Transition Matrix Cluster Algorithms
Yevick, David; Lee, Yong Hwan
2018-01-01
We demonstrate that a series of simple procedures for increasing the efficiency of transition matrix calculations can be realized by integrating the standard single-spin reversal transition matrix method with global cluster inversion techniques.
Comparison of transition-matrix sampling procedures
DEFF Research Database (Denmark)
Yevick, D.; Reimer, M.; Tromborg, Bjarne
2009-01-01
We compare the accuracy of the multicanonical procedure with that of transition-matrix models of static and dynamic communication system properties incorporating different acceptance rules. We find that for appropriate ranges of the underlying numerical parameters, algorithmically simple yet high...... accurate procedures can be employed in place of the standard multicanonical sampling algorithm....
Quantum phase transitions in matrix product states
International Nuclear Information System (INIS)
Zhu Jingmin
2008-01-01
We present a new general and much simpler scheme to construct various quantum phase transitions (QPTs) in spin chain systems with matrix product ground states. By use of the scheme we take into account one kind of matrix product state (MPS) QPT and provide a concrete model. We also study the properties of the concrete example and show that a kind of QPT appears, accompanied by the appearance of the discontinuity of the parity absent block physical observable, diverging correlation length only for the parity absent block operator, and other properties which are that the fixed point of the transition point is an isolated intermediate-coupling fixed point of renormalization flow and the entanglement entropy of a half-infinite chain is discontinuous. (authors)
Quantum Phase Transitions in Matrix Product States
International Nuclear Information System (INIS)
Jing-Min, Zhu
2008-01-01
We present a new general and much simpler scheme to construct various quantum phase transitions (QPTs) in spin chain systems with matrix product ground states. By use of the scheme we take into account one kind of matrix product state (MPS) QPT and provide a concrete model. We also study the properties of the concrete example and show that a kind of QPT appears, accompanied by the appearance of the discontinuity of the parity absent block physical observable, diverging correlation length only for the parity absent block operator, and other properties which are that the fixed point of the transition point is an isolated intermediate-coupling fixed point of renormalization flow and the entanglement entropy of a half-infinite chain is discontinuous
Convergence of Transition Probability Matrix in CLVMarkov Models
Permana, D.; Pasaribu, U. S.; Indratno, S. W.; Suprayogi, S.
2018-04-01
A transition probability matrix is an arrangement of transition probability from one states to another in a Markov chain model (MCM). One of interesting study on the MCM is its behavior for a long time in the future. The behavior is derived from one property of transition probabilty matrix for n steps. This term is called the convergence of the n-step transition matrix for n move to infinity. Mathematically, the convergence of the transition probability matrix is finding the limit of the transition matrix which is powered by n where n moves to infinity. The convergence form of the transition probability matrix is very interesting as it will bring the matrix to its stationary form. This form is useful for predicting the probability of transitions between states in the future. The method usually used to find the convergence of transition probability matrix is through the process of limiting the distribution. In this paper, the convergence of the transition probability matrix is searched using a simple concept of linear algebra that is by diagonalizing the matrix.This method has a higher level of complexity because it has to perform the process of diagonalization in its matrix. But this way has the advantage of obtaining a common form of power n of the transition probability matrix. This form is useful to see transition matrix before stationary. For example cases are taken from CLV model using MCM called Model of CLV-Markov. There are several models taken by its transition probability matrix to find its convergence form. The result is that the convergence of the matrix of transition probability through diagonalization has similarity with convergence with commonly used distribution of probability limiting method.
Dynamic Algorithms for Transition Matrix Generation
Yevick, David; Lee, Yong Hwan
The methods of [D. Yevick, Int. J. Mod. Phys. C, 1650041] for constructing transition matrices are applied to the two dimensional Ising model. Decreasing the system temperature during the acquisition of the matrix elements yields a reasonably precise specific heat curve for a 32x32 spin system for a limited number (50-100M) of realizations. If the system is instead evolved to first higher and then lower energies within a restricted interval that is steadily displaced in energy as the computation proceeds, a modification which permits backward displacements up to a certain lower bound for each forward step ensures acceptable accuracy. Additional constraints on the transition rule are also investigated. The Natural Sciences and Engineering Research Council of Canada (NSERC) and CIENA are acknowledged for financial support.
On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states
Energy Technology Data Exchange (ETDEWEB)
Kiselev, Yurii M [Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)
2009-01-31
The state-of-the-art in matrix stabilisation of d- and f-transition metal ions in unstable oxidation states is analysed. Main aspects of this problem concerning the genealogy of appropriate matrix systems are classified. Relevant examples are given and the data that contradict the scheme proposed are discussed. The thermodynamics of the matrix stabilisation effect is considered using the concept of isomorphic miscibility. The influence of defects and non-equilibrium on the matrix stabilisation effect is discussed. The problem of identification of the oxidation states in matrix systems is examined and various types of matrix systems are considered.
On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states
International Nuclear Information System (INIS)
Kiselev, Yurii M
2009-01-01
The state-of-the-art in matrix stabilisation of d- and f-transition metal ions in unstable oxidation states is analysed. Main aspects of this problem concerning the genealogy of appropriate matrix systems are classified. Relevant examples are given and the data that contradict the scheme proposed are discussed. The thermodynamics of the matrix stabilisation effect is considered using the concept of isomorphic miscibility. The influence of defects and non-equilibrium on the matrix stabilisation effect is discussed. The problem of identification of the oxidation states in matrix systems is examined and various types of matrix systems are considered.
Sparse Matrix for ECG Identification with Two-Lead Features
Directory of Open Access Journals (Sweden)
Kuo-Kun Tseng
2015-01-01
Full Text Available Electrocardiograph (ECG human identification has the potential to improve biometric security. However, improvements in ECG identification and feature extraction are required. Previous work has focused on single lead ECG signals. Our work proposes a new algorithm for human identification by mapping two-lead ECG signals onto a two-dimensional matrix then employing a sparse matrix method to process the matrix. And that is the first application of sparse matrix techniques for ECG identification. Moreover, the results of our experiments demonstrate the benefits of our approach over existing methods.
Research on Methods of Processing Transit IC Card Information and Constructing Transit OD Matrix
Han, Xiuhua; Li, Jin; Peng, Han
Transit OD matrix is of vital importance when planning urban transit system. Traditional transit OD matrix constructing method needs a large range of spot check survey. It is expensive and needs long cycle time to process information. Recently transit IC card charging systems have been widely applied in big cities. Being processed reasonably, transit passenger information stored in IC card database can turn into information resource. It will reduce survey cost a lot. The concept of transit trip chain is put forward in this paper. According to the characteristics of closed transit trip chain, it discusses how to process IC card information and construct transit OD matrix. It also points out that urban transit information platform and data warehouse should be constructed, and how to integrate IC card information.
Delocalization transition for the Google matrix.
Giraud, Olivier; Georgeot, Bertrand; Shepelyansky, Dima L
2009-08-01
We study the localization properties of eigenvectors of the Google matrix, generated both from the world wide web and from the Albert-Barabási model of networks. We establish the emergence of a delocalization phase for the PageRank vector when network parameters are changed. For networks with localized PageRank, eigenvalues of the matrix in the complex plane with a modulus above a certain threshold correspond to localized eigenfunctions while eigenvalues below this threshold are associated with delocalized relaxation modes. We argue that, for networks with delocalized PageRank, the efficiency of information retrieval by Google-type search is strongly affected since the PageRank values have no clear hierarchical structure in this case.
Hidden Identification on Parts: Magnetic Machine-Readable Matrix Symbols
Schramm, Harry F.; Jones, Clyde S.; Roxby, Donald L.; Teed, James D.; Shih, William C. L.; Fitzpatrick, Gerald L.; Knisely, Craig
2005-01-01
All NASA parts have identification, usually expressed in terms of part number, serial number, and the like. In most cases, this identification is permanently marked directly on the part for tracking throughout its life cycle. NASA has developed a method for reading the matrix symbol through up to 15 mils (25 m) of paint (5 or 6 layers). This method of part identification involves coating selected patches on the objects with magnetic materials in matrix symbol patterns and reading the patterns by use of magneto-optical imaging equipment.
Random matrix theory for transition strengths: Applications and open questions
Kota, V. K. B.
2017-12-01
Embedded random matrix ensembles are generic models for describing statistical properties of finite isolated interacting quantum many-particle systems. A finite quantum system, induced by a transition operator, makes transitions from its states to the states of the same system or to those of another system. Examples are electromagnetic transitions (then the initial and final systems are same), nuclear beta and double beta decay (then the initial and final systems are different) and so on. Using embedded ensembles (EE), there are efforts to derive a good statistical theory for transition strengths. With m fermions (or bosons) in N mean-field single particle levels and interacting via two-body forces, we have with GOE embedding, the so called EGOE(1+2). Now, the transition strength density (transition strength multiplied by the density of states at the initial and final energies) is a convolution of the density generated by the mean-field one-body part with a bivariate spreading function due to the two-body interaction. Using the embedding U(N) algebra, it is established, for a variety of transition operators, that the spreading function, for sufficiently strong interactions, is close to a bivariate Gaussian. Also, as the interaction strength increases, the spreading function exhibits a transition from bivariate Breit-Wigner to bivariate Gaussian form. In appropriate limits, this EE theory reduces to the polynomial theory of Draayer, French and Wong on one hand and to the theory due to Flambaum and Izrailev for one-body transition operators on the other. Using spin-cutoff factors for projecting angular momentum, the theory is applied to nuclear matrix elements for neutrinoless double beta decay (NDBD). In this paper we will describe: (i) various developments in the EE theory for transition strengths; (ii) results for nuclear matrix elements for 130Te and 136Xe NDBD; (iii) important open questions in the current form of the EE theory.
Marine wind data presentation using wind transition matrix
Digital Repository Service at National Institute of Oceanography (India)
Mascarenhas, A.J.; Gouveia, A.D.; Desai, R.G.P.
depends upon the direction from which the wind is presently blowing. The percentage cumulative wind transition matrix of the order of 49 x 49 has been presented for the data obtainEd. by the wind monitoring system. These observations were obtained at a...
Structure of nuclear transition matrix elements for neutrinoless ...
Indian Academy of Sciences (India)
Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double- decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...
Hanle-Zeeman Scattering Matrix for Magnetic Dipole Transitions
Energy Technology Data Exchange (ETDEWEB)
Megha, A.; Sampoorna, M.; Nagendra, K. N.; Sankarasubramanian, K., E-mail: megha@iiap.res.in, E-mail: sampoorna@iiap.res.in, E-mail: knn@iiap.res.in, E-mail: sankar@iiap.res.in [Indian Institute of Astrophysics, Koramangala, Bengaluru 560 034 (India)
2017-06-01
The polarization of the light that is scattered by the coronal ions is influenced by the anisotropic illumination from the photosphere and the magnetic field structuring in the solar corona. The properties of the coronal magnetic fields can be well studied by understanding the polarization properties of coronal forbidden emission lines that arise from magnetic dipole ( M 1) transitions in the highly ionized atoms that are present in the corona. We present the classical scattering theory of the forbidden lines for a more general case of arbitrary-strength magnetic fields. We derive the scattering matrix for M 1 transitions using the classical magnetic dipole model of Casini and Lin and applying the scattering matrix approach of Stenflo. We consider a two-level atom model and neglect collisional effects. The scattering matrix so derived is used to study the Stokes profiles formed in coronal conditions in those regions where the radiative excitations dominate collisional excitations. To this end, we take into account the integration over a cone of an unpolarized radiation from the solar disk incident on the scattering atoms. Furthermore, we also integrate along the line of sight to calculate the emerging polarized line profiles. We consider radial and dipole magnetic field configurations and spherically symmetric density distributions. For our studies we adopt the atomic parameters corresponding to the [Fe xiii] 10747 Å coronal forbidden line. We also discuss the nature of the scattering matrix for M 1 transitions and compare it with that for the electric dipole ( E 1) transitions.
Structure of nuclear transition matrix elements for neutrinoless ...
Indian Academy of Sciences (India)
Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double-β decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...
Non-equilibrium random matrix theory. Transition probabilities
International Nuclear Information System (INIS)
Pedro, Francisco Gil; Westphal, Alexander
2016-06-01
In this letter we present an analytic method for calculating the transition probability between two random Gaussian matrices with given eigenvalue spectra in the context of Dyson Brownian motion. We show that in the Coulomb gas language, in large N limit, memory of the initial state is preserved in the form of a universal linear potential acting on the eigenvalues. We compute the likelihood of any given transition as a function of time, showing that as memory of the initial state is lost, transition probabilities converge to those of the static ensemble.
Identification of Data Structures and Relationships by Matrix Reordering Techniques.
McCormick, William T., Jr.; And Others
Presented are the results of a study conducted to develop algorithms for ordering and organizing data that can be presented in a two-dimensional matrix form. The purpose of the work was to develop methods to extract latent data patterns, grouping, and structural relationships which are not apparent from the raw matrix data. The algorithms…
Matrix model of QCD: Edge localized glueballs and phase transitions
Acharyya, Nirmalendu; Balachandran, A. P.
2017-10-01
In a matrix model of pure SU(2) Yang-Mills theory, boundaries emerge in the space of Mat3(R ) and the Hamiltonian requires boundary conditions. We show the existence of edge localized glueball states that can have negative energies. These edge levels can be lifted to positive energies if the gluons acquire a London-like mass. This suggests a new phase of QCD with an incompressible bulk.
Calculation of the N to $\\Delta$ electromagnetic transition matrix element
Alexandrou, C; Lippert, T; Neff, H; Negele, J W; Schilling, K; Tsapalis, A; Forcrand, Ph. de; Lippert, Th.
2003-01-01
We present results on the ratio of electric quadrupole to magnetic dipole amplitudes, $R_{EM}={\\cal G}_{E2}/{\\cal G}_{M1}$, for the transition $\\gamma N\\to \\Delta$ from lattice QCD. We consider both the quenched and the 2-flavor theory.
Structure of nuclear transition matrix elements for neutrinoless ...
Indian Academy of Sciences (India)
Bogoliubov model; short-range correlations; .... transition strengths, as well as to reproduce the available measured (β−β−)2ν decay rates. The main objective of the ... The strength of proton–neutron (pn) component of the QQ interaction χpn is varied so ...
Identification of high-energetic particles by transition radiation
International Nuclear Information System (INIS)
Struczinski, W.
1986-01-01
This thesis gives a comprehensive survey on the application of the transition radiation for the particle identification. After a short historical review on the prediction and the detection of the transition radiation its theoretical foundations are more precisely explained. They form the foundations for the construction of an optimal transition radiation detector the principal construction of which is described. The next chapter shows some experiments by which the main predictions of the transition-radiation theory are confirmed. Then the construction and operation of two transition-radiation detectors are described which were applied at the ISR respectively SPS in the CERN in Geneva in complex experiments. The detector applied at the ISR served for the e ± identification. With two lithium radiators which were followed by xenon-filled proportional chambers an e/π separation of ≅ 10 -2 could be reached. The transition-radiation detector applied in the SPS was integrated into the European Hybrid Spectrometer. It served for the identification of high-energetic pions (> or approx. 90 GeV) against kaons and protons. With twenty units of carbon-fiber radiators which were followed by xenon-filled proportional chambers a π/K, p separation of better than 1:20 for momenta above 100 GeV could be reached. The cluster-counting method is then presented. Finally, a survey on the contemporary status in the development of transition-radiation detectors for the e/π separation is given. It is shown that by an about half a meter long detector the radiators of which consist of carbon fibers an e/π separation in the order of magnitude of ≅ 10 -2 can be reached. (orig./HSI) [de
Matrix effects in biological mass spectrometry imaging: identification and compensation.
Lanekoff, Ingela; Stevens, Susan L; Stenzel-Poore, Mary P; Laskin, Julia
2014-07-21
Matrix effects in mass spectrometry imaging (MSI) may affect the observed molecular distribution in chemical and biological systems. In this study, we use mouse brain tissue of a middle cerebral artery occlusion (MCAO) stroke model to examine matrix effects in nanospray desorption electrospray ionization MSI (nano-DESI MSI). This is achieved by normalizing the intensity of the sodium and potassium adducts of endogenous phosphatidylcholine (PC) species to the intensity of the corresponding adduct of the PC standard supplied at a constant rate with the nano-DESI solvent. The use of MCAO model with an ischemic region localized to one hemisphere of the brain enables immediate comparison of matrix effects within one ion image. Furthermore, significant differences in sodium and potassium concentrations in the ischemic region in comparison with the healthy tissue allowed us to distinguish between two types of matrix effects. Specifically, we discuss matrix effects originating from variations in alkali metal concentrations and matrix effects originating from variations in the molecular composition of the tissue. Compensation for both types of matrix effects was achieved by normalizing the signals corresponding to endogenous PC to the signals of the standards. This approach, which does not introduce any complexity in sample preparation, efficiently compensates for signal variations resulting from differences in the local concentrations of sodium and potassium in tissue sections and from the complexity of the extracted analyte mixture derived from local variations in molecular composition.
Directory of Open Access Journals (Sweden)
Nikola Trčka
2009-12-01
Full Text Available We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are standardly presented in real matrix theory. By interpreting the obtained matrix conditions for bisimulations in this setting, we automatically obtain the definitions of strong, weak, and branching bisimulation for Markov reward chains. The obtained strong and weak bisimulations are shown to coincide with some existing notions, while the obtained branching bisimulation is new, but its usefulness is questionable.
International Nuclear Information System (INIS)
Rajput, B.S.
1977-01-01
Using the reduced expansions of second quantized electromagnetic vector potential operator in terms of irreducible representations of Pioncare group in the interaction Hamiltonian, the exact matrix elements of interaction of electromagnetic field with a hydrogenic atom have been derived and the contributions of transitions for different combinations of angular momentum quantum numbers to the transition probabilities of various lines in Lyman-, Balmer-, and Paschen-series have been computed. (author)
TREATMENT OF NONADIABATIC TRANSITIONS BY DENSITY-MATRIX EVOLUTION AND MOLECULAR-DYNAMICS SIMULATIONS
MAVRI, J; BERENDSEN, HJC
1994-01-01
A density matrix evolution (DME) method (H.J.C. Berendsen and J. Mavri, J. Phys. Chem., 97 (1993) 13469) to simulate the dynamics of quantum systems embedded in a classical environment is presented. The DME method allows treatment of nonadiabatic transitions. As numerical examples the collinear
Time-Varying Transition Probability Matrix Estimation and Its Application to Brand Share Analysis
Chiba, Tomoaki; Akaho, Shotaro; Murata, Noboru
2017-01-01
In a product market or stock market, different products or stocks compete for the same consumers or purchasers. We propose a method to estimate the time-varying transition matrix of the product share using a multivariate time series of the product share. The method is based on the assumption that each of the observed time series of shares is a stationary distribution of the underlying Markov processes characterized by transition probability matrices. We estimate transition probability matrices for every observation under natural assumptions. We demonstrate, on a real-world dataset of the share of automobiles, that the proposed method can find intrinsic transition of shares. The resulting transition matrices reveal interesting phenomena, for example, the change in flows between TOYOTA group and GM group for the fiscal year where TOYOTA group’s sales beat GM’s sales, which is a reasonable scenario. PMID:28076383
Time-Varying Transition Probability Matrix Estimation and Its Application to Brand Share Analysis.
Chiba, Tomoaki; Hino, Hideitsu; Akaho, Shotaro; Murata, Noboru
2017-01-01
In a product market or stock market, different products or stocks compete for the same consumers or purchasers. We propose a method to estimate the time-varying transition matrix of the product share using a multivariate time series of the product share. The method is based on the assumption that each of the observed time series of shares is a stationary distribution of the underlying Markov processes characterized by transition probability matrices. We estimate transition probability matrices for every observation under natural assumptions. We demonstrate, on a real-world dataset of the share of automobiles, that the proposed method can find intrinsic transition of shares. The resulting transition matrices reveal interesting phenomena, for example, the change in flows between TOYOTA group and GM group for the fiscal year where TOYOTA group's sales beat GM's sales, which is a reasonable scenario.
Time-Varying Transition Probability Matrix Estimation and Its Application to Brand Share Analysis.
Directory of Open Access Journals (Sweden)
Tomoaki Chiba
Full Text Available In a product market or stock market, different products or stocks compete for the same consumers or purchasers. We propose a method to estimate the time-varying transition matrix of the product share using a multivariate time series of the product share. The method is based on the assumption that each of the observed time series of shares is a stationary distribution of the underlying Markov processes characterized by transition probability matrices. We estimate transition probability matrices for every observation under natural assumptions. We demonstrate, on a real-world dataset of the share of automobiles, that the proposed method can find intrinsic transition of shares. The resulting transition matrices reveal interesting phenomena, for example, the change in flows between TOYOTA group and GM group for the fiscal year where TOYOTA group's sales beat GM's sales, which is a reasonable scenario.
The efficient identification of relativistic particles by transition radiation
Cherry, M. L.; Mueller, D.; Prince, T. A.
1974-01-01
A system of transition radiation detectors has been constructed and exposed to beams of electrons and pions in the energy range of 3 to 15 GeV at SLAC. Transition radiation was generated in a variety of stacks of mylar foils (radiators), and its intensity was detected with 7 multiwire proportional chambers. The raw data demonstrate a good separation between electron and pion induced signals. A more detailed analysis shows that a very efficient identification of individual particles is possible. Typically, a detection efficiency for electrons above 90%, combined with a pion-electron discrimination ratio of .001, has been achieved. Some conclusions with respect to the design of a practical detector for relativistic particles are drawn.
Improved gel electrophoresis matrix for hydrophobic protein separation and identification.
Tokarski, Caroline; Fillet, Marianne; Rolando, Christian
2011-03-01
We propose an improved acrylamide gel for the separation of hydrophobic proteins. The separation strategy is based on the incorporation of N-alkylated and N,N'-dialkylated acrylamide monomers in the gel composition in order to increase hydrophobic interactions between the gel matrix and the membrane proteins. Focusing on the most efficient monomer, N,N'-dimethylacrylamide, the potentiality of the new matrix was evaluated on membrane proteins of the human colon HCT-116 cell line. Protein analysis was performed using an adapted analytical strategy based on FT-ICR tandem mass spectrometry. As a result of this comparative study, including advanced reproducibility experiments, more hydrophobic proteins were identified in the new gel (average GRAVY: -0.085) than in the classical gel (average GRAVY: -0.411). Highly hydrophobic peptides were identified reaching a GRAVY value up to 1.450, therefore indicating their probable locations in the membrane. Focusing on predicted transmembrane domains, it can be pointed out that 27 proteins were identified in the hydrophobic gel containing up to 11 transmembrane domains; in the classical gel, only 5 proteins containing 1 transmembrane domain were successfully identified. For example, multiple ionic channels and receptors were characterized in the hydrophobic gel such as the sodium/potassium channel and the glutamate or the transferrin receptors whereas they are traditionally detected using specific enrichment techniques such as immunoprecipitation. In total, membrane proteins identified in the classical gel are well documented in the literature, while most of the membrane proteins only identified on the hydrophobic gel have rarely or never been described using a proteomic-based approach. 2010 Elsevier Inc. All rights reserved.
The modular S-matrix as order parameter for topological phase transitions
International Nuclear Information System (INIS)
Bais, F A; Romers, J C
2012-01-01
We study topological phase transitions in discrete gauge theories in two spatial dimensions induced by the formation of a Bose condensate. We analyse a general class of euclidean lattice actions for these theories which contain one coupling constant for each conjugacy class of the gauge group. To probe the phase structure we use a complete set of open and closed anyonic string operators. The open strings allow one to determine the particle content of the condensate, whereas the closed strings enable us to determine the matrix elements of the modular S-matrix, in both the unbroken and broken phases. From the measured broken S-matrix we may read off the sectors that split or get identified in the broken phase, as well as the sectors that are confined. In this sense the modular S-matrix can be employed as a matrix valued nonlocal order parameter from which the low-energy effective theories that occur in different regions of parameter space can be fully determined. To verify our predictions, we studied a non-abelian anyon model based on the quaternion group H=D-bar 2 of the order of eight by Monte Carlo simulation. We probe part of the phase diagram for the pure gauge theory and find a variety of phases with magnetic condensates leading to various forms of (partial) confinement in complete agreement with the algebraic breaking analysis. Also the order of various transitions is established. (paper)
Kedney, Mollie G.; Strunk, Kevin B.; Giaquinto, Lisa M.; Wagner, Jennifer A.; Pollack, Sidney; Patton, Walter A.
2007-01-01
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS or simply MALDI) has become ubiquitous in the identification and analysis of biomacromolecules. As a technique that allows for the molecular weight determination of otherwise nonvolatile molecules, MALDI has had a profound impact in the molecular…
Haraldsdóttir, Hulda S.; Fleming, Ronan M. T.
2016-01-01
Conserved moieties are groups of atoms that remain intact in all reactions of a metabolic network. Identification of conserved moieties gives insight into the structure and function of metabolic networks and facilitates metabolic modelling. All moiety conservation relations can be represented as nonnegative integer vectors in the left null space of the stoichiometric matrix corresponding to a biochemical network. Algorithms exist to compute such vectors based only on reaction stoichiometry but their computational complexity has limited their application to relatively small metabolic networks. Moreover, the vectors returned by existing algorithms do not, in general, represent conservation of a specific moiety with a defined atomic structure. Here, we show that identification of conserved moieties requires data on reaction atom mappings in addition to stoichiometry. We present a novel method to identify conserved moieties in metabolic networks by graph theoretical analysis of their underlying atom transition networks. Our method returns the exact group of atoms belonging to each conserved moiety as well as the corresponding vector in the left null space of the stoichiometric matrix. It can be implemented as a pipeline of polynomial time algorithms. Our implementation completes in under five minutes on a metabolic network with more than 4,000 mass balanced reactions. The scalability of the method enables extension of existing applications for moiety conservation relations to genome-scale metabolic networks. We also give examples of new applications made possible by elucidating the atomic structure of conserved moieties. PMID:27870845
On the estimation of matrix elements for optical transitions in semiconductors
International Nuclear Information System (INIS)
Hassan, A.R.
1992-09-01
A semi-empirical method is used to calculate the numerical values of the interband momentum matrix elements of the allowed optical transitions in semiconductors. This method is based on the evaluation of the ratio of the two-photon and one-photon absorption coefficients and the compare the result with the corresponding experimental values in a number of semiconductors both for direct and indirect transition processes. The numerical values of the momentum matrix elements are compared with the convenient theoretical calculations available. The result is found to agree fairly well with the corresponding values computed using the k-vector · p-vector perturbation theory. (author). 19 refs, 2 figs, 2 tabs
Effect of the glass transition temperature on alpha-amylase activity in a starch matrix.
Chaudhary, Vinita; Panyoyai, Naksit; Small, Darryl M; Shanks, Robert A; Kasapis, Stefan
2017-02-10
This study optimises a protocol for the estimation of α-amylase activity in a condensed starch matrix in the vicinity of the glass transition region. Enzymatic activity on the vitrified starch system was compared with that of a reference substrate, maltodextrin. The activity was assayed as the rate of release of reducing sugar using a dinitrosalicylic acid procedure. The condensed carbohydrate matrices served the dual purpose of acting as a substrate as well as producing a pronounced effect on the ability to enzymatic hydrolysis. Activation energies were estimated throughout the glass transition region of condensed carbohydrate preparations based on the concept of the spectroscopic shift factor. Results were used to demonstrate a considerable moderation by the mechanical glass transition temperature, beyond the expected linear effect of the temperature dependence, on the reaction rate of starch hydrolysis by α-amylase in comparison with the low-molecular weight chain of maltodextrin. Copyright © 2016. Published by Elsevier Ltd.
Density induced phase transitions in the Schwinger model. A study with matrix product states
Energy Technology Data Exchange (ETDEWEB)
Banuls, Mari Carmen; Cirac, J. Ignacio; Kuehn, Stefan [Max-Planck-Institut fuer Quantenoptik (MPQ), Garching (Germany); Cichy, Krzysztof [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Adam Mickiewicz Univ., Poznan (Poland). Faculty of Physics; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC
2017-02-15
We numerically study the zero temperature phase structure of the multiflavor Schwinger model at nonzero chemical potential. Using matrix product states, we reproduce analytical results for the phase structure for two flavors in the massless case and extend the computation to the massive case, where no analytical predictions are available. Our calculations allow us to locate phase transitions in the mass-chemical potential plane with great precision and provide a concrete example of tensor networks overcoming the sign problem in a lattice gauge theory calculation.
Metal-insulator transition in disordered systems from the one-body density matrix
DEFF Research Database (Denmark)
Olsen, Thomas; Resta, Raffaele; Souza, Ivo
2017-01-01
systems. In particular, for noninteracting systems the geometrical marker can be obtained from the configurational average of the norm-squared one-body density matrix, which can be calculated within open as well as periodic boundary conditions. This is in sharp contrast to a classification based......The insulating state of matter can be probed by means of a ground state geometrical marker, which is closely related to the modern theory of polarization (based on a Berry phase). In the present work we show that this marker can be applied to determine the metal-insulator transition in disordered...
Calculating infinite-medium {alpha}-eigenvalue spectra with a transition rate matrix method
Energy Technology Data Exchange (ETDEWEB)
Betzler, B. R. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Kiedrowski, B. C.; Brown, F. B. [X-Computational Physics Division, Monte Carlo Codes Group, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Martin, W. R. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States)
2013-07-01
The time-dependent behavior of the energy spectrum in neutron transport was investigated with a formulation, based on continuous-time Markov processes, for computing {alpha}-eigenvalues and eigenvectors in an infinite medium. For this, a research Monte Carlo code called TORTE was created and used to estimate elements of a transition rate matrix. TORTE is capable of using both multigroup and continuous-energy nuclear data, and verification was performed. Eigenvalue spectra for infinite homogeneous mixtures were obtained and an eigenfunction expansion was used to investigate transient behavior of the neutron energy spectrum. (authors)
Energy Technology Data Exchange (ETDEWEB)
Zakhlevnykh, A. N., E-mail: anz@psu.ru; Petrov, D. A. [Perm State National Research University (Russian Federation)
2016-10-15
We study the orientational response of a ferromagnetic liquid crystal that is induced by magnetic and electric fields. A modified form of the energy of the orientational interaction between magnetic impurity particles and the liquid crystal matrix that leads to bistable coupling is considered. It is shown that apart from magnetic impurity segregation, first-order orientational transitions can be due to the bistability of the potential of the orientational coupling between the director and the magnetization. The ranges of material parameters that lead to optical bistability are determined. The possibility of first-order orientational transitions is analyzed for the optical phase difference between the ordinary and extraordinary light rays transmitted through a ferronematic cell. It is shown that an electric field applied in the given geometry considerably enhances the magneto-orientational response of the ferronematic.
International Nuclear Information System (INIS)
Luo, Da-Wei; Xu, Jing-Bo
2015-01-01
We use an alternative method to investigate the quantum criticality at zero and finite temperature using trace distance along with the density matrix renormalization group. It is shown that the average correlation measured by the trace distance between the system block and environment block in a DMRG sweep is able to detect the critical points of quantum phase transitions at finite temperature. As illustrative examples, we study spin-1 XXZ chains with uniaxial single-ion-type anisotropy and the Heisenberg spin chain with staggered coupling and external magnetic field. It is found that the trace distance shows discontinuity at the critical points of quantum phase transition and can be used as an indicator of QPTs
Directory of Open Access Journals (Sweden)
S. Sreehari Sastry
2012-01-01
Full Text Available This paper presents a method which combines the statistical analysis with texture structural analysis called Local Binary Gray Level Cooccurrence Matrix (LBGLCM to investigate the phase transition temperatures of thermotropic p,n-alkyloxy benzoic acid (nOBA, n=4,6,8,10 and 12 liquid crystals. Textures of the homeotropically aligned liquid crystal compounds are recorded as a function of temperature using polarizing optical microscope attached to the hot stage and high resolution camera. In this method, second-order statistical parameters (contrast, energy, homogeneity, and correlation are extracted from the LBGLCM of the textures. The changes associatedwiththe values of extracted parameters as a function of temperature are a helpful process to identify the phases and phase transition temperatures of the samples. Results obtained from this method have validity and are in good agreement with the literature.
Gorissen, Mieke; Hooyberghs, Jef; Vanderzande, Carlo
2009-02-01
Cumulants of a fluctuating current can be obtained from a free-energy-like generating function, which for Markov processes equals the largest eigenvalue of a generalized generator. We determine this eigenvalue with the density-matrix renormalization group for stochastic systems. We calculate the variance of the current in the different phases, and at the phase transitions, of the totally asymmetric exclusion process. Our results can be described in the terms of a scaling ansatz that involves the dynamical exponent z . We also calculate the generating function of the dynamical activity (total number of configuration changes) near the absorbing-state transition of the contact process. Its scaling properties can be expressed in terms of known critical exponents.
International Nuclear Information System (INIS)
Zhang, L.
1981-08-01
A method based on the tight-binding approximation is developed to calculate the electron-phonon matrix element for the disordered transition metals. With the method as a basis the experimental Tsub(c) data of the amorphous transition metal superconductors are re-analysed. Some comments on the superconductivity of the disordered materials are given
Columnar-to-Equiaxed Transition in Metal-Matrix Composites Reinforced with Silicon Carbide Particles
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Alicia E. Ares
2013-01-01
Full Text Available The present work is focused on the study of the effect of directional heat extraction on the silicon-carbide (SiC distribution in zinc-aluminum matrix composites (MMCs and on the columnar-to-equiaxed (CET position in directionally solidified samples. To this end, a ZA-27 alloy matrix was reinforced with ceramic particles of SiC and vertically directionally solidified. The cooling rates, temperature gradients, and interphase velocities were then measured, and their influence on the solidification microstructure of the MMCs was analyzed. The recalescence detected and measured during the equiaxed transition was of the order of 3.5°C to 1.1°C. The values of the temperature gradients reached a minimum during the CET and were even negative in most cases (between −3.89 K and 0.06 K. The interphase velocities varied between 0.07 mm/s and 0.44 mm/s at the transition. Also, the presence of ceramic particles in ZA-27 alloys affected the thermodynamic local conditions and the kinetics of nucleation, producing a finer microstructure.
Narayanan, Amal; Chandel, Shubham; Ghosh, Nirmalya; De, Priyadarsi
2015-09-15
Probing volume phase transition behavior of superdiluted polymer solutions both micro- and macroscopically still persists as an outstanding challenge. In this regard, we have explored 4 × 4 spectral Mueller matrix measurement and its inverse analysis for excavating the microarchitectural facts about stimuli responsiveness of "smart" polymers. Phase separation behavior of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and pH responsive poly(N,N-(dimethylamino)ethyl methacrylate) (PDMAEMA) and their copolymers were analyzed in terms of Mueller matrix derived polarization parameters, namely, depolarization (Δ), diattenuation (d), and linear retardance (δ). The Δ, d, and δ parameters provided useful information on both macro- and microstructural alterations during the phase separation. Additionally, the two step action ((i) breakage of polymer-water hydrogen bonding and (ii) polymer-polymer aggregation) at the molecular microenvironment during the cloud point generation was successfully probed via these parameters. It is demonstrated that, in comparison to the present techniques available for assessing the hydrophobic-hydrophilic switch over of simple stimuli-responsive polymers, Mueller matrix polarimetry offers an important advantage requiring a few hundred times dilute polymer solution (0.01 mg/mL, 1.1-1.4 μM) at a low-volume format.
Comparison between Two Methods to Calculate the Transition Matrix of Orbit Motion
Directory of Open Access Journals (Sweden)
Ana Paula Marins Chiaradia
2012-01-01
Full Text Available Two methods to evaluate the state transition matrix are implemented and analyzed to verify the computational cost and the accuracy of both methods. This evaluation represents one of the highest computational costs on the artificial satellite orbit determination task. The first method is an approximation of the Keplerian motion, providing an analytical solution which is then calculated numerically by solving Kepler's equation. The second one is a local numerical approximation that includes the effect of 2. The analysis is performed comparing these two methods with a reference generated by a numerical integrator. For small intervals of time (1 to 10 s and when one needs more accuracy, it is recommended to use the second method, since the CPU time does not excessively overload the computer during the orbit determination procedure. For larger intervals of time and when one expects more stability on the calculation, it is recommended to use the first method.
International Nuclear Information System (INIS)
Faifman, M.P.; Strizh, T.A.; Armour, E.A.G.; Harston, M.R.
1996-01-01
The calculated resonant formation rates of the muonic molecules DDμ and DTμ are presented. The approach developed earlier for calculating the transition matrix elements in the dipole approximation has been extended to include the quadrupole terms in the multipole expansion of the interaction operator. The calculated dependence of the DTμ formation rates on the energies of the incident Tμ muonic atoms shows that the effect of including the quadrupole correction is to reduce the magnitude of the peak rates by about 20-30% at the different temperatures, compared to those calculated in the dipole approximation. The dependence on temperature for the DDμ formation rates is obtained with the differences between the presented and previous calculations being less than 5%. (orig.)
Off-energy-shell variations of two-nucleon transition matrix and three-nucleon problem
International Nuclear Information System (INIS)
Stingl, M.; Sauer, P.U.
