WorldWideScience

Sample records for bound carbohydrate complexes

  1. Complex carbohydrates (image)

    Science.gov (United States)

    ... foods such as peas, beans, whole grains, and vegetables. Both simple and complex carbohydrates are turned to glucose (blood sugar) in the body and are used as energy. Glucose is used in the cells of the body and in the brain. Any ...

  2. Explicit bounds of complex exponential frames

    Directory of Open Access Journals (Sweden)

    Boivin André

    2006-01-01

    Full Text Available We discuss the stability of complex exponential frames in , . Specifically, we improve the -theorem and obtain explicit upper and lower bounds for some complex exponential frames perturbed along the real and imaginary axes, respectively. Two examples are given to show that the bounds are best possible. In addition, the growth of the entire functions of exponential type on the integer sequence is estimated.

  3. Molecular simulations of carbohydrate-protein complexes

    OpenAIRE

    Eid, Sameh Mansour Abbas

    2013-01-01

    I. Generation and validation of a free-energy model for carbohydrate binding. Carbohy-drates play a key role in a variety of physiological and pathological processes and, hence, represent a rich source for the development of novel therapeutic agents. Being able to predict binding mode and binding affinity is an essential, yet lacking, aspect of the stru-cture-based design of carbohydrate-based ligands. To this end, we assembled a diverse data set of 316 carbohydrate–protein crystal structu...

  4. Space-bounded communication complexity

    DEFF Research Database (Denmark)

    Brody, Joshua Eric; Chen, Shiteng; Papakonstantinou, Periklis A.;

    2013-01-01

    communicate his entire input. However, what if the players are limited in their ability to recall parts of their interaction? We introduce memory models for 2-party communication complexity. Our general model is as follows: two computationally unrestricted players, Alice and Bob, each have s(n) bits of memory...... controls two types of memory: (i) a large, oblivious memory, where updates are only a function of the received bit and the current memory content, and (ii) a smaller, non-oblivious/general memory, where updates can be a function of the input given to Bob. We exhibit natural protocols where this semi...

  5. Carbohydrate – protein complex of the waste of climacoptera obtusifolia

    Directory of Open Access Journals (Sweden)

    G. Seitimova

    2013-05-01

    Full Text Available Extract from Climacoptera obtusifolia family Chenopodiaceae has antidiabetic activity. For the first time carbohydrate-protein complex of the waste from Climacoptera obtusifolia was studied. It was found that the quantity of extractive substances with 80% ethanol in aerial part – 52;6% and in the waste – 12;35%. The technique of separation of the carbohydrate-protein complex from the waste from Climacoptera obtusifolia is developed by means of classical and physical-chemical methods. The composition of carbohydrate-protein complex was identified: oligosaccharide; polysaccharide and two glycoproteins.

  6. Carbohydrates

    Science.gov (United States)

    Carbohydrates are one of the main types of nutrients. They are the most important source of energy for your body. Your digestive system changes carbohydrates into glucose (blood sugar). Your body uses this ...

  7. Comparative analysis of carbohydrate active enzymes in Clostridium termitidis CT1112 reveals complex carbohydrate degradation ability.

    Directory of Open Access Journals (Sweden)

    Riffat I Munir

    Full Text Available Clostridium termitidis strain CT1112 is an anaerobic, gram positive, mesophilic, cellulolytic bacillus isolated from the gut of the wood-feeding termite, Nasutitermes lujae. It produces biofuels such as hydrogen and ethanol from cellulose, cellobiose, xylan, xylose, glucose, and other sugars, and therefore could be used for biofuel production from biomass through consolidated bioprocessing. The first step in the production of biofuel from biomass by microorganisms is the hydrolysis of complex carbohydrates present in biomass. This is achieved through the presence of a repertoire of secreted or complexed carbohydrate active enzymes (CAZymes, sometimes organized in an extracellular organelle called cellulosome. To assess the ability and understand the mechanism of polysaccharide hydrolysis in C. termitidis, the recently sequenced strain CT1112 of C. termitidis was analyzed for both CAZymes and cellulosomal components, and compared to other cellulolytic bacteria. A total of 355 CAZyme sequences were identified in C. termitidis, significantly higher than other Clostridial species. Of these, high numbers of glycoside hydrolases (199 and carbohydrate binding modules (95 were identified. The presence of a variety of CAZymes involved with polysaccharide utilization/degradation ability suggests hydrolysis potential for a wide range of polysaccharides. In addition, dockerin-bearing enzymes, cohesion domains and a cellulosomal gene cluster were identified, indicating the presence of potential cellulosome assembly.

  8. Comparative analysis of carbohydrate active enzymes in Clostridium termitidis CT1112 reveals complex carbohydrate degradation ability.

    Science.gov (United States)

    Munir, Riffat I; Schellenberg, John; Henrissat, Bernard; Verbeke, Tobin J; Sparling, Richard; Levin, David B

    2014-01-01

    Clostridium termitidis strain CT1112 is an anaerobic, gram positive, mesophilic, cellulolytic bacillus isolated from the gut of the wood-feeding termite, Nasutitermes lujae. It produces biofuels such as hydrogen and ethanol from cellulose, cellobiose, xylan, xylose, glucose, and other sugars, and therefore could be used for biofuel production from biomass through consolidated bioprocessing. The first step in the production of biofuel from biomass by microorganisms is the hydrolysis of complex carbohydrates present in biomass. This is achieved through the presence of a repertoire of secreted or complexed carbohydrate active enzymes (CAZymes), sometimes organized in an extracellular organelle called cellulosome. To assess the ability and understand the mechanism of polysaccharide hydrolysis in C. termitidis, the recently sequenced strain CT1112 of C. termitidis was analyzed for both CAZymes and cellulosomal components, and compared to other cellulolytic bacteria. A total of 355 CAZyme sequences were identified in C. termitidis, significantly higher than other Clostridial species. Of these, high numbers of glycoside hydrolases (199) and carbohydrate binding modules (95) were identified. The presence of a variety of CAZymes involved with polysaccharide utilization/degradation ability suggests hydrolysis potential for a wide range of polysaccharides. In addition, dockerin-bearing enzymes, cohesion domains and a cellulosomal gene cluster were identified, indicating the presence of potential cellulosome assembly.

  9. Lower Complexity Bounds for Lifted Inference

    CERN Document Server

    Jaeger, Manfred

    2012-01-01

    One of the big challenges in the development of probabilistic relational (or probabilistic logical) modeling and learning frameworks is the design of inference techniques that operate on the level of the abstract model representation language, rather than on the level of ground, propositional instances of the model. Numerous approaches for such "lifted inference" techniques have been proposed. While it has been demonstrated that these techniques will lead to significantly more efficient inference on some specific models, there are only very recent and still quite restricted results that show the feasibility of lifted inference on certain syntactically defined classes of models. Lower complexity bounds that imply some limitations for the feasibility of lifted inference on more expressive model classes were established early on in (Jaeger 2000). However, it is not immediate that these results also apply to the type of modeling languages that currently receive the most attention, i.e., weighted, quantifier-free ...

  10. Carbohydrate Content in the GDM Diet: Two Views: View 1: Nutrition Therapy in Gestational Diabetes: The Case for Complex Carbohydrates.

    Science.gov (United States)

    Hernandez, Teri L

    2016-05-01

    IN BRIEF Restriction of dietary carbohydrate has been the cornerstone for treatment of gestational diabetes mellitus (GDM). However, there is evidence that a balanced liberalization of complex carbohydrate as part of an overall eating plan in GDM meets treatment goals and may mitigate maternal adipose tissue insulin resistance, both of which may promote optimal metabolic outcomes for mother and offspring.

  11. Bounds on Transient Instability for Complex Ecosystems.

    Directory of Open Access Journals (Sweden)

    Francesco Caravelli

    Full Text Available Stability is a desirable property of complex ecosystems. If a community of interacting species is at a stable equilibrium point then it is able to withstand small perturbations to component species' abundances without suffering adverse effects. In ecology, the Jacobian matrix evaluated at an equilibrium point is known as the community matrix, which describes the population dynamics of interacting species. A system's asymptotic short- and long-term behaviour can be determined from eigenvalues derived from the community matrix. Here we use results from the theory of pseudospectra to describe intermediate, transient dynamics. We first recover the established result that the transition from stable to unstable dynamics includes a region of 'transient instability', where the effect of a small perturbation to species' abundances-to the population vector-is amplified before ultimately decaying. Then we show that the shift from stability to transient instability can be affected by uncertainty in, or small changes to, entries in the community matrix, and determine lower and upper bounds to the maximum amplitude of perturbations to the population vector. Of five different types of community matrix, we find that amplification is least severe when predator-prey interactions dominate. This analysis is relevant to other systems whose dynamics can be expressed in terms of the Jacobian matrix.

  12. Bounds on Transient Instability for Complex Ecosystems.

    Science.gov (United States)

    Caravelli, Francesco; Staniczenko, Phillip P A

    2016-01-01

    Stability is a desirable property of complex ecosystems. If a community of interacting species is at a stable equilibrium point then it is able to withstand small perturbations to component species' abundances without suffering adverse effects. In ecology, the Jacobian matrix evaluated at an equilibrium point is known as the community matrix, which describes the population dynamics of interacting species. A system's asymptotic short- and long-term behaviour can be determined from eigenvalues derived from the community matrix. Here we use results from the theory of pseudospectra to describe intermediate, transient dynamics. We first recover the established result that the transition from stable to unstable dynamics includes a region of 'transient instability', where the effect of a small perturbation to species' abundances-to the population vector-is amplified before ultimately decaying. Then we show that the shift from stability to transient instability can be affected by uncertainty in, or small changes to, entries in the community matrix, and determine lower and upper bounds to the maximum amplitude of perturbations to the population vector. Of five different types of community matrix, we find that amplification is least severe when predator-prey interactions dominate. This analysis is relevant to other systems whose dynamics can be expressed in terms of the Jacobian matrix. PMID:27327511

  13. Bounds on Transient Instability for Complex Ecosystems

    Science.gov (United States)

    2016-01-01

    Stability is a desirable property of complex ecosystems. If a community of interacting species is at a stable equilibrium point then it is able to withstand small perturbations to component species’ abundances without suffering adverse effects. In ecology, the Jacobian matrix evaluated at an equilibrium point is known as the community matrix, which describes the population dynamics of interacting species. A system’s asymptotic short- and long-term behaviour can be determined from eigenvalues derived from the community matrix. Here we use results from the theory of pseudospectra to describe intermediate, transient dynamics. We first recover the established result that the transition from stable to unstable dynamics includes a region of ‘transient instability’, where the effect of a small perturbation to species’ abundances—to the population vector—is amplified before ultimately decaying. Then we show that the shift from stability to transient instability can be affected by uncertainty in, or small changes to, entries in the community matrix, and determine lower and upper bounds to the maximum amplitude of perturbations to the population vector. Of five different types of community matrix, we find that amplification is least severe when predator-prey interactions dominate. This analysis is relevant to other systems whose dynamics can be expressed in terms of the Jacobian matrix. PMID:27327511

  14. Carbohydrates

    Science.gov (United States)

    ... is fine because they contain important vitamins and minerals. But your body rapidly digests the starch in white potatoes. This can raise your blood glucose level. Healthy carbohydrates include: Natural sugars in fruits, vegetables, milk, and milk products Dietary fiber Starches in whole- ...

  15. Modeling of Carbohydrate Binding Modules Complexed to Cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Nimlos, M. R.; Beckham, G. T.; Bu, L.; Himmel, M. E.; Crowley, M. F.; Bomble, Y. J.

    2012-01-01

    Modeling results are presented for the interaction of two carbohydrate binding modules (CBMs) with cellulose. The family 1 CBM from Trichoderma reesei's Cel7A cellulase was modeled using molecular dynamics to confirm that this protein selectively binds to the hydrophobic (100) surface of cellulose fibrils and to determine the energetics and mechanisms for locating this surface. Modeling was also conducted of binding of the family 4 CBM from the CbhA complex from Clostridium thermocellum. There is a cleft in this protein, which may accommodate a cellulose chain that is detached from crystalline cellulose. This possibility is explored using molecular dynamics.

  16. Bounds for Bilinear Complexity of Noncommutative Group Algebras

    CERN Document Server

    Pospelov, Alexey

    2010-01-01

    We study the complexity of multiplication in noncommutative group algebras which is closely related to the complexity of matrix multiplication. We characterize such semisimple group algebras of the minimal bilinear complexity and show nontrivial lower bounds for the rest of the group algebras. These lower bounds are built on the top of Bl\\"aser's results for semisimple algebras and algebras with large radical and the lower bound for arbitrary associative algebras due to Alder and Strassen. We also show subquadratic upper bounds for all group algebras turning into "almost linear" provided the exponent of matrix multiplication equals 2.

  17. Complex carbohydrate utilization by the healthy human microbiome.

    Directory of Open Access Journals (Sweden)

    Brandi L Cantarel

    Full Text Available The various ecological habitats in the human body provide microbes a wide array of nutrient sources and survival challenges. Advances in technology such as DNA sequencing have allowed a deeper perspective into the molecular function of the human microbiota than has been achievable in the past. Here we aimed to examine the enzymes that cleave complex carbohydrates (CAZymes in the human microbiome in order to determine (i whether the CAZyme profiles of bacterial genomes are more similar within body sites or bacterial families and (ii the sugar degradation and utilization capabilities of microbial communities inhabiting various human habitats. Upon examination of 493 bacterial references genomes from 12 human habitats, we found that sugar degradation capabilities of taxa are more similar to others in the same bacterial family than to those inhabiting the same habitat. Yet, the analysis of 520 metagenomic samples from five major body sites show that even when the community composition varies the CAZyme profiles are very similar within a body site, suggesting that the observed functional profile and microbial habitation have adapted to the local carbohydrate composition. When broad sugar utilization was compared within the five major body sites, the gastrointestinal track contained the highest potential for total sugar degradation, while dextran and peptidoglycan degradation were highest in oral and vaginal sites respectively. Our analysis suggests that the carbohydrate composition of each body site has a profound influence and probably constitutes one of the major driving forces that shapes the community composition and therefore the CAZyme profile of the local microbial communities, which in turn reflects the microbiome fitness to a body site.

  18. Cationic technetium and rhenium complexes with pendant carbohydrates

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Cara L. [Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1 (Canada); TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)], E-mail: cara.ferreira@mdsinc.com; Marques, Fabio L.N. [Centro de Medicina Nuclear, Faculdade de Medicina, Universidade de Sao Paulo, Trav. R. Dr. Ovidio Pires de Campos s/n Sao Paulo, 05403-010 (Brazil)], E-mail: flnmarqu@hcnet.usp.br; Okamoto, Miriam R.Y. [Centro de Medicina Nuclear, Faculdade de Medicina, Universidade de Sao Paulo, Trav. R. Dr. Ovidio Pires de Campos s/n Sao Paulo, 05403-010 (Brazil); Otake, Andreia H. [Laboratorio de Oncologia Experimental, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455, Sao Paulo 01246-903 (Brazil); Sugai, Yuko; Mikata, Yuji [KYOUSEI Science Center, Nara Women' s University, Nara 630-8506 (Japan); Storr, Tim; Bowen, Meryn [Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1 (Canada); Yano, Shigenobu [Division of Functional Material Science, Nara Women' s University, Nara 630-8506 (Japan); Adam, Michael J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Chammas, Roger [KYOUSEI Science Center, Nara Women' s University, Nara 630-8506 (Japan); Orvig, Chris [Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1 (Canada)

    2010-06-15

    Three carbohydrate conjugated dipicolylamine chelators, 2-bis(2-pyridinylmethyl)amino)ethyl 1-deoxy-1-thio-{beta}-D-glucopyranoside (L{sup 1}), 2-bis(2-pyridinylmethyl)amino)ethyl-{beta}-D-glucopyranoside (L{sup 2}), and 2-bis(2-pyridinylmethyl)amino) carboxamide-N-(2-amino-2-deoxy-D-glucopyranose) (L{sup 3}) were complexed to the [M(CO){sub 3}]{sup +} core (M=Tc, Re) and the properties of the resulting complexes were investigated. Synthesis and characterization of the chelator 2-bis(2-pyridinylmethyl)amino)ethyl 1-deoxy-1-thio-{beta}-D-glucopyranoside (L{sup 1}) and the corresponding Re complex are reported. All chelators were radiolabeled in high yield with [{sup 99m}Tc(CO){sub 3}(H{sub 2}O){sub 3}]{sup +} (>98%) and [{sup 186}Re(CO){sub 3}(H{sub 2}O){sub 3}]{sup +} (>80%). The chelators and Re-complexes were determined to not be substrates for the glucose metabolism enzyme hexokinase. However, the biodistribution of each of the {sup 99m}Tc complexes demonstrated fast clearance from most background tissue, including >75% clearance of the activity in the kidneys and the liver within 2 h post-injection.

  19. Complexity Considerations, cSAT Lower Bound

    CERN Document Server

    Hofman, Radoslaw

    2007-01-01

    This article discusses completeness of Boolean Algebra as First Order Theory in Goedel's meaning. If Theory is complete then any possible transformation is equivalent to some transformation using axioms, predicates etc. defined for this theory. If formula is to be proved (or disproved) then it has to be reduced to axioms. If every transformation is deducible then also optimal transformation is deducible. If every transformation is exponential then optimal one is too, what allows to define lower bound for discussed problem to be exponential (outside P). Then we show algorithm for NDTM solving the same problem in O(n^c) (so problem is in NP), what proves that P \

  20. A quadratically tight partition bound for classical communication complexity and query complexity

    OpenAIRE

    Jain, Rahul; Lee, Troy; Vishnoi, Nisheeth K.

    2014-01-01

    In this work we introduce, both for classical communication complexity and query complexity, a modification of the 'partition bound' introduced by Jain and Klauck [2010]. We call it the 'public-coin partition bound'. We show that (the logarithm to the base two of) its communication complexity and query complexity versions form, for all relations, a quadratically tight lower bound on the public-coin randomized communication complexity and randomized query complexity respectively.

  1. Synthesis, characterization and cytotoxic activity of palladium (II) carbohydrate complexes

    Indian Academy of Sciences (India)

    S Bhavya Deepthi; Rajiv Trivedi; P Sujitha; C Ganesh Kumar; B Sridhar; Suresh K Bhargava

    2012-11-01

    Carbohydrate containing pyridyl triazole ligands, 5-deoxy-1,2--isopropylidene-5-(4-(2-pyridyl)-1H-1,2,3-triazole-1-yl)--D-xylofuranose (2a), 3--Benzyl-5-deoxy-1,2--isopropylidene-5-(4-(2-pyridyl)-1H-1,2,3-triazol-1-yl)--D-xylofuranose (2b), methyl-5-deoxy-2,3--isopropylidene-5-(4-(2-pyridyl)-1H-1,2,3-triazol-1-yl)--D-ribofuranoside, (2c) and 6-deoxy-1,2:3,4-di--isopropylidene-6-(4-(2-pyridyl)-1H-1,2,3-triazol-1-yl)--D-galactopyranose (2d) were prepared by the `click’ reaction of 2-ethynyl pyridine with the corresponding azides. The palladium complexes were synthesised by the reaction of pyridyl triazole ligands with [Pd(COD)Cl2] in dichloromethane. All the compounds were characterized by NMR, IR, mass and elemental analysis. Structural characterization of the ligand 2a was done by X-ray crystallography. The ligands and complexes were tested for their cytotoxic activity on different cell lines like A549 (human alveolar adenocarcinoma cells), Neuro2a (mouse neuroblastoma cells), HeLa (cervical carcinoma cancer cells), MDA-MB-231 (human breast adenocarcinoma cells) and MCF7 (human breast adenocarcinoma cells). The complexes showed considerable cytotoxicity while the ligands were non-toxic on the tested cell lines.

  2. The pervasive reach of resource-bounded Kolmogorov complexity in computational complexity theory

    OpenAIRE

    Allender, E.; Koucký, M.; Ronneburger, D.; Roy, S.

    2011-01-01

    We continue an investigation into resource-bounded Kolmogorov complexity, which highlights the close connections between circuit complexity and Levin's time-bounded Kolmogorov complexity measure Kt (and other measures with a similar flavor), and also exploits derandomization techniques to provide new insights regarding Kolmogorov complexity. The Kolmogorov measures that have been introduced have many advantages over other approaches to defining resource-bounded Kolmogorov complexity. Here, we...

  3. Bounds on transient instability for complex ecosystems

    OpenAIRE

    Caravelli, Francesco; Staniczenko, Phillip P. A.

    2015-01-01

    Stability is a desirable property of complex ecosystems. If a community of interacting species is at a stable equilibrium point then it is able to withstand small perturbations to component species' abundances without suffering adverse effects. In ecology, the Jacobian matrix evaluated at an equilibrium point is known as the community matrix, which describes the population dynamics of interacting species. A system's asymptotic short- and long-term behaviour can be determined from eigenvalues ...

  4. COMPLEXITY OF LARGE TIME BEHAVIOUR OFEVOLUTION EQUATIONS WITH BOUNDED DATA

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The authors study the asymptotic behaviour of solutions of the heat equation and a number of evolution equations using scaling techniques. It is proved that in the framework of bounded data stabilization need not occur and the general asymptotic behaviour is complex. This behaviour reflects for large times,even on compact sets,the complexity of the initial data at infinity.

  5. The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center

    Energy Technology Data Exchange (ETDEWEB)

    Albersheim, P.; Darvill, A.

    1991-08-01

    Research from the Complex Carbohydrates Research Center at the University of Georgia is presented. Topics include: Structural determination of soybean isoflavones which specifically induce Bradyrhizobium japonicum nodD1 but not the nodYABCSUIJ operon; structural analysis of the lipopolysaccharides (LPSs) from symbiotic mutants of Bradyrhizobium japonicum; structural characterization of lipooligosaccharides from Bradyrhizobium japonicum that are required for the specific nodulation of soybean; structural characterization of the LPSs from R. Leguminosarum biovar phaseoli, the symbiont of bean; characterization of bacteroid-specific LPS epitopes in R. leguminosarum biovar viciae; analysis of the surface polysaccharides of Rhizobium meliloti mutants whose lipopolysaccharides and extracellular polysaccharides can have the same function in symbiosis; characterization of a polysaccharide produced by certain Bradyrhizobium japonicum strains within soybean nodules; structural analysis of a streptococcal adhesin polysaccharide receptor; conformational studies of xyloglucan, the role of the fucosylated side chain in surface-specific cellulose-xyloglucan interactions; the structure of an acylated glucosamine oligosaccharide signal molecule (nod factor) involved in the symbiosis of Rhizobium leguminosarum biovar viciae with its host Vicia sativa; investigating membrane responses induced by oligogalacturonides in cultured cells; the polygalacturonase inhibitor protein; characterization of the self-incompatability glycoproteins from Petunia hybrida; investigation of the cell wall polysaccharide structures of Arabidopsis thaliana; and the glucan inhibition of virus infection of tabacco.

  6. Bloch spaces on bounded symmetric domains in complex Banach spaces

    Institute of Scientific and Technical Information of China (English)

    DENG; Fangwen

    2006-01-01

    We give a definition of Bloch space on bounded symmetric domains in arbitrary complex Banach space and prove such function space is a Banach space. The properties such as boundedness, compactness and closed range of composition operators on such Bloch space are studied.

  7. CHANGES IN COMPLEX CARBOHYDRATE CONTENT AND STRUCTURE IN RAT LUNGS CAUSED BY PROLONGED OZONE INHALATION

    Science.gov (United States)

    EPA GRANT NUMBER: R828112C065IIITitle: Changes in Complex Carbohydrate Content and Structure in Rat Lungs Caused by Prolonged Ozone InhalationInvestigator: Bhandaru RadhakrishnamurthyInstitution: Tulane University of LouisianaEPA...

  8. Lower Bounds on Query Complexity for Testing Bounded-Degree CSPs

    CERN Document Server

    Yoshida, Yuichi

    2010-01-01

    In this paper, we consider lower bounds on the query complexity for testing CSPs in the bounded-degree model. First, for any ``symmetric'' predicate $P:{0,1}^{k} \\to {0,1}$ except \\equ where $k\\geq 3$, we show that every (randomized) algorithm that distinguishes satisfiable instances of CSP(P) from instances $(|P^{-1}(0)|/2^k-\\epsilon)$-far from satisfiability requires $\\Omega(n^{1/2+\\delta})$ queries where $n$ is the number of variables and $\\delta>0$ is a constant that depends on $P$ and $\\epsilon$. This breaks a natural lower bound $\\Omega(n^{1/2})$, which is obtained by the birthday paradox. We also show that every one-sided error tester requires $\\Omega(n)$ queries for such $P$. These results are hereditary in the sense that the same results hold for any predicate $Q$ such that $P^{-1}(1) \\subseteq Q^{-1}(1)$. For EQU, we give a one-sided error tester whose query complexity is $\\tilde{O}(n^{1/2})$. Also, for 2-XOR (or, equivalently E2LIN2), we show an $\\Omega(n^{1/2+\\delta})$ lower bound for distinguishi...

  9. Weakly bound systems in the case of complex potentials

    International Nuclear Information System (INIS)

    We consider weakly bound two-body systems. We study the behavior of the ground state mean square radius as the binding energy tends to zero in the case of complex potentials. We show that the asymptotic law, obtained with real potentials, is modified by the occurrence of a finite width in the case of finite-range potentials. The case of the PT-symmetric potentials is also discussed. We complete our study with few remarks concerning the same problem for three weakly bound particles. (author)

  10. Number theoretic methods in cryptography complexity lower bounds

    CERN Document Server

    Shparlinski, Igor

    1999-01-01

    The book introduces new techniques which imply rigorous lower bounds on the complexity of some number theoretic and cryptographic problems. These methods and techniques are based on bounds of character sums and numbers of solutions of some polynomial equations over finite fields and residue rings. It also contains a number of open problems and proposals for further research. We obtain several lower bounds, exponential in terms of logp, on the de­ grees and orders of • polynomials; • algebraic functions; • Boolean functions; • linear recurring sequences; coinciding with values of the discrete logarithm modulo a prime p at suf­ ficiently many points (the number of points can be as small as pI/He). These functions are considered over the residue ring modulo p and over the residue ring modulo an arbitrary divisor d of p - 1. The case of d = 2 is of special interest since it corresponds to the representation of the right­ most bit of the discrete logarithm and defines whether the argument is a quadratic...

  11. Quantum multiparty communication complexity and circuit lower bounds

    CERN Document Server

    Kerenidis, I

    2005-01-01

    We define a quantum model for multiparty communication complexity and prove a simulation theorem between the classical and quantum models. As a result of our simulation, we show that if the quantum k-party communication complexity of a function f is $\\Omega(n/2^k)$, then its classical k-party communication is $\\Omega(n/2^{k/2})$. Finding such an f would allow us to prove strong classical lower bounds for (k>log n) players and hence resolve a main open question about symmetric circuits. Furthermore, we prove that for the Generalized Inner Product (GIP) function, the quantum model is exponentially more efficient than the classical one. This provides the first exponential separation for a total function between any quantum and public coin randomized communication model.

  12. COMPLEX CARBOHYDRATES IN THE PREVENTION OF NOCTURNAL HYPOGLYCEMIA IN DIABETIC CHILDREN

    NARCIS (Netherlands)

    VERVERS, MTC; ROUWE, C; SMIT, GPA

    1993-01-01

    In order to prevent nocturnal hypoglycaemia in patients with insulin-dependent diabetes mellitus with complex carbohydrates a pilot-study was designed with nine children with ages of 9-18 years. The children were admitted twice to the hospital (control and test) and remained the evening, night and m

  13. Rhenium(V)-Carbohydrate Complexes with Amino Acids

    OpenAIRE

    Grimminger, Philipp

    2009-01-01

    This thesis is about the coordination chemistry of rhenium(V) with small biomolecules. Such rhenium complexes may be of medical significance in the field of radiopharmacy, since radioactive isotopes such as 186Re or 188Re are used for the diagnosis or treatment of tumors. But fundamental research is still necessary for the attachment of radiometals to biologically active molecules. Most rhenium(V)-based radiopharmaceuticals lack stability (at physiological conditions) or selectivity (in terms...

  14. Inhibiting oral intoxication of botulinum neurotoxin A complex by carbohydrate receptor mimics.

    Science.gov (United States)

    Lee, Kwangkook; Lam, Kwok-Ho; Kruel, Anna-Magdalena; Mahrhold, Stefan; Perry, Kay; Cheng, Luisa W; Rummel, Andreas; Jin, Rongsheng

    2015-12-01

    Botulinum neurotoxins (BoNTs) cause the disease botulism manifested by flaccid paralysis that could be fatal to humans and animals. Oral ingestion of the toxin with contaminated food is one of the most common routes for botulism. BoNT assembles with several auxiliary proteins to survive in the gastrointestinal tract and is subsequently transported through the intestinal epithelium into the general circulation. Several hemagglutinin proteins form a multi-protein complex (HA complex) that recognizes host glycans on the intestinal epithelial cell surface to facilitate BoNT absorption. Blocking carbohydrate binding to the HA complex could significantly inhibit the oral toxicity of BoNT. Here, we identify lactulose, a galactose-containing non-digestible sugar commonly used to treat constipation, as a prototype inhibitor against oral BoNT/A intoxication. As revealed by a crystal structure, lactulose binds to the HA complex at the same site where the host galactose-containing carbohydrate receptors bind. In vitro assays using intestinal Caco-2 cells demonstrated that lactulose inhibits HA from compromising the integrity of the epithelial cell monolayers and blocks the internalization of HA. Furthermore, co-administration of lactulose significantly protected mice against BoNT/A oral intoxication in vivo. Taken together, these data encourage the development of carbohydrate receptor mimics as a therapeutic intervention to prevent BoNT oral intoxication.

  15. The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center. Five-year report, September 15, 1987--December 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Albersheim, Peter; Darvill, Alan

    1992-05-01

    The Complex Carbohydrate Research Center (CCRC) is the home of ten independent but complementary interdisciplinary research groups led by nine regular faculty and one adjunct faculty. The research of these groups represents a broad spectrum of interests, and they are involved in about 90 collaborations with their CCRC and UGA colleagues and with scientists at other institutions and companies in the US, Canada, Europe, Israel, and Japan. The hallmark of the CCRC is the collaborative, interactive environment encouraged by its directors, faculty and tong-term staff. Newcomers to the CCRC or short-term members soon learn that everyone benefits from this process. The team-oriented approach in carbohydrate science translates into the day-today generous giving of one's time and expertise to the work of others, whether it be in sharing specialized instrumentation, participating in the design of experiments and interpretalon of data, providing service to scientists outside the CCRC, or joining collaborative projects. The CCRC is founded on the principle that the cross-fertilization of ideas and know-how leads to the synergistic advancement of science. This report contains a series of appendices that document the extent and breadth of the Plant and Microbial Carbohydrate Center's contributions to collaborative research and education. Several collaborative research projects that have received postdoctoral research associate support from the Grant are highlighted, as these projects are particularly illustrative of the wide-ranging collaborations that have evolved as a result of this Grant and the quality of the science that the Grant enables.

  16. Nitric oxide production by chicken macrophages activated by Acemannan, a complex carbohydrate extracted from Aloe vera.

    Science.gov (United States)

    Karaca, K; Sharma, J M; Nordgren, R

    1995-03-01

    Cultures of normal chicken spleen cells and HD11 line cells produce nitric oxide (NO) in response to Acemannan, a complex carbohydrate derived from the Aloe vera plant. Neither cell type produced detectable amounts of NO in response to similar concentrations of yeast mannan, another complex carbohydrate. Nitric oxide production was dose dependent and inhibitable by the nitric oxide synthase inhibitor NG-methyl-L-arginine. In addition, the production of NO was inhibited by preincubation of ACM with concanavalin A in a dose-dependent manner. These results suggest that ACM-induced NO synthesis may be mediated through macrophage mannose receptors, and macrophage activation may be accountable for some of the immunomodulatory effects of ACM in chickens.

  17. Protein-carbohydrate complex reveals circulating metastatic cells in a microfluidic assay

    KAUST Repository

    Simone, Giuseppina

    2013-02-11

    Advances in carbohydrate sequencing technologies reveal the tremendous complexity of the glycome and the role that glycomics might have to bring insight into the biological functions. Carbohydrate-protein interactions, in particular, are known to be crucial to most mammalian physiological processes as mediators of cell adhesion and metastasis, signal transducers, and organizers of protein interactions. An assay is developed here to mimic the multivalency of biological complexes that selectively and sensitively detect carbohydrate-protein interactions. The binding of β-galactosides and galectin-3 - a protein that is correlated to the progress of tumor and metastasis - is examined. The efficiency of the assay is related to the expression of the receptor while anchoring to the interaction\\'s strength. Comparative binding experiments reveal molecular binding preferences. This study establishes that the assay is robust to isolate metastatic cells from colon affected patients and paves the way to personalized medicine. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Protective Effect of Free and Bound Polyphenol Extracts from Ginger (Zingiber officinale Roscoe on the Hepatic Antioxidant and Some Carbohydrate Metabolizing Enzymes of Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Mutiu Idowu Kazeem

    2013-01-01

    Full Text Available This study investigated the hepatoprotective effects of polyphenols from Zingiber officinale on streptozotocin-induced diabetic rats by assessing liver antioxidant enzymes, carbohydrate-metabolizing enzymes and liver function indices. Initial oral glucose tolerance test was conducted using 125 mg/kg, 250 mg/kg, and 500 mg/kg body weight of both free and bound polyphenols from Z. officinale. 28 day daily oral administration of 500 mg/kg body weight of free and bound polyphenols from Z. officinale to streptozotocin-induced (50 mg/kg diabetic rats significantly reduced (P<0.05 the fasting blood glucose compared to control groups. There was significant increase (P<0.05 in the antioxidant enzymes activities in the animals treated with both polyphenols. Similarly, the polyphenols normalised the activities of some carbohydrate metabolic enzymes (hexokinase and phosphofructokinase in the liver of the rats treated with it and significantly reduced (P<0.05 the activities of liver function enzymes. The results from the present study have shown that both free and bound polyphenols from Z. officinale especially the free polyphenol could ameliorate liver disorders caused by diabetes mellitus in rats. This further validates the use of this species as medicinal herb and spice by the larger population of Nigerians.

  19. Influence of Grape Maturity on Complex Carbohydrate Composition of Red Sparkling Wines.

    Science.gov (United States)

    Martínez-Lapuente, Leticia; Apolinar-Valiente, Rafael; Guadalupe, Zenaida; Ayestarán, Belén; Pérez-Magariño, Silvia; Williams, Pascale; Doco, Thierry

    2016-06-22

    This paper studied how grape maturity affected complex carbohydrate composition during red sparkling wine making and wine aging. Grape ripening stage (premature and mature grapes) showed a significant impact on the content, composition, and evolution of polysaccharides and oligosaccharides of sparkling wines. Polysaccharides rich in arabinose and galactose, mannoproteins, rhamnogalacturonans II, and oligosaccharides in base wines increased with maturity. For both maturity stages, polysaccharides rich in arabinose and galactose, and the glucuronic acid glycosyl residue of the oligosaccharides were the major carbohydrates detected in all vinification stages. The total glycosyl content of oligosaccharides decreased during the whole period of aging on yeast lees. The reduction of polysaccharides rich in arabinose and galactose and rhamnogalacturonans type II during the aging was more pronounced in mature samples. To our knowledge, this is the first report of the polysaccharide and oligosaccharide composition of red sparkling wines. PMID:27226011

  20. Protective Effect of Free and Bound Polyphenol Extracts from Ginger (Zingiber officinale Roscoe) on the Hepatic Antioxidant and Some Carbohydrate Metabolizing Enzymes of Streptozotocin-Induced Diabetic Rats.

    Science.gov (United States)

    Kazeem, Mutiu Idowu; Akanji, Musbau Adewunmi; Yakubu, Musa Toyin; Ashafa, Anofi Omotayo Tom

    2013-01-01

    This study investigated the hepatoprotective effects of polyphenols from Zingiber officinale on streptozotocin-induced diabetic rats by assessing liver antioxidant enzymes, carbohydrate-metabolizing enzymes and liver function indices. Initial oral glucose tolerance test was conducted using 125 mg/kg, 250 mg/kg, and 500 mg/kg body weight of both free and bound polyphenols from Z. officinale. 28 day daily oral administration of 500 mg/kg body weight of free and bound polyphenols from Z. officinale to streptozotocin-induced (50 mg/kg) diabetic rats significantly reduced (P officinale especially the free polyphenol could ameliorate liver disorders caused by diabetes mellitus in rats. This further validates the use of this species as medicinal herb and spice by the larger population of Nigerians. PMID:24367390

  1. Structural Analysis of a Family 101 Glycoside Hydrolase in Complex with Carbohydrates Reveals Insights into Its Mechanism.

    Science.gov (United States)

    Gregg, Katie J; Suits, Michael D L; Deng, Lehua; Vocadlo, David J; Boraston, Alisdair B

    2015-10-16

    O-Linked glycosylation is one of the most abundant post-translational modifications of proteins. Within the secretory pathway of higher eukaryotes, the core of these glycans is frequently an N-acetylgalactosamine residue that is α-linked to serine or threonine residues. Glycoside hydrolases in family 101 are presently the only known enzymes to be able to hydrolyze this glycosidic linkage. Here we determine the high-resolution structures of the catalytic domain comprising a fragment of GH101 from Streptococcus pneumoniae TIGR4, SpGH101, in the absence of carbohydrate, and in complex with reaction products, inhibitor, and substrate analogues. Upon substrate binding, a tryptophan lid (residues 724-WNW-726) closes on the substrate. The closing of this lid fully engages the substrate in the active site with Asp-764 positioned directly beneath C1 of the sugar residue bound within the -1 subsite, consistent with its proposed role as the catalytic nucleophile. In all of the bound forms of the enzyme, however, the proposed catalytic acid/base residue was found to be too distant from the glycosidic oxygen (>4.3 Å) to serve directly as a general catalytic acid/base residue and thereby facilitate cleavage of the glycosidic bond. These same complexes, however, revealed a structurally conserved water molecule positioned between the catalytic acid/base and the glycosidic oxygen. On the basis of these structural observations we propose a new variation of the retaining glycoside hydrolase mechanism wherein the intervening water molecule enables a Grotthuss proton shuttle between Glu-796 and the glycosidic oxygen, permitting this residue to serve as the general acid/base catalytic residue.

  2. Electron Capture Dissociation of Weakly Bound Polypeptide Polycationic Complexes

    DEFF Research Database (Denmark)

    Haselmann, Kim F; Jørgensen, Thomas J D; Budnik, Bogdan A;

    2002-01-01

    We have previously reported that, in electron capture dissociation (ECD), rupture of strong intramolecular bonds in weakly bound supramolecular aggregates can proceed without dissociation of weak intermolecular bonds. This is now illustrated on a series of non-specific peptide-peptide dimers as w...

  3. Bounds on Average Time Complexity of Decision Trees

    KAUST Repository

    Chikalov, Igor

    2011-01-01

    In this chapter, bounds on the average depth and the average weighted depth of decision trees are considered. Similar problems are studied in search theory [1], coding theory [77], design and analysis of algorithms (e.g., sorting) [38]. For any diagnostic problem, the minimum average depth of decision tree is bounded from below by the entropy of probability distribution (with a multiplier 1/log2 k for a problem over a k-valued information system). Among diagnostic problems, the problems with a complete set of attributes have the lowest minimum average depth of decision trees (e.g, the problem of building optimal prefix code [1] and a blood test study in assumption that exactly one patient is ill [23]). For such problems, the minimum average depth of decision tree exceeds the lower bound by at most one. The minimum average depth reaches the maximum on the problems in which each attribute is "indispensable" [44] (e.g., a diagnostic problem with n attributes and kn pairwise different rows in the decision table and the problem of implementing the modulo 2 summation function). These problems have the minimum average depth of decision tree equal to the number of attributes in the problem description. © Springer-Verlag Berlin Heidelberg 2011.

  4. Lower bounds on information complexity via zero-communication protocols and applications

    CERN Document Server

    Kerenidis, Iordanis; Lerays, Virginie; Roland, Jeremie; Xiao, David

    2012-01-01

    We show that almost all known lower bound methods for communication complexity are also lower bounds for the information complexity. In particular, we define a relaxed version of the partition bound of Jain and Klauck and prove that it lower bounds the information complexity of any function. Our relaxed partition bound subsumes all norm based methods (e.g. the factorization norm method) and rectangle-based methods (e.g. the rectangle/corruption bound, the smooth rectangle bound, and the discrepancy bound), except the partition bound. Our result uses a new connection between rectangles and zero-communication protocols where the players can either output a value or abort. We prove the following compression lemma: given a protocol for a function f with information complexity I, one can construct a zero-communication protocol that has non-abort probability at least 2^{-O(I)} and that computes f correctly with high probability conditioned on not aborting. Then, we show how such a zero-communication protocol relate...

  5. The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center. Annual report, September 15, 1990--December 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Albersheim, P.; Darvill, A.

    1991-08-01

    Research from the Complex Carbohydrates Research Center at the University of Georgia is presented. Topics include: Structural determination of soybean isoflavones which specifically induce Bradyrhizobium japonicum nodD1 but not the nodYABCSUIJ operon; structural analysis of the lipopolysaccharides (LPSs) from symbiotic mutants of Bradyrhizobium japonicum; structural characterization of lipooligosaccharides from Bradyrhizobium japonicum that are required for the specific nodulation of soybean; structural characterization of the LPSs from R. Leguminosarum biovar phaseoli, the symbiont of bean; characterization of bacteroid-specific LPS epitopes in R. leguminosarum biovar viciae; analysis of the surface polysaccharides of Rhizobium meliloti mutants whose lipopolysaccharides and extracellular polysaccharides can have the same function in symbiosis; characterization of a polysaccharide produced by certain Bradyrhizobium japonicum strains within soybean nodules; structural analysis of a streptococcal adhesin polysaccharide receptor; conformational studies of xyloglucan, the role of the fucosylated side chain in surface-specific cellulose-xyloglucan interactions; the structure of an acylated glucosamine oligosaccharide signal molecule (nod factor) involved in the symbiosis of Rhizobium leguminosarum biovar viciae with its host Vicia sativa; investigating membrane responses induced by oligogalacturonides in cultured cells; the polygalacturonase inhibitor protein; characterization of the self-incompatability glycoproteins from Petunia hybrida; investigation of the cell wall polysaccharide structures of Arabidopsis thaliana; and the glucan inhibition of virus infection of tabacco.

  6. A complexity lower bound based on software engineering concepts

    OpenAIRE

    Rojas Paredes, Andrés

    2013-01-01

    We consider the problem of polynomial equation solving also known as quantifier elimination in Effective Algebraic Geometry. The complexity of the first elimination algorithms were double exponential, but a considerable progress was carried out when the polynomials were represented by arithmetic circuits evaluating them. This representation improves the complexity to pseudo–polynomial time. The question is whether the actual asymptotic complexity of circuit– based elimination algorithms ma...

  7. Limitations of Lower-Bound Methods for the Wire Complexity of Boolean Operators

    OpenAIRE

    Drucker, Andrew

    2012-01-01

    We study the circuit complexity of Boolean operators, i.e., collections of Boolean functions defined over a common input. Our focus is the well-studied model in which arbitrary Boolean functions are allowed as gates, and in which a circuit's complexity is measured by its depth and number of wires. We show sharp limitations of several existing lower-bound methods for this model. First, we study an information-theoretic lower-bound method due to Cherukhin, that yields bounds of form $\\Omega_d(n...

  8. Lifetime heterogeneity of DNA-bound dppz complexes originates from distinct intercalation geometries determined by complex-complex interactions.

    Science.gov (United States)

    Andersson, Johanna; Fornander, Louise H; Abrahamsson, Maria; Tuite, Eimer; Nordell, Pär; Lincoln, Per

    2013-01-18

    Despite the extensive interest in structurally explaining the photophysics of DNA-bound [Ru(phen)(2)dppz](2+) and [Ru(bpy)(2)dppz](2+), the origin of the two distinct emission lifetimes of the pure enantiomers when intercalated into DNA has remained elusive. In this report, we have combined a photophysical characterization with a detailed isothermal titration calorimetry study to investigate the binding of the pure Δ and Λ enantiomers of both complexes with [poly(dAdT)](2). We find that a binding model with two different binding geometries, proposed to be symmetric and canted intercalation from the minor groove, as recently reported in high-resolution X-ray structures, is required to appropriately explain the data. By assigning the long emission lifetime to the canted binding geometry, we can simultaneously fit both calorimetric data and the binding-density-dependent changes in the relative abundance of the two emission lifetimes using the same binding model. We find that all complex-complex interactions are slightly unfavorable for Δ-[Ru(bpy)(2)dppz](2+), whereas interactions involving a complex canted away from a neighbor are favorable for the other three complexes. We also conclude that Δ-[Ru(bpy)(2)dppz](2+) preferably binds isolated, Δ-[Ru(phen)(2)dppz](2+) preferably binds as duplets of canted complexes, and that all complexes are reluctant to form longer consecutive sequences than triplets. We propose that this is due to an interplay of repulsive complex-complex and attractive complex-DNA interactions modulated by allosteric DNA conformation changes that are largely affected by the nature of the ancillary ligands.

  9. Without bounds a scientific canvas of nonlinearity and complex dynamics

    CERN Document Server

    Ryazantsev, Yuri; Starov, Victor; Huang, Guo-Xiang; Chetverikov, Alexander; Arena, Paolo; Nepomnyashchy, Alex; Ferrus, Alberto; Morozov, Eugene

    2013-01-01

    Bringing together over fifty contributions on all aspects of nonlinear and complex dynamics, this impressive topical collection is both a scientific and personal tribute, on the occasion of his 70th birthday, by many outstanding colleagues in the broad fields of research pursued by Prof. Manuel G Velarde. The topics selected reflect the research areas covered by the famous Instituto Pluridisciplinar at the Universidad Complutense of Madrid, which he co-founded over two decades ago, and include: fluid physics and related nonlinear phenomena at interfaces and in other geometries, wetting and spreading dynamics, geophysical and astrophysical flows, and novel aspects of electronic transport in anharmonic lattices, as well as topics in neurodynamics and robotics.

  10. Complex carbohydrates--structure and function with respect to the glycoconjugate composition of the cupula of the semicircular canals.

    Science.gov (United States)

    Tauber, Rudolf; Reher, Kerstin; Helling, Kai; Scherer, Hans

    2002-03-01

    The review briefly describes the structure and function of complex carbohydrates of glycoproteins and proteoglycans both in general and with particular respect to the potential roles sugar chains may play in the cupula, i.e. the molecular organization of these constituents, their biophysical properties, and their biological functions.

  11. Structural studies of complex carbohydrates of plant cell walls. Progress report, June 15, 1992--June 14, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, A.G.

    1994-10-01

    This report contains the abstracts of fourteen papers published, in press, or in preparation reporting on research activities to investigate the structure, as well as the function of cell walls in plants. This document also contains research on methods to determine the structure of complex carbohydrates of the cell walls.

  12. Influence of the π-coordinated arene on the anticancer activity of ruthenium(II) carbohydrate organometallic complexes

    NARCIS (Netherlands)

    Hanif, Muhammad; Meier, Samuel M; Nazarov, Alexey A; Risse, Julie; Legin, Anton; Casini, Angela; Jakupec, Michael A; Keppler, Bernhard K; Hartinger, Christian G

    2013-01-01

    The synthesis and in vitro cytotoxicity of a series of Ru(II)(arene) complexes with carbohydrate-derived phosphite ligands and various arene co-ligands is described. The arene ligand has a strong influence on the in vitro anticancer activity of this series of compounds, which correlates fairly well

  13. Nanoparticle-enhanced fluorescence emission for non-separation assays of carbohydrates using a boronic acid-alizarin complex.

    Science.gov (United States)

    Li, Qianjin; Kamra, Tripta; Ye, Lei

    2016-03-01

    Addition of crosslinked polymer nanoparticles into a solution of a 3-nitrophenylboronic acid-alizarin complex leads to significant enhancement of fluorescence emission. Using the nanoparticle-enhanced boronic acid-alizarin system has improved greatly the sensitivity and extended the dynamic range of separation-free fluorescence assays for carbohydrates.

  14. Studies on immobilized polymer-bound imidazole copper(II) complexes as catalysts

    NARCIS (Netherlands)

    Chen, Wei

    2006-01-01

    This thesis describes the immobilization of polymer-bound imidazole Cu(I1) complexes on non-porous silica spheres. The catalytic properties of these immobilized polymeric Cu(I1) complexes and their non-immobilized polymeric or low-molar-mass analogues were examined in oxidative coupling (polymerizat

  15. Control of Future Air Traffic Systems via Complexity Bound Management

    Science.gov (United States)

    Alexandrov, Natalia

    2013-01-01

    The complexity of the present system for managing air traffic has led to "discreteness" in approaches to creating new concepts: new concepts are created as point designs, based on experience, expertise, and creativity of the proposer. Discrete point designs may be highly successful but they are difficult to substantiate in the face of equally strong substantiation of competing concepts, as well as the state of the art in concept evaluation via simulations. Hybrid concepts may present a compromise - the golden middle. Yet a hybrid of sometimes in principle incompatible concepts forms another point design that faces the challenge of substantiation and validation. We are faced with the need to re-design the air transportation system ab initio. This is a daunting task, especially considering the problem of transitioning from the present system to any fundamentally new system. However, design from scratch is also an opportunity to reconsider approaches to new concept development. In this position paper we propose an approach, Optimized Parametric Functional Design, for systematic development of concepts for management and control of airspace systems, based on optimization formulations in terms of required system functions and states. This reasoning framework, realizable in the context of ab initio system design, offers an approach to deriving substantiated airspace management and control concepts. With growing computational power, we hope that the approach will also yield a methodology for actual dynamic control of airspace

  16. Recent progress in heteronuclear long-range NMR of complex carbohydrates: 3D H2BC and clean HMBC

    DEFF Research Database (Denmark)

    Meier, Sebastian; Petersen, Bent O.; Duus, Jens Øllgaard;

    2009-01-01

    The new NMR experiments 3D H2BC and clean HMBC are explored for challenging applications to a complex carbohydrate at natural abundance of 13C. The 3D H2BC experiment is crucial for sequential assignment as it yields heteronuclear one- and two-bond together with COSY correlations for the 1H spins......, all in a single spectrum with good resolution and non-informative diagonal-type peaks suppressed. Clean HMBC is a remedy for the ubiquitous problem of strong coupling induced one-bond correlation artifacts in HMBC spectra of carbohydrates. Both experiments work well for one of the largest...... carbohydrates whose structure has been determined by NMR, not least due to the enhanced resolution offered by the third dimension in 3D H2BC and the improved spectral quality due to artifact suppression in clean HMBC. Hence these new experiments set the scene to take advantage of the sensitivity boost achieved...

  17. Complex carbohydrates in the dietary management of patients with glycogenosis caused by glucose-6-phosphatase deficiency.

    Science.gov (United States)

    Smit, G P; Ververs, M T; Belderok, B; Van Rijn, M; Berger, R; Fernandes, J

    1988-07-01

    Carbohydrates with digestion characteristics between those of lente uncooked starches and rapidly digestible oligosaccharides were administered in a dose of 1.5 g/kg body weight to five patients with glycogenosis from glucose-6-phosphatase deficiency. Postprandial duration of normoglycemia and concentrations of blood insulin and lactate were determined. Uncooked barley groats in water, or incorporated in a meal turned out to behave as lente carbohydrates. Uncooked couscous in water, couscous incorporated in a meal, and partially cooked macaroni given as a meal behaved as semilente carbohydrates as compared with uncooked cornstarch and glucose. The in vitro determination of the digestibility index along with the in vivo tolerance test enables us to choose and incorporate semilente carbohydrates in the day-time treatment of patients. PMID:3291600

  18. Mild and rational synthesis of palladium complexes comprising C(4)-bound N-heterocyclic carbenes

    OpenAIRE

    Kluser, Evelyne; Neels, Antonia; Albrecht, Martin

    2007-01-01

    Oxidative addition of pyridyl-functionalised 4-iodoimidazolium salts to palladium(0) gives catalytically active complexes in which the N-heterocyclic carbene is bound to the palladium(II) centre in a non-classical bonding mode via C(4).

  19. OXIDATIVE PHENOL COUPLING CATALYZED BY POLYMER-BOUND COPPER-IMIDAZOLE COMPLEXES

    NARCIS (Netherlands)

    CHALLA, G; REEDIJK, J

    1992-01-01

    Polymer-bound imidazole-copper(II) complexes were investigated and applied as catalysts for oxidative coupling (polymerization) of 2,6-dialkylphenols. These polymeric catalysts were also immobilized on silica particles through adsorption, quaternization and grafting. Especially, the grafted catalyst

  20. Sharp Growth Theorems and Coefficient Bounds for Starlike Mappings in Several Complex Variables

    Institute of Scientific and Technical Information of China (English)

    Hidetaka HAMADA; Tatsuhiro HONDA

    2008-01-01

    Let B be the unit ball in a complex Banach space. Let S*+1(B) be the family of normalized starlike mappings f on B such that z = 0 is a zero of order k + 1 of f(z) - z. The authors obtain sharp growth and covering theorems, as well as sharp coefficient bounds for various subsets of S*k+1(B).

  1. Lower Bounds on Quantum Query Complexity for Read-Once Formulas with XOR and MUX Operators

    Science.gov (United States)

    Fukuhara, Hideaki; Takimoto, Eiji

    We introduce a complexity measure r for the class F of read-once formulas over the basis {AND, OR, NOT, XOR, MUX} and show that for any Boolean formula F in the class F, r(F) is a lower bound on the quantum query complexity of the Boolean function that F represents. We also show that for any Boolean function f represented by a formula in F, the deterministic query complexity of f is only quadratically larger than the quantum query complexity of f. Thus, the paper gives further evidence for the conjecture that there is an only quadratic gap for all functions.

  2. Variation in the complex carbohydrate biosynthesis loci of Acinetobacter baumannii genomes.

    Directory of Open Access Journals (Sweden)

    Johanna J Kenyon

    Full Text Available Extracellular polysaccharides are major immunogenic components of the bacterial cell envelope. However, little is known about their biosynthesis in the genus Acinetobacter, which includes A. baumannii, an important nosocomial pathogen. Whether Acinetobacter sp. produce a capsule or a lipopolysaccharide carrying an O antigen or both is not resolved. To explore these issues, genes involved in the synthesis of complex polysaccharides were located in 10 complete A. baumannii genome sequences, and the function of each of their products was predicted via comparison to enzymes with a known function. The absence of a gene encoding a WaaL ligase, required to link the carbohydrate polymer to the lipid A-core oligosaccharide (lipooligosaccharide forming lipopolysaccharide, suggests that only a capsule is produced. Nine distinct arrangements of a large capsule biosynthesis locus, designated KL1 to KL9, were found in the genomes. Three forms of a second, smaller variable locus, likely to be required for synthesis of the outer core of the lipid A-core moiety, were designated OCL1 to OCL3 and also annotated. Each K locus includes genes for capsule export as well as genes for synthesis of activated sugar precursors, and for glycosyltransfer, glycan modification and oligosaccharide repeat-unit processing. The K loci all include the export genes at one end and genes for synthesis of common sugar precursors at the other, with a highly variable region that includes the remaining genes in between. Five different capsule loci, KL2, KL6, KL7, KL8 and KL9 were detected in multiply antibiotic resistant isolates belonging to global clone 2, and two other loci, KL1 and KL4, in global clone 1. This indicates that this region is being substituted repeatedly in multiply antibiotic resistant isolates from these clones.

  3. A Goppa-like bound on the trellis state complexity of algebraic geometric codes

    OpenAIRE

    Munuera, Carlos; Torres, Fernando

    2002-01-01

    For a linear code $\\cC$ of length $n$ and dimension $k$, Wolf noticed that the trellis state complexity $s(\\cC)$ of $\\cC$ is upper bounded by $w(\\cC):=\\min(k,n-k)$. In this paper we point out some new lower bounds for $s(\\cC)$. In particular, if $\\cC$ is an Algebraic Geometric code, then $s(\\cC)\\geq w(\\cC)-(g-a)$, where $g$ is the genus of the underlying curve and $a$ is the abundance of the code.

  4. Complexity of stochastic branch and bound methods for belief tree search in Bayesian reinforcement learning

    CERN Document Server

    Dimitrakakis, Christos

    2009-01-01

    There has been a lot of recent work on Bayesian methods for reinforcement learning exhibiting near-optimal online performance. The main obstacle facing such methods is that in most problems of interest, the optimal solution involves planning in an infinitely large tree. However, it is possible to obtain stochastic lower and upper bounds on the value of each tree node. This enables us to use stochastic branch and bound algorithms to search the tree efficiently. This paper proposes two such algorithms and examines their complexity in this setting.

  5. Cryptographic applications of analytic number theory complexity lower bounds and pseudorandomness

    CERN Document Server

    2003-01-01

    The book introduces new ways of using analytic number theory in cryptography and related areas, such as complexity theory and pseudorandom number generation. Key topics and features: - various lower bounds on the complexity of some number theoretic and cryptographic problems, associated with classical schemes such as RSA, Diffie-Hellman, DSA as well as with relatively new schemes like XTR and NTRU - a series of very recent results about certain important characteristics (period, distribution, linear complexity) of several commonly used pseudorandom number generators, such as the RSA generator, Blum-Blum-Shub generator, Naor-Reingold generator, inversive generator, and others - one of the principal tools is bounds of exponential sums, which are combined with other number theoretic methods such as lattice reduction and sieving - a number of open problems of different level of difficulty and proposals for further research - an extensive and up-to-date bibliography Cryptographers and number theorists will find th...

  6. POLYMER BOUND TRANSITION METAL COMPLEXES FOR CATALYTIC OXIDATION OF CYCLOHEXENE WITH MOLECULAR OXYGEN

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Polymer-bound Schiff-base ligand (PS-Sal-Cys) was prepared from the polystyrene-bound salicylaldehyde and L-cysteine, its complex (PS-Sal-Cys-Mn) was also synthesized. The polymer ligand and its complex were characterized by infrared spectra (IR), small area X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-atomic emission spectro (ICP-AES). In the presence of complex, cyclohexane can be effectively oxidized by molecular oxygen without a reductant. The major products of the reaction are 2-cyclohexen-1-ol, 2-cyclohexen-1-one, and 2-cyclohexen-1-hydroperoxide, which is different from the typical oxidation of cyclohexene. The mechanism of cyclohexene oxidation is also discussed.

  7. A Trichotomy Theorem for the Approximate Counting of Complex-Weighted Bounded-Degree Boolean CSPs

    CERN Document Server

    Yamakami, Tomoyuki

    2010-01-01

    We determine the complexity of approximate counting of the total weight of assignments for complex-weighted Boolean constraint satisfaction problems (or CSPs), particularly, when degrees of instances are bounded from above by a given constant, provided that all arity-1 constraints are freely available. All degree-1 counting CSPs are solvable in polynomial time. When the degree is more than 2, we present a trichotomy theorem that classifies all bounded-degree counting CSPs into only three categories with a help of free arity-1 constraints. This classification extends to complex-weighted problems an earlier result of Dyer, Goldberg, Jalsenius, and Richerby (2010) on the complexity of the approximate counting of bounded-degree unweighted Boolean CSPs. The framework of the proof of our trichotomy theorem is based on a theory of signatures (Cai and Lu, 2007, 2008) used in Valiant's holographic algorithms. Despite the use of arbitrary complex-weight, our proof is rather elementary and intuitive by an extensive use ...

  8. Assemblies composed of oligothiophene–ruthenium complexes bound to CdSe nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bair, Nathan; Hancock, Jared M.; Simonson, Cameron J. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Thalman, Scott W.; Colton, John S. [Department of Physics and Astronomy,Brigham Young University, Provo, UT 84602 (United States); Asplund, Matthew C. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States); Harrison, Roger G., E-mail: roger_harrison@byu.edu [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602 (United States)

    2015-02-15

    Molecular conjugates are important to link light sensitized materials to electron acceptors. We have synthesized oligothiophenes and oligothiophene–ruthenium complexes and bound them to CdSe nanoparticles. The absorption and fluorescence properties of the oligothiophenes bound to CdSe were measured. Steady-state luminescence and time correlated single photon counting were used to observe the effects on fluorescence and fluorescence lifetimes before and after binding. It was found that fluorescence of CdSe nanoparticles was quenched when they were bound to the oligothiophenes, and that the fluorescence of the oligothiophenes was also quenched. The fluorescence lifetimes of the quenched species were shortened and suggest electron transfer from oligothiophene to nanoparticle is on the order of one nanosecond. Orbital energy calculations predict that the Ru bound oligothiophenes have HOMO–LUMO energies of correct energy to allow electron and hole transfer. These experiments show that the oligothiophenes efficiently transfer optical energy between CdSe nanoparticles and could potentially be used as charge transfer junctions. - Highlights: • Ru bound thiophenes attached to CdSe nanoparticles. • Luminescence quenching of CdSe nanoparticles. • Molecular conjugates for photosensitized materials.

  9. Valence and diffuse-bound anions of noble-gas complexes with uracil

    Science.gov (United States)

    Streit, Lívia; Dolgounitcheva, O.; Zakrzewski, V. G.; Ortiz, J. V.

