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Sample records for dinitrosyl nonheme-iron complexes

  1. Dinitrosyl non-heme iron complexes at the gamma radiation treatment of animals

    International Nuclear Information System (INIS)

    Aliev, D.I.; Alieva, I.N.; Abilov, Z.G.; Gurbanov, I.S.

    2003-01-01

    Full text: At the present time there are a great number investigations dedicated to revealing of mechanism formation of 2,03 complexes at the some pathologies in an organism. These complexes are represented weakly bounded form of non-heme iron, including into beside iron two nitrogen oxide molecules (NO) and two paired RS- groups of proteins or low-molecular compounds. 2,03 complexes are characterized by an axial symmetrical tensory of the g-factor with g=2,037, g=2,012 and g=2,03. In this study the data testifying 2,03 complexes formation into liver of animal treated by the fatal dose of gamma-radiation are reported. The changing of the ESR signal form was observed. It was shown that the form and intensity of the 2,03 signal in healthy and irradiated animals are differ from each other. The analysis of the 2,03 signal parameters is confirm this fact, too. The conclusion was made that 2,03 complexes ESR signal may be considered as an indicator of integrity of intracellular membranes of the gamma-irradiated animals

  2. An isoelectronic NO dioxygenase reaction using a nonheme iron(III)-peroxo complex and nitrosonium ion.

    Science.gov (United States)

    Yokoyama, Atsutoshi; Han, Jung Eun; Karlin, Kenneth D; Nam, Wonwoo

    2014-02-18

    Reaction of a nonheme iron(III)-peroxo complex, [Fe(III)(14-TMC)(O2)](+), with NO(+), a transformation which is essentially isoelectronic with that for nitric oxide dioxygenases [Fe(III)(O2˙(-)) + NO], affords an iron(IV)-oxo complex, [Fe(IV)(14-TMC)(O)](2+), and nitrogen dioxide (NO2), followed by conversion to an iron(III)-nitrato complex, [Fe(III)(14-TMC)(NO3)(F)](+).

  3. An isoelectronic NO dioxygenase reaction using a nonheme iron(III)-peroxo complex and nitrosonium ion†

    Science.gov (United States)

    Yokoyama, Atsutoshi; Han, Jung Eun; Karlin, Kenneth D.; Nam, Wonwoo

    2014-01-01

    Reaction of a nonheme iron(III)-peroxo complex, [FeIII(14-TMC)(O2)]+, with NO+, a transformation which is essentially isoelectronic with that for nitric oxide dioxygenases [Fe(III)(O2•−) + NO], affords an iron(IV)-oxo complex, [FeIV(14-TMC)(O)]2+, and nitrogen dioxide (NO2), followed by conversion to an iron(III)-nitrato complex, [FeIII(14-TMC)(NO3)(F)]+. PMID:24394960

  4. An isoelectronic NO dioxygenase reaction using a nonheme iron(III)-peroxo complex and nitrosonium ion†

    OpenAIRE

    Yokoyama, Atsutoshi; Han, Jung Eun; Karlin, Kenneth D.; Nam, Wonwoo

    2014-01-01

    Reaction of a nonheme iron(III)-peroxo complex, [FeIII(14-TMC)(O2)]+, with NO+, a transformation which is essentially isoelectronic with that for nitric oxide dioxygenases [Fe(III)(O2•−) + NO], affords an iron(IV)-oxo complex, [FeIV(14-TMC)(O)]2+, and nitrogen dioxide (NO2), followed by conversion to an iron(III)-nitrato complex, [FeIII(14-TMC)(NO3)(F)]+.

  5. A functional mimic of natural peroxidases : synthesis and catalytic activity of a non-heme iron peptide hydroperoxide complex

    NARCIS (Netherlands)

    Choma, CT; Schudde, EP; Kellogg, RM; Robillard, GT; Feringa, BL

    1998-01-01

    Site-selective attachment of unprotected peptides to a non-heme iron complex is achieved by displacing two halides on the catalyst by peptide caesium thiolates, This coupling approach should be compatible with any peptide sequence provided there is only a single reduced cysteine. The oxidation

  6. Direct Observation of a Nonheme Iron(IV)–Oxo Complex That Mediates Aromatic C–F Hydroxylation

    OpenAIRE

    Sahu, Sumit; Quesne, Matthew G.; Davies, Casey G.; Dürr, Maximilian; Ivanović-Burmazović, Ivana; Siegler, Maxime A.; Jameson, Guy N. L.; de Visser, Sam P.; Goldberg, David P.

    2014-01-01

    The synthesis of a pentadentate ligand with strategically designed fluorinated arene groups in the second coordination sphere of a nonheme iron center is reported. The oxidatively resistant fluorine substituents allow for the trapping and characterization of an FeIV(O) complex at −20 °C. Upon warming of the FeIV(O) complex, an unprecedented arene C–F hydroxylation reaction occurs. Computational studies support the finding that substrate orientation is a critical factor in the observed reactiv...

  7. Mononuclear non-heme iron(III) complexes of linear and tripodal ...

    Indian Academy of Sciences (India)

    The rate of oxygenation depends on the solvent and the. Lewis acidity of iron(III) ... has been achieved by non-heme iron enzymes and their ..... oxygen atoms of nitrate ion (figure 3). ... enhanced covalency of iron-catecholate interaction and.

  8. Experimental and Computational Evidence for the Mechanism of Intradiol Catechol Dioxygenation by Non-Heme Iron(III) Complexes

    Science.gov (United States)

    Jastrzebski, Robin; Quesne, Matthew G; Weckhuysen, Bert M; de Visser, Sam P; Bruijnincx, Pieter C A

    2014-01-01

    Catechol intradiol dioxygenation is a unique reaction catalyzed by iron-dependent enzymes and non-heme iron(III) complexes. The mechanism by which these systems activate dioxygen in this important metabolic process remains controversial. Using a combination of kinetic measurements and computational modelling of multiple iron(III) catecholato complexes, we have elucidated the catechol cleavage mechanism and show that oxygen binds the iron center by partial dissociation of the substrate from the iron complex. The iron(III) superoxide complex that is formed subsequently attacks the carbon atom of the substrate by a rate-determining C=O bond formation step. PMID:25322920

  9. Water oxidation catalysis with nonheme iron complexes under acidic and basic conditions: homogeneous or heterogeneous?

    Science.gov (United States)

    Hong, Dachao; Mandal, Sukanta; Yamada, Yusuke; Lee, Yong-Min; Nam, Wonwoo; Llobet, Antoni; Fukuzumi, Shunichi

    2013-08-19

    Thermal water oxidation by cerium(IV) ammonium nitrate (CAN) was catalyzed by nonheme iron complexes, such as Fe(BQEN)(OTf)2 (1) and Fe(BQCN)(OTf)2 (2) (BQEN = N,N'-dimethyl-N,N'-bis(8-quinolyl)ethane-1,2-diamine, BQCN = N,N'-dimethyl-N,N'-bis(8-quinolyl)cyclohexanediamine, OTf = CF3SO3(-)) in a nonbuffered aqueous solution; turnover numbers of 80 ± 10 and 20 ± 5 were obtained in the O2 evolution reaction by 1 and 2, respectively. The ligand dissociation of the iron complexes was observed under acidic conditions, and the dissociated ligands were oxidized by CAN to yield CO2. We also observed that 1 was converted to an iron(IV)-oxo complex during the water oxidation in competition with the ligand oxidation. In addition, oxygen exchange between the iron(IV)-oxo complex and H2(18)O was found to occur at a much faster rate than the oxygen evolution. These results indicate that the iron complexes act as the true homogeneous catalyst for water oxidation by CAN at low pHs. In contrast, light-driven water oxidation using [Ru(bpy)3](2+) (bpy = 2,2'-bipyridine) as a photosensitizer and S2O8(2-) as a sacrificial electron acceptor was catalyzed by iron hydroxide nanoparticles derived from the iron complexes under basic conditions as the result of the ligand dissociation. In a buffer solution (initial pH 9.0) formation of the iron hydroxide nanoparticles with a size of around 100 nm at the end of the reaction was monitored by dynamic light scattering (DLS) in situ and characterized by X-ray photoelectron spectra (XPS) and transmission electron microscope (TEM) measurements. We thus conclude that the water oxidation by CAN was catalyzed by short-lived homogeneous iron complexes under acidic conditions, whereas iron hydroxide nanoparticles derived from iron complexes act as a heterogeneous catalyst in the light-driven water oxidation reaction under basic conditions.

  10. Arene activation by a nonheme iron(III)-hydroperoxo complex: pathways leading to phenol and ketone products.

    Science.gov (United States)

    Faponle, Abayomi S; Banse, Frédéric; de Visser, Sam P

    2016-07-01

    Iron(III)-hydroperoxo complexes are found in various nonheme iron enzymes as catalytic cycle intermediates; however, little is known on their catalytic properties. The recent work of Banse and co-workers on a biomimetic nonheme iron(III)-hydroperoxo complex provided evidence of its involvement in reactivity with arenes. This contrasts the behavior of heme iron(III)-hydroperoxo complexes that are known to be sluggish oxidants. To gain insight into the reaction mechanism of the biomimetic iron(III)-hydroperoxo complex with arenes, we performed a computational (density functional theory) study. The calculations show that iron(III)-hydroperoxo reacts with substrates via low free energies of activation that should be accessible at room temperature. Moreover, a dominant ketone reaction product is observed as primary products rather than the thermodynamically more stable phenols. These product distributions are analyzed and the calculations show that charge interaction between the iron(III)-hydroxo group and the substrate in the intermediate state pushes the transferring proton to the meta-carbon atom of the substrate and guides the selectivity of ketone formation. These studies show that the relative ratio of ketone versus phenol as primary products can be affected by external interactions of the oxidant with the substrate. Moreover, iron(III)-hydroperoxo complexes are shown to selectively give ketone products, whereas iron(IV)-oxo complexes will react with arenes to form phenols instead.

  11. Mononuclear non-heme iron(III)

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 123; Issue 2. Mononuclear non-heme iron(III) complexes of linear and tripodal tridentate ligands as functional models for catechol dioxygenases: Effect of -alkyl substitution on regioselectivity and reaction rate. Mallayan Palaniandavar Kusalendiran Visvaganesan.

  12. Photoenhanced Oxidative DNA Cleavage with Non-Heme Iron(II) Complexes

    NARCIS (Netherlands)

    Li, Qian; Browne, Wesley R.; Roelfes, Gerard

    2010-01-01

    The DNA cleavage activity of iron(II) complexes of a series of monotopic pentadentate N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine (N4Py)-derived ligands (1-5) was investigated under laser irradiation at 473, 400.8, and 355 nm in the absence of a reducing agent and compared to that under

  13. Influence of Ligand Architecture in Tuning Reaction Bifurcation Pathways for Chlorite Oxidation by Non-Heme Iron Complexes

    NARCIS (Netherlands)

    Barman, Prasenjit; Faponle, Abayomi S; Vardhaman, Anil Kumar; Angelone, Davide; Löhr, Anna-Maria; Browne, Wesley R; Comba, Peter; Sastri, Chivukula V; de Visser, Sam P

    2016-01-01

    Reaction bifurcation processes are often encountered in the oxidation of substrates by enzymes and generally lead to a mixture of products. One particular bifurcation process that is common in biology relates to electron transfer versus oxygen atom transfer by high-valent iron(IV)-oxo complexes,

  14. [Dinitrosyl iron complexes are endogenous signaling agents in animal and human cells and tissues (a hypothesis)].

    Science.gov (United States)

    Vanin, A F

    2004-01-01

    The hypothesis was advanced that dinitrosyl iron complexes generated in animal and human cells and tissues producing nitric oxide can function as endogenous universal regulators of biochemical and physiological processes. This function is realized by the ability of dinitrosyl iron complexes to act as donors of free nitric oxide molecules interacting with the heme groups of proteins, nitrosonium ions, or Fe+(NO+)2 interacting with the thiol groups of proteins. The effect of dinitrosyl iron complexes on the activity of some enzymes and the expression of the genome at the translation and transcription levels was considered.

  15. X-ray absorption spectroscopic studies of mononuclear non-heme iron enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Westre, Tami E. [Stanford Univ., CA (United States)

    1996-01-01

    Fe-K-edge X-ray absorption spectroscopy (XAS) has been used to investigate the electronic and geometric structure of the iron active site in non-heme iron enzymes. A new theoretical extended X-ray absorption fine structure (EXAFS) analysis approach, called GNXAS, has been tested on data for iron model complexes to evaluate the utility and reliability of this new technique, especially with respect to the effects of multiple-scattering. In addition, a detailed analysis of the 1s→3d pre-edge feature has been developed as a tool for investigating the oxidation state, spin state, and geometry of iron sites. Edge and EXAFS analyses have then been applied to the study of non-heme iron enzyme active sites.

  16. [Physico-chemical features of dinitrosyl iron complexes with natural thiol-containing ligands underlying biological activities of these complexes].

    Science.gov (United States)

    Vanin, A F; Borodulin, R R; Kubrina, L N; Mikoian, V D; Burbaev, D Sh

    2013-01-01

    Current notions and new experimental data of the authors on physico-chemical features of dinitrosyl iron complexes with natural thiol-containing ligands (glutathione or cysteine), underlying the ability of the complexes to act as NO molecule and nitrosonium ion donors, are considered. This ability determines various biological activities of dinitrosyl iron complexes--inducing long-lasting vasodilation and thereby long-lasting hypotension in human and animals, inhibiting pellet aggregation, increasing red blood cell elasticity, thereby stimulating microcirculation, and reducing necrotic zone in animals with myocardial infarction. Moreover, dinitrosyl iron complexes are capable of accelerating skin wound healing, improving the function of penile cavernous tissue, blocking apoptosis development in cell cultures. When decomposed dinitrosyl iron complexes can exert cytotoxic effect that can be used for curing infectious and carcinogenic pathologies.

  17. Mononuclear nonheme iron(III) complexes that show superoxide dismutase-like activity and antioxidant effects against menadione-mediated oxidative stress.

    Science.gov (United States)

    Hitomi, Yutaka; Iwamoto, Yuji; Kashida, Akihiro; Kodera, Masahito

    2015-05-21

    This communication describes the superoxide dismutase (SOD)-like activity of mononuclear iron(III) complexes with pentadentate monocarboxylamido ligands. The SOD activity can be controlled by the electronic nature of the substituent group on the ligand. The nitro-substituted complex showed clear cytoprotective activity against menadione-mediated oxidative stress in cultured cells.

  18. [Dinitrosyl iron complexes with glutathione recover rats with experimental endometriosis].

    Science.gov (United States)

    Adamian, L V; Burgova, E N; Tkachev, N A; Mikoian, V D; Stepanian, A A; Sonova, M M; Vanin, A F

    2013-01-01

    The effect of binuclear dinitrosyl iron complexes (DNIC) with glutathione on endometrioid tumors in rats with experimental endometriosis has been studied. The latter was induced by an autotransplantation model, where two fragments of endometrium with myometrium (2 x 2 mm) from the left uterine horn was grafted to the inner surface of the anterior abdominal wall. The test animals received intraperitoneal injections of 0.5 ml DNIC-glutathione at the dose of 12.5 micromole per kg daily for 12 days 28 days after operation. The injections resulted in more than a 2-fold decrease in the total volume of both large tumors formed from grafts and small additive tumors formed nearby grafts. The disappearance of the additive tumors was also observed in test animals. The EPR signal with g(av) = 2.03 characteristic of protein bound DNIC with thiol-containing ligands was recorded in livers, graft and additive tumors of test and control animals pointing out intensive generation of nitric oxide in rats with experimental endometriosis. Ribonucleotide reductase activation discovered by doublet the EPR signal at g = 2.0 with 2.3 mT hyperfine structure splitting was found in small tumors. The cytotoxic effect of DNIC-glutathione on endometrioid tumors was suggested to be due to DNIC degradation nearby the tumors induced by iron chelating compounds released from the tumors. The degradation resulted in release of a high amount of nitric oxide molecules and nitrosonium ions from DNICs affecting the tumors by way of the cytotoxic effect.

  19. The mechanism of stereospecific C-H oxidation by Fe(Pytacn) complexes: bioinspired non-heme iron catalysts containing cis-labile exchangeable sites.

    Science.gov (United States)

    Prat, Irene; Company, Anna; Postils, Verònica; Ribas, Xavi; Que, Lawrence; Luis, Josep M; Costas, Miquel

    2013-05-17

    A detailed mechanistic study of the hydroxylation of alkane C-H bonds using H2O2 by a family of mononuclear non heme iron catalysts with the formula [Fe(II)(CF3SO3)2(L)] is described, in which L is a tetradentate ligand containing a triazacyclononane tripod and a pyridine ring bearing different substituents at the α and γ positions, which tune the electronic or steric properties of the corresponding iron complexes. Two inequivalent cis-labile exchangeable sites, occupied by triflate ions, complete the octahedral iron coordination sphere. The C-H hydroxylation mediated by this family of complexes takes place with retention of configuration. Oxygen atoms from water are incorporated into hydroxylated products and the extent of this incorporation depends in a systematic manner on the nature of the catalyst, and the substrate. Mechanistic probes and isotopic analyses, in combination with detailed density functional theory (DFT) calculations, provide strong evidence that C-H hydroxylation is performed by highly electrophilic [Fe(V)(O)(OH)L] species through a concerted asynchronous mechanism, involving homolytic breakage of the C-H bond, followed by rebound of the hydroxyl ligand. The [Fe(V)(O)(OH)L] species can exist in two tautomeric forms, differing in the position of oxo and hydroxide ligands. Isotopic-labeling analysis shows that the relative reactivities of the two tautomeric forms are sensitively affected by the α substituent of the pyridine, and this reactivity behavior is rationalized by computational methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Electron Transport in a Dioxygenase-Ferredoxin Complex: Long Range Charge Coupling between the Rieske and Non-Heme Iron Center.

    Directory of Open Access Journals (Sweden)

    Wayne K Dawson

    Full Text Available Dioxygenase (dOx utilizes stereospecific oxidation on aromatic molecules; consequently, dOx has potential applications in bioremediation and stereospecific oxidation synthesis. The reactive components of dOx comprise a Rieske structure Cys2[2Fe-2S]His2 and a non-heme reactive oxygen center (ROC. Between the Rieske structure and the ROC, a universally conserved Asp residue appears to bridge the two structures forming a Rieske-Asp-ROC triad, where the Asp is known to be essential for electron transfer processes. The Rieske and ROC share hydrogen bonds with Asp through their His ligands; suggesting an ideal network for electron transfer via the carboxyl side chain of Asp. Associated with the dOx is an itinerant charge carrying protein Ferredoxin (Fdx. Depending on the specific cognate, Fdx may also possess either the Rieske structure or a related structure known as 4-Cys-[2Fe-2S] (4-Cys. In this study, we extensively explore, at different levels of theory, the behavior of the individual components (Rieske and ROC and their interaction together via the Asp using a variety of density function methods, basis sets, and a method known as Generalized Ionic Fragment Approach (GIFA that permits setting up spin configurations manually. We also report results on the 4-Cys structure for comparison. The individual optimized structures are compared with observed spectroscopic data from the Rieske, 4-Cys and ROC structures (where information is available. The separate pieces are then combined together into a large Rieske-Asp-ROC (donor/bridge/acceptor complex to estimate the overall coupling between individual components, based on changes to the partial charges. The results suggest that the partial charges are significantly altered when Asp bridges the Rieske and the ROC; hence, long range coupling through hydrogen bonding effects via the intercalated Asp bridge can drastically affect the partial charge distributions compared to the individual isolated

  1. Theoretical Investigations on the Mechanistic Aspects of O2 Activation by a Biomimetic Dinitrosyl Iron Complex

    NARCIS (Netherlands)

    Banerjee, Ambar; Sen, Souloke; Paul, Ankan

    2018-01-01

    Though dinitrosyl-iron complexes (DNICs) are largely believed to act as NO carriers, several experiments on model DNICs have suggested that they can also act as nitrating agents in presence of dioxygen. Oxygen activation by DNICs has been implicated as a possible route for protein tyrosine nitration

  2. [The dinitrosyl-iron complexes with cysteine block the development of experimental endometriosis in rats].

    Science.gov (United States)

    Burgova, E N; Tkachev, N A; Vanin, A F

    2012-01-01

    It has been shown that the administration of 0,5 ml of 5 mM aqueous solution of dinitrosyl-iron complexes (DNIC) with cysteine alleviated the development of experimental endometriosis in rats induced by surgical way: the size of endometriomes decreased 1.85 times when the DNIC was added every day during 10 days. The effect was suggested to be due to cytotoxic action of NO molecules and nitrosonium ions (NO+) released from rapidly decomposed DNIC in animal organism on endometriome tissues.

  3. Dinitrosyl iron complexes with thiol-containing ligands as a "working form" of endogenous nitric oxide.

    Science.gov (United States)

    Vanin, Anatoly F

    2016-04-01

    The material presented herein is an overview of the results obtained by our research team during the many years' study of biological activities and occurrence of dinitrosyl iron complexes (DNIC) with thiol-containing ligands in human and animal organisms. With regard to their dose dependence and vast diversity of biological activities, DNIC are similar to the system of endogenous NO, one of the most universal regulators of biological processes. The role of biologically active components in DNIC is played by their iron-dinitrosyl fragments, [Fe(NO)2], endowed with the ability to generate neutral NO molecules and nitrosonium ions (NO(+)). Their release is effected by heme-and thiol-containing proteins, which fulfill the function of biological targets and acceptors of NO and NO(+). Beneficial regulatory effects of DNIC on physiological and metabolic processes are numerous and diverse and include, among other things, lowering of arterial pressure and accelerated healing of skin wounds. In the course of fast decomposition of their Fe(NO)2 fragments (e.g., in the presence of iron chelators), DNIC produce adverse (cytotoxic) effects, which can best be exemplified by their ability to suppress the development of experimental endometriosis in animals. In animal tissues, DNIC with thiol-containing ligands are predominantly represented by the binuclear form, which, contrary to mononuclear DNIC detectable by the 2.03 signal, is EPR-silent. The ample body of evidence on biological activities and occurrence of DNIC gained so far clearly demonstrates that in human and animal organisms DNIC with thiol-containing ligands represent a "working form" of the system of endogenous NO responsible for its accumulation and stabilization in animal tissues as well as its further transfer to its biological targets. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Physiological Levels of Nitric Oxide Diminish Mitochondrial Superoxide. Potential Role of Mitochondrial Dinitrosyl Iron Complexes and Nitrosothiols

    Directory of Open Access Journals (Sweden)

    Sergey I. Dikalov

    2017-11-01

    Full Text Available Mitochondria are the major source of superoxide radicals and superoxide overproduction contributes to cardiovascular diseases and metabolic disorders. Endothelial dysfunction and diminished nitric oxide levels are early steps in the development of these pathological conditions. It is known that physiological production of nitric oxide reduces oxidative stress and inflammation, however, the precise mechanism of “antioxidant” effect of nitric oxide is not clear. In this work we tested the hypothesis that physiological levels of nitric oxide diminish mitochondrial superoxide production without inhibition of mitochondrial respiration. In order to test this hypothesis we analyzed effect of low physiological fluxes of nitric oxide (20 nM/min on superoxide and hydrogen peroxide production by ESR spin probes and Amplex Red in isolated rat brain mitochondria. Indeed, low levels of nitric oxide substantially attenuated both basal and antimycin A-stimulated production of reactive oxygen species in the presence of succinate or glutamate/malate as mitochondrial substrates. Furthermore, slow releasing NO donor DPTA-NONOate (100 μM did not change oxygen consumption in State 4 and State 3. However, the NO-donor strongly inhibited oxygen consumption in the presence of uncoupling agent CCCP, which is likely associated with inhibition of the over-reduced complex IV in uncoupled mitochondria. We have examined accumulation of dinitrosyl iron complexes and nitrosothiols in mitochondria treated with fast-releasing NO donor MAHMA NONOate (10 μM for 30 min until complete release of NO. Following treatment with NO donor, mitochondria were frozen for direct detection of dinitrosyl iron complexes using Electron Spin Resonance (ESR while accumulation of nitrosothiols was measured by ferrous-N-Methyl-D-glucamine dithiocarbamate complex, Fe(MGD2, in lysed mitochondria. Treatment of mitochondria with NO-donor gave rise to ESR signal of dinitrosyl iron complexes while ESR

  5. EPR Characterization of Dinitrosyl Iron Complexes with Thiol-Containing Ligands as an Approach to Their Identification in Biological Objects: An Overview.

    Science.gov (United States)

    Vanin, Anatoly F

    2018-06-01

    The overview demonstrates how the use of only one physico-chemical approach, viz., the electron paramagnetic resonance method, allowed detection and identification of dinitrosyl iron complexes with thiol-containing ligands in various animal and bacterial cells. These complexes are formed in biological objects in the paramagnetic (electron paramagnetic resonance-active) mononuclear and diamagnetic (electron paramagnetic resonance-silent) binuclear forms and control the activity of nitrogen monoxide, one of the most universal regulators of metabolic processes in the organism. The analysis of electronic and spatial structures of dinitrosyl iron complex sheds additional light on the mechanism whereby dinitrosyl iron complex with thiol-containing ligands function in human and animal cells as donors of nitrogen monoxide and its ionized form, viz., nitrosonium ions (NO + ).

  6. Formation of nitrosyl non-heme iron-sulphur complexes of a mitrochondria electron-transport chain in a liver and kidneys under prolonged permanent action of radiation contamination in the Chernobyl region

    International Nuclear Information System (INIS)

    Sidorik, E.P.; Burlaka, A.P.; Druzhina, N.A.

    1995-01-01

    No-complexes with iron-sulfur protein of the N-type (EPR signal g=2.03 at 77 K) have been revealed in a mitochondria electron transport chain in a liver and kidneys of animals which were hold for 1.5 years in the Chernobyl area under action of low intensity ionizing radiation as a result of incorporated radionuclides. These alterations in protein give evidence of changes in oxidation and phosphorylation in tissues

  7. Dinitrosyl iron complexes with thiolate ligands: physico-chemistry, biochemistry and physiology.

    Science.gov (United States)

    Vanin, Anatoly F

    2009-08-01

    Some present-day concepts on the origin and functional activities of dinitrosyl iron complexes (DNIC) with thiolate ligands are considered. Nitric oxide (NO) including to DNIC increases its stability and ensures effective targeting of NO to organs and tissues. DNIC have a square-planar structure; unpaired electron is localized on the d(z2) orbital of the d(7) iron atom. The formula of DNIC appears as [(RS(-))(2)Fe(+)(NO(+))(2)....((-)SR)(2)](-); electron spin is S=1/2. Conversion of an originally diamagnetic group, Fe(2+)(NO)(2) with electron configuration d(8), into a paramagnetic Fe(+)(NO(+))(2) group is a result of disproportionation of NO ligands and substitution of newly generated NO(-) for NO. The nitrosonium ions present in DNIC impart to them high nitrosylating activity, e.g., ability to induce S-nitrosylation of thiols. The ability of S-nitrosothiols to form DNIC in a direct reaction with bivalent iron is a prerequisite to effective mutual conversions of DNIC and S-nitrosothiols. In this work, I consider some mechanisms of destructive effects of low-molecular DNIC on active centers of iron-sulfur proteins, ability of DNIC to express certain genes, to activate guanylate cyclase, to exert hypotensive, vasodilator effects, to inhibit platelet aggregation, to accelerate wound healing and to produce potent erective action. Recently a stabilized powder-like polymeric composition based on dimeric glutathione DNIC the water-soluble polymer in which was used as a filling agent was designed. The advantages of this stable DNIC-glutathione preparation include their ability to retain their physico-chemical and functional activities within at least one year. At present, the preparation undergo testing as a base for the design of a wide variety of broad-spectrum drugs.

  8. Dinitrosyl iron complexes with glutathione as NO and NO⁺ donors.

    Science.gov (United States)

    Borodulin, Rostislav R; Kubrina, Lyudmila N; Mikoyan, Vasak D; Poltorakov, Alexander P; Shvydkiy, Vyacheslav О; Burbaev, Dosymzhan Sh; Serezhenkov, Vladimir A; Yakhontova, Elena R; Vanin, Anatoly F

    2013-02-28

    It has been found that heating of solutions of the binuclear form of dinitrosyl iron complexes (B-DNIC) with glutathione in a degassed Thunberg apparatus (рН 1.0, 70°С, 6 h) results in their decomposition with a concomitant release of four gaseous NO molecules per one B-DNIC. Further injection of air into the Thunberg apparatus initiates fast oxidation of NO to NO₂ and formation of two GS-NO molecules per one B-DNIC. Under similar conditions, the decomposition of B-DNIC solutions in the Thunberg apparatus in the presence of air is complete within 30-40 min and is accompanied by formation of four GS-NO molecules per one B-DNIC. It is suggested that the latter events are determined by oxidation of B-DNIC iron and concominant release of four nitrosonium ions (NO⁺) from each complex. Binding of NO⁺ to thiol groups of glutathione provokes GS-NO synthesis. At neutral рН, decomposition of B-DNIC is initiated by strong iron chelators, viz., о-phenanthroline and N-methyl-d-glucamine dithiocarbamate (MGD). In the former case, the reaction occurs under anaerobic conditions (degassed Thunberg apparatus) and is accompanied by a release of four NO molecules from B-DNIC. Under identical conditions, MGD-induced decomposition of B-DNIC gives two EPR-active mononuclear mononitrosyl iron complexes with MGD (MNIC-MGD) able to incorporate two iron molecules and two NO molecules from each B-DNIC. The other two NO molecules released from B-DNIC (most probably, in the form of nitrosonium ions) bind to thiol groups of MGD to give corresponding S-nitrosothiols. Acidification of test solutions to рН 1.0 initiates hydrolysis of MGD and, as a consequence, decomposition of MNIC-MGD and the S-nitrosated form of MGD; the gaseous phase contains four NO molecules (as calculated per each B-DNIC). The data obtained testify to the ability of B-DNIC with glutathione (and, probably, of B-DNIC with other thiol-containing ligands) to release both NO molecules and nitrosonium ions upon their

  9. Effects of illumination and packaging on non-heme iron and color attributes of sliced ham.

    Science.gov (United States)

    Li, H; Li, C B; Xu, X L; Zhou, G H

    2012-08-01

    This study was designed to investigate effects of illumination and packaging on color of cooked cured sliced ham during refrigeration, and the possibility of decomposition of nitrosylheme under light and oxygen exposure. Three illumination levels and three packaging films with different oxygen transmission rates (OTRs) were used in two separate experiments during 35 days storage, and pH value, a* value, nitrosylheme, residual nitrite and non-heme iron were evaluated. Packaging OTRs had significant effects (P0.05) nitrosylheme concentration during storage. For both groups, storage time had a significant effect (P<0.01) on a* value and nitrosylheme. Negative relationships between nitrosylheme and nitrite in the illumination group, and between nitrosylheme and non-heme iron in the packaging group were observed. Therefore, illumination level and packaging OTR had limited effects on overall pigment stability, but more discoloration and loss of redness occurred on the surface of products. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Green tea or rosemary extract added to foods reduces nonheme- iron absorption

    DEFF Research Database (Denmark)

    Samman, S.; Sandstrøm, B.; Toft, M.B.

    2001-01-01

    the effect of phenolic-rich extracts obtained from green tea or rosemary on nonheme-iron absorption. Design: Young women aged 19-39 y consumed test meals on 4 separate occasions. The meals were identical except for the absence (meal A) or presence (meal B) of a phenolic-rich extract from green tea (study 1......-body retention of 59Fe and the ratio of Fe-55 to 59Fe activity in blood samples. Results: The presence of the phenolic-rich extracts resulted in decreased nonheme-iron absorption. Mean (+/-SD) iron absorption decreased from 12.1 +/- 4.5% to 8.9 +/- 5.2% (P tea extract and from 7...

  11. Rieske non-heme iron-dependent oxygenases catalyse diverse reactions in natural product biosynthesis.

    Science.gov (United States)

    Perry, Christopher; de Los Santos, Emmanuel L C; Alkhalaf, Lona M; Challis, Gregory L

    2018-04-13

    Covering: up to the end of 2017The roles played by Rieske non-heme iron-dependent oxygenases in natural product biosynthesis are reviewed, with particular focus on experimentally characterised examples. Enzymes belonging to this class are known to catalyse a range of transformations, including oxidative carbocyclisation, N-oxygenation, C-hydroxylation and C-C desaturation. Examples of such enzymes that have yet to be experimentally investigated are also briefly described and their likely functions are discussed.

  12. Structural and Functional Models of Non-Heme Iron Enzymes : A Study of the 2-His-1-Carboxylate Facial Triad Structural Motif

    NARCIS (Netherlands)

    Bruijnincx, P.C.A.

    2007-01-01

    The structural and functional modeling of a specific group of non-heme iron enzymes by the synthesis of small synthetic analogues is the topic of this thesis. The group of non-heme iron enzymes with the 2-His-1-carboxylate facial triad has recently been established as a common platform for the

  13. Mono- and binuclear non-heme iron chemistry from a theoretical perspective

    Czech Academy of Sciences Publication Activity Database

    Rokob, T. A.; Chalupský, Jakub; Bím, Daniel; Andrikopoulos, Prokopis C.; Srnec, Martin; Rulíšek, Lubomír

    2016-01-01

    Roč. 21, 5/6 (2016), s. 619-644 ISSN 0949-8257 R&D Projects: GA ČR(CZ) GJ15-10279Y; GA ČR(CZ) GA14-31419S; GA ČR GA15-19143S Grant - others:COST(XE) CM1305 Institutional support: RVO:61388963 ; RVO:61388955 Keywords : non-heme iron * density functional theory * multireference methods * dioxygen activation * reactivity Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.894, year: 2016

  14. Structures of the multicomponent Rieske non-heme iron toluene 2, 3-dioxygenase enzyme system

    Energy Technology Data Exchange (ETDEWEB)

    Friemann, Rosmarie [Department of Molecular Biology, Swedish University of Agricultural Sciences, Box 590, 751 24 Uppsala (Sweden); Lee, Kyoung [Department of Microbiology, Changwon National University, Changwon, Kyoungnam 641-773 (Korea, Republic of); Department of Microbiology, The University of Iowa, Iowa City, Iowa 52242 (United States); Brown, Eric N. [Department of Biochemistry, The University of Iowa, Iowa City, Iowa 52242 (United States); Gibson, David T. [Department of Microbiology, The University of Iowa, Iowa City, Iowa 52242 (United States); Eklund, Hans [Department of Molecular Biology, Swedish University of Agricultural Sciences, Box 590, 751 24 Uppsala (Sweden); Ramaswamy, S., E-mail: s-ramaswamy@uiowa.edu [Department of Biochemistry, The University of Iowa, Iowa City, Iowa 52242 (United States); Department of Molecular Biology, Swedish University of Agricultural Sciences, Box 590, 751 24 Uppsala (Sweden)

    2009-01-01

    The crystal structures of the three-component toluene 2, 3-dioxygenase system provide a model for electron transfer among bacterial Rieske non-heme iron dioxygenases. Bacterial Rieske non-heme iron oxygenases catalyze the initial hydroxylation of aromatic hydrocarbon substrates. The structures of all three components of one such system, the toluene 2, 3-dioxygenase system, have now been determined. This system consists of a reductase, a ferredoxin and a terminal dioxygenase. The dioxygenase, which was cocrystallized with toluene, is a heterohexamer containing a catalytic and a structural subunit. The catalytic subunit contains a Rieske [2Fe–2S] cluster and mononuclear iron at the active site. This iron is not strongly bound and is easily removed during enzyme purification. The structures of the enzyme with and without mononuclear iron demonstrate that part of the structure is flexible in the absence of iron. The orientation of the toluene substrate in the active site is consistent with the regiospecificity of oxygen incorporation seen in the product formed. The ferredoxin is Rieske type and contains a [2Fe–2S] cluster close to the protein surface. The reductase belongs to the glutathione reductase family of flavoenzymes and consists of three domains: an FAD-binding domain, an NADH-binding domain and a C-terminal domain. A model for electron transfer from NADH via FAD in the reductase and the ferredoxin to the terminal active-site mononuclear iron of the dioxygenase is proposed.

  15. Peroxide Activation for Electrophilic Reactivity by the Binuclear Non-heme Iron Enzyme AurF

    International Nuclear Information System (INIS)

    Park, Kiyoung; Li, Ning; Kwak, Yeonju; Srnec, Martin

    2017-01-01

    Binuclear non-heme iron enzymes activate O 2 for diverse chemistries that include oxygenation of organic substrates and hydrogen atom abstraction. This process often involves the formation of peroxo-bridged biferric intermediates, only some of which can perform electrophilic reactions. To elucidate the geometric and electronic structural requirements to activate peroxo reactivity, the active peroxo intermediate in 4-aminobenzoate N-oxygenase (AurF) has been characterized spectroscopically and computationally. A magnetic circular dichroism study of reduced AurF shows that its electronic and geometric structures are poised to react rapidly with O 2 . Nuclear resonance vibrational spectroscopic definition of the peroxo intermediate formed in this reaction shows that the active intermediate has a protonated peroxo bridge. Density functional theory computations on the structure established here show that the protonation activates peroxide for electrophilic/single-electron-transfer reactivity. As a result, this activation of peroxide by protonation is likely also relevant to the reactive peroxo intermediates in other binuclear non-heme iron enzymes.

  16. Prebiotics increase heme iron bioavailability and do not affect non-heme iron bioavailability in humans.

    Science.gov (United States)

    Weinborn, Valerie; Valenzuela, Carolina; Olivares, Manuel; Arredondo, Miguel; Weill, Ricardo; Pizarro, Fernando

    2017-05-24

    The aim of this study was to establish the effect of a prebiotic mix on heme and non-heme iron (Fe) bioavailability in humans. To this purpose, twenty-four healthy women were randomized into one of two study groups. One group ate one yogurt per day for 12 days with a prebiotic mix (prebiotic group) and the other group received the same yogurt but without the prebiotic mix (control group). Before and after the intake period, the subjects participated in Fe absorption studies. These studies used 55 Fe and 59 Fe radioactive isotopes as markers of heme Fe and non-heme Fe, respectively, and Fe absorption was measured by the incorporation of radioactive Fe into erythrocytes. The results showed that there were no significant differences in heme and non-heme Fe bioavailability in the control group. Heme Fe bioavailability of the prebiotic group increased significantly by 56% post-prebiotic intake. There were no significant differences in non-heme Fe bioavailability in this group. We concluded that daily consumption of a prebiotic mix increases heme Fe bioavailability and does not affect non-heme iron bioavailability.

  17. Design and synthesis of a tetradentate '3-amine-1-carboxylate' ligand to mimic the metal binding environment at the non-heme iron(II) oxidase active site.

    Science.gov (United States)

    Dungan, Victoria J; Ortin, Yannick; Mueller-Bunz, Helge; Rutledge, Peter J

    2010-04-07

    Non-heme iron(II) oxidases (NHIOs) catalyse a diverse array of oxidative chemistry in Nature. As part of ongoing efforts to realize biomimetic, iron-mediated C-H activation, we report the synthesis of a new 'three-amine-one-carboxylate' ligand designed to complex with iron(II) and mimic the NHIO active site. The tetradentate ligand has been prepared as a single enantiomer in nine synthetic steps from N-Cbz-L-alanine, pyridine-2,6-dimethanol and diphenylamine, using Seebach oxazolidinone chemistry to control the stereochemistry. X-Ray crystal structures are reported for two important intermediates, along with variable temperature NMR experiments to probe the hindered interconversion of conformational isomers of several key intermediates, 2,6-disubstituted pyridine derivatives. The target ligand and an N-Cbz-protected precursor were each then complexed with iron(II) and tested for their ability to promote alkene dihydroxylation, using hydrogen peroxide as the oxidant.

  18. Heme and non-heme iron transporters in non-polarized and polarized cells

    Directory of Open Access Journals (Sweden)

    Yasui Yumiko

    2010-06-01

    Full Text Available Abstract Background Heme and non-heme iron from diet, and recycled iron from hemoglobin are important products of the synthesis of iron-containing molecules. In excess, iron is potentially toxic because it can produce reactive oxygen species through the Fenton reaction. Humans can absorb, transport, store, and recycle iron without an excretory system to remove excess iron. Two candidate heme transporters and two iron transporters have been reported thus far. Heme incorporated into cells is degraded by heme oxygenases (HOs, and the iron product is reutilized by the body. To specify the processes of heme uptake and degradation, and the reutilization of iron, we determined the subcellular localizations of these transporters and HOs. Results In this study, we analyzed the subcellular localizations of 2 isoenzymes of HOs, 4 isoforms of divalent metal transporter 1 (DMT1, and 2 candidate heme transporters--heme carrier protein 1 (HCP1 and heme responsive gene-1 (HRG-1--in non-polarized and polarized cells. In non-polarized cells, HCP1, HRG-1, and DMT1A-I are located in the plasma membrane. In polarized cells, they show distinct localizations: HCP1 and DMT1A-I are located in the apical membrane, whereas HRG-1 is located in the basolateral membrane and lysosome. 16Leu at DMT1A-I N-terminal cytosolic domain was found to be crucial for plasma membrane localization. HOs are located in smooth endoplasmic reticulum and colocalize with NADPH-cytochrome P450 reductase. Conclusions HCP1 and DMT1A-I are localized to the apical membrane, and HRG-1 to the basolateral membrane and lysosome. These findings suggest that HCP1 and DMT1A-I have functions in the uptake of dietary heme and non-heme iron. HRG-1 can transport endocytosed heme from the lysosome into the cytosol. These localization studies support a model in which cytosolic heme can be degraded by HOs, and the resulting iron is exported into tissue fluids via the iron transporter ferroportin 1, which is expressed in the basolateral membrane in enterocytes or in the plasma membrane in macrophages. The liberated iron is transported by transferrin and reutilized for hemoglobin synthesis in the erythroid system.

  19. Sugars increase non-heme iron bioavailability in human epithelial intestinal and liver cells.

    Directory of Open Access Journals (Sweden)

    Tatiana Christides

    Full Text Available Previous studies have suggested that sugars enhance iron bioavailability, possibly through either chelation or altering the oxidation state of the metal, however, results have been inconclusive. Sugar intake in the last 20 years has increased dramatically, and iron status disorders are significant public health problems worldwide; therefore understanding the nutritional implications of iron-sugar interactions is particularly relevant. In this study we measured the effects of sugars on non-heme iron bioavailability in human intestinal Caco-2 cells and HepG2 hepatoma cells using ferritin formation as a surrogate marker for iron uptake. The effect of sugars on iron oxidation state was examined by measuring ferrous iron formation in different sugar-iron solutions with a ferrozine-based assay. Fructose significantly increased iron-induced ferritin formation in both Caco-2 and HepG2 cells. In addition, high-fructose corn syrup (HFCS-55 increased Caco-2 cell iron-induced ferritin; these effects were negated by the addition of either tannic acid or phytic acid. Fructose combined with FeCl3 increased ferrozine-chelatable ferrous iron levels by approximately 300%. In conclusion, fructose increases iron bioavailability in human intestinal Caco-2 and HepG2 cells. Given the large amount of simple and rapidly digestible sugars in the modern diet their effects on iron bioavailability may have important patho-physiological consequences. Further studies are warranted to characterize these interactions.

  20. Synthesis of 5-hydroxyectoine from ectoine: crystal structure of the non-heme iron(II and 2-oxoglutarate-dependent dioxygenase EctD.

    Directory of Open Access Journals (Sweden)

    Klaus Reuter

    2010-05-01

    Full Text Available As a response to high osmolality, many microorganisms synthesize various types of compatible solutes. These organic osmolytes aid in offsetting the detrimental effects of low water activity on cell physiology. One of these compatible solutes is ectoine. A sub-group of the ectoine producer's enzymatically convert this tetrahydropyrimidine into a hydroxylated derivative, 5-hydroxyectoine. This compound also functions as an effective osmostress protectant and compatible solute but it possesses properties that differ in several aspects from those of ectoine. The enzyme responsible for ectoine hydroxylation (EctD is a member of the non-heme iron(II-containing and 2-oxoglutarate-dependent dioxygenases (EC 1.14.11. These enzymes couple the decarboxylation of 2-oxoglutarate with the formation of a high-energy ferryl-oxo intermediate to catalyze the oxidation of the bound organic substrate. We report here the crystal structure of the ectoine hydroxylase EctD from the moderate halophile Virgibacillus salexigens in complex with Fe(3+ at a resolution of 1.85 A. Like other non-heme iron(II and 2-oxoglutarate dependent dioxygenases, the core of the EctD structure consists of a double-stranded beta-helix forming the main portion of the active-site of the enzyme. The positioning of the iron ligand in the active-site of EctD is mediated by an evolutionarily conserved 2-His-1-carboxylate iron-binding motif. The side chains of the three residues forming this iron-binding site protrude into a deep cavity in the EctD structure that also harbours the 2-oxoglutarate co-substrate-binding site. Database searches revealed a widespread occurrence of EctD-type proteins in members of the Bacteria but only in a single representative of the Archaea, the marine crenarchaeon Nitrosopumilus maritimus. The EctD crystal structure reported here can serve as a template to guide further biochemical and structural studies of this biotechnologically interesting enzyme family.

  1. Polynuclear water-soluble dinitrosyl iron complexes with cysteine or glutathione ligands: electron paramagnetic resonance and optical studies.

    Science.gov (United States)

    Vanin, Anatoly F; Poltorakov, Alexander P; Mikoyan, Vasak D; Kubrina, Lyudmila N; Burbaev, Dosymzhan S

    2010-09-15

    Electron paramagnetic resonance and optical spectrophotometric studies have demonstrated that low-molecular dinitrosyl iron complexes (DNICs) with cysteine or glutathione exist in aqueous solutions in the form of paramagnetic mononuclear (capital EM, Cyrillic-DNICs) and diamagnetic binuclear complexes (B-DNICs). The latter represent Roussin's red salt esters and can be prepared by treatment of aqueous solutions of Fe(2+) and thiols (small er, Cyrilliccapital EN, Cyrillic 7.4) with gaseous nitric oxide (NO) at the thiol:Fe(2+) ratio 1:1. capital EM, Cyrillic-DNICs are synthesized under identical conditions at the thiol:Fe(2+) ratios above 20 and produce an EPR signal with an electronic configuration {Fe(NO)(2)}(7) at g(aver.)=2.03. At neutral pH, aqueous solutions contain both M-DNICs and B-DNICs (the content of the latter makes up to 50% of the total DNIC pool). The concentration of B-DNICs decreases with a rise in pH; at small er, Cyrilliccapital EN, Cyrillic 9-10, the solutions contain predominantly M-DNICs. The addition of thiol excess to aqueous solutions of B-DNICs synthesized at the thiol:Fe(2+) ratio 1:2 results in their conversion into capital EM, Cyrillic-DNICs, the total amount of iron incorporated into M-DNICs not exceeding 50% of the total iron pool in B-DNICs. Air bubbling of cys-capital EM, Cyrillic-DNIC solutions results in cysteine oxidation-controlled conversion of capital EM, Cyrillic-DNICs first into cys-B-DNICs and then into the EPR-silent compound capital HA, Cyrillic able to generate a strong absorption band at 278 nm. In the presence of glutathione or cysteine excess, compound capital HA, Cyrillic is converted into B-DNIC/M-DNIC and is completely decomposed under effect of the Fe(2+) chelator small o, Cyrillic-phenanthroline or N-methyl-d-glucamine dithiocarbamate (MGD). Moreover, MGD initiates the synthesis of paramagnetic mononitrosyl iron complexes with MGD. It is hypothesized that compound capital HA, Cyrillic represents a polynuclear

  2. Dinitrosyl iron complexes and S-nitrosothiols are two possible forms for stabilization and transport of nitric oxide in biological systems.