1975-01-01
For a schematic three-nucleon problem, approximate analytic expressions are derived for the functional derivatives of measurable three-particle quantities with respect to off-shell variations of the triplet-s two-nucleon transition matrix. Those quantities include neutron-deuteron scattering lengths, trinucleon binding energies, and the 3 He charge form-factor minimum; correlations between off-shell changes in the latter two are discussed. An indication is given how results of this kind may be to decide whether or not a given set of discrepancies between calculated and experimental three-nucleon observables can be reconciled in terms of off-shell variations of a nonretarded hermitean two-nucleon interaction. The treatment is not restricted to special classes of phase-shift equivalent potentials or phase-shift preserving transformations but instead makes use of a systematic parameterization of off-shell variations in terms of symmetric rational approximants of increasing order
Entanglement and quantum phase transitions in matrix-product spin-1 chains
International Nuclear Information System (INIS)
Alipour, S.; Karimipour, V.; Memarzadeh, L.
2007-01-01
We consider a one-parameter family of matrix-product states of spin-1 particles on a periodic chain and study in detail the entanglement properties of such a state. In particular, we calculate exactly the entanglement of one site with the rest of the chain, and the entanglement of two distant sites with each other, and show that the derivative of both these properties diverge when the parameter g of the states passes through a critical point. Such a point can be called a point of quantum phase transition, since at this point the character of the matrix-product state, which is the ground state of a Hamiltonian, changes discontinuously. We also study the finite size effects and show how the entanglement depends on the size of the chain. This later part is relevant to the field of quantum computation where the problem of initial state preparation in finite arrays of qubits or qutrits is important. It is also shown that the entanglement of two sites have scaling behavior near the critical point
Sun, Yan; Yu, Chin-Hui; Kouri, Donald J.; Schwenke, David W.; Halvick, Philippe
1989-01-01
A new formalism of the generalized Newton variational principle for the calculation of quantum mechanical state-to-state reaction probabilities is presented. The reformulation involves solving directly for the transition matrix rather than the reactance mtrix so that calculations may be carried out for individual columns of the transition matrix without obtaining solutions for all possible initial channels. The convergence of calculations with real and complex boundary conditions are compared for H + H2 - H2 + H, O + H2 - OH + H, and O + HD - OH + D and OD + H.
Han, Xiao; Gao, Xiguang; Song, Yingdong
2017-10-01
An approach to identify parameters of interface friction model for Ceramic Matrix composites based on stress-strain response was developed. The stress distribution of fibers in the interface slip region and intact region of the damaged composite was determined by adopting the interface friction model. The relation between maximum strain, secant moduli of hysteresis loop and interface shear stress, interface de-bonding stress was established respectively with the method of symbolic-graphic combination. By comparing the experimental strain, secant moduli of hysteresis loop with computation values, the interface shear stress and interface de-bonding stress corresponding to first cycle were identified. Substituting the identification of parameters into interface friction model, the stress-strain curves were predicted and the predicted results fit experiments well. Besides, the influence of number of data points on identifying the value of interface parameters was discussed. And the approach was compared with the method based on the area of hysteresis loop.
Transition radiators for electron identification at the CERN ISR
International Nuclear Information System (INIS)
Cobb, J.; Iwata, S.; Palmer, R.; Fabjan, C.W.; Nappi, A.; Struczinski, W.; Willis, W.; Kourkoumelis, C.; Lankford, A.J.; Rehak, P.; Moneti, G.-C.
1977-01-01
Transition radiators constructed from thin foils of lithium used to separate electrons from heavier charged particles at the CERN Intersecting Storage Rings (ISR) are described. The optimization of the system of the radiator and detector is discussed, leading to the choice of parameters for this design. The special features of the construction of a structure of lithium is described. Results of a number of different measurements of the transition radiation are given. (Auth.)
Transition radiators for electron identification at the CERN ISR
Cobb, J; Iwata, S; Kourkoumelis, C; Lankford, A J; Moneti, G C; Nappi, A; Palmer, R B; Rehak, P; Struczinski, W; Willis, W J
1977-01-01
The authors describe transition radiators constructed from thin foils of lithium, used to separate electrons from heavier charged particles at the CERN Intersecting Storage Rings (ISR). The optimisation of the system of the radiator and detector is discussed, leading to the choice of parameters for this design. The special features of the construction of a structure of lithium is described. Results of a number of different measurements of the transition radiation are given. (11 refs).
Ellison, Donald; Conway, Bruce; Englander, Jacob
2015-01-01
A significant body of work exists showing that providing a nonlinear programming (NLP) solver with expressions for the problem constraint gradient substantially increases the speed of program execution and can also improve the robustness of convergence, especially for local optimizers. Calculation of these derivatives is often accomplished through the computation of spacecraft's state transition matrix (STM). If the two-body gravitational model is employed as is often done in the context of preliminary design, closed form expressions for these derivatives may be provided. If a high fidelity dynamics model, that might include perturbing forces such as the gravitational effect from multiple third bodies and solar radiation pressure is used then these STM's must be computed numerically. We present a method for the power hardward model and a full ephemeris model. An adaptive-step embedded eight order Dormand-Prince numerical integrator is discussed and a method for the computation of the time of flight derivatives in this framework is presented. The use of these numerically calculated derivatieves offer a substantial improvement over finite differencing in the context of a global optimizer. Specifically the inclusion of these STM's into the low thrust missiondesign tool chain in use at NASA Goddard Spaceflight Center allows for an increased preliminary mission design cadence.
Analytical transition-matrix treatment of electric multipole polarizabilities of hydrogen-like atoms
International Nuclear Information System (INIS)
Kharchenko, V.F.
2015-01-01
The direct transition-matrix approach to the description of the electric polarization of the quantum bound system of particles is used to determine the electric multipole polarizabilities of the hydrogen-like atoms. It is shown that in the case of the bound system formed by the Coulomb interaction the corresponding inhomogeneous integral equation determining an off-shell scattering function, which consistently describes virtual multiple scattering, can be solved exactly analytically for all electric multipole polarizabilities. Our method allows to reproduce the known Dalgarno–Lewis formula for electric multipole polarizabilities of the hydrogen atom in the ground state and can also be applied to determine the polarizability of the atom in excited bound states. - Highlights: • A new description for electric polarization of hydrogen-like atoms. • Expression for multipole polarizabilities in terms of off-shell scattering functions. • Derivation of integral equation determining the off-shell scattering function. • Rigorous analytic solving the integral equations both for ground and excited states. • Study of contributions of virtual multiple scattering to electric polarizabilities
Manthe, Uwe; Ellerbrock, Roman
2016-05-28
A new approach for the quantum-state resolved analysis of polyatomic reactions is introduced. Based on the singular value decomposition of the S-matrix, energy-dependent natural reaction channels and natural reaction probabilities are defined. It is shown that the natural reaction probabilities are equal to the eigenvalues of the reaction probability operator [U. Manthe and W. H. Miller, J. Chem. Phys. 99, 3411 (1993)]. Consequently, the natural reaction channels can be interpreted as uniquely defined pathways through the transition state of the reaction. The analysis can efficiently be combined with reactive scattering calculations based on the propagation of thermal flux eigenstates. In contrast to a decomposition based straightforwardly on thermal flux eigenstates, it does not depend on the choice of the dividing surface separating reactants from products. The new approach is illustrated studying a prototypical example, the H + CH4 → H2 + CH3 reaction. The natural reaction probabilities and the contributions of the different vibrational states of the methyl product to the natural reaction channels are calculated and discussed. The relation between the thermal flux eigenstates and the natural reaction channels is studied in detail.
Using the Boston Matrix at Identification of the Corporate Life Cycle Stage
Directory of Open Access Journals (Sweden)
Zdeněk Konečný
2015-01-01
Full Text Available The main aim of this article is to develop a new model supporting the identification of the particular corporate life stage within the corporate life cycle. This model will be derived from the Boston matrix. The main reason for using this approach as the base for making new model of the corporate life cycle is the fact, that every quadrant of the Boston matrix can be assigned to one phase of the product life cycle and there is supposed, that the phase, in which are most products, determines the phase of the corporate life cycle. For application the Boston matrix by identification phases of the corporate life cycle is necessary to define low and high values of both its variables using some quantities from the model of corporate- and market life cycle by Reiners (2004. So the interval of low and high sales growth is determined by comparing sales of the company and sales of the market and furthermore, there is considered the rate of inflation to eliminate the impact of price changes. And for determination low and high market shares, there are compared the shares of sales and shares of total assets. After that, there will be possible to identify all the quadrants and thus all the individual phases unequivocally, which is the basic advantage compared to most existing models of the corporate life cycle. The following aim of this article is to compare the occurrence of individual phases, identified by this modified model, depending on the sector sensitivity to the economic cycle, measured by the coefficient of correlation between sales on the market and GDP. There are selected two sectors of the Czech economy, namely one cyclical and one neutral sector. Subsequently there is selected a sample of companies from both these sectors. The data are collected from financial statements of companies and from analytical materials by the Czech Ministry of Industry and Trade and by the Czech Statistical Office. On the basis of this research, there were recorded
Identification of Factors Influencing Third Birth Transition in Manipur
Directory of Open Access Journals (Sweden)
Sharat Singh N
2011-04-01
Full Text Available The third birth transition has a negative impact on the national goal of fertility replacement level (2.1 which is to be achieved by 2010. To identify the factors influencing the demographic phenomenon, a cross sectional as well as community based study consisting of 1397 eligible women was conducted in the four valley districts of Manipur under cluster sampling scheme. Analysing the empirical information through SPSS, 42% of the study subjects transit their 3rd birth and its major determinants could be detected to be sex preference, age at marriage, and educational level each at 0.01 probability level of significance.
Agar/gelatin bilayer gel matrix fabricated by simple thermo-responsive sol-gel transition method.
Wang, Yifeng; Dong, Meng; Guo, Mengmeng; Wang, Xia; Zhou, Jing; Lei, Jian; Guo, Chuanhang; Qin, Chaoran
2017-08-01
We present a simple and environmentally-friendly method to generate an agar/gelatin bilayer gel matrix for further biomedical applications. In this method, the thermally responsive sol-gel transitions of agar and gelatin combined with the different transition temperatures are exquisitely employed to fabricate the agar/gelatin bilayer gel matrix and achieve separate loading for various materials (e.g., drugs, fluorescent materials, and nanoparticles). Importantly, the resulting bilayer gel matrix provides two different biopolymer environments (a polysaccharide environment vs a protein environment) with a well-defined border, which allows the loaded materials in different layers to retain their original properties (e.g., magnetism and fluorescence) and reduce mutual interference. In addition, the loaded materials in the bilayer gel matrix exhibit an interesting release behavior under the control of thermal stimuli. Consequently, the resulting agar/gelatin bilayer gel matrix is a promising candidate for biomedical applications in drug delivery, controlled release, fluorescence labeling, and bio-imaging. Copyright © 2017 Elsevier B.V. All rights reserved.
Rams, Thomas E; Sautter, Jacqueline D; Getreu, Adam; van Winkelhoff, Arie J
OBJECTIVE: Porphyromonas gingivalis is a major bacterial pathogen in human periodontitis. This study used matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry to assess the accuracy of a rapid phenotypic identification scheme for detection of cultivable P.
Energy Technology Data Exchange (ETDEWEB)
Betzler, Benjamin R., E-mail: betzlerbr@ornl.gov [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Kiedrowski, Brian C., E-mail: bckiedro@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Brown, Forrest B., E-mail: fbrown@lanl.gov [Los Alamos National Laboratory, P.O. Box 1663, MS A143, Los Alamos, NM 87545 (United States); Martin, William R., E-mail: wrm@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States)
2015-12-15
Highlights: • A transition rate matrix method for calculating α-eigenvalues is formulated. • Verification of this method is performed using multigroup infinite-medium problems. • Applications to continuous-energy media examine the slowing down of neutrons. • The effect of the α-eigenvalue spectrum on the short-time flux behavior is discussed. - Abstract: The time-dependent behavior of the energy spectrum in neutron transport was investigated with a formulation, based on continuous-time Markov processes, for computing α eigenvalues and eigenvectors in an infinite medium. For this, a research Monte Carlo code called “TORTE” (To Obtain Real Time Eigenvalues) was created and used to estimate elements of a transition rate matrix. TORTE is capable of using both multigroup and continuous-energy nuclear data, and verification was performed. Eigenvalue spectra for infinite homogeneous mixtures were obtained, and an eigenfunction expansion was used to investigate transient behavior of the neutron energy spectrum.
The transition matrix element Agq(N) of the variable flavor number scheme at O(α3s)
International Nuclear Information System (INIS)
Ablinger, J.; Hasselhuhn, A.; Schneider, C.; Manteuffel, A. von
2014-01-01
We calculate the massive operator matrix element A (3) gq (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This is the first complete transition function needed in the variable flavor number scheme obtained at O(α 3 s ). A fist independent recalculation is performed for the contributions ∝ N F of the 3-loop anomalous dimension γ (2) gq (N).
International and Interdisciplinary Identification of Health Care Transition Outcomes.
Fair, Cynthia; Cuttance, Jessica; Sharma, Niraj; Maslow, Gary; Wiener, Lori; Betz, Cecily; Porter, Jerlym; McLaughlin, Suzanne; Gilleland-Marchak, Jordan; Renwick, Amy; Naranjo, Diana; Jan, Sophia; Javalkar, Karina; Ferris, Maria
2016-03-01
There is a lack of agreement on what constitutes successful outcomes for the process of health care transition (HCT) among adolescent and young adults with special health care needs. To present HCT outcomes identified by a Delphi process with an interdisciplinary group of participants. A Delphi method involving 3 stages was deployed to refine a list of HCT outcomes. This 18-month study (from January 5, 2013, of stage 1 to July 3, 2014, of stage 3) included an initial literature search, expert interviews, and then 2 waves of a web-based survey. On this survey, 93 participants from outpatient, community-based, and primary care clinics rated the importance of the top HCT outcomes identified by the Delphi process. Analyses were performed from July 5, 2014, to December 5, 2014. Health care transition outcomes of adolescents and young adults with special health care needs. Importance ratings of identified HCT outcomes rated on a Likert scale from 1 (not important) to 9 (very important). The 2 waves of surveys included 117 and 93 participants as the list of outcomes was refined. Transition outcomes were refined by the 3 waves of the Delphi process, with quality of life being the highest-rated outcome with broad agreement. The 10 final outcomes identified included individual outcomes (quality of life, understanding the characteristics of conditions and complications, knowledge of medication, self-management, adherence to medication, and understanding health insurance), health services outcomes (attending medical appointments, having a medical home, and avoidance of unnecessary hospitalization), and a social outcome (having a social network). Participants indicated that different outcomes were likely needed for individuals with cognitive disabilities. Quality of life is an important construct relevant to HCT. Future research should identify valid measures associated with each outcome and further explore the role that quality of life plays in the HCT process. Achieving
Energy Technology Data Exchange (ETDEWEB)
Iwahara, M. [Isuzu Advanced Engineering Center, Ltd., Tokyo (Japan); Sugiura, T.; Takaiwa, H.; Nagamatsu, A. [Tokyo Institute of Technology, Tokyo (Japan)
1997-10-01
An approach is presented for the identification of spatial matrix with modal parameters in the frequency domain. Modal parameters are transformed to spatial matrix with constraints of modal vector orthogonality and characteristic equation. Adding the connecting conditions or unconnected conditions of measuring points, spatial matrix is determined by modal parameters whose number is smaller than that of dimension of spatial matrix. 9 refs., 4 figs., 2 tabs.
Martin, Tyler; Mongcopa, Katrina; Ashkar, Rana; Butler, Paul; Krishnamoorti, Ramanan; Jayaraman, Arthi
Significant efforts have been focused towards controlling morphology of the nanoscale fillers and matrix polymer in polymer nanocomposites as the composite morphology is directly related to the macroscopic properties of that material. For nanocomposites with chemically identical graft and matrix polymers, it is well understood that the polymer grafted particle dispersion to aggregation transition is directly linked to and synonymous with wetting/dewetting of the graft and matrix polymer. Our recent work has focused on exploring composites with chemically different graft and matrix polymers, specifically those with attractive graft-matrix interactions that lead to a dispersed filler state at low temperature and aggregated filler state at high temperatures. We show, using coarse-grained molecular simulations, that the sharp phase transition from dispersed to aggregated states is distinct from the continuous wetting-dewetting transition. The onset of wetting to dewetting occurs at temperatures lower than the dispersion to aggregation transition, and dewetting continues at temperatures above the transition temperature in the aggregated state. Furthermore, the graft and matrix chain composition can be varied to tune the dispersion-aggregation transition temperature and the degree of wetting of the grafted layer. Experiments using SANS and SAXS of deuterated poly(styrene) grafted silica particles in a poly(vinyl methyl ether) matrix show remarkable agreement with our simulations.
Jakimowicz, Aleksander
2009-10-01
The 7-fold interdisciplinary matrix is introduced. This integrated methodological point of view is original, although it is based on ideas of others in various ways. The name for this new approach draws on the Kuhnian notion of a disciplinary matrix. There are four components of the Kuhnian matrix on which the existence of scientific communities hinges: symbolic generalizations, models, values, and exemplars. In this context the term "paradigm" should refer to exemplars. The interdisciplinary matrix is composed of seven elements: cybernetics, catastrophe theory, fractal geometry, deterministic chaos, artificial intelligence, theory of complexity, and humanistic values. Scientific developments have recently brought substantial changes in the structure of scientific communities. Transferability of ideas and thoughts contributed to the creation of scientific communities, which unite representatives of various professions. When researching into certain phenomena we no longer need to develop theories for them from scratch, as we can draw on the achievements in other disciplines. Two examples of the employment of the interdisciplinary matrix in macroeconomics are elaborated here: the investment cycle model in socialist economy, and the model of economic transformation based on chaotic hysteresis.
Toprak, Umut; Erlandson, Martin; Baldwin, Doug; Karcz, Steve; Wan, Lianglu; Coutu, Cathy; Gillott, Cedric; Hegedus, Dwayne D
2016-10-01
The peritrophic matrix (PM) is essential for insect digestive system physiology as it protects the midgut epithelium from damage by food particles, pathogens, and toxins. The PM is also an attractive target for development of new pest control strategies due to its per os accessibility. To understand how the PM performs these functions, the molecular architecture of the PM was examined using genomic and proteomic approaches in Mamestra configurata (Lepidoptera: Noctuidae), a major pest of cruciferous oilseed crops in North America. Liquid chromatography-tandem mass spectrometry analyses of the PM identified 82 proteins classified as: (i) peritrophins, including a new class with a CBDIII domain; (ii) enzymes involved in chitin modification (chitin deacetylases), digestion (serine proteases, aminopeptidases, carboxypeptidases, lipases and α-amylase) or other reactions (β-1,3-glucanase, alkaline phosphatase, dsRNase, astacin, pantetheinase); (iii) a heterogenous group consisting of polycalin, REPATs, serpin, C-Type lectin and Lsti99/Lsti201 and 3 novel proteins without known orthologs. The genes encoding PM proteins were expressed predominantly in the midgut. cDNAs encoding chitin synthase-2 (McCHS-2), chitinase (McCHI), and β-N-acetylglucosaminidase (McNAG) enzymes, involved in PM chitin metabolism, were also identified. McCHS-2 expression was specific to the midgut indicating that it is responsible for chitin synthesis in the PM, the only chitinous material in the midgut. In contrast, the genes encoding the chitinolytic enzymes were expressed in multiple tissues. McCHS-2, McCHI, and McNAG were expressed in the midgut of feeding larvae, and NAG activity was present in the PM. This information was used to generate an updated model of the lepidopteran PM architecture. © 2015 Institute of Zoology, Chinese Academy of Sciences.
Image-based modeling of the flow transition from a Berea rock matrix to a propped fracture
Sanematsu, P.; Willson, C. S.; Thompson, K. E.
2013-12-01
In the past decade, new technologies and advances in horizontal hydraulic fracturing to extract oil and gas from tight rocks have raised questions regarding the physics of the flow and transport processes that occur during production. Many of the multi-dimensional details of flow from the rock matrix into the fracture and within the proppant-filled fracture are still unknown, which leads to unreliable well production estimations. In this work, we use x-ray computed micro tomography (XCT) to image 30/60 CarboEconoprop light weight ceramic proppant packed between berea sandstone cores (6 mm in diameter and ~2 mm in height) under 4000 psi (~28 MPa) loading stress. Image processing and segmentation of the 6 micron voxel resolution tomography dataset into solid and void space involved filtering with anisotropic diffusion (AD), segmentation using an indicator kriging (IK) algorithm, and removal of noise using a remove islands and holes program. Physically-representative pore network structures were generated from the XCT images, and a representative elementary volume (REV) was analyzed using both permeability and effective porosity convergence. Boundary conditions were introduced to mimic the flow patterns that occur when fluid moves from the matrix into the proppant-filled fracture and then downstream within the proppant-filled fracture. A smaller domain, containing Berea and proppants close to the interface, was meshed using an in-house unstructured meshing algorithm that allows different levels of refinement. Although most of this domain contains proppants, the Berea section accounted for the majority of the elements due to mesh refinement in this region of smaller pores. A finite element method (FEM) Stokes flow model was used to provide more detailed insights on the flow transition from rock matrix to fracture. Results using different pressure gradients are used to describe the flow transition from the Berea rock matrix to proppant-filled fracture.
Location identification of closed crack based on Duffing oscillator transient transition
Liu, Xiaofeng; Bo, Lin; Liu, Yaolu; Zhao, Youxuan; Zhang, Jun; Deng, Mingxi; Hu, Ning
2018-02-01
The existence of a closed micro-crack in plates can be detected by using the nonlinear harmonic characteristics of the Lamb wave. However, its location identification is difficult. By considering the transient nonlinear Lamb under the noise interference, we proposed a location identification method for the closed crack based on the quantitative measurement of Duffing oscillator transient transfer in the phase space. The sliding short-time window was used to create a window truncation of to-be-detected signal. And then, the periodic extension processing for transient nonlinear Lamb wave was performed to ensure that the Duffing oscillator has adequate response time to reach a steady state. The transient autocorrelation method was used to reduce the occurrence of missed harmonic detection due to the random variable phase of nonlinear Lamb wave. Moreover, to overcome the deficiency in the quantitative analysis of Duffing system state by phase trajectory diagram and eliminate the misjudgment caused by harmonic frequency component contained in broadband noise, logic operation method of oscillator state transition function based on circular zone partition was adopted to establish the mapping relation between the oscillator transition state and the nonlinear harmonic time domain information. Final state transition discriminant function of Duffing oscillator was used as basis for identifying the reflected and transmitted harmonics from the crack. Chirplet time-frequency analysis was conducted to identify the mode of generated harmonics and determine the propagation speed. Through these steps, accurate position identification of the closed crack was achieved.
Energy Technology Data Exchange (ETDEWEB)
O`Brien, E.; Lissauer, D.; McCorkle, S.; Polychronakos, V.; Takai, H. [Brookhaven National Lab., Upton, NY (United States); Chi, C.Y.; Nagamiya, S.; Sippach, W.; Toy, M.; Wang, D.; Wang, Y.F.; Wiggins, C.; Willis, W. [Columbia Univ., New York, NY (United States); Cherniatin, V.; Dolgoshein, B. [Moscow Institute of Physics and Engineering, (Russian Federation); Bennett, M.; Chikanian, A.; Kumar, S.; Mitchell, J.T.; Pope, K. [Yale Univ., New Haven, CT (United States)
1991-12-31
We describe the results of a test ran involving a Transition Radiation Detector that can both distinguish electrons from pions which momenta greater titan 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most, efficient below 2 GeV/c while particle ID utilizing Transition Radiation effective above 1.5 GeV/c. Combined, the electron-pion separation is-better than 5 {times} 10{sup 2}. The single-wire, track-position resolution for the TRD is {approximately}230 {mu}m.
A transition radiation detector which features accurate tracking and dE/dx particle identification
International Nuclear Information System (INIS)
O'Brien, E.; Lissauer, D.; McCorkle, S.; Polychronakos, V.; Takai, H.; Chi, C.Y.; Nagamiya, S.; Sippach, W.; Toy, M.; Wang, D.; Wang, Y.F.; Wiggins, C.; Willis, W.; Cherniatin, V.; Dolgoshein, B.; Bennett, M.; Chikanian, A.; Kumar, S.; Mitchell, J.T.; Pope, K.
1991-01-01
We describe the results of a test run involving a Transition Radiation Detector that can both distinguish electrons from pions with momenta greater than 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most efficient below 2 GeV/c while particle ID utilizing Transition Radiation is effective above 1.5 GeV/c. Combined, the electron-pion separation is better than 5 x l0 2 . The single-wire, track-position resolution for the TRD is ∼230μm
Kazemi Amiri, A; Bucher, C
2015-05-26
This paper provides new formulations to derive the impulse response matrix, which is then used in the problem of load identification with application to wind induced vibration. The applied loads are inversely identified based on the measured structural responses by solving the associated discrete ill-posed problem. To this end - based on an existing parametric structural model - the impulse response functions of acceleration, velocity and displacement have been computed. Time discretization of convolution integral has been implemented according to an existing and a newly proposed procedure, which differ in the numerical integration methods. The former was evaluated based on a constant rectangular approximation of the sampled data and impulse response function in a number of steps corresponding to the sampling rate, while the latter interpolates the sampled data in an arbitrary number of sub-steps and then integrates over the sub-steps and steps. The identification procedure was implemented for a simulation example as well as an experimental laboratory case. The ill-conditioning of the impulse response matrix made it necessary to use Tikhonov regularization to recover the applied force from noise polluted measured response. The optimal regularization parameter has been obtained by L-curve and GCV method. The results of simulation represent good agreement between identified and measured force. In the experiments the identification results based on the measured displacement as well as acceleration are provided. Further it is shown that the accuracy of experimentally identified load depends on the sensitivity of measurement instruments over the different frequency ranges.
Reppe, Sjur; Sachse, Daniel; Olstad, Ole K; Gautvik, Vigdis T; Sanderson, Paul; Datta, Harish K; Berg, Jens P; Gautvik, Kaare M
2013-03-01
Intracellular signaling is critically dependent on gene regulatory networks comprising physical molecular interactions. Presently, there is a lack of comprehensive databases for most human tissue types to verify such macromolecular interactions. We present a user friendly browser which helps to identify functional macromolecular interactions in human bone as significant correlations at the transcriptional level. The molecular skeletal phenotype has been characterized by transcriptome analysis of iliac crest bone biopsies from 84 postmenopausal women through quantifications of ~23,000 mRNA species. When the signal levels were inter-correlated, an array containing >260 million correlations was generated, thus recognizing the human bone interactome at the RNA level. The matrix correlation and p values were made easily accessible by a freely available online browser. We show that significant correlations within the giant matrix are reproduced in a replica set of 13 male vertebral biopsies. The identified correlations differ somewhat from transcriptional interactions identified in cell culture experiments and transgenic mice, thus demonstrating that care should be taken in extrapolating such results to the in vivo situation in human bone. The current giant matrix and web browser are a valuable tool for easy access to the human bone transcriptome and molecular interactions represented as significant correlations at the RNA-level. The browser and matrix should be a valuable hypothesis generating tool for identification of regulatory mechanisms and serve as a library of transcript relationships in human bone, a relatively inaccessible tissue. Copyright © 2012 Elsevier Inc. All rights reserved.
Thomas, Randy; Stueber, Thomas J.
2013-01-01
The System Identification (SysID) Rack is a real-time hardware-in-the-loop data acquisition (DAQ) and control instrument rack that was designed and built to support inlet testing in the NASA Glenn Research Center 10- by 10-Foot Supersonic Wind Tunnel. This instrument rack is used to support experiments on the Combined-Cycle Engine Large-Scale Inlet for Mode Transition Experiment (CCE? LIMX). The CCE?LIMX is a testbed for an integrated dual flow-path inlet configuration with the two flow paths in an over-and-under arrangement such that the high-speed flow path is located below the lowspeed flow path. The CCE?LIMX includes multiple actuators that are designed to redirect airflow from one flow path to the other; this action is referred to as "inlet mode transition." Multiple phases of experiments have been planned to support research that investigates inlet mode transition: inlet characterization (Phase-1) and system identification (Phase-2). The SysID Rack hardware design met the following requirements to support Phase-1 and Phase-2 experiments: safely and effectively move multiple actuators individually or synchronously; sample and save effector control and position sensor feedback signals; automate control of actuator positioning based on a mode transition schedule; sample and save pressure sensor signals; and perform DAQ and control processes operating at 2.5 KHz. This document describes the hardware components used to build the SysID Rack including their function, specifications, and system interface. Furthermore, provided in this document are a SysID Rack effectors signal list (signal flow); system identification experiment setup; illustrations indicating a typical SysID Rack experiment; and a SysID Rack performance overview for Phase-1 and Phase-2 experiments. The SysID Rack described in this document was a useful tool to meet the project objectives.
Nie, Shuping; Tian, Baoyu; Wang, Xiaowei; Pincus, David H; Welker, Martin; Gilhuley, Kathleen; Lu, Xuedong; Han, Yiping W; Tang, Yi-Wei
2015-04-01
We explored the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for identification of Fusobacterium nucleatum subspecies. MALDI-TOF MS spectra of five F. nucleatum subspecies (animalis, fusiforme, nucleatum, polymorphum, and vincentii) were analyzed and divided into four distinct clusters, including subsp. animalis, nucleatum, polymorphum, and fusiforme/vincentii. MALDI-TOF MS with the modified SARAMIS database further correctly identified 28 of 34 F. nucleatum clinical isolates to the subspecies level. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Dinh Vu, Ngo; Dinh Bui, Nhi; Thi Minh, Thao; Thi Thanh Dam, Huong; Thi Tran, Hang
2016-05-01
We investigate the activity of heterogeneous catalysts of transition metal oxides deposited on the polymeric matrix in the oxidation of sulfur-containing compounds. It is shown that MnO2-10/CuO-10 has the highest catalytic activity. The physicomechanical properties of polymeric heterogeneous catalysts of transition-metal oxides, including the specific surface area, elongation at break and breaking strength, specific electrical resistance, and volume resistivity were studied by using an Inspekt mini 3 kN universal tensile machine in accordance with TCVN 4509:2006 at a temperature of 20 ± 2°C. Results show that heterogeneous polymeric catalysts were stable under severe reaction conditions. Scanning electron microscopy, and energy-dispersive analysis are used to study the surfaces of the catalysts. Microstructural characterization of the catalysts is performed by using x-ray computed tomography. We demonstrate the potential application of polymeric heterogeneous catalysts of transition-metal oxides in industrial wastewater treatment.
Probing emergent geometry through phase transitions in free vector and matrix models
Energy Technology Data Exchange (ETDEWEB)
Amado, Irene; Sundborg, Bo [The Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University,AlbaNova, 106 91 Stockholm (Sweden); Thorlacius, Larus [The Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University,AlbaNova, 106 91 Stockholm (Sweden); Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavik (Iceland); Wintergerst, Nico [The Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University,AlbaNova, 106 91 Stockholm (Sweden)
2017-02-01
Boundary correlation functions provide insight into the emergence of an effective geometry in higher spin gravity duals of O(N) or U(N) symmetric field theories. On a compact manifold, the singlet constraint leads to nontrivial dynamics at finite temperature and large N phase transitions even at vanishing ’t Hooft coupling. At low temperature, the leading behavior of boundary two-point functions is consistent with propagation through a bulk thermal anti de Sitter space. Above the phase transition, the two-point function shows significant departure from thermal AdS space and the emergence of localized black hole like objects in the bulk. In adjoint models, these objects appear at length scales of order of the AdS radius, consistent with a Hawking-Page transition, but in vector models they are parametrically larger than the AdS scale. In low dimensions, we find another crossover at large distances beyond which the correlation function again takes a thermal AdS form, albeit with a temperature dependent normalization factor.
Fast Step Transition and State Identification (STaSI) for Discrete Single-Molecule Data Analysis.
Shuang, Bo; Cooper, David; Taylor, J Nick; Kisley, Lydia; Chen, Jixin; Wang, Wenxiao; Li, Chun Biu; Komatsuzaki, Tamiki; Landes, Christy F
2014-09-18
We introduce a step transition and state identification (STaSI) method for piecewise constant single-molecule data with a newly derived minimum description length equation as the objective function. We detect the step transitions using the Student's t test and group the segments into states by hierarchical clustering. The optimum number of states is determined based on the minimum description length equation. This method provides comprehensive, objective analysis of multiple traces requiring few user inputs about the underlying physical models and is faster and more precise in determining the number of states than established and cutting-edge methods for single-molecule data analysis. Perhaps most importantly, the method does not require either time-tagged photon counting or photon counting in general and thus can be applied to a broad range of experimental setups and analytes.
International Nuclear Information System (INIS)
Karaziya, R.I.; Rudzikajte, L.S.
1988-01-01
The general method to obtain the explicit expressions for sums of the matrix elements of Hamiltonian and transition operators has been extended. It can be used for determining the main characteristics of atomic spectra, such as the mean energy, the variance, the asymmetry coefficient, etc., as well as for the average quantities which describe the configuration mixing. By mean of this method the formula for the variance of the emission spectrum has been derived. It has been shown that this quantity of the emission spectrum can be expressed by the variances of the energy spectra of the initial and final configurations and by additional terms, caused by the distribution of the intensity in spectrum
Directory of Open Access Journals (Sweden)
Antje Hoppenheit
Full Text Available Glossina (G. spp. (Diptera: Glossinidae, known as tsetse flies, are vectors of African trypanosomes that cause sleeping sickness in humans and nagana in domestic livestock. Knowledge on tsetse distribution and accurate species identification help identify potential vector intervention sites. Morphological species identification of tsetse is challenging and sometimes not accurate. The matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI TOF MS technique, already standardised for microbial identification, could become a standard method for tsetse fly diagnostics. Therefore, a unique spectra reference database was created for five lab-reared species of riverine-, savannah- and forest- type tsetse flies and incorporated with the commercial Biotyper 3.0 database. The standard formic acid/acetonitrile extraction of male and female whole insects and their body parts (head, thorax, abdomen, wings and legs was used to obtain the flies' proteins. The computed composite correlation index and cluster analysis revealed the suitability of any tsetse body part for a rapid taxonomical identification. Phyloproteomic analysis revealed that the peak patterns of G. brevipalpis differed greatly from the other tsetse. This outcome was comparable to previous theories that they might be considered as a sister group to other tsetse spp. Freshly extracted samples were found to be matched at the species level. However, sex differentiation proved to be less reliable. Similarly processed samples of the common house fly Musca domestica (Diptera: Muscidae; strain: Lei did not yield any match with the tsetse reference database. The inclusion of additional strains of morphologically defined wild caught flies of known origin and the availability of large-scale mass spectrometry data could facilitate rapid tsetse species identification in the future.
Ishiki, Goro; Kim, Sang-Woo; Nishimura, Jun; Tsuchiya, Asato
2009-03-20
We test the recent claim that supersymmetric matrix quantum mechanics with mass deformation preserving maximal supersymmetry can be used to study N=4 super Yang-Mills theory on R x S{3} in the planar limit. When the mass parameter is large, we can integrate out all of the massive fluctuations around a particular classical solution, which corresponds to R x S{3}. The resulting effective theory for the gauge field moduli at finite temperature reproduces the deconfinement phase transition in N=4 super Yang-Mills theory on R x S{3} at weak coupling. This transition was speculated to be a continuation of the conjectured phase transition at strong coupling, which corresponds to the Hawking-Page transition based on the gauge-gravity duality. At strong coupling, one can study the target theory by the new simulation method for supersymmetric matrix quantum mechanics.
DEFF Research Database (Denmark)
Justesen, Ulrik Stenz; Holm, Anette; Knudsen, Elisa
2011-01-01
We compared two matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems (Shimadzu/SARAMIS and Bruker) on a collection of consecutive clinically important anaerobic bacteria (n = 290). The Bruker system had more correct identifications to the species level...... (67.2% versus 49.0%), but also more incorrect identifications (7.9% versus 1.4%). The system databases need to be optimized to increase identification levels. However, MALDI-TOF MS in its present version seems to be a fast and inexpensive method for identification of most clinically important...
Staines, Katherine Ann; Zhu, Dongxing; Farquharson, Colin; MacRae, Vicky Elizabeth
2014-05-01
Bone mineralization is a carefully orchestrated process, regulated by a number of promoters and inhibitors that function to ensure effective hydroxyapatite formation. Here we sought to identify new regulators of this process through a time series microarray analysis of mineralising primary osteoblast cultures over a 27 day culture period. To our knowledge this is the first microarray study investigating murine calvarial osteoblasts cultured under conditions that permit both physiological extracellular matrix mineralization through the formation of discrete nodules and the terminal differentiation of osteoblasts into osteocytes. RT-qPCR was used to validate and expand the microarray findings. We demonstrate the significant up-regulation of >6,000 genes during the osteoblast mineralization process, the highest-ranked differentially expressed genes of which were those dominated by members of the PPAR-γ signalling pathway, namely Adipoq, Cd36 and Fabp4. Furthermore, we show that the inhibition of this signalling pathway promotes matrix mineralisation in these primary osteoblast cultures. We also identify Cilp, Phex, Trb3, Sox11, and Psat1 as novel regulators of matrix mineralization. Further studies examining the precise function of the identified genes and their interactions will advance our understanding of the mechanisms underpinning biomineralization.
Litvinenko, Alexander
2017-09-24
The main goal of this article is to introduce the parallel hierarchical matrix library HLIBpro to the statistical community. We describe the HLIBCov package, which is an extension of the HLIBpro library for approximating large covariance matrices and maximizing likelihood functions. We show that an approximate Cholesky factorization of a dense matrix of size $2M\\\\times 2M$ can be computed on a modern multi-core desktop in few minutes. Further, HLIBCov is used for estimating the unknown parameters such as the covariance length, variance and smoothness parameter of a Mat\\\\\\'ern covariance function by maximizing the joint Gaussian log-likelihood function. The computational bottleneck here is expensive linear algebra arithmetics due to large and dense covariance matrices. Therefore covariance matrices are approximated in the hierarchical ($\\\\mathcal{H}$-) matrix format with computational cost $\\\\mathcal{O}(k^2n \\\\log^2 n/p)$ and storage $\\\\mathcal{O}(kn \\\\log n)$, where the rank $k$ is a small integer (typically $k<25$), $p$ the number of cores and $n$ the number of locations on a fairly general mesh. We demonstrate a synthetic example, where the true values of known parameters are known. For reproducibility we provide the C++ code, the documentation, and the synthetic data.