    2012-11-01

    Valence-bound (VB) and diffuse-bound (DB) anions of noble-gas (Ar, Kr, and Xe) complexes with uracil have been studied with ab initio methods. MP2 optimizations revealed minima corresponding to anions of both kinds in each case. Coupled-cluster singles and doubles with perturbative triples, CCSD(T), and electron propagator single-point calculations were performed in order to assess vertical and adiabatic electron detachment energies of these complexes. Ab initio electron propagator calculations employed the outer valence Green's function and partial third-order approximations, and the algebraic diagrammatic construction in third order. Basis set effects have been systematically examined. DB anions of all three complexes were adiabatically bound, with calculated adiabatic electron attachment energies below 0.06 eV. Corresponding vertical electron detachment energies were below 0.1 eV. As to VB anions, only the Xe complex had a positive adiabatic electron detachment energy, of 0.01 eV, with a corresponding vertical electron detachment energy of 0.6 eV. These computational findings are consistent with the interpretation of results previously obtained experimentally by Hendricks et al.

  10. Influence of the π-coordinated arene on the anticancer activity of ruthenium(II carbohydrate organometallic complexes

    Directory of Open Access Journals (Sweden)

    Muhammad eHanif

    2013-10-01

    Full Text Available The synthesis and in vitro cytotoxicity of a series of RuII(arene complexes with carbohydrate-derived phosphite ligands and various arene co-ligands is described. The arene ligand has a strong influence on the in vitro anticancer activity of this series of compounds, which correlates fairly well with cellular accumulation. The most lipophilic compound bearing a biphenyl moiety and a cyclohexylidene-protected carbohydrate is the most cytotoxic with unprecedented IC50 values for the compound class in three human cancer cell lines. This compound shows reactivity to the DNA model nucleobase 9-ethylguanine, but does not alter the secondary structure of plasmid DNA indicating that other biological targets are responsible for its cytotoxic effect.

  11. CarbBank: A structural and bibliographic database for complex carbohydrates

    Energy Technology Data Exchange (ETDEWEB)

    Albersheim, P.

    1992-06-01

    The CarbBank project has several key facets: building a computer database that presents carbohydrate sequence information derived from the published literature, programming to create computer applications that use the information in the database, creating software for multiple computer platforms, and distributing software to end users.

  12. Extension of a Spectral Bounding Method to Complex Rotated Hamiltonians, with Application to $p^2-ix^3$

    OpenAIRE

    Handy, C. R.; Wang, Xiao Qian

    2001-01-01

    We show that a recently developed method for generating bounds for the discrete energy states of the non-hermitian $-ix^3$ potential (Handy 2001) is applicable to complex rotated versions of the Hamiltonian. This has important implications for extension of the method in the analysis of resonant states, Regge poles, and general bound states in the complex plane (Bender and Boettcher (1998)).

  13. Complexity of a Duopoly Game in the Electricity Market with Delayed Bounded Rationality

    Directory of Open Access Journals (Sweden)

    Junhai Ma

    2012-01-01

    Full Text Available According to a triopoly game model in the electricity market with bounded rational players, a new Cournot duopoly game model with delayed bounded rationality is established. The model is closer to the reality of the electricity market and worth spreading in oligopoly. By using the theory of bifurcations of dynamical systems, local stable region of Nash equilibrium point is obtained. Its complex dynamics is demonstrated by means of the largest Lyapunov exponent, bifurcation diagrams, phase portraits, and fractal dimensions. Since the output adjustment speed parameters are varied, the stability of Nash equilibrium gives rise to complex dynamics such as cycles of higher order and chaos. Furthermore, by using the straight-line stabilization method, the chaos can be eliminated. This paper has an important theoretical and practical significance to the electricity market under the background of developing new energy.

  14. Hydrogen Bound Complexes with Tropolone: Binding Motifs, Barrier Heights, and the Search for Bifurcating Systems

    Science.gov (United States)

    Nemchick, Deacon; Chew, Kathryn; Vaccaro, Patrick

    2014-06-01

    The potentially frustrated transfer of a proton between the hydroxylic (proton-donating) and ketonic (proton-accepting) oxygen atom centers in tropolone (TrOH) long has served as a model system for the study of coherent (symmetrical) proton-transfer events. A litany of hydrogen-bound complexes [TrOH \\cdot Xn] can be formed in situ by docking amphoteric ligands onto the TrOH substrate under supersonic free-jet expansion conditions. Binary (n = 1) and higher order (n = 2, 3, ldots) complexes formed with formic acid, hydrogen fluoride, acetic acid and propiolic acid (X = FA, HF, AA, and PA) have been synthesized and interrogated using a variety of spectroscopic probes built upon the intense ˜{A1}B2-˜{X1}{A}1 (π *←π) near-ultraviolet absorption system of bare tropolone, thereby providing vibronically resolved information through combined use of laser-induced fluorescence (LIF), dispersed fluorescence (DF), fluorescence hole-burning (FHB), and stimulated emission pumping (SEP) methods. Experimental results reveal the propensity for binary complexes to adopt a higher-energy external binding motif (ligand attached to the seven membered aromatic ring) over the energetically preferred internal form (ligand bound to the O-H\\cdotsO reaction center), where the latter cleft-bound species can undergo unique symmetric (coherent) double proton-transfer reactions. These findings will be discussed in light of supporting quantum-chemical calculations.

  15. A New Boundary Model for Simulating Complex and Flexible Wall Bounded Domain in Dissipative Particle Dynamics

    Directory of Open Access Journals (Sweden)

    Saeid Mokhtarian

    2014-01-01

    Full Text Available Despite extensive area of applications, simulation of complex wall bounded problems or any deformable boundary is still a challenge in a Dissipative Particle Dynamics simulation. This limitation is rooted in the soft force nature of DPD and the fact that we need to use an antipenetration model for escaped particles. In the present paper, we propose a new model of antipenetration which preserves the conservation of linear momentum on the boundaries and enables us to simulate complex and flexible boundaries. Finally by performing numerical simulations, we demonstrate the validity of our new model.

  16. Bounds on the sample complexity for private learning and private data release

    Energy Technology Data Exchange (ETDEWEB)

    Kasiviswanathan, Shiva [Los Alamos National Laboratory; Beime, Amos [BEN-GURION UNIV.; Nissim, Kobbi [BEN-GURION UNIV.

    2009-01-01

    Learning is a task that generalizes many of the analyses that are applied to collections of data, and in particular, collections of sensitive individual information. Hence, it is natural to ask what can be learned while preserving individual privacy. [Kasiviswanathan, Lee, Nissim, Raskhodnikova, and Smith; FOCS 2008] initiated such a discussion. They formalized the notion of private learning, as a combination of PAC learning and differential privacy, and investigated what concept classes can be learned privately. Somewhat surprisingly, they showed that, ignoring time complexity, every PAC learning task could be performed privately with polynomially many samples, and in many natural cases this could even be done in polynomial time. While these results seem to equate non-private and private learning, there is still a significant gap: the sample complexity of (non-private) PAC learning is crisply characterized in terms of the VC-dimension of the concept class, whereas this relationship is lost in the constructions of private learners, which exhibit, generally, a higher sample complexity. Looking into this gap, we examine several private learning tasks and give tight bounds on their sample complexity. In particular, we show strong separations between sample complexities of proper and improper private learners (such separation does not exist for non-private learners), and between sample complexities of efficient and inefficient proper private learners. Our results show that VC-dimension is not the right measure for characterizing the sample complexity of proper private learning. We also examine the task of private data release (as initiated by [Blum, Ligett, and Roth; STOC 2008]), and give new lower bounds on the sample complexity. Our results show that the logarithmic dependence on size of the instance space is essential for private data release.

  17. Carbohydrates in Supramolecular Chemistry.

    Science.gov (United States)

    Delbianco, Martina; Bharate, Priya; Varela-Aramburu, Silvia; Seeberger, Peter H

    2016-02-24

    Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed. PMID:26702928

  18. Counting carbohydrates

    Science.gov (United States)

    Carb counting; Carbohydrate-controlled diet; Diabetic diet; Diabetes-counting carbohydrates ... goal is not to limit carbohydrates in the diet completely, but to make ... with diabetes can better control their blood sugar if they ...

  19. On an intraparticle complex of cationic nanogel with a stoichiometric amount of bound polyanions.

    Science.gov (United States)

    Ogawa, Kazuyoshi; Sato, Seigo; Kokufuta, Etsuo

    2007-02-13

    A polyelectrolyte nanogel (PENG) particle consisting of lightly cross-linked terpolymer chains of N-isopropylacrylamide, acrylic acid, and 1-vinylimidazole has positive charges in an aqueous medium at pH 3 due to protonation of the imidazole groups, and thereby forms a polyelectrolyte complex with the linear polyanion, potassium poly(vinyl alcohol) sulfate (KPVS). It has been demonstrated that the hydrodynamic radius (Rh), by dynamic light scattering (DLS), and the radius of gyration (Rg), by static light scattering (SLS), of the complex particles are smallest at approximately 1:1 mixing ratio (rm) of anions to cations, in the absence of simple salts such as KCl (Langmuir 2005, 21, 4830). Here, we aimed to study the nature of the complex formed at rm=1 and examined the complex formation process by electrophoretic light scattering (ELS). It was found that the mobility of the cationic PENG with a stoichiometric amount of bound KPVS anions (i.e., the complex formed at rm=1) is positive but not zero at 25 degrees C. This was also the case when the complex was examined by ELS at 45 degrees C, where DLS and SLS show a temperature-driven collapse of the complex. We thus assumed that (a) electroneutrality is maintained in the complex particle with the aid of counterions, but (b) the complex is highly polarizable, and hence (c) during ELS the KPVS anions would dissociate in part from the complex. This hypothesis was supported by the following results: (i) Mixing complexed and uncomplexed PENG particles at different ratios brings about an increase in Rh and a decrease in the light scattering intensity of the complex at the same time, suggesting a polyelectrolyte exchange reaction. (ii) The same phenomenon is seen when poly(diallyldimethylammonium chloride) (PDDA as a polysalt) is added to the complex dispersion, meaning that the PDDA takes out the KPVS from the complex to form a stable PDDA-KPVS complex. (iii) Upon addition of KCl, the complex undergoes little change in Rh

  20. The complexity of membrane-bound glycans in health and disease and the beneficial properties of glyconutrients

    OpenAIRE

    Wagner, Lynn

    2013-01-01

    The surface of all free living cells and all multicellular cell types are covered with a dense and complex array of sugars mostly attached to proteins and lipids. These specific sugars are referred to as glycans and the biological role of these sugars includes cell-cell, cell-matrix, cell-molecule interactions, and interactions between other organisms. The chemistry of carbohydrates has been studied well since the first part of the 20th century without understanding the complexity of the glyc...

  1. Pinning-controlled synchronization of complex networks with bounded or unbounded synchronized regions

    Institute of Scientific and Technical Information of China (English)

    Zou Yan-Li; Chen Guan-Rong

    2009-01-01

    This paper studies pinning-controlled synchronization of complex networks with bounded or unbounded synchro nized regions.To study a state-feedback pinning-controlled network with N nodes,it first converts the controlled network to an extended network of N+1 nodes without controls.It is shown that the controlled synchronizability of the given network is determined by the real part of the smallest nonzero eigenvalue of the coupling matrix of its extended network when the synchronized region is unbounded; but it is determined by the ratio of the real parts of the largest and the smallest nonzero eigenvalues of the coupling matrix when the synchronized region is bounded.Both theoretical analysis and numerical simulation show that the portion of controlled nodes has no critical values when the synchronized region is unbounded,but it has a critical value when the synchronized region is bounded.In the former case,therefore,it is possible to control the network to achieve synchronization by pinning only one node.In the latter ease,the network can achieve controlled synchronization only when the portion of controlled nodes is larger than the critical value.

  2. Communication: Photoactivation of nucleobase bound platinumII metal complexes: Probing the influence of the nucleobase

    International Nuclear Information System (INIS)

    We present UV laser action spectra (220-300 nm) of isolated nucleobase-bound PtII(CN)42− complexes, i.e., Pt(CN)42−⋅M, where M = uracil, thymine, cytosine, and adenine. These metal complex-nucleobase clusters represent model systems for identifying the fundamental photophysical and photochemical processes occurring in photodynamic platinum (II) drug therapies that target DNA. This is the first study to explore the specific role of the nucleobase in the photophysics of the aggregate complex. Each of the complexes studied displays a broadly similar absorption spectra, with a strong λmax ∼ 4.7 eV absorption band (nucleobase localized chromophore) and a subsequent increase in the absorption intensity towards higher spectral-energy (Pt(CN)42− localized chromophore). However, strikingly different band widths are observed across the series of complexes, decreasing in the order Pt(CN)42−⋅Thymine > Pt(CN)42−⋅Uracil > Pt(CN)42−⋅Adenine > Pt(CN)42−⋅Cytosine. Changes in the bandwidth of the ∼4.7 eV band are accompanied by distinctive changes in the photofragment product ions observed following photoexcitation, with the narrower-bandwidth complexes showing a greater propensity to decay via electron detachment decay. We discuss these observations in the context of the distinctive nucleobase-dependent excited state lifetimes

  3. Complex bounds and microstructural recovery from measurements of sea ice permittivity

    International Nuclear Information System (INIS)

    Sea ice is a porous composite of pure ice with brine, air, and salt inclusions. The polar sea ice packs play a key role in the earth's ocean-climate system, and they host robust algal and bacterial communities that support the Arctic and Antarctic ecosystems. Monitoring the sea ice packs on global or regional scales is an increasingly important problem, typically involving the interaction of an electromagnetic wave with sea ice. In the quasistatic regime where the wavelength is much longer than the composite microstructural scale, the electromagnetic behavior is characterized by the effective complex permittivity tensor ε*. In assessing the impact of climate change on the polar sea ice covers, current satellites and algorithms can predict ice extent, but the thickness distribution remains an elusive, yet most important feature. In recent years, electromagnetic induction devices using low frequency waves have been deployed on ships, helicopters and planes to obtain thickness data. Here we compare two sets of theoretical bounds to extensive outdoor tank and in situ field data on ε* at 50MHz taken in the Arctic and Antarctic. The sea ice is assumed to be a two phase composite of ice and brine with known constituent permittivities. The first set of bounds assumes only knowledge of the brine volume fraction or porosity, and the second set further assumes statistical isotropy of the microstructure. We obtain excellent agreement between theory and experiment, and are able to observe the apparent violation of the isotropic bounds as the vertically oriented microstructure becomes increasingly connected for higher porosities. Moreover, these bounds are inverted to obtain estimates of the porosity from the measurements of ε*. We find that the temporal variations of the reconstructed porosity, which is directly related to temperature, closely follow the actual behavior

  4. Heck Arylation of Acrylonitrile with Aryl Iodides Catalyzed by a Silica-bound Arsine Palladium(0) Complex

    Institute of Scientific and Technical Information of China (English)

    Ming Zhong CAI; Hong ZHAO; Rong Li ZHANG

    2005-01-01

    Acrylonitrile reacts with aryl iodides in the presence of tri-n-butylamine and a catalytic amount of a silica-bound arsine palladium(0) complex to afford stereoselectively (E)-cinnamonitriles in high yields.

  5. Bound anions differentially stabilize multiprotein complexes in the absence of bulk solvent.

    Science.gov (United States)

    Han, Linjie; Hyung, Suk-Joon; Mayers, Jonathan J S; Ruotolo, Brandon T

    2011-07-27

    The combination of ion mobility separation with mass spectrometry is an emergent and powerful structural biology tool, capable of simultaneously assessing the structure, topology, dynamics, and composition of large protein assemblies within complex mixtures. An integral part of the ion mobility-mass spectrometry measurement is the ionization of intact multiprotein complexes and their removal from bulk solvent. This process, during which a substantial portion of protein structure and organization is likely to be preserved, imposes a foreign environment on proteins that may cause structural rearrangements to occur. Thus, a general means must be identified to stabilize protein structures in the absence of bulk solvent. Our approach to this problem involves the protection of protein complex structure through the addition of salts in solution prior to desorption/ionization. Anionic components of the added salts bind to the complex either in solution or during the electrospray process, and those that remain bound in the gas phase tend to have high gas phase acidities. The resulting 'shell' of counterions is able to carry away excess energy from the protein complex ion upon activation and can result in significant structural stabilization of the gas-phase protein assembly overall. By using ion mobility-mass spectrometry, we observe both the dissociation and unfolding transitions for four tetrameric protein complexes bound to populations of 12 different anions using collisional activation. The data presented here quantifies, for the first time, the influence of a large range of counterions on gas-phase protein structure and allows us to rank and classify counterions as structure stabilizers in the absence of bulk solvent. Our measurements indicate that tartrate, citrate, chloride, and nitrate anions are among the strongest stabilizers of gas-phase protein structure identified in this screen. The rank order determined by our data is substantially different when compared to

  6. Competitive exclusion of Salmonella typhimurium in broilers fed with vermicompost and complex carbohydrates.

    Science.gov (United States)

    Spencer, J L; Chambers, J R; Modler, H W

    1998-01-01

    Vermicompost (VC) was produced by earthworms fed with fresh chicken faeces, and was earth-like in appearance and odour. In three experiments, VC was sprinkled on the first feed of newly-hatched broiler chicks. Treated and control groups were challenged on day 6 by the addition of seeder chicks that had been inoculated orally with Salmonella typhimurium. Chickens were killed at intervals during a 6-week period and were tested for colonization of the pathogen in the crop, caecum and internal organs. The VC-treated groups were significantly more resistant (p < 0.01) to colonization by S. typhimurium than the untreated controls. In one experiment, the VC treatment appeared to have conferred complete protection against colonization of both the crop and caecum. Colonization of the crop was increased transiently by addition to the diet of 2.5% fructooligosaccharide, xylo-oligosaccharide or transgalactosylated oligosaccharide. The influence of these carbohydrates on colonization of the caecum was variable. PMID:18484271

  7. Aspergillus oryzae-Saccharomyces cerevisiae Consortium Allows Bio-Hybrid Fuel Cell to Run on Complex Carbohydrates.

    Science.gov (United States)

    Jahnke, Justin P; Hoyt, Thomas; LeFors, Hannah M; Sumner, James J; Mackie, David M

    2016-01-01

    Consortia of Aspergillus oryzae and Saccharomyces cerevisiae are examined for their abilities to turn complex carbohydrates into ethanol. To understand the interactions between microorganisms in consortia, Fourier-transform infrared spectroscopy is used to follow the concentrations of various metabolites such as sugars (e.g., glucose, maltose), longer chain carbohydrates, and ethanol to optimize consortia conditions for the production of ethanol. It is shown that with proper design A. oryzae can digest food waste simulants into soluble sugars that S. cerevisiae can ferment into ethanol. Depending on the substrate and conditions used, concentrations of 13% ethanol were achieved in 10 days. It is further shown that a direct alcohol fuel cell (FC) can be coupled with these A. oryzae-enabled S. cerevisiae fermentations using a reverse osmosis membrane. This "bio-hybrid FC" continually extracted ethanol from an ongoing consortium, enhancing ethanol production and allowing the bio-hybrid FC to run for at least one week. Obtained bio-hybrid FC currents were comparable to those from pure ethanol-water mixtures, using the same FC. The A. oryzae-S. cerevisiae consortium, coupled to a bio-hybrid FC, converted food waste simulants into electricity without any pre- or post-processing. PMID:27681904

  8. Facilitating the enzymatic saccharification of pulped bamboo residues by degrading the remained xylan and lignin-carbohydrates complexes.

    Science.gov (United States)

    Huang, Caoxing; He, Juan; Li, Xin; Min, Douyong; Yong, Qiang

    2015-09-01

    Kraft pulping was performed on bamboo residues and its impact on the chemical compositions and the enzymatic digestibility of the samples were investigated. To improve the digestibility of sample by degrading the xylan and lignin-carbohydrates complexes (LCCs), xylanase and α-L-arabinofuranosidase (AF) were supplemented with cellulase. The results showed more carbohydrates were remained in the samples pulped with low effective alkali (EA) charge, compared to conventional kraft pulping. When 120 IU/g xylanase and 15 IU/g AF were supplemented with 20 FPU/g cellulase, the xylan degradation yield of the sample pulped with 12% EA charge increased from 68.20% to 88.35%, resulting in an increased enzymatic saccharification efficiency from 58.98% to 83.23%. The amount of LCCs in this sample decreased from 8.63/100C9 to 2.99/100C9 after saccharification with these enzymes. The results indicated that degrading the remained xylan and LCCs in the pulp could improve its enzymatic digestibility.

  9. Structures and characterization of digoxin- and bufalin-bound Na+,K+-ATPase compared with the ouabain-bound complex

    DEFF Research Database (Denmark)

    Laursen, Mette; Gregersen, Jonas Lindholt; Yatime, Laure;

    2015-01-01

    . These functionalities have specific influence on the binding properties. We report crystal structures of the Na+,K+-ATPase in the E2P form in complex with bufalin (a nonglycosylated CTS with a six-membered lactone) and digoxin (a trisaccharide-conjugated CTS with a five-membered lactone) and compare...... in site II of the digoxin and ouabain complexes, whereas both sites are occupied by K+ in the E2P–bufalin complex. In all complexes, αM4 adopts a wound form, characteristic for the E2P state and favorable for high-affinity CTS binding. We conclude that the occupants of the cation-binding site and the type...

  10. Micro-Spectroscopic Imaging of Lignin-Carbohydrate Complexes in Plant Cell Walls and Their Migration During Biomass Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yining; Zhao, Shuai; Wei, Hui; Tucker, Melvin P.; Johnson, David K.; Himmel, Michael E.; Mosier, Nathan S.; Meilan, Richard; Ding, Shi-You

    2015-04-27

    In lignocellulosic biomass, lignin is the second most abundant biopolymer. In plant cell walls, lignin is associated with polysaccharides to form lignin-carbohydrate complexes (LCC). LCC have been considered to be a major factor that negatively affects the process of deconstructing biomass to simple sugars by cellulosic enzymes. Here, we report a micro-spectroscopic approach that combines fluorescence lifetime imaging microscopy and Stimulated Raman Scattering microscopy to probe in situ lignin concentration and conformation at each cell wall layer. This technique does not require extensive sample preparation or any external labels. Using poplar as a feedstock, for example, we observe variation of LCC in untreated tracheid poplar cell walls. The redistribution of LCC at tracheid poplar cell wall layers is also investigated when the chemical linkages between lignin and hemicellulose are cleaved during pretreatment. Our study would provide new insights into further improvement of the biomass pretreatment process.

  11. Catalytic activity of polymer-bound Ru(III)–EDTA complex

    Indian Academy of Sciences (India)

    Mahesh K Dalal; R N Ram

    2001-04-01

    Chloromethylated styrene–divinylbenzene copolymer was chemically modified with ethylenediaminetetraacetic acid ligand. Catalytically active polymer containing Ru(III) moieties were synthesized from this polymeric ligand. They were characterized using FTIR, UV-vis, SEM, ESR and TGA. Other physico-chemical properties such as bulk density, surface area, moisture content and swelling behaviour in different solvents were also studied. The polymer bound complex was used to study hydrogenation of 1-hexene to -hexane under mild conditions. Influence of [1-hexene], [catalyst], temperature and nature of the solvent on the rate of the reaction was investigated. A rate expression is proposed based on the observed initial rate data. Recycling efficiency of the catalyst has also been studied.

  12. A Ribosome-Bound Quality Control Complex Triggers Degradation of Nascent Peptides and Signals Translation Stress

    Science.gov (United States)

    Brandman, Onn; Stewart-Ornstein, Jacob; Wong, Daisy; Larson, Adam; Williams, Christopher C.; Li, Gene-Wei; Zhou, Sharleen; King, David; Shen, Peter S.; Weibezahn, Jimena; Dunn, Joshua G.; Rouskin, Silvi; Inada, Toshifumi; Frost, Adam; Weissman, Jonathan S.

    2012-01-01

    Summary The conserved transcriptional regulator Heat Shock Factor 1 (Hsf1) is a key sensor of proteotoxic and other stress in the eukaryotic cytosol, yet its regulation is poorly understood. We surveyed Hsf1 activity in a genome-wide loss-of-function library in Saccaromyces cerevisiae as well as ~78,000 double mutants and found Hsf1 activity to be modulated by highly diverse stresses. These included disruption of a ribosome-bound complex we named the Ribosome Quality Control Complex (RQC) comprising the Ltn1 E3 ubiquitin ligase, two highly conserved but poorly characterized proteins (Tae2 and Rqc1), and Cdc48 and its cofactors. Electron microscopy and biochemical analyses revealed that the RQC forms a stable complex with 60S ribosomal subunits containing stalled polypeptides and triggers their degradation. A negative feedback loop regulates the RQC and Hsf1 senses an RQC-mediated translation stress signal distinctly from other stresses. Our work reveals the range of stresses Hsf1 monitors and elucidates a conserved cotranslational protein quality control mechanism. PMID:23178123

  13. Study of transient luminescence of three kinds of Ru complexes bound to DNA

    Institute of Scientific and Technical Information of China (English)

    ZHU WeiLing; LIU XueWen; WANG Hui; YU HuiJuan; LI AiZheng; CHAO Hui; ZHENG KangCheng; JI LiangNian

    2008-01-01

    The transient luminescence of three kinds of ruthenium complexes [Ru(bpy)2(7-CH3-dppz)]2+, [Ru(bpy)2(7-F-dppz)]2+ and [Ru(phen)2(7-F-dppz)]2+ bound to calf thy-mus DNA (ctDNA) has been studied by using the time-resolved spectroscopy. The results show that the luminescence is due to the radiative decay from the charge-transfer states to the ground state. By the Interaction with DNA, the radla-tiveless rate of the photoexcited Ru complex molecules decreases, which results In the increase of luminescence lifetime and efficiency. The structure of the Ru com-plex has an important impact on the interaction with DNA. The [Ru(bpy)2(7-CH3-dppz)]2+shows the longest luminescence lifetime (about 382 ns), while the [Ru(bpy)2(7-F-dppz)]2+ shows the shortest lifetime (about 65 ns). The possible origin of the luminescence dynamics is discussed.

  14. Study of transient luminescence of three kinds of Ru complexes bound to DNA

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The transient luminescence of three kinds of ruthenium complexes [Ru(bpy)2(7-CH3-dppz)]2+, [Ru(bpy)2(7-F-dppz)]2+ and [Ru(phen)2(7-F-dppz)]2+ bound to calf thy-mus DNA (ctDNA) has been studied by using the time-resolved spectroscopy. The results show that the luminescence is due to the radiative decay from the charge-transfer states to the ground state. By the interaction with DNA, the radia-tiveless rate of the photoexcited Ru complex molecules decreases, which results in the increase of luminescence lifetime and efficiency. The structure of the Ru com-plex has an important impact on the interaction with DNA. The [Ru(bpy)2(7-CH3-dppz)]2+ shows the longest luminescence lifetime (about 382 ns), while the [Ru(bpy)2(7-F-dppz)]2+ shows the shortest lifetime (about 65 ns). The possible origin of the luminescence dynamics is discussed.

  15. Enhancing the copper(II) complexes cytotoxicity to cancer cells through bound to human serum albumin.

    Science.gov (United States)

    Gou, Yi; Zhang, Yao; Qi, Jinxu; Zhou, Zuping; Yang, Feng; Liang, Hong

    2015-03-01

    We use Schiff-base salicylaldehyde benzoylhydrazone (HL) as the ligand for copper(II), resulting in the complexes [CuCl(L)]·H2O (C1), [CuNO3(L)]·H2O (C2) and [CuBr(L)]2 (C3). We characterize the Cu(II) compounds' interactions with human serum albumin (HSA) using fluorescence spectroscopy and molecular docking. These studies revealed that Cu(II) compounds propensity bound to IIA subdomain of HSA possible by hydrophobic interactions and hydrogen bond. Cu(II) compounds produce intracellular reactive oxygen species (ROS) in cancer cells. Complexes of HSA and copper(II) compounds enhance about 2-fold cytotoxicity in cancer cells but do not raise cytotoxicity levels in normal cells in vitro. Compared with C3 alone, HSA-C3 complex promotes HepG2 cell apoptosis and has a stronger capacity to promote cell cycle arrest at the G2/M phase of HepG2.

  16. Structure of an Rrp6-RNA exosome complex bound to poly(A) RNA

    Energy Technology Data Exchange (ETDEWEB)

    Wasmuth, Elizabeth V.; Januszyk, Kurt; Lima, Christopher D. [MSKCC

    2014-08-20

    The eukaryotic RNA exosome processes and degrades RNA by directing substrates to the distributive or processive 3' to 5' exoribonuclease activities of Rrp6 or Rrp44, respectively. The non-catalytic nine-subunit exosome core (Exo9) features a prominent central channel. Although RNA can pass through the channel to engage Rrp44, it is not clear how RNA is directed to Rrp6 or whether Rrp6 uses the central channel. Here we report a 3.3 Å crystal structure of a ten-subunit RNA exosome complex from Saccharomyces cerevisiae composed of the Exo9 core and Rrp6 bound to single-stranded poly(A) RNA. The Rrp6 catalytic domain rests on top of the Exo9 S1/KH ring above the central channel, the RNA 3' end is anchored in the Rrp6 active site, and the remaining RNA traverses the S1/KH ring in an opposite orientation to that observed in a structure of a Rrp44-containing exosome complex. Solution studies with human and yeast RNA exosome complexes suggest that the RNA path to Rrp6 is conserved and dependent on the integrity of the S1/KH ring. Although path selection to Rrp6 or Rrp44 is stochastic in vitro, the fate of a particular RNA may be determined in vivo by the manner in which cofactors present RNA to the RNA exosome.

  17. ONO-pincer ruthenium complex-bound norvaline for efficient catalytic oxidation of methoxybenzenes with hydrogen peroxide.

    Science.gov (United States)

    Yoshida, Ryota; Isozaki, Katsuhiro; Yokoi, Tomoya; Yasuda, Nobuhiro; Sadakane, Koichiro; Iwamoto, Takahiro; Takaya, Hikaru; Nakamura, Masaharu

    2016-08-21

    The enhanced catalytic activity of ruthenium complex-bound norvaline Boc-l-[Ru]Nva-OMe 1, in which the ONO-pincer ruthenium complex Ru(pydc)(terpy) 2 is tethered to the α-side chain of norvaline, has been demonstrated for the oxidation of methoxybenzenes to p-benzoquinones with a wide scope of substrates and unique chemoselectivity. PMID:27314504

  18. Effect of vitamin E on protein bound carbohydrate complexes in radiation treated oral squamous cell carcinoma patients

    International Nuclear Information System (INIS)

    Serum glycoproteins were evaluated in oral squamous cell carcinoma patients treated with radiotherapy and also the effect of vitamin E was studied. Cell surface glycoconjugates are important parameters in the detection of malignancy. Thus, the objective of the present study is to evaluate the efficacy of vitamin E on glycoproteins in oral cavity cancer patients treated with radiotherapy. The study includes 26 age and sex matched normal healthy individuals and 26 patients with squamous cell carcinoma of oral cavity. These patients were divided into two groups, one for radiotherapy alone (at a dosage of 6000 cGy in five fractions per week for a period of six weeks) and the other for radiotherapy plus vitamin E supplementation (at a dosage of 400 IU/day of vitamin E) for the entire period of radiotherapy. Levels of hexose, hexosamine, fucose and sialic acid were increased in oral squamous cell carcinoma patients and a significant decrease was observed in radiation treated patients when compared to control. The levels of glycoconjugates were significantly decreased in radiation treated patients supplemented with vitamin E. This measurement may be useful in assessing disease progression and identifying patients resistant to therapy and a possible role of vitamin E on reduction in glycoconjugate levels of radiation treated oral squamous cell carcinoma patients. (author)

  19. Transcriptome, carbohydrate and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress

    Directory of Open Access Journals (Sweden)

    Martin Andreas Bauerfeind

    2015-07-01

    Full Text Available Cultivation of chilling-tolerant ornamental crops at lower temperature could reduce the energy demands of heated greenhouses. To provide a better understanding of how sub-optimal temperatures (12°C vs. 16°C affect growth of the sensitive Petunia hybrida cultivar `SweetSunshine Williams´, the transcriptome, carbohydrate metabolism and phytohormone homeostasis were monitored in aerial plant parts over four weeks by use of a microarray, enzymatic assays and GC-MS/MS. The data revealed three consecutive phases of chilling response. The first days were marked by a strong accumulation of sugars, particularly in source leaves, preferential up-regulation of genes in the same tissue and down-regulation of several genes in the shoot apex, especially those involved in the abiotic stress response. The midterm phase featured a partial normalization of carbohydrate levels and gene expression. After three weeks of chilling exposure, a new stabilized balance was established. Reduced hexose levels in the shoot apex, reduced ratios of sugar levels between the apex and source leaves and a higher apical sucrose/hexose ratio, associated with decreased activity and expression of cell wall invertase, indicate that prolonged chilling induced sugar accumulation in source leaves at the expense of reduced sugar transport to and reduced sucrose utilization in the shoot. This was associated with reduced levels of indole-3-acetic acid and abscisic acid in the apex and high numbers of differentially, particularly up-regulated genes, especially in the source leaves, including those regulating histones, ethylene action, transcription factors and a jasmonate-ZIM-domain protein. Transcripts of one Jumonji C domain containing protein and one expansin accumulated in source leaves throughout the chilling period. The results reveal a dynamic and complex disturbance of plant function in response to mild chilling, opening new perspectives for the comparative analysis of differently

  20. Transcriptome, carbohydrate, and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress.

    Science.gov (United States)

    Bauerfeind, Martin Andreas; Winkelmann, Traud; Franken, Philipp; Druege, Uwe

    2015-01-01

    Cultivation of chilling-tolerant ornamental crops at lower temperature could reduce the energy demands of heated greenhouses. To provide a better understanding of how sub-optimal temperatures (12°C vs. 16°C) affect growth of the sensitive Petunia hybrida cultivar 'SweetSunshine Williams', the transcriptome, carbohydrate metabolism, and phytohormone homeostasis were monitored in aerial plant parts over 4 weeks by use of a microarray, enzymatic assays and GC-MS/MS. The data revealed three consecutive phases of chilling response. The first days were marked by a strong accumulation of sugars, particularly in source leaves, preferential up-regulation of genes in the same tissue and down-regulation of several genes in the shoot apex, especially those involved in the abiotic stress response. The midterm phase featured a partial normalization of carbohydrate levels and gene expression. After 3 weeks of chilling exposure, a new stabilized balance was established. Reduced hexose levels in the shoot apex, reduced ratios of sugar levels between the apex and source leaves and a higher apical sucrose/hexose ratio, associated with decreased activity and expression of cell wall invertase, indicate that prolonged chilling induced sugar accumulation in source leaves at the expense of reduced sugar transport to and reduced sucrose utilization in the shoot. This was associated with reduced levels of indole-3-acetic acid and abscisic acid in the apex and high numbers of differentially, particularly up-regulated genes, especially in the source leaves, including those regulating histones, ethylene action, transcription factors, and a jasmonate-ZIM-domain protein. Transcripts of one Jumonji C domain containing protein and one expansin accumulated in source leaves throughout the chilling period. The results reveal a dynamic and complex disturbance of plant function in response to mild chilling, opening new perspectives for the comparative analysis of differently tolerant cultivars. PMID

  1. Ab initio potential energy surface and bound states for the Kr-OCS complex.

    Science.gov (United States)

    Feng, Eryin; Sun, Chunyan; Yu, Chunhua; Shao, Xi; Huang, Wuying

    2011-09-28

    The first ab initio potential energy surface of the Kr-OCS complex is developed using the coupled-cluster singles and doubles with noniterative inclusion of connected triples [CCSD(T)]. The mixed basis sets, aug-cc-pVTZ for the O, C, and S atom, and aug-cc-pVQZ-PP for the Kr atom, with an additional (3s3p2d1f) set of midbond functions are used. A potential model is represented by an analytical function whose parameters are fitted numerically to the single point energies computed at 228 configurations. The potential has a T-shaped global minimum and a local linear minimum. The global minimum occurs at R = 7.146 a(0), θ = 105.0° with energy of -270.73 cm(-1). Bound state energies up to J = 9 are calculated for three isotopomers (82)Kr-OCS, (84)Kr-OCS, and (86)Kr-OCS. Analysis of the vibrational wavefunctions and energies suggests the complex can exist in two isomeric forms: T-shaped and quasi-linear. The calculated transition frequencies and spectroscopic constants of the three isotopomers are in good agreement with the experimental values.

  2. Polynomial Complexity Bounds of Mehrotra-typ e Predictor-corrector Algorithms for Linear Programming over Symmetric Cones

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-he; SHANG You-lin; LI Zhen-guo

    2015-01-01

    We establish polynomial complexity bounds of the Mehrotra-type predictor-corrector algorithms for linear programming over symmetric cones. We first slightly modify the maximum step size in the predictor step of the safeguard based Mehrotra-type algorithm for linear programming, that was proposed by Salahi et al[18]. Then, using the machinery of Euclidean Jordan algebras, we extend the modified algorithm to symmetric cones. Based on the Nesterov-Todd direction, we obtain O(r logε−1) iteration complexity bound of this algorithm, where r is the rank of the Jordan algebras andεis the required precision. We also present a new variant of Mehrotra-type algorithm using a new adaptive updating scheme of centering parameter and show that this algorithm enjoys the same order of complexity bound as the safeguard algorithm. We illustrate the numerical behaviour of the methods on some small examples.

  3. Insights into carbohydrate recognition by Narcissus pseudonarcissus lectin: the crystal structure at 2 A resolution in complex with alpha1-3 mannobiose.

    Science.gov (United States)

    Sauerborn, M K; Wright, L M; Reynolds, C D; Grossmann, J G; Rizkallah, P J

    1999-07-01

    Carbohydrate recognition by monocot mannose-binding lectins was studied via the crystal structure determination of daffodil (Narcissus pseudonarcissus) lectin. The lectin was extracted from daffodil bulbs, and crystallised in the presence of alpha-1,3 mannobiose. Molecular replacement methods were used to solve the structure using the partially refined model of Hippeastrum hybrid agglutinin as a search model. The structure was refined at 2.0 A resolution to a final R -factor of 18.7 %, and Rfreeof 26.7 %. The main feature of the daffodil lectin structure is the presence of three fully occupied binding pockets per monomer, arranged around the faces of a triangular beta-prism motif. The pockets have identical topology, and can bind mono-, di- or oligosaccharides. Strand exchange forms tightly bound dimers, and higher aggregation states are achieved through hydrophobic patches on the surface, completing a tetramer with internal 222-symmetry. There are therefore 12 fully occupied binding pockets per tetrameric cluster. The tetramer persists in solution, as shown with small-angle X-ray solution scattering. Extensive sideways and out-of-plane interactions between tetramers, some mediated via the ligand, make up the bulk of the lattice contacts.A fourth binding site was also observed. This is unique and has not been observed in similar structures. The site is only partially occupied by a ligand molecule due to the much lower binding affinity. A comparison with the Galanthus nivalis agglutinin/mannopentaose complex suggests an involvement of this site in the recognition mechanism for naturally occurring glycans.

  4. Towards Intelligent Dynamic Deployment of Mobile Sensors in Complex Resource-Bounded Environments

    Energy Technology Data Exchange (ETDEWEB)

    Ng, B M; Hanley, W G

    2007-05-08

    Decision-making in the face of uncertainty requires an understanding of the probabilistic mechanisms that govern the complex behavior of these systems. This issue applies to many domains: financial investments, disease control, military planning and homeland security. In each of these areas, there is a practical need for efficient resource-bounded reasoning capabilities to support optimal decision-making. Specifically, given a highly complex system, with numerous random variables and their dynamic interactions, how do we monitor such a system and detect crucial events that might impact our decision making process? More importantly, how do we perform this reasoning efficiently--to an acceptable degree of accuracy in real time--when there are only limited computational power and sensory capabilities? These questions encapsulate nontrivial key issues faced by many high-profile Laboratory missions: the problem of efficient inference and dynamic sensor deployment for risk/uncertainty reduction. By leveraging solid ideas such as system decomposition into loosely coupled subsystems and smart resource allocation among these subsystems, we can parallelize inference and data acquisition for faster and improved computational performance. In this report, we propose technical approaches for developing algorithmic tools to enable future scientific and engineering endeavors to better achieve the optimal use of limited resources for maximal return of information on a complex system. The result of the proposed research effort will be an efficient reasoning framework that would enable mobile sensors to work collaboratively as teams of adaptive and responsive agents, whose joint goal is to gather useful information that would assist in the inference process.

  5. Carbohydrates as allergens.

    Science.gov (United States)

    Commins, Scott P

    2015-01-01

    Complex carbohydrates are effective inducers of Th2 responses, and carbohydrate antigens can stimulate the production of glycan-specific antibodies. In instances where the antigen exposure occurs through the skin, the resulting antibody production can contain IgE class antibody. The glycan-stimulated IgE may be non-specific but may also be antigen specific. This review focuses on the production of cross-reactive carbohydrate determinants, the recently identified IgE antibody response to a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal), as well as discusses practical implications of carbohydrates in allergy. In addition, the biological effects of carbohydrate antigens are reviewed in setting of receptors and host recognition.

  6. Quantum Tomography via Compressed Sensing: Error Bounds, Sample Complexity, and Efficient Estimators

    CERN Document Server

    Flammia, Steven T; Liu, Yi-Kai; Eisert, Jens

    2012-01-01

    Intuitively, if a density operator has only a few non-zero eigenvalues, then it should be easier to estimate from experimental data, since in this case only a few eigenvectors need to be learned. We exhibit two complementary ways of making this intuition precise. On the one hand, we show that the sample complexity decreases with the rank of the density operator. In other words, fewer copies of the state need to be prepared in order to estimate a low-rank density matrix. On the other hand---and maybe more surprisingly---we prove that unknown low-rank states may be reconstructed using an incomplete set of measurement settings. The method does not require any a priori assumptions about the unknown state, uses only simple Pauli measurements, and can be efficiently and unconditionally certified. Our results extend earlier work on compressed tomography, building on ideas from compressed sensing and matrix completion. Instrumental to the improved analysis are new error bounds for compressed tomography, based on the ...

  7. Synthesis and structure of new carbohydrate metal-organic frameworks and inclusion complexes

    Science.gov (United States)

    Sha, Jing-Quan; Wu, Lian-He; Li, Shu-Xian; Yang, Xiao-Ning; Zhang, Yu; Zhang, Qian-Nan; Zhu, Pei-Pei

    2015-12-01

    Two new metal-organic framework compounds based on natural β-cyclodextrin molecules (β-CD) and alkali metals (Na+/K+) were synthesized and characterized by elemental analyses, IR, XPRD and 1HNMR. Single-crystal X-ray diffraction analysis reveals that compounds 1 and 2 possess the bowl-like pore and the "8" type double channels configuration. Due to the [blow + channel] double configuration, 5-Fluorouracil (5-FU) and Quercetin inclusion complexes of compound 1 are studied, and the results show that the two kinds of drug with different structure and size can be included into the compound at the same time, which is expected to become a new type of multi-functional green crystalline solid material.

  8. Gastrointestinal responses of rats fed on white and wholemeal breads: complex carbohydrate digestibility and the influence of dietary fat content.

    Science.gov (United States)

    Key, F B; Mathers, J C

    1993-03-01

    To obtain quantitative information on the digestibility of the non-starch polysaccharides (NSP) fraction of white and wholemeal breads, rats were fed on diets in which freeze-dried bread (white, wholemeal or mixtures of the two) provided all the complex carbohydrates. In a second experiment the possibility that dietary fat concentration might influence NSP digestibility was tested by feeding diets containing 30 or 170 g maize oil/kg and either white or wholemeal bread. Multiple linear regression analysis provided little evidence of associative effects of dietary components on NSP digestibility and in the two experiments digestibilities of NSP for white and wholemeal breads were 0.77-0.82 and 0.47-0.52 respectively. Xylose- and arabinose-containing polymers were better digested than was cellulose for both breads. Replacing white by wholemeal bread markedly increased the molar proportion of butyrate in caecal volatile fatty acids at the expense of acetate. This was associated with greater flows of organic matter to the large bowel (LB) and a reduction in caecal transit time (Expt 2). There was little detectable effect of dietary maize oil concentration on NSP digestibility or on LB fermentation. All breads contained some starch resistant to pancreatic alpha-amylase (EC 3.2.1.1) without previous treatment with dimethyl sulphoxide. The digestibility of this starch fraction was not significantly different from 1.0 for all diets except that containing wholemeal bread and the higher maize oil concentration where the apparent digestibility was 0.89.

  9. Ab initio treatment of the chemical reaction precursor complex Cl(P-2)-HF. 2 : Bound states and infrared spectrum

    NARCIS (Netherlands)

    Fishchuk, A.V.; Groenenboom, G.C.; Avoird, A. van der

    2006-01-01

    Bound energy levels and properties of the Cl((2)p)-HF complex were obtained from full three-dimensional (3D) calculations, with the use of the ab initio computed diabatic potential surfaces from the preceding paper and the inclusion of spin-orbit coupling. For a better understanding of the dynamics

  10. Carbohydrate Analysis

    Science.gov (United States)

    Bemiller, James N.

    Carbohydrates are important in foods as a major source of energy, to impart crucial textural properties, and as dietary fiber which influences physiological processes. Digestible carbohydrates, which are converted into monosaccharides, which are absorbed, provide metabolic energy. Worldwide, carbohydrates account for more than 70% of the caloric value of the human diet. It is recommended that all persons should limit calories from fat (the other significant source) to not more than 30% and that most of the carbohydrate calories should come from starch. Nondigestible polysaccharides (all those other than starch) comprise the major portion of dietary fiber (Sect. 10.5). Carbohydrates also contribute other attributes, including bulk, body, viscosity, stability to emulsions and foams, water-holding capacity, freeze-thaw stability, browning, flavors, aromas, and a range of desirable textures (from crispness to smooth, soft gels). They also provide satiety. Basic carbohydrate structures, chemistry, and terminology can be found in references (1, 2).

  11. In-situ annotation of carbohydrate diversity, abundance, and degradability in highly complex mixtures using NMR spectroscopy

    DEFF Research Database (Denmark)

    Meier, Sebastian

    2014-01-01

    Many functions of carbohydrates depend on the detection of short structural motifs, approximately up to hexasaccharide length, by receptors or catalysts. This study investigates the usefulness of state-of-the-art 1H–13C nuclear-magnetic-resonance (NMR) spectroscopy for characterizing the diversity......, abundance, and degradability of such short structural motifs in plant-derived carbohydrates. Assignments of carbohydrate signals for 1H–13C NMR spectra of beer, wine, and fruit juice yield up to >130 assignments in situ, i.e. in individual samples without separation or derivatization. More than 500...... structural motifs can be resolved over a concentration range of ~103 in experiments of a few hours duration. The diversity of carbohydrate units increases according to power laws at lower concentrations for both cereal and fruit-derived samples. Simple graphs resolve the smaller overall contribution of more...

  12. Carbon dioxide is tightly bound in the [Co(Pyridine)(CO{sub 2})]{sup −} anionic complex

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Jacob D.; Buytendyk, Allyson M.; Zhang, Xinxing; Bowen, Kit H., E-mail: kbowen@jhu.edu [Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Kim, Seong K. [Department of Chemistry, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2015-11-14

    The [Co(Pyridine)(CO{sub 2})]{sup −} anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO{sub 2} binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO{sub 2})]{sup −} in which a central cobalt atom is bound to pyridine and CO{sub 2} moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO{sub 2} to be bound within the anionic complex by 1.4 eV.

  13. The program complexity on Universal Turing Machines, and a proposal to find efficient n-bounded algorithms of NPC problems by machine enumeration

    CERN Document Server

    Zhou, YuQian

    2012-01-01

    This paper proposes a method to find efficient bounded algorithms of NPC problems by machine enumeration. The key contributions are: * On Universal Turing Machines, a program's time complexity should be characterized as: execution time(n) = loading time(n) + running time(n). * Introduces the concept of bounded algorithms; proposes a comparison based criterion to decide if a bounded algorithm is inefficient; and establishes the length upper bound of efficient bounded programs. * Introduces a new way to evaluate program complexity by using the growth rate characteristic function, which is more easily machine checkable based on observations.

  14. C-type lectin-like carbohydrate recognition of the hemolytic lectin CEL-III containing ricin-type -trefoil folds.

    Science.gov (United States)

    Hatakeyama, Tomomitsu; Unno, Hideaki; Kouzuma, Yoshiaki; Uchida, Tatsuya; Eto, Seiichiro; Hidemura, Haruki; Kato, Norihisa; Yonekura, Masami; Kusunoki, Masami

    2007-12-28

    CEL-III is a Ca(2+)-dependent hemolytic lectin, isolated from the marine invertebrate Cucumaria echinata. The three-dimensional structure of CEL-III/GalNAc and CEL-III/methyl alpha-galactoside complexes was solved by x-ray crystallographic analysis. In these complexes, five carbohydrate molecules were found to be bound to two carbohydrate-binding domains (domains 1 and 2) located in the N-terminal 2/3 portion of the polypeptide and that contained beta-trefoil folds similar to ricin B-chain. The 3-OH and 4-OH of bound carbohydrate molecules were coordinated with Ca(2+) located at the subdomains 1alpha, 1gamma, 2alpha, 2beta, and 2gamma, simultaneously forming hydrogen bond networks with nearby amino acid side chains, which is similar to carbohydrate binding in C-type lectins. The binding of carbohydrates was further stabilized by aromatic amino acid residues, such as tyrosine and tryptophan, through a stacking interaction with the hydrophobic face of carbohydrates. The importance of amino acid residues in the carbohydrate-binding sites was confirmed by the mutational analyses. The orientation of bound GalNAc and methyl alpha-galactoside was similar to the galactose moiety of lactose bound to the carbohydrate-binding site of the ricin B-chain, although the ricin B-chain does not require Ca(2+) ions for carbohydrate binding. The binding of the carbohydrates induced local structural changes in carbohydrate-binding sites in subdomains 2alpha and 2beta. Binding of GalNAc also induced a slight change in the main chain structure of domain 3, which could be related to the conformational change upon binding of specific carbohydrates to induce oligomerization of the protein. PMID:17977832

  15. Carbohydrate Loading.

    Science.gov (United States)

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  16. Tight bounds on the randomized communication complexity of symmetric XOR functions in one-way and SMP models

    CERN Document Server

    Leung, Ming Lam; Zhang, Shengyu

    2011-01-01

    We study the communication complexity of symmetric XOR functions, namely functions $f: \\{0,1\\}^n \\times \\{0,1\\}^n \\rightarrow \\{0,1\\}$ that can be formulated as $f(x,y)=D(|x\\oplus y|)$ for some predicate $D: \\{0,1,...,n\\} \\rightarrow \\{0,1\\}$, where $|x\\oplus y|$ is the Hamming weight of the bitwise XOR of $x$ and $y$. We give a public-coin randomized protocol in the Simultaneous Message Passing (SMP) model, with the communication cost matching the known lower bound for the \\emph{quantum} and \\emph{two-way} model up to a logarithm factor. As a corollary, this closes a quadratic gap between quantum lower bound and randomized upper bound for the one-way model, answering an open question raised in Shi and Zhang \\cite{SZ09}.

  17. Detection of long-lived bound water molecules in complexes of human dihydrofolate reductase with methotrexate and NADPH.

    Science.gov (United States)

    Meiering, E M; Wagner, G

    1995-03-24

    The locations of long-lived bound water molecules in the binary complex of human dihydrofolate reductase (hDHFR) with methotrexate (MTX) and the ternary complex of hDHFR with MTX and NADPH have been investigated using 15N-resolved, three-dimensional ROESY-HMQC and NOESY-HSQC spectra acquired at 25 degrees C and 8 degrees C. NOEs with NH groups of the protein are detected for five bound water molecules in the binary complex and six bound water molecules in the ternary complex. Inspection of crystal structures of hDHFR reveals that the bound water molecules perform structural and functional roles in the complexes. Two water molecules located outside the active site, WatA and WatB, have similar NOEs in the binary and ternary complexes. These water molecules from multiple hydrogen bonds bridging loops and/or secondary structural elements in crystal structures of hDHFR and so stabilize the tertiary fold of the enzyme. Two water molecules in the active site, WatC and WatD, also have similar NOEs in both complexes. In crystal structures of hDHFR, WatC is involved in MTX binding by forming hydrogen bonds to the ligand and protein, while WatD stabilizes WatC by hydrogen bonding to it and the protein. A third active-site water molecule, WatE, has a markedly stronger NOE in the ternary complex than in the binary complex. Differences in the binding of WatE in the binary and ternary complexes are important for understanding the mechanism of DHFR, since this water molecule is believed to be involved in substrate protonation. Although the increased NOE intensity for WatE could be caused by a change in the position of water molecule, it may also be caused by an increase in its lifetime, since structural fluctuations in the active site are decreased upon cofactor binding. NOEs for one other water molecule, WatF, may be observed in the ternary complex but not the binary complex. WatF forms hydrogen bonds bridging the cofactor and the protein in crystal structures of hDHFR.

  18. Microbial degradation of whole-grain complex carbohydrates and impact on short-chain fatty acids and health.

    Science.gov (United States)

    Bach Knudsen, Knud Erik

    2015-03-01

    Whole-grain cereals have a complex dietary fiber (DF) composition consisting of oligosaccharides (mostly fructans), resistant starch, and nonstarch polysaccharides (NSPs); the most important are arabinoxylans, mixed-linkage β(1,3; 1,4)-d-glucan (β-glucan), and cellulose and the noncarbohydrate polyphenolic ether lignin. The highest concentration of NSPs and lignin is found in the outer cell layers of the grain, and refined flour will consequently be depleted of a large proportion of insoluble DF components. The flow and composition of carbohydrates to the large intestine are directly related to the intake of DF. The type and composition of cereal DF can consequently be used to modulate the microbial composition and activity as well as the production and molar ratios of short-chain fatty acids (SCFAs). Arabinoxylans and β-glucan in whole-grain cereals and cereal ingredients have been shown to augment SCFA production, with the strongest relative effect on butyrate. When arabinoxylans were provided as a concentrate, the effect was only on total SCFA production. Increased SCFA production in the large intestine was shown by the concentration in the portal vein, whereas the impact on the concentration in peripheral blood was less because the majority of propionate and butyrate is cleared in the liver. Active microbial fermentation with increased SCFA production reduced the exposure of potentially toxic compounds to the epithelium, potentially stimulating anorectic hormones and acting as signaling molecules between the gut and the peripheral tissues. The latter can have implications for insulin sensitivity and glucose homeostasis. PMID:25770259

  19. NMR-based, molecular dynamics- and random walk molecular mechanics-supported study of conformational aspects of a carbohydrate ligand (Galβ1-2Galβ1-R) for an animal galectin in the free and in the bound state

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Siebert, H.-C; Gilleron, M.; Kaltner, H.; Lieth, C.-W. von der; Kozár, T.; Bovin, N.; Korchagina, E.Y.

    1996-01-01

    The binding of a carbohydrate to a lectin may affect the conformation of the ligand. To address this question for the galectin from chicken liver, the conformation of Gal@b1-R was analyzed in the free and in the galectin-bound state with 2D-ROESY- and 1D- as well as 2D-transferred NOE-experiments. A

  20. Host-Guest Chemistry in the Gas Phase: Complex Formation of Cucurbit[6]uril with Proton-bound Water Dimer

    Science.gov (United States)

    Noh, Dong Hun; Lee, Shin Jung C.; Lee, Jong Wha; Kim, Hugh I.

    2014-03-01

    The hydration of cucurbit[6]uril (CB[6]) in the gas phase is investigated using electrospray ionization traveling wave ion mobility mass spectrometry (ESI-TWIM-MS). Highly abundant dihydrated and tetrahydrated species of diprotonated CB[6] are found in the ESI-TWIM-MS spectrum. The hydration patterns of the CB[6] ion and the dissociation patterns of the hydrated CB[6] ion indicate that two water molecules are bound to each other, forming a water dimer in the CB[6] complex. Ion mobility studies combined with the structures calculated by density functional theory suggest that the proton-bound water dimer is present as a Zundel-like structure in the CB[6] portal, forming a hydrogen bond network with carbonyl groups of the CB[6]. When a large guest molecule is bound to a CB[6] portal, water molecules cannot bind to the portal. In addition, the strong binding energy of the water dimer blocks the portal, hindering the insertion of the long alkyl chain of the guest molecule into the CB[6] cavity. With small alkali metal cations, such as Li+ and Na+, a single water molecule interacts with the CB[6] portal, forming hydrogen bonds with the carbonyl groups of CB[6]. A highly stable Zundel-like structure of the proton-bound water dimer or a metal-bound water molecule at the CB[6] portal is suggested as an initial hydration process for CB[6], which is only dissolved in aqueous solution with acid or alkali metal ions.

  1. Peptide-lanthanide cation equilibria in aqueous phase. I. Bound shifts for L-carnosine-praseodymium complexes

    Science.gov (United States)

    Mossoyan, J.; Asso, M.; Benlian, D.

    L-Carnosine complexes of Pr 3+ were characterized in aqueous solution by 1H NMR and potentiometric titration. A rigorous treatment of chemical shifts and pH variation data with lanthanide concentration is presented. Two different forms of the peptide ligand, forming simultaneously two complexes, were taken into account. At low pH values the cation is only coordinated at the carboxylate site of the ligand in a weak complex ( β2 = 6) whereas in neutral solution a stronger complex ( β1 = 37) is present as a consequence of the deprotonation of the imidazole ring. The computation of induced bound shifts † 2 and Δ1 for resonating nuclei of the peptide in both forms yields consistent figures. These provide the experimental basis for a conformational model which is usually not obtainable for labile complexes with low stability constants.

  2. Ab initio characterization of the Ne-I2 van der Waals complex: Intermolecular potentials and vibrational bound states

    OpenAIRE

    Delgado Tellez, Laura; Valdés, Álvaro; Prosmiti, Rita; Villarreal, Pablo; Delgado Barrio, Gerardo

    2011-01-01

    A theoretical study of the potential energy surface and bound states is performed for the ground state of the NeI2 van der Waals (vdW) complex. The three-dimensional interaction energies are obtained from ab initio coupled-cluster, coupled-cluster single double (triple)/complete basis set, calculations using large basis sets, of quadruple- through quintuple-zeta quality, in conjunction with relativistic effective core potentials for the heavy iodine atoms. For the analytical representation of...

  3. Carbohydrate malabsorption

    DEFF Research Database (Denmark)

    Rumessen, J J; Nordgaard-Andersen, I; Gudmand-Høyer, E

    1994-01-01

    Previous studies in small series of healthy adults have suggested that parallel measurement of hydrogen and methane resulting from gut fermentation may improve the precision of quantitative estimates of carbohydrate malabsorption. Systematic, controlled studies of the role of simultaneous hydrogen...

  4. CarbBank: A structural and bibliographic database for complex carbohydrates. Progress report, September 15, 1991--September 14, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Albersheim, P.

    1992-06-01

    The CarbBank project has several key facets: building a computer database that presents carbohydrate sequence information derived from the published literature, programming to create computer applications that use the information in the database, creating software for multiple computer platforms, and distributing software to end users.

  5. Structural insights into calcium-bound S100P and the V domain of the RAGE complex.

    Directory of Open Access Journals (Sweden)

    Srinivasa R Penumutchu

    Full Text Available The S100P protein is a member of the S100 family of calcium-binding proteins and possesses both intracellular and extracellular functions. Extracellular S100P binds to the cell surface receptor for advanced glycation end products (RAGE and activates its downstream signaling cascade to meditate tumor growth, drug resistance and metastasis. Preventing the formation of this S100P-RAGE complex is an effective strategy to treat various disease conditions. Despite its importance, the detailed structural characterization of the S100P-RAGE complex has not yet been reported. In this study, we report that S100P preferentially binds to the V domain of RAGE. Furthermore, we characterized the interactions between the RAGE V domain and Ca(2+-bound S100P using various biophysical techniques, including isothermal titration calorimetry (ITC, fluorescence spectroscopy, multidimensional NMR spectroscopy, functional assays and site-directed mutagenesis. The entropy-driven binding between the V domain of RAGE and Ca(+2-bound S100P was found to lie in the micromolar range (Kd of ∼ 6 µM. NMR data-driven HADDOCK modeling revealed the putative sites that interact to yield a proposed heterotetrameric model of the S100P-RAGE V domain complex. Our study on the spatial structural information of the proposed protein-protein complex has pharmaceutical relevance and will significantly contribute toward drug development for the prevention of RAGE-related multifarious diseases.

  6. Iron-sulfur Proteins Are the Major Source of Protein-bound Dinitrosyl Iron Complexes Formed in Escherichia coli Cells under Nitric Oxide Stress

    OpenAIRE

    Landry, Aaron P.; Duan, Xuewu; Huang, Hao; Ding, Huangen

    2011-01-01

    Protein-bound dinitrosyl iron complexes (DNICs) have been observed in prokaryotic and eukaryotic cells under nitric oxide (NO) stress. The identity of proteins that bind DNICs, however, still remains elusive. Here we demonstrate that iron-sulfur proteins are the major source of protein-bound DNICs formed in Escherichia coli cells under NO stress. Expression of recombinant iron-sulfur proteins, but not the proteins without iron-sulfur clusters, almost doubles the amount of protein-bound DNICs ...

  7. Crystal Structure of a CRISPR RNA-guided Surveillance Complex Bound to a ssDNA Target

    Energy Technology Data Exchange (ETDEWEB)

    Mulepati, Sabin [Johns Hopkins Univ., Baltimore, MD (United States); Heroux, Annie; Bailey, Scott [Johns Hopkins Univ., Baltimore, MD (United States)

    2014-09-19

    In prokaryotes, RNA derived from type I and type III CRISPR loci direct large ribonucleoprotein complexes to destroy invading bacteriophage and plasmids. In Escherichia coli, this 405-kilodalton complex is called Cascade. We report the crystal structure of Cascade bound to a single-stranded DNA (ssDNA) target at a resolution of 3.03 angstroms. The structure reveals that the CRISPR RNA and target strands do not form a double helix but instead adopt an underwound ribbon-like structure. This noncanonical structure is facilitated by rotation of every sixth nucleotide out of the RNA-DNA hybrid and is stabilized by the highly interlocked organization of protein subunits. These studies provide insight into both the assembly and the activity of this complex and suggest a mechanism to enforce fidelity of target binding.

