidneys, and is not significantly deiodinated in vivo. Thus, the kidney uptake rate should be proportional to the blood level, the appearance rate of activity in the bladder is equal to the disappearance rate from the kidneys, and direct measurement of activity in the urine after voiding provides an internal standard for imaging measurements of bladder activity. Since the activity levels in the kidneys, bladder, and remainder of the body changed fairly rapidly, especially in the first 20 to 30 minutes following injection, posterior images of the trunk including kidneys and bladder were obtained continuously using a gamma camera fitted with a diverging collimator for 30 minutes and then at intervals for several hours. Simultaneous conjugate counting determinations were made using a whole body scanning system previously described at these meetings. Imaging data corrected for decay and adjacent background were fitted by least squares methods to curves representing a sum of exponentials, and the curves were normalized to the conjugate uptake measurements. The uptake curves of the kidneys and bladder matched well with the direct measurements of the urinary excretion. Data were collected in 16 normal subjects, and the estimated absorbed dose was calculated for the kidneys, the bladder and the remainder of the body for seven radioisotopes of iodine. 4 references, 6 figures, 2 tables

  18. Interplay of alternative conjugated pathways and steric interactions on the electronic and optical properties of donor-acceptor conjugated polymers

    Lima, Igo T.; Risko, Chad; Aziz, Saadullah Gary; Da Silva Filho, Demé trio A Da Silva; Bredas, Jean-Luc

    2014-01-01

    Donor-acceptor π-conjugated copolymers are of interest for a wide range of electronic applications, including field-effect transistors and solar cells. Here, we present a density functional theory (DFT) study of the impact of varying the conjugation pathway on the geometric, electronic, and optical properties of donor-acceptor systems. We consider both linear ("in series"), traditional conjugation among the donor-acceptor moieties versus structures where the acceptor units are appended orthogonally to the linear, donor-only conjugated backbone. Long-range-corrected hybrid functionals are used in the investigation with the values of the tuned long-range separation parameters providing an estimate of the extent of conjugation as a function of the oligomer architecture. Considerable differences in the electronic and optical properties are determined as a function of the nature of the conjugation pathway, features that should be taken into account in the design of donor-acceptor copolymers.

  19. A method of the asymmetric Abel's inversion in plasma diagnosis

    Matoba, Tohru; Funahashi, Akimasa

    1975-09-01

    In the case of a noncylindrical plasma, axis symmetric components are drawn from observed projected intensities of physical quantities, assuming an asymmetric form. And the radial intensity distribution is determined by Abel's inversion method. The best fitting curve is obtained analytically from measured values by the least-square estimation of nonlinear parameters. The cylindrical symmetric Abel's inversion code ( ABELIC ) and the asymmetric Abel's inversion code ( ABELILSENP 2 ) are described. (auth.)

  20. Fluorescent nanohybrids based on asymmetrical cyanine dyes decorated carbon nanotubes

    Çavuşlar, Özge; Cavuslar, Ozge

    2015-01-01

    In this thesis, we focused on imparting new optical properties to carbon nanotubes (CNTs) to allow their optical detection and visualization in biomedical applications. We investigated the interactions of CNTs and DNA wrapped CNTs with asymmetrical cyanine dye molecules to study the applicability of resulting hybrid materials to fluorescent based systems. When CNTs interacted with asymmetrical cyanine dyes, they constructed a light absorbing nanoarray. However, the fluorescence emission of th...

  1. Asymmetric Effects on Escape Rates of Bistable System

    Wang Canjun; Mei Dongcheng; Dai Zucheng

    2011-01-01

    The asymmetric effects on the escape rates from the stable states x ± in the bistable system are analyzed. The results indicate that the multiplicative noise and the additive noise always enhance the particle escape from stable states x ± of bistable. However, the asymmetric parameter r enhances the particle escape from stable state x + , and holds back the particle escape from stable state x - . (general)

  2. Method development of damage detection in asymmetric buildings

    Wang, Yi; Thambiratnam, David P.; Chan, Tommy H. T.; Nguyen, Andy

    2018-01-01

    Aesthetics and functionality requirements have caused most buildings to be asymmetric in recent times. Such buildings exhibit complex vibration characteristics under dynamic loads as there is coupling between the lateral and torsional components of vibration, and are referred to as torsionally coupled buildings. These buildings require three dimensional modelling and analysis. In spite of much recent research and some successful applications of vibration based damage detection methods to civil structures in recent years, the applications to asymmetric buildings has been a challenging task for structural engineers. There has been relatively little research on detecting and locating damage specific to torsionally coupled asymmetric buildings. This paper aims to compare the difference in vibration behaviour between symmetric and asymmetric buildings and then use the vibration characteristics for predicting damage in them. The need for developing a special method to detect damage in asymmetric buildings thus becomes evident. Towards this end, this paper modifies the traditional modal strain energy based damage index by decomposing the mode shapes into their lateral and vertical components and to form component specific damage indices. The improved approach is then developed by combining the modified strain energy based damage indices with the modal flexibility method which was modified to suit three dimensional structures to form a new damage indicator. The procedure is illustrated through numerical studies conducted on three dimensional five-story symmetric and asymmetric frame structures with the same layout, after validating the modelling techniques through experimental testing of a laboratory scale asymmetric building model. Vibration parameters obtained from finite element analysis of the intact and damaged building models are then applied into the proposed algorithms for detecting and locating the single and multiple damages in these buildings. The results

  3. Asymmetric Price Transmission in Indonesia's Wheat Flour Market

    Varela, Gonzalo J.; Taniguchi, Kiyoshi

    2014-01-01

    Data indicate that its domestic price in Indonesia has been increasing regardless of movements in the international price of wheat. A test for asymmetric price transmission from international wheat to domestic wheat flour markets is conducted using an error correction model and find the presence of asymmetric price transmission. The upward adjustment in the domestic price of wheat flour is much faster than its adjustment downward when it deviates from long-run equilibrium. Our results are rob...

  4. Project financing versus corporate financing under asymmetric information

    Anton Miglo

    2008-01-01

    In recent years financing through the creation of an independent project company or financing by non-recourse debt has become an important part of corporate decisions. Shah and Thakor (JET, 1987) argue that project financing can be optimal when asymmetric information exists between firm's insiders and market participants. In contrast to that paper, we provide an asymmetric information argument for project financing without relying on corporate taxes, costly information production or an assump...

  5. Asymmetric Shaped-Pattern Synthesis for Planar Antenna Arrays

    T. M. Bruintjes

    2016-01-01

    Full Text Available A procedure to synthesize asymmetrically shaped beam patterns is developed for planar antenna arrays. As it is based on the quasi-analytical method of collapsed distributions, the main advantage of this procedure is the ability to realize a shaped (null-free region with very low ripple. Smooth and asymmetrically shaped regions can be used for Direction-of-Arrival estimation and subsequently for efficient tracking with a single output (fully analog beamformer.

  6. Conjugated polymer photovoltaic devices and materials

    Mozer, A.J.; Niyazi, Serdar Sariciftci

    2006-01-01

    The science and technology of conjugated polymer-based photovoltaic devices (bulk heterojunction solar cells) is highlighted focusing on three major issues, i.e. (i) nano-morphology optimization, (ii) improving charge carrier mobility, (iii) improving spectral sensitivity. Successful strategies towards improved photovoltaic performance are presented using various novel materials, including double-cable polymers, regioregular polymers and low bandgap polymers. The examples presented herein demonstrate that the bulk heterojunction concept is a viable approach towards developing photovoltaic systems by inexpensive solution-based fabrication technologies. (authors)

  7. Complex conjugate poles and parton distributions

    Tiburzi, B.C.; Detmold, W.; Miller, G.A.

    2003-01-01

    We calculate parton and generalized parton distributions in Minkowski space using a scalar propagator with a pair of complex conjugate poles. Correct spectral and support properties are obtained only after careful analytic continuation from Euclidean space. Alternately the quark distribution function can be calculated from modified cutting rules, which put the intermediate state on its complex mass shells. Distribution functions agree with those resulting from the model's Euclidean space double distribution which we calculate via nondiagonal matrix elements of twist-two operators. Thus one can use a wide class of analytic parametrizations of the quark propagator to connect Euclidean space Green functions to light-cone dominated amplitudes

  8. PET regularization by envelope guided conjugate gradients

    Kaufman, L.; Neumaier, A.

    1996-01-01

    The authors propose a new way to iteratively solve large scale ill-posed problems and in particular the image reconstruction problem in positron emission tomography by exploiting the relation between Tikhonov regularization and multiobjective optimization to obtain iteratively approximations to the Tikhonov L-curve and its corner. Monitoring the change of the approximate L-curves allows us to adjust the regularization parameter adaptively during a preconditioned conjugate gradient iteration, so that the desired solution can be reconstructed with a small number of iterations

  9. Rhenium 188 labelling of peptide conjugates

    Melendez-Alafort, Laura

    2001-01-01

    Many human tumours express high levels, of somatostatin receptors. In order to make possible a radiotherapeutic treatment of this kind for tumour a series of somatostatin analogues that can tightly chelate beta emitting isotopes have been developed in recent years. The work carried out for this thesis has been aimed towards development of a new therapeutic radiopharmaceutical for treatment of somatostatin receptor positive tumours. The first chapters describe work with technetium-99m to establish the labelling and analytical conditions for a somatostatin analogue, [Tyr 3 ]-octreotide (TOC), as a precursor to undertaking labelling studies with the beta emitter rhenium-188. 6-Hydrazinopyridine-3-carboxylic acid (HYNIC) was conjugated to TOC and labelled with 99m using different coligands. Then the stability, receptor binding and biodistribution of each complex were assessed. 99m Tc-HYNIC-TOC using EDDA as coligand showed the best characteristics, and was superior for tumour imaging in humans than the commercially available 111 In-DTPA-octreotide. The conditions for labelling the HYNIC-TOC conjugate with 188 Re were then optimised using tricine as a co-ligand. A labelling yield of ∼80% was achieved. After purification however, the stability of the complex was low. The use of other coligand systems which had proved useful for 99m Tc labelling was explored, but yields were very poor. Other chelators such as diethylenetriamine pentaacetic acid (DTPA), dimercaptosuccinic acid (DMSA) and mercaptoacetyltriglycine (MAG 3 ) were studied as potential co-ligand agents to label the HYNIC-TOC conjugate with 188 Re but, again low yields of the labelled peptide complexes were achieved. A novel 188 Re-HYNIC complex was prepared in high yields using N-N-disubstituted dithiocarbamates as coligands. However to date, the specific activities achieved with this system are relatively low. The use of the [ 99m Tc(CO) 3 (H 2 O) 3 ] complex to label the HYNIC-TOC conjugate was investigated

  10. Asymmetric strand segregation: epigenetic costs of genetic fidelity?

    Diane P Genereux

    2009-06-01

    Full Text Available Asymmetric strand segregation has been proposed as a mechanism to minimize effective mutation rates in epithelial tissues. Under asymmetric strand segregation, the double-stranded molecule that contains the oldest DNA strand is preferentially targeted to the somatic stem cell after each round of DNA replication. This oldest DNA strand is expected to have fewer errors than younger strands because some of the errors that arise on daughter strands during their synthesis fail to be repaired. Empirical findings suggest the possibility of asymmetric strand segregation in a subset of mammalian cell lineages, indicating that it may indeed function to increase genetic fidelity. However, the implications of asymmetric strand segregation for the fidelity of epigenetic information remain unexplored. Here, I explore the impact of strand-segregation dynamics on epigenetic fidelity using a mathematical-modelling approach that draws on the known molecular mechanisms of DNA methylation and existing rate estimates from empirical methylation data. I find that, for a wide range of starting methylation densities, asymmetric -- but not symmetric -- strand segregation leads to systematic increases in methylation levels if parent strands are subject to de novo methylation events. I found that epigenetic fidelity can be compromised when enhanced genetic fidelity is achieved through asymmetric strand segregation. Strand segregation dynamics could thus explain the increased DNA methylation densities that are observed in structured cellular populations during aging and in disease.

  11. The chiral Gaussian two-matrix ensemble of real asymmetric matrices

    Akemann, G; Phillips, M J; Sommers, H-J

    2010-01-01

    We solve a family of Gaussian two-matrix models with rectangular N x (N + ν) matrices, having real asymmetric matrix elements and depending on a non-Hermiticity parameter μ. Our model can be thought of as the chiral extension of the real Ginibre ensemble, relevant for Dirac operators in the same symmetry class. It has the property that its eigenvalues are either real, purely imaginary or come in complex conjugate eigenvalue pairs. The eigenvalue joint probability distribution for our model is explicitly computed, leading to a non-Gaussian distribution including K-Bessel functions. All n-point density correlation functions are expressed for finite N in terms of a Pfaffian form. This contains a kernel involving Laguerre polynomials in the complex plane as a building block which was previously computed by the authors. This kernel can be expressed in terms of the kernel for complex non-Hermitian matrices, generalizing the known relation among ensembles of Hermitian random matrices. Compact expressions are given for the density at finite N as an example, as well as its microscopic large-N limits at the origin for fixed ν at strong and weak non-Hermiticity.

  12. Acoustic interactions between inversion symmetric and asymmetric two-level systems

    Churkin, A; Schechter, M; Barash, D

    2014-01-01

    Amorphous solids, as well as many disordered lattices, display remarkable universality in their low temperature acoustic properties. This universality is attributed to the attenuation of phonons by tunneling two-level systems (TLSs), facilitated by the interaction of the TLSs with the phonon field. TLS-phonon interaction also mediates effective TLS–TLS interactions, which dictates the existence of a glassy phase and its low energy properties. Here we consider KBr:CN, the archetypal disordered lattice showing universality. We calculate numerically, using conjugate gradients method, the effective TLS–TLS interactions for inversion symmetric (CN flips) and asymmetric (CN rotations) TLSs, in the absence and presence of disorder, in two and three dimensions. The observed dependence of the magnitude and spatial power law of the interaction on TLS symmetry, and its change with disorder, characterizes TLS–TLS interactions in disordered lattices in both extreme and moderate dilutions. Our results are in good agreement with the two-TLS model, recently introduced to explain long-standing questions regarding the quantitative universality of phonon attenuation and the energy scale of ≈1–3 K below which universality is observed. (paper)

  13. Enantiopure N-Acyldihydropyridones as Synthetic Intermediates: Asymmetric Synthesis of (-)-Septicine and (-)-Tylophorine.

    Comins, Daniel L.; Chen, Xinghai; Morgan, Lawrence A.

    1997-10-17

    A concise asymmetric synthesis of (-)-septicine (1) and (-)-tylophorine (2) was accomplished with a high degree of stereocontrol in eight and nine steps, respectively. Addition of 4-(1-butenyl)magnesium bromide to 1-acylpyridinium salt 3, prepared in situ from 4-methoxy-3-(triisopropylsilyl)pyridine and the chloroformate of (-)-trans-2-(alpha-cumyl)cyclohexanol, gave a 91% yield of diastereomerically pure dihydropyridone 7. Oxidative cleavage of 7 and subsequent reduction provided alcohol 6 in 81% yield. Conversion of 6 to the chloride followed by treatment with sodium methoxide gave indolizidinone 9 in high yield. Bromination and conjugate reduction of 9 with L-Selectride, and trapping the intermediate enolate with N-(5-chloro-2-pyridyl)triflimide, provided bromovinyl triflate 11. Palladium-catalyzed cross-coupling of excess (3,4-dimethoxyphenyl)zinc bromide and 11 gave (-)-septicine (1). On the basis of this synthesis, (-)-1 was assigned the Rconfiguration. Reaction of 1 with vanadium(V) trifluoride oxide in TFA/CH(2)Cl(2) effected oxidative coupling to give a 68% yield of (-)-tylophorine (2).

  14. Orientation- and position-controlled alignment of asymmetric silicon microrod on a substrate with asymmetric electrodes

    Shibata, Akihide; Watanabe, Keiji; Sato, Takuya; Kotaki, Hiroshi; Schuele, Paul J.; Crowder, Mark A.; Zhan, Changqing; Hartzell, John W.; Nakatani, Ryoichi

    2014-03-01

    In this paper, we demonstrate the orientation-controlled alignment of asymmetric Si microrods on a glass substrate with an asymmetric pair of electrodes. The Si microrods have the shape of a paddle with a blade and a shaft part, and the pair of electrodes consists of a narrow electrode and a wide electrode. By applying AC bias to the electrodes, the Si microrods suspended in a fluid align in such a way to settle across the electrode pair, and over 80% of the aligned Si microrods have an orientation with the blade and the shaft of the paddle on the wide and the narrow electrodes, respectively. When Si microrods have a shell of dielectric film and its thickness on the top face is thicker than that on the bottom face, 97.8% of the Si microrods are aligned with the top face facing upwards. This technique is useful for orientation-controlled alignment of nano- and microsized devices that have polarity or a distinction between the top and bottom faces.

  15. Asymmetric Facial Bone Fragmentation Mirrors Asymmetric Distribution of Cranial Neuromasts in Blind Mexican Cavefish

    Joshua B. Gross

    2016-10-01

    Full Text Available Craniofacial asymmetry is a convergent trait widely distributed across animals that colonize the extreme cave environment. Although craniofacial asymmetry can be discerned easily, other complex phenotypes (such as sensory organ position and numerical variation are challenging to score and compare. Certain bones of the craniofacial complex demonstrate substantial asymmetry, and co-localize to regions harboring dramatically expanded numbers of mechanosensory neuromasts. To determine if a relationship exists between this expansion and bone fragmentation in cavefish, we developed a quantitative measure of positional symmetry across the left-right axis. We found that three different cave-dwelling populations were significantly more asymmetric compared to surface-dwelling fish. Moreover, cave populations did not differ in the degree of neuromast asymmetry. This work establishes a method for quantifying symmetry of a complex phenotype, and demonstrates that facial bone fragmentation mirrors the asymmetric distribution of neuromasts in different cavefish populations. Further developmental studies will provide a clearer picture of the developmental and cellular changes that accompany this extreme phenotype, and help illuminate the genetic basis for facial asymmetry in vertebrates.

  16. In Vitro Evaluation of Third Generation PAMAM Dendrimer Conjugates

    Mohammad Najlah

    2017-10-01

    Full Text Available The present study compares the use of high generation G3 and low generation G0 Polyamidoamine (PAMAM dendrimers as drug carriers of naproxen (NAP, a poorly water soluble drug. Naproxen was conjugated to G3 in different ratios and to G0 in a 1:1 ratio via a diethylene glycol linker. A lauroyl chain (L, a lipophilic permeability enhancer, was attached to G3 and G0 prodrugs. The G3 and G0 conjugates were more hydrophilic than naproxen as evaluated by the measurement of partitioning between 1-octanol and a phosphate buffer at pH 7.4 and pH 1.2. The unmodified surface PAMAM-NAP conjugates showed significant solubility enhancements of NAP at pH 1.2; however, with the number of NAP conjugated to G3, this was limited to 10 molecules. The lactate dehydrogenase (LDH assay indicated that the G3 dendrimer conjugates had a concentration dependent toxicity towards Caco-2 cells. Attaching naproxen to the surface of the dendrimer increased the IC50 of the resulting prodrugs towards Caco-2 cells. The lauroyl G3 conjugates showed the highest toxicity amongst the PAMAM dendrimer conjugates investigated and were significantly more toxic than the lauroyl-G0-naproxen conjugates. The permeability of naproxen across monolayers of Caco-2 cells was significantly increased by its conjugation to either G3 or G0 PAMAM dendrimers. Lauroyl-G0 conjugates displayed considerably lower cytotoxicity than G3 conjugates and may be preferable for use as a drug carrier for low soluble drugs such as naproxen.

  17. Chilly dark sectors and asymmetric reheating

    Adshead, Peter; Cui, Yanou; Shelton, Jessie

    2016-01-01

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N eff , we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  18. Chilly dark sectors and asymmetric reheating

    Adshead, Peter [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, IL 61801 (United States); Cui, Yanou [Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2L 2Y5 (Canada); Maryland Center for Fundamental Physics, University of Maryland,College Park, MD 20742 (United States); Shelton, Jessie [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, IL 61801 (United States)

    2016-06-06

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N{sub eff}, we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  19. Asymmetric inhibitory treatment effects in multilingual aphasia.