Litvinenko, Alexander
2017-09-26
The main goal of this article is to introduce the parallel hierarchical matrix library HLIBpro to the statistical community. We describe the HLIBCov package, which is an extension of the HLIBpro library for approximating large covariance matrices and maximizing likelihood functions. We show that an approximate Cholesky factorization of a dense matrix of size $2M\\\\times 2M$ can be computed on a modern multi-core desktop in few minutes. Further, HLIBCov is used for estimating the unknown parameters such as the covariance length, variance and smoothness parameter of a Mat\\\\\\'ern covariance function by maximizing the joint Gaussian log-likelihood function. The computational bottleneck here is expensive linear algebra arithmetics due to large and dense covariance matrices. Therefore covariance matrices are approximated in the hierarchical ($\\\\H$-) matrix format with computational cost $\\\\mathcal{O}(k^2n \\\\log^2 n/p)$ and storage $\\\\mathcal{O}(kn \\\\log n)$, where the rank $k$ is a small integer (typically $k<25$), $p$ the number of cores and $n$ the number of locations on a fairly general mesh. We demonstrate a synthetic example, where the true values of known parameters are known. For reproducibility we provide the C++ code, the documentation, and the synthetic data.
Fyodorov, Yan V; Keating, Jonathan P
2014-01-28
We argue that the freezing transition scenario, previously conjectured to occur in the statistical mechanics of 1/f-noise random energy models, governs, after reinterpretation, the value distribution of the maximum of the modulus of the characteristic polynomials pN(θ) of large N×N random unitary (circular unitary ensemble) matrices UN; i.e. the extreme value statistics of pN(θ) when N → ∞. In addition, we argue that it leads to multi-fractal-like behaviour in the total length μN(x) of the intervals in which |pN(θ)|>N(x), x>0, in the same limit. We speculate that our results extend to the large values taken by the Riemann zeta function ζ(s) over stretches of the critical line s = 1/2 + it of given constant length and present the results of numerical computations of the large values of ζ(1/2 + it). Our main purpose is to draw attention to the unexpected connections between these different extreme value problems.
Nagdas, Subir K; Smith, Linda; Medina-Ortiz, Ilza; Hernandez-Encarnacion, Luisa; Raychoudhury, Samir
2016-03-01
Mammalian fertilization is accomplished by the interaction between sperm and egg. Previous studies from this laboratory have identified a stable acrosomal matrix assembly from the bovine sperm acrosome termed the outer acrosomal membrane-matrix complex (OMC). This stable matrix assembly exhibits precise binding activity for acrosin and N-acetylglucosaminidase. A highly purified OMC fraction comprises three major (54, 50, and 45 kDa) and several minor (38-19 kDa) polypeptides. The set of minor polypeptides (38-19 kDa) termed "OMCrpf polypeptides" is selectively solubilized by high-pH extraction (pH 10.5), while the three major polypeptides (55, 50, and 45 kDa) remain insoluble. Proteomic identification of the OMC32 polypeptide (32 kDa polypeptide isolated from high-pH soluble fraction of OMC) yielded two peptides that matched the NCBI database sequence of acrosin-binding protein. Anti-OMC32 recognized an antigenically related family of polypeptides (OMCrpf polypeptides) in the 38-19-kDa range with isoelectric points ranging between 4.0 and 5.1. Other than glycohydrolases, OMC32 may also be complexed to other acrosomal proteins. The present study was undertaken to identify and localize the OMC32 binding polypeptides and to elucidate the potential role of the acrosomal protein complex in sperm function. OMC32 affinity chromatography of a detergent-soluble fraction of bovine cauda sperm acrosome followed by mass spectrometry-based identification of bound proteins identified acrosin, lactadherin, SPACA3, and IZUMO1. Co-immunoprecipitation analysis also demonstrated the interaction of OMC32 with acrosin, lactadherin, SPACA3, and IZUMO1. Our immunofluorescence studies revealed the presence of SPACA3 and lactadherin over the apical segment, whereas IZUMO1 is localized over the equatorial segment of Triton X-100 permeabilized cauda sperm. Immunoblot analysis showed that a significant portion of SPACA3 was released after the lysophosphatidylcholine (LPC)-induced acrosome
Loving Nature From the Inside Out: A Biophilia Matrix Identification Strategy for Designers.
McGee, Beth; Marshall-Baker, Anna
2015-01-01
The development of the Biophilic Design Matrix (BDM) was to aid designers or other specialists in identifying and quantifying biophilic features through a visual inventory of interior spaces. With mounting evidence to support the healing attributes of biophilic environments, we propose a method to identify biophilic content within interior spaces. Such a strategy offers much promise to the advancement of restorative environments. The BDM was based on Stephen Kellert's biophilic design attribute list and modified to be appropriate for interior environments, specifically children's healthcare spaces. A photo-ethnographic documentation method of 24 child life play spaces within a South Atlantic state was used to determine whether the BDM could reliably reveal biophilic features (listed as attributes by Kellert in 2008). This matrix appears useful in documenting biophilia within the pediatric healthcare context, attesting to the usability and functionality of the BDM for this special population. Specifically, the BDM revealed that biophilic attributes were constantly present in some spaces while others were completely absent. When a biophilic attribute was present, the BDM indicated that they varied considerably in type and occurrence. Thus, use of the BDM in the hospital areas designed for patient recreation and play successfully provided a visual inventory of biophilic features as well as the frequency of application. Further use of the BDM as a tool for strategizing biophilic feature inclusion can thus increase the connections available with nature in the interior, beneficial for optimizing health and wellness. © The Author(s) 2015.
Directory of Open Access Journals (Sweden)
Nathalie Godin
2016-02-01
Full Text Available Non-oxide fiber-reinforced ceramic-matrix composites are promising candidates for some aeronautic applications that require good thermomechanical behavior over long periods of time. This study focuses on the behavior of a SiCf/[Si-B-C] composite with a self-healing matrix at intermediate temperature under air. Static fatigue experiments were performed below 600 °C and a lifetime diagram is presented. Damage is monitored both by strain measurement and acoustic emission during the static fatigue experiments. Two methods of real-time analysis of associated energy release have been developed. They allow for the identification of a characteristic time that was found to be close to 55% of the measured rupture time. This critical time reflects a critical local energy release assessed by the applicability of the Benioff law. This critical aspect is linked to a damage phase where slow crack growth in fibers is prevailing leading to ultimate fracture of the composite.
Identification of the 9/2+ to 5/2- transition in 69Se
International Nuclear Information System (INIS)
Ramdane, M.; Baumann, P.; Dessagne, P.; Huck, A.; Klotz, G.; Miehe, C.; Walter, G.
1987-01-01
Gamma rays from 69 Se have been investigated using the reaction 40 Ca( 32 S,2pinγ) 69 Se between 80 and 110 MeV beam energy. Isotopic identification was based on excitation functions, n-γ coincidences as well as genetic relationships. The first excited state was found to be at 534.8±0.3 keV and its half-life has been measured. The excitation energy is consistent with the systematic trend of the first 9/2 + state in the N=35 and N=37 isotones. The lifetime reveals the same degree of inhibition as in analogous M2 (9/2 + → 5/2 - ) transitions. A first level scheme, including three levels in 69 Se, is proposed
Sangaletti, Sabina; Tripodo, Claudio; Santangelo, Alessandra; Castioni, Nadia; Portararo, Paola; Gulino, Alessandro; Botti, Laura; Parenza, Mariella; Cappetti, Barbara; Orlandi, Rosaria; Tagliabue, Elda; Chiodoni, Claudia; Colombo, Mario P
2016-09-27
The extracellular matrix (ECM) contributes to the biological and clinical heterogeneity of breast cancer, and different prognostic groups can be identified according to specific ECM signatures. In high-grade, but not low-grade, tumors, an ECM signature characterized by high SPARC expression (ECM3) identifies tumors with increased epithelial-to-mesenchymal transition (EMT), reduced treatment response, and poor prognosis. To better understand how this ECM3 signature is contributing to tumorigenesis, we expressed SPARC in isogenic cell lines and found that SPARC overexpression in tumor cells reduces their growth rate and induces EMT. SPARC expression also results in the formation of a highly immunosuppressive microenvironment, composed by infiltrating T regulatory cells, mast cells, and myeloid-derived suppressor cells (MDSCs). The ability of SPARC to induce EMT depended on the localization and suppressive function of myeloid cells, and inhibition of the suppressive function MDSCs by administration of aminobisphosphonates could revert EMT, rendering SPARC-overexpressing tumor cells sensitive to Doxil. We conclude that that SPARC is regulating the interplay between MDSCs and the ECM to drive the induction of EMT in tumor cells. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Nelson, Celeste M.; Khauv, Davitte; Bissell, Mina J.; Radisky, Derek C.
2008-06-26
Cell morphology dictates response to a wide variety of stimuli, controlling cell metabolism, differentiation, proliferation, and death. Epithelial-mesenchymal transition (EMT) is a developmental process in which epithelial cells acquire migratory characteristics, and in the process convert from a 'cuboidal' epithelial structure into an elongated mesenchymal shape. We had shown previously that matrix metalloproteinase-3 (MMP3) can stimulate EMT of cultured mouse mammary epithelial cells through a process that involves increased expression of Rac1b, a protein that stimulates alterations in cytoskeletal structure. We show here that cells treated with MMP-3 or induced to express Rac1b spread to cover a larger surface, and that this induction of cell spreading is a requirement of MMP-3/Rac1b-induced EMT. We find that limiting cell spreading, either by increasing cell density or by culturing cells on precisely defined micropatterned substrata, blocks expression of characteristic markers of EMT in cells treated with MMP-3. These effects are not caused by general disruptions in cell signaling pathways, as TGF-{beta}-induced EMT is not affected by similar limitations on cell spreading. Our data reveal a previously unanticipated cell shape-dependent mechanism that controls this key phenotypic alteration and provide insight into the distinct mechanisms activated by different EMT-inducing agents.
International Nuclear Information System (INIS)
Veklerov, E.; Llacer, J.; Hoffman, E.J.
1987-10-01
In order to study properties of the Maximum Likelihood Estimator (MLE) algorithm for image reconstruction in Positron Emission Tomographyy (PET), the algorithm is applied to data obtained by the ECAT-III tomograph from a brain phantom. The procedure for subtracting accidental coincidences from the data stream generated by this physical phantom is such that he resultant data are not Poisson distributed. This makes the present investigation different from other investigations based on computer-simulated phantoms. It is shown that the MLE algorithm is robust enough to yield comparatively good images, especially when the phantom is in the periphery of the field of view, even though the underlying assumption of the algorithm is violated. Two transition matrices are utilized. The first uses geometric considerations only. The second is derived by a Monte Carlo simulation which takes into account Compton scattering in the detectors, positron range, etc. in the detectors. It is demonstrated that the images obtained from the Monte Carlo matrix are superior in some specific ways. A stopping rule derived earlier and allowing the user to stop the iterative process before the images begin to deteriorate is tested. Since the rule is based on the Poisson assumption, it does not work well with the presently available data, although it is successful wit computer-simulated Poisson data
Lv, Yonggang; Chen, Can; Zhao, Boyuan; Zhang, Xiaomei
2017-06-01
Substrate stiffness and hypoxia are associated with tumor development and progression, respectively. However, the synergy of them on the biological behavior of human breast cancer cell is still largely unknown. This study explored how substrate stiffness regulates the cell phenotype, viability, and epithelial-mesenchymal transition (EMT) of human breast cancer cells MCF-7 under hypoxia (1% O2). TRITC-phalloidin staining showed that MCF-7 cells transformed from round to irregular polygon with stiffness increase either in normoxia or hypoxia. While being accompanied with the upward tendency from a 0.5- to a 20-kPa substrate, the percentage of cell apoptosis was significantly higher in hypoxia than that in normoxia, especially on the 20-kPa substrate. Additionally, it was hypoxia, but not normoxia, that promoted the EMT of MCF-7 by upregulating hypoxia-inducible factor-1α (HIF-1α), vimentin, Snail 1, and matrix metalloproteinase 2 (MMP 2) and 9 (MMP 9), and downregulating E-cadherin simultaneously regardless of the change of substrate stiffness. In summary, this study discovered that hypoxia and stiffer substrate (20 kPa) could synergistically induce phenotype change, apoptosis, and EMT of MCF-7 cells. Results of this study have an important significance on further exploring the synergistic effect of stiffness and hypoxia on the EMT of breast cancer cells and its molecular mechanism.
Kolecka, A.; Khayhan, K.; Groenewald, M.; Theelen, B.; Arabatzis, M.; Velegraki, A.; Kostrzewa, M.; Mares, M.; Taj-Aldeen, S.J.; Boekhout, T.
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used for an extensive identification study of arthroconidial yeasts, using 85 reference strains from the CBS-KNAW yeast collection and 134 clinical isolates collected from medical centers in Qatar,
Directory of Open Access Journals (Sweden)
Li Y
2017-12-01
Full Text Available Yong Li, John J Voorhees, Gary J FisherDepartment of Dermatology, University of Michigan, Ann Arbor, MI, USAType I collagen (COL1 is the predominant structural protein in the skin. COL1 forms densely packed fibrils which are essential for maintaining skin mechanical properties and youthful appearance.1 The enzyme matrix metalloproteinase-1 (MMP1 cleaves COL1 fibrils at a single site.2 Once cleaved by MMP1, COL1 fibrils can be degraded by other proteases. MMP1 expression is elevated during natural aging and chronic sun exposure, ie, photoaging, leading to excessive degradation of COL1.3 This excessive degradation contributes to COL1 deficiency in the skin of the elderly. COL1 deficiency impairs skin structural integrity and appearance.Given the detrimental role of MMP1 in mediating age-associated fragmentation of COL1 fibrils, it would be beneficial to include MMP1 inhibitors in topical antiaging skin care products. Naturally existing substances that are safe for human use, such as botanical extracts, are often used in skin care products. We have utilized highthroughput screening (HTS to identify naturally existing MMP1 inhibitors that could be used for cosmetic purposes.
International Nuclear Information System (INIS)
Xu, Hongbo; Chen, Xiaohong; Huang, Junwei; Deng, Weiwei; Zhong, Qi; Yue, Changli; Wang, Pingzhang; Huang, Zhigang
2013-01-01
Highlights: •A novel mechanism of MMP3 regulation by proton-sensing G-protein-coupled receptors was defined. •GPR65 was identified to induce the MMP3 expression. •GPR65 mediated MMP induction under acidic conditions. •AP-1 binding site in MMP3 promoter was crucial for MMP3 induction. •GPR65 overexpression can accelerate the invision of A549 cells. -- Abstract: Matrix metalloproteinases (MMPs) are over-expressed in nearly all cancers. To study novel regulatory factors of MMP expression in head and neck cancer (HNC), we screened a total of 636 candidate genes encoding putative human transmembrane proteins using MMP promoter reporter in a dual luciferase assay system. Three genes GPR65, AXL and TNFRSF10B dramatically activated the induction of MMP3 expression. The induction of MMP expression by GPR65 was further confirmed in A549 and/or FaDu cells. GPR65 mediated MMP induction under acidic conditions. The AP-1 binding site in MMP3 promoter was crucial for MMP3 induction. Moreover, the A549 cells infected by recombinant adenovirus of GPR65 showed accelerated cell invasion. In conclusion, we validate that GPR65 is vital regulatory genes upstream of MMP3, and define a novel mechanism of MMP3 regulation by proton-sensing G-protein-coupled receptors
Energy Technology Data Exchange (ETDEWEB)
Xu, Hongbo; Chen, Xiaohong; Huang, Junwei [Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Beijing (China); Deng, Weiwei [Functional Genomics Group, Chinese National Human Genome Center (CHGB) at Beijing (China); Zhong, Qi [Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Beijing (China); Yue, Changli [Department of Pathology, Beijing Tongren Hospital, Capital Medical University, Beijing (China); Wang, Pingzhang, E-mail: wangpzh@bjmu.edu.cn [Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Peking University Center for Human Disease Genomics, Key Laboratory of Medical Immunology, Ministry of Health (China); Functional Genomics Group, Chinese National Human Genome Center (CHGB) at Beijing (China); Huang, Zhigang, E-mail: enthuangzhigang@sohu.com [Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Beijing (China)
2013-06-21
Highlights: •A novel mechanism of MMP3 regulation by proton-sensing G-protein-coupled receptors was defined. •GPR65 was identified to induce the MMP3 expression. •GPR65 mediated MMP induction under acidic conditions. •AP-1 binding site in MMP3 promoter was crucial for MMP3 induction. •GPR65 overexpression can accelerate the invision of A549 cells. -- Abstract: Matrix metalloproteinases (MMPs) are over-expressed in nearly all cancers. To study novel regulatory factors of MMP expression in head and neck cancer (HNC), we screened a total of 636 candidate genes encoding putative human transmembrane proteins using MMP promoter reporter in a dual luciferase assay system. Three genes GPR65, AXL and TNFRSF10B dramatically activated the induction of MMP3 expression. The induction of MMP expression by GPR65 was further confirmed in A549 and/or FaDu cells. GPR65 mediated MMP induction under acidic conditions. The AP-1 binding site in MMP3 promoter was crucial for MMP3 induction. Moreover, the A549 cells infected by recombinant adenovirus of GPR65 showed accelerated cell invasion. In conclusion, we validate that GPR65 is vital regulatory genes upstream of MMP3, and define a novel mechanism of MMP3 regulation by proton-sensing G-protein-coupled receptors.
Rams, Thomas E; Sautter, Jacqueline D; Getreu, Adam; van Winkelhoff, Arie J
2016-05-01
Porphyromonas gingivalis is a major bacterial pathogen in human periodontitis. This study used matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry to assess the accuracy of a rapid phenotypic identification scheme for detection of cultivable P. gingivalis in human subgingival plaque biofilms. A total of 314 fresh cultivable subgingival isolates from 38 adults with chronic periodontitis were presumptively identified on anaerobically-incubated enriched Brucella blood agar primary isolation plates as P. gingivalis based on dark-pigmented colony morphology, lack of a brick-red autofluorescence reaction under long-wave ultraviolet light, and a positive CAAM fluorescence test for trypsin-like enzyme activity. Each presumptive P. gingivalis isolate, and a panel of other human subgingival bacterial species, were subjected to MALDI-TOF mass spectrometry analysis using a benchtop mass spectrometer equipped with software containing mass spectra for P. gingivalis in its reference library of bacterial protein profiles. A MALDI-TOF mass spectrometry log score of ≥1.7 was required for species identification of the subgingival isolates. All 314 (100%) presumptive P. gingivalis subgingival isolates were confirmed as P. gingivalis with MALDI-TOF mass spectrometry analysis (Cohen's kappa coefficient = 1.0). MALDI-TOF mass spectrometry log scores between 1.7 and 1.9, and ≥2.0, were found for 92 (29.3%) and 222 (70.7%), respectively, of the presumptive P. gingivalis clinical isolates. No other tested bacterial species was identified as P. gingivalis by MALDI-TOF mass spectrometry. Rapid phenotypic identification of cultivable P. gingivalis in human subgingival biofilm specimens was found to be 100% accurate with MALDI-TOF mass spectrometry. These findings provide validation for the continued use of P. gingivalis research data based on this species identification methodology. Copyright © 2016 Elsevier Ltd. All rights reserved.
American Society for Testing and Materials. Philadelphia
2000-01-01
1.1 This guide establishes essential and desirable data elements for fiber-reinforced composite materials for two purposes: to establish the material identification component of data-reporting requirements for test reporting and to provide information for the design of material property databases. 1.1.1 This guide is the first part of a two-part modular approach. The first part serves to identify the material and the second part serves to describe testing procedures and variables and to record results. 1.1.2 For mechanical testing, the related document is Guide E 1434. The interaction of this guide with Guide E 1434 is emphasized by the common numbering of data elements. Data Elements A1 through G13 are included in this guide, and numbering of data elements in Guide E 1434 begins with H1 for the next data element block. This guide is most commonly used in combination with a guide for reporting the test procedures and results such as Guide E 1434. 1.2 These guidelines are specific to fiber-reinforced polyme...
Paul, Saikat; Singh, Pankaj; Rudramurthy, Shivaprakash M; Chakrabarti, Arunaloke; Ghosh, Anup K
2017-12-01
To standardize the matrix-assisted laser desorption ionization-time of flight mass spectrometry protocols and expansion of existing Bruker Biotyper database for mold identification. Four different sample preparation methods (protocol A, B, C and D) were evaluated. On analyzing each protein extraction method, reliable identification and best log scores were achieved through protocol D. The same protocol was used to identify 153 clinical isolates. Of these 153, 123 (80.3%) were accurately identified by using existing database and remaining 30 (19.7%) were not identified due to unavailability in database. On inclusion of missing main spectrum profile in existing database, all 153 isolates were identified. Matrix-assisted laser desorption ionization-time of flight mass spectrometry can be used for routine identification of clinically important molds.
Directory of Open Access Journals (Sweden)
Anne Mayer-Scholl
Full Text Available Human trichinellosis occurs through consumption of raw or inadequately processed meat or meat products containing larvae of the parasitic nematodes of the genus Trichinella. Currently, nine species and three genotypes are recognized, of which T. spiralis, T. britovi and T. pseudospiralis have the highest public health relevance. To date, the differentiation of the larvae to the species and genotype level is based primarily on molecular methods, which can be relatively time consuming and labor intensive. Due to its rapidness and ease of use a matrix assisted laser desorption / ionization time of flight mass spectrometry (MALDI-TOF MS reference spectra database using Trichinella strains of all known species and genotypes was created. A formicacid/acetonitrile protein extraction was carried out after pooling 10 larvae of each Trichinella species and genotype. Each sample was spotted 9 times using α-cyano 4-hydoxy cinnamic acid matrix and a MicroFlex LT mass spectrometer was used to acquire 3 spectra (m/z 2000 to 20000 Da from each spot resulting in 27 spectra/species or genotype. Following the spectra quality assessment, Biotyper software was used to create a main spectra library (MSP representing nine species and three genotypes of Trichinella. The evaluation of the spectra generated by MALDI-TOF MS revealed a classification which was comparable to the results obtained by molecular methods. Also, each Trichinella species utilized in this study was distinct and distinguishable with a high confidence level. Further, different conservation methods such as freezing and conservation in alcohol and the host species origin of the isolated larvae did not have a significant influence on the generated spectra. Therefore, the described MALDI-TOF MS can successfully be implemented for both genus and species level identification and represents a major step forward in the use of this technique in foodborne parasitology.
Energy Technology Data Exchange (ETDEWEB)
Benlliure, P.; Chbihi, A.
1992-12-31
The authors propose a new representation of a {Delta}E-CsI matrix that keeps the necessary information for the light particle discrimination in INDRA radiation detector. They also propose an automatic identification method based upon the fact, that the particle production rate is higher than the production rate of heavier fragments.
Jones, Kirstin; Reilly, Matthew A.; Glickman, Randolph D.
2017-02-01
Current treatments for ocular and optic nerve trauma are largely ineffective and may have adverse side effects; therefore, new approaches are needed to understand trauma mechanisms. Identification of trauma-related biomarkers may yield insights into the molecular aspects of tissue trauma that can contribute to the development of better diagnostics and treatments. The conventional approach for protein biomarker measurement largely relies on immunoaffinity methods that typically can only be applied to analytes for which antibodies or other targeting means are available. Matrix assisted laser-assisted desorption/ionization imaging mass spectrometry (MALDI-IMS) is a specialized application of mass spectrometry that not only is well suited to the discovery of novel or unanticipated biomarkers, but also provides information about the spatial localization of biomarkers in tissue. We have been using MALDI-IMS to find traumarelated protein biomarkers in retina and optic nerve tissue from animal models subjected to ocular injury produced by either blast overpressure or mechanical torsion. Work to date by our group, using MALDI-IMS, found that the pattern of protein expression is modified in the injured ocular tissue as soon as 24 hr post-injury, compared to controls. Specific proteins may be up- or down-regulated by trauma, suggesting different tissue responses to a given injury. Ongoing work is directed at identifying the proteins affected and mapping their expression in the ocular tissue, anticipating that systematic analysis can be used to identify targets for prospective therapies for ocular trauma.
Sleiman, Sue; Halliday, Catriona L; Chapman, Belinda; Brown, Mitchell; Nitschke, Joanne; Lau, Anna F; Chen, Sharon C-A
2016-08-01
We developed an Australian database for the identification of Aspergillus, Scedosporium, and Fusarium species (n = 28) by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). In a challenge against 117 isolates, species identification significantly improved when the in-house-built database was combined with the Bruker Filamentous Fungi Library compared with that for the Bruker library alone (Aspergillus, 93% versus 69%; Fusarium, 84% versus 42%; and Scedosporium, 94% versus 18%, respectively). Copyright © 2016, American Society for Microbiology. All Rights Reserved.
DEFF Research Database (Denmark)
Bloch, Helle Aagaard; Kesmir, Can; Petersen, Marianne Kjerstine
1999-01-01
A novel tool for variety identification of wheat (Triticum aestivum L,) has been developed: an artificial neural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness of this no......A novel tool for variety identification of wheat (Triticum aestivum L,) has been developed: an artificial neural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness...... of this novel method with respect to various experimental parameters has been tested, The results can be summarised: (i) With this approach 97% of the wheat varieties can be classified correctly with a corresponding correlation coefficient of 1.0, (ii) The method is fast since the time of extracting gliadins...
Bhanuprasad, S. G.; Venkataraman, Chandra; Bhushan, Mani
The sources of aerosols on a regional scale over India have only recently received attention in studies using back trajectory analysis and chemical transport modelling. Receptor modelling approaches such as positive matrix factorization (PMF) and the potential source contribution function (PSCF) are effective tools in source identification of urban and regional-scale pollution. In this work, PMF and PSCF analysis is applied to identify categories and locations of sources that influenced surface concentrations of aerosols in the Indian Ocean Experiment (INDOEX) domain measured on-board the research vessel Ron Brown [Quinn, P.K., Coffman, D.J., Bates, T.S., Miller, T.L., Johnson, J.E., Welton, E.J., et al., 2002. Aerosol optical properties during INDOEX 1999: means, variability, and controlling factors. Journal of Geophysical Research 107, 8020, doi:10.1029/2000JD000037]. Emissions inventory information is used to identify sources co-located with probable source regions from PSCF. PMF analysis identified six factors influencing PM concentrations during the INDOEX cruise of the Ron Brown including a biomass combustion factor (35-40%), three industrial emissions factors (35-40%), primarily secondary sulphate-nitrate, balance trace elements and Zn, and two dust factors (20-30%) of Si- and Ca-dust. The identified factors effectively predict the measured submicron PM concentrations (slope of regression line=0.90±0.20; R2=0.76). Probable source regions shifted based on changes in surface and elevated flows during different times in the ship cruise. They were in India in the early part of the cruise, but in west Asia, south-east Asia and Africa, during later parts of the cruise. Co-located sources include coal-fired electric utilities, cement, metals and petroleum production in India and west Asia, biofuel combustion for energy and crop residue burning in India, woodland/forest burning in north sub-Saharan Africa and forest burning in south-east Asia. Significant findings
Nagdas, Subir K; Smith, Linda; Mcnamara, Allen; Hernandez–Encarnacion, Luisa; Medina-Ortiz, Ilza
2015-01-01
Fertilization, the union of male and female gametes to create offspring, is an intricate biological process dependent upon several biochemical and physiological events. Our understanding of the functions of protein constituents of the outer acrosomal membrane-associated matrix complex (OMC) is limited. A highly purified OMC fraction isolated from bovine cauda sperm heads is comprised of 54, 50, 45, and 38–19kDa polypeptides. The objective of this study is to identify and to characterize the 45kDa (OMC45) polypeptide and to define its role in binding acrosomal hydrolases and to examine the fate of OMC45 polypeptide during the acrosome reaction. We isolated OMC45 polypeptide from the high-pH insoluble fraction of OMC. Proteomic analysis of OMC45 by MALDI–TOF–TOF yielded 8 peptides that matched the NCBI database sequence of Tektin 3 (TEKT3). Triton X–100–permeabilized cauda sperm exhibited intense staining of the acrosomal segment with anti–OMC45 and anti–TEKT3. The OMC45 polypeptide was solubilized by RIPA (radio-immunoprecipitation assay) buffer extraction. The solubilized fraction was subjected to immunoprecipitation analysis. The OMC45 polypeptide was recovered in the anti–OMC45 immunoprecipitation pellet. An identical blot stained with anti–TEKT3 exhibited the presence of TEKT3 polypeptide in the anti–OMC45 pellet. Our immunofluorescence and biochemical studies confirm the proteomics identification of OMC45 polypeptide; that it exhibits a sequence similarity to TEKT3. OMC45 glycoprotein possesses both N–linked and O–linked oligosaccharides. Deglycosylated OMC45 revealed a significant reduction in both acrosin and N–acetylglucosaminidase (NAGA) binding in comparison with acrosin and NAGA binding to a native OMC45 polypeptide, demonstrating the important role of oligosaccharides in hydrolase binding. OMC45 polypeptide is not released during the acrosome reaction but remains in the particulate cell subfraction, associated with the hybrid
Najbauer, Eszter E.; Bazsó, Gábor; Apóstolo, Rui; Fausto, Rui; Biczysko, Malgorzata; Barone, Vincenzo; Tarczay, György
2018-01-01
The conformers of α-serine were investigated by matrix-isolation IR spectroscopy combined with NIR laser irradiation. This method, aided by 2D correlation analysis, enabled unambiguously grouping the spectral lines to individual conformers. On the basis of comparison of at least nine experimentally observed vibrational transitions of each conformer with empirically scaled (SQM) and anharmonic (GVPT2) computed IR spectra, 6 conformers were identified. In addition, the presence of at least one more conformer in Ar matrix was proved, and a short-lived conformer with a half-live of (3.7±0.5)·103 s in N2 matrix was generated by NIR irradiation. The analysis of the NIR laser induced conversions revealed that the excitation of the stretching overtone of both the side-chain and the carboxylic OH groups can effectively promote conformational changes, but remarkably different paths were observed for the two kinds of excitations. PMID:26201050
Stubbe, Dirk; De Cremer, Koen; Piérard, Denis; Normand, Anne-Cécile; Piarroux, Renaud; Detandt, Monique; Hendrickx, Marijke
2014-01-01
The rates of infection with Fusarium molds are increasing, and a diverse number of Fusarium spp. belonging to different species complexes can cause infection. Conventional species identification in the clinical laboratory is time-consuming and prone to errors. We therefore evaluated whether matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is a useful alternative. The 289 Fusarium strains from the Belgian Coordinated Collections of Microorganisms (BCCM)/Institute of Hygiene and Epidemiology Mycology (IHEM) culture collection with validated sequence-based identities and comprising 40 species were used in this study. An identification strategy was developed, applying a standardized MALDI-TOF MS assay and an in-house reference spectrum database. In vitro antifungal testing was performed to assess important differences in susceptibility between clinically relevant species/species complexes. We observed that no incorrect species complex identifications were made by MALDI-TOF MS, and 82.8% of the identifications were correct to the species level. This success rate was increased to 91% by lowering the cutoff for identification. Although the identification of the correct species complex member was not always guaranteed, antifungal susceptibility testing showed that discriminating between Fusarium species complexes can be important for treatment but is not necessarily required between members of a species complex. With this perspective, some Fusarium species complexes with closely related members can be considered as a whole, increasing the success rate of correct identifications to 97%. The application of our user-friendly MALDI-TOF MS identification approach resulted in a dramatic improvement in both time and accuracy compared to identification with the conventional method. A proof of principle of our MALDI-TOF MS approach in the clinical setting using recently isolated Fusarium strains demonstrated its validity. PMID:25411180
Indian Academy of Sciences (India)
First page Back Continue Last page Overview Graphics. TRANSIT. SYSTEM: DETERMINE 2D-POSITION GLOBALLY BUT INTERMITTENT (POST-FACTO). IMPROVED ACCURACY. PRINCIPLE: POLAR SATELLITES WITH INNOVATIONS OF: GRAVITY-GRADIENT ATTITUDE CONTROL; DRAG COMPENSATION. WORKS ...
Sternstein, S. S.; Yang, P.
1983-01-01
A new test geometry, referred to as centro-symmetric deformation (CSD), is proposed for characterizing the viscoelastic behavior of the matrix of carbon-epoxy laminates. The sample consists of a thin disk, typically 6-14 plies thick, having a nominal diameter of 30 mm. The disk is freely supported on a circular anvil; the load is applied to the center of the disk using an 8-mm-diameter ball bearing nosepiece. The CSD test geometry provides viscoelastic dispersion data which are independent of the angular orientation of the sample. The test geometry is sufficiently sensitive to matrix changes to allow its use for postcuring, humidity, crosslink density, and other matrix change studies. Test results are presented for a carbon-epoxy laminate.
Directory of Open Access Journals (Sweden)
Yifei Zhang
Full Text Available Matrix-assisted laser desorption/ionization (MALDI time-of-flight (TOF mass spectrometry (MS has been presented as a superior method for the detection of microorganisms in body fluid samples (e.g., blood, saliva, pus, etc. However, the performance of MALDI-TOF MS in routine identification of caries-related Lactobacillus isolates from saliva of adult patients with caries has not been determined. In the present study, we introduced a new MALDI-TOF MS system for identification of lactobacilli. Saliva samples were collected from 120 subjects with caries. Bacteria were isolated and cultured, and each isolate was identified by both 16S rRNA sequencing and MALDI-TOF MS. The identification results obtained by MALDI-TOF MS were concordant at the genus level with those of conventional 16S rRNA-based sequencing for 88.6% of lactobacilli (62/70 and 95.5% of non-lactobacilli (21/22. Up to 96 results could be obtained in parallel on a single MALDI target, suggesting that this is a reliable high-throughput approach for routine identification of lactobacilli. However, additional reference strains are necessary to increase the sensitivity and specificity of species-level identification.
Toyokawa, Masahiro; Kimura, Keigo; Nishi, Isao; Sunada, Atsuko; Ueda, Akiko; Sakata, Tomomi; Asari, Seishi
2013-01-01
Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been challenged for the identification of Nocardia species. However, the standard ethanol-formic acid extraction alone is insufficient in allowing the membrane proteins of Nocardia species to be ionized by the matrix. We therefore aimed to establish our new extraction method for the MALDI-TOF MS-based identification of Nocardia species isolates. Our modified extraction procedure is through dissociation in 0.5% Tween-20 followed by bacterial heat-inactivation, mechanical breaking of the cell wall by acid-washed glass beads and protein extraction with formic acid and acetonitrile. As reference methods for species identification, full-length 16S rRNA gene sequencing and some phenotypical tests were used. In a first step, we made our own Nocardia database by analyzing 13 strains (13 different species including N. elegans, N. otitidiscaviarum, N. asiatica, N. abscessus, N. brasiliensis, N. thailandica, N. farcinica, N. nova, N. mikamii, N. cyriacigeorgica, N. asteroids, Nocardiopsis alba, and Micromonospora sp.) and registered to the MALDI BioTyper database. Then we established our database. The analysis of 12 challenge strains using the our database gave a 100% correct identification, including 8 strains identified to the species level and 4 strains to the genus level (N. elegans, N. nova, N. farcinica, Micromonospora sp.) according to the manufacture's log score specifications. In the estimation of reproducibility of our method intended for 4 strains, both within-run and between-run reproducibility were excellent. These data indicates that our method for rapid identification of Nocardia species is with reliability, reproducibility and cost effective.
van Veen, S Q; Claas, E C J; Kuijper, Ed J
2010-03-01
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is suitable for high-throughput and rapid diagnostics at low costs and can be considered an alternative for conventional biochemical and molecular identification systems in a conventional microbiological laboratory. First, we evaluated MALDI-TOF MS using 327 clinical isolates previously cultured from patient materials and identified by conventional techniques (Vitek-II, API, and biochemical tests). Discrepancies were analyzed by molecular analysis of the 16S genes. Of 327 isolates, 95.1% were identified correctly to genus level, and 85.6% were identified to species level by MALDI-TOF MS. Second, we performed a prospective validation study, including 980 clinical isolates of bacteria and yeasts. Overall performance of MALDI-TOF MS was significantly better than conventional biochemical systems for correct species identification (92.2% and 83.1%, respectively) and produced fewer incorrect genus identifications (0.1% and 1.6%, respectively). Correct species identification by MALDI-TOF MS was observed in 97.7% of Enterobacteriaceae, 92% of nonfermentative Gram-negative bacteria, 94.3% of staphylococci, 84.8% of streptococci, 84% of a miscellaneous group (mainly Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella [HACEK]), and 85.2% of yeasts. MALDI-TOF MS had significantly better performance than conventional methods for species identification of staphylococci and genus identification of bacteria belonging to HACEK group. Misidentifications by MALDI-TOF MS were clearly associated with an absence of sufficient spectra from suitable reference strains in the MALDI-TOF MS database. We conclude that MALDI-TOF MS can be implemented easily for routine identification of bacteria (except for pneumococci and viridans streptococci) and yeasts in a medical microbiological laboratory.