    Science.gov (United States)

    Vanin, A F

    1998-07-01

    The physicochemical properties, mechanisms of synthesis and decomposition of dinitrosyl iron complexes (DNICs) with thiol-containing ligands and of S-nitrosothiols (RS-NO), and the potential role of these compounds in storage and transport of NO in biological systems are reviewed. Special attention is given to the phenomenon of mutual transformation of DNIC and RS-NO catalyzed by Fe2+. Each Fe2+ binds two neutral NO molecules in the DNICs, catalyzes their mutual oxidation--reduction with formation of nitrous oxide and nitrosonium ions appearing in the DNICs. These ions S-nitrosate thiol-compounds with RS-NO formation. Fe2+ binds two RS-NO molecules and catalyzes their mutual oxidation--reduction followed by decomposition of the resulting molecules. Mutual conversion of DNICs and RS-NO regulated by iron, thiol, and NO levels is suggested to provide NO transport in cells and tissues.

  3. Formation of a dinitrosyl iron complex by NorA, a nitric oxide-binding di-iron protein from Ralstonia eutropha H16.

    Science.gov (United States)

    Strube, Katja; de Vries, Simon; Cramm, Rainer

    2007-07-13

    In Ralstonia eutropha H16, two genes, norA and norB, form a dicistronic operon that is controlled by the NO-responsive transcriptional regulator NorR. NorB has been identified as a membrane-bound NO reductase, but the physiological function of NorA is unknown. We found that, in a NorA deletion mutant, the promoter activity of the norAB operon was increased 3-fold, indicating that NorA attenuates activation of NorR. NorA shows limited sequence similarity to the oxygen carrier hemerythrin, which contains a di-iron center. Indeed, optical and EPR spectroscopy of purified NorA revealed the presence of a di-iron center, which binds oxygen in a similar way as hemerythrin. Diferrous NorA binds two molecules of NO maximally. Unexpectedly, binding of NO to the diferrous NorA required an external reductant. Two different NorA-NO species could be resolved. A minor species (up to 20%) showed an S = (1/2) EPR signal with g( perpendicular) = 2.041, and g( parallel) = 2.018, typical of a paramagnetic dinitrosyl iron complex. The major species was EPR-silent, showing characteristic signals at 420 nm and 750 nm in the optical spectrum. This species is proposed to represent a novel dinitrosyl iron complex of the form Fe(2+)-[NO](2)(2-), i.e. NO is bound as NO(-). The NO binding capacity of NorA in conjunction with its high cytoplasmic concentration (20 mum) suggests that NorA regulates transcription by lowering the free cytoplasmic concentration of NO.

  4. [Hemodynamic effects of the synthetic analogue of endogenous nitric oxide (II) donors a dinitrosyl iron complex in hypertensive patients with uncomplicated hypertensive crisis].

    Science.gov (United States)

    Gosteev, A Iu; Zorin, A V; Rodnenkov, O V; Dragnev, A G; Chazov, E I

    2014-01-01

    To examine the antihypertensive effect of the synthetic analogue of the endogenous nitric oxide donors in patients with grades 2-3 hypertension and uncomplicated hypertensive crisis (HC). The study included 30 male patients aged 35 to 73 years (mean age 55.5 ± 10.8 years). All the patients had grades 2-3 essential or secondary hypertension. Thirteen (43.3%) patients were observed to have signs of HC; 17 (56.7%) patients had persistent blood pressure (BP) elevation. A dinitrosyl iron complex was injected in a dose of 1.5 or 3 mg per kg of body weight. The purpose of its administration was to lower BP by at least 20% of its baseline level. No significant side effects associated with the administration of the test drug were recorded when the clinical trial protocol was implemented. All the patients reported fever and facial hyperemia during and 10-20 minutes after injection. They all (100%) showed efficient blood pressure reduction of at least 20% of the baseline level. Blood pressure changes were similar when the agent was administered in doses of 1.5 or 3 mg/kg. At 6-8 minutes after the drug was injected, there was a maximal decrease in blood pressure, then its gradual rise and stabilization at a lower level than the baseline one within the following 8 hours. There were no significant differences in the magnitude of a blood pressure reduction after administration of 1.5 and 3 mg/kg. The findings suggest that the dinitrosyl iron complex is highly effective in treating uncomplicated HC. The antihypertensive effect of the drug persists for 8 hours after its injection, which is very important during prehospital therapy. The drug is well tolerated by patients and causes an insignificant number of side effects.

  5. Increasing the cooking temperature of meat does not affect nonheme iron absorption from a phytate-rich meal in women

    DEFF Research Database (Denmark)

    Baech, S.B.; Hansen, M.; Bukhave, Klaus

    2003-01-01

    The effect of increasing cooking temperatures of meat on nonheme iron absorption from a composite meal was investigated. Cysteine-containing peptides may have a role in the iron absorption enhancing effect of muscle proteins. Heat treatment can change the content of sulfhydryl groups produced from...... cysteine and thereby affect iron absorption. Twenty-one women (25 +/- 3 y) were served a basic meal without meat and two other meals consisting of the basic meal plus 75 g of pork meat cooked at 70, 95 or 120degreesC. The meals were extrinsically labeled with Fe-55 or Fe-59. Iron absorption was determined...... from measurements of wholebody Fe-59 retention and the activity of Fe-55 and Fe-59 in blood samples. Nonheme iron absorptions were 0.9 (0.5-4.0)% (P = 0.06), 0.7 (0.4-3.9)% (P = 0.1) and 2.0 (1.3-3.1)% (P cooked at 70, 95 or 120degreesC, respectively, was added to the basic...

  6. Nonheme-iron absorption from a phytate-rich meal is increased by the addition of small amounts of pork meat

    DEFF Research Database (Denmark)

    Boech, S.B.; Hansen, M.; Bukhave, Klaus

    2003-01-01

    of small amounts of meat on nonheme-iron absorption from a meal presumed to have low iron bioavailability. Design: Forty-five healthy women with a mean (+/-SD) age of 24 +/- 3 y were randomly assigned to I of 3 groups, each of which was served (A) a basic meal (rice, tomato sauce, pea puree, and a wheat...

  7. X-ray absorption spectroscopy of soybean lipoxygenase-1 : Influence of lipid hydroperoxide activation and lyophilization on the structure of the non-heme iron active site

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Heijdt, L.M. van der; Feiters, M.C.; Navaratnam, S.; Nolting, H.-F.; Hermes, C.; Veldink, G.A.

    1992-01-01

    X-ray absorption spectra at the Fe K-edge of the non-heme iron site in Fe(II) as well as Fe(III) soybean lipoxygenase-1, in frozen solution or lyophilized, are presented; the latter spectra were obtained by incubation of the Fe(II) enzyme with its product hydroperoxide. An edge shift of about 23 eV

  8. Dinitrosyl iron complexes with natural thiol-containing ligands in aqueous solutions: Synthesis and some physico-chemical characteristics (A methodological review).

    Science.gov (United States)

    Vanin, Anatoly F; Borodulin, Rostislav R; Mikoyan, Vasak D

    2017-06-01

    Two approaches to the synthesis of dinitrosyl iron complexes (DNIC) with glutathione and l-cysteine in aqueous solutions based on the use of gaseous NO and appropriate S-nitrosothiols, viz., S-nitrosoglutathione (GS-NO) or S-nitrosocysteine (Cys-NO), respectively, are considered. A schematic representation of a vacuum unit for generation and accumulation of gaseous NO purified from the NO 2 admixture and its application for obtaining aqueous solutions of DNIC in a Thunberg apparatus is given. To achieve this, a solution of bivalent iron in distilled water is loaded into the upper chamber of the Thunberg apparatus, while the thiol solution in an appropriate buffer (рН 7.4) is loaded into its lower chamber. Further steps, which include degassing, addition of gaseous NO, shaking of both solutions and formation of the Fe 2+ -thiol mixture, culminate in the synthesis of DNIC. The second approach consists in a stepwise addition of Fe 2+ salts and nitrite to aqueous solutions of glutathione or cysteine. In the presence of Fe 2+ and after the increase in рН to the physiological level, GS-NO or Cys-NO generated at acid media (pH nitrosonium ions (NO + ) and the peculiar characteristics of the EPR signal of their mononuclear form (M-DNIC). Copyright © 2017. Published by Elsevier Inc.

  9. Electronic and Spatial Structures of Water-Soluble Dinitrosyl Iron Complexes with Thiol-Containing Ligands Underlying Their Ability to Act as Nitric Oxide and Nitrosonium Ion Donors

    OpenAIRE

    Vanin, Anatoly F.; Burbaev, Dosymzhan Sh.

    2011-01-01

    The ability of mononuclear dinitrosyl iron commplexes (M-DNICs) with thiolate ligands to act as NO donors and to trigger S-nitrosation of thiols can be explain only in the paradigm of the model of the [Fe+(NO+)2] core ({Fe(NO)2}7 according to the Enemark-Feltham classification). Similarly, the {(RS−)2Fe+(NO+)2}+ structure describing the distribution of unpaired electron density in M-DNIC corresponds to the low-spin (S = 1/2) state with a d7 electron configuration of the iron atom and predomin...

  10. Mononuclear non-heme iron enzymes with the 2-His-1-carboxylate facial triad: recent developments in enzymology and modeling studies.

    Science.gov (United States)

    Bruijnincx, Pieter C A; van Koten, Gerard; Klein Gebbink, Robertus J M

    2008-12-01

    Iron-containing enzymes are one of Nature's main means of effecting key biological transformations. The mononuclear non-heme iron oxygenases and oxidases have received the most attention recently, primarily because of the recent availability of crystal structures of many different enzymes and the stunningly diverse oxidative transformations that these enzymes catalyze. The wealth of available structural data has furthermore established the so-called 2-His-1-carboxylate facial triad as a new common structural motif for the activation of dioxygen. This superfamily of mononuclear iron(ii) enzymes catalyzes a wide range of oxidative transformations, ranging from the cis-dihydroxylation of arenes to the biosynthesis of antibiotics such as isopenicillin and fosfomycin. The remarkable scope of oxidative transformations seems to be even broader than that associated with oxidative heme enzymes. Not only are many of these oxidative transformations of key biological importance, many of these selective oxidations are also unprecedented in synthetic organic chemistry. In this critical review, we wish to provide a concise background on the chemistry of the mononuclear non-heme iron enzymes characterized by the 2-His-1-carboxylate facial triad and to discuss the many recent developments in the field. New examples of enzymes with unique reactivities belonging to the superfamily have been reported. Furthermore, key insights into the intricate mechanistic details and reactive intermediates have been obtained from both enzyme and modeling studies. Sections of this review are devoted to each of these subjects, i.e. the enzymes, biomimetic models, and reactive intermediates (225 references).

  11. Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates

    NARCIS (Netherlands)

    Draksharapu, Apparao; Angelone, Davide; Quesne, Matthew G.; Padamati, Sandeep K.; Gomez, Laura; Hage, Ronald; Costas, Miquel; Browne, Wesley R.; de Visser, Sam P.

    2015-01-01

    Fe-III-hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their

  12. A Non-Heme Iron Photocatalyst for Light-Driven Aerobic Oxidation of Methanol

    NARCIS (Netherlands)

    Chen, Juan; Stepanovic, Stepan; Draksharapu, Apparao; Gruden, Maja; Browne, Wesley R

    2018-01-01

    Non-heme (L)FeIIIand (L)FeIII-O-FeIII(L) complexes (L=1,1-di(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)ethan-1-amine) underwent reduction under irradiation to the FeIIstate with concomitant oxidation of methanol to methanal, without the need for a secondary photosensitizer. Spectroscopic and DFT

  13. Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates**

    Science.gov (United States)

    Draksharapu, Apparao; Angelone, Davide; Quesne, Matthew G; Padamati, Sandeep K; Gómez, Laura; Hage, Ronald; Costas, Miquel; Browne, Wesley R; de Visser, Sam P

    2015-01-01

    FeIII–hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their identification. Herein, we report the generation and spectroscopic characterization of nonheme FeIII–hypohalite intermediates of possible relevance to iron halogenases. We show that FeIII-OCl polypyridylamine complexes can be sufficiently stable at room temperature to be characterized by UV/Vis absorption, resonance Raman and EPR spectroscopies, and cryo-ESIMS. DFT methods rationalize the pathways to the formation of the FeIII-OCl, and ultimately FeIV=O, species and provide indirect evidence for a short-lived FeII-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases. PMID:25663379

  14. A non-heme iron-mediated chemical demethylation in DNA and RNA.

    Science.gov (United States)

    Yi, Chengqi; Yang, Cai-Guang; He, Chuan

    2009-04-21

    DNA methylation is arguably one of the most important chemical signals in biology. However, aberrant DNA methylation can lead to cytotoxic or mutagenic consequences. A DNA repair protein in Escherichia coli, AlkB, corrects some of the unwanted methylations of DNA bases by a unique oxidative demethylation in which the methyl carbon is liberated as formaldehyde. The enzyme also repairs exocyclic DNA lesions--that is, derivatives in which the base is augmented with an additional heterocyclic subunit--by a similar mechanism. Two proteins in humans that are homologous to AlkB, ABH2 and ABH3, repair the same spectrum of lesions; another human homologue of AlkB, FTO, is linked to obesity. In this Account, we describe our studies of AlkB, ABH2, and ABH3, including our development of a general strategy to trap homogeneous protein-DNA complexes through active-site disulfide cross-linking. AlkB uses a non-heme mononuclear iron(II) and the cofactors 2-ketoglutarate (2KG) and dioxygen to effect oxidative demethylation of the DNA base lesions 1-methyladenine (1-meA), 3-methylcytosine (3-meC), 1-methylguanine (1-meG), and 3-methylthymine (3-meT). ABH3, like AlkB, works better on single-stranded DNA (ssDNA) and is capable of repairing damaged bases in RNA. Conversely, ABH2 primarily repairs lesions in double-stranded DNA (dsDNA); it is the main housekeeping enzyme that protects the mammalian genome from 1-meA base damage. The AlkB-family proteins have moderate affinities for their substrates and bind DNA in a non-sequence-specific manner. Knowing that these proteins flip the damaged base out from the duplex DNA and insert it into the active site for further processing, we first engineered a disulfide cross-link in the active site to stabilize the Michaelis complex. Based on the detailed structural information afforded by the active-site cross-linked structures, we can readily install a cross-link away from the active site to obtain the native-like structures of these complexes

  15. Electronic and spatial structures of water-soluble dinitrosyl iron complexes with thiol-containing ligands underlying their ability to act as nitric oxide and nitrosonium ion donors.

    Science.gov (United States)

    Vanin, Anatoly F; Burbaev, Dosymzhan Sh

    2011-01-01

    The ability of mononuclear dinitrosyl iron commplexes (M-DNICs) with thiolate ligands to act as NO donors and to trigger S-nitrosation of thiols can be explain only in the paradigm of the model of the [Fe(+)(NO(+))(2)] core ({Fe(NO)(2)}(7) according to the Enemark-Feltham classification). Similarly, the {(RS(-))(2)Fe(+)(NO(+))(2)}(+) structure describing the distribution of unpaired electron density in M-DNIC corresponds to the low-spin (S = 1/2) state with a d(7) electron configuration of the iron atom and predominant localization of the unpaired electron on MO(d(z2)) and the square planar structure of M-DNIC. On the other side, the formation of molecular orbitals of M-DNIC including orbitals of the iron atom, thiolate and nitrosyl ligands results in a transfer of electron density from sulfur atoms to the iron atom and nitrosyl ligands. Under these conditions, the positive charge on the nitrosyl ligands diminishes appreciably, the interaction of the ligands with hydroxyl ions or with thiols slows down and the hydrolysis of nitrosyl ligands and the S-nitrosating effect of the latter are not manifested. Most probably, the S-nitrosating effect of nitrosyl ligands is a result of weak binding of thiolate ligands to the iron atom under conditions favoring destabilization of M-DNIC.

  16. Iron(III) complexes of certain tetradentate phenolate ligands as ...

    Indian Academy of Sciences (India)

    non-heme iron enzymes, which catalyse the oxidative cleavage of catechols to cis, cis-muconic acids with the incorporation of ... nature of heterocyclic rings of the ligands and the methyl substituents on them regulate the electronic spectral features .... and simple substitution reactions.19,21 The complexes of [H2(L5)] and ...

  17. [Generation of Superoxide Radicals by Complex III in Heart Mitochondria and Antioxidant Effect of Dinitrosyl Iron Complexes at Different Partial Pressure of Oxygen].

    Science.gov (United States)

    Dudylina, A L; Ivanova, M V; Shumaev, K B; Ruuge, E K

    2016-01-01

    The EPR spin-trapping technique and EPR-oximetry were used to study generation of superoxide radicals in heart mitochondria isolated from Wistar rats under conditions of variable oxygen concentration. Lithium phthalocyanine and TEMPONE-15N-D16 were chosen to determine oxygen content in a gas-permeable capillary tube containing mitochondria. TIRON was used as a spin trap. We investigated the influence of different oxygen concentrations in incubation mixture and demonstrated that heart mitochondria can generate superoxide in complex III at different partial pressure of oxygen as well as under the conditions of deep hypoxia (partial pressure of oxygen, but the magnitude and kinetic characteristics of the effect depended on the concentration of the drug.

  18. Unusual Synthetic Pathway for an {Fe(NO)2}9 Dinitrosyl Iron Complex (DNIC) and Insight into DNIC Electronic Structure via Nuclear Resonance Vibrational Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Speelman, Amy L.; Zhang, Bo; Silakov, Alexey; Skodje, Kelsey M.; Alp, E. Ercan; Zhao, Jiyong; Hu, Michael Y.; Kim, Eunsuk; Krebs, Karsten; Lehnert, Nicolai

    2016-06-06

    Dinitrosyl iron complexes (DNICs) are among the most abundant NO-derived cellular species. Monomeric DNICs can exist in the {Fe(NO)2}9 or {Fe(NO)2}10 oxidation state (in the Enemark -Feltham notation). However, experimental studies of analogous DNICs in both oxidation states are rare, which prevents a thorough understanding of the di ff erences in the electronic structures of these species. Here, the {Fe(NO)2}9 DNIC [Fe(dmp)(NO)2](OTf) ( 1 ; dmp = 2,9-dimethyl-1,10- phenanthroline) is synthesized from a ferrous precursor via an unusual pathway, involving disproportionation of an {FeNO}7 complex to yield the {Fe(NO)2}9 DNIC and a ferric species, which is subsequently reduced by NO gas to generate a ferrous complex that re-enters the reaction cycle. In contrast to most {Fe(NO)2}9 DNICs with neutral N-donor ligands, 1 exhibits high solution stability and can be characterized structurally and spectroscopically. Reduction of 1 yields the corresponding {Fe(NO)2}10 DNIC [Fe(dmp)(NO)2](2). The Mo ssbauer isomer shift of 2 is 0.08 mm/s smaller than that of 1 , which indicates that the iron center is slightly more oxidized in the reduced complex. The nuclear resonance vibrational spectra (NRVS) of 1 and 2 are distinct and provide direct experimental insight into di ff erences in bonding in these complexes. In particular, the symmetric out-of-plane Fe -N - O bending mode is shifted to higher energy by 188 cm-1 in 2 in comparison to 1 . Using quantum chemistry centered normal coordinate analysis (QCC-NCA), this is shown to arise from an increase in Fe - NO bond order and a sti ff ening of the Fe(NO)2 unit upon reduction of 1 to 2 . DFT calculations demonstrate that the changes in bonding arise from an iron- centered reduction which leads to a distinct increase in Fe - NO π -back-bonding in

  19. Experimental and Computational Evidence for the Mechanism of Intradiol Catechol Dioxygenation by Non- Heme Iron(III) Complexes

    NARCIS (Netherlands)

    Jastrzebski, Robin; Quesne, Matthew G.; Weckhuysen, Bert M.; de Visser, Sam P.; Bruijnincx, Pieter C. A.

    2014-01-01

    Catechol intradiol dioxygenation is a unique reaction catalyzed by iron-dependent enzymes and nonheme iron(III) complexes. The mechanism by which these systems activate dioxygen in this important metabolic process remains controversial. Using a combination of kinetic measurements and computational

  20. Spectroscopic and computational study of a nonheme iron nitrosyl center in a biosynthetic model of nitric oxide reductase.

    Science.gov (United States)

    Chakraborty, Saumen; Reed, Julian; Ross, Matthew; Nilges, Mark J; Petrik, Igor D; Ghosh, Soumya; Hammes-Schiffer, Sharon; Sage, J Timothy; Zhang, Yong; Schulz, Charles E; Lu, Yi

    2014-02-24

    A major barrier to understanding the mechanism of nitric oxide reductases (NORs) is the lack of a selective probe of NO binding to the nonheme FeB center. By replacing the heme in a biosynthetic model of NORs, which structurally and functionally mimics NORs, with isostructural ZnPP, the electronic structure and functional properties of the FeB nitrosyl complex was probed. This approach allowed observation of the first S=3/2 nonheme {FeNO}(7) complex in a protein-based model system of NOR. Detailed spectroscopic and computational studies show that the electronic state of the {FeNO}(7) complex is best described as a high spin ferrous iron (S=2) antiferromagnetically coupled to an NO radical (S=1/2) [Fe(2+)-NO(.)]. The radical nature of the FeB -bound NO would facilitate N-N bond formation by radical coupling with the heme-bound NO. This finding, therefore, supports the proposed trans mechanism of NO reduction by NORs. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Determination of Spin Inversion Probability, H-Tunneling Correction, and Regioselectivity in the Two-State Reactivity of Nonheme Iron(IV)-Oxo Complexes.

    Science.gov (United States)

    Kwon, Yoon Hye; Mai, Binh Khanh; Lee, Yong-Min; Dhuri, Sunder N; Mandal, Debasish; Cho, Kyung-Bin; Kim, Yongho; Shaik, Sason; Nam, Wonwoo

    2015-04-16

    We show by experiments that nonheme Fe(IV)O species react with cyclohexene to yield selective hydrogen atom transfer (HAT) reactions with virtually no C═C epoxidation. Straightforward DFT calculations reveal, however, that C═C epoxidation on the S = 2 state possesses a low-energy barrier and should contribute substantially to the oxidation of cyclohexene by the nonheme Fe(IV)O species. By modeling the selectivity of this two-site reactivity, we show that an interplay of tunneling and spin inversion probability (SIP) reverses the apparent barriers and prefers exclusive S = 1 HAT over mixed HAT and C═C epoxidation on S = 2. The model enables us to derive a SIP value by combining experimental and theoretical results.

  2. Enhanced selectivity in non-heme iron catalysed oxidation of alkanes with peracids : evidence for involvement of Fe(IV)=O species

    NARCIS (Netherlands)

    Berg, Tieme A. van den; Boer, Johannes W. de; Browne, Wesley R.; Roelfes, Gerard; Feringa, Bernard

    2004-01-01

    Catalytic alkane oxidation with high selectivity using peracids and an (N4Py)Fe complex is presented and the role of [(N4Py)Fe(IV)=O]2+ species, molecular oxygen and hydroxyl radicals in the catalysis is discussed.

  3. Non-Heme Iron Catalysts with a Rigid Bis-Isoindoline Backbone and Their Use in Selective Aliphatic C−H Oxidation

    NARCIS (Netherlands)

    Chen, Jianming; Lutz, Martin; Milan, Michela; Costas, Miquel; Otte, Matthias; Klein Gebbink, Bert

    2017-01-01

    Iron complexes derived from a bis-isoindoline-bis-pyridine ligand platform based on the BPBP ligand (BPBP=N,N′-bis(2-picolyl)-2,2′-bis-pyrrolidine) have been synthesized and applied in selective aliphatic C−H oxidation with hydrogen peroxide under mild conditions. The introduction of benzene

  4. Nonheme oxoiron(IV) complexes of pentadentate N5 ligands: spectroscopy, electrochemistry, and oxidative reactivity

    OpenAIRE

    Wang, Dong; Ray, Kallol; Collins, Michael J.; Farquhar, Erik R.; Frisch, Jonathan R.; Gomez, Laura; Jackson, Timothy A.; Kerscher, Marion; Waleska, Arkadius; Comba, Peter; Costas, Miquel; Que, Lawrence, Jr.

    2013-01-01

    Oxoiron(IV) species have been found to act as the oxidants in the catalytic cycles of several mononuclear nonheme iron enzymes that activate dioxygen. To gain insight into the factors that govern the oxidative reactivity of such complexes, a series of five synthetic S = 1 [FeIV(O)(LN5)]2+ complexes has been characterized with respect to their spectroscopic and electrochemical properties as well as their relative abilities to carry out oxo transfer and hydrogen atom abstraction. The Fe=O units...

  5. Redox-controlled dinitrosyl formation at the diiron-oxo center of NorA.

    Science.gov (United States)

    Cramm, Rainer; Strube, Katja

    2008-01-01

    In the denitrifying bacterium Ralstonia eutropha H16, the NorA protein is coproduced with the respiratory nitric oxide (NO) reductase. NorA contains a diiron-oxo center, which can form stable adducts with dioxygen and NO. In contrast to other diiron proteins, the formation of NorA-NO requires both fully reduced protein and additional electrons. A minor fraction of in vitro NorA-NO represents a paramagnetic dinitrosyl iron complex (DNIC), while the major fraction is attributed to a DNIC of the structure {Fe(NO)(2)}, which shows no electron paramagnetic resonance. The NorA-DNIC may be formed either upon direct reaction of the protein with NO or upon incubation with nitrite due to an intrinsic nitrite reduction activity of NorA that liberates NO. NorA can be purified rapidly as a six histidine-tagged derivative from overproducing cells of Escherichia coli. This chapter describes procedures for the preparation of different redox forms of NorA for the formation of NorA adducts with NO, dioxygen, and azide, as well as for the quantification of NorA-bound NO.

  6. Differences and Comparisons of the Properties and Reactivities of Iron(III)–hydroperoxo Complexes with Saturated Coordination Sphere

    Science.gov (United States)

    Faponle, Abayomi S; Quesne, Matthew G; Sastri, Chivukula V; Banse, Frédéric; de Visser, Sam P

    2015-01-01

    Heme and nonheme monoxygenases and dioxygenases catalyze important oxygen atom transfer reactions to substrates in the body. It is now well established that the cytochrome P450 enzymes react through the formation of a high-valent iron(IV)–oxo heme cation radical. Its precursor in the catalytic cycle, the iron(III)–hydroperoxo complex, was tested for catalytic activity and found to be a sluggish oxidant of hydroxylation, epoxidation and sulfoxidation reactions. In a recent twist of events, evidence has emerged of several nonheme iron(III)–hydroperoxo complexes that appear to react with substrates via oxygen atom transfer processes. Although it was not clear from these studies whether the iron(III)–hydroperoxo reacted directly with substrates or that an initial O–O bond cleavage preceded the reaction. Clearly, the catalytic activity of heme and nonheme iron(III)–hydroperoxo complexes is substantially different, but the origins of this are still poorly understood and warrant a detailed analysis. In this work, an extensive computational analysis of aromatic hydroxylation by biomimetic nonheme and heme iron systems is presented, starting from an iron(III)–hydroperoxo complex with pentadentate ligand system (L52). Direct C–O bond formation by an iron(III)–hydroperoxo complex is investigated, as well as the initial heterolytic and homolytic bond cleavage of the hydroperoxo group. The calculations show that [(L52)FeIII(OOH)]2+ should be able to initiate an aromatic hydroxylation process, although a low-energy homolytic cleavage pathway is only slightly higher in energy. A detailed valence bond and thermochemical analysis rationalizes the differences in chemical reactivity of heme and nonheme iron(III)–hydroperoxo and show that the main reason for this particular nonheme complex to be reactive comes from the fact that they homolytically split the O–O bond, whereas a heterolytic O–O bond breaking in heme iron(III)–hydroperoxo is found. PMID:25399782

  7. Thioether-ligated iron(ii) and iron(iii)-hydroperoxo/alkylperoxo complexes with an H-bond donor in the second coordination sphere†

    OpenAIRE

    Widger, Leland R.; Jiang, Yunbo; McQuilken, Alison C.; Yang, Tzuhsiung; Siegler, Maxime A.; Matsumura, Hirotoshi; Moënne-Loccoz, Pierre; Kumar, Devesh; de Visser, Sam P.; Goldberg, David P.

    2014-01-01

    The non-heme iron complexes, [FeII(N3PySR)(CH3CN)](BF4)2 (1) and [FeII(N3PyamideSR)](BF4)2 (2), afford rare examples of metastable Fe(iii)-OOH and Fe(iii)-OOtBu complexes containing equatorial thioether ligands and a single H-bond donor in the second coordination sphere. These peroxo complexes were characterized by a range of spectroscopic methods and density functional theory studies. The influence of a thioether ligand and of one H-bond donor on the stability and spectroscopic properties of...

  8. An assessment of pure, hybrid, meta, and hybrid-meta GGA density functional theory methods for open-shell systems: the case of the nonheme iron enzyme 8R-LOX.

    Science.gov (United States)

    Bushnell, Eric A C; Gauld, James W

    2013-01-15

    The performance of a range density functional theory functionals combined in a quantum mechanical (QM)/molecular mechanical (MM) approach was investigated in their ability to reliably provide geometries, electronic distributions, and relative energies of a multicentered open-shell mechanistic intermediate in the mechanism 8R-Lipoxygenase. With the use of large QM/MM active site chemical models, the smallest average differences in geometries between the catalytically relevant quartet and sextet complexes were obtained with the B3LYP(*) functional. Moreover, in the case of the relative energies between (4) II and (6) II, the use of the B3LYP(*) functional provided a difference of 0.0 kcal mol(-1). However, B3LYP(±) and B3LYP also predicted differences in energies of less than 1 kcal mol(-1). In the case of describing the electronic distribution (i.e., spin density), the B3LYP(*), B3LYP, or M06-L functionals appeared to be the most suitable. Overall, the results obtained suggest that for systems with multiple centers having unpaired electrons, the B3LYP(*) appears most well rounded to provide reliable geometries, electronic structures, and relative energies. Copyright © 2012 Wiley Periodicals, Inc.

  9. Models for non-heme iron containing oxidation enzymes

    NARCIS (Netherlands)

    Roelfes, Johannes Gerhardus

    2000-01-01

    IJzer is een van de essentiël elementen voor alle levende wezens. Heel veel belangrijke functies in organismen worden vervuld door ijzer bevattende eiwitten. De bekendste voorbeelden hiervan zijn ongetwijfeld hemoglobine en myoglobine, die het transport van zuurstof van de longen naar de rest van

  10. Structure and mechanism leading to formation of the cysteine sulfinate product complex of a biomimetic cysteine dioxygenase model.

    Science.gov (United States)

    Sallmann, Madleen; Kumar, Suresh; Chernev, Petko; Nehrkorn, Joscha; Schnegg, Alexander; Kumar, Devesh; Dau, Holger; Limberg, Christian; de Visser, Sam P

    2015-05-11

    Cysteine dioxygenase is a unique nonheme iron enzyme that is involved in the metabolism of cysteine in the body. It contains an iron active site with an unusual 3-His ligation to the protein, which contrasts with the structural features of common nonheme iron dioxygenases. Recently, some of us reported a truly biomimetic model for this enzyme, namely a trispyrazolylborato iron(II) cysteinato complex, which not only has a structure very similar to the enzyme-substrate complex but also represents a functional model: Treatment of the model with dioxygen leads to cysteine dioxygenation, as shown by isolating the cysteine part of the product in the course of the work-up. However, little is known on the conversion mechanism and, so far, not even the structure of the actual product complex had been characterised, which is also unknown in case of the enzyme. In a multidisciplinary approach including density functional theory calculations and X-ray absorption spectroscopy, we have now determined the structure of the actual sulfinato complex for the first time. The Cys-SO2 (-) functional group was found to be bound in an η(2) -O,O-coordination mode, which, based on the excellent resemblance between model and enzyme, also provides the first support for a corresponding binding mode within the enzymatic product complex. Indeed, this is again confirmed by theory, which had predicted a η(2) -O,O-binding mode for synthetic as well as the natural enzyme. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Theoretical investigation of dinitrosyl complexes in Cu-zeolites as intermediates in deNOx process

    Czech Academy of Sciences Publication Activity Database

    Pulido, Maria Angeles; Nachtigall, Petr

    2009-01-01

    Roč. 11, č. 9 (2009), s. 1447-1458 ISSN 1463-9076 R&D Projects: GA ČR GA203/06/0324; GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : zeolites * deNOx * DFT Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.116, year: 2009

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

    Science.gov (United States)

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

    2009-01-01

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

  13. Water-Soluble Dinitrosyl Iron Complex (DNIC): a Nitric Oxide Vehicle Triggering Cancer Cell Death via Apoptosis.

    Science.gov (United States)

    Wu, Shou-Cheng; Lu, Chung-Yen; Chen, Yi-Lin; Lo, Feng-Chun; Wang, Ting-Yin; Chen, Yu-Jen; Yuan, Shyng-Shiou; Liaw, Wen-Feng; Wang, Yun-Ming

    2016-09-19

    Nitric oxide (NO) is an important cellular signaling molecule that modulates various physiological activities. Angiogenesis-promoting activities of NO-donor drugs have been explored in both experimental and clinical studies. In this study, a structurally well characterized and water-soluble neutral {Fe(NO)2}(9) DNIC [(S(CH2)2OH)(S(CH2)2NH3)Fe(NO)2] (DNIC 2) was synthesized to serve as a NO-donor species. The antitumor activity of DNIC 2 was determined by MTT assay, confocal imaging, and Annexin-V/PI staining. The IC50 values of DNIC 2 were 18.8, 42.9, and 38.6 μM for PC-3, SKBR-3, and CRL5866 tumor cells, respectively. Moreover, DNIC 2 promoted apoptotic cell death via activation of apoptosis-associated proteins and inhibition of survival associated proteins. In particular, DNIC 2 treatment suppressed PC-3 tumor growth by 2.34- and 19.3-fold at 7 and 21 days, in comparison with the control group. These results indicate that water-soluble DNIC 2 may serve as a promising drug for cancer therapy.

  14. A Neisseria meningitidis fbpABC mutant is incapable of using nonheme iron for growth.

    Science.gov (United States)

    Khun, H H; Kirby, S D; Lee, B C

    1998-05-01

    The neisserial fbpABC locus has been proposed to act as an iron-specific ABC transporter system. To confirm this assigned function, we constructed an fbpABC mutant in Neisseria meningitidis by insertional inactivation of fbpABC with a selectable antibiotic marker. The mutant was unable to use iron supplied from human transferrin, human lactoferrin, or iron chelates. However, the use of iron from heme and human hemoglobin was unimpaired. These results support the obligatory participation of fbpABC in neisserial periplasmic iron transport and do not indicate a role for this genetic locus in the heme iron pathway.

  15. Natural selection on HFE in Asian populations contributes to enhanced non-heme iron absorption.

    Science.gov (United States)

    Ye, Kaixiong; Cao, Chang; Lin, Xu; O'Brien, Kimberly O; Gu, Zhenglong

    2015-06-10

    HFE, a major regulator of iron (Fe) homeostasis, has been suggested to be under positive selection in both European and Asian populations. While the genetic variant under selection in Europeans (a non-synonymous mutation, C282Y) has been relatively well-studied, the adaptive variant in Asians and its functional consequences are still unknown. Identifying the adaptive HFE variants in Asians will not only elucidate the evolutionary history and the genetic basis of population difference in Fe status, but also assist the future practice of genome-informed dietary recommendation. Using data from the International HapMap Project, we confirmed the signatures of positive selection on HFE in Asian populations and identified a candidate adaptive haplotype that is common in Asians (52.35-54.71%) but rare in Europeans (5.98%) and Africans (4.35%). The T allele at tag SNP rs9366637 (C/T) captured 95.8% of this Asian-common haplotype. A significantly reduced HFE expression was observed in individuals carrying T/T at rs9366637 compared to C/C and C/T, indicating a possible role of gene regulation in adaptation. We recruited 57 women of Asian descent and measured Fe absorption using stable isotopes in those homozygous at rs9366637. We observed a 22% higher absorption in women homozygous for the Asian-common haplotype (T/T) compared to the control genotype (C/C). Additionally, compared with a group of age-matched Caucasian women, Asian women exhibited significantly elevated Fe absorption. Our results indicate parallel adaptation of HFE gene in Europeans and Asians with different genetic variants. Moreover, natural selection on HFE may have contributed to elevated Fe absorption in Asians. This study regarding population differences in Fe homeostasis has significant medical impact as high Fe level has been linked to an increased disease risk of metabolic syndromes.

  16. Directing a Non-Heme Iron(III)-Hydroperoxide Species on a Trifurcated Reactivity Pathway

    DEFF Research Database (Denmark)

    Wegeberg, Christina; Lauritsen, Frants R.; Frandsen, Cathrine

    2018-01-01

    The reactivity of [FeIII(tpena)]2+ (tpena=N,N,N'-tris(2-pyridylmethyl)ethylenediamine-N'-acetate) as a catalyst for oxidation reactions depends on its ratio to the terminal oxidant H2O2 and presence or absence of sacrificial substrates. The outcome can be switched between: 1)catalysed H2O2...

  17. Iron and Zinc Complexes of Bulky Bis-Imidazole Ligands : Enzyme Mimicry and Ligand-Centered Redox Activity

    NARCIS (Netherlands)

    Folkertsma, E.

    2016-01-01

    The research described in this thesis is directed to the development of cheap and non-toxic iron-based homogeneous catalysts, using enzyme models and redox non-innocent ligands. Inspired by nature, the first approach focuses on the synthesis of structural models of the active site of non-heme iron

  18. Frontier Molecular Orbital Contributions to Chlorination versus Hydroxylation Selectivity in the Non-Heme Iron Halogenase SyrB2

    Czech Academy of Sciences Publication Activity Database

    Srnec, Martin; Solomon, E. I.

    2017-01-01

    Roč. 139, č. 6 (2017), s. 2396-2407 ISSN 0002-7863 R&D Projects: GA ČR(CZ) GJ15-10279Y Institutional support: RVO:61388955 Keywords : Chlorination * Chlorine compounds * Free radical reactions Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 13.858, year: 2016

  19. Peroxo-Type Intermediates in Class I Ribonucleotide Reductase and Related Binuclear Non-Heme Iron Enzymes

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta; Bell, Caleb B.; Clay, MIchael D.

    2009-01-01

    We have performed a systematic study of chemically possible peroxo-type intermediates occurring in the non-heme di-iron enzyme class la ribonucleotide reductase, using spectroscopically calibrated computational chemistry. Density functional computations of equilibrium structures, Fe-O and O-O str...

  20. Frontier Molecular Orbital Contributions to Chlorination versus Hydroxylation Selectivity in the Non-Heme Iron Halogenase SyrB2

    Czech Academy of Sciences Publication Activity Database

    Srnec, Martin; Solomon, E. I.

    2017-01-01

    Roč. 139, č. 6 (2017), s. 2396-2407 ISSN 0002-7863 R&D Projects: GA ČR(CZ) GJ15-10279Y Institutional support: RVO:61388955 Keywords : Chlorination * Chlorine compounds * Free radical reaction s Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 13.858, year: 2016

  1. Bio-inspired Iron Catalysts for Hydrocarbon Oxidations

    Energy Technology Data Exchange (ETDEWEB)

    Que, Jr., Lawrence [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-03-22

    Stereoselective oxidation of C–H and C=C bonds are catalyzed by nonheme iron enzymes. Inspired by these bioinorganic systems, our group has been exploring the use of nonheme iron complexes as catalysts for the oxidation of hydrocarbons using H2O2 as an environmentally friendly and atom-efficient oxidant in order to gain mechanistic insights into these novel transformations. In particular, we have focused on clarifying the nature of the high-valent iron oxidants likely to be involved in these transformations.

  2. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Catechol 1,2-dioxygenase (CTD) and protocatechuate 3,4-dioxygenase (PCD) are bacterial non-heme iron enzymes, which catalyse the oxidative cleavage of catechols to cis, cis-muconic acids with the incorporation of molecular oxygen via a mechanism involving a high-spin ferric centre. The iron(III) complexes of tripodal ...

  3. The Crystal Structure of a High-Spin Oxoiron(IV) Complex and Characterization of Its Self-Decay Pathway

    Energy Technology Data Exchange (ETDEWEB)

    England, J.; Guo, Y; Farquhar, E; Young, Jr., V; Münck, E; Que, Jr., L

    2010-01-01

    [Fe{sup IV}(O)(TMG{sub 3}tren)]{sup 2+} (1; TMG{sub 3}tren = 1,1,1-tris{l_brace}2-[N{sup 2}-(1,1,3,3-tetramethylguanidino)]ethyl{r_brace}amine) is a unique example of an isolable synthetic S = 2 oxoiron(IV) complex, which serves as a model for the high-valent oxoiron(IV) intermediates observed in nonheme iron enzymes. Congruent with DFT calculations predicting a more reactive S = 2 oxoiron(IV) center, 1 has a lifetime significantly shorter than those of related S = 1 oxoiron(IV) complexes. The self-decay of 1 exhibits strictly first-order kinetic behavior and is unaffected by solvent deuteration, suggesting an intramolecular process. This hypothesis was supported by ESI-MS analysis of the iron products and a significant retardation of self-decay upon use of a perdeuteromethyl TMG{sub 3}tren isotopomer, d{sub 36}-1 (KIE = 24 at 25 C). The greatly enhanced thermal stability of d{sub 36}-1 allowed growth of diffraction quality crystals for which a high-resolution crystal structure was obtained. This structure showed an Fe=O unit (r = 1.661(2) {angstrom}) in the intended trigonal bipyramidal geometry enforced by the sterically bulky tetramethylguanidinyl donors of the tetradentate tripodal TMG{sub 3}tren ligand. The close proximity of the methyl substituents to the oxoiron unit yielded three symmetrically oriented short C-D {hor_ellipsis} O nonbonded contacts (2.38-2.49 {angstrom}), an arrangement that facilitated self-decay by rate-determining intramolecular hydrogen atom abstraction and subsequent formation of a ligand-hydroxylated iron(III) product. EPR and Moessbauer quantification of the various iron products, referenced against those obtained from reaction of 1 with 1,4-cyclohexadiene, allowed formulation of a detailed mechanism for the self-decay process. The solution of this first crystal structure of a high-spin (S = 2) oxoiron(IV) center represents a fundamental step on the path toward a full understanding of these pivotal biological intermediates.

  4. Electronic Structure of the Ferryl Intermediate in the α-Ketoglutarate Dependent Non-Heme Iron Halogenase SyrB2: Contributions to H Atom Abstraction Reactivity

    Czech Academy of Sciences Publication Activity Database

    Srnec, Martin; Wong, S. D.; Matthews, M. L.; Krebs, C.; Bollinger, J. M.; Solomon, E. I.

    2016-01-01

    Roč. 138, č. 15 (2016), s. 5110-5122 ISSN 0002-7863 R&D Projects: GA ČR(CZ) GJ15-10279Y Institutional support: RVO:61388955 Keywords : Ferryl intermediate * syringomycin halogenase * electronic structure Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.858, year: 2016

  5. The effect of soy products in the diet on retention of non-heme iron from radiolabeled test meals fed to marginally iron-deficient young rats

    International Nuclear Information System (INIS)

    Thompson, D.B.

    1984-01-01

    Diets based either on casein or soy products and containing about 25 ppm iron were fed to weanling rats for 13 days. Rats were fasted overnight and fed a 59 Fe-radiolabeled casein test meal the morning of day 14. On day 21 less 59 Fe was retained by rats fed various diets based on selected soy products than by rats fed the casein-based diet. A similar adverse effect of diet components on 59 Fe retention from a casein test meal was observed for lactalbumin and for psyllium husk. No adverse effect of diet on 59 Fe retention was observed for the fiber of soy cotyledons or for rapeseed protein concentrate. For a commercial soy protein isolated (SPI) fed throughout the 21-day experiment, the adverse effect of diet on 59 Fe retention was observed to the sum of the effect of dietary SPI previous to the 59 Fe-radiolabeled casein test meal fed on day 14 and the effect of dietary SPI subsequent to the casein test meal. An effect of dietary soy products on 59 Fe retention from a casein test meal was not observed with diets containing higher iron levels (83 ppm) or when diets were fed for a longer period prior to the test meal (56 days). The present work shows that in some circumstances the concept of iron bioavailability must be expanded to include not only the influence of meal composition, but also the influence of diet previous to and subsequent to a meal

  6. Reactivity of the binuclear non-heme iron active site of delta(9) desaturase studied by large-scale multireference ab initio calculations

    Czech Academy of Sciences Publication Activity Database

    Chalupský, Jakub; Rokob, Tibor András; Kurashige, Y.; Yanai, T.; Solomon, E. I.; Rulíšek, Lubomír; Srnec, Martin

    2014-01-01

    Roč. 136, č. 45 (2014), s. 15977-15991 ISSN 0002-7863 R&D Projects: GA ČR(CZ) GA14-31419S Institutional support: RVO:61388963 ; RVO:61388955 Keywords : DMRG-CASPT2 * ab initio calculations * reaction mechanisms Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 12.113, year: 2014

  7. Design, Preparation, and Characterization of Zn and Cu Metallopeptides Based On Tetradentate Aminopyridine Ligands Showing Enhanced DNA Cleavage Activity

    Czech Academy of Sciences Publication Activity Database

    Soler, M.; Figueras, E.; Serrano-Plana, J.; Gonzalez-Bartulos, M.; Massaguer, A.; Company, A.; Martinez, M.A.; Malina, Jaroslav; Brabec, Viktor; Feliu, L.; Planas, M.; Ribas, X.; Costas, M.

    2015-01-01

    Roč. 54, č. 22 (2015), s. 10542-10558 ISSN 0020-1669 R&D Projects: GA ČR(CZ) GAP205/11/0856; GA ČR(CZ) GA14-21053S Institutional support: RVO:68081707 Keywords : SOLID-PHASE SYNTHESIS * NONHEME IRON CATALYSTS * METAL-COMPLEXES Subject RIV: BO - Biophysics Impact factor: 4.820, year: 2015

  8. The Semireduced Mechanism for Nitric Oxide Reduction by Non-Heme Diiron Complexes: Modeling Flavodiiron Nitric Oxide Reductases.

    Science.gov (United States)

    White, Corey J; Speelman, Amy L; Kupper, Claudia; Demeshko, Serhiy; Meyer, Franc; Shanahan, James P; Alp, E Ercan; Hu, Michael; Zhao, Jiyong; Lehnert, Nicolai

    2018-02-21

    Flavodiiron nitric oxide reductases (FNORs) are a subclass of flavodiiron proteins (FDPs) capable of preferential binding and subsequent reduction of NO to N 2 O. FNORs are found in certain pathogenic bacteria, equipping them with resistance to nitrosative stress, generated as a part of the immune defense in humans, and allowing them to proliferate. Here, we report the spectroscopic characterization and detailed reactivity studies of the diiron dinitrosyl model complex [Fe 2 (BPMP)(OPr)(NO) 2 ](OTf) 2 for the FNOR active site that is capable of reducing NO to N 2 O [Zheng et al., J. Am. Chem. Soc. 2013, 135, 4902-4905]. Using UV-vis spectroscopy, cyclic voltammetry, and spectro-electrochemistry, we show that one reductive equivalent is in fact sufficient for the quantitative generation of N 2 O, following a semireduced reaction mechanism. This reaction is very efficient and produces N 2 O with a first-order rate constant k > 10 2 s -1 . Further isotope labeling studies confirm an intramolecular N-N coupling mechanism, consistent with the rapid time scale of the reduction and a very low barrier for N-N bond formation. Accordingly, the reaction proceeds at -80 °C, allowing for the direct observation of the mixed-valent product of the reaction. At higher temperatures, the initial reaction product is unstable and decays, ultimately generating the diferrous complex [Fe 2 (BPMP)(OPr) 2 ](OTf) and an unidentified ferric product. These results combined offer deep insight into the mechanism of NO reduction by the relevant model complex [Fe 2 (BPMP)(OPr)(NO) 2 ] 2+ and provide direct evidence that the semireduced mechanism would constitute a highly efficient pathway to accomplish NO reduction to N 2 O in FNORs and in synthetic catalysts.