    Goral, Mira; Naghibolhosseini, Maryam; Conner, Peggy S

    2013-01-01

    Findings from recent psycholinguistic studies of bilingual processing support the hypothesis that both languages of a bilingual are always active and that bilinguals continually engage in processes of language selection. This view aligns with the convergence hypothesis of bilingual language representation. Furthermore, it is hypothesized that when bilinguals perform a task in one language they need to inhibit their other, nontarget language(s) and that stronger inhibition is required when the task is performed in the weaker language than in the stronger one. The study of multilingual individuals who acquire aphasia resulting from a focal brain lesion offers a unique opportunity to test the convergence hypothesis and the inhibition asymmetry. We report on a trilingual person with chronic nonfluent aphasia who at the time of testing demonstrated greater impairment in her first acquired language (Persian) than in her third, later learned language (English). She received treatment in English followed by treatment in Persian. An examination of her connected language production revealed improvement in her grammatical skills in each language following intervention in that language, but decreased grammatical accuracy in English following treatment in Persian. The increased error rate was evident in structures that are used differently in the two languages (e.g., auxiliary verbs). The results support the prediction that greater inhibition is applied to the stronger language than to the weaker language, regardless of their age of acquisition. We interpret the findings as consistent with convergence theories that posit overlapping neuronal representation and simultaneous activation of multiple languages and with proficiency-dependent asymmetric inhibition in multilinguals.

  20. Chilly dark sectors and asymmetric reheating

    Adshead, Peter; Cui, Yanou; Shelton, Jessie

    2016-06-01

    In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model (SM). We point out that these theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? Motivated in part by the difficulty of accommodating large amounts of entropy carried in dark radiation with cosmic microwave background measurements of the effective number of relativistic species at recombination, N eff , we aim to establish which admissible cosmological histories can populate a thermal dark sector that never reaches thermal equilibrium with the SM. The minimal cosmological origin for such a dark sector is asymmetric reheating, when the same mechanism that populates the SM in the early universe also populates the dark sector at a lower temperature. Here we demonstrate that the resulting inevitable inflaton-mediated scattering between the dark sector and the SM can wash out a would-be temperature asymmetry, and establish the regions of parameter space where temperature asymmetries can be generated in minimal reheating scenarios. Thus obtaining a temperature asymmetry of a given size either restricts possible inflaton masses and couplings or necessitates a non-minimal cosmology for one or both sectors. As a side benefit, we develop techniques for evaluating collision terms in the relativistic Boltzmann equation when the full dependence on Bose-Einstein or Fermi-Dirac phase space distributions must be retained, and present several new results on relativistic thermal averages in an appendix.

  1. Asymmetric Planetary Nebulae VI: the conference summary

    De Marco, O.

    2014-04-01

    The Asymmetric Planetary Nebulae conference series, now in its sixth edition, aims to resolve the shaping mechanism of PN. Eighty percent of PN have non spherical shapes and during this conference the last nails in the coffin of single stars models for non spherical PN have been put. Binary theories abound but observational tests are lagging. The highlight of APN6 has been the arrival of ALMA which allowed us to measure magnetic fields on AGB stars systematically. AGB star halos, with their spiral patterns are now connected to PPN and PN halos. New models give us hope that binary parameters may be decoded from these images. In the post-AGB and pre-PN evolutionary phase the naked post-AGB stars present us with an increasingly curious puzzle as complexity is added to the phenomenologies of objects in transition between the AGB and the central star regimes. Binary central stars continue to be detected, including the first detection of longer period binaries, however a binary fraction is still at large. Hydro models of binary interactions still fail to give us results, if we make an exception for the wider types of binary interactions. More promise is shown by analytical considerations and models driven by simpler, 1D simulations such as those carried out with the code MESA. Large community efforts have given us more homogeneous datasets which will yield results for years to come. Examples are the ChanPlaN and HerPlaNe collaborations that have been working with the Chandra and Herschel space telescopes, respectively. Finally, the new kid in town is the intermediate-luminosity optical transient, a new class of events that may have contributed to forming several peculiar PN and pre-PN.

  2. Asymmetric explosion of core-collapse supernovae

    Kazeroni, Remi

    2016-01-01

    A core-collapse supernova represents the ultimate stage of the evolution of massive stars.The iron core contraction may be followed by a gigantic explosion which gives birth to a neutron star.The multidimensional dynamics of the innermost region, during the first hundreds milliseconds, plays a decisive role on the explosion success because hydrodynamical instabilities are able to break the spherical symmetry of the collapse. Large scale transverse motions generated by two instabilities, the neutrino-driven convection and the Standing Accretion Shock Instability (SASI),increase the heating efficiency up to the point of launching an asymmetric explosion and influencing the birth properties of the neutron star. In this thesis, hydrodynamical instabilities are studied using numerical simulations of simplified models. These models enable a wide exploration of the parameter space and a better physical understanding of the instabilities, generally inaccessible to realistic models.The non-linear regime of SASI is analysed to characterize the conditions under which a spiral mode prevails and to assess its ability to redistribute angular momentum radially.The influence of rotation on the shock dynamics is also addressed. For fast enough rotation rates, a corotation instability overlaps with SASI and greatly impacts the dynamics. The simulations enable to better constrain the effect of non-axisymmetric modes on the angular momentum budget of the iron core collapsing into a neutron star. SASI may under specific conditions spin up or down the pulsar born during the explosion. Finally, an idealised model of the heating region is studied to characterize the non-linear onset of convection by perturbations such as those produced by SASI or pre-collapse combustion inhomogeneities. The dimensionality issue is examined to stress the beneficial consequences of the three-dimensional dynamics on the onset of the explosion. (author) [fr

  3. Affective privilege: Asymmetric interference by emotional distracters

    Crystal eReeck

    2011-09-01

    Full Text Available Numerous theories posit that affectively salient stimuli are privileged in their capacity to capture attention and disrupt ongoing cognition. Two underlying assumptions in this theoretical position are that the potency of affective stimuli transcends task boundaries (i.e., emotional distracters do not have to belong to a current task-set to disrupt processing and that there is an asymmetry between emotional and cognitive processing (i.e., emotional distracters disrupt cognitive processing, but not vice versa. These assumptions have remained largely untested, as common experimental probes of emotion-cognition interaction rarely manipulate task-relevance and only examine one side of the presumed asymmetry of interference. To test these propositions directly, a face-word Stroop protocol was adapted to independently manipulate (a the congruency between target and distracter stimulus features, (b the affective salience of distracter features, and (c the task-relevance of emotional compared to non-emotional target features. A three-way interaction revealed interdependent effects of distracter relevance, congruence, and affective salience. Compared to task-irrelevant distracters, task-relevant congruent distracters facilitated performance and task-relevant incongruent distracters impaired performance, but the latter effect depended on the nature of the target feature and task. Specifically, task-irrelevant emotional distracters resulted in equivalent performance costs as task-relevant non-emotional distracters, whereas task-irrelevant non-emotional distracters did not produce performance costs comparable to those generated by task-relevant emotional distracters. These results document asymmetric cross-task interference effects for affectively salient stimuli, supporting the notion of affective prioritization in human information processing.

  4. Asymmetric Dimethyl Arginine in Hypothyroid Patients

    Abdel-Messeih, P.L.

    2012-01-01

    Thyroid diseases may lead to endothelial dysfunction, however, the mechanism underlying the endothelial dysfunction in thyroid disease is still not clear. Asymmetric dimethyl arginine (ADMA), a novel inhibitor of endothelial nitric oxide synthetase (eNOS), was reported to inhibit nitric oxide (NO) synthesis from L-arginine. The present study was carried out to investigate ADMA levels together with effects of dislipidemia in sub-clinical and overt hypothyroid females. There were significant increase in the levels of total cholesterol, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein-cholesterol (HDL-c), thyroid stimulating hormone (TSH) and ADMA in hypothyroid females as compared to controls while the levels of NO and free T 4 were significantly decreased than controls. Sub-clinical hypothyroid females had significant high TSH, LDL-c and non-significantly high ADMA levels and total cholesterol as compared to controls while they had significant decrease in NO, HDL-c and non-significant decrease in free T 4 as compared to controls. There were significant negative correlations between NO and both ADMA (r 2 = 0.84) and free T 4 (r 2 = 0.95) in overt hypothyroid group while significant positive correlation (r 2 = 0.85) was detected between TSH and HDL-c in the same group. These results are highly suggestive that the decrease of nitric oxide secondary to accumulation of ADMA represent an important pathogenic factor together with dyslipidemia in endothelial dysfunction and increased cardiovascular risk especially in hypothyroid females

  5. Asymmetric Dimethyl Arginine in Hypothyroid Patients

    Abdel-Messeih, P. L. [Health Radiation Research Department, National Centre for Radiation Research and Technology, Cairo (Egypt)

    2012-07-01

    Thyroid diseases may lead to endothelial dysfunction, however, the mechanism underlying the endothelial dysfunction in thyroid disease is still not clear. Asymmetric dimethyl arginine (ADMA), a novel inhibitor of endothelial nitric oxide synthetase (eNOS), was reported to inhibit nitric oxide (NO) synthesis from L-arginine. The present study was carried out to investigate ADMA levels together with effects of dislipidemia in sub-clinical and overt hypothyroid females. There were significant increase in the levels of total cholesterol, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein-cholesterol (HDL-c), thyroid stimulating hormone (TSH) and ADMA in hypothyroid females as compared to controls while the levels of NO and free T{sub 4} were significantly decreased than controls. Sub-clinical hypothyroid females had significant high TSH, LDL-c and non-significantly high ADMA levels and total cholesterol as compared to controls while they had significant decrease in NO, HDL-c and non-significant decrease in free T{sub 4} as compared to controls. There were significant negative correlations between NO and both ADMA (r{sup 2} = 0.84) and free T{sub 4} (r{sup 2} = 0.95) in overt hypothyroid group while significant positive correlation (r{sup 2} = 0.85) was detected between TSH and HDL-c in the same group. These results are highly suggestive that the decrease of nitric oxide secondary to accumulation of ADMA represent an important pathogenic factor together with dyslipidemia in endothelial dysfunction and increased cardiovascular risk especially in hypothyroid females.

  6. Antibody-Conjugated Nanoparticles for Biomedical Applications

    Manuel Arruebo

    2009-01-01

    Full Text Available Nanoscience and Nanotechnology have found their way into the fields of Biotechnology and Medicine. Nanoparticles by themselves offer specific physicochemical properties that they do not exhibit in bulk form, where materials show constant physical properties regardless of size. Antibodies are nanosize biological products that are part of the specific immune system. In addition to their own properties as pathogens or toxin neutralizers, as well as in the recruitment of immune elements (complement, improving phagocytosis, cytotoxicity antibody dependent by natural killer cells, etc., they could carry several elements (toxins, drugs, fluorochroms, or even nanoparticles, etc. and be used in several diagnostic procedures, or even in therapy to destroy a specific target. The conjugation of antibodies to nanoparticles can generate a product that combines the properties of both. For example, they can combine the small size of nanoparticles and their special thermal, imaging, drug carrier, or magnetic characteristics with the abilities of antibodies, such as specific and selective recognition. The hybrid product will show versatility and specificity. In this review, we analyse both antibodies and nanoparticles, focusing especially on the recent developments for antibody-conjugated nanoparticles, offering the researcher an overview of the different applications and possibilities of these hybrid carriers.

  7. π-Clamp-mediated cysteine conjugation

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  8. The multigrid preconditioned conjugate gradient method

    Tatebe, Osamu

    1993-01-01

    A multigrid preconditioned conjugate gradient method (MGCG method), which uses the multigrid method as a preconditioner of the PCG method, is proposed. The multigrid method has inherent high parallelism and improves convergence of long wavelength components, which is important in iterative methods. By using this method as a preconditioner of the PCG method, an efficient method with high parallelism and fast convergence is obtained. First, it is considered a necessary condition of the multigrid preconditioner in order to satisfy requirements of a preconditioner of the PCG method. Next numerical experiments show a behavior of the MGCG method and that the MGCG method is superior to both the ICCG method and the multigrid method in point of fast convergence and high parallelism. This fast convergence is understood in terms of the eigenvalue analysis of the preconditioned matrix. From this observation of the multigrid preconditioner, it is realized that the MGCG method converges in very few iterations and the multigrid preconditioner is a desirable preconditioner of the conjugate gradient method.

  9. Preparation and biodistribution study of 99Tcm labelled dextran conjugates

    Yang Chunhui; Li Hongyu; Liang Jixin; Lu Jia; Luo Hongyi; Zheng Deqiang; Sun Guiquan

    2012-01-01

    99 Tc m Mannosylated dextran conjugates were prepared through [ 99 Tc m (CO) 3 ] + precursor synthesized by carbonyl Isolink kit. The labelled conjugates were injected sub-dermally into the rear foots of the mice, and the patent blue solution was injected at the same site 10 min before sacrifice. The mice were killed at 1 h and 4 h postinjection, and the samples of different tissues including SLN, 2LN, injection site, liver, spleen, blood were dissected and counted. The uptake in terms was calculated. The results of biodistribution demonstrated that the SLN uptakes of radiopharmaceutical (without mannose in the molecules) were rather low and in vivo excretion of these conjugates were comparatively faster, and the uptake of injection site was also low; on the other hand, the SLN uptakes of radio pharmaceutical (with mannose in their molecules) were much higher than those of their corresponding dextran conjugates without mannose, but the retention in the injection site of these conjugates increased too. The results indicated that the affinity of mannosyl-dextran conjugates to the receptors on the surface of macrophages in the lymph node. In addition, the different relative molecular mass of dextran conjugates also cause different biodistribution results, the major one had higher SLN uptake, the difference was significant (P 99 Tc m (CO) 3 ] + labelled mannosylated dextran conjugates showed promising properties as SLN imaging agent and worth further investigation. (authors)

  10. PREPARATION OF CHEMICALLY WELL-DEFINED CARBOHYDRATE DENDRIMER CONJUGATES

    2004-01-01

    A method for the synthesis of dendrimer conjugates having a well-defined chemical structure, comprising one or more carbohydrate moieties and one or more immunomodulating substances coupled to a dendrimer, is presented. First, the carbohydrate is bound to the dendrimer in a chemoselective manner...... conjugates and their use in vaccination, production of antibodies, high throughput screening, diagnostic assays and libraries....

  11. Cross-conjugation and quantum interference: a general correlation?

    Valkenier, Hennie; Guedon, Constant M.; Markussen, Troels

    2014-01-01

    We discuss the relationship between the pi-conjugation pattern, molecular length, and charge transport properties of molecular wires, both from an experimental and a theoretical viewpoint. Specifically, we focus on the role of quantum interference in the conductance properties of cross-conjugated...

  12. The Synthesis of Substituted Piperazine-cholesterol Conjugates for ...

    A small library of cholesterol-piperazine conjugates were synthesized by the reaction of cholesteryl chloroformate with a set of substituted piperazines in dichloromethane at room temperature. The conjugates, all obtained in good to excellent yields, were synthesized to be key components of nucleic acid transfection ...

  13. New preconditioned conjugate gradient algorithms for nonlinear unconstrained optimization problems

    Al-Bayati, A.; Al-Asadi, N.

    1997-01-01

    This paper presents two new predilection conjugate gradient algorithms for nonlinear unconstrained optimization problems and examines their computational performance. Computational experience shows that the new proposed algorithms generally imp lone the efficiency of Nazareth's [13] preconditioned conjugate gradient algorithm. (authors). 16 refs., 1 tab

  14. Preparation and characterization of microspheres of albumin-heparin conjugates

    Kwon, Glen S.; Bae, You Han; Kim, Sung Wan; Cremers, Harry; Cremers, H.F.M.; Feijen, Jan

    1991-01-01

    Albumin-heparin microspheres have been prepared as a new drug carrier. A soluble albumin-heparin conjugate was synthesized by forming amide bonds between human serum albumin and heparin. After purification the albumin-heparin conjugate was crosslinked in a water-in-oil emulsion to form

  15. Parallel coupling of symmetric and asymmetric exclusion processes

    Tsekouras, K; Kolomeisky, A B

    2008-01-01

    A system consisting of two parallel coupled channels where particles in one of them follow the rules of totally asymmetric exclusion processes (TASEP) and in another one move as in symmetric simple exclusion processes (SSEP) is investigated theoretically. Particles interact with each other via hard-core exclusion potential, and in the asymmetric channel they can only hop in one direction, while on the symmetric lattice particles jump in both directions with equal probabilities. Inter-channel transitions are also allowed at every site of both lattices. Stationary state properties of the system are solved exactly in the limit of strong couplings between the channels. It is shown that strong symmetric couplings between totally asymmetric and symmetric channels lead to an effective partially asymmetric simple exclusion process (PASEP) and properties of both channels become almost identical. However, strong asymmetric couplings between symmetric and asymmetric channels yield an effective TASEP with nonzero particle flux in the asymmetric channel and zero flux on the symmetric lattice. For intermediate strength of couplings between the lattices a vertical-cluster mean-field method is developed. This approximate approach treats exactly particle dynamics during the vertical transitions between the channels and it neglects the correlations along the channels. Our calculations show that in all cases there are three stationary phases defined by particle dynamics at entrances, at exits or in the bulk of the system, while phase boundaries depend on the strength and symmetry of couplings between the channels. Extensive Monte Carlo computer simulations strongly support our theoretical predictions. Theoretical calculations and computer simulations predict that inter-channel couplings have a strong effect on stationary properties. It is also argued that our results might be relevant for understanding multi-particle dynamics of motor proteins

  16. Enhanced photodynamic efficacy of zinc phthalocyanine by conjugating to heptalysine.

    Li, Linsen; Luo, Zhipu; Chen, Zhuo; Chen, Jincan; Zhou, Shanyong; Xu, Peng; Hu, Ping; Wang, Jundong; Chen, Naisheng; Huang, Jinling; Huang, Mingdong

    2012-11-21

    Zinc phthalocyanine (ZnPc) is a promising photosensitizer for photodynamic therapy, but faces some challenges: ZnPc is insoluble in water and thus requires either special formulation of ZnPc by, e.g., liposome or Cremophor EL, or chemical modification of Pc ring to enhance its bioavailability and photodynamic efficacy. Here, we conjugated monosubstituted ZnPc-COOH with a series of oligolysine moieties with different numbers of lysine residues (ZnPc-(Lys)(n) (n = 1, 3, 5, 7, 9) to improve the water solubility of the ZnPc conjugates. We measured the photosensitizing efficacies and the cellular uptakes of this series of conjugates on a normal and a cancerous cell line. In addition, we developed a sensitive in situ method to distinguish the difference in photodynamic efficacy among conjugates. Our results showed that ZnPc-(Lys)(7) has the highest photodynamic efficacy compared to the other conjugates investigated.

  17. Effects of clofibric acid on the biliary excretion of benoxaprofen glucuronide and taurine conjugate in rats.

    Okada, K; Kanoh, H; Mohri, K

    2011-10-01

    Benoxaprofen (BOP) is a 2-methyl propionic acid derivative with anti-inflammatory activity. BOP has an asymmetric carbon, and receives chiral inversion from R to S in vivo. BOP is metabolized to glucuronide (BOP-G) and taurine conjugate (BOP-T). The configuration of BOP-G is mainly S, and that of BOP-T is R. Chiral inversion of R to S of the propionic acid moiety and amino acid conjugation of carboxyl compounds proceed via an acyl CoA intermediate. It is known that fibrates, used in hyperlipidemia, induce acyl CoA synthetase and increase CoA concentration. We administered racemic BOP (10 mg/kg body weight) to rats (CFA+) pre-administered clofibric acid (CFA, 280 mg/kg/day), and studied BOP, BOP-G, and BOP-T enantiomer concentrations in plasma and bile up to 12 h after administration. The findings were compared with those in rats (CFA-) that had not received CFA. Furthermore, we studied the amounts of BOP-G enantiomer produced by glucuronidation in vitro using microsomes pretreated with CFA. The amounts of (S)-BOP-G in CFA+ rats were 2.7-fold larger than that in CFA- rats. Although (R)-BOP-T was excreted in CFA- rats, BOP-T could not be detected in CFA+ rats. Plasma clearance values of racemic BOP and (S)-BOP in CFA+ rats were 5-fold and 6-fold larger than those in CFA- rats, respectively. (S)-BOP-G formation activities were higher than (R)-BOP-G formation activities in both CFA+and CFA- microsomes. These findings suggest that CFA increases biliary excretion of (S)-BOP-G and facilitates plasma elimination of BOP, and further suggests that CFA predominantly induces chiral inversion to S rather than metabolic reaction to (R)-BOP-T, resulting in an increase of (S)-BOP-G.