Directory of Open Access Journals (Sweden)
Jonathan H.K. Chen
2017-10-01
Full Text Available The clinical workflow of using chromogenic agar and matrix-assisted laser desorption ionization time-of-fight mass spectrometry (MALDI-TOF MS for Clostridium difficile identification was evaluated. The addition of MALDI-TOF MS identification after the chromID C. difficile chromogenic agar culture could significantly improve the diagnostic accuracy of C. difficile.
Directory of Open Access Journals (Sweden)
V. Yu. Kleshnin
2016-01-01
Full Text Available The article describes the matrix algebra libraries based on the modern technologies of parallel programming for the Spectrum software, which can use a spectral method (in the spectral form of mathematical description to analyse, synthesise and identify deterministic and stochastic dynamical systems. The developed matrix algebra libraries use the following technologies for the GPUs: OmniThreadLibrary, OpenMP, Intel Threading Building Blocks, Intel Cilk Plus for CPUs nVidia CUDA, OpenCL, and Microsoft Accelerated Massive Parallelism.The developed libraries support matrices with real elements (single and double precision. The matrix dimensions are limited by 32-bit or 64-bit memory model and computer configuration. These libraries are general-purpose and can be used not only for the Spectrum software. They can also find application in the other projects where there is a need to perform operations with large matrices.The article provides a comparative analysis of the libraries developed for various matrix operations (addition, subtraction, scalar multiplication, multiplication, powers of matrices, tensor multiplication, transpose, inverse matrix, finding a solution of the system of linear equations through the numerical experiments using different CPU and GPU. The article contains sample programs and performance test results for matrix multiplication, which requires most of all computational resources in regard to the other operations.
Calvano, Cosima Damiana; van der Werf, Inez Dorothé; Palmisano, Francesco; Sabbatini, Luigia
2015-01-01
Direct on-target plate processing of small (ca. 100 μg) fragments of paint samples for MALDI-MS identification of lipid- and protein-based binders is described. Fragments were fixed on a conventional stainless steel target plate by colloidal graphite followed by in situ fast tryptic digestion and matrix addition. The new protocol was first developed on paint replicas composed of chicken egg, collagen, and cow milk mixed with inorganic pigments and then successfully applied on historical paint samples taken from a fifteenth century Italian panel painting. The present work contributes a step forward in the simplification of binder identification in very small paint samples since no conventional solvent extraction is required, speeding up the whole sample preparation to 10 min and reducing lipid/protein loss.
Directory of Open Access Journals (Sweden)
Parveen Rahi
2016-08-01
Full Text Available Matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS based biotyping is an emerging technique for high-throughput and rapid microbial identification. Due to its relatively higher accuracy, comprehensive database of clinically important microorganisms and low-cost compared to other microbial identification methods, MALDI-TOF MS has started replacing existing practices prevalent in clinical diagnosis. However, applicability of MALDI-TOF MS in the area of microbial ecology research is still limited mainly due to the lack of data on non-clinical microorganisms. Intense research activities on cultivation of microbial diversity by conventional as well as by innovative and high-throughput methods has substantially increased the number of microbial species known today. This important area of research is in urgent need of rapid and reliable method(s for characterization and de-replication of microorganisms from various ecosystems. MALDI-TOF MS based characterization, in our opinion, appears to be the most suitable technique for such studies. Reliability of MALDI-TOF MS based identification method depends mainly on accuracy and width of reference databases, which need continuous expansion and improvement. In this review, we propose a common strategy to generate MALDI-TOF MS spectral database and advocated its sharing, and also discuss the role of MALDI-TOF MS based high-throughput microbial identification in microbial ecology studies.
Ayyadurai, Saravanan; Flaudrops, Christophe; Raoult, Didier; Drancourt, Michel
2010-11-12
Accurate identification is necessary to discriminate harmless environmental Yersinia species from the food-borne pathogens Yersinia enterocolitica and Yersinia pseudotuberculosis and from the group A bioterrorism plague agent Yersinia pestis. In order to circumvent the limitations of current phenotypic and PCR-based identification methods, we aimed to assess the usefulness of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) protein profiling for accurate and rapid identification of Yersinia species. As a first step, we built a database of 39 different Yersinia strains representing 12 different Yersinia species, including 13 Y. pestis isolates representative of the Antiqua, Medievalis and Orientalis biotypes. The organisms were deposited on the MALDI-TOF plate after appropriate ethanol-based inactivation, and a protein profile was obtained within 6 minutes for each of the Yersinia species. When compared with a 3,025-profile database, every Yersinia species yielded a unique protein profile and was unambiguously identified. In the second step of analysis, environmental and clinical isolates of Y. pestis (n = 2) and Y. enterocolitica (n = 11) were compared to the database and correctly identified. In particular, Y. pestis was unambiguously identified at the species level, and MALDI-TOF was able to successfully differentiate the three biotypes. These data indicate that MALDI-TOF can be used as a rapid and accurate first-line method for the identification of Yersinia isolates.
Matsuda, Naoto; Matsuda, Mari; Notake, Shigeyuki; Yokokawa, Hirohide; Kawamura, Yoshiaki; Hiramatsu, Keiichi; Kikuchi, Ken
2012-12-01
In clinical microbiology, bacterial identification is labor-intensive and time-consuming. A solution for this problem is the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). In this study, we evaluated a modified protein extraction method of identification performed on target plates (on-plate extraction method) with MALDI-TOF (Bruker Microflex LT with Biotyper version 3.0) and compared it to 2 previously described methods: the direct colony method and a standard protein extraction method (standard extraction method). We evaluated the species of 273 clinical strains and 14 reference strains of staphylococci. All isolates were characterized using the superoxide dismutase A sequence as a reference. For the species identification, the on-plate, standard extraction, and direct colony methods identified 257 isolates (89.5%), 232 isolates (80.8%), and 173 isolates (60.2%), respectively, with statistically significant differences among the three methods (P extraction method is at least as good as standard extraction in identification rate and has the advantage of a shorter processing time.
Buckwalter, S P; Olson, S L; Connelly, B J; Lucas, B C; Rodning, A A; Walchak, R C; Deml, S M; Wohlfiel, S L; Wengenack, N L
2016-02-01
The value of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the identification of bacteria and yeasts is well documented in the literature. Its utility for the identification of mycobacteria and Nocardia spp. has also been reported in a limited scope. In this work, we report the specificity of MALDI-TOF MS for the identification of 162 Mycobacterium species and subspecies, 53 Nocardia species, and 13 genera (totaling 43 species) of other aerobic actinomycetes using both the MALDI-TOF MS manufacturer's supplied database(s) and a custom database generated in our laboratory. The performance of a simplified processing and extraction procedure was also evaluated, and, similar to the results in an earlier literature report, our viability studies confirmed the ability of this process to inactivate Mycobacterium tuberculosis prior to analysis. Following library construction and the specificity study, the performance of MALDI-TOF MS was directly compared with that of 16S rRNA gene sequencing for the evaluation of 297 mycobacteria isolates, 148 Nocardia species isolates, and 61 other aerobic actinomycetes isolates under routine clinical laboratory working conditions over a 6-month period. MALDI-TOF MS is a valuable tool for the identification of these groups of organisms. Limitations in the databases and in the ability of MALDI-TOF MS to rapidly identify slowly growing mycobacteria are discussed. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Kärpänoja, P; Harju, I; Rantakokko-Jalava, K; Haanperä, M; Sarkkinen, H
2014-05-01
In this study, the performances of two matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems, MALDI Biotyper (Bruker Daltonics) and VITEK MS (bioMérieux), were evaluated in the identification of viridans group streptococci. Two collections of isolates were tested with both methods. From a panel of type collection strains (n = 54), MALDI Biotyper gave correct species-level identification for 51/54 (94 %) strains and 37/54 (69 %) strains for the VITEK MS in vitro diagnostic (IVD) method. Additionally, a collection of blood cultures isolates which had been characterized earlier with partial sequencing of 16S rRNA (n = 97) was analyzed. MALDI Biotyper classified 89 % and VITEK MS 93 % of these correctly to the group level. Comparison of species-level identification from the blood culture collection was possible for 36 strains. MALDI Biotyper identified 75 % and VITEK MS 97 % of these strains consistently. Among the clinical isolates, MALDI Biotyper misidentified 36 strains as Streptococcus pneumoniae. Nevertheless, our results suggest that the current MALDI-TOF methods are a good alternative for the identification of viridans streptococci and do perform as well as or better than commercial phenotypical methods.
Energy Technology Data Exchange (ETDEWEB)
Egede, U.
1998-01-01
The large Hadron Collider (LHC) will be ready for proton-proton collisions in the year 2005 and the ATLAS detector will be one of the two experiments at the LHC which will explore a new and higher energy range for particle physics. In this thesis, an analysis of the power of the ATLAS detector to detect a Standard Model Higgs boson has been performed. It is shown that it will be possible to discover a Higgs particle across the complete mass range from the lower limit defined by the reach of the LEP2 collider experiments to the upper theoretical limit around 1 TeV. The role of the inner tracking detector of ATLAS for the detection of conversions and the identification of the primary vertex in the detection of a Higgs particle in the Higgs to two photon decay channel is demonstrated with a detailed detector simulation. The identification of a 1 TeV Higgs particle requires a good understanding of both the signal and the backgrounds. The related uncertainties are covered in detail and it is shown that the Higgs can be identified in the H{yields}WW{yields}lvjj, H{yields}ZZ{yields}llvv and H{yields}ZZ{yields}lljj decay channels. The Transition Radiation Tracker (TRT) is a combined tracking and electron identification device which will be a part of the inner tracking detector of ATLAS. For a prototype of the TRT the electron identification performance is analysed and it is shown that the full scale TRT together with the calorimeters will provide the electron identification power required for a clean electron and photon signal at the LHC. For the prototype a rejection factor of 100 against pions was achieved with an electron efficiency of 90%. the importance of the TRT for a clear detection of a Higgs particle is demonstrated. 82 refs, figs, tabs.
Directory of Open Access Journals (Sweden)
Carole Cassagne
Full Text Available BACKGROUND: MALDI-TOF MS recently emerged as a valuable identification tool for bacteria and yeasts and revolutionized the daily clinical laboratory routine. But it has not been established for routine mould identification. This study aimed to validate a standardized procedure for MALDI-TOF MS-based mould identification in clinical laboratory. MATERIALS AND METHODS: First, pre-extraction and extraction procedures were optimized. With this standardized procedure, a 143 mould strains reference spectra library was built. Then, the mould isolates cultured from sequential clinical samples were prospectively subjected to this MALDI-TOF MS based-identification assay. MALDI-TOF MS-based identification was considered correct if it was concordant with the phenotypic identification; otherwise, the gold standard was DNA sequence comparison-based identification. RESULTS: The optimized procedure comprised a culture on sabouraud-gentamicin-chloramphenicol agar followed by a chemical extraction of the fungal colonies with formic acid and acetonitril. The identification was done using a reference database built with references from at least four culture replicates. For five months, 197 clinical isolates were analyzed; 20 were excluded because they were not identified at the species level. MALDI-TOF MS-based approach correctly identified 87% (154/177 of the isolates analyzed in a routine clinical laboratory activity. It failed in 12% (21/177, whose species were not represented in the reference library. MALDI-TOF MS-based identification was correct in 154 out of the remaining 156 isolates. One Beauveria bassiana was not identified and one Rhizopus oryzae was misidentified as Mucor circinelloides. CONCLUSIONS: This work's seminal finding is that a standardized procedure can also be used for MALDI-TOF MS-based identification of a wide array of clinically relevant mould species. It thus makes it possible to identify moulds in the routine clinical laboratory setting
DEFF Research Database (Denmark)
Rosenvinge, Flemming S; Dzajic, Esad; Knudsen, Elisa
2013-01-01
participating laboratories. Of the 102 archived isolates, 81 (79%) and 92 (90%) were correctly identified by Saramis/AXIMA and BioTyper/Bruker respectively. Saramis/AXIMA was unable to separate Candida albicans, C. africana and C. dubliniensis in 13 of 32 isolates. After manual interpretation of the mass...... identification, respectively, whereas the other laboratory identified 83/98 (85%) to species level by both BioTyper/Bruker and conventional identification. Both MALDI-TOF-MS systems are fast, have built-in databases that cover the majority of clinically relevant Candida species, and have an accuracy...
International Nuclear Information System (INIS)
Jafri, Y.Z.; Kamal, L.
2009-01-01
A generalized theory of ARMA modeling, covering a wide range of researches. with model identification, order determination, estimation and diagnostic checking is presented. We evolved standardization of wind data to overcome non-stationarity. With our techniques on generating synthetic values of wind series using MTM, we modeled and simulated autocorrelated function (ACF). MTM is found relatively a better simulator as compared to ARMA. We used twenty year of wind data. MTM required fast computation and suitable algorithm for backward calculations to yield ACF values. We found ARMA (p, q) model suitableble for both large range (1-6 hours) and short range (1-2 hours). This indicates that forecast values can be considered for appropriate wind energy conversion system. (author)
Identification of salivary components that induce transition of hyphae to yeast in Candida albicans
Leito, J.T.D.; Ligtenberg, A.J.M.; Nazmi, K.; Veerman, E.C.I.
2009-01-01
Candida albicans, the major human fungal pathogen, undergoes a reversible morphological transition from single yeast cells to pseudohyphae and hyphae filaments. The hyphae form is considered the most invasive form of the fungus. The purpose of this study is to investigate the effect of saliva on
K. Kolijn (Kimberley); E.I. Verhoef (Esther); G.J.H.L. Leenders (Geert)
2015-01-01
textabstractEpithelial-to-mesenchymal transition (EMT) is a process known to be associated with aggressive tumor behavior, metastasis and treatment resistance. It is characterized by coincidental upregulation of mesenchymal markers such as vimentin, fibronectin and N-cadherin concurrent with
DEFF Research Database (Denmark)
Nonnemann, Bettina; Tvede, Michael; Bjarnsholt, Thomas
2013-01-01
Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) is a promising and fast method for identifying fungi and bacteria directly from positive blood cultures. Various pre-treatment methods for MALDI-TOF MS identification have been reported for this purpose. In......-house results for identification of bacterial colonies by MALDI-TOF MS using a cut-off score of 1.5 did not reduce the diagnostic accuracy compared with the recommended cut-off score of 1.8. A 3-month consecutive study of positive blood cultures was carried out in our laboratory to evaluate whether......% with the value of 1.5. The overall identification rate was 63% (cut-off 1.5) and 54% (cut-off 1.8). Seventy-seven per cent of fungal species were identified with both log scores. MALDI-TOF MS was in this study found to be a powerful tool in fast diagnosis of Gram-negative bacteria and fungi and to a lesser...
Cameron, M; Barkema, H W; De Buck, J; De Vliegher, S; Chaffer, M; Lewis, J; Keefe, G P
2017-03-01
This study evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) for the identification of bovine-associated coagulase-negative staphylococci (CNS), a heterogeneous group of different species. Additionally, we aimed to expand the MALDI-ToF MS database with new reference spectra as required to fill the gaps within the existing commercial spectral library. A total of 258 isolates of CNS were used in the study, covering 16 different CNS species. The majority of the isolates were previously identified by rpoB gene sequencing (n = 219), and the remainder were identified by sequencing of 16S rRNA, hsp60, or both rpoB and hsp60. The genotypic identification was considered the gold standard identification. All MALDI-ToF MS identifications were carried out using the direct transfer method. In a preliminary evaluation (n = 32 isolates; 2 of each species) with the existing commercial database, MALDI-ToF MS showed a typeability of 81% (26/32) and an accuracy of 96% (25/26). In the main evaluation (n = 226 isolates), MALDI-ToF MS with the existing commercial Biotyper (Bruker Daltonics Inc., Billerica, MA) database achieved a typeability of 92.0% (208/226) and an accuracy of 99.5% (207/208). Based on the assessment of the existing commercial database and prior knowledge of the species, a total of 13 custom reference spectra, covering 8 species, were created and added to the commercial database. Using the custom reference spectra expanded database, isolates were identified by MALDI-ToF MS with 100% typeability and 100% accuracy. Whereas the MALDI-ToF MS manufacturer's cutoff for species-level identification is 2.000, the reduction of the species level cutpoint to ≥1.700 improved the species-level identification rates (from 64 to 92% for the existing commercial database) when classifying CNS isolates. Overall, MALDI-ToF MS using the direct transfer method was shown to be a highly reliable tool for the identification of bovine
Directory of Open Access Journals (Sweden)
Gautam Pennathur
2010-06-01
Full Text Available Abstract Background Chromatin in the nucleus of all eukaryotes is organized into a system of loops and domains. These loops remain fastened at their bases to the fundamental framework of the nucleus, the matrix or the scaffold. The DNA sequences which anchor the bases of the chromatin loops to the matrix are known as Scaffold/Matrix Attachment Regions or S/MARs. Though S/MARs have been studied in yeast and higher eukaryotes and they have been found to be associated with gene organization and regulation of gene expression, they have not been reported in protists like Giardia. Several tools have been discovered and formulated to predict S/MARs from a genome of a higher eukaryote which take into account a number of features. However, the lack of a definitive consensus sequence in S/MARs and the randomness of the protozoan genome in general, make it a challenge to predict and identify such sequences from protists. Results Here, we have analysed the Giardia genome for the probable S/MARs predicted by the available computational tools; and then shown these sequences to be physically associated with the nuclear matrix. Our study also reflects that while no single computational tool is competent to predict such complex elements from protist genomes, a combination of tools followed by experimental verification is the only way to confirm the presence of these elements from these organisms. Conclusion This is the first report of S/MAR elements from the protozoan parasite Giardia lamblia. This initial work is expected to lay a framework for future studies relating to genome organization as well as gene regulatory elements in this parasite.
Directory of Open Access Journals (Sweden)
Weinrib AZ
2017-03-01
Full Text Available Aliza Z Weinrib,1,2 Lindsay C Burns,1,2 Alex Mu,1 Muhammad Abid Azam,1,2 Salima SJ Ladak,1 Karen McRae,1,3 Rita Katznelson,1,3 Saam Azargive,1 Cieran Tran,1 Joel Katz,1–3 Hance Clarke1,3 1Pain Research Unit, Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, 2Department of Psychology, York University, 3Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada Abstract: In an era of growing concern about opioid prescribing, the postsurgical period remains a critical window with the risk of significant opioid dose escalation, particularly in patients with a history of chronic pain and presurgical opioid use. The purpose of this case report is to describe the multidisciplinary care of a complex, postsurgical pain patient by an innovative transitional pain service (TPS. A 59-year-old male with complex chronic pain, as well as escalating long-term opioid use, presented with a bleeding duodenal ulcer requiring emergency surgery. After surgery, the TPS provided integrated pharmacological and behavioral treatment, including buprenorphine combined with naloxone and acceptance and commitment therapy (ACT using the ACT Matrix. The result was dramatic pain reduction and improved functioning and quality of life after 40+ years of chronic pain, thus changing the pain trajectory of a chronic, complex, opioid-dependent patient. Keywords: transitional pain service, postsurgical pain, chronic pain, opioid dependence, opioid weaning, acceptance and commitment therapy
Identification of alcohol abuse and transition from long-term unemployment to disability pension.
Nurmela, Kirsti; Heikkinen, Virpi; Hokkanen, Risto; Ylinen, Aarne; Uitti, Jukka; Mattila, Aino; Joukamaa, Matti; Virtanen, Pekka
2015-07-01
The aim of the study was to reveal potential gaps and inconsistencies in the identification of alcohol abuse in health care and in employment services and to analyse the granting of disability pensions with respect to the alcohol abuse identification pattern. The material consisted of documentary information on 505 long-term unemployed subjects with low employability sent to the development project entitled 'Eligibility for a Disability Pension' in 2001-2006 in Finland. The dichotomous variables 'Alcohol abuse identified in employment services' and 'Alcohol abuse identified in health care' were cross-tabulated to obtain a four-class variable 'Alcohol abuse identification pattern'. Logistic regression analyses were conducted to ascertain the association of alcohol abuse identification pattern with the granting of disability pensions. Alcohol abuse was detected by both health care and employment services in 47% of those identified as abusers (41% of examinees). Each service systems also identified cases that the other did not. When alcohol abuse was identified in health care only, the OR for a disability pension being granted was 2.8 (95% CI 1.5-5.2) compared with applicants without identified alcohol abuse. The result remained the same and statistically significant after adjusting for confounders. Alcohol abuse identified in health care was positively associated with the granting of a disability pension. Closer co-operation between employment services and health care could help to identify those long-term unemployed individuals with impaired work ability in need of thorough medical examination. © 2015 the Nordic Societies of Public Health.
Akesson, T.; Arik, E.; Assamagan, K.; Baker, K.; Barberio, E.; Barberis, D.; Bertelsen, H.; Bytchkov, V.; Callahan, J.; Catinaccio, A.; Danielsson, H.; Dittus, F.; Dolgoshein, B.; Dressnandt, N.; Ebenstein, W. L.; Eerola, P.; Farthouat, P.; Froidevaux, D.; Grichkevitch, Y.; Hajduk, Z.; Hansen, J. R.; Keener, P. T.; Kekelidze, G.; Konovalov, S.; Kowalski, T.; Kramarenko, V. A.; Krivchitch, A.; Laritchev, A.; Lichard, P.; Lucotte, A.; Lundberg, B.; Luehring, F.; Mailov, A.; Manara, A.; McFarlane, K.; Mitsou, V. A.; Morozov, S.; Muraviev, S.; Nadtochy, A.; Newcomer, F. M.; Olszowska, J.; Ogren, H.; Oh, S. H.; Peshekhonov, V.; Rembser, C.; Romaniouk, A.; Rousseau, D.; Rust, D. R.; Schegelsky, V.; Sapinski, M.; Shmeleva, A.; Smirnov, S.; Smirnova, L. N.; Sosnovtsev, V.; Soutchkov, S.; Spiridenkov, E.; Tikhomirov, V.; Van Berg, R.; Vassilakopoulos, V.; Wang, C.; Williams, H. H.
2001-12-01
Test-beam studies of the ATLAS Transition Radiation Tracker (TRT) straw tube performance in terms of electron-pion separation using a time-over-threshold method are described. The test-beam data are compared with Monte Carlo simulations of charged particles passing through the straw tubes of the TRT. For energies below 10 GeV, the time-over-threshold method combined with the standard transition-radiation cluster-counting technique significantly improves the electron-pion separation in the TRT. The use of the time-over-threshold information also provides some kaon-pion separation, thereby significantly enhancing the B-physics capabilities of the ATLAS detector.
Stevenson, Lindsay G; Drake, Steven K; Shea, Yvonne R; Zelazny, Adrian M; Murray, Patrick R
2010-10-01
We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the rapid identification of yeast species. Using Bruker Daltonics MALDI BioTyper software, we created a spectral database library with m/z ratios of 2,000 to 20,000 Da for 109 type and reference strains of yeast (44 species in 8 genera). The database was tested for accuracy by use of 194 clinical isolates (23 species in 6 genera). A total of 192 (99.0%) of the clinical isolates were identified accurately by MALDI-TOF MS. The MALDI-TOF MS-based method was found to be reproducible and accurate, with low consumable costs and minimal preparation time.
Directory of Open Access Journals (Sweden)
Daniel V. Oliveira
2012-01-01
Full Text Available Nacre, when implanted in vivo in bones of dogs, sheep, mice, and humans, induces a biological response that includes integration and osteogenic activity on the host tissue that seems to be activated by a set of proteins present in the nacre water-soluble matrix (WSM. We describe here an experimental approach that can accurately identify the proteins present in the WSM of shell mollusk nacre. Four proteins (three gigasin-2 isoforms and a cystatin A2 were for the first time identified in WSM of Crassostrea gigas nacre using 2DE and LC-MS/MS for protein identification. These proteins are thought to be involved in bone remodeling processes and could be responsible for the biocompatibility shown between bone and nacre grafts. These results represent a contribution to the study of shell biomineralization process and opens new perspectives for the development of new nacre biomaterials for orthopedic applications.
AUTHOR|(INSPIRE)INSPIRE-00220535; The ATLAS collaboration
2016-01-01
The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three inner detector tracking subsystems and consists of ∼300,000 thin-walled drift tubes (“straw tubes”) that are 4 mm in diameter. The TRT system provides ∼30 space points with ∼130 micron resolution for charged tracks with |η| 0.5 GeV/c . The TRT also provides electron identification capability by detecting transition radiation (TR) X-ray photons in an Xe-based working gas mixture. Compared to Run 1, the LHC beams now provide a higher centre of mass energy (13 TeV), more bunches with a reduced spacing (25 ns), and more particles in each bunch leading to very challenging, higher occupancies in the TRT. Significant modifications of the TRT detector have been made for LHC Run 2 mainly to improve response to the expected much higher rate of hits and to mitigate leaks of the Xe-based active gas mixture. The higher rates required changes to the data acquisition system and introduction of validity gate to reject out-of-time hits. Man...
Mindur, Bartosz; The ATLAS collaboration
2016-01-01
The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three inner detector tracking subsystems and consists of 300000 thin-walled drift tubes (“straw tubes”) that are 4 mm in diameter. The TRT system provides 30 space points with 130 micron resolution for charged tracks with |η| 0.5 GeV/c. The TRT also provides electron identification capability by detecting transition radiation (TR) X-ray photons in a Xe-based working gas mixture. Compared to Run 1, the LHC beams now provide a higher center of mass energy (13 TeV), more bunches with a reduced spacing (25 ns), and more particles in each bunch leading to very challenging, higher occupancies in the TRT. We will present TRT modifications made for Run 2 for in areas: to improve response to the expected much higher rate of hits and to mitigate leaks of the Xe-based active gas mixture. The higher rates required changes to the data acquisition system and introduction of validity gate to reject out-of-time hits. Radiation-induced gain changes in ...
First identification of the 0{sub 2}{sup +} state in {sup 30}Mg via its E0 transition
Energy Technology Data Exchange (ETDEWEB)
Schwerdtfeger, Wolfgang Norbert Erik
2008-08-28
The known 1789 keV level in {sup 30}Mg turned out to be a candidate for the 0{sub 2}{sup +} state due to its long lifetime of 3.9(4) ns and the absence of a {gamma} transition to the ground state. This triggered our search on the 0{sub 2}{sup +}{yields}0{sub 1}{sup +} E0 transition in {sup 30}Mg following the {beta} decay of {sup 30}Na: {beta} decay electrons were detected in a scintillation detector, while conversion electrons were focused onto a cooled Si(Li) detector using a Mini-Orange and detected with high resolution, which simultaneously suppresses the high background of {beta} decay electrons. Due to the large Q value of the {beta} decay of {sup 30}Na (17.3 MeV) the suppression of the coincident background induced by high-energy {gamma} rays and subsequently Compton-scattered electrons turned out to be the key challenge for the success of this experiment. In order to optimise the background suppression and thus the sensitivity to weak E0 transitions, offline test measurements using an {sup 90}Y and a {sup 152}Eu source were performed together with GEANT4 simulations. Resulting from these test measurements a highly sensitive experimental setup was designed and built, consequently minimising the amount of high-Z material in the target chamber, reducing X-ray production. As a by-product from test measurements the database value of the half-life of the 0{sub 2}{sup +} state in {sup 90}Zr could be corrected by more than 30 % to be t{sub 1/2}=41(1) ns. Finally, in a {beta} decay experiment at the ISOLDE facility at CERN the 0{sub 2}{sup +}{yields}0{sub 1}{sup +} E0 transition in {sup 30}Mg could be identified at the expected transition energy of 1788 keV proving for the first time shape coexistence at the borderline of the 'Island of Inversion'. This identification allows to determine the electric monopole strength as {rho}{sup 2}(E0)=26.2(7.5) x 10{sup -3}, indicating a rather weak mixing between the states in two potential minima in a simplified two
DEFF Research Database (Denmark)
Granzotto, Clara; Sutherland, Ken
2017-01-01
to the analysis of naturally aged (∼80 year) gum arabic samples, pure and mixed with lead white pigment, and allowed the detection of gum arabic in samples from a late painting (1949/1954) by Georges Braque in the collection of the Art Institute of Chicago. This first application of the technique to characterize...... to the reproducibility of the gum MS profile, even in the presence of other organic and inorganic components, together with the minimal sample size required, demonstrate the value of this new MALDI-TOF MS method as an analytical tool for the identification of gum arabic in microsamples from museum artifacts....
Directory of Open Access Journals (Sweden)
Hu Xiaohua
2011-07-01
Full Text Available Abstract Background The wide use of high-throughput DNA microarray technology provide an increasingly detailed view of human transcriptome from hundreds to thousands of genes. Although biomedical researchers typically design microarray experiments to explore specific biological contexts, the relationships between genes are hard to identified because they are complex and noisy high-dimensional data and are often hindered by low statistical power. The main challenge now is to extract valuable biological information from the colossal amount of data to gain insight into biological processes and the mechanisms of human disease. To overcome the challenge requires mathematical and computational methods that are versatile enough to capture the underlying biological features and simple enough to be applied efficiently to large datasets. Methods Unsupervised machine learning approaches provide new and efficient analysis of gene expression profiles. In our study, two unsupervised knowledge-based matrix factorization methods, independent component analysis (ICA and nonnegative matrix factorization (NMF are integrated to identify significant genes and related pathways in microarray gene expression dataset of Alzheimer’s disease. The advantage of these two approaches is they can be performed as a biclustering method by which genes and conditions can be clustered simultaneously. Furthermore, they can group genes into different categories for identifying related diagnostic pathways and regulatory networks. The difference between these two method lies in ICA assume statistical independence of the expression modes, while NMF need positivity constrains to generate localized gene expression profiles. Results In our work, we performed FastICA and non-smooth NMF methods on DNA microarray gene expression data of Alzheimer’s disease respectively. The simulation results shows that both of the methods can clearly classify severe AD samples from control samples, and
Heredia, Guillermo; Ollero, Aníbal
2010-01-01
The Helicopter Adaptive Aircraft (HADA) is a morphing aircraft which is able to take-off as a helicopter and, when in forward flight, unfold the wings that are hidden under the fuselage, and transfer the power from the main rotor to a propeller, thus morphing from a helicopter to an airplane. In this process, the reliable folding and unfolding of the wings is critical, since a failure may determine the ability to perform a mission, and may even be catastrophic. This paper proposes a virtual sensor based Fault Detection, Identification and Recovery (FDIR) system to increase the reliability of the HADA aircraft. The virtual sensor is able to capture the nonlinear interaction between the folding/unfolding wings aerodynamics and the HADA airframe using the navigation sensor measurements. The proposed FDIR system has been validated using a simulation model of the HADA aircraft, which includes real phenomena as sensor noise and sampling characteristics and turbulence and wind perturbations.
Bruin, J P; Kostrzewa, M; van der Ende, A; Badoux, P; Jansen, R; Boers, S A; Diederen, B M W
2014-02-01
Generally accepted laboratory methods that have been used for decades do not reliably distinguish between H. influenzae and H. haemolyticus isolates. H. haemolyticus strains are often incorrectly identified as nontypeable Haemophilus influenzae (NTHi). To distinguish H. influenzae from H. haemolyticus we have created a new database on the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) bio-typer 2 and compared the results with routine determination of Haemophilus (growth requirement for X and V factor), and multilocus sequence typing (MLST). In total we have tested 277 isolates, 244 H. influenzae and 33 H. haemolyticus. Using MLST as the gold standard, the agreement of MALDI-TOF MS was 99.6 %. MALDI-TOF MS allows reliable and rapid discrimination between H. influenzae and H. haemolyticus.
Ingber, D. E.
1992-01-01
Angiogenesis, the growth of blood capillaries, is regulated by soluble growth factors and insoluble extracellular matrix (ECM) molecules. Soluble angiogenic mitogens act over large distances to initiate capillary growth whereas changes in ECM govern whether individual cells will grow, differentiate, or involute in response to these stimuli in the local tissue microenvironment. Analysis of this local control mechanism has revealed that ECM molecules switch capillary endothelial cells between differentiation and growth by both binding specific transmembrane integrin receptors and physically resisting cell-generated mechanical loads that are applied to these receptors. Control of capillary endothelial cell form and function therefore may be exerted by altering the mechanical properties of the ECM as well as its chemical composition. Understanding of this mechanochemical control mechanism has led to the development of new angiogenesis inhibitors that may be useful for the treatment of cancer.
Durighello, Emie; Bellanger, Laurent; Ezan, Eric; Armengaud, Jean
2014-10-07
Francisella tularensis is the causative agent of tularemia. Because some Francisella strains are very virulent, this species is considered by the Centers for Disease Control and Prevention to be a potential category A bioweapon. A mass spectrometry method to quickly and robustly distinguish between virulent and nonvirulent Francisella strains is desirable. A combination of shotgun proteomics and whole-cell matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry on the Francisella tularensis subsp. holarctica LVS defined three protein biomarkers that allow such discrimination: the histone-like protein HU form B, the 10 kDa chaperonin Cpn10, and the 50S ribosomal protein L24. We established that their combined detection by whole-cell MALDI-TOF spectrum could enable (i) the identification of Francisella species, and (ii) the prediction of their virulence level, i.e., gain of a taxonomical level with the identification of Francisella tularensis subspecies. The detection of these biomarkers by MALDI-TOF mass spectrometry is straightforward because of their abundance and the absence of other abundant protein species closely related in terms of m/z. The predicted molecular weights for the three biomarkers and their presence as intense peaks were confirmed with MALDI-TOF/MS spectra acquired on Francisella philomiragia ATCC 25015 and on Francisella tularensis subsp. tularensis CCUG 2112, the most virulent Francisella subspecies.
Kolecka, Anna; Khayhan, Kantarawee; Groenewald, Marizeth; Theelen, Bart; Arabatzis, Michael; Velegraki, Aristea; Kostrzewa, Markus; Mares, Mihai; Taj-Aldeen, Saad J; Boekhout, Teun
2013-08-01
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used for an extensive identification study of arthroconidial yeasts, using 85 reference strains from the CBS-KNAW yeast collection and 134 clinical isolates collected from medical centers in Qatar, Greece, and Romania. The test set included 72 strains of ascomycetous yeasts (Galactomyces, Geotrichum, Saprochaete, and Magnusiomyces spp.) and 147 strains of basidiomycetous yeasts (Trichosporon and Guehomyces spp.). With minimal preparation time, MALDI-TOF MS proved to be an excellent diagnostic tool that provided reliable identification of most (98%) of the tested strains to the species level, with good discriminatory power. The majority of strains were correctly identified at the species level with good scores (>2.0) and seven of the tested strains with log score values between 1.7 and 2.0. The MALDI-TOF MS results obtained were consistent with validated internal transcribed spacer (ITS) and/or large subunit (LSU) ribosomal DNA sequencing results. Expanding the mass spectrum database by increasing the number of reference strains for closely related species, including those of nonclinical origin, should enhance the usefulness of MALDI-TOF MS-based diagnostic analysis of these arthroconidial fungi in medical and other laboratories.
Kolecka, Anna; Khayhan, Kantarawee; Groenewald, Marizeth; Theelen, Bart; Arabatzis, Michael; Velegraki, Aristea; Kostrzewa, Markus; Mares, Mihai; Taj-Aldeen, Saad J.
2013-01-01
Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) was used for an extensive identification study of arthroconidial yeasts, using 85 reference strains from the CBS-KNAW yeast collection and 134 clinical isolates collected from medical centers in Qatar, Greece, and Romania. The test set included 72 strains of ascomycetous yeasts (Galactomyces, Geotrichum, Saprochaete, and Magnusiomyces spp.) and 147 strains of basidiomycetous yeasts (Trichosporon and Guehomyces spp.). With minimal preparation time, MALDI-TOF MS proved to be an excellent diagnostic tool that provided reliable identification of most (98%) of the tested strains to the species level, with good discriminatory power. The majority of strains were correctly identified at the species level with good scores (>2.0) and seven of the tested strains with log score values between 1.7 and 2.0. The MALDI-TOF MS results obtained were consistent with validated internal transcribed spacer (ITS) and/or large subunit (LSU) ribosomal DNA sequencing results. Expanding the mass spectrum database by increasing the number of reference strains for closely related species, including those of nonclinical origin, should enhance the usefulness of MALDI-TOF MS-based diagnostic analysis of these arthroconidial fungi in medical and other laboratories. PMID:23678074
Stone, Bradley M.
1998-01-01
The Astrochemistry Group at NASA Ames Research Center is interested in the identification of large organic molecules in the interstellar medium Many smaller organic species (e.g. hydrocarbons, alcohols, etc.) have been previously identified by their radiofrequency signature due to molecular rotations. However, this becomes increasingly difficult to observe as the size of the molecule increases. Our group in interested in the identification of the carriers of the Diffuse Interstellar Bands (absorption features observed throughout the visible and near-infrared in the spectra of stars, due to species in the interstellar medium). Polycyclic Aromatic Hydrocarbons (PAHs) and related molecules are thought to be good candidates for these carriers. Laboratory experiments am performed at Ames to simulate the interstellar environment, and to compare spectra obtained from molecules in the laboratory to those derived astronomically. We are also interested in PAHs with respect to their possible connection to the UIR (Unidentified infrared) and ERE (Extended Red Emission) bands - emission features found to emanate from particular regions of our galaxy (e.g. Orion nebula, Red Rectangle, etc.). An old, "tried and proven spectroscopic technique, matrix isolation spectroscopy creates molecular conditions ideal for performing laboratory astrophysics.
International Nuclear Information System (INIS)
Barbarito, E.; Bellotti, R.; Cafagna, F.; Castellano, M.; Circella, M.; De Cataldo, G.; De Marzo, C.; Fusco, P.; Giglietto, N.; Mongelli, M.; Marangelli, B.; Perchiazzi, M.; Raino, A.; Sacchetti, A.; Spinelli, P.