  9. Electrochemically Generated cis-Carboxylato-Coordinated Iron(IV) Oxo Acid-Base Congeners as Promiscuous Oxidants of Water Pollutants

    DEFF Research Database (Denmark)

    de Sousa, David P; Miller, Christopher J; Chang, Yingyue

    2017-01-01

    The nonheme iron(IV) oxo complex [FeIV(O)(tpenaH)]2+ and its conjugate base [FeIV(O)(tpena)]+ [tpena- = N,N,N'-tris(2-pyridylmethyl)ethylenediamine-N'-acetate] have been prepared electrochemically in water by bulk electrolysis of solutions prepared from [FeIII2(μ-O)(tpenaH)2](ClO4)4 at potentials...... of the electrochemically generated iron(IV) oxo complexes, in terms of the broad range of substrates examined, represents an important step toward the goal of cost-effective electrocatalytic water purification....

  10. Bis[1,3-bis(2,4,6-trimethylphenyl-2,3-dihydro-1H-imidazol-2-ylidene]dinitrosyl(tetrahydroborato-κ2H,H′tungsten(0

    Directory of Open Access Journals (Sweden)

    Heinz Berke

    2011-01-01

    Full Text Available In the title paramagnetic 19-electron neutral complex, [W(BH4(C21H24N22(NO2], the W(0 atom is coordinated by two 1,3-bis(2,4,6-trimethylphenylimidazol-2-ylidene (IMes carbene ligands, two NO groups and two H atoms of an η2-tetrahydroborate ligand. Depending on the number of coordination sites (n assigned to the BH4− ligand, the coordination geometry of the W atom may either be described as approximately trigonal–bipyramidal (n = 1 or as very distorted octahedral with the bridging H atoms filling two coordination positions (n = 2. In the latter case, the coplanar NO groups and bridging H atoms (r.m.s. deviation = 0.032 Å form one octahedral plane, with mutually trans-oriented carbene ligands. In the crystal, molecules are connected via C—H...O interactions.

  11. Cobalt-mediated [3 + 2]-annulation reaction of alkenes with alpha,beta-unsaturated ketones and imines.

    Science.gov (United States)

    Schomaker, Jennifer M; Toste, F Dean; Bergman, Robert G

    2009-08-20

    The utility of cobalt dinitrosyl complexes for the [3 + 2] annulation of alkenes with unsaturated enones and ketimines has been demonstrated. Reaction of a series of cobalt dinitrosyl/alkene adducts with conjugate acceptors in the presence of Sc(OTf)(3)/LHMDS formed two new C-C bonds at the carbons alpha to the nitrosyl groups of the substrate, leading to unusual tri- and tetracycles. Retrocycloaddition of these products in the presence of norbornadiene yielded functionalized tetrasubstituted bicyclic olefins.

  12. Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review

    OpenAIRE

    Delimont, Nicole M.; Rosenkranz, Sara K.; Haub, Mark D.; Lindshield, Brian L.

    2017-01-01

    Background Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. Aim To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme ir...

  13. Complexity explained

    CERN Document Server

    Erdi, Peter

    2008-01-01

    This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.

  14. Complex chemistry

    International Nuclear Information System (INIS)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-01

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  15. (II) complexes

    African Journals Online (AJOL)

    activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

  16. Communication complexity and information complexity

    Science.gov (United States)

    Pankratov, Denis

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

  17. Complexity Plots

    KAUST Repository

    Thiyagalingam, Jeyarajan

    2013-06-01

    In this paper, we present a novel visualization technique for assisting the observation and analysis of algorithmic complexity. In comparison with conventional line graphs, this new technique is not sensitive to the units of measurement, allowing multivariate data series of different physical qualities (e.g., time, space and energy) to be juxtaposed together conveniently and consistently. It supports multivariate visualization as well as uncertainty visualization. It enables users to focus on algorithm categorization by complexity classes, while reducing visual impact caused by constants and algorithmic components that are insignificant to complexity analysis. It provides an effective means for observing the algorithmic complexity of programs with a mixture of algorithms and black-box software through visualization. Through two case studies, we demonstrate the effectiveness of complexity plots in complexity analysis in research, education and application. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  18. Complexity Theory

    Science.gov (United States)

    Lee, William H K.

    2016-01-01

    A complex system consists of many interacting parts, generates new collective behavior through self organization, and adaptively evolves through time. Many theories have been developed to study complex systems, including chaos, fractals, cellular automata, self organization, stochastic processes, turbulence, and genetic algorithms.

  19. Managing Complexity

    DEFF Research Database (Denmark)

    Maylath, Bruce; Vandepitte, Sonia; Minacori, Patricia

    2013-01-01

    and into French. The complexity of the undertaking proved to be a central element in the students' learning, as the collaboration closely resembles the complexity of international documentation workplaces of language service providers. © Association of Teachers of Technical Writing.......This article discusses the largest and most complex international learning-by-doing project to date- a project involving translation from Danish and Dutch into English and editing into American English alongside a project involving writing, usability testing, and translation from English into Dutch...

  20. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  1. Softball Complex

    Science.gov (United States)

    Ellis, Jim

    1977-01-01

    The Parks and Recreation Department of Montgomery, Alabama, has developed a five-field softball complex as part of a growing community park with facilities for camping, golf, aquatics, tennis, and picnicking. (MJB)

  2. Lecithin Complex

    African Journals Online (AJOL)

    1Department of Food Science and Engineering, Xinyang College of Agriculture and ... Results: The UV and IR spectra of the complex showed an additive effect of polydatin-lecithin, in which .... Monochromatic Cu Ka radiation (wavelength =.

  3. Complex analysis

    CERN Document Server

    Freitag, Eberhard

    2005-01-01

    The guiding principle of this presentation of ``Classical Complex Analysis'' is to proceed as quickly as possible to the central results while using a small number of notions and concepts from other fields. Thus the prerequisites for understanding this book are minimal; only elementary facts of calculus and algebra are required. The first four chapters cover the essential core of complex analysis: - differentiation in C (including elementary facts about conformal mappings) - integration in C (including complex line integrals, Cauchy's Integral Theorem, and the Integral Formulas) - sequences and series of analytic functions, (isolated) singularities, Laurent series, calculus of residues - construction of analytic functions: the gamma function, Weierstrass' Factorization Theorem, Mittag-Leffler Partial Fraction Decomposition, and -as a particular highlight- the Riemann Mapping Theorem, which characterizes the simply connected domains in C. Further topics included are: - the theory of elliptic functions based on...

  4. Subgroup complexes

    CERN Document Server

    Smith, Stephen D

    2011-01-01

    This book is intended as an overview of a research area that combines geometries for groups (such as Tits buildings and generalizations), topological aspects of simplicial complexes from p-subgroups of a group (in the spirit of Brown, Quillen, and Webb), and combinatorics of partially ordered sets. The material is intended to serve as an advanced graduate-level text and partly as a general reference on the research area. The treatment offers optional tracks for the reader interested in buildings, geometries for sporadic simple groups, and G-equivariant equivalences and homology for subgroup complexes.

  5. Complex manifolds

    CERN Document Server

    Morrow, James

    2006-01-01

    This book, a revision and organization of lectures given by Kodaira at Stanford University in 1965-66, is an excellent, well-written introduction to the study of abstract complex (analytic) manifolds-a subject that began in the late 1940's and early 1950's. It is largely self-contained, except for some standard results about elliptic partial differential equations, for which complete references are given. -D. C. Spencer, MathSciNet The book under review is the faithful reprint of the original edition of one of the most influential textbooks in modern complex analysis and geometry. The classic

  6. Complex Networks

    CERN Document Server

    Evsukoff, Alexandre; González, Marta

    2013-01-01

    In the last decade we have seen the emergence of a new inter-disciplinary field focusing on the understanding of networks which are dynamic, large, open, and have a structure sometimes called random-biased. The field of Complex Networks is helping us better understand many complex phenomena such as the spread of  deseases, protein interactions, social relationships, to name but a few. Studies in Complex Networks are gaining attention due to some major scientific breakthroughs proposed by network scientists helping us understand and model interactions contained in large datasets. In fact, if we could point to one event leading to the widespread use of complex network analysis is the availability of online databases. Theories of Random Graphs from Erdös and Rényi from the late 1950s led us to believe that most networks had random characteristics. The work on large online datasets told us otherwise. Starting with the work of Barabási and Albert as well as Watts and Strogatz in the late 1990s, we now know th...

  7. Managing Complexity

    Energy Technology Data Exchange (ETDEWEB)

    Chassin, David P.; Posse, Christian; Malard, Joel M.

    2004-08-01

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust control strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.

  8. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  9. Complex dynamics

    CERN Document Server

    Carleson, Lennart

    1993-01-01

    Complex dynamics is today very much a focus of interest. Though several fine expository articles were available, by P. Blanchard and by M. Yu. Lyubich in particular, until recently there was no single source where students could find the material with proofs. For anyone in our position, gathering and organizing the material required a great deal of work going through preprints and papers and in some cases even finding a proof. We hope that the results of our efforts will be of help to others who plan to learn about complex dynamics and perhaps even lecture. Meanwhile books in the field a. re beginning to appear. The Stony Brook course notes of J. Milnor were particularly welcome and useful. Still we hope that our special emphasis on the analytic side will satisfy a need. This book is a revised and expanded version of notes based on lectures of the first author at UCLA over several \\Vinter Quarters, particularly 1986 and 1990. We owe Chris Bishop a great deal of gratitude for supervising the production of cour...

  10. Cosmic Complexity

    Science.gov (United States)

    Mather, John C.

    2012-01-01

    What explains the extraordinary complexity of the observed universe, on all scales from quarks to the accelerating universe? My favorite explanation (which I certainty did not invent) ls that the fundamental laws of physics produce natural instability, energy flows, and chaos. Some call the result the Life Force, some note that the Earth is a living system itself (Gaia, a "tough bitch" according to Margulis), and some conclude that the observed complexity requires a supernatural explanation (of which we have many). But my dad was a statistician (of dairy cows) and he told me about cells and genes and evolution and chance when I was very small. So a scientist must look for me explanation of how nature's laws and statistics brought us into conscious existence. And how is that seemll"!gly Improbable events are actually happening a!1 the time? Well, the physicists have countless examples of natural instability, in which energy is released to power change from simplicity to complexity. One of the most common to see is that cooling water vapor below the freezing point produces snowflakes, no two alike, and all complex and beautiful. We see it often so we are not amazed. But physlc!sts have observed so many kinds of these changes from one structure to another (we call them phase transitions) that the Nobel Prize in 1992 could be awarded for understanding the mathematics of their common features. Now for a few examples of how the laws of nature produce the instabilities that lead to our own existence. First, the Big Bang (what an insufficient name!) apparently came from an instability, in which the "false vacuum" eventually decayed into the ordinary vacuum we have today, plus the most fundamental particles we know, the quarks and leptons. So the universe as a whole started with an instability. Then, a great expansion and cooling happened, and the loose quarks, finding themselves unstable too, bound themselves together into today's less elementary particles like protons and

  11. Cobalt-Mediated [3+2]-Annulation Reaction of Alkenes with α,β-Unsaturated Ketones and Imines

    Science.gov (United States)

    Schomaker, Jennifer M.; Toste, F. Dean; Bergman, Robert G.

    2009-01-01

    The utility of cobalt dinitrosyl complexes for the [3+2] annulation of alkenes with unsaturated enones and ketimines has been demonstrated. Reaction of a series of cobalt dinitrosyl/alkene adducts with conjugate acceptors in the presence of Sc(OTf)3/LHMDS formed two new C-C bonds at the carbons α to the nitrosyl groups of the substrate, leading to unusual tri- and tetracycles. Retrocycloaddition of these products in the presence of norbornadiene yielded functionalized tetrasubstituted bicyclic olefins. PMID:19639989

  12. Overview of Minerals

    Science.gov (United States)

    ... content of local soil) Required for the formation of thyroid hormones 150 micrograms 1,100 micrograms Iron As heme iron: Beef, poultry, fish, kidneys, and liver As nonheme iron: Soybean flour, beans, molasses, spinach, clams, and fortified grains and ...

  13. Complex analysis and geometry

    CERN Document Server

    Silva, Alessandro

    1993-01-01

    The papers in this wide-ranging collection report on the results of investigations from a number of linked disciplines, including complex algebraic geometry, complex analytic geometry of manifolds and spaces, and complex differential geometry.

  14. Complex Systems: An Introduction

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 9. Complex Systems: An Introduction - Anthropic Principle, Terrestrial Complexity, Complex Materials. V K Wadhawan. General Article Volume 14 Issue 9 September 2009 pp 894-906 ...

  15. Complex differential geometry

    CERN Document Server

    Zheng, Fangyang

    2002-01-01

    The theory of complex manifolds overlaps with several branches of mathematics, including differential geometry, algebraic geometry, several complex variables, global analysis, topology, algebraic number theory, and mathematical physics. Complex manifolds provide a rich class of geometric objects, for example the (common) zero locus of any generic set of complex polynomials is always a complex manifold. Yet complex manifolds behave differently than generic smooth manifolds; they are more coherent and fragile. The rich yet restrictive character of complex manifolds makes them a special and interesting object of study. This book is a self-contained graduate textbook that discusses the differential geometric aspects of complex manifolds. The first part contains standard materials from general topology, differentiable manifolds, and basic Riemannian geometry. The second part discusses complex manifolds and analytic varieties, sheaves and holomorphic vector bundles, and gives a brief account of the surface classifi...

  16. Complex and symplectic geometry

    CERN Document Server

    Medori, Costantino; Tomassini, Adriano

    2017-01-01

    This book arises from the INdAM Meeting "Complex and Symplectic Geometry", which was held in Cortona in June 2016. Several leading specialists, including young researchers, in the field of complex and symplectic geometry, present the state of the art of their research on topics such as the cohomology of complex manifolds; analytic techniques in Kähler and non-Kähler geometry; almost-complex and symplectic structures; special structures on complex manifolds; and deformations of complex objects. The work is intended for researchers in these areas.

  17. Oligocyclopentadienyl transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    de Azevedo, Cristina G.; Vollhardt, K. Peter C.

    2002-01-18

    Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

  18. Photocytotoxic lanthanide complexes

    Indian Academy of Sciences (India)

    Among many applications of lanthanides, gadolinium complexes are used as magnetic resonance imaging (MRI) contrast agents in clinical radiology and luminescent lanthanides for bioanalysis, imaging and sensing. The chemistry of photoactive lanthanide complexes showing biological applications is of recent origin.

  19. ComplexRec 2017

    DEFF Research Database (Denmark)

    a single step in the user's more complex background need. These background needs can often place a variety of constraints on which recommendations are interesting to the user and when they are appropriate. However, relatively little research has been done on these complex recommendation scenarios....... The ComplexRec 2017 workshop addressed this by providing an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all-solution....

  20. Complex Correspondence Principle

    International Nuclear Information System (INIS)

    Bender, Carl M.; Meisinger, Peter N.; Hook, Daniel W.; Wang Qinghai

    2010-01-01

    Quantum mechanics and classical mechanics are distinctly different theories, but the correspondence principle states that quantum particles behave classically in the limit of high quantum number. In recent years much research has been done on extending both quantum and classical mechanics into the complex domain. These complex extensions continue to exhibit a correspondence, and this correspondence becomes more pronounced in the complex domain. The association between complex quantum mechanics and complex classical mechanics is subtle and demonstrating this relationship requires the use of asymptotics beyond all orders.

  1. Uranium thiolate complexes

    International Nuclear Information System (INIS)

    Leverd, Pascal C.

    1994-01-01

    This research thesis proposes a new approach to the chemistry of uranium thiolate complexes as these compounds are very promising for various uses (in bio-inorganic chemistry, in some industrial processes like oil desulphurization). It more particularly addresses the U-S bond or more generally bonds between polarizable materials and hard metals. The author thus reports the study of uranium organometallic thiolates (tricyclo-penta-dienic and mono-cyclo-octa-tetraenylic complexes), and of uranium homoleptic thiolates (tetra-thiolate complexes, hexa-thiolate complexes, reactivity of homoleptic thiolate complexes) [fr

  2. Simplicial complexes of graphs

    CERN Document Server

    Jonsson, Jakob

    2008-01-01

    A graph complex is a finite family of graphs closed under deletion of edges. Graph complexes show up naturally in many different areas of mathematics, including commutative algebra, geometry, and knot theory. Identifying each graph with its edge set, one may view a graph complex as a simplicial complex and hence interpret it as a geometric object. This volume examines topological properties of graph complexes, focusing on homotopy type and homology. Many of the proofs are based on Robin Forman's discrete version of Morse theory. As a byproduct, this volume also provides a loosely defined toolbox for attacking problems in topological combinatorics via discrete Morse theory. In terms of simplicity and power, arguably the most efficient tool is Forman's divide and conquer approach via decision trees; it is successfully applied to a large number of graph and digraph complexes.

  3. On Complex Random Variables

    Directory of Open Access Journals (Sweden)

    Anwer Khurshid

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this paper, it is shown that a complex multivariate random variable  is a complex multivariate normal random variable of dimensionality if and only if all nondegenerate complex linear combinations of  have a complex univariate normal distribution. The characteristic function of  has been derived, and simpler forms of some theorems have been given using this characterization theorem without assuming that the variance-covariance matrix of the vector  is Hermitian positive definite. Marginal distributions of  have been given. In addition, a complex multivariate t-distribution has been defined and the density derived. A characterization of the complex multivariate t-distribution is given. A few possible uses of this distribution have been suggested.

  4. Cobalt(III) complex

    Indian Academy of Sciences (India)

    Administrator

    e, 40 µM complex, 10 hrs after dissolution, f, 40 µM complex, after irradiation dose 15 Gy. and H-atoms result in reduction of Co(III) to Co. (II). 6. It is interesting to see in complex containing multiple ligands what is the fate of electron adduct species formed by electron addition. Reduction to. Co(II) and intramolecular transfer ...

  5. Complex Systems and Dependability

    CERN Document Server

    Zamojski, Wojciech; Sugier, Jaroslaw

    2012-01-01

    Typical contemporary complex system is a multifaceted amalgamation of technical, information, organization, software and human (users, administrators and management) resources. Complexity of such a system comes not only from its involved technical and organizational structure but mainly from complexity of information processes that must be implemented in the operational environment (data processing, monitoring, management, etc.). In such case traditional methods of reliability analysis focused mainly on technical level are usually insufficient in performance evaluation and more innovative meth

  6. Lanthanide complexes with pivaloylacetone

    International Nuclear Information System (INIS)

    Eliseeva, S.V.; Chugarov, N.V.; Kuz'mina, N.P.; Martynenko, L.I.; Nichiporuk, R.V.; Ivanov, S.A.

    2003-01-01

    Complexes Ln(pa) 3 ·2H 2 O (Ln=La, Gd, Lu, Hpa - pivaloylacetone) are synthesized and investigated by the methods of element, IR spectroscopic and thermal analyses. Behaviour of the complexes during heating in vacuum is compared with such one for acetylacetonates and dipivaloylmethanates. Structure of the complexes in solution is studied by 1 H NMR and MALDI-MS [ru

  7. Phospholyl-uranium complexes

    International Nuclear Information System (INIS)

    Gradoz, Philippe

    1993-01-01

    After having reported a bibliographical study on penta-methylcyclopentadienyl uranium complexes, and a description of the synthesis and radioactivity of uranium (III) and (IV) boron hydrides compounds, this research thesis reports the study of mono and bis-tetramethyl-phospholyl uranium complexes comprising chloride, boron hydride, alkyl and alkoxide ligands. The third part reports the comparison of structures, stabilities and reactions of homologue complexes in penta-methylcyclopentadienyl and tetramethyl-phospholyl series. The last part addresses the synthesis of tris-phospholyl uranium (III) and (IV) complexes. [fr

  8. Nuclear weapons complex

    International Nuclear Information System (INIS)

    Rezendes, V.S.

    1991-03-01

    In this book, GAO characterizes DOE's January 1991 Nuclear Weapons Complex Reconfiguration Study as a starting point for reaching agreement on solutions to many of the complex's safety and environmental problems. Key decisions still need to be made about the size of the complex, where to relocate plutonium operations, what technologies to use for new tritium production, and what to do with excess plutonium. The total cost for reconfiguring and modernizing the complex is still uncertain, and some management issues remain unresolved. Congress faces a difficult task in making test decisions given the conflicting demands for scarce resources in a time of growing budget deficits and war in the Persian Gulf

  9. Conducting metal dithiolate complexes

    DEFF Research Database (Denmark)

    Underhill, A. E.; Ahmad, M. M.; Turner, D. J.

    1985-01-01

    Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound......Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound...

  10. Visual Complexity: A Review

    Science.gov (United States)

    Donderi, Don C.

    2006-01-01

    The idea of visual complexity, the history of its measurement, and its implications for behavior are reviewed, starting with structuralism and Gestalt psychology at the beginning of the 20th century and ending with visual complexity theory, perceptual learning theory, and neural circuit theory at the beginning of the 21st. Evidence is drawn from…

  11. Complexity in Picture Books

    Science.gov (United States)

    Sierschynski, Jarek; Louie, Belinda; Pughe, Bronwyn

    2015-01-01

    One of the key requirements of Common Core State Standards (CCSS) in English Language Arts is that students are able to read and access complex texts across all grade levels. The CCSS authors emphasize both the limitations and lack of accuracy in the current CCSS model of text complexity, calling for the development of new frameworks. In response…

  12. Method of complex scaling

    International Nuclear Information System (INIS)

    Braendas, E.

    1986-01-01

    The method of complex scaling is taken to include bound states, resonances, remaining scattering background and interference. Particular points of the general complex coordinate formulation are presented. It is shown that care must be exercised to avoid paradoxical situations resulting from inadequate definitions of operator domains. A new resonance localization theorem is presented

  13. Is dense codeswitching complex?

    NARCIS (Netherlands)

    Dorleijn, M.

    In this paper the question is raised to what extent dense code switching can be considered complex. Psycholinguistic experiments indicate that code switching involves cognitive costs, both in production and comprehension, a conclusion that could indicate that code switching is indeed complex. In

  14. Complex conductivity of soils

    NARCIS (Netherlands)

    Revil, A.; Coperey, A.; Shao, Z.; Florsch, N.; Fabricus, I.L.; Deng, Y.; Delsman, J.R.; Pauw, P.S.; Karaoulis, M.; Louw, P.G.B. de; Baaren, E.S. van; Dabekaussen, W.; Menkovic, A.; Gunnink, J.L.

    2017-01-01

    The complex conductivity of soils remains poorly known despite the growing importance of this method in hydrogeophysics. In order to fill this gap of knowledge, we investigate the complex conductivity of 71 soils samples (including four peat samples) and one clean sand in the frequency range 0.1 Hz

  15. Leading healthcare in complexity.

    Science.gov (United States)

    Cohn, Jeffrey

    2014-12-01

    Healthcare institutions and providers are in complexity. Networks of interconnections from relationships and technology create conditions in which interdependencies and non-linear dynamics lead to surprising, unpredictable outcomes. Previous effective approaches to leadership, focusing on top-down bureaucratic methods, are no longer effective. Leading in complexity requires leaders to accept the complexity, create an adaptive space in which innovation and creativity can flourish and then integrate the successful practices that emerge into the formal organizational structure. Several methods for doing adaptive space work will be discussed. Readers will be able to contrast traditional leadership approaches with leading in complexity. They will learn new behaviours that are required of complexity leaders, along with challenges they will face, often from other leaders within the organization.

  16. Selenophene transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    White, Carter James [Iowa State Univ., Ames, IA (United States)

    1994-07-27

    This research shows that selenophene transition metal complexes have a chemistry that is similar to their thiophene analogs. Selenophene coordination has been demonstrated and confirmed by molecular structure in both the η5- and the η1(Se)-coordination modes. The reaction chemistry of selenophene complexes closely resembles that of the analogous thiophene complexes. One major difference, however, is that selenophene is a better donor ligand than thiophene making the selenophene complexes more stable than the corresponding thiophene complexes. The 77Se NMR chemical shift values for selenophene complexes fall within distinct regions primarily depending on the coordination mode of the selenophene ligand. In the final paper, the C-H bond activation of η1(S)-bound thiophenes, η1(S)-benzothiophene and η1(Se)-bound selenophenes has been demonstrated. The deprotonation and rearrangement of the η1(E)-bound ligand to the carbon bound L-yl complex readily occurs in the presence of base. Reprotonation with a strong acid gives a carbene complex that is unreactive towards nucleophilic attack at the carbene carbon and is stable towards exposure to air. The molecular structure of [Cp(NO)(PPh3)Re(2-benzothioenylcarbene)]O3SCF3 was determined and contains a Re-C bond with substantial double bond character. Methyl substitution for the thienylcarbene or selenylcarbene gives a carbene that rearranges thermally to give back the η1(E)-bound complex. Based on these model reactions, a new mechanism for the H/D exchange of thiophene over the hydrodesulfurization catalyst has been proposed.

  17. Study of complex modes

    International Nuclear Information System (INIS)

    Pastrnak, J.W.

    1986-01-01

    This eighteen-month study has been successful in providing the designer and analyst with qualitative guidelines on the occurrence of complex modes in the dynamics of linear structures, and also in developing computer codes for determining quantitatively which vibration modes are complex and to what degree. The presence of complex modes in a test structure has been verified. Finite element analysis of a structure with non-proportional dumping has been performed. A partial differential equation has been formed to eliminate possible modeling errors

  18. Nuclear weapons complex

    International Nuclear Information System (INIS)

    Rezendes, V.S.

    1992-04-01

    In addition to long-standing safety and environmental problems plaguing the nuclear weapons complex, this paper reports that the Department of Energy (DOE) faces a major new challenge-how to reconfigure the weapons complex to meet the nation's defense needs in the 21st century. Key decisions still need to be made about the size of the complex; where, if necessary, to relocate various operations; what technologies to use for new tritium production; and what to do with excess weapons-grade material. The choices confronting DOE and Congress are difficult given the conflicting demands for limited resources

  19. Managing complex child law

    DEFF Research Database (Denmark)

    Svendsen, Idamarie Leth

    2017-01-01

    The article reports the findings of a qualitative study of Danish legal regulation of the public initial assessment of children and young persons and municipal practitioners’ decision-making under this regulation. The regulation mirrors new and complex relations between families and society...... in the form of 7 individual vignette interviews with municipal mid-level managers and professional consultants in five Danish municipalities. The study finds that the regulation is more complex than it looks, and that the complexity is handled through simplifying decision-making patterns that can be seen...

  20. Indicators: Physical Habitat Complexity

    Science.gov (United States)

    Physical habitat complexity measures the amount and variety of all types of cove at the water’s edge in lakes. In general, dense and varied shoreline habitat is able to support more diverse communities of aquatic life.

  1. Several complex variables

    International Nuclear Information System (INIS)

    Field, M.J.

    1976-01-01

    Topics discussed include the elementary of holomorphic functions of several complex variables; the Weierstrass preparation theorem; meromorphic functions, holomorphic line bundles and divisors; elliptic operators on compact manifolds; hermitian connections; the Hodge decomposition theorem. ( author)

  2. Power grid complexity

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Shengwei; Zhang, Xuemin [Tsinghua Univ., Beijing, BJ (China). Dept. of Electrical Engineering; Cao, Ming [Groningen Univ. (Netherlands). Faculty of Mathematics and Natural Sciences

    2011-07-01

    ''Power Grid Complexity'' introduces the complex system theory known as self-organized criticality (SOC) theory and complex network theory, and their applications to power systems. It studies the network characteristics of power systems, such as their small-world properties, structural vulnerability, decomposition and coordination strategies, and simplification and equivalence methods. The book also establishes four blackout models based on SOC theory through which the SOC of power systems is studied at both the macroscopic and microscopic levels. Additionally, applications of complex system theory in power system planning and emergency management platforms are also discussed in depth. This book can serve as a useful reference for engineers and researchers working with power systems. (orig.)

  3. Statistical electromagnetics: Complex cavities

    NARCIS (Netherlands)

    Naus, H.W.L.

    2008-01-01

    A selection of the literature on the statistical description of electromagnetic fields and complex cavities is concisely reviewed. Some essential concepts, for example, the application of the central limit theorem and the maximum entropy principle, are scrutinized. Implicit assumptions, biased

  4. Complex and unpredictable Cardano

    Science.gov (United States)

    Ekert, Artur

    2008-08-01

    This purely recreational paper is about one of the most colorful characters of the Italian Renaissance, Girolamo Cardano, and the discovery of two basic ingredients of quantum theory, probability and complex numbers.

  5. Coxeter-like complexes

    Directory of Open Access Journals (Sweden)

    Eric Babson

    2004-12-01

    Full Text Available Motivated by the Coxeter complex associated to a Coxeter system (W,S, we introduce a simplicial regular cell complex Δ(G,S with a G-action associated to any pair (G,S where G is a group and S is a finite set of generators for G which is minimal with respect to inclusion. We examine the topology of Δ(G,S, and in particular the representations of G on its homology groups. We look closely at the case of the symmetric group S n minimally generated by (not necessarily adjacent transpositions, and their type-selected subcomplexes. These include not only the Coxeter complexes of type A, but also the well-studied chessboard complexes.

  6. Physical Sciences Complex

    Data.gov (United States)

    Federal Laboratory Consortium — This 88,000 square foot complex is used to investigate basic physical science in support of missile technology development. It incorporates office space, dedicated...

  7. Life: Complexity and Diversity

    Indian Academy of Sciences (India)

    tinual increase in the diversity of life over evolutionary time. Ways of ... Centre for Ecological. Scienc'es .... plants evolved flowers to attract pollinators and reward them with .... with the evolving complexity of their interactions in communi- ties.

  8. Complex Flow Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-05-01

    This report documents findings from a workshop on the impacts of complex wind flows in and out of wind turbine environments, the research needs, and the challenges of meteorological and engineering modeling at regional, wind plant, and wind turbine scales.

  9. Complexity for Artificial Substrates (

    NARCIS (Netherlands)

    Loke, L.H.L.; Jachowski, N.R.; Bouma, T.J.; Ladle, R.J.; Todd, P.A.

    2014-01-01

    Physical habitat complexity regulates the structure and function of biological communities, although the mechanisms underlying this relationship remain unclear. Urbanisation, pollution, unsustainable resource exploitation and climate change have resulted in the widespread simplification (and loss)

  10. Photocytotoxic lanthanide complexes

    Indian Academy of Sciences (India)

    Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 ... complexes showing photoactivated DNA cleavage activity and cytotoxicity in cancer cells. .... considerable importance for their selectivity in killing.

  11. Complex Networks IX

    CERN Document Server

    Coronges, Kate; Gonçalves, Bruno; Sinatra, Roberta; Vespignani, Alessandro; Proceedings of the 9th Conference on Complex Networks; CompleNet 2018

    2018-01-01

    This book aims to bring together researchers and practitioners working across domains and research disciplines to measure, model, and visualize complex networks. It collects the works presented at the 9th International Conference on Complex Networks (CompleNet) 2018 in Boston, MA in March, 2018. With roots in physical, information and social science, the study of complex networks provides a formal set of mathematical methods, computational tools and theories to describe prescribe and predict dynamics and behaviors of complex systems. Despite their diversity, whether the systems are made up of physical, technological, informational, or social networks, they share many common organizing principles and thus can be studied with similar approaches. This book provides a view of the state-of-the-art in this dynamic field and covers topics such as group decision-making, brain and cellular connectivity, network controllability and resiliency, online activism, recommendation systems, and cyber security.

  12. Provability, complexity, grammars

    CERN Document Server

    Beklemishev, Lev; Vereshchagin, Nikolai

    1999-01-01

    The book contains English translations of three outstanding dissertations in mathematical logic and complexity theory. L. Beklemishev proves that all provability logics must belong to one of the four previously known classes. The dissertation of M. Pentus proves the Chomsky conjecture about the equivalence of two approaches to formal languages: the Chomsky hierarchy and the Lambek calculus. The dissertation of N. Vereshchagin describes a general framework for criteria of reversability in complexity theory.

  13. Conversation, coupling and complexity

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Abney, Drew; Bahrami, Bahador

    We investigate the linguistic co-construction of interpersonal synergies. By applying a measure of coupling between complex systems to an experimentally elicited corpus of joint decision dialogues, we show that interlocutors’ linguistic behavior displays increasing signature of multi-scale coupling......, known as complexity matching, over the course of interaction. Furthermore, we show that stronger coupling corresponds with more effective interaction, as measured by collective task performance....

  14. Advances in network complexity

    CERN Document Server

    Dehmer, Matthias; Emmert-Streib, Frank

    2013-01-01

    A well-balanced overview of mathematical approaches to describe complex systems, ranging from chemical reactions to gene regulation networks, from ecological systems to examples from social sciences. Matthias Dehmer and Abbe Mowshowitz, a well-known pioneer in the field, co-edit this volume and are careful to include not only classical but also non-classical approaches so as to ensure topicality. Overall, a valuable addition to the literature and a must-have for anyone dealing with complex systems.

  15. Electrospun complexes - functionalised nanofibres

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, T.; Wolf, M.; Dreyer, B.; Unruh, D.; Krüger, C.; Menze, M. [Leibniz University Hannover, Institute of Inorganic Chemistry (Germany); Sindelar, R. [University of Applied Science Hannover, Faculty II (Germany); Klingelhöfer, G. [Gutenberg-University, Institute of Inorganic and Analytic Chemistry (Germany); Renz, F., E-mail: renz@acd.uni-hannover.de [Leibniz University Hannover, Institute of Inorganic Chemistry (Germany)

    2016-12-15

    Here we present a new approach of using iron-complexes in electro-spun fibres. We modify poly(methyl methacrylate) (PMMA) by replacing the methoxy group with Diaminopropane or Ethylenediamine. The complex is bound covalently via an imine-bridge or an amide. The resulting polymer can be used in the electrospinning process without any further modifications in method either as pure reagent or mixed with small amounts of not functionalised polymer resulting in fibres of different qualities (Fig. 1).

  16. MANAGEMENT OF SPORT COMPLEXES

    Directory of Open Access Journals (Sweden)

    Marian STAN

    2015-07-01

    Full Text Available The actuality of the investigated theme. Nowadays, human evolution, including his intellectual development, proves the fact that especially the creation manpower and the employment was the solution of all life’s ambitions in society. So, the fact is that in reality, man is the most important capital of the society. Also, in an individual’s life, the practice of sport plays a significant role and that’s why the initiation, the launch and the management of sports complexes activity reveal the existence of specific management features that we will identify and explain in the current study. The aim of the research refers to the elaboration of a theoretical base of the management of the sport complexes, to the pointing of the factors that influence the efficient existence and function of a sport complex in our country and to the determination of the responsibilities that have a manager who directs successfully the activity of the sport complexes. The investigation is based on theoretical methods, such as: scientific documentation, analysis, synthesis, comparison and on empirical research methods, like: study of researched literature and observation. The results of the research indicate the fact that the profitability of a sport complex must assure a particular structure to avoid the bankruptcy risk and also, that the administration of the sport complexes activity must keep in view the reliable functions of the contemporaneous management.

  17. Organotin complexes with phosphines

    International Nuclear Information System (INIS)

    Passos, B. de F.T.; Jesus Filho, M.F. de; Filgueiras, C.A.L.; Abras, A.

    1988-01-01

    A series of organotin complexes was prepared involving phosphines bonded to the organotin moiety. The series include derivatives of SnCl x Ph 4-x (where x varied from zero to four with the phosphines Ph 3 P, (Ph 2 P)CH 2 , (Ph 2 P) 2 (CH 2 ) 2 , cis-(Ph 2 P)CH 2 , and CH 3 C(CH 2 PPh 2 ) 3 . A host of new complexes was obtained, showing different stoichiometries, bonding modes, and coordination numbers around the tin atom. These complexes were characterized by several different chemical and physical methods. The 119 Sn Moessbauer parameters varied differently. Whereas isomer shift values did not great variation for each group of complexs with the same organotin parent (SnCl x Ph 4-x ), reflecting a small change in s charge distribution on the Sn atom upon complexation, quadrupole splitting results varied widely, however, when the parent organotin compound was wholly symmetric (SnCl 4 and SnPPh 4 ), the complexes also tended to show quadrupole splitting values approaching zero. (author)

  18. Hypoxia targeting copper complexes

    International Nuclear Information System (INIS)

    Dearling, J.L.

    1998-11-01

    The importance and incidence of tumour hypoxia, its measurement and current treatments available, including pharmacological and radiopharmacological methods of targeting hypoxia, are discussed. A variety of in vitro and in vivo methods for imposing hypoxia have been developed and are reviewed. Copper, its chemistry, biochemistry and radiochemistry, the potential for use of copper radionuclides and its use to date in this field is considered with particular reference to the thiosemicarbazones. Their biological activity, metal chelation, in vitro and in vivo studies of their radiocopper complexes and the potential for their use as hypoxia targeting radiopharmaceuticals is described. The reduction of the copper(II) complex to copper(l), its pivotal importance in their biological behaviour, and the potential for manipulation of this to effect hypoxia selectivity are described. An in vitro method for assessing the hypoxia selectivity of radiopharmaceuticals is reported. The rapid deoxygenation and high viability of a mammalian cell culture in this system is discussed and factors which may affect the cellular uptake of a radiopharmaceutical are described. The design, synthesis and complexation with copper and radiocopper of a range of bis(thiosemicarbazones) is reported. Synthesis of these compounds is simple giving high yields of pure products. The characteristics of the radiocopper complexes ( 64 Cu) including lipophilicity and redox activity are reported (reduction potentials in the range -0.314 - -0.590 V). High cellular uptakes of the radiocopper complexes of the ligands, in hypoxic and normoxic EMT6 and CHO320 cells, were observed. Extremes of selectivity are shown ranging from the hypoxia selective 64 Cu(II)ATSM to normoxic cell selective 64 Cu(II)GTS. The selectivities observed are compared with the physico chemical characteristics of the complexes. A good correlation exists between selectivity of the complex and its Cu(II)/Cu(I) reduction potential, with hypoxia

  19. Complexity and Dynamical Depth

    Directory of Open Access Journals (Sweden)

    Terrence Deacon

    2014-07-01

    Full Text Available We argue that a critical difference distinguishing machines from organisms and computers from brains is not complexity in a structural sense, but a difference in dynamical organization that is not well accounted for by current complexity measures. We propose a measure of the complexity of a system that is largely orthogonal to computational, information theoretic, or thermodynamic conceptions of structural complexity. What we call a system’s dynamical depth is a separate dimension of system complexity that measures the degree to which it exhibits discrete levels of nonlinear dynamical organization in which successive levels are distinguished by local entropy reduction and constraint generation. A system with greater dynamical depth than another consists of a greater number of such nested dynamical levels. Thus, a mechanical or linear thermodynamic system has less dynamical depth than an inorganic self-organized system, which has less dynamical depth than a living system. Including an assessment of dynamical depth can provide a more precise and systematic account of the fundamental difference between inorganic systems (low dynamical depth and living systems (high dynamical depth, irrespective of the number of their parts and the causal relations between them.

  20. The Orion complex

    International Nuclear Information System (INIS)

    Goudis, C.

    1982-01-01

    This work deals with some of the most typical complexes of interstellar matter and presents a holistic view of the well studied complexes in Orion, built on information derived from various branches of modern astrophysics. A wealth of published data is presented in the form of photographs, contour maps, diagrams and numerous heavily annotated tables. Chapter 1, which is concerned with the large scale view of the Orion region, outlines the morphology of the area and examines in particular the nature of Barnard's Loop and the associated filamentary structure in addition to the origin of the I Orion OB association. Chapter 2 focuses on the Great Orion Nebula (M42 or NGC 1976) and the small H II region to the north (M43 or NGC 1982). Chapter 3 examines the Orion Complex as a whole, i.e. the H II regions M42 and M43, the associated molecular clouds OMC 1 and OMC 2 and their interrelations. Chapter 4 contains a discussion of the empirical models introduced to attempt to explain certain aspects of this very complex region, and chapter 5 investigates the second prominent H II region and molecular cloud complex, NGC 2024 (Orion B, W12). (Auth.)

  1. Complexity of Economical Systems

    Directory of Open Access Journals (Sweden)

    G. P. Pavlos

    2015-01-01

    Full Text Available In this study new theoretical concepts are described concerning the interpretation of economical complex dynamics. In addition a summary of an extended algorithm of nonlinear time series analysis is provided which is applied not only in economical time series but also in other physical complex systems (e.g. [22, 24]. In general, Economy is a vast and complicated set of arrangements and actions wherein agents—consumers, firms, banks, investors, government agencies—buy and sell, speculate, trade, oversee, bring products into being, offer services, invest in companies, strategize, explore, forecast, compete, learn, innovate, and adapt. As a result the economic and financial variables such as foreign exchange rates, gross domestic product, interest rates, production, stock market prices and unemployment exhibit large-amplitude and aperiodic fluctuations evident in complex systems. Thus, the Economics can be considered as spatially distributed non-equilibrium complex system, for which new theoretical concepts, such as Tsallis non extensive statistical mechanics and strange dynamics, percolation, nonGaussian, multifractal and multiscale dynamics related to fractional Langevin equations can be used for modeling and understanding of the economical complexity locally or globally.

  2. Complexes and imagination.

    Science.gov (United States)

    Kast, Verena

    2014-11-01

    Fantasies as imaginative activities are seen by Jung as expressions of psychic energy. In the various descriptions of active imagination the observation of the inner image and the dialogue with inner figures, if possible, are important. The model of symbol formation, as Jung describes it, can be experienced in doing active imagination. There is a correspondence between Jung's understanding of complexes and our imaginations: complexes develop a fantasy life. Complex episodes are narratives of difficult dysfunctional relationship episodes that have occurred repeatedly and are internalized with episodic memory. This means that the whole complex episode (the image for the child and the image for the aggressor, connected with emotions) is internalized and can get constellated in everyday relationship. Therefore inner dialogues do not necessarily qualify as active imaginations, often they are the expression of complex-episodes, very similar to fruitless soliloquies. If imaginations of this kind are repeated, new symbols and new possibilities of behaviour are not found. On the contrary, old patterns of behaviour and fantasies are perpetuated and become cemented. Imaginations of this kind need an intervention by the analyst. In clinical examples different kinds of imaginations are discussed. © 2014, The Society of Analytical Psychology.

  3. Algorithmic Relative Complexity

    Directory of Open Access Journals (Sweden)

    Daniele Cerra

    2011-04-01

    Full Text Available Information content and compression are tightly related concepts that can be addressed through both classical and algorithmic information theories, on the basis of Shannon entropy and Kolmogorov complexity, respectively. The definition of several entities in Kolmogorov’s framework relies upon ideas from classical information theory, and these two approaches share many common traits. In this work, we expand the relations between these two frameworks by introducing algorithmic cross-complexity and relative complexity, counterparts of the cross-entropy and relative entropy (or Kullback-Leibler divergence found in Shannon’s framework. We define the cross-complexity of an object x with respect to another object y as the amount of computational resources needed to specify x in terms of y, and the complexity of x related to y as the compression power which is lost when adopting such a description for x, compared to the shortest representation of x. Properties of analogous quantities in classical information theory hold for these new concepts. As these notions are incomputable, a suitable approximation based upon data compression is derived to enable the application to real data, yielding a divergence measure applicable to any pair of strings. Example applications are outlined, involving authorship attribution and satellite image classification, as well as a comparison to similar established techniques.

  4. Nuclear weapons complex

    International Nuclear Information System (INIS)

    Peach, J.D.

    1991-02-01

    In this paper, GAO provides its views on DOE's January 1991 Nuclear Weapons Complex Reconfiguration Study. GAO believes that DOE's new reconfiguration study provides a starting point for reaching agreement on solutions to many of the complex's problems. Key decisions still need to be made about the size of the complex, where to relocate plutonium operations, what technologies should be used for new tritium production, and what to do with excess plutonium. The total cost for reconfiguring and modernizing is still uncertain and some management issues remain unresolved. Congress faces a difficult task in making these decisions given the conflicting demands for scare resources in a time of growing budget deficits and war in the Persian Gulf

  5. Can Complexity be Planned?

    Directory of Open Access Journals (Sweden)

    Ilona Koutny

    2015-04-01

    Full Text Available The long accepted complexity invariance of human languages has become controversial within the last decade. In investigations of the problem, both creole and planned languages have often been neglected. After a presentation of the scope of the invariance problem and the proposition of the natural to planned language continuum, this article will discuss the contribution of planned languages. It will analyze the complexity of Esperanto at the phonological, morphological, syntactic and semantic levels, using linguistic data bases. The role of the L2 speech community and development of the language will also be taken into account when discussing the endurance of the same level of simplicity of this planned international language. The author argues that complexity can be variable and to some extent planned and maintained.

  6. Introduction to complex plasmas

    International Nuclear Information System (INIS)

    Bonitz, Michael; Ludwig, Patrick; Horing, Norman

    2010-01-01

    Complex plasmas differ from traditional plasmas in many ways: these are low-temperature high pressure systems containing nanometer to micrometer size particles which may be highly charged and strongly interacting. The particles may be chemically reacting or be in contact with solid surfaces, and the electrons may show quantum behaviour. These interesting properties have led to many applications of complex plasmas in technology, medicine and science. Yet complex plasmas are extremely complicated, both experimentally and theoretically, and require a variety of new approaches which go beyond standard plasma physics courses. This book fills this gap presenting an introduction to theory, experiment and computer simulation in this field. Based on tutorial lectures at a very successful recent Summer Institute, the presentation is ideally suited for graduate students, plasma physicists and experienced undergraduates. (orig.)

  7. Introduction to Complex Plasmas

    CERN Document Server

    Bonitz, Michael; Ludwig, Patrick

    2010-01-01

    Complex plasmas differ from traditional plasmas in many ways: these are low-temperature high pressure systems containing nanometer to micrometer size particles which may be highly charged and strongly interacting. The particles may be chemically reacting or be in contact with solid surfaces, and the electrons may show quantum behaviour. These interesting properties have led to many applications of complex plasmas in technology, medicine and science. Yet complex plasmas are extremely complicated, both experimentally and theoretically, and require a variety of new approaches which go beyond standard plasma physics courses. This book fills this gap presenting an introduction to theory, experiment and computer simulation in this field. Based on tutorial lectures at a very successful recent Summer Institute, the presentation is ideally suited for graduate students, plasma physicists and experienced undergraduates.

  8. BRAND program complex

    International Nuclear Information System (INIS)

    Androsenko, A.A.; Androsenko, P.A.

    1983-01-01

    A description is given of the structure, input procedure and recording rules of initial data for the BRAND programme complex intended for the Monte Carlo simulation of neutron physics experiments. The BRAND complex ideology is based on non-analogous simulation of the neutron and photon transport process (statistic weights are used, absorption and escape of particles from the considered region is taken into account, shifted readouts from a coordinate part of transition nucleus density are applied, local estimations, etc. are used). The preparation of initial data for three sections is described in detail: general information for Monte Carlo calculation, source definition and data for describing the geometry of the system. The complex is to be processed with the BESM-6 computer, the basic programming lan-- guage is FORTRAN, volume - more than 8000 operators

  9. Synchronization in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, A.; Diaz-Guilera, A.; Moreno, Y.; Zhou, C.; Kurths, J.

    2007-12-12

    Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.

  10. Simulation in Complex Modelling

    DEFF Research Database (Denmark)

    Nicholas, Paul; Ramsgaard Thomsen, Mette; Tamke, Martin

    2017-01-01

    This paper will discuss the role of simulation in extended architectural design modelling. As a framing paper, the aim is to present and discuss the role of integrated design simulation and feedback between design and simulation in a series of projects under the Complex Modelling framework. Complex...... performance, engage with high degrees of interdependency and allow the emergence of design agency and feedback between the multiple scales of architectural construction. This paper presents examples for integrated design simulation from a series of projects including Lace Wall, A Bridge Too Far and Inflated...... Restraint developed for the research exhibition Complex Modelling, Meldahls Smedie Gallery, Copenhagen in 2016. Where the direct project aims and outcomes have been reported elsewhere, the aim for this paper is to discuss overarching strategies for working with design integrated simulation....