  8. Structural biology. Crystal structure of a CRISPR RNA-guided surveillance complex bound to a ssDNA target.

    Science.gov (United States)

    Mulepati, Sabin; Héroux, Annie; Bailey, Scott

    2014-09-19

    In prokaryotes, RNA derived from type I and type III CRISPR loci direct large ribonucleoprotein complexes to destroy invading bacteriophage and plasmids. In Escherichia coli, this 405-kilodalton complex is called Cascade. We report the crystal structure of Cascade bound to a single-stranded DNA (ssDNA) target at a resolution of 3.03 angstroms. The structure reveals that the CRISPR RNA and target strands do not form a double helix but instead adopt an underwound ribbon-like structure. This noncanonical structure is facilitated by rotation of every sixth nucleotide out of the RNA-DNA hybrid and is stabilized by the highly interlocked organization of protein subunits. These studies provide insight into both the assembly and the activity of this complex and suggest a mechanism to enforce fidelity of target binding.

  9. Peptide specific expansion of CD8(+) T cells by recombinant plate bound MHC/peptide complexes

    DEFF Research Database (Denmark)

    Schmidt, Esben G W; Buus, Soren; Thorn, Mette;

    2009-01-01

    in vitro T cell stimulation was investigated. By use of an antigenic peptide derived from the cytomegalovirus (CMVp) we tested the stimulatory efficacy of recombinant plate bound MHC molecules (PB-MHC), being immobilized in culture plates. A single stimulation of non-adherent peripheral blood...... effect of new stimulatory cocktails, e.g. cytokines and co-stimulatory molecules, by use of the present rapid and easy-to-use method of expanding peptide specific T cells.......Development of methods for efficient in vitro stimulation and expansion of peptide specific CD8(+) T cells is compelling not only with respect to adoptive T cell therapy but also regarding analysis of T cell responses and search for new immunogenic peptides. In the present study, a new approach to...

  10. Catalytic Properties of Polymer-bound Imine Copper(Ⅱ) Complex

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ As heterogeneous catalyst, polymer metal complexes is stable in air, low corrosive, low toxic, easy to separate and reclaim,1,2 which superior than organic metal low-molecular complexes, so be paid close attention since 1960' and apply in industry gradually. There are many reports in polymer metal catalyst which is used in oxidation and hydrogenation3 In this paper, complexes of Cu(II) with polymer schiff base ligand: poly (dinitrobenzaldehyde aminating styrene)-Cu(PDNBA-Cu), poly(m-nitrobenzaldehyde aminating styrene)-Cu(PMNBA-Cu), poly(dihydroxybenzaldehyde aminating styrene)Cu(PDHBA-Cu), PDNBA-Cu-Phen were synthesized and characterized by FT-IR, XPS, GC-MS and element analysis. The results show that oxygen atom of hydroxide radical and nitrogen atom are both coordinating with Cu2+ and N:Cu≈ 1: 1. The results also show the complexes are well stability.

  11. Understanding Carbohydrates

    Science.gov (United States)

    ... Low-calorie sweeteners are also called artificial sweeteners, sugar substitutes or non-nutritive sweeteners. They can be used to sweeten food and drinks for less calories and carbohydrate when they replace sugar. Sugar and Desserts With diabetes, it's important to ...

  12. Theoretical investigation of potential energy surface and bound states for the van der Waals complex Ar–BrCl dimer

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Rui [School of Mathematics and Information Science, North China University of Water Resources and Electric Power, Zhengzhou (China); Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan (China); Li, Song, E-mail: lsong@yangtzeu.edu.cn [School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou (China); Chen, Shan-Jun; Chen, Yan [School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou (China); Zheng, Li-Min [Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan (China)

    2015-09-08

    Highlights: • A two-dimensional potential for Ar–BrCl is constructed at the CCSD(T) level. • The PES is characterized by three minima and two saddle points between them. • Bound state calculations were carried out for the complex. - Abstract: The intermolecular potential energy surface (PES) of the ground electronic state for the Ar–BrCl dimer is constructed at the CCSD(T) level with the aug-cc-pVQZ basis set and mid-bond functions. The PES is characterized by three minima and two saddle points. The global minimum corresponding to a collinear Ar–BrCl configuration, which has been observed experimentally, is located at R = 4.10 Å and θ = 2.5° with a well depth of −285.207 cm{sup −1}. A nearly T-shaped structure and an anti-linear Ar–ClBr geometry is also predicted. The bound state calculations are preformed to study intermolecular vibrational modes, rotational levels and average structures for the complex. Our transition frequencies, spectroscopic constants and average structures for all isotopomers of the collinear isomer agree well with experimental data. We have also provided pure rotational transitional frequencies for both nearly T-shaped and anti-linear isomers. These results are significant for further experimental investigations of the Ar–BrCl dimer.

  13. The weakly bound He-HCCCN complex: High-resolution microwave spectra and intermolecular potential-energy surface

    Science.gov (United States)

    Topic, Wendy C.; Jäger, Wolfgang

    2005-08-01

    Rotational spectra of the weakly bound He-HCCCN and He-DCCCN van der Waals complexes were observed using a pulsed-nozzle Fourier-transform microwave spectrometer in the 7-26-GHz frequency region. Nuclear quadrupole hyperfine structures due to the N14 and D nuclei (both with nuclear-spin quantum number I =1) were resolved and assigned. Both strong a and weaker b-type transitions were observed and the assigned transitions were used to fit the parameters of a distortable asymmetric rotor model. The dimers are floppy, near T-shaped complexes. Three intermolecular potential-energy surfaces were calculated using the coupled-cluster method with single and double excitations and noniterative inclusion of triple excitations. Bound-state rotational energy levels supported by these surfaces were determined. The quality of the potential-energy surfaces was assessed by comparing the experimental and calculated transition frequencies and also the corresponding spectroscopic parameters. Simple scaling of the surfaces improved both the transition frequencies and spectroscopic constants. Five other recently reported surfaces [O. Akin-Ojo, R. Bukowski, and K. Szalewicz, J. Chem. Phys. 119, 8379 (2003)], calculated using a variety of methods, and their agreement with spectroscopic properties of He-HCCCN are discussed.

  14. A Polycomb complex remains bound through DNA replication in the absence of other eukaryotic proteins

    KAUST Repository

    Lengsfeld, Bettina M.

    2012-09-17

    Propagation of chromatin states through DNA replication is central to epigenetic regulation and can involve recruitment of chromatin proteins to replicating chromatin through interactions with replication fork components. Here we show using a fully reconstituted T7 bacteriophage system that eukaryotic proteins are not required to tether the Polycomb complex PRC1 to templates during DNA replication. Instead, DNA binding by PRC1 can withstand passage of a simple replication fork.

  15. Magnitude and nature of carbohydrate-aromatic interactions in fucose-phenol and fucose-indole complexes: CCSD(T) level interaction energy calculations.

    Science.gov (United States)

    Tsuzuki, Seiji; Uchimaru, Tadafumi; Mikami, Masuhiro

    2011-10-20

    The CH/π contact structures of the fucose-phenol and fucose-indole complexes and the stabilization energies by formation of the complexes (E(form)) were studied by ab initio molecular orbital calculations. The three types of interactions (CH/π and OH/π interactions and OH/O hydrogen bonds) were compared and evaluated in a single molecular system and at the same level of theory. The E(form) calculated for the most stable CH/π contact structure of the fucose-phenol complex at the CCSD(T) level (-4.9 kcal/mol) is close to that for the most stable CH/π contact structure of the fucose-benzene complex (-4.5 kcal/mol). On the other hand the most stable CH/π contact structure of the fucose-indole complex has substantially larger E(form) (-6.5 kcal/mol). The dispersion interaction is the major source of the attraction in the CH/π contact structures of the fucose-phenol and fucose-indole complexes as in the case of the fucose-benzene complex. The electrostatic interactions in the CH/π contact structures are small (less than 1.5 kcal/mol). The nature of the interactions between the nonpolar surface of the carbohydrate and aromatic rings is completely different from that of the conventional hydrogen bonds where the electrostatic interaction is the major source of the attraction. The distributed multipole analysis and DFT-SATP analysis show that the dispersion interactions in the CH/π contact structure of fucose-indole complex are substantially larger than those in the CH/π contact structures of fucose-benzene and fucose-phenol complexes. The large dispersion interactions are responsible for the large E(form) for the fucose-indole complex.

  16. Proteomics to study DNA-bound and chromatin-associated gene regulatory complexes

    Science.gov (United States)

    Wierer, Michael; Mann, Matthias

    2016-01-01

    High-resolution mass spectrometry (MS)-based proteomics is a powerful method for the identification of soluble protein complexes and large-scale affinity purification screens can decode entire protein interaction networks. In contrast, protein complexes residing on chromatin have been much more challenging, because they are difficult to purify and often of very low abundance. However, this is changing due to recent methodological and technological advances in proteomics. Proteins interacting with chromatin marks can directly be identified by pulldowns with synthesized histone tails containing posttranslational modifications (PTMs). Similarly, pulldowns with DNA baits harbouring single nucleotide polymorphisms or DNA modifications reveal the impact of those DNA alterations on the recruitment of transcription factors. Accurate quantitation – either isotope-based or label free – unambiguously pinpoints proteins that are significantly enriched over control pulldowns. In addition, protocols that combine classical chromatin immunoprecipitation (ChIP) methods with mass spectrometry (ChIP-MS) target gene regulatory complexes in their in-vivo context. Similar to classical ChIP, cells are crosslinked with formaldehyde and chromatin sheared by sonication or nuclease digested. ChIP-MS baits can be proteins in tagged or endogenous form, histone PTMs, or lncRNAs. Locus-specific ChIP-MS methods would allow direct purification of a single genomic locus and the proteins associated with it. There, loci can be targeted either by artificial DNA-binding sites and corresponding binding proteins or via proteins with sequence specificity such as TAL or nuclease deficient Cas9 in combination with a specific guide RNA. We predict that advances in MS technology will soon make such approaches generally applicable tools in epigenetics. PMID:27402878

  17. Structure of the complex of Neisseria gonorrhoeae N-acetyl-L-glutamate synthase with a bound bisubstrate analog.

    Science.gov (United States)

    Zhao, Gengxiang; Allewell, Norma M; Tuchman, Mendel; Shi, Dashuang

    2013-01-25

    N-Acetyl-L-glutamate synthase catalyzes the conversion of AcCoA and glutamate to CoA and N-acetyl-L-glutamate (NAG), the first step of the arginine biosynthetic pathway in lower organisms. In mammals, NAG is an obligate cofactor of carbamoyl phosphate synthetase I in the urea cycle. We have previously reported the structures of NAGS from Neisseria gonorrhoeae (ngNAGS) with various substrates bound. Here we reported the preparation of the bisubstrate analog, CoA-S-acetyl-L-glutamate, the crystal structure of ngNAGS with CoA-NAG bound, and kinetic studies of several active site mutants. The results are consistent with a one-step nucleophilic addition-elimination mechanism with Glu353 as the catalytic base and Ser392 as the catalytic acid. The structure of the ngNAGS-bisubstrate complex together with the previous ngNAGS structures delineates the catalytic reaction path for ngNAGS. PMID:23261468

  18. Separation of galactoglucomannans, lignin, and lignin-carbohydrate complexes from hot-water-extracted Norway spruce by cross-flow filtration and adsorption chromatography

    Directory of Open Access Journals (Sweden)

    Niklas Westerberg

    2012-11-01

    Full Text Available A simple method to simultaneously recover polymeric carbohydrates, mainly galactoglucomannans (GGM, lignin, and lignin-carbohydrate complex (LCC from hot-water-extracted Norway spruce wood is presented. The isolation method consists of cross-flow filtration, where high and low molecular mass species are removed, followed by fixed-bed adsorption on a hydrophobic polymeric resin (XAD-16 to remove lignins and lignans. In the second step of fixed-bed adsorption, a phenylic reversed-phase analytical chromatography column, where mass transport resistance is minimized and a very high selectivity towards aromatic compounds have been observed, was used to separate LCC from GGM. The isolated LCC fraction contained about 10% aromatics, whereas the upgraded GGM fraction contained about 1.5% aromatics and the lignin fraction contained about 56% aromatics. Polymeric xylan was accumulated in the GGM fraction, while mannose was the dominant sugar found in the LCC fraction. As products, approximately 7% was recovered in the lignin fraction in the first adsorptive step, 5% was recovered as LCC, and 88% as upgraded hemicelluloses.

  19. TOWARD THE ASTRONOMICAL DETECTION OF THE PROTON-BOUND COMPLEX NN–HCO{sup +}: IMPLICATIONS FOR THE SPECTRA OF PROTOPLANETARY DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Fortenberry, Ryan C. [Department of Chemistry, Georgia Southern University, Statesboro, GA 30460 (United States); Francisco, Joseph S. [Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Lee, Timothy J., E-mail: rfortenberry@georgiasouthern.edu [NASA Ames Research Center, Moffett Field, CA 94035-1000 (United States)

    2016-03-10

    Proton-bound complexes have been hypothesized as further means of detecting the nitrogen molecule in the interstellar medium. The study of such complexes has largely been hindered by the necessary experimental setups utilized or by their difficulty in producing and/or analyzing computed potential energy surfaces. Here the NN–HCO{sup +} proton-bound complex is analyzed via quartic force fields (QFFs). While QFFs have produced meaningful results for other proton-bound complexes, they have been hindered by double-well potentials or flat potential surfaces. NN–HCO{sup +} is not affected by these constraints. This strongly dipolar (3.63 D) molecule can be observed rotationally unlike the more heavily analyzed OCHCO{sup +} and NNHNN{sup +} proton-bound complexes. Additionally, the large absorption feature corresponding to the proton motion, a hallmark of proton-bound complexes, is much higher in frequency at 2547.1 cm{sup −1}, changing the range of experimental observation for the bright frequency. NN–HCO{sup +} is hypothesized to be present in protoplanetary disks where N{sub 2}H{sup +} and CO are known. As such, it may help to influence the nitrogen budget of planet-forming astronomical regions.

  20. Chirality of weakly bound complexes: The potential energy surfaces for the hydrogen-peroxide−noble-gas interactions

    Energy Technology Data Exchange (ETDEWEB)

    Roncaratti, L. F., E-mail: lz@fis.unb.br; Leal, L. A.; Silva, G. M. de [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Pirani, F. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Aquilanti, V. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Instituto de Física, Universidade Federal da Bahia, 40210 Salvador (Brazil); Gargano, R. [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Departments of Chemistry and Physics, University of Florida, Quantum Theory Project, Gainesville, Florida 32611 (United States)

    2014-10-07

    We consider the analytical representation of the potential energy surfaces of relevance for the intermolecular dynamics of weakly bound complexes of chiral molecules. In this paper we study the H{sub 2}O{sub 2}−Ng (Ng=He, Ne, Ar, Kr, and Xe) systems providing the radial and the angular dependence of the potential energy surface on the relative position of the Ng atom. We accomplish this by introducing an analytical representation which is able to fit the ab initio energies of these complexes in a wide range of geometries. Our analysis sheds light on the role that the enantiomeric forms and the symmetry of the H{sub 2}O{sub 2} molecule play on the resulting barriers and equilibrium geometries. The proposed theoretical framework is useful to study the dynamics of the H{sub 2}O{sub 2} molecule, or other systems involving O–O and S–S bonds, interacting by non-covalent forces with atoms or molecules and to understand how the relative orientation of the O–H bonds changes along collisional events that may lead to a hydrogen bond formation or even to selectivity in chemical reactions.

  1. Cryo-EM of Mitotic Checkpoint Complex-Bound APC/C Reveals Reciprocal and Conformational Regulation of Ubiquitin Ligation.

    Science.gov (United States)

    Yamaguchi, Masaya; VanderLinden, Ryan; Weissmann, Florian; Qiao, Renping; Dube, Prakash; Brown, Nicholas G; Haselbach, David; Zhang, Wei; Sidhu, Sachdev S; Peters, Jan-Michael; Stark, Holger; Schulman, Brenda A

    2016-08-18

    The mitotic checkpoint complex (MCC) coordinates proper chromosome biorientation on the spindle with ubiquitination activities of CDC20-activated anaphase-promoting complex/cyclosome (APC/C(CDC20)). APC/C(CDC20) and two E2s, UBE2C and UBE2S, catalyze ubiquitination through distinct architectures for linking ubiquitin (UB) to substrates and elongating polyUB chains, respectively. MCC, which contains a second molecule of CDC20, blocks APC/C(CDC20)-UBE2C-dependent ubiquitination of Securin and Cyclins, while differentially determining or inhibiting CDC20 ubiquitination to regulate spindle surveillance, checkpoint activation, and checkpoint termination. Here electron microscopy reveals conformational variation of APC/C(CDC20)-MCC underlying this multifaceted regulation. MCC binds APC/C-bound CDC20 to inhibit substrate access. However, rotation about the CDC20-MCC assembly and conformational variability of APC/C modulate UBE2C-catalyzed ubiquitination of MCC's CDC20 molecule. Access of UBE2C is limiting for subsequent polyubiquitination by UBE2S. We propose that conformational dynamics of APC/C(CDC20)-MCC modulate E2 activation and determine distinctive ubiquitination activities as part of a response mechanism ensuring accurate sister chromatid segregation. PMID:27522463

  2. Carbohydrates and dietary fiber.

    Science.gov (United States)

    Suter, P M

    2005-01-01

    The most widely spread eating habit is characterized by a reduced intake of dietary fiber, an increased intake of simple sugars, a high intake of refined grain products, an altered fat composition of the diet, and a dietary pattern characterized by a high glycemic load, an increased body weight and reduced physical activity. In this chapter the effects of this eating pattern on disease risk will be outlined. There are no epidemiological studies showing that the increase of glucose, fructose or sucrose intake is directly and independently associated with an increased risk of atherosclerosis or coronary heart disease (CHD). On the other hand a large number of studies has reported a reduction of fatal and non-fatal CHD events as a function of the intake of complex carbohydrates--respectively 'dietary fiber' or selected fiber-rich food (e.g., whole grain cereals). It seems that eating too much 'fast' carbohydrate [i.e., carbohydrates with a high glycemic index (GI)] may have deleterious long-term consequences. Indeed the last decades have shown that a low fat (and consecutively high carbohydrate) diet alone is not the best strategy to combat modern diseases including atherosclerosis. Quantity and quality issues in carbohydrate nutrient content are as important as they are for fat. Multiple lines of evidence suggest that for cardiovascular disease prevention a high sugar intake should be avoided. There is growing evidence of the high impact of dietary fiber and foods with a low GI on single risk factors (e.g., lipid pattern, diabetes, inflammation, endothelial function etc.) as well as also the development of the endpoints of atherosclerosis especially CHD. PMID:16596802

  3. Effect of pullulan nanoparticle surface charges on HSA complexation and drug release behavior of HSA-bound nanoparticles.

    Directory of Open Access Journals (Sweden)

    Xiaojun Tao

    Full Text Available Nanoparticle (NP compositions such as hydrophobicity and surface charge are vital to determine the presence and amount of human serum albumin (HSA binding. The HSA binding influences drug release, biocompatibility, biodistribution, and intercellular trafficking of nanoparticles (NPs. Here, we prepared 2 kinds of nanomaterials to investigate HSA binding and evaluated drug release of HSA-bound NPs. Polysaccharides (pullulan carboxyethylated to provide ionic derivatives were then conjugated to cholesterol groups to obtain cholesterol-modified carboxyethyl pullulan (CHCP. Cholesterol-modified pullulan (CHP conjugate was synthesized with a similar degree of substitution of cholesterol moiety to CHCP. CHCP formed self-aggregated NPs in aqueous solution with a spherical structure and zeta potential of -19.9 ± 0.23 mV, in contrast to -1.21 ± 0.12 mV of CHP NPs. NPs could quench albumin fluorescence intensity with maximum emission intensity gradually decreasing up to a plateau at 9 to 12 h. Binding constants were 1.12 × 10(5 M(-1 and 0.70 × 10(5 M(-1 to CHP and CHCP, respectively, as determined by Stern-Volmer analysis. The complexation between HSA and NPs was a gradual process driven by hydrophobic force and inhibited by NP surface charge and shell-core structure. HSA conformation was altered by NPs with reduction of α-helical content, depending on interaction time and particle surface charges. These NPs could represent a sustained release carrier for mitoxantrone in vitro, and the bound HSA assisted in enhancing sustained drug release.

  4. Complete genome sequence of the complex carbohydrate-degrading marine bacterium, Saccharophagus degradans strain 2-40 T.

    OpenAIRE

    Weiner, Ronald M.; Taylor, Larry E.; Bernard Henrissat; Loren Hauser; Miriam Land; Coutinho, Pedro M; Corinne Rancurel; Saunders, Elizabeth H.; Atkinson G Longmire; Haitao Zhang; Bayer, Edward A.; Gilbert, Harry J.; Frank Larimer; Zhulin, Igor B.; Ekborg, Nathan A.

    2008-01-01

    The marine bacterium Saccharophagus degradans strain 2-40 (Sde 2-40) is emerging as a vanguard of a recently discovered group of marine and estuarine bacteria that recycles complex polysaccharides. We report its complete genome sequence, analysis of which identifies an unusually large number of enzymes that degrade >10 complex polysaccharides. Not only is this an extraordinary range of catabolic capability, many of the enzymes exhibit unusual architecture including novel combinations of catal...

  5. Strategies for improved modeling of GPCR-drug complexes: blind predictions of serotonin receptors bound to ergotamine.

    Science.gov (United States)

    Rodríguez, David; Ranganathan, Anirudh; Carlsson, Jens

    2014-07-28

    The recent increase in the number of atomic-resolution structures of G protein-coupled receptors (GPCRs) has contributed to a deeper understanding of ligand binding to several important drug targets. However, reliable modeling of GPCR-ligand complexes for the vast majority of receptors with unknown structure remains to be one of the most challenging goals for computer-aided drug design. The GPCR Dock 2013 assessment, in which researchers were challenged to predict the crystallographic structures of serotonin 5-HT(1B) and 5-HT(2B) receptors bound to ergotamine, provided an excellent opportunity to benchmark the current state of this field. Our contributions to GPCR Dock 2013 accurately predicted the binding mode of ergotamine with RMSDs below 1.8 Å for both receptors, which included the best submissions for the 5-HT(1B) complex. Our models also had the most accurate description of the binding sites and receptor-ligand contacts. These results were obtained using a ligand-guided homology modeling approach, which combines extensive molecular docking screening with incorporation of information from multiple crystal structures and experimentally derived restraints. In this work, we retrospectively analyzed thousands of structures that were generated during the assessment to evaluate our modeling strategies. Major contributors to accuracy were found to be improved modeling of extracellular loop two in combination with the use of molecular docking to optimize the binding site for ligand recognition. Our results suggest that modeling of GPCR-drug complexes has reached a level of accuracy at which structure-based drug design could be applied to a large number of pharmaceutically relevant targets. PMID:25030302

  6. Functions that Protect Escherichia coli from Tightly Bound DNA-Protein Complexes Created by Mutant EcoRII Methyltransferase.

    Directory of Open Access Journals (Sweden)

    Morgan L Henderson

    Full Text Available Expression of mutant EcoRII methyltransferase protein (M.EcoRII-C186A in Escherichia coli leads to tightly bound DNA-protein complexes (TBCs, located sporadically on the chromosome rather than in tandem arrays. The mechanisms behind the lethality induced by such sporadic TBCs are not well studied, nor is it clear whether very tight binding but non-covalent complexes are processed in the same way as covalent DNA-protein crosslinks (DPCs. Using 2D gel electrophoresis, we found that TBCs induced by M.EcoRII-C186A block replication forks in vivo. Specific bubble molecules were detected as spots on the 2D gel, only when M.EcoRII-C186A was induced, and a mutation that eliminates a specific EcoRII methylation site led to disappearance of the corresponding spot. We also performed a candidate gene screen for mutants that are hypersensitive to TBCs induced by M.EcoRII-C186A. We found several gene products necessary for protection against these TBCs that are known to also protect against DPCs induced with wild-type M.EcoRII (after 5-azacytidine incorporation: RecA, RecBC, RecG, RuvABC, UvrD, FtsK, XerCD and SsrA (tmRNA. In contrast, the RecFOR pathway and Rep helicase are needed for protection against TBCs but not DPCs induced by M.EcoRII. We propose that stalled fork processing by RecFOR and RecA promotes release of tightly bound (but non-covalent blocking proteins, perhaps by licensing Rep helicase-driven dissociation of the blocking M.EcoRII-C186A. Our studies also argued against the involvement of several proteins that might be expected to protect against TBCs. We took the opportunity to directly compare the sensitivity of all tested mutants to two quinolone antibiotics, which target bacterial type II topoisomerases and induce a unique form of DPC. We uncovered rep, ftsK and xerCD as novel quinolone hypersensitive mutants, and also obtained evidence against the involvement of a number of functions that might be expected to protect against quinolones.

  7. Functions that Protect Escherichia coli from Tightly Bound DNA-Protein Complexes Created by Mutant EcoRII Methyltransferase.

    Science.gov (United States)

    Henderson, Morgan L; Kreuzer, Kenneth N

    2015-01-01

    Expression of mutant EcoRII methyltransferase protein (M.EcoRII-C186A) in Escherichia coli leads to tightly bound DNA-protein complexes (TBCs), located sporadically on the chromosome rather than in tandem arrays. The mechanisms behind the lethality induced by such sporadic TBCs are not well studied, nor is it clear whether very tight binding but non-covalent complexes are processed in the same way as covalent DNA-protein crosslinks (DPCs). Using 2D gel electrophoresis, we found that TBCs induced by M.EcoRII-C186A block replication forks in vivo. Specific bubble molecules were detected as spots on the 2D gel, only when M.EcoRII-C186A was induced, and a mutation that eliminates a specific EcoRII methylation site led to disappearance of the corresponding spot. We also performed a candidate gene screen for mutants that are hypersensitive to TBCs induced by M.EcoRII-C186A. We found several gene products necessary for protection against these TBCs that are known to also protect against DPCs induced with wild-type M.EcoRII (after 5-azacytidine incorporation): RecA, RecBC, RecG, RuvABC, UvrD, FtsK, XerCD and SsrA (tmRNA). In contrast, the RecFOR pathway and Rep helicase are needed for protection against TBCs but not DPCs induced by M.EcoRII. We propose that stalled fork processing by RecFOR and RecA promotes release of tightly bound (but non-covalent) blocking proteins, perhaps by licensing Rep helicase-driven dissociation of the blocking M.EcoRII-C186A. Our studies also argued against the involvement of several proteins that might be expected to protect against TBCs. We took the opportunity to directly compare the sensitivity of all tested mutants to two quinolone antibiotics, which target bacterial type II topoisomerases and induce a unique form of DPC. We uncovered rep, ftsK and xerCD as novel quinolone hypersensitive mutants, and also obtained evidence against the involvement of a number of functions that might be expected to protect against quinolones. PMID:25993347

  8. Crystal structures of artocarpin, a Moraceae lectin with mannose specificity, and its complex with methyl-alpha-D-mannose: implications to the generation of carbohydrate specificity.

    Science.gov (United States)

    Pratap, J V; Jeyaprakash, A Arockia; Rani, P Geetha; Sekar, K; Surolia, A; Vijayan, M

    2002-03-22

    The seeds of jack fruit (Artocarpus integrifolia) contain two tetrameric lectins, jacalin and artocarpin. Jacalin was the first lectin found to exhibit the beta-prism I fold, which is characteristic of the Moraceae plant lectin family. Jacalin contains two polypeptide chains produced by a post-translational proteolysis which has been shown to be crucial for generating its specificity for galactose. Artocarpin is a single chain protein with considerable sequence similarity with jacalin. It, however, exhibits many properties different from those of jacalin. In particular, it is specific to mannose. The structures of two crystal forms, form I and form II, of the native lectin have been determined at 2.4 and 2.5 A resolution, respectively. The structure of the lectin complexed with methyl-alpha-mannose, has also been determined at 2.9 A resolution. The structure is similar to jacalin, although differences exist in details. The crystal structures and detailed modelling studies indicate that the following differences between the carbohydrate binding sites of artocarpin and jacalin are responsible for the difference in the specificities of the two lectins. Firstly, artocarpin does not contain, unlike jacalin, an N terminus generated by post-translational proteolysis. Secondly, there is no aromatic residue in the binding site of artocarpin whereas there are four in that of jacalin. A comparison with similar lectins of known structures or sequences, suggests that, in general, stacking interactions with aromatic residues are important for the binding of galactose while such interactions are usually absent in the carbohydrate binding sites of mannose-specific lectins with the beta-prism I fold.

  9. Complete genome sequence of the complex carbohydrate-degrading marine bacterium, Saccharophagus degradans strain 2-40 T.

    Directory of Open Access Journals (Sweden)

    Ronald M Weiner

    2008-05-01

    Full Text Available The marine bacterium Saccharophagus degradans strain 2-40 (Sde 2-40 is emerging as a vanguard of a recently discovered group of marine and estuarine bacteria that recycles complex polysaccharides. We report its complete genome sequence, analysis of which identifies an unusually large number of enzymes that degrade >10 complex polysaccharides. Not only is this an extraordinary range of catabolic capability, many of the enzymes exhibit unusual architecture including novel combinations of catalytic and substrate-binding modules. We hypothesize that many of these features are adaptations that facilitate depolymerization of complex polysaccharides in the marine environment. This is the first sequenced genome of a marine bacterium that can degrade plant cell walls, an important component of the carbon cycle that is not well-characterized in the marine environment.

  10. Structure of human Eg5 in complex with a new monastrol-based inhibitor bound in the R configuration.

    Science.gov (United States)

    Garcia-Saez, Isabel; DeBonis, Salvatore; Lopez, Roman; Trucco, Fernando; Rousseau, Bernard; Thuéry, Pierre; Kozielski, Frank

    2007-03-30

    Drugs that target mitotic spindle proteins have been proven useful for tackling tumor growth. Eg5, a kinesin-5 family member, represents a potential target, since its inhibition leads to prolonged mitotic arrest through the activation of the mitotic checkpoint and apoptotic cell death. Monastrol, a specific dihydropyrimidine inhibitor of Eg5, shows stereo-specificity, since predominantly the (S)-, but not the (R)-, enantiomer has been shown to be the biologically active compound in vitro and in cell-based assays. Here, we solved the crystal structure (2.7A) of the complex between human Eg5 and a new keto derivative of monastrol (named mon-97), a potent antimitotic inhibitor. Surprisingly, we identified the (R)-enantiomer bound in the active site, and not, as for monastrol, the (S)-enantiomer. The absolute configuration of this more active (R)-enantiomer has been unambiguously determined via chemical correlation and x-ray analysis. Unexpectedly, both the R- and the S-forms inhibit Eg5 ATPase activity with IC(50) values of 110 and 520 nM (basal assays) and 150 nm and 650 nm (microtubule-stimulated assays), respectively. However, the difference was large enough for the protein to select the (R)- over the (S)-enantiomer. Taken together, these results show that in this new monastrol family, both (R)- and (S)-enantiomers can be active as Eg5 inhibitors. This considerably broadens the alternatives for rational drug design.

  11. Bistable molecular switches based on linkage isomerization in ruthenium polypyridyl complexes with a ligand-bound ambidentate motif.

    Science.gov (United States)

    Johansson, Olof; Johannissen, Linus O; Lomoth, Reiner

    2009-01-01

    Electron-transfer-induced linkage isomerization was investigated in a series of bis-tridentate Ru polypyridyl complexes [Ru(L-X-OH)(Y-tpy)](2+) with ambidentate ligand L-X-OH=bpy-C(R)(OH)-py (bpy=2,2'-bipyridine; py=pyridine; R=H, Me, Ph, or tBu) and spectator ligand Y-tpy (tpy=2,2':6',2''-terpyridine; Y=p-tolyl, p-PhCO(2)Me, Cl, OEt, N-pyrrolidine). The ligand-bound ambidentate motif switches reversibly between N and O coordination in the Ru(II) and Ru(III) state, respectively. The potentials of the Ru(III/II) couple differ by about 0.5 V between the isomers, and this results in a bistable electrochemical response of the molecular switches. The effects of structural modifications in form of substituents on the linking carbon atom of the ambidentate ligand and on the central pyridine moiety of the spectator ligand were investigated by electrochemical and computational methods. Differences in isomerization behavior span six orders of magnitude in rate constants and two orders of magnitude in equilibrium constants. The results can be interpreted in terms of steric and electronic substituent effects and their influence on rotational barriers, ligation geometry, and electron deficiency of the metal center. PMID:19072945

  12. A strategy for co-translational folding studies of ribosome-bound nascent chain complexes using NMR spectroscopy.

    Science.gov (United States)

    Cassaignau, Anaïs M E; Launay, Hélène M M; Karyadi, Maria-Evangelia; Wang, Xiaolin; Waudby, Christopher A; Deckert, Annika; Robertson, Amy L; Christodoulou, John; Cabrita, Lisa D

    2016-08-01

    During biosynthesis on the ribosome, an elongating nascent polypeptide chain can begin to fold, in a process that is central to all living systems. Detailed structural studies of co-translational protein folding are now beginning to emerge; such studies were previously limited, at least in part, by the inherently dynamic nature of emerging nascent chains, which precluded most structural techniques. NMR spectroscopy is able to provide atomic-resolution information for ribosome-nascent chain complexes (RNCs), but it requires large quantities (≥10 mg) of homogeneous, isotopically labeled RNCs. Further challenges include limited sample working concentration and stability of the RNC sample (which contribute to weak NMR signals) and resonance broadening caused by attachment to the large (2.4-MDa) ribosomal complex. Here, we present a strategy to generate isotopically labeled RNCs in Escherichia coli that are suitable for NMR studies. Uniform translational arrest of the nascent chains is achieved using a stalling motif, and isotopically labeled RNCs are produced at high yield using high-cell-density E. coli growth conditions. Homogeneous RNCs are isolated by combining metal affinity chromatography (to isolate ribosome-bound species) with sucrose density centrifugation (to recover intact 70S monosomes). Sensitivity-optimized NMR spectroscopy is then applied to the RNCs, combined with a suite of parallel NMR and biochemical analyses to cross-validate their integrity, including RNC-optimized NMR diffusion measurements to report on ribosome attachment in situ. Comparative NMR studies of RNCs with the analogous isolated proteins permit a high-resolution description of the structure and dynamics of a nascent chain during its progressive biosynthesis on the ribosome. PMID:27466710

  13. Microbial Degradation of Whole-Grain Complex Carbohydrates and Impact on Short-Chain Fatty Acids and Health1234

    OpenAIRE

    Bach Knudsen, Knud Erik

    2015-01-01

    Whole-grain cereals have a complex dietary fiber (DF) composition consisting of oligosaccharides (mostly fructans), resistant starch, and nonstarch polysaccharides (NSPs); the most important are arabinoxylans, mixed-linkage β(1,3; 1,4)-d-glucan (β-glucan), and cellulose and the noncarbohydrate polyphenolic ether lignin. The highest concentration of NSPs and lignin is found in the outer cell layers of the grain, and refined flour will consequently be depleted of a large proportion of insoluble...

  14. Structural complexes of the agonist, inverse agonist and antagonist bound C5a receptor: insights into pharmacology and signaling.

    Science.gov (United States)

    Rana, Soumendra; Sahoo, Amita Rani; Majhi, Bharat Kumar

    2016-04-26

    The C5a receptor (C5aR) is a pharmacologically important G-protein coupled receptor (GPCR) that interacts with (h)C5a, by recruiting both the "orthosteric" sites (site1 at the N-terminus and site2 at the ECS, extra cellular surface) on C5aR in a two site-binding model. However, the complex pharmacological landscape and the distinguishing chemistry operating either at the "orthosteric" site1 or at the functionally important "orthosteric" site2 of C5aR are still not clear, which greatly limits the understanding of C5aR pharmacology. One of the major bottlenecks is the lack of an experimental structure or a refined model structure of C5aR with appropriately defined active sites. The study attempts to understand the pharmacology at the "orthosteric" site2 of C5aR rationally by generating a highly refined full-blown model structure of C5aR through advanced molecular modeling techniques, and further subjecting it to automated docking and molecular dynamics (MD) studies in the POPC bilayer. The first series of structural complexes of C5aR respectively bound to a linear native peptide agonist ((h)C5a-CT), a small molecule inverse agonist (NDT) and a cyclic peptide antagonist (PMX53) are reported, apparently establishing the unique pharmacological landscape of the "orthosteric" site2, which also illustrates an energetically distinct but coherent competitive chemistry ("cation-π" vs. "π-π" interactions) involved in distinguishing the established ligands known for targeting the "orthosteric" site2 of C5aR. Over a total of 1 μs molecular dynamics (MD) simulation in the POPC bilayer, it is evidenced that while the agonist prefers a "cation-π" interaction, the inverse agonist prefers a "cogwheel/L-shaped" interaction in contrast to the "edge-to-face/T-shaped" type π-π interactions demonstrated by the antagonist by engaging the F275(7.28) of the C5aR. In the absence of a NMR or crystallographically guided model structure of C5aR, the computational model complexes not only

  15. [Carbohydrates and fiber].

    Science.gov (United States)

    Lajolo, F M; de Menezes, E W; Filisetti-Cozzi, T M

    1988-09-01

    Dietary carbohydrates comprise two fractions that may be classified as digestible, and which are useful as energy sources (simple and complex carbohydrates) and fiber, which is presumed to be of no use to the human body. There are insufficient epidemiologic data on the metabolic effects of simple carbohydrates and it is not advisable to make quantitative recommendations of intake. It is questionable to recommend in developing countries that a fixed proportion of dietary energy be derived from simple sugars, due to the high prevalence of deficient energy intake, cultural habits, and regional differences in food intake and physical activity. In relation to recommendations of complex carbohydrates, it should be considered that their absorption is influenced by many factors inherent to the individual and to the foods. Fiber is defined as a series of different substances derived from tissue structures, cellular residues and undigested chemical substances that may be partially utilized after intestinal bacteria have acted on them. There is not a clear definition of the chemical composition of fiber, but it consists mainly of polysaccharides (such as cellulose, hemicellulose and pectins), lignin and end products of the interactions of various food components. The effects of fiber, such as control of food intake, regulation of gastrointestinal transit, post-prandial blood concentrations of cholesterol, glucose and insulin, flatulence and alterations in nutrient bioavailability are due to various physical properties inherent to its chemical components. Impairment of nutrient absorption may be harmful, mainly among populations whose food intake is lower than their energy needs, and with a high fiber content. This may be particularly important in pregnant women, growing children and the elderly, and should be considered when making nutrient recommendations. A precise knowledge of fiber is also important to calculate the real energy value of foods, mainly for two reasons: 1

  16. Carbohydrate clearance receptors in transfusion medicine

    DEFF Research Database (Denmark)

    Sørensen, Anne Louise Tølbøll; Clausen, Henrik; Wandall, Hans H

    2012-01-01

    Complex carbohydrates play important functions for circulation of proteins and cells. They provide protective shields and refraction from non-specific interactions with negative charges from sialic acids to enhance circulatory half-life. For recombinant protein therapeutics carbohydrates are espe...

  17. 4-Nitrocatecholato iron(III) complexes of 2-aminomethyl pyridine-based bis(phenol) amine as structural models for catechol-bound 3,4-PCD

    Science.gov (United States)

    Safaei, Elham; Heidari, Sima; Wojtczak, Andrzej; Cotič, Patricia; Kozakiewicz, Anna

    2016-02-01

    Two nitrocatecholato(HNC) iron(III) complexes, [FeLAMPX(H-NC)]. NEt3, of the tetradendate ligand (2-aminomethylpyridine)bis(2-pyridylmethyl)amine (H2LAMPX) were synthesized and structurally characterized. These structural models for catechol-bound 3,4-PCD were characterized by IR, UV-vis, elemental analysis and magnetic measurements. X-ray crystallography studies revealed that in both complexes the iron(III) centers are distorted octahedral and coordinated by two phenolate oxygen's, two amine nitrogen's of the ligand and mono anionic nitrocatecholate group (HNC). The variable-temperature magnetic susceptibility studies revealed paramagnetic properties of the reported complexes. The effective magnetic moments for the complexes lie between 5.3 and 5.4 BM correspond to the reported values for high spin Fe(III) center. The ligand-centered oxidation and metal-centered reduction of complexes was studies using cyclic voltammetry (CV) technique.

  18. Bounded Earthquakes

    OpenAIRE

    Saric, Dragomir

    2006-01-01

    We give a short proof of the fact that bounded earthquakes of the unit disk induce quasisymmetric maps of the unit circle. By a similar method, we show that symmetric maps are induced by bounded earthquakes with asymptotically trivial measures.

  19. Carbohydrate Metabolism Disorders

    Science.gov (United States)

    ... you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system (enzymes) ... metabolic disorder, something goes wrong with this process. Carbohydrate metabolism disorders are a group of metabolic disorders. ...

  20. The DMM Bound

    DEFF Research Database (Denmark)

    Emiris, Ioannis Z.; Mourrain, Bernard; Tsigaridas, Elias

    2010-01-01

    ) resultant by means of mixed volume, as well as recent advances on aggregate root bounds for univariate polynomials, and are applicable to arbitrary positive dimensional systems. We improve upon Canny's gap theorem [7] by a factor of O(dn-1), where d bounds the degree of the polynomials, and n is the number...... bound on the number of steps that subdivision-based algorithms perform in order to isolate all real roots of a polynomial system. This leads to the first complexity bound of Milne's algorithm [22] in 2D....

  1. Bound entanglement and entanglement bounds

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, Simeon [Physikalisch-Astronomische Fakultaet, Friedrich-Schiller-Univesitaet Jena (Germany)]|[Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg (Germany); Melo, Fernando de; Mintert, Florian; Buchleitner, Andreas [Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg (Germany)]|[Max-Planck-Institut fuer Physik komplexer Systeme, Noethnitzer Str.38, D-01187 Dresden (Germany); Bae, Joonwoo [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea); Hiesmayr, Beatrix [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria)

    2008-07-01

    We investigate the separability of Bell-diagonal states of two qutrits. By using lower bounds to algebraically estimate concurrence, we find convex regions of bound entangled states. Some of these regions exactly coincide with the obtained results when employing optimal entanglement witnesses, what shows that the lower bound can serve as a precise detector of entanglement. Some hitherto unknown regions of bound entangled states were discovered with this approach, and delimited efficiently.

  2. Crystal structures of complexes containing domains from two viral internal ribosome entry site (IRES) RNAs bound to the 70S ribosome

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Jianyu; Korostelev, Andrei; Costantino, David A.; Donohue, John P.; Noller, Harry F.; Kieft, Jeffrey S. (UCSC); (Colorado)

    2011-08-24

    Internal ribosome entry site (IRES) RNAs are elements of viral or cellular mRNAs that bypass steps of canonical eukaryotic cap-dependent translation initiation. Understanding of the structural basis of IRES mechanisms is limited, partially due to a lack of high-resolution structures of IRES RNAs bound to their cellular targets. Prompted by the universal phylogenetic conservation of the ribosomal P site, we solved the crystal structures of proposed P site binding domains from two intergenic region IRES RNAs bound to bacterial 70S ribosomes. The structures show that these IRES domains nearly perfectly mimic a tRNA-mRNA interaction. However, there are clear differences in the global shape and position of this IRES domain in the intersubunit space compared to those of tRNA, supporting a mechanism for IRES action that invokes hybrid state mimicry to drive a noncanonical mode of translocation. These structures suggest how relatively small structured RNAs can manipulate complex biological machines.

  3. ParAB Partition Dynamics in Firmicutes: Nucleoid Bound ParA Captures and Tethers ParB-Plasmid Complexes

    OpenAIRE

    Lioy, Virginia S.; Andrea Volante; Nora E Soberón; Rudi Lurz; Silvia Ayora; Alonso, Juan C.

    2015-01-01

    In Firmicutes, small homodimeric ParA-like (δ2) and ParB-like (ω2) proteins, in concert with cis-acting plasmid-borne parS and the host chromosome, secure stable plasmid inheritance in a growing bacterial population. This study shows that (ω:YFP)2 binding to parS facilitates plasmid clustering in the cytosol. (δ:GFP)2 requires ATP binding but not hydrolysis to localize onto the cell's nucleoid as a fluorescent cloud. The interaction of (δ:CFP)2 or δ2 bound to the nucleoid with (ω:YFP)2 foci f...

  4. Bounded rationality and voting decisions over 160 years: voter behavior and increasing complexity in decision-making.

    Directory of Open Access Journals (Sweden)

    David Stadelmann

    Full Text Available Using a quasi-natural voting experiment encompassing a 160-year period (1848-2009 in Switzerland, we investigate whether a higher level of complexity leads to increased reliance on trusted parliamentary representatives. We find that when more referenda are held on the same day, constituents are more likely to refer to parliamentary recommendations when making their decisions. This finding holds true even when we narrow our focus to referenda with a relatively lower voter turnout on days on which more than one referendum is held. We also demonstrate that when constituents face a higher level of complexity, they follow the parliamentary recommendations rather than those of interest groups. "Viewed as a geometric figure, the ant's path is irregular, complex, hard to describe. But its complexity is really a complexity in the surface of the beach, not a complexity in the ant." ( [1] p. 51.

  5. A flow calculus of mwp-bounds for complexity analysis

    DEFF Research Database (Denmark)

    Jones, Neil D.; Kristiansen, Lars

    2010-01-01

    We present a method for certifying that the values computed by an imperative program will be bounded by polynomials in the program's inputs. To this end, we introduce mwp-matrices and define a semantic relation ⊧ C : M, where C is a program and M is an mwp-matrix. It follows...... straightforwardly from our definitions that there exists M such that ⊧ C : M holds iff every value computed by C is bounded by a polynomial in the inputs. Furthermore, we provide a syntactical proof calculus and define the relation ⊢ C : M to hold iff there exists a derivation in the calculus where C...... : M is the bottom line. We prove that ⊢ C : M implies ⊧ C : M. By means of exhaustive proof search, an algorithm can decide if there exists M such that the relation ⊢ C : M holds, and thus, our results yield a computational method....

  6. Structural comparison of the Caenorhabditis elegans and human Ndc80 complexes bound to microtubules reveals distinct binding behavior

    Science.gov (United States)

    Wilson-Kubalek, Elizabeth M.; Cheeseman, Iain M.; Milligan, Ronald A.

    2016-01-01

    During cell division, kinetochores must remain tethered to the plus ends of dynamic microtubule polymers. However, the molecular basis for robust kinetochore–microtubule interactions remains poorly understood. The conserved four-subunit Ndc80 complex plays an essential and direct role in generating dynamic kinetochore–microtubule attachments. Here we compare the binding of the Caenorhabditis elegans and human Ndc80 complexes to microtubules at high resolution using cryo–electron microscopy reconstructions. Despite the conserved roles of the Ndc80 complex in diverse organisms, we find that the attachment mode of these complexes for microtubules is distinct. The human Ndc80 complex binds every tubulin monomer along the microtubule protofilament, whereas the C. elegans Ndc80 complex binds more tightly to β-tubulin. In addition, the C. elegans Ndc80 complex tilts more toward the adjacent protofilament. These structural differences in the Ndc80 complex between different species may play significant roles in the nature of kinetochore–microtubule interactions. PMID:26941333

  7. Structure of the exon junction core complex with a trapped DEAD-box ATPase bound to RNA

    DEFF Research Database (Denmark)

    Andersen, Christian Brix Folsted; Ballut, Lionel; Johansen, Jesper Sanderhoff;

    2006-01-01

    In higher eukaryotes, a multiprotein exon junction complex is deposited on spliced messenger RNAs. The complex is organized around a stable core, which serves as a binding platform for numerous factors that influence messenger RNA function. Here, we present the crystal structure of a tetrameric e...

  8. Cellular Delivery of Quantum Dot-Bound Hybridization Probe for Detection of Intracellular Pre-MicroRNA Using Chitosan/Poly(γ-Glutamic Acid) Complex as a Carrier

    OpenAIRE

    Yao Geng; Dajie Lin; Lijia Shao; Feng Yan; Huangxian Ju

    2013-01-01

    A quantum dot (QD)-bound hybridization probe was designed for detection of intracellular pre-miRNA using chitosan (CS)/poly(γ-glutamic acid) (γ-PGA) complex as a gene vector. The probe was prepared by assembling thiolated RNA to gold nanoparticle (Au NP) via Au-S bond and then binding 3'-end amine of the RNA to the carboxy group capped on quantum dot surface. The QD-RNA-Au NP probe was assembled on the vector by mixing with aqueous γ-PGA solution and then CS solution to construct a gene deliv...

  9. MCM-41 Bound Ruthenium Complex as Heterogeneous Catalyst for Hydrogenation Ⅰ: Effect of Support, Ligand and Solvent on the Catalyst Performance

    Institute of Scientific and Technical Information of China (English)

    YU, Ying-Min; FEI, Jin-Hua; ZHANG, Yi-Ping; ZHENG, Xiao-Ming

    2006-01-01

    The functionalized MCM-41 mesoporous bound ruthenium complex was synthesized and characterized using elemental analysis, atomic absorption spectrophotometer, BET, XRD and FTIR. Hydrogenation of carbon dioxide to formic acid was investigated over these catalysts under supercritical CO2 condition. The effect of reactant gas partial pressure, supports, solvents and ligands on the synthesis of formic acid was studied. These factors could influence the catalyst activity, stability and reuse performance greatly and no byproduct was detected. These promising catalysts also offered the industrial advantages such as easy separation.

  10. Platinum(II) and platinum(IV) complexes stabilized by abnormal/mesoionic C4-bound dicarbenes

    OpenAIRE

    Khlebnikov, Vsevolod; Heckenroth, Marion; Müller-Bunz, Helge; Albrecht, Martin

    2013-01-01

    Platinum(II) complexes comprising abnormal diimidazolylidene ligands were synthesized from cis-PtMe2(DMSO)(2) using microwave-assisted double C-H bond activation. NMR analysis revealed an unusual solvolysis process, induced by coordinating solvents such as DMSO and MeCN, which has not been observed in related normal dicarbene complexes. NMR and IR spectroscopy and crystallographic analysis of the mono-substituted DMSO complex indicate a sulfur-bonding of the DMSO ligand to the platinum(II) ce...

  11. Functional Feed Assessment on Litopenaeus vannamei Using 100% Fish Meal Replacement by Soybean Meal, High Levels of Complex Carbohydrates and Bacillus Probiotic Strains

    OpenAIRE

    Rosalia Contreras; Jesus Paniagua-Michel; Leonel Ochoa; Jorge Olmos

    2011-01-01

    Functional feed supplemented with alternative-economic nutrient sources (protein, carbohydrates, lipids) and probiotics are being considered in shrimp/fish aquaculture production systems as an option to increase yield and profits and to reduce water pollution. In this study the probiotic potential to formulate functional feeds have been evaluated using four dietary treatments: Treatment 1 (B + Bs); Bacillus subtilis potential probiotic strain was supplemented to a soybeanmeal (SBM)—carbohydra...

  12. Functional Feed Assessment on Litopenaeus vannamei Using 100% Fish Meal Replacement by Soybean Meal, High Levels of Complex Carbohydrates and Bacillus Probiotic Strains

    Directory of Open Access Journals (Sweden)

    Rosalia Contreras

    2011-06-01

    Full Text Available Functional feed supplemented with alternative-economic nutrient sources (protein, carbohydrates, lipids and probiotics are being considered in shrimp/fish aquaculture production systems as an option to increase yield and profits and to reduce water pollution. In this study the probiotic potential to formulate functional feeds have been evaluated using four dietary treatments: Treatment 1 (B + Bs; Bacillus subtilis potential probiotic strain was supplemented to a soybeanmeal (SBM—carbohydrates (CHO basal feed. Treatment 2 (B + Bm; Bacillus megaterium potential probiotic strain was supplemented to the same SBM-CHO basal feed. In Treatment 3 (B; SBM-CHO basal feed was not supplemented with probiotic strains. Treatment 4 (C; fishmeal commercial feed (FM was utilized as positive control. Feeding trials evaluated the survival, growth, and food conversion ratio and stress tolerance of juvenile Litopenaeus vannamei (Boone Pacific white shrimp. Best overall shrimp performance was observed for animals fed with Treatment 1 (B+Bs; additionally, stress tolerance and hemolymph metabolites also showed the best performance in this treatment. SBM-CHO basal feed not supplemented with probiotic strains (B presented smaller growth and lower feed conversion ratio (FCR. Shrimps fed with the fishmeal commercial feed (C presented the lowest stress tolerance to high ammonia and low oxygen levels. Specifically selected B. subtilis strains are recommended to formulate functional and economical feeds containing high levels of vegetable; protein and carbohydrates as main dietary sources in L. vannamei cultures.

  13. Workshop to establish databases of carbohydrate spectra

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The workshop was organized to formulate guidelines for establishing spectral databases of complex carbohydrates. The databases will enable the scientific community to avoid the great waste of research effort and funds that frequently occurs when carbohydrate chemists are forced to duplicate the structural characterization of previously characterized complex carbohydrates. Chemists waste their effort on repetitive characterizations because in the absence of spectral databases they are unaware they are analyzing a known molecule until they have completely determined its structure. Chemists will be able to avoid much of this wasted effort when the collections of mass and of nuclear magnetic resonance (NMR) spectra initiated at the workshop are subsequently developed into searchable databases. Then scientists only need query the databases with the spectrum or with information defining the spectrum of an unidentified carbohydrate to find out if it has been previously characterized.

  14. Cationic half-sandwich Ru(II) complexes containing (N,N)-bound Schiff-base ligands: Synthesis, crystal structure analysis and spectroscopic studies

    Science.gov (United States)

    Tao, Li; Miao, Qian; Tehrani, Alireza Azhdari; Hajiashrafi, Taraneh; Hu, Mao-Lin; Morsali, Ali

    2016-08-01

    Three Ru(II) half-sandwich complexes containing (N,N)-bound Schiff-base ligands, [(η6-C6H6) RuCl(L1)]PF6 (1) L1 = (E)-1-(6-methylpyridin-2-yl)-N-(p-tolyl)methanimine, [(η6-p-cymene)RuCl(L1)]PF6 (2) and [(η6-p-cymene)RuCl(L2)]PF6(3) L2 = (E)-1-(6-bromopyridin-2-yl)-N-(p-tolyl)methanimine, were synthesized, characterized and their supramolecular structures were analyzed. The crystal packing of these compounds was studied using geometrical analysis and Hirshfeld surface analysis. The fluorescence behavior of these compounds was also studied. TD-DFT calculations were carried out to better understand the fluorescence properties of complexes 1-3. These compounds could be promising for the design of organometallic dye systems.

  15. Quasi-bound complexes in collisions of different linear molecules: Classical trajectory study of their manifestations in rotational relaxation and spectral line broadening

    Science.gov (United States)

    Ivanov, Sergey V.

    2016-07-01

    Stable bimolecular complexes (tightly bound dimers) in the gas phase are usually created during third body stabilization of their unstable precursors-quasi-bound complexes (QCs). The latter can arise under the condition that at least one of the colliding partners has an internal degree of freedom. In this article, the principal difference between "orbitings" and QCs is demonstrated in the classical nonreactive scattering picture. Additionally, fractions of QCs in binary collisions of different linear molecules are compared. Also in the article the influence of QCs on rotational R-T relaxation and on vibration-rotational spectral line broadening is discussed. Explicit formulae shedding light on the QCs contribution to the R-T relaxation cross section and the line width and shift are presented. The obtained results emphasize the need for including QCs in every theoretical modeling of spectroscopic manifestation of intermolecular interactions. Besides the topics above, the possible manifestation of non-impact effects in the central regions of spectral lines due to QCs is stated. And finally, special consideration is given to the problem of adequate simulation of QCs formation at different pressures.

  16. Structure, stability, and nature of bonding in carbon monoxide bound EX3+ complexes (E = group 14 element; X = H, F, Cl, Br, I).

    Science.gov (United States)

    Ghara, Manas; Pan, Sudip; Kumar, Anand; Merino, Gabriel; Chattaraj, Pratim K

    2016-09-15

    A density functional theory study is performed to predict the structures and stability of carbon monoxide (CO) bound EX3+ (E = C, Si, Ge, Sn, Pb; X = H, F, Cl, Br, I) complexes. The possibility of bonding through both C- and O-sides of CO is considered. Thermochemical analysis reveals that all the dissociation processes producing CO and EX3+ are endothermic in nature whereas most of the dissociation reactions are endergonic in nature at room temperature. The nature of bonding in EC/O bonds is analyzed via Wiberg bond index, natural population analysis, electron density, and energy decomposition analyses in conjunction with natural orbitals for chemical valence scheme. In comparison to CO stretching frequency ( ν∼CO) in free CO, while a red shift is noted in O-side binding, the C-side binding results in a blue shift in ν∼CO. The relative change in ν∼CO values in CO bound EX3+ complexes on changing either E or X is scrutinized and possible explanation is provided in terms of polarization in the σ- and π-orbitals and the relative strength of C→E or O→E σ-donation and E→C or E→O π-back-donation. © 2016 Wiley Periodicals, Inc. PMID:27425405

  17. KINETIC STUDY OF CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE OVER A NOVEL COPOLYMER- BOUND CIS- DICARBONYLRHODIUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuying; YUAN Guoqing; CHEN Rongyao

    1989-01-01

    The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh)coordinated with the ethylene diacrylate (M')crosslinked copolymer of methyl acrylate (M) and 2 - vinylpyridine (V) shows that the rate of reaction is zero order with respect to both reactants methanol and carbon monoxide, but first order in the concentrations of promoter methyl iodide and rhodium in the complex . Polar solvents can accelerate the reaction .Activation parameters were calculated from the experimental results, being comparable to that of the homogeneous system . A mechanism similar to that of soluble rhodium catalyst was proposed .

  18. Bounding the $\

    CERN Document Server

    Gutiérrez-Rodríguez, A

    2003-01-01

    A bound on the nu /sup tau / magnetic moment is calculated through the reaction e/sup +/e/sup -/ to nu nu gamma at the Z/sub 1/-pole, and in the framework of a left-right symmetric model at LEP energies. We find that the bound is almost independent of the mixing angle phi of the model in the allowed experimental range for this parameter. (31 refs).

  19. Polymer-bound oxidovanadium(IV) and dioxidovanadium(V) complexes as catalysts for the oxidative desulfurization of model fuel diesel.

    Science.gov (United States)

    Maurya, Mannar R; Arya, Aarti; Kumar, Amit; Kuznetsov, Maxim L; Avecilla, Fernando; Costa Pessoa, João

    2010-07-19

    The Schiff base (Hfsal-dmen) derived from 3-formylsalicylic acid and N,N-dimethyl ethylenediamine has been covalently bonded to chloromethylated polystyrene to give the polymer-bound ligand, PS-Hfsal-dmen (I). Treatment of PS-Hfsal-dmen with [V(IV)O(acac)(2)] in the presence of MeOH gave the oxidovanadium(IV) complex PS-[V(IV)O(fsal-dmen)(MeO)] (1). On aerial oxidation in methanol, complex 1 was oxidized to PS-[V(V)O(2)(fsal-dmen)] (2). The corresponding neat complexes, [V(IV)O(sal-dmen)(acac)] (3) and [V(V)O(2)(sal-dmen)] (4) were similarly prepared. All these complexes are characterized by various spectroscopic techniques (IR, electronic, NMR, and electron paramagnetic resonance (EPR)) and thermal as well as field-emission scanning electron micrographs (FE-SEM) studies, and the molecular structures of 3 and 4 were determined by single crystal X-ray diffraction. The EPR spectrum of the polymer supported V(IV)O-complex 1 is characteristic of magnetically diluted V(IV)O-complexes, the resolved EPR pattern indicating that the V(IV)O-centers are well dispersed in the polymer matrix. A good (51)V NMR spectrum could also be measured with 4 suspended in dimethyl sulfoxide (DMSO), the chemical shift (-503 ppm) being compatible with a VO(2)(+)-center and a N,O binding set. The catalytic oxidative desulfurization of organosulfur compounds thiophene, dibenzothiophene, benzothiophene, and 2-methyl thiophene (model of fuel diesel) was carried out using complexes 1 and 2. The sulfur in model organosulfur compounds oxidizes to the corresponding sulfone in the presence of H(2)O(2). The systems 1 and 2 do not loose efficiency for sulfoxidation at least up to the third cycle of reaction, this indicating that they preserve their integrity under the conditions used. Plausible intermediates involved in these catalytic processes are established by UV-vis, EPR, (51)V NMR, and density functional theory (DFT) studies, and an outline of the mechanism is proposed. The (51)V NMR spectra

  20. Radioiodinated branched carbohydrates

    Science.gov (United States)

    Goodman, Mark M.; Knapp, Jr., Furn F.

    1989-01-01

    A radioiodinated branched carbohydrate for tissue imaging. Iodine-123 is stabilized in the compound by attaching it to a vinyl functional group that is on the carbohydrate. The compound exhibits good uptake and retention and is promising in the development of radiopharmaceuticals for brain, heart and tumor imaging.

  1. A heteromeric membrane-bound prenyltransferase complex from hop catalyzes three sequential aromatic prenylations in the bitter acid pathway.