1995-01-01
We have built and tested a transition radiation detector of about 76x80 cm 2 active surface to discriminate positrons from protons in an experiment performed on a balloon flight to search for primordial antimatter. The TRD is made of ten modules each consisting of a carbon fiber radiator followed by a multiwire proportional chamber. In order to achieve a proton-electron rejection factor of the order of 10 -3 with a strict limitation on power consumption to about 40 mW per chamber channel, as required by experimental constraints, we have developed a low power consumption ''cluster counting'' electronics. Different analysis procedures of calibration data are shown. In addition, comparisons of the performances of this detector are also made with a previous similar prototype equipped with standard fast electronics and similar detectors from other authors. ((orig.))
A high rate transition radiation detector for particle identification in a hadron beam
International Nuclear Information System (INIS)
Errede, D.; Sheaff, M.; Fenker, H.; Mantsch, P.
1989-08-01
A Transition Radiation Detector (TRD) was built for the purpose of tagging beam particles in a high rate (∼2 MHz) 250 GeV/c hadron beam during data taking for Experiment 769 at Fermilab. The availability of a good ''tool kit'', including a Monte Carlo program which could reliably predict the detector performance, made it possible to design and build the TRD in approximately one year. Pion or proton samples, each with a small contamination due to the other, could be selected with high efficiency by making cuts on the number of planes of the TRD registering hits for each incident beam particle. The detector is expected to work well to separate kaons from pions in the 500 GeV/c negative beam for E791. 15 refs., 8 figs., 1 tab
Lasch, Peter; Beyer, Wolfgang; Nattermann, Herbert; Stämmler, Maren; Siegbrecht, Enrico; Grunow, Roland; Naumann, Dieter
2009-11-01
This report demonstrates the applicability of a combination of matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) and chemometrics for rapid and reliable identification of vegetative cells of the causative agent of anthrax, Bacillus anthracis. Bacillus cultures were prepared under standardized conditions and inactivated according to a recently developed MS-compatible inactivation protocol for highly pathogenic microorganisms. MALDI-TOF MS was then employed to collect spectra from the microbial samples and to build up a database of bacterial reference spectra. This database comprised mass peak profiles of 374 strains from Bacillus and related genera, among them 102 strains of B. anthracis and 121 strains of B. cereus. The information contained in the database was investigated by means of visual inspection of gel view representations, univariate t tests for biomarker identification, unsupervised hierarchical clustering, and artificial neural networks (ANNs). Analysis of gel views and independent t tests suggested B. anthracis- and B. cereus group-specific signals. For example, mass spectra of B. anthracis exhibited discriminating biomarkers at 4,606, 5,413, and 6,679 Da. A systematic search in proteomic databases allowed tentative assignment of some of the biomarkers to ribosomal protein or small acid-soluble proteins. Multivariate pattern analysis by unsupervised hierarchical cluster analysis further revealed a subproteome-based taxonomy of the genus Bacillus. Superior classification accuracy was achieved when supervised ANNs were employed. For the identification of B. anthracis, independent validation of optimized ANN models yielded a diagnostic sensitivity of 100% and a specificity of 100%.
Bishop, B; Geffen, Y; Plaut, A; Kassis, O; Bitterman, R; Paul, M; Neuberger, A
2018-02-01
To assess the potential of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in rapid identification of bacteria from smear-positive cerebrospinal fluid (CSF) in a cohort of patients with meningitis. Single-centre observational study, including adults and children with community-acquired or postneurosurgical bacterial meningitis. Meningitis was defined using established criteria. Samples of CSF that had a positive CSF Gram stain were directly examined by MALDI-TOF-MS. Identification was considered accurate when identical to the CSF culture or PCR results (species and genus level). Laboratory workers performing the MALDI-TOF-MS and interpreting its results were blinded to the direct smear results, except for the fact that it was positive. MALDI-TOF-MS results were not conveyed to clinicians. MALDI-TOF-MS was tested on 44 CSF samples; ten samples were obtained from patients with community-acquired meningitis, and 34 samples were from patients with postneurosurgical meningitis. The assay identified bacteria correctly in 17/21 of the samples with Gram-negative rods observed on the direct smear, all obtained from patients who had undergone neurosurgery, (sensitivity 81%, 95% CI 64.2%-97.7%). In the postneurosurgical group, Gram-positive cocci were identified correctly in only 1/11 (9.1%) of the samples, and Candida species were not identified in two samples. Among patients with community-acquired meningitis, the assay did not identify Streptococcus pneumoniae in eight of eight samples, Neisseria meningitidis in one sample (1/1), and Streptococcus agalactiae in one sample (1/1). We found MALDI-TOF-MS to be useful in the rapid identification of Gram-negative rods directly from smear-positive CSF samples, but not of Gram-positive bacteria. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Zhao, Bin; Sun, Zhigang; Guo, Hua
2014-10-21
This work is concerned with the calculation of state-to-state S-matrix elements for four-atom reactions using a recently proposed method based on the quantum transition-state theory. In this approach, the S-matrix elements are computed from the thermal flux cross-correlation functions obtained in both the reactant and product arrangement channels. Since transition-state wave packets are propagated with only single arrangement channels, the bases/grids required are significantly smaller than those needed in state-to-state approaches based on a single set of scattering coordinates. Furthermore, the propagation of multiple transition-state wave packets can be carried out in parallel. This method is demonstrated for the H2/D2 + OH → H/D + H2O/HOD reactions (J = 0) and the reaction probabilities are in excellent agreement with benchmark results.
Hanifeh, Mohsen; Rajamäki, Minna Marjaana; Syrjä, Pernilla; Mäkitalo, Laura; Kilpinen, Susanne; Spillmann, Thomas
2018-03-12
Matrix metalloproteinases (MMPs) 2 and 9 are zinc- and calcium-dependent endopeptidases involved in the breakdown and reconstitution of extracellular matrix under both physiological and pathological conditions. Mucosal MMP-2 and -9 activities have been reported to be upregulated in the intestine of humans with inflammatory bowel disease (IBD), and in animal models of IBD. However, their involvement in the pathogenesis of canine chronic enteropathies (CE) is unknown. This study investigated mucosal pro- and active MMP-2 and -9 activities in dogs with CE and healthy dogs using gelatin zymography, and also to determine the association of their activities in dogs with CE with the canine IBD activity index (CIBDAI), histopathologic findings, the clinical outcome, and hypoalbuminemia. Intestinal mucosal samples from duodenum, ileum, colon, and cecum were collected from 40 dogs with CE and 18 healthy Beagle dogs. In dogs with CE, the number of samples positive for mucosal pro- and active MMP-2 was significantly higher in the duodenum (P < 0.0001 and P = 0.011, respectively), ileum (P = 0.002 and P = 0.018, respectively), and colon (P < 0.0001 and P = 0.002, respectively), compared with healthy controls. Mucosal pro-MMP-9-positive samples in the duodenum and colon were significantly more frequent in dogs with CE than in healthy dogs (P = 0.0004 and P = 0.001, respectively). Despite the presence of mucosal samples positive for active MMP-9 in the intestinal segments of dogs with CE, the difference compared to healthy controls did not reach statistical significance. None of the intestinal mucosal samples in healthy dogs showed gelatinolytic activity corresponding to the control bands of active MMP-2 and -9. Mucosal active MMP-9 activities displayed a significant positive association with the severity of neutrophil infiltration in the duodenum (P = 00.040), eosinophils in the cecum (P = 00.037), and the CIBDAI score for ileum samples
Identification of predictive biomarkers of disease state in transition dairy cows.
Hailemariam, D; Mandal, R; Saleem, F; Dunn, S M; Wishart, D S; Ametaj, B N
2014-05-01
In dairy cows, periparturient disease states, such as metritis, mastitis, and laminitis, are leading to increasingly significant economic losses for the dairy industry. Treatments for these pathologies are often expensive, ineffective, or not cost-efficient, leading to production losses, high veterinary bills, or early culling of the cows. Early diagnosis or detection of these conditions before they manifest themselves could lower their incidence, level of morbidity, and the associated economic losses. In an effort to identify predictive biomarkers for postpartum or periparturient disease states in dairy cows, we undertook a cross-sectional and longitudinal metabolomics study to look at plasma metabolite levels of dairy cows during the transition period, before and after becoming ill with postpartum diseases. Specifically we employed a targeted quantitative metabolomics approach that uses direct flow injection mass spectrometry to track the metabolite changes in 120 different plasma metabolites. Blood plasma samples were collected from 12 dairy cows at 4 time points during the transition period (-4 and -1 wk before and 1 and 4 wk after parturition). Out of the 12 cows studied, 6 developed multiple periparturient disorders in the postcalving period, whereas the other 6 remained healthy during the entire experimental period. Multivariate data analysis (principal component analysis and partial least squares discriminant analysis) revealed a clear separation between healthy controls and diseased cows at all 4 time points. This analysis allowed us to identify several metabolites most responsible for separating the 2 groups, especially before parturition and the start of any postpartum disease. Three metabolites, carnitine, propionyl carnitine, and lysophosphatidylcholine acyl C14:0, were significantly elevated in diseased cows as compared with healthy controls as early as 4 wk before parturition, whereas 2 metabolites, phosphatidylcholine acyl-alkyl C42:4 and
Directory of Open Access Journals (Sweden)
Fernanda Kreuzberg
2015-12-01
Full Text Available Currently companies have to think about its management system to meet not only their economic interests but also their social interests aiming at the activities’ sustainability and longevity. In this research, the goal is to identify the Nash equilibrium point in the bi-matrix game of economic and social indicators of the companies of Public Utilities sector listed on the BM & FBovespa. The research was conducted with a sample of 26 companies. To evaluate the economic performance it was used the profitability and market indicators; for evaluating the social performance, it was used the indicators derived from the VAD (Value Added Statement. In the estimation of earnings among indicators, it was used the standard parameters of the multiple linear regression. The obtained results highlighted the existence of at least one point of equilibrium for the years analyzed and, especially in the models, two points of equilibrium were proposed for 2009 and 2011 and three for 2010. It is noteworthy that, in the proposed model it was confirmed the hypothesis of the existence of at least one point of equilibrium. Thus, it was possible to meet the research objective, namely, that it is possible to meet both economic aspects and the social aspects of the companies when the indicators are taken as basic information.
Identification of a nuclear matrix attachment region like sequence in the last intron of PI3Kγ
International Nuclear Information System (INIS)
Dai Bingbing; Ying Lei; Cai Rong; Li Ying; Zhang Xingqian; Lu Jian; Qian Guanxiang
2006-01-01
MARs are not only the structure bases of chromatin higher order structure but also have much biological significance. In this study, the whole sequence of about 100 kb in length from BAC clone of GS1-223D4 (GI: 5931478), in which human PI3Kγ gene is localized, was analyzed by two online-based computer programs, MARFinder and SMARTest. A strong potential MAR was predicted in the last and largest intron of PI3Kγ. The predicted 2 kb MAR, we refer to PIMAR, was further analyzed through biochemical methods in vitro and in vivo. The results showed that the PIMAR could be associated with nuclear matrices from HeLa cells both in vitro and in vivo. Further reporter gene analysis showed that in the transient transfection the expression of reporter gene linked with reversed PIMAR was repressed slightly, while in stably integrated state, the luciferase reporter both linked with reversed and orientated PIMAR was enhanced greatly in NIH-3T3 and K-562. These results suggest that the PIMAR maybe has the capacity of shielding integrated heterogeneous gene from chromatin position effect. Through combination of computer program analysis with confirmation by biochemical methods, we identified, for First time, a 2 kb matrix attachment region like sequence in the last intron of human PI3Kγ
Nakayama, Seiji; Suzuki, Michio; Endo, Hirotoshi; Iimura, Kurin; Kinoshita, Shigeharu; Watabe, Shugo; Kogure, Toshihiro; Nagasawa, Hiromichi
2013-01-01
The periostracum is a layered structure that is formed as a mollusk shell grows. The shell is covered by the periostracum, which consists of organic matrices that prevent decalcification of the shell. In the present study, we discovered the presence of chitin in the periostracum and identified a novel matrix protein, Pinctada fucata periostracum protein named PPP-10. It was purified from the sodium dodecyl sulfate/dithiothreitol-soluble fraction of the periostracum of the Japanese pearl oyster, P. fucata. The deduced amino acid sequence was determined by a combination of amino acid sequence analysis and cDNA cloning. The open reading frame encoded a precursor protein of 112 amino acid residues including a 21-residue signal peptide. The 91 residues following the signal peptide contained abundant Cys and Tyr residues. PPP-10 was expressed on the outer side of the outer fold in the mantle, indicating that PPP-10 was present in the second or third layer of the periostracum. We also determined that the recombinant PPP-10 had chitin-binding activity and could incorporate chitin into the scaffolds of the periostracum. These results shed light on the early steps in mollusk shell formation.
Nakayama, Seiji; Suzuki, Michio; Endo, Hirotoshi; Iimura, Kurin; Kinoshita, Shigeharu; Watabe, Shugo; Kogure, Toshihiro; Nagasawa, Hiromichi
2013-01-01
The periostracum is a layered structure that is formed as a mollusk shell grows. The shell is covered by the periostracum, which consists of organic matrices that prevent decalcification of the shell. In the present study, we discovered the presence of chitin in the periostracum and identified a novel matrix protein, Pinctada fucata periostracum protein named PPP-10. It was purified from the sodium dodecyl sulfate/dithiothreitol-soluble fraction of the periostracum of the Japanese pearl oyster, P. fucata. The deduced amino acid sequence was determined by a combination of amino acid sequence analysis and cDNA cloning. The open reading frame encoded a precursor protein of 112 amino acid residues including a 21-residue signal peptide. The 91 residues following the signal peptide contained abundant Cys and Tyr residues. PPP-10 was expressed on the outer side of the outer fold in the mantle, indicating that PPP-10 was present in the second or third layer of the periostracum. We also determined that the recombinant PPP-10 had chitin-binding activity and could incorporate chitin into the scaffolds of the periostracum. These results shed light on the early steps in mollusk shell formation. PMID:24251105
Identification of a transitional fibroblast function in very early rheumatoid arthritis.
Filer, Andrew; Ward, Lewis S C; Kemble, Samuel; Davies, Christopher S; Munir, Hafsa; Rogers, Rebekah; Raza, Karim; Buckley, Christopher Dominic; Nash, Gerard B; McGettrick, Helen M
2017-12-01
Synovial fibroblasts actively regulate the inflammatory infiltrate by communicating with neighbouring endothelial cells (EC). Surprisingly, little is known about how the development of rheumatoid arthritis (RA) alters these immunomodulatory properties. We examined the effects of phase of RA and disease outcome (resolving vs persistence) on fibroblast crosstalk with EC and regulation of lymphocyte recruitment. Fibroblasts were isolated from patients without synovitis, with resolving arthritis, very early RA (VeRA; symptom ≤12 weeks) and established RA undergoing joint replacement (JRep) surgery. Endothelial-fibroblast cocultures were formed on opposite sides of porous filters. Lymphocyte adhesion from flow, secretion of soluble mediators and interleukin 6 (IL-6) signalling were assessed. Fibroblasts from non-inflamed and resolving arthritis were immunosuppressive, inhibiting lymphocyte recruitment to cytokine-treated endothelium. This effect was lost very early in the development of RA, such that fibroblasts no longer suppressed recruitment. Changes in IL-6 and transforming growth factor beta 1 (TGF-β 1 ) signalling appeared critical for the loss of the immunosuppressive phenotype. In the absence of exogenous cytokines, JRep, but not VeRA, fibroblasts activated endothelium to support lymphocyte. In RA, fibroblasts undergo two distinct changes in function: first a loss of immunosuppressive responses early in disease development, followed by the later acquisition of a stimulatory phenotype. Fibroblasts exhibit a transitional functional phenotype during the first 3 months of symptoms that contributes to the accumulation of persistent infiltrates. Finally, the role of IL-6 and TGF-β 1 changes from immunosuppressive in resolving arthritis to stimulatory very early in the development of RA. Early interventions targeting 'pathogenic' fibroblasts may be required in order to restore protective regulatory processes. © Article author(s) (or their employer(s) unless
Ratnaparkhe, Supriya M; Egertsdotter, E M Ulrika; Flinn, Barry S
2009-07-01
Extracellular matrix (ECM) modifications occur during plant growth, development, and in response to environmental stimuli. Key modulators of ECM modification in vertebrates, the extracellular matrix metalloproteinases (MMPs), have also been described in a few plants. Here, we report the identification of Loblolly pine (Pinus taeda) Pta1-MMP and its characterization during seed development and germination. Pta1-MMP protein has the structural characteristics of other plant MMPs, the recombinant protein exhibits Zn(2+)-dependent protease activity, and is inhibited by EDTA and the active site-binding hydroxamate inhibitor GM6001. The Pta1-MMP gene is expressed in both embryo and megagametophyte, with transcript levels increasing in both during the period from proembryo to early cotyledonary stage, then declining during late embryogenesis and maturation drying. Protein extracts exhibited similar developmental-stage MMP-like activity. Seed germination was stimulated by GA(3) and inhibited by ABA, and the timing of germination completion was mirrored by the presence of MMP-like protease activity in both water- and GA(3)-imbibed embryos. Pta1-MMP gene transcript levels increased in association with radicle protrusion for both GA(3)- and water-treated embryos, in agreement with MMP-like activity. In contrast, by 11 days after imbibition, Pta1-MMP gene transcripts in ABA-treated embryos were at levels similar to the other treatments, although MMP-like activity was not observed. The application of GM6001 during Loblolly pine seed germination inhibited radicle protrusion. Our results suggest that MMP activity may be involved in ECM modification, facilitating the cell division and expansion required during seed development, germination completion, and subsequent seedling establishment.
Energy Technology Data Exchange (ETDEWEB)
Li, Hongzhong; Huang, Jing; Yang, Bing; Xiang, Tingxiu; Yin, Xuedong; Peng, Weiyan; Cheng, Wei [Molecular Oncology and Epigenetics Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Wan, Jingyuan; Luo, Fuling [Department of Pharmacology, Chongqing Medical University, Chongqing (China); Li, Hongyuan [Molecular Oncology and Epigenetics Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Ren, Guosheng, E-mail: rgs726@163.com [Molecular Oncology and Epigenetics Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China)
2013-10-01
Although mangiferin which is a naturally occurring glucosylxanthone has exhibited promising anticancer activities, the detailed molecular mechanism of mangiferin on cancers still remains enigmatic. In this study, the anticancer activity of mangiferin was evaluated in breast cancer cell line-based in vitro and in vivo models. We showed that mangiferin treatment resulted in decreased cell viability and suppression of metastatic potential in breast cancer cells. Further mechanistic investigation revealed that mangiferin induced decreased matrix metalloproteinase (MMP)-7 and -9, and reversal of epithelial–mesenchymal transition (EMT). Moreover, it was demonstrated that mangiferin significantly inhibited the activation of β-catenin pathway. Subsequent experiments showed that inhibiting β-catenin pathway might play a central role in mangiferin-induced anticancer activity through modulation of MMP-7 and -9, and EMT. Consistent with these findings in vitro, the antitumor potential was also verified in mangiferin-treated MDA-MB-231 xenograft mice where significantly decreased tumor volume, weight and proliferation, and increased apoptosis were obtained, with lower expression of MMP-7 and -9, vimentin and active β-catenin, and higher expression of E-cadherin. Taken together, our study suggests that mangiferin might be used as an effective chemopreventive agent against breast cancer. - Highlights: • Mangiferin inhibits growth and metastatic potential in breast cancer cells. • Mangiferin down-regulates MMP-7 and -9 in breast cancer cells. • Mangiferin induces the reversal of EMT in metastatic breast cancer cells. • Mangiferin inhibits the activation of β-catenin pathway in breast cancer cells. • Inhibiting β-catenin is responsible for the antitumor activity of mangiferin.
Directory of Open Access Journals (Sweden)
Wenfa Ng
2013-01-01
Full Text Available Ever since the first observation of “animalcules” under a microscope, and the subsequent discovery of microorganisms of myriad size, shape, pigmentation and motility modes, classification in aid of microbial identification is key to understanding inter-relationships between diverse microbes. Combining universal applicability with robustness, 16S rRNA sequencing is the gold standard for microbial typing; however, recent developments in clinical diagnostics have called attention to a shift towards PCR-independent instrumentation and methods given PCR’s requirement for expensive and complex sample preparation. Using ribosomal proteins as biomarkers for evolutionary relatedness, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS - originally developed for the soft ionization of proteins and peptides in proteomics studies - has been successfully applied to identifying bacteria, archaea, fungi and viruses to the species, and, on occasions, sub-species level. Though experimentally proven and increasingly adopted in the clinic, the relatively low-cost (on a per sample basis and rapid MALDI-TOF MS microbial identification technique, along with its theoretical principles and methodology, is a conspicuous absentee in contemporary microbiology curricula. Motivated by a desire to close the curriculum gap, this article describes a discovery-based activity for teaching microbial identification - using MALDI-TOF MS in combination with open-source genomics and proteomics search tools – while providing tips on mass spectra interpretation and activity implementation for lowering the barrier for classroom adoption. Infused with inquiry-based learning concepts guiding students in identifying microbes from environmental water samples with unknown species diversity, the activity spurs students’ learning by igniting their spirit of inquiry, which leads to better mastery of concepts; a significant departure from
Belitsky, A. V.
2017-10-01
The Operator Product Expansion for null polygonal Wilson loop in planar maximally supersymmetric Yang-Mills theory runs systematically in terms of multi-particle pentagon transitions which encode the physics of excitations propagating on the color flux tube ending on the sides of the four-dimensional contour. Their dynamics was unraveled in the past several years and culminated in a complete description of pentagons as an exact function of the 't Hooft coupling. In this paper we provide a solution for the last building block in this program, the SU(4) matrix structure arising from internal symmetry indices of scalars and fermions. This is achieved by a recursive solution of the Mirror and Watson equations obeyed by the so-called singlet pentagons and fixing the form of the twisted component in their tensor decomposition. The non-singlet, or charged, pentagons are deduced from these by a limiting procedure.
Directory of Open Access Journals (Sweden)
A.V. Belitsky
2017-10-01
Full Text Available The Operator Product Expansion for null polygonal Wilson loop in planar maximally supersymmetric Yang–Mills theory runs systematically in terms of multi-particle pentagon transitions which encode the physics of excitations propagating on the color flux tube ending on the sides of the four-dimensional contour. Their dynamics was unraveled in the past several years and culminated in a complete description of pentagons as an exact function of the 't Hooft coupling. In this paper we provide a solution for the last building block in this program, the SU(4 matrix structure arising from internal symmetry indices of scalars and fermions. This is achieved by a recursive solution of the Mirror and Watson equations obeyed by the so-called singlet pentagons and fixing the form of the twisted component in their tensor decomposition. The non-singlet, or charged, pentagons are deduced from these by a limiting procedure.
An Application of Matrix Multiplication
Indian Academy of Sciences (India)
IAS Admin
vector whose entries are all non-negative and have sum. 1, and a transition matrix to be a square matrix, each of whose rows is a probability vector. We then define a finite Markov chain (or simply a chain) to consist of an n × n transition matrix P and a 1 × n row vector x: The positions Ei are the states of the chain and our aim.
Bradshaw, Robert; Wolstenholme, Rosalind; Blackledge, Robert D; Clench, Malcolm R; Ferguson, Leesa S; Francese, Simona
2011-02-15
An increase in the use of condoms by sexual offenders has been observed. This is likely to be due both to the risk of sexually transmitted diseases and to prevent the transfer of DNA evidence. In this scenario the detection of condom lubricants at a crime scene could aid in proving corpus delicti. Here we show a novel application of Matrix-Assisted Laser Desorption/Ionisation Mass Spectrometry Imaging (MALDI MSI) for mapping the fingermark ridge pattern simultaneously to the detection of the condom lubricant within the fingermark itself. Two condom brands have been investigated to prove the concept. Condoms were handled producing lubricant-contaminated fingermarks. Images of the ridge pattern were obtained simultaneously to the detection of two lubricants, even several weeks after the fingermark deposition. The results therefore show the potential of MALDI MSI to link the suspect (identification through fingermark ridge pattern) to the crime (detection of condom lubricant) in one analysis. This would enable forensic scientists to provide evidence with stronger support in alleged cases of sexual assault. Copyright © 2011 John Wiley & Sons, Ltd.
Burgasser, Adam J.; Cruz, Kelle L.; Cushing, Michael C.; Gelino, Christopher R.; Looper, Dagny L.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy; Reid, I. Neill
2009-01-01
We report the identification of 17 candidate brown dwarf binaries whose components straddle the L dwarf/T dwarf transition. These sources were culled from a large near-infrared spectral sample of L and T dwarfs observed with the Infrared Telescope Facility SpeX spectrograph. Candidates were selected on the basis of spectral ratios which segregate known (resolved) L dwarf/T dwarf pairs from presumably single sources. Composite templates, constructed by combining 13581 pairs of absolute flux-ca...
Application of random matrix theory to biological networks
Energy Technology Data Exchange (ETDEWEB)
Luo Feng [Department of Computer Science, Clemson University, 100 McAdams Hall, Clemson, SC 29634 (United States); Department of Pathology, U.T. Southwestern Medical Center, 5323 Harry Hines Blvd. Dallas, TX 75390-9072 (United States); Zhong Jianxin [Department of Physics, Xiangtan University, Hunan 411105 (China) and Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)]. E-mail: zhongjn@ornl.gov; Yang Yunfeng [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Scheuermann, Richard H. [Department of Pathology, U.T. Southwestern Medical Center, 5323 Harry Hines Blvd. Dallas, TX 75390-9072 (United States); Zhou Jizhong [Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019 (United States) and Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)]. E-mail: zhouj@ornl.gov
2006-09-25
We show that spectral fluctuation of interaction matrices of a yeast protein-protein interaction network and a yeast metabolic network follows the description of the Gaussian orthogonal ensemble (GOE) of random matrix theory (RMT). Furthermore, we demonstrate that while the global biological networks evaluated belong to GOE, removal of interactions between constituents transitions the networks to systems of isolated modules described by the Poisson distribution. Our results indicate that although biological networks are very different from other complex systems at the molecular level, they display the same statistical properties at network scale. The transition point provides a new objective approach for the identification of functional modules.
Czerwinski, Michael; Spence, Jason R
2017-01-05
Recently in Nature, Gjorevski et al. (2016) describe a fully defined synthetic hydrogel that mimics the extracellular matrix to support in vitro growth of intestinal stem cells and organoids. The hydrogel allows exquisite control over the chemical and physical in vitro niche and enables identification of regulatory properties of the matrix. Copyright © 2017 Elsevier Inc. All rights reserved.
Gribbon, Chris; Dahm, Ralf; Prescott, Alan R; Quinlan, Roy A
2002-10-01
The transcriptional status of cells can be deduced from the staining pattern of various nuclear markers such as the Cajal body, nucleolus and nuclear speckles. In this study we have used these markers to correlate transcriptional status with cell differentiation in the lens. As a closed system with no cell loss and with each stage being spatially preserved, it is particularly well suited to such studies. To confirm that the nuclear markers in lens cells follow the same trends as in other cells, primary bovine lens epithelial cells were cultured and then treated with actinomycin D to inhibit transcription. This reduced the Cajal body markers to one or two foci per nucleus and the nucleoli became compacted as revealed by fibrillarin staining. The nuclear speckles, containing snRNPs (e.g. Sm) and the splicing factor, SC35, also became larger and more numerous while the signal for trimethylguanine (TMG) decreased suggesting a role hierarchy for the various speckle factors during transcriptional shutdown. The signal for survival of motor neurones gene product (SMN) also decreased at this point. In the lens epithelium, postmitotic cells near the equatorial region had one or two Cajal bodies per nucleus, indicating these cells had only basal levels of transcription. Sm was also present as large foci in these cells. Interestingly, both the speckles and Cajal bodies were NuMA-positive in these post-mitotic cells. At the epithelial-fibre cell transition, Cajal body number increased, while their size decreased indicative of increased transcriptional activity. Fibrillarin adopted the open floret pattern indicating increased transcriptional activity. The nuclear speckles adopted a more diffuse nucleoplasmic pattern, although some spots were still observed. All NuMA colocalisation with the Cajal bodies and nuclear speckles was lost at this stage of lens cell differentiation. Transcriptional shutdown occurs at a later stage in fibre cell differentiation, prior to programmed
Singh, R; Mandhani, A; Agrawal, V; Garg, Minal
2018-01-18
Involvement of matrix metalloproteinases (MMPs) in the pathogenesis of urothelial carcinoma elects them to be sensitive marker for clinical and prognostic implications. MMPs regulate tumor growth and invasion by inducing epithelial-to-mesenchymal transition (EMT) which is characterized by the complex reprogramming of epithelial cells and ultimately bring about major changes in the structural organization of bladder urothelium. The present study has been undertaken to evaluate the clinical relevance of MMPs in two distinct types of bladder cancer disease. Expression analysis of MMPs namely MMP-2, MMP-7, MMP-9 and EMT markers including epithelial marker, E-cadherin; mesenchymal markers, N-cadherin and Vimentin; and EMT-activating transcriptional factors (EMT-ATFs), Snail, Slug, Twist and Zeb was done in 64 cases of bladder tumor tissues [{Non-muscle invasive bladder cancer (NMIBC): 35 cases} and {Muscle invasive bladder cancer (MIBC): 29 cases}] by real-time quantitative polymerase chain reaction (RT-qPCR). Immunohistochemistry (IHC) staining was done in matched bladder tumor tissues to evaluate the protein expression and localization of E-cadherin, N-cadherin, Vimentin, Snail, and Slug. Our data showed overexpression of MMP-2, MMP-7 and MMP-9 at transcriptome level in 32.8%, 25% and 37.5% bladder tumor cases respectively. These tumor tissues were examined for higher expression of mesenchymal markers (N-cadherin and Vimentin) at mRNA and protein level and exhibited statistical association with tumor stage and tumor grade (p = 0.02, p = 0.04, Mann-Whitney test). Significant statistical correlation in tumor tissues with overexpressed MMPs has also been observed between gain of transcriptional factors and weak expression of E-cadherin with tumor stage, grade, gender, presence of hematuria and smoking history of the patients. Gene expression patterns of EMT markers in bladder tumors with overexpressed MMPs and their significant association with clinical profile
Gonçalves, Juliano Leonel; Barreiro, Juliana Regina; Braga, Patrícia Aparecida de Campos; Prada e Silva, Luis Felipe; Eberlin, Marcos Nogueira
2014-01-01
Coagulase-negative staphylococci (CoNS) are among the main pathogens causing bovine intramammary infection (IMI) in many countries. However, one of the limitations related to the specific diagnosis of CoNS is the lack of an accurate, rapid, and convenient method that can differentiate the bacterial species comprising this group. The aim of this study was to evaluate the ability of matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) to accurately identify CoNS species in dairy cow IMI. In addition, the study aimed to determine the frequency of CoNS species causing bovine IMI. A total of 108 bacterial isolates were diagnosed as CoNS by microbiological cultures from two milk samples collected from 21 dairy herds; the first sample was collected at the cow level (i.e., 1,242 composite samples from all quarters), while the second sample was collected at the mammary quarter level (i.e., 1,140 mammary samples collected from 285 cows). After CoNS isolation was confirmed by microbiological culture for both samples, all CoNS isolates (n = 108) were genotypically differentiated by PCR restriction fragment length polymorphism (RFLP) analysis of a partial groEL gene sequence and subjected to the MALDI-TOF MS identification procedure. MALDI-TOF MS correctly identified 103 (95.4%) of the CoNS isolates identified by PCR-RFLP at the species level. Eleven CoNS species isolated from bovine IMI were identified by PCR-RFLP, and the most prevalent species was Staphylococcus chromogenes (n = 80; 74.1%). In conclusion, MALDI-TOF MS may be a reliable alternative method for differentiating CoNS species causing bovine IMI. PMID:24622096
Bano, Luca; Drigo, Ilenia; Tonon, Elena; Pascoletti, Simone; Puiatti, Cinzia; Anniballi, Fabrizio; Auricchio, Bruna; Lista, Florigio; Montecucco, Cesare; Agnoletti, Fabrizio
2017-12-01
Animal botulism is primarily due to botulinum neurotoxin (BoNT) types C, D or their chimeric variants C/D or D/C, produced by Clostridium botulinum group III, which appears to include the genetically indistinguishable Clostridium haemolyticum and Clostridium novyi. In the present study, we used matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI TOF MS) to identify and characterize 81 BoNT-producing Clostridia isolated in 47 episodes of animal botulism. The instrument's default database, containing no entries for Clostridium botulinum, permitted reliable identification of 26 strains at the genus level. Although supplementation of the database with reference strains enhanced the instrument's ability to identify the neurotoxic strains at the genus level, resolution was not sufficient to recognize field strains at species level. Characterization by MALDI TOF confirmed the well-documented phenotypic and genetic differences between Clostridium botulinum strains of serotypes normally implicated in human botulism (A, B, E, F) and other Clostridium species able to produce BoNTs type C and D. The chimeric and non-chimeric field strains grouped separately. In particular, very low similarity was found between two non-chimeric type C field strains isolated in the same outbreak and the other field strains. This difference was comparable with the differences among the various Clostridia species included in the study. Characterization by MALDI TOF confirmed that BoNT-producing Clostridia isolated from animals are closely related and indistinguishable at the species level from Clostridium haemolyticum and Clostridium novyi reference strains. On the contrary, there seem to be substantial differences among chimeric and some non-chimeric type C strains. Copyright © 2017 Elsevier Ltd. All rights reserved.
Dybwad, Marius; van der Laaken, Anton L; Blatny, Janet Martha; Paauw, Armand
2013-09-01
Rapid and reliable identification of Bacillus anthracis spores in suspicious powders is important to mitigate the safety risks and economic burdens associated with such incidents. The aim of this study was to develop and validate a rapid and reliable laboratory-based matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis method for identifying B. anthracis spores in suspicious powder samples. A reference library containing 22 different Bacillus sp. strains or hoax materials was constructed and coupled with a novel classification algorithm and standardized processing protocol for various powder samples. The method's limit of B. anthracis detection was determined to be 2.5 × 10(6) spores, equivalent to a 55-μg sample size of the crudest B. anthracis-containing powder discovered during the 2001 Amerithrax incidents. The end-to-end analysis method was able to successfully discriminate among samples containing B. anthracis spores, closely related Bacillus sp. spores, and commonly encountered hoax materials. No false-positive or -negative classifications of B. anthracis spores were observed, even when the analysis method was challenged with a wide range of other bacterial agents. The robustness of the method was demonstrated by analyzing samples (i) at an external facility using a different MALDI-TOF MS instrument, (ii) using an untrained operator, and (iii) using mixtures of Bacillus sp. spores and hoax materials. Taken together, the observed performance of the analysis method developed demonstrates its potential applicability as a rapid, specific, sensitive, robust, and cost-effective laboratory-based analysis tool for resolving incidents involving suspicious powders in less than 30 min.
Najbauer, Eszter E; Bazsó, Gábor; Apóstolo, Rui; Fausto, Rui; Biczysko, Malgorzata; Barone, Vincenzo; Tarczay, György
2015-08-20
The conformers of α-serine were investigated by matrix-isolation IR spectroscopy combined with NIR laser irradiation. This method, aided by 2D correlation analysis, enabled unambiguously grouping the spectral lines to individual conformers. On the basis of comparison of at least nine experimentally observed vibrational transitions of each conformer with empirically scaled (SQM) and anharmonic (GVPT2) computed IR spectra, six conformers were identified. In addition, the presence of at least one more conformer in Ar matrix was proved, and a short-lived conformer with a half-life of (3.7 ± 0.5) × 10(3) s in N2 matrix was generated by NIR irradiation. The analysis of the NIR laser-induced conversions revealed that the excitation of the stretching overtone of both the side chain and the carboxylic OH groups can effectively promote conformational changes, but remarkably different paths were observed for the two kinds of excitations.
Fatania, Nita; Fraser, Mark; Savage, Mike; Hart, Jason; Abdolrasouli, Alireza
2015-12-01
Performance of matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) was compared in a side-by side-analysis with conventional phenotypic methods currently in use in our laboratory for identification of yeasts in a routine diagnostic setting. A diverse collection of 200 clinically important yeasts (19 species, five genera) were identified by both methods using standard protocols. Discordant or unreliable identifications were resolved by sequencing of the internal transcribed spacer region of the rRNA gene. MALDI-TOF and conventional methods were in agreement for 182 isolates (91%) with correct identification to species level. Eighteen discordant results (9%) were due to rarely encountered species, hence the difficulty in their identification using traditional phenotypic methods. MALDI-TOF MS enabled rapid, reliable and accurate identification of clinically important yeasts in a routine diagnostic microbiology laboratory. Isolates with rare, unusual or low probability identifications should be confirmed using robust molecular methods. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Banach, T; Bochniarz, M; Łyp, P; Adaszek, Ł; Wawron, W; Furmaga, B; Skrzypczak, M; Ziętek, J; Winiarczyk, S
2016-09-01
The aim of this study was to use matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification of coagulase-negative staphylococci (CNS) isolated from the milk of cows with subclinical mastitis. The study material consisted of 33 isolates of CNS, identified by the results of API Staph tests, obtained from the milk of cows with subclinical mastitis. Based on the spectra analyses, MALDI-TOF MS tests of 33 bacterial samples allowed identification of the microorganisms in 27 cases (81.8%). The most frequent cause of subclinical mastitis was found to be Staphylococcus sciuri (39%), while S. vitulinus was detected in 15% of the milk samples. The results obtained indicate that MALDI-TOF MS can be used for the identification of CNS isolated from bovine mastitis as a method supplementary to biochemical tests.