  11. Modeling Complex Systems

    CERN Document Server

    Boccara, Nino

    2010-01-01

    Modeling Complex Systems, 2nd Edition, explores the process of modeling complex systems, providing examples from such diverse fields as ecology, epidemiology, sociology, seismology, and economics. It illustrates how models of complex systems are built and provides indispensable mathematical tools for studying their dynamics. This vital introductory text is useful for advanced undergraduate students in various scientific disciplines, and serves as an important reference book for graduate students and young researchers. This enhanced second edition includes: . -recent research results and bibliographic references -extra footnotes which provide biographical information on cited scientists who have made significant contributions to the field -new and improved worked-out examples to aid a student’s comprehension of the content -exercises to challenge the reader and complement the material Nino Boccara is also the author of Essentials of Mathematica: With Applications to Mathematics and Physics (Springer, 2007).

  12. The multitalented Mediator complex.

    Science.gov (United States)

    Carlsten, Jonas O P; Zhu, Xuefeng; Gustafsson, Claes M

    2013-11-01

    The Mediator complex is needed for regulated transcription of RNA polymerase II (Pol II)-dependent genes. Initially, Mediator was only seen as a protein bridge that conveyed regulatory information from enhancers to the promoter. Later studies have added many other functions to the Mediator repertoire. Indeed, recent findings show that Mediator influences nearly all stages of transcription and coordinates these events with concomitant changes in chromatin organization. We review the multitude of activities associated with Mediator and discuss how this complex coordinates transcription with other cellular events. We also discuss the inherent difficulties associated with in vivo characterization of a coactivator complex that can indirectly affect diverse cellular processes via changes in gene transcription. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Modeling Complex Time Limits

    Directory of Open Access Journals (Sweden)

    Oleg Svatos

    2013-01-01

    Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.

  14. Large erupted complex odontoma

    Directory of Open Access Journals (Sweden)

    Vijeev Vasudevan

    2009-01-01

    Full Text Available Odontomas are a heterogeneous group of jaw bone lesions, classified as odontogenic tumors which usually include well-diversified dental tissues. Odontoma is a term introduced to the literature by Broca in 1867. Trauma, infection and hereditary factors are the possible causes of forming this kind of lesions. Among odontogenic tumors, they constitute about 2/3 of cases. These lesions usually develop slowly and asymptomatically, and in most cases they do not cross the bone borders. Two types of odontoma are recognized: compound and complex. Complex odontomas are less common than the compound variety in the ratio 1:2.3. Eruption of an odontoma in the oral cavity is rare. We present a case of complex odontoma, in which apparent eruption has occurred in the area of the right maxillary second molar region.

  15. Alanine water complexes.

    Science.gov (United States)

    Vaquero, Vanesa; Sanz, M Eugenia; Peña, Isabel; Mata, Santiago; Cabezas, Carlos; López, Juan C; Alonso, José L

    2014-04-10

    Two complexes of alanine with water, alanine-(H2O)n (n = 1,2), have been generated by laser ablation of the amino acid in a supersonic jet containing water vapor and characterized using Fourier transform microwave spectroscopy. In the observed complexes, water molecules bind to the carboxylic group of alanine acting as both proton donors and acceptors. In alanine-H2O, the water molecule establishes two intermolecular hydrogen bonds forming a six-membered cycle, while in alanine-(H2O)2 the two water molecules establish three hydrogen bonds forming an eight-membered ring. In both complexes, the amino acid moiety is in its neutral form and shows the conformation observed to be the most stable for the bare molecule. The microsolvation study of alanine-(H2O)n (n = 1,2) can be taken as a first step toward understanding bulk properties at a microscopic level.

  16. Philosophy of complex systems

    CERN Document Server

    2011-01-01

    The domain of nonlinear dynamical systems and its mathematical underpinnings has been developing exponentially for a century, the last 35 years seeing an outpouring of new ideas and applications and a concomitant confluence with ideas of complex systems and their applications from irreversible thermodynamics. A few examples are in meteorology, ecological dynamics, and social and economic dynamics. These new ideas have profound implications for our understanding and practice in domains involving complexity, predictability and determinism, equilibrium, control, planning, individuality, responsibility and so on. Our intention is to draw together in this volume, we believe for the first time, a comprehensive picture of the manifold philosophically interesting impacts of recent developments in understanding nonlinear systems and the unique aspects of their complexity. The book will focus specifically on the philosophical concepts, principles, judgments and problems distinctly raised by work in the domain of comple...

  17. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    Dias, Kealey

    vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields.......The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...

  18. Complex manifolds in relativity

    International Nuclear Information System (INIS)

    Flaherty, E.J. Jr.

    1975-01-01

    Complex manifold theory is applied to the study of certain problems in general relativity. The first half of the work is devoted to the mathematical theory of complex manifold. Then a brief review of general relativity is given. It is shown that any spacetime admits locally an almost Hermitian structure, suitably modified to be compatible with the indefinite metric of spacetime. This structure is integrable if and only if the spacetime admits two geodesic and shearfree null congruences, thus in particular if the spacetime is type D vacuum or electrified. The structure is ''half-integrable'' in a suitable sense if and only if the spacetime admits one geodesic and shearfree null congruence, thus in particular for all algebraically special vacuum spacetimes. Conditions for the modified Hermitian spacetime to be Kahlerian are presented. The most general metric for such a modified Kahlerian spacetime is found. It is shown that the type D vacuum and electrified spacetimes are conformally related to modified Kahlerian spacetimes by a generally complex conformal factor. These latter are shown to possess a very rich structure, including the existence of Killing tensors and Killing vectors. A new ''explanation'' of Newman's complex coordinate transformations is given. It is felt to be superior to previous ''explanations'' on several counts. For example, a physical interpretation in terms of a symmetry group is given. The existence of new complex coordinate transformations is established: Nt is shown that any type D vacuum spacetime is obtainable from either Schwarzschild spacetime or ''C'' spacetime by a complex coordinate transformation. Finally, some related topics are discussed and areas for future work are outlined. (Diss. Abstr. Int., B)

  19. Complex quantum groups

    International Nuclear Information System (INIS)

    Drabant, B.; Schlieker, M.

    1993-01-01

    The complex quantum groups are constructed. They are q-deformations of the real Lie groups which are obtained as the complex groups corresponding to the Lie algebras of type A n-1 , B n , C n . Following the ideas of Faddeev, Reshetikhin and Takhtajan Hopf algebras of regular functionals U R for these complexified quantum groups are constructed. One has thus in particular found a construction scheme for the q-Lorentz algebra to be identified as U(sl q (2,C). (orig.)

  20. Complex function theory

    CERN Document Server

    Sarason, Donald

    2007-01-01

    Complex Function Theory is a concise and rigorous introduction to the theory of functions of a complex variable. Written in a classical style, it is in the spirit of the books by Ahlfors and by Saks and Zygmund. Being designed for a one-semester course, it is much shorter than many of the standard texts. Sarason covers the basic material through Cauchy's theorem and applications, plus the Riemann mapping theorem. It is suitable for either an introductory graduate course or an undergraduate course for students with adequate preparation. The first edition was published with the title Notes on Co

  1. Complex matrix model duality

    International Nuclear Information System (INIS)

    Brown, T.W.

    2010-11-01

    The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)

  2. Resilience and Complexity

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus

    2015-01-01

    This paper explores two key concepts: resilience and complexity. The first is understood as an emergent property of the latter, and their inter-relatedness is discussed using a three tier approach. First, by exploring the discourse of each concept, next, by analyzing underlying relationships and...... robust. Robustness is a property of simple or complicated systems characterized by predictable behavior, enabling the system to bounce back to its normal state following a perturbation. Resilience, however, is an emergent property of complex adaptive systems. It is suggested that this distinction...

  3. Theories of computational complexity

    CERN Document Server

    Calude, C

    1988-01-01

    This volume presents four machine-independent theories of computational complexity, which have been chosen for their intrinsic importance and practical relevance. The book includes a wealth of results - classical, recent, and others which have not been published before.In developing the mathematics underlying the size, dynamic and structural complexity measures, various connections with mathematical logic, constructive topology, probability and programming theories are established. The facts are presented in detail. Extensive examples are provided, to help clarify notions and constructions. The lists of exercises and problems include routine exercises, interesting results, as well as some open problems.

  4. Planning Complex Projects Automatically

    Science.gov (United States)

    Henke, Andrea L.; Stottler, Richard H.; Maher, Timothy P.

    1995-01-01

    Automated Manifest Planner (AMP) computer program applies combination of artificial-intelligence techniques to assist both expert and novice planners, reducing planning time by orders of magnitude. Gives planners flexibility to modify plans and constraints easily, without need for programming expertise. Developed specifically for planning space shuttle missions 5 to 10 years ahead, with modifications, applicable in general to planning other complex projects requiring scheduling of activities depending on other activities and/or timely allocation of resources. Adaptable to variety of complex scheduling problems in manufacturing, transportation, business, architecture, and construction.

  5. Complex matrix model duality

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.W.

    2010-11-15

    The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)

  6. Nonlinear dynamics and complexity

    CERN Document Server

    Luo, Albert; Fu, Xilin

    2014-01-01

    This important collection presents recent advances in nonlinear dynamics including analytical solutions, chaos in Hamiltonian systems, time-delay, uncertainty, and bio-network dynamics. Nonlinear Dynamics and Complexity equips readers to appreciate this increasingly main-stream approach to understanding complex phenomena in nonlinear systems as they are examined in a broad array of disciplines. The book facilitates a better understanding of the mechanisms and phenomena in nonlinear dynamics and develops the corresponding mathematical theory to apply nonlinear design to practical engineering.

  7. Complex/Symplectic Mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Wu-yen; Kachru, Shamit; /Stanford U., ITP /SLAC; Tomasiello, Alessandro; /Stanford U., ITP

    2005-10-28

    We construct a class of symplectic non-Kaehler and complex non-Kaehler string theory vacua, extending and providing evidence for an earlier suggestion by Polchinski and Strominger. The class admits a mirror pairing by construction. Comparing hints from a variety of sources, including ten-dimensional supergravity and KK reduction on SU(3)-structure manifolds, suggests a picture in which string theory extends Reid's fantasy to connect classes of both complex non-Kaehler and symplectic non-Kaehler manifolds.

  8. Complex logistics audit system

    Directory of Open Access Journals (Sweden)

    Zuzana Marková

    2010-02-01

    Full Text Available Complex logistics audit system is a tool for realization of logistical audit in the company. The current methods for logistics auditare based on “ad hok” analysis of logisticsl system. This paper describes system for complex logistics audit. It is a global diagnosticsof logistics processes and functions of enterprise. The goal of logistics audit is to provide comparative documentation for managementabout state of logistics in company and to show the potential of logistics changes in order to achieve more effective companyperformance.

  9. Simulations with complex measure

    International Nuclear Information System (INIS)

    Markham, J.K.; Kieu, T.D.

    1997-01-01

    A method is proposed to handle the sign problem in the simulation of systems having indefinite or complex-valued measures. In general, this new approach, which is based on renormalisation blocking, is shown to yield statistical errors smaller that the crude Monte Carlo method using absolute values of the original measures. The improved method is applied to the 2D Ising model with temperature generalised to take on complex values. It is also adapted to implement Monte Carlo Renormalisation Group calculations of the magnetic and thermal critical exponents. 10 refs., 4 tabs., 7 figs

  10. Qubit Complexity of Continuous Problems

    National Research Council Canada - National Science Library

    Papageorgiou, A; Traub, J. F

    2005-01-01

    .... The authors show how to obtain the classical query complexity for continuous problems. They then establish a simple formula for a lower bound on the qubit complexity in terms of the classical query complexity...

  11. Prediction of Biomolecular Complexes

    KAUST Repository

    Vangone, Anna

    2017-04-12

    Almost all processes in living organisms occur through specific interactions between biomolecules. Any dysfunction of those interactions can lead to pathological events. Understanding such interactions is therefore a crucial step in the investigation of biological systems and a starting point for drug design. In recent years, experimental studies have been devoted to unravel the principles of biomolecular interactions; however, due to experimental difficulties in solving the three-dimensional (3D) structure of biomolecular complexes, the number of available, high-resolution experimental 3D structures does not fulfill the current needs. Therefore, complementary computational approaches to model such interactions are necessary to assist experimentalists since a full understanding of how biomolecules interact (and consequently how they perform their function) only comes from 3D structures which provide crucial atomic details about binding and recognition processes. In this chapter we review approaches to predict biomolecular complexesBiomolecular complexes, introducing the concept of molecular dockingDocking, a technique which uses a combination of geometric, steric and energetics considerations to predict the 3D structure of a biological complex starting from the individual structures of its constituent parts. We provide a mini-guide about docking concepts, its potential and challenges, along with post-docking analysis and a list of related software.

  12. Real and complex analysis

    CERN Document Server

    Apelian, Christopher; Taft, Earl; Nashed, Zuhair

    2009-01-01

    The Spaces R, Rk, and CThe Real Numbers RThe Real Spaces RkThe Complex Numbers CPoint-Set Topology Bounded SetsClassification of Points Open and Closed SetsNested Intervals and the Bolzano-Weierstrass Theorem Compactness and Connectedness Limits and Convergence Definitions and First Properties Convergence Results for SequencesTopological Results for Sequences Properties of Infinite SeriesManipulations of Series in RFunctions: Definitions and Limits DefinitionsFunctions as MappingsSome Elementary Complex FunctionsLimits of FunctionsFunctions: Continuity and Convergence Continuity Uniform Continuity Sequences and Series of FunctionsThe DerivativeThe Derivative for f: D1 → RThe Derivative for f: Dk → RThe Derivative for f: Dk → RpThe Derivative for f: D → CThe Inverse and Implicit Function TheoremsReal IntegrationThe Integral of f: [a, b] → RProperties of the Riemann Integral Further Development of Integration TheoryVector-Valued and Line IntegralsComplex IntegrationIntroduction to Complex Integrals Fu...

  13. Automatic Complexity Analysis

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    1989-01-01

    One way to analyse programs is to to derive expressions for their computational behaviour. A time bound function (or worst-case complexity) gives an upper bound for the computation time as a function of the size of input. We describe a system to derive such time bounds automatically using abstract...

  14. Complexity and ecology

    International Nuclear Information System (INIS)

    Gomez Giraldo, Luis Jair

    2002-01-01

    The present article examines the transformation that the construction of the theoretical body of ecology as a science has been going through since it first appeared in the XIX century within the logic of classical science until recent developments comprised within complex systemic. Mainly departing from the analysis from thermodynamics of irreversible phenomena

  15. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    , is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...

  16. Managing Complex Dynamical Systems

    Science.gov (United States)

    Cox, John C.; Webster, Robert L.; Curry, Jeanie A.; Hammond, Kevin L.

    2011-01-01

    Management commonly engages in a variety of research designed to provide insight into the motivation and relationships of individuals, departments, organizations, etc. This paper demonstrates how the application of concepts associated with the analysis of complex systems applied to such data sets can yield enhanced insights for managerial action.

  17. benzimidazole metal complexes

    Indian Academy of Sciences (India)

    aUnité de Recherche de Chimie de l'Environnement et Moléculaire Structurale, Université des Frères. Mentouri .... determine the quantum chemical parameters for the title ..... retical study of benzazole thioether and its zinc complex.

  18. COMPLEXITY AND UNIVERSITY

    Directory of Open Access Journals (Sweden)

    Edna Lemes Martins Pereira

    2013-12-01

    Full Text Available Economic globalization affects different countries on the globe, has positive effects mainly related to access to communication, which promotes the exchange of ideas, information, products and quality of life. However, extends numerous negative aspects such as marginalization, economic dependencies, political, cultural, scientific, educational accentuate social inequalities and cultural conflicts and territorial. In this article it is a dialogue with authors (Cunha 2009; BARNETT 2005; MORIN 1999, 2006, among others, who understand these changes in society from the contemporary world as conceived as the "Complexity era" or "supercomplexity". To understand and cope with this reality, they propose a paradigm that is able to overcome the fragmentation and reductionism of knowledge and to relate the multiple approaches and visions to meet the complexity of reality. Although this paper presents proposals to the aforementioned authors point to education and the university found in this tangle of interconnected global transformations, given the need to be subject to act in a complex reality that requires critical and self-critical professionals, able to think about their own ability to think, understand and act within this complex context.

  19. (VI) ML6 Complexes

    African Journals Online (AJOL)

    A geometric analysis revealed that beta-(C-H) and alpha-(C-C) can occupy the seventh and eighth coordination sites in the title Fischer carbene complexes as agostic interactions, which allows classifying the carbene as a η3 ligand in these cases. This theory was supported by the relative energies of the conformers and an ...

  20. The CERN accelerator complex

    CERN Multimedia

    Mobs, Esma Anais

    2016-01-01

    The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  1. The CERN accelerator complex

    CERN Multimedia

    Christiane Lefèvre

    2008-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  2. Nature, computation and complexity

    International Nuclear Information System (INIS)

    Binder, P-M; Ellis, G F R

    2016-01-01

    The issue of whether the unfolding of events in the world can be considered a computation is explored in this paper. We come to different conclusions for inert and for living systems (‘no’ and ‘qualified yes’, respectively). We suggest that physical computation as we know it exists only as a tool of complex biological systems: us. (paper)

  3. Complex Regional Pain Syndrome

    Science.gov (United States)

    Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. It may happen ... move the affected body part The cause of CRPS is unknown. There is no specific diagnostic test. ...

  4. Prediction of Biomolecular Complexes

    KAUST Repository

    Vangone, Anna; Oliva, Romina; Cavallo, Luigi; Bonvin, Alexandre M. J. J.

    2017-01-01

    Almost all processes in living organisms occur through specific interactions between biomolecules. Any dysfunction of those interactions can lead to pathological events. Understanding such interactions is therefore a crucial step in the investigation of biological systems and a starting point for drug design. In recent years, experimental studies have been devoted to unravel the principles of biomolecular interactions; however, due to experimental difficulties in solving the three-dimensional (3D) structure of biomolecular complexes, the number of available, high-resolution experimental 3D structures does not fulfill the current needs. Therefore, complementary computational approaches to model such interactions are necessary to assist experimentalists since a full understanding of how biomolecules interact (and consequently how they perform their function) only comes from 3D structures which provide crucial atomic details about binding and recognition processes. In this chapter we review approaches to predict biomolecular complexesBiomolecular complexes, introducing the concept of molecular dockingDocking, a technique which uses a combination of geometric, steric and energetics considerations to predict the 3D structure of a biological complex starting from the individual structures of its constituent parts. We provide a mini-guide about docking concepts, its potential and challenges, along with post-docking analysis and a list of related software.

  5. COMPLEX PROMOTIONSIN RETAIL

    Directory of Open Access Journals (Sweden)

    O. Yusupova

    2015-10-01

    Full Text Available Complex promotions used by retailers introduce to the consumers several rules that must be satisfied in order to get some benefits and usually refer to multiple products (e.g. “buy two, get one free”. Rules of complex promotions can be quite sophisticated and complicated themselves. Since diversity of complex promotions limited only by marketers’ imagination we can observe broad variety of promotions’ rules and representa¬tions of those rules in retailers’ commercials. Such diversification makes no good for fellow scientist who’s trying to sort all type of promotions into the neatly organized classification. Although we can simple add every single set of rules offered by retailers as a separate form of sales promotion it seems not to be the best way of dealing with such a problem. The better way is to realize that mechanisms underlying that variety of promotions are basically the same, namely changes in demand or quantity demanded. Those two concepts alone provide powerful insight into classification of complex promotions and allow us to comprehend the variety of promotions offered by marketers nowadays.

  6. Uranyl complexes of glutathione

    Energy Technology Data Exchange (ETDEWEB)

    Marzotto, A [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi

    1977-01-01

    Dioxouranium(VI) complexes of the tripeptide glutathione having different molar ratios were prepared and studied by IR, PMR, electronic absorption and circular dichroism spectra. The results indicate that coordination occurs at the carboxylato groups, acting as monodentate ligands, whereas no significant interaction with the amino and sulfhydrylic groups takes place.

  7. Complexity and formative experiences

    Directory of Open Access Journals (Sweden)

    Roque Strieder

    2017-12-01

    Full Text Available The contemporaneity is characterized by instability and diversity calling into question certainties and truths proposed in modernity. We recognize that the reality of things and phenomena become effective as a set of events, interactions, retroactions and chances. This different frame extends the need for revision of the epistemological foundations that sustain educational practices and give them sense. The complex thinking is an alternative option for acting as a counterpoint to classical science and its reductionist logic and knowledge compartmentalization, as well as to answer to contemporary epistemological and educational challenges. It aims to associate different areas and forms of knowledge, without, however merge them, distinguishing without separating the several disciplines and instances of the realities. This study, in theoretical references, highlights the relevance of complex approaches to support formative experiences because also able to produce complexities in reflections about educational issues. We conclude that formative possibilities from complexity potentialize the resignification of human’s conception and the understanding of its singularity in interdependence; The understanding that pedagogical and educational activities is a constant interrogation about the possibilities of knowing the knowledge and reframe learning, far beyond knowing its functions and utilitarian purposes; and, as a formative possibility, places us on the trail of responsibility, not as something eventual, but present and indicative of freedom to choose to stay or go beyond.

  8. pyridine-carboxamide complexes

    Indian Academy of Sciences (India)

    of the solution was reduced by slow evaporation. The prod- uct was ... Data collection, data reduction, structure solu- ... and a selection of bond lengths and angles are shown in. Table 2. ...... Zn(II) complexes featuring a disulfide bridge and H-.

  9. Complexity driven photonics

    KAUST Repository

    Fratalocchi, Andrea

    2014-01-01

    Disorder and chaos are ubiquitous phenomena that are mostly unwanted in applications. On the contrary, they can be exploited to create a new technology. In this talk I will summarize my research in this field, discussing chaotic energy harvesting, nonlinear stochastic resonance and complex nanolasers.

  10. Unifying Complexity and Information

    Science.gov (United States)

    Ke, Da-Guan

    2013-04-01

    Complex systems, arising in many contexts in the computer, life, social, and physical sciences, have not shared a generally-accepted complexity measure playing a fundamental role as the Shannon entropy H in statistical mechanics. Superficially-conflicting criteria of complexity measurement, i.e. complexity-randomness (C-R) relations, have given rise to a special measure intrinsically adaptable to more than one criterion. However, deep causes of the conflict and the adaptability are not much clear. Here I trace the root of each representative or adaptable measure to its particular universal data-generating or -regenerating model (UDGM or UDRM). A representative measure for deterministic dynamical systems is found as a counterpart of the H for random process, clearly redefining the boundary of different criteria. And a specific UDRM achieving the intrinsic adaptability enables a general information measure that ultimately solves all major disputes. This work encourages a single framework coving deterministic systems, statistical mechanics and real-world living organisms.

  11. (II) COMPLEX COMPOUND

    African Journals Online (AJOL)

    user

    electrochemical sensors, as well as in various chromatographic ... were carried out using Jenway pH meter Model 3320 and a conductivity ... Figure 1: the proposed molecular structure of the copper (II) Schiff base complex. M = Cu (II) or Mn (II).

  12. Complexity driven photonics

    KAUST Repository

    Fratalocchi, Andrea

    2014-12-01

    Disorder and chaos are ubiquitous phenomena that are mostly unwanted in applications. On the contrary, they can be exploited to create a new technology. In this talk I will summarize my research in this field, discussing chaotic energy harvesting, nonlinear stochastic resonance and complex nanolasers.

  13. The Colletotrichum acutatum complex

    NARCIS (Netherlands)

    Damm, U.; Cannon, P.F.; Woudenberg, J.H.C.; Crous, P.W.

    2012-01-01

    Colletotrichum acutatum is known as an important anthracnose pathogen of a wide range of host plants worldwide. Numerous studies have reported subgroups within the C. acutatum species complex. Multilocus molecular phylogenetic analysis (ITS, ACT, TUB2, CHS-1, GAPDH, HIS3) of 331 strains previously

  14. Architecture of Intermodal Complex

    NARCIS (Netherlands)

    Lee, S.; Herneoja, Aulikki; Österlund, Toni; Markkanen, Piia

    This paper focuses on the conception and design of architecture as the work of producing media about buildings and other environmental artifacts. I approach
    the questions regarding simplicity and complexity through "interdependence" and "intermodality." I believe the two concepts offer more

  15. unsymmetrical Schiff base complexes

    Indian Academy of Sciences (India)

    the effect of the substitutional groups of the Schiff base on the oxidation and reduction potentials, we used ... Electrochemistry of these complexes showed that the presence of electron .... a solution of the ligand (1 mmol) in methanol (15 mL).

  16. Management of complex fisheries

    DEFF Research Database (Denmark)

    Frost, Hans Staby; Andersen, Peder; Hoff, Ayoe

    2013-01-01

    , including taking into account the response of the fishermen to implemented management measures. To demonstrate the use of complex management models this paper assesses a number of second best management schemes against a first rank optimum (FRO), an ideal individual transferable quotas (ITQ) system...

  17. Herding Complex Networks

    KAUST Repository

    Ruf, Sebastian F.; Egersted, Magnus; Shamma, Jeff S.

    2018-01-01

    the ability to drive a system to a specific set in the state space, was recently introduced as an alternative network control notion. This paper considers the application of herdability to the study of complex networks. The herdability of a class of networked

  18. The hamstring muscle complex

    NARCIS (Netherlands)

    van der Made, A. D.; Wieldraaijer, T.; Kerkhoffs, G. M.; Kleipool, R. P.; Engebretsen, L.; van Dijk, C. N.; Golanó, P.

    2015-01-01

    The anatomical appearance of the hamstring muscle complex was studied to provide hypotheses for the hamstring injury pattern and to provide reference values of origin dimensions, muscle length, tendon length, musculotendinous junction (MTJ) length as well as width and length of a tendinous

  19. Symmetry in Complex Networks

    Directory of Open Access Journals (Sweden)

    Angel Garrido

    2011-01-01

    Full Text Available In this paper, we analyze a few interrelated concepts about graphs, such as their degree, entropy, or their symmetry/asymmetry levels. These concepts prove useful in the study of different types of Systems, and particularly, in the analysis of Complex Networks. A System can be defined as any set of components functioning together as a whole. A systemic point of view allows us to isolate a part of the world, and so, we can focus on those aspects that interact more closely than others. Network Science analyzes the interconnections among diverse networks from different domains: physics, engineering, biology, semantics, and so on. Current developments in the quantitative analysis of Complex Networks, based on graph theory, have been rapidly translated to studies of brain network organization. The brain's systems have complex network features—such as the small-world topology, highly connected hubs and modularity. These networks are not random. The topology of many different networks shows striking similarities, such as the scale-free structure, with the degree distribution following a Power Law. How can very different systems have the same underlying topological features? Modeling and characterizing these networks, looking for their governing laws, are the current lines of research. So, we will dedicate this Special Issue paper to show measures of symmetry in Complex Networks, and highlight their close relation with measures of information and entropy.

  20. Light in complex dielectrics

    NARCIS (Netherlands)

    Schuurmans, F.J.P.

    1999-01-01

    In this thesis the properties of light in complex dielectrics are described, with the two general topics of "modification of spontaneous emission" and "Anderson localization of light". The first part focuses on the spontaneous emission rate of an excited atom in a dielectric host with variable

  1. Typical Complexity Numbers

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Typical Complexity Numbers. Say. 1000 tones,; 100 Users,; Transmission every 10 msec. Full Crosstalk cancellation would require. Full cancellation requires a matrix multiplication of order 100*100 for all the tones. 1000*100*100*100 operations every second for the ...

  2. Life: Complexity and Diversity

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 4. Life : Complexity and Diversity Growing Larger. Madhav Gadgil. Series Article Volume 1 Issue 4 April 1996 pp 15-22. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/04/0015-0022 ...

  3. The CERN accelerator complex

    CERN Multimedia

    Haffner, Julie

    2013-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  4. Complexity measures of music

    Science.gov (United States)

    Pease, April; Mahmoodi, Korosh; West, Bruce J.

    2018-03-01

    We present a technique to search for the presence of crucial events in music, based on the analysis of the music volume. Earlier work on this issue was based on the assumption that crucial events correspond to the change of music notes, with the interesting result that the complexity index of the crucial events is mu ~ 2, which is the same inverse power-law index of the dynamics of the brain. The search technique analyzes music volume and confirms the results of the earlier work, thereby contributing to the explanation as to why the brain is sensitive to music, through the phenomenon of complexity matching. Complexity matching has recently been interpreted as the transfer of multifractality from one complex network to another. For this reason we also examine the mulifractality of music, with the observation that the multifractal spectrum of a computer performance is significantly narrower than the multifractal spectrum of a human performance of the same musical score. We conjecture that although crucial events are demonstrably important for information transmission, they alone are not suficient to define musicality, which is more adequately measured by the multifractality spectrum.

  5. Complexes Tickling the $ubject

    Directory of Open Access Journals (Sweden)

    Matthew Gildersleeve

    2016-11-01

    Full Text Available This article continues my earlier work of reading Jung with Lacan. This article will develop Zizek’s work on Lacan’s concept of objet petit a by relating it to a phenomenological interpretation of Jung. I use a number of different examples, including Zizek’s interpretation of Francis Bacon, Edvard Munch, Hans Holbein and Johann Gottlieb Fichte, to describe the objet petit a and its relationship to a phenomenological interpretation of complexes. By integrating other Lacanian concepts, such as subject, drive, fantasy, jouissance, gaze, desire, and ego as well as the imaginary, symbolic and Real, this work also highlights how Hegel and Heidegger can elucidate the relationship between objet petit a and complexes. Jung’s transcendent function and the Rosarium Philosophorum also elucidate the relationship between Jung and Lacan.

  6. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...

  7. THO/TREX complex

    KAUST Repository

    Dö ll, Stefanie; Kuhlmann, Markus; Rutten, Twan; Mette, Michael F.; Scharfenberg, Sarah; Petridis, Antonios; Berreth, Dorothee-Carina; Mock, Hans-Peter

    2017-01-01

    Secondary metabolites are involved in the plant stress response. Among these are scopolin and its active form scopoletin, which are coumarin derivatives associated with reactive oxygen species scavenging and pathogen defence. Here we show that scopolin accumulation can be induced in the root by osmotic stress and in the leaf by low-temperature stress in Arabidopsis thaliana. A genetic screen for altered scopolin levels in A. thaliana revealed a mutant compromised in scopolin accumulation in response to stress; the lesion was present in a homologue of THO1 coding for a subunit of the THO/TREX complex. The THO/TREX complex contributes to RNA silencing, supposedly by trafficking precursors of small RNAs. Mutants defective in THO, AGO1, SDS3 and RDR6 were impaired with respect to scopolin accumulation in response to stress, suggesting a mechanism based on RNA silencing such as the trans-acting small interfering RNA pathway, which requires THO/TREX function.

  8. Complexity is simple!

    Science.gov (United States)

    Cottrell, William; Montero, Miguel

    2018-02-01

    In this note we investigate the role of Lloyd's computational bound in holographic complexity. Our goal is to translate the assumptions behind Lloyd's proof into the bulk language. In particular, we discuss the distinction between orthogonalizing and `simple' gates and argue that these notions are useful for diagnosing holographic complexity. We show that large black holes constructed from series circuits necessarily employ simple gates, and thus do not satisfy Lloyd's assumptions. We also estimate the degree of parallel processing required in this case for elementary gates to orthogonalize. Finally, we show that for small black holes at fixed chemical potential, the orthogonalization condition is satisfied near the phase transition, supporting a possible argument for the Weak Gravity Conjecture first advocated in [1].

  9. The medial patellofemoral complex.

    Science.gov (United States)

    Loeb, Alexander E; Tanaka, Miho J

    2018-06-01

    The purpose of this review is to describe the current understanding of the medial patellofemoral complex, including recent anatomic advances, evaluation of indications for reconstruction with concomitant pathology, and surgical reconstruction techniques. Recent advances in our understanding of MPFC anatomy have found that there are fibers that insert onto the deep quadriceps tendon as well as the patella, thus earning the name "medial patellofemoral complex" to allow for the variability in its anatomy. In MPFC reconstruction, anatomic origin and insertion points and appropriate graft length are critical to prevent overconstraint of the patellofemoral joint. The MPFC is a crucial soft tissue checkrein to lateral patellar translation, and its repair or reconstruction results in good restoration of patellofemoral stability. As our understanding of MPFC anatomy evolves, further studies are needed to apply its relevance in kinematics and surgical applications to its role in maintaining patellar stability.

  10. Polystochastic Models for Complexity

    CERN Document Server

    Iordache, Octavian

    2010-01-01

    This book is devoted to complexity understanding and management, considered as the main source of efficiency and prosperity for the next decades. Divided into six chapters, the book begins with a presentation of basic concepts as complexity, emergence and closure. The second chapter looks to methods and introduces polystochastic models, the wave equation, possibilities and entropy. The third chapter focusing on physical and chemical systems analyzes flow-sheet synthesis, cyclic operations of separation, drug delivery systems and entropy production. Biomimetic systems represent the main objective of the fourth chapter. Case studies refer to bio-inspired calculation methods, to the role of artificial genetic codes, neural networks and neural codes for evolutionary calculus and for evolvable circuits as biomimetic devices. The fifth chapter, taking its inspiration from systems sciences and cognitive sciences looks to engineering design, case base reasoning methods, failure analysis, and multi-agent manufacturing...

  11. Rhodium thioacetate complexes

    International Nuclear Information System (INIS)

    Baranovskij, I.B.; Golubnichaya, M.A.; Mazo, G.Ya.

    1976-01-01

    Thioacetato-complexes of rhodium(II) were prepared by the reaction of thioacetic acid with rhodium(II) carboxylates. Diamagnetic compounds of the type Rh 2 (CH 3 COS) 4 2A, where A=H 2 O, Py, N 2 H 4 .HCl, Thio, KNCS, DMSO, CH 3 CN, CsCl, or CH 3 COSH, were isolated. Their infrared spectra were recorded, and the principal vibrational wavenumbers assigned. The X-ray electron spectra confirm that rhodium is divalent. The thioacetato-complexes are dimeric, with a metal-metal bond. [Rh(NH 3 ) 5 (CH 3 COS)]I 2 was prepared, and its properties studied. The significant decrease in the strength of the bonds formed by the axial ligands with rhodium is due to the strong trans-influence of the covalent rhodium-rhodium sigma-bond

  12. Complex conductivity of soils

    DEFF Research Database (Denmark)

    Revil, A.; Coperey, A.; Shao, Z.

    2017-01-01

    The complex conductivity of soil remains poorly known despite the growing importance of this method in hyrogeophysics. In order to fill this gap of knowledge, we investigate the complex conductivity of 71 soils samples (including 4 peat samples) and one clean sand in the frequency range 0.1 Hertz...... to 45 kHz. The soil samples are saturated with 6 different NaCl brines with conductivities (0.031, 0.53, 1.15, 5.7, 14.7, and 22 S m-1, NaCl, 25°C) in order to determine their intrinsic formation factor and surface conductivity. This dataset is used to test the predictions of the dynamic Stern...

  13. Modeling Complex Systems

    International Nuclear Information System (INIS)

    Schreckenberg, M

    2004-01-01

    This book by Nino Boccara presents a compilation of model systems commonly termed as 'complex'. It starts with a definition of the systems under consideration and how to build up a model to describe the complex dynamics. The subsequent chapters are devoted to various categories of mean-field type models (differential and recurrence equations, chaos) and of agent-based models (cellular automata, networks and power-law distributions). Each chapter is supplemented by a number of exercises and their solutions. The table of contents looks a little arbitrary but the author took the most prominent model systems investigated over the years (and up until now there has been no unified theory covering the various aspects of complex dynamics). The model systems are explained by looking at a number of applications in various fields. The book is written as a textbook for interested students as well as serving as a comprehensive reference for experts. It is an ideal source for topics to be presented in a lecture on dynamics of complex systems. This is the first book on this 'wide' topic and I have long awaited such a book (in fact I planned to write it myself but this is much better than I could ever have written it!). Only section 6 on cellular automata is a little too limited to the author's point of view and one would have expected more about the famous Domany-Kinzel model (and more accurate citation!). In my opinion this is one of the best textbooks published during the last decade and even experts can learn a lot from it. Hopefully there will be an actualization after, say, five years since this field is growing so quickly. The price is too high for students but this, unfortunately, is the normal case today. Nevertheless I think it will be a great success! (book review)

  14. On convex complexity measures

    Czech Academy of Sciences Publication Activity Database

    Hrubeš, P.; Jukna, S.; Kulikov, A.; Pudlák, Pavel

    2010-01-01

    Roč. 411, 16-18 (2010), s. 1842-1854 ISSN 0304-3975 R&D Projects: GA AV ČR IAA1019401 Institutional research plan: CEZ:AV0Z10190503 Keywords : boolean formula * complexity measure * combinatorial rectangle * convexity Subject RIV: BA - General Mathematics Impact factor: 0.838, year: 2010 http://www.sciencedirect.com/science/article/pii/S0304397510000885

  15. Complexity in Dynamical Systems

    Science.gov (United States)

    Moore, Cristopher David

    The study of chaos has shown us that deterministic systems can have a kind of unpredictability, based on a limited knowledge of their initial conditions; after a finite time, the motion appears essentially random. This observation has inspired a general interest in the subject of unpredictability, and more generally, complexity; how can we characterize how "complex" a dynamical system is?. In this thesis, we attempt to answer this question with a paradigm of complexity that comes from computer science, we extract sets of symbol sequences, or languages, from a dynamical system using standard methods of symbolic dynamics; we then ask what kinds of grammars or automata are needed a generate these languages. This places them in the Chomsky heirarchy, which in turn tells us something about how subtle and complex the dynamical system's behavior is. This gives us insight into the question of unpredictability, since these automata can also be thought of as computers attempting to predict the system. In the culmination of the thesis, we find a class of smooth, two-dimensional maps which are equivalent to the highest class in the Chomsky heirarchy, the turning machine; they are capable of universal computation. Therefore, these systems possess a kind of unpredictability qualitatively different from the usual "chaos": even if the initial conditions are known exactly, questions about the system's long-term dynamics are undecidable. No algorithm exists to answer them. Although this kind of unpredictability has been discussed in the context of distributed, many-degree-of -freedom systems (for instance, cellular automata) we believe this is the first example of such phenomena in a smooth, finite-degree-of-freedom system.

  16. Complex Business Negotiation

    OpenAIRE

    Lindholst, Morten

    2015-01-01

    Most scholars agree that engaging in preparation and planning is key to a negotiation’s effectiveness but research has largely focused solely on what happens at the negotiation table, rather than in preparation for it. This thesis addresses the balance by clarifying which preparation and planning activities are undertaken to conduct a complex business negotiation. It examines not only what activities are conducted, but also by whom, and when. One important question for both pra...

  17. Volatile uranyl hexafluoroacetoacetonate complexes

    International Nuclear Information System (INIS)

    Dines, M.B.; Hall, R.B.; Kaldor, A.; Kramer, G.M.; Maas, E.T. Jr.

    1980-01-01

    A composition of matter is described, characterized by the formula UO 2 (CF 3 COCHCOCF 3 ).L where L is a ligand selected from isopropanol, ethanol, isobutanol, tert-butanol, methanol, tetrahydrofuran, acetone, dimethylformamide, n-propanol and ethyl acetate. A process for producing the complex comprises reacting uranyl chloride with a hexafluoroacetylacetonate dissolved in a ligand L: experimental details are given. (U.K.)

  18. Operational Shock Complexity Theory

    Science.gov (United States)

    2005-05-26

    Theory : Recommendations For The National Strategy To Defeat Terrorism.” Student Issue Paper, Center for Strategic Leadership , US Army War College, July...Lens of Complexity Theory : Recommendations For The National Strategy To Defeat Terrorism.” (Student Issue Paper, Center for Strategic Leadership , US...planners managed to cause confusion in the enemy’s internal model by operating in an unexpected manner. 140 Glenn E. James, “Chaos Theory : The

  19. Engineering Complex Tissues

    Science.gov (United States)

    MIKOS, ANTONIOS G.; HERRING, SUSAN W.; OCHAREON, PANNEE; ELISSEEFF, JENNIFER; LU, HELEN H.; KANDEL, RITA; SCHOEN, FREDERICK J.; TONER, MEHMET; MOONEY, DAVID; ATALA, ANTHONY; VAN DYKE, MARK E.; KAPLAN, DAVID; VUNJAK-NOVAKOVIC, GORDANA

    2010-01-01

    This article summarizes the views expressed at the third session of the workshop “Tissue Engineering—The Next Generation,” which was devoted to the engineering of complex tissue structures. Antonios Mikos described the engineering of complex oral and craniofacial tissues as a “guided interplay” between biomaterial scaffolds, growth factors, and local cell populations toward the restoration of the original architecture and function of complex tissues. Susan Herring, reviewing osteogenesis and vasculogenesis, explained that the vascular arrangement precedes and dictates the architecture of the new bone, and proposed that engineering of osseous tissues might benefit from preconstruction of an appropriate vasculature. Jennifer Elisseeff explored the formation of complex tissue structures based on the example of stratified cartilage engineered using stem cells and hydrogels. Helen Lu discussed engineering of tissue interfaces, a problem critical for biological fixation of tendons and ligaments, and the development of a new generation of fixation devices. Rita Kandel discussed the challenges related to the re-creation of the cartilage-bone interface, in the context of tissue engineered joint repair. Frederick Schoen emphasized, in the context of heart valve engineering, the need for including the requirements derived from “adult biology” of tissue remodeling and establishing reliable early predictors of success or failure of tissue engineered implants. Mehmet Toner presented a review of biopreservation techniques and stressed that a new breakthrough in this field may be necessary to meet all the needs of tissue engineering. David Mooney described systems providing temporal and spatial regulation of growth factor availability, which may find utility in virtually all tissue engineering and regeneration applications, including directed in vitro and in vivo vascularization of tissues. Anthony Atala offered a clinician’s perspective for functional tissue

  20. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  1. Fluorido complexes of technetium

    International Nuclear Information System (INIS)

    Mariappan Balasekaran, Samundeeswari

    2013-01-01

    Fluorine chemistry has received considerable interest during recent years due to its significant role in the life sciences, especially for drug development. Despite the great nuclear medicinal importance of the radioactive metal technetium in radiopharmaceuticals, its coordination chemistry with the fluorido ligand is by far less explored than that of other ligands. Up to now, only a few technetium fluorides are known. This thesis contains the synthesis, spectroscopic and structural characterization of novel technetium fluorides in the oxidation states ''+1'', ''+2'', ''+4'' and ''+6''. In the oxidation state ''+6'', the fluoridotechnetates were synthesized either from nitridotechnetic(VI) acid or from pertechnetate by using reducing agent and have been isolated as cesium or tetraethylammonium salts. The compounds were characterized spectroscopically and structurally. In the intermediate oxidation state ''+4'', hexafluoridotechnetate(IV) was known for long time and studied spectroscopically. This thesis reports novel and improved syntheses and solved the critical issues of early publications such as the color, some spectroscopic properties and the structure of this key compound. Single crystal analyses of alkali metal, ammonium and tetramethylammonium salts of hexafluoridotechnetate(IV) are presented. In aqueous alkaline solutions, the ammonium salt of hexafluoridotechnetate(IV) undergoes hydrolysis and forms an oxido-bridged dimeric complex. It is the first step hydrolysis product of hexafluoridotechnetate(IV) and was characterized by spectroscopic and crystallographic methods. Low-valent technetium fluorides with the metal in the oxidation states of ''+2'' or ''+1'' are almost unknown. A detailed description of the synthesis and characterization of pentafluoridonitrosyltechnetate(II) is presented. The complex was isolated as alkali metal salts, and spectroscopic as well as structural features of the complexes are presented. Different salts of the trans

  2. Arithmetic of Complex Manifolds

    CERN Document Server

    Lange, Herbert

    1989-01-01

    It was the aim of the Erlangen meeting in May 1988 to bring together number theoretists and algebraic geometers to discuss problems of common interest, such as moduli problems, complex tori, integral points, rationality questions, automorphic forms. In recent years such problems, which are simultaneously of arithmetic and geometric interest, have become increasingly important. This proceedings volume contains 12 original research papers. Its main topics are theta functions, modular forms, abelian varieties and algebraic three-folds.

  3. Complex concentrate pretreatment

    International Nuclear Information System (INIS)

    Lokken, R.O.; Scheele, R.D.; Strachan, D.M.; Toste, A.P.

    1991-03-01

    After removal of the transuranics (TRU) by the TRUEX process, complex concentrate waste will be grouted for final storage. The purpose of this project, conducted at the Pacific Northwest Laboratory, is to support a future decision to grout the complexant waste without destruction of the organic contents. It has been demonstrated that grouts with acceptable parameters for the Transportable Grout Facility can be made using actual waste. The acceptability of these grouts from a regulatory view seems to be less of a problem than previously. None of the organics found in the waste have been found on the EPA hazardous chemicals list. Two potential problems with the processing of the complex concentrate wastes were identified during the use of the TRUEX process on samples of several milliliters. One was the amount of foam that is generated during acid addition to the alkaline waste. Some of this foam appears to be of a waxy nature but does redissolve when the waste is strongly acid. The second potential problem is that noticeable amounts of NO x gases are generated. No quantitative measure of the NO x gas generation was made. The problem relates to processing the waste in B-plant where there are no facilities to handle NO x gases. 5 refs., 4 figs., 4 tabs

  4. Predictive Surface Complexation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, Dimitri A. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Earth and Planetary Sciences

    2016-11-29

    Surface complexation plays an important role in the equilibria and kinetics of processes controlling the compositions of soilwaters and groundwaters, the fate of contaminants in groundwaters, and the subsurface storage of CO2 and nuclear waste. Over the last several decades, many dozens of individual experimental studies have addressed aspects of surface complexation that have contributed to an increased understanding of its role in natural systems. However, there has been no previous attempt to develop a model of surface complexation that can be used to link all the experimental studies in order to place them on a predictive basis. Overall, my research has successfully integrated the results of the work of many experimentalists published over several decades. For the first time in studies of the geochemistry of the mineral-water interface, a practical predictive capability for modeling has become available. The predictive correlations developed in my research now enable extrapolations of experimental studies to provide estimates of surface chemistry for systems not yet studied experimentally and for natural and anthropogenically perturbed systems.

  5. Control of complex systems

    CERN Document Server

    Albertos, Pedro; Blanke, Mogens; Isidori, Alberto; Schaufelberger, Walter; Sanz, Ricardo

    2001-01-01

    The world of artificial systems is reaching complexity levels that es­ cape human understanding. Surface traffic, electricity distribution, air­ planes, mobile communications, etc. , are examples that demonstrate that we are running into problems that are beyond classical scientific or engi­ neering knowledge. There is an ongoing world-wide effort to understand these systems and develop models that can capture its behavior. The reason for this work is clear, if our lack of understanding deepens, we will lose our capability to control these systems and make they behave as we want. Researchers from many different fields are trying to understand and develop theories for complex man-made systems. This book presents re­ search from the perspective of control and systems theory. The book has grown out of activities in the research program Control of Complex Systems (COSY). The program has been sponsored by the Eu­ ropean Science Foundation (ESF) which for 25 years has been one of the leading players in stimula...

  6. [VGKC-complex antibodies].

    Science.gov (United States)

    Watanabe, Osamu

    2013-04-01

    Various antibodies are associated with voltage-gated potassium channels (VGKCs). Representative antibodies to VGKCs were first identified by radioimmunoassays using radioisotope-labeled alpha-dendrotoxin-VGKCs solubilized from rabbit brain. These antibodies were detected only in a proportion of patients with acquired neuromyotonia (Isaacs' syndrome). VGKC antibodies were also detected in patients with Morvan's syndrome and in those with a form of autoimmune limbic encephalitis. Recent studies indicated that the "VGKC" antibodies are mainly directed toward associated proteins (for example LGI-1 and CASPR-2) that complex with the VGKCs themselves. The "VGKC" antibodies are now commonly known as VGKC-complex antibodies. In general, LGI-1 antibodies are most commonly detected in patients with limbic encephalitis with syndrome of inappropriate secretion of antidiuretic hormone. CASPR-2 antibodies are present in the majority of patients with Morvan's syndrome. These patients develop combinations of CNS symptoms, autonomic dysfunction, and peripheral nerve hyperexcitability. Furthermore, VGKC-complex antibodies are tightly associated with chronic idiopathic pain. Hyperexcitability of nociceptive pathways has also been implicated. These antibodies may be detected in sera of some patients with neurodegenerative diseases (for example, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease).