    Science.gov (United States)

    Li, Haoxun; Ban, Zhaonan; Qin, Hao; Ma, Liya; King, Andrew J; Wang, Guodong

    2015-03-01

    Bitter acids (α and β types) account for more than 30% of the fresh weight of hop (Humulus lupulus) glandular trichomes and are well known for their contribution to the bitter taste of beer. These multiprenylated chemicals also show diverse biological activities, some of which have potential benefits to human health. The bitter acid biosynthetic pathway has been investigated extensively, and the genes for the early steps of bitter acid synthesis have been cloned and functionally characterized. However, little is known about the enzyme(s) that catalyze three sequential prenylation steps in the β-bitter acid pathway. Here, we employed a yeast (Saccharomyces cerevisiae) system for the functional identification of aromatic prenyltransferase (PT) genes. Two PT genes (HlPT1L and HlPT2) obtained from a hop trichome-specific complementary DNA library were functionally characterized using this yeast system. Coexpression of codon-optimized PT1L and PT2 in yeast, together with upstream genes, led to the production of bitter acids, but no bitter acids were detected when either of the PT genes was expressed by itself. Stepwise mutation of the aspartate-rich motifs in PT1L and PT2 further revealed the prenylation sequence of these two enzymes in β-bitter acid biosynthesis: PT1L catalyzed only the first prenylation step, and PT2 catalyzed the two subsequent prenylation steps. A metabolon formed through interactions between PT1L and PT2 was demonstrated using a yeast two-hybrid system, reciprocal coimmunoprecipitation, and in vitro biochemical assays. These results provide direct evidence of the involvement of a functional metabolon of membrane-bound prenyltransferases in bitter acid biosynthesis in hop. PMID:25564559

  2. A NOVEL COPOLYMER-BOUND CIS- DICARBONYLRHODIUM COMPLEX FOR THE CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    YUAN Guoqing; CHEN Yuying; CHEN Rongyao

    1989-01-01

    A series of porous microspheres of linear and ethylene diacrylate (M ') cross-linked copolymers of 2 - vinylpyridine (V) and methyl acrylate (M) reacted with tetracarbonyldichlorodirhodium to form a series of cis-dicarbonylrhodium chelate complex (MVRh and MVM 'Rh). They are thermally stable yet very reactive in the carbonylation of methanol to acetic acid, and of methanol - acetic acid mixture to acetic acid and acetic anhydride with a selectivity of 100% under relatively mild and anhydrous conditions.

  3. Effects of isolated and complex dietary fibre matrices in breads on carbohydrate digestibility and physicochemical properties of ileal effluent from pigs

    DEFF Research Database (Denmark)

    Kasprzak, Miroslaw Marek; Lærke, Helle Nygaard; Knudsen, Knud Erik Bach

    2012-01-01

    To assess the effects of content and structure of dietary fiber (DF) on the carbohydrate digestibility and physicochemical properties of ileal digesta, five bread diets were studied in an experiment with ileum-cannulated pigs in a crossover design. The diets consisted of two experimental breads...... based on white wheat flour with added wheat arabinoxylan (AX) or with added isolated oat β-glucan (BG), which were compared with a low-DF commercial white wheat bread (WF) and two commercial high-DF, dark ground rye bread (GR) and rye bread with kernels (RK) as positive controls. There was no profound...

  4. Inactivation of lacZ gene expression by UV light and bound DNA photolyase implies formation of extended complexes in the genomes of specific Escherichia coli strains

    International Nuclear Information System (INIS)

    In Escherichia coli strains WU and CS101, UV inactivation of lacZ gene expression is more effective when the cells contain amplified DNA photolyase, and flash photoreactivation (fPR) after 15 min of metabolism does not reverse inactivation by the photolyasedimer complexes. In other strains, also studied with or without amplified DNA photolyase, there is no differential UV inactivation and fPR reverses inactivation by the complexes regardless of continued metabolism. The irreparable condition in strain WU is not due to dysfunction of photolyase: during post-UV metabolism, fPR still restores viability and dimers are removed from the region of the lac operon. When the wild-type lac promoter is replaced by the UV5 promoter, making expression insensitive to relaxed supercoiling and catabolite repression, inactivation by dimers alone becomes more resistant, i.e. requires higher fluences, but inactivation in WU and CS101 is still exceptionally sensitive to photolyasedimer complexes. This indicates that dimers external to the wild-type lac operon may inhibit expression by altering supercoiling but that complexes must involve some other mechanism for their special effect in WU and CS101. The exceptionally efficient inactivation and irreparable condition are consistent with the idea that, in two specific laboratory strains, photolyase bound to dimers at a considerable distance from the lac operon may initiate an aggregation of DNA with other cellular molecules that extends to, and inactivates expression from, the operon

  5. Computerized molecular modeling of carbohydrates

    Science.gov (United States)

    Computerized molecular modleing continues to increase in capability and applicability to carbohydrates. This chapter covers nomenclature and conformational aspects of carbohydrates, perhaps of greater use to carbohydrate-inexperienced computational chemists. Its comments on various methods and studi...

  6. Chitosan-bound pyridinedicarboxylate Ni(II) and Fe(III) complex biopolymer films as waste water decyanidation agents.

    Science.gov (United States)

    Adewuyi, Sheriff; Jacob, Julianah Modupe; Olaleye, Oluwatoyin Omolola; Abdulraheem, Taofiq Olanrewaju; Tayo, Jubril Ayopo; Oladoyinbo, Fatai Oladipupo

    2016-10-20

    Chitosan is a biopolymer with immense structural advantage for chemical and mechanical modifications to generate novel properties, functions and applications. This work depicts new pyridinedicarboxylicacid (PDC) crosslinked chitosan-metal ion films as veritable material for cyanide ion removal from aqueous solution. The PDC-crosslinked chitosan-metal films (PDC-Chit-Ni(II) and PDC-Chit-Fe(III)) were formed by complexing PDC-crosslinked chitosan film with anhydrous nickel(II) and iron(III) chloride salts respectively. The PDC-Chit and its metal films were characterized employing various analytical and spectroscopic techniques. The FT-IR, UV-vis and the XRD results confirm the presence of the metal ions in the metal coordinated PDC-crosslinked chitosan film. The surface morphological difference of PDC-Chit-Ni(II) film before and after decyanidation was explored with scanning electron microscopy. Furthermore, the quantitative amount of nickel(II) and iron(III) present in the complex were determined using Atomic Absorption Spectrophotometer as 32.3 and 37.2μg/g respectively which portends the biopolymer film as a good complexing agent. Removal of cyanide from aqueous solution with PDC-Chit, PDC-Chit-Ni(II) and PDC-Chit-Fe(III) films was studied with batch equilibrium experiments. At equilibrium, decyanidation capacity (DC) followed the order PDC-Chit-Ni (II)≈PDC-Chit-Fe(III)>PDC-Chit. PDC-Chit-Ni(II) film gave 100% CN(-) removal within 40min decyanidation owing to favorable coordination geometry. PMID:27474675

  7. Analysis and validation of carbohydrate three-dimensional structures

    International Nuclear Information System (INIS)

    The article summarizes the information that is gained from and the errors that are found in carbohydrate structures in the Protein Data Bank. Validation tools that can locate these errors are described. Knowledge of the three-dimensional structures of the carbohydrate molecules is indispensable for a full understanding of the molecular processes in which carbohydrates are involved, such as protein glycosylation or protein–carbohydrate interactions. The Protein Data Bank (PDB) is a valuable resource for three-dimensional structural information on glycoproteins and protein–carbohydrate complexes. Unfortunately, many carbohydrate moieties in the PDB contain inconsistencies or errors. This article gives an overview of the information that can be obtained from individual PDB entries and from statistical analyses of sets of three-dimensional structures, of typical problems that arise during the analysis of carbohydrate three-dimensional structures and of the validation tools that are currently available to scientists to evaluate the quality of these structures

  8. Crystal structures of complexes containing domains from two viral internal ribosome entry site (IRES) RNAs bound to the 70S ribosome.

    Science.gov (United States)

    Zhu, Jianyu; Korostelev, Andrei; Costantino, David A; Donohue, John P; Noller, Harry F; Kieft, Jeffrey S

    2011-02-01

    Internal ribosome entry site (IRES) RNAs are elements of viral or cellular mRNAs that bypass steps of canonical eukaryotic cap-dependent translation initiation. Understanding of the structural basis of IRES mechanisms is limited, partially due to a lack of high-resolution structures of IRES RNAs bound to their cellular targets. Prompted by the universal phylogenetic conservation of the ribosomal P site, we solved the crystal structures of proposed P site binding domains from two intergenic region IRES RNAs bound to bacterial 70S ribosomes. The structures show that these IRES domains nearly perfectly mimic a tRNA • mRNA interaction. However, there are clear differences in the global shape and position of this IRES domain in the intersubunit space compared to those of tRNA, supporting a mechanism for IRES action that invokes hybrid state mimicry to drive a noncanonical mode of translocation. These structures suggest how relatively small structured RNAs can manipulate complex biological machines. PMID:21245352

  9. Crystal structures of antibiotic-bound complexes of aminoglycoside 2''-phosphotransferase IVa highlight the diversity in substrate binding modes among aminoglycoside kinases.

    Science.gov (United States)

    Shi, Kun; Houston, Douglas R; Berghuis, Albert M

    2011-07-19

    Aminoglycoside 2''-phosphotransferase IVa [APH(2'')-IVa] is a member of a family of bacterial enzymes responsible for medically relevant resistance to antibiotics. APH(2'')-IVa confers high-level resistance against several clinically used aminoglycoside antibiotics in various pathogenic Enterococcus species by phosphorylating the drug, thereby preventing it from binding to its ribosomal target and producing a bactericidal effect. We describe here three crystal structures of APH(2'')-IVa, one in its apo form and two in complex with a bound antibiotic, tobramycin and kanamycin A. The apo structure was refined to a resolution of 2.05 Å, and the APH(2'')-IVa structures with tobramycin and kanamycin A bound were refined to resolutions of 1.80 and 2.15 Å, respectively. Comparison among the structures provides insight concerning the substrate selectivity of this enzyme. In particular, conformational changes upon substrate binding, involving rotational shifts of two distinct segments of the enzyme, are observed. These substrate-induced shifts may also rationalize the altered substrate preference of APH(2'')-IVa in comparison to those of other members of the APH(2'') subfamily, which are structurally closely related. Finally, analysis of the interactions between the enzyme and aminoglycoside reveals a distinct binding mode as compared to the intended ribosomal target. The differences in the pattern of interactions can be utilized as a structural basis for the development of improved aminoglycosides that are not susceptible to these resistance factors.

  10. Quaternionic bound states

    Energy Technology Data Exchange (ETDEWEB)

    De Leo, Stefano [Department of Applied Mathematics, University of Campinas, PO Box 6065, SP 13083-970, Campinas (Brazil); Ducati, Gisele C [Department of Mathematics, University of Parana PO Box 19081, PR 81531-970, Curitiba (Brazil)

    2005-04-15

    We study the bound-state solutions of vanishing angular momentum in a quaternionic spherical square-well potential of finite depth. As in standard quantum mechanics, such solutions occur for discrete values of energy. At first glance, it seems that the continuity conditions impose a very restrictive constraint on the energy eigenvalues and, consequently, no bound states were expected for energy values below the pure quaternionic potential. Nevertheless, a careful analysis shows that pure quaternionic potentials do not remove bound states. It is also interesting to compare these new solutions with the bound state solutions of the trial-complex potential. The study presented in this paper represents a preliminary step towards a full understanding of the role that quaternionic potentials could play in quantum mechanics. Of particular interest for the authors is the analysis of confined wave packets and tunnelling times in this new formulation of quantum theory.

  11. Carbohydrate nanotechnology: hierarchical assembly using nature's other information carrying biopolymers.

    Science.gov (United States)

    Han, Xu; Zheng, Yeting; Munro, Catherine J; Ji, Yiwen; Braunschweig, Adam B

    2015-08-01

    Despite their central role in directing some of the most complex biological processes, carbohydrates--nature's other information carrying biopolymer--have been largely ignored as building blocks for synthetic hierarchical assemblies. The non-stoichiometric binding and astronomical diversity characteristic of carbohydrates could lead to tantalizingly complex assembly algorithms, but these attributes simultaneously increase the difficulty of preparing carbohydrate assemblies and anticipating their behavior. Convergences in biotechnology, nanotechnology, polymer chemistry, surface science, and supramolecular chemistry have led to many recent important breakthroughs in glycan microarrays and synthetic carbohydrate receptors, where the idiosyncrasies of carbohydrate structure and binding are increasingly considered. We hope to inspire more researchers to consider carbohydrate structure, diversity, and binding as attractive tools for constructing synthetic hierarchical assemblies.

  12. Steady state and time-resolved fluorescence spectroscopy of quinine sulfate dication bound to sodium dodecylsulfate micelles: Fluorescent complex formation

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Sunita; Pant, Debi D., E-mail: ddpant@pilani.bits-pilani.ac.in

    2014-01-15

    Interaction of quinine sulfate dication (QSD) with anionic, sodium dodecylsulphate (SDS) surfactant has been studied at different premicellar, micellar and postmicellar concentrations in aqueous phase using steady state, time-resolved fluorescence and fluorescence anisotropy techniques. At premicellar concentrations of SDS, the decrease in absorbance, appearance of an extra fluorescence band at lower wavelengths and tri-exponential decay behavior of fluorescence, are attributed to complex formation between QSD molecules and surfactant monomers. At postmicellar concentrations the red shift in fluorescence spectrum, increase in quantum yield and increase in fluorescence lifetimes are attributed to incorporation of solute molecules to micelles. At lower concentrations of SDS, a large shift in fluorescence is observed on excitation at the red edge of absorption spectrum and this is explained in terms of distribution of ion pairs of different energies in the ground state and the observed fluorescence lifetime behavior corroborates with this model. The temporal fluorescence anisotropy decay of QSD in SDS micelles allowed determination of restriction on the motion of the fluorophore. All the different techniques used in this study reveal that the photophysics of QSD is very sensitive to the microenvironments of SDS micelles and QSD molecules reside at the water-micelle interface. -- Highlights: • Probe molecule is very sensitive to microenvironment of micelles. • Highly fluorescent ion-pair formation has been observed. • Modulated photophysics of probe molecule in micellar solutions has been observed. • Probe molecules strongly bind with micelles and reside at probe–micelle interface.

  13. Carbohydrates and Depression.

    Science.gov (United States)

    Wurtman, Richard J.; Wurtman, Judith J.

    1989-01-01

    Describes the symptoms, such as appetite change and mood fluctuation, basic mechanisms, and some treatments of Seasonal Affective Disorder (SAD), Carbohydrate-Craving Obesity (CCO) and Premenstrual Syndrome (PMS). Provides several tables and diagrams, and three reading references. (YP)

  14. The mannose-specific lectin domains of Flo1p from Saccharomyces cerevisiae and Lg-Flo1p from S. pastorianus: crystallization and preliminary X-ray diffraction analysis of the adhesin-carbohydrate complexes.

    Science.gov (United States)

    Ielasi, Francesco S; Goyal, Parveen; Sleutel, Mike; Wohlkonig, Alexandre; Willaert, Ronnie G

    2013-07-01

    Flo1p and Lg-Flo1p are two cell-wall adhesins belonging to the Flo (flocculation) protein family from the yeasts Saccharomyces cerevisiae and S. pastorianus. The main function of these modular proteins endowed with calcium-dependent lectin activity is to mediate cell-cell adhesion events during yeast flocculation, a process which is well known at the cellular level but still not fully characterized from a molecular perspective. Recently, structural features of the N-terminal Flo lectin domains, including the N-terminal domain of Lg-Flo1p (N-Lg-Flo1p), and their interactions with carbohydrate molecules have been investigated. However, structural data concerning the N-terminal domain of Flo1p (N-Flo1p), which is the most specific among the Flo proteins, are missing and information about the N-Lg-Flo1p-carbohydrate interaction still lacks detailed structural insight. Here, the crystallization and preliminary X-ray characterization of the apo form and the mannose complex of N-Flo1p and X-ray analysis of N-Lg-Flo1p crystals soaked in α-1,2-mannobiose are reported. The N-Flo1p crystals diffracted to a resolution of 1.43 Å in the case of the apo form and to 2.12 Å resolution for the mannose complex. Both crystals were orthorhombic and belonged to space group P212121, with one molecule in the asymmetric unit. The N-Lg-Flo1p-α-1,2-mannobiose complex crystal diffracted to 1.73 Å resolution and belonged to the monoclinic space group P1211 with two molecules in the asymmetric unit.

  15. Dietary Carbohydrates and Childhood Functional Abdominal Pain.

    Science.gov (United States)

    Chumpitazi, Bruno P; Shulman, Robert J

    2016-01-01

    Childhood functional gastrointestinal disorders (FGIDs) affect a large number of children throughout the world. Carbohydrates (which provide the majority of calories consumed in the Western diet) have been implicated both as culprits for the etiology of symptoms and as potential therapeutic agents (e.g., fiber) in childhood FGIDs. In this review, we detail how carbohydrate malabsorption may cause gastrointestinal symptoms (e.g., bloating) via the physiologic effects of both increased osmotic activity and increased gas production from bacterial fermentation. Several factors may play a role, including: (1) the amount of carbohydrate ingested; (2) whether ingestion is accompanied by a meal or other food; (3) the rate of gastric emptying (how quickly the meal enters the small intestine); (4) small intestinal transit time (the time it takes for a meal to enter the large intestine after first entering the small intestine); (5) whether the meal contains bacteria with enzymes capable of breaking down the carbohydrate; (6) colonic bacterial adaptation to one's diet, and (7) host factors such as the presence or absence of visceral hypersensitivity. By detailing controlled and uncontrolled trials, we describe how there is a general lack of strong evidence supporting restriction of individual carbohydrates (e.g., lactose, fructose) for childhood FGIDs. We review emerging evidence suggesting that a more comprehensive restriction of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) may be effective. Finally, we review how soluble fiber (a complex carbohydrate) supplementation via randomized controlled intervention trials in childhood functional gastrointestinal disorders has demonstrated efficacy. PMID:27355647

  16. Characterization and reactivity of the weakly bound complexes of the [H, N, S]{sup −} anionic system with astrophysical and biological implications

    Energy Technology Data Exchange (ETDEWEB)

    Trabelsi, T.; Ajili, Y.; Ben Yaghlane, S.; Jaidane, N.-E. [Laboratoire de Spectroscopie Atomique, Moléculaire et Applications–LSAMA, Université de Tunis El Manar, Tunis (Tunisia); Mogren Al-Mogren, M. [Chemistry Department, Faculty of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Francisco, J. S. [Department of Chemistry and Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, Indiana 47906 (United States); Hochlaf, M., E-mail: hochlaf@univ-mlv.fr [Laboratoire Modélisation et Simulation Multi Echelle, Université Paris-Est, MSME UMR 8208 CNRS, 5 Blvd. Descartes, 77454 Marne-la-Vallée (France)

    2015-07-21

    We investigate the lowest electronic states of doublet and quartet spin multiplicity states of HNS{sup −} and HSN{sup −} together with their parent neutral triatomic molecules. Computations were performed using highly accurate ab initio methods with a large basis set. One-dimensional cuts of the full-dimensional potential energy surfaces (PESs) along the interatomic distances and bending angle are presented for each isomer. Results show that the ground anionic states are stable with respect to the electron detachment process and that the long range parts of the PESs correlating to the SH{sup −} + N, SN{sup −} + H, SN + H{sup −}, NH + S{sup −}, and NH{sup −} + S are bound. In addition, we predict the existence of long-lived weakly bound anionic complexes that can be formed after cold collisions between SN{sup −} and H or SH{sup −} and N. The implications for the reactivity of these species are discussed; specifically, it is shown that the reactions involving SH{sup −}, SN{sup −}, and NH{sup −} lead either to the formation of HNS{sup −} or HSN{sup −} in their electronic ground states or to autodetachment processes. Thus, providing an explanation for why the anions, SH{sup −}, SN{sup −}, and NH{sup −}, have limiting detectability in astrophysical media despite the observation of their corresponding neutral species. In a biological context, we suggest that HSN{sup −} and HNS{sup −} should be incorporated into H{sub 2}S-assisted heme-catalyzed reduction mechanism of nitrites in vivo.

  17. Weak interactions in ion–ligand complexes of C3H3(+) isomers: competition between H-bound and C-bound structures in c-C3H3(+)·L and H2CCCH(+)·L (L = Ne, Ar, N2, CO2, and O2).

    Science.gov (United States)

    Botschwina, Peter; Oswald, Rainer; Dopfer, Otto

    2011-08-21

    Explicitly correlated coupled cluster theory at the CCSD(T)-F12x level (T. B. Adler, G. Knizia, and H.-J. Werner, J. Chem. Phys.127, 221106, 2007) has been employed to study structures and vibrations of complexes of type c-C(3)H(3)(+)·L and H(2)C(3)H(+)·L (L = Ne, Ar, N(2), CO(2), and O(2)). Both cations have different binding sites, allowing for the formation of weak to moderately strong hydrogen bonds as well as "C-bound" or "π-bound" structures. In contrast to previous expectations, the energetically most favourable structures of all H(2)C(3)H(+)·L complexes investigated are "C-bound", with the ligand bound to the methylenic carbon atom. The theoretical predictions enable a more detailed interpretation of infrared photodissociation (IRPD) spectra than was possible hitherto. In particular, the bands observed in the range 3238-3245 cm(-1) (D. Roth and O. Dopfer, Phys. Chem. Chem. Phys.4, 4855, 2002) are assigned to essentially free acetylenic CH stretching vibrations of the propargyl cation in "C-bound" H(2)C(3)H(+)·L complexes. PMID:21637871

  18. Role of weakly bound complexes in temperature-dependence and relative rates of MxOy- + H2O (M = Mo, W) reactions

    Science.gov (United States)

    Kafader, Jared O.; Ray, Manisha; Raghavachari, Krishnan; Jarrold, Caroline Chick

    2016-02-01

    Results of a systematic comparison of the MoxOy- + H2O and WxOy- + H2O reaction rate coefficients are reported and compared to previous experimental and computational studies on these reactions. WxOy- clusters undergo more direct oxidation by water to yield WxOy+1- + H2, while for MoxOy- clusters, production of MoxOyH2- (trapped intermediates in the oxidation reaction) is comparatively more prevalent. However, MoxOy- clusters generally have higher rate coefficients than analogous WxOy- clusters if MoxOy+1H2- formation is included. Results of calculations on the M2Oy- + H2O (M = Mo, W; y = 4, 5) reaction entrance channel are reported. They include charge-dipole complexes formed from long-range interactions, and the requisite conversion to a Lewis acid-base complex that leads to MxOy+1H2- formation. The results predict that the Lewis acid-base complex is more strongly bound for MoxOy- clusters than for WxOy- clusters. The calculated free energies along this portion of the reaction path are also consistent with the modest anti-Arrhenius temperature dependence measured for most MoxOy- + H2O reactions, and the WxOy- + H2O reaction rate coefficients generally being constant over the temperature range sampled in this study. For clusters that exhibit evidence of both water addition and oxidation reactions, increasing the temperature increases the branching ratio toward oxidation for both species. A more direct reaction path to H2 production may therefore become accessible at modest temperatures for certain cluster stoichiometries and structures.

  19. Synthesis, characterization, cytotoxic and antitubercular activities of new gold(I) and gold(III) complexes containing ligands derived from carbohydrates.

    Science.gov (United States)

    Chaves, Joana Darc Souza; Damasceno, Jaqueline Lopes; Paula, Marcela Cristina Ferreira; de Oliveira, Pollyanna Francielli; Azevedo, Gustavo Chevitarese; Matos, Renato Camargo; Lourenço, Maria Cristina S; Tavares, Denise Crispim; Silva, Heveline; Fontes, Ana Paula Soares; de Almeida, Mauro Vieira

    2015-10-01

    Novel gold(I) and gold(III) complexes containing derivatives of D-galactose, D-ribose and D-glucono-1,5-lactone as ligands were synthesized and characterized by IR, (1)H, and (13)C NMR, high resolution mass spectra and cyclic voltammetry. The compounds were evaluated in vitro for their cytotoxicity against three types of tumor cells: cervical carcinoma (HeLa) breast adenocarcinoma (MCF-7) and glioblastoma (MO59J) and one non-tumor cell line: human lung fibroblasts (GM07492A). Their antitubercular activity was evaluated as well expressed as the minimum inhibitory concentration (MIC90) in μg/mL. In general, the gold(I) complexes were more active than gold(III) complexes, for example, the gold(I) complex (1) was about 8.8 times and 7.6 times more cytotoxic than gold(III) complex (8) in MO59J and MCF-7 cells, respectively. Ribose and alkyl phosphine derivative complexes were more active than galactose and aryl phosphine complexes. The presence of a thiazolidine ring did not improve the cytotoxicity. The study of the cytotoxic activity revealed effective antitumor activities for the gold(I) complexes, being more active than cisplatin in all the tested tumor cell lines. Gold(I) compounds (1), (2), (3), (4) and (6) exhibited relevant antitubercular activity even when compared with first line drugs such as rifampicin.

  20. Cellular delivery of quantum dot-bound hybridization probe for detection of intracellular pre-microRNA using chitosan/poly(γ-glutamic acid complex as a carrier.

    Directory of Open Access Journals (Sweden)

    Yao Geng

    Full Text Available A quantum dot (QD-bound hybridization probe was designed for detection of intracellular pre-miRNA using chitosan (CS/poly(γ-glutamic acid (γ-PGA complex as a gene vector. The probe was prepared by assembling thiolated RNA to gold nanoparticle (Au NP via Au-S bond and then binding 3'-end amine of the RNA to the carboxy group capped on quantum dot surface. The QD-RNA-Au NP probe was assembled on the vector by mixing with aqueous γ-PGA solution and then CS solution to construct a gene delivery system for highly effective cellular uptake and delivery. After the probe was released from CS/γ-PGA complex to the cytoplasm by electrostatic repulsion at intracellular pH, it hybridized with pre-miRNA precursor as target. The formed product was then cleaved by RNase III Dicer, leading to the separation of QDs from Au NPs and fluorescence emission of QDs, which could be detected by confocal microscopic imaging to monitor the amount of the intracellular pre-miRNA precursor. The in vitro assays revealed that the QD-RNA-Au NP was a robust, sensitive and selective probe for quantitative detection of target pre-miRNA. Using MDA-MB231 and MCF-7 breast cancer cells as models, the relative amount of pre-miRNA let-7a could be successfully compared. Since the amount of miRNA is related to the progress and prognosis of cancer, this strategy could be expected to hold promising application potential in medical research and clinical diagnostics.

  1. Cellular delivery of quantum dot-bound hybridization probe for detection of intracellular pre-microRNA using chitosan/poly(γ-glutamic acid) complex as a carrier.

    Science.gov (United States)

    Geng, Yao; Lin, Dajie; Shao, Lijia; Yan, Feng; Ju, Huangxian

    2013-01-01

    A quantum dot (QD)-bound hybridization probe was designed for detection of intracellular pre-miRNA using chitosan (CS)/poly(γ-glutamic acid) (γ-PGA) complex as a gene vector. The probe was prepared by assembling thiolated RNA to gold nanoparticle (Au NP) via Au-S bond and then binding 3'-end amine of the RNA to the carboxy group capped on quantum dot surface. The QD-RNA-Au NP probe was assembled on the vector by mixing with aqueous γ-PGA solution and then CS solution to construct a gene delivery system for highly effective cellular uptake and delivery. After the probe was released from CS/γ-PGA complex to the cytoplasm by electrostatic repulsion at intracellular pH, it hybridized with pre-miRNA precursor as target. The formed product was then cleaved by RNase III Dicer, leading to the separation of QDs from Au NPs and fluorescence emission of QDs, which could be detected by confocal microscopic imaging to monitor the amount of the intracellular pre-miRNA precursor. The in vitro assays revealed that the QD-RNA-Au NP was a robust, sensitive and selective probe for quantitative detection of target pre-miRNA. Using MDA-MB231 and MCF-7 breast cancer cells as models, the relative amount of pre-miRNA let-7a could be successfully compared. Since the amount of miRNA is related to the progress and prognosis of cancer, this strategy could be expected to hold promising application potential in medical research and clinical diagnostics. PMID:23762388

  2. Detection of gear cracks in a complex gearbox of wind turbines using supervised bounded component analysis of vibration signals collected from multi-channel sensors

    Science.gov (United States)

    Li, Zhixiong; Yan, Xinping; Wang, Xuping; Peng, Zhongxiao

    2016-06-01

    In the complex gear transmission systems, in wind turbines a crack is one of the most common failure modes and can be fatal to the wind turbine power systems. A single sensor may suffer with issues relating to its installation position and direction, resulting in the collection of weak dynamic responses of the cracked gear. A multi-channel sensor system is hence applied in the signal acquisition and the blind source separation (BSS) technologies are employed to optimally process the information collected from multiple sensors. However, literature review finds that most of the BSS based fault detectors did not address the dependence/correlation between different moving components in the gear systems; particularly, the popular used independent component analysis (ICA) assumes mutual independence of different vibration sources. The fault detection performance may be significantly influenced by the dependence/correlation between vibration sources. In order to address this issue, this paper presents a new method based on the supervised order tracking bounded component analysis (SOTBCA) for gear crack detection in wind turbines. The bounded component analysis (BCA) is a state of art technology for dependent source separation and is applied limitedly to communication signals. To make it applicable for vibration analysis, in this work, the order tracking has been appropriately incorporated into the BCA framework to eliminate the noise and disturbance signal components. Then an autoregressive (AR) model built with prior knowledge about the crack fault is employed to supervise the reconstruction of the crack vibration source signature. The SOTBCA only outputs one source signal that has the closest distance with the AR model. Owing to the dependence tolerance ability of the BCA framework, interfering vibration sources that are dependent/correlated with the crack vibration source could be recognized by the SOTBCA, and hence, only useful fault information could be preserved in

  3. NMR investigations of protein-carbohydrate interactions : Studies on the relevance of Trp/Tyr variations in lectin binding sites as deduced from titration microcalorimetry and NMR studies on hevein domains. Determination of the NMR structure of the complex between pseudohevein and N,N ',N ''-triacetylchitotriose

    NARCIS (Netherlands)

    Asensio, JL; Siebert, HC; von der Lieth, CW; Laynez, J; Bruix, M; Soedjanaamadja, UM; Beintema, JJ; Canada, FJ; Gabius, HJ; Jimenez-Barbero, J

    2000-01-01

    Model studies on lectins and their interactions with carbohydrate ligands in solution are essential to gain insights into the driving forces for complex formation and to optimize programs for computer simulations. The specific interaction of pseudohevein with N,N',N"-triacetylchitotriose has been an

  4. Bounded Rationality

    Directory of Open Access Journals (Sweden)

    Ballester Pla, Coralio

    2012-03-01

    Full Text Available The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models. The goal of this paper is to illustrate the difficulties involved in providing a correct definition of what a rational (or irrational agent is. In this paper we describe two frameworks that employ different approaches for analyzing bounded rationality. The first is a spatial segregation set-up that encompasses two optimization methodologies: backward induction and forward induction. The main result is that, even under the same state of knowledge, rational and non-rational agents may match their actions. The second framework elaborates on the relationship between irrationality and informational restrictions. We use the beauty contest (Nagel, 1995 as a device to explain this relationship.

    La observación del comportamiento de los agentes económicos tanto en el laboratorio como en la vida real justifica que la racionalidad acotada sea un supuesto aceptado en numerosos modelos socio-económicos. El objetivo de este artículo es ilustrar las dificultades que conlleva una correcta definición de qué es un agente racional (irracional. En este artículo se describen dos marcos que emplean diferentes metodologías para analizar la racionalidad acotada. El primero es un modelo de segregación espacial donde se contrastan dos metodologías de optimización: inducción hacia atrás y hacia adelante. El resultado principal es que, incluso con el mismo nivel de conocimiento, tanto agentes racionales como irracionales podrían coincidir en sus acciones. El segundo marco trabaja sobre la relación entre irracionalidad y restricción de información. Se utiliza el juego llamado “beauty contest” (Nagel 1995 como mecanismo para explicar dicha relación.

  5. The binding of platinum hexahalides (Cl, Br and I) to hen egg-white lysozyme and the chemical transformation of the PtI{sub 6} octahedral complex to a PtI{sub 3} moiety bound to His15

    Energy Technology Data Exchange (ETDEWEB)

    Tanley, Simon W. M.; Starkey, Laurina-Victoria; Lamplough, Lucinda; Kaenket, Surasek; Helliwell, John R., E-mail: john.helliwell@manchester.ac.uk [University of Manchester, Brunswick Street, Manchester M13 9PL (United Kingdom)

    2014-08-29

    The platinum hexahalides have an octahedral arrangement of six halogen atoms bound to a Pt centre, thus having an octahedral shape that could prove to be useful in interpreting poor electron-density maps. In a detailed characterization, PtI{sub 6} chemically transformed to a square-planar PtI{sub 3} complex bound to the N{sup δ} atom of His15 of HEWL was also observed, which was not observed for PtBr{sub 6} or PtCl{sub 6}. This study examines the binding and chemical stability of the platinum hexahalides K{sub 2}PtCl{sub 6}, K{sub 2}PtBr{sub 6} and K{sub 2}PtI{sub 6} when soaked into pre-grown hen egg-white lysozyme (HEWL) crystals as the protein host. Direct comparison of the iodo complex with the chloro and bromo complexes shows that the iodo complex is partly chemically transformed to a square-planar PtI{sub 3} complex bound to the N{sup δ} atom of His15, a chemical behaviour that is not exhibited by the chloro or bromo complexes. Each complex does, however, bind to HEWL in its octahedral form either at one site (PtI{sub 6}) or at two sites (PtBr{sub 6} and PtCl{sub 6}). As heavy-atom derivatives of a protein, the octahedral shape of the hexahalides could be helpful in cases of difficult-to-interpret electron-density maps as they would be recognisable ‘objects’.

  6. Effects of Carbohydrate Consumption Case Study: carbohydrates in Bread

    Directory of Open Access Journals (Sweden)

    Neacsu N.A.

    2014-12-01

    Full Text Available Carbohydrates perform numerous roles in living organisms; they are an important source of energy. The body uses carbohydrates to make glucose which is the fuel that gives it energy and helps keep everything going. However, excess carbohydrate consumption has negative health effects. Bread is a basic product in our nutrition and it also is a product with a high content of carbohydrates. So, it is important to find out more information on bread and on the recommended bread type best for consumption.

  7. Lactobacillus plantarum gene clusters encoding putative cell-surface protein complexes for carbohydrate utilization are conserved in specific gram-positive bacteria

    Directory of Open Access Journals (Sweden)

    Muscariello Lidia

    2006-05-01

    D proteins form cell-surface protein complexes and play a role in carbon source acquisition. Primary occurrence in plant-associated gram-positive bacteria suggests a possible role in degradation and utilization of plant oligo- or poly-saccharides.

  8. Separation and quantification of microalgal carbohydrates.

    Science.gov (United States)

    Templeton, David W; Quinn, Matthew; Van Wychen, Stefanie; Hyman, Deborah; Laurens, Lieve M L

    2012-12-28

    Structural carbohydrates can constitute a large fraction of the dry weight of algal biomass and thus accurate identification and quantification is important for summative mass closure. Two limitations to the accurate characterization of microalgal carbohydrates are the lack of a robust analytical procedure to hydrolyze polymeric carbohydrates to their respective monomers and the subsequent identification and quantification of those monosaccharides. We address the second limitation, chromatographic separation of monosaccharides, here by identifying optimum conditions for the resolution of a synthetic mixture of 13 microalgae-specific monosaccharides, comprised of 8 neutral, 2 amino sugars, 2 uronic acids and 1 alditol (myo-inositol as an internal standard). The synthetic 13-carbohydrate mix showed incomplete resolution across 11 traditional high performance liquid chromatography (HPLC) methods, but showed improved resolution and accurate quantification using anion exchange chromatography (HPAEC) as well as alditol acetate derivatization followed by gas chromatography (for the neutral- and amino-sugars only). We demonstrate the application of monosaccharide quantification using optimized chromatography conditions after sulfuric acid analytical hydrolysis for three model algae strains and compare the quantification and complexity of monosaccharides in analytical hydrolysates relative to a typical terrestrial feedstock, sugarcane bagasse. PMID:23177152

  9. Measurement of homonuclear three-bond J(HNH{alpha}) coupling constants in unlabeled peptides complexed with labeled proteins: Application to a decapeptide inhibitor bound to the proteinase domain of the NS3 protein of hepatitis C virus (HCV)

    Energy Technology Data Exchange (ETDEWEB)

    Cicero, Daniel O.; Barbato, Gaetano; Koch, Uwe; Ingallinella, Paolo; Bianchi, Elisabetta; Sambucini, Sonia; Neddermann, Petra; De Francesco, Raffaele; Pessi, Antonello; Bazzo, Renzo

    2001-05-15

    A new isotope-filtered experiment has been designed to measure homonuclear three-bond J(H{sup N}H{sup {alpha}}) coupling constants of unlabeled peptides complexed with labeled proteins. The new experiment is based on the 3D HNHA pulse scheme, and belongs to the 'quantitative J-correlation' type. It has been applied to a decapeptide inhibitor bound to the proteinase domain of the NS3 protein of human hepatitis C virus (HCV)

  10. The Carbohydrate-linked Phosphorylcholine of the Parasitic Nematode Product ES-62 Modulates Complement Activation.

    Science.gov (United States)

    Ahmed, Umul Kulthum; Maller, N Claire; Iqbal, Asif J; Al-Riyami, Lamyaa; Harnett, William; Raynes, John G

    2016-05-27

    Parasitic nematodes manufacture various carbohydrate-linked phosphorylcholine (PCh)-containing molecules, including ES-62, a protein with an N-linked glycan terminally substituted with PCh. The PCh component is biologically important because it is required for immunomodulatory effects. We showed that most ES-62 was bound to a single protein, C-reactive protein (CRP), in normal human serum, displaying a calcium-dependent, high-avidity interaction and ability to form large complexes. Unexpectedly, CRP binding to ES-62 failed to efficiently activate complement as far as the C3 convertase stage in comparison with PCh-BSA and PCh-containing Streptococcus pneumoniae cell wall polysaccharide. C1q capture assays demonstrated an ES-62-CRP-C1q interaction in serum. The three ligands all activated C1 and generated C4b to similar extents. However, a C2a active site was not generated following ES-62 binding to CRP, demonstrating that C2 cleavage was far less efficient for ES-62-containing complexes. We proposed that failure of C2 cleavage was due to the flexible nature of carbohydrate-bound PCh and that reduced proximity of the C1 complex was the reason that C2 was poorly cleaved. This was confirmed using synthetic analogues that were similar to ES-62 only in respect of having a flexible PCh. Furthermore, ES-62 was shown to deplete early complement components, such as the rate-limiting C4, following CRP interaction and thereby inhibit classical pathway activation. Thus, flexible PCh-glycan represents a novel mechanism for subversion of complement activation. These data illustrate the importance of the rate-limiting C4/C2 stage of complement activation and reveal a new addition to the repertoire of ES-62 immunomodulatory mechanisms with possible therapeutic applications. PMID:27044740

  11. Impact of Dietary Carbohydrate and Protein Levels on Carbohydrate Metabolism

    Science.gov (United States)

    Lasker, Denise Ann

    2009-01-01

    The goal of this dissertation was to investigate the impact of changing dietary carbohydrate (CARB) intakes within recommended dietary guidelines on metabolic outcomes specifically associated with glycemic regulations and carbohydrate metabolism. This research utilized both human and animal studies to examine changes in metabolism across a wide…

  12. Polynomially Bounded Sequences and Polynomial Sequences

    Directory of Open Access Journals (Sweden)

    Okazaki Hiroyuki

    2015-09-01

    Full Text Available In this article, we formalize polynomially bounded sequences that plays an important role in computational complexity theory. Class P is a fundamental computational complexity class that contains all polynomial-time decision problems [11], [12]. It takes polynomially bounded amount of computation time to solve polynomial-time decision problems by the deterministic Turing machine. Moreover we formalize polynomial sequences [5].

  13. Exercise and Regulation of Carbohydrate Metabolism.

    Science.gov (United States)

    Mul, Joram D; Stanford, Kristin I; Hirshman, Michael F; Goodyear, Laurie J

    2015-01-01

    Carbohydrates are the preferred substrate for contracting skeletal muscles during high-intensity exercise and are also readily utilized during moderate intensity exercise. This use of carbohydrates during physical activity likely played an important role during the survival of early Homo sapiens, and genes and traits regulating physical activity, carbohydrate metabolism, and energy storage have undoubtedly been selected throughout evolution. In contrast to the life of early H. sapiens, modern lifestyles are predominantly sedentary. As a result, intake of excessive amounts of carbohydrates due to the easy and continuous accessibility to modern high-energy food and drinks has not only become unnecessary but also led to metabolic diseases in the face of physical inactivity. A resulting metabolic disease is type 2 diabetes, a complex endocrine disorder characterized by abnormally high concentrations of circulating glucose. This disease now affects millions of people worldwide. Exercise has beneficial effects to help control impaired glucose homeostasis with metabolic disease, and is a well-established tool to prevent and combat type 2 diabetes. This chapter focuses on the effects of exercise on carbohydrate metabolism in skeletal muscle and systemic glucose homeostasis. We will also focus on the molecular mechanisms that mediate the effects of exercise to increase glucose uptake in skeletal muscle. It is now well established that there are different proximal signaling pathways that mediate the effects of exercise and insulin on glucose uptake, and these distinct mechanisms are consistent with the ability of exercise to increase glucose uptake in the face of insulin resistance in people with type 2 diabetes. Ongoing research in this area is aimed at defining the precise mechanism by which exercise increases glucose uptake and insulin sensitivity and the types of exercise necessary for these important health benefits.

  14. STUDY OF CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE OVER A BIDENTATE POLYMER BOUND CIS-DICARBONYLRHODIUM COMPLEX AS CATALYST

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaojun; LIU Zhongyang; PAN Pinglai; YUAN Guoqing

    1996-01-01

    Copolymer of 2-vinylpyridine and vinylacetate coordinated with dicarbonylrhodium used as a catalyst for carbonylation of methanol to acetic acid and anhydride has been studied. The structural characteristics of the copolymer ligand and complex, and the influences of the reaction conditions on the carbonylation catalyzed by this polymer complex have been investigated. In comparison with small molecule catalyst of Rh complex, the bidentate copolymer coordinated complex has better thermal stability. The reaction mechanism of the carbonylation reaction is also illustrated.

  15. Carbohydrates and Diabetes (For Parents)

    Science.gov (United States)

    ... of diet foods. These foods may contain extra sugar as a substitute for fat calories. Try to include your child or teen as you evaluate and select healthy carbohydrate-containing foods. With ... blood sugar. By taking a smart approach to balancing carbohydrates, ...

  16. Galacturonosyltransferase (GAUT)1 and GAUT7 are the core of a plant cell wall pectin biosynthetic homogalacturonan:galacturonosyltransferase complex

    OpenAIRE

    Atmodjo, Melani A.; Sakuragi, Yumiko; Zhu, Xiang; Burrell, Amy J.; Mohanty, Sushree S; Atwood, James A.; Orlando, Ron; Henrik V. Scheller; Mohnen, Debra

    2011-01-01

    Plant cell wall pectic polysaccharides are arguably the most complex carbohydrates in nature. Progress in understanding pectin synthesis has been slow due to its complex structure and difficulties in purifying and expressing the low-abundance, Golgi membrane-bound pectin biosynthetic enzymes. Arabidopsis galacturonosyltransferase (GAUT) 1 is an α-1,4-galacturonosyltransferase (GalAT) that synthesizes homogalacturonan (HG), the most abundant pectic polysaccharide. We now show that GAUT1 functi...

  17. Oral carbohydrate loading with 18% carbohydrate beverage alleviates insulin resistance.

    Science.gov (United States)

    Tamura, Takahiko; Yatabe, Tomoaki; Kitagawa, Hiroyuki; Yamashita, Koichi; Hanazaki, Kazuhiro; Yokoyama, Masataka

    2013-01-01

    Preoperative 12.6% oral carbohydrate loading is an element of the Enhanced Recovery After Surgery (ERAS) protocol aimed at alleviating postoperative insulin resistance; however, in Japan, beverages with 18% carbohydrate content are generally used for preoperative carbohydrate loading. We investigated the effect of 18% carbohydrate loading on alleviating insulin resistance. Six healthy volunteers participated in this crossover-randomized study and were segregated into 2 groups: volunteers in the carbohydrate-loading group (group A) who fasted from after 9 pm and ingested 375 mL of a beverage containing 18% carbohydrate (ArginaidWaterTM; Nestle, Tokyo, Japan) between 9 pm and 12 pm, and 250 mL of the same liquid at 6:30 am. Volunteers in control group (group B) drank only water. At 8:30 am, a hyperinsulinemic normoglycemic clamp was initiated. Glucose infusion rate (GIR) and levels of ketone bodies and cytokines (IL-1β, IL-6, and TNF-α) before clamping were evaluated. p<0.05 was considered statistically significant. Levels of blood glucose, insulin, and cytokines at the start of the clamp were similar in both the groups. The GIR in group A was significantly higher than that in group B (11.5±2.4 vs 6.2±2.2 mg/kg/min, p=0.005), while blood ketone body levels were significantly lower in group A (22±4 vs 124±119 μmol/L, p=0.04). Preoperative 18% carbohydrate loading could prevent the decrease in insulin sensitivity and suppress catabolism in healthy volunteers. Thus, carbohydrate loading with a beverage with 18% carbohydrate content might contribute to improvements in perioperative management. PMID:23353610

  18. Correlation between carbohydrate structures on the envelope glycoprotein gp120 of HIV-1 and HIV-2 and syncytium inhibition with lectins

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C M; Nielsen, C;

    1989-01-01

    The binding of 13 different lectins to gp120 partially purified from two HIV-1 isolates and one HIV-2 isolate was studied by in situ staining on electrophoretically separated and electroblotted HIV antigens. The lectins concanavalin A, wheat germ agglutinin, Lens culinaris agglutinin, Vicia faba...... agglutinin, Pisum sativum agglutinin and phytohaem(erythro)agglutinin bound to gp120 of all three isolates. The carbohydrate of gp120 recognized by lectins was thus arranged in at least four types of glycans: a high mannose type glycan, a bisected hybrid or complex type glycan, a biantennary fucosylated...

  19. Biophysical insights into the intercalative interaction of surfactant cobalt(III) complexes of certain diimine ligands bound to yeast tRNA: Effects of hydrophobicity

    Science.gov (United States)

    Nagaraj, Karuppiah; Sakthinathan, Subramanian; Arunachalam, Sankaralingam

    2015-08-01

    The interaction of two surfactant cobalt(III) complexes, cis-[Co(ip)2(DA)2](ClO4)3 1 and cis-[Co(dpq)2(DA)2](ClO4)3 2 where ip = imidazo[4,5-f][1,10]phenanthroline and dpq = dipyrido[3,2-d:2‧-3‧-f]quinoxaline with yeast tRNA have been explored by using electronic absorption, competitive binding, electrochemical studies and viscosity measurements. The results suggest that these complexes can bind to tRNA by intercalation. The presence of hydrophobic diimine ligand and the long aliphatic double chains of these complexes facilitate its intercalative interaction with the hydrophobic interior of the tRNA. The extent of tRNA binding of complex 2 has greater affinity than that of complex containing imidazo[4,5-f][1,10]phenanthroline ligands.

  20. Biophysical insights into the intercalative interaction of surfactant cobalt(III) complexes of certain diimine ligands bound to yeast tRNA: Effects of hydrophobicity.

    Science.gov (United States)

    Nagaraj, Karuppiah; Sakthinathan, Subramanian; Arunachalam, Sankaralingam

    2015-08-01

    The interaction of two surfactant cobalt(III) complexes, cis-[Co(ip)₂(DA)₂](ClO₄)₃ 1 and cis-[Co(dpq)₂(DA)₂](ClO₄)₃ 2 where ip=imidazo[4,5-f][1,10]phenanthroline and dpq=dipyrido[3,2-d:2'-3'-f]quinoxaline with yeast tRNA have been explored by using electronic absorption, competitive binding, electrochemical studies and viscosity measurements. The results suggest that these complexes can bind to tRNA by intercalation. The presence of hydrophobic diimine ligand and the long aliphatic double chains of these complexes facilitate its intercalative interaction with the hydrophobic interior of the tRNA. The extent of tRNA binding of complex 2 has greater affinity than that of complex containing imidazo[4,5-f][1,10]phenanthroline ligands.

  1. 多糖存在下异丁香酚的脱氢聚合及LCC的形成%Dehydrogenation Polymerization of Isoeugenol and Formation of Lignin-carbohydrate Complexes with Presence of Polysaccharide

    Institute of Scientific and Technical Information of China (English)

    叶哲孜; 谢益民; 吴晨曦; 王鹏; 乐喜

    2016-01-01

    Dehydrogenation polymer ( DHP ) and lignin-carbohydrate complexes ( LCC ) were prepared using isoeugenol as precursor of lignin biosynthesis by mixing method. The chemical structure of the polymers was analyzed with Fourier transform infrared spectroscopy ( FT-IR ) and 13C NMR spectroscopy. The dehydrogenation polymerization reaction between DHP and polysaccharide ( arabinogalactan) using the laccase as catalyst was investigated. The results showed that isoeugenol could be polymerized with arabinogalactan to form DHP and LCC catalyzed by laccase. The analysis of the 13C NMR spectra also indicated that the DHP was mainly composed ofβ-O-4,β-β,β-5 andβ-1 subunits. The information from the aromatic carbons of lignin and resonance signals of the arabinogalactan could be found in the 13C NMR spectrum of the LCC.%以异丁香酚为木质素生物合成的前驱物,采用混合法合成了木质素脱氢聚合物( DHP)和木质素-碳水化合物复合体( LCC),同时采用红外光谱、13C NMR波谱分析聚合产物的结构,探讨了漆酶催化脱氢聚合过程中形成的DHP与多糖(阿拉伯半乳聚糖)的聚合反应机理。结果表明:在漆酶的催化作用下,异丁香酚与阿拉伯半乳聚糖发生聚合形成了DHP与LCC,13C NMR波谱结果证实DHP中以β-O-4,β-β,β-5和β-1等结构为主,而LCC的13C NMR谱图中既有来自木质素的芳香族碳原子的信息,也有来自阿拉伯半乳聚糖的共振信号。

  2. Capacity Bounds for Parallel Optical Wireless Channels

    KAUST Repository

    Chaaban, Anas

    2016-01-01

    A system consisting of parallel optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. Under perfect channel-state information at the transmitter (CSIT), the bounds have to be optimized with respect to the power allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the KKT conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose low-complexity power allocation algorithms which are nearly optimal. The optimized capacity lower bound nearly coincides with the capacity at high SNR. Without CSIT, our capacity bounds lead to upper and lower bounds on the outage probability. The outage probability bounds meet at high SNR. The system with average and peak intensity constraints is also discussed.

  3. Transition metals in carbohydrate chemistry

    DEFF Research Database (Denmark)

    Madsen, Robert

    1997-01-01

    This review describes the application of transition metal mediated reactions in carbohydrate synthesis. The different metal mediated transformations are divided into reaction types and illustrated by various examples on monosaccharide derivatives. Carbon-carbon bond forming reactions are further ...

  4. Carbohydrates, Sugar, and Your Child

    Science.gov (United States)

    ... are: simple carbohydrates (or simple sugars): these include fructose, glucose, and lactose, which also are found in nutritious ... look at the ingredient list for sugar, corn syrup or sweetener, dextrose, fructose, honey, or molasses, to name just a few. ...

  5. Method Optimization for Rapid Measurement of Carbohydrates in Plasma by Liquid Chromatography Tandem Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ductoan; Yu, Jondong; Mho, Sunil; Lee, Gwang [Ajou Univ., Suwon (Korea, Republic of); Lee, Haelee; Paik, Manjeong [Sangdosijang Pharmacy, Seoul (Korea, Republic of); Yee, Sungtae [Sunchon National Univ., Suncheon (Korea, Republic of)

    2013-05-15

    In conclusion, the developed HPLC coupled with ESI-MS was a powerful technique for the separation and characterization of carbohydrates by either SIM or MRM mode. The present method will be useful for the monitoring of carbohydrate profile in biological fluids from various diseases including diabetic ketoacidosis, hypoglycemia and hyperosmolar coma. Carbohydrates are one of the most abundant classes of organic compounds in nature, which not only constitute complex biomolecules in human and animals but are also distributed in plants and bacteria.

  6. Investigations of Reactive Carbohydrates in Glycosidic Bond Formation and Degradation

    DEFF Research Database (Denmark)

    Heuckendorff, Mads

    was to develop new synthetic methods to evolve the field of synthetic carbohydrate chemistry. In addition, easy methods for obtaining complex oligosaccharides are needed to accommodate biochemical research and drug development. Furthermore, the aim was to shed light on the complex mechanisms of glycosylation...... and hy rolysis of glycosides. This mechanistic insight can then be used to develop new synthetic methods and obtain a better understanding of already existing methods. In Chapter 1 general aspects of synthetic carbohydrate chemistry is described with an emphasis on elements that affects reactivity...

  7. Racemic carbohydrates - fact or fiction?

    DEFF Research Database (Denmark)

    Senning, Alexander Erich Eugen

    2007-01-01

    Chemical Abstracts Service has developed unsound practices in the naming and handling of simple carbohydrates such as aldopentoses 1, aldohexoses 2, and ketohexoses 3. Typically, the common name glucose is sometimes, inappropriately, interpreted as meaning DL-glucose DL-2d. Thus, a considerable...... number of CA names and registry numbers have been created for non-existing racemic carbohydrates and linked to irrelevant references which, moreover, in many cases cannot be retrieved by the SciFinder Scholar program....

  8. Carbohydrate drugs: current status and development prospect.

    Science.gov (United States)

    Zhang, Yan; Wang, Fengshan

    2015-04-01

    In recent years, there has been a great effort devoted to the investigation of the roles of carbohydrates in various essential biological processes and the development of carbohydrates to therapeutic drugs. This review summarizes the carbohydrate drugs which have been recorded in several pharmacopoeias, marketed, and under development. A prospect of the future development of carbohydrate drugs is discussed as well.

  9. "Lantern-Shaped" Platinum(III) Complexes with Axially Bound 9-Ethylguanine or 1-Methylcytosine (L) of General Formula [Pt(2){HN=C(Bu)O}(4)L(2)](NO(3))(2).

    Science.gov (United States)

    Pacifico, Concetta; Intini, Francesco Paolo; Nushi, Fiorentin; Natile, Giovanni

    2010-01-01

    The synthesis, NMR characterization, and X-ray crystallography of "lantern-shaped" platinum(III) complexes with four pivaloamidate bridging ligands and two 9-ethylguanines (9-EtG) or 1-methylcytosines (1-MeC) in axial positions are reported: cis-N(2)O(2)-[Pt(2){HN=C(Bu(t))O}(4)(9-EtG)(2)](NO(3))(2) and cis-N(2)O(2)-[Pt(2){HN=C(Bu(t))O}(4)(1-MeC)(2)](NO(3))(2). The last complex is, to the best of our knowledge, the first dinuclear compound of platinum(III) with axially bound 1-MeC.

  10. “Lantern-Shaped” Platinum(III Complexes with Axially Bound 9-Ethylguanine or 1-Methylcytosine (L of General Formula [Pt2{HN=C(ButO}4L2](NO32

    Directory of Open Access Journals (Sweden)

    Concetta Pacifico

    2010-01-01

    Full Text Available The synthesis, NMR characterization, and X-ray crystallography of “lantern-shaped” platinum(III complexes with four pivaloamidate bridging ligands and two 9-ethylguanines (9-EtG or 1-methylcytosines (1-MeC in axial positions are reported: cis-N2O2-[Pt2{HN=C(ButO}4(9-EtG2](NO32 and cis-N2O2-[Pt2{HN=C(ButO}4(1-MeC2](NO32. The last complex is, to the best of our knowledge, the first dinuclear compound of platinum(III with axially bound 1-MeC.

  11. Scattering by bound nucleons

    International Nuclear Information System (INIS)

    Scattering of a particle by bound nucleons is discussed. Effects of nucleons that are bound in a nucleus are taken as a structure function. The way how to calculate the structure function is given. (author)

  12. On the range of completely bounded maps

    Directory of Open Access Journals (Sweden)

    Richard I. Loebl

    1978-01-01

    Full Text Available It is shown that if every bounded linear map from a C*-algebra α to a von Neumann algebra β is completely bounded, then either α is finite-dimensional or β⫅⊗Mn, where is a commutative von Neumann algebra and Mn is the algebra of n×n complex matrices.

  13. Quantum Lower Bounds by Entropy Numbers

    OpenAIRE

    Heinrich, Stefan

    2006-01-01

    We use entropy numbers in combination with the polynomial method to derive a new general lower bound for the n-th minimal error in the quantum setting of information-based complexity. As an application, we improve some lower bounds on quantum approximation of embeddings between finite dimensional L_p spaces and of Sobolev embeddings.

  14. Lanthanide(III) complexes of aminoethyl-DO3A as PARACEST contrast agents based on decoordination of the weakly bound amino group.

    Science.gov (United States)

    Krchová, Tereza; Kotek, Jan; Jirák, Daniel; Havlíčková, Jana; Císařová, Ivana; Hermann, Petr

    2013-11-28

    2-Aminoethyl DOTA analogues with unsubstituted (H3L1), monomethylated (H3L2) and dimethylated (H3L3) amino groups were prepared by improved synthetic procedures. Their solid-state structures exhibit an extensive system of intramolecular hydrogen bonds, which is probably present in solution and leads to the rather high value of the last dissociation constant. The protonation sequence of H3L1 in solution corresponds to that found in the solid state. The stability constants of the H3L1 complexes with La(3+) and Gd(3+) (20.02 and 22.23, respectively) are similar to those of DO3A and the reduction of the pK(A) value of the pendant amino group from 10.51 in the free ligand to 6.06 and 5.83 in the La(3+) and Gd(3+) complexes, respectively, points to coordination of the amino group. It was confirmed in the solid state structure of the [Yb(L1)] complex, where disorder between the SA' and TSA' isomers was found. A similar situation is expected in solution, where a fast equilibration among the isomers hampers the unambiguous determination of the isomer ratio in solution. The PARACEST effect was observed in Eu(III)-H3L1/H3L2 and Yb(III)-H3L1/H3L2 complexes, being dependent on pH in the region of 4.5-7.5 and pH-independent in more alkaline solutions. The decrease of the PARACEST effect parallels with the increasing abundance of the complex protonated species, where the pendant amino group is not coordinating. Surprisingly, a small PARACEST effect was also observed in solutions of Eu(III)/Yb(III)-H3L3 complexes, where the pendant amino group is dimethylated. The effect is detectable in a narrow pH region, where both protonated and deprotonated complex species are present in equilibrium. The data points to the new mechanism of the PARACEST effect, where the slow coordination-decoordination of the pendant amine is coupled with the fast proton exchange between the free amino group and bulk water mediates the magnetization transfer. The pH-dependence of the effect was proved to be

  15. Improved Range Searching Lower Bounds

    DEFF Research Database (Denmark)

    Larsen, Kasper Green; Nguyen, Huy L.

    2012-01-01

    range reporting problem. In approximate simplex range reporting, points that lie within a distance of ε ⋅ Diam(s) from the border of a query simplex s, are free to be included or excluded from the output, where ε ≥ 0 is an input parameter to the range searching problem. We prove our lower bounds......Table of Contents -------------------------------------------------------------------------------- In this paper we present a number of improved lower bounds for range searching in the pointer machine and the group model. In the pointer machine, we prove lower bounds for the approximate simplex...... by constructing a hard input set and query set, and then invoking Chazelle and Rosenberg's [CGTA'96] general theorem on the complexity of navigation in the pointer machine. For the group model, we show that input sets and query sets that are hard for range reporting in the pointer machine (i.e. by Chazelle...

  16. Variance bounding Markov chains

    OpenAIRE

    Roberts, Gareth O.; Jeffrey S. Rosenthal

    2008-01-01

    We introduce a new property of Markov chains, called variance bounding. We prove that, for reversible chains at least, variance bounding is weaker than, but closely related to, geometric ergodicity. Furthermore, variance bounding is equivalent to the existence of usual central limit theorems for all L2 functionals. Also, variance bounding (unlike geometric ergodicity) is preserved under the Peskun order. We close with some applications to Metropolis–Hastings algorithms.

  17. Phosphate inhibits in vitro Fe3+ loading into transferrin by forming a soluble Fe(III)-phosphate complex: a potential non-transferrin bound iron species.

    Science.gov (United States)

    Hilton, Robert J; Seare, Matthew C; Andros, N David; Kenealey, Zachary; Orozco, Catalina Matias; Webb, Michael; Watt, Richard K

    2012-05-01

    In chronic kidney diseases, NTBI can occur even when total iron levels in serum are low and transferrin is not saturated. We postulated that elevated serum phosphate concentrations, present in CKD patients, might disrupt Fe(3+) loading into apo-transferrin by forming Fe(III)-phosphate species. We report that phosphate competes with apo-transferrin for Fe(3+) by forming a soluble Fe(III)-phosphate complex. Once formed, the Fe(III)-phosphate complex is not a substrate for donating Fe(3+) to apo-transferrin. Phosphate (1-10mM) does not chelate Fe(III) from diferric transferrin under the conditions examined. Complexed forms of Fe(3+), such as iron nitrilotriacetic acid (Fe(3+)-NTA), and Fe(III)-citrate are not susceptible to this phosphate complexation reaction and efficiently deliver Fe(3+) to apo-transferrin in the presence of phosphate. This reaction suggests that citrate might play an important role in protecting against Fe(III), phosphate interactions in vivo. In contrast to the reactions of Fe(3+) and phosphate, the addition of Fe(2+) to a solution of apo-transferrin and phosphate lead to rapid oxidation and deposition of Fe(3+) into apo-transferrin. These in vitro data suggest that, in principle, elevated phosphate concentrations can influence the ability of apo-transferrin to bind iron, depending on the oxidation state of the iron.