XUV spectra of 2nd transition row elements: identification of 3d-4p and 3d-4f transition arrays
Czech Academy of Sciences Publication Activity Database
Lokasani, R.; Long, E.; Maguire, O.; Sheridan, P.; Hayden, P.; O'Reilly, F.; Dunne, P.; Sokell, E.; Endo, Akira; Limpouch, Jiří; O'Sullivan, G.
2015-01-01
Roč. 48, č. 24 (2015), 1-12, č. článku 245009. ISSN 0953-4075 R&D Projects: GA MŠk(CZ) LG13029 Institutional support: RVO:68378271 Keywords : laser produced plasma * water window * unresolved transition arrays * yttrium * niobium * ruthenium * rhodium Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.833, year: 2015
Identification of the transition arrays 3d74s-3d74p in Br X and 3d64s-3d64p in Br XI
International Nuclear Information System (INIS)
Zeng, X.T.; Jupen, C.; Bengtsson, P.; Engstroem, L.; Westerlind, M.; Martinson, I.
1991-01-01
We report a beam-foil study of multiply ionized bromine in the region 400-1300A, performed with 6 and 8 MeV Br ions from a tandem accelerator. At these energies transitions belonging to Fe-like Br X and Mn-like Br XI are expected to be prominent. We have identified 31 lines as 3d 7 4s-3d 7 4p transitions in Br X, from which 16 levels of the previously unknown 3d 7 4s configuration could be established. We have also added 6 new 3d 7 4p levels to the 99 previously known. For Br XI we have classified 9 lines as 3d 6 4s-3d 6 4p combinations. The line identifications have been corroborated by isoelectronic comparisons and theoretical calculations using the superposition-of-configurations technique. (orig.)
Lee, Tai-Fen; Du, Shin-Hei; Teng, Shih-Hua; Liao, Chun-Hsing; Sheng, Wang-Hui; Teng, Lee-Jene
2014-01-01
We evaluated whether the Bruker Biotyper matrix-associated laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system provides accurate species-level identifications of 147 isolates of aerobically growing Gram-positive rods (GPRs). The bacterial isolates included Nocardia (n = 74), Listeria (n = 39), Kocuria (n = 15), Rhodococcus (n = 10), Gordonia (n = 7), and Tsukamurella (n = 2) species, which had all been identified by conventional methods, molecular methods, or both. In total, 89.7% of Listeria monocytogenes, 80% of Rhodococcus species, 26.7% of Kocuria species, and 14.9% of Nocardia species (n = 11, all N. nova and N. otitidiscaviarum) were correctly identified to the species level (score values, ≥2.0). A clustering analysis of spectra generated by the Bruker Biotyper identified six clusters of Nocardia species, i.e., cluster 1 (N. cyriacigeorgica), cluster 2 (N. brasiliensis), cluster 3 (N. farcinica), cluster 4 (N. puris), cluster 5 (N. asiatica), and cluster 6 (N. beijingensis), based on the six peaks generated by ClinProTools with the genetic algorithm, i.e., m/z 2,774.477 (cluster 1), m/z 5,389.792 (cluster 2), m/z 6,505.720 (cluster 3), m/z 5,428.795 (cluster 4), m/z 6,525.326 (cluster 5), and m/z 16,085.216 (cluster 6). Two clusters of L. monocytogenes spectra were also found according to the five peaks, i.e., m/z 5,594.85, m/z 6,184.39, and m/z 11,187.31, for cluster 1 (serotype 1/2a) and m/z 5,601.21 and m/z 11,199.33 for cluster 2 (serotypes 1/2b and 4b). The Bruker Biotyper system was unable to accurately identify Nocardia (except for N. nova and N. otitidiscaviarum), Tsukamurella, or Gordonia species. Continuous expansion of the MALDI-TOF MS databases to include more GPRs is necessary. PMID:24759706
Hsueh, Po-Ren; Lee, Tai-Fen; Du, Shin-Hei; Teng, Shih-Hua; Liao, Chun-Hsing; Sheng, Wang-Hui; Teng, Lee-Jene
2014-07-01
We evaluated whether the Bruker Biotyper matrix-associated laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system provides accurate species-level identifications of 147 isolates of aerobically growing Gram-positive rods (GPRs). The bacterial isolates included Nocardia (n = 74), Listeria (n = 39), Kocuria (n = 15), Rhodococcus (n = 10), Gordonia (n = 7), and Tsukamurella (n = 2) species, which had all been identified by conventional methods, molecular methods, or both. In total, 89.7% of Listeria monocytogenes, 80% of Rhodococcus species, 26.7% of Kocuria species, and 14.9% of Nocardia species (n = 11, all N. nova and N. otitidiscaviarum) were correctly identified to the species level (score values, ≥ 2.0). A clustering analysis of spectra generated by the Bruker Biotyper identified six clusters of Nocardia species, i.e., cluster 1 (N. cyriacigeorgica), cluster 2 (N. brasiliensis), cluster 3 (N. farcinica), cluster 4 (N. puris), cluster 5 (N. asiatica), and cluster 6 (N. beijingensis), based on the six peaks generated by ClinProTools with the genetic algorithm, i.e., m/z 2,774.477 (cluster 1), m/z 5,389.792 (cluster 2), m/z 6,505.720 (cluster 3), m/z 5,428.795 (cluster 4), m/z 6,525.326 (cluster 5), and m/z 16,085.216 (cluster 6). Two clusters of L. monocytogenes spectra were also found according to the five peaks, i.e., m/z 5,594.85, m/z 6,184.39, and m/z 11,187.31, for cluster 1 (serotype 1/2a) and m/z 5,601.21 and m/z 11,199.33 for cluster 2 (serotypes 1/2b and 4b). The Bruker Biotyper system was unable to accurately identify Nocardia (except for N. nova and N. otitidiscaviarum), Tsukamurella, or Gordonia species. Continuous expansion of the MALDI-TOF MS databases to include more GPRs is necessary. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
Xing, Libo; Zhang, Dong; Li, Youmei; Zhao, Caiping; Zhang, Songwen; Shen, Yawen; An, Na; Han, Mingyu
2014-12-17
A long juvenile period between germination and flowering is a common characteristic among fruit trees, including Malus hupehensis (Pamp.) Rehd., which is an apple rootstock widely used in China. microRNAs (miRNAs) play an important role in the regulation of phase transition and reproductive growth processes. M. hupehensis RNA libraries, one adult and one juvenile phase, were constructed using tree leaves and underwent high-throughput sequencing. We identified 42 known miRNA families and 172 novel miRNAs. We also identified 127 targets for 25 known miRNA families and 168 targets for 35 unique novel miRNAs using degradome sequencing. The identified miRNA targets were categorized into 58 biological processes, and the 123 targets of known miRNAs were associated with phase transition processes. The KEGG analysis revealed that these targets were involved in starch and sucrose metabolism, and plant hormone signal transduction. Expression profiling of miRNAs and their targets indicated multiple regulatory functions in the phase transition. The higher expression level of mdm-miR156 and lower expression level of mdm-miR172 in the juvenile phase leaves implied that these two small miRNAs regulated the phase transition. mdm-miR160 and miRNA393, which regulate genes involved in auxin signal transduction, could also be involved in controlling this process. The identification of known and novel miRNAs and their targets provides new information on this regulatory process in M. hupehensis, which will contribute to the understanding of miRNA functions during growth, phase transition and reproduction in woody fruit trees. The combination of sRNA and degradome sequencing can be used to better illustrate the profiling of hormone-regulated miRNAs and miRNA targets involving complex regulatory networks, which will contribute to the understanding of miRNA functions during growth, phase transition and reproductive growth in perennial woody fruit trees.
Franklin, Joel N
2003-01-01
Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.
Yamamoto, Mikachi; Umeda, Yoshiko; Yo, Ayaka; Yamaura, Mariko; Makimura, Koichi
2014-02-01
Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been utilized for identification of various microorganisms. Malassezia species, including Malassezia restricta, which is associated with seborrheic dermatitis, has been difficult to identify by traditional means. This study was performed to develop a system for identification of Malassezia species with MALDI-TOF-MS and to investigate the incidence and variety of cutaneous Malassezia microbiota of 1-month-old infants using this technique. A Malassezia species-specific MALDI-TOF-MS database was developed from eight standard strains, and the availability of this system was assessed using 54 clinical strains isolated from the skin of 1-month-old infants. Clinical isolates were cultured initially on CHROMagar Malassezia growth medium, and the 28S ribosomal DNA (D1/D2) sequence was analyzed for confirmatory identification. Using this database, we detected and analyzed Malassezia species in 68% and 44% of infants with and without infantile seborrheic dermatitis, respectively. The results of MALDI-TOF-MS analysis were consistent with those of rDNA sequencing identification (100% accuracy rate). To our knowledge, this is the first report of a MALDI-TOF-MS database for major skin pathogenic Malassezia species. This system is an easy, rapid and reliable method for identification of Malassezia. © 2014 Japanese Dermatological Association.
Szabados, F; Tix, H; Anders, A; Kaase, M; Gatermann, S G; Geis, G
2012-06-01
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was introduced a few years ago as a new method for bacterial identification. A variety of studies have been published concerning MALDI-TOF MS-based identification, most of them using culture collections for the validation of the respective databases in a retrospective manner in favor of a parallel investigation. The score cutoff value is of special importance for reliable species identification in the Biotyper database. The score cutoff values suggested by the manufacturer have been validated using a previously published formic acid extraction protocol. In most of the previously published studies investigating the Biotyper database, only little information was given concerning species-specific score values. In addition, the mass spectrometer instruments, the number of replicates, the number of spectra used to calculate a sum-spectrum by the supplied software, and the score cutoff values which have been applied varied within these studies. In this study, we compared a straightforward direct smear preparation and measurement without replicate testing to defined biochemical identifications in a parallel manner. In addition, we described new species-specific score cutoff values for the identification of certain bacteria.
Chackerian, C., Jr.
1976-01-01
The electric dipole moment function of the ground electronic state of carbon monoxide has been determined by combining numerical solutions of the radial Schrodinger equation with absolute intensity data of vibration-rotation bands. The derived dipole moment function is used to calculate matrix elements of interest to stellar astronomy and of importance in the carbon monoxide laser.
Gautam Pennathur; Banerjee Santanu; Gupta Ravi; Lakshmanan Jagannathan; Padmaja Sushma S; Banerjee Sulagna
2010-01-01
Abstract Background Chromatin in the nucleus of all eukaryotes is organized into a system of loops and domains. These loops remain fastened at their bases to the fundamental framework of the nucleus, the matrix or the scaffold. The DNA sequences which anchor the bases of the chromatin loops to the matrix are known as Scaffold/Matrix Attachment Regions or S/MARs. Though S/MARs have been studied in yeast and higher eukaryotes and they have been found to be associated with gene organization and ...
Ford, Bradley A; Burnham, Carey-Ann D
2013-05-01
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) might complement and one day replace phenotypic identification of bacteria in the clinical microbiology laboratory, but there is no consensus standard regarding the requirements for its validation prior to clinical use in the United States. The objective of this study was to assess the preanalytical variables influencing Gram-negative identification by use of the Bruker Biotyper MALDI-TOF MS system, including density of organism spotting on a stainless steel target plate and the direct overlay of organisms with formic acid. A heavy smear with formic acid overlay was either superior or equivalent to alternative smear conditions. Microbiological preanalytical variables were also assayed, such as culture medium, growth temperature, and use of serial subculture. Postanalytical analysis included the application of modified species-level identification acceptance criteria. Biotyper identifications were compared with those using traditional phenotypic methods, and discrepancies were resolved with 16S rRNA gene sequencing. Compared to the recommended score cutoffs of the manufacturer, the application of optimized Biotyper score cutoffs for species-level identification increased the rate of identification by 6.75% for the enteric Gram-negative bacteria and 4.25% for the nonfermenting Gram-negative bacteria. Various incubation temperatures, growth medium types, and repeat subcultures did not result in misidentification. We conclude that the Bruker MALDI Biotyper is a robust system for the identification of Gram-negative organisms in the clinical laboratory and that meaningful performance improvements can be made by implementing simple pre- and postanalytical techniques.
Harms, Jack C.; Grames, Ethan M.; O'Brien, Leah C.; O'Brien, James J.
2017-06-01
Four new electronic transitions with blue-degraded bandheads were observed in the orange-red region of the visible spectrum. The transitions were observed in the plasma discharge of a hollow copper cathode placed within the cavity of a tunable dye laser system, allowing molecular absorbance to be enhanced upon laser amplification. To produce the molecules, the surface of the copper cathode was soaked in a dilute ammonia solution prior to installation, and 1 torr of H_2 was used as the sputter gas in the dc plasma discharge. The bandheads were observed at 16,560 \\wn, 16,485 \\wn, 16,027 \\wn, and 15,960 \\wn. Using 1.5 torr of D_2 as the sputter gas resulted in a -3 \\wn shift in origin for the bands in the 16,000 \\wn region. Four rotational branches have been identified in each transition, and the transitions have been fit to independent ^{2}Σ - ^{2}Π transitions using PGOPHER, with spin-orbit splittings in the Hund's case (a) Π-states of -71.2 \\wn and -65.4 \\wn. The transitions have tentatively been assigned to HCuN. Results of this analysis will be presented.
Huang, Yanfei; Zhang, Mingxin; Zhu, Min; Wang, Mei; Sun, Yufeng; Gu, Haitong; Cao, Jingjing; Li, Xue; Zhang, Shaoya; Wang, Jinglin; Lu, Xinxin
2017-07-01
Infections caused by filamentous fungi have become a health concern, and require rapid and accurate identification in order for effective treatment of the pathogens. To compare the performance of two MALDI-TOF MS systems (Bruker Microflex LT and Xiamen Microtyper) in the identification of filamentous fungal species. A total of 374 clinical filamentous fungal isolates sequentially collected in the Clinical Laboratory at the Beijing Tongren Hospital between January 2014 and December 2015 were identified by traditional phenotypic methods, Bruker Microflex LT and Xiamen Microtyper MALDI-TOF MS, respectively. The discrepancy between these methods was resolved by sequencing for definitive identification. Bruker Microflex LT and Xiamen Microtyper had similar correct species ID (98.9 vs. 99.2%), genus ID (99.7 vs. 100%), mis-ID (0.3 vs. 0%) and no ID (0 vs. 0). The rate of correct species identification by both MALDI-TOF MS (98.9 and 99.2%, respectively) was much higher compared with phenotypic approach (91.9%). Both MALDI-TOF MS systems provide accurate identification of clinical filamentous fungi compared with conventional phenotypic method, and have the potential to replace identification for routine identification of these fungi in clinical mycology laboratories. Both systems have similar performance in the identification of clinical filamentous fungi.
Veloo, A. C. M.; Knoester, M.; Degener, J. E.; Kuijper, E. J.
2011-01-01
Two commercially available MALDI-TOF MS systems, Bruker MS and Shimadzu MS, were compared for the identification of clinically relevant anaerobic bacteria. A selection of 79 clinical isolates, representing 19 different genera, were tested and compared with identification obtained by 16S rRNA gene
International Nuclear Information System (INIS)
Akishina, T.P.; Denisova, O.Yu.; Ivanov, V.V.
2009-01-01
The problem of pion-electron identification based on their energy losses in the TRD is considered in the frame of the CBM experiment. For particles identification an artificial neural network (ANN) was used, a multilayer perceptron realized in JETNET and ROOT packages. It is demonstrated that, in order to get correct and comparable results, it is important to define the network structure correctly. The recommendations for such a selection are given. In order to achieve an acceptable level of pions suppression, the energy losses need to be transformed to more 'effective' variables. The dependency of ANN output threshold for a fixed portion of electron loss on the particle momentum is presented
Idelevich, Evgeny A.; Grünastel, Barbara
2016-01-01
ABSTRACT Candida sepsis is a life-threatening condition with increasing prevalence. In this study, direct blood culturing on solid medium using a lysis-centrifugation procedure enabled successful Candida species identification by matrix-assisted laser desorption–ionization time of flight mass spectrometry on average 3.8 h (Sabouraud agar) or 7.4 h (chocolate agar) before the positivity signal for control samples in Bactec mycosis-IC/F or Bactec Plus aerobic/F bottles, respectively. Direct culturing on solid medium accelerated candidemia diagnostics compared to that with automated broth-based systems. PMID:27795344
Idelevich, Evgeny A; Grünastel, Barbara; Becker, Karsten
2017-01-01
Candida sepsis is a life-threatening condition with increasing prevalence. In this study, direct blood culturing on solid medium using a lysis-centrifugation procedure enabled successful Candida species identification by matrix-assisted laser desorption-ionization time of flight mass spectrometry on average 3.8 h (Sabouraud agar) or 7.4 h (chocolate agar) before the positivity signal for control samples in Bactec mycosis-IC/F or Bactec Plus aerobic/F bottles, respectively. Direct culturing on solid medium accelerated candidemia diagnostics compared to that with automated broth-based systems. Copyright © 2016 American Society for Microbiology.
Suwantarat, Nuntra; Grundy, Maureen; Rubin, Mayer; Harris, Renee; Miller, Jo-Anne; Romagnoli, Mark; Hanlon, Ann; Tekle, Tsigereda; Ellis, Brandon C; Witter, Frank R; Carroll, Karen C
2015-12-01
During a 14-month period of using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for group B streptococcus (GBS) identification, we recovered 32 (1%) Streptococcus pseudoporcinus isolates from 3,276 GBS screening cultures from female genital sources (25 isolates from pregnant women and 7 from nonpregnant women). An additional two S. pseudoporcinus isolates were identified from a urine culture and a posthysterectomy wound culture. These isolates were found to cross-react with three different GBS antigen agglutination kits, PathoDx (Remel) (93%), Prolex (Pro-Lab Diagnostics) (38%), and Streptex (Remel) (53%). New approaches to bacterial identification in routine clinical microbiology laboratories may affect the prevalence of S. pseudoporcinus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Marko, Daniel C; Saffert, Ryan T; Cunningham, Scott A; Hyman, Jay; Walsh, John; Arbefeville, Sophie; Howard, Wanita; Pruessner, Jon; Safwat, Nedal; Cockerill, Franklin R; Bossler, Aaron D; Patel, Robin; Richter, Sandra S
2012-06-01
The Bruker Biotyper and Vitek MS matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) instruments were evaluated for the identification of nonfermenting gram-negative bacilli (NFGNB) by a blinded comparison to conventional biochemical or molecular methods. Two hundred NFGNB that were recovered from cultures from cystic fibrosis patients in the University of Iowa Health Care (UIHC) Microbiology Laboratory between 1 January 2006 and 31 October 2010 were sent to Mayo Clinic for analysis with the Bruker Biotyper (software version 3.0) and to bioMérieux for testing with Vitek MS (SARAMIS database version 3.62). If two attempts at direct colony testing failed to provide an acceptable MALDI-TOF identification, an extraction procedure was performed. The MS identifications from both of these systems were provided to UIHC for comparison to the biochemical or molecular identification that had been reported in the patient record. Isolates with discordant results were analyzed by 16S rRNA gene sequencing at UIHC. After discrepancy testing, the Bruker Biotyper result agreed with the biochemical or molecular method, with 72.5% of isolates to the species level, 5.5% to the complex level, and 19% to the genus level (3% not identified). The level of agreement for Vitek MS was 80% species, 3.5% complex, 6% genus, and 3.5% family (7% not identified). Both MS systems provided rapid (≤3 min per isolate) and reliable identifications. The agreement of combined species/complex/genus-level identification with the reference method was higher for the Bruker Biotyper (97% versus 89.5%, P = 0.004) but required an extraction step more often. Species-level agreement with the reference method was similar for both MS systems (72.5% and 80%, P = 0.099).
Kolecka, A; Khayhan, K; Arabatzis, M; Velegraki, A; Kostrzewa, M; Andersson, A; Scheynius, A; Cafarchia, C; Iatta, R; Montagna, M T; Youngchim, S; Cabañes, F J; Hoopman, P; Kraak, B; Groenewald, M; Boekhout, T
BACKGROUND: Infections caused by Malassezia yeasts are most likely underdiagnosed, because fatty acid supplementation is needed for growth. Rapid identification of Malassezia species is essential for appropriate treatment of Malassezia-related skin infections, fungaemia and nosocomial outbreaks in
Directory of Open Access Journals (Sweden)
Mao-Cheng Ge
2017-10-01
Conclusions: MALDI-TOF MS is a rapid, reliable, economical, and environmentally friendly method for routine microbial identification and may contribute to early appropriate antibiotic treatment in clinical settings.
The deviation matrix of a continuous-time Markov chain
Coolen-Schrijner, Pauline; van Doorn, Erik A.
2002-01-01
he deviation matrix of an ergodic, continuous-time Markov chain with transition probability matrix $P(.)$ and ergodic matrix $\\Pi$ is the matrix $D \\equiv \\int_0^{\\infty} (P(t)-\\Pi)dt$. We give conditions for $D$ to exist and discuss properties and a representation of $D$. The deviation matrix of a
The deviation matrix of a continuous-time Markov chain
Coolen-Schrijner, P.; van Doorn, E.A.
2001-01-01
The deviation matrix of an ergodic, continuous-time Markov chain with transition probability matrix $P(.)$ and ergodic matrix $\\Pi$ is the matrix $D \\equiv \\int_0^{\\infty} (P(t)-\\Pi)dt$. We give conditions for $D$ to exist and discuss properties and a representation of $D$. The deviation matrix of a
Kolecka, A; Khayhan, K; Arabatzis, M; Velegraki, A; Kostrzewa, M; Andersson, A; Scheynius, A; Cafarchia, C; Iatta, R; Montagna, M T; Youngchim, S; Cabañes, F J; Hoopman, P; Kraak, B; Groenewald, M; Boekhout, T
2014-02-01
Infections caused by Malassezia yeasts are most likely underdiagnosed, because fatty acid supplementation is needed for growth. Rapid identification of Malassezia species is essential for appropriate treatment of Malassezia-related skin infections, fungaemia and nosocomial outbreaks in neonates, children and adults and can be life-saving for those patients. Ma-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been reported to be a rapid and reliable diagnostic tool to identify clinically important yeasts, but so far no data have been reported on identification of Malassezia isolates with this technique. To create an extensive database of main mass spectra (MSPs) that will allow quick identification of Malassezia species by MALDI-TOF MS. An in-house library of 113 MSPs was created from 48 reference strains from the CBS-KNAW yeast collection. The in-house library was challenged with two test sets of Malassezia strains, namely 165 reference strains from the CBS collection and 338 isolates collected in Greece, Italy, Sweden and Thailand. MALDI-TOF MS allowed correct identification of all 14 Malassezia spp. MALDI-TOF MS results were concordant with those of sequence analyses of the internal transcribed spacers (ITS1/ITS2) and the D1/D2 domains of the large subunit of the ribosomal DNA. Implementation of the MALDI-TOF MS system as a routine identification tool will contribute to correct identification of Malassezia yeasts with minimal effort and in a short turnaround time, which is especially important for the rapid identification of Malassezia in skin diseases and nosocomial outbreaks. © 2013 British Association of Dermatologists.
Harmon, Christopher W.; Mang, Stephen A.; Greaves, John; Finlayson-Pitts, Barbara J.
2010-01-01
Electrospray ionization mass spectrometry (ESI-MS) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) have found increasing application in the analysis of biological samples. Using these techniques to solve problems in analytical chemistry should be an essential component of the training of undergraduate chemists. We…
Hara, Masatoshi; Lourido, Sebastian; Petrova, Boryana; Lou, Hua Jane; Von Stetina, Jessica R; Kashevsky, Helena; Turk, Benjamin E; Orr-Weaver, Terry L
2018-02-26
The Drosophila Pan Gu (PNG) kinase complex regulates hundreds of maternal mRNAs that become translationally repressed or activated as the oocyte transitions to an embryo. In a previous paper (Hara et al., 2017), we demonstrated PNG activity is under tight developmental control and restricted to this transition. Here, examination of PNG specificity showed it to be a Thr-kinase yet lacking a clear phosphorylation site consensus sequence. An unbiased biochemical screen for PNG substrates identified the conserved translational repressor Trailer Hitch (TRAL). Phosphomimetic mutation of the PNG phospho-sites in TRAL reduced its ability to inhibit translation in vitro. In vivo, mutation of tral dominantly suppressed png mutants and restored Cyclin B protein levels. The repressor Pumilio (PUM) has the same relationship with PNG, and we also show that PUM is a PNG substrate. Furthermore, PNG can phosphorylate BICC and ME31B, repressors that bind TRAL in cytoplasmic RNPs. Therefore, PNG likely promotes translation at the oocyte-to-embryo transition by phosphorylating and inactivating translational repressors. © 2018, Hara et al.
Williams, K.; Locke, W. W.
2009-12-01
Where hillslopes end and hollows and first order channels begin continues to be a relevant question for landscape evolution and development of channel networks. In this work, we test a technique using LIDAR-derived topographic indices to define the transition from hillslopes to unchannelized (zero order) hollows, and from hollows to first order channels in four small (self-organization. Analytically-derived thresholds were verified against field mapping of channel heads and hollows. Results show that the power law portions of the frequency-magnitude relationships were successfully used to locate domain transitions. The transition zones of hillslope to hollow and hollow to channel were identified, for continuous and discontinuous headwater channels of 0.5 to 1 meter in width. Incisive flow alternates downstream with diffusive flow resulting in a discontinuous headwater channel network. The degree of network evolution and self organization of the networks was also evaluated using frequency-magnitude relationships of the topographic indices and total energy dissipation of each catchment. The southwest Montana catchments exhibited more advanced landscape evolution based upon the extent of self organization and optimality, as evidenced by minimum total catchment energy dissipation. The network development of the central Montana catchments appears constrained by debris flow lag deposit in portions of the catchment.
Bodewig, E
1959-01-01
Matrix Calculus, Second Revised and Enlarged Edition focuses on systematic calculation with the building blocks of a matrix and rows and columns, shunning the use of individual elements. The publication first offers information on vectors, matrices, further applications, measures of the magnitude of a matrix, and forms. The text then examines eigenvalues and exact solutions, including the characteristic equation, eigenrows, extremum properties of the eigenvalues, bounds for the eigenvalues, elementary divisors, and bounds for the determinant. The text ponders on approximate solutions, as well
Directory of Open Access Journals (Sweden)
Miroslava Kačániová
2017-11-01
Full Text Available Identification of microorganisms by MALDI-TOF MS Biotyper has been demonstrated to be accurate, rapid and lower cost than conventional food investigation methods. Rapid identification of pathogenic and spoilage microorganisms is crucial for dairy industry to ensure the quality and safety of milk and milk products. In this study, the bacterial species representing the Enterobacteriaceae family were identified in raw milk and milk products using the MALDI-TOF MS mass spectrometry. Altogether, 20 samples of Slovak milk and milk products were examined. Samples were cultured on VRBG agar at 37 °C for 24-48 h. Typical bacterial colonies were selected for identification with MALDI-TOF MS Biotyper. Escherichia coli and Enterobacter sp. were the most abundant Enterobacteriaceae family representatives identified. E. coli was found in nine and Enterobacter sp. in eight samples. Enterobacter sp. comprised 49 % and Escherichia coli 23 % of all bacterial isolates. The study shows that MALDI-TOF MS Biotyper was reliable identification method of Enterobacteriaceae in milk and dairy products. This method was helpful in evaluation of bacterial contamination of milk.
DEFF Research Database (Denmark)
Bloch, H.A.; Petersen, Marianne Kjerstine; Sperotto, Maria Maddalena
2001-01-01
Cereal varieties are normally identified using time-consuming methods such as visual examination of either the intact grain or one-dimensional electrophoretic patterns of the grain storage proteins. A fast method for identification of wheat (Triticum aestivum L.) varieties has previously been...
Almuzara, Marisa; Barberis, Claudia; Traglia, Germán; Famiglietti, Angela; Ramirez, Maria Soledad; Vay, Carlos
2015-05-01
Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) to identify 396 Nonfermenting Gram-Negative Bacilli clinical isolates was evaluated in comparison with conventional phenotypic tests and/or molecular methods. MALDI-TOF MS identified to species level 256 isolates and to genus or complex level 112 isolates. It identified 29 genera including uncommon species. Copyright © 2015 Elsevier B.V. All rights reserved.
Li, Xiuyuan; Tang, Yanyan; Lu, Xinxin
2018-04-01
Currently, the capability of identification for Acinetobacter species using MALDI-TOF MS still remains unclear in clinical laboratories due to certain elusory phenomena. Thus, we conducted this research to evaluate this technique and reveal the causes of misidentification. Briefly, a total of 788 Acinetobacter strains were collected and confirmed at the species level by 16S rDNA and rpoB sequencing, and subsequently compared to the identification by MALDI-TOF MS using direct smear and bacterial extraction pretreatments. Cluster analysis was performed based on the mass spectra and 16S rDNA to reflect the diversity among different species. Eventually, 19 Acinetobacter species were confirmed, including 6 species unavailable in Biotyper 3.0 database. Another novel species was observed, temporarily named A. corallinus. The accuracy of identification for Acinetobacter species using MALDI-TOF MS was 97.08% (765/788), regardless of which pretreatment was applied. The misidentification only occurred on 3 A. parvus strains and 20 strains of species unavailable in the database. The proportions of strains with identification score ≥ 2.000 using direct smear and bacterial extraction pretreatments were 86.04% (678/788) and 95.43% (752/788), χ 2 = 41.336, P clinical samples was deemed reliable. Misidentification occurred occasionally due to the insufficiency of the database rather than sample extraction failure. We suggest gene sequencing should be performed when the identification score is under 2.000 even when using bacterial extraction pretreatment. [Figure not available: see fulltext.
Nikitin, Anatoly G.; Karadzhov, Yuri
2011-07-01
We present a collection of matrix-valued shape invariant potentials which give rise to new exactly solvable problems of SUSY quantum mechanics. It includes all irreducible matrix superpotentials of the generic form W=kQ+\\frac{1}{k} R+P, where k is a variable parameter, Q is the unit matrix multiplied by a real-valued function of independent variable x, and P and R are the Hermitian matrices depending on x. In particular, we recover the Pron'ko-Stroganov 'matrix Coulomb potential' and all known scalar shape invariant potentials of SUSY quantum mechanics. In addition, five new shape invariant potentials are presented. Three of them admit a dual shape invariance, i.e. the related Hamiltonians can be factorized using two non-equivalent superpotentials. We find discrete spectrum and eigenvectors for the corresponding Schrödinger equations and prove that these eigenvectors are normalizable.
Yang, Bing; Huang, Jing; Xiang, Tingxiu; Yin, Xuedong; Luo, Xinrong; Huang, Jianbo; Luo, Fuling; Li, Hongyuan; Li, Hongzhong; Ren, Guosheng
2014-01-01
Chrysin, a naturally occurring flavone, has been shown to inhibit cell proliferation and induce cell apoptosis in various cancers. However, the effect and mechanisms of chrysin on cancer metastasis are still enigmatic. In this study, metastatic triple-negative breast cancer (TNBC) cell lines were used to evaluate the antimetastatic activity of chrysin. The results showed that chrysin (5, 10 and 20 μM) significantly suppressed TNBC cell migration and invasion in a dose-dependent manner. Human matrix metalloproteinase (MMP) antibody array demonstrated that MMP-10 was downregulated by chrysin, which was further verified by Western blotting and ELISA. Moreover, it was shown that chrysin induced increased E-cadherin expression and decreased expression of vimentin, snail and slug in TNBC cells, suggesting that chrysin had a reversal effect on epithelial-mesenchymal transition. More importantly, it was demonstrated that inhibiting the Akt signal pathway might play a central role in chrysin-induced antimetastatic activity by regulating MMP-10 and epithelial-mesenchymal transition. In conclusion, our study indicates that chrysin exerts antimetastatic activities in TNBC cells, which suggests that chrysin might be a potential therapeutic candidate for the treatment of advanced or metastatic breast cancer. Copyright © 2013 John Wiley & Sons, Ltd.
Segonds, Christine; Prere, Marie-Françoise; Marty, Nicole; Oswald, Eric
2013-01-01
Discrimination between Streptococcus pneumoniae and its close relatives of the viridans group is a common difficulty in matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry-based identification. In the present study, the performances of the Vitek MS MALDI-TOF mass spectrometry system were assessed using 334 pneumococci, 166 other S. mitis group streptococci, 184 non-S. mitis group streptococci, and 19 related alpha- and nonhemolytic aerobic Gram-positive catalase-negative coccal isolates. Pneumococci had been identified by means of optochin susceptibility and bile solubility or serotyping, and other isolates mainly by use of RapidID32 Strep strips. In case of discordant or low-discrimination results, genotypic methods were used. The sensitivity of the Vitek MS for the identification of S. pneumoniae was 99.1%, since only three bile-insoluble isolates were misidentified as Streptococcus mitis/Streptococcus oralis. Conversely, two optochin-resistant pneumococci were correctly identified (specificity, 100%). Three Streptococcus pseudopneumoniae isolates were also correctly identified. Among nonpneumococcal isolates, 90.8% (n = 335) were correctly identified to the species or subspecies level and 2.4% (n = 9) at the group level. For the remaining 25 isolates, the Vitek MS proposed a bacterial species included in the list of possible species suggested by genotypic methods, except for 4 isolates which were not identified due to the absence of the species in the database. According to our study, the Vitek MS displays performance similar to that of the optochin susceptibility test for routine identification of pneumococcal isolates. Moreover, the Vitek MS is efficient for the identification of other viridans group streptococci and related isolates, provided that the species are included in the database. PMID:23576536
Li, Huiping; Wu, Hongjin; Zhang, Hongfang; Li, Ying; Li, Shuang; Hou, Qiang; Wu, Shixiu; Yang, Shuan-Ying
2017-06-01
Curcumin is a potent anti-cancer drug in several types of human cancers. Despite of several preclinical and clinical studies of curcumin, the precise mechanism of curcumin in cancer prevention has remained unclear. In our study, we for the first time investigated whole transcriptome alteration in A549 non-small cell lung cancer (NSCLC) cell lines after treatment with curcumin using RNA sequencing. We found that lots of genes and signaling pathways were significantly altered after curcumin treatment in A549 cells. With bioinformatics approaches (gene ontology, Kyoto Encyclopedia of Genes and Genomes, and STRING), we found that those curcumin altered genes were not only the genes that induce cell death but also those extracellular matrix receptors and mitogen-activated protein kinase signaling pathway genes which regulate cell migration and proliferation. Among those significantly altered genes, eight genes ( COL1A1, COL4A1, COL5A1, LAMA5, ITGA3, ITGA2B, DDIT3, and DUSP1) were further examined by quantitative reverse transcription polymerase chain reaction and western blot analysis in four non-small cell lung cancer cell lines. Both in cell lines and in mouse model, the extracellular matrix receptors including the integrin ( ITGA3 and ITGA2B), collagen ( COL5A1), and laminin ( LAMA5) were significantly inhibited by curcumin at messenger RNA and protein levels. Functional studies confirmed that curcumin not only induced A549 cell death but also repressed cell proliferation and migration by regulating extracellular matrix receptors. Collectively, our study suggests that curcumin may be used as a promising drug candidate for intervening lung cancer in future studies.
International Nuclear Information System (INIS)
Quoc-Thang Vo
2013-01-01
This work is focused on a matrix/inclusion metal composite. A simple method is proposed to evaluate the elastic properties of one phase while the properties of the other phase are assumed to be known. The method is based on both an inverse homogenization scheme and mechanical field's measurements by 2D digital image correlation. The originality of the approach rests on the scale studied, i.e. the microstructure scale of material: the characteristic size of the inclusions is about few tens of microns. The evaluation is performed on standard uniaxial tensile tests associated with a long-distance microscope. It allows observation of the surface of a specimen on the microstructure scale during the mechanical stress. First, the accuracy of the method is estimated on 'perfect' mechanical fields coming from numerical simulations for four microstructures: elastic or porous single inclusions having either spherical or cylindrical shape. Second, this accuracy is estimated on real mechanical field for two simple microstructures: an elasto-plastic metallic matrix containing a single cylindrical micro void or four cylindrical micro voids arranged in a square pattern. Third, the method is used to evaluate elastic properties of αZr inclusions with arbitrary shape in an oxidized Zircaloy-4 sample of the fuel cladding of a pressurized water reactor after an accident loss of coolant accident (LOCA). In all this study, the phases are assumed to have isotropic properties. (author) [fr
Varrault, Annie; Dantec, Christelle; Le Digarcher, Anne; Chotard, Laëtitia; Bilanges, Benoit; Parrinello, Hugues; Dubois, Emeric; Rialle, Stéphanie; Severac, Dany; Bouschet, Tristan; Journot, Laurent
2017-10-13
PLAGL1/ZAC1 undergoes parental genomic imprinting, is paternally expressed, and is a member of the imprinted gene network (IGN). It encodes a zinc finger transcription factor with anti-proliferative activity and is a candidate tumor suppressor gene on 6q24 whose expression is frequently lost in various neoplasms. Conversely, gain of PLAGL1 function is responsible for transient neonatal diabetes mellitus, a rare genetic disease that results from defective pancreas development. In the present work, we showed that Plagl1 up-regulation was not associated with DNA damage-induced cell cycle arrest. It was rather associated with physiological cell cycle exit that occurred with contact inhibition, growth factor withdrawal, or cell differentiation. To gain insights into Plagl1 mechanism of action, we identified Plagl1 target genes by combining chromatin immunoprecipitation and genome-wide transcriptomics in transfected cell lines. Plagl1-elicited gene regulation correlated with multiple binding to the proximal promoter region through a GC-rich motif. Plagl1 target genes included numerous genes involved in signaling, cell adhesion, and extracellular matrix composition, including collagens. Plagl1 targets also included 22% of the 409 genes that make up the IGN. Altogether, this work identified Plagl1 as a transcription factor that coordinated the regulation of a subset of IGN genes and controlled extracellular matrix composition. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.