  7. [Complex posttraumatic stress disorder].

    Science.gov (United States)

    Green, Tamar; Kotler, Moshe

    2007-11-01

    The characteristic symptoms resulting from exposure to an extreme trauma include three clusters of symptoms: persistent experience of the traumatic event, persistent avoidance of stimuli associated with the trauma and persistent symptoms of increased arousal. Beyond the accepted clusters of symptoms for posttraumatic stress disorder exists a formation of symptoms related to exposure to extreme or prolonged stress e.g. childhood abuse, physical violence, rape, and confinement within a concentration camp. With accumulated evidence of the existence of these symptoms began a trail to classify a more complex syndrome, which included, but was not confined to the symptoms of posttraumatic stress disorder. This review addresses several subjects for study in complex posttraumatic stress disorder, which is a complicated and controversial topic. Firstly, the concept of complex posttraumatic stress disorder is presented. Secondly, the professional literature relevant to this disturbance is reviewed and finally, the authors present the polemic being conducted between the researchers of posttraumatic disturbances regarding validity, reliability and the need for separate diagnosis for these symptoms.

  8. Complexity Leadership: A Theoretical Perspective

    Science.gov (United States)

    Baltaci, Ali; Balci, Ali

    2017-01-01

    Complex systems are social networks composed of interactive employees interconnected through collaborative, dynamic ties such as shared goals, perspectives and needs. Complex systems are largely based on "the complex system theory". The complex system theory focuses mainly on finding out and developing strategies and behaviours that…

  9. Complex Neutrosophic Subsemigroups and Ideals

    Directory of Open Access Journals (Sweden)

    Muhammad Gulistan

    2018-01-01

    Full Text Available In this article we study the idea of complex neutrosophic subsemigroups. We define the Cartesian product of complex neutrosophic subsemigroups, give some examples and study some of its related results. We also define complex neutrosophic (left, right, interior ideal in semigroup. Furthermore, we introduce the concept of characteristic function of complex neutrosophic sets, direct product of complex neutrosophic sets and study some results prove on its.

  10. Transition Complexity of Incomplete DFAs

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2010-08-01

    Full Text Available In this paper, we consider the transition complexity of regular languages based on the incomplete deterministic finite automata. A number of results on Boolean operations have been obtained. It is shown that the transition complexity results for union and complementation are very different from the state complexity results for the same operations. However, for intersection, the transition complexity result is similar to that of state complexity.

  11. The Stigma Complex

    Science.gov (United States)

    Pescosolido, Bernice A.; Martin, Jack K.

    2016-01-01

    Since the beginning of the twenty-first century, research on stigma has continued. Building on conceptual and empirical work, the recent period clarifies new types of stigmas, expansion of measures, identification of new directions, and increasingly complex levels. Standard beliefs have been challenged, the relationship between stigma research and public debates reconsidered, and new scientific foundations for policy and programs suggested. We begin with a summary of the most recent Annual Review articles on stigma, which reminded sociologists of conceptual tools, informed them of developments from academic neighbors, and claimed findings from the early period of “resurgence.” Continued (even accelerated) progress has also revealed a central problem. Terms and measures are often used interchangeably, leading to confusion and decreasing accumulated knowledge. Drawing from this work but focusing on the past 14 years of stigma research (including mental illness, sexual orientation, HIV/AIDS, and race/ethnicity), we provide a theoretical architecture of concepts (e.g., prejudice, experienced/received discrimination), drawn together through a stigma process (i.e., stigmatization), based on four theoretical premises. Many characteristics of the mark (e.g., discredited, concealable) and variants (i.e., stigma types and targets) become the focus of increasingly specific and multidimensional definitions. Drawing from complex and systems science, we propose a stigma complex, a system of interrelated, heterogeneous parts bringing together insights across disciplines to provide a more realistic and complicated sense of the challenge facing research and change efforts. The Framework Integrating Normative Influences on Stigma (FINIS) offers a multilevel approach that can be tailored to stigmatized statuses. Finally, we outline challenges for the next phase of stigma research, with the goal of continuing scientific activity that enhances our understanding of stigma and builds

  12. Organization of complex networks

    Science.gov (United States)

    Kitsak, Maksim

    Many large complex systems can be successfully analyzed using the language of graphs and networks. Interactions between the objects in a network are treated as links connecting nodes. This approach to understanding the structure of networks is an important step toward understanding the way corresponding complex systems function. Using the tools of statistical physics, we analyze the structure of networks as they are found in complex systems such as the Internet, the World Wide Web, and numerous industrial and social networks. In the first chapter we apply the concept of self-similarity to the study of transport properties in complex networks. Self-similar or fractal networks, unlike non-fractal networks, exhibit similarity on a range of scales. We find that these fractal networks have transport properties that differ from those of non-fractal networks. In non-fractal networks, transport flows primarily through the hubs. In fractal networks, the self-similar structure requires any transport to also flow through nodes that have only a few connections. We also study, in models and in real networks, the crossover from fractal to non-fractal networks that occurs when a small number of random interactions are added by means of scaling techniques. In the second chapter we use k-core techniques to study dynamic processes in networks. The k-core of a network is the network's largest component that, within itself, exhibits all nodes with at least k connections. We use this k-core analysis to estimate the relative leadership positions of firms in the Life Science (LS) and Information and Communication Technology (ICT) sectors of industry. We study the differences in the k-core structure between the LS and the ICT sectors. We find that the lead segment (highest k-core) of the LS sector, unlike that of the ICT sector, is remarkably stable over time: once a particular firm enters the lead segment, it is likely to remain there for many years. In the third chapter we study how

  13. Magnox waste storage complex

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This article looks at the design and construction of British Nuclear Fuel Limited's (BNFL) Magnox waste storage complex by Costain Engineering Limited. Magnox swarf from fuel decanning is stored underwater in specially designed silos. Gas processing capabilities from Costain Engineering Limited and the experience of BNFL combined in this project to provide the necessary problem-solving skills necessary for this waste storage upgrading and extension project. A retrofitted inerting facility was fitted to an existing building and a new storage extension was fitted, both without interrupting reprocessing operations at Sellafield. (UK)

  14. Computability, complexity, logic

    CERN Document Server

    Börger, Egon

    1989-01-01

    The theme of this book is formed by a pair of concepts: the concept of formal language as carrier of the precise expression of meaning, facts and problems, and the concept of algorithm or calculus, i.e. a formally operating procedure for the solution of precisely described questions and problems. The book is a unified introduction to the modern theory of these concepts, to the way in which they developed first in mathematical logic and computability theory and later in automata theory, and to the theory of formal languages and complexity theory. Apart from considering the fundamental themes an

  15. Complex adaptive systems ecology

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2003-01-01

    In the following, I will analyze two articles called Complex Adaptive Systems EcologyI & II (Molin & Molin, 1997 & 2000). The CASE-articles are some of the more quirkyarticles that have come out of the Molecular Microbial Ecology Group - a groupwhere I am currently making observational studies....... They are the result of acooperation between Søren Molin, professor in the group, and his brother, JanMolin, professor at Department of Organization and Industrial Sociology atCopenhagen Business School. The cooperation arises from the recognition that bothmicrobial ecology and sociology/organization theory works...

  16. Complexity in Managing Modularization

    DEFF Research Database (Denmark)

    Hansen, Poul H. Kyvsgård; Sun, Hongyi

    2011-01-01

    In general, the phenomenon of managing modularization is not well known. The cause-effect relationships between modularization and realized benefits are complex and comprehensive. Though a number of research works have contributed to the study of the phenomenon of efficient and effective...... modularization management it is far from clarified. Recognizing the need for further empirical research, we have studied 40 modularity cases in various companies. The studies have been designed as long-term studies leaving time for various types of modularization benefits to emerge. Based on these studies we...... have developed a framework to support the heuristic and iterative process of planning and realizing modularization benefits....

  17. Procuring complex performance

    DEFF Research Database (Denmark)

    Hartmann, A.; Roehrich, J.; Frederiksen, Lars

    2014-01-01

    the transition process. Design/methodology/approach – A multiple, longitudinal case study method is used to examine the transition towards PCP. The study deploys rich qualitative data sets by combining semi-structured interviews, focus group meetings and organisational reports and documents. Findings...... and relational challenges they need to master when facing higher levels of performance and infrastructural complexity. Originality/value – The study adds to the limited empirical and conceptual understanding on the nature of long-term public-private interactions in PCP. It contributes through a rare focus...

  18. Complex photonic structures

    International Nuclear Information System (INIS)

    Wiersma, D.S.

    2013-01-01

    We discuss in detail the optical properties of complex photonic structures, in particular those with a dominating disorder component. We will focus on their general transport properties, as well as on their use as light sources (random lasers). The basis for the theory of multiple light scattering in random systems will be explained as a tutorial introduction to the topic, including the explicit calculation of the effect of coherent backscattering. We will discuss various structures that go beyond regular disordered ones, in particular Levy glasses, liquid crystals, and quasicrystals, and show examples of their optical properties both from a conceptual and practical point of view.

  19. Fluorido complexes of technetium

    Energy Technology Data Exchange (ETDEWEB)

    Mariappan Balasekaran, Samundeeswari

    2013-07-04

    Fluorine chemistry has received considerable interest during recent years due to its significant role in the life sciences, especially for drug development. Despite the great nuclear medicinal importance of the radioactive metal technetium in radiopharmaceuticals, its coordination chemistry with the fluorido ligand is by far less explored than that of other ligands. Up to now, only a few technetium fluorides are known. This thesis contains the synthesis, spectroscopic and structural characterization of novel technetium fluorides in the oxidation states ''+1'', ''+2'', ''+4'' and ''+6''. In the oxidation state ''+6'', the fluoridotechnetates were synthesized either from nitridotechnetic(VI) acid or from pertechnetate by using reducing agent and have been isolated as cesium or tetraethylammonium salts. The compounds were characterized spectroscopically and structurally. In the intermediate oxidation state ''+4'', hexafluoridotechnetate(IV) was known for long time and studied spectroscopically. This thesis reports novel and improved syntheses and solved the critical issues of early publications such as the color, some spectroscopic properties and the structure of this key compound. Single crystal analyses of alkali metal, ammonium and tetramethylammonium salts of hexafluoridotechnetate(IV) are presented. In aqueous alkaline solutions, the ammonium salt of hexafluoridotechnetate(IV) undergoes hydrolysis and forms an oxido-bridged dimeric complex. It is the first step hydrolysis product of hexafluoridotechnetate(IV) and was characterized by spectroscopic and crystallographic methods. Low-valent technetium fluorides with the metal in the oxidation states of ''+2'' or ''+1'' are almost unknown. A detailed description of the synthesis and characterization of pentafluoridonitrosyltechnetate(II) is presented. The

  20. Complex Strategic Choices

    DEFF Research Database (Denmark)

    Leleur, Steen

    to strategic decision making, Complex Strategic Choices presents a methodology which is further illustrated by a number of case studies and example applications. Dr. Techn. Steen Leleur has adapted previously established research based on feedback and input from various conferences, journals and students...... resulting in new material stemming from and focusing on practical application of a systemic approach. The outcome is a coherent and flexible approach named systemic planning. The inclusion of both the theoretical and practical aspects of systemic planning makes this book a key resource for researchers...

  1. Dismounted Complex Blast Injury.

    Science.gov (United States)

    Andersen, Romney C; Fleming, Mark; Forsberg, Jonathan A; Gordon, Wade T; Nanos, George P; Charlton, Michael T; Ficke, James R

    2012-01-01

    The severe Dismounted Complex Blast Injury (DCBI) is characterized by high-energy injuries to the bilateral lower extremities (usually proximal transfemoral amputations) and/or upper extremity (usually involving the non-dominant side), in addition to open pelvic injuries, genitourinary, and abdominal trauma. Initial resuscitation and multidisciplinary surgical management appear to be the keys to survival. Definitive treatment follows general principals of open wound management and includes decontamination through aggressive and frequent debridement, hemorrhage control, viable tissue preservation, and appropriate timing of wound closure. These devastating injuries are associated with paradoxically favorable survival rates, but associated injuries and higher amputation levels lead to more difficult reconstructive challenges.

  2. The Frankenstein Complex

    DEFF Research Database (Denmark)

    Jensen, Boris Brorman

    2016-01-01

    In his polemic essay Boris Brorman Jensen raises the issue of a perceived academic reluctance to acknowledge the impact of real-world pragmatics on the architectural expression of built architecture. “One might claim that parts of architectural academia suffer from a Frankenstein complex that seems...... to feed a certain academic fear of dealing with the messiness of the real world. This professional fear that the political, social, technical, economic and legal realities will fundamentally weaken and compromise pure architectural thinking rests on the misperception that architecture is not, essentially...

  3. Complex performance in construction

    DEFF Research Database (Denmark)

    Bougrain, Frédéric; Forman, Marianne; Gottlieb, Stefan Christoffer

    To fulfil the expectations of demanding clients, new project-delivery mechanisms have been developed. Approaches focusing on performance-based building or new procurement processers such as new forms of private-public partnerships are considered as solutions improving the overall performance...... to the end users. This report summarises the results from work undertaken in the international collaborative project “Procuring and Operating Complex Products and Systems in Construction” (POCOPSC). POCOPSC was carried out in the period 2010-2014. The project was executed in collaboration between CSTB...

  4. Herding Complex Networks

    KAUST Repository

    Ruf, Sebastian F.

    2018-04-12

    The problem of controlling complex networks is of interest to disciplines ranging from biology to swarm robotics. However, controllability can be too strict a condition, failing to capture a range of desirable behaviors. Herdability, which describes the ability to drive a system to a specific set in the state space, was recently introduced as an alternative network control notion. This paper considers the application of herdability to the study of complex networks. The herdability of a class of networked systems is investigated and two problems related to ensuring system herdability are explored. The first is the input addition problem, which investigates which nodes in a network should receive inputs to ensure that the system is herdable. The second is a related problem of selecting the best single node from which to herd the network, in the case that a single node is guaranteed to make the system is herdable. In order to select the best herding node, a novel control energy based herdability centrality measure is introduced.

  5. Complexity in language acquisition.

    Science.gov (United States)

    Clark, Alexander; Lappin, Shalom

    2013-01-01

    Learning theory has frequently been applied to language acquisition, but discussion has largely focused on information theoretic problems-in particular on the absence of direct negative evidence. Such arguments typically neglect the probabilistic nature of cognition and learning in general. We argue first that these arguments, and analyses based on them, suffer from a major flaw: they systematically conflate the hypothesis class and the learnable concept class. As a result, they do not allow one to draw significant conclusions about the learner. Second, we claim that the real problem for language learning is the computational complexity of constructing a hypothesis from input data. Studying this problem allows for a more direct approach to the object of study--the language acquisition device-rather than the learnable class of languages, which is epiphenomenal and possibly hard to characterize. The learnability results informed by complexity studies are much more insightful. They strongly suggest that target grammars need to be objective, in the sense that the primitive elements of these grammars are based on objectively definable properties of the language itself. These considerations support the view that language acquisition proceeds primarily through data-driven learning of some form. Copyright © 2013 Cognitive Science Society, Inc.

  6. Dynamics in Complex Coacervates

    Science.gov (United States)

    Perry, Sarah

    Understanding the dynamics of a material provides detailed information about the self-assembly, structure, and intermolecular interactions present in a material. While rheological methods have long been used for the characterization of complex coacervate-based materials, it remains a challenge to predict the dynamics for a new system of materials. Furthermore, most work reports only qualitative trends exist as to how parameters such as charge stoichiometry, ionic strength, and polymer chain length impact self-assembly and material dynamics, and there is little information on the effects of polymer architecture or the organization of charges within a polymer. We seek to link thermodynamic studies of coacervation phase behavior with material dynamics through a carefully-controlled, systematic study of coacervate linear viscoelasticity for different polymer chemistries. We couple various methods of characterizing the dynamics of polymer-based complex coacervates, including the time-salt superposition methods developed first by Spruijt and coworkers to establish a more mechanistic strategy for comparing the material dynamics and linear viscoelasticity of different systems. Acknowledgment is made to the Donors of the American Chemical Society Petroleum Research Fund for support of this research.

  7. River rating complexity

    Science.gov (United States)

    Holmes, Robert R.

    2016-01-01

    Accuracy of streamflow data depends on the veracity of the rating model used to derive a continuous time series of discharge from the surrogate variables that can readily be collected autonomously at a streamgage. Ratings are typically represented as a simple monotonic increasing function (simple rating), meaning the discharge is a function of stage alone, however this is never truly the case unless the flow is completely uniform at all stages and in transitions from one stage to the next. For example, at some streamflow-monitoring sites the discharge on the rising limb of the hydrograph is discernably larger than the discharge at the same stage on the falling limb of the hydrograph. This is the so-called “loop rating curve” (loop rating). In many cases, these loops are quite small and variation between rising- and falling-limb discharge measurements made at the same stage are well within the accuracy of the measurements. However, certain hydraulic conditions can produce a loop that is large enough to preclude use of a monotonic rating. A detailed data campaign for the Mississippi River at St. Louis, Missouri during a multi-peaked flood over a 56-day period in 2015 demonstrates the rating complexity at this location. The shifting-control method used to deal with complexity at this site matched all measurements within 8%.

  8. Shapes of interacting RNA complexes

    DEFF Research Database (Denmark)

    Fu, Benjamin Mingming; Reidys, Christian

    2014-01-01

    Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....

  9. Complex dynamical invariants for two-dimensional complex potentials

    Indian Academy of Sciences (India)

    Abstract. Complex dynamical invariants are searched out for two-dimensional complex poten- tials using rationalization method within the framework of an extended complex phase space characterized by x = x1 + ip3, y = x2 + ip4, px = p1 + ix3, py = p2 + ix4. It is found that the cubic oscillator and shifted harmonic oscillator ...

  10. OF AGROINDUSTRIAL COMPLEX MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Ruslan E. Mansurov

    2017-06-01

    Full Text Available The relevance of this work is determined, on the one hand, by tightening of the foreign political situation and its possible negative impact on the food security of the country, and, on the other hand, by the crisis of the domestic agricultural sector. These factors demand the development of new approaches to regional agroindustrial complex (AIC management. The aim is to develop a methodology for assessing the level of food self-sufficiency in main food areas of the Volgograd region. The author used the results of the statistical materials of AIC of the Volgograd region for 2016. The analytical methods included mathematical analysis and comparison. The main results are as follows. Based on the analysis of the current situation to ensure food security of Russia it was proved that at the present time it is necessary to develop effective indicators showing the level of self-sufficiency in basic food regions. It was also revealed that at the moment this indicator in the system of regional agrarian and industrial complex is not controlled. As a result of generalization of existing approaches the author’s method of rating the level of self-sufficiency of regions was offered. Its testing was carried out in several districts of the Volgograd region. The proposed authoring method of rating estimation of self-sufficiency in basic foodstuffs can be used in the regional agroindustrial complex management system at the federal and local levels. It can be used to rank areas in terms of their self-sufficiency in basic foodstuffs. This allows us to focus on the development of backward areas of agro-food and make appropriate management decisions. The final rating value - 0.759 obtained by the results of analysis of the situation in the Volgograd region means that the situation in matters of selfsufficiency in basic foodstuffs in general is good. However, we should aim at the maximum possible value of the rating - 1. In the application of the proposed

  11. Thermodynamics of complexity

    DEFF Research Database (Denmark)

    Westerhoff, Hans V.; Jensen, Peter Ruhdal; Snoep, Jacky L.

    1998-01-01

    -called emergent properties. Tendency towards increased entropy is an essential determinant for the behaviour of ideal gas mixtures, showing that even in the simplest physical/chemical systems, (dys)organisation of components is crucial for the behaviour of systems. This presentation aims at illustrating...... that the behaviour of two functionally interacting biological components (molecules, protein domains, pathways, organelles) differs from the behaviour these components would exhibit in isolation from one another, where the difference should be essential for the maintenance and growth of the living state, For a true...... understanding of this BioComplexity, modem thermodynamic concepts and methods (nonequilibrium thermodynamics, metabolic and hierarchical control analysis) will be needed. We shall propose to redefine nonequilibrium thermodynamics as: The science that aims at understanding the behaviour of nonequilibrium systems...

  12. Complexity, Metastability and Nonextensivity

    Science.gov (United States)

    Beck, C.; Benedek, G.; Rapisarda, A.; Tsallis, C.

    Work and heat fluctuations in systems with deterministic and stochastic forces / E. G. D. Cohen and R. Van Zon -- Is the entropy S[symbol] extensive or nonextensive? / C. Tsallis -- Superstatistics: recent developments and applications / C. Beck -- Two stories outside Boltzmann-Gibbs statistics: Mori's Q-phase transitions and glassy dynamics at the onset of chaos / A. Robledo, F. Baldovin and E. Mayoral -- Time-averages and the heat theorem / A. Carati -- Fundamental formulae and numerical evidences for the central limit theorem in Tsallis statistics / H. Suyari -- Generalizing the Planck distribution / A. M. C. Soma and C. Tsallis -- The physical roots of complexity: renewal or modulation? / P. Grigolini -- Nonequivalent ensembles and metastability / H. Touchette and R. S. Ellis -- Statistical physics for cosmic structures / L. Pietronero and F. Sylos Labini -- Metastability and anomalous behavior in the HMF model: connections to nonextensive thermodynamics and glassy dynamics / A. Pluchino, A. Rapisarda and V. Latora -- Vlasov analysis of relaxation and meta-equilibrium / C. Anteneodo and R. O. Vallejos -- Weak chaos in large conservative systems - infinite-range coupled standard maps / L. G. Moyano, A. P. Majtey and C. Tsallis -- Deterministc aging / E. Barkai -- Edge of chaos of the classical kicked top map: sensitivity to initial conditions / S. M. Duarte Queirós and C. Tsallis -- What entropy at the edge of chaos? / M. Lissia, M. Coraddu and R. Tonelli -- Fractal growth of carbon schwarzites / G. Benedek ... [et al.] -- Clustering and interface propagation in interacting particle dynamics / A. Provata and V. K. Noussiou -- Resonant activation and noise enhanced stability in Josephson junctions / A. L. Pankratov and B. Spagnolo -- Symmetry breaking induced directed motions / C.-H. Chang and T. Y. Tsong -- General theory of Galilean-invariant entropic lattic Boltzmann models / B. M. Boghosian -- Unifying approach to the jamming transition in granular media and

  13. Complex algebraic geometry

    CERN Document Server

    Kollár, János

    1997-01-01

    This volume contains the lectures presented at the third Regional Geometry Institute at Park City in 1993. The lectures provide an introduction to the subject, complex algebraic geometry, making the book suitable as a text for second- and third-year graduate students. The book deals with topics in algebraic geometry where one can reach the level of current research while starting with the basics. Topics covered include the theory of surfaces from the viewpoint of recent higher-dimensional developments, providing an excellent introduction to more advanced topics such as the minimal model program. Also included is an introduction to Hodge theory and intersection homology based on the simple topological ideas of Lefschetz and an overview of the recent interactions between algebraic geometry and theoretical physics, which involve mirror symmetry and string theory.

  14. Mutagenicity of complex mixtures

    International Nuclear Information System (INIS)

    Pelroy, R.A.

    1985-01-01

    The effect of coal-derived complex chemical mixtures on the mutagenicity of 6-aminochrysene (6-AC) was determined with Salmonella typhimurium TA98. Previous results suggested that the mutagenic potency of 6-AC for TA98 in the standard microsomal activation (Ames) assay increased if it was presented to the cells mixed with high-boiling coal liquids (CL) from the solvent refined coal (SRC) process. In this year's work, the apparent mutational synergism of CL and 6-AC was independently verified in a fluctuation bioassay which allowed quantitation of mutational frequencies and cell viability. The results of this assay system were similar to those in the Ames assay. Moreover, the fluctation assay revealed that mutagenesis and cellular toxicity induced by 6-AC were both strongly enhanced if 6-AC was presented to the cells mixed in a high-boiling CL. 4 figures

  15. Complex Algebraic Varieties

    CERN Document Server

    Peternell, Thomas; Schneider, Michael; Schreyer, Frank-Olaf

    1992-01-01

    The Bayreuth meeting on "Complex Algebraic Varieties" focussed on the classification of algebraic varieties and topics such as vector bundles, Hodge theory and hermitian differential geometry. Most of the articles in this volume are closely related to talks given at the conference: all are original, fully refereed research articles. CONTENTS: A. Beauville: Annulation du H(1) pour les fibres en droites plats.- M. Beltrametti, A.J. Sommese, J.A. Wisniewski: Results on varieties with many lines and their applications to adjunction theory.- G. Bohnhorst, H. Spindler: The stability of certain vector bundles on P(n) .- F. Catanese, F. Tovena: Vector bundles, linear systems and extensions of (1).- O. Debarre: Vers uns stratification de l'espace des modules des varietes abeliennes principalement polarisees.- J.P. Demailly: Singular hermitian metrics on positive line bundles.- T. Fujita: On adjoint bundles of ample vector bundles.- Y. Kawamata: Moderate degenerations of algebraic surfaces.- U. Persson: Genus two fibra...

  16. Invitation to complex analysis

    CERN Document Server

    Boas, Ralph P

    2010-01-01

    Ideal for a first course in complex analysis, this book can be used either as a classroom text or for independent study. Written at a level accessible to advanced undergraduates and beginning graduate students, the book is suitable for readers acquainted with advanced calculus or introductory real analysis. The treatment goes beyond the standard material of power series, Cauchy's theorem, residues, conformal mapping, and harmonic functions by including accessible discussions of intriguing topics that are uncommon in a book at this level. The flexibility afforded by the supplementary topics and applications makes the book adaptable either to a short, one-term course or to a comprehensive, full-year course. Detailed solutions of the exercises both serve as models for students and facilitate independent study. Supplementary exercises, not solved in the book, provide an additional teaching tool. This second edition has been painstakingly revised by the author's son, himself an award-winning mathematical expositor...

  17. Genetics of complex diseases

    DEFF Research Database (Denmark)

    Mellerup, Erling; Møller, Gert Lykke; Koefoed, Pernille

    2012-01-01

    A complex disease with an inheritable component is polygenic, meaning that several different changes in DNA are the genetic basis for the disease. Such a disease may also be genetically heterogeneous, meaning that independent changes in DNA, i.e. various genotypes, can be the genetic basis...... for the disease. Each of these genotypes may be characterized by specific combinations of key genetic changes. It is suggested that even if all key changes are found in genes related to the biology of a certain disease, the number of combinations may be so large that the number of different genotypes may be close...... to the number of patients suffering from the disease. This hypothesis is based on a study of bipolar disorder....

  18. A Cryo Complex Control

    CERN Document Server

    Alferov, V; Fedorchenko, V; Ivanova, N; Kholkin, A; Klimov, S; Krendelev, V; Kuznetsov, S; Lukyantsev, A; Lutchev, A; Milutkin, V; Sytin, A N; Vasilev, D

    2004-01-01

    A Cryogenic complex is being constructed to provide by liquid helium and nitrogen the RF-separator of kaons. About 500 parameters including temperature (1,8…300)K, liquid helium/nitrogen level, vacuum, 300 digital signals have to be measured, 70 commands generated, 20 closed loops activated. The paper describes controls electronics which includes home made I8051 compatible controllers connected by the CAN field bus to a bus controller and interface electronic modules for: - temperature measurements; - liquid Ni and He level measurements; - vacuum pumps current measurements; - analog and digital signals measurements and generations. The modules are tested together with signal imitators within a vertical slice of the Control System based on EPICS tools.

  19. Segmentation of complex document

    Directory of Open Access Journals (Sweden)

    Souad Oudjemia

    2014-06-01

    Full Text Available In this paper we present a method for segmentation of documents image with complex structure. This technique based on GLCM (Grey Level Co-occurrence Matrix used to segment this type of document in three regions namely, 'graphics', 'background' and 'text'. Very briefly, this method is to divide the document image, in block size chosen after a series of tests and then applying the co-occurrence matrix to each block in order to extract five textural parameters which are energy, entropy, the sum entropy, difference entropy and standard deviation. These parameters are then used to classify the image into three regions using the k-means algorithm; the last step of segmentation is obtained by grouping connected pixels. Two performance measurements are performed for both graphics and text zones; we have obtained a classification rate of 98.3% and a Misclassification rate of 1.79%.

  20. Complexity in Evolutionary Processes

    International Nuclear Information System (INIS)

    Schuster, P.

    2010-01-01

    Darwin's principle of evolution by natural selection is readily casted into a mathematical formalism. Molecular biology revealed the mechanism of mutation and provides the basis for a kinetic theory of evolution that models correct reproduction and mutation as parallel chemical reaction channels. A result of the kinetic theory is the existence of a phase transition in evolution occurring at a critical mutation rate, which represents a localization threshold for the population in sequence space. Occurrence and nature of such phase transitions depend critically on fitness landscapes. The fitness landscape being tantamount to a mapping from sequence or genotype space into phenotype space is identified as the true source of complexity in evolution. Modeling evolution as a stochastic process is discussed and neutrality with respect to selection is shown to provide a major challenge for understanding evolutionary processes (author)

  1. Complex Interfaces Under Change

    DEFF Research Database (Denmark)

    Rosbjerg, Dan

    The hydrosphere is dynamic across the major compartments of the Earth system: the atmosphere, the oceans and seas, the land surface water, and the groundwater within the strata below the two last compartments. The global geography of the hydrosphere essentially depends on thermodynamic and mechan...... these interfaces and interfaced compartments and processes. Climate, sea-level, oceanographic currents and hydrological processes are all affected, while anthropogenic changes are often intense in the geographic settings corresponding to such interfaces....... and mechanical processes that develop within this structure. Water-related processes at the interfaces between the compartments are complex, depending both on the interface itself, and on the characteristics of the interfaced compartments. Various aspects of global change directly or indirectly impact...

  2. Iridium complexes for electrocatalysis

    Science.gov (United States)

    Sheehan, Stafford Wheeler; Hintermair, Ulrich; Thomsen, Julianne M; Brudvig, Gary W; Crabtree, Robert H

    2017-10-17

    Solution-phase (e.g., homogeneous) or surface-immobilized (e.g., heterogeneous) electrode-driven oxidation catalysts based on iridium coordination compounds which self-assemble upon chemical or electrochemical oxidation of suitable precursors and methods of making and using thereof are. Iridium species such as {[Ir(LX).sub.x(H.sub.2O).sub.y(.mu.-O)].sub.z.sup.m+}.sub.n wherein x, y, m are integers from 0-4, z and n from 1-4 and LX is an oxidation-resistant chelate ligand or ligands, such as such as 2(2-pyridyl)-2-propanolate, form upon oxidation of various molecular iridium complexes, for instance [Cp*Ir(LX)OH] or [(cod)Ir(LX)] (Cp*=pentamethylcyclopentadienyl, cod=cis-cis,1,5-cyclooctadiene) when exposed to oxidative conditions, such as sodium periodate (NaIO.sub.4) in aqueous solution at ambient conditions.

  3. Complex Hamiltonian Dynamics

    CERN Document Server

    Bountis, Tassos

    2012-01-01

    This book introduces and explores modern developments in the well established field of Hamiltonian dynamical systems. It focuses on high degree-of-freedom systems and the transitional regimes between regular and chaotic motion. The role of nonlinear normal modes is highlighted and the importance of low-dimensional tori in the resolution of the famous FPU paradox is emphasized. Novel powerful numerical methods are used to study localization phenomena and distinguish order from strongly and weakly chaotic regimes. The emerging hierarchy of complex structures in such regimes gives rise to particularly long-lived patterns and phenomena called quasi-stationary states, which are explored in particular in the concrete setting of one-dimensional Hamiltonian lattices and physical applications in condensed matter systems.  The self-contained and pedagogical approach is blended with a unique balance between mathematical rigor, physics insights and concrete applications. End of chapter exercises and (more demanding) res...

  4. Turbulence in complex terrain

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Jakob [Risoe National Lab., Wind Energy and Atmosheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    The purpose of this work is to develop a model of the spectral velocity-tensor in neutral flow over complex terrain. The resulting equations are implemented in a computer code using the mean flow generated by a linear mean flow model as input. It estimates turbulence structure over hills (except on the lee side if recirculation is present) in the so-called outer layer and also models the changes in turbulence statistics in the vicinity roughness changes. The generated turbulence fields are suitable as input for dynamic load calculations on wind turbines and other tall structures and is under implementation in the collection of programs called WA{sup s}P Engineering. (au) EFP-97; EU-JOULE-3. 15 refs.

  5. Evolution of complex dynamics

    Science.gov (United States)

    Wilds, Roy; Kauffman, Stuart A.; Glass, Leon

    2008-09-01

    We study the evolution of complex dynamics in a model of a genetic regulatory network. The fitness is associated with the topological entropy in a class of piecewise linear equations, and the mutations are associated with changes in the logical structure of the network. We compare hill climbing evolution, in which only mutations that increase the fitness are allowed, with neutral evolution, in which mutations that leave the fitness unchanged are allowed. The simple structure of the fitness landscape enables us to estimate analytically the rates of hill climbing and neutral evolution. In this model, allowing neutral mutations accelerates the rate of evolutionary advancement for low mutation frequencies. These results are applicable to evolution in natural and technological systems.

  6. Early AIDS dementia complex

    International Nuclear Information System (INIS)

    Mountz, J.M.; Speed, N.M.; Adams, K.; Schwartz, J.A.; Gross, M.D.; Ostrow, D.G.

    1988-01-01

    A frequent complication of the acquired immunodeficiency syndrome (AIDS) is AIDS dementia complex (ADC). The authors evaluated seven patients with AIDS (aged 28-55 years, all male) for ADC by psychiatric evaluation, neuropsychological testing, CT scanning, and IMP-SPECT. Six of seven patients exhibited cognitive or behavioral abnormalities. Neuropsychological testing showed general deficits but no cases of explicit dementia. SPECT showed marked abnormalities in two cases: posterior temporal-parietal diminution of tracer uptake in one case (posterior/anterior=0.81) and marked right/left subcortical asymmetry (1.17) in the other. In three additional cases there was asymmetric tracer uptake in the subcortical and parietal regions. CT findings were normal in all seven cases. The authors conclude that functional imaging with the use of IMP-SPECT may be a useful method to follow ADC progression and response to therapy

  7. Measurement of complex surfaces

    International Nuclear Information System (INIS)

    Brown, G.M.

    1993-05-01

    Several of the components used in coil fabrication involve complex surfaces and dimensions that are not well suited to measurements using conventional dimensional measuring equipment. Some relatively simple techniques that are in use in the SSCL Magnet Systems Division (MSD) for incoming inspection will be described, with discussion of their suitability for specific applications. Components that are submitted for MSD Quality Assurance (QA) dimensional inspection may be divided into two distinct categories; the first category involves components for which there is an approved drawing and for which all nominal dimensions are known; the second category involves parts for which 'reverse engineering' is required, the part is available but there are no available drawings or dimensions. This second category typically occurs during development of coil end parts and coil turn filler parts where it is necessary to manually shape the part and then measure it to develop the information required to prepare a drawing for the part

  8. Complexity Science for Simpletons

    Directory of Open Access Journals (Sweden)

    Feinstein C. A.

    2006-07-01

    Full Text Available In this article, we shall describe some of the most interesting topics in the subject of Complexity Science for a general audience. Anyone with a solid foundation in high school mathematics (with some calculus and an elementary understanding of computer programming will be able to follow this article. First, we shall explain the significance of the P versus NP problem and solve it. Next, we shall describe two other famous mathematics problems, the Collatz 3n+ 1 Conjecture and the Riemann Hypothesis, and show how both Chaitin’s incompleteness theorem and Wolfram’s notion of “computational irreducibility” are important for understanding why no one has, as of yet, solved these two problems.

  9. The Complex Cepstrum - Revisited

    Science.gov (United States)

    Kemerait, R. C., Sr.

    2016-12-01

    Since this paper comes at the twilight of my career, it is appropriate to share my views on a subject very dear to my heart and to my long career. In 2004 "From Frequency to Quefrency: A History of the Cepstrum" was published in the IEEE Signal Processing magazine. There is no question that the authors, Alan V. Oppenheim and Ronald W. Schafer, were pioneers in this area of research, and this publication documents their involvement quite nicely. In parallel research also performed in the 1960's, Childers, et. al., renamed the original "Cepstrum" to the "Power Cepstrum" to avoid confusion with the principal topic of their research, that being the "Complex Cepstrum." The term "Power Cepstrum" has become widely used in the literature since that time. The Childers team, including Dr. Kemerait, published a summary of their work, as of that date, in the IEEE Proceedings of October 1977, and titled the article "The Cepstrum: A Guide to Processing." In the subsequent 40 years, Dr. Kemerait has continued to research cepstral techniques applied to many diverse problems; however, his primary research has been on estimating the depth of underground and underwater events. He has also applied these techniques to biomedical data: EEG, EKG, and Visua-evoked responses as well as on hydroacoustic data ; thereby, determining the "bubble pulse frequency", and the depths of the explosion and the ocean depth at the explosion point. He has also used cepstral techniques in the processing of ground penetrating radar, speech, machine diagnostics, and, throughout these years, seismic data. This paper emphasizes his recent improvements in processing primarily seismic and infrasound data associated with nuclear treaty monitoring. The emphasis is mainly on the recent improvements and the automation of the Complex Cepstrum process.

  10. Complex wounds Feridas complexas

    Directory of Open Access Journals (Sweden)

    Marcus Castro Ferreira

    2006-01-01

    Full Text Available Complex wound is the term used more recently to group those well-known difficult wounds, either chronic or acute, that challenge medical and nursing teams. They defy cure using conventional and simple "dressings" therapy and currently have a major socioeconomic impact. The purpose of this review is to bring these wounds to the attention of the health-care community, suggesting that they should be treated by multidisciplinary teams in specialized hospital centers. In most cases, surgical treatment is unavoidable, because the extent of skin and subcutaneous tissue loss requires reconstruction with grafts and flaps. New technologies, such as the negative pressure device, should be introduced. A brief review is provided of the major groups of complex wounds-diabetic wounds, pressure sores, chronic venous ulcers, post-infection soft-tissue gangrenes, and ulcers resulting from vasculitis.Ferida complexa é uma nova definição para identificar aquelas feridas crônicas e algumas agudas já bem conhecidas e que desafiam equipes médicas e de enfermagem. São difíceis de serem resolvidas usando tratamentos convencionais e simples curativos. Têm atualmente grande impacto sócio-econômico. Esta revisão procura atrair atenção da comunidade de profissionais de saúde para estas feridas, sugerindo que devam ser tratadas por equipe multidisciplinar em centro hospitalar especializado. Na maioria dos casos o tratamento cirúrgico deve ser indicado, uma vez que a perda de pele e tecido subcutâneo é extensa, necessitando de reconstrução com enxertos e retalhos. Nova tecnologia, como uso da terapia por pressão negativa foi introduzido. Breves comentários sobre os principais grupos de feridas complexas: pé diabético, úlceras por pressão, úlceras venosas, síndrome de Fournier e vasculites.

  11. Complex sleep apnea syndrome

    Directory of Open Access Journals (Sweden)

    Wang J

    2013-07-01

    Full Text Available Juan Wang,1,* Yan Wang,1,* Jing Feng,1,2 Bao-yuan Chen,1 Jie Cao1 1Respiratory Department of Tianjin Medical University General Hospital, Tianjin, People's Republic of China; 2Division of Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, USA *The first two authors contributed equally to this work Abstract: Complex sleep apnea syndrome (CompSAS is a distinct form of sleep-disordered breathing characterized as central sleep apnea (CSA, and presents in obstructive sleep apnea (OSA patients during initial treatment with a continuous positive airway pressure (CPAP device. The mechanisms of why CompSAS occurs are not well understood, though we have a high loop gain theory that may help to explain it. It is still controversial regarding the prevalence and the clinical significance of CompSAS. Patients with CompSAS have clinical features similar to OSA, but they do exhibit breathing patterns like CSA. In most CompSAS cases, CSA events during initial CPAP titration are transient and they may disappear after continued CPAP use for 4–8 weeks or even longer. However, the poor initial experience of CompSAS patients with CPAP may not be avoided, and nonadherence with continued therapy may often result. Treatment options like adaptive servo-ventilation are available now that may rapidly resolve the disorder and relieve the symptoms of this disease with the potential of increasing early adherence to therapy. But these approaches are associated with more expensive and complicated devices. In this review, the definition, potential plausible mechanisms, clinical characteristics, and treatment approaches of CompSAS will be summarized. Keywords: complex sleep apnea syndrome, obstructive sleep apnea, central sleep apnea, apnea threshold, continuous positive airway pressure, adaptive servo-ventilation

  12. Amphotericin B Lipid Complex Injection

    Science.gov (United States)

    Amphotericin B lipid complex injection is used to treat serious, possibly life-threatening fungal infections in people who did ... respond or are unable to tolerate conventional amphotericin B therapy. Amphotericin B lipid complex injection is in ...

  13. Ethylene biosynthesis by 1-aminocyclopropane-1-carboxylic acid oxidase: a DFT study.

    Science.gov (United States)

    Bassan, Arianna; Borowski, Tomasz; Schofield, Christopher J; Siegbahn, Per E M

    2006-11-24

    The reaction catalyzed by the plant enzyme 1-aminocyclopropane-1-carboxylic acid oxidase (ACCO) was investigated by using hybrid density functional theory. ACCO belongs to the non-heme iron(II) enzyme superfamily and carries out the bicarbonate-dependent two-electron oxidation of its substrate ACC (1-aminocyclopropane-1-carboxylic acid) concomitant with the reduction of dioxygen and oxidation of a reducing agent probably ascorbate. The reaction gives ethylene, CO(2), cyanide and two water molecules. A model including the mononuclear iron complex with ACC in the first coordination sphere was used to study the details of O-O bond cleavage and cyclopropane ring opening. Calculations imply that this unusual and complex reaction is triggered by a hydrogen atom abstraction step generating a radical on the amino nitrogen of ACC. Subsequently, cyclopropane ring opening followed by O-O bond heterolysis leads to a very reactive iron(IV)-oxo intermediate, which decomposes to ethylene and cyanoformate with very low energy barriers. The reaction is assisted by bicarbonate located in the second coordination sphere of the metal.

  14. The role of metals in production and scavenging of reactive oxygen species in photosystem II.

    Science.gov (United States)

    Pospíšil, Pavel

    2014-07-01

    Metal ions play a crucial role in enzymatic reactions in all photosynthetic organisms such as cyanobacteria, algae and plants. It well known that metal ions maintain the binding of substrate in the active site of the metalloenzymes and control the redox activity of the metalloenzyme in the enzymatic reaction. A large pigment-protein complex, PSII, known to serve as a water-plastoquinone oxidoreductase, contains three metal centers comprising non-heme iron, heme iron of Cyt b559 and the water-splitting manganese complex. Metal ions bound to PSII proteins maintain the electron transport from water to plastoquinone and regulate the pro-oxidant and antioxidant activity in PSII. In this review, attention is focused on the role of PSII metal centers in (i) the formation of superoxide anion and hydroxyl radicals by sequential one-electron reduction of molecular oxygen and the formation of hydrogen peroxide by incomplete two-electron oxidation of water; and (ii) the elimination of superoxide anion radical by one-electron oxidation and reduction (superoxide dismutase activity) and of hydrogen peroxide by two-electron oxidation and reduction (catalase activity). The balance between the formation and elimination of reactive oxygen species by PSII metal centers is discussed as an important aspect in the prevention of photo-oxidative damage of PSII proteins and lipids. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  15. A comparison of in vivo and in vitro methods for determining availability of iron from meals

    International Nuclear Information System (INIS)

    Schricker, B.R.; Miller, D.D.; Rasmussen, R.R.; Van Campen, D.

    1981-01-01

    A comparison is made between in vitro and human and rat in vivo methods for estimating food iron availability. Complex meals formulated to replicate meals used by Cook and Monsen (Am J Clin Nutr 1976;29:859) in human iron availability trials were used in the comparison. The meals were prepared by substituting pork, fish, cheese, egg, liver, or chicken for beef in two basic test meals and were evaluated for iron availability using in vitro and rat in vivo methods. When the criterion for comparison was the ability to show statistically significant differences between iron availability in the various meals, there was substantial agreement between the in vitro and human in vivo methods. There was less agreement between the human in vivo and the rat in vivo and between the in vivo and the rat in vivo and between the in vitro and the rat in vivo methods. Correlation analysis indicated significant agreement between in vitro and human in vivo methods. Correlation between the rat in vivo and human in vivo methods were also significant but correlations between the in vitro and rat in vivo methods were less significant and, in some cases, not significant. The comparison supports the contention that the in vitro method allows a rapid, inexpensive, and accurate estimation of nonheme iron availability in complex meals

  16. [Tissue-specific nucleoprotein complexes].

    Science.gov (United States)

    Riadnova, I Iu; Shataeva, L K; Khavinson, V Kh

    2000-01-01

    A method of isolation of native nucleorprotein complexes from cattle cerebral cortex, thymus, and liver was developed. Compositions of these complexes were studied by means of gel-chromatography and ion-exchange chromatography. These preparations were shown to consist of several fractions of proteins and their complexes differ by molecular mass and electro-chemical properties. Native nucleoprotein complexes revealed high tissue specific activity, which was not species-specific.

  17. Cooperativity of complex salt bridges

    OpenAIRE

    Gvritishvili, Anzor G.; Gribenko, Alexey V.; Makhatadze, George I.

    2008-01-01

    The energetic contribution of complex salt bridges, in which one charged residue (anchor residue) forms salt bridges with two or more residues simultaneously, has been suggested to have importance for protein stability. Detailed analysis of the net energetics of complex salt bridge formation using double- and triple-mutant cycle analysis revealed conflicting results. In two cases, it was shown that complex salt bridge formation is cooperative, i.e., the net strength of the complex salt bridge...

  18. Uranium nucleophilic carbene complexes

    International Nuclear Information System (INIS)

    Tourneux, Jean-Christophe

    2012-01-01

    The only stable f-metal carbene complexes (excluding NHC) metals f present R 2 C 2- groups having one or two phosphorus atoms in the central carbon in alpha position. The objective of this work was to develop the chemistry of carbenes for uranium (metal 5f) with the di-anion C{Ph 2 P(=S)} 2 2- (SCS 2- ) to extend the organometallic chemistry of this element in its various oxidation states (+3-+6), and to reveal the influence of the 5f orbitals on the nature and reactivity of the double bond C=U. We first isolated the reactants M(SCHS) (M = Li and K) and demonstrated the role of the cation M + on the evolution of the di-anion M 2 SCS (M = Li, K, Tl) which is transformed into LiSCHS in THF or into product of intramolecular cyclization K 2 [C(PhPS) 2 (C 6 H 4 )]. We have developed the necessary conditions mono-, bis- and tris-carbene directly from the di-anion SCS 2- and UCl 4 , as the precursor used in uranium chemistry. The protonolysis reactions of amides compounds (U-NEt 2 ) by the neutral ligand SCH 2 S were also studied. The compounds [Li(THF)] 2 [U(SCS)Cl 3 ] and [U(SCS)Cl 2 (THF) 2 ] were then used to prepare a variety of cyclopentadienyl and mono-cyclo-octa-tetra-enyliques uranium(IV) carbene compounds of the DFT analysis of compounds [M(SCS)Cl 2 (py) 2 ] and [M(Cp) 2 (SCS)] (M = U, Zr) reveals the strong polarization of the M=C double bond, provides information on the nature of the σ and π interactions in this binding, and shows the important role of f orbitals. The influence of ancillary ligands on the M=C bond is revealed by examining the effects of replacing Cl - ligands and pyridine by C 5 H 5 - groups. Mulliken and NBO analyzes show that U=C bond, unlike the Zr=C bond, is not affected by the change in environment of the metal center. While the oxidation tests of carbene complexes of U(IV) were disappointing, the first carbene complex of uranium (VI), [UO 2 (SCS)(THF) 2 ], was isolated with the uranyl ion UO 2 2+ . The reactions of compounds UO 2 X 2

  19. Complex mixtures biostudies

    International Nuclear Information System (INIS)

    Springer, D.L.