  18. p53 and cell cycle dependent transcription of kinesin family member 23 (KIF23 is controlled via a CHR promoter element bound by DREAM and MMB complexes.

    Directory of Open Access Journals (Sweden)

    Martin Fischer

    Full Text Available The microtubule-dependent molecular motor KIF23 (Kinesin family member 23 is one of two components of the centralspindlin complex assembled during late stages of mitosis. Formation of this complex is known as an essential step for cytokinesis. Here, we identified KIF23 as a new transcriptional target gene of the tumor suppressor protein p53. We showed that p53 reduces expression of KIF23 on the mRNA as well as the protein level in different cell types. Promoter reporter assays revealed that this repression results from downregulation of KIF23 promoter activity. CDK inhibitor p21(WAF1/CIP1 was shown to be necessary to mediate p53-dependent repression. Furthermore, we identified the highly conserved cell cycle genes homology region (CHR in the KIF23 promoter to be strictly required for p53-dependent repression as well as for cell cycle-dependent expression of KIF23. Cell cycle- and p53-dependent regulation of KIF23 appeared to be controlled by differential binding of DREAM and MMB complexes to the CHR element. With this study, we describe a new mechanism for transcriptional regulation of KIF23. Considering the strongly supporting function of KIF23 in cytokinesis, its p53-dependent repression may contribute to the prevention of uncontrolled cell growth.

  19. p53 and cell cycle dependent transcription of kinesin family member 23 (KIF23) is controlled via a CHR promoter element bound by DREAM and MMB complexes.

    Science.gov (United States)

    Fischer, Martin; Grundke, Inga; Sohr, Sindy; Quaas, Marianne; Hoffmann, Saskia; Knörck, Arne; Gumhold, Catalina; Rother, Karen

    2013-01-01

    The microtubule-dependent molecular motor KIF23 (Kinesin family member 23) is one of two components of the centralspindlin complex assembled during late stages of mitosis. Formation of this complex is known as an essential step for cytokinesis. Here, we identified KIF23 as a new transcriptional target gene of the tumor suppressor protein p53. We showed that p53 reduces expression of KIF23 on the mRNA as well as the protein level in different cell types. Promoter reporter assays revealed that this repression results from downregulation of KIF23 promoter activity. CDK inhibitor p21(WAF1/CIP1) was shown to be necessary to mediate p53-dependent repression. Furthermore, we identified the highly conserved cell cycle genes homology region (CHR) in the KIF23 promoter to be strictly required for p53-dependent repression as well as for cell cycle-dependent expression of KIF23. Cell cycle- and p53-dependent regulation of KIF23 appeared to be controlled by differential binding of DREAM and MMB complexes to the CHR element. With this study, we describe a new mechanism for transcriptional regulation of KIF23. Considering the strongly supporting function of KIF23 in cytokinesis, its p53-dependent repression may contribute to the prevention of uncontrolled cell growth.

  20. Purification of a NifEN protein complex that contains bound molybdenum and a FeMo-Co precursor from an Azotobacter vinelandii DeltanifHDK strain.

    Science.gov (United States)

    Soboh, Basem; Igarashi, Robert Y; Hernandez, Jose A; Rubio, Luis M

    2006-12-01

    The NifEN protein complex serves as a molecular scaffold where some of the steps for the assembly of the iron-molybdenum cofactor (FeMo-co) of nitrogenase take place. A His-tagged version of the NifEN complex has been previously purified and shown to carry two identical [4Fe-4S] clusters of unknown function and a [Fe-S]-containing FeMo-co precursor. We have improved the purification of the his-NifEN protein from a DeltanifHDK strain of Azotobacter vinelandii and have found that the amounts of iron and molybdenum within NifEN were significantly higher than those reported previously. In an in vitro FeMo-co synthesis system with purified components, the NifEN protein served as a source of both molybdenum and a [Fe-S]-containing FeMo-co precursor, showing significant FeMo-co synthesis activity in the absence of externally added molybdate. Thus, the NifEN scaffold protein, purified from DeltanifHDK background, contained the Nif-Bco-derived Fe-S cluster and molybdenum, although these FeMo-co constituents were present at different levels within the protein complex. PMID:17012743

  1. Using Carbohydrate Interaction Assays to Reveal Novel Binding Sites in Carbohydrate Active Enzymes

    DEFF Research Database (Denmark)

    Cockburn, Darrell; Wilkens, Casper; Dilokpimol, Adiphol;

    2016-01-01

    Carbohydrate active enzymes often contain auxiliary binding sites located either on independent domains termed carbohydrate binding modules (CBMs) or as so-called surface binding sites (SBSs) on the catalytic module at a certain distance from the active site. The SBSs are usually critical...... for the activity of their cognate enzyme, though they are not readily detected in the sequence of a protein, but normally require a crystal structure of a complex for their identification. A variety of methods, including affinity electrophoresis (AE), insoluble polysaccharide pulldown (IPP) and surface plasmon...... resonance (SPR) have been used to study auxiliary binding sites. These techniques are complementary as AE allows monitoring of binding to soluble polysaccharides, IPP to insoluble polysaccharides and SPR to oligosaccharides. Here we show that these methods are useful not only for analyzing known binding...

  2. Carbohydrates Through Animation: Preliminary Step

    Directory of Open Access Journals (Sweden)

    J.K. Sugai

    2004-05-01

    Full Text Available Methods of education are changing, so the educational tools must change too. The developmentof the systems of information and communication gave the opportunity to bring new technology tothe learning process. Modern education needs interactive programs that may be available to theacademic community, in order to ease the learning process and sharing of the knowledge. Then,an educational software on Carbohydrates is being developed using concept maps and FLASH-MXanimations program, and approached through six modules. The introduction of Carbohydrates wasmade by the module Carbohydrates on Nature, which shows the animations gures of a teacher andstudents, visiting a farm, identifying the carbohydrates found in vegetables, animals, and microor-ganisms, integrated by links containing short texts to help understanding the structure and functionof carbohydrates. This module was presented, as pilot experiment, to teachers and students, whichdemonstrated satisfaction, and high receptivity, by using animation and interactivitys program asstrategy to biochemistrys education. The present work is part of the project Biochemistry throughanimation, which is having continuity.

  3. New ruthenium nitrosyl complexes with tris(1-pyrazolyl)methane (tpm) and 2,2'-bipyridine (bpy) coligands. Structure, spectroscopy, and electrophilic and nucleophilic reactivities of bound nitrosyl.

    Science.gov (United States)

    Videla, Mariela; Jacinto, Julian S; Baggio, Ricardo; Garland, María T; Singh, Priti; Kaim, Wolfgang; Slep, Leonardo D; Olabe, José A

    2006-10-16

    The new compound [Ru(bpy)(tpm)NO](ClO4)3 [tpm = tris(1-pyrazolyl)methane; bpy = 2,2'-bipyridine] has been prepared in a stepwise procedure that involves the conversion of [Ru(bpy)(tpm)Cl]+ into the aqua and nitro intermediates, followed by acidification. The diamagnetic complex crystallizes to exhibit distorted octahedral geometry around the metal, with the Ru-N(O) bond length 1.774(12) A and the RuNO angle 179.1(12) degrees , typical for a {RuNO}6 description. The [Ru(bpy)(tpm)NO]3+ ion (I) has been characterized by 1H NMR and IR spectroscopies (nu(NO) = 1959 cm(-1)) and through density functional theory calculations. Intense electronic transitions in the 300-350-nm region are assigned through time-dependent (TD)DFT as intraligand pi --> pi for bpy and tpm. The dpi --> pi(bpy) metal-to-ligand charge-transfer transitions appear at higher energies. Aqueous cyclic voltammetric studies show a reversible wave at 0.31 V (vs Ag/AgCl, 3 M Cl-), which shifts to 0.60 V in MeCN, along with the onset of a wave of an irreversible process at -0.2 V. The waves are assigned to the one- and two-electron reductions centered at the NO ligand, leading to species with {RuNO}(7) and {RuNO}(8) configurations, respectively. Controlled potential reduction of I in MeCN led to the [Ru(bpy)(tpm)NO]2+ ion (II), revealing a significant downward shift of nu(NO) to 1660 cm(-1) as well as changes in the electronic absorption bands. II was also characterized by electron paramagnetic resonance, showing an anisotropic signal at 110 K that arises from an S = 1/2 electronic ground state; the g-matrix components and hyperfine coupling tensor resemble the behavior of related {RuNO}7 complexes. Both I and II were characterized through their main reactivity modes, electrophilic and nucleophilic, respectively. The addition of OH- into I generated the nitro complex, with k(OH) = 3.05 x 10(6) M(-1) s(-1) (25 degrees C). This value is among the highest obtained for related nitrosyl complexes and correlates

  4. Protective group strategies in carbohydrate and peptide chemistry

    NARCIS (Netherlands)

    Ali, Asghar

    2010-01-01

    Protecting groups play a key role in the synthesis of complex natural products.This holds especially true for the synthesis of oligosaccharides, of which the monomeric carbohydrate building blocks usually contain up to five different hydroxyl functions. The discrimination of these hydroxyl functions

  5. Advancing Analytical Methods for Characterization of Anionic Carbohydrate Biopolymers

    OpenAIRE

    Langeslay, Derek Joseph

    2013-01-01

    The focus of this dissertation is on the development of improved analytical methods for the characterization of anionic carbohydrate biopolymers. Our goal is to extract important information from complex mixtures of heterogeneous polysaccharides by characterizing their substituent oligosaccharides in terms of monosaccharide composition and primary and secondary structure. This work focuses on the application of two major analytical platforms: spectroscopy and chromatography. The development ...

  6. An intermolecular binding mechanism involving multiple LysM domains mediates carbohydrate recognition by an endopeptidase

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Jaslyn E. M. M. [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus (Denmark); Midtgaard, Søren Roi [University of Copenhagen, Universitetsparken 5, 2100 Copenhagen (Denmark); Gysel, Kira [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus (Denmark); Thygesen, Mikkel B.; Sørensen, Kasper K.; Jensen, Knud J. [University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Stougaard, Jens; Thirup, Søren; Blaise, Mickaël, E-mail: mickael.blaise@cpbs.cnrs.fr [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus (Denmark)

    2015-03-01

    The crystal and solution structures of the T. thermophilus NlpC/P60 d, l-endopeptidase as well as the co-crystal structure of its N-terminal LysM domains bound to chitohexaose allow a proposal to be made regarding how the enzyme recognizes peptidoglycan. LysM domains, which are frequently present as repetitive entities in both bacterial and plant proteins, are known to interact with carbohydrates containing N-acetylglucosamine (GlcNAc) moieties, such as chitin and peptidoglycan. In bacteria, the functional significance of the involvement of multiple LysM domains in substrate binding has so far lacked support from high-resolution structures of ligand-bound complexes. Here, a structural study of the Thermus thermophilus NlpC/P60 endopeptidase containing two LysM domains is presented. The crystal structure and small-angle X-ray scattering solution studies of this endopeptidase revealed the presence of a homodimer. The structure of the two LysM domains co-crystallized with N-acetyl-chitohexaose revealed a new intermolecular binding mode that may explain the differential interaction between LysM domains and short or long chitin oligomers. By combining the structural information with the three-dimensional model of peptidoglycan, a model suggesting how protein dimerization enhances the recognition of peptidoglycan is proposed.

  7. X-Ray Crystal Structure of the Ancestral 3-Ketosteroid Receptor-Progesterone-Mifepristone Complex Shows Mifepristone Bound at the Coactivator Binding Interface

    Energy Technology Data Exchange (ETDEWEB)

    Colucci, Jennifer K.; Ortlund, Eric A. [Emory-MED

    2013-12-12

    Steroid receptors are a subfamily of nuclear receptors found throughout all metazoans. They are highly important in the regulation of development, inflammation, and reproduction and their misregulation has been implicated in hormone insensitivity syndromes and cancer. Steroid binding to SRs drives a conformational change in the ligand binding domain that promotes nuclear localization and subsequent interaction with coregulator proteins to affect gene regulation. SRs are important pharmaceutical targets, yet most SR-targeting drugs have off-target pharmacology leading to unwanted side effects. A better understanding of the structural mechanisms dictating ligand specificity and the evolution of the forces that created the SR-hormone pairs will enable the design of better pharmaceutical ligands. In order to investigate this relationship, we attempted to crystallize the ancestral 3-ketosteroid receptor (ancSR2) with mifepristone, a SR antagonist. Here, we present the x-ray crystal structure of the ancestral 3-keto steroid receptor (ancSR2)-progesterone complex at a resolution of 2.05 Å. This improves upon our previously reported structure of the ancSR2-progesterone complex, permitting unambiguous assignment of the ligand conformation within the binding pocket. Surprisingly, we find mifepristone, fortuitously docked at the protein surface, poised to interfere with coregulator binding. Recent attention has been given to generating pharmaceuticals that block the coregulator binding site in order to obstruct coregulator binding and achieve tissue-specific SR regulation independent of hormone binding. Mifepristone’s interaction with the coactivator cleft of this SR suggests that it may be a useful molecular scaffold for further coactivator binding inhibitor development.

  8. Physical Uncertainty Bounds (PUB)

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-19

    This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.

  9. Microbial oxidative sulfur metabolism: biochemical evidence of the membrane-bound heterodisulfide reductase-like complex of the bacterium Aquifex aeolicus.

    Science.gov (United States)

    Boughanemi, Souhela; Lyonnet, Jordan; Infossi, Pascale; Bauzan, Marielle; Kosta, Artémis; Lignon, Sabrina; Giudici-Orticoni, Marie-Thérèse; Guiral, Marianne

    2016-08-01

    The Hdr (heterodisulfide reductase)-like enzyme is predicted, from gene transcript profiling experiments previously published, to be essential in oxidative sulfur metabolism in a number of bacteria and archaea. Nevertheless, no biochemical and physicochemical data are available so far about this enzyme. Genes coding for it were identified in Aquifex aeolicus, a Gram-negative, hyperthermophilic, chemolithoautotrophic and microaerophilic bacterium that uses inorganic sulfur compounds as electron donor to grow. We provide biochemical evidence that this Hdr-like enzyme is present in this sulfur-oxidizing prokaryote (cultivated with thiosulfate or elemental sulfur). We demonstrate, by immunolocalization and cell fractionation, that Hdr-like enzyme is associated, presumably monotopically, with the membrane fraction. We show by co-immunoprecipitation assay or partial purification, that the Hdr proteins form a stable complex composed of at least five subunits, HdrA, HdrB1, HdrB2, HdrC1 and HdrC2, present in two forms of high molecular mass on native gel (∼240 and 450 kDa). These studies allow us to propose a revised model for dissimilatory sulfur oxidation pathways in A. aeolicus, with Hdr predicted to generate sulfite. PMID:27284018

  10. Separation of carbohydrates using hydrophilic interaction liquid chromatography.

    Science.gov (United States)

    Fu, Qing; Liang, Tu; Li, Zhenyu; Xu, Xiaoyong; Ke, Yanxiong; Jin, Yu; Liang, Xinmiao

    2013-09-20

    A strategy was developed to rapidly evaluate chromatographic properties of hydrophilic interaction chromatography (HILIC) columns for separating carbohydrates. Seven HILIC columns (Silica, Diol, TSK Amide-80, XAmide, Click Maltose, Click β-CD, and Click TE-Cys columns) were evaluated by using three monosaccharide and seven disaccharides as probes. The influence of column temperature on the peak shape and tautomerization of carbohydrates, as well as column selectivity were investigated. The influence of surface charge property on the retention was also studied by using glucose, glucuronic acid, and glucosamine, which indicated that buffer salt concentration and pH value in mobile phase was necessary to control the ionic interactions between ionic carbohydrates and HILIC columns. According to evaluation results, the XAmide column was selected as an example to establish experimental schemes for separation of complex mixtures of oligosaccharide.

  11. Carbohydrates of human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, J E

    1992-01-01

    Elucidation of the mechanism by which viral infection induces the appearance of carbohydrate neoantigens is highly important. Results from such studies could be expected to be significant for a general understanding of the regulation of glycosylation, and perhaps especially important for the unde...

  12. Carbohydrates - Multiple Languages: MedlinePlus

    Science.gov (United States)

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Carbohydrates URL of this page: https://medlineplus.gov/languages/carbohydrates.html Other topics A-Z A B ...

  13. Carbohydrate-based immune adjuvants

    Science.gov (United States)

    Petrovsky, Nikolai; Cooper, Peter D

    2011-01-01

    The role for adjuvants in human vaccines has been a matter of vigorous scientific debate, with the field hindered by the fact that for over 80 years, aluminum salts were the only adjuvants approved for human use. To this day, alum-based adjuvants, alone or combined with additional immune activators, remain the only adjuvants approved for use in the USA. This situation has not been helped by the fact that the mechanism of action of most adjuvants has been poorly understood. A relative lack of resources and funding for adjuvant development has only helped to maintain alum’s relative monopoly. To seriously challenge alum’s supremacy a new adjuvant has many major hurdles to overcome, not least being alum’s simplicity, tolerability, safety record and minimal cost. Carbohydrate structures play critical roles in immune system function and carbohydrates also have the virtue of a strong safety and tolerability record. A number of carbohydrate compounds from plant, bacterial, yeast and synthetic sources have emerged as promising vaccine adjuvant candidates. Carbohydrates are readily biodegradable and therefore unlikely to cause problems of long-term tissue deposits seen with alum adjuvants. Above all, the Holy Grail of human adjuvant development is to identify a compound that combines potent vaccine enhancement with maximum tolerability and safety. This has proved to be a tough challenge for many adjuvant contenders. Nevertheless, carbohydrate-based compounds have many favorable properties that could place them in a unique position to challenge alum’s monopoly over human vaccine usage. PMID:21506649

  14. Vina-Carb: Improving Glycosidic Angles during Carbohydrate Docking.

    Science.gov (United States)

    Nivedha, Anita K; Thieker, David F; Makeneni, Spandana; Hu, Huimin; Woods, Robert J

    2016-02-01

    Molecular docking programs are primarily designed to align rigid, drug-like fragments into the binding sites of macromolecules and frequently display poor performance when applied to flexible carbohydrate molecules. A critical source of flexibility within an oligosaccharide is the glycosidic linkages. Recently, Carbohydrate Intrinsic (CHI) energy functions were reported that attempt to quantify the glycosidic torsion angle preferences. In the present work, the CHI-energy functions have been incorporated into the AutoDock Vina (ADV) scoring function, subsequently termed Vina-Carb (VC). Two user-adjustable parameters have been introduced, namely, a CHI- energy weight term (chi_coeff) that affects the magnitude of the CHI-energy penalty and a CHI-cutoff term (chi_cutoff) that negates CHI-energy penalties below a specified value. A data set consisting of 101 protein-carbohydrate complexes and 29 apoprotein structures was used in the development and testing of VC, including antibodies, lectins, and carbohydrate binding modules. Accounting for the intramolecular energies of the glycosidic linkages in the oligosaccharides during docking led VC to produce acceptable structures within the top five ranked poses in 74% of the systems tested, compared to a success rate of 55% for ADV. An enzyme system was employed in order to illustrate the potential application of VC to proteins that may distort glycosidic linkages of carbohydrate ligands upon binding. VC represents a significant step toward accurately predicting the structures of protein-carbohydrate complexes. Furthermore, the described approach is conceptually applicable to any class of ligands that populate well-defined conformational states. PMID:26744922

  15. Entirely Carbohydrate-Based Vaccines: An Emerging Field for Specific and Selective Immune Responses

    Science.gov (United States)

    Nishat, Sharmeen; Andreana, Peter R.

    2016-01-01

    Carbohydrates are regarded as promising targets for vaccine development against infectious disease because cell surface glycans on many infectious agents are attributed to playing an important role in pathogenesis. In addition, oncogenic transformation of normal cells, in many cases, is associated with aberrant glycosylation of the cell surface glycan generating tumor associated carbohydrate antigens (TACAs). Technological advances in glycobiology have added a new dimension to immunotherapy when considering carbohydrates as key targets in developing safe and effective vaccines to combat cancer, bacterial infections, viral infections, etc. Many consider effective vaccines induce T-cell dependent immunity with satisfactory levels of immunological memory that preclude recurrence. Unfortunately, carbohydrates alone are poorly immunogenic as they do not bind strongly to the MHCII complex and thus fail to elicit T-cell immunity. To increase immunogenicity, carbohydrates have been conjugated to carrier proteins, which sometimes can impede carbohydrate specific immunity as peptide-based immune responses can negate antibodies directed at the targeted carbohydrate antigens. To overcome many challenges in using carbohydrate-based vaccine design and development approaches targeting cancer and other diseases, zwitterionic polysaccharides (ZPSs), isolated from the capsule of commensal anaerobic bacteria, will be discussed as promising carriers of carbohydrate antigens to achieve desired immunological responses. PMID:27213458

  16. Entirely Carbohydrate-Based Vaccines: An Emerging Field for Specific and Selective Immune Responses

    Directory of Open Access Journals (Sweden)

    Sharmeen Nishat

    2016-05-01

    Full Text Available Carbohydrates are regarded as promising targets for vaccine development against infectious disease because cell surface glycans on many infectious agents are attributed to playing an important role in pathogenesis. In addition, oncogenic transformation of normal cells, in many cases, is associated with aberrant glycosylation of the cell surface glycan generating tumor associated carbohydrate antigens (TACAs. Technological advances in glycobiology have added a new dimension to immunotherapy when considering carbohydrates as key targets in developing safe and effective vaccines to combat cancer, bacterial infections, viral infections, etc. Many consider effective vaccines induce T-cell dependent immunity with satisfactory levels of immunological memory that preclude recurrence. Unfortunately, carbohydrates alone are poorly immunogenic as they do not bind strongly to the MHCII complex and thus fail to elicit T-cell immunity. To increase immunogenicity, carbohydrates have been conjugated to carrier proteins, which sometimes can impede carbohydrate specific immunity as peptide-based immune responses can negate antibodies directed at the targeted carbohydrate antigens. To overcome many challenges in using carbohydrate-based vaccine design and development approaches targeting cancer and other diseases, zwitterionic polysaccharides (ZPSs, isolated from the capsule of commensal anaerobic bacteria, will be discussed as promising carriers of carbohydrate antigens to achieve desired immunological responses.

  17. Different allocation of carbohydrates and phenolics in dehydrated leaves of triticale.

    Science.gov (United States)

    Hura, Tomasz; Dziurka, Michał; Hura, Katarzyna; Ostrowska, Agnieszka; Dziurka, Kinga

    2016-09-01

    Carbohydrates are used in plant growth processes, osmotic regulation and secondary metabolism. A study of the allocation of carbohydrates to a target set of metabolites during triticale acclimation to soil drought was performed. The study included a semi-dwarf cultivar 'Woltario' and a long-stemmed cultivar 'Moderato', differing in the activity of the photosynthetic apparatus under optimum growth conditions. Differences were found in the quantitative and qualitative composition of individual carbohydrates and phenolic compounds, depending on the developmental stage and water availability. Soluble carbohydrates in the semi-dwarf 'Woltario' cv. under soil drought were utilized for synthesis of starch, soluble phenolic compounds and an accumulation of cell wall carbohydrates. In the typical 'Moderato' cv., soluble carbohydrates were primarily used for the synthesis of phenolic compounds that were then incorporated into cell wall structures. Increased content of cell wall-bound phenolics in 'Moderato' cv. improved the cell wall tightness and reduced the rate of leaf water loss. In 'Woltario' cv., the increase in cell osmotic potential due to an enhanced concentration of carbohydrates and proline was insufficient to slow down the rate of leaf water loss. The mechanism of cell wall tightening in response to leaf desiccation may be the main key in the process of triticale acclimation to soil drought.

  18. Fluorous-based carbohydrate quartz crystal microbalance.

    Science.gov (United States)

    Chen, Lei; Sun, Pengfei; Chen, Guosong

    2015-03-20

    Fluorous chemistry has brought many applications from catalysis to separation science, from supramolecular materials to analytical chemistry. However, fluorous-based quartz crystal microbalance (QCM) has not been reported so far. In the current paper, fluorous interaction has been firstly utilized in QCM, and carbohydrate-protein interaction and carbohydrate-carbohydrate interaction have been detected afterward. PMID:25541017

  19. A single-molecule force spectroscopy study of the interactions between lectins and carbohydrates on cancer and normal cells

    Science.gov (United States)

    Zhao, Weidong; Cai, Mingjun; Xu, Haijiao; Jiang, Junguang; Wang, Hongda

    2013-03-01

    The interaction forces between carbohydrates and lectins were investigated by single-molecule force spectroscopy on both cancer and normal cells. The binding kinetics was also studied, which shows that the carbohydrate-lectin complex on cancer cells is less stable than that on normal cells.The interaction forces between carbohydrates and lectins were investigated by single-molecule force spectroscopy on both cancer and normal cells. The binding kinetics was also studied, which shows that the carbohydrate-lectin complex on cancer cells is less stable than that on normal cells. Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c3nr00553d

  20. Graviton Mass Bounds

    CERN Document Server

    de Rham, Claudia; Tolley, Andrew J; Zhou, Shuang-Yong

    2016-01-01

    Recently, aLIGO has announced the first direct detections of gravitational waves, a direct manifestation of the propagating degrees of freedom of gravity. The detected signals GW150914 and GW151226 have been used to examine the basic properties of these gravitational degrees of freedom, particularly setting an upper bound on their mass. It is timely to review what the mass of these gravitational degrees of freedom means from the theoretical point of view, particularly taking into account the recent developments in constructing consistent massive gravity theories. Apart from the GW150914 mass bound, a few other observational bounds have been established from the effects of the Yukawa potential, modified dispersion relation and fifth force that are all induced when the fundamental gravitational degrees of freedom are massive. We review these different mass bounds and examine how they stand in the wake of recent theoretical developments and how they compare to the bound from GW150914.

  1. Interactions of carbohydrates and proteins by fluorophore-assisted carbohydrate electrophoresis

    Indian Academy of Sciences (India)

    Gang-Liang Huang; Xin-Ya Mei; Peng-George Wang

    2006-06-01

    A sensitive, specific, and rapid method for the detection of carbohydrate-protein interactions is demonstrated by fluorophore-assisted carbohydrate electrophoresis (FACE). The procedure is simple and the cost is low. The advantage of this method is that carbohydrate-protein interactions can be easily displayed by FACE, and the carbohydrates do not need to be purified.

  2. Cell surface carbohydrates as prognostic markers in human carcinomas

    DEFF Research Database (Denmark)

    Dabelsteen, Erik

    1996-01-01

    Tumour development is usually associated with changes in cell surface carbohydrates. These are often divided into changes related to terminal carbohydrate structures, which include incomplete synthesis and modification of normally existing carbohydrates, and changes in the carbohydrate core struc...

  3. Structural Bounds on the Dyadic Effect

    CERN Document Server

    Cinelli, Matteo; Iovanella, Antonio

    2016-01-01

    In this paper we consider the dyadic effect introduced in complex networks when nodes are distinguished by a binary characteristic. Under these circumstances two independent parameters, namely dyadicity and heterophilicity, are able to measure how much the assigned characteristic affects the network topology. All possible configurations can be represented in a phase diagram lying in a two-dimensional space that represents the feasible region of the dyadic effect, which is bound by two upper bounds on dyadicity and heterophilicity. Using some network's structural arguments, we are able to improve such upper bounds and introduce two new lower bounds, providing a reduction of the feasible region of the dyadic effect as well as constraining dyadicity and heterophilicity within a specific range. Some computational experiences show the bounds' effectiveness and their usefulness with regards to different classes of networks.

  4. Properties of Excitons Bound to Ionized Donors

    DEFF Research Database (Denmark)

    Skettrup, Torben; Suffczynski, M.; Gorzkowski, W.

    1971-01-01

    Binding energies, interparticle distances, oscillator strengths, and exchange corrections are calculated for the three-particle complex corresponding to an exciton bound to an ionized donor. The results are given as functions of the mass ratio of the electron and hole. Binding of the complex is o...

  5. Complexity

    CERN Document Server

    Gershenson, Carlos

    2011-01-01

    The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.

  6. Carbohydrate Microarrays in Plant Science

    DEFF Research Database (Denmark)

    Fangel, Jonatan Ulrik; Pedersen, H.L.; Vidal-Melgosa, S.;

    2012-01-01

    Almost all plant cells are surrounded by glycan-rich cell walls, which form much of the plant body and collectively are the largest source of biomass on earth. Plants use polysaccharides for support, defense, signaling, cell adhesion, and as energy storage, and many plant glycans are also important...... industrially and nutritionally. Understanding the biological roles of plant glycans and the effective exploitation of their useful properties requires a detailed understanding of their structures, occurrence, and molecular interactions. Microarray technology has revolutionized the massively high...... for plant research and can be used to map glycan populations across large numbers of samples to screen antibodies, carbohydrate binding proteins, and carbohydrate binding modules and to investigate enzyme activities....

  7. Multicolor Bound Soliton Molecule

    CERN Document Server

    Luo, Rui; Lin, Qiang

    2015-01-01

    We show a new class of bound soliton molecule that exists in a parametrically driven nonlinear optical cavity with appropriate dispersion characteristics. The composed solitons exhibit distinctive colors but coincide in time and share a common phase, bound together via strong inter-soliton four-wave mixing and Cherenkov radiation. The multicolor bound soliton molecule shows intriguing spectral locking characteristics and remarkable capability of spectrum management to tailor soliton frequencies, which may open up a great avenue towards versatile generation and manipulation of multi-octave spanning phase-locked Kerr frequency combs, with great potential for applications in frequency metrology, optical frequency synthesis, and spectroscopy.

  8. Continuous bounded cohomology of locally compact groups

    CERN Document Server

    2001-01-01

    Recent research has repeatedly led to connections between important rigidity questions and bounded cohomology. However, the latter has remained by and large intractable. This monograph introduces the functorial study of the continuous bounded cohomology for topological groups, with coefficients in Banach modules. The powerful techniques of this more general theory have successfully solved a number of the original problems in bounded cohomology. As applications, one obtains, in particular, rigidity results for actions on the circle, for representations on complex hyperbolic spaces and on Teichmüller spaces. A special effort has been made to provide detailed proofs or references in quite some generality.

  9. The nature of nonfreezing water in carbohydrate polymers.

    Science.gov (United States)

    Kocherbitov, Vitaly

    2016-10-01

    In an aqueous environment, carbohydrate polymers are surrounded by hydration shells consisting of water molecules that are sometimes called "bound". When polymer solutions are subjected to low temperatures, a part of water turns into ice, another part remains in the biopolymer phase and is called "nonfreezing water". Thermodynamic analysis of water freezing shows that the amount of non-freezing water does not reflect the amount of bound water, neither can it be used as a measure of strength of polymer-water interactions. Upon deep cooling, crystallization of water should desiccate polymers more than is observed in experiment. The reason for existence of non-freezing water is an interplay between the crystallization of water and the glass transition in biopolymers that prevents dehydration. PMID:27312645

  10. Lower Bounds on Quantum Query Complexity

    NARCIS (Netherlands)

    P. Hoyer; R. Spalek

    2005-01-01

    Shor's and Grover's famous quantum algorithms for factoring and searching show that quantum computers can solve certain computational problems significantly faster than any classical computer. We discuss here what quantum computers cannot do, and specifically how to prove limits on their computation

  11. Lower complexity bounds for lifted inference

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2015-01-01

    One of the big challenges in the development of probabilistic relational (or probabilistic logical) modeling and learning frameworks is the design of inference techniques that operate on the level of the abstract model representation language, rather than on the level of ground, propositional...

  12. Sample Complexity Bounds for Differentially Private Learning

    OpenAIRE

    Chaudhuri, Kamalika; Hsu, Daniel

    2011-01-01

    This work studies the problem of privacy-preserving classification – namely, learning a classifier from sensitive data while preserving the privacy of individuals in the training set. In particular, the learning algorithm is required in this problem to guarantee differential privacy, a very strong notion of privacy that has gained significant attention in recent years.

  13. Solution study of a structurally characterized monoalkoxo-bound monooxo-vanadium(V) complex: spontaneous generation of the corresponding oxobridged divanadium(V,V) complex and its electroreduction to a mixed-valence species in solution.

    Science.gov (United States)

    Dinda, Rupam; Sengupta, Parbati; Sutradhar, Manas; Mak, Thomas C W; Ghosh, Saktiprosad

    2008-07-01

    An interesting transformation of a structurally characterized monooxoalkoxovanadium(V) complex [VO(OEt)L] (LH 2 = a dibasic tridentate ONO donor ligand) in solution leading to the formation of the corresponding monooxobridged divanadium(V,V) complex (VOL) 2O is reported. This binuclear species in solution is adequately characterized by elemental analysis, measurement of conductance (in solution), various spectroscopic (UV-vis, IR, NMR, and mass spectrometry) techiniques and by cyclic voltammetry. The corresponding mixed-valence vanadium(IV,V) species has been generated in CH 3CN solution by controlled potential electrolysis of (VOL) 2O. This mixed-valence species is identified and studied by EPR technique (at room temperature and at liquid nitrogen temperature) and also by UV-vis spectroscopy. This study may be regarded as a general method of obtaining monooxo-bridged binuclear vanadium(V,V) species from the corresponding mononuclear monooxoalkoxovanadium(V) complexes of some selected dibasic tridentate ONO chelating ligands, which can be utilized as the precursor of monooxobridged divanadium(IV,V) mixed-valence species in solution obtainable by controlled potential electrolysis. PMID:18543908

  14. Alteration of the carbohydrate-binding specificity of a C-type lectin CEL-I mutant with an EPN carbohydrate-binding motif.

    Science.gov (United States)

    Hatakeyama, Tomomitsu; Ishimine, Tomohiro; Baba, Tomohiro; Kimura, Masanari; Unno, Hideaki; Goda, Shuichiro

    2013-07-01

    CEL-I is a Gal/GalNAc-specific C-type lectin isolated from the sea cucumber Cucumaria echinata. This lectin is composed of two carbohydrate-recognition domains (CRDs) with the carbohydrate-recognition motif QPD (Gln-Pro- Asp), which is generally known to exist in galactose-specific C-type CRDs. In the present study, a mutant CEL-I with EPN (Glu-Pro-Asn) motif, which is thought to be responsible for the carbohydrate-recognition of mannose-specific Ctype CRDs, was produced in Escherichia coli, and its effects on the carbohydrate-binding specificity were examined using polyamidoamine dendrimer (PD) conjugated with carbohydrates. Although wild-type CEL-I effectively formed complexes with N-acetylgalactosamine (GalNAc)-PD but not with mannose-PD, the mutant CEL-I showed relatively weak but definite affinity for mannose-PD. These results indicated that the QPD and EPN motifs play a significant role in the carbohydrate-recognition mechanism of CEL-I, especially in the discrimination of galactose and mannose. Additional mutations in the recombinant CEL-I binding site may further increase its specificity for mannose, and should provide insights into designing novel carbohydrate-recognition proteins. PMID:23157284

  15. A systematic study of chemogenomics of carbohydrates.

    Science.gov (United States)

    Gu, Jiangyong; Luo, Fang; Chen, Lirong; Yuan, Gu; Xu, Xiaojie

    2014-03-01

    Chemogenomics focuses on the interactions between biologically active molecules and protein targets for drug discovery. Carbohydrates are the most abundant compounds in natural products. Compared with other drugs, the carbohydrate drugs show weaker side effects. Searching for multi-target carbohydrate drugs can be regarded as a solution to improve therapeutic efficacy and safety. In this work, we collected 60 344 carbohydrates from the Universal Natural Products Database (UNPD) and explored the chemical space of carbohydrates by principal component analysis. We found that there is a large quantity of potential lead compounds among carbohydrates. Then we explored the potential of carbohydrates in drug discovery by using a network-based multi-target computational approach. All carbohydrates were docked to 2389 target proteins. The most potential carbohydrates for drug discovery and their indications were predicted based on a docking score-weighted prediction model. We also explored the interactions between carbohydrates and target proteins to find the pathological networks, potential drug candidates and new indications.

  16. Carbohydrates

    Science.gov (United States)

    ... with added sugar provide calories, but they lack vitamins, minerals, and fiber. Because they lack nutrients, these foods ... foods. In addition to calories, whole foods provide vitamins, minerals, and fiber. By making smart food choices, you ...

  17. Ternary complex structures of human farnesyl pyrophosphate synthase bound with a novel inhibitor and secondary ligands provide insights into the molecular details of the enzyme’s active site closure

    Directory of Open Access Journals (Sweden)

    Park Jaeok

    2012-12-01

    Full Text Available Abstract Background Human farnesyl pyrophosphate synthase (FPPS controls intracellular levels of farnesyl pyrophosphate, which is essential for various biological processes. Bisphosphonate inhibitors of human FPPS are valuable therapeutics for the treatment of bone-resorption disorders and have also demonstrated efficacy in multiple tumor types. Inhibition of human FPPS by bisphosphonates in vivo is thought to involve closing of the enzyme’s C-terminal tail induced by the binding of the second substrate isopentenyl pyrophosphate (IPP. This conformational change, which occurs through a yet unclear mechanism, seals off the enzyme’s active site from the solvent environment and is essential for catalysis. The crystal structure of human FPPS in complex with a novel bisphosphonate YS0470 and in the absence of a second substrate showed partial ordering of the tail in the closed conformation. Results We have determined crystal structures of human FPPS in ternary complex with YS0470 and the secondary ligands inorganic phosphate (Pi, inorganic pyrophosphate (PPi, and IPP. Binding of PPi or IPP to the enzyme-inhibitor complex, but not that of Pi, resulted in full ordering of the C-terminal tail, which is most notably characterized by the anchoring of the R351 side chain to the main frame of the enzyme. Isothermal titration calorimetry experiments demonstrated that PPi binds more tightly to the enzyme-inhibitor complex than IPP, and differential scanning fluorometry experiments confirmed that Pi binding does not induce the tail ordering. Structure analysis identified a cascade of conformational changes required for the C-terminal tail rigidification involving Y349, F238, and Q242. The residues K57 and N59 upon PPi/IPP binding undergo subtler conformational changes, which may initiate this cascade. Conclusions In human FPPS, Y349 functions as a safety switch that prevents any futile C-terminal closure and is locked in the “off” position in the

  18. Lectures on Bound states

    CERN Document Server

    Hoyer, Paul

    2016-01-01

    Even a first approximation of bound states requires contributions of all powers in the coupling. This means that the concept of "lowest order bound state" needs to be defined. In these lectures I discuss the "Born" (no loop, lowest order in $\\hbar$) approximation. Born level states are bound by gauge fields which satisfy the classical field equations. As a check of the method, Positronium states of any momentum are determined as eigenstates of the QED Hamiltonian, quantized at equal time. Analogously, states bound by a strong external field $A^\\mu(\\xv)$ are found as eigenstates of the Dirac Hamiltonian. Their Fock states have dynamically created $e^+e^-$ pairs, whose distribution is determined by the Dirac wave function. The linear potential of $D=1+1$ dimensions confines electrons but repels positrons. As a result, the mass spectrum is continuous and the wave functions have features of both bound states and plane waves. The classical solutions of Gauss' law are explored for hadrons in QCD. A non-vanishing bo...

  19. Bounding species distribution models

    Institute of Scientific and Technical Information of China (English)

    Thomas J. STOHLGREN; Catherine S. JARNEVICH; Wayne E. ESAIAS; Jeffrey T. MORISETTE

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern.Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development,yet there is no recommended best practice for “clamping” model extrapolations.We relied on two commonly used modeling approaches:classification and regression tree (CART) and maximum entropy (Maxent) models,and we tested a simple alteration of the model extrapolations,bounding extrapolations to the maximum and minimum values of primary environmental predictors,to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States.Findings suggest that multiple models of bounding,and the most conservative bounding of species distribution models,like those presented here,should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5):642-647,2011].

  20. Protective group strategies in carbohydrate and peptide chemistry

    OpenAIRE

    Ali, Asghar

    2010-01-01

    Protecting groups play a key role in the synthesis of complex natural products.This holds especially true for the synthesis of oligosaccharides, of which the monomeric carbohydrate building blocks usually contain up to five different hydroxyl functions. The discrimination of these hydroxyl functions requires a careful protecting group strategy and typically involves multistep protocols.This thesis describes the prepartion, installation, their use in the synthesis of stereoselective glycosidic...

  1. Validation of EMP bounds

    Energy Technology Data Exchange (ETDEWEB)

    Warne, L.K.; Merewether, K.O.; Chen, K.C.; Jorgenson, R.E.; Morris, M.E.; Solberg, J.E.; Lewis, J.G. [Sandia National Labs., Albuquerque, NM (United States); Derr, W. [Derr Enterprises, Albuquerque, NM (United States)

    1996-07-01

    Test data on canonical weapon-like fixtures are used to validate previously developed analytical bounding results. The test fixtures were constructed to simulate (but be slightly worse than) weapon ports of entry but have known geometries (and electrical points of contact). The exterior of the test fixtures exhibited exterior resonant enhancement of the incident fields at the ports of entry with magnitudes equal to those of weapon geometries. The interior consisted of loaded transmission lines adjusted to maximize received energy or voltage but incorporating practical weapon geometrical constraints. New analytical results are also presented for bounding the energies associated with multiple bolt joints and for bounding the exterior resonant enhancement of the exciting fields.

  2. Information, Utility & Bounded Rationality

    CERN Document Server

    Ortega, Pedro A

    2011-01-01

    Perfectly rational decision-makers maximize expected utility, but crucially ignore the resource costs incurred when determining optimal actions. Here we employ an axiomatic framework for bounded rational decision-making based on a thermodynamic interpretation of resource costs as information costs. This leads to a variational "free utility" principle akin to thermodynamical free energy that trades off utility and information costs. We show that bounded optimal control solutions can be derived from this variational principle, which leads in general to stochastic policies. Furthermore, we show that risk-sensitive and robust (minimax) control schemes fall out naturally from this framework if the environment is considered as a bounded rational and perfectly rational opponent, respectively. When resource costs are ignored, the maximum expected utility principle is recovered.

  3. Mutualistic growth of the sulfate-reducer Desulfovibrio vulgaris Hildenborough with different carbohydrates.

    Science.gov (United States)

    Santana, M M; Portillo, M C; Gonzalez, J M

    2012-01-01

    Desulfovibrio vulgaris Hildenborough genome presents a phosphotransferase system putatively involved in the transport of carbohydrates. However, utilization of sugars by this sulfate-reducing bacterium has never been reported. Herein, we have observed proliferation of D. vulgaris Hildenborough with some carbohydrates, in mutualism with Stenotrophomonas maltophilia, a non-fermentative, gram-negative gammaproteobacterium, or Microbacterium, a gram-positive actinobacterium. These results suggest the importance of feedback interactions between different heterotrophic bacterial species including the alternative for D. vulgaris of exploiting additional organic resources and novel habitats. Thus, D. vulgaris strongly participates in the mineralization of carbohydrates both in complex natural and artificial systems.

  4. Synthetic Strategies for Converting Carbohydrates into Carbocycles by the Use of Olefin Metathesis

    DEFF Research Database (Denmark)

    Madsen, Robert

    2007-01-01

    This microreview covers recent advances in the use of ring-closing metathesis for the synthesis of carbocycles from carbohydrates. Various strategies for the synthesis of a,w-dienes from carbohydrates are presented, which give rise to a large variety of dienes with different stereochemistry......, protecting groups and substituents. Subsequent ring-closing metathesis with a ruthenium carbene complex affords highly functionalized carbocycles with ring-sizes ranging from five- to eight-membered rings. The application of these methods for the synthesis of carbocyclic natural products from carbohydrates...

  5. Novel interactions of complex carbohydrates with peanut (PNA), Ricinus communis (RCA-I), Sambucus nigra (SNA-I) and wheat germ (WGA) agglutinins as revealed by the binding specificities of these lectins towards mucin core-2 O-linked and N-linked glycans and related structures.

    Science.gov (United States)

    Chandrasekaran, E V; Xue, Jun; Xia, Jie; Khaja, Siraj D; Piskorz, Conrad F; Locke, Robert D; Neelamegham, Sriram; Matta, Khushi L

    2016-10-01

    Plant lectins through their multivalent quaternary structures bind intrinsically flexible oligosaccharides. They recognize fine structural differences in carbohydrates and interact with different sequences in mucin core 2 or complex-type N-glycan chain and also in healthy and malignant tissues. They are used in characterizing cellular and extracellular glycoconjugates modified in pathological processes. We study here, the complex carbohydrate-lectin interactions by determining the effects of substituents in mucin core 2 tetrasaccharide Galβ1-4GlcNAcβ1-6(Galβ1-3)GalNAcα-O-R and fetuin glycopeptides on their binding to agarose-immobilized lectins PNA, RCA-I, SNA-I and WGA. Briefly, in mucin core 2 tetrasaccharide (i) structures modified by α2-3/6-Sialyl LacNAc, LewisX and α1-3-Galactosyl LacNAc resulted in regular binding to PNA whereas compounds with 6-sulfo LacNAc displayed no-binding; (ii) strucures bearing α2-6-sialyl 6-sulfo LacNAc, or 6-sialyl LacdiNAc carbohydrates displayed strong binding to SNA-I; (iii) structures with α2-3/6-sialyl, α1-3Gal LacNAc or LewisX were non-binder to RCA-I and compounds with 6-sulfo LacNAc only displayed weak binding; (iv) structures containing LewisX, 6-Sulfo LewisX, α2-3/6-sialyl LacNAc, α2-3/6-sialyl 6-sulfo LacNAc and GalNAc Lewis-a were non-binding to WGA, those with α1-2Fucosyl, α1-3-Galactosyl LacNAc, α2-3-sialyl T-hapten plus 3'/6'sulfo LacNAc displayed weak binding, and compounds with α2-3-sialyl T-hapten, α2.6-Sialyl LacdiNAc, α2-3-sialyl D-Fucβ1-3 GalNAc and Fucα-1-2 D-Fucβ-1-3GalNAc displaying regular binding and GalNAc LewisX and LacdiNAc plus D-Fuc β-1-3 GalNAcα resulting in tight binding. RCA-I binds Fetuin triantennary asialoglycopeptide 100 % after α-2-3 and 25 % after α-2-6 sialylation, 30 % after α-1-2 and 100 % after α-1-3 fucosylation, and 50 % after α-1-3 galactosylation. WGA binds 3-but not 6-Fucosyl chitobiose core. Thus, information on the influence of complex carbohydrate

  6. Carbohydrate metabolism in Spirochaeta stenostrepta.

    Science.gov (United States)

    Hespell, R B; Canale-Parola, E

    1970-07-01

    The pathways of carbohydrate metabolism in Spirochaeta stenostrepta, a free-living, strictly anaerobic spirochete, were studied. The organism fermented glucose to ethyl alcohol, acetate, lactate, CO(2), and H(2). Assays of enzymatic activities in cell extracts, and determinations of radioactivity distribution in products formed from (14)C-labeled glucose indicated that S. stenostrepta degraded glucose via the Embden-Meyerhof pathway. The spirochete utilized a clostridial-type clastic reaction to metabolize pyruvate to acetyl-coenzyme A, CO(2), and H(2), without production of formate. Acetyl-coenzyme A was converted to ethyl alcohol by nicotinamide adenine dinucleotide-dependent acetaldehyde and alcohol dehydrogenase activities. Phosphotransacetylase and acetate kinase catalyzed the formation of acetate from acetyl-coenzyme A. Hydrogenase and lactate dehydrogenase activities were detected in cell extracts. A rubredoxin was isolated from cell extracts of S. stenostrepta. Preparations of this rubredoxin stimulated acetyl phosphate formation from pyruvate by diethylaminoethyl cellulose-treated extracts of S. stenostrepta, an indication that rubredoxin may participate in pyruvate cleavage by this spirochete. Nutritional studies showed that S. stenostrepta fermented a variety of carbohydrates, but did not ferment amino acids or other organic acids. An unidentified growth factor present in yeast extract was required by the organism. Exogenous supplements of biotin, riboflavin, and vitamin B(12) were either stimulatory or required for growth. PMID:5423371

  7. The effects of carbohydrate variation in isocaloric diets on glycogenolysis and gluconeogenesis in healthy men

    NARCIS (Netherlands)

    Bisschop, PH; Arias, AMP; Ackermans, MT; Endert, E; Pijl, H; Kuipers, F; Meijer, AJ; Sauerwein, HP; Romijn, JA

    2000-01-01

    To evaluate the effect of dietary carbohydrate content on postabsorptive glucose metabolism, we quantified gluconeogenesis and glycogenolysis after 11 days of high carbohydrate (85% carbohydrate), control (44% carbohydrate), and very low carbohydrate (2% carbohydrate) diets in six healthy men. Diets

  8. A mannanase, ManA, of the polycentric anaerobic fungus Orpinomyces sp. strain PC-2 has carbohydrate binding and docking modules.

    Science.gov (United States)

    Ximenes, Eduardo A; Chen, Huizhong; Kataeva, Irina A; Cotta, Michael A; Felix, Carlos R; Ljungdahl, Lars G; Li, Xin-Liang

    2005-07-01

    The anaerobic fungus Orpinomyces sp. strain PC-2 produces a broad spectrum of glycoside hydrolases, most of which are components of a high molecular mass cellulosomal complex. Here we report about a cDNA (manA) having 1924 bp isolated from the fungus and found to encode a polypeptide of 579 amino acid residues. Analysis of the deduced sequence revealed that it had a mannanase catalytic module, a family 1 carbohydrate-binding module, and a noncatalytic docking module. The catalytic module was homologous to aerobic fungal mannanases belonging to family 5 glycoside hydrolases, but unrelated to the previously isolated mannanases (family 26) of the anaerobic fungus Piromyces. No mannanase activity could be detected in Escherichia coli harboring a manA-containing plasmid. The manA was expressed in Saccharomyces cerevisiae and ManA was secreted into the culture medium in multiple forms. The purified extracellular heterologous mannanase hydrolyzed several types of mannan but lacked activity against cellulose, chitin, or beta-glucan. The enzyme had high specific activity toward locust bean mannan and an extremely broad pH profile. It was stable for several hours at 50 degrees C, but was rapidly inactivated at 60 degrees C. The carbohydrate-binding module of the Man A produced separately in E. coli bound preferably to insoluble lignocellulosic substrates, suggesting that it might play an important role in the complex enzyme system of the fungus for lignocellulose degradation. PMID:16175204

  9. Using Carbohydrate Interaction Assays to Reveal Novel Binding Sites in Carbohydrate Active Enzymes.

    Science.gov (United States)

    Cockburn, Darrell; Wilkens, Casper; Dilokpimol, Adiphol; Nakai, Hiroyuki; Lewińska, Anna; Abou Hachem, Maher; Svensson, Birte

    2016-01-01

    Carbohydrate active enzymes often contain auxiliary binding sites located either on independent domains termed carbohydrate binding modules (CBMs) or as so-called surface binding sites (SBSs) on the catalytic module at a certain distance from the active site. The SBSs are usually critical for the activity of their cognate enzyme, though they are not readily detected in the sequence of a protein, but normally require a crystal structure of a complex for their identification. A variety of methods, including affinity electrophoresis (AE), insoluble polysaccharide pulldown (IPP) and surface plasmon resonance (SPR) have been used to study auxiliary binding sites. These techniques are complementary as AE allows monitoring of binding to soluble polysaccharides, IPP to insoluble polysaccharides and SPR to oligosaccharides. Here we show that these methods are useful not only for analyzing known binding sites, but also for identifying new ones, even without structural data available. We further verify the chosen assays discriminate between known SBS/CBM containing enzymes and negative controls. Altogether 35 enzymes are screened for the presence of SBSs or CBMs and several novel binding sites are identified, including the first SBS ever reported in a cellulase. This work demonstrates that combinations of these methods can be used as a part of routine enzyme characterization to identify new binding sites and advance the study of SBSs and CBMs, allowing them to be detected in the absence of structural data. PMID:27504624

  10. Bounded Tamper Resilience

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Faust, Sebastian; Mukherjee, Pratyay;

    2013-01-01

    a public tamper-proof common reference string. Finally, we explain how to boost bounded tampering and leakage resilience (as in 1. and 2. above) to continuous tampering and leakage resilience, in the so-called floppy model where each user has a personal hardware token (containing leak- and tamper...

  11. Effect of soil carbohydrates on nutrient availability in natural forests and cultivated lands in Sri Lanka

    Science.gov (United States)

    Ratnayake, R. R.; Seneviratne, G.; Kulasooriya, S. A.

    2013-05-01

    Carbohydrates supply carbon sources for microbial activities that contribute to mineral nutrient production in soil. Their role on soil nutrient availability has not yet been properly elucidated. This was studied in forests and cultivated lands in Sri Lanka. Soil organic matter (SOM) fractions affecting carbohydrate availability were also determined. Soil litter contributed to sugars of plant origin (SPO) in croplands. The negative relationship found between clay bound organic matter (CBO) and glucose indicates higher SOM fixation in clay that lower its availability in cultivated lands. In forests, negative relationships between litter and sugars of microbial origin (SMO) showed that litter fuelled microbes to produce sugars. Fucose and glucose increased the availability of Cu, Zn and Mn in forests. Xylose increased Ca availability in cultivated lands. Arabinose, the main carbon source of soil respiration reduced the P availability. This study showed soil carbohydrates and their relationships with mineral nutrients could provide vital information on the availability of limiting nutrients in tropical ecosystems.

  12. Biochemical software: Carbohydrates on Laboratory

    Directory of Open Access Journals (Sweden)

    D.N. Heidrich

    2005-07-01

    Full Text Available Educators around  the  world  are  being  challenged  to  develop  and  design  better and  more  effective strategies for student learning  using a variety  of modern  resources.  In this  present  work, an educa- tional  hypermedia  software  was constructed as a support tool to biochemistry teaching.  Occurrence, structure, main  characteristics and  biological  function  of the  biomolecule  Carbohydrates were pre- sented  through  modules.  The  software was developed  using concept  maps,  ISIS-Draw,  and  FLASH- MX animation program.  The chapter  Carbohydrates on Laboratory illustrates experimental methods of carbohydrates characterization, through  animation of a laboratory scenery.   The  subject was de- veloped showing reactions  as Bial, Benedict, Selliwanoff, Barfoed, Phenol  Sulphuric,  and Iodines, and also enzymatic  reactions  as glucose oxidase and amylase.  There are also links with short texts  in order to help the understanding of the contents  and principles of laboratory practice  as well as background reactions. Application of the software to undergraduate students and high school teachers  showed an excellent  acceptance.   All of them  considered  the  software  a very good learning  tool.  Both  teachers and students welcomed this program  as it is more flexible, and allows the learning in a more individual rhythm. In addition, application of the software would be suitable  to a more effective learning  and it is less expensive than conventional experimental teaching.

  13. Carbohydrate composition of circulating multiple-modified low-density lipoprotein

    Science.gov (United States)

    Zakiev, Emile R; Sobenin, Igor A; Sukhorukov, Vasily N; Myasoedova, Veronika A; Ivanova, Ekaterina A; Orekhov, Alexander N

    2016-01-01

    Atherogenic modification of low-density lipoprotein (LDL) plays a crucial role in the pathogenesis of atherosclerosis, as modified LDL, but not native LDL, induces pronounced accumulation of cholesterol and lipids in the arterial wall. It is likely that LDL particles undergo multiple modifications in human plasma: desialylation, changes in size and density, acquisition of negative electric charge, oxidation, and complex formation. In a total LDL preparation isolated from pooled plasma of patients with coronary atherosclerosis and from healthy subjects, two subfractions of LDL could be identified: desialylated LDL bound by a lectin affinity column and normally sialylated (native) LDL that passed through the column. The desialylated LDL subfraction therefore represents circulating modified LDL. In this work, we performed a careful analysis of LDL particles to reveal changes in the composition of glycoconjugates associated with proteins and lipids. Protein fraction of LDL from atherosclerotic patients contained similar amounts of glucosamine, galactose, and mannose, but a 1.6-fold lower level of sialic acid as compared to healthy donors. Lipid-bound glycoconjugates of total LDL from patients with coronary atherosclerosis contained 1.5–2-fold less neutral monosaccharides than total LDL from healthy donors. Patient-derived LDL also contained significantly less sialic acid. Our results demonstrate that carbohydrate composition of LDL from atherosclerotic patients was altered in comparison to healthy controls. In particular, prominent decrease in the sialic acid content was observed. This strengthens the hypothesis of multiple modification of LDL particles in the bloodstream and underscores the clinical importance of desialylated LDL as a possible marker of atherosclerosis progression.

  14. Conversion of carbohydrates to levulinic acid esters

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to the field of converting carbohydrates into levulinic acid, a platform chemical for many chemical end products. More specifically the invention relates to a method for converting carbohydrates such as mono-, di- or polysaccharides, obtained from for example biomass...

  15. A Holographic Bound for D3-Brane

    CERN Document Server

    Momeni, Davood; Bahamonde, Sebastian; Myrzakul, Aizhan; Myrzakulov, Ratbay

    2016-01-01

    In this paper, we will calculate the holographic entanglement entropy, holographic complexity, and fidelity susceptibility for a D3-brane. It will be demonstrated that for a D3-brane the holographic complexity is always greater than or equal to than the fidelity susceptibility. Furthermore, we will also demonstrate that the holographic complexity is related to the holographic entanglement entropy for this system. Thus, we will obtain a holographic bound involving holographic complexity, holographic entanglement entropy and fidelity susceptibility of a D3-brane.

  16. Derivatization Reaction of Carbohydrates with Urea as the Reagent and Fluorimetric Determination of Carbohydrates

    Institute of Scientific and Technical Information of China (English)

    YANG,Jing-He(杨景和); CAO,Xi-Hui(曹西慧); WANG,Min(王敏); WU,Xia(吴霞); SUN,Chang-Xia(孙长侠)

    2002-01-01

    It is found that in the presence of sulfuric acid carbohydrates condense with urea to afford the condensation products, which emit fluorescence. Under optimum conditions, the fluorescence intensities of system are proportional to the concentrations of carbohydrates. Based on this linear relationship,quantitative determination of kinds of carbohydrates has been made. Among an the carbohydrates tested, the sensitivity of α-rhamnose is the highest and its limits of detection reaches 3.5 × 10-8 mol/L. So α-rhamnose can be selectively determed in the presence of other carbohydrates. A interaction mechanism is also discussed.

  17. Carbohydrates in diversity-oriented synthesis: challenges and opportunities.

    Science.gov (United States)

    Lenci, E; Menchi, G; Trabocchi, A

    2016-01-21

    Over the last decade, Diversity-Oriented Synthesis (DOS) has become a new paradigm for developing large collections of structurally diverse small molecules as probes to investigate biological pathways, and to provide a larger array of the chemical space. Drug discovery and chemical biology are taking advantage of DOS approaches to exploit highly-diverse and complex molecular platforms, producing advances in both target and ligand discovery. In this view, carbohydrates are attractive building blocks for DOS libraries, due to their stereochemical diversity and high density of polar functional groups, thus offering many possibilities for chemical manipulation and scaffold decoration. This review will discuss research contributions and perspectives on the application of carbohydrate chemistry to explore the accessible chemical space through appendage, stereochemical and scaffold diversity.

  18. Description of Wiener bounds of multicomponent composites by barycentric coordinates

    Science.gov (United States)

    Peiponen, Kai-Erik; Gornov, Evgeny

    2006-07-01

    Wiener bounds for effective complex permittivity of multicomponent composites are treated by use of barycentric coordinates, a convex hull, and conformal mapping in a complex plane. Depending on the complexity of the multiphase system, the bounds provide singly or multiply connected regions that can be used in estimating the limits of the effective permittivity of the composite. The present modeling is important, e.g., in estimating spectral properties of nanocomposites in engineering and nanomedicine and in terahertz-based security imaging.

  19. Technological aspects of functional food-related carbohydrates.

    NARCIS (Netherlands)

    Voragen, A.G.J.

    1998-01-01

    Carbohydrates in food occur as natural constituents or are added as ingredients or additives. The most important endogenous carbohydrates in food are starch, depolymerized starch, sucrose, lactose, glucose, fructose and sorbitol (digestible) and carbohydrates such as raffinose, stachyose, resistant

  20. Towards Secure Distance Bounding

    OpenAIRE

    Boureanu, Ioana; Mitrokotsa, Aikaterini; Vaudenay, Serge

    2013-01-01

    Relay attacks (and, more generally, man-in-the-middle attacks) are a serious threat against many access control and payment schemes. In this work, we present distance-bounding protocols, how these can deter relay attacks, and the security models formalizing these protocols. We show several pitfalls making existing protocols insecure (or at least, vulnerable, in some cases). Then, we introduce the SKI protocol which enjoys resistance to all popular attack-models and features provable security....

  1. Maps of Bounded Rationality

    OpenAIRE

    Kahneman, Daniel

    2002-01-01

    The work cited by the Nobel committee was done jointly with the late Amos Tversky (1937-1996) during a long and unusually close collaboration. Together, we explored the psychology of intuitive beliefs and choices and examined their bounded rationality. This essay presents a current perspective on the three major topics of our joint work: heuristics of judgment, risky choice, and framing effects. In all three domains we studied intuitions - thoughts and preferences that come to mind quickly an...