Park, Sujin; Yang, Kyung-Min; Park, Yuna; Hong, Eunji; Hong, Chang Pyo; Park, Jinah; Pang, Kyoungwha; Lee, Jihee; Park, Bora; Lee, Siyoung; An, Haein; Kwak, Mi-Kyung; Kim, Junil; Kang, Jin Muk; Kim, Pyunggang; Xiao, Yang; Nie, Guangjun; Ooshima, Akira
2018-01-01
Background Smad3 linker phosphorylation plays essential roles in tumor progression and metastasis. We have previously reported that the mutation of Smad3 linker phosphorylation sites (Smad3-Erk/Pro-directed kinase site mutant constructs [EPSM]) markedly reduced the tumor progression while increasing the lung metastasis in breast cancer. Methods We performed high-throughput RNA-Sequencing of the human prostate cancer cell lines infected with adenoviral Smad3-EPSM to identify the genes regulated by Smad3-EPSM. Results In this study, we identified genes which are differentially regulated in the presence of Smad3-EPSM. We first confirmed that Smad3-EPSM strongly enhanced a capability of cell motility and invasiveness as well as the expression of epithelial-mesenchymal transition marker genes, CDH2, SNAI1, and ZEB1 in response to TGF-β1 in human pancreatic and prostate cancer cell lines. We identified GADD45B, CTGF, and JUNB genes in the expression profiles associated with cell motility and invasiveness induced by the Smad3-EPSM. Conclusions These results suggested that inhibition of Smad3 linker phosphorylation may enhance cell motility and invasiveness by inducing expression of GADD45B, CTGF, and JUNB genes in various cancers. PMID:29629343
Widder, Lukas; Ristic, Andjelka; Brenner, Florian; Brenner, Josef; Hutter, Herbert
2015-11-17
For many tasks in failure and damage analysis of surfaces deteriorated in heavy tribological contact, the detailed characterization of used lubricants and their additives is essential. The objective of the presented work is to establish accessibility of tribostressed surfaces for direct characterization via modified atmospheric pressure-matrix assisted laser desorption/ionization-mass spectrometry (m-AP-MALDI-MS). Special target holders were constructed to allow target samples of differing shape and form to fit into the desorption/ionization chamber. The best results of desorption and ionization on different target materials and varying roughnesses were achieved on smooth surfaces with low matrix/substrate interaction. M-AP-MALDI characterization of tribologically stressed steel surfaces after pin-on-disc sliding wear tests (SRV-tribotests) yielded positive identification of used friction modifier additives. Further structure elucidation by electrospray ionization mass spectrometry (ESI-MS) and measurements of worn surfaces by time-of-flight-secondary ion mass spectrometry (TOF-SIMS) accompanied findings about additive behavior and deterioration during tribological contact. Using m-AP-MALDI for direct offline examinations of worn surfaces may set up a quick method for determination of additives used for lubrication and general characterization of a tribological system.
Energy Technology Data Exchange (ETDEWEB)
Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University, Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Nguyen, Kévin [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium)
2017-02-08
Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.
Mayhew, Emily J; Schmidt, Shelly J; Schlich, Pascal; Lee, Soo-Yeun
2017-09-01
Stickiness is an important texture attribute in many food systems, but its meaning can vary by person, product, and throughout mastication. This variability and complexity makes it difficult to devise analytical tests that accurately and consistently predict sensory stickiness. Glass transition temperature (T g ) is a promising candidate for texture prediction. Our objective is to elucidate the temporal profile of stickiness in order to probe the relationship between T g and dynamic stickiness perception. Nine caramel samples with diverse texture and thermal profiles were produced for sensory testing and differential scanning calorimetry. Sixteen trained panelists generated stickiness-relevant terms to be used in a subsequent temporal dominance of sensation (TDS) test with the same panelists. Following the TDS study, these panelists also rated samples for overall tactile and oral stickiness. Stickiness ratings were then correlated to TDS dominance parameters across the full evaluation period and within the first, middle, and final thirds of the evaluation period. Samples with temporal texture profiles dominated by tacky, stringy, and enveloping attributes consistently received the highest stickiness scores, although the correlation strength varied by time period. T g was found to correlate well with trained panelist and consumer ratings of oral (R 2 trained = 0.85; R 2 consumer = 0.96) and tactile (R 2 trained = 0.78; R 2 consumer = 0.79) stickiness intensity, and stickiness intensity ratings decreased with T g of completely amorphous samples. Further, glassy samples followed a different texture trajectory (brittle-cohesive-toothpacking) than rubbery samples (deformable-tacky-enveloping). These results illuminate the dynamic perception of stickiness and support the potential of T g to predict both stickiness intensity and texture trajectory in caramel systems. © 2017 Institute of Food Technologists®.
Li, Jin-Xue; Hou, Xiao-Jin; Zhu, Jiao; Zhou, Jing-Jing; Huang, Hua-Bin; Yue, Jian-Qiang; Gao, Jun-Yan; Du, Yu-Xia; Hu, Cheng-Xiao; Hu, Chun-Gen; Zhang, Jin-Zhi
2017-01-01
Water deficit is a key factor to induce flowering in many woody plants, but reports on the molecular mechanisms of floral induction and flowering by water deficit are scarce. Here, we analyzed the morphology, cytology, and different hormone levels of lemon buds during floral inductive water deficits. Higher levels of ABA were observed, and the initiation of floral bud differentiation was examined by paraffin sections analysis. A total of 1638 differentially expressed genes (DEGs) were identified by RNA sequencing. DEGs were related to flowering, hormone biosynthesis, or metabolism. The expression of some DEGs was associated with floral induction by real-time PCR analysis. However, some DEGs may not have anything to do with flowering induction/flower development; they may be involved in general stress/drought response. Four genes from the phosphatidylethanolamine-binding protein family were further investigated. Ectopic expression of these genes in Arabidopsis changed the flowering time of transgenic plants. Furthermore, the 5' flanking region of these genes was also isolated and sequence analysis revealed the presence of several putative cis -regulatory elements, including basic elements and hormone regulation elements. The spatial and temporal expression patterns of these promoters were investigated under water deficit treatment. Based on these findings, we propose a model for citrus flowering under water deficit conditions, which will enable us to further understand the molecular mechanism of water deficit-regulated flowering in citrus. Based on gene activity during floral inductive water deficits identified by RNA sequencing and genes associated with lemon floral transition, a model for citrus flowering under water deficit conditions is proposed.
Identification of Apo-A1 as a biomarker for early diagnosis of bladder transitional cell carcinoma
Directory of Open Access Journals (Sweden)
Wang Shixin
2011-04-01
Full Text Available Abstract Background Bladder transitional cell carcinoma (BTCC is the fourth most frequent neoplasia in men, clinically characterized by high recurrent rates and poor prognosis. Availability of urinary tumor biomarkers represents a convenient alternative for early detection and disease surveillance because of its direct contact with the tumor and sample accessibility. Results We tested urine samples from healthy volunteers and patients with low malignant or aggressive BTCC to identify potential biomarkers for early detection of BTCC by two-dimensional electrophoresis (2-DE coupled with mass spectrometry (MS and bioinformatics analysis. We observed increased expression of five proteins, including fibrinogen (Fb, lactate dehydrogenase B (LDHB, apolipoprotein-A1 (Apo-A1, clusterin (CLU and haptoglobin (Hp, which were increased in urine samples of patients with low malignant or aggressive bladder cancer. Further analysis of urine samples of aggressive BTCC showed significant increase in Apo-A1 expression compared to low malignant BTCC. Apo-A1 level was measured quantitatively using enzyme-linked immunosorbent assay (ELISA and was suggested to provide diagnostic utility to distinguish patients with bladder cancer from controls at 18.22 ng/ml, and distinguish patients with low malignant BTCC from patients with aggressive BTCC in two-tie grading system at 29.86 ng/ml respectively. Further validation assay showed that Apo-A1 could be used as a biomarker to diagnosis BTCC with a sensitivity and specificity of 91.6% and 85.7% respectively, and classify BTCC in two-tie grading system with a sensitivity and specificity of 83.7% and 89.7% respectively. Conclusion Taken together, our findings suggest Apo-A1 could be a potential biomarker related with early diagnosis and classification in two-tie grading system for bladder cancer.
Zhang, Jun; Yao, Duoxi; Su, Yue
2018-02-01
Under the current situation of energy demand, coal is still one of the major energy sources in China for a certain period of time, so the task of coal mine safety production remains arduous. In order to identify the water source of the mine accurately, this article takes the example from Renlou and Tongting coal mines in the northern Anhui mining area. A total of 7 conventional water chemical indexes were selected, including Ca2+, Mg2+, Na++K+, Cl-, SO4 2-, HCO3 - and TDS, to establish a multivariate matrix model for the source identifying inrush water. The results show that the model is simple and is rarely limited by the quantity of water samples, and the recognition effect is ideal, which can be applied to the control and treatment for water inrush.
Vlek, Anneloes; Kolecka, Anna; Khayhan, Kantarawee; Theelen, Bart; Groenewald, Marizeth; Boel, Edwin; Boekhout, Teun
2014-08-01
An interlaboratory study using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to determine the identification of clinically important yeasts (n = 35) was performed at 11 clinical centers, one company, and one reference center using the Bruker Daltonics MALDI Biotyper system. The optimal cutoff for the MALDI-TOF MS score was investigated using receiver operating characteristic (ROC) curve analyses. The percentages of correct identifications were compared for different sample preparation methods and different databases. Logistic regression analysis was performed to analyze the association between the number of spectra in the database and the percentage of strains that were correctly identified. A total of 5,460 MALDI-TOF MS results were obtained. Using all results, the area under the ROC curve was 0.95 (95% confidence interval [CI], 0.94 to 0.96). With a sensitivity of 0.84 and a specificity of 0.97, a cutoff value of 1.7 was considered optimal. The overall percentage of correct identifications (formic acid-ethanol extraction method, score ≥ 1.7) was 61.5% when the commercial Bruker Daltonics database (BDAL) was used, and it increased to 86.8% by using an extended BDAL supplemented with a Centraalbureau voor Schimmelcultures (CBS)-KNAW Fungal Biodiversity Centre in-house database (BDAL+CBS in-house). A greater number of main spectra (MSP) in the database was associated with a higher percentage of correct identifications (odds ratio [OR], 1.10; 95% CI, 1.05 to 1.15; P value of 1.7 for the identification of yeasts using MALDI-TOF MS. The inclusion of enough isolates of the same species in the database can enhance the proportion of correctly identified strains. Further optimization of the preparation methods, especially of the direct transfer method, may contribute to improved diagnosis of yeast-related infections. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
Pizauro, Lucas J L; de Almeida, Camila C; Soltes, Glenn A; Slavic, Durda; Rossi-Junior, Oswaldo D; de Ávila, Fernando A; Zafalon, Luiz F; MacInnes, Janet I
2017-05-01
Incorrect identification of Staphylococcus spp. can have serious clinical and zoonotic repercussions. Accordingly, the aim of this study was to determine if matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and/or cydB real- time quantitative PCR (qPCR) could be used to accurately identify coagulase negative Staphylococcus spp. (CoNS) obtained from buffalo milk and milking environment samples. Seventy-five of 84 CoNS isolates could be identified to the species level (score value >1.99) using MALDI-TOF MS. However, as determined by cytochrome d ubiquinol oxidase subunit II (cydB) qPCR and by 16S RNA and cydB gene sequencing, 10S. agnetis strains were wrongly identified as S. hyicus by MALDI-TOF MS. In addition, 9 isolates identified by MALDI-TOF only to the genus level (score values between 1.70 and 1.99) could be identified to species by cydB qPCR. Our findings suggest that MALDI-TOF MS is a reliable method for rapid identification of S. chromogenes and S. epidermidis (species of interest both in human and veterinary medicine) and may be able to correctly identify other Staphylococcus spp. However, at present not all Staphylococcus spp. found in buffalo milk can be accurately identified by MALDI-TOF MS and for these organisms, the cydB qPCR developed in the current study may provide a reliable alternative method for rapid identification of CoNS species. Copyright © 2017 Elsevier B.V. All rights reserved.
Argemi, Xavier; Riegel, Philippe; Lavigne, Thierry; Lefebvre, Nicolas; Grandpré, Nicolas; Hansmann, Yves; Jaulhac, Benoit; Prévost, Gilles; Schramm, Frédéric
2015-07-01
The use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for staphylococcal identification is now considered routine in laboratories compared with the conventional phenotypical methods previously used. We verified its microbiological relevance for identifying the main species of coagulase-negative staphylococci (CoNS) by randomly selecting 50 isolates. From 1 January 2007 to 31 August 2008, 12,479 staphylococci were isolated with phenotypic methods, of which 4,594 were identified as Staphylococcus aureus and 7,885 were coagulase negative staphylococci. Using MALDI-TOF MS from 1 January 2011 to 31 August 2012, 14,913 staphylococci were identified, with 5,066 as S. aureus and 9,847 as CoNS. MALDI-TOF MS allowed the identification of approximately 85% of the CoNS strains, whereas only 14% of the CoNS strains were identified to the species level with phenotypic methods because they were often considered contaminants. Furthermore, the use of MALDI-TOF MS revealed the occurrence of recently characterized Staphylococcus species, such as S. pettenkoferi, S. condimenti, and S. piscifermentans. Microbiological relevance analysis further revealed that some species displayed a high rate of microbiological significance, i.e., 40% of the S. lugdunensis strains included in the analysis were associated with infection risk. This retrospective microbiological study confirms the role of MALDI-TOF MS in clinical settings for the identification of staphylococci with clinical consequences. The species distribution reveals the occurrence of the recently identified species S. pettenkoferi and putative virulent species, including S. lugdunensis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
DEFF Research Database (Denmark)
Stensballe, A; Jensen, Ole Nørregaard
2001-01-01
/ionization-time of flight mass spectrometry (MALDI-TOF-MS) is used as the first protein screening method in many laboratories because of its inherent simplicity, mass accuracy, sensitivity and relatively high sample throughput. We present a simplified sample preparation method for MALDI-MS that enables in-gel digestion...... for protein identification similar to that obtained by the traditional protocols for in-gel digestion and MALDI peptide mass mapping of human proteins, i.e. approximately 60%. The overall performance of the novel on-probe digestion method is comparable with that of the standard in-gel sample preparation...... of protein samples directly on the MALDI-MS metal probe. Removal of detergent and reagents as well as protein reduction and S-alkylation were performed prior to cutting of protein samples from the polyacrylamide gel slab. The general utility of this approach was demonstrated by on-probe digestion and MALDI...
EISPACK, Subroutines for Eigenvalues, Eigenvectors, Matrix Operations
International Nuclear Information System (INIS)
Garbow, Burton S.; Cline, A.K.; Meyering, J.
1993-01-01
1 - Description of problem or function: EISPACK3 is a collection of 75 FORTRAN subroutines, both single- and double-precision, that compute the eigenvalues and eigenvectors of nine classes of matrices. The package can determine the Eigen-system of complex general, complex Hermitian, real general, real symmetric, real symmetric band, real symmetric tridiagonal, special real tridiagonal, generalized real, and generalized real symmetric matrices. In addition, there are two routines which use the singular value decomposition to solve certain least squares problem. The individual subroutines are - Identification/Description: BAKVEC: Back transform vectors of matrix formed by FIGI; BALANC: Balance a real general matrix; BALBAK: Back transform vectors of matrix formed by BALANC; BANDR: Reduce sym. band matrix to sym. tridiag. matrix; BANDV: Find some vectors of sym. band matrix; BISECT: Find some values of sym. tridiag. matrix; BQR: Find some values of sym. band matrix; CBABK2: Back transform vectors of matrix formed by CBAL; CBAL: Balance a complex general matrix; CDIV: Perform division of two complex quantities; CG: Driver subroutine for a complex general matrix; CH: Driver subroutine for a complex Hermitian matrix; CINVIT: Find some vectors of complex Hess. matrix; COMBAK: Back transform vectors of matrix formed by COMHES; COMHES: Reduce complex matrix to complex Hess. (elementary); COMLR: Find all values of complex Hess. matrix (LR); COMLR2: Find all values/vectors of cmplx Hess. matrix (LR); CCMQR: Find all values of complex Hessenberg matrix (QR); COMQR2: Find all values/vectors of cmplx Hess. matrix (QR); CORTB: Back transform vectors of matrix formed by CORTH; CORTH: Reduce complex matrix to complex Hess. (unitary); CSROOT: Find square root of complex quantity; ELMBAK: Back transform vectors of matrix formed by ELMHES; ELMHES: Reduce real matrix to real Hess. (elementary); ELTRAN: Accumulate transformations from ELMHES (for HQR2); EPSLON: Estimate unit roundoff
Richardson, Thomas M.
2014-01-01
The reciprocal Pascal matrix is the Hadamard inverse of the symmetric Pascal matrix. We show that the ordinary matrix inverse of the reciprocal Pascal matrix has integer elements. The proof uses two factorizations of the matrix of super Catalan numbers.
Robinson, John J; Sharpe, Christopher; Calloway, Carolyn
2003-04-07
We have identified two inducible, gelatin-cleaving activities in the sea urchin extraembryonic matrix, the hyaline layer. Isolated hyaline layers, incubated in the presence of benzamidine, were devoid of gelatin-cleavage activities with apparent molecular mass less then 80k. However, when layers were incubated for 9-11 h in the absence of benzamidine, gelatin-cleavage activities, with apparent molecular mass 40- and 50k, were detected. Induction required the presence of NaCl and CaCl(2) at concentrations similar to those found in seawater and readdition of the reversible serine protease inhibitor benzamidine prevented induction. Both gelatin-cleaving activities were activated by calcium at a concentration similar to the calcium concentration found in seawater. Magnesium, also a major cationic species present in seawater, could not replace calcium as the activating ion. In addition, magnesium could not compete with calcium for binding to the gelatinases. Both cleavage activities showed substrate specificity and each failed to cleave bovine serum albumin, bovine hemoglobin or casein. Cleavage activity towards gelatin was inhibited by benzamidine and aminoethyl benzenesulfonyl fluoride, indicating that both activities belonged to the serine class of proteases. The induced 40-kDa activity displayed similar properties to those of a comigrating, gelatin-cleaving activity present in 69-h-old embryos.
Tarbin, J A; Fussell, R J
2013-06-30
Griseofulvin is an antifungal agent with potential for misuse in food-producing animals. Little is known about its metabolism in ruminants and hence what are suitable marker residues and target matrices for monitoring purposes. Tissues harvested from cattle treated with the antifungal agent griseofulvin were screened using liquid chromatography coupled to positive and negative electrospray ionization (ESI) quadrupole time-of-flight mass spectrometry (qToFMS) operated in ToF mode. Twenty-five possible metabolites were detected across all tissue types, but two isomeric compounds with accurate masses corresponding to loss of a methyl group from parent griseofulvin were considered to be the best candidate markers. Data from fragmentation experiments enabled a tentative assignment of the structures of the two compounds as 4-demethylgriseofulvin and 6-demethylgriseofulvin. These assignments were confirmed by matching the product ion spectra of incurred residues to those of custom synthesized reference standards. 4-Demethyl- and 6-demethylgriseofulvin have been identified as potential marker compounds of griseofulvin use in cattle. Liver was identified as the target matrix. Hair was shown to have potential for non-invasive testing. © Crown copyright 2013. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Rudrik, James T.; Perry, Michael J.; Sullivan, Maureen M.; Reiter-Kintz, Wanda; Lee, Philip A.; Pettit, Denise; Tran, Anthony; Swaney, Erin
2017-01-01
ABSTRACT Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) sample preparation methods, including the direct, on-plate formic acid, and ethanol/formic acid tube extraction methods, were evaluated for their ability to render highly pathogenic organisms nonviable and safe for handling in a biosafety level 2 laboratory. Of these, the tube extraction procedure was the most successful, with none of the tested strains surviving this sample preparation method. Tube extracts from several agents of bioterrorism and their near neighbors were analyzed in an eight-laboratory study to examine the utility of the Bruker Biotyper and Vitek MS MALDI-TOF MS systems and their in vitro diagnostic (IVD), research-use-only, and Security-Relevant databases, as applicable, to accurately identify these agents. Forty-six distinct strains of Bacillus anthracis, Yersinia pestis, Francisella tularensis, Burkholderia mallei, Burkholderia pseudomallei, Clostridium botulinum, Brucella melitensis, Brucella abortus, Brucella suis, and Brucella canis were extracted and distributed to participating laboratories for analysis. A total of 35 near-neighbor isolates were also analyzed. PMID:29021156
Zhan, Xingzhi
2002-01-01
The main purpose of this monograph is to report on recent developments in the field of matrix inequalities, with emphasis on useful techniques and ingenious ideas. Among other results this book contains the affirmative solutions of eight conjectures. Many theorems unify or sharpen previous inequalities. The author's aim is to streamline the ideas in the literature. The book can be read by research workers, graduate students and advanced undergraduates.
Nguyen Lan, Tran; Kurashige, Yuki; Yanai, Takeshi
2015-01-13
We have developed a new computational scheme for high-accuracy prediction of the isotropic hyperfine coupling constant (HFCC) of heavy molecules, accounting for the high-level electron correlation effects, as well as the scalar-relativistic effects. For electron correlation, we employed the ab initio density matrix renormalization group (DMRG) method in conjunction with a complete active space model. The orbital-optimization procedure was employed to obtain the optimized orbitals required for accurately determining the isotropic HFCC. For the scalar-relativistic effects, we initially derived and implemented the Douglas-Kroll-Hess (DKH) hyperfine coupling operators up to the third order (DKH3) by using the direct transformation scheme. A set of 4d transition-metal radicals consisting of Ag atom, PdH, and RhH2 were chosen as test cases. Good agreement between the isotropic HFCC values obtained from DMRG/DKH3 and experiment was archived. Because there are no available gas-phase values for PdH and RhH2 radicals in the literature, the results from the present high-level theory may serve as benchmark data.
Suzuki, Shigeki; Hoshino, Hiroaki; Yoshida, Kazuma; Nakanishi, Jun; Tsuchiya-Hirata, Shizu; Kobuke, Seiji; Haruyama, Naoto; Nishimura, Fusanori; Shiba, Hideki
2018-01-15
Chromatin-enriched noncoding RNAs (ncRNAs) have emerged as key molecules in epigenetic processes by interacting with chromatin-associated proteins. Recently, protein-coding mRNA genes have been reported to be chromatin-tethered, similar with ncRNA. However, very little is known about whether chromatin-enriched mRNA is involved in the chromatin modification process. Here, we comprehensively examined chromatin-enriched RNA in squamous cell carcinoma (SQCC) cells by RNA subcellular localization analysis, which was a combination of RNA fractionation and RNA-seq. We identified 11 mRNAs as highly chromatin-enriched RNAs. Among these, we focused on the dentin matrix protein-1 (DMP-1) gene because its expression in SQCC cells has not been reported. Furthermore, we clarified that DMP-1 mRNA was retained in chromatin in its unspliced form in SQCC in vitro and in vivo. As the inhibition of the unspliced DMP-1 mRNA (unspDMP-1) expression resulted in decreased cellular proliferation in SQCC cells, we performed ChIP-qPCR to identify cell cycle-related genes whose expression was epigenetically modified by unspDMP-1, and found that the CDKN1B promoter became active in SQCC cells by inhibiting unspDMP-1 expression. This result was further validated by the increased CDKN1B gene expression in the cells treated with siRNA for unspDMP-1 and by restoration of the decreased cellular proliferation rate by simultaneously inhibiting CDKN1B expression in SQCC cells. Further, to examine whether unspDMP-1 was able to associate with the CDKN1B promoter region, SQCC cells stably expressing PP7-mCherry fusion protein were transiently transfected with the unspDMP-1 fused to 24 repeats of the PP7 RNA stem loop (unspDMP-1-24xPP7) and we found that unspDMP-1-24xPP7 was efficiently precipitated with the antibody against mCherry and was significantly enriched in the CDKN1B promoter region. Thus, unspDMP-1 is a novel chromatin-enriched RNA that epigenetically regulates cellular proliferation of SQCC
Directory of Open Access Journals (Sweden)
Naiara Miranda Bento Rodrigues
Full Text Available Abstract Mastitis adversely affects milk production and in general cows do not regain their full production levels post recovery, leading to considerable economic losses. Moreover the percentage decrease in milk production depends on the specific pathogen that caused the infection and enterobacteria are responsible for this greater reduction. Phenotypic tests are among the currently available methods used worldwide to identify enterobacteria; however they tend to misdiagnose the species despite the multiple tests carried out. On the other hand The Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS technique has been attracting attention for its precise identification of several microorganisms at species level. In the current study, 183 enterobacteria were detected in milk (n = 47 and fecal samples (n = 94 from cows, and samples from water (n = 23 and milk lines (n = 19. All these samples were collected from a farm in Rio de Janeiro with the specific purpose of presenting the MALDI-TOF MS technique as an efficient methodology to identify Enterobacteriaceae from bovine environments. The MALDI-TOF MS technique results matched the biochemical test results in 92.9% (170/183 of the enterobacteria species and the gyrB sequencing confirmed 100% of the proteomic technique results. The amino acid decarboxylation test made the most misidentifications and Enterobacter spp. was the most misidentified genus (76.9%, 10/13. These results aim to clarify the current biochemical errors in enterobacteria identification, considering isolates from a bovine environment, and show the importance for more careful readings of phenotypic tests which are often used in veterinary microbiology laboratories.
Han, Jingqi; Zhang, Xin; Li, Hao; Hou, Yue; Hou, Jingdan; Li, Zhongfeng; Yang, Feng; Liu, Yang; Han, Tianyu
2018-02-01
In this work, we synthesize a series of compounds with electron donor (D) and acceptor (A) units. They show general solvent effect in aprotic solvents, suggesting a charge transfer (CT) process. While in protic solvents including water, ethanol and methanol, the spectra exert no polarity-dependence but a remarkable hypochromatic shift together with the fading of CT band. Dynamic analysis implies that intermolecular hydrogen bond will be formed between carboxylic acid and protic solvent, boosting another deactivation pathway that jumps off a bigger energy gap, in other words, favoring the locally excited (LE) state emission. The CT-LE transition involves variations in both absorption and emission spectra, and further poses competition with other mechanisms including activated/restricted intramolecular rotation (IR/RIR). Inspired by the cross-reactivity, we turn our attention to the development of sensor array, in order to identify white wine varieties. The differential spectral responses are recorded, generating multiple factors including absorption wavelength (λab), emission wavelength (λem), absorbance (Abs.) and emission intensity (Int.). These factors are processed with principal component analysis (PCA), creating a three-dimensional fingerprint data base for white wines. The data points in the coordinate system are clustered into 10 different groups, demonstrating a clear differentiation of all the white wines. More importantly, as our final test for whether the sensor array can identify the counterfeits, an adulterated liquor sample, which is provided by police officers, is fingerprinted on the three-dimensional diagram. Its canonical factors fall into an area distinct from the adulterated wine, indicating a clear identification.
Nowakiewicz, Aneta; Ziółkowska, Grażyna; Zięba, Przemysław; Trościańczyk, Aleksandra; Banach, Tomasz; Kowalski, Cezary
2015-03-01
Fast and reliable identification of bacteria to at least the species level is currently the basis for correct diagnosis and appropriate treatment of infections. This is particularly important in the case of bacteria of the genus Enterococcus, whose resistance profile is often correlated with their species (e.g. resistance to vancomycin). In this study, we evaluated restriction endonuclease analysis of the 16S-23S rRNA gene intergenic transcribed spacer (ITS) region for species identification of Enterococcus. The utility of the method was compared with that of phenotypic methods [biochemical profile evaluation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)]. Identification was based on 21 Enterococcus reference strains, of the species E. faecalis, E. faecium, E. hirae, E. durans, E. casseliflavus, E. gallinarum, E. avium, E. cecorum and E. columbae, and 47 Enterococcus field strains isolated from pigs. Restriction endonuclease analysis of the ITS-PCR product using HinfI, RsaI and MboI, in the order specified, enabled species differentiation of the Enterococcus reference and field strains, and in the case of the latter, the results of species identification were identical (47/47) to those obtained by MALDI-TOF MS. Moreover, as a result of digestion with MboI, a unique restriction profile was also obtained for the strains (3/3) identified by MALDI-TOF MS as E. thailandicus. In our opinion, restriction endonuclease analysis of the 16S-23S rRNA gene ITS region of Enterococcus may be a simple and relatively fast (less than 4 h) alternative method for identifying the species occurring most frequently in humans and animals. © 2015 The Authors.
Directory of Open Access Journals (Sweden)
Idalia Estefania Ponce Jaramillo
2016-01-01
Full Text Available Introducción: La innovación es reconocida como una actividad esencial para aumentar la competitividad de un país Etzkowitz define el modelo de la triple hélice para el proceso de innovación en el cual se describe la relación entre la interacción industria-academia-gobierno en una institución, región o país. En las últimas dos décadas México ha adoptado gradualmente un enfoque tecnológico, mediante el cambio y la implementación de políticas tecnológicas, que incluyen la transformación del a industria, el gobierno y la academia. Una de las mayores dificultades ha sido la implementación de esas políticas dentro de las instituciones académicas debido a su organización y estructura. Método: Se usó la metodología de matrix del estado del arte (SAM con el objetivo de colectar, compilar y analizar la literatura disponible sobre el tema de innovación y triple hélice en México. La selección de la literatura se realizó buscando artículos de revistar científicas, libros, conferencias relacionadas con el modelo de la triple hélice, en bases de datos digitales y libros impresos en México. Posteriormente se codificaron los artículos encontrados y usando diagramas de afinidad (matrices y se clasificaron en tres tipos de factores: internos, estructurales y ambientales. Resultados: El principal objetivo de la academia en México es la educación, la cual carece de una visión innovadora. Esto tiene como consecuencia que a pesar de los esfuerzos para lograr la vinculación, el número de proyectos de vinculación entre la academia y la industria sea mínimo. Conclusión: En los últimos 20 años ha habido un incremento en el número de investigaciones sobre el modelo de la triple hélice de la innovación en México, debido a la desarticulación de los actores en México. Los investigadores han estudiado la situación y descrito las áreas de oportunidad, experiencias y mejores prácticas, con la finalidad de compartir, trasmitir
Bhatia, Rajendra
1997-01-01
A good part of matrix theory is functional analytic in spirit. This statement can be turned around. There are many problems in operator theory, where most of the complexities and subtleties are present in the finite-dimensional case. My purpose in writing this book is to present a systematic treatment of methods that are useful in the study of such problems. This book is intended for use as a text for upper division and gradu ate courses. Courses based on parts of the material have been given by me at the Indian Statistical Institute and at the University of Toronto (in collaboration with Chandler Davis). The book should also be useful as a reference for research workers in linear algebra, operator theory, mathe matical physics and numerical analysis. A possible subtitle of this book could be Matrix Inequalities. A reader who works through the book should expect to become proficient in the art of deriving such inequalities. Other authors have compared this art to that of cutting diamonds. One first has to...
Matrix groups for undergraduates
Tapp, Kristopher
2016-01-01
Matrix groups touch an enormous spectrum of the mathematical arena. This textbook brings them into the undergraduate curriculum. It makes an excellent one-semester course for students familiar with linear and abstract algebra and prepares them for a graduate course on Lie groups. Matrix Groups for Undergraduates is concrete and example-driven, with geometric motivation and rigorous proofs. The story begins and ends with the rotations of a globe. In between, the author combines rigor and intuition to describe the basic objects of Lie theory: Lie algebras, matrix exponentiation, Lie brackets, maximal tori, homogeneous spaces, and roots. This second edition includes two new chapters that allow for an easier transition to the general theory of Lie groups. From reviews of the First Edition: This book could be used as an excellent textbook for a one semester course at university and it will prepare students for a graduate course on Lie groups, Lie algebras, etc. … The book combines an intuitive style of writing w...
Leipert, Jan; Treitz, Christian; Leippe, Matthias; Tholey, Andreas
2017-12-01
N-acyl homoserine lactones (AHL) are small signal molecules involved in the quorum sensing of many gram-negative bacteria, and play an important role in biofilm formation and pathogenesis. Present analytical methods for identification and quantification of AHL require time-consuming sample preparation steps and are hampered by the lack of appropriate standards. By aiming at a fast and straightforward method for AHL analytics, we investigated the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Suitable MALDI matrices, including crystalline and ionic liquid matrices, were tested and the fragmentation of different AHL in collision-induced dissociation MS/MS was studied, providing information about characteristic marker fragments ions. Employing small-scale synthesis protocols, we established a versatile and cost-efficient procedure for fast generation of isotope-labeled AHL standards, which can be used without extensive purification and yielded accurate standard curves. Quantitative analysis was possible in the low pico-molar range, with lower limits of quantification reaching from 1 to 5 pmol for different AHL. The developed methodology was successfully applied in a quantitative MALDI MS analysis of low-volume culture supernatants of Pseudomonas aeruginosa. [Figure not available: see fulltext.
The Matrix Element Method and Vector-Like Quark Searches
Morrison, Benjamin
2016-01-01
In my time at the CERN summer student program, I worked on applying the matrix element method to vector-like quark identification. I worked in the ATLAS University of Geneva group under Dr. Olaf Nackenhorst. I developed automated plotting tools with ROOT, a script for implementing and optimizing generated matrix element calculation code, and kinematic transforms for the matrix element method.
Stamm, Ivonne; Hailer, Mandy; Depner, Barbara; Kopp, Peter A.
2013-01-01
Yersinia enterocolitica is the main cause of yersiniosis in Europe, one of the five main bacterial gastrointestinal diseases of humans. Beside pigs, companion animals, especially dogs and cats, were repeatedly discussed in the past as a possible source of pathogenic Y. enterocolitica. To investigate the presence and types of Y. enterocolitica in companion animals, a total of 4,325 diagnostic fecal samples from dogs and 2,624 samples from cats were tested. The isolates obtained were differentiated by using matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared spectroscopy (FT-IR). Isolated Y. enterocolitica strains were bioserotyped. The detection of the ail gene by PCR and confirmation by FT-IR were used as a pathogenicity marker. Y. enterocolitica strains were isolated from 198 (4.6%) of the dog and 8 (0.3%) of the cat fecal samples investigated. One hundred seventy-nine isolates from dogs were analyzed in detail. The virulence factor Ail was detected in 91.6% of isolates. Isolates of biotype 4 (54.7%) and, to a lesser extent, biotypes 2 (23.5%), 3 (11.2%), and 5 (2.2%) were detected. The remaining 8.4% of strains belonged to the ail-negative biotype 1A. All 7 isolates from cats that were investigated in detail were ail positive. These results indicate that companion animals could be a relevant reservoir for a broad range of presumptively human-pathogenic Y. enterocolitica types. MALDI-TOF MS and FT-IR proved to be valuable methods for the rapid identification of Y. enterocolitica, especially in regard to the large number of samples that were investigated in a short time frame. PMID:23284028
Stamm, Ivonne; Hailer, Mandy; Depner, Barbara; Kopp, Peter A; Rau, Jörg
2013-03-01
Yersinia enterocolitica is the main cause of yersiniosis in Europe, one of the five main bacterial gastrointestinal diseases of humans. Beside pigs, companion animals, especially dogs and cats, were repeatedly discussed in the past as a possible source of pathogenic Y. enterocolitica. To investigate the presence and types of Y. enterocolitica in companion animals, a total of 4,325 diagnostic fecal samples from dogs and 2,624 samples from cats were tested. The isolates obtained were differentiated by using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared spectroscopy (FT-IR). Isolated Y. enterocolitica strains were bioserotyped. The detection of the ail gene by PCR and confirmation by FT-IR were used as a pathogenicity marker. Y. enterocolitica strains were isolated from 198 (4.6%) of the dog and 8 (0.3%) of the cat fecal samples investigated. One hundred seventy-nine isolates from dogs were analyzed in detail. The virulence factor Ail was detected in 91.6% of isolates. Isolates of biotype 4 (54.7%) and, to a lesser extent, biotypes 2 (23.5%), 3 (11.2%), and 5 (2.2%) were detected. The remaining 8.4% of strains belonged to the ail-negative biotype 1A. All 7 isolates from cats that were investigated in detail were ail positive. These results indicate that companion animals could be a relevant reservoir for a broad range of presumptively human-pathogenic Y. enterocolitica types. MALDI-TOF MS and FT-IR proved to be valuable methods for the rapid identification of Y. enterocolitica, especially in regard to the large number of samples that were investigated in a short time frame.