    1987-01-01

    The objective of the project is to identify potential adverse biological activities associated with human exposures to complex organic mixtures (COM) from energy-related industries. Studies to identify the influence of chemical class fractions from a COM on the initiating activity of a known carcinogen, benzo(a)pyrene (BaP), demonstrated that the polycyclic aromatic hydrocarbons (PAH) and nitrogen-containing polycyclic aromatic compound (NPAC) fractions were the most effective inhibitors of initiation. In an effort to determine the contribution of BaP to the initiating activity of the COM, binding of radiolabeled BaP to mouse skin DNA was measured. Results indicated that binding of BaP to DNA decreased in the presence of the COM so that at initiating COM doses, BaP binding was near the limit detection. Addition of unlabeled BaP to the COM at an amount similar to that originally present in the COM did not significantly increase the binding. Studies to determine the rates of disappearance of carcinogenic PAH from the site of application on the skin indicated that half-lives for PAH differed by a factor of about 2. Analytical methods developed to identify PAH from COM which covalently bind to DNA demonstrated that the lower level of detection is approximately 200 picograms. Developmental studies demonstrated that both pregnant rats and mice treated dermally with a high-boiling COM developed fetuses with major malformations including cleft palate, small lungs, edema, and sagittal suture hemorrhages. 3 figures, 5 tables

  20. Managing Complex Environmental Risks

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Mikael [Karlstad Univ. (Sweden). Dept. of Environmental Sciences

    2006-09-15

    Environmental and public health risks are often handled in a process in which experts, and sometimes policy makers, try their best to quantitatively assess, evaluate and manage risks. This approach harmonises with mainstream interpretations of sustainable development, which aim at defining a desirable relationship between human and natural systems, for instance by policies that define limit values of different forms of disturbances. However, under conditions of high scientific incertitude, diverging values and distrust, this approach is far from satisfactory. The use of cell phones, hazardous chemicals, nuclear or fossil energy systems, and modern biotechnology are examples of activities causing such risks with high complexity. Against this background, a complementary interpretation of the concept of sustainable development is suggested. This interpretation is operationalised through new formulations of three common principles for public risk management; the precautionary principle, the polluter pays principle and the principle of public participation. Implementation of these reformulated principles would challenge some foundations of present mainstream views on environmental decision-making, but would on the other hand contribute to improved practices for long-term human welfare and planetary survival (full text of contribution)

  1. Managing Complex Environmental Risks

    International Nuclear Information System (INIS)

    Karlsson, Mikael

    2006-01-01

    Environmental and public health risks are often handled in a process in which experts, and sometimes policy makers, try their best to quantitatively assess, evaluate and manage risks. This approach harmonises with mainstream interpretations of sustainable development, which aim at defining a desirable relationship between human and natural systems, for instance by policies that define limit values of different forms of disturbances. However, under conditions of high scientific incertitude, diverging values and distrust, this approach is far from satisfactory. The use of cell phones, hazardous chemicals, nuclear or fossil energy systems, and modern biotechnology are examples of activities causing such risks with high complexity. Against this background, a complementary interpretation of the concept of sustainable development is suggested. This interpretation is operationalised through new formulations of three common principles for public risk management; the precautionary principle, the polluter pays principle and the principle of public participation. Implementation of these reformulated principles would challenge some foundations of present mainstream views on environmental decision-making, but would on the other hand contribute to improved practices for long-term human welfare and planetary survival (full text of contribution)

  2. On Measuring the Complexity of Networks: Kolmogorov Complexity versus Entropy

    Directory of Open Access Journals (Sweden)

    Mikołaj Morzy

    2017-01-01

    Full Text Available One of the most popular methods of estimating the complexity of networks is to measure the entropy of network invariants, such as adjacency matrices or degree sequences. Unfortunately, entropy and all entropy-based information-theoretic measures have several vulnerabilities. These measures neither are independent of a particular representation of the network nor can capture the properties of the generative process, which produces the network. Instead, we advocate the use of the algorithmic entropy as the basis for complexity definition for networks. Algorithmic entropy (also known as Kolmogorov complexity or K-complexity for short evaluates the complexity of the description required for a lossless recreation of the network. This measure is not affected by a particular choice of network features and it does not depend on the method of network representation. We perform experiments on Shannon entropy and K-complexity for gradually evolving networks. The results of these experiments point to K-complexity as the more robust and reliable measure of network complexity. The original contribution of the paper includes the introduction of several new entropy-deceiving networks and the empirical comparison of entropy and K-complexity as fundamental quantities for constructing complexity measures for networks.

  3. Technetium complexation by macrocyclic compounds

    International Nuclear Information System (INIS)

    Li Fan Yu.

    1983-01-01

    Research in nuclear medicine are directed towards the labelling of biological molecules, however, sup(99m)Tc does not show sufficient affinity for these molecules. The aim of this study was to evaluate the ability of macrocyclic compounds to bind strongly technetium in order to be used as complexation intermediate. The reducing agents used were a stannous complex and sodium dithionite. Cryptates and polyesters are not good complexing agents. They form two complexes: a 2:1 sandwich complex or 3:2 and a 1:1 complex. Cyclams are good complexing agents for technetium their complexations strength was determined by competition with pyrophosphate, gluconate and DTPA. Using the method of ligand exchange, the oxidation state of technetium in the Tc-cyclam complex was IV or V. They are 1:1 cationic complexes, the complex charge is +1. The biodistribution in rats of labelling solutions containing (cyclam 14 ane N 4 ) C 12 H 25 shows a good urinary excretion without intoxication risks [fr

  4. Complexity a very short introduction

    CERN Document Server

    Holland, John H

    2014-01-01

    The importance of complexity is well-captured by Hawking's comment: "Complexity is the science of the 21st century". From the movement of flocks of birds to the Internet, environmental sustainability, and market regulation, the study and understanding of complex non-linear systems has become highly influential over the last 30 years. In this Very Short Introduction, one of the leading figures in the field, John Holland, introduces the key elements and conceptual framework of complexity. From complex physical systems such as fluid flow and the difficulties of predicting weather, to complex adaptive systems such as the highly diverse and interdependent ecosystems of rainforests, he combines simple, well-known examples - Adam Smith's pin factory, Darwin's comet orchid, and Simon's 'watchmaker' - with an account of the approaches, involving agents and urn models, taken by complexity theory. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost eve...

  5. Complexity of formation in holography

    International Nuclear Information System (INIS)

    Chapman, Shira; Marrochio, Hugo; Myers, Robert C.

    2017-01-01

    It was recently conjectured that the quantum complexity of a holographic boundary state can be computed by evaluating the gravitational action on a bulk region known as the Wheeler-DeWitt patch. We apply this complexity=action duality to evaluate the ‘complexity of formation’ (DOI: 10.1103/PhysRevLett.116.191301; 10.1103/PhysRevD.93.086006), i.e. the additional complexity arising in preparing the entangled thermofield double state with two copies of the boundary CFT compared to preparing the individual vacuum states of the two copies. We find that for boundary dimensions d>2, the difference in the complexities grows linearly with the thermal entropy at high temperatures. For the special case d=2, the complexity of formation is a fixed constant, independent of the temperature. We compare these results to those found using the complexity=volume duality.

  6. Complexity of formation in holography

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Shira [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada); Marrochio, Hugo [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada); Department of Physics & Astronomy and Guelph-Waterloo Physics Institute,University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Myers, Robert C. [Perimeter Institute for Theoretical Physics,Waterloo, ON N2L 2Y5 (Canada)

    2017-01-16

    It was recently conjectured that the quantum complexity of a holographic boundary state can be computed by evaluating the gravitational action on a bulk region known as the Wheeler-DeWitt patch. We apply this complexity=action duality to evaluate the ‘complexity of formation’ (DOI: 10.1103/PhysRevLett.116.191301; 10.1103/PhysRevD.93.086006), i.e. the additional complexity arising in preparing the entangled thermofield double state with two copies of the boundary CFT compared to preparing the individual vacuum states of the two copies. We find that for boundary dimensions d>2, the difference in the complexities grows linearly with the thermal entropy at high temperatures. For the special case d=2, the complexity of formation is a fixed constant, independent of the temperature. We compare these results to those found using the complexity=volume duality.

  7. Carney complex (CNC

    Directory of Open Access Journals (Sweden)

    Bertherat Jérôme

    2006-06-01

    Full Text Available Abstract The Carney complex (CNC is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD. PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A, has been identified to encode the regulatory subunit (R1A of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65 % of CNC index cases, and may be present in about 80 % of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing

  8. Carney complex (CNC).

    Science.gov (United States)

    Bertherat, Jérôme

    2006-06-06

    The Carney complex (CNC) is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A), has been identified to encode the regulatory subunit (R1A) of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65% of CNC index cases, and may be present in about 80% of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing's syndrome due to PPNAD.

  9. Complexity Management In Projects Between Rational Momentum And Complex Conditions

    DEFF Research Database (Denmark)

    Mac, Anita; Schlamovitz, Jesper

    2015-01-01

    Abstract: This study takes its departure in a model of complexity, developed by Stacey (1993), to test and discuss its practical benefit as perceived by practicing project managers. Based on a survey, the study finds that complexity is a phenomenon recognized by project managers, and complexity...... management is associated with benefits in the development of tasks and managing stakeholders. It is also associated with some difficulty in terms of an increased need for dialogue and a risk of creating goal ambiguity. Based on the findings, we conclude that classical project management approaches can...... benefit from incorporating complexity management....

  10. Complexity management in projects between rational momentum and complex conditions

    DEFF Research Database (Denmark)

    Mac, Anita; Schlamovitz, Jesper

    This study takes its departure in a model of complexity, developed by Stacey (1993), to test and discuss its practical benefit as perceived by practicing project managers. Based on a survey, the study finds that complexity is a phenomenon recognized by project managers, and complexity management...... is associated with benefits in the development of tasks and managing stakeholders. It is also associated with some difficulty in terms of an increased need for dialogue and a risk of creating goal ambiguity. Based on the findings, we conclude that classical project management approaches can benefit from...... incorporating complexity management....

  11. Physical Complexity and Cognitive Evolution

    Science.gov (United States)

    Jedlicka, Peter

    Our intuition tells us that there is a general trend in the evolution of nature, a trend towards greater complexity. However, there are several definitions of complexity and hence it is difficult to argue for or against the validity of this intuition. Christoph Adami has recently introduced a novel measure called physical complexity that assigns low complexity to both ordered and random systems and high complexity to those in between. Physical complexity measures the amount of information that an organism stores in its genome about the environment in which it evolves. The theory of physical complexity predicts that evolution increases the amount of `knowledge' an organism accumulates about its niche. It might be fruitful to generalize Adami's concept of complexity to the entire evolution (including the evolution of man). Physical complexity fits nicely into the philosophical framework of cognitive biology which considers biological evolution as a progressing process of accumulation of knowledge (as a gradual increase of epistemic complexity). According to this paradigm, evolution is a cognitive `ratchet' that pushes the organisms unidirectionally towards higher complexity. Dynamic environment continually creates problems to be solved. To survive in the environment means to solve the problem, and the solution is an embodied knowledge. Cognitive biology (as well as the theory of physical complexity) uses the concepts of information and entropy and views the evolution from both the information-theoretical and thermodynamical perspective. Concerning humans as conscious beings, it seems necessary to postulate an emergence of a new kind of knowledge - a self-aware and self-referential knowledge. Appearence of selfreflection in evolution indicates that the human brain reached a new qualitative level in the epistemic complexity.

  12. Probes of the catalytic site of cysteine dioxygenase.

    Science.gov (United States)

    Chai, Sergio C; Bruyere, John R; Maroney, Michael J

    2006-06-09

    The first major step of cysteine catabolism, the oxidation of cysteine to cysteine sulfinic acid, is catalyzed by cysteine dioxygenase (CDO). In the present work, we utilize recombinant rat liver CDO and cysteine derivatives to elucidate structural parameters involved in substrate recognition and x-ray absorption spectroscopy to probe the interaction of the active site iron center with cysteine. Kinetic studies using cysteine structural analogs show that most are inhibitors and that a terminal functional group bearing a negative charge (e.g. a carboxylate) is required for binding. The substrate-binding site has no stringent restrictions with respect to the size of the amino acid. Lack of the amino or carboxyl groups at the alpha-carbon does not prevent the molecules from interacting with the active site. In fact, cysteamine is shown to be a potent activator of the enzyme without being a substrate. CDO was also rendered inactive upon complexation with the metal-binding inhibitors azide and cyanide. Unlike many non-heme iron dioxygenases that employ alpha-keto acids as cofactors, CDO was shown to be the only dioxygenase known to be inhibited by alpha-ketoglutarate.

  13. DNA Damage: Quantum Mechanics/Molecular Mechanics Study on the Oxygen Binding and Substrate Hydroxylation Step in AlkB Repair Enzymes

    Science.gov (United States)

    Quesne, Matthew G; Latifi, Reza; Gonzalez-Ovalle, Luis E; Kumar, Devesh; de Visser, Sam P

    2014-01-01

    AlkB repair enzymes are important nonheme iron enzymes that catalyse the demethylation of alkylated DNA bases in humans, which is a vital reaction in the body that heals externally damaged DNA bases. Its mechanism is currently controversial and in order to resolve the catalytic mechanism of these enzymes, a quantum mechanics/molecular mechanics (QM/MM) study was performed on the demethylation of the N1-methyladenine fragment by AlkB repair enzymes. Firstly, the initial modelling identified the oxygen binding site of the enzyme. Secondly, the oxygen activation mechanism was investigated and a novel pathway was found, whereby the catalytically active iron(IV)–oxo intermediate in the catalytic cycle undergoes an initial isomerisation assisted by an Arg residue in the substrate binding pocket, which then brings the oxo group in close contact with the methyl group of the alkylated DNA base. This enables a subsequent rate-determining hydrogen-atom abstraction on competitive σ-and π-pathways on a quintet spin-state surface. These findings give evidence of different locations of the oxygen and substrate binding channels in the enzyme and the origin of the separation of the oxygen-bound intermediates in the catalytic cycle from substrate. Our studies are compared with small model complexes and the effect of protein and environment on the kinetics and mechanism is explained. PMID:24339041

  14. Oxygen Atom Transfer Using an Iron(IV)-Oxo Embedded in a Tetracyclic N-Heterocyclic Carbene System: How Does the Reactivity Compare to Cytochrome P450 Compound I?

    Science.gov (United States)

    Cantú Reinhard, Fabián G; de Visser, Sam P

    2017-02-24

    N-Heterocyclic carbenes (NHC) are commonly featured as ligands in transition metal catalysis. Recently, a cyclic system containing four NHC groups with a central iron atom was synthesized and its iron(IV)-oxo species, [Fe IV (O)(cNHC 4 )] 2+ , was characterized. This tetracyclic NHC ligand system may give the iron(IV)-oxo species unique catalytic properties as compared to traditional non-heme and heme iron ligand systems. Therefore, we performed a computational study on the structure and reactivity of the [Fe IV (O)(cNHC 4 )] 2+ complex in substrate hydroxylation and epoxidation reactions. The reactivity patterns are compared with cytochrome P450 Compound I and non-heme iron(IV)-oxo models and it is shown that the [Fe IV (O)(cNHC 4 )] 2+ system is an effective oxidant with oxidative power analogous to P450 Compound I. Unfortunately, in polar solvents, a solvent molecule will bind to the sixth ligand position and decrease the catalytic activity of the oxidant. A molecular orbital and valence bond analysis provides insight into the origin of the reactivity differences and makes predictions of how to further exploit these systems in chemical catalysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Forecasting in Complex Systems

    Science.gov (United States)

    Rundle, J. B.; Holliday, J. R.; Graves, W. R.; Turcotte, D. L.; Donnellan, A.

    2014-12-01

    Complex nonlinear systems are typically characterized by many degrees of freedom, as well as interactions between the elements. Interesting examples can be found in the areas of earthquakes and finance. In these two systems, fat tails play an important role in the statistical dynamics. For earthquake systems, the Gutenberg-Richter magnitude-frequency is applicable, whereas for daily returns for the securities in the financial markets are known to be characterized by leptokurtotic statistics in which the tails are power law. Very large fluctuations are present in both systems. In earthquake systems, one has the example of great earthquakes such as the M9.1, March 11, 2011 Tohoku event. In financial systems, one has the example of the market crash of October 19, 1987. Both were largely unexpected events that severely impacted the earth and financial systems systemically. Other examples include the M9.3 Andaman earthquake of December 26, 2004, and the Great Recession which began with the fall of Lehman Brothers investment bank on September 12, 2013. Forecasting the occurrence of these damaging events has great societal importance. In recent years, national funding agencies in a variety of countries have emphasized the importance of societal relevance in research, and in particular, the goal of improved forecasting technology. Previous work has shown that both earthquakes and financial crashes can be described by a common Landau-Ginzburg-type free energy model. These metastable systems are characterized by fat tail statistics near the classical spinodal. Correlations in these systems can grow and recede, but do not imply causation, a common source of misunderstanding. In both systems, a common set of techniques can be used to compute the probabilities of future earthquakes or crashes. In this talk, we describe the basic phenomenology of these systems and emphasize their similarities and differences. We also consider the problem of forecast validation and verification

  16. Bell Inequalities for Complex Networks

    Science.gov (United States)

    2015-10-26

    AFRL-AFOSR-VA-TR-2015-0355 YIP Bell Inequalities for Complex Networks Greg Ver Steeg UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES Final Report 10/26...performance report PI: Greg Ver Steeg Young Investigator Award Grant Title: Bell Inequalities for Complex Networks Grant #: FA9550-12-1-0417 Reporting...October 20, 2015 Final Report for “Bell Inequalities for Complex Networks” Greg Ver Steeg Abstract This effort studied new methods to understand the effect

  17. Increasing complexity with quantum physics.

    Science.gov (United States)

    Anders, Janet; Wiesner, Karoline

    2011-09-01

    We argue that complex systems science and the rules of quantum physics are intricately related. We discuss a range of quantum phenomena, such as cryptography, computation and quantum phases, and the rules responsible for their complexity. We identify correlations as a central concept connecting quantum information and complex systems science. We present two examples for the power of correlations: using quantum resources to simulate the correlations of a stochastic process and to implement a classically impossible computational task.

  18. Epidemic processes in complex networks

    OpenAIRE

    Pastor Satorras, Romualdo; Castellano, Claudio; Van Mieghem, Piet; Vespignani, Alessandro

    2015-01-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The t...

  19. Rhodium complexes as therapeutic agents.

    Science.gov (United States)

    Ma, Dik-Lung; Wang, Modi; Mao, Zhifeng; Yang, Chao; Ng, Chan-Tat; Leung, Chung-Hang

    2016-02-21

    The landscape of inorganic medicinal chemistry has been dominated by the investigation of platinum, and to a lesser extent ruthenium, complexes over the past few decades. Recently, complexes based on other metal centers such as rhodium have attracted attention due to their tunable chemical and biological properties as well as distinct mechanisms of action. This perspective highlights recent examples of rhodium complexes that show diverse biological activities against various targets, including enzymes and protein-protein interactions.

  20. Complexity leadership: a healthcare imperative.

    Science.gov (United States)

    Weberg, Dan

    2012-01-01

    The healthcare system is plagued with increasing cost and poor quality outcomes. A major contributing factor for these issues is that outdated leadership practices, such as leader-centricity, linear thinking, and poor readiness for innovation, are being used in healthcare organizations. Complexity leadership theory provides a new framework with which healthcare leaders may practice leadership. Complexity leadership theory conceptualizes leadership as a continual process that stems from collaboration, complex systems thinking, and innovation mindsets. Compared to transactional and transformational leadership concepts, complexity leadership practices hold promise to improve cost and quality in health care. © 2012 Wiley Periodicals, Inc.

  1. Complexity Intelligence and Cultural Coaching:

    Directory of Open Access Journals (Sweden)

    Jan Inglis

    2005-06-01

    Full Text Available In this article, we present the term complexity intelligence as a useful moniker to describe the reasoning ability, emotional capacity and social cognition necessary to meet the challenges of our prevailing life conditions. We suggest that, as a society and as individuals, we develop complexity intelligence as we navigate the gap between our current capacities and the capacities needed to respond to the next stage of complex challenges in our lives. We further suggest that it is possible to stimulate and support the emergence of complexity intelligence in a society, but we need a new form of social change agent - a cultural coach, to midwife its emergence.

  2. Measuring Complexity of SAP Systems

    Directory of Open Access Journals (Sweden)

    Ilja Holub

    2016-10-01

    Full Text Available The paper discusses the reasons of complexity rise in ERP system SAP R/3. It proposes a method for measuring complexity of SAP. Based on this method, the computer program in ABAP for measuring complexity of particular SAP implementation is proposed as a tool for keeping ERP complexity under control. The main principle of the measurement method is counting the number of items or relations in the system. The proposed computer program is based on counting of records in organization tables in SAP.

  3. Technetium-aspirin molecule complexes

    International Nuclear Information System (INIS)

    El-Shahawy, A.S.; Mahfouz, R.M.; Aly, A.A.M.; El-Zohry, M.

    1993-01-01

    Technetium-aspirin and technetium-aspirin-like molecule complexes were prepared. The structure of N-acetylanthranilic acid (NAA) has been decided through CNDO calculations. The ionization potential and electron affinity of the NAA molecule as well as the charge densities were calculated. The electronic absorption spectra of Tc(V)-Asp and Tc(V)-ATS complexes have two characteristic absorption bands at 450 and 600 nm, but the Tc(V)-NAA spectrum has one characteristic band at 450 nm. As a comparative study, Mo-ATS complex was prepared and its electronic absorption spectrum is comparable with the Tc-ATS complex spectrum. (author)

  4. Cyclomatic Complexity: theme and variations

    Directory of Open Access Journals (Sweden)

    Brian Henderson-Sellers

    1993-11-01

    Full Text Available Focussing on the "McCabe family" of measures for the decision/logic structure of a program, leads to an evaluation of extensions to modularization, nesting and, potentially, to object-oriented program structures. A comparison of rated, operating and essential complexities of programs suggests two new metrics: "inessential complexity" as a measure of unstructuredness and "product complexity" as a potential objective measure of structural complexity. Finally, nesting and abstraction levels are considered, especially as to how metrics from the "McCabe family" might be applied in an object-oriented systems development environment.

  5. Complexity-management in SME : organization of complex relationships

    NARCIS (Netherlands)

    Gregus, M.; Mandorf, S.

    2009-01-01

    The complexity of companies' environment IS growmg. Complexity management and restructuring of small and medium-sized enterprises (SME) become big challenges of business studies in the next future. A chance could be seen in the use of e-business strategies and the implementation of information

  6. Complex Constructivism: A Theoretical Model of Complexity and Cognition

    Science.gov (United States)

    Doolittle, Peter E.

    2014-01-01

    Education has long been driven by its metaphors for teaching and learning. These metaphors have influenced both educational research and educational practice. Complexity and constructivism are two theories that provide functional and robust metaphors. Complexity provides a metaphor for the structure of myriad phenomena, while constructivism…

  7. Complexity in phonology: The complex consonants of simple CV ...

    African Journals Online (AJOL)

    The main objective of this article is to investigate the interplay of simplicity and complexity in the phonological structure of Zezuru. The article argues that Zezuru affricates, prenasalised consonants (NCs) and velarised consonants (Cws) are subsegmentally complex segments which function as simple onsets. Treating them ...

  8. Workshop on Recommendation in Complex Scenarios (ComplexRec 2017)

    DEFF Research Database (Denmark)

    Bogers, Toine; Koolen, Marijn; Mobasher, Bamshad

    2017-01-01

    Recommendation algorithms for ratings prediction and item ranking have steadily matured during the past decade. However, these state-of-the-art algorithms are typically applied in relatively straightforward scenarios. In reality, recommendation is often a more complex problem: it is usually just...... a single step in the user's more complex background need. These background needs can often place a variety of constraints on which recommendations are interesting to the user and when they are appropriate. However, relatively little research has been done on these complex recommendation scenarios....... The ComplexRec 2017 workshop addressed this by providing an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all-solution....

  9. ComplexViewer: visualization of curated macromolecular complexes.

    Science.gov (United States)

    Combe, Colin W; Sivade, Marine Dumousseau; Hermjakob, Henning; Heimbach, Joshua; Meldal, Birgit H M; Micklem, Gos; Orchard, Sandra; Rappsilber, Juri

    2017-11-15

    Proteins frequently function as parts of complexes, assemblages of multiple proteins and other biomolecules, yet network visualizations usually only show proteins as parts of binary interactions. ComplexViewer visualizes interactions with more than two participants and thereby avoids the need to first expand these into multiple binary interactions. Furthermore, if binding regions between molecules are known then these can be displayed in the context of the larger complex. freely available under Apache version 2 license; EMBL-EBI Complex Portal: http://www.ebi.ac.uk/complexportal; Source code: https://github.com/MICommunity/ComplexViewer; Package: https://www.npmjs.com/package/complexviewer; http://biojs.io/d/complexviewer. Language: JavaScript; Web technology: Scalable Vector Graphics; Libraries: D3.js. colin.combe@ed.ac.uk or juri.rappsilber@ed.ac.uk. © The Author 2017. Published by Oxford University Press.

  10. Dynamic complexity: plant receptor complexes at the plasma membrane.

    Science.gov (United States)

    Burkart, Rebecca C; Stahl, Yvonne

    2017-12-01

    Plant receptor complexes at the cell surface perceive many different external and internal signalling molecules and relay these signals into the cell to regulate development, growth and immunity. Recent progress in the analyses of receptor complexes using different live cell imaging approaches have shown that receptor complex formation and composition are dynamic and take place at specific microdomains at the plasma membrane. In this review we focus on three prominent examples of Arabidopsis thaliana receptor complexes and how their dynamic spatio-temporal distribution at the PM has been studied recently. We will elaborate on the newly emerging concept of plasma membrane microdomains as potential hubs for specific receptor complex assembly and signalling outputs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Intermittency in Complex Flows

    Science.gov (United States)

    Ben Mahjoub, Otman; Redondo, Jose M.

    2017-04-01

    Experimental results of the complex turbulent wake of a cilinder in 2D [1] and 3D flows [2] were used to investigate the scaling of structure functions, similar research was also performed on wave propagation and breaking in the Ocean [3], in the the stratified Atmosphere (ABL) [4] and in a 100large flume (UPC) for both regular and irregular waves, where long time series of waves propagating and generating breaking turbulence velocity rms and higher order measurements were taken in depth. [3,5] by means of a velocimeter SONTEK3-D. The probability distribution functions of the velocity differences and their non Gaussian distribution related to the energy spectrum indicate that irregularity is an important source of turbulence. From Kolmogorov's K41 and K61 intermittency correction: the p th-order longitudinal velocity structure function δul at scale l in the inertial range of three-dimensional fully developed turbulence is related by ⟨δup⟩ = ⟨(u(x+ l)- u(x))p⟩ ˜ ɛp0/3lp/3 l where ⟨...⟩ represents the spatial average over flow domain, with ɛ0 the mean energy dissipation per unit mass and l is the separation distance. The importance of the random nature of the energy dissipation led to the K62 theory of intermittency, but locality and non-homogeneity are key issues. p p/3 p/3 ξd ⟨δul⟩ ˜ ⟨ɛl ⟩l ˜ l and ξp = p 3 + τp/3 , where now ɛl is a fractal energy dissipation at scale l, τp/3 is the scaling of and ξp is the scaling exponent of the velocity structure function of order p. Both in K41 and K62, the structure functions of third order related to skewness is ξ3 = 1. But this is not true either. We show that scaling exponents ξp do deviate from early studies that only investigated homogeneous turbulence, where a large inertial range dominates. The use of multi-fractal analysis and improvements on Structure function calculations on standard Enhanced mixing is an essential property of turbulence and efforts to alter and to control

  12. Complex Variables throughout the Curriculum

    Science.gov (United States)

    D'Angelo, John P.

    2017-01-01

    We offer many specific detailed examples, several of which are new, that instructors can use (in lecture or as student projects) to revitalize the role of complex variables throughout the curriculum. We conclude with three primary recommendations: revise the syllabus of Calculus II to allow early introductions of complex numbers and linear…

  13. Information geometric methods for complexity

    Science.gov (United States)

    Felice, Domenico; Cafaro, Carlo; Mancini, Stefano

    2018-03-01

    Research on the use of information geometry (IG) in modern physics has witnessed significant advances recently. In this review article, we report on the utilization of IG methods to define measures of complexity in both classical and, whenever available, quantum physical settings. A paradigmatic example of a dramatic change in complexity is given by phase transitions (PTs). Hence, we review both global and local aspects of PTs described in terms of the scalar curvature of the parameter manifold and the components of the metric tensor, respectively. We also report on the behavior of geodesic paths on the parameter manifold used to gain insight into the dynamics of PTs. Going further, we survey measures of complexity arising in the geometric framework. In particular, we quantify complexity of networks in terms of the Riemannian volume of the parameter space of a statistical manifold associated with a given network. We are also concerned with complexity measures that account for the interactions of a given number of parts of a system that cannot be described in terms of a smaller number of parts of the system. Finally, we investigate complexity measures of entropic motion on curved statistical manifolds that arise from a probabilistic description of physical systems in the presence of limited information. The Kullback-Leibler divergence, the distance to an exponential family and volumes of curved parameter manifolds, are examples of essential IG notions exploited in our discussion of complexity. We conclude by discussing strengths, limits, and possible future applications of IG methods to the physics of complexity.

  14. Holistic education and complexity thinking

    NARCIS (Netherlands)

    Jörg, T.

    2007-01-01

    Paper proposal for the SIG Holistic Education at AERA 2007 Title: Holistic Education and Complexity Thinking Ton Jörg IVLOS Institute of Education University of Utrecht The Netherlands A.G.D.Jorg@ivlos.uu.nl ABSTRACT In this paper I link complexity thinking with Holistic Education (HE). It is a

  15. Communication Analysis of Information Complexes.

    Science.gov (United States)

    Malik, M. F.

    Communication analysis is a tool for perceptual assessment of existing or projected information complexes, i.e., an established reality perceived by one or many humans. An information complex could be of a physical nature, such as a building, landscape, city street; or of a pure informational nature, such as a film, television program,…

  16. Team dynamics in complex projects

    NARCIS (Netherlands)

    Oeij, P.; Vroome, E.E.M. de; Dhondt, S.; Gaspersz, J.B.R.

    2012-01-01

    Complexity of projects is hotly debated and a factor which affects innovativeness of team performance. Much attention in the past is paid to technical complexity and many issues are related to natural and physical sciences. A growing awareness of the importance of socioorganisational issues is

  17. Producers' Complex Risk Management Choices

    NARCIS (Netherlands)

    Pennings, J.M.E.; Isengildina, O.; Irwin, S.H.; Garcia, P.; Good, D.L.

    2008-01-01

    Producers have a wide variety of risk management instruments available, making their choice(s) complex. The way producers deal with this complexity can vary and may influence the impact that the determinants, such as risk aversion, have on their choices. A recently developed choice bracketing

  18. Complexity control in statistical learning

    Indian Academy of Sciences (India)

    complexity of the class of models from which we are to choose our model. In this ... As is explained in §2, we use the concept of covering numbers to quantify the complexity of a class of ..... called structural risk minimization (SRM). Vapnik ...

  19. Analyzing the complexity of nanotechnology

    NARCIS (Netherlands)

    Vries, de M.J.; Schummer, J.; Baird, D.

    2006-01-01

    Nanotechnology is a highly complex technological development due to many uncertainties in our knowledge about it. The Dutch philosopher Herman Dooyeweerd has developed a conceptual framework that can be used (1) to analyze the complexity of technological developments and (2) to see how priorities

  20. Rhythmic complexity and predictive coding

    DEFF Research Database (Denmark)

    Vuust, Peter; Witek, Maria A G

    2014-01-01

    Musical rhythm, consisting of apparently abstract intervals of accented temporal events,has a remarkable capacity to move our minds and bodies. How does the cognitive systemenable our experiences of rhythmically complex music? In this paper, we describe somecommon forms of rhythmic complexity...

  1. Holographic complexity and spacetime singularities

    Energy Technology Data Exchange (ETDEWEB)

    Barbón, José L.F. [Instituto de Física Teórica IFT UAM/CSIC,C/ Nicolás Cabrera 13, Campus Universidad Autónoma de Madrid,Madrid 28049 (Spain); Rabinovici, Eliezer [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)

    2016-01-15

    We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.

  2. Innovation in a complex environment

    Directory of Open Access Journals (Sweden)

    René Pellissier

    2012-11-01

    Objectives: The study objectives were, firstly, to establish the determinants for complexity and how these can be addressed from a design point of view in order to ensure innovation success and, secondly, to determine how this changes innovation forms and applications. Method: Two approaches were offered to deal with a complex environment – one allowing for complexity for organisational innovation and the other introducing reductionism to minimise complexity. These approaches were examined in a qualitative study involving case studies, open-ended interviews and content analysis between seven developing economy (South African organisations and seven developed economy (US organisations. Results: This study presented a proposed framework for (organisational innovation in a complex environment versus a framework that minimises complexity. The comparative organisational analysis demonstrated the importance of initiating organisational innovation to address internal and external complexity, with the focus being on the leadership actions, their selected operating models and resultant organisational innovations designs, rather than on technological innovations. Conclusion: This study cautioned the preference for technological innovation within organisations and suggested alternative innovation forms (such as organisational and management innovation be used to remain competitive in a complex environment.

  3. Complexes and aggregates of chlorophylls

    NARCIS (Netherlands)

    Kooyman, R.P.H.

    1980-01-01

    Chlorophyll (Chl) molecules can form complexes in two important ways: by ligation at the magnesium atom and/or by hydrogen bonding at the keto- carbonyl group. Under certain conditions these processes may give rise to dimer formation. This thesis describes some properties of complexes and dimers of

  4. Thermogravimetric investigations of vanadium complexes

    International Nuclear Information System (INIS)

    Bechmann, W.; Uhlemann, E.; Ludwig, W.

    1987-01-01

    Extensive studies on oxovanadium(IV) and (V) complexes with bidentate chelating ligands include thermogravimetric investigations. TG, DTG, and DTA data provide additional facts to redox behaviour and stability of the complexes. These data also allow a critical appreciation of the given melting temperatures. (author)

  5. The Algebra of Complex Numbers.

    Science.gov (United States)

    LePage, Wilbur R.

    This programed text is an introduction to the algebra of complex numbers for engineering students, particularly because of its relevance to important problems of applications in electrical engineering. It is designed for a person who is well experienced with the algebra of real numbers and calculus, but who has no experience with complex number…

  6. Holographic complexity and spacetime singularities

    International Nuclear Information System (INIS)

    Barbón, José L.F.; Rabinovici, Eliezer

    2016-01-01

    We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.

  7. How to lead complex situations

    DEFF Research Database (Denmark)

    Hansen, Michael Pingel

    2013-01-01

    The military leader is experiencing increasingly more complex situations, whether it is as leader in a foreign combat environment or in the home-based public administration. Complex situations like these call for a special set of managerial responses and a special way of leading organisations...

  8. Servitization, Services and Managing Complexity

    DEFF Research Database (Denmark)

    Harjo, Ieva; Frandsen, Thomas; Hsuan, Juliana

    This paper explores how seemingly complex servitized solutions can become tradable in a customer–supplier relationship by objectification and abbreviation. The key argument is that the complexity of product-service solutions can be reduced by abbreviation of the reality in written form of contracts...

  9. The complex portal--an encyclopaedia of macromolecular complexes.

    Science.gov (United States)

    Meldal, Birgit H M; Forner-Martinez, Oscar; Costanzo, Maria C; Dana, Jose; Demeter, Janos; Dumousseau, Marine; Dwight, Selina S; Gaulton, Anna; Licata, Luana; Melidoni, Anna N; Ricard-Blum, Sylvie; Roechert, Bernd; Skyzypek, Marek S; Tiwari, Manu; Velankar, Sameer; Wong, Edith D; Hermjakob, Henning; Orchard, Sandra

    2015-01-01

    The IntAct molecular interaction database has created a new, free, open-source, manually curated resource, the Complex Portal (www.ebi.ac.uk/intact/complex), through which protein complexes from major model organisms are being collated and made available for search, viewing and download. It has been built in close collaboration with other bioinformatics services and populated with data from ChEMBL, MatrixDB, PDBe, Reactome and UniProtKB. Each entry contains information about the participating molecules (including small molecules and nucleic acids), their stoichiometry, topology and structural assembly. Complexes are annotated with details about their function, properties and complex-specific Gene Ontology (GO) terms. Consistent nomenclature is used throughout the resource with systematic names, recommended names and a list of synonyms all provided. The use of the Evidence Code Ontology allows us to indicate for which entries direct experimental evidence is available or if the complex has been inferred based on homology or orthology. The data are searchable using standard identifiers, such as UniProt, ChEBI and GO IDs, protein, gene and complex names or synonyms. This reference resource will be maintained and grow to encompass an increasing number of organisms. Input from groups and individuals with specific areas of expertise is welcome. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Epidemic modeling in complex realities.

    Science.gov (United States)

    Colizza, Vittoria; Barthélemy, Marc; Barrat, Alain; Vespignani, Alessandro

    2007-04-01

    In our global world, the increasing complexity of social relations and transport infrastructures are key factors in the spread of epidemics. In recent years, the increasing availability of computer power has enabled both to obtain reliable data allowing one to quantify the complexity of the networks on which epidemics may propagate and to envision computational tools able to tackle the analysis of such propagation phenomena. These advances have put in evidence the limits of homogeneous assumptions and simple spatial diffusion approaches, and stimulated the inclusion of complex features and heterogeneities relevant in the description of epidemic diffusion. In this paper, we review recent progresses that integrate complex systems and networks analysis with epidemic modelling and focus on the impact of the various complex features of real systems on the dynamics of epidemic spreading.

  11. COMPLEX TRAINING: A BRIEF REVIEW

    Directory of Open Access Journals (Sweden)

    William P. Ebben

    2002-06-01

    Full Text Available The effectiveness of plyometric training is well supported by research. Complex training has gained popularity as a training strategy combining weight training and plyometric training. Anecdotal reports recommend training in this fashion in order to improve muscular power and athletic performance. Recently, several studies have examined complex training. Despite the fact that questions remain about the potential effectiveness and implementation of this type of training, results of recent studies are useful in guiding practitioners in the development and implementation of complex training programs. In some cases, research suggests that complex training has an acute ergogenic effect on upper body power and the results of acute and chronic complex training include improved jumping performance. Improved performance may require three to four minutes rest between the weight training and plyometrics sets and the use of heavy weight training loads

  12. European Conference on Complex Systems

    CERN Document Server

    Pellegrini, Francesco; Caldarelli, Guido; Merelli, Emanuela

    2016-01-01

    This work contains a stringent selection of extended contributions presented at the meeting of 2014 and its satellite meetings, reflecting scope, diversity and richness of research areas in the field, both fundamental and applied. The ECCS meeting, held under the patronage of the Complex Systems Society, is an annual event that has become the leading European conference devoted to complexity science. It offers cutting edge research and unique opportunities to study novel scientific approaches in a multitude of application areas. ECCS'14, its eleventh occurrence, took place in Lucca, Italy. It gathered some 650 scholars representing a wide range of topics relating to complex systems research, with emphasis on interdisciplinary approaches. The editors are among the best specialists in the area. The book is of great interest to scientists, researchers and graduate students in complexity, complex systems and networks.

  13. Managing complexity insights, concepts, applications

    CERN Document Server

    Helbing, Dirk

    2007-01-01

    Each chapter in Managing Complexity focuses on analyzing real-world complex systems and transferring knowledge from the complex-systems sciences to applications in business, industry and society. The interdisciplinary contributions range from markets and production through logistics, traffic control, and critical infrastructures, up to network design, information systems, social conflicts and building consensus. They serve to raise readers' awareness concerning the often counter-intuitive behavior of complex systems and to help them integrate insights gained in complexity research into everyday planning, decision making, strategic optimization, and policy. Intended for a broad readership, the contributions have been kept largely non-technical and address a general, scientifically literate audience involved in corporate, academic, and public institutions.

  14. The Seis Lagos Carbonatite Complex

    International Nuclear Information System (INIS)

    Issler, R.S.; Silva, G.G. da.

    1980-01-01

    The Seis Lagos Carbonatite Complex located about 840 Km from Manaus, on the northwestern part of the Estado do Amazonas, Brazil is described. Geological reconnaissance mapping by Radam Project/DNPM, of the southwestern portion of the Guianes Craton, determined three circular features arranged in a north-south trend and outcroping as thick lateritic radioactive hills surrounded by gneisses and mignatites of the peneplained Guianense Complex. Results of core drilling samples analysis of the Seis Lagos Carbonatite Complex are compared with some igneous rocks and limestones of the world on the basis of abundance of their minor and trace elements. Log-log variation diagram of strontium and barium in carbonatite and limestone, exemplifield by South Africa and Angola carbonatites, are compared with the Seis Lagos Carbonatite Complex. The Seis Lagos Carbonatite Complex belongs to the siderite-soevite type. (E.G.) [pt

  15. Complexity Metrics for Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.

    2009-01-01

    analysts have difficulties grasping the dynamics implied by a process model. Recent empirical studies show that people make numerous errors when modeling complex business processes, e.g., about 20 percent of the EPCs in the SAP reference model have design flaws resulting in potential deadlocks, livelocks......, etc. It seems obvious that the complexity of the model contributes to design errors and a lack of understanding. It is not easy to measure complexity, however. This paper presents three complexity metrics that have been implemented in the process analysis tool ProM. The metrics are defined...... for a subclass of Petri nets named Workflow nets, but the results can easily be applied to other languages. To demonstrate the applicability of these metrics, we have applied our approach and tool to 262 relatively complex Protos models made in the context of various student projects. This allows us to validate...

  16. Innovation in a complex environment

    Directory of Open Access Journals (Sweden)

    René Pellissier

    2012-02-01

    Full Text Available Background: As our world becomes more global and competitive yet less predictable, the focus seems to be increasingly on looking to innovation activities to remain competitive. Although there is little doubt that a nation’s competitiveness is embedded in its innovativeness, the complex environment should not be ignored. Complexity is not accounted for in balance sheets or reported in reports; it becomes entrenched in every activity in the organisation. Innovation takes many forms and comes in different shapes.Objectives: The study objectives were, firstly, to establish the determinants for complexity and how these can be addressed from a design point of view in order to ensure innovation success and, secondly, to determine how this changes innovation forms and applications.Method: Two approaches were offered to deal with a complex environment – one allowing for complexity for organisational innovation and the other introducing reductionism to minimise complexity. These approaches were examined in a qualitative study involving case studies, open-ended interviews and content analysis between seven developing economy (South African organisations and seven developed economy (US organisations.Results: This study presented a proposed framework for (organisational innovation in a complex environment versus a framework that minimises complexity. The comparative organisational analysis demonstrated the importance of initiating organisational innovation to address internal and external complexity, with the focus being on the leadership actions, their selected operating models and resultant organisational innovations designs, rather than on technological innovations.Conclusion: This study cautioned the preference for technological innovation within organisations and suggested alternative innovation forms (such as organisational and management innovation be used to remain competitive in a complex environment. 

  17. Mapping on complex neutrosophic soft expert sets

    Science.gov (United States)

    Al-Quran, Ashraf; Hassan, Nasruddin

    2018-04-01

    We introduce the mapping on complex neutrosophic soft expert sets. Further, we investigated the basic operations and other related properties of complex neutrosophic soft expert image and complex neutrosophic soft expert inverse image of complex neutrosophic soft expert sets.

  18. Quantify the complexity of turbulence

    Science.gov (United States)

    Tao, Xingtian; Wu, Huixuan

    2017-11-01

    Many researchers have used Reynolds stress, power spectrum and Shannon entropy to characterize a turbulent flow, but few of them have measured the complexity of turbulence. Yet as this study shows, conventional turbulence statistics and Shannon entropy have limits when quantifying the flow complexity. Thus, it is necessary to introduce new complexity measures- such as topology complexity and excess information-to describe turbulence. Our test flow is a classic turbulent cylinder wake at Reynolds number 8100. Along the stream-wise direction, the flow becomes more isotropic and the magnitudes of normal Reynolds stresses decrease monotonically. These seem to indicate the flow dynamics becomes simpler downstream. However, the Shannon entropy keeps increasing along the flow direction and the dynamics seems to be more complex, because the large-scale vortices cascade to small eddies, the flow is less correlated and more unpredictable. In fact, these two contradictory observations partially describe the complexity of a turbulent wake. Our measurements (up to 40 diameters downstream the cylinder) show that the flow's degree-of-complexity actually increases firstly and then becomes a constant (or drops slightly) along the stream-wise direction. University of Kansas General Research Fund.

  19. Solution chemistry of lanthanide complexes

    International Nuclear Information System (INIS)

    Brittain, H.G.

    1979-01-01

    Intermolecular energy transfer from Tb 3+ to Eu 3+ , luminescence intensity measurements, potentiometric titrations, differential absorption spectroscopy, and spectroscopic titrations were all used to study the binding of lanthanide ions by serine and threonine. At low pH (3.0 to 6.0) the complexes are mononuclear and ligand is only weakly bound. In the pH interval of 6.0 to 8.5 stronger interaction takes place between the ligand and the metal (with possible coordination of the undissociated hydroxyl group), and self-association of complexes becomes important. Above pH 8.5, base hydrolysis of the complexes leads to highly associated species in solution and shortly above this pH an insoluble precipitate is formed. It was found that energy could be transferred from Tb 3+ to Eu 3+ more efficiently among complexes prepared from racemic ligands than in complexes made from resolved ligand, but this stereoselectivity was only observed at pH values greater than 6.5 and in solutions having a 1:10 ratio of metal-to-ligand. No stereoselectivity was found in solutions having 1:5 ratios, and this observation was explained by the existence of 1:2 metal-ligand complexes existing in solutions having the higher ratio of metal-to-ligand (only 1:1 complexes are then found at lower ratios of metal-to-ligand). (author)

  20. 3D complex: a structural classification of protein complexes.

    Directory of Open Access Journals (Sweden)

    Emmanuel D Levy

    2006-11-01

    Full Text Available Most of the proteins in a cell assemble into complexes to carry out their function. It is therefore crucial to understand the physicochemical properties as well as the evolution of interactions between proteins. The Protein Data Bank represents an important source of information for such studies, because more than half of the structures are homo- or heteromeric protein complexes. Here we propose the first hierarchical classification of whole protein complexes of known 3-D structure, based on representing their fundamental structural features as a graph. This classification provides the first overview of all the complexes in the Protein Data Bank and allows nonredundant sets to be derived at different levels of detail. This reveals that between one-half and two-thirds of known structures are multimeric, depending on the level of redundancy accepted. We also analyse the structures in terms of the topological arrangement of their subunits and find that they form a small number of arrangements compared with all theoretically possible ones. This is because most complexes contain four subunits or less, and the large majority are homomeric. In addition, there is a strong tendency for symmetry in complexes, even for heteromeric complexes. Finally, through comparison of Biological Units in the Protein Data Bank with the Protein Quaternary Structure database, we identified many possible errors in quaternary structure assignments. Our classification, available as a database and Web server at http://www.3Dcomplex.org, will be a starting point for future work aimed at understanding the structure and evolution of protein complexes.

  1. Actinide cation-cation complexes

    International Nuclear Information System (INIS)

    Stoyer, N.J.; Seaborg, G.T.