  2. Interactions Between Metal Ions and Carbohydrates: Coordination Behavior of D-Ribose to Lanthanide Ions

    Institute of Scientific and Technical Information of China (English)

    苏允兰; 杨丽敏; 翁诗甫; 吴瑾光

    2002-01-01

    Lanthanum chloride α-D-ribopyranose pentahydrate complex was prepared and speculated its structure from the similar IR spectra of corresponding praseodymium and neodymium-D-ribose complexes, which reveal the coordination behavior of D-ribose to lanthanide ions and give us a model of the interactions between metal ions and carbohydrates.

  3. Antibaryon-nucleus bound states

    CERN Document Server

    Hrtánková, J

    2014-01-01

    We calculated antibaryon ($\\bar{B}$ = $\\bar{p}$, $\\bar{\\Lambda}$, $\\bar{\\Sigma}$, $\\bar{\\Xi}$) bound states in selected nuclei within the relativistic mean-field (RMF) model. The G-parity motivated $\\bar{B}$-meson coupling constants were scaled to yield corresponding potentials consistent with available experimental data. Large polarization of the nuclear core caused by $\\bar{B}$ was confirmed. The $\\bar{p}$ annihilation in the nuclear medium was incorporated by including a phenomenological imaginary part of the optical potential. The calculations using a complex $\\bar{p}$-nucleus potential were performed fully self-consistently. The $\\bar{p}$ widths significantly decrease when the phase space reduction is considered for $\\bar{p}$ annihilation products, but they still remain sizeable for potentials consistent with $\\bar{p}$-atom data.

  4. Carbohydrate metabolism before and after dehiscence in the recalcitrant pollen of pumpkin (Cucurbita pepo L.).

    Science.gov (United States)

    Carrizo García, C; Guarnieri, M; Pacini, E

    2015-05-01

    Pumpkin (Cucurbita pepo L.) pollen is starchy, sucrose-poor and recalcitrant, features opposite to those of several model species; therefore, some differences in carbohydrate metabolism could be expected in this species. By studying pumpkin recalcitrant pollen, the objective was to provide new biochemical evidence to improve understanding of how carbohydrate metabolism might be involved in pollen functioning in advanced stages. Four stages were analysed: immature pollen from 1 day before anthesis, mature pollen, mature pollen exposed to the environment for 7 h, and pollen rehydrated in a culture medium. Pollen viability, water and carbohydrate content and activity of enzymes involved in carbohydrate metabolism were quantified in each stage. Pollen viability and water content dropped quickly after dehiscence, as expected. The slight changes in carbohydrate concentration and enzyme activity during pollen maturation contrast with major changes recorded with ageing and rehydration. Pumpkin pollen seems highly active and closely related to its surrounding environment in all the stages analysed; the latter is particularly evident among insoluble sucrolytic enzymes, mainly wall-bound acid invertase, which would be the most relevant for sucrose cleavage. Each stage was characterised by a particular metabolic/enzymatic profile; some particular features, such as the minor changes during maturation, fast sucrolysis upon rehydration or sharp decrease in insoluble sucrolytic activity with ageing seem to be related to the lack of dormancy and recalcitrant nature of pumpkin pollen. PMID:25353653

  5. Carbohydrate metabolism before and after dehiscence in the recalcitrant pollen of pumpkin (Cucurbita pepo L.).

    Science.gov (United States)

    Carrizo García, C; Guarnieri, M; Pacini, E

    2015-05-01

    Pumpkin (Cucurbita pepo L.) pollen is starchy, sucrose-poor and recalcitrant, features opposite to those of several model species; therefore, some differences in carbohydrate metabolism could be expected in this species. By studying pumpkin recalcitrant pollen, the objective was to provide new biochemical evidence to improve understanding of how carbohydrate metabolism might be involved in pollen functioning in advanced stages. Four stages were analysed: immature pollen from 1 day before anthesis, mature pollen, mature pollen exposed to the environment for 7 h, and pollen rehydrated in a culture medium. Pollen viability, water and carbohydrate content and activity of enzymes involved in carbohydrate metabolism were quantified in each stage. Pollen viability and water content dropped quickly after dehiscence, as expected. The slight changes in carbohydrate concentration and enzyme activity during pollen maturation contrast with major changes recorded with ageing and rehydration. Pumpkin pollen seems highly active and closely related to its surrounding environment in all the stages analysed; the latter is particularly evident among insoluble sucrolytic enzymes, mainly wall-bound acid invertase, which would be the most relevant for sucrose cleavage. Each stage was characterised by a particular metabolic/enzymatic profile; some particular features, such as the minor changes during maturation, fast sucrolysis upon rehydration or sharp decrease in insoluble sucrolytic activity with ageing seem to be related to the lack of dormancy and recalcitrant nature of pumpkin pollen.

  6. Quantum dots assisted laser desorption/ionization mass spectrometric detection of carbohydrates: qualitative and quantitative analysis.

    Science.gov (United States)

    Bibi, Aisha; Ju, Huangxian

    2016-04-01

    A quantum dots (QDs) assisted laser desorption/ionization mass spectrometric (QDA-LDI-MS) strategy was proposed for qualitative and quantitative analysis of a series of carbohydrates. The adsorption of carbohydrates on the modified surface of different QDs as the matrices depended mainly on the formation of hydrogen bonding, which led to higher MS intensity than those with conventional organic matrix. The effects of QDs concentration and sample preparation method were explored for improving the selective ionization process and the detection sensitivity. The proposed approach offered a new dimension to the application of QDs as matrices for MALDI-MS research of carbohydrates. It could be used for quantitative measurement of glucose concentration in human serum with good performance. The QDs served as a matrix showed the advantages of low background, higher sensitivity, convenient sample preparation and excellent stability under vacuum. The QDs assisted LDI-MS approach has promising application to the analysis of carbohydrates in complex biological samples.

  7. BOUNDING PYRAMIDS AND BOUNDING CONES FOR TRIANGULAR BEZIER SURFACES

    Institute of Scientific and Technical Information of China (English)

    Jian-song Deng; Fa-lai Chen; Li-li Wang

    2000-01-01

    This paper describes practical approaches on how to construct bounding pyramids and bounding cones for triangular Bézier surfaces. Examples are provided to illustrate the process of construction and comparison is made between various surface bounding volumes. Furthermore, as a starting point for the construction,we provide a way to compute hodographs of triangular Bézier surfaces and improve the algorithm for computing the bounding cone of a set of vectors.

  8. Universal bounds on current fluctuations

    Science.gov (United States)

    Pietzonka, Patrick; Barato, Andre C.; Seifert, Udo

    2016-05-01

    For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.

  9. How mushrooms feed on compost: conversion of carbohydrates and linin in industrial wheat straw based compost enabling the growth of Agaricus bisporus

    OpenAIRE

    Jurak, E.

    2015-01-01

    Abstract In this thesis, the fate of carbohydrates and lignin was studied in industrial wheat straw based compost during composting and growth of Agaricus bisporus. The aim was to understand the availability and degradability of carbohydrates in order to help improve their utilization in the compost. The wheat straw based compost was characterized as being composed mainly of cellulose and lowly substituted xylan. During the first phase of composting, ester-bound substituents were removed from...

  10. Utilization of carbohydrates by radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Kume, T. E-mail: kume@taka.jaeri.go.jp; Nagasawa, N.; Yoshii, F

    2002-03-01

    Upgrading and utilization of carbohydrates such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated for recycling these bio-resources and reducing the environmental pollution. These carbohydrates were easily degraded by irradiation and various kinds of biological activities such as anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction, etc. were induced. On the other hand, some carbohydrate derivatives, carboxymethylcellulose and carboxymethylstarch, could be crosslinked under certain radiation condition and produce the biodegradable hydrogel for medical and agricultural use.

  11. A bound on chaos

    CERN Document Server

    Maldacena, Juan; Stanford, Douglas

    2015-01-01

    We conjecture a sharp bound on the rate of growth of chaos in thermal quantum systems with a large number of degrees of freedom. Chaos can be diagnosed using an out-of-time-order correlation function closely related to the commutator of operators separated in time. We conjecture that the influence of chaos on this correlator can develop no faster than exponentially, with Lyapunov exponent $\\lambda_L \\le 2 \\pi k_B T/\\hbar$. We give a precise mathematical argument, based on plausible physical assumptions, establishing this conjecture.

  12. Regularity of Bound States

    DEFF Research Database (Denmark)

    Faupin, Jeremy; Møller, Jacob Schach; Skibsted, Erik

    2011-01-01

    We study regularity of bound states pertaining to embedded eigenvalues of a self-adjoint operator H, with respect to an auxiliary operator A that is conjugate to H in the sense of Mourre. We work within the framework of singular Mourre theory which enables us to deal with confined massless Pauli......–Fierz models, our primary example, and many-body AC-Stark Hamiltonians. In the simpler context of regular Mourre theory, our results boil down to an improvement of results obtained recently in [8, 9]....

  13. Blog life: Entropy Bound

    Science.gov (United States)

    Steinberg, Peter

    2008-06-01

    Who is the blog written by? Peter Steinberg is a nuclear physicist at the Brookhaven National Laboratory in New York, US. He is acting project manager of the PHOBOS experiment, which used Brookhaven's Relativistic Heavy Ion Collider (RHIC) to search for unusual events produced during collisions between gold nuclei. He is also involved with the PHENIX experiment, which seeks to discover a new state of matter known as the quark-gluon plasma. In addition to his own blog Entropy Bound, Steinberg is currently blogging on a website that was set up last year to publicize the involvement of US scientists with the Large Hadron Collider (LHC) at CERN.

  14. Bounded link prediction in very large networks

    Science.gov (United States)

    Cui, Wei; Pu, Cunlai; Xu, Zhongqi; Cai, Shimin; Yang, Jian; Michaelson, Andrew

    2016-09-01

    Evaluating link prediction methods is a hard task in very large complex networks due to the prohibitive computational cost. However, if we consider the lower bound of node pairs' similarity scores, this task can be greatly optimized. In this paper, we study CN index in the bounded link prediction framework, which is applicable to enormous heterogeneous networks. Specifically, we propose a fast algorithm based on the parallel computing scheme to obtain all node pairs with CN values larger than the lower bound. Furthermore, we propose a general measurement, called self-predictability, to quantify the performance of similarity indices in link prediction, which can also indicate the link predictability of networks with respect to given similarity indices.

  15. Novel Bounds on Marginal Probabilities

    OpenAIRE

    Mooij, Joris M.; Kappen, Hilbert J

    2008-01-01

    We derive two related novel bounds on single-variable marginal probability distributions in factor graphs with discrete variables. The first method propagates bounds over a subtree of the factor graph rooted in the variable, and the second method propagates bounds over the self-avoiding walk tree starting at the variable. By construction, both methods not only bound the exact marginal probability distribution of a variable, but also its approximate Belief Propagation marginal (``belief''). Th...

  16. Tight Bernoulli tail probability bounds

    OpenAIRE

    Dzindzalieta, Dainius

    2014-01-01

    The purpose of the dissertation is to prove universal tight bounds for deviation from the mean probability inequalities for functions of random variables. Universal bounds shows that they are uniform with respect to some class of distributions and quantity of variables and other parameters. The bounds are called tight, if we can construct a sequence of random variables, such that the upper bounds are achieved. Such inequalities are useful for example in insurance mathematics, for constructing...

  17. Carbohydrate feeding and exercise: effect of beverage carbohydrate content.

    Science.gov (United States)

    Murray, R; Seifert, J G; Eddy, D E; Paul, G L; Halaby, G A

    1989-01-01

    The purpose of this study was to determine the effect of ingesting fluids of varying carbohydrate content upon sensory response, physiologic function, and exercise performance during 1.25 h of intermittent cycling in a warm environment (Tdb = 33.4 degrees C). Twelve subjects (7 male, 5 female) completed four separate exercise sessions; each session consisted of three 20 min bouts of cycling at 65% VO2max, with each bout followed by 5 min rest. A timed cycling task (1200 pedal revolutions) completed each exercise session. Immediately prior to the first 20 min cycling bout and during each rest period, subjects consumed 2.5 ml.kg BW-1 of water placebo (WP), or solutions of 6%, 8%, or 10% sucrose with electrolytes (20 mmol.l-1 Na+, 3.2 mmol.l-1 K+). Beverages were administered in double blind, counterbalanced order. Mean (+/- SE) times for the 1200 cycling task differed significantly: WP = 13.62 +/- 0.33 min, *6% = 13.03 +/- 0.24 min, 8% = 13.30 +/- 0.25 min, 10% = 13.57 +/- 0.22 min (* = different from WP and 10%, P less than 0.05). Compared to WP, ingestion of the CHO beverages resulted in higher plasma glucose and insulin concentrations, and higher RER values during the final 20 min of exercise (P less than 0.05). Markers of physiologic function and sensory perception changed similarly throughout exercise; no differences were observed among subjects in response to beverage treatments for changes in plasma concentrations of lactate, sodium, potassium, for changes in plasma volume, plasma osmolality, rectal temperature, heart rate, oxygen uptake, rating of perceived exertion, or for indices of gastrointestinal distress, perceived thirst, and overall beverage acceptance.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Lanthanide-IMAC enrichment of carbohydrates and polyols.

    Science.gov (United States)

    Schemeth, Dieter; Rainer, Matthias; Messner, Christoph B; Rode, Bernd M; Bonn, Günther K

    2014-03-01

    In this study a new type of immobilized metal ion affinity chromatography resin for the enrichment of carbohydrates and polyols was synthesized by radical polymerization reaction of vinyl phosphonic acid and 1,4-butandiole dimethacrylate using azo-bis-isobutyronitrile as radical initiator. Interaction between the chelated trivalent lanthanide ions and negatively charged hydroxyl groups of carbohydrates and polyols was observed by applying high pH values. The new method was evaluated by single standard solutions, mixtures of standards, honey and a more complex extract of Cynara scolymus. The washing step was accomplished by acetonitrile in excess volumes. Elution of enriched carbohydrates was successfully performed with deionized water. The subsequent analysis was carried out with matrix-free laser desorption/ionization-time of flight mass spectrometry involving a TiO2 -coated steel target, especially suitable for the measurement of low-molecular-weight substances. Quantitative analysis of the sugar alcohol xylitol as well as the determination of the maximal loading capacity was performed by gas chromatography in conjunction with mass spectrometric detection after chemical derivatization. In a parallel approach quantum mechanical geometry optimizations were performed in order to compare the coordination behavior of various trivalent lanthanide ions. PMID:24097333

  19. Lanthanide-IMAC enrichment of carbohydrates and polyols.

    Science.gov (United States)

    Schemeth, Dieter; Rainer, Matthias; Messner, Christoph B; Rode, Bernd M; Bonn, Günther K

    2014-03-01

    In this study a new type of immobilized metal ion affinity chromatography resin for the enrichment of carbohydrates and polyols was synthesized by radical polymerization reaction of vinyl phosphonic acid and 1,4-butandiole dimethacrylate using azo-bis-isobutyronitrile as radical initiator. Interaction between the chelated trivalent lanthanide ions and negatively charged hydroxyl groups of carbohydrates and polyols was observed by applying high pH values. The new method was evaluated by single standard solutions, mixtures of standards, honey and a more complex extract of Cynara scolymus. The washing step was accomplished by acetonitrile in excess volumes. Elution of enriched carbohydrates was successfully performed with deionized water. The subsequent analysis was carried out with matrix-free laser desorption/ionization-time of flight mass spectrometry involving a TiO2 -coated steel target, especially suitable for the measurement of low-molecular-weight substances. Quantitative analysis of the sugar alcohol xylitol as well as the determination of the maximal loading capacity was performed by gas chromatography in conjunction with mass spectrometric detection after chemical derivatization. In a parallel approach quantum mechanical geometry optimizations were performed in order to compare the coordination behavior of various trivalent lanthanide ions.

  20. Error bounds for set inclusions

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Xiyin(郑喜印)

    2003-01-01

    A variant of Robinson-Ursescu Theorem is given in normed spaces. Several error bound theorems for convex inclusions are proved and in particular a positive answer to Li and Singer's conjecture is given under weaker assumption than the assumption required in their conjecture. Perturbation error bounds are also studied. As applications, we study error bounds for convex inequality systems.

  1. Bounded Fixed-Point Iteration

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming

    1992-01-01

    they obtain a quadratic bound. These bounds are shown to be tight. Specializing the case of strict and additive functions to functionals of a form that would correspond to iterative programs they show that a linear bound is tight. This is related to several analyses studied in the literature (including...

  2. Separable subgroups have bounded packing

    CERN Document Server

    Yang, Wen-yuan

    2010-01-01

    In this note, we prove that separable subgroups have bounded packing in ambient groups. The notion bounded packing was introduced by Hruska-Wise \\cite{HrWi} and in particular, our result confirms a conjecture in \\cite{HrWi} which states each subgroup of a virtually polycyclic group has the bounded packing property.

  3. A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation

    Science.gov (United States)

    Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

    2013-07-01

    A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 1010. The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and

  4. The Origin of the Constant Carbohydrate Diet

    Directory of Open Access Journals (Sweden)

    Charles Herbert Read

    2009-01-01

    Full Text Available The Constant Carbohydrate diet, based entirely on carbohydrate exchanges, is now widely used in the dietary treatment of diabetes mellitus. Being based on sound scientific principles and simple in design, the Constant Carabohydrate diet is appropriate for all those having diabetes mellitus, young or old, no matter their ethncity. This report describes why and how it was developed in 1951. Its simplicity makes it adaptable to all ethnic diets.

  5. The Origin of the Constant Carbohydrate Diet

    Directory of Open Access Journals (Sweden)

    Read CharlesHerbert

    2008-01-01

    Full Text Available The Constant Carbohydrate diet, based entirely on carbohydrate exchanges, is now widely used in the dietary treatment of diabetes mellitus. Being based on sound scientific principles and simple in design, the Constant Carabohydrate diet is appropriate for all those having diabetes mellitus, young or old, no matter their ethncity. This report describes why and how it was developed in 1951. Its simplicity makes it adaptable to all ethnic diets.

  6. 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...

  7. Carbohydrate Nutrition and Team Sport Performance.

    Science.gov (United States)

    Williams, Clyde; Rollo, Ian

    2015-11-01

    The common pattern of play in 'team sports' is 'stop and go', i.e. where players perform repeated bouts of brief high-intensity exercise punctuated by lower intensity activity. Sprints are generally 2-4 s long and recovery between sprints is of variable length. Energy production during brief sprints is derived from the degradation of intra-muscular phosphocreatine and glycogen (anaerobic metabolism). Prolonged periods of multiple sprints drain muscle glycogen stores, leading to a decrease in power output and a reduction in general work rate during training and competition. The impact of dietary carbohydrate interventions on team sport performance have been typically assessed using intermittent variable-speed shuttle running over a distance of 20 m. This method has evolved to include specific work to rest ratios and skills specific to team sports such as soccer, rugby and basketball. Increasing liver and muscle carbohydrate stores before sports helps delay the onset of fatigue during prolonged intermittent variable-speed running. Carbohydrate intake during exercise, typically ingested as carbohydrate-electrolyte solutions, is also associated with improved performance. The mechanisms responsible are likely to be the availability of carbohydrate as a substrate for central and peripheral functions. Variable-speed running in hot environments is limited by the degree of hyperthermia before muscle glycogen availability becomes a significant contributor to the onset of fatigue. Finally, ingesting carbohydrate immediately after training and competition will rapidly recover liver and muscle glycogen stores. PMID:26553494

  8. A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation.

    Science.gov (United States)

    Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

    2013-08-21

    A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 10(10). The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.

  9. Impact of lignin and carbohydrate chemical structures on degradation reactions during hardwood kraft pulping processes

    Directory of Open Access Journals (Sweden)

    Ricardo B. Santos

    2013-02-01

    Full Text Available Most studies aimed at determining rates of hardwood delignification and carbohydrate degradation have focused on understanding the behavior of a single wood species. Such studies tend to determine either the delignification rate or the rate of carbohydrate degradation without examining the potential interactions resulting from related variables. The current study provides a comprehensive evaluation on both lignin and carbohydrate degradation during kraft pulping of multiple hardwood species. The kraft delignification rates of E. urograndis, E. nitens, E. globulus, sweet gum, maple, red oak, red alder, cottonwood, and acacia were obtained. Furthermore, the kinetics of glucan, xylan, and total carbohydrate dissolution during the bulk phase of the kraft pulping process for the above species were also investigated. The wide ranges of delignification and carbohydrate degradation rates were correlated to wood chemical characteristics. It appears that the S/G ratio and lignin-carbohydrate-complexes (LCCs are the main characteristics responsible for the differences in kraft pulping performance among the hardwoods studied.

  10. Formation of "bound

    Science.gov (United States)

    Nowak, K.; Kästner, M.; Miltner, A.

    2009-04-01

    During degradation of organic pollutants in soil, metabolites, microbial biomass, CO2and "bound" residues ("non-extractable" residues in soil organic matter) are formed. Enhanced transformation of these contaminants into "bound" residues has been proposed as an alternative remediation method for polluted soils. However, this kind of residues may pose a potential risk for the environment due to their chemical structure and possible remobilization under different conditions. Therefore particular attention is given actually to "bound" residues. Part of these non-extractable residues may be "biogenic," because microorganisms use the carbon from the pollutant to form their biomass components (fatty acids, amino acids, amino sugars), which subsequently may be incorporated into soil organic matter. Furthermore, the CO2 originating from mineralization of xenobiotics, can be re-assimilated by microorganisms and also incorporated into "biogenic residue". The hazard posed by "bound" residues may be overestimated because they are "biogenic" (contain microbial fatty acids and amino acids). The knowledge about the pathways of "biogenic residue" formation is necessary for a proper assessment of the fate of tested pollutants and their turnover in the soil environment. Moreover, these data are needed to establish the realistic degradation rates of the contaminants in soil. The main objectives of this study are: to quantify the extent of "biogenic residue" (fatty acids, amino acids, amino sugars) formation during the degradation of a model pollutant (2,4-dichlorophenoxyacetic acid = 2,4-D) and during CO2 assimilation by microorganisms and to evaluate which components are mainly incorporated into "bound" residues. To investigate the extent of "biogenic residue" formation in soil during the degradation of 2,4-D, experiments with either 14C-U-ring and 13C6-2,4-D or carboxyl-14C 2,4-D were performed. The incubation experiments were performed according to OECD test guideline 307, in the

  11. Nutritional and metabolic responses in common dentex (Dentex dentex) fed on different types and levels of carbohydrates.

    Science.gov (United States)

    Pérez-Jiménez, Amalia; Abellán, Emilia; Arizcun, Marta; Cardenete, Gabriel; Morales, Amalia E; Hidalgo, M Carmen

    2015-06-01

    The present study was aimed to evaluate the capacity of common dentex (Dentex dentex) to efficiently use dietary carbohydrates. So, the effects of different type and levels of carbohydrates on growth performance, feed utilization, fish composition, plasma metabolites and key metabolic pathways in liver and white muscle of common dentex are presented. Nine isonitrogenous (43%) and isoenergetic (22 MJ kg(-1)) diets were formulated combining three types, pregelatinized starch (PS), dextrin (Dx) and maltodextrin (Mx), and three levels (12, 18 and 24%) of carbohydrates. Growth performance was not significantly influenced by treatments. The best feed utilization was observed in 18% Mx group. Higher hepatic lipid content was found in fish fed lower dietary carbohydrate levels. PS induced higher liver and white muscle hexokinase and pyruvate kinase activities compared to the lower values observed for Mx. Malic enzyme and glucose 6-phosphate dehydrogenase in liver and white muscle were lower in Mx group. The influence of dietary carbohydrates source was more noticeable than those induced by the carbohydrate level, when glycolysis and lipogenesis pathways were considered. Common dentex is able to use properly dietary carbohydrates, although optimal dietary inclusion levels are below 24%. The greater protein-sparing effect was promoted by the less complex carbohydrate (maltodextrin) and the best feed utilization indices were obtained at intermediate levels of inclusion (18%).

  12. The Chemical Neurobiology of Carbohydrates

    OpenAIRE

    Murrey, Heather E.; Hsieh-Wilson, Linda C.

    2008-01-01

    The cell surface displays a complex array of oligosaccharides, glycoproteins, and glycolipids. This diverse mixture of glycans contains a wealth of information, modulating a wide range of processes such as cell migration, proliferation, transcriptional regulation, and differentiation. Glycosylation is one of the most ubiquitous forms of post-translational modification, with more than 50% of the human proteome estimated to be glycosylated. Glycosylation adds another dimension to the complexity...

  13. Metabolic aspects of low carbohydrate diets and exercise

    Directory of Open Access Journals (Sweden)

    Peters Sandra

    2004-01-01

    Full Text Available Abstract Following a low carbohydrate diet, there is a shift towards more fat and less carbohydrate oxidation to provide energy to skeletal muscle, both at rest and during exercise. This review summarizes recent work on human skeletal muscle carbohydrate and fat metabolic adaptations to a low carbohydrate diet, focusing mainly on pyruvate dehydrogenase and pyruvate dehydrogenase kinase, and how these changes relate to the capacity for carbohydrate oxidation during exercise.

  14. Moment Problems on Bounded and Unbounded Domains

    Directory of Open Access Journals (Sweden)

    Octav Olteanu

    2013-01-01

    Full Text Available Using approximation results, we characterize the existence of the solution for a two-dimensional moment problem in the first quadrant, in terms of quadratic forms, similar to the one-dimensional case. For the bounded domain case, one considers a space of complex analytic functions in a disk and a space of continuous functions on a compact interval. The latter result seems to give sufficient (and necessary conditions for the existence of a multiplicative solution.

  15. Unique carbohydrate-carbohydrate interactions are required for high affinity binding between FcgammaRIII and antibodies lacking core fucose.

    Science.gov (United States)

    Ferrara, Claudia; Grau, Sandra; Jäger, Christiane; Sondermann, Peter; Brünker, Peter; Waldhauer, Inja; Hennig, Michael; Ruf, Armin; Rufer, Arne Christian; Stihle, Martine; Umaña, Pablo; Benz, Jörg

    2011-08-01

    Antibody-mediated cellular cytotoxicity (ADCC), a key immune effector mechanism, relies on the binding of antigen-antibody complexes to Fcγ receptors expressed on immune cells. Antibodies lacking core fucosylation show a large increase in affinity for FcγRIIIa leading to an improved receptor-mediated effector function. Although afucosylated IgGs exist naturally, a next generation of recombinant therapeutic, glycoenginereed antibodies is currently being developed to exploit this finding. In this study, the crystal structures of a glycosylated Fcγ receptor complexed with either afucosylated or fucosylated Fc were determined allowing a detailed, molecular understanding of the regulatory role of Fc-oligosaccharide core fucosylation in improving ADCC. The structures reveal a unique type of interface consisting of carbohydrate-carbohydrate interactions between glycans of the receptor and the afucosylated Fc. In contrast, in the complex structure with fucosylated Fc, these contacts are weakened or nonexistent, explaining the decreased affinity for the receptor. These findings allow us to understand the higher efficacy of therapeutic antibodies lacking the core fucose and also suggest a unique mechanism by which the immune system can regulate antibody-mediated effector functions.

  16. PROCARB: A Database of Known and Modelled Carbohydrate-Binding Protein Structures with Sequence-Based Prediction Tools

    Directory of Open Access Journals (Sweden)

    Adeel Malik

    2010-01-01

    Full Text Available Understanding of the three-dimensional structures of proteins that interact with carbohydrates covalently (glycoproteins as well as noncovalently (protein-carbohydrate complexes is essential to many biological processes and plays a significant role in normal and disease-associated functions. It is important to have a central repository of knowledge available about these protein-carbohydrate complexes as well as preprocessed data of predicted structures. This can be significantly enhanced by tools de novo which can predict carbohydrate-binding sites for proteins in the absence of structure of experimentally known binding site. PROCARB is an open-access database comprising three independently working components, namely, (i Core PROCARB module, consisting of three-dimensional structures of protein-carbohydrate complexes taken from Protein Data Bank (PDB, (ii Homology Models module, consisting of manually developed three-dimensional models of N-linked and O-linked glycoproteins of unknown three-dimensional structure, and (iii CBS-Pred prediction module, consisting of web servers to predict carbohydrate-binding sites using single sequence or server-generated PSSM. Several precomputed structural and functional properties of complexes are also included in the database for quick analysis. In particular, information about function, secondary structure, solvent accessibility, hydrogen bonds and literature reference, and so forth, is included. In addition, each protein in the database is mapped to Uniprot, Pfam, PDB, and so forth.

  17. Bounding approaches to system identification

    CERN Document Server

    Norton, John; Piet-Lahanier, Hélène; Walter, Éric

    1996-01-01

    In response to the growing interest in bounding error approaches, the editors of this volume offer the first collection of papers to describe advances in techniques and applications of bounding of the parameters, or state variables, of uncertain dynamical systems. Contributors explore the application of the bounding approach as an alternative to the probabilistic analysis of such systems, relating its importance to robust control-system design.

  18. Potential effect of ultrasound on carbohydrates.

    Science.gov (United States)

    Bera, Smritilekha; Mondal, Dhananjoy; Martin, Jacob T; Singh, Man

    2015-06-17

    The use of ultrasound has emerged as one of the most useful alternative energy sources for the synthesis of carbohydrate-derived biologically and pharmaceutically potential compounds. Spectacular advances have been made in the field of sonication-assisted organic reactions, which are known for producing superior yields, enhanced reactivity of the reactant, improved stereoselectivity, and shortened reaction times. Orthogonal protection-deprotection reactions and/or modification and manipulation of functional groups in carbohydrates are common synthetic steps in carbohydrate chemistry. These reaction steps can be driven by the ultrasonic energy generated by acoustic cavitation via the formation and subsequent collapse of ultrasound-induced bubbles. The ultrasound-assisted synthesis of differently functionalised monosaccharides is useful in a wide variety of applications of carbohydrate chemistry such as the glycosylation of oligosaccharides, one pot domino reactions, thioglycoside syntheses, azidoglycoside syntheses, 1,3-dipolar cycloaddition reactions, and syntheses of natural products. This review article covers ultrasound-mediated reactions on carbohydrates that have been described in the literature since 2000.

  19. A novel approach for the quantitation of carbohydrates in mash, wort, and beer with RP-HPLC using 1-naphthylamine for precolumn derivatization.

    Science.gov (United States)

    Rakete, Stefan; Glomb, Marcus A

    2013-04-24

    A novel universal method for the determination of reducing mono-, di-, and oligosaccharides in complex matrices on RP-HPLC using 1-naphthylamine for precolumn derivatization with sodium cyanoborhydride was established to study changes in the carbohydrate profile during beer brewing. Fluorescence and mass spectrometric detection enabled very sensitive analyses of beer-relevant carbohydrates. Mass spectrometry additionally allowed the identification of the molecular weight and thereby the degree of polymerization of unknown carbohydrates. Thus, carbohydrates with up to 16 glucose units were detected. Comparison demonstrated that the novel method was superior to fluorophore-assisted carbohydrate electrophoresis (FACE). The results proved the HPLC method clearly to be more powerful in regard to sensitivity and resolution. Analogous to FACE, this method was designated fluorophore-assisted carbohydrate HPLC (FAC-HPLC).

  20. Bounded Rationality in Transposition Processes

    DEFF Research Database (Denmark)

    Vollaard, Hans; Martinsen, Dorte Sindbjerg

    2014-01-01

    that concerns the organisation and financing of national healthcare systems. This article applies the perspective of bounded rationality to explain (irregularities in) the timely and correct transposition of EU directives. The cognitive and organisational constraints long posited by the bounded rationality...... perspective may affect the commonly employed explanatory factors of administrative capacities, misfit and the heterogeneity of preferences among veto players. To prevent retrospective rationalisation of the transposition process, this paper traces this process as it unfolded in Denmark and the Netherlands....... As bounded rationality is apparent in the transposition processes in these relatively well-organised countries, future transposition studies should devote greater consideration to the bounded rationality perspective....

  1. Curve complexes are rigid

    OpenAIRE

    Rafi, Kasra; Schleimer, Saul

    2007-01-01

    Any quasi-isometry of the complex of curves is bounded distance from a simplicial automorphism. As a consequence, the quasi-isometry type of the curve complex determines the homeomorphism type of the surface.

  2. Quantum Communication Complexity

    OpenAIRE

    Klauck, Hartmut

    2000-01-01

    This paper surveys the field of quantum communication complexity. Some interesting recent results are collected concerning relations to classical communication, lower bound methods, one-way communication, and applications of quantum communication complexity.

  3. Nutraceutical and pharmacological implications of marine carbohydrates.

    Science.gov (United States)

    Pallela, Ramjee

    2014-01-01

    Current day's research has been focusing much on the potential pharmacological or nutraceutical agents of selective health benefits with less toxicity. As a consequence of increased demand of nutritional supplements of great medicinal values, development of therapeutic agents from natural sources, in particular, marine environment are being considered much important. A diverse array of marine natural products containing medicinally useful nutritional substances, i.e., marine nutraceuticals have been focused to the benefit of mankind. Carbohydrates, by being constituted in considerable amount of many marine organisms display several nutraceutical and pharmaceutical behavior to defend from various diseases. Moreover, the carbohydrates from algae as well as from shellfish wastes, like chitosan and its derivatives, showed tremendous applications in biology and biomedicine. In the current chapter, several of marine carbohydrates from various marine flora and fauna have been covered with their applications and prospects in the development of nutraceuticals and pharmaceuticals.

  4. Investigation of Carbohydrate Recognition via Computer Simulation

    Directory of Open Access Journals (Sweden)

    Quentin R. Johnson

    2015-04-01

    Full Text Available Carbohydrate recognition by proteins, such as lectins and other (biomolecules, can be essential for many biological functions. Recently, interest has arisen due to potential protein and drug design and future bioengineering applications. A quantitative measurement of carbohydrate-protein interaction is thus important for the full characterization of sugar recognition. We focus on the aspect of utilizing computer simulations and biophysical models to evaluate the strength and specificity of carbohydrate recognition in this review. With increasing computational resources, better algorithms and refined modeling parameters, using state-of-the-art supercomputers to calculate the strength of the interaction between molecules has become increasingly mainstream. We review the current state of this technique and its successful applications for studying protein-sugar interactions in recent years.

  5. Structural basis for the carbohydrate recognition of the Sclerotium rolfsii lectin.

    Science.gov (United States)

    Leonidas, Demetres D; Swamy, Bale M; Hatzopoulos, George N; Gonchigar, Sathisha J; Chachadi, Vishwanath B; Inamdar, Shashikala R; Zographos, Spyros E; Oikonomakos, Nikos G

    2007-05-11

    The crystal structure of a novel fungal lectin from Sclerotium rolfsii (SRL) in its free form and in complex with N-acetyl-d-galactosamine (GalNAc) and N-acetyl- d -glucosamine (GlcNAc) has been determined at 1.1 A, 2.0 A, and 1.7 A resolution, respectively. The protein structure is composed of two beta-sheets, which consist of four and six beta-strands, connected by two alpha-helices. Sequence and structural comparisons reveal that SRL is the third member of a newly identified family of fungal lectins, which includes lectins from Agaricus bisporus and Xerocomus chrysenteron that share a high degree of structural similarity and carbohydrate specificity. The data for the free SRL are the highest resolution data for any protein of this family. The crystal structures of the SRL in complex with two carbohydrates, GalNAc and GlcNAc, which differ only in the configuration of a single epimeric hydroxyl group, provide the structural basis for its carbohydrate specificity. SRL has two distinct carbohydrate-binding sites, a primary and a secondary. GalNAc binds at the primary site, whereas GlcNAc binds only at the secondary site. Thus, SRL has the ability to recognize and probably bind at the same time two different carbohydrate structures. Structural comparison to Agaricus bisporus lectin-carbohydrate complexes reveals that the primary site is also able to bind the Thomsen-Friedenreich antigen (Galbeta1-->3GalNAc-alpha- glycan structures) whereas the secondary site cannot. The features of the molecular recognition at the two sites are described in detail. PMID:17391699

  6. Synthesis of chiral dopants based on carbohydrates.

    Science.gov (United States)

    Tsuruta, Toru; Koyama, Tetsuo; Yasutake, Mikio; Hatano, Ken; Matsuoka, Koji

    2014-07-01

    Chiral dopants based on carbohydrates for nematic liquid crystals were synthesized from D-glucose, and their helical twisting power (HTP) values were evaluated. The chiral dopants induced helices in the host nematic liquid crystals. An acetyl derivative having an ether-type glycosidic linkage between carbohydrate and a mesogenic moiety showed the highest HTP value of 10.4 μm(-1), while an acetyl derivative having an anomeric ester-type linkage did not show any HTP. It was surprising that this molecule had no HTP despite the presence of chirality in the molecule. A relationship between HTP and specific rotation was not observed in this study.

  7. Structural Studies of Complex Carbohydrates of Plant Cell Walls

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, Alan [Univ. of Georgia, Athens, GA (United States); Hahn, Michael G. [Univ. of Georgia, Athens, GA (United States); O' Neill, Malcolm A. [Univ. of Georgia, Athens, GA (United States); York, William S. [Univ. of Georgia, Athens, GA (United States)

    2015-02-17

    Most of the solar energy captured by land plants is converted into the polysaccharides (cellulose, hemicellulose, and pectin) that are the predominant components of the cell wall. These walls, which account for the bulk of plant biomass, have numerous roles in the growth and development of plants. Moreover, these walls have a major impact on human life as they are a renewable source of biomass, a source of diverse commercially useful polymers, a major component of wood, and a source of nutrition for humans and livestock. Thus, understanding the molecular mechanisms that lead to wall assembly and how cell walls and their component polysaccharides contribute to plant growth and development is essential to improve and extend the productivity and value of plant materials. The proposed research will develop and apply advanced analytical and immunological techniques to study specific changes in the structures and interactions of the hemicellulosic and pectic polysaccharides that occur during differentiation and in response to genetic modification and chemical treatments that affect wall biosynthesis. These new techniques will make it possible to accurately characterize minute amounts of cell wall polysaccharides so that subtle changes in structure that occur in individual cell types can be identified and correlated to the physiological or developmental state of the plant. Successful implementation of this research will reveal fundamental relationships between polysaccharide structure, cell wall architecture, and cell wall functions.

  8. Stability and Sugar Recognition Ability of Ricin-Like Carbohydrate Binding Domains

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jianzhuang [ORNL; Nellas, Ricky B [ORNL; Glover, Mary M [ORNL; Shen, Tongye [ORNL

    2011-01-01

    Lectins are a class of proteins known for their novel binding to saccharides. Understanding this sugar recognition process can be crucial in creating structure-based designs of proteins with various biological roles. We focus on the sugar binding of a particular lectin, ricin, which has two -trefoil carbohydrate-binding domains (CRDs) found in several plant protein toxins. The binding ability of possible sites of ricin-like CRD has been puzzling. The apo and various (multiple) ligand-bound forms of the sugar-binding domains of ricin were studied by molecular dynamics simulations. By evaluating structural stability, hydrogen bond dynamics, flexibility, and binding energy, we obtained a detailed picture of the sugar recognition of the ricin-like CRD. Unlike what was previously believed, we found that the binding abilities of the two known sites are not independent of each other. The binding ability of one site is positively affected by the other site. While the mean positions of different binding scenarios are not altered significantly, the flexibility of the binding pockets visibly decreases upon multiple ligand binding. This change in flexibility seems to be the origin of the binding cooperativity. All the hydrogen bonds that are strong in the monoligand state are also strong in the double-ligand complex, although the stability is much higher in the latter form due to cooperativity. These strong hydrogen bonds in a monoligand state are deemed to be the essential hydrogen bonds. Furthermore, by examining the structural correlation matrix, the two domains are structurally one entity. Galactose hydroxyl groups, OH4 and OH3, are the most critical parts in both site 1 and site 2 recognition.

  9. Bounds for Asian basket options

    Science.gov (United States)

    Deelstra, Griselda; Diallo, Ibrahima; Vanmaele, Michèle

    2008-09-01

    In this paper we propose pricing bounds for European-style discrete arithmetic Asian basket options in a Black and Scholes framework. We start from methods used for basket options and Asian options. First, we use the general approach for deriving upper and lower bounds for stop-loss premia of sums of non-independent random variables as in Kaas et al. [Upper and lower bounds for sums of random variables, Insurance Math. Econom. 27 (2000) 151-168] or Dhaene et al. [The concept of comonotonicity in actuarial science and finance: theory, Insurance Math. Econom. 31(1) (2002) 3-33]. We generalize the methods in Deelstra et al. [Pricing of arithmetic basket options by conditioning, Insurance Math. Econom. 34 (2004) 55-57] and Vanmaele et al. [Bounds for the price of discrete sampled arithmetic Asian options, J. Comput. Appl. Math. 185(1) (2006) 51-90]. Afterwards we show how to derive an analytical closed-form expression for a lower bound in the non-comonotonic case. Finally, we derive upper bounds for Asian basket options by applying techniques as in Thompson [Fast narrow bounds on the value of Asian options, Working Paper, University of Cambridge, 1999] and Lord [Partially exact and bounded approximations for arithmetic Asian options, J. Comput. Finance 10 (2) (2006) 1-52]. Numerical results are included and on the basis of our numerical tests, we explain which method we recommend depending on moneyness and time-to-maturity.

  10. A Lower Bound on Concurrence

    Institute of Scientific and Technical Information of China (English)

    LIU Li-Guo; TIAN Cheng-Lin; CHEN Ping-Xing; YUAN Nai-Chang

    2009-01-01

    We derive an analytical lower bound on the concurrence for bipartite quantum systems with an improved computable cross norm or realignment criterion and an improved positive partial transpose criterion respectively.Furthermore we demonstrate that our bound is better than that obtained from the local uncertainty relations criterion with optimal local orthogonal observables which is known as one of the best estimations of concurrence.

  11. Lower Bound Bayesian Networks - An Efficient Inference of Lower Bounds on Probability Distributions in Bayesian Networks

    CERN Document Server

    Andrade, Daniel

    2012-01-01

    We present a new method to propagate lower bounds on conditional probability distributions in conventional Bayesian networks. Our method guarantees to provide outer approximations of the exact lower bounds. A key advantage is that we can use any available algorithms and tools for Bayesian networks in order to represent and infer lower bounds. This new method yields results that are provable exact for trees with binary variables, and results which are competitive to existing approximations in credal networks for all other network structures. Our method is not limited to a specific kind of network structure. Basically, it is also not restricted to a specific kind of inference, but we restrict our analysis to prognostic inference in this article. The computational complexity is superior to that of other existing approaches.

  12. Species Differences in the Carbohydrate Binding Preferences of Surfactant Protein D

    DEFF Research Database (Denmark)

    Crouch, Erika C.; Smith, Kelly; McDonald, Barbara;

    2006-01-01

    Interactions of surfactant protein D (SP-D) with micro-organisms and organic antigens involve binding to the trimeric neck plus carbohydrate recognition domain (neck+CRD). In these studies, we compared the ligand binding of homologous human, rat, and mouse trimeric neck+CRD fusion proteins, each...... of the corresponding murine sequence (Asn324-Asn325) conferred a capacity to interact with immobilized maltose. Thus, ligand recognition by human SP-D involves a complex interplay between saccharide presentation, the valency of trimeric subunits, and species-specific residues that flank the primary carbohydrate...

  13. Stacking interactions between carbohydrate and protein quantified by combination of theoretical and experimental methods.

    Directory of Open Access Journals (Sweden)

    Michaela Wimmerová

    Full Text Available Carbohydrate-receptor interactions are an integral part of biological events. They play an important role in many cellular processes, such as cell-cell adhesion, cell differentiation and in-cell signaling. Carbohydrates can interact with a receptor by using several types of intermolecular interactions. One of the most important is the interaction of a carbohydrate's apolar part with aromatic amino acid residues, known as dispersion interaction or CH/π interaction. In the study presented here, we attempted for the first time to quantify how the CH/π interaction contributes to a more general carbohydrate-protein interaction. We used a combined experimental approach, creating single and double point mutants with high level computational methods, and applied both to Ralstonia solanacearum (RSL lectin complexes with α-L-Me-fucoside. Experimentally measured binding affinities were compared with computed carbohydrate-aromatic amino acid residue interaction energies. Experimental binding affinities for the RSL wild type, phenylalanine and alanine mutants were -8.5, -7.1 and -4.1 kcal x mol(-1, respectively. These affinities agree with the computed dispersion interaction energy between carbohydrate and aromatic amino acid residues for RSL wild type and phenylalanine, with values -8.8, -7.9 kcal x mol(-1, excluding the alanine mutant where the interaction energy was -0.9 kcal x mol(-1. Molecular dynamics simulations show that discrepancy can be caused by creation of a new hydrogen bond between the α-L-Me-fucoside and RSL. Observed results suggest that in this and similar cases the carbohydrate-receptor interaction can be driven mainly by a dispersion interaction.

  14. Analysis of Price Stackelberg Duopoly Game with Bounded Rationality

    Directory of Open Access Journals (Sweden)

    Lian Shi

    2014-01-01

    Full Text Available The classical Stackelberg game is extended to boundedly rational price Stackelberg game, and the dynamic duopoly game model is described in detail. By using the theory of bifurcation of dynamical systems, the existence and stability of the equilibrium points of this model are studied. And some comparisons with Bertrand game with bounded rationality are also performed. Stable region, bifurcation diagram, The Largest Lyapunov exponent, strange attractor, and sensitive dependence on initial conditions are used to show complex dynamic behavior. The results of theoretical and numerical analysis show that the stability of the price Stackelberg duopoly game with boundedly rational players is only relevant to the speed of price adjustment of the leader and not relevant to the follower’s. This is different from the classical Cournot and Bertrand duopoly game with bounded rationality. And the speed of price adjustment of the boundedly rational leader has a destabilizing effect on this model.

  15. Classical and quantum partition bound and detector inefficiency

    CERN Document Server

    Laplante, S; Roland, J

    2012-01-01

    In communication complexity, two players each have an input and they wish to compute some function of the joint inputs. This has been the object of much study and a wide variety of lower bound methods have been introduced to address the problem of showing lower bounds on communication. Recently, Jain and Klauck introduced the partition bound, which subsumes many of the known methods, in particular factorization norm, discrepancy, and the rectangle (corruption) bound. Physicists have considered a closely related scenario where two players share a predefined entangled state. Each is given a measurement as input, which they perform on their share of the system. The outcomes of the measurements follow a distribution which is predicted by quantum mechanics. In an experimental setting, Bell inequalities are used to distinguish truly quantum from classical behavior. We present a new lower bound technique based on the notion of detector inefficiency (where some runs are discarded by either of the players) for the ext...

  16. Carbohydrate recognition by the antiviral lectin cyanovirin-N.

    Science.gov (United States)

    Fujimoto, Yukiji K; Green, David F

    2012-12-01

    Cyanovirin-N (CVN) is a cyanobacterial lectin with potent antiviral activity and has been the focus of extensive preclinical investigation as a potential prophylactic for the prevention of the sexual transmission of the human immunodeficiency virus (HIV). Here we present a detailed analysis of carbohydrate recognition by this important protein, using a combination of computational methods, including extensive molecular dynamics simulations and molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) energetic analysis. The simulation results strongly suggest that the observed tendency of wild-type CVN to form domain-swapped dimers is the result of a previously unidentified cis-peptide bond present in the monomeric state. The energetic analysis additionally indicates that the highest-affinity ligand for CVN characterized to date (α-Man-(1,2)-α-Man-(1,2)-α-Man) is recognized asymmetrically by the two binding sites. Finally, we are able to provide a detailed map of the role of all binding site functional groups (both backbone and side chain) to various aspects of molecular recognition: general affinity for cognate ligands, specificity for distinct oligosaccharide targets, and the asymmetric recognition of α-Man-(1,2)-α-Man-(1,2)-α-Man. Taken as a whole, these results complement past experimental characterization (both structural and thermodynamic) to provide the most complete understanding of carbohydrate recognition by CVN to date. The results also provide strong support for the application of similar approaches to the understanding of other protein-carbohydrate complexes. PMID:23057413

  17. A Metric Encoding for Bounded Model Checking

    Science.gov (United States)

    Pradella, Matteo; Morzenti, Angelo; San Pietro, Pierluigi

    In Bounded Model Checking, both the system model and the checked property are translated into a Boolean formula to be analyzed by a SAT-solver. We introduce a new encoding technique which is particularly optimized for managing quantitative future and past metric temporal operators, typically found in properties of hard real time systems. The encoding is simple and intuitive in principle, but it is made more complex by the presence, typical of the Bounded Model Checking technique, of backward and forward loops used to represent an ultimately periodic infinite domain by a finite structure. We report and comment on the new encoding technique and on an extensive set of experiments carried out to assess its feasibility and effectiveness.

  18. Tight Bounds for Distributed Functional Monitoring

    DEFF Research Database (Denmark)

    Woodruff, David P.; Zhang, Qin

    2011-01-01

    We resolve several fundamental questions in the area of distributed functional monitoring, initiated by Cormode, Muthukrishnan, and Yi (SODA, 2008). In this model there are $k$ sites each tracking their input and communicating with a central coordinator that continuously maintain an approximate...... output to a function $f$ computed over the union of the inputs. The goal is to minimize the communication. We show the randomized communication complexity of estimating the number of distinct elements up to a $1+\\eps$ factor is $\\Omega(k/\\eps^2)$, improving the previous $\\Omega(k + 1/\\eps^2)$ bound......} t))$ to $\\tilde{\\Omega}(n^{1-2/p}/(\\eps^{4/p} t))$, giving the first bound for estimating $F_0$ in $t$ passes of $\\Omega(1/(\\eps^2 t))$ bits of space that does not use the gap-hamming problem, and showing a distribution for the gap-hamming problem with high external information cost or super-polynomial...

  19. Mutual information rate and bounds for it.

    Directory of Open Access Journals (Sweden)

    Murilo S Baptista

    Full Text Available The amount of information exchanged per unit of time between two nodes in a dynamical network or between two data sets is a powerful concept for analysing complex systems. This quantity, known as the mutual information rate (MIR, is calculated from the mutual information, which is rigorously defined only for random systems. Moreover, the definition of mutual information is based on probabilities of significant events. This work offers a simple alternative way to calculate the MIR in dynamical (deterministic networks or between two time series (not fully deterministic, and to calculate its upper and lower bounds without having to calculate probabilities, but rather in terms of well known and well defined quantities in dynamical systems. As possible applications of our bounds, we study the relationship between synchronisation and the exchange of information in a system of two coupled maps and in experimental networks of coupled oscillators.

  20. Mutual information rate and bounds for it.

    Science.gov (United States)

    Baptista, Murilo S; Rubinger, Rero M; Viana, Emilson R; Sartorelli, José C; Parlitz, Ulrich; Grebogi, Celso

    2012-01-01

    The amount of information exchanged per unit of time between two nodes in a dynamical network or between two data sets is a powerful concept for analysing complex systems. This quantity, known as the mutual information rate (MIR), is calculated from the mutual information, which is rigorously defined only for random systems. Moreover, the definition of mutual information is based on probabilities of significant events. This work offers a simple alternative way to calculate the MIR in dynamical (deterministic) networks or between two time series (not fully deterministic), and to calculate its upper and lower bounds without having to calculate probabilities, but rather in terms of well known and well defined quantities in dynamical systems. As possible applications of our bounds, we study the relationship between synchronisation and the exchange of information in a system of two coupled maps and in experimental networks of coupled oscillators. PMID:23112809

  1. Bounded link prediction for very large networks

    CERN Document Server

    Cui, Wei; Xu, Zhongqi

    2015-01-01

    Evaluation of link prediction methods is a hard task in very large complex networks because of the inhibitive computational cost. By setting a lower bound of the number of common neighbors (CN), we propose a new framework to efficiently and precisely evaluate the performances of CN-based similarity indices in link prediction for very large heterogeneous networks. Specifically, we propose a fast algorithm based on the parallel computing scheme to obtain all the node pairs with CN values larger than the lower bound. Furthermore, we propose a new measurement, called self-predictability, to quantify the performance of the CN-based similarity indices in link prediction, which on the other side can indicate the link predictability of a network.

  2. Optimal Bounds in Parametric LTL Games

    Directory of Open Access Journals (Sweden)

    Martin Zimmermann

    2011-06-01

    Full Text Available We consider graph games of infinite duration with winning conditions in parameterized linear temporal logic, where the temporal operators are equipped with variables for time bounds. In model checking such specifications were introduced as "PLTL" by Alur et al. and (in a different version called "PROMPT-LTL" by Kupferman et al.. We present an algorithm to determine optimal variable valuations that allow a player to win a game. Furthermore, we show how to determine whether a player wins a game with respect to some, infinitely many, or all valuations. All our algorithms run in doubly-exponential time; so, adding bounded temporal operators does not increase the complexity compared to solving plain LTL games.

  3. Identification and characterization of sulfated carbohydrate-binding protein from Lactobacillus reuteri.

    Directory of Open Access Journals (Sweden)

    Keita Nishiyama

    Full Text Available We previously purified a putative sulfated-galactosylceramide (sulfatide-binding protein with a molecular weight of 47 kDa from the cell surface of Lactobacillus reuteri JCM1081. The aim of this study was to identify the 47-kDa protein, examine its binding to sulfated glycolipids and mucins, and evaluate its role in bacterial adhesion to mucosal surfaces. By cloning and sequencing analysis, the 47-kDa protein was identified as elongation factor-Tu (EF-Tu. Adhesion properties were examined using 6 × Histidine-fused EF-Tu (His6-EF-Tu. Surface plasmon resonance analysis demonstrated pH-dependent binding of His6-EF-Tu to sulfated glycolipids, but not to neutral or sialylated glycolipids, suggesting that a sulfated galactose residue was responsible for EF-Tu binding. Furthermore, His6-EF-Tu was found to bind to porcine gastric mucin (PGM by enzyme-linked immunosorbent assay. Binding was markedly reduced by sulfatase treatment of PGM and in the presence of acidic and desialylated oligosaccharide fractions containing sulfated carbohydrate residues prepared from PGM, demonstrating that sulfated carbohydrate moieties mediated binding. Histochemical staining revealed similar localization of His6-EF-Tu and high iron diamine staining in porcine mucosa. These results indicated that EF-Tu bound PGM via sulfated carbohydrate moieties. To characterize the contribution of EF-Tu to the interaction between bacterial cells and PGM, we tested whether anti-EF-Tu antibodies could inhibit the interaction. Binding of L. reuteri JCM1081 to PGM was significantly blocked in a concentration-dependent matter, demonstrating the involvement of EF-Tu in bacterial adhesion. In conclusion, the present results demonstrated, for the first time, that EF-Tu bound sulfated carbohydrate moieties of sulfated glycolipids and sulfomucin, thereby promoting adhesion of L. reuteri to mucosal surfaces.

  4. Nutrient and carbohydrate partitioning in sorghum stover

    International Nuclear Information System (INIS)

    Sorghum [Sorghum bicolor (L.) Moench] stover has been demonstrated to be a potential biomass energy source. Complete aboveground crop removal, however, can result in soil degradation. Differential dry matter, nutrient, and carbohydrate partitioning by sorghum cultivars may allow management strategies that return certain parts to the field while removing other portions for alternative uses, such as energy production. A field study was conducted to determine N,P,K, nonstructural carbohydrate, cellulose hemicellulose, and lignin distributions in stover of three diverse sorghum cultivars of differing harvest indices. Determinations were based on total vegetative biomass; total blades; total stalks; and upper middle, and lower blades and stalks. Concentrations of N and P were higher in blades than stalks and generally declines from upper to lower stover parts. Large carbohydrate and lignin concentration differences were observed on the basis of cultivar and stover part. Greater nutrient partitioning to the upper third of the intermediate and forage-type sorghum stovers was observed as compared to the conventional grain cultivar. Stover carbohydrates for all cultivars were mainly contained in the lower two-thirds of the stalk fraction. A system was proposed for returning upper stover portion to soil, while removing remaining portions for alternative uses

  5. The diagenesis of carbohydrates by hydrogen sulfide

    Science.gov (United States)

    Mango, Frank D.

    1983-08-01

    Carbohydrates react with hydrogen sulfide under low temperature (100° to 200°C) yielding a variety of organosulfur compounds including thiophenes, thiols, sulfides and sulfones. A polymer is also produced, whose elemental composition is within the range of natural coals. When reductive dehydration is carried out in the presence of hydrocarbon, organosulfur compounds are formed in the carbon number range of the hydrocarbon used. In these processes, an active hydrogen transfer catalyst is produced which facilitates the passage of hydrogen between normal paraffins and saccharide units, distributing sulfur between these two families primarily in the form of thiophene rings. The simplicity of these systems - H 2S, carbohydrates, H 2O, hydrocarbon - and the facility of the chemistry would suggest that the carbohydrates and hydrogen sulfide may be important agents in the diagenetic processes leading to petroleum and coal. Carbohydrate reduction by hydrogen sulfide may constitute an important route through which certain organosulfur compounds found in petroleum and coal entered these materials in early diagenesis.

  6. Saturated fat, carbohydrates and cardiovascular disease

    NARCIS (Netherlands)

    Kuipers, R. S.; de Graaf, D. J.; Luxwolda, M. F.; Muskiet, M. H. A.; Dijck-Brouwer, D. A. J.; Muskiet, F. A. J.

    2011-01-01

    The dietary intake of saturated fatty acids (SAFA) is associated with a modest increase in serum total cholesterol, but not with cardiovascular disease (CVD). Replacing dietary SAFA with carbohydrates (CHO), notably those with a high glycaemic index, is associated with an increase in CVD risk in obs

  7. General Properties, Occurrence, and Preparation of Carbohydrates

    Science.gov (United States)

    Robyt, John F.

    D-Glucose and its derivatives and analogues, N-acetyl-D-glucosamine, N-acetyl-D-muramic acid, D-glucopyranosyl uronic acid, and D-glucitol represent 99.9% of the carbohydrates on the earth. D-Glucose is found in the free state in human blood and in the combined state in disaccharides, sucrose, lactose, and α,α-trehalose, in cyclic dextrins, and in polysaccharides, starch, glycogen, cellulose, dextrans; N-acetyl-D-glucosamine and an analogue N-acetyl-D-muramic acid are found in bacterial cell wall polysaccharide, murein, along with teichoic acids made up of poly-glycerol or -ribitol phosphodiesters. Other carbohydrates, D-mannose, D-mannuronic acid, D-galactose, N-acetyl-D-galactosamine, D-galacturonic acid, D-iduronic acid, L-guluronic acid, L-rhamnose, L-fucose, D-xylose, and N-acetyl-D-neuraminic acid are found in glycoproteins, hemicelluloses, glycosaminoglycans, and polysaccharides of plant exudates, bacterial capsules, alginates, and heparin. D-Ribofuranose-5-phosphate is found in many coenzymes and is the backbone of RNAs (ribonucleic acid), and 2-deoxy-D-ribofuranose-5-phosphate is the backbone of DNA (deoxyribonucleic acid). D-Fructofuranose is found in sucrose, inulin, and levan. The general properties and occurrence of these carbohydrates and general methods of isolation and preparation of carbohydrates are presented.

  8. Structure of Dioclea virgata lectin: relations between carbohydrate binding site and nitric oxide production

    Energy Technology Data Exchange (ETDEWEB)

    Delatorre, P.; Gadelha, C.A.A.; Santi-Gadelha, T. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Nobrega, R.B.; Rocha, B.A.M.; Nascimento, K.S.; Naganao, C.S.; Sampaio, A.H.; Cavada, B.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Pires, A.F.; Assreuy, A.M.S. [Universidade Estadual do Ceara (UECE), Fortaleza, CE (Brazil)

    2012-07-01

    Full text: Lectins are proteins/glycoproteins with at least one noncatalytic domain binding reversibly to specific monosaccharides or oligosaccharides. By binding to carbohydrate moieties on the cell surface, lectins participate in a range of cellular processes without changing the properties of the carbohydrates involved. The lectin of Dioclea virgata (DvirL), both native and complexed with X-man, was submitted to X-ray diffraction analysis and the crystal structure was compared to that of other Diocleinae lectins in order to better understand differences in biological proper- ties, especially with regard to the ability of lectins to induce nitric oxide (NO) production. The DvirL diffraction analysis revealed that both the native crystal and the X-Man-complexed form are orthorhombic and belong to space group I222. The cell parameters were: a=65.4 , b=86.6 and c=90.2 (native structure), and a=61.89 , b=87.67 and c=88.78 (X-Man-complexed structure). An association was observed between the volume of the carbohydrate recognition domain (CRD), the ability to induce NO production and the relative positions of Tyr12, Arg228 and Leu99. Thus, differences in biological activity induced by Diocleinae lectins are related to the configuration of amino acid residues in the carbohydrate binding site and to the structural conformation of subsequent regions capable of influencing site-ligand interactions. In conclusion, the ability of Diocleinae lectins to induce NO production depends on CRD configuration. (author)

  9. Hydrogen and methane breath tests for evaluation of resistant carbohydrates

    DEFF Research Database (Denmark)

    Rumessen, J J

    1992-01-01

    This review considers in detail the background, principles, techniques, limitations and advantages of the hydrogen and methane breath tests. Resistant food carbohydrates, defined as dietary carbohydrates partly or totally escaping small intestinal assimilation, are fermented in the human colon. T...