  18. Asymmetrical reinforcement and Wolbachia infection in Drosophila.

    John Jaenike

    2006-10-01

    Full Text Available Reinforcement refers to the evolution of increased mating discrimination against heterospecific individuals in zones of geographic overlap and can be considered a final stage in the speciation process. One the factors that may affect reinforcement is the degree to which hybrid matings result in the permanent loss of genes from a species' gene pool. Matings between females of Drosophila subquinaria and males of D. recens result in high levels of offspring mortality, due to interspecific cytoplasmic incompatibility caused by Wolbachia infection of D. recens. Such hybrid inviability is not manifested in matings between D. recens females and D. subquinaria males. Here we ask whether the asymmetrical hybrid inviability is associated with a corresponding asymmetry in the level of reinforcement. The geographic ranges of D. recens and D. subquinaria were found to overlap across a broad belt of boreal forest in central Canada. Females of D. subquinaria from the zone of sympatry exhibit much stronger levels of discrimination against males of D. recens than do females from allopatric populations. In contrast, such reproductive character displacement is not evident in D. recens, consistent with the expected effects of unidirectional cytoplasmic incompatibility. Furthermore, there is substantial behavioral isolation within D. subquinaria, because females from populations sympatric with D. recens discriminate against allopatric conspecific males, whereas females from populations allopatric with D. recens show no discrimination against any conspecific males. Patterns of general genetic differentiation among populations are not consistent with patterns of behavioral discrimination, which suggests that the behavioral isolation within D. subquinaria results from selection against mating with Wolbachia-infected D. recens. Interspecific cytoplasmic incompatibility may contribute not only to post-mating isolation, an effect already widely recognized, but also to

  19. Human glutathione S-transferase-mediated glutathione conjugation of curcumin and efflux of these conjugates in caco-2 cells

    Usta, M.; Wortelboer, H.M.; Vervoort, J.; Boersma, M.G.; Rietjens, I.M.C.M.; Bladeren, P.J. van; Cnubben, N.H.P.

    2007-01-01

    Curcumin, an α,β-unsaturated carbonyl compound, reacts with glutathione, leading to the formation of two monoglutathionyl curcumin conjugates. In the present study, the structures of both glutathione conjugates of curcumin were identified by LC-MS and one- and two-dimensional 1H NMR analysis, and

  20. Human glutathione S-transferase-mediated glutathione conjugation of curcumin and efflux of these conjugates in Caco-2 cells

    Usta, M.; Wortelboer, H.M.; Vervoort, J.J.M.; Boersma, M.G.; Rietjens, I.M.C.M.; Bladeren, van P.J.; Cnubben, N.H.P.

    2007-01-01

    Curcumin, an alpha,beta-unsaturated carbonyl compound, reacts with glutathione, leading to the formation of two monoglutathionyl curcumin conjugates. In the present study, the structures of both glutathione conjugates of curcumin were identified by LC-MS and one- and two-dimensional H-1 NMR

  1. Are conjugated linolenic acid isomers an alternative to conjugated linoleic acid isomers in obesity prevention?

    Miranda, Jonatan; Arias, Noemi; Fernández-Quintela, Alfredo; del Puy Portillo, María

    2014-04-01

    Despite its benefits, conjugated linoleic acid (CLA) may cause side effects after long-term administration. Because of this and the controversial efficacy of CLA in humans, alternative biomolecules that may be used as functional ingredients have been studied in recent years. Thus, conjugated linolenic acid (CLNA) has been reported to be a potential anti-obesity molecule which may have additional positive effects related to obesity. According to the results reported in obesity, CLNA needs to be given at higher doses than CLA to be effective. However, because of the few studies conducted so far, it is still difficult to reach clear conclusions about the potential use of these CLNAs in obesity and its related changes (insulin resistance, dyslipidemia, or inflammation). Copyright © 2012 SEEN. Published by Elsevier Espana. All rights reserved.

  2. Performance of JPEG Image Transmission Using Proposed Asymmetric Turbo Code

    Siddiqi Mohammad Umar

    2007-01-01

    Full Text Available This paper gives the results of a simulation study on the performance of JPEG image transmission over AWGN and Rayleigh fading channels using typical and proposed asymmetric turbo codes for error control coding. The baseline JPEG algorithm is used to compress a QCIF ( "Suzie" image. The recursive systematic convolutional (RSC encoder with generator polynomials , that is, (13/11 in decimal, and 3G interleaver are used for the typical WCDMA and CDMA2000 turbo codes. The proposed asymmetric turbo code uses generator polynomials , that is, (13/11; 13/9 in decimal, and a code-matched interleaver. The effect of interleaver in the proposed asymmetric turbo code is studied using weight distribution and simulation. The simulation results and performance bound for proposed asymmetric turbo code for the frame length , code rate with Log-MAP decoder over AWGN channel are compared with the typical system. From the simulation results, it is observed that the image transmission using proposed asymmetric turbo code performs better than that with the typical system.

  3. Success Factors of Asymmetric Connections - Example of Large Slovenian Enterprises

    Viktor Vračar

    2014-11-01

    Full Text Available More and more companies realize the fact that networking or partner collaborations, which are based on partner relations between companies, are essential for their long-term existence. In today’s global competitive environment each company is included at least in some different connections. Very common connections occur between large and smaller enterprises, where the so called asymmetric connections occur, which may be understood as the ability of one organisation to establish power, influence and control over the other organisation and its resources. According to numerous statements, the connections between enterprises are very frequently uneffectivenessful, with opinions on the optimal nature of asymmetric connections being quite common as well, whereby it is, as a rule, a synergic complementing of missing content for both partners. To verify the thesis, that companies achieve more competitiveness and effectiveness through connections, whereby the so called asymmetric connections are common, a structural model of the evolution of asymmetric connection has been developed, which connects the theoretically identified factors and all dependent concepts of competitiveness, efficiency and effectiveness. The empirical research also attempts to further expose the factors of asymmetric connections, which affect efficiency and effectiveness of the connected enterprises.

  4. Time-Dependent-Asymmetric-Linear-Parsimonious Ancestral State Reconstruction.

    Didier, Gilles

    2017-10-01

    The time-dependent-asymmetric-linear parsimony is an ancestral state reconstruction method which extends the standard linear parsimony (a.k.a. Wagner parsimony) approach by taking into account both branch lengths and asymmetric evolutionary costs for reconstructing quantitative characters (asymmetric costs amount to assuming an evolutionary trend toward the direction with the lowest cost). A formal study of the influence of the asymmetry parameter shows that the time-dependent-asymmetric-linear parsimony infers states which are all taken among the known states, except for some degenerate cases corresponding to special values of the asymmetry parameter. This remarkable property holds in particular for the Wagner parsimony. This study leads to a polynomial algorithm which determines, and provides a compact representation of, the parametric reconstruction of a phylogenetic tree, that is for all the unknown nodes, the set of all the possible reconstructed states associated with the asymmetry parameters leading to them. The time-dependent-asymmetric-linear parsimony is finally illustrated with the parametric reconstruction of the body size of cetaceans.

  5. Conjugate Heat Transfer Study in Hypersonic Flows

    Sahoo, Niranjan; Kulkarni, Vinayak; Peetala, Ravi Kumar

    2018-04-01

    Coupled and decoupled conjugate heat transfer (CHT) studies are carried out to imitate experimental studies for heat transfer measurement in hypersonic flow regime. The finite volume based solvers are used for analyzing the heat interaction between fluid and solid domains. Temperature and surface heat flux signals are predicted by both coupled and decoupled CHT analysis techniques for hypersonic Mach numbers. These two methodologies are also used to study the effect of different wall materials on surface parameters. Effectiveness of these CHT solvers has been verified for the inverse problem of wall heat flux recovery using various techniques reported in the literature. Both coupled and decoupled CHT techniques are seen to be equally useful for prediction of local temperature and heat flux signals prior to the experiments in hypersonic flows.

  6. A fast, preconditioned conjugate gradient Toeplitz solver

    Pan, Victor; Schrieber, Robert

    1989-01-01

    A simple factorization is given of an arbitrary hermitian, positive definite matrix in which the factors are well-conditioned, hermitian, and positive definite. In fact, given knowledge of the extreme eigenvalues of the original matrix A, an optimal improvement can be achieved, making the condition numbers of each of the two factors equal to the square root of the condition number of A. This technique is to applied to the solution of hermitian, positive definite Toeplitz systems. Large linear systems with hermitian, positive definite Toeplitz matrices arise in some signal processing applications. A stable fast algorithm is given for solving these systems that is based on the preconditioned conjugate gradient method. The algorithm exploits Toeplitz structure to reduce the cost of an iteration to O(n log n) by applying the fast Fourier Transform to compute matrix-vector products. Matrix factorization is used as a preconditioner.

  7. Double diffusive conjugate heat transfer: Part I

    Azeem, Soudagar, Manzoor Elahi M.

    2018-05-01

    The present work is undertaken to investigate the effect of solid wall being placed at left of square cavity filled with porous medium. The presence of a solid wall in the porous medium turns the situation into a conjugate heat transfer problem. The boundary conditions are such that the left vertical surface is maintained at highest temperature and concentration whereas right vertical surface at lowest temperature and concentration in the medium. The top and bottom surfaces are adiabatic. The additional conduction equation along with the regular momentum and energy equations of porous medium are solved in an iterative manner with the help of finite element method. It is seen that the heat and mass transfer rate is lesser due to smaller thermal and concentration gradients.

  8. Conjugated Polymers Atypically Prepared in Water

    Invernale, Michael A.; Pendergraph, Samuel A.; Yavuz, Mustafa S.; Ombaba, Matthew; Sotzing, Gregory A.

    2010-01-01

    Processability remains a fundamental issue for the implementation of conducting polymer technology. A simple synthetic route towards processable precursors to conducting polymers (main chain and side chain) was developed using commercially available materials. These soluble precursor systems were converted to conjugated polymers electrochemically in aqueous media, offering a cheaper and greener method of processing. Oxidative conversion in aqueous and organic media each produced equivalent electrochromics. The precursor method enhances the yield of the electrochromic polymer obtained over that of electrodeposition, and it relies on a less corruptible electrolyte bath. However, electrochemical conversion of the precursor polymers often relies on organic salts and solvents. The ability to achieve oxidative conversion in brine offers a less costly and a more environmentally friendly processing step. It is also beneficial for biological applications. The electrochromics obtained herein were evaluated for electronic, spectral, and morphological properties. PMID:20959869

  9. Males unveiling the different forms of conjugal violence Hombres develando las formas de la violencia conyugal Homens desvelando as formas da violência conjugal

    Nadirlene Pereira Gomes

    2008-01-01

    Full Text Available OBJECTIVES: To identify the forms of unveiling violence from the discourse of a male group that perform violent acts against their partners. METHODS: Qualitative approach study. Seven males were interviewed and they beat their partners, residing in the outskirts of Salvador, BA. The subjects speeches were analyzed by means of content analysis. RESULTS: The study showed that the males interviewed experienced conjugal violence, which is revealed psychologically, sexually, morally and physically. CONCLUSION: The conjugal relationship is marked by an asymmetrical relation between males and females. When males feel they are being threatened, they use some means to control their partners, resorting to physical violence, inclusive. It is imperative to implement public policies that guarantee interventions with males and females, leading them to understand the social construction of gender identity.OBJETIVOS: Identificar las formas de develamiento de la violencia a partir del discurso de un grupo de hombres que practican actos violentos contra sus compañeras. MÉTODOS: Se trata de un estudio de abordaje cualitativo. Fueron entrevistados siete hombres que cometían actos violentos contra sus compañeras, residentes en la periferie de Salvador-BA. Las narrativas de los sujetos fueron analizadas por medio del análisis de contenido. RESULTADOS: El estudio mostró que los hombres entrevistados vivencian la violencia conyugal, la cual se devela bajo las formas psicológica, sexual, moral y física. CONCLUSIÓN: El relacionamiento conyugal está marcado por una relación asimétrica entre hombres y mujeres, de modo que, al sentir que su poder está siendo amenazado, el hombre utiliza algunos medios para controlar a sus compañeras, haciendo uso, inclusive, de la violencia física. Se hace necesaria la implementación de políticas públicas que garanticen intervenciones junto a hombres y mujeres que conduzcan a unos y otros a la comprensión de la construcci

  10. Gravity-induced asymmetric distribution of a plant growth hormone

    Bandurski, R. S.; Schulze, A.; Momonoki, Y.

    1984-01-01

    Dolk (1936) demonstrated that gravistimulation induced an asymmetric distribution of auxin in a horizontally-placed shoot. An attempt is made to determine where and how that asymmetry arises, and to demonstrate that the endogenous auxin, indole-3-acetic acid, becomes asymmetrically distributed in the cortical cells of the Zea mays mesocotyl during 3 min of geostimulation. Further, indole-3-acetic acid derived by hydrolysis of an applied transport form of the hormone, indole-3-acetyl-myo-inositol, becomes asymmetrically distributed within 15 min of geostimulus time. From these and prior data is developed a working theory that the gravitational stimulus induces a selective leakage, or secretion, of the hormone from the vascular tissue to the cortical cells of the mesocotyl.

  11. Best Speed Fit EDF Scheduling for Performance Asymmetric Multiprocessors

    Peng Wu

    2017-01-01

    Full Text Available In order to improve the performance of a real-time system, asymmetric multiprocessors have been proposed. The benefits of improved system performance and reduced power consumption from such architectures cannot be fully exploited unless suitable task scheduling and task allocation approaches are implemented at the operating system level. Unfortunately, most of the previous research on scheduling algorithms for performance asymmetric multiprocessors is focused on task priority assignment. They simply assign the highest priority task to the fastest processor. In this paper, we propose BSF-EDF (best speed fit for earliest deadline first for performance asymmetric multiprocessor scheduling. This approach chooses a suitable processor rather than the fastest one, when allocating tasks. With this proposed BSF-EDF scheduling, we also derive an effective schedulability test.

  12. Lower Bounds in the Asymmetric External Memory Model

    Jacob, Riko; Sitchinava, Nodari

    2017-01-01

    Motivated by the asymmetric read and write costs of emerging non-volatile memory technologies, we study lower bounds for the problems of sorting, permuting and multiplying a sparse matrix by a dense vector in the asymmetric external memory model (AEM). Given an AEM with internal (symmetric) memory...... of size M, transfers between symmetric and asymmetric memory in blocks of size B and the ratio ω between write and read costs, we show Ω(min (N, ωN/B logω M/B N/B) lower bound for the cost of permuting N input elements. This lower bound also applies to the problem of sorting N elements. This proves...

  13. Electromagnetic resonance in the asymmetric terahertz metamaterials with triangle microstructure

    Xing, Yuanyuan; Zhang, Xiaoyu; Zhang, Qiang; Gu, Yanping; Qian, Yunan; Lin, Xingyue; Tang, Yunhai; Cheng, Xinli; Qin, Changfa; Shen, Jiaoyan; Zang, Taocheng; Ma, Chunlan

    2018-05-01

    We investigate terahertz transmission properties and electromagnetic resonance modes in the asymmetric triangle structures with the change of asymmetric distance and the direction of electric field. When the THz electric field is perpendicular to the split gap of triangle, the electric field can better excite the THz absorption in the triangle structures. Importantly, electromagnetically induced transparency (EIT) characteristics are observed in the triangle structures due to the destructive interference of the different excited modes. The distributions of electric field and surface current density simulated by finite difference time domain indicate that the bright mode is excited by the side of triangle structures and dark mode is excited by the gap-side of triangle. The present study is helpful to understand the electromagnetic resonance in the asymmetric triangular metamaterials.

  14. Tourist Demand Reactions: Symmetric or Asymmetric across the Business Cycle?

    Bronner, Fred; de Hoog, Robert

    2017-09-01

    Economizing and spending priorities on different types of vacations are investigated during two periods: an economic downturn and returning prosperity. Two nation-wide samples of vacationers are used: one during a downturn, the other one at the start of the recovery period. Through comparing the results, conclusions can be drawn about symmetric or asymmetric tourist demand across the business cycle. The main summer holiday has an asymmetric profile: being fairly crisis-resistant during a recession and showing considerable growth during an expansion. This does not apply to short vacations and day trips, each having a symmetric profile: during a recession they experience substantial reductions and during expansion comparable growth. So when talking about tourist demand in general , one cannot say that it is symmetric or asymmetric across the business cycle: it depends on the type of vacation. Differences in tourist demand are best explained by the role of Quality-of-Life for vacationers.

  15. Two-channel totally asymmetric simple exclusion processes

    Pronina, Ekaterina; Kolomeisky, Anatoly B

    2004-01-01

    Totally asymmetric simple exclusion processes, consisting of two coupled parallel lattice chains with particles interacting with hard-core exclusion and moving along the channels and between them, are considered. In the limit of strong coupling between the channels, the particle currents, density profiles and a phase diagram are calculated exactly by mapping the system into an effective one-channel totally asymmetric exclusion model. For intermediate couplings, a simple approximate theory, that describes the particle dynamics in vertical clusters of two corresponding parallel sites exactly and neglects the correlations between different vertical clusters, is developed. It is found that, similarly to the case of one-channel totally asymmetric simple exclusion processes, there are three stationary state phases, although the phase boundaries and stationary properties strongly depend on inter-channel coupling. Extensive computer Monte Carlo simulations fully support the theoretical predictions

  16. Controllable asymmetric transmission via gap-tunable acoustic metasurface

    Liu, Bingyi; Jiang, Yongyuan

    2018-04-01

    In this work, we utilize the acoustic gradient metasurface (AGM) of a bilayer configuration to realize the controllable asymmetric transmission. Relying on the adjustable gap between the two composing layers, the metasurface could switch from symmetric transmission to asymmetric transmission at a certain gap value. The underlying mechanism is attributed to the interference between the forward diffracted waves scattered by the surface bound waves at two air-AGM interfaces, which is apparently influenced by the interlayer distance. We further utilize the hybrid acoustic elements to construct the desired gradient metasurface with a tunable gap and validate the controllable asymmetric transmission with full-wave simulations. Our work provides the solution for actively controlling the transmission property of an acoustic element, which shows potential application in acoustic communication as a dynamic tunable acoustic diode.

  17. Asymmetric adsorption of alanine by quartz powder from ethanol solution

    Furuyama, Shozo; Sawada, Michio; Hachiya, Kinji; Morimoto, Tetsuo (Okayama Univ. (Japan). Faculty of Science)

    1982-11-01

    The asymmetric adsorption of the racemic alanine by the optically active quartz from ethanol solution at 8/sup 0/C was studied by the /sup 14/C-tracer method and the newly developed /sup 14/C-tracer ninhydrin-colorimetry combination method. The preferential adsorption of L-alanine by levorotatory quartz (l-quartz) and D-alanine by dextrorotatory quartz (d-quartz) was confirmed. The asymmetric adsorptivity (Asub(s)) falls in the range of 1.1 - 1.3, which is comparable with the value determined at - 80/sup 0/C in the previous paper. The effects of water content in the ethanol solution and of the adsorption temperature upon the adsorption affinity of alanine to quartz were also measured. The cause for the asymmetric adsorption is discussed from the crystallographic point of view.

  18. Dynamic JUNQ inclusion bodies are asymmetrically inherited in mammalian cell lines through the asymmetric partitioning of vimentin.