    1994-12-01

    The +5 oxidation state of U, Np, Pu, and Am is a linear dioxo cation (AnO 2 + ) with a formal charge of +1. These cations form complexes with a variety of other cations, including actinide cations. Other oxidation states of actinides do not form these cation-cation complexes with any cation other than AnO 2 + ; therefore, cation-cation complexes indicate something unique about AnO 2 + cations compared to actinide cations in general. The first cation-cation complex, NpO 2 + ·UO 2 2+ , was reported by Sullivan, Hindman, and Zielen in 1961. Of the four actinides that form AnO 2 + species, the cation-cation complexes of NpO 2 + have been studied most extensively while the other actinides have not. The only PuO 2 + cation-cation complexes that have been studied are with Fe 3+ and Cr 3+ and neither one has had its equilibrium constant measured. Actinides have small molar absorptivities and cation-cation complexes have small equilibrium constants; therefore, to overcome these obstacles a sensitive technique is required. Spectroscopic techniques are used most often to study cation-cation complexes. Laser-Induced Photacoustic Spectroscopy equilibrium constants for the complexes NpO 2 + ·UO 2 2+ , NpO 2 + ·Th 4+ , PuO 2 + ·UO 2 2+ , and PuO 2 + ·Th 4+ at an ionic strength of 6 M using LIPAS are 2.4 ± 0.2, 1.8 ± 0.9, 2.2 ± 1.5, and ∼0.8 M -1

  2. Neurosurgical implications of Carney complex.

    Science.gov (United States)

    Watson, J C; Stratakis, C A; Bryant-Greenwood, P K; Koch, C A; Kirschner, L S; Nguyen, T; Carney, J A; Oldfield, E H

    2000-03-01

    The authors present their neurosurgical experience with Carney complex. Carney complex, characterized by spotty skin pigmentation, cardiac myxomas, primary pigmented nodular adrenocortical disease, pituitary tumors, and nerve sheath tumors (NSTs), is a recently described, rare, autosomal-dominant familial syndrome that is relatively unknown to neurosurgeons. Neurosurgery is required to treat pituitary adenomas and a rare NST, the psammomatous melanotic schwannoma (PMS), in patients with Carney complex. Cushing's syndrome, a common component of the complex, is caused by primary pigmented nodular adrenocortical disease and is not secondary to an adrenocorticotropic hormone-secreting pituitary adenoma. The authors reviewed 14 cases of Carney complex, five from the literature and nine from their own experience. Of the 14 pituitary adenomas recognized in association with Carney complex, 12 developed growth hormone (GH) hypersecretion (producing gigantism in two patients and acromegaly in 10), and results of immunohistochemical studies in one of the other two were positive for GH. The association of PMSs with Carney complex was established in 1990. Of the reported tumors, 28% were associated with spinal nerve sheaths. The spinal tumors occurred in adults (mean age 32 years, range 18-49 years) who presented with pain and radiculopathy. These NSTs may be malignant (10%) and, as with the cardiac myxomas, are associated with significant rates of morbidity and mortality. Because of the surgical comorbidity associated with cardiac myxoma and/or Cushing's syndrome, recognition of Carney complex has important implications for perisurgical patient management and family screening. Study of the genetics of Carney complex and of the biological abnormalities associated with the tumors may provide insight into the general pathobiological abnormalities associated with the tumors may provide insight into the general pathobiological features of pituitary adenomas and NSTs.

  3. Persistent homology of complex networks

    International Nuclear Information System (INIS)

    Horak, Danijela; Maletić, Slobodan; Rajković, Milan

    2009-01-01

    Long-lived topological features are distinguished from short-lived ones (considered as topological noise) in simplicial complexes constructed from complex networks. A new topological invariant, persistent homology, is determined and presented as a parameterized version of a Betti number. Complex networks with distinct degree distributions exhibit distinct persistent topological features. Persistent topological attributes, shown to be related to the robust quality of networks, also reflect the deficiency in certain connectivity properties of networks. Random networks, networks with exponential connectivity distribution and scale-free networks were considered for homological persistency analysis

  4. Implicit computational complexity and compilers

    DEFF Research Database (Denmark)

    Rubiano, Thomas

    Complexity theory helps us predict and control resources, usually time and space, consumed by programs. Static analysis on specific syntactic criterion allows us to categorize some programs. A common approach is to observe the program’s data’s behavior. For instance, the detection of non...... evolution and a lot of research came from this theory. Until now, these implicit complexity theories were essentially applied on more or less toy languages. This thesis applies implicit computational complexity methods into “real life” programs by manipulating intermediate representation languages...

  5. Interdisciplinary conflict and organizational complexity.

    Science.gov (United States)

    Guy, M E

    1986-01-01

    Most people think that conflict among the professional staff is inevitable and results from each profession's unique set of values. Each profession then defends itself by claiming its own turf. This article demonstrates that organizational complexity, not professional territorialism, influences the amount of intraorganizational conflict. In a comparison of two psychiatric hospitals, this study shows that there is not necessarily greater conflict across professions than within professions. However, there is a significantly greater amount of conflict among staff at a structurally more complex hospital than at a less-complex hospital, regardless of profession. Implications for management are discussed.

  6. Management of complex dynamical systems

    Science.gov (United States)

    MacKay, R. S.

    2018-02-01

    Complex dynamical systems are systems with many interdependent components which evolve in time. One might wish to control their trajectories, but a more practical alternative is to control just their statistical behaviour. In many contexts this would be both sufficient and a more realistic goal, e.g. climate and socio-economic systems. I refer to it as ‘management’ of complex dynamical systems. In this paper, some mathematics for management of complex dynamical systems is developed in the weakly dependent regime, and questions are posed for the strongly dependent regime.

  7. Advances in computational complexity theory

    CERN Document Server

    Cai, Jin-Yi

    1993-01-01

    This collection of recent papers on computational complexity theory grew out of activities during a special year at DIMACS. With contributions by some of the leading experts in the field, this book is of lasting value in this fast-moving field, providing expositions not found elsewhere. Although aimed primarily at researchers in complexity theory and graduate students in mathematics or computer science, the book is accessible to anyone with an undergraduate education in mathematics or computer science. By touching on some of the major topics in complexity theory, this book sheds light on this burgeoning area of research.

  8. Complexity in physics and technology

    CERN Document Server

    Garrido, Manuel S

    1992-01-01

    A system is loosely defined as complex if it is composed of a large number of elements, interacting with each other, and the emergent global dynamics is qualitatively different from the dynamics of each one of the parts. The global dynamics may be either ordered or chaotic and among the most interesting emergent global properties are those of learning and adaptation.Complex systems, in the above sense, appear in many fields ranging from physics and technology to life and social sciences. Research in complex systems involves therefore a wide range of topics, studied in seemingly disparate field

  9. Scattering methods in complex fluids

    CERN Document Server

    Chen, Sow-Hsin

    2015-01-01

    Summarising recent research on the physics of complex liquids, this in-depth analysis examines the topic of complex liquids from a modern perspective, addressing experimental, computational and theoretical aspects of the field. Selecting only the most interesting contemporary developments in this rich field of research, the authors present multiple examples including aggregation, gel formation and glass transition, in systems undergoing percolation, at criticality, or in supercooled states. Connecting experiments and simulation with key theoretical principles, and covering numerous systems including micelles, micro-emulsions, biological systems, and cement pastes, this unique text is an invaluable resource for graduate students and researchers looking to explore and understand the expanding field of complex fluids.

  10. The Complexity of Indirect Translation

    DEFF Research Database (Denmark)

    Wenjie, L. I.

    2017-01-01

    its complex nature, and thus determined that many facets of ITr remain to be studied. The present article will try to encompass the complexity of ITr by looking into the reasons for translating indirectly, the challenge of finding out mediating texts (MTs), indirectness in both translation...... of which have been translated and interpreted indirectly through major languages like English, will be employed as examples. Hopefully, this study will offer more insights into the nature of translation as a social activity and raise further interests in studying translation as a complex phenomenon....

  11. Theory of complex potential scattering

    International Nuclear Information System (INIS)

    Kok, L.P.; Haeringen, H.v.

    1981-01-01

    We study the effect of the addition of a complex potential lambdaV/sub sep/ to an arbitrary Schroedinger operator H = H 0 +V on the singularities of the S matrix, as a function of lambda. Here V/sub sep/ is a separable interaction, and lambda is a complex coupling parameter. The paths of these singularities are determined to a great extent by certain saddle points in the momentum (or energy) plane. We explain certain critical phenomena recently reported in the literature. Associated with these saddles are branch-type singularities in the complex lambda plane, which are dynamical in origin. Some examples are discussed in detail

  12. Global aspects of complex geometry

    CERN Document Server

    Catanese, Fabrizio; Huckleberry, Alan T

    2006-01-01

    Present an overview of developments in Complex Geometry. This book covers topics that range from curve and surface theory through special varieties in higher dimensions, moduli theory, Kahler geometry, and group actions to Hodge theory and characteristic p-geometry.

  13. Complex Topographic Feature Ontology Patterns

    Science.gov (United States)

    Varanka, Dalia E.; Jerris, Thomas J.

    2015-01-01

    Semantic ontologies are examined as effective data models for the representation of complex topographic feature types. Complex feature types are viewed as integrated relations between basic features for a basic purpose. In the context of topographic science, such component assemblages are supported by resource systems and found on the local landscape. Ontologies are organized within six thematic modules of a domain ontology called Topography that includes within its sphere basic feature types, resource systems, and landscape types. Context is constructed not only as a spatial and temporal setting, but a setting also based on environmental processes. Types of spatial relations that exist between components include location, generative processes, and description. An example is offered in a complex feature type ‘mine.’ The identification and extraction of complex feature types are an area for future research.

  14. Complexity for survival of livings

    International Nuclear Information System (INIS)

    Zak, Michail

    2007-01-01

    A connection between survivability of livings and complexity of their behavior is established. New physical paradigms-exchange of information via reflections, and chain of abstractions-explaining and describing progressive evolution of complexity in living (active) systems are introduced. A biological origin of these paradigms is associated with a recently discovered mirror neuron that is able to learn by imitation. As a result, an active element possesses the self-nonself images and interacts with them creating the world of mental dynamics. Three fundamental types of complexity of mental dynamics that contribute to survivability are identified. Mathematical model of the corresponding active systems is described by coupled motor-mental dynamics represented by Langevin and Fokker-Planck equations, respectively, while the progressive evolution of complexity is provided by nonlinear evolution of probability density. Application of the proposed formalism to modeling common-sense-based decision-making process is discussed

  15. Complexity for survival of livings

    Energy Technology Data Exchange (ETDEWEB)

    Zak, Michail [Jet Propulsion Laboratory, California Institute of Technology, Advance Computing Algorithms and IVHM Group, Pasadena, CA 91109 (United States)]. E-mail: Michail.Zak@jpl.nasa.gov

    2007-05-15

    A connection between survivability of livings and complexity of their behavior is established. New physical paradigms-exchange of information via reflections, and chain of abstractions-explaining and describing progressive evolution of complexity in living (active) systems are introduced. A biological origin of these paradigms is associated with a recently discovered mirror neuron that is able to learn by imitation. As a result, an active element possesses the self-nonself images and interacts with them creating the world of mental dynamics. Three fundamental types of complexity of mental dynamics that contribute to survivability are identified. Mathematical model of the corresponding active systems is described by coupled motor-mental dynamics represented by Langevin and Fokker-Planck equations, respectively, while the progressive evolution of complexity is provided by nonlinear evolution of probability density. Application of the proposed formalism to modeling common-sense-based decision-making process is discussed.

  16. Neural complexity, dissociation, and schizophrenia

    Czech Academy of Sciences Publication Activity Database

    Bob, P.; Šusta, M.; Chládek, Jan; Glaslová, K.; Fedor-Ferybergh, P.

    2007-01-01

    Roč. 13, č. 10 (2007), HY1-5 ISSN 1234-1010 Institutional research plan: CEZ:AV0Z20650511 Keywords : neural complexity * dissociation * schizophrenia Subject RIV: FH - Neurology Impact factor: 1.607, year: 2007

  17. Machining of Complex Sculptured Surfaces

    CERN Document Server

    2012-01-01

    The machining of complex sculptured surfaces is a global technological topic in modern manufacturing with relevance in both industrialized and emerging in countries particularly within the moulds and dies sector whose applications include highly technological industries such as the automotive and aircraft industry. Machining of Complex Sculptured Surfaces considers new approaches to the manufacture of moulds and dies within these industries. The traditional technology employed in the manufacture of moulds and dies combined conventional milling and electro-discharge machining (EDM) but this has been replaced with  high-speed milling (HSM) which has been applied in roughing, semi-finishing and finishing of moulds and dies with great success. Machining of Complex Sculptured Surfaces provides recent information on machining of complex sculptured surfaces including modern CAM systems and process planning for three and five axis machining as well as explanations of the advantages of HSM over traditional methods ra...

  18. Genetics Home Reference: Carney complex

    Science.gov (United States)

    ... cortisol (hypercortisolism) can lead to the development of Cushing syndrome. This syndrome causes weight gain in the face ... Institute of Diabetes and Digestive and Kidney Diseases: Cushing's Syndrome Educational Resources (6 links) Disease InfoSearch: Carney Complex ...

  19. Mathematicians, Attributional Complexity, and Gender

    Science.gov (United States)

    Stalder, Daniel R.

    Given indirect indications in sex role and soda! psychology research that mathematical-deductive reasoning may negatively relate to social acuity, Study 1 investigated whether mathematicians were less attributionally complex than nonmathematicians. Study 1 administered the Attributional Complexity Scale, a measure of social acuity, to female and male faculty members and graduate students in four Midwestern schools. Atlrihutional complexity (AC) is the ability and motivation to give complex explanations for behavior. Study 1 found a significant interaction between field and gender. Only among women did mathematicians score lower on AC. In addition, an established gender difference in AC (that women score higher than men) was present only among nonmathematicians. Studies 2 and 3 offered some preliminary support for the possibility that it is generally female students who score tow on AC who aspire to he mathematicians and for the underlying view that female students' perceived similarity to mathematicians can influence their vocational choices.

  20. Making the Tent Function Complex

    Science.gov (United States)

    Sprows, David J.

    2010-01-01

    This note can be used to illustrate to the student such concepts as periodicity in the complex plane. The basic construction makes use of the Tent function which requires only that the student have some working knowledge of binary arithmetic.

  1. TETRACYANONICKELATE(II) PYRIDAZINE COMPLEXES

    African Journals Online (AJOL)

    B. S. Chandravanshi

    and therefore they have been attracting increasing attention from scientists [1]. .... in the spectra of the complexes studied are listed in Table 1, together with free ..... Raman spectra were recorded at Anadolu University, Department of Physics.

  2. Complex Hydrides for Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Slattery, Darlene; Hampton, Michael

    2003-03-10

    This report describes research into the use of complex hydrides for hydrogen storage. The synthesis of a number of alanates, (AIH4) compounds, was investigated. Both wet chemical and mechano-chemical methods were studied.

  3. Disordered Plamonics and Complex Metamaterials

    KAUST Repository

    Gongora, J. S. Totero

    2017-01-01

    Complex systems are ensembles of interconnected elements where mutual interaction and an optimized amount of disorder produce advanced functionalities. These systems are abundant in our daily experience: typical examples are the brain, biological

  4. Anomaly Detection for Complex Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — In performance maintenance in large, complex systems, sensor information from sub-components tends to be readily available, and can be used to make predictions about...

  5. Complex Hybrid Inflation and Baryogenesis

    OpenAIRE

    Delepine, David; Martinez, Carlos; Urena-Lopez, L. Arturo

    2006-01-01

    We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated to the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vev of the waterfall field, which is well constrained by diverse cosmological observations.

  6. Complex Hybrid Inflation and Baryogenesis

    International Nuclear Information System (INIS)

    Delepine, David; Martinez, Carlos; Urena-Lopez, L. Arturo

    2007-01-01

    We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated with the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vacuum expectation value of the waterfall field, which is well constrained by diverse cosmological observations

  7. Complex hybrid inflation and baryogenesis.

    Science.gov (United States)

    Delepine, David; Martínez, Carlos; Ureña-López, L Arturo

    2007-04-20

    We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated with the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vacuum expectation value of the waterfall field, which is well constrained by diverse cosmological observations.

  8. Symbolic Dynamics and Grammatical Complexity

    Science.gov (United States)

    Hao, Bai-Lin; Zheng, Wei-Mou

    The following sections are included: * Formal Languages and Their Complexity * Formal Language * Chomsky Hierarchy of Grammatical Complexity * The L-System * Regular Language and Finite Automaton * Finite Automaton * Regular Language * Stefan Matrix as Transfer Function for Automaton * Beyond Regular Languages * Feigenbaum and Generalized Feigenbaum Limiting Sets * Even and Odd Fibonacci Sequences * Odd Maximal Primitive Prefixes and Kneading Map * Even Maximal Primitive Prefixes and Distinct Excluded Blocks * Summary of Results

  9. Decentralized control of complex systems

    CERN Document Server

    Siljak, Dragoslav D

    2011-01-01

    Complex systems require fast control action in response to local input, and perturbations dictate the use of decentralized information and control structures. This much-cited reference book explores the approaches to synthesizing control laws under decentralized information structure constraints.Starting with a graph-theoretic framework for structural modeling of complex systems, the text presents results related to robust stabilization via decentralized state feedback. Subsequent chapters explore optimization, output feedback, the manipulative power of graphs, overlapping decompositions and t

  10. Statistical mechanics of complex networks

    CERN Document Server

    Rubi, Miguel; Diaz-Guilera, Albert

    2003-01-01

    Networks can provide a useful model and graphic image useful for the description of a wide variety of web-like structures in the physical and man-made realms, e.g. protein networks, food webs and the Internet. The contributions gathered in the present volume provide both an introduction to, and an overview of, the multifaceted phenomenology of complex networks. Statistical Mechanics of Complex Networks also provides a state-of-the-art picture of current theoretical methods and approaches.

  11. Recent developments in complex scaling

    International Nuclear Information System (INIS)

    Rescigno, T.N.

    1980-01-01

    Some recent developments in the use of complex basis function techniques to study resonance as well as certain types of non-resonant, scattering phenomena are discussed. Complex scaling techniques and other closely related methods have continued to attract the attention of computational physicists and chemists and have now reached a point of development where meaningful calculations on many-electron atoms and molecules are beginning to appear feasible

  12. Substitution reactions of technetium complexes

    International Nuclear Information System (INIS)

    Omori, T.

    1997-01-01

    Substitution reactions of a series of technetium complexes are considered in comparison with corresponding reactions of rhenium. Rhenium and technetium complexes are rather inert in substitution reactions, the latter are characterized by greater rate constants when they proceed according to dissociative mechanism. In rare cases when k Tc /k Re id little it is assumed that the reaction proceeds according to the associative mechanism. (author)

  13. Determinants of Hospital Casemix Complexity

    Science.gov (United States)

    Becker, Edmund R.; Steinwald, Bruce

    1981-01-01

    Using the Commission on Professional and Hospital Activities' Resource Need Index as a measure of casemix complexity, this paper examines the relative contributions of teaching commitment and other hospital characteristics, hospital service and insurer distributions, and area characteristics to variations in casemix complexity. The empirical estimates indicate that all three types of independent variables have a substantial influence. These results are discussed in light of recent casemix research as well as current policy implications. PMID:6799430

  14. Strategic Complexity and Global Expansion

    DEFF Research Database (Denmark)

    Oladottir, Asta Dis; Hobdari, Bersant; Papanastassiou, Marina

    2012-01-01

    The purpose of this paper is to analyse the determinants of global expansion strategies of newcomer Multinational Corporations (MNCs) by focusing on Iceland, Israel and Ireland. We argue that newcomer MNCs from small open economies pursue complex global expansion strategies (CGES). We distinguish....... The empirical evidence suggests that newcomer MNCs move away from simplistic dualities in the formulation of their strategic choices towards more complex options as a means of maintaining and enhancing their global competitiveness....

  15. Complex ray analysis for plasmas

    International Nuclear Information System (INIS)

    Connor, K.A.

    1980-01-01

    An extension of ray tracing techniques is considered for a variety of cases in which the dispersion relation of the plasma medium is complex. The ray trajectories are permitted to begin and/or at least travel through complex space-time; the wave propagation process so characterized becomes significant only where the rays intersect real space-time. It is found that rules and guidelines can be established for limited application of this idea

  16. Linearization Method and Linear Complexity

    Science.gov (United States)

    Tanaka, Hidema

    We focus on the relationship between the linearization method and linear complexity and show that the linearization method is another effective technique for calculating linear complexity. We analyze its effectiveness by comparing with the logic circuit method. We compare the relevant conditions and necessary computational cost with those of the Berlekamp-Massey algorithm and the Games-Chan algorithm. The significant property of a linearization method is that it needs no output sequence from a pseudo-random number generator (PRNG) because it calculates linear complexity using the algebraic expression of its algorithm. When a PRNG has n [bit] stages (registers or internal states), the necessary computational cost is smaller than O(2n). On the other hand, the Berlekamp-Massey algorithm needs O(N2) where N(≅2n) denotes period. Since existing methods calculate using the output sequence, an initial value of PRNG influences a resultant value of linear complexity. Therefore, a linear complexity is generally given as an estimate value. On the other hand, a linearization method calculates from an algorithm of PRNG, it can determine the lower bound of linear complexity.

  17. Analysis of nanoparticle biomolecule complexes.

    Science.gov (United States)

    Gunnarsson, Stefán B; Bernfur, Katja; Mikkelsen, Anders; Cedervall, Tommy

    2018-03-01

    Nanoparticles exposed to biological fluids adsorb biomolecules on their surface forming a biomolecular corona. This corona determines, on a molecular level, the interactions and impact the newly formed complex has on cells and organisms. The corona formation as well as the physiological and toxicological relevance are commonly investigated. However, an acknowledged but rarely addressed problem in many fields of nanobiotechnology is aggregation and broadened size distribution of nanoparticles following their interactions with the molecules of biological fluids. In blood serum, TiO 2 nanoparticles form complexes with a size distribution from 30 nm to more than 500 nm. In this study we have separated these complexes, with good resolution, using preparative centrifugation in a sucrose gradient. Two main apparent size populations were obtained, a fast sedimenting population of complexes that formed a pellet in the preparative centrifugation tube, and a slow sedimenting complex population still suspended in the gradient after centrifugation. Concentration and surface area dependent differences are found in the biomolecular corona between the slow and fast sedimenting fractions. There are more immunoglobulins, lipid binding proteins, and lipid-rich complexes at higher serum concentrations. Sedimentation rate and the biomolecular corona are important factors for evaluating any experiment including nanoparticle exposure. Our results show that traditional description of nanoparticles in biological fluids is an oversimplification and that more thorough characterisations are needed.

  18. Complexity

    Indian Academy of Sciences (India)

    Rahul Pandit

    2008-10-31

    Oct 31, 2008 ... Centre for Condensed Matter Theory. Department of Physics. Indian Institute ... Interactions between a system's components are important role. ... Scale-free networks in, say, social networks or the world-wide web. ▻ A system ...

  19. Coopetition and Complexity : Exploring a Coopetitive Relationship with Complexity

    OpenAIRE

    Wennberg, Andreas; Persson, Emil

    2011-01-01

    Cooperation have in previous research been seen as a negative impact on competition and  vice versa. This thesis is building on a concept called coopetition in which cooperation and  competition is studied simultaneously. Coopetition have been studied in terms of the level of  cooperation and competition. However, we found a possible link between coopetition and  complexity in previous literature. Thus, the purpose of this study is to explore whether  complexity can develop an understanding f...

  20. The fifth adaptor protein complex.

    Directory of Open Access Journals (Sweden)

    Jennifer Hirst

    2011-10-01

    Full Text Available Adaptor protein (AP complexes sort cargo into vesicles for transport from one membrane compartment of the cell to another. Four distinct AP complexes have been identified, which are present in most eukaryotes. We report the existence of a fifth AP complex, AP-5. Tagged AP-5 localises to a late endosomal compartment in HeLa cells. AP-5 does not associate with clathrin and is insensitive to brefeldin A. Knocking down AP-5 subunits interferes with the trafficking of the cation-independent mannose 6-phosphate receptor and causes the cell to form swollen endosomal structures with emanating tubules. AP-5 subunits can be found in all five eukaryotic supergroups, but they have been co-ordinately lost in many organisms. Concatenated phylogenetic analysis provides robust resolution, for the first time, into the evolutionary order of emergence of the adaptor subunit families, showing AP-3 as the basal complex, followed by AP-5, AP-4, and AP-1 and AP-2. Thus, AP-5 is an evolutionarily ancient complex, which is involved in endosomal sorting, and which has links with hereditary spastic paraplegia.

  1. Complexity in White Noise Analysis

    Science.gov (United States)

    Hida, Takeyuki

    We restrict our attention to random complex systems and discuss degree their degree of complexity based on a white noise. The white noise is realized as the time derivative of a Brownian motion B(t), and denoted by Ḃ(t). The collection {Ḃ(t)}, is a system of idealized elementary variables and at the same time the system is a stochastic representation of the time t, in other words it is time-oriented. Having expressed the given evolutional random phenomena in question in terms of the Ḃ(t), we introduce the notion of spectral multiplicity, which describes how much the phenomena are complex. The multiplicity is the number of cyclic subspaces that are spanned by the given random phenomena. Each cyclic subspace has further structure. Typical property is multiple Markov property, although this property appears only particular cases. As a related property, in fact as a characteristic of a complex system, one can speak of the time reversibility and irreversibility of certain random phenomena in terms of the white noise. We expect an irreversible random complex system may be decomposed into reversible systems.

  2. Separations in Communication Complexity Using Cheat Sheets and Information Complexity

    NARCIS (Netherlands)

    A. Anshu (Anurag); A. Belovs (Aleksandr); S. Ben-David (Shalev); M. Goos (Mika); R. Jain (Rahul); R. Kothari (Robin); T. J. Lee (Troy); M. Santha (Miklos)

    2016-01-01

    textabstractWhile exponential separations are known between quantum and randomized communication complexity for partial functions (Raz, STOC 1999), the best known separation between these measures for a total function is quadratic, witnessed by the disjointness function. We give the first

  3. Complex Solutions for Complex Needs: Towards Holistic and Collaborative Practice

    Science.gov (United States)

    Beadle, Sally

    2009-01-01

    While the need for holistic health and social service responses is increasingly being articulated in Australia, the discussion is not always matched by improvements in service delivery. This project looked at one service setting where youth workers were encouraged to take a holistic approach to their clients' often-complex needs. Interviews with…

  4. Hyperbolic isometries of systolic complexes

    DEFF Research Database (Denmark)

    Prytula, Tomasz Pawel

    The main topics of this thesis are the geometric features of systolic complexesarising from the actions of hyperbolic isometries. The thesis consists ofan introduction followed by two articles.Given a hyperbolic isometry h of a systolic complex X, our central theme isto study the minimal displace......The main topics of this thesis are the geometric features of systolic complexesarising from the actions of hyperbolic isometries. The thesis consists ofan introduction followed by two articles.Given a hyperbolic isometry h of a systolic complex X, our central theme isto study the minimal...... algebraic-topological features of systolic groups. In addition, we provide newexamples of systolic groups.In the first article we show that the minimal displacement set of a hyperbolicisometry of a systolic complex is quasi-isometric to the product of a tree andthe real line. We use this theorem...

  5. The new science of complexity

    Directory of Open Access Journals (Sweden)

    Joseph L. McCauley

    1997-01-01

    Full Text Available Deterministic chaos, and even maximum computational complexity, have been discovered within Newtonian dynamics. Economists assume that prices and price changes can also obey abstract mathematical laws of motion. Sociologists and other postmodernists advertise that physics and chemistry have outgrown their former limitations, that chaos and complexity provide new holistic paradigms for science, and that the boundaries between the hard and the soft sciences, once impenetrable, have disappeared like the Berlin Wall. Three hundred years after the deaths of Galileo, Descartes, and Kepler, and the birth of Newton, reductionism appears to be on the decline, with holistic approaches to science on the upswing. We therefore examine the evidence that dynamical laws of motion may be discovered from empirical studies of chaotic or complex phenomena, and also review the foundation of reductionism in invariance principles.

  6. Complexity hints for economic policy

    CERN Document Server

    Salzano, Massimo

    2007-01-01

    This volume extends the complexity approach to economics. This complexity approach is not a completely new way of doing economics, and that it is a replacement for existing economics, but rather the integration of some new analytic and computational techniques into economists’ bag of tools. It provides some alternative pattern generators, which can supplement existing approaches by providing an alternative way of finding patterns than be obtained by the traditional scientific approach. On this new kind of policy hints can be obtained. The reason why the complexity approach is taking hold now in economics is because the computing technology has advanced. This advance allows consideration of analytical systems that could not previously be considered by economists. Consideration of these systems suggested that the results of the "control-based" models might not extend easily to more complicated systems, and that we now have a method—piggybacking computer assisted analysis onto analytic methods—to start gen...

  7. Carney complex review: Genetic features.

    Science.gov (United States)

    Bosco Schamun, María Belén; Correa, Ricardo; Graffigna, Patricia; de Miguel, Valeria; Fainstein Day, Patricia

    2018-01-01

    Carney complex is a multiple neoplasia syndrome having endocrine and non-endocrine manifestations. Diagnostic criteria include myxoma, lentigines, and primary pigmented nodular adrenocortical disease, amongst other signs/symptoms. In most cases it is an autosomal dominant disease, and diagnosis therefore requires study and follow-up of the family members. Inactivating mutations of the PRKAR1A gene were identified as the main cause of the disease, although since 2015 other disease-related genes, including PRKACA and PRKACB activating mutations, have also been related with Carney complex. This review will address the genetic aspects related to Carney complex. Copyright © 2017 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. Simulating social complexity a handbook

    CERN Document Server

    Meyer, Ruth

    2013-01-01

    Social systems are among the most complex known. This poses particular problems for those who wish to understand them. The complexity often makes analytic approaches infeasible and natural language approaches inadequate for relating intricate cause and effect. However, individual- and agent-based computational approaches hold out the possibility of new and deeper understanding of such systems.  Simulating Social Complexity examines all aspects of using agent- or individual-based simulation. This approach represents systems as individual elements having each their own set of differing states and internal processes. The interactions between elements in the simulation represent interactions in the target systems. What makes these elements "social" is that they are usefully interpretable as interacting elements of an observed society. In this, the focus is on human society, but can be extended to include social animals or artificial agents where such work enhances our understanding of human society.  The phenom...

  9. Complexity, cognition and the city

    CERN Document Server

    Portugali, Juval

    2011-01-01

    Complexity, Cognition and the City aims at a deeper understanding of urbanism, while invoking, on an equal footing, the contributions both the hard and soft sciences have made, and are still making, when grappling with the many issues and facets of regional planning and dynamics. In this work, the author goes beyond merely seeing the city as a self-organized, emerging pattern of some collective interaction between many stylized urban "agents" – he makes the crucial step of attributing cognition to his agents and thus raises, for the first time, the question on how to deal with a complex system composed of many interacting complex agents in clearly defined settings. Accordingly, the author eventually addresses issues of practical relevance for urban planners and decision makers. The book unfolds its message in a largely nontechnical manner, so as to provide a broad interdisciplinary readership with insights, ideas, and other stimuli to encourage further research – with the twofold aim of further pushing ba...

  10. Metal complexes with 5-aminotetrazole

    International Nuclear Information System (INIS)

    Lavrenova, L.G.; Larionov, S.V.; Grankina, Z.A.; Ikorskij, V.N.

    1983-01-01

    Nitrate and chloride complexes of Co(2), Ni(2), Cu(2), Cd(2), Hg(2), Pb(2) with 5 aminotetrazole (ATE) and compoUnds Zn(ATE') 2 and Cd(ATEE') 2 , where ATE' is a 5 aminotetrazole ano /nion. On the base of spectroscopic data (spectrophotometry, IR- spectra, EPR and magnetic measurements assumptions on M(2) coordination in complexes are made. Most probably ATE is a bridge ligand which is joined by two nitrogen atoms to various M(2) ions. In Co(2), Ni(2) and Cu(ATE) 3 -Cl 2 compounds the metal has a distorted actahedral coordination and forms MN 6 unit, which suggests the interaction of metal ions with ATE nitrogen atoms along the Z-axis. In the Cu(ATE) 2 (NO 3 ) 2 octahedral complex the CuN 4 O 2 coordination unit is realized at the expense of participation of nitratogroups in coordination

  11. Characterising Complex Enzyme Reaction Data.

    Directory of Open Access Journals (Sweden)

    Handan Melike Dönertaş

    Full Text Available The relationship between enzyme-catalysed reactions and the Enzyme Commission (EC number, the widely accepted classification scheme used to characterise enzyme activity, is complex and with the rapid increase in our knowledge of the reactions catalysed by enzymes needs revisiting. We present a manual and computational analysis to investigate this complexity and found that almost one-third of all known EC numbers are linked to more than one reaction in the secondary reaction databases (e.g., KEGG. Although this complexity is often resolved by defining generic, alternative and partial reactions, we have also found individual EC numbers with more than one reaction catalysing different types of bond changes. This analysis adds a new dimension to our understanding of enzyme function and might be useful for the accurate annotation of the function of enzymes and to study the changes in enzyme function during evolution.

  12. 1989 lectures in complex systems

    International Nuclear Information System (INIS)

    Jen, E.

    1990-01-01

    This report contains papers on the following topics: Lectures on a Theory of Computation and Complexity over the Reals; Algorithmic Information Content, Church-Turing Thesis, Physical Entroph, and Maxwell's Demon; Physical Measures of Complexity; An Introduction to Chaos and Prediction; Hamiltonian Chaos in Nonlinear Polarized Optical Beam; Chemical Oscillators and Nonlinear Chemical Dynamics; Isotropic Navier-Stokes Turbulence. I. Qualitative Features and Basic Equations; Isotropic Navier-Stokes Turbulence. II. Statistical Approximation Methods; Lattice Gases; Data-Parallel Computation and the Connection Machine; Preimages and Forecasting for Cellular Automata; Lattice-Gas Models for Multiphase Flows and Magnetohydrodynamics; Probabilistic Cellular Automata: Some Statistical Mechanical Considerations; Complexity Due to Disorder and Frustration; Self-Organization by Simulated Evolution; Theoretical Immunology; Morphogenesis by Cell Intercalation; and Theoretical Physics Meets Experimental Neurobiology

  13. Complexation thermodynamics of modified cyclodextrins

    DEFF Research Database (Denmark)

    Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, Rene

    2014-01-01

    Inclusion complexes between two bile salts and a range of differently methylated β-cyclodextrins were studied in an attempt to rationalize the complexation thermodynamics of modified cyclodextrins. Calorimetric titrations at a range of temperatures provided precise values of the enthalpies (ΔH......°), entropies (ΔS°), and heat capacities (ΔCp) of complexation, while molecular dynamics simulations assisted the interpretation of the obtained thermodynamic parameters. As previously observed for several types of modified cyclodextrins, the substituents at the rims of the cyclodextrin induced large changes......° and then a strong decrease when the degree of substitution exceeded some threshold. Exactly the same trend was observed for ΔCp. The dehydration of nonpolar surface, as quantified by the simulations, can to a large extent explain the variation in the thermodynamic parameters. The methyl substituents form additional...

  14. Complex proofs of real theorems

    CERN Document Server

    Lax, Peter D

    2011-01-01

    Complex Proofs of Real Theorems is an extended meditation on Hadamard's famous dictum, "The shortest and best way between two truths of the real domain often passes through the imaginary one." Directed at an audience acquainted with analysis at the first year graduate level, it aims at illustrating how complex variables can be used to provide quick and efficient proofs of a wide variety of important results in such areas of analysis as approximation theory, operator theory, harmonic analysis, and complex dynamics. Topics discussed include weighted approximation on the line, Müntz's theorem, Toeplitz operators, Beurling's theorem on the invariant spaces of the shift operator, prediction theory, the Riesz convexity theorem, the Paley-Wiener theorem, the Titchmarsh convolution theorem, the Gleason-Kahane-Żelazko theorem, and the Fatou-Julia-Baker theorem. The discussion begins with the world's shortest proof of the fundamental theorem of algebra and concludes with Newman's almost effortless proof of the prime ...

  15. Chansporter complexes in cell signaling.

    Science.gov (United States)

    Abbott, Geoffrey W

    2017-09-01

    Ion channels facilitate diffusion of ions across cell membranes for such diverse purposes as neuronal signaling, muscular contraction, and fluid homeostasis. Solute transporters often utilize ionic gradients to move aqueous solutes up their concentration gradient, also fulfilling a wide variety of tasks. Recently, an increasing number of ion channel-transporter ('chansporter') complexes have been discovered. Chansporter complex formation may overcome what could otherwise be considerable spatial barriers to rapid signal integration and feedback between channels and transporters, the ions and other substrates they transport, and environmental factors to which they must respond. Here, current knowledge in this field is summarized, covering both heterologous expression structure/function findings and potential mechanisms by which chansporter complexes fulfill contrasting roles in cell signaling in vivo. © 2017 Federation of European Biochemical Societies.

  16. Association theories for complex thermodynamics

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios; Rafiqul Gani

    2013-01-01

    of this review is two-fold: first to illustrate some of the significant capabilities of these association theories and why indeed they have already been extensively used and are expected to find even more applications in the future. The second and most important aspect of this review is to outline many...... applications. While specialized models can handle different cases, even complex ones, with the advent of powerful theories and computers there is the hope that a single or a few models could be suitable for a general modeling of complex thermodynamics. After more than 100 years with active use of thermodynamic...... models, we have now come to the understanding that simple one-fluid theories like the cubic equations of state or the various forms of local composition models will never be able to model a wide range of complex systems with sufficient accuracy. While various modern approaches have appeared, one very...

  17. Polymerization of lanthanide acrylonitrile complexes.

    Science.gov (United States)

    el-Mossalamy, El-Sayed H; Khalil, Ahmed A

    2002-01-01

    The molecular complexes of some lanthanides scandium (Sc3+), yttrium (Y3+), lanthanum (La3+), gadolinium (Gd3+), cerium (Ce3+) and ytterbium (Yb3) have been studies in dimethyl formamide (DMF) spectrophtometrically equilibrium constants (K), molar extintion coefficient (epsilon), energy of transition (E) and free energy (delta G*) were calculated. The polymerization of acrylonitrile has been studied and investigated in the presence of Sc3+, Y3+, La3+, Gd3+, Ce3+, and Yb3+ ions. The IR spectra of the formed AN-M (III) Br3 polymer complexes show the absence of the C identical to N band and the presence of two new bands corresponding to NH2 and OH groups. Magnetic moment values and the thermal stabilities of homopolymer and the polymer complexes were studied by means of thermogravimetric analysis and the activation energies for degradation were calculated.

  18. Characterization of complex renal cysts

    DEFF Research Database (Denmark)

    Graumann, Ole; Osther, Susanne Sloth; Osther, Palle Jörn Sloth

    2010-01-01

    Abstract Objective. Complex renal cysts represent a major clinical problem, since it is often difficult to exclude malignancy. The Bosniak classification system, based on computed tomography (CT), is widely used to categorize cystic renal lesions. The aim of this study was to evaluate critically...... available data on the Bosniak classification. Material and methods. All publications from an Entrez Pubmed search were reviewed, focusing on clinical applicability and the use of imaging modalities other than CT to categorize complex renal cysts. Results. Fifteen retrospective studies were found. Most...

  19. Thermodynamic properties of actinide complexes

    International Nuclear Information System (INIS)

    Bismondo, A.; Cassol, A.; Di Bernardo, P.; Magon, L.; Tomat, G.; Consiglio Nazionale delle Ricerche, Padua

    1981-01-01

    In a previous paper the stability constants and the enthalpies of formation of uranyl(VI)-malonate complexes in 1 M Na(ClO 4 ) and at 25.0 0 C, have been reported. In order to assess the influence of the number of methylenic groups in the ligand chain on the stability constants of the formed complexes and on their ΔH and ΔS values, a series of potentiometric and calorimetric investigations were carried out on the uranyl(VI)-succinate system. The results are given and discussed. (author)

  20. Border detection in complex networks

    International Nuclear Information System (INIS)

    Travencolo, Bruno A N; Viana, Matheus Palhares; Costa, Luciano da Fontoura

    2009-01-01

    One important issue implied by the finite nature of real-world networks regards the identification of their more external (border) and internal nodes. The present work proposes a formal and objective definition of these properties, founded on the recently introduced concept of node diversity. It is shown that this feature does not exhibit any relevant correlation with several well-established complex networks measurements. A methodology for the identification of the borders of complex networks is described and illustrated with respect to theoretical (geographical and knitted networks) as well as real-world networks (urban and word association networks), yielding interesting results and insights in both cases.

  1. CNN a paradigm for complexity

    CERN Document Server

    Chua, Leon O

    1998-01-01

    Revolutionary and original, this treatise presents a new paradigm of EMERGENCE and COMPLEXITY, with applications drawn from numerous disciplines, including artificial life, biology, chemistry, computation, physics, image processing, information science, etc.CNN is an acronym for Cellular Neural Networks when used in the context of brain science, or Cellular Nonlinear Networks, when used in the context of emergence and complexity. A CNN is modeled by cells and interactions: cells are defined as dynamical systems and interactions are defined via coupling laws. The CNN paradigm is a universal Tur

  2. Detergent zeolite complex "Alusil", Zvornik

    OpenAIRE

    Stanković Mirjana S.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed the basis technological and machine projects for a detergent zeolite complex, on the basis of which a pilot plant with an initial capacity of 5,000 t/y was constructed in 1983 within Birač-Zvornik production complex. Additional projects were done afterwards and the starting capacity increased to 200,000 t/y in 1988. This plant became the biggest producer of detergent zeolite in the world. These projects were manufactured on the basis of specific techno...

  3. Duodenal Cytochrome b (DCYTB in Iron Metabolism: An Update on Function and Regulation

    Directory of Open Access Journals (Sweden)

    Darius J. R. Lane

    2015-03-01

    Full Text Available Iron and ascorbate are vital cellular constituents in mammalian systems. The bulk-requirement for iron is during erythropoiesis leading to the generation of hemoglobin-containing erythrocytes. Additionally; both iron and ascorbate are required as co-factors in numerous metabolic reactions. Iron homeostasis is controlled at the level of uptake; rather than excretion. Accumulating evidence strongly suggests that in addition to the known ability of dietary ascorbate to enhance non-heme iron absorption in the gut; ascorbate regulates iron homeostasis. The involvement of ascorbate in dietary iron absorption extends beyond the direct chemical reduction of non-heme iron by dietary ascorbate. Among other activities; intra-enterocyte ascorbate appears to be involved in the provision of electrons to a family of trans-membrane redox enzymes; namely those of the cytochrome b561 class. These hemoproteins oxidize a pool of ascorbate on one side of the membrane in order to reduce an electron acceptor (e.g., non-heme iron on the opposite side of the membrane. One member of this family; duodenal cytochrome b (DCYTB; may play an important role in ascorbate-dependent reduction of non-heme iron in the gut prior to uptake by ferrous-iron transporters. This review discusses the emerging relationship between cellular iron homeostasis; the emergent “IRP1-HIF2α axis”; DCYTB and ascorbate in relation to iron metabolism.

  4. Quantum chemical study of hydroxylation of alkanes by hypofluorous acid

    Czech Academy of Sciences Publication Activity Database

    Ončák, Milan; Srnec, Martin; Zahradník, Rudolf

    2008-01-01

    Roč. 82, č. 4 (2008), s. 649-659 ISSN 0137-5083 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40550506 Keywords : electronic structure * nonheme iron * basis-set Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.518, year: 2008

  5. Structural and Spectroscopic Properties of the Peroxodiferric Intermediate of Ricinus communis Soluble Delta(9) Desaturase

    Czech Academy of Sciences Publication Activity Database

    Srnec, Martin; Rokob, Tibor András; Schwartz, J. K.; Kwak, Y.; Rulíšek, Lubomír; Solomon, E. I.

    2012-01-01

    Roč. 51, č. 5 (2012), s. 2806-2820 ISSN 0020-1669 R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : diferrous non-heme iron enzyme * QM/MM calculations * delta-9 * desaturase * reaction mechanism Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.593, year: 2012

  6. Serum hepcidin is significantly associated with iron absorption from food and supplemental sources in healthy young woman

    Science.gov (United States)

    Hepcidin is a key regulator of iron homeostasis, but to date no studies have examined the effect of hepcidin on iron absorption in humans. Our objective was to assess relations between both serum hepcidin and serum prohepcidin with nonheme-iron absorption in the presence and absence of food with the...

  7. NRVS Studies of the Peroxide Shunt Intermediate in a Rieske Dioxygenase and Its Relation to the Native FesupII/supOinf2/infReaction

    Czech Academy of Sciences Publication Activity Database

    Sutherlin, K. D.; Rivard, B. S.; Böttger, L. H.; Liu, L. V.; Rogers, M. S.; Srnec, Martin; Park, K.; Yoda, Y.; Kitao, S.; Kobayashi, Y.; Saito, M.; Seto, M.; Hu, M.; Zhao, J.; Lipscomb, J. D.; Solomon, E. I.

    2018-01-01

    Roč. 140, č. 16 (2018), s. 5544-5559 ISSN 0002-7863 Institutional support: RVO:61388955 Keywords : NRVS studies * Rieske dioxygenase * mononuclear nonheme iron enzymes Subject RIV: CF - Physical ; The oretical Chemistry OBOR OECD: Physical chemistry Impact factor: 13.858, year: 2016

  8. Workspace Program for Complex-Number Arithmetic

    Science.gov (United States)

    Patrick, M. C.; Howell, Leonard W., Jr.

    1986-01-01

    COMPLEX is workspace program designed to empower APL with complexnumber capabilities. Complex-variable methods provide analytical tools invaluable for applications in mathematics, science, and engineering. COMPLEX written in APL.

  9. Sequence complexity and work extraction

    International Nuclear Information System (INIS)

    Merhav, Neri

    2015-01-01

    We consider a simplified version of a solvable model by Mandal and Jarzynski, which constructively demonstrates the interplay between work extraction and the increase of the Shannon entropy of an information reservoir which is in contact with a physical system. We extend Mandal and Jarzynski’s main findings in several directions: first, we allow sequences of correlated bits rather than just independent bits. Secondly, at least for the case of binary information, we show that, in fact, the Shannon entropy is only one measure of complexity of the information that must increase in order for work to be extracted. The extracted work can also be upper bounded in terms of the increase in other quantities that measure complexity, like the predictability of future bits from past ones. Third, we provide an extension to the case of non-binary information (i.e. a larger alphabet), and finally, we extend the scope to the case where the incoming bits (before the interaction) form an individual sequence, rather than a random one. In this case, the entropy before the interaction can be replaced by the Lempel–Ziv (LZ) complexity of the incoming sequence, a fact that gives rise to an entropic meaning of the LZ complexity, not only in information theory, but also in physics. (paper)

  10. Structural insights into transcription complexes

    NARCIS (Netherlands)

    Berger, I.; Blanco, A.G.; Boelens, R.; Cavarelli, J.; Coll, M.; Folkers, G.E.; Nie, Y.; Pogenberg, V.; Schultz, P.; Wilmanns, M.; Moras, D.; Poterszman, A.

    2011-01-01

    Control of transcription allows the regulation of cell activity in response to external stimuli and research in the field has greatly benefited from efforts in structural biology. In this review, based on specific examples from the European SPINE2-COMPLEXES initiative, we illustrate the impact of

  11. Language Networks as Complex Systems

    Science.gov (United States)

    Lee, Max Kueiming; Ou, Sheue-Jen

    2008-01-01

    Starting in the late eighties, with a growing discontent with analytical methods in science and the growing power of computers, researchers began to study complex systems such as living organisms, evolution of genes, biological systems, brain neural networks, epidemics, ecology, economy, social networks, etc. In the early nineties, the research…

  12. Complexity control in statistical learning

    Indian Academy of Sciences (India)

    Then we describe how the method of regularization is used to control complexity in learning. We discuss two examples of regularization, one in which the function space used is finite dimensional, and another in which it is a reproducing kernel Hilbert space. Our exposition follows the formulation of Cucker and Smale.

  13. Thermodynamic properties of actinide complexes

    International Nuclear Information System (INIS)

    Di Bernardo, P.; Tomat, G.; Bismondo, A.