  10. Energy and carbohydrate for training and recovery.

    Science.gov (United States)

    Burke, Louise M; Loucks, Anne B; Broad, Nick

    2006-07-01

    Soccer players should achieve an energy intake that provides sufficient carbohydrate to fuel the training and competition programme, supplies all nutrient requirements, and allows manipulation of energy or nutrient balance to achieve changes in lean body mass, body fat or growth. Although the traditional culture of soccer has focused on carbohydrate intake for immediate match preparation, top players should adapt their carbohydrate intake on a daily basis to ensure adequate fuel for training and recovery between matches. For players with a mobile playing style, there is sound evidence that dietary programmes that restore and even super-compensate muscle glycogen levels can enhance activity patterns during matches. This will presumably also benefit intensive training, such as twice daily practices. As well as achieving a total intake of carbohydrate commensurate with fuel needs, the everyday diet should promote strategic intake of carbohydrate and protein before and after key training sessions to optimize the adaptations and enhance recovery. The achievement of the ideal physique for soccer is a long-term goal that should be undertaken over successive years, and particularly during the off-season and pre-season. An increase in lean body mass or a decrease in body fat is the product of a targeted training and eating programme. Consultation with a sports nutrition expert can assist soccer players to manipulate energy and nutrient intake to meet such goals. Players should be warned against the accidental or deliberate mismatch of energy intake and energy expenditure, such that energy availability (intake minus the cost of exercise) falls below 125 kJ (30 kcal) per kilogram of fat-free mass per day. Such low energy availability causes disturbances to hormonal, metabolic, and immune function. PMID:16766497

  11. Combining Alphas via Bounded Regression

    Directory of Open Access Journals (Sweden)

    Zura Kakushadze

    2015-11-01

    Full Text Available We give an explicit algorithm and source code for combining alpha streams via bounded regression. In practical applications, typically, there is insufficient history to compute a sample covariance matrix (SCM for a large number of alphas. To compute alpha allocation weights, one then resorts to (weighted regression over SCM principal components. Regression often produces alpha weights with insufficient diversification and/or skewed distribution against, e.g., turnover. This can be rectified by imposing bounds on alpha weights within the regression procedure. Bounded regression can also be applied to stock and other asset portfolio construction. We discuss illustrative examples.

  12. Bounded Model Checking of CTL

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hong Tao; Cong-Hua Zhou; Zhong Chen; Li-Fu Wang

    2007-01-01

    Bounded Model Checking has been recently introduced as an efficient verification method for reactive systems.This technique reduces model checking of linear temporal logic to propositional satisfiability.In this paper we first present how quantified Boolean decision procedures can replace BDDs.We introduce a bounded model checking procedure for temporal logic CTL* which reduces model checking to the satisfiability of quantified Boolean formulas.Our new technique avoids the space blow up of BDDs, and extends the concept of bounded model checking.

  13. Quantum computation speedup limits from quantum metrological precision bounds

    OpenAIRE

    Demkowicz-Dobrzanski, Rafal; Markiewicz, Marcin

    2014-01-01

    We propose a scheme for translating metrological precision bounds into lower bounds on query complexity of quantum search algorithms. Within the scheme the link between quadratic performance enhancement in idealized quantum metrological and quantum computing schemes becomes clear. More importantly, we utilize results from the field of quantum metrology on a generic loss of quadratic quantum precision enhancement in presence of decoherence to infer an analogous generic loss of quadratic speed-...

  14. New worst upper bound for #SAT

    CERN Document Server

    Zhou, Junping; Zhou, Chunguang

    2010-01-01

    The rigorous theoretical analyses of algorithms for #SAT have been proposed in the literature. As we know, previous algorithms for solving #SAT have been analyzed only regarding the number of variables as the parameter. However, the time complexity for solving #SAT instances depends not only on the number of variables, but also on the number of clauses. Therefore, it is significant to exploit the time complexity from the other point of view, i.e. the number of clauses. In this paper, we present algorithms for solving #2-SAT and #3-SAT with rigorous complexity analyses using the number of clauses as the parameter. By analyzing the algorithms, we obtain the new worst-case upper bounds O(1.1892m) for #2-SAT and O(1.4142m) for #3-SAT, where m is the number of clauses.

  15. Carbohydrate deficient transferrin (CDT) in alcoholic cirrhosis: a kinetic study

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Grønbaek, M; Møller, Søren;

    1997-01-01

    controls (n = 8), which indicates a slow turnover rate of carbohydrate deficient transferrin. Food ingestion did not affect the circulating level of carbohydrate deficient transferrin, and the analysis of carbohydrate deficient transferrin was almost unaffected by the presence of ethanol in plasma within...... alcohol intake, but the overlap is substantial in patients with cirrhosis. Carbohydrate deficient transferrin has a low turnover rate in both patients with cirrhosis and normals....

  16. Glycosynapses: microdomains controlling carbohydrate-dependent cell adhesion and signaling

    Directory of Open Access Journals (Sweden)

    Hakomori Senitiroh

    2004-01-01

    Full Text Available The concept of microdomains in plasma membranes was developed over two decades, following observation of polarity of membrane based on clustering of specific membrane components. Microdomains involved in carbohydrate-dependent cell adhesion with concurrent signal transduction that affect cellular phenotype are termed "glycosynapse". Three types of glycosynapse have been distinguished: "type 1" having glycosphingolipid associated with signal transducers (small G-proteins, cSrc, Src family kinases and proteolipids; "type 2" having O-linked mucin-type glycoprotein associated with Src family kinases; and "type 3" having N-linked integrin receptor complexed with tetraspanin and ganglioside. Different cell types are characterized by presence of specific types of glycosynapse or their combinations, whose adhesion induces signal transduction to either facilitate or inhibit signaling. E.g., signaling through type 3 glycosynapse inhibits cell motility and differentiation. Glycosynapses are distinct from classically-known microdomains termed "caveolae", "caveolar membrane", or more recently "lipid raft", which are not involved in carbohydrate-dependent cell adhesion. Type 1 and type 3 glycosynapses are resistant to cholesterol-binding reagents, whereas structure and function of "caveolar membrane" or "lipid raft" are disrupted by these reagents. Various data indicate a functional role of glycosynapses during differentiation, development, and oncogenic transformation.

  17. Bound states in string nets

    CERN Document Server

    Schulz, M D; Vidal, J

    2016-01-01

    We discuss the emergence of bound states in the low-energy spectrum of the string-net Hamiltonian in the presence of a string tension. In the ladder geometry, we show that a single bound state arises either for a finite tension or in the zero-tension limit depending on the theory considered. In the latter case, we perturbatively compute the binding energy as a function of the total quantum dimension. We also address this issue in the honeycomb lattice where the number of bound states in the topological phase depends on the total quantum dimension. Finally, the internal structure of these bound states is analyzed in the zero-tension limit.

  18. Curvature bounds for configuration spaces

    OpenAIRE

    Erbar, Matthias; Huesmann, Martin

    2014-01-01

    We show that the configuration space over a manifold M inherits many curvature properties of the manifold. For instance, we show that a lower Ricci curvature bound on M implies for the configuration space a lower Ricci curvature bound in the sense of Lott-Sturm-Villani, the Bochner inequality, gradient estimates and Wasserstein contraction. Moreover, we show that the heat flow on the configuration space, or the infinite independent particle process, can be identified as the gradient flow of t...

  19. Finite Domain Bounds Consistency Revisited

    OpenAIRE

    Choi, Chiu Wo; Harvey, Warwick; Lee, Jimmy Ho-Man; Stuckey, Peter J.

    2004-01-01

    A widely adopted approach to solving constraint satisfaction problems combines systematic tree search with constraint propagation for pruning the search space. Constraint propagation is performed by propagators implementing a certain notion of consistency. Bounds consistency is the method of choice for building propagators for arithmetic constraints and several global constraints in the finite integer domain. However, there has been some confusion in the definition of bounds consistency. In t...

  20. Entropy bounds for uncollapsed matter

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Gabriel; Visser, Matt, E-mail: Gabriel.Abreu@msor.vuw.ac.nz, E-mail: Matt.Visser@msor.vuw.ac.nz [School of Mathematics, Statistics and Operation Research Victoria University of Wellington Wellington (New Zealand)

    2011-09-22

    In any static spacetime the quasilocal Tolman mass contained within a volume can be reduced to a Gauss-like surface integral involving the flux of a suitably defined generalized surface gravity. By introducing some basic thermodynamics, and invoking the Unruh effect, one can then develop elementary bounds on the quasilocal entropy that are very similar in spirit to the holographic bound, and closely related to entanglement entropy.

  1. Syntheses and reactions of polymer-bound molybdenum complexes and hydrogenolyses of an alkynyl cobalt carbonyl cluster. [Co/sub 3/(CO)/sub 9/CCH/sub 2/CCH/sub 2/C(CH/sub 3/)/sub 3/; cyclopentadienyl-(tricarbonyl) hydridomolybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Frommer, J.E.

    1980-08-01

    Co/sub 3/(CO)/sub 9/CCH/sub 2/C(CH/sub 3/)/sub 3/ reacted with hydrogen in aromatic solvents to yield 3,3-dimethylbutene, 2,2-dimethylbutane, and 4,4-dimethylpentanal. First order decomposition of starting material and a hydrogen pressure dependence for the rate of appearance of total products were indicated. The hydrogenation was inhibited in the presence of carbon monoxide (CO:H/sub 2/, 3.7:3.7 atm, 60/sup 0/C), but at 85/sup 0/ under the same CO/H/sub 2/ atmosphere, aldehyde production became the predominant reaction pathway at the expense of earlier-formed olefin. Incorporation of independently added olefins in the hydrogenation suggested the intermediacy of olefin aldehyde ad alkane production. A polystyrene-attached n/sup 5/-cyclopentadienyl(tricarbonyl)-hydridomolybdenum complex was prepared and its reactions with several THF-soluble bases were investigated. Enolates of ..beta..-dicarbonyl compounds quantitatively deprotonated this complex, giving polymer-bound salts of the corresponding anion. Little change in pKa in THF was induced by binding the molybdenum hydride to the polymer. Even though the polymer-supported partners rendered the reactions heterogeneous, the systems adhered reasonably well to conventional equilibrium behavior. A polymer-bound carboxylic acid and its conjugate base also displayed essentially conventional equilibrium dynamics.

  2. Valuation models and Simon's bounded rationality

    Directory of Open Access Journals (Sweden)

    Alexandra Strommer de Farias Godoi

    2009-09-01

    Full Text Available This paper aims at reconciling the evidence that sophisticated valuation models are increasingly used by companies in their investment appraisal with the literature of bounded rationality, according to which objective optimization is impracticable in the real world because it would demand an immense level of sophistication of the analytical and computational processes of human beings. We show how normative valuation models should rather be viewed as forms of reality representation, frameworks according to which the real world is perceived, fragmented for a better understanding, and recomposed, providing an orderly method for undertaking a task as complex as the investment decision.

  3. Topological edge states of bound photon pairs

    CERN Document Server

    Gorlach, Maxim A

    2016-01-01

    We predict the existence of interaction-driven edge states of bound two-photon quasiparticles in a dimer periodic array of nonlinear optical cavities. Energy spectrum of photon pairs is dramatically richer than in the noninteracting case or in a simple lattice, featuring collapse and revival of multiple edge and bulk modes as well as edge states in continuum. Despite the unexpected breakdown of the Zak phase technique and the edge mixing of internal and center-of-mass motion we link the edge state existence to the two-photon quantum walk graph connectivity, thus uncovering the topological nature of the many-body problem in complex lattices.

  4. Jackson's Theorem on Bounded Symmetric Domains

    Institute of Scientific and Technical Information of China (English)

    Ming Zhi WANG; Guang Bin REN

    2007-01-01

    Polynomial approximation is studied on bounded symmetric domain Ω in C n for holo-morphic function spaces X ,such as Bloch-type spaces,Bergman-type spaces,Hardy spaces,Ω algebra and Lipschitz space.We extend the classical Jackson ’s theorem to several complex variables:E k f,X ) ω (1 /k,f,X ),where E k f,X )is the deviation of the best approximation of f ∈X by polynomials of degree at mostk with respect to the X -metric and ω (1/k,f,X )is the corresponding modulus of continuity.

  5. Glycosylated Conductive Polymer: A Multimodal Biointerface for Studying Carbohydrate-Protein Interactions.

    Science.gov (United States)

    Zeng, Xiangqun; Qu, Ke; Rehman, Abdul

    2016-09-20

    Carbohydrate-protein interactions occur through glycoproteins, glycolipids, or polysaccharides displayed on the cell surface with lectins. However, studying these interactions is challenging because of the complexity and heterogeneity of the cell surface, the inherent structural complexity of carbohydrates, and the typically weak affinities of the binding reactions between the lectins and monovalent carbohydrates. The lack of chromophores and fluorophores in carbohydrate structures often drives such investigations toward fluorescence labeling techniques, which usually require tedious and complex synthetic work to conjugate fluorescent tags with additional risk of altering the reaction dynamics. Probing these interactions directly on the cell surface is even more difficult since cells could be too fragile for labeling or labile dynamics could be affected by the labeled molecules that may interfere with the cellular activities, resulting in unwanted cell responses. In contrast, label-free biosensors allow real-time monitoring of carbohydrate-protein interactions in their natural states. A prerequisite, though, for this strategy to work is to mimic the coding information on potential interactions of cell surfaces onto different biosensing platforms, while the complementary binding process can be transduced into a useful signal noninvasively. Through carbohydrate self-assembled monolayers and glycopolymer scaffolds, the multivalency of the naturally existing simple and complex carbohydrates can be mimicked and exploited with label-free readouts (e.g., optical, acoustic, mechanical, electrochemical, and electrical sensors), yet such inquiries reflect only limited aspects of complicated biointeraction processes due to the unimodal transduction. In this Account, we illustrate that functionalized glycosylated conductive polymer scaffolds are the ideal multimodal biointerfaces that not only simplify the immobilization process for surface fabrication via electrochemical

  6. Quantum Computational Complexity

    OpenAIRE

    Watrous, John

    2008-01-01

    This article surveys quantum computational complexity, with a focus on three fundamental notions: polynomial-time quantum computations, the efficient verification of quantum proofs, and quantum interactive proof systems. Properties of quantum complexity classes based on these notions, such as BQP, QMA, and QIP, are presented. Other topics in quantum complexity, including quantum advice, space-bounded quantum computation, and bounded-depth quantum circuits, are also discussed.

  7. Role of carbohydrate metabolism in grass tetany

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.K.; Madsen, F.C.; Lentz, D.E.; Hansard, S.L.

    1977-01-01

    Clinical hypomagnesemia is confined primarily to beef cattle in the United States but also occurs in dairy cattle in other countries, probably due to different management practices. During periods when grass tetany is likely, early vegetative temperate zone grasses are usually low in total readily available carbohydrates and magnesium but high in potassium and nitrogen. The tetany syndrome may include hypoglycemia and ketosis, suggesting an imbalance in intermediary energy metabolism. Many enzyme systems critical to cellular metabolism, including those which hydrolyze and transfer phosphate groups, are activated by Mg. Thus, by inference, Mg is required for normal glucose utilization, fat, protein, nucleic acid and coenzyme synthesis, muscle contraction, methyl group transfer, and sulfate, acetate, and formate activation. Numerous clinical and experimental studies suggest an intimate relationship between metabolism of Mg and that of carbohydrate, glucagon, and insulin. The objective is to review this literature and suggest ways in which these relationships might contribute to a chain of events leading to grass tetany.

  8. Solubility of carbohydrates in heavy water.

    Science.gov (United States)

    Cardoso, Marcus V C; Carvalho, Larissa V C; Sabadini, Edvaldo

    2012-05-15

    The solubility of several mono-(glucose and xylose), di-(sucrose and maltose), tri-(raffinose) and cyclic (α-cyclodextrin) saccharides in H(2)O and in D(2)O were measured over a range of temperatures. The solution enthalpies for the different carbohydrates in the two solvents were determined using the vant' Hoff equation and the values in D(2)O are presented here for the first time. Our findings indicate that the replacement of H(2)O by D(2)O remarkably decreases the solubilities of the less soluble carbohydrates, such as maltose, raffinose and α-cyclodextrin. On the other hand, the more soluble saccharides, glucose, xylose, and sucrose, are practically insensitive to the H/D replacement in water. PMID:22480785

  9. Carbohydrate drugs%糖类药物

    Institute of Scientific and Technical Information of China (English)

    杜晓光; 耿美玉

    2011-01-01

    As an important biological information molecules and high-density information carriers, sugar chain involved in almost all life processes in living beings, especially in cell differentiation, development, immunity, aging, cancer, signal transduction and other basic life activities and diseases. For the bioactivities of carbohydrates, carbohydrate drugs had been widely used in anti-tumor, Alzheimer's disease, immune, anti-virus, and other diseases. And the use of carbohydrates is still expanding. Therefore, the various bioactivities and low toxicity endow carbohydrates broad prospects.%糖链作为重要的生物信息分了和高密度的信息载体,参与细胞生物几乎所有的生命过程,特别是在细胞分化、发育、免疫、老化、癌变、信息传递等生命基础活动和重大疾病过程中起着特异性的识别、介导与调控作用.由于糖类物质的多种多样的生物活性,糖类药物在抗肿瘤、老年痴呆、免疫、抗病毒等多个重大疾病领域广泛应用,而且其使用范围还在不断开拓中.因此,糖类药物生物活性多样,毒副作用低,具有广阔的发展前景.

  10. Direct synthesis of methyl phosphoramidates in carbohydrates.

    Science.gov (United States)

    Dhurandhare, Vijay M; Mishra, Girija Prasad; Lam, Sarah; Wang, Cheng-Chung

    2015-09-28

    A direct installation of a methyl phosphoramidate group by using methyl benzylphosphoramidochloridate into carbohydrates and amino acid is described. This one-step synthesis is efficient for both primary and secondary alcohols and exhibited excellent regioselectivity and functional group compatibility. Formation of a single diastereomer is observed in certain cases. The N-benzyl protecting group on methyl phosphoramidates is easily removed under mild conditions.

  11. On a Generalization of Kingman's Bounds

    OpenAIRE

    Liu, Zhen; Nain, Philippe; Towsley, Don

    1994-01-01

    In this paper we develop a framework for computing upper and lower bounds of an exponential form for a class of single server queueing systems with non-renewal inputs. These bounds generalize Kingman's bounds for queues with renewal inputs.

  12. Quantification of Carbohydrates in Grape Tissues Using Capillary Zone Electrophoresis

    Science.gov (United States)

    Zhao, Lu; Chanon, Ann M.; Chattopadhyay, Nabanita; Dami, Imed E.; Blakeslee, Joshua J.

    2016-01-01

    Soluble sugars play an important role in freezing tolerance in both herbaceous and woody plants, functioning in both the reduction of freezing-induced dehydration and the cryoprotection of cellular constituents. The quantification of soluble sugars in plant tissues is, therefore, essential in understanding freezing tolerance. While a number of analytical techniques and methods have been used to quantify sugars, most of these are expensive and time-consuming due to complex sample preparation procedures which require the derivatization of the carbohydrates being analyzed. Analysis of soluble sugars using capillary zone electrophoresis (CZE) under alkaline conditions with direct UV detection has previously been used to quantify simple sugars in fruit juices. However, it was unclear whether CZE-based methods could be successfully used to quantify the broader range of sugars present in complex plant extracts. Here, we present the development of an optimized CZE method capable of separating and quantifying mono-, di-, and tri-saccharides isolated from plant tissues. This optimized CZE method employs a column electrolyte buffer containing 130 mM NaOH, pH 13.0, creating a current of 185 μA when a separation voltage of 10 kV is employed. The optimized CZE method provides limits-of-detection (an average of 1.5 ng/μL) for individual carbohydrates comparable or superior to those obtained using gas chromatography–mass spectrometry, and allows resolution of non-structural sugars and cell wall components (structural sugars). The optimized CZE method was successfully used to quantify sugars from grape leaves and buds, and is a robust tool for the quantification of plant sugars found in vegetative and woody tissues. The increased analytical efficiency of this CZE method makes it ideal for use in high-throughput metabolomics studies designed to quantify plant sugars. PMID:27379118

  13. Crystallization and preliminary X-ray analysis of the Ca2+-bound C-terminal lobe of troponin C in complex with a troponin I-derived peptide fragment from Akazara scallop

    International Nuclear Information System (INIS)

    Recombinant TnC was expressed in Escherichia coli, purified, complexed with a 24-residue synthetic peptide derived from scallop troponin I (TnI) and crystallized. Troponin C (TnC) is the Ca2+-binding component of troponin and triggers muscle contraction. TnC of the invertebrate Akazara scallop can bind only one Ca2+ at the C-terminal EF-hand motif. Recombinant TnC was expressed in Escherichia coli, purified, complexed with a 24-residue synthetic peptide derived from scallop troponin I (TnI) and crystallized. The crystals diffracted X-rays to 1.80 Å resolution and belonged to space group P212121, with unit-cell parameters a = 32.1, b = 42.2, c = 60.0 Å. The asymmetric unit was assumed to contain one molecular complex of the Akazara scallop TnC C-lobe and TnI fragment, with a Matthews coefficient of 1.83 Å3 Da−1 and a solvent content of 33.0%

  14. Crystallization and preliminary X-ray analysis of the Ca{sup 2+}-bound C-terminal lobe of troponin C in complex with a troponin I-derived peptide fragment from Akazara scallop

    Energy Technology Data Exchange (ETDEWEB)

    Yumoto, Fumiaki [Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, Bunkyo-ku, Tokyo 113-8657 (Japan); Department of Physiology II, The Jikei University School of Medicine, 3-19-18 Nishi-shinbashi, Minato-ku, Tokyo 105-8461 (Japan); Nagata, Koji; Miyauchi, Yumiko [Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, Bunkyo-ku, Tokyo 113-8657 (Japan); Ojima, Takao; Tanaka, Hiroyuki; Nishita, Kiyoyoshi [Laboratory of Biochemistry and Biotechnology, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611 (Japan); Ohtsuki, Iwao [Department of Physiology II, The Jikei University School of Medicine, 3-19-18 Nishi-shinbashi, Minato-ku, Tokyo 105-8461 (Japan); Tanokura, Masaru, E-mail: amtanok@mail.ecc.u-tokyo.ac.jp [Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, Bunkyo-ku, Tokyo 113-8657 (Japan)

    2007-06-01

    Recombinant TnC was expressed in Escherichia coli, purified, complexed with a 24-residue synthetic peptide derived from scallop troponin I (TnI) and crystallized. Troponin C (TnC) is the Ca{sup 2+}-binding component of troponin and triggers muscle contraction. TnC of the invertebrate Akazara scallop can bind only one Ca{sup 2+} at the C-terminal EF-hand motif. Recombinant TnC was expressed in Escherichia coli, purified, complexed with a 24-residue synthetic peptide derived from scallop troponin I (TnI) and crystallized. The crystals diffracted X-rays to 1.80 Å resolution and belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 32.1, b = 42.2, c = 60.0 Å. The asymmetric unit was assumed to contain one molecular complex of the Akazara scallop TnC C-lobe and TnI fragment, with a Matthews coefficient of 1.83 Å{sup 3} Da{sup −1} and a solvent content of 33.0%.

  15. UV-B radiation does not limit carbohydrate level and carbohydrate metabolism in cucumber leaves

    Directory of Open Access Journals (Sweden)

    Magdalena Rybus-Zając

    2014-08-01

    Full Text Available Cucumber is a vegetable exhibiting relatively high sensitivity to environmental stress factors. When it is grown outdoors, from early stages of development there is a real risk of exposure to elevated UV-B radiation. In order to explain the effects of time-dependent UV-B doses on carbohydrate level and metabolism, the photosynthetic activity, accumulation of carbohydrates and activities of carbohydrate-related enzymes were determined in the cucumber leaves. Elevated UV-B radiation led to an increase in the rate of photosynthesis, which was reflected by an increase in SPAD values. Higher photosynthetic activity resulted in an increase in levels of soluble sugars. In view of the above-mentioned results, radiation stress led to a UV-B time-dependent dose increase in the activity of two enzymes decomposing carbohydrate: invertase and glucosidase. Our results suggest that the exposure of cucumber plants to supplemental UV-B doses does not limit the availability of the photoassimilate. Carbohydrates are required to provide not only respiratory energy for protection, maintenance (and repair of plant activity and structure, but also provide biosynthetic carbon skeletons for secondary metabolite synthesis

  16. Eta nuclear bound states revisited

    CERN Document Server

    Friedman, E; Mareš, J

    2013-01-01

    The strong energy dependence of the s-wave eta-N scattering amplitude at and below threshold, as evident in coupled-channels K-matrix fits and chiral models that incorporate the S11 N*(1535) resonance, is included self consistently in eta-nuclear bound state calculations. This approach, applied recently in calculations of kaonic atoms and Kbar-nuclear bound states, is found to impose stronger constraints than ever on the onset of eta-nuclear binding, with a minimum value of Re a_{eta N} approximately 0.9 fm required to accommodate an eta-4He bound state. Binding energies and widths of eta-nuclear states are calculated within several underlying eta-N models for nuclei across the periodic table, including eta-25Mg for which some evidence was proposed in a recent COSY experiment.

  17. Simulation bounds for system availability

    International Nuclear Information System (INIS)

    System availability is a dominant factor in the practicality of nuclear power electrical generating plants. A proposed model for obtaining either lower bounds or interval estimates on availability uses observed data on ''n'' failure-to-repair cycles of the system to estimate the parameters in the time-to-failure and time-to-repair models. These estimates are then used in simulating failure/repair cycles of the system. The availability estimate is obtained for each of 5000 samples of ''n'' failure/repair cycles to form a distribution of estimates. Specific percentile points of those simulated distributions are selected as lower simulation bounds or simulation interval bounds for the system availability. The method is illustrated with operational data from two nuclear plants for which an exponential time-to-failure and a lognormal time-to-repair are assumed

  18. Energy bounds in designer gravity

    Science.gov (United States)

    Amsel, Aaron J.; Marolf, Donald

    2006-09-01

    We consider asymptotically anti-de Sitter gravity coupled to tachyonic scalar fields with mass at or slightly above the Breitenlohner-Freedman bound in d≥4 spacetime dimensions. The boundary conditions in these “designer gravity” theories are defined in terms of an arbitrary function W. We give a general argument that the Hamiltonian generators of asymptotic symmetries for such systems will be finite, and proceed to construct these generators using the covariant phase space method. The direct calculation confirms that the generators are finite and shows that they take the form of the pure gravity result plus additional contributions from the scalar fields. By comparing the generators to the spinor charge, we derive a lower bound on the gravitational energy when W has a global minimum and the Breitenlohner-Freedman bound is not saturated.

  19. Experimental activation of bound entanglement.

    Science.gov (United States)

    Kaneda, Fumihiro; Shimizu, Ryosuke; Ishizaka, Satoshi; Mitsumori, Yasuyoshi; Kosaka, Hideo; Edamatsu, Keiichi

    2012-07-27

    Entanglement is one of the essential resources in quantum information and communication technology (QICT). The entanglement thus far explored and applied to QICT has been pure and distillable entanglement. Yet, there is another type of entanglement, called "bound entanglement," which is not distillable by local operations and classical communication. We demonstrate the experimental "activation" of the bound entanglement held in the four-qubit Smolin state, unleashing its immanent entanglement in distillable form, with the help of auxiliary two-qubit entanglement and local operations and classical communication. We anticipate that it opens the way to a new class of QICT applications that utilize more general classes of entanglement than ever, including bound entanglement.

  20. Reset Complexity of Ideal Languages

    OpenAIRE

    Maslennikova, Marina

    2014-01-01

    We present a new characteristic of a regular ideal language called reset complexity. We find some bounds on the reset complexity in terms of the state complexity of a given language. We also compare the reset complexity and the state complexity for languages related to slowly synchronizing automata and study uniqueness question for automata yielding the minimum of reset complexity.

  1. Refining Castelnuovo-Halphen bounds

    CERN Document Server

    Di Gennaro, Vincenzo

    2011-01-01

    Fix integers $r,d,s,\\pi$ with $r\\geq 4$, $d\\gg s$, $r-1\\leq s \\leq 2r-4$, and $\\pi\\geq 0$. Refining classical results for the genus of a projective curve, we exhibit a sharp upper bound for the arithmetic genus $p_a(C)$ of an integral projective curve $C\\subset {\\mathbb{P}^r}$ of degree $d$, assuming that $C$ is not contained in any surface of degree $ \\pi$. Next we discuss other types of bound for $p_a(C)$, involving conditions on the entire Hilbert polynomial of the integral surfaces on which $C$ may lie.

  2. Variables Bounding Based Retiming Algorithm

    Institute of Scientific and Technical Information of China (English)

    宫宗伟; 林争辉; 陈后鹏

    2002-01-01

    Retiming is a technique for optimizing sequential circuits. In this paper, wediscuss this problem and propose an improved retiming algorithm based on variables bounding.Through the computation of the lower and upper bounds on variables, the algorithm can signi-ficantly reduce the number of constraints and speed up the execution of retiming. Furthermore,the elements of matrixes D and W are computed in a demand-driven way, which can reducethe capacity of memory. It is shown through the experimental results on ISCAS89 benchmarksthat our algorithm is very effective for large-scale sequential circuits.

  3. Characterization of Cu(II-ACC Complexes and Conversion of the Bound ACC into Ethylene in the Presence of Hydrogen Peroxide. Detection of a Brown Intermediate at Low Temperature

    Directory of Open Access Journals (Sweden)

    Wadih Ghattas

    2007-01-01

    Full Text Available Two copper(II-ACC complexes were prepared and characterized: [Cu(bpy(ACC(H2O]⋅CO4 (1 and [Cu(ACC2]3⋅4H2O (2. Their crystallographic structures are described and analyzed. Spectroscopic characterizations (UV-visible and EPR confirm that the structure is maintained in solution. These complexes are able to produce ethylene in the presence of hydrogen peroxide in an “ACC Oxidase-like” reaction in water and in methanol. The conversion of ACC into ethylene depends on the amount of base, and, in methanol, 3 equivalents of NaOH are needed for optimum activity. The base is proposed to play a role in H2O2 deprotonation. The presence of an exogenic ligand (bpy is important for the reactivity and may stabilize a reaction intermediate. Indeed, a brown intermediate with an absorption band centered at 433 nm can be detected at low temperature when 1 is treated with 10 equivalents of H2O2.

  4. Analytic continuation of bound states to solve resonance states

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Norimichi; Arai, Koji [Niigata Univ. (Japan); Suzuki, Yoshiyuki; Varga, K.

    1997-05-01

    As a method to determine the parameters of the resonance state, a method is proposed using analytic continuation on bound constants of correlation. The characteristics of this method consists in probability of prediction of the parameters of the resonance state only by calculation of the bound state. Owing to conducting the analytic continuation on square root of energy in the bound state as a function relating to the bound constant, energy and width in the bound state was determined. Here was reported on a result of application of this method to three systems. Some partial wave on two systems showing correlation at a simple potential and a resonance state of zero of all orbital angular motion quality in three boson system were determined using the analytic continuation method. These results agreed well with one used a method of integrating Schroedinger equation directly and one used the complex scaling method, and this method was found to be much efficient for the study of the resonance state. Under a background of becoming applicable to the method of analytic continuation, there was development of calculating method for the recent small number multi system. As the characteristics of the analytic continuation method is used for only calculation of the bound state, it is convenient at a point applicable to the method to obtain conventional bound state and then is much efficient in a point of applicability of calculus of variations. However, in order to obtain coefficient of Pade approximation correctly, the bound state must be solved correctly, which is difficult for more complex system and is not always applicable to every systems. (G.K.)

  5. Interleukin-2 carbohydrate recognition modulates CTLL-2 cell proliferation.

    Science.gov (United States)

    Fukushima, K; Yamashita, K

    2001-03-01

    Interleukin-2 (IL-2) specifically recognizes high-mannose type glycans with five or six mannosyl residues. To determine whether the carbohydrate recognition activity of IL-2 contributes to its physiological activity, the inhibitory effects of high-mannose type glycans on IL-2-dependent CTLL-2 cell proliferation were investigated. Man(5)GlcNAc(2)Asn added to CTLL-2 cell cultures inhibited not only phosphorylation of tyrosine kinases but also IL-2-dependent cell proliferation. We found that a complex of IL-2, IL-2 receptor alpha, beta, gamma subunits, and tyrosine kinases was formed in rhIL-2-stimulated CTLL-2 cells. Among the components of this complex, only the IL-2 receptor alpha subunit was stained with Galanthus nivalis agglutinin which specifically recognizes high-mannose type glycans. This staining was diminished after digestion of the glycans with endo-beta-N-acetylglucosaminidase H or D, suggesting that at least a N-glycan containing Man(5)GlcNAc(2) is linked to the extracellular portion of the IL-2 receptor alpha subunit. Our findings indicate that IL-2 binds the IL-2 receptor alpha subunit through Man(5)GlcNAc(2) and a specific peptide sequence on the surface of CTLL-2 cells. When IL-2 binds to the IL-2Ralpha subunit, this may trigger formation of the high affinity complex of IL-2-IL-2Ralpha, -beta, and -gamma subunits, leading to cellular signaling.

  6. Development of a rapid in vitro protein refolding assay which discriminates between peptide-bound and peptide-free forms of recombinant porcine major histocompatibility class I complex (SLA-I)

    DEFF Research Database (Denmark)

    Oleksiewicz, M.B.; Kristensen, B.; Ladekjaer-Mikkelsen, A.S.;

    2002-01-01

    The extracellular domains of swine leukocyte antigen class I (SLA-I, major histocompatibility complex protein class 1) were cloned and sequenced for two haplotypes (114 and H7) which do not share any alleles based on serological typing, and which are the most important in Danish farmed pigs....... The extracellular domain of SLA-I was connected to porcine beta2 microglobulin by glycine-rich linkers. The engineered sin.-le-chain proteins, consisting of fused SLA-I and beta2 microglobulin, were overexpressed as inclusion bodies in Escherichia coli. Also, variants were made of the single-chain proteins......, by linking them through glycine-rich linkers to peptides representing T-cell epitopes from classical swine fever virus (CSFV) and foot-and-mouth disease virus (FMDV). An in vitro refold assay was developed, using a monoclonal anti-SLA antibody (PT85A) to gauge refolding. The single best-defined, SLA...

  7. Bounded Densities and Their Derivatives

    DEFF Research Database (Denmark)

    Kozine, Igor; Krymsky, V.

    2009-01-01

    This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing...

  8. Market Access through Bound Tariffs

    DEFF Research Database (Denmark)

    Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal

    WTO negotiations deal predominantly with bound - besides applied - tariff rates. But, how can reductions in tariffs ceilings, i.e. tariff rates that no exporter may ever actually be confronted with, generate market access? The answer to this question relates to the effects of tariff bindings on t...

  9. Market access through bound tariffs

    DEFF Research Database (Denmark)

    Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal

    2010-01-01

    WTO negotiations deal predominantly with bound - besides applied - tariff rates. But, how can reductions in tariffs ceilings, i.e. tariff rates that no exporter may ever actually be confronted with, generate market access? The answer to this question relates to the effects of tariff bindings on t...

  10. Unconditional lower bounds against advice

    NARCIS (Netherlands)

    H. Buhrman; L. Fortnow; R. Santhanam

    2009-01-01

    We show several unconditional lower bounds for exponential time classes against polynomial time classes with advice, including: (1) For any constant c, NEXP not in P^{NP[n^c]} (2) For any constant c, MAEXP not in MA/n^c (3) BPEXP not in BPP/n^{o(1)}. It was previously unknown even whether NEXP in NP

  11. A Functional Calculus for Quotient Bounded Operators

    Directory of Open Access Journals (Sweden)

    Sorin Mirel Stoian

    2006-12-01

    Full Text Available If (X, P is a sequentially locally convex space, then a quotient bounded operator T beloging to QP is regular (in the sense of Waelbroeck if and only if it is a bounded element (in the sense of Allan of algebra QP. The classic functional calculus for bounded operators on Banach space is generalized for bounded elements of algebra QP.

  12. Quantum dots assisted laser desorption/ionization mass spectrometric detection of carbohydrates: qualitative and quantitative analysis.

    Science.gov (United States)

    Bibi, Aisha; Ju, Huangxian

    2016-04-01

    A quantum dots (QDs) assisted laser desorption/ionization mass spectrometric (QDA-LDI-MS) strategy was proposed for qualitative and quantitative analysis of a series of carbohydrates. The adsorption of carbohydrates on the modified surface of different QDs as the matrices depended mainly on the formation of hydrogen bonding, which led to higher MS intensity than those with conventional organic matrix. The effects of QDs concentration and sample preparation method were explored for improving the selective ionization process and the detection sensitivity. The proposed approach offered a new dimension to the application of QDs as matrices for MALDI-MS research of carbohydrates. It could be used for quantitative measurement of glucose concentration in human serum with good performance. The QDs served as a matrix showed the advantages of low background, higher sensitivity, convenient sample preparation and excellent stability under vacuum. The QDs assisted LDI-MS approach has promising application to the analysis of carbohydrates in complex biological samples. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27041659

  13. A functional genomics approach to establish the complement of carbohydrate transporters in Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Alessandro Bidossi

    Full Text Available The aerotolerant anaerobe Streptococcus pneumoniae is part of the normal nasopharyngeal microbiota of humans and one of the most important invasive pathogens. A genomic survey allowed establishing the occurrence of twenty-one phosphotransferase systems, seven carbohydrate uptake ABC transporters, one sodium:solute symporter and a permease, underlining an exceptionally high capacity for uptake of carbohydrate substrates. Despite high genomic variability, combined phenotypic and genomic analysis of twenty sequenced strains did assign the substrate specificity only to two uptake systems. Systematic analysis of mutants for most carbohydrate transporters enabled us to assign a phenotype and substrate specificity to twenty-three transport systems. For five putative transporters for galactose, pentoses, ribonucleosides and sulphated glycans activity was inferred, but not experimentally confirmed and only one transport system remains with an unknown substrate and lack of any functional annotation. Using a metabolic approach, 80% of the thirty-two fermentable carbon substrates were assigned to the corresponding transporter. The complexity and robustness of sugar uptake is underlined by the finding that many transporters have multiple substrates, and many sugars are transported by more than one system. The present work permits to draw a functional map of the complete arsenal of carbohydrate utilisation proteins of pneumococci, allows re-annotation of genomic data and might serve as a reference for related species. These data provide tools for specific investigation of the roles of the different carbon substrates on pneumococcal physiology in the host during carriage and invasive infection.

  14. A Functional Genomics Approach to Establish the Complement of Carbohydrate Transporters in Streptococcus pneumoniae

    Science.gov (United States)

    Bidossi, Alessandro; Mulas, Laura; Decorosi, Francesca; Colomba, Leonarda; Ricci, Susanna; Pozzi, Gianni; Deutscher, Josef; Viti, Carlo; Oggioni, Marco Rinaldo

    2012-01-01

    The aerotolerant anaerobe Streptococcus pneumoniae is part of the normal nasopharyngeal microbiota of humans and one of the most important invasive pathogens. A genomic survey allowed establishing the occurrence of twenty-one phosphotransferase systems, seven carbohydrate uptake ABC transporters, one sodium∶solute symporter and a permease, underlining an exceptionally high capacity for uptake of carbohydrate substrates. Despite high genomic variability, combined phenotypic and genomic analysis of twenty sequenced strains did assign the substrate specificity only to two uptake systems. Systematic analysis of mutants for most carbohydrate transporters enabled us to assign a phenotype and substrate specificity to twenty-three transport systems. For five putative transporters for galactose, pentoses, ribonucleosides and sulphated glycans activity was inferred, but not experimentally confirmed and only one transport system remains with an unknown substrate and lack of any functional annotation. Using a metabolic approach, 80% of the thirty-two fermentable carbon substrates were assigned to the corresponding transporter. The complexity and robustness of sugar uptake is underlined by the finding that many transporters have multiple substrates, and many sugars are transported by more than one system. The present work permits to draw a functional map of the complete arsenal of carbohydrate utilisation proteins of pneumococci, allows re-annotation of genomic data and might serve as a reference for related species. These data provide tools for specific investigation of the roles of the different carbon substrates on pneumococcal physiology in the host during carriage and invasive infection. PMID:22428019

  15. Effects of carbohydrate, protein and lipid content of organic waste on hydrogen production and fermentation products.

    Science.gov (United States)

    Alibardi, Luca; Cossu, Raffaello

    2016-01-01

    Organic waste from municipalities, food waste and agro-industrial residues are ideal feedstocks for use in biological conversion processes in biorefinery chains, representing biodegradable materials containing a series of substances belonging to the three main groups of the organic matter: carbohydrates, proteins and lipids. Biological hydrogen production by dark fermentation may assume a central role in the biorefinery concept, representing an up-front treatment for organic waste capable of hydrolysing complex organics and producing biohydrogen. This research study was aimed at evaluating the effects of carbohydrate, protein and lipid content of organic waste on hydrogen yields, volatile fatty acid production and carbon-fate. Biogas and hydrogen productions were linearly correlated to carbohydrate content of substrates while proteins and lipids failed to produce significant contributions. Chemical composition also produced effects on the final products of dark fermentation. Acetic and butyric acids were the main fermentation products, with their ratio proving to correlate with carbohydrate and protein content. The results obtained in this research study enhance the understanding of data variability on hydrogen yields from organic waste. Detailed information on waste composition and chemical characterisation are essential to clearly identify the potential performances of the dark fermentation process. PMID:26254676

  16. Effects of carbohydrate, protein and lipid content of organic waste on hydrogen production and fermentation products.

    Science.gov (United States)

    Alibardi, Luca; Cossu, Raffaello

    2016-01-01

    Organic waste from municipalities, food waste and agro-industrial residues are ideal feedstocks for use in biological conversion processes in biorefinery chains, representing biodegradable materials containing a series of substances belonging to the three main groups of the organic matter: carbohydrates, proteins and lipids. Biological hydrogen production by dark fermentation may assume a central role in the biorefinery concept, representing an up-front treatment for organic waste capable of hydrolysing complex organics and producing biohydrogen. This research study was aimed at evaluating the effects of carbohydrate, protein and lipid content of organic waste on hydrogen yields, volatile fatty acid production and carbon-fate. Biogas and hydrogen productions were linearly correlated to carbohydrate content of substrates while proteins and lipids failed to produce significant contributions. Chemical composition also produced effects on the final products of dark fermentation. Acetic and butyric acids were the main fermentation products, with their ratio proving to correlate with carbohydrate and protein content. The results obtained in this research study enhance the understanding of data variability on hydrogen yields from organic waste. Detailed information on waste composition and chemical characterisation are essential to clearly identify the potential performances of the dark fermentation process.

  17. Diastereoselective B(C6F5)3-Catalyzed Reductive Carbocyclization of Unsaturated Carbohydrates.

    Science.gov (United States)

    Bender, Trandon A; Dabrowski, Jennifer A; Zhong, Hongyu; Gagné, Michel R

    2016-08-19

    A B(C6F5)3-catalyzed method for the selective conversion of unsaturated carbohydrates to cyclopentanes and cyclopropanes is disclosed. Catalyst activation of tertiary silanes generates the ion pair [(C6F5)3B-H][ROSi2] whose components synergistically activate C-O bonds for diastereoselective C-C bond formation. Sila-THF cations are invoked as key intermediates facilitating carbocyclizations. Complex chiral synthons are thereby obtained in a single pot.

  18. Modulation of carbohydrate residues in regenerative nodules and neoplasms of canine and feline pancreas.

    OpenAIRE

    Skutelsky, E.; Alroy, J.; Ucci, A. A.; Carpenter, J.L.; Moore, F. M.

    1987-01-01

    The glycoconjugates of regenerative acinar cells, acinic cell carcinomas, islet cell tumors, and normal canine and feline pancreas were studied. The authors used biotinylated lectins as probes and avidin-biotin-peroxidase complex as visualant to identify and to compare the distribution of carbohydrate residues on paraffin sections from 74 cases. The findings demonstrate a difference in the staining pattern between normal acinar, islet, and ductal cells in each species and small differences in...

  19. Carbohydrates/nucleosides/RNA-DNA-ligand interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kaptein, R.; McConnell, B.; Serianni, A.S.; Silks, L.A. III

    1994-12-01

    Carbohydrate and nucleotide structural determination using modern spectroscopic techniques is dependent on our ability to label oligonucleotides and oligosaccharides with stable isotopes. Uniform Carbon 13 and Nitrogen 15 labeling of oligonucleotides is important to present-day efforts, which are focused on determining the structure of relatively small oligosaccharides and oligonucleotides, which form the elements of larger structures. Because of the relatively recent interest in three-dimensional structure, the development of techniques used to label them has lagged behind parallel techniques used to label peptides and proteins. Therefore, this group`s discussion focused primarily on problems faced today in obtaining oligonucleotides labeled uniformly with carbon 13 and nitrogen 15.

  20. Multimodal CARS microscopy of structured carbohydrate biopolymers

    Science.gov (United States)

    Slepkov, Aaron D.; Ridsdale, Andrew; Pegoraro, Adrian F.; Moffatt, Douglas J.; Stolow, Albert

    2010-01-01

    We demonstrate the utility of multimodal coherent anti-Stokes Raman scattering (CARS) microscopy for the study of structured condensed carbohydrate systems. Simultaneous second-harmonic generation (SHG) and spectrally-scanned CARS microscopy was used to elucidate structure, alignment, and density in cellulose cotton fibers and in starch grains undergoing rapid heat-moisture swelling. Our results suggest that CARS response of the O-H stretch region (3000 cm−1–3400 cm−1), together with the commonly-measured C-H stretch (2750 cm−1–2970 cm−1) and SHG provide potentially important structural information and contrast in these materials. PMID:21258555

  1. A high-power carbohydrate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Ragnar [SuFuCell AB, Bytaregatan 23, SE 222 21 Lund (Sweden); Folkesson, Boerje [Bronsaaldersvaegen 21, SE-226 54 Lund (Sweden); Spaziante, Placido M. [Cellennium Co., Ltd., 14th Floor Gypsum Metropolitan Tower, 539 Sri Ayudhaya Rd., Bangkok 10400 (Thailand); Veerasai, Waret [Chemistry Department, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand); Exell, Robert H.B. [Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, 91 Prachauthit Rd., Bangmod, Tungkru, Bangkok 10140 (Thailand)

    2006-04-01

    This paper reports the development of a fuel cell consisting of a vanadium flow battery in which the vanadium ions are reduced by sugar (from a carbohydrate) to oxidation state +3 on one side of a membrane, and are oxidized to state +5 on the other side by oxygen. The theoretical upper limit to the conversion efficiency of the energy in sugar by this method under standard conditions is 54%. We have obtained efficiencies up to 45% in our laboratory tests. This way of using biomass for electricity production avoids the Carnot cycle losses in heat engines. (author)

  2. Carbohydrate-active enzymes from pigmented Bacilli: a genomic approach to assess carbohydrate utilization and degradation

    Directory of Open Access Journals (Sweden)

    Henrissat Bernard

    2011-09-01

    Full Text Available Abstract Background Spore-forming Bacilli are Gram-positive bacteria commonly found in a variety of natural habitats, including soil, water and the gastro-intestinal (GI-tract of animals. Isolates of various Bacillus species produce pigments, mostly carotenoids, with a putative protective role against UV irradiation and oxygen-reactive forms. Results We report the annotation of carbohydrate active enzymes (CAZymes of two pigmented Bacilli isolated from the human GI-tract and belonging to the Bacillus indicus and B. firmus species. A high number of glycoside hydrolases (GHs and carbohydrate binding modules (CBMs were found in both isolates. A detailed analysis of CAZyme families, was performed and supported by growth data. Carbohydrates able to support growth as the sole carbon source negatively effected carotenoid formation in rich medium, suggesting that a catabolite repression-like mechanism controls carotenoid biosynthesis in both Bacilli. Experimental results on biofilm formation confirmed genomic data on the potentials of B. indicus HU36 to produce a levan-based biofilm, while mucin-binding and -degradation experiments supported genomic data suggesting the ability of both Bacilli to degrade mammalian glycans. Conclusions CAZy analyses of the genomes of the two pigmented Bacilli, compared to other Bacillus species and validated by experimental data on carbohydrate utilization, biofilm formation and mucin degradation, suggests that the two pigmented Bacilli are adapted to the intestinal environment and are suited to grow in and colonize the human gut.

  3. CARBOHYDRATE INGESTION AND EXERCISE: EFFECTS ON METABOLISM AND PERFORMANCE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@KEY POINTS ■ Carbohydrate is the preferred fuel for most competitive sports;an inadequate supply of carbohydrate in the body often leads to poor performance. ■ Carbohydrate ingestion during exercise increases blood glucose availability and maintains the ability of the body to use carbohydrate as fuel during exercise.When carbohydrate is consumed during exercise,glucose uptake by muscles is increased,and the breakdown of glycogen in the liver into blood glucose is reduced,thus saving liver glycogen until late in exercise.The use of muscle glycogen for energy is generally unaffected by carbohydrate feeding.However,during prolonged running,the breakdown of muscle glycogen may be slowed because the supply of blood glucose is improved when carbohydrate is consumed.These metabolic responses underlie the performance benefit that accompanies carbohydrate ingestion during exercise. ■ There are some minor differences among glucose,sucrose,and maltodextrins in their effects on metabolism,but each of them can enhance performance when ingested in the appropriate quantity during exercise.Fructose alone is not an effective carbohydrate supplement because of its slow absorption and slow conversion by the body to glucose,but when small amounts of fructose are combined with other carbohydrates,fructose can be beneficial. ■ Ingesting carbohydrate at a rate of 30-60 grams per hour can improve exercise erformance.A good way to achieve this carbohydrate intake is to consume 600-to-1200 ml(20-to-40 oz)of a sports drink during each hour of exercise.Consuming carbohydrate in a beverage provides an added benefit of preventing potentially harmful effects of dehydration on performance.

  4. Synthesis and evaluation of novel carbocyclic carbohydrate analogues

    OpenAIRE

    Adamson, Christopher William

    2016-01-01

    Carbohydrate analogues play an indispensible role in the study of glycan processing enzymes. These compounds have attracted attention as probes of enzyme mechanisms, as chemical tools for the elucidation of enzyme function and as potential pharmaceuticals. The development of organocatalytic aldol chemistry has fundamentally altered the way chemists approach the synthesis of carbohydrate analogues. In this thesis I highlight a novel strategy toward the synthesis of carbocyclic carbohydrate ana...

  5. Communication Complexity (for Algorithm Designers)

    OpenAIRE

    Roughgarden, Tim

    2015-01-01

    This document collects the lecture notes from my course "Communication Complexity (for Algorithm Designers),'' taught at Stanford in the winter quarter of 2015. The two primary goals of the course are: 1. Learn several canonical problems that have proved the most useful for proving lower bounds (Disjointness, Index, Gap-Hamming, etc.). 2. Learn how to reduce lower bounds for fundamental algorithmic problems to communication complexity lower bounds. Along the way, we'll also: 3. Get exposure t...

  6. The least-cost low-carbohydrate diet is expensive.

    Science.gov (United States)

    Raffensperger, John F

    2008-01-01

    This article describes the use of operations research methods to study the minimum possible cost of a low-carbohydrate diet. The study compares this cost to the minimum cost of a diet with no limitation on carbohydrate. The rationale for this study is the popularity of the low-carbohydrate diets and their perceived high cost. The method used was an operations research approach to find a set of least cost diets, varying the required carbohydrate. This method was chosen to avoid potential concerns with real diets that may be nutritionally deficient or could be had for a lower cost. The major finding is that the cheapest possible low-carbohydrate diet costs about triple the cost of the cheapest diet with no constraint on carbohydrate. Furthermore, the minimum cost of a diet low in both carbohydrate and fat is 5 to 10 times the cost of the cheapest diet, depending on the relative amounts of these nutrients. As carbohydrate and fat are constrained, cost increases dramatically and nonlinearly. The study identifies which nutrients had the greatest effect on cost for a low-carbohydrate and low-fat diet.

  7. Renewable Hydrogen Carrier — Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy

    Directory of Open Access Journals (Sweden)

    Y.-H. Percival Zhang

    2011-01-01

    Full Text Available The hydrogen economy presents an appealing energy future but its implementation must solve numerous problems ranging from low-cost sustainable production, high-density storage, costly infrastructure, to eliminating safety concern. The use of renewable carbohydrate as a high-density hydrogen carrier and energy source for hydrogen production is possible due to emerging cell-free synthetic biology technology—cell-free synthetic pathway biotransformation (SyPaB. Assembly of numerous enzymes and co-enzymes in vitro can create complicated set of biological reactions or pathways that microorganisms or catalysts cannot complete, for example, C6H10O5 (aq + 7 H2O (l à 12 H2 (g + 6 CO2 (g (PLoS One 2007, 2:e456. Thanks to 100% selectivity of enzymes, modest reaction conditions, and high-purity of generated hydrogen, carbohydrate is a promising hydrogen carrier for end users. Gravimetric density of carbohydrate is 14.8 H2 mass% if water can be recycled from proton exchange membrane fuel cells or 8.33% H2 mass% without water recycling. Renewable carbohydrate can be isolated from plant biomass or would be produced from a combination of solar electricity/hydrogen and carbon dioxide fixation mediated by high-efficiency artificial photosynthesis mediated by SyPaB. The construction of this carbon-neutral carbohydrate economy would address numerous sustainability challenges, such as electricity and hydrogen storage, CO2 fixation and long-term storage, water conservation, transportation fuel production, plus feed and food production.

  8. CARBOHYDRATE INTAKE CONSIDERATIONS FOR YOUNG ATHLETES

    Directory of Open Access Journals (Sweden)

    Veronica Montfort-Steiger

    2007-09-01

    Full Text Available Good nutritional practices are important for exercise performance and health during all ages. Athletes and especially growing children engaged in heavy training have higher energy and nutrient requirements compared to their non-active counterparts. Scientific understanding of sports nutrition for the young athlete is lacking behind the growing number of young athletes engaged in sports. Most of the sports nutrition recommendations given to athletic children and adolescents are based on adult findings due to the deficiency in age specific information in young athletes. Therefore, this review reflects on child specific sports nutrition, particularly on carbohydrate intake and metabolism that distinguishes the child athlete from the adult athlete. Children are characterised to be in an insulin resistance stage during certain periods of maturation, have different glycolytic/metabolic responses during exercise, have a tendency for higher fat oxidation during exercise and show different heat dissipation mechanisms compared to adults. These features point out that young athletes may need different nutritional advice on carbohydrate for exercise to those from adult athletes. Sport drinks for example may need to be adapted to children specific needs. However, more research in this area is warranted to clarify sports nutrition needs of the young athlete to provide better and healthy nutritional guidance to young athletes

  9. Impact of dietary polyphenols on carbohydrate metabolism.

    Science.gov (United States)

    Hanhineva, Kati; Törrönen, Riitta; Bondia-Pons, Isabel; Pekkinen, Jenna; Kolehmainen, Marjukka; Mykkänen, Hannu; Poutanen, Kaisa

    2010-03-31

    Polyphenols, including flavonoids, phenolic acids, proanthocyanidins and resveratrol, are a large and heterogeneous group of phytochemicals in plant-based foods, such as tea, coffee, wine, cocoa, cereal grains, soy, fruits and berries. Growing evidence indicates that various dietary polyphenols may influence carbohydrate metabolism at many levels. In animal models and a limited number of human studies carried out so far, polyphenols and foods or beverages rich in polyphenols have attenuated postprandial glycemic responses and fasting hyperglycemia, and improved acute insulin secretion and insulin sensitivity. The possible mechanisms include inhibition of carbohydrate digestion and glucose absorption in the intestine, stimulation of insulin secretion from the pancreatic beta-cells, modulation of glucose release from the liver, activation of insulin receptors and glucose uptake in the insulin-sensitive tissues, and modulation of intracellular signalling pathways and gene expression. The positive effects of polyphenols on glucose homeostasis observed in a large number of in vitro and animal models are supported by epidemiological evidence on polyphenol-rich diets. To confirm the implications of polyphenol consumption for prevention of insulin resistance, metabolic syndrome and eventually type 2 diabetes, human trials with well-defined diets, controlled study designs and clinically relevant end-points together with holistic approaches e.g., systems biology profiling technologies are needed.

  10. Impact of Dietary Polyphenols on Carbohydrate Metabolism

    Directory of Open Access Journals (Sweden)

    Kati Hanhineva

    2010-03-01

    Full Text Available Polyphenols, including flavonoids, phenolic acids, proanthocyanidins and resveratrol, are a large and heterogeneous group of phytochemicals in plant-based foods, such as tea, coffee, wine, cocoa, cereal grains, soy, fruits and berries. Growing evidence indicates that various dietary polyphenols may influence carbohydrate metabolism at many levels. In animal models and a limited number of human studies carried out so far, polyphenols and foods or beverages rich in polyphenols have attenuated postprandial glycemic responses and fasting hyperglycemia, and improved acute insulin secretion and insulin sensitivity. The possible mechanisms include inhibition of carbohydrate digestion and glucose absorption in the intestine, stimulation of insulin secretion from the pancreatic b-cells, modulation of glucose release from the liver, activation of insulin receptors and glucose uptake in the insulin-sensitive tissues, and modulation of intracellular signalling pathways and gene expression. The positive effects of polyphenols on glucose homeostasis observed in a large number of in vitro and animal models are supported by epidemiological evidence on polyphenol-rich diets. To confirm the implications of polyphenol consumption for prevention of insulin resistance, metabolic syndrome and eventually type 2 diabetes, human trials with well-defined diets, controlled study designs and clinically relevant end-points together with holistic approaches e.g., systems biology profiling technologies are needed.

  11. Catalytic Deoxydehydration of Carbohydrates and Polyols to Chemicals and Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas, Kenneth M. [Univ. of Oklahoma, Norman, OK (United States)

    2016-01-15

    As the world's fossil fuel resources are being depleted and their costs increase, there is an urgent need to discover and develop new processes for the conversion of renewable, biomass resources into fuels and chemical feedstocks. Research and development in this area have been given high priority by both governmental agencies and industry. To increase the energy content and decrease the boiling points of biomass-derived carbohydrates and polyols to the useful liquid range it is necessary to chemically remove water (dehydrate) and, preferably, oxygen (deoxygenate/reduce). The poly-hydroxylic nature of carbohydrates is attractive for their use as functionalized chemical building blocks, but it presents a daunting challenge for their selective conversion to single product chemicals or fuels. The long term, practical objective of this project is to develop catalytic processes for the deoxydehydration (DODH) of biomass-derived carbohydrates and polyols to produce unsaturated alcohols and hydrocarbons of value as chemical feedstocks and fuels; DODH: polyol + reductant --(LMOx catalyst)--> unsaturate + oxidized reductant + H2O. Limited prior studies have established the viability of the DODH process with expensive phosphine reductants and rhenium-catalysts. Initial studies in the PI's laboratory have now demonstrated: 1) the moderately efficient conversion of glycols to olefins by the economical sulfite salts is catalyzed by MeReO3 and Z+ReO4-; 2) effective phosphine-based catalytic DODH of representative glycols to olefins by cheap LMoO2 complexes; and 3) computational studies (with K. Houk, UCLA) have identified several Mo-, W-, and V-oxo complexes that are likely to catalyze glycol DODH. Seeking practically useful DODH reactions of complex polyols and new understanding of the reactivity of polyoxo-metal species with biomass-oxygenates we will employ a two-pronged approach: 1) investigate experimentally the reactivity, both stoichiometric and catalytic, of

  12. Physics with loosely bound nuclei

    Indian Academy of Sciences (India)

    Chhanda Samanta

    2001-08-01

    The essential aspect of contemporary physics is to understand properties of nucleonic matter that constitutes the world around us. Over the years research in nuclear physics has provided strong guidance in understanding the basic principles of nuclear interactions. But, the scenario of nuclear physics changed drastically as the new generation of accelerators started providing more and more rare isotopes, which are away from the line of stability. These weakly bound nuclei are found to exhibit new forms of nuclear matter and unprecedented exotic behaviour. The low breakup thresholds of these rare nuclei are posing new challenges to both theory and experiments. Fortunately, nature has provided a few loosely bound stable nuclei that have been studied thoroughly for decades. Attempts are being made to find a consistent picture for the unstable nuclei starting from their stable counterparts. Some significant differences in the structure and reaction mechanisms are found.

  13. Concentration Bounds for Stochastic Approximations

    CERN Document Server

    Frikha, Noufel

    2012-01-01

    We obtain non asymptotic concentration bounds for two kinds of stochastic approximations. We first consider the deviations between the expectation of a given function of the Euler scheme of some diffusion process at a fixed deterministic time and its empirical mean obtained by the Monte-Carlo procedure. We then give some estimates concerning the deviation between the value at a given time-step of a stochastic approximation algorithm and its target. Under suitable assumptions both concentration bounds turn out to be Gaussian. The key tool consists in exploiting accurately the concentration properties of the increments of the schemes. For the first case, as opposed to the previous work of Lemaire and Menozzi (EJP, 2010), we do not have any systematic bias in our estimates. Also, no specific non-degeneracy conditions are assumed.

  14. Generalized bounds for convex multistage stochastic programs

    CERN Document Server

    Künzi, H; Fandel, G; Trockel, W; Basile, A; Drexl, A; Dawid, H; Inderfurth, K; Kürsten, W; Schittko, U

    2005-01-01

    This work was completed during my tenure as a scientific assistant and d- toral student at the Institute for Operations Research at the University of St. Gallen. During that time, I was involved in several industry projects in the field of power management, on the occasion of which I was repeatedly c- fronted with complex decision problems under uncertainty. Although usually hard to solve, I quickly learned to appreciate the benefit of stochastic progr- ming models and developed a strong interest in their theoretical properties. Motivated both by practical questions and theoretical concerns, I became p- ticularly interested in the art of finding tight bounds on the optimal value of a given model. The present work attempts to make a contribution to this important branch of stochastic optimization theory. In particular, it aims at extending some classical bounding methods to broader problem classes of practical relevance. This book was accepted as a doctoral thesis by the University of St. Gallen in June 2004.1...