    Ogrodnik, Mikołaj; Salmonowicz, Hanna; Brown, Rachel; Turkowska, Joanna; Średniawa, Władysław; Pattabiraman, Sundararaghavan; Amen, Triana; Abraham, Ayelet-chen; Eichler, Noam; Lyakhovetsky, Roman; Kaganovich, Daniel

    2014-06-03

    Aging is associated with the accumulation of several types of damage: in particular, damage to the proteome. Recent work points to a conserved replicative rejuvenation mechanism that works by preventing the inheritance of damaged and misfolded proteins by specific cells during division. Asymmetric inheritance of misfolded and aggregated proteins has been shown in bacteria and yeast, but relatively little evidence exists for a similar mechanism in mammalian cells. Here, we demonstrate, using long-term 4D imaging, that the vimentin intermediate filament establishes mitotic polarity in mammalian cell lines and mediates the asymmetric partitioning of damaged proteins. We show that mammalian JUNQ inclusion bodies containing soluble misfolded proteins are inherited asymmetrically, similarly to JUNQ quality-control inclusions observed in yeast. Mammalian IPOD-like inclusion bodies, meanwhile, are not always inherited by the same cell as the JUNQ. Our study suggests that the mammalian cytoskeleton and intermediate filaments provide the physical scaffold for asymmetric inheritance of dynamic quality-control JUNQ inclusions. Mammalian IPOD inclusions containing amyloidogenic proteins are not partitioned as effectively during mitosis as their counterparts in yeast. These findings provide a valuable mechanistic basis for studying the process of asymmetric inheritance in mammalian cells, including cells potentially undergoing polar divisions, such as differentiating stem cells and cancer cells.

  19. Selective Covalent Conjugation of Phosphorothioate DNA Oligonucleotides with Streptavidin

    Christof M. Niemeyer

    2011-08-01

    Full Text Available Protein-DNA conjugates have found numerous applications in the field of diagnostics and nanobiotechnology, however, their intrinsic susceptibility to DNA degradation by nucleases represents a major obstacle for many applications. We here report the selective covalent conjugation of the protein streptavidin (STV with phosphorothioate oligonucleotides (psDNA containing a terminal alkylthiolgroup as the chemically addressable linking unit, using a heterobifunctional NHS-/maleimide crosslinker. The psDNA-STV conjugates were synthesized in about 10% isolated yields. We demonstrate that the terminal alkylthiol group selectively reacts with the maleimide while the backbone sulfur atoms are not engaged in chemical conjugation. The novel psDNA-STV conjugates retain their binding capabilities for both biotinylated macromolecules and the complementary nucleic acid. Moreover, the psDNA-STV conjugate retained its binding capacity for complementary oligomers even after a nuclease digestion step, which effectively degrades deoxyribonucleotide oligomers and thus the binding capability of regular DNA-STV conjugates. The psDNA-STV therefore hold particular promise for applications e.g. in proteome research and novel biosensing devices, where interfering endogenous nucleic acids need to be removed from analytes by nuclease digestion.

  20. Preparation and immunological properties of procaine-protein conjugates

    Liakopoulou, A.

    1981-01-01

    Procaine was conjugated to BSA and rat and rabbit Gf using the carbodiimide method and 14 C-procaine as tracer. The composition of the conjugates could be varied depending on the time of incubation and the concentration of procaine in the reaction mixtures. Procaine-BSA conjugates were soluble in water or saline. However, procaine conjugates to rat or rabbit Gf were not readily soluble in saline. These conjugates were good for immunization purposes, but it was cumbersome to work with them when clear solutions were needed, as in the immunochemical procedures used in this study. The immunological properties of the conjugates were studied in rats and rabbits. Rats responded with production of IgGa and precipitating antibodies to the procaine group, but IgE antibodies to the immunogen could not be detected. Furthermore, precipitating antibodies towards the procaine group were raised in rabbits. When BSA was the protein carrier, antibodies to the carrier molecule were also detected in both rats and rabbits. The conjugates of procaine to rat or rabbit Gf did not elicit antibody response to the carrier molecule when used in the homologous species. Hapten inhibition studies suggested that, in the rabbit, antibodies were also produced with specificity directed towards the molecular configuration of the hapten-carrier bond. (author)

  1. Nanostructured conjugated polymers in chemical sensors: synthesis, properties and applications.

    Correa, D S; Medeiros, E S; Oliveira, J E; Paterno, L G; Mattoso, Luiz C

    2014-09-01

    Conjugated polymers are organic materials endowed with a π-electron conjugation along the polymer backbone that present appealing electrical and optical properties for technological applications. By using conjugated polymeric materials in the nanoscale, such properties can be further enhanced. In addition, the use of nanostructured materials makes possible miniaturize devices at the micro/nano scale. The applications of conjugated nanostructured polymers include sensors, actuators, flexible displays, discrete electronic devices, and smart fabric, to name a few. In particular, the use of conjugated polymers in chemical and biological sensors is made feasible owning to their sensitivity to the physicochemical conditions of its surrounding environment, such as chemical composition, pH, dielectric constant, humidity or even temperature. Subtle changes in these conditions bring about variations on the electrical (resistivity and capacitance), optical (absorptivity, luminescence, etc.), and mechanical properties of the conjugated polymer, which can be precisely measured by different experimental methods and ultimately associated with a specific analyte and its concentration. The present review article highlights the main features of conjugated polymers that make them suitable for chemical sensors. An especial emphasis is given to nanostructured sensors systems, which present high sensitivity and selectivity, and find application in beverage and food quality control, pharmaceutical industries, medical diagnosis, environmental monitoring, and homeland security, and other applications as discussed throughout this review.

  2. IRDye78 Conjugates for Near-Infrared Fluorescence Imaging

    Atif Zaheer

    2002-10-01

    Full Text Available The detection of human malignancies by near-infrared (NIR fluorescence will require the conjugation of cancer-specific ligands to NIR fluorophores that have optimal photoproperties and pharmacokinetics. IRDye78, a tetra-sulfonated heptamethine indocyanine NIR fluorophore, meets most of the criteria for an in vivo imaging agent, and is available as an N-hydroxysuccinimide ester for conjugation to low-molecular-weight ligands. However, IRDye78 has a high charge-to-mass ratio, complicating purification of conjugates. It also has a potentially labile linkage between fluorophore and ligand. We have developed an ion-pairing purification strategy for IRDye78 that can be performed with a standard C18 column under neutral conditions, thus preserving the stability of fluorophore, ligand, and conjugate. By employing parallel evaporative light scatter and absorbance detectors, all reactants and products are identified, and conjugate purity is maximized. We describe reversible and irreversible conversions of IRDye78 that can occur during sample purification, and describe methods for preserving conjugate stability. Using seven ligands, spanning several classes of small molecules and peptides (neutral, charged, and/or hydrophobic, we illustrate the robustness of these methods, and confirm that IRDye78 conjugates so purified retain bioactivity and permit NIR fluorescence imaging of specific targets.

  3. Synthesis and antimicrobial activity of gold nanoparticle conjugates with cefotaxime

    Titanova, Elena O.; Burygin, Gennady L.

    2016-04-01

    Gold nanoparticles (GNPs) have attracted significant interest as a novel platform for various applications to nanobiotechnology and biomedicine. The conjugates of GNPs with antibiotics and antibodies were also used for selective photothermal killing of protozoa and bacteria. Also the conjugates of some antibiotics with GNPs decreased the number of bacterial growing cells. In this work was made the procedure optimization for conjugation of cefotaxime (a third-generation cephalosporin antibiotic) with GNPs (15 nm) and we examined the antimicrobial properties of this conjugate to bacteria culture of E. coli K-12. Addition of cefotaxime solution to colloidal gold does not change their color and extinction spectrum. For physiologically active concentration of cefotaxime (3 μg/mL), it was shown that the optimum pH for the conjugation was more than 9.5. A partial aggregation of the GNPs in saline medium was observed at pH 6.5-7.5. The optimum concentration of K2CO3 for conjugation cefotaxime with GNPs-15 was 5 mM. The optimum concentration of cefotaxime was at 0.36 μg/mL. We found the inhibition of the growth of E. coli K12 upon application cefotaxime-GNP conjugates.

  4. The rationality of EIA forecasts under symmetric and asymmetric loss

    Auffhammer, Maximilian

    2007-01-01

    The United States Energy Information Administration publishes annual forecasts of nationally aggregated energy consumption, production, prices, intensity and GDP. These government issued forecasts often serve as reference cases in the calibration of simulation and econometric models, which climate and energy policy are based on. This study tests for rationality of published EIA forecasts under symmetric and asymmetric loss. We find strong empirical evidence of asymmetric loss for oil, coal and electricity prices as well as natural gas consumption, electricity sales, GDP and energy intensity. (author)

  5. Data analysis of asymmetric structures advanced approaches in computational statistics

    Saito, Takayuki

    2004-01-01

    Data Analysis of Asymmetric Structures provides a comprehensive presentation of a variety of models and theories for the analysis of asymmetry and its applications and provides a wealth of new approaches in every section. It meets both the practical and theoretical needs of research professionals across a wide range of disciplines and  considers data analysis in fields such as psychology, sociology, social science, ecology, and marketing. In seven comprehensive chapters this guide details theories, methods, and models for the analysis of asymmetric structures in a variety of disciplines and presents future opportunities and challenges affecting research developments and business applications.

  6. Current drive by asymmetrical heating in a toroidal plasma

    Gahl, J.M.

    1986-01-01

    This report describes the first experimental observation of current generation by asymmetrical heating of ions. A unidirectional fast Alfven wave launched by a slow-wave antenna inside the Texas Tech Tokamak, asymmetrically heated the ions. Measurements of the asymmetry of the toroidal plasma current with probes at the top and bottom of the toroidal plasma column confirmed the current generation indirectly. Current generation, obtained in a one-species, hydrogen plasma, is a phenomenon which had not been predicted previously. Calculations of the dispersion relation for the fast Alfven wave near the fundamental cyclotron resonance in a one-species, hydrogen plasma, using warm plasma theory, support the experimental results

  7. Climate agreements under limited participation, asymmetric information and market imperfections

    Hagem, Cathrine

    1996-12-31

    This thesis relates to climate agreements and cost efficiency by analysing the formation of a system of quota leading to distributed discharge of emissions between countries. Main fields concerned are the greenhouse effect, the political process, efficient and cost-effective climate agreements, and climate agreements under limited participation, asymmetric information and market imperfections covering fields like limited participation in climate agreements, limited participation and indirect impact on non-participating countries` emissions, limited participation and direct impact on non-participating countries` emissions under asymmetric information, and non-competitive market for tradeable quotas. 166 refs., 7 tabs.

  8. Experimental research on photovoltaic module for asymmetrical compound parabolic concentrator

    Yuan, Jinshe; Wang, Mingyue [Chongqing Normal University, Chongqing (China). Department of Physics; Yang, Changmin [Xian University of Technology, Xian (China). Department of Applied Physics

    2008-07-01

    The photovoltaic module for the use of fixed asymmetrical CPC concentrator was designed and fabricated based on the performance of polycrystalline-silicon solar cells with back surface field (BSF) structure. The performance of the combination of the module and asymmetrical CPC concentrator was investigated. The results show its effective concentration ratio to be 2.46 and the output power of the PV-a-CPC system to be increased by 2.13 times compared with that of the module approximately. (orig.)

  9. Asymptotic behavior of observables in the asymmetric quantum Rabi model

    Semple, J.; Kollar, M.

    2018-01-01

    The asymmetric quantum Rabi model with broken parity invariance shows spectral degeneracies in the integer case, that is when the asymmetry parameter equals an integer multiple of half the oscillator frequency, thus hinting at a hidden symmetry and accompanying integrability of the model. We study the expectation values of spin observables for each eigenstate and observe characteristic differences between the integer and noninteger cases for the asymptotics in the deep strong coupling regime, which can be understood from a perturbative expansion in the qubit splitting. We also construct a parent Hamiltonian whose exact eigenstates possess the same symmetries as the perturbative eigenstates of the asymmetric quantum Rabi model in the integer case.

  10. Testing for asymmetric pricing in the Canadian retail gasoline market

    Godby, R.; Lintner, A.M.; Stengos, T.; Wandschneider, B.

    2000-01-01

    This paper applies a Threshold Regression model to test for asymmetric pricing in the retail gasoline market in Canada, using weekly data for the period January 1990 to December 1996. We present results for 13 Canadian cities for both premium and regular gasoline. Within the context of an error correction model we test for the presence of asymmetric price behaviour using average changes in crude prices as well as various lags for the change in crude as possible thresholds. We are unable to find any evidence to support this view. 23 refs

  11. Decoding Pure Rotational Molecular Spectra for Asymmetric Molecules

    S. A. Cooke

    2013-01-01

    Full Text Available Rotational spectroscopy can provide insights of unparalleled precision with respect to the wavefunctions of molecular systems that have relevance in fields as diverse as astronomy and biology. In this paper, we demonstrate how asymmetric molecular pure rotational spectra may be analyzed “pictorially” and with simple formulae. It is shown that the interpretation of such spectra relies heavily upon pattern recognition. The presentation of some common spectral line positions in near-prolate asymmetric rotational spectra provides a means by which spectral assignment, and approximate rotational constant determination, may be usefully explored. To aid in this endeavor we have created a supporting, free, web page and mobile web page.

  12. Ideal MHD beta-limits of poloidally asymmetric equilibria

    Todd, A.M.M.; Miller, A.E.; Grimm, R.C.; Okabayashi, M.; Dalhed, H.E. Jr.

    1981-05-01

    The ideal MHD stability of poloidally asymmetric equilibria, which are typical of a tokamak reactor design with a single-null poloidal divertor is examined. As with symmetric equilibria, stability to non-axisymmetric modes improves with increasing triangularity and ellipticity, and with lower edge safety factor. Pressure profiles optimized with respect to ballooning stability are obtained for an asymmetric shape, resulting in ..beta../sub critical/ approx. = 5.7%. The corresponding value for an equivalent symmetric shape is ..beta../sub critical/ approx. = 6.5%.

  13. Axisymmetric stability of vertically asymmetric tokamaks at large beta poloidal

    Yamazaki, K.; Fishman, H.; Okabayashi, M.; Todd, A.M.M.

    1981-09-01

    The stability of high-β vertically asymmetric tokamak equilibria to rigid displacements is investigated analytically. It is found that vertical stability at large beta poloidal is mainly determined by a coupling between the shape of the plasma surface and the Shafranov shift of the magnetic axis. To the lowest order, symmetric components of the plasma surface shape are found to be the critical destabilizing elements. Asymmetric components have little effect. The inclusion of higher order terms in the high β tokamak expansion leads to further destabilization. Qualitative agreement between these analytic results and numerical stability calculations using the PEST code is demonstrated

  14. Ideal MHD beta-limits of poloidally asymmetric equilibria

    Todd, A.M.M.; Miller, A.E.; Grimm, R.C.; Okabayashi, M.; Dalhed, H.E. Jr.

    1981-05-01

    The ideal MHD stability of poloidally asymmetric equilibria, which are typical of a tokamak reactor design with a single-null poloidal divertor is examined. As with symmetric equilibria, stability to non-axisymmetric modes improves with increasing triangularity and ellipticity, and with lower edge safety factor. Pressure profiles optimized with respect to ballooning stability are obtained for an asymmetric shape, resulting in β/sub critical/ approx. = 5.7%. The corresponding value for an equivalent symmetric shape is β/sub critical/ approx. = 6.5%

  15. Electron Raman scattering in asymmetrical multiple quantum wells

    Betancourt-Riera, R; Rosas, R; Marin-Enriquez, I; Riera, R; Marin, J L

    2005-01-01

    Optical properties of asymmetrical multiple quantum wells for the construction of quantum cascade lasers are calculated, and expressions for the electronic states of asymmetrical multiple quantum wells are presented. The gain and differential cross-section for an electron Raman scattering process are obtained. Also, the emission spectra for several scattering configurations are discussed, and the corresponding selection rules for the processes involved are studied; an interpretation of the singularities found in the spectra is given. The electron Raman scattering studied here can be used to provide direct information about the efficiency of the lasers

  16. Six transformer based asymmetrical embedded Z-source inverters

    Wei, Mo; Poh Chiang, Loh; Chi, Jin

    2013-01-01

    Embedded/Asymmetrical embedded Z-source inverters were proposed to maintain smooth input current/voltage across the dc source and within the impedance network, remain the shoot-through feature used to boost up the dc-link voltage without adding bulky filter at input side. This paper introduces a ...... a class of transformer based asymmetrical embedded Z-source inverters which keep the smooth input current and voltage while achieving enhanced voltage boost capability. The presented inverters are verified by laboratory prototypes experimentally....

  17. Finite stage asymmetric repeated games: Both players' viewpoints

    Li, Lichun

    2017-01-05

    In asymmetric zero-sum games, one player has superior information about the game over the other. It is known that the informed players (maximizer) face the tradeoff of exploiting its superior information at the cost of revealing its superior information, but the basic point of the uninformed player (minimizer)\\'s decision making remains unknown. This paper studies the finite stage asymmetric repeated games from both players\\' viewpoints, and derives that not only security strategies but also the opponents\\' corresponding best responses depends only on the informed player\\'s history action sequences. Moreover, efficient LP formulations to compute both player\\'s security strategies are provided.

  18. The rationality of EIA forecasts under symmetric and asymmetric loss

    Auffhammer, Maximilian [Department of Agricultural and Resource Economics, University of California, 207 Giannini Hall 3310, Berkeley, CA 94720 (United States)

    2007-05-15

    The United States Energy Information Administration publishes annual forecasts of nationally aggregated energy consumption, production, prices, intensity and GDP. These government issued forecasts often serve as reference cases in the calibration of simulation and econometric models, which climate and energy policy are based on. This study tests for rationality of published EIA forecasts under symmetric and asymmetric loss. We find strong empirical evidence of asymmetric loss for oil, coal and electricity prices as well as natural gas consumption, electricity sales, GDP and energy intensity. (author)

  19. An optical tweezer in asymmetrical vortex Bessel-Gaussian beams

    Kotlyar, V. V.; Kovalev, A. A., E-mail: alexeysmr@mail.ru; Porfirev, A. P. [Image Processing Systems Institute, 151 Molodogvardeiskaya St., 443001 Samara (Russian Federation); Department of Technical cybernetics, Samara State Aerospace University, Samara 443086 (Russian Federation)

    2016-07-14

    We study an optical micromanipulation that comprises trapping, rotating, and transporting 5-μm polystyrene microbeads in asymmetric Bessel-Gaussian (BG) laser beams. The beams that carry orbital angular momentum are generated by means of a liquid crystal microdisplay and focused by a microobjective with a numerical aperture of NA = 0.85. We experimentally show that given a constant topological charge, the rate of microparticle motion increases near linearly with increasing asymmetry of the BG beam. Asymmetric BG beams can be used instead of conventional Gaussian beam for trapping and transferring live cells without thermal damage.

  20. Preview-based Asymmetric Load Reduction of Wind Turbines

    Madsen, Mathias; Filsø, Jakob; Soltani, Mohsen

    2012-01-01

    Controller (MPC) developed is based on a model with individual blade pitching to utilize the LIDAR measurements. The MPC must also maintain a given power reference while satisfying a set of actuator constraints. The designed controller was tested on a 5 MW wind turbine in the FAST simulator and compared......Fatigue loads on wind turbines caused by an asymmetric wind field become an increasing concern when the scale of wind turbines increases. This paper presents a model based predictive approach to reduce asymmetric loads by using Light Detection And Ranging (LIDAR) measurements. The Model Predictive...

  1. Dicer is dispensable for asymmetric RISC loading in mammals.

    Betancur, Juan G; Tomari, Yukihide

    2012-01-01

    In flies, asymmetric loading of small RNA duplexes into Argonaute2-containing RNA-induced silencing complex (Ago2-RISC) requires Dicer-2/R2D2 heterodimer, which acts as a protein sensor for the thermodynamic stabilities of the ends of small RNA duplexes. However, the mechanism of small RNA asymmetry sensing in mammalian RISC assembly remains obscure. Here, we quantitatively examined RISC assembly and target silencing activity in the presence or absence of Dicer in mammals. Our data show that, unlike the well-characterized fly Ago2-RISC assembly pathway, mammalian Dicer is dispensable for asymmetric RISC loading in vivo and in vitro.

  2. Applications of organocatalytic asymmetric synthesis to drug prototypes--dual action and selective inhibitors of n-nitric oxide synthase with activity against the 5-HT1D/1B subreceptors.

    Hanessian, Stephen; Stoffman, Eli; Mi, Xueling; Renton, Paul

    2011-03-04

    The scope of MacMillan's organocatalytic asymmetric conjugate addition reaction of indoles and electron-rich aromatics to α,β-unsaturated aldehydes has been extended to the use of 3-amino crotonaldehydes as substrates. The aromatics used include indoles as well as an aniline and a furan. The scope and effect of the groups on nitrogen (R, R') has also been studied. The method has been applied to the concise synthesis of an advanced precursor to S-(+)-1, a drug prototype for the treatment of migraine headaches.