    1980-01-01

    The present paper reports a continuation of investigations on the complexing ability of substituted polycarboxylate ligands toward the uranyl(VI) ion. The changes in free energy were computed from the stability constants determined by potentiometric measurements; the enthalpy changes were measured by direct calorimetric titrations. The acid formation constants and the complex formation constants were calculated with the aid of a CDC/CRYBER '76 computer using the programs LETAGROP VRID and MINIQUAD 75. The enthalpy changes for the proton ligand and metal ligand complex formation were calculated by the least-squares program LETAGROP KALLE. The data obtained for a relatively wide range of concentrations of the metal and hydrogen ions may be interpreted in terms of the formation of simple mononuclear, ML, and acid complexes, Msub(p)Hsub(q)Lsub(r), where p = 1; q = 1, 2; r = 1, 2. The values of free energy enthalpy, and entropy changes for the systems investigated are reported together with the logarithms of the corresponding stability constants. (author)

  14. Copper complexes as chemical nucleases

    Indian Academy of Sciences (India)

    Unknown

    anticancer drug famotidine has been shown as a better catalyst than CuCl2 for sulfite ... Effect of addition of bis-chelate copper(II) complexes (dpq, •; phen, ; ..... Reproduction, Development & Genetics for their help in the DNA cleavage studies ...

  15. Simulating complex noise barrier reflections

    NARCIS (Netherlands)

    Eerden, F.J.M. van der; Lutgendorf, D.; Roo, F. de

    2011-01-01

    Within the EU FP7 QUIESST project, QUIeting the Environment for a Sustainable Surface Transport, a test method is being developed for the reflectivity of noise barriers. The method needs to account for a complex shape of barriers and the use of various types of absorbing materials. The performance

  16. Disentangling the Trichoderma viridescens complex

    NARCIS (Netherlands)

    Jaklitsch, W.M.; Samuels, G.J.; Ismaiel, A.; Voglmayr, H.

    2013-01-01

    Trichoderma viridescens is recognised as a species complex. Multigene analyses based on the translation elongation factor 1-alpha encoding gene (tef1), a part of the rpb2 gene, encoding the second largest RNA polymerase subunit and the larger subunit of ATP citrate lyase (acl1) reveals 13

  17. Data complexity in pattern recognition

    CERN Document Server

    Kam Ho Tin

    2006-01-01

    Machines capable of automatic pattern recognition have many fascinating uses. Algorithms for supervised classification, where one infers a decision boundary from a set of training examples, are at the core of this capability. This book looks at data complexity and its role in shaping the theories and techniques in different disciplines

  18. AIDS dementia complex: a review

    NARCIS (Netherlands)

    Portegies, P.

    1994-01-01

    AIDS dementia complex (ADC) is a constellation of cognitive, motor, and behavioral dysfunctions frequently observed in persons with AIDS. Estimates of its prevalence vary. ADC may occur at any stage of AIDS but is usually associated with later stages of disease. Its severity varies among patients

  19. Complexity, Accountability, and School Improvement.

    Science.gov (United States)

    O'Day, Jennifer A.

    2002-01-01

    Using complexity theory, examines standards-based accountability focused on improving school organization. Compares Chicago Public Schools' outcomes-based bureaucratic accountability approach with Baltimore City Schools' combined administrator-professional accountability. Concludes that the combined approach should result in more lasting change.…

  20. Chromatic polynomials for simplicial complexes

    DEFF Research Database (Denmark)

    Møller, Jesper Michael; Nord, Gesche

    2016-01-01

    In this note we consider s s -chromatic polynomials for finite simplicial complexes. When s=1 s=1 , the 1 1 -chromatic polynomial is just the usual graph chromatic polynomial of the 1 1 -skeleton. In general, the s s -chromatic polynomial depends on the s s -skeleton and its value at r...

  1. Simulating geometrically complex blast scenarios

    Directory of Open Access Journals (Sweden)

    Ian G. Cullis

    2016-04-01

    Full Text Available The effects of blast waves generated by energetic and non-energetic sources are of continuing interest to the ballistics research community. Modern conflicts are increasingly characterised by asymmetric urban warfare, with improvised explosive devices (IEDs often playing a dominant role on the one hand and an armed forces requirement for minimal collateral effects from their weapons on the other. These problems are characterised by disparate length- and time-scales and may also be governed by complex physics. There is thus an increasing need to be able to rapidly assess and accurately predict the effects of energetic blast in topologically complex scenarios. To this end, this paper presents a new QinetiQ-developed advanced computational package called EAGLE-Blast, which is capable of accurately resolving the generation, propagation and interaction of blast waves around geometrically complex shapes such as vehicles and buildings. After a brief description of the numerical methodology, various blast scenario simulations are described and the results compared with experimental data to demonstrate the validation of the scheme and its ability to describe these complex scenarios accurately and efficiently. The paper concludes with a brief discussion on the use of the code in supporting the development of algorithms for fast running engineering models.

  2. Complex networks: Dynamics and security

    Indian Academy of Sciences (India)

    This paper presents a perspective in the study of complex networks by focusing on how dynamics may affect network security under attacks. ... Department of Mathematics and Statistics, Arizona State University, Tempe, Arizona 85287, USA; Institute of Mathematics and Computer Science, University of Sao Paulo, Brazil ...

  3. Complexity theory and financial regulation

    NARCIS (Netherlands)

    Battiston, Stefano; Farmer, J.D.; Flache, Andreas; Garlaschelli, Diego; Haldane, Andrew G.; Heesterbeek, Hans; Hommes, Cars; Jaeger, Carlo; May, Robert; Scheffer, Marten

    2016-01-01

    Traditional economic theory could not explain, much less predict, the near collapse of the financial system and its long-lasting effects on the global economy. Since the 2008 crisis, there has been increasing interest in using ideas from complexity theory to make sense of economic and financial

  4. Leadership Learning for Complex Organizations

    Science.gov (United States)

    Ng, F. S. David

    2015-01-01

    Many school leadership programs are set and delivered in specific modules or workshops in order to achieve a pre-determined set of competencies, knowledge, and skills. In addition, these programs are driven by the faculty member and the prescribed content. As Singapore schools become more complex in the roles and responsibilities to educate the…

  5. On badly approximable complex numbers

    DEFF Research Database (Denmark)

    Esdahl-Schou, Rune; Kristensen, S.

    We show that the set of complex numbers which are badly approximable by ratios of elements of , where has maximal Hausdorff dimension. In addition, the intersection of these sets is shown to have maximal dimension. The results remain true when the sets in question are intersected with a suitably...

  6. Learning To Live with Complexity.

    Science.gov (United States)

    Dosa, Marta

    Neither the design of information systems and networks nor the delivery of library services can claim true user centricity without an understanding of the multifaceted psychological environment of users and potential users. The complexity of the political process, social problems, challenges to scientific inquiry, entrepreneurship, and…

  7. Trauma to the nail complex

    Directory of Open Access Journals (Sweden)

    Jefferson Braga Silva

    2014-04-01

    Full Text Available OBJECTIVE: to analyze the results from surgical intervention to treat trauma of the nail complex.METHODS: we retrospectively reviewed a series of 94 consecutive patients with trauma of the nail complex who were treated between 2000 and 2009. In 42 patients, nail bed suturing was performed. In 27 patients, nail bed suturing was performed subsequent to osteosynthesis of the distal phalanx. In 15, immediate grafting was performed, and in 10, late-stage grafting of the nail bed. The growth, size and shape of the nail were evaluated in comparison with the contralateral finger. The results were obtained by summing scores and classifying them as good, fair or poor.RESULTS: the results were considered to be good particularly in the patients who underwent nail bed suturing or nail bed suturing with osteosynthesis of the distal phalanx. Patients who underwent immediate or late-stage nail grafting had poor results.CONCLUSION: trauma of the nail complex without loss of substance presented better results than did deferred treatment for reconstruction of the nail complex.

  8. Teacher Transformation from Complex Thinking

    Directory of Open Access Journals (Sweden)

    Johana Carolina Peña Lozada

    2018-02-01

    Full Text Available The present article is a qualitative investigation of phenomenological interpretative paradigm, of documentary type; and seeks to analyze the transformation of the teacher from the complex thinking, centered on the teacher-student benefit, through a bibliographic documentary triangulation of the authors Edgar Morin and Matthew Lipman with the subject of complex thinking and the necessary knowledge for education, David Ausubel, Jean Piaget and Lev Vygotsky with educational psychology, Pérez Esclarín with the humanization of education, and finally with contributions from Honore Bernard, UNESCO in the field of teacher transformation. Faced with the crisis and the evolution of education in Latin America requires an educational reform where innovation, creativity, training, vocation and love of teaching practices are contemplated, looking towards the adjustment profile of the current reality of apprentices, assuming in a continuous way the challenge of breaking barriers that obstruct the goal that is pursued in the multidimensional, professional, spiritual and human field, immersed in the complexity of their work, and interacting with all the interior and exterior elements of their humanity that are exposed in the challenge of complex thinking.

  9. Complexity Results in Epistemic Planning

    DEFF Research Database (Denmark)

    Bolander, Thomas; Jensen, Martin Holm; Schwarzentruber, Francois

    2015-01-01

    Epistemic planning is a very expressive framework that extends automated planning by the incorporation of dynamic epistemic logic (DEL). We provide complexity results on the plan existence problem for multi-agent planning tasks, focusing on purely epistemic actions with propositional preconditions...

  10. Transition Metal Complexes and Catalysis

    Indian Academy of Sciences (India)

    approaches towards the study of bonding in transition metal complexes. Despite .... industrial scale reactions for the production of organic compounds using transition ..... It has found several applications as an engineering thermoplastic. .... and processes of interest to the company, that is, applied research. It is this very ...

  11. Lagoa Real complex - implementation program

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The description of the activities from the Lagoa Real Complex is presented, including the development of a complementation process with available drill core samples and drilling an evaluation Cachoeira Deposit. Studies already developed indicate that Cachoeira Deposit has about 70 ton of U3O8 per meter of depth. (author)

  12. Hierarchy Measure for Complex Networks

    Science.gov (United States)

    Mones, Enys; Vicsek, Lilla; Vicsek, Tamás

    2012-01-01

    Nature, technology and society are full of complexity arising from the intricate web of the interactions among the units of the related systems (e.g., proteins, computers, people). Consequently, one of the most successful recent approaches to capturing the fundamental features of the structure and dynamics of complex systems has been the investigation of the networks associated with the above units (nodes) together with their relations (edges). Most complex systems have an inherently hierarchical organization and, correspondingly, the networks behind them also exhibit hierarchical features. Indeed, several papers have been devoted to describing this essential aspect of networks, however, without resulting in a widely accepted, converging concept concerning the quantitative characterization of the level of their hierarchy. Here we develop an approach and propose a quantity (measure) which is simple enough to be widely applicable, reveals a number of universal features of the organization of real-world networks and, as we demonstrate, is capable of capturing the essential features of the structure and the degree of hierarchy in a complex network. The measure we introduce is based on a generalization of the m-reach centrality, which we first extend to directed/partially directed graphs. Then, we define the global reaching centrality (GRC), which is the difference between the maximum and the average value of the generalized reach centralities over the network. We investigate the behavior of the GRC considering both a synthetic model with an adjustable level of hierarchy and real networks. Results for real networks show that our hierarchy measure is related to the controllability of the given system. We also propose a visualization procedure for large complex networks that can be used to obtain an overall qualitative picture about the nature of their hierarchical structure. PMID:22470477

  13. Complex DNA structures and structures of DNA complexes

    International Nuclear Information System (INIS)

    Chazin, W.J.; Carlstroem, G.; Shiow-Meei Chen; Miick, S.; Gomez-Paloma, L.; Smith, J.; Rydzewski, J.

    1994-01-01

    Complex DNA structures (for example, triplexes, quadruplexes, junctions) and DNA-ligand complexes are more difficult to study by NMR than standard DNA duplexes are because they have high molecular weights, show nonstandard or distorted local conformations, and exhibit large resonance linewidths and severe 1 H spectral overlap. These systems also tend to have limited solubility and may require specialized solution conditions to maintain favorable spectral characteristics, which adds to the spectroscopic difficulties. Furthermore, with more atoms in the system, both assignment and structure calculation become more challenging. In this article, we focus on demonstrating the current status of NMR studies of such systems and the limitations to further progress; we also indicate in what ways isotopic enrichment can be useful

  14. Complex DNA structures and structures of DNA complexes

    Energy Technology Data Exchange (ETDEWEB)

    Chazin, W.J.; Carlstroem, G.; Shiow-Meei Chen; Miick, S.; Gomez-Paloma, L.; Smith, J.; Rydzewski, J. [Scripps Research Institute, La Jolla, CA (United States)

    1994-12-01

    Complex DNA structures (for example, triplexes, quadruplexes, junctions) and DNA-ligand complexes are more difficult to study by NMR than standard DNA duplexes are because they have high molecular weights, show nonstandard or distorted local conformations, and exhibit large resonance linewidths and severe {sup 1}H spectral overlap. These systems also tend to have limited solubility and may require specialized solution conditions to maintain favorable spectral characteristics, which adds to the spectroscopic difficulties. Furthermore, with more atoms in the system, both assignment and structure calculation become more challenging. In this article, we focus on demonstrating the current status of NMR studies of such systems and the limitations to further progress; we also indicate in what ways isotopic enrichment can be useful.

  15. I. Redox chemistry of bimetallic fulvalene complexes II. Oligocyclopentadienyl complexes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, David Stephen [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley Lab., CA (United States). Chemical Sciences Div.

    1993-11-01

    The electrochemistry of the heterobimetallic complexes (fulvalene)WFe(CO)5 (30) and (fulvalene)WRu(CO)5 (31) has been investigated. Compound 30 is reduced in two one-electron processes, and this behavior was exploited synthetically to prepare a tetranuclear dimer by selective metal reduction. Complex 31 displayed a distinction between the metals upon reoxidation of the dianion, allowing the formation of a dimer by selective metal anion oxidation. The redox behavior of 30 led to an investigation of the use of electrocatalysis to effect metal-specific ligand substitution. It was found that reduction of 30 with a catalytic amount of CpFe(C6Me6) (97) in the presence of excess P(OMe)3 or PMe5 led to the formation of the zwitterions (fulvalene)[W(CO)3-][Fe(CO)PR3+] (107, R = P(OMe)3; 108, R = PMe3). Compound 31 also displayed unique behavior with different reducing agents, as the monosubstituted zwitterion (fulvalene)[W(CO)3-][Ru(CO)2(PMe3+] was obtained when 97 was used while the disubstituted complex (fulvalene) [W(CO)3-] [Ru(CO)(PMe3)2+] was produced when Cp*Fe(C6Me6) was the catalyst. Potential synthetic routes to quatercyclopentadienyl complexes were also explored. Various attempts to couple heterobimetallic fulvalene compounds proved to be unsuccessful. 138 refs.

  16. Rapid Mission Design for Dynamically Complex Environments

    Data.gov (United States)

    National Aeronautics and Space Administration — Designing trajectories in dynamically complex environments is very challenging and easily becomes an intractable problem. More complex planning implies potentially...

  17. Physical approach to complex systems

    Science.gov (United States)

    Kwapień, Jarosław; Drożdż, Stanisław

    2012-06-01

    Typically, complex systems are natural or social systems which consist of a large number of nonlinearly interacting elements. These systems are open, they interchange information or mass with environment and constantly modify their internal structure and patterns of activity in the process of self-organization. As a result, they are flexible and easily adapt to variable external conditions. However, the most striking property of such systems is the existence of emergent phenomena which cannot be simply derived or predicted solely from the knowledge of the systems’ structure and the interactions among their individual elements. This property points to the holistic approaches which require giving parallel descriptions of the same system on different levels of its organization. There is strong evidence-consolidated also in the present review-that different, even apparently disparate complex systems can have astonishingly similar characteristics both in their structure and in their behaviour. One can thus expect the existence of some common, universal laws that govern their properties. Physics methodology proves helpful in addressing many of the related issues. In this review, we advocate some of the computational methods which in our opinion are especially fruitful in extracting information on selected-but at the same time most representative-complex systems like human brain, financial markets and natural language, from the time series representing the observables associated with these systems. The properties we focus on comprise the collective effects and their coexistence with noise, long-range interactions, the interplay between determinism and flexibility in evolution, scale invariance, criticality, multifractality and hierarchical structure. The methods described either originate from “hard” physics-like the random matrix theory-and then were transmitted to other fields of science via the field of complex systems research, or they originated elsewhere but

  18. Complex terrain and wind lidars

    Energy Technology Data Exchange (ETDEWEB)

    Bingoel, F.

    2009-08-15

    This thesis includes the results of a PhD study about complex terrain and wind lidars. The study mostly focuses on hilly and forested areas. Lidars have been used in combination with cups, sonics and vanes, to reach the desired vertical measurement heights. Several experiments are performed in complex terrain sites and the measurements are compared with two different flow models; a linearised flow model LINCOM and specialised forest model SCADIS. In respect to the lidar performance in complex terrain, the results showed that horizontal wind speed errors measured by a conically scanning lidar can be of the order of 3-4% in moderately-complex terrain and up to 10% in complex terrain. The findings were based on experiments involving collocated lidars and meteorological masts, together with flow calculations over the same terrains. The lidar performance was also simulated with the commercial software WAsP Engineering 2.0 and was well predicted except for some sectors where the terrain is particularly steep. Subsequently, two experiments were performed in forested areas; where the measurements are recorded at a location deep-in forest and at the forest edge. Both sites were modelled with flow models and the comparison of the measurement data with the flow model outputs showed that the mean wind speed calculated by LINCOM model was only reliable between 1 and 2 tree height (h) above canopy. The SCADIS model reported better correlation with the measurements in forest up to approx6h. At the forest edge, LINCOM model was used by allocating a slope half-in half out of the forest based on the suggestions of previous studies. The optimum slope angle was reported as 17 deg.. Thus, a suggestion was made to use WAsP Engineering 2.0 for forest edge modelling with known limitations and the applied method. The SCADIS model worked better than the LINCOM model at the forest edge but the model reported closer results to the measurements at upwind than the downwind and this should be

  19. Is a "Complex" Task Really Complex? Validating the Assumption of Cognitive Task Complexity

    Science.gov (United States)

    Sasayama, Shoko

    2016-01-01

    In research on task-based learning and teaching, it has traditionally been assumed that differing degrees of cognitive task complexity can be inferred through task design and/or observations of differing qualities in linguistic production elicited by second language (L2) communication tasks. Without validating this assumption, however, it is…

  20. Revitalizing Complex Analysis: A Transition-to-Proof Course Centered on Complex Topics

    Science.gov (United States)

    Sachs, Robert

    2017-01-01

    A new transition course centered on complex topics would help in revitalizing complex analysis in two ways: first, provide early exposure to complex functions, sparking greater interest in the complex analysis course; second, create extra time in the complex analysis course by eliminating the "complex precalculus" part of the course. In…

  1. Leptogenesis in Complex Hybrid Inflation

    International Nuclear Information System (INIS)

    Martinez-Prieto, Carlos

    2008-01-01

    We study the transference of an initial leptonic charge contained in a complex scalar field (waterfall field) at the end of the inflation to the leptons of the standard model and then convert this leptonic charge in baryonic charge by sphaleron process. The proposal is that this is done trough the decay of the complex scalar field particles into the the right-handed neutrino which in turn decays into the left-handed lepton doublet and the Higgs field of the standard model. It must be analyzed in what environment the transference is done. We propose that the inflaton (the dominant energy density of the universe) decay into ultrarelativistic fermions before the waterfall field particles decay in the right handed-neutrino, leaving a thermalized bath where the transference of the leptonic asymmetry can be achieved.

  2. Complex multiplication and lifting problems

    CERN Document Server

    Chai, Ching-Li; Oort, Frans

    2013-01-01

    Abelian varieties with complex multiplication lie at the origins of class field theory, and they play a central role in the contemporary theory of Shimura varieties. They are special in characteristic 0 and ubiquitous over finite fields. This book explores the relationship between such abelian varieties over finite fields and over arithmetically interesting fields of characteristic 0 via the study of several natural CM lifting problems which had previously been solved only in special cases. In addition to giving complete solutions to such questions, the authors provide numerous examples to illustrate the general theory and present a detailed treatment of many fundamental results and concepts in the arithmetic of abelian varieties, such as the Main Theorem of Complex Multiplication and its generalizations, the finer aspects of Tate's work on abelian varieties over finite fields, and deformation theory. This book provides an ideal illustration of how modern techniques in arithmetic geometry (such as descent the...

  3. Computational complexity of Boolean functions

    Energy Technology Data Exchange (ETDEWEB)

    Korshunov, Aleksei D [Sobolev Institute of Mathematics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2012-02-28

    Boolean functions are among the fundamental objects of discrete mathematics, especially in those of its subdisciplines which fall under mathematical logic and mathematical cybernetics. The language of Boolean functions is convenient for describing the operation of many discrete systems such as contact networks, Boolean circuits, branching programs, and some others. An important parameter of discrete systems of this kind is their complexity. This characteristic has been actively investigated starting from Shannon's works. There is a large body of scientific literature presenting many fundamental results. The purpose of this survey is to give an account of the main results over the last sixty years related to the complexity of computation (realization) of Boolean functions by contact networks, Boolean circuits, and Boolean circuits without branching. Bibliography: 165 titles.

  4. Complex-Valued Neural Networks

    CERN Document Server

    Hirose, Akira

    2012-01-01

    This book is the second enlarged and revised edition of the first successful monograph on complex-valued neural networks (CVNNs) published in 2006, which lends itself to graduate and undergraduate courses in electrical engineering, informatics, control engineering, mechanics, robotics, bioengineering, and other relevant fields. In the second edition the recent trends in CVNNs research are included, resulting in e.g. almost a doubled number of references. The parametron invented in 1954 is also referred to with discussion on analogy and disparity. Also various additional arguments on the advantages of the complex-valued neural networks enhancing the difference to real-valued neural networks are given in various sections. The book is useful for those beginning their studies, for instance, in adaptive signal processing for highly functional sensing and imaging, control in unknown and changing environment, robotics inspired by human neural systems, and brain-like information processing, as well as interdisciplina...

  5. Computational models of complex systems

    CERN Document Server

    Dabbaghian, Vahid

    2014-01-01

    Computational and mathematical models provide us with the opportunities to investigate the complexities of real world problems. They allow us to apply our best analytical methods to define problems in a clearly mathematical manner and exhaustively test our solutions before committing expensive resources. This is made possible by assuming parameter(s) in a bounded environment, allowing for controllable experimentation, not always possible in live scenarios. For example, simulation of computational models allows the testing of theories in a manner that is both fundamentally deductive and experimental in nature. The main ingredients for such research ideas come from multiple disciplines and the importance of interdisciplinary research is well recognized by the scientific community. This book provides a window to the novel endeavours of the research communities to present their works by highlighting the value of computational modelling as a research tool when investigating complex systems. We hope that the reader...

  6. From real to complex analysis

    CERN Document Server

    Dyer, R H

    2014-01-01

    The purpose of this book is to provide an integrated course in real and complex analysis for those who have already taken a preliminary course in real analysis. It particularly emphasises the interplay between analysis and topology. Beginning with the theory of the Riemann integral (and its improper extension) on the real line, the fundamentals of metric spaces are then developed, with special attention being paid to connectedness, simple connectedness and various forms of homotopy. The final chapter develops the theory of complex analysis, in which emphasis is placed on the argument, the winding number, and a general (homology) version of Cauchy's theorem which is proved using the approach due to Dixon. Special features are the inclusion of proofs of Montel's theorem, the Riemann mapping theorem and the Jordan curve theorem that arise naturally from the earlier development. Extensive exercises are included in each of the chapters, detailed solutions of the majority of which are given at the end. From Real to...

  7. Chaos and complexity by design

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Daniel A. [Center for Theoretical Physics and Department of Physics,Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); School of Natural Sciences, Institute for Advanced Study,Princeton, NJ 08540 (United States); Yoshida, Beni [Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2L 2Y5 (Canada)

    2017-04-20

    We study the relationship between quantum chaos and pseudorandomness by developing probes of unitary design. A natural probe of randomness is the “frame potential,” which is minimized by unitary k-designs and measures the 2-norm distance between the Haar random unitary ensemble and another ensemble. A natural probe of quantum chaos is out-of-time-order (OTO) four-point correlation functions. We show that the norm squared of a generalization of out-of-time-order 2k-point correlators is proportional to the kth frame potential, providing a quantitative connection between chaos and pseudorandomness. Additionally, we prove that these 2k-point correlators for Pauli operators completely determine the k-fold channel of an ensemble of unitary operators. Finally, we use a counting argument to obtain a lower bound on the quantum circuit complexity in terms of the frame potential. This provides a direct link between chaos, complexity, and randomness.

  8. Boundaries of a complex world

    CERN Document Server

    Ludu, Andrei

    2016-01-01

    The central theme of this book is the extent to which the structure of the free dynamical boundaries of a system controls the evolution of the system as a whole. Applying three orthogonal types of thinking - mathematical, constructivist and morphological, it illustrates these concepts using applications to selected problems from the social and life sciences, as well as economics. In a broader context, it introduces and reviews some modern mathematical approaches to the science of complex systems. Standard modeling approaches (based on non-linear differential equations, dynamic systems, graph theory, cellular automata, stochastic processes, or information theory) are suitable for studying local problems. However they cannot simultaneously take into account all the different facets and phenomena of a complex system, and new approaches are required to solve the challenging problem of correlations between phenomena at different levels and hierarchies, their self-organization and memory-evolutive aspects, the grow...

  9. Chaos and complexity by design

    International Nuclear Information System (INIS)

    Roberts, Daniel A.; Yoshida, Beni

    2017-01-01

    We study the relationship between quantum chaos and pseudorandomness by developing probes of unitary design. A natural probe of randomness is the “frame potential,” which is minimized by unitary k-designs and measures the 2-norm distance between the Haar random unitary ensemble and another ensemble. A natural probe of quantum chaos is out-of-time-order (OTO) four-point correlation functions. We show that the norm squared of a generalization of out-of-time-order 2k-point correlators is proportional to the kth frame potential, providing a quantitative connection between chaos and pseudorandomness. Additionally, we prove that these 2k-point correlators for Pauli operators completely determine the k-fold channel of an ensemble of unitary operators. Finally, we use a counting argument to obtain a lower bound on the quantum circuit complexity in terms of the frame potential. This provides a direct link between chaos, complexity, and randomness.

  10. Anomie in the Complex Socium

    Directory of Open Access Journals (Sweden)

    Natalia N. Mescheryakova

    2014-01-01

    Full Text Available The article deals with the question of what changes should be made in the theory of social anomie, formulated by Emile Durkheim and developed by Robert Merton. This is necessary because modern society has entered a qualitatively new stage in its development and is characterized by the notion of a complex socium. Anomie in a simple socium can be defined as structural. Social system itself creates the conditions in which the destructive behavior is "normal" response to the social situation. Anomie of modern complex society can be defined as reflexive. Variety of value-normative systems leads to the fact that norms become an act of choice. Decision-making center has shifted to the level of the microcosm. They have become as unpredictable as social life in general.

  11. Complexity of Curved Glass Structures

    Science.gov (United States)

    Kosić, T.; Svetel, I.; Cekić, Z.

    2017-11-01

    Despite the increasing number of research on the architectural structures of curvilinear forms and technological and practical improvement of the glass production observed over recent years, there is still a lack of comprehensive codes and standards, recommendations and experience data linked to real-life curved glass structures applications regarding design, manufacture, use, performance and economy. However, more and more complex buildings and structures with the large areas of glass envelope geometrically complex shape are built every year. The aim of the presented research is to collect data on the existing design philosophy on curved glass structure cases. The investigation includes a survey about how architects and engineers deal with different design aspects of curved glass structures with a special focus on the design and construction process, glass types and structural and fixing systems. The current paper gives a brief overview of the survey findings.

  12. Feasible quantum communication complexity protocol

    International Nuclear Information System (INIS)

    Galvao, Ernesto F.

    2002-01-01

    I show that a simple multiparty communication task can be performed more efficiently with quantum communication than with classical communication, even with low detection efficiency η. The task is a communication complexity problem in which distant parties need to compute a function of the distributed inputs, while minimizing the amount of communication between them. A realistic quantum optical setup is suggested that can demonstrate a five-party quantum protocol with higher-than-classical performance, provided η>0.33

  13. On real quadric line complexes

    International Nuclear Information System (INIS)

    Krasnov, Vyacheslav A

    2010-01-01

    We describe the topological types of the real parts of the Kummer surfaces associated with real three-dimensional quadric line complexes. The topological type of the real part of such a surface is shown to depend on the number of real singular points: it is determined by the number of such points if any exist, and otherwise the real part of the Kummer surface is either empty or consists of one or two tori.

  14. Information processing in complex networks

    OpenAIRE

    Quax, R.

    2013-01-01

    Eerste resultaten van onderzoek van Rick Quax suggereren dat een combinatie van informatietheorie, netwerktheorie en statistische mechanica kan leiden tot een veelbelovende theorie om het gedrag van complexe netwerken te voorspellen. Er bestaat nog weinig theorie over het gedrag van dynamische eenheden die verbonden zijn in een netwerk, zoals neuronen in een breinnetwerk of genen in een gen-regulatienetwerk. Quax combineert informatietheorie, netwerktheorie, en statistische onderzoeken en mec...

  15. Complex hydrides for hydrogen storage

    Science.gov (United States)

    Zidan, Ragaiy

    2006-08-22

    A hydrogen storage material and process of forming the material is provided in which complex hydrides are combined under conditions of elevated temperatures and/or elevated temperature and pressure with a titanium metal such as titanium butoxide. The resulting fused product exhibits hydrogen desorption kinetics having a first hydrogen release point which occurs at normal atmospheres and at a temperature between 50.degree. C. and 90.degree. C.

  16. Polycomb complexes and silencing mechanisms

    DEFF Research Database (Denmark)

    Lund, Anders H; van Lohuizen, Maarten

    2004-01-01

    Advances in the past couple of years have brought important new knowledge on the mechanisms by which Polycomb-group proteins regulate gene expression and on the consequences of their actions. The discovery of histone methylation imprints specific for Polycomb and Trithorax complexes has provided...... mechanistic insight on how this ancient epigenetic memory system acts to repress and indicates that it may share mechanistic aspects with other silencing and genome-protective processes, such as RNA interference....

  17. Reduced and Superreduced Diplatinum Complexes

    Czech Academy of Sciences Publication Activity Database

    Darnton, T. V.; Hunter, B. M.; Hill, M. G.; Záliš, Stanislav; Vlček, Antonín; Gray, H. B.

    2016-01-01

    Roč. 138, č. 17 (2016), s. 5699-5705 ISSN 0002-7863 R&D Projects: GA MŠk LH13015; GA MŠk LD14129 Grant - others:COST(XE) cm1202; COST(XE) CM1405 Institutional support: RVO:61388955 Keywords : diplatinum complexes * EPR spectrum * TD-DFT Subject RIV: CG - Electrochemistry Impact factor: 13.858, year: 2016

  18. Space complexity in polynomial calculus

    Czech Academy of Sciences Publication Activity Database

    Filmus, Y.; Lauria, M.; Nordström, J.; Ron-Zewi, N.; Thapen, Neil

    2015-01-01

    Roč. 44, č. 4 (2015), s. 1119-1153 ISSN 0097-5397 R&D Projects: GA AV ČR IAA100190902; GA ČR GBP202/12/G061 Institutional support: RVO:67985840 Keywords : proof complexity * polynomial calculus * lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.841, year: 2015 http://epubs.siam.org/doi/10.1137/120895950

  19. Complexity of infimal observable superlanguages

    Czech Academy of Sciences Publication Activity Database

    Masopust, Tomáš

    2018-01-01

    Roč. 63, č. 1 (2018), s. 249-254 ISSN 0018-9286 Institutional support: RVO:67985840 Keywords : discrete event systems * observable language * complexity Subject RIV: BA - General Mathematics OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 4.270, year: 2016 http://ieeexplore.ieee.org/document/7962165/

  20. Circuit complexity of regular languages

    Czech Academy of Sciences Publication Activity Database

    Koucký, Michal

    2009-01-01

    Roč. 45, č. 4 (2009), s. 865-879 ISSN 1432-4350 R&D Projects: GA ČR GP201/07/P276; GA MŠk(CZ) 1M0545 Institutional research plan: CEZ:AV0Z10190503 Keywords : regular languages * circuit complexity * upper and lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.726, year: 2009

  1. Collaborative engineering for complex products

    CSIR Research Space (South Africa)

    Erasmus, J

    2015-10-01

    Full Text Available stream_source_info Erasmus_2015.pdf.txt stream_content_type text/plain stream_size 6206 Content-Encoding UTF-8 stream_name Erasmus_2015.pdf.txt Content-Type text/plain; charset=UTF-8 Collaborative engineering... with collaboration and cooperation • Now they compete on implementation (application) instead of standards (infrastructure) Reyes, V., 2014. Dealing with automotive software complexity with virtual prototyping – Part 1: Virtual HIL development basics (accessed 9...

  2. Renovation of the hotel complex

    OpenAIRE

    DRHA, Aleš

    2012-01-01

    The theme of this work is reconstruction the hotel complex. The theoretical part informs readers about tourism, marketing and how to build a business plan. Analytical part shows the issue of tourism in the region and technical condition of the hotel. In the synthetic part is suggested business plan to hotel reconstruction, marketing mix for tourism and financial plan, that shows operating costs and revenues. The investment could be paid off by the 13th year since the start of the hotel service.

  3. Complexing and hydrothermal ore deposition

    CERN Document Server

    Helgeson, Harold C

    1964-01-01

    Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

  4. Relaxation effects in ferrous complexes

    International Nuclear Information System (INIS)

    Nicolini, C.; Mathieu, J.P.; Chappert, J.

    1976-01-01

    The slow relaxation mechanism of the Fe 2+ ion in the tri-fluorinated TF(acac) and hexafluorinated HF(acac) complexes of Fe(II) acetylacetonate was investigated. The 300K and 77K Moessbauer spectra for TF(acac) consist in a slightly asymmetric quadrupole doublet. On the contrary, at 4.2K the higher energy line is strongly widened; that is typical of a slowing down in the electron relaxation frequency [fr

  5. Chaos in a complex plasma

    International Nuclear Information System (INIS)

    Sheridan, T.E.

    2005-01-01

    Chaotic dynamics is observed experimentally in a complex (dusty) plasma of three particles. A low-frequency sinusoidal modulation of the plasma density excites both the center-of-mass and breathing modes. Low-dimensional chaos is seen for a 1:2 resonance between these modes. A strange attractor with a dimension of 2.48±0.05 is observed. The largest Lyapunov exponent is positive

  6. State Complexity of Testing Divisibility

    Directory of Open Access Journals (Sweden)

    Emilie Charlier

    2010-08-01

    Full Text Available Under some mild assumptions, we study the state complexity of the trim minimal automaton accepting the greedy representations of the multiples of m >= 2 for a wide class of linear numeration systems. As an example, the number of states of the trim minimal automaton accepting the greedy representations of the multiples of m in the Fibonacci system is exactly 2m^2.

  7. Dimethyl sulfoxide complexing with iodine

    Energy Technology Data Exchange (ETDEWEB)

    Borovikov, Yu Ya; Serguchev, Yu A; Staninets, V I

    1986-01-01

    Dielectrometry, conductometry, IR-spectroscopy are used to study dimethyl sulfoxide complexing with iodine in binary system and in CCl/sub 4/, C/sub 6/H/sub 6/, C/sub 6/H/sub 5/Cl, C/sub 6/H/sub 5/CF/sub 3/, 1, 2-dichloroethane solutions. Complexes of 1:1 composition are formed in solutions, in the binary system of 2:1 and 2:2 composition. I/sub 2/ molecules add to oxygen atoms. In CCl/sub 4/ and in binary system gradual transformation of so called external charge transfer complexes (CTC-1) to internal ones (CTC-2) that are described by the 1st order reaction kinetic equations is observed. On dissolution of CTC of 2:2 composition they disproportionate into two CTC molecules 1:1. Enthalpy of forming CTC-1 1:1 is approximately 4 kcal/mol, CTC-2 1:1 - 8, CTC-1 2:1 - 8 kcal/mol.

  8. Emergence: Complexity Pedagogy in Action

    Science.gov (United States)

    Jonas-Simpson, Christine

    2015-01-01

    Many educators are looking for new ways to engage students and each other in order to enrich curriculum and the teaching-learning process. We describe an example of how we enacted teaching-learning approaches through the insights of complexity thinking, an approach that supports the emergence of new possibilities for teaching-learning in the classroom and online. Our story begins with an occasion to meet with 10 nursing colleagues in a three-hour workshop using four activities that engaged learning about complexity thinking and pedagogy. Guiding concepts for the collaborative workshop were nonlinearity, distributed decision-making, divergent thinking, self-organization, emergence, and creative exploration. The workshop approach considered critical questions to spark our collective inquiry. We asked, “What is emergent learning?” and “How do we, as educators and learners, engage a community so that new learning surfaces?” We integrated the arts, creative play, and perturbations within a complexity approach. PMID:25838945

  9. Decision paths in complex tasks

    Science.gov (United States)

    Galanter, Eugene

    1991-01-01

    Complex real world action and its prediction and control has escaped analysis by the classical methods of psychological research. The reason is that psychologists have no procedures to parse complex tasks into their constituents. Where such a division can be made, based say on expert judgment, there is no natural scale to measure the positive or negative values of the components. Even if we could assign numbers to task parts, we lack rules i.e., a theory, to combine them into a total task representation. We compare here two plausible theories for the amalgamation of the value of task components. Both of these theories require a numerical representation of motivation, for motivation is the primary variable that guides choice and action in well-learned tasks. We address this problem of motivational quantification and performance prediction by developing psychophysical scales of the desireability or aversiveness of task components based on utility scaling methods (Galanter 1990). We modify methods used originally to scale sensory magnitudes (Stevens and Galanter 1957), and that have been applied recently to the measure of task 'workload' by Gopher and Braune (1984). Our modification uses utility comparison scaling techniques which avoid the unnecessary assumptions made by Gopher and Braune. Formula for the utility of complex tasks based on the theoretical models are used to predict decision and choice of alternate paths to the same goal.

  10. Physics of Complex Polymeric Molecules

    Science.gov (United States)

    Kelly, Joshua Walter

    The statistical physics of complex polymers with branches and circuits is the topic of this dissertation. An important motivation are large, single-stranded (ss) RNA molecules. Such molecules form complex ``secondary" and ``tertiary" structures that can be represented as branched polymers with circuits. Such structures are in part directly determined by the nucleotide sequence and in part subject to thermal fluctuations. The polymer physics literature on molecules in this class has mostly focused on randomly branched polymers without circuits while there has been minimal research on polymers with specific structures and on polymers that contain circuits. The dissertation is composed of three parts: Part I studies branched polymers with thermally fluctuating structure confined to a potential well as a simple model for the encapsidation of viral RNA. Excluded volume interactions were ignored. In Part II, I apply Flory theory to the study of the encapsidation of viral ss RNA molecules with specific branched structures, but without circuits, in the presence of excluded volume interaction. In Part III, I expand on Part II and consider complex polymers with specific structure including both branching and circuits. I introduce a method based on the mathematics of Laplacian matrices that allows me to calculate density profiles for such molecules, which was not possible within Flory theory.

  11. Ranking in evolving complex networks

    Science.gov (United States)

    Liao, Hao; Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng; Zhou, Ming-Yang

    2017-05-01

    Complex networks have emerged as a simple yet powerful framework to represent and analyze a wide range of complex systems. The problem of ranking the nodes and the edges in complex networks is critical for a broad range of real-world problems because it affects how we access online information and products, how success and talent are evaluated in human activities, and how scarce resources are allocated by companies and policymakers, among others. This calls for a deep understanding of how existing ranking algorithms perform, and which are their possible biases that may impair their effectiveness. Many popular ranking algorithms (such as Google's PageRank) are static in nature and, as a consequence, they exhibit important shortcomings when applied to real networks that rapidly evolve in time. At the same time, recent advances in the understanding and modeling of evolving networks have enabled the development of a wide and diverse range of ranking algorithms that take the temporal dimension into account. The aim of this review is to survey the existing ranking algorithms, both static and time-aware, and their applications to evolving networks. We emphasize both the impact of network evolution on well-established static algorithms and the benefits from including the temporal dimension for tasks such as prediction of network traffic, prediction of future links, and identification of significant nodes.

  12. Overview of the Orion Complex

    Science.gov (United States)

    Bally, J.

    2008-12-01

    The Orion star formation complex is the nearest region of on-going star formation that continues to produce both low and high mass stars. Orion is discussed in the larger context of star formation in the Solar vicinity over the last 100 Myr. The Orion complex is located on the far side of the Gould's Belt system of clouds and young stars through which our Solar system is drifting. A review is given of the overall structure and properties of the Orion star forming complex, the best studied OB association. Over the last 12 Myr, Orion has given birth to at least ten thousand stars contained in a half dozen sub-groups and short-lived clusters. The Orion OB association has been the source of several massive, high-velocity run-away stars, including μ Columbae and AE Aurigae. Some of Orion's most massive members died in supernova explosions that created the 300 pc diameter Orion / Eridanus super-bubble whose near wall may be as close as 180 pc. The combined effects of UV radiation, stellar winds, and supernovae have impacted surviving molecular clouds in Orion. The large Orion A, IC 2118 molecular clouds and dozens of smaller clouds strewn throughout the interior of the superbubble have cometary shapes pointing back towards the center of the Orion OB association. Most are forming stars in the compressed layers facing the bubble interior.

  13. Epidemic processes in complex networks

    Science.gov (United States)

    Pastor-Satorras, Romualdo; Castellano, Claudio; Van Mieghem, Piet; Vespignani, Alessandro

    2015-07-01

    In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The theoretical analysis of epidemic spreading in heterogeneous networks requires the development of novel analytical frameworks, and it has produced results of conceptual and practical relevance. A coherent and comprehensive review of the vast research activity concerning epidemic processes is presented, detailing the successful theoretical approaches as well as making their limits and assumptions clear. Physicists, mathematicians, epidemiologists, computer, and social scientists share a common interest in studying epidemic spreading and rely on similar models for the description of the diffusion of pathogens, knowledge, and innovation. For this reason, while focusing on the main results and the paradigmatic models in infectious disease modeling, the major results concerning generalized social contagion processes are also presented. Finally, the research activity at the forefront in the study of epidemic spreading in coevolving, coupled, and time-varying networks is reported.

  14. HIV surveillance in complex emergencies.

    Science.gov (United States)

    Salama, P; Dondero, T J

    2001-04-01

    Many studies have shown a positive association between both migration and temporary expatriation and HIV risk. This association is likely to be similar or even more pronounced for forced migrants. In general, HIV transmission in host-migrant or host-forced-migrant interactions depends on the maturity of the HIV epidemic in both the host and the migrant population, the relative seroprevalence of HIV in the host and the migrant population, the prevalence of other sexually transmitted infections (STIs) that may facilitate transmission, and the level of sexual interaction between the two communities. Complex emergencies are the major cause of mass population movement today. In complex emergencies, additional factors such as sexual interaction between forced-migrant populations and the military; sexual violence; increasing commercial sex work; psychological trauma; and disruption of preventive and curative health services may increase the risk for HIV transmission. Despite recent success in preventing HIV infection in stable populations in selected developing countries, internally displaced persons and refugees (or forced migrants) have not been systematically included in HIV surveillance systems, nor consequently in prevention activities. Standard surveillance systems that rely on functioning health services may not provide useful data in many complex emergency settings. Secondary sources can provide some information in these settings. Little attempt has been made, however, to develop innovative HIV surveillance systems in countries affected by complex emergencies. Consequently, data on the HIV epidemic in these countries are scarce and HIV prevention programs are either not implemented or interventions are not effectively targeted. Second generation surveillance methods such as cross-sectional, population-based surveys can provide rapid information on HIV, STIs, and sexual behavior. The risks for stigmatization and breaches of confidentiality must be recognized

  15. Disordered Plamonics and Complex Metamaterials

    KAUST Repository

    Gongora, J. S. Totero

    2017-05-01

    Complex systems are ensembles of interconnected elements where mutual interaction and an optimized amount of disorder produce advanced functionalities. These systems are abundant in our daily experience: typical examples are the brain, biological ecosystems, society, and finance. In the last century, researchers have investigated the fundamental properties of disordered systems, unveiling fascinating and counterintuitive dynamics. The main aim of this Dissertation is the study of a new platform of disorder-enhanced photonics systems, denoted as Complex Metamaterials. Due to its ultrafast time scale nanophotonics represents an ideal framework to investigate and harness complex dynamics. Starting from the theoretical modeling of disordered plasmonic systems, I discuss advanced real-life applications, including the generation of highly-resistant structural colors from porous metal surfaces and the realization of early-stage cancer detectors based on surface roughness and self-similarity. In addition to the effects of structural disorder on plasmonic systems I also investigate the complex emission dynamics from non-conventional nanolasers. Lasers represent the quintessential example of a complex photonic system due to the simultaneous presence of strong nonlinearities and multi-mode interactions. At the same time, the integration of nanolasers with silicon-based electronic circuitry represents one of the greatest technological challenges in the field of nanophotonics. By combining ab-initio simulations and analytical modeling, I characterize the nonlinear emission from three-dimensional plasmonic nanolasers known as SPASERs. My results show for the first time the occurrence of a spontaneous rotational emission in spherical SPASERs, which originates from the nonlinear interaction of several lasing modes. I further discuss how rotating nanolasers can be employed as a fundamental building block for integrated quantum simulators, random information sources, and brain

  16. 5th International Conference on Complex Systems

    CERN Document Server

    Braha, Dan; Bar-Yam, Yaneer

    2011-01-01

    The International Conference on Complex Systems (ICCS) creates a unique atmosphere for scientists of all fields, engineers, physicians, executives, and a host of other professionals to explore common themes and applications of complex system science. With this new volume, Unifying Themes in Complex Systems continues to build common ground between the wide-ranging domains of complex system science.

  17. Tensor Product of Polygonal Cell Complexes

    OpenAIRE

    Chien, Yu-Yen

    2017-01-01

    We introduce the tensor product of polygonal cell complexes, which interacts nicely with the tensor product of link graphs of complexes. We also develop the unique factorization property of polygonal cell complexes with respect to the tensor product, and study the symmetries of tensor products of polygonal cell complexes.

  18. 7th International Conference on Complex Systems

    CERN Document Server

    Braha, Dan; Bar-Yam, Yaneer

    2012-01-01

    The International Conference on Complex Systems (ICCS) creates a unique atmosphere for scientists of all fields, engineers, physicians, executives, and a host of other professionals to explore common themes and applications of complex system science. With this new volume, Unifying Themes in Complex Systems continues to build common ground between the wide-ranging domains of complex system science.

  19. Organization structures for dealing with complexity

    NARCIS (Netherlands)

    Meijer, B.R.

    2006-01-01

    "Complexity is in the eye of the beholder" is a well known quote in the research field of complexity. In the world of managers the word complex is often a synonym for difficult, complicated, involving many factors and highly uncertain. A complex business decision requires careful preparation and

  20. Synchronization in node of complex networks consist of complex chaotic system

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Qiang, E-mail: qiangweibeihua@163.com [Beihua University computer and technology College, BeiHua University, Jilin, 132021, Jilin (China); Digital Images Processing Institute of Beihua University, BeiHua University, Jilin, 132011, Jilin (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, 116024 (China); Xie, Cheng-jun [Beihua University computer and technology College, BeiHua University, Jilin, 132021, Jilin (China); Digital Images Processing Institute of Beihua University, BeiHua University, Jilin, 132011, Jilin (China); Liu, Hong-jun [School of Information Engineering, Weifang Vocational College, Weifang, 261041 (China); Li, Yan-hui [The Library, Weifang Vocational College, Weifang, 261041 (China)

    2014-07-15

    A new synchronization method is investigated for node of complex networks consists of complex chaotic system. When complex networks realize synchronization, different component of complex state variable synchronize up to different scaling complex function by a designed complex feedback controller. This paper change synchronization scaling function from real field to complex field for synchronization in node of complex networks with complex chaotic system. Synchronization in constant delay and time-varying coupling delay complex networks are investigated, respectively. Numerical simulations are provided to show the effectiveness of the proposed method.