  15. ADMonium: Asymmetric Dark Matter Bound State

    CERN Document Server

    Bi, Xiao-Jun; Ko, P; Li, Jinmian; Li, Tianjun

    2016-01-01

    We propose a novel framework for asymmetric scalar dark matter (ADM), which has interesting collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local $U(1)_d$ symmetry which is broken at a low scale and provides a light gauge boson $X$. The dark gauge coupling is strong and then ADM can annihilate away into $X$-pair effectively. Therefore, the ADM can form bound state due to its large self-interaction via $X$ mediation. To explore the collider signature of ADMonium, we propose that ADM has a two-Higgs doublet portal. The ADMonium can have a sizable mixing with the heavier Higgs boson, which admits a large cross section of ADMonium production associated with $b\\bar b$. Of particular interest, our setup nicely explains the recent di-photon anomaly at 750 GeV via the events from ${\\rm ADMonium}\\ra 2X(\\ra e^+e^-)$, where the electrons are identified as ...

  16. On Bounding Problems of Quantitative Information Flow

    CERN Document Server

    Yasuoka, Hirotoshi

    2011-01-01

    Researchers have proposed formal definitions of quantitative information flow based on information theoretic notions such as the Shannon entropy, the min entropy, the guessing entropy, belief, and channel capacity. This paper investigates the hardness of precisely checking the quantitative information flow of a program according to such definitions. More precisely, we study the "bounding problem" of quantitative information flow, defined as follows: Given a program M and a positive real number q, decide if the quantitative information flow of M is less than or equal to q. We prove that the bounding problem is not a k-safety property for any k (even when q is fixed, for the Shannon-entropy-based definition with the uniform distribution), and therefore is not amenable to the self-composition technique that has been successfully applied to checking non-interference. We also prove complexity theoretic hardness results for the case when the program is restricted to loop-free boolean programs. Specifically, we show...

  17. Effect of two breakfasts, different in carbohydrate composition, on hunger and satiety and mood in healthy men

    NARCIS (Netherlands)

    Pasman, W.J.; Blokdijk, V.M.; Bertina, F.M.; Hopman, W.P.M.; Hendriks, H.F.J.

    2003-01-01

    OBJECTIVE: To study the effect of simple vs complex carbohydrates (SCHO and CCHO respectively) containing breakfasts on blood parameters, hunger and satiety and mood. DESIGN: A 2-day, open, randomised, cross-over trial. SUBJECTS: A total of 26 male subjects (34±6y; BMI 23.4±2.2 kg m-2). MEASUREMENTS

  18. Development and Application of a New Microarray- Based Method for High-Throughput Screening of Carbohydrate Active Enzymes

    DEFF Research Database (Denmark)

    Vidal Melgosa, Silvia

    single defined polysaccharides, mixtures of defined polysaccharides and complex biomass extracts. Furthermore, the capacity of the technique to analyse endo- and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases and lytic polysaccharide monooxygenases has been confirmed...... will contribute to both the discovery of CAZymes and the empirical characterisation of their activities, thus aiding their industrial utilisation and biological understanding...

  19. Entropy Bounds in Spherical Space

    CERN Document Server

    Brevik, I; Odintsov, S D; Brevik, Iver; Milton, Kimball A.; Odintsov, Sergei D.

    2002-01-01

    Exact calculations are given for the Casimir energy for various fields in $R\\times S^3$ geometry. The Green's function method naturally gives a result in a form convenient in the high-temperature limit, while the statistical mechanical approach gives a form appropriate for low temperatures. The equivalence of these two representations is demonstrated. Some discrepancies with previous work are noted. In no case, even for ${\\cal N}=4$ SUSY, is the ratio of entropy to energy found to be bounded.

  20. Donor substrate recognition in the raffinose-bound E342A mutant of fructosyltransferase Bacillus subtilis levansucrase

    Directory of Open Access Journals (Sweden)

    Meng Guoyu

    2008-03-01

    Full Text Available Abstract Background Fructans – β-D-fructofuranosyl polymers with a sucrose starter unit – constitute a carbohydrate reservoir synthesised by a considerable number of bacteria and plant species. Biosynthesis of levan (αGlc(1–2βFru [(2–6βFru]n, an abundant form of bacterial fructan, is catalysed by levansucrase (sucrose:2,6-β-D-fructan-6-β-D-fructosyl transferase, utilizing sucrose as the sole substrate. Previously, we described the tertiary structure of Bacillus subtilis levansucrase in the ligand-free and sucrose-bound forms, establishing the mechanistic roles of three invariant carboxylate side chains, Asp86, Asp247 and Glu342, which are central to the double displacement reaction mechanism of fructosyl transfer. Still, the structural determinants of the fructosyl transfer reaction thus far have been only partially defined. Results Here, we report high-resolution structures of three levansucrase point mutants, D86A, D247A, and E342A, and that of raffinose-bound levansucrase-E342A. The D86A and D247A substitutions have little effect on the active site geometry. In marked contrast, the E342A mutant reveals conformational flexibility of functionally relevant side chains in the vicinity of the general acid Glu342, including Arg360, a residue required for levan polymerisation. The raffinose-complex reveals a conserved mode of donor substrate binding, involving minimal contacts with the raffinose galactosyl unit, which protrudes out of the active site, and specificity-determining contacts essentially restricted to the sucrosyl moiety. Conclusion The present structures, in conjunction with prior biochemical data, lead us to hypothesise that the conformational flexibility of Arg360 is linked to it forming a transient docking site for the fructosyl-acceptor substrate, through an interaction network involving nearby Glu340 and Asn242 at the rim of a central pocket forming the active site.

  1. 78 FR 18326 - Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math...

    Science.gov (United States)

    2013-03-26

    ... Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math Science... Upward Bound Math Science Annual Performance Report. OMB Control Number: 1840-NEW. Type of Review: New... under the regular Upward Bound (UB) and Upward Bound Math and Science (UBMS) Programs. The Department...

  2. GlycomeDB – integration of open-access carbohydrate structure databases

    Directory of Open Access Journals (Sweden)

    von der Lieth Claus-Wilhelm

    2008-09-01

    Full Text Available Abstract Background Although carbohydrates are the third major class of biological macromolecules, after proteins and DNA, there is neither a comprehensive database for carbohydrate structures nor an established universal structure encoding scheme for computational purposes. Funding for further development of the Complex Carbohydrate Structure Database (CCSD or CarbBank ceased in 1997, and since then several initiatives have developed independent databases with partially overlapping foci. For each database, different encoding schemes for residues and sequence topology were designed. Therefore, it is virtually impossible to obtain an overview of all deposited structures or to compare the contents of the various databases. Results We have implemented procedures which download the structures contained in the seven major databases, e.g. GLYCOSCIENCES.de, the Consortium for Functional Glycomics (CFG, the Kyoto Encyclopedia of Genes and Genomes (KEGG and the Bacterial Carbohydrate Structure Database (BCSDB. We have created a new database called GlycomeDB, containing all structures, their taxonomic annotations and references (IDs for the original databases. More than 100000 datasets were imported, resulting in more than 33000 unique sequences now encoded in GlycomeDB using the universal format GlycoCT. Inconsistencies were found in all public databases, which were discussed and corrected in multiple feedback rounds with the responsible curators. Conclusion GlycomeDB is a new, publicly available database for carbohydrate sequences with a unified, all-encompassing structure encoding format and NCBI taxonomic referencing. The database is updated weekly and can be downloaded free of charge. The JAVA application GlycoUpdateDB is also available for establishing and updating a local installation of GlycomeDB. With the advent of GlycomeDB, the distributed islands of knowledge in glycomics are now bridged to form a single resource.

  3. Global microarray analysis of carbohydrate use in alkaliphilic hemicellulolytic bacterium Bacillus sp. N16-5.

    Directory of Open Access Journals (Sweden)

    Yajian Song

    Full Text Available The alkaliphilic hemicellulolytic bacterium Bacillus sp. N16-5 has a broad substrate spectrum and exhibits the capacity to utilize complex carbohydrates such as galactomannan, xylan, and pectin. In the monosaccharide mixture, sequential utilization by Bacillus sp. N16-5 was observed. Glucose appeared to be its preferential monosaccharide, followed by fructose, mannose, arabinose, xylose, and galactose. Global transcription profiles of the strain were determined separately for growth on six monosaccharides (glucose, fructose, mannose, galactose, arabinose, and xylose and four polysaccharides (galactomannan, xylan, pectin, and sodium carboxymethylcellulose using one-color microarrays. Numerous genes potentially related to polysaccharide degradation, sugar transport, and monosaccharide metabolism were found to respond to a specific substrate. Putative gene clusters for different carbohydrates were identified according to transcriptional patterns and genome annotation. Identification and analysis of these gene clusters contributed to pathway reconstruction for carbohydrate utilization in Bacillus sp. N16-5. Several genes encoding putative sugar transporters were highly expressed during growth on specific sugars, suggesting their functional roles. Two phosphoenolpyruvate-dependent phosphotransferase systems were identified as candidate transporters for mannose and fructose, and a major facilitator superfamily transporter was identified as a candidate transporter for arabinose and xylose. Five carbohydrate uptake transporter 1 family ATP-binding cassette transporters were predicted to participate in the uptake of hemicellulose and pectin degradation products. Collectively, microarray data improved the pathway reconstruction involved in carbohydrate utilization of Bacillus sp. N16-5 and revealed that the organism precisely regulates gene transcription in response to fluctuations in energy resources.

  4. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Directory of Open Access Journals (Sweden)

    Lindsay B. Baker

    2015-07-01

    Full Text Available Intermittent sports (e.g., team sports are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h. Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1 potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2 the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3 what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports. Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before

  5. Cognitive awareness of carbohydrate intake does not alter exercise‐induced lymphocyte apoptosis

    OpenAIRE

    James Wilfred Navalta; Brian Keith McFarlin; Scott Lyons; Scott Wesley Arnett; Mark Anthony Schafer

    2011-01-01

    OBJECTIVE: The purpose of this investigation was to determine whether cognitive awareness of carbohydrate beverage consumption affects exercise‐induced lymphocyte apoptosis, independent of actual carbohydrate intake. INTRODUCTION: Carbohydrate supplementation during aerobic exercise generally protects against the immunosuppressive effects of exercise. It is not currently known whether carbohydrate consumption or simply the knowledge of carbohydrate consumption also has that effect. METHODS: E...

  6. Bounded Delay Packet Scheduling in a Bounded Buffer

    CERN Document Server

    Fung, Stanley P Y

    2009-01-01

    We study the problem of buffer management in QoS-enabled network switches in the bounded delay model where each packet is associated with a weight and a deadline. We consider the more realistic situation where the network switch has a finite buffer size. A 9.82-competitive algorithm is known for the case of multiple buffers (Azar and Levy, SWAT'06). Recently, for the case of a single buffer, a 3-competitive deterministic algorithm and a 2.618-competitive randomized algorithm was known (Li, INFOCOM'09). In this paper we give a simple deterministic 2-competitive algorithm for the case of a single buffer.

  7. Using structure to inform carbohydrate binding module function

    NARCIS (Netherlands)

    Abbott, D. Wade; Lammerts van Bueren, Alicia

    2014-01-01

    Generally, non-catalytic carbohydrate binding module (CBM) specificity has been shown to parallel the catalytic activity of the carbohydrate active enzyme (CAZyme) module it is appended to. With the rapid expansion in metagenomic sequence space for the potential discovery of new CBMs in addition to

  8. Frankincense tapping reduces the carbohydrate storage of Boswellia trees

    NARCIS (Netherlands)

    Mengistu, T.; Sterck, F.J.; Fetene, M.; Bongers, F.

    2013-01-01

    Carbohydrates fixed by photosynthesis are stored in plant organs in the form of starch or sugars. Starch and sugars sum to the total non-structural carbohydrate pool (TNC) and may serve as intermediate pools between assimilation and utilization. We examined the impact of tapping on TNC concentration

  9. Chemical Changes in Carbohydrates Produced by Thermal Processing.

    Science.gov (United States)

    Hoseney, R. Carl

    1984-01-01

    Discusses chemical changes that occur in the carbohydrates found in food products when these products are subjected to thermal processing. Topics considered include browning reactions, starch found in food systems, hydrolysis of carbohydrates, extrusion cooking, processing of cookies and candies, and alterations in gums. (JN)

  10. Structural and Functional Studies of Peptide-Carbohydrate Mimicry

    Science.gov (United States)

    Johnson, Margaret A.; Pinto, B. Mario

    Certain peptides act as molecular mimics of carbohydrates in that they are specifically recognized by carbohydrate-binding proteins. Peptides that bind to anti-carbohydrate antibodies, carbohydrate-processing enzymes, and lectins have been identified. These peptides are potentially useful as vaccines and therapeutics; for example, immunologically functional peptide molecular mimics (mimotopes) can strengthen or modify immune responses induced by carbohydrate antigens. However, peptides that bind specifically to carbohydrate-binding proteins may not necessarily show the corresponding biological activity, and further selection based on biochemical studies is always required. The degree of structural mimicry required to generate the desired biological activity is therefore an interesting question. This review will discuss recent structural studies of peptide-carbohydrate mimicry employing NMR spectroscopy, X-ray crystallography, and molecular modeling, as well as relevant biochemical data. These studies provide insights into the basis of mimicry at the molecular level. Comparisons with other carbohydrate-mimetic compounds, namely proteins and glycopeptides, will be drawn. Finally, implications for the design of new therapeutic compounds will also be presented.

  11. Influence of dietary carbohydrate level on endocrine status and hepatic carbohydrate metabolism in the marine fish Sparus sarba.

    Science.gov (United States)

    Leung, L Y; Woo, Norman Y S

    2012-04-01

    Silver sea bream, Sparus sarba, were fed two diets of different carbohydrate levels (2 and 20% dextrin) for 4 weeks, and the effects on organ indices, liver composition, serum metabolite and hormone levels and gene expression profile of key enzymes of carbohydrate metabolism in the liver were investigated. By using real-time PCR, mRNA expression levels of carbohydrate metabolic enzymes including glucokinase (GK, glycolysis), glucose-6-phosphatase (G6Pase, gluconeogenesis), glycogen synthase (GS, glycogenesis), glycogen phosphorylase (GP, glycogenolysis) and glucose-6-phosphate dehydrogenase (G6PDH, pentose phosphate pathway) in liver of sea bream have been examined, and it was found that high dietary carbohydrate level increased mRNA level of GK but decreased mRNA levels of G6Pase and GP. However, mRNA levels of GS and G6PDH were not significantly influenced by dietary carbohydrate. Silver sea bream fed high dietary carbohydrate had higher hepatosomatic index (HSI), liver glycogen and protein, but there were no significant changes in gonadosomatic index (GSI), serum glucose and protein level, as well as liver lipid and moisture level. Pituitary growth hormone (GH) and hepatic insulin-like growth factor I (IGF-I) transcript abundance were assayed by real-time PCR, and it was found that both parameters remained unchanged in fish fed different dietary carbohydrate levels. Serum triiodothyronine (T(3)) and thyroxine (T(4)) were not significantly affected by dietary carbohydrate levels, but lower serum cortisol level was found in fish fed high dietary carbohydrate level. These results suggest that silver sea bream is able to adapt to a diet with high carbohydrate content (up to 20% dextrin), the consumption of which would lead to fundamental re-organization of carbohydrate metabolism resulting in hepatic glycogen deposition.

  12. Carbohydrate loading in the preoperative setting.

    Science.gov (United States)

    Hill, L T; Miller, M G A

    2015-03-01

    Nutrition support is an evolving field, and modern clinical nutrition practice should actively incorporate strategies to enhance various clinical outcomes. In surgical patients, clinical benefits can be maximised by nutritional support protocols that minimise and manage the perioperative fasting period. This approach, which includes the perioperative provision of clear carbohydrate-containing fluids, has been shown to be safe, is evidence based, and is supported by many professional societies. Such a strategy has been shown to aid the anaesthetic process and maintain an optimal metabolic state, including improved insulin sensitivity and blunted muscle catabolic activity. Some important consequences of this improved metabolic control include shorter hospital stay and fewer postoperative complications. A proactive multidisciplinary team approach is essential to use this nutrition support strategy with success across a hospital's surgical service. PMID:26294840

  13. Arabinogalactan proteins: focus on carbohydrate active enzymes

    Directory of Open Access Journals (Sweden)

    Eva eKnoch

    2014-06-01

    Full Text Available Arabinogalactan proteins (AGPs are a highly diverse class of cell surface proteoglycans that are commonly found in most plant species. AGPs play important roles in many cellular processes during plant development, such as reproduction, cell proliferation, pattern formation and growth, and in plant-microbe interaction. However, little is known about the molecular mechanisms of their function. Numerous studies using monoclonal antibodies that recognize different AGP glycan epitopes have shown the appearance of a slightly altered AGP glycan in a specific stage of development in plant cells. Therefore, it is anticipated that the biosynthesis and degradation of AGP glycan is tightly regulated during development. Until recently, however, little was known about the enzymes involved in the metabolism of AGP glycans. In this review, we summarize recent discoveries of carbohydrate active enzymes (CAZy; http://www.cazy.org/ involved in the biosynthesis and degradation of AGP glycans, and we discuss the biological role of these enzymes in plant development.

  14. Phosphoglucan-bound structure of starch phosphatase Starch Excess4 reveals the mechanism for C6 specificity

    OpenAIRE

    Meekins, David A.; Raththagala, Madushi; Husodo, Satrio; White, Cory J.; Guo, Hou-Fu; Kötting, Oliver; Vander Kooi, Craig W.; Gentry, Matthew S.

    2014-01-01

    Starch is the main carbohydrate storage molecule in plants and is ubiquitous in human life. Reversible starch phosphorylation is the key regulatory event in starch catabolism. Starch Excess4 (SEX4) preferentially dephosphorylates the C6 position of starch glucose and its absence results in a dramatic accumulation of leaf starch. We present the structure of SEX4 bound to a phosphoglucan product, define its mechanism of specific activity, and reverse its specificity to the C3 position via mutag...

  15. Analysis of carbohydrate residues on recombinant human thyrotropin receptor.

    Science.gov (United States)

    Oda, Y; Sanders, J; Roberts, S; Maruyama, M; Kiddie, A; Furmaniak, J; Smith, B R

    1999-06-01

    An investigation of the sugar groups on recombinant human TSH receptors (TSHR) expressed in CHO-K1 cells and solubilized with detergents is described. Western blotting studies with TSHR monoclonal antibodies showed that the receptor was present principally as two bands with approximate molecular masses of 120 and 100 kDa. Further blotting studies using lectins and/or involving treatment with different glycosidases indicated that the 100-kDa band contained about 16 kDa of high mannose-type sugars, and the 120-kDa band contained about 33 kDa of complex-type sugars. It was possible to separate the 120- and 100-kDa components of the TSHRs by lectin affinity chromatography. In particular, Galanthus nivalis lectin, which binds high mannose-type sugars, bound the 100-kDa band, but not the 120-kDa band, whereas Datura stramonium lectin, which binds complex-type sugars, bound the 120-kDa band, but not the 100-kDa band. 125I-Labeled TSH binding studies with the various lectin column fractions showed that TSH-binding activity was principally associated with the complex-type sugar containing the 120-kDa form of the receptor rather than the high mannose-containing 100-kDa form. During peptide chain glycosylation, high mannose-type sugar residues are attached first and then modified by the formation of complex type structures to form the mature glycoprotein. Our data suggest that in the case of the TSH receptor, this type of posttranslational processing has an important role in forming the TSH-binding site.

  16. Sensitive LC MS quantitative analysis of carbohydrates by Cs+ attachment.

    Science.gov (United States)

    Rogatsky, Eduard; Jayatillake, Harsha; Goswami, Gayotri; Tomuta, Vlad; Stein, Daniel

    2005-11-01

    The development of a sensitive assay for the quantitative analysis of carbohydrates from human plasma using LC/MS/MS is described in this paper. After sample preparation, carbohydrates were cationized by Cs(+) after their separation by normal phase liquid chromatography on an amino based column. Cesium is capable of forming a quasi-molecular ion [M + Cs](+) with neutral carbohydrate molecules in the positive ion mode of electrospray ionization mass spectrometry. The mass spectrometer was operated in multiple reaction monitoring mode, and transitions [M + 133] --> 133 were monitored (M, carbohydrate molecular weight). The new method is robust, highly sensitive, rapid, and does not require postcolumn addition or derivatization. It is useful in clinical research for measurement of carbohydrate molecules by isotope dilution assay. PMID:16182559

  17. Mining anaerobic digester consortia metagenomes for secreted carbohydrate active enzymes

    DEFF Research Database (Denmark)

    Wilkens, Casper; Busk, Peter Kamp; Pilgaard, Bo;

    . To gain insight into both the degradation of the carbohydrates and the various roles of the microbes in the ADs we have mined metagenomes from both types of ADs for glycoside hydrolases, carbohydrate esterases, polysaccharide lyases, auxiliary activities, and carbohydrate binding modules. The mining...... thermophilic and mesophilic ADs a wide variety of carbohydrate active enzyme functions were discovered in the metagenomic sequencing of the microbial consortia. The most dominating type of glycoside hydrolases were β-glucosidases (up to 27%), α-amylases (up to 10%), α-glucosidases (up to 8%), α......-galactosidases (up to 9%) and β-galactosidases (up to 7%). For carbohydrate esterases the by far most dominating type was acetylxylan esterases (up to 59%) followed by feruloyl esterases (up to 16%). Less than 15 polysaccharide lyases were identified in the different metagenomes and not surprisingly...

  18. A central role of abscisic acid in stress-regulated carbohydrate metabolism.

    Directory of Open Access Journals (Sweden)

    Stefan Kempa

    Full Text Available BACKGROUND: Abiotic stresses adversely affect plant growth and development. The hormone abscisic acid (ABA plays a central role in the response and adaptation to environmental constraints. However, apart from the well established role of ABA in regulating gene expression programmes, little is known about its function in plant stress metabolism. PRINCIPAL FINDINGS: Using an integrative multiparallel approach of metabolome and transcriptome analyses, we studied the dynamic response of the model glyophyte Arabidopsis thaliana to ABA and high salt conditions. Our work shows that salt stress induces complex re-adjustment of carbohydrate metabolism and that ABA triggers the initial steps of carbon mobilisation. SIGNIFICANCE: These findings open new perspectives on how high salinity and ABA impact on central carbohydrate metabolism and highlight the power of iterative combinatorial approaches of non-targeted and hypothesis-driven experiments in stress biology.

  19. Mice lacking pituitary tumor transforming gene show elevated exposure of DGalNAc carbohydrate determinants

    Directory of Open Access Journals (Sweden)

    Lutsyk A. D.

    2012-04-01

    Full Text Available Aim. To investigate the influence of pituitary tumor transforming gene (pttg-1 knockout on glycome of parenchimal organs by means of lectin histochemistry. Methods. DGalNAc, DGlcNAc, NeuNAc carbohydrate determinants were labelled with soybean agglutinin (SBA and wheat germ agglutinin (WGA, conjugated to peroxidase, with subsequent visualization of the lectin-binding sites with diaminobenzidine. The testes and kidneys of murine strain BL6/C57 with the pttg-1 gene knockout (PTTG-KO were compared to the wild type (PTTG-WT animals, both groups 1 month of age. Results. Knockout of the pttg-1 gene was accompanied by enhanced exposure of the DGalNAc sugar residues within the Golgi complex of secondary spermatocytes, in a brush border of renal tubules and on the lumenal surface of collecting ducts. Conclusions. This study suggests that knockout of the pttg-1 gene may lead to the changes in carbohydrate processing in mammalian organism.

  20. Prediction of Pectin Yield and Quality by FTIR and Carbohydrate Microarray Analysis

    DEFF Research Database (Denmark)

    Baum, Andreas; Dominiak, Malgorzata Maria; Vidal-Melgosa, Silvia;

    2016-01-01

    Pectin production is complex, and final product quality assessment is generally accomplished at the end of the process using time-consuming off-line laboratory analysis. In this study, pectin was extracted from lime peel either by acid or by enzymes. Fourier transform infrared spectroscopy...... and carbohydrate microarray analysis were performed directly on the crude lime peel extracts during the time course of the extractions. Multivariate analysis of the data was carried out to predict final pectin yields. Fourier transform infrared spectroscopy (FTIR) was found applicable for determining the optimal...... extraction time for the enzymatic and acidic extraction processes, respectively. The combined results of FTIR and carbohydrate microarray analysis suggested major differences in the crude pectin extracts obtained by enzymatic and acid extraction, respectively. Enzymatically extracted pectin, thus, showed...

  1. Bound Polaron Pair Formation in Poly (phenylenevinylenes)

    Science.gov (United States)

    Rothberg, Lewis

    The following sections are included: * INTRODUCTION * PHOTOGENERATED YIELD OF SINGLET EXCITONS * AGGREGRATION EFFECTS ON EXCITED STATE PHOTO-GENERATION * ASSIGNMENT TO BOUND POLARON PAIRS AND DISCUSSION * PROBLEMS WITH THE BOUND POLARON PAIR PICTURE AND CONCLUSION * REFERENCES

  2. An Exponential Bound for Cox Regression☆

    Science.gov (United States)

    Kosorok, M. R.

    2012-01-01

    We present an asymptotic exponential bound for the deviation of the survival function estimator of the Cox model. We show that the bound holds even when the proportional hazards assumption does not hold. PMID:23565013

  3. An Exponential Bound for Cox Regression.

    Science.gov (United States)

    Goldberg, Y; Kosorok, M R

    2012-07-01

    We present an asymptotic exponential bound for the deviation of the survival function estimator of the Cox model. We show that the bound holds even when the proportional hazards assumption does not hold.

  4. Relationship of carbohydrate molecular spectroscopic features in combined feeds to carbohydrate utilization and availability in ruminants

    Science.gov (United States)

    Zhang, Xuewei; Yu, Peiqiang

    To date, there is no study on the relationship between carbohydrate (CHO) molecular structures and nutrient availability of combined feeds in ruminants. The objective of this study was to use molecular spectroscopy to reveal the relationship between CHO molecular spectral profiles (in terms of functional groups (biomolecular, biopolymer) spectral peak area and height intensity) and CHO chemical profiles, CHO subfractions, energy values, and CHO rumen degradation kinetics of combined feeds of hulless barley with pure wheat dried distillers grains with solubles (DDGS) at five different combination ratios (hulless barley to pure wheat DDGS: 100:0, 75:25, 50:50, 25:75, 0:100). The molecular spectroscopic parameters assessed included: lignin biopolymer molecular spectra profile (peak area and height, region and baseline: ca. 1539-1504 cm-1); structural carbohydrate (STCHO, peaks area region and baseline: ca. 1485-1186 cm-1) mainly associated with hemi- and cellulosic compounds; cellulosic materials peak area (centered at ca. 1240 cm-1 with region and baseline: ca. 1272-1186 cm-1); total carbohydrate (CHO, peaks area region and baseline: ca. 1186-946 cm-1). The results showed that the functional groups (biomolecular, biopolymer) in the combined feeds are sensitive to the changes of carbohydrate chemical and nutrient profiles. The changes of the CHO molecular spectroscopic features in the combined feeds were highly correlated with CHO chemical profiles, CHO subfractions, in situ CHO rumen degradation kinetics and fermentable organic matter supply. Further study is needed to investigate possibility of using CHO molecular spectral features as a predictor to estimate nutrient availability in combined feeds for animals and quantify their relationship.

  5. Renewable Hydrogen Carrier — Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy

    OpenAIRE

    Y.-H. Percival Zhang; Mielenz, Jonathan R.

    2011-01-01

    The hydrogen economy presents an appealing energy future but its implementation must solve numerous problems ranging from low-cost sustainable production, high-density storage, costly infrastructure, to eliminating safety concern. The use of renewable carbohydrate as a high-density hydrogen carrier and energy source for hydrogen production is possible due to emerging cell-free synthetic biology technology—cell-free synthetic pathway biotransformation (SyPaB). Assembly of numerous enzymes and ...

  6. Renewable Hydrogen Carrier — Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy

    OpenAIRE

    Y.-H. Percival Zhang; Mielenz, Jonathan R.

    2011-01-01

    The hydrogen economy presents an appealing energy future but its implementation must solve numerous problems ranging from low-cost sustainable production, high-density storage, costly infrastructure, to eliminating safety concern. The use of renewable carbohydrate as a high-density hydrogen carrier and energy source for hydrogen production is possible due to emerging cell-free synthetic biology technology–cell-free synthetic pathway biotransformation (SyPaB). Assembly of numerous enzymes and ...

  7. Data Structure Lower Bounds on Random Access to Grammar-Compressed Strings

    DEFF Research Database (Denmark)

    Chen, Shiteng; Verbin, Elad; Yu, Wei

    2012-01-01

    ). The proof works by reduction to communication complexity, namely to the LSD problem, recently employed by Patrascu and others. We prove lower bounds also for the case of LZ-compression and Burrows-Wheeler (BWT) compression. All of our lower bounds hold even when the strings are over an alphabet of size 2...

  8. Blood Triglycerides Levels and Dietary Carbohydrate Indices in Healthy Koreans

    Science.gov (United States)

    Kang, Ji Yeon

    2016-01-01

    Objectives: Previous studies have obtained conflicting findings regarding possible associations between indices measuring carbohydrate intake and dyslipidemia, which is an established risk factor of coronary heart disease. In the present study, we examined cross-sectional associations between carbohydrate indices, including the dietary glycemic index (GI), glycemic load (GL), total amount of carbohydrates, and the percentage of energy from carbohydrates, and a range of blood lipid parameters. Methods: This study included 1530 participants (554 men and 976 women) from 246 families within the Healthy Twin Study. We analyzed the associations using a generalized linear mixed model to control for familial relationships. Results: Levels of the Apo B were inversely associated with dietary GI, GL, and the amount of carbohydrate intake for men, but these relationships were not significant when fat-adjusted values of the carbohydrate indices were used. Triglyceride levels were positively associated with dietary GI and GL in women, and this pattern was more notable in overweight participants (body mass index [BMI] ≥25 kg/m2). However, total, low-density lipoprotein and high-density lipoprotein cholesterol levels were not significantly related with carbohydrate intake overall. Conclusions: Of the blood lipid parameters we investigated, only triglyceride levels were positively related with dietary carbohydrate indices among women participants in the Healthy Twin Study, with an interactive role observed for BMI. However, these associations were not observed in men, suggesting that the association between blood lipid levels and carbohydrate intake depends on the type of lipid, specific carbohydrate indices, gender, and BMI. PMID:27255074

  9. The case for low carbohydrate diets in diabetes management

    Directory of Open Access Journals (Sweden)

    McFarlane Samy I

    2005-07-01

    Full Text Available Abstract A low fat, high carbohydrate diet in combination with regular exercise is the traditional recommendation for treating diabetes. Compliance with these lifestyle modifications is less than satisfactory, however, and a high carbohydrate diet raises postprandial plasma glucose and insulin secretion, thereby increasing risk of CVD, hypertension, dyslipidemia, obesity and diabetes. Moreover, the current epidemic of diabetes and obesity has been, over the past three decades, accompanied by a significant decrease in fat consumption and an increase in carbohydrate consumption. This apparent failure of the traditional diet, from a public health point of view, indicates that alternative dietary approaches are needed. Because carbohydrate is the major secretagogue of insulin, some form of carbohydrate restriction is a prima facie candidate for dietary control of diabetes. Evidence from various randomized controlled trials in recent years has convinced us that such diets are safe and effective, at least in short-term. These data show low carbohydrate diets to be comparable or better than traditional low fat high carbohydrate diets for weight reduction, improvement in the dyslipidemia of diabetes and metabolic syndrome as well as control of blood pressure, postprandial glycemia and insulin secretion. Furthermore, the ability of low carbohydrate diets to reduce triglycerides and to increase HDL is of particular importance. Resistance to such strategies has been due, in part, to equating it with the popular Atkins diet. However, there are many variations and room for individual physician planning. Some form of low carbohydrate diet, in combination with exercise, is a viable option for patients with diabetes. However, the extreme reduction of carbohydrate of popular diets (

  10. Communication Lower Bounds for Distributed-Memory Computations

    DEFF Research Database (Denmark)

    Scquizzato, Michele; Silvestri, Francesco

    2014-01-01

    In this paper we propose a new approach to the study of the communication requirements of distributed computations, which advocates for the removal of the restrictive assumptions under which earlier results were derived. We illustrate our approach by giving tight lower bounds on the communication...... previous results which require either the computation to be balanced among the processors, or specific initial distributions of the input data, or an upper bound on the size of processors' local memories....... complexity required to solve several computational problems in a distributed-memory parallel machine, namely standard matrix multiplication, stencil computations, comparison sorting, and the Fast Fourier Transform. Our bounds rely only on a mild assumption on work distribution, and significantly strengthen...

  11. On Some Properties of Squeezing Functions of Bounded Domains

    CERN Document Server

    Deng, Fusheng; Zhang, Liyou

    2011-01-01

    The main purpose of the present paper is to introduce the notion of squeezing functions of bounded domains and study some properties of them. The relation to geometric and analytic structures of bounded domains will be investigated. Existence of related extremal maps and continuity of squeezing functions are proved. Holomorphic homogeneous regular domains are exactly domains whose squeezing functions have positive lower bounds. Completeness of certain intrinsic metrics and pseudoconvexity of holomorphic homogeneous regular domains are proved by alternative method. In dimension one case, we get a neat description of boundary behavior of squeezing functions of finitely connected planar domains. This leads to a necessary and sufficient conditions for a finitely connected planar domain to be a holomorphic homogeneous regular domain. Consequently, we can recover some important results in complex analysis. For annuli, we obtain some interesting properties of their squeezing functions. We finally exhibit some exampl...

  12. Relativistic bound state approach to fundamental forces including gravitation

    Directory of Open Access Journals (Sweden)

    Morsch H.P.

    2012-06-01

    Full Text Available To describe the structure of particle bound states of nature, a relativistic bound state formalism is presented, which requires a Lagrangian including scalar coupling of two boson fields. The underlying mechanisms are quite complex and require an interplay of overlapping boson fields and fermion-antifermion production. This gives rise to two potentials, a boson-exchange potential and one identified with the long sought confinement potential in hadrons. With minimal requirements, two elementary massless fermions (quantons - with and without charge - and one gauge boson, hadrons and leptons but also atoms and gravitational systems are described by bound states with electric and magnetic coupling between the charges and spins of quantons. No need is found for colour, Higgs-coupling and supersymmetry.

  13. Monotonicity of the quantum linear programming bound

    OpenAIRE

    Eric M. Rains

    1998-01-01

    The most powerful technique known at present for bounding the size of quantum codes of prescribed minimum distance is the quantum linear programming bound. Unlike the classical linear programming bound, it is not immediately obvious that if the quantum linear programming constraints are satisfiable for dimension K, that the constraints can be satisfied for all lower dimensions. We show that the quantum linear programming bound is indeed monotonic in this sense, and give an explicitly monotoni...

  14. Carbohydrate-enriched cyanobacterial biomass as feedstock for bio-methane production through anaerobic digestion

    DEFF Research Database (Denmark)

    Markou, Giorgos; Angelidaki, Irini; Georgakakis, Dimitris

    2013-01-01

    The anaerobic digestion performance using carbohydrate-enriched biomass of Arthrospira platensis was studied. The carbohydrate enrichment was achieved after the cultivation of A. platensis under phosphorus limitation conditions. Three biomass compositions (60%, 40% and 20% carbohydrates content) ...

  15. Dietary non-digestible carbohydrates and the resistance to intestinal infections

    NARCIS (Netherlands)

    Bruggencate, ten S.J.M.

    2004-01-01

    Keywords: Non-digestible carbohydrates, prebiotics, inulin, FOS, calcium, microflora, short-chain fatty acids, mucin, intestinal permeability, salmonella, infection, rat, humanDietary non-digestible carbohydrates and the resistance to intestinal infectionsNon-digestible carbohydrates (NDC) stimulate

  16. [Performance enhancement by carbohydrate intake during sport: effects of carbohydrates during and after high-intensity exercise].

    Science.gov (United States)

    Beelen, Milou; Cermak, Naomi M; van Loon, Luc J C

    2015-01-01

    Endogenous carbohydrate availability does not provide sufficient energy for prolonged moderate to high-intensity exercise. Carbohydrate ingestion during high-intensity exercise can therefore enhance performance.- For exercise lasting 1 to 2.5 hours, athletes are advised to ingest 30-60 g of carbohydrates per hour.- Well-trained endurance athletes competing for longer than 2.5 hours at high intensity can metabolise up to 90 g of carbohydrates per hour, provided that a mixture of glucose and fructose is ingested.- Athletes participating in intermittent or team sports are advised to follow the same strategies but the timing of carbohydrate intake depends on the type of sport.- If top performance is required again within 24 hours after strenuous exercise, the advice is to supplement endogenous carbohydrate supplies quickly within the first few hours post-exercise by ingesting large amounts of carbohydrate (1.2 g/kg/h) or a lower amount of carbohydrate (0.8 g/kg/h) with a small amount of protein (0.2-0.4 g/kg/h).

  17. Bound entangled states invariant under Ux

    Institute of Scientific and Technical Information of China (English)

    Wang Zhen; Wang Zhi-Xi

    2008-01-01

    This paper obtains an entangled condition for isotropic-like states by using an atomic map. It constructs a class of bound entangled states from the entangled condition and shows that the partial transposition of the state from the constructed bound entangled class is an edge bound entangled state by using range criterion.

  18. Bounded rationality and heterogeneous expectations in macroeconomics

    NARCIS (Netherlands)

    D. Massaro

    2012-01-01

    This thesis studies the effect of individual bounded rationality on aggregate macroeconomic dynamics. Boundedly rational agents are specified as using simple heuristics in their decision making. An important aspect of the type of bounded rationality described in this thesis is that the population of

  19. Upper Bounds on Numerical Approximation Errors

    DEFF Research Database (Denmark)

    Raahauge, Peter

    2004-01-01

    This paper suggests a method for determining rigorous upper bounds on approximationerrors of numerical solutions to infinite horizon dynamic programming models.Bounds are provided for approximations of the value function and the policyfunction as well as the derivatives of the value function...... to approximations of a standard (strictly concave)growth model.KEYWORDS: Numerical approximation errors, Bellman contractions, Error bounds...

  20. Counting Young Tableaux of Bounded Height

    Science.gov (United States)

    Bergeron, Francois; Gascon, Francis

    2000-03-01

    We show that formulas of Gessel, for the generating functions for Young standard tableaux of height bounded by k (see [2]), satisfy linear differential equations, with polynomial coefficients, equivalent to P-recurrences conjectured by Favreau, Krob and the first author (see [1]) for the number of bounded height tableaux and pairs of bounded height tableaux.

  1. On Bounds for Spectra of Operator Pencils in a Hilbert Space

    Institute of Scientific and Technical Information of China (English)

    Michael Iosif GIL'

    2003-01-01

    A class of pencils (operator-valued functions of a complex argument) in a separable Hilbert space is considered. Bounds for the spectra are derived. Applications to differential operators, integral operators with delay and infinite matrix pencils are discussed.

  2. Higgs mass bounds from the functional RG

    International Nuclear Information System (INIS)

    We investigate a Top-Yukawa toy model to study Higgs mass bounds in the framework of the functional renormalization group (RG). Starting the calculations with a quartic ultraviolet (UV) potential we get a finite range of values for the Higgs mass in the infrared for a given cutoff. The bounds appear in a natural way as a consequence of the RG flow. The lower mass bound is approached for a vanishing UV quartic coupling. Furthermore, we study the influence of higher-dimensional operators on the lower Higgs mass bound. We find that even seemingly RG irrelevant interactions can take a substantial influence on the lower bound for the Higgs mass.

  3. Algebraic Proof Complexity: Progress, Frontiers and Challenges

    OpenAIRE

    Pitassi, Tonnian; Tzameret, Iddo

    2016-01-01

    We survey recent progress in the proof complexity of strong proof systems and its connection to algebraic circuit complexity, showing how the synergy between the two gives rise to new approaches to fundamental open questions, solutions to old problems, and new directions of research. In particular, we focus on tight connections between proof complexity lower bounds (namely, lower bounds on the size of proofs of certain tautologies), algebraic circuit lower bounds, and the Polynomial Identity ...

  4. Carbohydrate Binding Modules: Biochemical Properties and Novel Applications

    Science.gov (United States)

    Shoseyov, Oded; Shani, Ziv; Levy, Ilan

    2006-01-01

    Polysaccharide-degrading microorganisms express a repertoire of hydrolytic enzymes that act in synergy on plant cell wall and other natural polysaccharides to elicit the degradation of often-recalcitrant substrates. These enzymes, particularly those that hydrolyze cellulose and hemicellulose, have a complex molecular architecture comprising discrete modules which are normally joined by relatively unstructured linker sequences. This structure is typically comprised of a catalytic module and one or more carbohydrate binding modules (CBMs) that bind to the polysaccharide. CBMs, by bringing the biocatalyst into intimate and prolonged association with its substrate, allow and promote catalysis. Based on their properties, CBMs are grouped into 43 families that display substantial variation in substrate specificity, along with other properties that make them a gold mine for biotechnologists who seek natural molecular “Velcro” for diverse and unusual applications. In this article, we review recent progress in the field of CBMs and provide an up-to-date summary of the latest developments in CBM applications. PMID:16760304

  5. Assessing Bacterial Interactions Using Carbohydrate-Based Microarrays

    Directory of Open Access Journals (Sweden)

    Andrea Flannery

    2015-12-01

    Full Text Available Carbohydrates play a crucial role in host-microorganism interactions and many host glycoconjugates are receptors or co-receptors for microbial binding. Host glycosylation varies with species and location in the body, and this contributes to species specificity and tropism of commensal and pathogenic bacteria. Additionally, bacterial glycosylation is often the first bacterial molecular species encountered and responded to by the host system. Accordingly, characterising and identifying the exact structures involved in these critical interactions is an important priority in deciphering microbial pathogenesis. Carbohydrate-based microarray platforms have been an underused tool for screening bacterial interactions with specific carbohydrate structures, but they are growing in popularity in recent years. In this review, we discuss carbohydrate-based microarrays that have been profiled with whole bacteria, recombinantly expressed adhesins or serum antibodies. Three main types of carbohydrate-based microarray platform are considered; (i conventional carbohydrate or glycan microarrays; (ii whole mucin microarrays; and (iii microarrays constructed from bacterial polysaccharides or their components. Determining the nature of the interactions between bacteria and host can help clarify the molecular mechanisms of carbohydrate-mediated interactions in microbial pathogenesis, infectious disease and host immune response and may lead to new strategies to boost therapeutic treatments.

  6. Sugar for my honey: carbohydrate partitioning in ectomycorrhizal symbiosis.

    Science.gov (United States)

    Nehls, Uwe; Grunze, Nina; Willmann, Martin; Reich, Marlis; Küster, Helge

    2007-01-01

    Simple, readily utilizable carbohydrates, necessary for growth and maintenance of large numbers of microbes are rare in forest soils. Among other types of mutualistic interactions, the formation of ectomycorrhizas, a symbiosis between tree roots and certain soil fungi, is a way to overcome nutrient and carbohydrate limitations typical for many forest ecosystems. Ectomycorrhiza formation is typical for trees in boreal and temperate forests of the northern hemisphere and alpine regions world-wide. The main function of this symbiosis is the exchange of fungus-derived nutrients for plant-derived carbohydrates, enabling the colonization of mineral nutrient-poor environments. In ectomycorrhizal symbiosis up to 1/3 of plant photoassimilates could be transferred toward the fungal partner. The creation of such a strong sink is directly related to the efficiency of fungal hexose uptake at the plant/fungus interface, a modulated fungal carbohydrate metabolism in the ectomycorrhiza, and the export of carbohydrates towards soil growing hyphae. However, not only the fungus but also the plant partner increase its expression of hexose importer genes at the plant/fungus interface. This increase in hexose uptake capacity of plant roots in combination with an increase in photosynthesis may explain how the plant deals with the growing fungal carbohydrate demand in symbiosis and how it can restrict this loss of carbohydrates under certain conditions to avoid fungal parasitism. PMID:17078984

  7. Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity.

    Science.gov (United States)

    Warda, Alicja K; Siezen, Roland J; Boekhorst, Jos; Wells-Bennik, Marjon H J; de Jong, Anne; Kuipers, Oscar P; Nierop Groot, Masja N; Abee, Tjakko

    2016-01-01

    We characterised carbohydrate utilisation of 20 newly sequenced Bacillus cereus strains isolated from food products and food processing environments and two laboratory strains, B. cereus ATCC 10987 and B. cereus ATCC 14579. Subsequently, genome sequences of these strains were analysed together with 11 additional B. cereus reference genomes to provide an overview of the different types of carbohydrate transporters and utilization systems found in B. cereus strains. The combined application of API tests, defined growth media experiments and comparative genomics enabled us to link the carbohydrate utilisation capacity of 22 B. cereus strains with their genome content and in some cases to the panC phylogenetic grouping. A core set of carbohydrates including glucose, fructose, maltose, trehalose, N-acetyl-glucosamine, and ribose could be used by all strains, whereas utilisation of other carbohydrates like xylose, galactose, and lactose, and typical host-derived carbohydrates such as fucose, mannose, N-acetyl-galactosamine and inositol is limited to a subset of strains. Finally, the roles of selected carbohydrate transporters and utilisation systems in specific niches such as soil, foods and the human host are discussed. PMID:27272929

  8. Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity

    Science.gov (United States)

    Warda, Alicja K.; Siezen, Roland J.; Boekhorst, Jos; Wells-Bennik, Marjon H. J.; de Jong, Anne; Kuipers, Oscar P.; Nierop Groot, Masja N.; Abee, Tjakko

    2016-01-01

    We characterised carbohydrate utilisation of 20 newly sequenced Bacillus cereus strains isolated from food products and food processing environments and two laboratory strains, B. cereus ATCC 10987 and B. cereus ATCC 14579. Subsequently, genome sequences of these strains were analysed together with 11 additional B. cereus reference genomes to provide an overview of the different types of carbohydrate transporters and utilization systems found in B. cereus strains. The combined application of API tests, defined growth media experiments and comparative genomics enabled us to link the carbohydrate utilisation capacity of 22 B. cereus strains with their genome content and in some cases to the panC phylogenetic grouping. A core set of carbohydrates including glucose, fructose, maltose, trehalose, N-acetyl-glucosamine, and ribose could be used by all strains, whereas utilisation of other carbohydrates like xylose, galactose, and lactose, and typical host-derived carbohydrates such as fucose, mannose, N-acetyl-galactosamine and inositol is limited to a subset of strains. Finally, the roles of selected carbohydrate transporters and utilisation systems in specific niches such as soil, foods and the human host are discussed. PMID:27272929

  9. Linking Bacillus cereus Genotypes and Carbohydrate Utilization Capacity.

    Directory of Open Access Journals (Sweden)

    Alicja K Warda

    Full Text Available We characterised carbohydrate utilisation of 20 newly sequenced Bacillus cereus strains isolated from food products and food processing environments and two laboratory strains, B. cereus ATCC 10987 and B. cereus ATCC 14579. Subsequently, genome sequences of these strains were analysed together with 11 additional B. cereus reference genomes to provide an overview of the different types of carbohydrate transporters and utilization systems found in B. cereus strains. The combined application of API tests, defined growth media experiments and comparative genomics enabled us to link the carbohydrate utilisation capacity of 22 B. cereus strains with their genome content and in some cases to the panC phylogenetic grouping. A core set of carbohydrates including glucose, fructose, maltose, trehalose, N-acetyl-glucosamine, and ribose could be used by all strains, whereas utilisation of other carbohydrates like xylose, galactose, and lactose, and typical host-derived carbohydrates such as fucose, mannose, N-acetyl-galactosamine and inositol is limited to a subset of strains. Finally, the roles of selected carbohydrate transporters and utilisation systems in specific niches such as soil, foods and the human host are discussed.

  10. Characterization of carbohydrates in rainwater from the southeastern North Carolina.

    Science.gov (United States)

    Mullaugh, Katherine M; Byrd, Jade N; Avery, G Brooks; Mead, Ralph N; Willey, Joan D; Kieber, Robert J

    2014-07-01

    Carbohydrates have been widely reported in atmospheric aerosols, but have not previously been quantified in rainwater. We have identified and quantified a series of 11 specific compounds including monosaccharides (glucose, fructose, arabinose, galactose and pinitol), disaccharides (sucrose and trehalose), sugar alcohols (arabitol, dulcitol and mannitol) and the anhydrosaccharide levoglucosan. Rainwater analyzed in this study includes 52 distinct precipitation events in Wilmington, NC between June 2011 and October 2012. Our analysis indicates carbohydrates typically contribute carbohydrates reached as high as 5.8 μM, with glucose and sucrose typically being the predominant species. The distribution of carbohydrates exhibited a distinct seasonal pattern, with higher concentrations of most carbohydrates, especially sucrose, in spring and summer, driven primarily by increased biogenic inputs during the growing season. Concentrations of carbohydrates were an order of magnitude higher in storms of terrestrial origin compared to marine events, further supporting a terrestrial biogenic origin of most species. Sequential sampling of Hurricane Irene showed significant quantities of carbohydrates present at the end of the storm when air mass back trajectories traversed over land. The highest level of levoglucosan, a compound associated with biomass burning, was detected in rain with an air mass back trajectory that traveled over a region affected by wildfires. When compared to aerosol concentrations reported by others, the sugar concentrations in rain demonstrate wet deposition is an important removal mechanism of this water-soluble and bioavailable fraction of atmospheric particulate organic matter.

  11. Radiolabeled Peptide Scaffolds for PET/SPECT - Optical in Vivo Imaging of Carbohydrate-Lectin Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Deutscher, Susan

    2014-09-30

    The objective of this research is to develop phage display-selected peptides into radio- and fluoresecently- labeled scaffolds for the multimodal imaging of carbohydrate-lectin interactions. While numerous protein and receptor systems are being explored for the development of targeted imaging agents, the targeting and analysis of carbohydrate-lectin complexes in vivo remains relatively unexplored. Antibodies, nanoparticles, and peptides are being developed that target carbohydrate-lectin complexes in living systems. However, antibodies and nanoparticles often suffer from slow clearance and toxicity problems. Peptides are attractive alternative vehicles for the specific delivery of radionuclides or fluorophores to sites of interest in vivo, although, because of their size, uptake and retention may be less than antibodies. We have selected high affinity peptides that bind a specific carbohydrate-lectin complex involved in cell-cell adhesion and cross-linking using bacteriophage (phage) display technologies (1,2). These peptides have allowed us to probe the role of these antigens in cell adhesion. Fluorescent versions of the peptides have been developed for optical imaging and radiolabeled versions have been used in single photon emission computed tomography (SPECT) and positron emission tomography (PET) in vivo imaging (3-6). A benefit in employing the radiolabeled peptides in SPECT and PET is that these imaging modalities are widely used in living systems and offer deep tissue sensitivity. Radiolabeled peptides, however, often exhibit poor stability and high kidney uptake in vivo. Conversely, optical imaging is sensitive and offers good spatial resolution, but is not useful for deep tissue penetration and is semi-quantitative. Thus, multimodality imaging that relies on the strengths of both radio- and optical- imaging is a current focus for development of new in vivo imaging agents. We propose a novel means to improve the efficacy of radiolabeled and fluorescently

  12. Bound states in the continuum

    Science.gov (United States)

    Hsu, Chia Wei; Zhen, Bo; Stone, A. Douglas; Joannopoulos, John D.; Soljačić, Marin

    2016-09-01

    Bound states in the continuum (BICs) are waves that remain localized even though they coexist with a continuous spectrum of radiating waves that can carry energy away. Their very existence defies conventional wisdom. Although BICs were first proposed in quantum mechanics, they are a general wave phenomenon and have since been identified in electromagnetic waves, acoustic waves in air, water waves and elastic waves in solids. These states have been studied in a wide range of material systems, such as piezoelectric materials, dielectric photonic crystals, optical waveguides and fibres, quantum dots, graphene and topological insulators. In this Review, we describe recent developments in this field with an emphasis on the physical mechanisms that lead to BICs across seemingly very different materials and types of waves. We also discuss experimental realizations, existing applications and directions for future work.

  13. Performance Bounds of Quaternion Estimators.

    Science.gov (United States)

    Xia, Yili; Jahanchahi, Cyrus; Nitta, Tohru; Mandic, Danilo P

    2015-12-01

    The quaternion widely linear (WL) estimator has been recently introduced for optimal second-order modeling of the generality of quaternion data, both second-order circular (proper) and second-order noncircular (improper). Experimental evidence exists of its performance advantage over the conventional strictly linear (SL) as well as the semi-WL (SWL) estimators for improper data. However, rigorous theoretical and practical performance bounds are still missing in the literature, yet this is crucial for the development of quaternion valued learning systems for 3-D and 4-D data. To this end, based on the orthogonality principle, we introduce a rigorous closed-form solution to quantify the degree of performance benefits, in terms of the mean square error, obtained when using the WL models. The cases when the optimal WL estimation can simplify into the SWL or the SL estimation are also discussed. PMID:25643416

  14. Towards Bounded Infeasible Code Detection

    CERN Document Server

    Christ, Jürgen; Schäf, Martin

    2012-01-01

    A first step towards more reliable software is to execute each statement and each control-flow path in a method once. In this paper, we present a formal method to automatically compute test cases for this purpose based on the idea of a bounded infeasible code detection. The method first unwinds all loops in a program finitely often and then encodes all feasible executions of the loop-free programs in a logical formula. Helper variables are introduced such that a theorem prover can reconstruct the control-flow path of a feasible execution from a satisfying valuation of this formula. Based on this formula, we present one algorithm that computes a feasible path cover and one algorithm that computes a feasible statement cover. We show that the algorithms are complete for loop-free programs and that they can be implemented efficiently. We further provide a sound algorithm to compute procedure summaries which makes the method scalable to larger programs.

  15. Spectral computations for bounded operators

    CERN Document Server

    Ahues, Mario; Limaye, Balmohan

    2001-01-01

    Exact eigenvalues, eigenvectors, and principal vectors of operators with infinite dimensional ranges can rarely be found. Therefore, one must approximate such operators by finite rank operators, then solve the original eigenvalue problem approximately. Serving as both an outstanding text for graduate students and as a source of current results for research scientists, Spectral Computations for Bounded Operators addresses the issue of solving eigenvalue problems for operators on infinite dimensional spaces. From a review of classical spectral theory through concrete approximation techniques to finite dimensional situations that can be implemented on a computer, this volume illustrates the marriage of pure and applied mathematics. It contains a variety of recent developments, including a new type of approximation that encompasses a variety of approximation methods but is simple to verify in practice. It also suggests a new stopping criterion for the QR Method and outlines advances in both the iterative refineme...

  16. VORONOI DIAGRAMS WITHOUT BOUNDING BOXES

    Directory of Open Access Journals (Sweden)

    E. T. K. Sang

    2015-10-01

    Full Text Available We present a technique for presenting geographic data in Voronoi diagrams without having to specify a bounding box. The method restricts Voronoi cells to points within a user-defined distance of the data points. The mathematical foundation of the approach is presented as well. The cell clipping method is particularly useful for presenting geographic data that is spread in an irregular way over a map, as for example the Dutch dialect data displayed in Figure 2. The automatic generation of reasonable cell boundaries also makes redundant a frequently used solution to this problem that requires data owners to specify region boundaries, as in Goebl (2010 and Nerbonne et al (2011.

  17. Information bounds for Gaussian copulas

    CERN Document Server

    Hoff, Peter D; Wellner, Jon A

    2011-01-01

    Often of primary interest in the analysis of multivariate data are the copula parameters describing the dependence among the variables, rather than the univariate marginal distributions. Since the ranks of a multivariate dataset are invariant to changes in the univariate marginal distributions, rank-based procedures are natural candidates as semiparametric estimators of copula parameters. Asymptotic information bounds for such estimators can be obtained from an asymptotic analysis of the rank likelihood, i.e. the probability of the multivariate ranks. In this article, we obtain limiting normal distributions of the rank likelihood for Gaussian copula models. Our results cover models with structured correlation matrices, such as exchangeable, autoregressive and circular correlation, as well as unstructured correlation matrices. For all Gaussian copula models, the limiting distribution of the rank likelihood ratio is shown to be equal to that of a parametric likelihood ratio for an appropriately chosen multivari...

  18. Role of the carbohydrate-binding sites of griffithsin in the prevention of DC-SIGN-mediated capture and transmission of HIV-1.

    Directory of Open Access Journals (Sweden)

    Bart Hoorelbeke

    Full Text Available BACKGROUND: The glycan-targeting C-type DC-SIGN lectin receptor is implicated in the transmission of the human immunodeficiency virus (HIV by binding the virus and transferring the captured HIV-1 to CD4(+ T lymphocytes. Carbohydrate binding agents (CBAs have been reported to block HIV-1 infection. We have now investigated the potent mannose-specific anti-HIV CBA griffithsin (GRFT on its ability to inhibit the capture of HIV-1 to DC-SIGN, its DC-SIGN-directed transmission to CD4(+ T-lymphocytes and the role of the three carbohydrate-binding sites (CBS of GRFT in these processes. FINDINGS: GRFT inhibited HIV-1(IIIB infection of CEM and HIV-1(NL4.3 infection of C8166 CD4(+ T-lymphocytes at an EC50 of 0.059 and 0.444 nM, respectively. The single mutant CBS variants of GRFT (in which a key Asp in one of the CBS was mutated to Ala were about ∼20 to 60-fold less potent to prevent HIV-1 infection and ∼20 to 90-fold less potent to inhibit syncytia formation in co-cultures of persistently HIV-1 infected HuT-78 and uninfected C8166 CD4(+ T-lymphocytes. GRFT prevents DC-SIGN-mediated virus capture and HIV-1 transmission to CD4(+ T-lymphocytes at an EC50 of 1.5 nM and 0.012 nM, respectively. Surface plasmon resonance (SPR studies revealed that wild-type GRFT efficiently blocked the binding between DC-SIGN and immobilized gp120, whereas the point mutant CBS variants of GRFT were ∼10- to 15-fold less efficient. SPR-analysis also demonstrated that wild-type GRFT and its single mutant CBS variants have the capacity to expel bound gp120 from the gp120-DC-SIGN complex in a dose dependent manner, a property that was not observed for HHA, another mannose-specific potent anti-HIV-1 CBA. CONCLUSION: GRFT is inhibitory against HIV gp120 binding to DC-SIGN, efficiently prevents DC-SIGN-mediated transfer of HIV-1 to CD4(+ T-lymphocytes and is able to expel gp120 from the gp120-DC-SIGN complex. Functionally intact CBS of GRFT are important for the optimal action of

  19. Selenium Protects Retinal Cells from Cisplatin-Induced Alterations in Carbohydrate Residues

    Science.gov (United States)

    Akşit, Dilek; Yazıcı, Alper; Akşit, Hasan; Sarı, Esin S.; Yay, Arzu; Yıldız, Onur; Kılıç, Adil; Ermiş, Sıtkı S.; Seyrek, Kamil

    2016-01-01

    Background: Investigate alterations in the expression and localization of carbohydrate units in rat retinal cells exposed to cisplatin toxicity. Aims: The aim of the study was to evaluate putative protective effects of selenium on retinal cells subjected to cisplatin. Study Design: Animal experiment. Methods: Eighteen healthy Wistar rats were divided into three equal groups: 1. Control, 2. Cisplatin and 3. Cisplatin+selenium groups. After anesthesia, the right eye of each rat was enucleated. Results: Histochemically, retinal cells of control groups reacted with α-2,3-bound sialic acid-specific Maackia amurensis lectin (MAA) strongly, while cisplatin reduced the staining intensity for MAA. However, selenium administration alleviated the reducing effect of cisplatin on the binding sites for MAA in retinal cells. The staining intensity for N-acetylgalactosamine (GalNAc residues) specific Griffonia simplicifolia-1 (GSL–1) was relatively slight in control animals and cisplatin reduced this slight staining for GSL-1 further. Selenium administration mitigated the reducing effect of cisplatin on the binding sites for GSL-1. A diffuse staining for N-acetylglucosamine (GlcNAc) specific wheat germ agglutinin (WGA) was observed throughout the retina of the control animals. In particular, cells localized in the inner plexiform and photoreceptor layers are reacted strongly with WGA. Compared to the control animals, binding sites for WGA in the retina of rats given cisplatin were remarkably decreased. However, the retinal cells of rats given selenium reacted strongly with WGA. Conclusion: Cisplatin reduces α-2,3-bound sialic acid, GlcNAc and GalNAc residues in certain retinal cells. However, selenium alleviates the reducing effect of cisplatin on carbohydrate residues in retinal cells. PMID:27606141

  20. Application of radiation degraded carbohydrates for plants

    International Nuclear Information System (INIS)

    Radiation degraded carbohydrates such as chitosan, sodium alginate, carageenan, cellulose, pectin, etc. were applied for plant cultivation. Chitosan (poly-β -D-glucosamine) was easily degraded by irradiation and induced various kinds of biological activities such as anti-microbacterial activity, promotion of plant growth, suppression of heavy metal stress on plants, phytoalexins induction, etc. Pectic fragments obtained from degraded pectin also induced the phytoalexins such as glyceollins in soybean and pisafin in pea. The irradiated chitosan shows the higher elicitor activity for pisafin than that of pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. The hot water and ethanol extracts from EFB and sugar cane bagasse were increased by irradiation. These extracts promoted the growth of plants and suppressed the damage on barley with salt and Zn stress. The results show that the degraded polysaccharides by radiation have the potential to induce various biological activities and the products can be use for agricultural and medical fields