  3. Modern methods for the synthesis of peptide-oligonucleotide conjugates

    Zubin, Evgenii M; Oretskaya, Tat'yana S; Romanova, Elena A

    2002-01-01

    The published data on the methods of chemical solution and solid-phase synthesis of peptide-oligonucleotide conjugates are reviewed. The known methods are systematised and their advantages and disadvantages are considered. The approaches to the solution synthesis of peptide-oligonucleotide conjugates are systematised according to the type of chemical bonds between the fragments, whereas those to the solid-phase synthesis are classified according to the procedure used for the preparation of conjugates, viz., stepwise elongation of oligonucleotide and peptide chains on the same polymeric support or solid-phase condensation of two presynthesised fragments. The bibliography includes 141 references.

  4. Lipid-peptide-polymer conjugates and nanoparticles thereof

    Xu, Ting; Dong, He; Shu, Jessica

    2015-06-02

    The present invention provides a conjugate having a peptide with from about 10 to about 100 amino acids, wherein the peptide adopts a helical structure. The conjugate also includes a first polymer covalently linked to the peptide, and a hydrophobic moiety covalently linked to the N-terminus of the peptide, wherein the hydrophobic moiety comprises a second polymer or a lipid moiety. The present invention also provides helix bundles form by self-assembling the conjugates, and particles formed by self-assembling the helix bundles. Methods of preparing the helix bundles and particles are also provided.

  5. Conjugation vs hyperconjugation in molecular structure of acrolein

    Shishkina, Svitlana V.; Slabko, Anzhelika I.; Shishkin, Oleg V.

    2013-01-01

    Analysis of geometric parameters of butadiene and acrolein reveals the contradiction between the Csp2-Csp2 bond length in acrolein and classical concept of conjugation degree in the polarized molecules. In this Letter the reasons of this contradiction have been investigated. It is concluded that the Csp2-Csp2 bond length in acrolein is determined by influence of the bonding for it π-π conjugation and antibonding n → σ∗ hyperconjugation between the oxygen lone pair and the antibonding orbital of the single bond. It was shown also this bond length depends on the difference in energy of conjugative and hyperconjugative interactions.

  6. Perfect lensing with phase-conjugating surfaces: toward practical realization

    Maslovski, Stanislav; Tretyakov, Sergei

    2012-01-01

    It is theoretically known that a pair of phase-conjugating surfaces can function as a perfect lens, focusing propagating waves and enhancing evanescent waves. However, the known experimental approaches based on thin sheets of nonlinear materials cannot fully realize the required phase conjugation boundary condition. In this paper, we show that the ideal phase-conjugating surface is, in principle, physically realizable and investigate the necessary properties of nonlinear and nonreciprocal particles which can be used to build a perfect lens system. The physical principle of the lens operation is discussed in detail and directions of possible experimental realizations are outlined. (paper)

  7. CONJUGATED POLYMERS AND POLYELECTROLYTES IN SOLAR PHOTOCONVERSION, Final Technical Report

    Schanze, Kirk S [University of Florida

    2014-08-05

    This DOE-supported program investigated the fundamental properties of conjugated polyelectrolytes, with emphasis placed on studies of excited state energy transport, self-assembly into conjugated polyelectroyte (CPE) based films and colloids, and exciton transport and charge injection in CPE films constructed atop wide bandgap semiconductors. In the most recent grant period we have also extended efforts to examine the properties of low-bandgap donor-acceptor conjugated polyelectrolytes that feature strong visible light absorption and the ability to adsorb to metal-oxide interfaces.

  8. Emission variation in infrared (CdSeTe)/ZnS quantum dots conjugated to antibodies

    Jaramillo Gómez, J.A. [UPIITA – Instituto Politécnico Nacional, México D. F. 07320, México (Mexico); Casas Espinola, J.L., E-mail: jlcasas@esfm.ipn.mx [ESFM – Instituto Politécnico Nacional, México D. F. 07738, México (Mexico); Douda, J. [UPIITA – Instituto Politécnico Nacional, México D. F. 07320, México (Mexico)

    2014-11-15

    The paper presents the photoluminescence (PL) and Raman scattering investigations of infrared CdSeTe/ZnS quantum dots (QDs) with emission at 800 nm (1.60 eV) in nonconjugated states and after the conjugation to the anti-papilloma virus antibodies (Ab). The Raman scattering study has shown that the CdSeTe core includes two layers with different material compositions such as: CdSe{sub 0.5}Te{sub 0.5} and CdSe{sub 0.7}Te{sub 0.3}. PL spectra of nonconjugated CdSeTe/ZnS QDs are characterized by two Gaussian shape PL bands related to exciton emission in the CdSeTe core and in intermediate layer at the core/shell interface. PL spectra of bioconjugated QDs have changed essentially: the main PL band related to the core emission shifts into high energy and become asymmetric. The energy diagram of double core/shell CdSeTe/ZnS QDs has been analyzed to explain the PL spectrum of nonconjugated QDs and its transformation at the bioconjugation to the papiloma virus antibodies. It is shown that the PL spectrum transformation in bioconjugated QDs can be a powerful technique for biology and medicine.

  9. Preparation, structural analysis and bioactivity of ribonuclease A-albumin conjugate: tetra-conjugation or PEG as the linker.

    Li, Chunju; Lin, Qixun; Wang, Jun; Shen, Lijuan; Ma, Guanghui; Su, Zhiguo; Hu, Tao

    2012-12-31

    Ribonuclease A (RNase A) is a therapeutic enzyme with cytotoxic action against tumor cells. Its clinical application is limited by the short half-life and insufficient stability. Conjugation of albumin can overcome the limitation, whereas dramatically decrease the enzymatic activity of RNase A. Here, three strategies were proposed to prepare the RNase A-bovine serum albumin (BSA) conjugates. R-SMCC-B (a conjugate of four RNase A attached with one BSA) and R-PEG-B (a mono-conjugate) were prepared using Sulfo-SMCC (a short bifunctional linker) and mal-PEG-NHS (a bifunctional PEG), respectively. Mal-PEG-NHS and hexadecylamine (HDA) were used to prepare the mono-conjugate, R-HDA-B, where HDA was adopted to bind BSA. The PEG linker can elongate the proximity between RNase A and BSA. In contrast, four RNase A were closely located on BSA in R-SMCC-B. R-SMCC-B showed the lowest K(m) and the highest relative enzymatic activity and k(cat)/K(m) in the three conjugates. Presumably, the tetravalent interaction of RNase A in R-SMCC-B can increase the binding affinity to its substrate. In addition, the slow release of BSA from R-HDA-B may increase the enzymatic activity of R-HDA-B. Our study is expected to provide strategies to develop protein-albumin conjugate with high therapeutic potential. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Autorefraction versus subjective refraction in a radially asymmetric multifocal intraocular lens

    van der Linden, Jan Willem; Vrijman, Violette; Al-Saady, Rana; El-Saady, Rana; van der Meulen, Ivanka J.; Mourits, Maarten P.; Lapid-Gortzak, Ruth

    2014-01-01

    To evaluate whether the automated refraction (AR) correlates with subjective manifest (MR) refraction in eyes implanted with radially asymmetric multifocal intraocular lens (IOLs). This retrospective study evaluated 52 eyes (52 patients) implanted with a radially asymmetric multifocal IOL (LS-312

  11. Autorefraction versus subjective refraction in a radially asymmetric multifocal intraocular lens

    Linden, J.W.M. van der; Vrijman, V.; El-Saady, R.; Meulen, I.J. van der; Mourits, M.P.; Lapid-Gortzak, R.

    2014-01-01

    PURPOSE: To evaluate whether the automated refraction (AR) correlates with subjective manifest (MR) refraction in eyes implanted with radially asymmetric multifocal intraocular lens (IOLs). METHODS: This retrospective study evaluated 52 eyes (52 patients) implanted with a radially asymmetric

  12. Conjugated Polymers and Oligomers: Structural and Soft Matter Aspects

    This book identifies modern topics and current trends of structural and soft matter aspects of conjugated polymers and oligomers. Each chapter recognizes an active research line where structural perspective dominates research and therefore the book covers fundamental aspects of persistent...

  13. Guanidinylated polyethyleneimine-polyoxypropylene-polyoxyethylene conjugates as gene transfection agents.

    Bromberg, Lev; Raduyk, Svetlana; Hatton, T Alan; Concheiro, Angel; Rodriguez-Valencia, Cosme; Silva, Maite; Alvarez-Lorenzo, Carmen

    2009-05-20

    Conjugates of linear and branched polyethyleneimine (PEI) and monoamine polyether Jeffamine M-2070 (PO/EO mol ratio 10/31, 2000 Da) were synthesized through polyether activation by cyanuric chloride followed by attachment to PEI and guanidinylation by 1H-pyrazole-carboxamidine hydrochloride. The resulting guanidinylated PEI-polyether conjugates (termed gPEI-Jeffamine) efficiently complexed plasmid DNA, and their polyplexes possessed enhanced colloidal stability in the presence of serum proteins. In vitro studies with mammalian CHO-1, 3T3, and Cos-7 cell lines demonstrated improved transfection efficiency of the pCMVbeta-gal plasmid/gPEI-Jeffamine polyplexes. The guanidinylation of the amino groups of PEI and the conjugation of PEI with the Jeffamine polyether enhanced the conjugates' interaction with genetic material and reduced the cytotoxicity of the polyplexes in experiments with the L929 cell line.

  14. Two novel plasma diagnostic tools: fiber sensors and phase conjugation

    Jahoda, F.C.

    1985-01-01

    A rapidly developing technology (single-mode optical fiber sensors) and recent fundamental research in nonlinear optics (phase conjugation) both offer opportunities for novel plasma diagnostics. Single-mode fiber sensors can replace electrical wire probes for current and magnetic field measurements with advantages in voltage insulation requirements, electromagnetic noise immunity, much greater bandwidth, and some configuration flexibility. Faraday rotation measurements through fibers wound on the ZT-40M RFP have demonstrated quantitative results, but competing linear birefringence effects still hinder independent interpretation. Twisted fiber may solve this problem. Optical phase conjugation (in which a phase reversed copy of a laser beam is generated) allows real time distortion corrections in laser diagnostics. Self-pumped phase conjugation in BaTiO 3 improves the quality of phase conjugation imagery and greatly simplifies experimentation directed toward plasma diagnostics. Our initial applications are a) time-differential refractometry with high spatial resolution and b) intracavity absorption Zeeman spectroscopy

  15. On conjugate points and the Leitmann equivalent problem approach

    Wagener, F.O.O.

    2009-01-01

    This article extends the Leitmann equivalence method to a class of problems featuring conjugate points. The class is characterised by the requirement that the set of indifference points of a given problem forms a finite stratification.

  16. Enantioselective conjugate addition of hydroxylamines to pyrazolidinone acrylamides.

    Sibi, M P; Liu, M

    2001-12-27

    Chiral relay templates provide amplification of selectivity in conjugate addition reactions. Reversal of stereochemistry of the product isoxazolidinones has also been demonstrated by a simple change of the Lewis acid. [reaction: see text

  17. Site-Selective Conjugation of Native Proteins with DNA

    Trads, Julie Brender; Tørring, Thomas; Gothelf, Kurt Vesterager

    2017-01-01

    Conjugation of DNA to proteins is increasingly used in academia and industry to provide proteins with tags for identification or handles for hybridization to other DNA strands. Assay technologies such as immuno-PCR and proximity ligation and the imaging technology DNA-PAINT require DNA-protein....... The introduction of a bioorthogonal handle at a specific position of a protein by recombinant techniques provides an excellent approach to site-specific conjugation, but for many laboratories and for applications where several proteins are to be labeled, the expression of recombinant proteins may be cumbersome...... conjugates. In DNA nanotechnology, the DNA handle is exploited to precisely position proteins by self-assembly. For these applications, site-selective conjugation is almost always desired because fully functional proteins are required to maintain the specificity of antibodies and the activity of enzymes...

  18. Conjugal conflict and violence: a review and theoretical paradigm.

    Smilkstein, G; Aspy, C B; Quiggins, P A

    1994-02-01

    Conjugal violence has been described as having multiple etiologies. The variables are so numerous that intervention and research protocols are difficult to effect. This paper proposes a paradigm that establishes conjugal conflict and violence as separate entities. According to the paradigm, conjugal conflict is viewed as "an inevitable part of human association," whereas conjugal violence is determined to be a learned behavioral tactic that is employed as a coping strategy when an individual's conflict threshold potential is exceeded. Evidence will be offered that violence is learned from family of origin and from observing what is common or accepted practice in the community. Use of this paradigm would give primacy to community education programs that advance the concept of conflict resolution through rational discourse.

  19. Modeling of SBS Phase Conjugation in Multimode Step Index Fibers

    Spring, Justin B

    2008-01-01

    ... limited, double-pass high-power amplifiers or coherent beam combination. Little modeling of such a fiber-based phase-conjugator has been done, making it difficult to make decisions about the right fiber to use...

  20. DEGRADATION AND INTRAHEPATIC COMPATIBILITY OF ALBUMIN-HEPARIN CONJUGATE MICROSPHERES

    CREMERS, HFM; WOLF, RFE; BLAAUW, EH; SCHAKENRAAD, JM; LAM, KH; NIEUWENHUIS, P; VERRIJK, R; KWON, G; BAE, YH; KIM, SW; FEIJEN, J

    The in vitro degradation properties of glutaraldehyde cross-linked albumin and albumin-heparin conjugate microspheres (AMS and AHCMS respectively) were evaluated using light microscopy, turbidity measurements and heparin release determinations, showing that the microspheres are degraded by

  1. Intergenic and intragenic conjugal transfer of multiple antibiotic ...

    Conjugation process was conducted to determine the means of transferring ... In this study, it was surprisingly observed that tetracycline resistant gene was ... among pathogenic bacteria, particularly since antibiotics are indiscriminately used in ...

  2. Conjugated Polymers for Flexible Energy Harvesting and Storage.

    Zhang, Zhitao; Liao, Meng; Lou, Huiqing; Hu, Yajie; Sun, Xuemei; Peng, Huisheng

    2018-03-01

    Since the discovery of conjugated polymers in the 1970s, they have attracted considerable interest in light of their advantages of having a tunable bandgap, high electroactivity, high flexibility, and good processability compared to inorganic conducting materials. The above combined advantages make them promising for effective energy harvesting and storage, which have been widely studied in recent decades. Herein, the key advancements in the use of conjugated polymers for flexible energy harvesting and storage are reviewed. The synthesis, structure, and properties of conjugated polymers are first summarized. Then, their applications in flexible polymer solar cells, thermoelectric generators, supercapacitors, and lithium-ion batteries are described. The remaining challenges are then discussed to highlight the future direction in the development of conjugated polymers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Fullerene-biomolecule conjugates and their biomedicinal applications.

    Yang, Xinlin; Ebrahimi, Ali; Li, Jie; Cui, Quanjun

    2014-01-01

    Fullerenes are among the strongest antioxidants and are characterized as "radical sponges." The research on biomedicinal applications of fullerenes has achieved significant progress since the landmark publication by Friedman et al in 1993. Fullerene-biomolecule conjugates have become an important area of research during the past 2 decades. By a thorough literature search, we attempt to update the information about the synthesis of different types of fullerene-biomolecule conjugates, including fullerene-containing amino acids and peptides, oligonucleotides, sugars, and esters. Moreover, we also discuss in this review recently reported data on the biological and pharmaceutical utilities of these compounds and some other fullerene derivatives of biomedical importance. While within the fullerene-biomolecule conjugates, in which fullerene may act as both an antioxidant and a carrier, specific targeting biomolecules conjugated to fullerene will undoubtedly strengthen the delivery of functional fullerenes to sites of clinical interest.

  4. Factors contributing to the immunogenicity of meningococcal conjugate vaccines

    Bröker, Michael; Berti, Francesco; Costantino, Paolo

    2016-01-01

    ABSTRACT Various glycoprotein conjugate vaccines have been developed for the prevention of invasive meningococcal disease, having significant advantages over pure polysaccharide vaccines. One of the most important features of the conjugate vaccines is the induction of a T-cell dependent immune response, which enables both the induction of immune memory and a booster response after repeated immunization. The nature of the carrier protein to which the polysaccharides are chemically linked, is often regarded as the main component of the vaccine in determining its immunogenicity. However, other factors can have a significant impact on the vaccine's profile. In this review, we explore the physico-chemical properties of meningococcal conjugate vaccines, which can significantly contribute to the vaccine's immunogenicity. We demonstrate that the carrier is not the sole determining factor of the vaccine's profile, but, moreover, that the conjugate vaccine's immunogenicity is the result of multiple physico-chemical structures and characteristics. PMID:26934310

  5. Side Chain Engineering in Solution-Processable Conjugated Polymers

    Mei, Jianguo; Bao, Zhenan

    2014-01-01

    Side chains in conjugated polymers have been primarily utilized as solubilizing groups. However, these side chains have roles that are far beyond. We advocate using side chain engineering to tune a polymer's physical properties, including absorption

  6. Augmented asymmetrical visual field dependence in asymptomatic diabetics: evidence of subclinical asymmetrical bilateral vestibular dysfunction.

    Razzak, Rima Abdul; Bagust, Jeffery; Docherty, Sharon; Hussein, Wiam; Al-Otaibi, Abdullah

    2015-01-01

    Diabetes negatively affects the vestibular system in many ways, with vestibular dysfunction (VD), a co-morbidity with a high prevalence in diabetics. The ability to perceive subjective visual vertical (SVV), as a sign of vestibular dysfunction, and visual field dependence was measured using a computerized rod and frame test (CRAF). Alignment errors recorded from 47 asymptomatic Type II diabetics (no vertigo or falls, without peripheral neuropathy or retinopathy) were compared to 29 healthy age matched (46-69years) controls. Visual field dependence was significantly larger and more asymmetrical in the diabetics than controls. In the absence of any visual references, or when a vertical reference frame was provided, SVV perception was accurate in both groups, with no significant difference between the controls and diabetics. During tilted frame presentations, the proportion of subjects with either SVV deviations, or an asymmetry index, larger than an upper limit derived from the control data was significantly greater in diabetics than controls. These results suggest that the decreased ability to resolve visuo-vestibular conflict in asymptomatic diabetic patients (free of retinopathy and peripheral neuropathy) compared to controls may be related to diabetic complications affecting vestibular structures and thus causing a decompensation of subclinical vestibular asymmetries. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Option Pricing with Asymmetric Heteroskedastic Normal Mixture Models

    Rombouts, Jeroen V. K; Stentoft, Lars

    2015-01-01

    We propose an asymmetric GARCH in mean mixture model and provide a feasible method for option pricing within this general framework by deriving the appropriate risk neutral dynamics. We forecast the out-of-sample prices of a large sample of options on the S&P 500 index from January 2006 to December...

  8. Reputations in Markets with Asymmetric Information: A Classroom Game

    Wolf, James R.; Myerscough, Mark A.

    2007-01-01

    The authors describe a classroom game used to teach students about the impact of reputations in markets with asymmetric information. The game is an extension of Holt and Sherman's lemons market game and simulates a market under three information conditions. In the full information setting, all participants know both the quality and the price of…

  9. DNA-based asymmetric organometallic catalysis in water

    Oelerich, Jens; Roelfes, Gerard

    2013-01-01

    Here, the first examples of DNA-based organometallic catalysis in water that give rise to high enantioselectivities are described. Copper complexes of strongly intercalating ligands were found to enable the asymmetric intramolecular cyclopropanation of alpha-diazo-beta-keto sulfones in water. Up to

  10. Bertrand Competition with Asymmetric Costs: A Solution in Pure Strategies

    Demuynck, Thomas; Herings, P. Jean-Jacques; Saulle, Riccardo D.; Seel, Christian

    2018-01-01

    We consider two versions of a Bertrand duopoly with asymmetric costs and homogeneous goods. They differ in whether predatory pricing is allowed. For each version, we derive the Myopic Stable Set in pure strategies as introduced by Demuynck, Herings, Saulle, and Seel (2017). We contrast our

  11. Asymmetric block copolymers confined in a thin film

    Huinink, HP; Brokken-Zijp, JCM; van Dijk, MA; Sevink, GJA

    2000-01-01

    We have used a dynamic density functional theory (DDFT) for polymeric systems, to simulate the formation of micro phases in a melt of an asymmetric block copolymer, A(n)B(m)(f(A) = 1/3), both in the bulk and in a thin film. In the DDFT model a polymer is represented as a chain of springs and beads.

  12. On the topology defined by Thurston's asymmetric metric

    Papadopoulos, Athanase; Theret, Guillaume

    2007-01-01

    that the topology that the asymmetric metric L induces on Teichmüller space is the same as the usual topology. Furthermore, we show that L satisfies the axioms of a (not necessarily symmetric) metric in the sense of Busemann and conclude that L is complete in the sense of Busemann....

  13. Economic Dispatch of Demand Response Balancing through Asymmetric Block Offers

    O'Connell, Niamh; Pinson, Pierre; Madsen, Henrik

    2015-01-01

    This paper proposes a method of describing the load shifting ability of flexible electrical loads in a manner suitable for existing power system dispatch frameworks. The concept of an asymmetric block offer for flexible loads is introduced. This offer structure describes the ability of a flexible...

  14. All Pseudocapacitive MXene-RuO2 Asymmetric Supercapacitors

    Jiang, Qiu

    2018-01-23

    2D transition metal carbides and nitrides, known as MXenes, are an emerging class of 2D materials with a wide spectrum of potential applications, in particular in electrochemical energy storage. The hydrophilicity of MXenes combined with their metallic conductivity and surface redox reactions is the key for high-rate pseudocapacitive energy storage in MXene electrodes. However, symmetric MXene supercapacitors have a limited voltage window of around 0.6 V due to possible oxidation at high anodic potentials. In this study, the fact that titanium carbide MXene (Ti3C2Tx) can operate at negative potentials in acidic electrolyte is exploited, to design an all-pseudocapacitive asymmetric device by combining it with a ruthenium oxide (RuO2) positive electrode. This asymmetric device operates at a voltage window of 1.5 V, which is about two times wider than the operating voltage window of symmetric MXene supercapacitors, and is the widest voltage window reported to date for MXene-based supercapacitors. The complementary working potential windows of MXene and RuO2, along with proton-induced pseudocapacitance, significantly enhance the device performance. As a result, the asymmetric devices can deliver an energy density of 37 µW h cm−2 at a power density of 40 mW cm−2, with 86% capacitance retention after 20 000 charge–discharge cycles. These results show that pseudocapacitive negative MXene electrodes can potentially replace carbon-based materials in asymmetric electrochemical capacitors, leading to an increased energy density.

  15. Design of activated carbon/activated carbon asymmetric capacitors

    Piñeiro-Prado, Isabel; Salinas-Torres, David; Ruiz Rosas, Ramiro; Morallon, Emilia; Cazorla-Amoros, Diego

    2016-03-01

    Supercapacitors are energy storage devices that offer a high power density and a low energy density in comparison with batteries. Their limited energy density can be overcome by using asymmetric configuration in mass electrodes, where each electrode works within their maximum available potential window, rendering the maximum voltage output of the system. Such asymmetric capacitors must be optimized through careful electrochemical characterization of the electrodes for accurate determination of the capacitance and the potential stability limits. The results of the characterization are then used for optimizing mass ratio of the electrodes from the balance of stored charge. The reliability of the design largely depends on the approach taken for the electrochemical characterization. Therefore, the performance could be lower than expected and even the system could break down, if a well thought out procedure is not followed. In this work, a procedure for the development of asymmetric supercapacitors based on activated carbons is detailed. Three activated carbon materials with different textural properties and surface chemistry have been systematically characterized in neutral aqueous electrolyte. The asymmetric configuration of the masses of both electrodes in the supercapacitor has allowed to cover a higher potential window, resulting in an increase of the energy density of the three devices studied when compared with the symmetric systems, and an improved cycle life.

  16. Investment and Internal Finance: Asymmetric Information or Managerial Discretion?

    H. Degryse (Hans); A. de Jong (Abe)

    2001-01-01

    textabstractThis paper examines the relation between cash-flow availability and investment spending in the Netherlands. In particular, we are interested whether managerial discretion and/or asymmetric information drive the positive relation between cash-flow and investment spending. This relation

  17. Non-stationary probabilities for the asymmetric exclusion process on ...

    rich picture of relaxation processes which provides an extension of notions of equi- librium statistical mechanics such as phase transitions and spontaneous symmetry breaking to the non-equilibrium case. The asymmetric exclusion process (ASEP) is the simplest model of non-equilibrium theory of many interacting particles ...

  18. Non-stationary probabilities for the asymmetric exclusion process

    A solution of the master equation for a system of interacting particles for finite time and particle density is presented. By using a new form of the Bethe ansatz, the totally asymmetric exclusion process on a ring is solved for arbitrary initial conditions and time intervals.

  19. Linguistic Correlates of Asymmetric Motor Symptom Severity in Parkinson's Disease

    Holtgraves, Thomas; McNamara, Patrick; Cappaert, Kevin; Durso, Raymond

    2010-01-01

    Asymmetric motor severity is common in Parkinson's Disease (PD) and provides a method for examining the neurobiologic mechanisms underlying cognitive and linguistic deficits associated with the disorder. In the present research, PD participants (N = 31) were assessed in terms of the asymmetry of their motor symptoms. Interviews with the…

  20. Asymmetric Modeling of the Industrial Heavy Water Plant (PIAP)

    Teruel, Federico; Aprea, J; Guido Lavalle, German

    2000-01-01

    Software of asymmetric stationary simulation for the Industrial Heavy Water Plant (PIAP) was developed, based on an existing symmetric simulator (Brigitte 2.0).This software allows to turn off some of the isotopic enrichment twin units present in the plant and to simulate them asymmetrically, in other words, with different selection of parameters between twins.Other incorporations were done, such as passing flows between units and entering flows in strategic points of the plant.The iterative system in which the symmetric simulator is based was insufficient to develop the asymmetric simulator, so the system was modeled according to an implicit scheme for the units that form the simulator.This type of resolution resulted in a simulator that supports a big range of boundary conditions and internal parameters.Moreover, the time of calculus is short (∼3 minutes), making it actually useful.The asymmetric simulator is at the PIAP now, for its study and validation. It shows expected tendencies and results according to the symmetric simulator already validated

  1. Proline-catalysed asymmetric ketol cyclizations: The template ...

    Unknown

    Abstract. A modified template mechanism based on modelling studies of energy minimised complexes is presented for the asymmetric proline-catalysed cyclization of triketones 1, 2 and 3 to the 2S,3S-ketols. 1a, 2a and 3a respectively. The template model involves a three-point contact as favoured in enzyme– substrate ...

  2. Asymmetric Adjustment in the Ethanol and Grains Markets

    C-L. Chang (Chia-Lin); L.H. Chen (Li-Hsueh); S.M. Hammoudeh (Shawkat); M.J. McAleer (Michael)

    2011-01-01

    textabstractThis paper examines the long- and short-run asymmetric adjustments for nine pairs of spot and futures prices, itemized as three own pairs for three different bio-fuel ethanol types, three own pairs for three related agricultural products, namely corn, soybeans and sugar, and three cross

  3. The catalystic asymmetric synthesis of optically active epoxy ketones

    Marsman, Bertha Gerda

    1981-01-01

    In this thesis the use of catalytic asymmetric synthesis to prepare optically active epoxy ketones is described. This means that the auxiliary chirality, necessary to obtain an optically active product, is added in a catalytic quantity . In principle this is a very efficient way to make opticlly

  4. Cell Chirality Drives Left-Right Asymmetric Morphogenesis.

    Inaki, Mikiko; Sasamura, Takeshi; Matsuno, Kenji

    2018-01-01

    Most macromolecules found in cells are chiral, meaning that they cannot be superimposed onto their mirror image. However, cells themselves can also be chiral, a subject that has received little attention until very recently. In our studies on the mechanisms of left-right (LR) asymmetric development in Drosophila , we discovered that cells can have an intrinsic chirality to their structure, and that this "cell chirality" is generally responsible for the LR asymmetric development of certain organs in this species. The actin cytoskeleton plays important roles in the formation of cell chirality. In addition, Myosin31DF ( Myo31DF ), which encodes Drosophila Myosin ID, was identified as a molecular switch for cell chirality. In other invertebrate species, including snails and Caenorhabditis elegans , chirality of the blastomeres, another type of cell chirality, determines the LR asymmetry of structures in the body. Thus, chirality at the cellular level may broadly contribute to LR asymmetric development in various invertebrate species. Recently, cell chirality was also reported for various vertebrate cultured cells, and studies suggested that cell chirality is evolutionarily conserved, including the essential role of the actin cytoskeleton. Although the biological roles of cell chirality in vertebrates remain unknown, it may control LR asymmetric development or other morphogenetic events. The investigation of cell chirality has just begun, and this new field should provide valuable new insights in biology and medicine.

  5. Asymmetrical Modulation for Uplink Communication in Cooperative Networks

    Zhang, Qi; Fitzek, Frank H.P.; Iversen, Villy Bæk

    2008-01-01

    -range links with neighboring mobile devices to form cooperative clusters. So far the physical communication over cellular links and over short-range links are separated in time or in frequency. Beyond this state of the art, we exploit a method, referred to as asymmetrical modulation, where a mobile device...

  6. Review of literature on the asymmetric collapse of vapor bubbles

    Fremd, R.; Froehlich, G.

    1977-06-01

    This report contains a review of literature on the asymmetric collape of vapor bubbles by cavitation with special consideration to vapor explosions. Two numerical models, which describe the collapse of cavities in the neighbourhood of a solid surface, are presented. Moreover experimental results for this case are provided. Propositions to apply the numerical models to vapor explosions are made. (orig.) [de

  7. Symmetrical and asymmetrical growth restriction in preterm-born children

    Bocca-Tjeertes, Inger; Bos, Arend; Kerstjens, Jorien; de Winter, Andrea; Reijneveld, Sijmen

    OBJECTIVE: To determine how symmetric (proportionate; SGR) and asymmetric (disproportionate; AGR) growth restriction influence growth and development in preterms from birth to 4 years. METHODS: This community-based cohort study of 810 children comprised 86 SGR, 61 AGR, and 663 non-growth restricted

  8. Analysis of the asymmetrical shortest two-server queueing model

    J.W. Cohen

    1995-01-01

    textabstractThis study presents the analytic solution for the asymmetrical two-server queueing model with arriving customers joining the shorter queue for the case with Poisson arrivals and negative exponentially distributed service times. The bivariate generating function of the stationary joint

  9. New approaches in asymmetric synthesis using γ-alkoxybutenolides

    Lange, Ben de; Jansen, Johan F.G.A.; Jong, Johannes C. de; Lubben, Marcel; Faber, Wijnand; Schudde, Ebe P.; Feringa, Bernard

    1992-01-01

    The synthesis of a new class of auxiliary based chiral synthons, γ-alkoxy-2(5H)-furanones, is described. The multifunctional compounds enter a variety of asymmetric transformations leading to acyclic- and cyclic-products with up to four new stereogenic centers in a single operation with

  10. Materials dependence of mixed gas plasticization behavior in asymmetric membranes

    Visser, Tymen; Masetto, N.; Wessling, Matthias

    2007-01-01

    The mass transport of asymmetric membranes for the separation of carbon dioxide/methane mixtures is determined by competitive sorption and plasticization. With increasing feed pressure in mixed gas experiments, the selectivity decreases due to both effects. Distinction whether one or the other

  11. Design of activated carbon/activated carbon asymmetric capacitors

    Isabel ePiñeiro-Prado

    2016-03-01

    Full Text Available Supercapacitors are energy storage devices that offer a high power density and a low energy density in comparison with batteries. Their limited energy density can be overcome by using asymmetric configuration in mass electrodes, where each electrode works within their maximum available potential window, rendering the maximum voltage output of the system. Such asymmetric capacitors must be optimized through careful electrochemical characterization of the electrodes for accurate determination of the capacitance and the potential stability limits. The results of the characterization are then used for optimizing mass ratio of the electrodes from the balance of stored charge. The reliability of the design largely depends on the approach taken for the electrochemical characterization. Therefore, the performance could be lower than expected and even the system could break down, if a well thought out procedure is not followed.In this work, a procedure for the development of asymmetric supercapacitors based on activated carbons is detailed. Three activated carbon materials with different textural properties and surface chemistry have been systematically characterized in neutral aqueous electrolyte. The asymmetric configuration of the masses of both electrodes in the supercapacitor has allowed to cover a higher potential window, resulting in an increase of the energy density of the three devices studied when compared with the symmetric systems, and an improved cycle life.

  12. Asymmetric electroresistance of cluster glass state in manganites

    Lourembam, James; Ding, Junfeng; Bera, Ashok; Lin, Weinan; Wu, Tao

    2014-01-01

    cluster glass magnetic state emerges at low temperatures with a spin freezing temperature of about 99 K, which is accompanied by the reentrant insulating state with high resistance below 30 K. In the EDLT, we observe bipolar and asymmetric modulation

  13. Clinical characteristics in patients with asymmetric idiopathic pulmonary fibrosis.

    Callahan, Sean J; Xia, Meng; Murray, Susan; Flaherty, Kevin R

    2016-10-01

    A group of patients with idiopathic pulmonary fibrosis (IPF) presents with disease affecting one lung markedly more than the other. At this time, it is unclear how this population differs from those who present with more symmetric disease. We sought to explain the characteristics of the asymmetric group and how their disease progresses. In this retrospective case-control study we accessed an interstitial lung disease (ILD) database and identified 14 asymmetric IPF cases via high-resolution computed tomography (HRCT) scoring of each lung lobe's disease severity. We identified 28 symmetric IPF controls from the same database using the same methods, and compared the clinical features of each group. Patients with asymmetric disease exhibited similar demographics as those in the general IPF population; they were predominantly male (64%), elderly (69 years old), and used tobacco (57%). We found a trend toward significantly increased all-cause mortality in the case population two years following diagnosis (p = 0.089). Pulmonary function tests were significantly lower in the case group at the time of diagnosis, then both groups experienced gradual decline. We found no statistically significant differences in number of IPF exacerbations (cases 43%, controls 39%, p = 0.824) and gastro-esophageal reflux (both groups 50%). Patients with asymmetric IPF resemble patients in the general IPF population but may have a lower overall survival rate. Further systemic factors may be studied to identify reasons for disease asymmetry and clinical decline in this population. Published by Elsevier Ltd.

  14. Simulation of seismic signals from asymmetric LANL hydrodynamic calculations

    Stevens, J.L.; Rimer, N.; Halda, E.J.; Barker, T.G.; Davis, C.G.; Johnson, W.E.

    1993-01-01

    Hydrodynamic calculations of an asymmetric nuclear explosion source were propagated to teleseismic distances to investigate the effects of the asymmetric source on seismic signals. The source is an explosion in a 12 meter long canister with the device at one end of the canister and a metal plate adjacent to the explosion. This produces a strongly asymmetric two-lobed source in the hydrodynamic region. The hydrodynamic source is propagated to the far field using a three-step process. The Eulerian hydrodynamic code SOIL was used by LANL to calculate the material velocity, density, and internal energy up to a time of 8.9 milliseconds after the explosion. These quantities were then transferred to an initial grid for the Lagrangian elastic/plastic finite difference code CRAM, which was used by S-CUBED to propagate the signal through the region of nonlinear deformation into the external elastic region. The cavity size and shape at the time of the overlay were determined by searching for a rapid density change in the SOIL grid, and this interior region was then rezoned into a single zone. The CRAM calculation includes material strength and gravity, and includes the effect of the free surface above the explosion. Finally, far field body waves were calculated by integrating over a closed surface in the elastic region and using the representation theorem. A second calculation was performed using an initially spherical source for comparison with the asymmetric calculation

  15. Novel Cinchona derived organocatalysts: new asymmetric transformations and catalysis

    Breman, A.C.

    2014-01-01

    Cinchona alkaloids have a long history as being a powerful medicine against malaria. Since a relative short period (about 50 years) chemist have also used these alkaloids as chiral catalyst for a wide variety of asymmetric transformations. Especially since the beginning of this century, when strong

  16. Stability of asymmetric lipid bilayers assessed by molecular dynamics simulations

    Esteban-Martin, Santi; Risselada, H. Jelger; Salgado, Jesus; Marrink, Siewert J.

    2009-01-01

    The asymmetric insertion of amphiphiles into biological membranes compromises the balance between the inner and outer monolayers. As a result, area expansion of the receiving leaflet and curvature strain may lead to membrane permeation, shape changes, or membrane fusion events. We have conducted

  17. Current Topics in the Asymmetric Transfer Hydrogenation of Imines

    Januščák, J.; Václavík, Jiří; Šot, P.; Pecháček, J.; Vilhanová, B.; Kuzma, Marek; Kačer, P.

    2015-01-01

    Roč. 109, č. 7 (2015), s. 492-498 ISSN 0009-2770 R&D Projects: GA ČR GAP106/12/1276; GA MŠk(CZ) LO1509 Institutional support: RVO:61388971 Keywords : asymmetric transfer hydrogenation * ruthenium * isoquinoline Subject RIV: EE - Microbiology, Virology Impact factor: 0.279, year: 2015

  18. Beamwidth for asymmetric and multilayer semiconductor laser structures

    Buus, Jens

    1981-01-01

    An expression for the far field of the fundamental TE0mode in an asymmetrical dielectric slab waveguide is derived. By using normalized waveguide parameters, universal plots of the beamwidth are presented. These plots include the obliquity factor correction. Experimental results for symmetrical G...

  19. Accelerating foreign-key joins using asymmetric memory channels

    Pirk, H.; Manegold, S.; Kersten, M.

    2011-01-01

    Indexed Foreign-Key Joins expose a very asymmetric access pattern: the Foreign-Key Index is sequentially scanned whilst the Primary-Key table is target of many quasi-random lookups which is the dominant cost factor. To reduce the costs of the random lookups the fact-table can be (re-) partitioned at

  20. Ion Motion Stability in Asymmetric Surface Electrode Ion Traps

    Shaikh, Fayaz; Ozakin, Arkadas

    2010-03-01

    Many recently developed designs of the surface electrode ion traps for quantum information processing have asymmetry built into their geometries. The asymmetry helps rotate the trap axes to angles with respect to electrode surface that facilitate laser cooling of ions but introduces a relative angle between the RF and DC fields and invalidates the classical stability analysis of the symmetric case for which the equations of motion are decoupled. For asymmetric case the classical motion of a single ion is given by a coupled, multi-dimensional version of Mathieu's equation. In this poster we discuss the stability diagram of asymmetric surface traps by performing an approximate multiple scale perturbation analysis of the coupled Mathieu equations, and validate the results with numerical simulations. After obtaining the stability diagram for the linear fields, we simulate the motion of an ion in a given asymmetric surface trap, utilizing a method-of-moments calculation of the electrode fields. We obtain the stability diagram and compare it with the ideal case to find the region of validity. Finally, we compare the results of our stability analysis to experiments conducted on a microfabricated asymmetric surface trap.

  1. The on-line asymmetric traveling salesman problem

    Ausiello, G.; Bonifaci, V.; Laura, L.

    2008-01-01

    We consider two on-line versions of the asymmetric traveling salesman problem with triangle inequality. For the homing version, in which the salesman is required to return in the city where it started from, we give a -competitive algorithm and prove that this is best possible. For the nomadic

  2. Bertrand Competition with an Asymmetric No-Discrimination Constraint

    Bouckaert, J.M.C.; Degryse, H.A.; van Dijk, T.

    2012-01-01

    Abstract: We study the competitive and welfare consequences when only one firm must commit to uniform pricing while the competitor’s pricing policy is left unconstrained. The asymmetric no-discrimination constraint prohibits both behaviour-based price discrimination within the competitive segment

  3. Modulational Instability in Linearly Coupled Asymmetric Dual-Core Fibers

    Arjunan Govindarajan

    2017-06-01

    Full Text Available We investigate modulational instability (MI in asymmetric dual-core nonlinear directional couplers incorporating the effects of the differences in effective mode areas and group velocity dispersions, as well as phase- and group-velocity mismatches. Using coupled-mode equations for this system, we identify MI conditions from the linearization with respect to small perturbations. First, we compare the MI spectra of the asymmetric system and its symmetric counterpart in the case of the anomalous group-velocity dispersion (GVD. In particular, it is demonstrated that the increase of the inter-core linear-coupling coefficient leads to a reduction of the MI gain spectrum in the asymmetric coupler. The analysis is extended for the asymmetric system in the normal-GVD regime, where the coupling induces and controls the MI, as well as for the system with opposite GVD signs in the two cores. Following the analytical consideration of the MI, numerical simulations are carried out to explore nonlinear development of the MI, revealing the generation of periodic chains of localized peaks with growing amplitudes, which may transform into arrays of solitons.

  4. QUARTZ: a numerical simulation of an asymmetric electrostatic accelerator

    Wooten, J.W.; Drooks, L.J.; McCollough, D.H.; McGaffey, R.W.; Whealton, J.H.

    1979-01-01

    The physics and numerical aspects of the development of the computer code QUARTZ are given. This code includes the (1) use of a finite element code to obtain solutions of Poisson's equation in an asymmetric, three-dimensional volume; (2) inclusion of space charge neutralization by electrons; and (3) inclusion of ion space charge through an iterative procedure

  5. Simulation of the longitudinal instabilities of the asymmetric bunches

    Dai Jianping; Zhao Zhentang

    2002-01-01

    The computational model of the code used to simulate the longitudinal instabilities of the asymmetric bunches was introduced. The growth rates of the longitudinal instabilities of the symmetric bunches got by this code were compared with those got by the code ZAP, and they were almost the same. As an example, the simulation results of the BEPC-II were presented

  6. Asymmetric bipolar membrane: A tool to improve product purity

    Balster, J.H.; Sumbharaju, R.; Srikantharajah, S.; Punt, Ineke G.M.; Stamatialis, Dimitrios; Jordan, V.; Wessling, Matthias

    2007-01-01

    Bipolar membranes (BPMs) are catalytic membranes for electro-membrane processes splitting water into protons and hydroxyl ions. To improve selectivity and current efficiency of BPMs, we prepare new asymmetric BPMs with reduced salt leakages. The flux of salt ions across a BPM is determined by the

  7. Gold Nanoparticle Conjugation Enhances the Antiacanthamoebic Effects of Chlorhexidine

    Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Anwar, Ayaz; Shah, Muhammad Raza

    2015-01-01

    Acanthamoeba keratitis is a serious infection with blinding consequences and often associated with contact lens wear. Early diagnosis, followed by aggressive topical application of drugs, is a prerequisite in successful treatment, but even then prognosis remains poor. Several drugs have shown promise, including chlorhexidine gluconate; however, host cell toxicity at physiologically relevant concentrations remains a challenge. Nanoparticles, subcolloidal structures ranging in size from 10 to 100 nm, are effective drug carriers for enhancing drug potency. The overall aim of the present study was to determine whether conjugation with gold nanoparticles enhances the antiacanthamoebic potential of chlorhexidine. Gold-conjugated chlorhexidine nanoparticles were synthesized. Briefly, gold solution was mixed with chlorhexidine and reduced by adding sodium borohydride, resulting in an intense deep red color, indicative of colloidal gold-conjugated chlorhexidine nanoparticles. The synthesis was confirmed using UV-visible spectrophotometry that shows a plasmon resonance peak of 500 to 550 nm, indicative of gold nanoparticles. Further characterization using matrix-assisted laser desorption ionization-mass spectrometry showed a gold-conjugated chlorhexidine complex at m/z 699 ranging in size from 20 to 100 nm, as determined using atomic force microscopy. To determine the amoebicidal and amoebistatic effects, amoebae were incubated with gold-conjugated chlorhexidine nanoparticles. For controls, amoebae also were incubated with gold and silver nanoparticles alone, chlorhexidine alone, neomycin-conjugated nanoparticles, and neomycin alone. The findings showed that gold-conjugated chlorhexidine nanoparticles exhibited significant amoebicidal and amoebistatic effects at 5 μM. Amoebicidal effects were observed by parasite viability testing using a Trypan blue exclusion assay and flow-cytometric analysis using propidium iodide, while amoebistatic effects were observed using growth

  8. Occurrence of Conjugated Linolenic Acids in Purified Soybean Oil

    Kinami, Tomohisa; Horii, Naoto; Narayan, Bhaskar; Arato, Shingo; Hosokawa, Masashi; Miyashita, Kazuo; Negishi, Hironori; Ikuina, Junichi; Noda, Ryuji; Shirasawa, Seiichi

    2007-01-01

    A high-performance liquid chromatographic (HPLC) method is described for the determination of conjugated linoleic acids (CLA) and conjugated linolenic acids (CLN). Methyl esters prepared from purified lipid fractions of soybean oil were analyzed using an HPLC system equipped with photodiode-array detector to detect peaks having maximum absorption around 233 and 275 nm. These peaks were concentrated by AgNO3-silicic acid column chromatography and reversed-phase HPLC. The structural analysis, o...

  9. Ways to Optimize Therapy of Prolonged Conjugation Jaundice in Infants

    O.G. Shadrin

    2015-09-01

    Full Text Available The article is devoted to the optimization of the treatment of prolonged conjugation jaundice. Inclusion of ursodeoxycholic acid in the treatment of neonatal prolonged conjugation jaundice in a dose of 15–20 mg/kg of body mass per day increases the terms of regression of clinical and paraclinical signs of jaundice as much as 2 times and leads to cytolysis normalization. The preparation has a sufficient level of safety, there were not revealed side effects whilst its application.

  10. Information properties of a hologram of mutually conjugate waves

    Rubanov, A.S.; Serebryakova, L.M.

    1995-01-01

    A theoretical study of information properties of a correlation response to a fragment of an image of a thin referenceless hologram of mutually conjugate waves that is recorded with a phase-conjugating (PC) mirror is reported. It is shown that this hologram reconstructs a full image in reflected light and can be used as an associative storage device and as a selective PC mirror. 7 refs., 1 fig

  11. New Conjugacy Conditions and Related Nonlinear Conjugate Gradient Methods

    Dai, Y.-H.; Liao, L.-Z.

    2001-01-01

    Conjugate gradient methods are a class of important methods for unconstrained optimization, especially when the dimension is large. This paper proposes a new conjugacy condition, which considers an inexact line search scheme but reduces to the old one if the line search is exact. Based on the new conjugacy condition, two nonlinear conjugate gradient methods are constructed. Convergence analysis for the two methods is provided. Our numerical results show that one of the methods is very efficient for the given test problems

  12. Several Guaranteed Descent Conjugate Gradient Methods for Unconstrained Optimization

    San-Yang Liu

    2014-01-01

    Full Text Available This paper investigates a general form of guaranteed descent conjugate gradient methods which satisfies the descent condition gkTdk≤-1-1/4θkgk2  θk>1/4 and which is strongly convergent whenever the weak Wolfe line search is fulfilled. Moreover, we present several specific guaranteed descent conjugate gradient methods and give their numerical results for large-scale unconstrained optimization.

  13. Conjugated linoleic acid in ewe milk fat.

    Luna, Pilar; Fontecha, Javier; Juárez, Manuela; de la Fuente, Miguel Angel

    2005-11-01

    Ewe milk fat from five different herds was studied to determine the content of conjugated linoleic acid (CLA) isomers. Research was carried out by combining gas chromatography-mass spectrometry (GC-MS) of fatty acid methyl esters (FAME) and 4,4-dimethyloxazolyne derivatives (DMOX) with silver ion-high performance liquid chromatography (Ag+-HPLC). Reconstructed mass spectral profiles of CLA characteristic ions from DMOX were used to identify positional isomers and Ag+-HPLC to quantify them. Total CLA content varied from 0.57 to 0.97 g/100 g of total fatty acids. FAME and DMOX were separated into a complex mixture of minor isomers and major rumenic acid (9-cis 11-trans C18:2) by GC-MS using a 100-m polar capillary column. Rumenic acid would represent more than 75% of total CLA. 11-trans 13-trans, 11-13 cis/trans plus trans/cis and 7-9 cis/trans plus trans/cis were the main CLA isomers after rumenic acid. Minor amounts of 8-10 and 10-12 C18:2 isomers were also found. Although most of the isomers were present in each herd's milk, differences in content were observed for some CLA species.

  14. Microfluidic Fabrication of Conjugated Polymer Sensor Fibers

    Yoo, Imsung; Song, Simon [Hanyang University, Seoul (Korea, Republic of)

    2014-10-15

    We propose a fabrication method for polydiacetylene (PDA)-embedded hydrogel microfibers on a microfluidic chip. These fibers can be applied to the detection of cyclodextrines (CDs), which are a family of sugar and aluminum ions. PDA, a family of conjugated polymers, has unique characteristics when used for a sensor, because it undergoes a blue-to-red color transition and nonfluorescence-to-fluorescence transition in response to environmental stimulation. PDAs have different sensing characteristics depending on the head group of PCDA. By taking advantage of ionic crosslinking-induced hydrogel formation and the 3D hydrodynamic focusing effect on a microfluidic chip, PCDA-EDEA-derived diacetylene (DA) monomer-embedded microfibers were successfully fabricated. UV irradiation of the fibers afforded blue-colored PDA, and the resulting blue PDA fibers underwent a phase transition to red and emitted red fluorescence upon exposure to CDs and aluminum ions. Their fluorescence intensity varied depending on the CDs and aluminum ion concentrations. This phase transition was also observed when the fibers were dried.

  15. Theory of Periodic Conjugate Heat Transfer

    Zudin, Yuri B

    2012-01-01

    This book presents the theory of periodic conjugate heat transfer in a detailed way. The effects of thermophysical properties and geometry of a solid body on the commonly used and experimentally determined heat transfer coefficient are analytically presented from a general point of view. The main objective of the book is a simplified description of the interaction between a solid body and a fluid as a boundary value problem of the heat conduction equation for the solid body. At the body surface, the true heat transfer coefficient is composed of two parts: the true mean value resulting from the solution of the steady state heat transfer problem and a periodically variable part, the periodic time and length to describe the oscillatory hydrodynamic effects. The second edition is extended by (i) the analysis of stability boundaries in helium flow at supercritical conditions in a heated channel with respect to the interaction between a solid body and a fluid; (ii) a periodic model and a method of heat transfer sim...

  16. Photodynamic tissue adhesion with chlorin(e6) protein conjugates.

    Khadem, J; Veloso, A A; Tolentino, F; Hasan, T; Hamblin, M R

    1999-12-01

    To test the hypothesis that a photodynamic laser-activated tissue solder would perform better in sealing scleral incisions when the photosensitizer was covalently linked to the protein than when it was noncovalently mixed. Conjugates and mixtures were prepared between the photosensitizer chlorin(e6) and various proteins (albumin, fibrinogen, and gelatin) in different ratios and used to weld penetrating scleral incisions made in human cadaveric eyes. A blue-green (488-514 nm) argon laser activated the adhesive, and the strength of the closure was measured by increasing the intraocular pressure until the wound showed leakage. Both covalent conjugates and noncovalent mixtures showed a light dose-dependent increase in leaking pressure. A preparation of albumin chlorin(e6) conjugate with additional albumin added (2.5 protein to chlorin(e6) molar ratio) showed significantly higher weld strength than other protein conjugates and mixtures. This is the first report of dye-protein conjugates as tissue solders. These conjugates may have applications in ophthalmology.

  17. Intense correlation between brain infarction and protein-conjugated acrolein.

    Saiki, Ryotaro; Nishimura, Kazuhiro; Ishii, Itsuko; Omura, Tomohiro; Okuyama, Shigeru; Kashiwagi, Keiko; Igarashi, Kazuei

    2009-10-01

    We recently found that increases in plasma levels of protein-conjugated acrolein and polyamine oxidases, enzymes that produce acrolein, are good markers for stroke. The aim of this study was to determine whether the level of protein-conjugated acrolein is increased and levels of spermine and spermidine, the substrates of acrolein production, are decreased at the locus of infarction. A unilateral infarction was induced in mouse brain by photoinduction after injection of Rose Bengal. The volume of the infarction was analyzed using the public domain National Institutes of Health image program. The level of protein-conjugated acrolein at the locus of infarction and in plasma was measured by Western blotting and enzyme-linked immunosorbent assay, respectively. The levels of polyamines at the locus of infarction and in plasma were measured by high-performance liquid chromatography. The level of protein-conjugated acrolein was greatly increased, and levels of spermine and spermidine were decreased at the locus of infarction at 24 hours after the induction of stroke. The size of infarction was significantly decreased by N-acetylcysteine, a scavenger of acrolein. It was also found that the increases in the protein-conjugated acrolein, polyamines, and polyamine oxidases in plasma were observed after the induction of stroke. The results indicate that the induction of infarction is well correlated with the increase in protein-conjugated acrolein at the locus of infarction and in plasma.

  18. O:2-CRM(197) conjugates against Salmonella Paratyphi A.

    Micoli, Francesca; Rondini, Simona; Gavini, Massimiliano; Lanzilao, Luisa; Medaglini, Donata; Saul, Allan; Martin, Laura B

    2012-01-01

    Enteric fevers remain a common and serious disease, affecting mainly children and adolescents in developing countries. Salmonella enterica serovar Typhi was believed to cause most enteric fever episodes, but several recent reports have shown an increasing incidence of S. Paratyphi A, encouraging the development of a bivalent vaccine to protect against both serovars, especially considering that at present there is no vaccine against S. Paratyphi A. The O-specific polysaccharide (O:2) of S. Paratyphi A is a protective antigen and clinical data have previously demonstrated the potential of using O:2 conjugate vaccines. Here we describe a new conjugation chemistry to link O:2 and the carrier protein CRM(197), using the terminus 3-deoxy-D-manno-octulosonic acid (KDO), thus leaving the O:2 chain unmodified. The new conjugates were tested in mice and compared with other O:2-antigen conjugates, synthesized adopting previously described methods that use CRM(197) as carrier protein. The newly developed conjugation chemistry yielded immunogenic conjugates with strong serum bactericidal activity against S. Paratyphi A.

  19. O:2-CRM(197 conjugates against Salmonella Paratyphi A.

    Francesca Micoli

    Full Text Available Enteric fevers remain a common and serious disease, affecting mainly children and adolescents in developing countries. Salmonella enterica serovar Typhi was believed to cause most enteric fever episodes, but several recent reports have shown an increasing incidence of S. Paratyphi A, encouraging the development of a bivalent vaccine to protect against both serovars, especially considering that at present there is no vaccine against S. Paratyphi A. The O-specific polysaccharide (O:2 of S. Paratyphi A is a protective antigen and clinical data have previously demonstrated the potential of using O:2 conjugate vaccines. Here we describe a new conjugation chemistry to link O:2 and the carrier protein CRM(197, using the terminus 3-deoxy-D-manno-octulosonic acid (KDO, thus leaving the O:2 chain unmodified. The new conjugates were tested in mice and compared with other O:2-antigen conjugates, synthesized adopting previously described methods that use CRM(197 as carrier protein. The newly developed conjugation chemistry yielded immunogenic conjugates with strong serum bactericidal activity against S. Paratyphi A.

  20. Protein carriers of conjugate vaccines: characteristics, development, and clinical trials.

    Pichichero, Michael E

    2013-12-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products.

  1. Totally Asymmetric Limit for Models of Heat Conduction

    De Carlo, Leonardo; Gabrielli, Davide

    2017-08-01

    We consider one dimensional weakly asymmetric boundary driven models of heat conduction. In the cases of a constant diffusion coefficient and of a quadratic mobility we compute the quasi-potential that is a non local functional obtained by the solution of a variational problem. This is done using the dynamic variational approach of the macroscopic fluctuation theory (Bertini et al. in Rev Mod Phys 87:593, 2015). The case of a concave mobility corresponds essentially to the exclusion model that has been discussed in Bertini et al. (J Stat Mech L11001, 2010; Pure Appl Math 64(5):649-696, 2011; Commun Math Phys 289(1):311-334, 2009) and Enaud and Derrida (J Stat Phys 114:537-562, 2004). We consider here the convex case that includes for example the Kipnis-Marchioro-Presutti (KMP) model and its dual (KMPd) (Kipnis et al. in J Stat Phys 27:6574, 1982). This extends to the weakly asymmetric regime the computations in Bertini et al. (J Stat Phys 121(5/6):843-885, 2005). We consider then, both microscopically and macroscopically, the limit of large externalfields. Microscopically we discuss some possible totally asymmetric limits of the KMP model. In one case the totally asymmetric dynamics has a product invariant measure. Another possible limit dynamics has instead a non trivial invariant measure for which we give a duality representation. Macroscopically we show that the quasi-potentials of KMP and KMPd, which are non local for any value of the external field, become local in the limit. Moreover the dependence on one of the external reservoirs disappears. For models having strictly positive quadratic mobilities we obtain instead in the limit a non local functional having a structure similar to the one of the boundary driven asymmetric exclusion process.

  2. Uniform versus asymmetric shading mediates crown recession in conifers.

    Amanda L Schoonmaker

    Full Text Available In this study we explore the impact of asymmetrical vs. uniform crown shading on the mortality and growth of upper and lower branches within tree crowns, for two conifer species: shade intolerant lodgepole pine (Pinus contorta and shade tolerant white spruce (Picea glauca. We also explore xylem hydraulics, foliar nutrition, and carbohydrate status as drivers for growth and expansion of the lower and upper branches in various types of shading. This study was conducted over a two-year period across 10 regenerating forest sites dominated by lodgepole pine and white spruce, in the lower foothills of Alberta, Canada. Trees were assigned to one of four shading treatments: (1, complete uniform shading of the entire tree, (2 light asymmetric shading where the lower 1/4-1/3 of the tree crown was shaded, (3 heavy asymmetric shading as in (2 except with greater light reduction and (4 control in which no artificial shading occurred and most of the entire crown was exposed to full light. Asymmetrical shading of only the lower crown had a larger negative impact on the bud expansion and growth than did uniform shading, and the effect was stronger in pine relative to spruce. In addition, lower branches in pine also had lower carbon reserves, and reduced xylem-area specific conductivity compared to spruce. For both species, but particularly the pine, the needles of lower branches tended to store less C than upper branches in the asymmetric shade, which could suggest a movement of reserves away from the lower branches. The implications of these findings correspond with the inherent shade tolerance and self-pruning behavior of these conifers and supports a carbon based mechanism for branch mortality--mediated by an asymmetry in light exposure of the crown.

  3. The Impacts of Dry Dynamic Cores on Asymmetric Hurricane Intensification

    Guimond, Stephen R.; Reisner, Jon M.; Marras, Simone; Giraldo, Francis X.

    2016-01-01

    The fundamental pathways for tropical cyclone (TC) intensification are explored by considering axisymmetric and asymmetric impulsive thermal perturbations to balanced, TC-like vortices using the dynamic cores of three different nonlinear numerical models. Attempts at reproducing the results of previous work, which used the community WRF Model, revealed a discrepancy with the impacts of purely asymmetric thermal forcing. The current study finds that thermal asymmetries can have an important, largely positive role on the vortex intensification, whereas other studies find that asymmetric impacts are negligible. Analysis of the spectral energetics of each numerical model indicates that the vortex response to asymmetric thermal perturbations is significantly damped in WRF relative to the other models. Spectral kinetic energy budgets show that this anomalous damping is primarily due to the increased removal of kinetic energy from the vertical divergence of the vertical pressure flux, which is related to the flux of inertia-gravity wave energy. The increased kinetic energy in the other two models is shown to originate around the scales of the heating and propagate upscale with time from nonlinear effects. For very large thermal amplitudes (50 K), the anomalous removal of kinetic energy due to inertia-gravity wave activity is much smaller, resulting in good agreement between models. The results of this paper indicate that the numerical treatment of small-scale processes that project strongly onto inertia-gravity wave energy can lead to significant differences in asymmetric TC intensification. Sensitivity tests with different time integration schemes suggest that diffusion entering into the implicit solution procedure is partly responsible for the anomalous damping of energy.

  4. Asymmetric Aldol Additions: A Guided-Inquiry Laboratory Activity on Catalysis

    King, Jorge H. Torres; Wang, Hong; Yezierski, Ellen J.

    2018-01-01

    Despite the importance of asymmetric catalysis in both the pharmaceutical and commodity chemicals industries, asymmetric catalysis is under-represented in undergraduate chemistry laboratory curricula. A novel guided-inquiry experiment based on the asymmetric aldol addition was developed. Students conduct lab work to compare the effectiveness of…

  5. Comparison of the pharmacological and biological properties of HPMA copolymer-pirarubicin conjugates: A single-chain copolymer conjugate and its biodegradable tandem-diblock copolymer conjugate

    Etrych, Tomáš; Tsukigawa, K.; Nakamura, H.; Chytil, Petr; Fang, J.; Ulbrich, Karel; Otagiri, M.; Maeda, H.

    2017-01-01

    Roč. 106, 30 August (2017), s. 10-19 ISSN 0928-0987 R&D Projects: GA ČR(CZ) GA15-02986S; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Grant - others:AV ČR,Japan Society for the Promotion of Science(CZ) JSPS-16-05 Program:Bilaterální spolupráce Institutional support: RVO:61389013 Keywords : pirarubicin * PHPMA conjugate * tandem-diblock PHPMA conjugate Subject RIV: FR - Pharmacology ; Medidal Chemistry OBOR OECD: Pharmacology and pharmacy Impact factor: 3.756, year: 2016

  6. Fast optimal wavefront reconstruction for multi-conjugate adaptive optics using the Fourier domain preconditioned conjugate gradient algorithm.

    Vogel, Curtis R; Yang, Qiang

    2006-08-21

    We present two different implementations of the Fourier domain preconditioned conjugate gradient algorithm (FD-PCG) to efficiently solve the large structured linear systems that arise in optimal volume turbulence estimation, or tomography, for multi-conjugate adaptive optics (MCAO). We describe how to deal with several critical technical issues, including the cone coordinate transformation problem and sensor subaperture grid spacing. We also extend the FD-PCG approach to handle the deformable mirror fitting problem for MCAO.

  7. Development of melanoma-targeted polymer micelles by conjugation of a melanocortin 1 receptor (MC1R) specific ligand.

    Barkey, Natalie M; Tafreshi, Narges K; Josan, Jatinder S; De Silva, Channa R; Sill, Kevin N; Hruby, Victor J; Gillies, Robert J; Morse, David L; Vagner, Josef

    2011-12-08

    The incidence of malignant melanoma is rising faster than that of any other cancer in the United States. Because of its high expression on the surface of melanomas, MC1R has been investigated as a target for selective imaging and therapeutic agents against melanoma. Eight ligands were screened against cell lines engineered to overexpress MC1R, MC4R, or MC5R. Of these, compound 1 (4-phenylbutyryl-His-dPhe-Arg-Trp-NH(2)) exhibited high (0.2 nM) binding affinity for MC1R and low (high nanomolar) affinities for MC4R and MC5R. Functionalization of the ligand at the C-terminus with an alkyne for use in Cu-catalyzed click chemistry was shown not to affect the binding affinity. Finally, formation of the targeted polymer, as well as the targeted micelle formulation, also resulted in constructs with low nanomolar binding affinity.

  8. Investigation of Radioiodination of Meta-Iodobenzylguanidine Compound with 131I Isotope in Solid Phase Using Cu Catalyzer

    Davarpanah, M. R.; Attar Nosrati, S.; Khoshhosn, H.; Kazemi Boudani, M.; Fazlali, M.; Ghannadi Maragheh, M.

    2012-01-01

    In this study the radioiodination process of meta-iodobenzylguanidine with 131 I isotope in presence of ammonium sulphate and Cu(II) Catalyzer was investigated. In order to optimize the process, the influence of different parameters on labeling yield was studied. The results of experiments showed that the use of oil bath with temperature of 160 d egree C is necessary. After the labeling process, purification step of the final product was carried out using Dowex-1 x 8 resin. The mean labeling yield was 97.2 p ercent . In this method radiolabelling of MIBG with 131 I (185 MBq for diagnostic dose and 3330 MBq for therapeutic dose) is quite simple and it complies with the requirements of routine production of 13 1I-MIBG radiopharmaceutical for diagnostic and therapeutic purposes. This paper is a narration of industrial scale production of 131 I-MIBG radiopharmaceutical.

  9. Chemoselective Switch in the Asymmetric Organocatalysis of 5 H -Oxazol-4-ones and N -Itaconimides: Addition-Protonation or [4+2] Cycloaddition

    Zhu, Bo

    2015-12-09

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. We report a synthetic strategy for a chemoselective switch and a diastereo-divergent approach for the asymmetric reaction of 5H-oxazol-4-ones and N-itaconimides catalyzed by L-tert-leucine-derived tertiary amine-urea compounds. The reaction was modulated to harness either tandem conjugate addition-protonation or [4+2] cycloaddition as major product with excellent enantio- and diastereoselectivities. Subjecting the enantio-enriched cycloaddition products to a basic silica gel reagent yields the diastereomer vis-à-vis the product directly obtained under conditions for addition-protonation, thus opening a diastereo-divergent route for creating 1,3-tertiary-hetero-quaternary stereocenters. Quantum chemical studies further provide stereochemical analysis for the [4+2] process and a plausible mechanism for this chemoselective switch is proposed.

  10. Multivalent peptidic linker enables identification of preferred sites of conjugation for a potent thialanstatin antibody drug conjugate.

    Sujiet Puthenveetil

    Full Text Available Antibody drug conjugates (ADCs are no longer an unknown entity in the field of cancer therapy with the success of marketed ADCs like ADCETRIS and KADCYLA and numerous others advancing through clinical trials. The pursuit of novel cytotoxic payloads beyond the mictotubule inhibitors and DNA damaging agents has led us to the recent discovery of an mRNA splicing inhibitor, thailanstatin, as a potent ADC payload. In our previous work, we observed that the potency of this payload was uniquely tied to the method of conjugation, with lysine conjugates showing much superior potency as compared to cysteine conjugates. However, the ADC field is rapidly shifting towards site-specific ADCs due to their advantages in manufacturability, characterization and safety. In this work we report the identification of a highly efficacious site-specific thailanstatin ADC. The site of conjugation played a critical role on both the in vitro and in vivo potency of these ADCs. During the course of this study, we developed a novel methodology of loading a single site with multiple payloads using an in situ generated multi-drug carrying peptidic linker that allowed us to rapidly screen for optimal conjugation sites. Using this methodology, we were able to identify a double-cysteine mutant ADC delivering four-loaded thailanstatin that was very efficacious in a gastric cancer xenograft model at 3mg/kg and was also shown to be efficacious against T-DM1 resistant and MDR1 overexpressing tumor cell lines.

  11. Multivalent peptidic linker enables identification of preferred sites of conjugation for a potent thialanstatin antibody drug conjugate.

    Puthenveetil, Sujiet; He, Haiyin; Loganzo, Frank; Musto, Sylvia; Teske, Jesse; Green, Michael; Tan, Xingzhi; Hosselet, Christine; Lucas, Judy; Tumey, L Nathan; Sapra, Puja; Subramanyam, Chakrapani; O'Donnell, Christopher J; Graziani, Edmund I

    2017-01-01

    Antibody drug conjugates (ADCs) are no longer an unknown entity in the field of cancer therapy with the success of marketed ADCs like ADCETRIS and KADCYLA and numerous others advancing through clinical trials. The pursuit of novel cytotoxic payloads beyond the mictotubule inhibitors and DNA damaging agents has led us to the recent discovery of an mRNA splicing inhibitor, thailanstatin, as a potent ADC payload. In our previous work, we observed that the potency of this payload was uniquely tied to the method of conjugation, with lysine conjugates showing much superior potency as compared to cysteine conjugates. However, the ADC field is rapidly shifting towards site-specific ADCs due to their advantages in manufacturability, characterization and safety. In this work we report the identification of a highly efficacious site-specific thailanstatin ADC. The site of conjugation played a critical role on both the in vitro and in vivo potency of these ADCs. During the course of this study, we developed a novel methodology of loading a single site with multiple payloads using an in situ generated multi-drug carrying peptidic linker that allowed us to rapidly screen for optimal conjugation sites. Using this methodology, we were able to identify a double-cysteine mutant ADC delivering four-loaded thailanstatin that was very efficacious in a gastric cancer xenograft model at 3mg/kg and was also shown to be efficacious against T-DM1 resistant and MDR1 overexpressing tumor cell lines.

  12. Chemical de-conjugation for investigating the stability of small molecule drugs in antibody-drug conjugates.

    Chen, Tao; Su, Dian; Gruenhagen, Jason; Gu, Christine; Li, Yi; Yehl, Peter; Chetwyn, Nik P; Medley, Colin D

    2016-01-05

    Antibody-drug conjugates (ADCs) offer new therapeutic options for advanced cancer patients through precision killing with fewer side effects. The stability and efficacy of ADCs are closely related, emphasizing the urgency and importance of gaining a comprehensive understanding of ADC stability. In this work, a chemical de-conjugation approach was developed to investigate the in-situ stability of the small molecule drug while it is conjugated to the antibody. This method involves chemical-mediated release of the small molecule drug from the ADC and subsequent characterization of the released small molecule drug by HPLC. The feasibility of this technique was demonstrated utilizing a model ADC containing a disulfide linker that is sensitive to the reducing environment within cancer cells. Five reducing agents were screened for use in de-conjugation; tris(2-carboxyethyl) phosphine (TCEP) was selected for further optimization due to its high efficiency and clean impurity profile. The optimized de-conjugation assay was shown to have excellent specificity and precision. More importantly, it was shown to be stability indicating, enabling the identification and quantification of the small molecule drug and its degradation products under different formulation pHs and storage temperatures. In summary, the chemical de-conjugation strategy demonstrated here offers a powerful tool to assess the in-situ stability of small molecule drugs on ADCs and the resulting information will shed light on ADC formulation/process development and storage condition selection. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Identification of excited states in conjugated polymers

    Hartwell, Lewis John

    2003-01-01

    This thesis reports quasi steady state photoinduced absorption measurements from three conjugated polymers: polypyridine (PPy), polyfluorene (PFO) and the emeraldine base (EB) form of polyaniline. The aim of these experiments was to determine the nature of the photoexcited states existing in these materials in the millisecond time domain, as this has important consequences for the operation of real devices manufactured using these materials. The results from the photoinduced absorption experiments are closely compared with published results from pulse radiolysis experiments. In all cases there is very good correspondence between the two data sets, which has enabled the photoexcited states to be assigned with a high degree of confidence. Quasi steady-state photoinduced absorption involves the measurement of the change in absorption of a material in response to optical excitation with a laser beam. The changes in absorption are small, so a dedicated instrument was developed and optimised for each different sample. Lock-in techniques were used to recover the small signals from the samples. The samples involved were thin films of the polymer spin coated onto sapphire substrates in the cases of PPy and EB. Solution state experiments were conducted on EB. The experiments on PFO were conducted on aligned and unaligned thin films provided by Sony. In the case of the aligned PFO samples, the photoinduced absorption spectrometer was modified to enable polarisation-sensitive data collection. In PPy, both triplet excitons and polarons have been shown to be long-lived photoexcitations, with photoinduced absorption features at 2.29 eV (triplet exciton transition), 1.5 eV and 0.8 eV (polaron transitions). In PFO, the one observed photoinduced band at 1.52 eV is assigned to a triplet exciton. Two photoinduced absorption bands are observed in EB, at 1.4 eV and 0.8 eV. These are assigned to a self-trapped CT singlet exciton and triplet exciton, respectively. (author)

  14. Computer simulation of molecular absorption spectra for asymmetric top molecules

    Bende, A.; Tosa, V.; Cosma, V.

    2001-01-01

    The effective Hamiltonian formalism has been used to develop a model for infrared multiple-photon absorption (IRMPA) process in asymmetric top molecules. Assuming a collisionless regime, the interaction between the molecule and laser field can be described by the time-dependent Schroedinger equation. By using the rotating wave approximation and Laplace transformation, the time-dependent problem reduces to a time-independent eigen problem for an effective Hamiltonian which can be solved only numerically for a real vibrational-rotational structure of polyatomic molecule. The vibrational-rotational structure is assumed to be an anharmonic oscillator coupled to an asymmetric rigid rotor. The main assumptions taken into account for this model are the following: (1) the excitation is coherent, i.e. the collision (if present during the laser pulse) does not influence the excitation; (2) the excitation starts from the ground state and is near resonant to a normal mode, thus, the rotating wave approximation can be applied; (3) after absorbing N photons the vibrational energy of the excited mode leak into a quasicontinuum; (4) the thermal population of the ground state is given by the Maxwell-Boltzmann distribution law. The energy levels of the asymmetric top molecules cannot be represented by an explicit formula analogous to that for the symmetric top, according to quantum mechanics, but we can consider it a deviation from the prolate or oblate case of the symmetric top, and we can find in the same manner the selection rules of the asymmetric case using the selection rules for the symmetric case. The infrared bands of asymmetric top molecules are not resolved, but if the dispersion used is not too small, so that the envelopes of the bands can be distinguished from simple maxima, it is possible to draw conclusions as to the type of the bands. In this case, the simulation of the absorption spectra can give us some important information about the types of these bands. In

  15. Four-wave mixing and phase conjugation in plasmas

    Federici, J.F.

    1989-01-01

    Nonlinear optical effects such as Stimulated Brillouin Scattering, Stimulated Raman Scattering, self-focusing, wave-mixing, parametric mixing, etc., have a long history in plasma physics. Recently, four-wave mixing in plasmas and its applications to phase conjugation has been extensively studied. Although four-wave mixing (FWM), using various nonlinear mediums, has many practical applications in the visible regime, no successful attempt has been made to study or demonstrate FWM for wavelengths longer than 10μm. Plasmas as phase conjugate mirrors have received considerable attention since they become more efficient at longer wavelengths (far-infrared to microwave). The purpose of this thesis is to study various fundamental issues which concern the suitability of plasmas for four-wave mixing and phase conjugation. The major contributions of this thesis are the identification and study of thermal and ionization nonlinearities as potential four-wave mixing and phase conjugation mechanisms and the study of the affect of density inhomogeneities on the FWM process. Using a fluid description for the plasma, this thesis demonstrates that collisional heating generates a thermal force which substantially enhances the phase conjugate reflectivity. The prospect of using a novel ionization nonlinearity in weakly ionized plasmas for wave-mixing and phase conjugation is discussed. The ionization nonlinearity arises from localized heating of the plasma by the beat-wave. Wherever, the local temperature is increased, a plasma density grating is produced due to increased electron-impact ionization. Numerical estimates of the phase conjugate reflectivity indicate reflectivities in the range of 10 -4 -10 -3 are possible in a weakly ionized steady-state gas discharge plasma

  16. Optical observations geomagnetically conjugate to sprite-producing lightning discharges

    R. A. Marshall

    2005-09-01

    Full Text Available Theoretical studies have predicted that large positive cloud-to-ground discharges can trigger a runaway avalanche process of relativistic electrons, forming a geomagnetically trapped electron beam. The beam may undergo pitch angle and energy scattering during its traverse of the Earth's magnetosphere, with a small percentage of electrons remaining in the loss cone and precipitating in the magnetically conjugate atmosphere. In particular, N2 1P and N2+1N optical emissions are expected to be observable. In July and August 2003, an attempt was made to detect these optical emissions, called "conjugate sprites", in correlation with sprite observations in Europe near . Sprite observations were made from the Observatoire du Pic du Midi (OMP in the French Pyrenées, and VLF receivers were installed in Europe to detect causative sferics and ionospheric disturbances associated with sprites. In the Southern Hemisphere conjugate region, the Wide-angle Array for Sprite Photometry (WASP was deployed at the South African Astronomical Observatory (SAAO, near Sutherland, South Africa, to observe optical emissions with a field-of-view magnetically conjugate to the Northern Hemisphere observing region. Observations at OMP revealed over 130 documented sprites, with WASP observations covering the conjugate region successfully for 30 of these events. However, no incidences of optical emissions in the conjugate hemisphere were found. Analysis of the conjugate optical data from SAAO, along with ELF energy measurements from Palmer Station, Antarctica, and charge-moment analysis, show that the lightning events during the course of this experiment likely had insufficient intensity to create a relativistic beam.

    Keywords. Ionosphere (Ionsophere-magnetosphere interactions; Ionospheric disturbances; Instruments and techniques

  17. Recent Advances in Conjugated Polymers for Light Emitting Devices

    AlSalhi, Mohamad Saleh; Alam, Javed; Dass, Lawrence Arockiasamy; Raja, Mohan

    2011-01-01

    A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED) and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs) in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs) and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review. PMID:21673938

  18. Optical observations geomagnetically conjugate to sprite-producing lightning discharges

    R. A. Marshall

    2005-09-01

    Full Text Available Theoretical studies have predicted that large positive cloud-to-ground discharges can trigger a runaway avalanche process of relativistic electrons, forming a geomagnetically trapped electron beam. The beam may undergo pitch angle and energy scattering during its traverse of the Earth's magnetosphere, with a small percentage of electrons remaining in the loss cone and precipitating in the magnetically conjugate atmosphere. In particular, N2 1P and N2+1N optical emissions are expected to be observable. In July and August 2003, an attempt was made to detect these optical emissions, called "conjugate sprites", in correlation with sprite observations in Europe near . Sprite observations were made from the Observatoire du Pic du Midi (OMP in the French Pyrenées, and VLF receivers were installed in Europe to detect causative sferics and ionospheric disturbances associated with sprites. In the Southern Hemisphere conjugate region, the Wide-angle Array for Sprite Photometry (WASP was deployed at the South African Astronomical Observatory (SAAO, near Sutherland, South Africa, to observe optical emissions with a field-of-view magnetically conjugate to the Northern Hemisphere observing region. Observations at OMP revealed over 130 documented sprites, with WASP observations covering the conjugate region successfully for 30 of these events. However, no incidences of optical emissions in the conjugate hemisphere were found. Analysis of the conjugate optical data from SAAO, along with ELF energy measurements from Palmer Station, Antarctica, and charge-moment analysis, show that the lightning events during the course of this experiment likely had insufficient intensity to create a relativistic beam. Keywords. Ionosphere (Ionsophere-magnetosphere interactions; Ionospheric disturbances; Instruments and techniques

  19. New heparin–indomethacin conjugate with an ester linkage: Synthesis, self aggregation and drug delivery behavior

    Li, Nan-Nan; Zheng, Bing-Na [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Lin, Jian-Tao [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Guangdong Medical College, Dongguan 523808 (China); Zhang, Li-Ming, E-mail: ceszhlm@mail.sysu.edu.cn [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2014-01-01

    New heparin–indomethacin conjugate with an ester linkage was prepared by the carbodiimide-mediated condensation reaction, and then characterized by FTIR and {sup 1}HNMR analyses. Due to its amphiphilic character, such a conjugate could self-aggregate into spherical nanoparticles in aqueous system, as confirmed by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. By the in vitro drug release tests, the resultant conjugate nanoparticles were found to have a sustained and esterase-sensitive release behavior for conjugated indomethacin. In addition, the uptake of these conjugate nanoparticles into human nasopharyngeal carcinoma CNE1 cells was confirmed by fluorescence microscopy. - Highlights: • New heparin–indomethacin conjugate with an ester linkage was prepared. • Such a conjugate could self-aggregate into spherical nanoparticles in aqueous system. • The resultant conjugate nanoparticles exhibited an esterase-sensitive drug release behavior. • The resultant conjugate nanoparticles showed the cellular uptake ability in CNE1 cells.

  20. Examining Asymmetrical Relationships of Organizational Learning Antecedents: A Theoretical Model

    Ery Tri Djatmika

    2016-02-01

    Full Text Available Global era is characterized by highly competitive advantage market demand. Responding to the challenge of rapid environmental changes, organizational learning is becoming a strategic way and solution to empower people themselves within the organization in order to create a novelty as valuable positioning source. For research purposes, determining the influential antecedents that affect organizational learning is vital to understand research-based solutions given for practical implications. Accordingly, identification of variables examined by asymmetrical relationships is critical to establish. Possible antecedent variables come from organizational and personal point of views. It is also possible to include a moderating one. A proposed theoretical model of asymmetrical effects of organizational learning and its antecedents is discussed in this article.