Directory of Open Access Journals (Sweden)
Yumao Jiang
2018-03-01
Full Text Available As shown in our previous study, sinomenine hydrochloride (SH, the major bioactive alkaloid isolated from Sinomenium acutum Rehd. et Wils. (Fam. Menispermaceae, initiates the autophagy-mediated death of human glioblastoma cells by generating reactive oxygen species and activating the autophagy-lysosome pathway. However, its effects on the migration and invasion of human glioblastoma cells have not yet been elucidated. Therefore, human glioblastoma U87 and SF767 cells were treated with SH (0.125 and 0.25 mM for 24 h, and cell migration and invasion were assessed using scratch wound healing, migration and invasion assays. SH promoted G0/G1 phase arrest, inhibited the migration and invasion of the two cell lines, suppressed the activation of nuclear factor kappa B (NFκB and the expression of matrix metalloproteinase (MMP-2/-9, triggered endoplasmic reticulum (ER stress, reversed the exogenous epithelial-mesenchymal transition (EMT induced by the inflammatory microenvironment and the endogenous EMT. Additionally, NFκB p65 overexpression blocked the SH-mediated inhibitory effects on MMP-2/-9 expression and cell invasion. SH-induced autophagy was reduced in CCAAT/enhancer binding protein (C/EBP homologous protein (CHOP or autophagy-related 5 (ATG5-silenced human glioblastoma cells and cells treated with 4-phenylbutyric acid (4-PBA or 3-methyladenine (3-MA, as shown by the decreased levels of the microtubule-associated protein light chain 3B (LC3B-II and autophagic vacuoles (AVs stained with monodansylcadaverine (MDC, respectively. Moreover, knockdown of CHOP or ATG5 and treatment with 4-PBA or 3-MA abolished the SH-mediated inhibition of mesenchymal markers (vimentin, Snail and Slug expression and cell invasion, respectively. Importantly, SH also regulated the above related pathways in nude mice. Based on these findings, SH inhibited cell proliferation by inducing cell cycle arrest, and attenuated the metastasis of U87 and SF767 cells by suppressing
Material parameter identification on metal matrix composites
CSIR Research Space (South Africa)
Jansen van Rensburg, GJ
2012-07-01
Full Text Available of the material, compression tests were only performed to about 2% uniaxial strain as measured by the displacement of the hydraulic cylinder. In room temperature tests, three strain gauges are secured evenly around the centre of the test section. The results from...
The cellulose resource matrix.
Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G
2013-03-01
The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the
Hebard, A.F.; Palstra, T.T.M.
1989-01-01
Analysis of resistive transitions of YBa2Cu3O7, crystals reveals a scaling behavior which identifies the vortex-depinning critical field Hcp, hence the crossover in behavior from flux creep to flux flow. The inferred Hcp for YBa2Cu3O7 crystals closely approximates the magnitude and temperature
Efficiency criterion for teleportation via channel matrix, measurement matrix and collapsed matrix
Directory of Open Access Journals (Sweden)
Xin-Wei Zha
Full Text Available In this paper, three kinds of coefficient matrixes (channel matrix, measurement matrix, collapsed matrix associated with the pure state for teleportation are presented, the general relation among channel matrix, measurement matrix and collapsed matrix is obtained. In addition, a criterion for judging whether a state can be teleported successfully is given, depending on the relation between the number of parameter of an unknown state and the rank of the collapsed matrix. Keywords: Channel matrix, Measurement matrix, Collapsed matrix, Teleportation
Extended biorthogonal matrix polynomials
Directory of Open Access Journals (Sweden)
Ayman Shehata
2017-01-01
Full Text Available The pair of biorthogonal matrix polynomials for commutative matrices were first introduced by Varma and Tasdelen in [22]. The main aim of this paper is to extend the properties of the pair of biorthogonal matrix polynomials of Varma and Tasdelen and certain generating matrix functions, finite series, some matrix recurrence relations, several important properties of matrix differential recurrence relations, biorthogonality relations and matrix differential equation for the pair of biorthogonal matrix polynomials J(A,B n (x, k and K(A,B n (x, k are discussed. For the matrix polynomials J(A,B n (x, k, various families of bilinear and bilateral generating matrix functions are constructed in the sequel.
Energy Technology Data Exchange (ETDEWEB)
Grcar, Joseph F.
2002-02-04
A matrix lower bound is defined that generalizes ideas apparently due to S. Banach and J. von Neumann. The matrix lower bound has a natural interpretation in functional analysis, and it satisfies many of the properties that von Neumann stated for it in a restricted case. Applications for the matrix lower bound are demonstrated in several areas. In linear algebra, the matrix lower bound of a full rank matrix equals the distance to the set of rank-deficient matrices. In numerical analysis, the ratio of the matrix norm to the matrix lower bound is a condition number for all consistent systems of linear equations. In optimization theory, the matrix lower bound suggests an identity for a class of min-max problems. In real analysis, a recursive construction that depends on the matrix lower bound shows that the level sets of continuously differential functions lie asymptotically near those of their tangents.
Matrix completion by deep matrix factorization.
Fan, Jicong; Cheng, Jieyu
2018-02-01
Conventional methods of matrix completion are linear methods that are not effective in handling data of nonlinear structures. Recently a few researchers attempted to incorporate nonlinear techniques into matrix completion but there still exists considerable limitations. In this paper, a novel method called deep matrix factorization (DMF) is proposed for nonlinear matrix completion. Different from conventional matrix completion methods that are based on linear latent variable models, DMF is on the basis of a nonlinear latent variable model. DMF is formulated as a deep-structure neural network, in which the inputs are the low-dimensional unknown latent variables and the outputs are the partially observed variables. In DMF, the inputs and the parameters of the multilayer neural network are simultaneously optimized to minimize the reconstruction errors for the observed entries. Then the missing entries can be readily recovered by propagating the latent variables to the output layer. DMF is compared with state-of-the-art methods of linear and nonlinear matrix completion in the tasks of toy matrix completion, image inpainting and collaborative filtering. The experimental results verify that DMF is able to provide higher matrix completion accuracy than existing methods do and DMF is applicable to large matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Fazio, T.
1995-01-01
This thesis presents a work included in an experiment of research concerning neutrino oscillations in the channel ν μ → ν τ at CERN (NOMAD-WA96). This experiments need several detectors, and particularly a transition radiation detector with specific characteristics. The work consists, in a first part, in the study of neutrino physic and of the NOMAD detector. In a second part, the report presents how was implemented the transition radiation detector and how works the simulation of a such radiation. Then, the detector is optimised by comparing experiments and simulations; the thesis also presents how to control the detector. The last part talks about algorithms of pions-electrons separation. (TEC). 95 refs., 78 figs., 12 tabs
Interpreting the change detection error matrix
Oort, van P.A.J.
2007-01-01
Two different matrices are commonly reported in assessment of change detection accuracy: (1) single date error matrices and (2) binary change/no change error matrices. The third, less common form of reporting, is the transition error matrix. This paper discuses the relation between these matrices.
Data-Driven Learning of Q-Matrix
Liu, Jingchen; Xu, Gongjun; Ying, Zhiliang
2012-01-01
The recent surge of interests in cognitive assessment has led to developments of novel statistical models for diagnostic classification. Central to many such models is the well-known "Q"-matrix, which specifies the item-attribute relationships. This article proposes a data-driven approach to identification of the "Q"-matrix and estimation of…
DEFF Research Database (Denmark)
Petersen, Kaare Brandt; Pedersen, Michael Syskind
Matrix identities, relations and approximations. A desktop reference for quick overview of mathematics of matrices.......Matrix identities, relations and approximations. A desktop reference for quick overview of mathematics of matrices....
Stochastic Matrix Factorization
Adams, Christopher
2016-01-01
This paper considers a restriction to non-negative matrix factorization in which at least one matrix factor is stochastic. That is, the elements of the matrix factors are non-negative and the columns of one matrix factor sum to 1. This restriction includes topic models, a popular method for analyzing unstructured data. It also includes a method for storing and finding pictures. The paper presents necessary and sufficient conditions on the observed data such that the factorization is unique. I...
International Nuclear Information System (INIS)
Avakyan, R.A.; Avakyan, K.M.; Alikhanyan, A.I.
1974-01-01
The spectrum of cosmic hadrons with an energy of 300 GeV or more at the height of 3250 m above the sea level has been studied. The objective has been to determine the Nsub(π)/Nsub(p) ratio at the given energies. The device consists of a 830 g/cm 2 scintillation calorimeter and an X-ray transition radiation detector, comprising three sections of laminated medium each having 200 layers, and multi-filament proportional counters. The lower limit of the Nsub(π)/Nsub(p) ratio has been obtained, it is equal to 0.37+-0.16
Phase identification and superconducting transitions in Sr-doped Pr1.85Ce0.15CuO4+δ
International Nuclear Information System (INIS)
Varela, A.; Vallet-Regi, M.; Gonazalez-Calbet, J.M.
1997-01-01
Sr-doped Pr 1.85 Ce 0.15 CuO 4+δ samples have been prepared with accurate control of the oxygen content. The stability of both T ' and T * phases is strongly dependent on Sr and oxygen content. An electron diffraction study indicates that, in some cases, anionic vacancies are ordered leading to a pseudo-tetragonal superlattice with unit cell parameters 2√2a t xc t . Structural transitions and superconducting phases created by hole doping in such a system are also reported. copyright 1997 Materials Research Society
Matrix with Prescribed Eigenvectors
Ahmad, Faiz
2011-01-01
It is a routine matter for undergraduates to find eigenvalues and eigenvectors of a given matrix. But the converse problem of finding a matrix with prescribed eigenvalues and eigenvectors is rarely discussed in elementary texts on linear algebra. This problem is related to the "spectral" decomposition of a matrix and has important technical…
Transition Metal Compounds Towards Holography
Directory of Open Access Journals (Sweden)
Volker Dieckmann
2012-06-01
Full Text Available We have successfully proposed the application of transition metal compounds in holographic recording media. Such compounds feature an ultra-fast light-induced linkage isomerization of the transition-metal–ligand bond with switching times in the sub-picosecond regime and lifetimes from microseconds up to hours at room temperature. This article highlights the photofunctionality of two of the most promising transition metal compounds and the photophysical mechanisms that are underlying the hologram recording. We present the latest progress with respect to the key measures of holographic media assembled from transition metal compounds, the molecular embedding in a dielectric matrix and their impressive potential for modern holographic applications.
Martinez-Vazquez, Azul; Gonzalez-Hernandez, Angelica; Domínguez, Ángel; Rachubinski, Richard; Riquelme, Meritxell; Cuellar-Mata, Patricia; Guzman, Juan Carlos Torres
2013-01-01
The dimorphic yeast Yarrowia lipolytica is used as a model to study fungal differentiation because it grows as yeast-like cells or forms hyphal cells in response to changes in environmental conditions. Here, we report the isolation and characterization of a gene, ZNC1, involved in the dimorphic transition in Y. lipolytica. The ZNC1 gene encodes a 782 amino acid protein that contains a Zn(II)2C6 fungal-type zinc finger DNA-binding domain and a leucine zipper domain. ZNC1 transcription is elevated during yeast growth and decreases during the formation of mycelium. Cells in which ZNC1 has been deleted show increased hyphal cell formation. Znc1p-GFP localizes to the nucleus, but mutations within the leucine zipper domain of Znc1p, and to a lesser extent within the Zn(II)2C6 domain, result in a mislocalization of Znc1p to the cytoplasm. Microarrays comparing gene expression between znc1::URA3 and wild-type cells during both exponential growth and the induction of the yeast-to-hypha transition revealed 1,214 genes whose expression was changed by 2-fold or more under at least one of the conditions analyzed. Our results suggest that Znc1p acts as a transcription factor repressing hyphal cell formation and functions as part of a complex network regulating mycelial growth in Y. lipolytica. PMID:23826133
Matthews, Nicole L; Malligo, Amanda; Smith, Christopher J
2017-12-01
Little is known about specific adaptive functioning impairments in intellectually-able individuals with autism spectrum disorder. In adolescents (n = 22) and young adults (n = 22) matched on composite IQ scores, this study examined profiles of cognitive and adaptive functioning, and caregiver responses on individual Vineland-II items. Adaptive functioning standard scores were significantly lower than IQ scores, and the adult group had significantly lower adaptive functioning standard scores than the adolescent group. Examination of caregiver responses to individual Vineland-II items identified more than 100 potential intervention targets. Differences favoring the adult group were observed on only 16 items across all three adaptive functioning domains, suggesting that little skill development is occurring during the transition to adulthood. Future research will examine the relevance of identified intervention targets to optimal outcomes. Autism Res 2017, 10: 2023-2036. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Adolescents and young adults with autism spectrum disorder (ASD) without intellectual disability demonstrated impaired adaptive functioning skills (i.e., age appropriate skills necessary for independent living). Development of adaptive functioning skills appears to slow with age among individuals without intellectual disability. Findings clarify the specific adaptive functioning skills that transition-aged youth with ASD have difficulty completing independently and will inform the development of interventions to increase the likelihood of independent living in adulthood. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
International Nuclear Information System (INIS)
Marzban, C.; Viswanathan, R.R.
1990-12-01
Within the framework of c = 1 matrix models, we consider multi-matrix models. A connection is established between a D-dimensional gas of fermions (bosons) for odd (even) values of D. A statistical mechanical analysis yields the scaling law for the free energy, and hence the susceptibility exponents for the various models. The exponents turn out to be positive for the multi-matrix models, suggesting that these could represent models of 2 d-gravity coupled to c>1 matter. Whereas in the c=1 case the density of states itself diverges as one approaches the critical point, in the D-matrix models various derivatives of the density of states diverge, with the order of the derivative depending on D. This qualitatively different behaviour of the density of states could be a signal of the conjectured ''phase transition'' at c=1. (author). 14 refs
Kassim, Ali; Pflüger, Valentin; Premji, Zul; Daubenberger, Claudia; Revathi, Gunturu
2017-05-25
MALDI-TOF MS is an analytical method that has recently become integral in the identification of microorganisms in clinical laboratories. It relies on databases that majorly employ pattern recognition or fingerprinting. Biomarker based databases have also been developed and there is optimism that these may be superior to pattern recognition based databases. This study compared the performance of ribosomal biomarker based MALDI-TOF MS and conventional methods in the identification of selected bacteria and yeast. The study was a cross sectional study identifying clinically relevant bacteria and yeast isolated from varied clinical specimens submitted to a clinical laboratory. The identification of bacteria using conventional Vitek 2™ automated system, serotyping and MALDI-TOF MS was performed as per standard operating procedures. Comparison of sensitivities were then carried out using Pearson Chi-Square test and p-value of bacteria and Gram positive bacteria to the species level. For the Gram positive bacteria, significant difference was observed in the identification of Coagulase negative Staphylococci (p = 0.000) and Enterococcus (p = 0.008). Significant difference was also observed between serotyping and MALDI-TOF MS (p = 0.005) and this was attributed to the lack of identification of Shigella species by MALDI-TOF MS. There was no significant difference observed in the identification of yeast however some species of Candida were unidentified by MALDI-TOF MS. Biomarker based MALDI-TOF MS had good performance in a clinical laboratory setting with high sensitivities in the identification of clinically relevant microorganisms.
Ayeni, Funmilola A; Andersen, Camilla; Nørskov-Lauritsen, Niels
2017-04-01
Mannitol salt agar (MSA) is often used in resources' limited laboratories for identification of S. aureus however, coagulase-negative staphylococci (CoNS) grows and ferments mannitol on MSA. 171 strains of CoNS which have been previously misidentified as S. aureus due to growth on MSA were collected from different locations in Nigeria and two methods for identification of CoNS were compared i.e. ViTEK 2 and MALDI-TOF MS with partial 16S rRNA gene sequencing as gold standard. Partial tuf gene sequencing was used for contradicting identification. All 171 strains (13 species) grew on MSA and ferments mannitol. All tested strains of S. epidermidis, S. haemolyticus, S. nepalensis, S. pasteuri, S. sciuri,, S. warneri, S. xylosus, S. capitis were correctly identified by MALDI-TOF while variable identification were observed in S. saprophyticus and S. cohnii (90%, 81%). There was low identification of S. arlettae (14%) while all strains of S. kloosii and S. gallinarum were misidentified. There is absence of S. gallinarum in the MALDI-TOF database at the period of this study. All tested strains of S. epidermidis, S. gallinarum, S. haemolyticus, S. sciuri,, S. warneri, S. xylosus and S. capitis were correctly identified by ViTEK while variable identification were observed in S. saprophyticus, S. arlettae, S. cohnii, S. kloosii, (84%, 86%, 75%, 60%) and misidentification of S. nepalensis, S. pasteuri. Partial sequencing of 16S rRNA gene was used as gold standard for most strains except S. capitis and S. xylosus where the two species were misidentified by partial sequencing of 16S rRNA contrary to MALDI-TOF and ViTEK identification. Tuf gene sequencing was used for correct identification. Characteristic growth on MSA for CoNS is also identical to S. aureus growth on the media and therefore, MSA could not differentiate between S. aureus and CoNS. The percentage accuracy of ViTEK was better than MALDI-TOF in identification of CoNS. Although partial sequencing of
Hicks, Julie A; Porter, Tom E; Liu, Hsiao-Ching
2017-09-05
The transition from embryonic to posthatch development in the chicken represents a massive metabolic switch from primarily lipolytic to primarily lipogenic metabolism. This metabolic switch is essential for the chick to successfully transition from the metabolism of stored egg yolk to the utilization of carbohydrate-based feed. However, regulation of this metabolic switch is not well understood. We hypothesized that microRNAs (miRNAs) play an important role in the metabolic switch that is essential to efficient growth of chickens. We used high-throughput RNA sequencing to characterize expression profiles of mRNA and miRNA in liver during late embryonic and early posthatch development of the chicken. This extensive data set was used to define the contributions of microRNAs to the metabolic switch during development that is critical to growth and nutrient utilization in chickens. We found that expression of over 800 mRNAs and 30 miRNAs was altered in the embryonic liver between embryonic day 18 and posthatch day 3, and many of these differentially expressed mRNAs and miRNAs are associated with metabolic processes. We confirmed the regulation of some of these mRNAs by miRNAs expressed in a reciprocal pattern using luciferase reporter assays. Finally, through the use of yeast one-hybrid screens, we identified several proteins that likely regulate expression of one of these important miRNAs. Integration of the upstream regulatory mechanisms governing miRNA expression along with monitoring the downstream effects of this expression will ultimately allow for the construction of complete miRNA regulatory networks associated with the hepatic metabolic switch in chickens. Our findings support a key role for miRNAs in controlling the metabolic switch that occurs between embryonic and posthatch development in the chicken.
Parameter identification in the logistic STAR model
DEFF Research Database (Denmark)
Ekner, Line Elvstrøm; Nejstgaard, Emil
We propose a new and simple parametrization of the so-called speed of transition parameter of the logistic smooth transition autoregressive (LSTAR) model. The new parametrization highlights that a consequence of the well-known identification problem of the speed of transition parameter is that th......We propose a new and simple parametrization of the so-called speed of transition parameter of the logistic smooth transition autoregressive (LSTAR) model. The new parametrization highlights that a consequence of the well-known identification problem of the speed of transition parameter...
DEFF Research Database (Denmark)
Gissel, Line Engbo
This presentation builds on an earlier published article, 'Contemporary Transitional Justice: Normalising a Politics of Exception'. It argues that the field of transitional justice has undergone a shift in conceptualisation and hence practice. Transitional justice is presently understood...... to be the provision of ordinary criminal justice in contexts of exceptional political transition....
Finding a Hadamard matrix by simulated annealing of spin vectors
Bayu Suksmono, Andriyan
2017-05-01
Reformulation of a combinatorial problem into optimization of a statistical-mechanics system enables finding a better solution using heuristics derived from a physical process, such as by the simulated annealing (SA). In this paper, we present a Hadamard matrix (H-matrix) searching method based on the SA on an Ising model. By equivalence, an H-matrix can be converted into a seminormalized Hadamard (SH) matrix, whose first column is unit vector and the rest ones are vectors with equal number of -1 and +1 called SH-vectors. We define SH spin vectors as representation of the SH vectors, which play a similar role as the spins on Ising model. The topology of the lattice is generalized into a graph, whose edges represent orthogonality relationship among the SH spin vectors. Starting from a randomly generated quasi H-matrix Q, which is a matrix similar to the SH-matrix without imposing orthogonality, we perform the SA. The transitions of Q are conducted by random exchange of {+, -} spin-pair within the SH-spin vectors that follow the Metropolis update rule. Upon transition toward zeroth energy, the Q-matrix is evolved following a Markov chain toward an orthogonal matrix, at which the H-matrix is said to be found. We demonstrate the capability of the proposed method to find some low-order H-matrices, including the ones that cannot trivially be constructed by the Sylvester method.
Parallelism in matrix computations
Gallopoulos, Efstratios; Sameh, Ahmed H
2016-01-01
This book is primarily intended as a research monograph that could also be used in graduate courses for the design of parallel algorithms in matrix computations. It assumes general but not extensive knowledge of numerical linear algebra, parallel architectures, and parallel programming paradigms. The book consists of four parts: (I) Basics; (II) Dense and Special Matrix Computations; (III) Sparse Matrix Computations; and (IV) Matrix functions and characteristics. Part I deals with parallel programming paradigms and fundamental kernels, including reordering schemes for sparse matrices. Part II is devoted to dense matrix computations such as parallel algorithms for solving linear systems, linear least squares, the symmetric algebraic eigenvalue problem, and the singular-value decomposition. It also deals with the development of parallel algorithms for special linear systems such as banded ,Vandermonde ,Toeplitz ,and block Toeplitz systems. Part III addresses sparse matrix computations: (a) the development of pa...
Czech Academy of Sciences Publication Activity Database
Bobálová, Janette; Chmelík, Josef
2007-01-01
Roč. 1163, 1-2 (2007), s. 80-85 ISSN 0021-9673 R&D Projects: GA MŠk 1M0570 Institutional research plan: CEZ:AV0Z40310501 Keywords : protein identification * MALDI-TOF/TOF MS Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.641, year: 2007
Czech Academy of Sciences Publication Activity Database
Horká, Marie; Karásek, Pavel; Šalplachta, Jiří; Růžička, F.; Vykydalová, Marie; Kubesová, Anna; Dráb, V.; Roth, Michal; Šlais, Karel
2013-01-01
Roč. 788, JUL (2013), s. 193-199 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GAP106/12/0522; GA MV VG20102015023 Institutional support: RVO:68081715 Keywords : capillary isoelectric focusing * matrix-assisted laser desorption/ionization time-of-flight mass spectrometry * lactic acid bacteria Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.517, year: 2013
Stochastic R matrix for Uq (An(1))
Kuniba, A.; Mangazeev, V. V.; Maruyama, S.; Okado, M.
2016-12-01
We show that the quantum R matrix for symmetric tensor representations of Uq (An(1)) satisfies the sum rule required for its stochastic interpretation under a suitable gauge. Its matrix elements at a special point of the spectral parameter are found to factorize into the form that naturally extends Povolotsky's local transition rate in the q-Hahn process for n = 1. Based on these results we formulate new discrete and continuous time integrable Markov processes on a one-dimensional chain in terms of n species of particles obeying asymmetric stochastic dynamics. Bethe ansatz eigenvalues of the Markov matrices are also given.
Entrepreneurship and Economic Transition
Ruta Aidis
2003-01-01
Identification of the entrepreneur's economic function has engaged economistsfor more than 200 years. In this paper we address the issue of entrepreneurship intwo distinct ways: a) as it has historically developed within the field of economicsand b) as it develops in the transitional context. In contrast to advanced westerneconomies, productive entrepreneurship cannot be taken for granted in transitioncountries. Therefore we propose a working definition and model for productiveentrepreneurshi...
Covariance, correlation matrix, and the multiscale community structure of networks.
Shen, Hua-Wei; Cheng, Xue-Qi; Fang, Bin-Xing
2010-07-01
Empirical studies show that real world networks often exhibit multiple scales of topological descriptions. However, it is still an open problem how to identify the intrinsic multiple scales of networks. In this paper, we consider detecting the multiscale community structure of network from the perspective of dimension reduction. According to this perspective, a covariance matrix of network is defined to uncover the multiscale community structure through the translation and rotation transformations. It is proved that the covariance matrix is the unbiased version of the well-known modularity matrix. We then point out that the translation and rotation transformations fail to deal with the heterogeneous network, which is very common in nature and society. To address this problem, a correlation matrix is proposed through introducing the rescaling transformation into the covariance matrix. Extensive tests on real world and artificial networks demonstrate that the correlation matrix significantly outperforms the covariance matrix, identically the modularity matrix, as regards identifying the multiscale community structure of network. This work provides a novel perspective to the identification of community structure and thus various dimension reduction methods might be used for the identification of community structure. Through introducing the correlation matrix, we further conclude that the rescaling transformation is crucial to identify the multiscale community structure of network, as well as the translation and rotation transformations.
Czech Academy of Sciences Publication Activity Database
Šalplachta, Jiří; Řehulka, Pavel; Chmelík, Josef
2004-01-01
Roč. 39, č. 12 (2004), s. 1395-1401 ISSN 1076-5174. [Informal Meeting on Mass Spectrometry /22./. Tokaj, 02.05.2004-06.05.2004] R&D Projects: GA MZe QD1023 Institutional research plan: CEZ:AV0Z4031919 Keywords : MALDI-TOF mass spectrometry * sample cleanup * protein identification Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.056, year: 2004
DEFF Research Database (Denmark)
Hansen, Kristoffer Arnsfelt; Ibsen-Jensen, Rasmus; Podolskii, Vladimir V.
2013-01-01
For matrix games we study how small nonzero probability must be used in optimal strategies. We show that for image win–lose–draw games (i.e. image matrix games) nonzero probabilities smaller than image are never needed. We also construct an explicit image win–lose game such that the unique optimal...
Saleem, M
2002-01-01
The Unitarity of the CKM matrix is examined in the light of the latest available accurate data. The analysis shows that a conclusive result cannot be derived at present. Only more precise data can determine whether the CKM matrix opens new vistas beyond the standard model or not.
Probability matrix decomposition models
Maris, E.; DeBoeck, P.; Mechelen, I. van
1996-01-01
In this paper, we consider a class of models for two-way matrices with binary entries of 0 and 1. First, we consider Boolean matrix decomposition, conceptualize it as a latent response model (LRM) and, by making use of this conceptualization, generalize it to a larger class of matrix decomposition
Indian Academy of Sciences (India)
). From this one can see that this equality is als9 true for diagonalizable matrices; just note that eSAs-. 1 = SeAS-I. Finally, the equality car- ries over to all matrices since both sides are continuous functions of a matrix and every matrix is a limit ...
Nanostructured transition metal oxides useful for water oxidation catalysis
Frei, Heinz M; Jiao, Feng
2013-12-24
The present invention provides for a composition comprising a nanostructured transition metal oxide capable of oxidizing two H.sub.2O molecules to obtain four protons. In some embodiments of the invention, the composition further comprises a porous matrix wherein the nanocluster of the transition metal oxide is embedded on and/or in the porous matrix.
International Nuclear Information System (INIS)
Baron, Jorge H.; Rivera, S.S.
2000-01-01
The so-called vulnerability matrix is used in the evaluation part of the probabilistic safety assessment for a nuclear power plant, during the containment event trees calculations. This matrix is established from what is knows as Numerical Categories for Engineering Judgement. This matrix is usually established with numerical values obtained with traditional arithmetic using the set theory. The representation of this matrix with fuzzy numbers is much more adequate, due to the fact that the Numerical Categories for Engineering Judgement are better represented with linguistic variables, such as 'highly probable', 'probable', 'impossible', etc. In the present paper a methodology to obtain a Fuzzy Vulnerability Matrix is presented, starting from the recommendations on the Numerical Categories for Engineering Judgement. (author)
DEFF Research Database (Denmark)
Schneider, Jesper Wiborg; Borlund, Pia
2007-01-01
The present two-part article introduces matrix comparison as a formal means for evaluation purposes in informetric studies such as cocitation analysis. In the first part, the motivation behind introducing matrix comparison to informetric studies, as well as two important issues influencing...... such comparisons, matrix generation, and the composition of proximity measures, are introduced and discussed. In this second part, the authors introduce and thoroughly demonstrate two related matrix comparison techniques the Mantel test and Procrustes analysis, respectively. These techniques can compare...... and evaluate the degree of monotonicity between different proximity measures or their ordination results. In common with these techniques is the application of permutation procedures to test hypotheses about matrix resemblances. The choice of technique is related to the validation at hand. In the case...
Qureshi, Asima; Petrucco, James
2018-01-01
Meadowbrook Primary School has explored the use of The Teacher Assessment in Primary Science (TAPS) to support transition, initially for transfer to secondary school and now for transition from Early Years Foundation Stage (EYFS) into Key Stage 1 (ages 5-7). This article will consider an example of a secondary transition project and discuss the…
Uclés, S; Lozano, A; Sosa, A; Parrilla Vázquez, P; Valverde, A; Fernández-Alba, A R
2017-11-01
Gas and liquid chromatography coupled to triple quadrupole tandem mass spectrometry are currently the most powerful tools employed for the routine analysis of pesticide residues in food control laboratories. However, whatever the multiresidue extraction method, there will be a residual matrix effect making it difficult to identify/quantify some specific compounds in certain cases. Two main effects stand out: (i) co-elution with isobaric matrix interferents, which can be a major drawback for unequivocal identification, and therefore false negative detections, and (ii) signal suppression/enhancement, commonly called the "matrix effect", which may cause serious problems including inaccurate quantitation, low analyte detectability and increased method uncertainty. The aim of this analytical study is to provide a framework for evaluating the maximum expected errors associated with the matrix effects. The worst-case study contrived to give an estimation of the extreme errors caused by matrix effects when extraction/determination protocols are applied in routine multiresidue analysis. Twenty-five different blank matrices extracted with the four most common extraction methods used in routine analysis (citrate QuEChERS with/without PSA clean-up, ethyl acetate and the Dutch mini-Luke "NL" methods) were evaluated by both GC-QqQ-MS/MS and LC-QqQ-MS/MS. The results showed that the presence of matrix compounds with isobaric transitions to target pesticides was higher in GC than under LC in the experimental conditions tested. In a second study, the number of "potential" false negatives was evaluated. For that, ten matrices with higher percentages of natural interfering components were checked. Additionally, the results showed that for more than 90% of the cases, pesticide quantification was not affected by matrix-matched standard calibration when an interferent was kept constant along the calibration curve. The error in quantification depended on the concentration level. In a
The transition probabilities of the reciprocity model
Snijders, T.A.B.
1999-01-01
The reciprocity model is a continuous-time Markov chain model used for modeling longitudinal network data. A new explicit expression is derived for its transition probability matrix. This expression can be checked relatively easily. Some properties of the transition probabilities are given, as well
International Nuclear Information System (INIS)
Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.; and Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794)
1976-01-01
Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the Aapprox. =18 region are performed following this procedure and treating the Pauli exclusion operator Q 2 /sub p/ by the method of Tsai and Kuo. The treatment of Q 2 /sub p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close agreement is obtained with the matrix elements calculated by Kuo and Brown using approximate methods
International Nuclear Information System (INIS)
Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.
1975-01-01
Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the A approximately 18 region are performed following this procedure and treating the Pauli exclusion operator Q/sub 2p/ by the method of Tsai and Kuo. The treatment of Q/sub 2p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close argument is obtained with the matrix elements calculated by Kuo and Brown using approximate methods
Araújo, C. Mendes; Torregrosa, Juan R.; Urbano, Ana M.
2003-01-01
An n x n matrix is called an N-matrix if all principal minors are negative. In this paper, we are interested in N-matrix completion problems, that is, when a partial N-matrix hás an N-matrix completion. In general, a combinatorially or non-combinatorially symmetric partial N-matrix does not have an N-matrix completion. Here we prove that a combinatorially symmetric partial N-matrix has an N-matrix completion if the graph of its specified entries is a 1-chordal graph. We also prove that there ...
Czech Academy of Sciences Publication Activity Database
Uhlík, Ondřej; Strejček, M.; Junková, P.; Šanda, Miloslav; Hroudová, Miluše; Vlček, Čestmír; Macková, Martina; Macek, Tomáš
2011-01-01
Roč. 77, č. 19 (2011), s. 6858-6866 ISSN 0099-2240 Grant - others:GA MŠk(CZ) ME09024; GA ČR(CZ) GA525/09/1058; GA MŠk(CZ) 2B06156 Program:GA; 2B Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520514 Keywords : MALDI-TOF MS * bioremediation * MALDI Biotyper * bacterial identification Subject RIV: CC - Organic Chemistry Impact factor: 3.829, year: 2011
Eves, Howard
1980-01-01
The usefulness of matrix theory as a tool in disciplines ranging from quantum mechanics to psychometrics is widely recognized, and courses in matrix theory are increasingly a standard part of the undergraduate curriculum.This outstanding text offers an unusual introduction to matrix theory at the undergraduate level. Unlike most texts dealing with the topic, which tend to remain on an abstract level, Dr. Eves' book employs a concrete elementary approach, avoiding abstraction until the final chapter. This practical method renders the text especially accessible to students of physics, engineeri
Quantifying matrix product state
Bhatia, Amandeep Singh; Kumar, Ajay
2018-03-01
Motivated by the concept of quantum finite-state machines, we have investigated their relation with matrix product state of quantum spin systems. Matrix product states play a crucial role in the context of quantum information processing and are considered as a valuable asset for quantum information and communication purpose. It is an effective way to represent states of entangled systems. In this paper, we have designed quantum finite-state machines of one-dimensional matrix product state representations for quantum spin systems.
Flemming, Hans-Curt; Wingender, Jost
2010-09-01
The microorganisms in biofilms live in a self-produced matrix of hydrated extracellular polymeric substances (EPS) that form their immediate environment. EPS are mainly polysaccharides, proteins, nucleic acids and lipids; they provide the mechanical stability of biofilms, mediate their adhesion to surfaces and form a cohesive, three-dimensional polymer network that interconnects and transiently immobilizes biofilm cells. In addition, the biofilm matrix acts as an external digestive system by keeping extracellular enzymes close to the cells, enabling them to metabolize dissolved, colloidal and solid biopolymers. Here we describe the functions, properties and constituents of the EPS matrix that make biofilms the most successful forms of life on earth.
Intelligent data analysis based on rough correlativity matrix
Geng, Zhiqiang; Zhu, Qunxiong
2003-09-01
This paper proposes a new data analysis method based on rough sets by rough correlativity matrix. In rough set theory, a table called information system or database is used as a special kind of formal language to represent knowledge, a rough correlativity matrix (RCM) can be seen as an internal representation of equivalence relations. Furthermore, this paper provides a new heuristic attributes reduction algorithm based on matrix computing, such as using matrix correlative implements to replace the relations computing between sets. Finally the paper adopts information transition matrix (ITM) of information theory to represent the certainty or uncertainty decision rules based on probability theory, namely, the information matrix composed of certainty factors gives the degree of belief of decision rules, on the contrary the "invert" ITM composed of coverage factor gives the interpretation of decision rules. The result of instance analysis is shown that it is an efficient and feasible method to deal with decision information table.
Mao, Wenjing; Sun, Yan; Zhang, Huankang; Cao, Luhong; Wang, Jiajia; He, Peijie
2016-11-01
Photodynamic therapy (PDT) has been developed as a promising treatment modality for laryngeal cancer. 9-Hydroxypheophorbide α (9-HPbD), a novel chlorophyll-derived photosensitizer, has a longer absorption wavelength, which increases the penetration of light to malignant tissues. Carboplatin (CBDCA), a second-generation platinum derivative, also has gained more popularity for the treatment of laryngeal cancer. Our previous studies have elucidated that 9-HPbD-PDT could inhibit the migration and invasion of HEp-2 cells. The objective of this study is to investigate the change of migration and invasion of HEp-2 cells induced by a combined modality of CBDCA and 9-HPbD-PDT in vitro. A wound healing assay, cell migration assay and Matrigel invasion assay were used to evaluate the cellular migration and invasion. Reactive oxygen species (ROS) and Western blots for epithelial-mesenchymal transition (EMT) markers (E-cadherin, N-cadherin and vimentin), MMPs (MMP-2 and MMP-9) and MEK/ERK signalling pathway were performed to investigate the possible mechanisms that may be involved. We observed that CBDCA and 9-HPbD-PDT administration synergistically inhibited the migration and invasion of HEp-2 cells. Moreover, the combined modality cooperatively repressed the EMT process and down-regulated expressions of MMP-2 and MMP-9 via ROS-mediated inhibition of phosphorylation in the MEK/ERK signalling pathway. Our results suggested that the combination of CBDCA and 9-HPbD-PDT might be a promising therapeutic strategy for laryngeal cancer metastasis.
Tendon functional extracellular matrix.
Screen, Hazel R C; Berk, David E; Kadler, Karl E; Ramirez, Francesco; Young, Marian F
2015-06-01
This article is one of a series, summarizing views expressed at the Orthopaedic Research Society New Frontiers in Tendon Research Conference. This particular article reviews the three workshops held under the "Functional Extracellular Matrix" stream. The workshops focused on the roles of the tendon extracellular matrix, such as performing the mechanical functions of tendon, creating the local cell environment, and providing cellular cues. Tendon is a complex network of matrix and cells, and its biological functions are influenced by widely varying extrinsic and intrinsic factors such as age, nutrition, exercise levels, and biomechanics. Consequently, tendon adapts dynamically during development, aging, and injury. The workshop discussions identified research directions associated with understanding cell-matrix interactions to be of prime importance for developing novel strategies to target tendon healing or repair. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
Transition radiation and transition scattering
International Nuclear Information System (INIS)
Ginzburg, V.L.
1982-01-01
Transition radiation is a process of a rather general character. It occurs when some source, which does not have a proper frequency (for example, a charge) moves at a constant velocity in an inhomogeneous and (or) nonstationary medium or near such a medium. The simplest type of transition radiation takes place when a charge crosses a boundary between two media (the role of one of the media may be played by vacuum). In the case of periodic variation of the medium, transition radiation possesses some specific features (resonance transition radiation or transition scattering). Transition scattering occurs, in particular, when a permittivity wave falls onto an nonmoving (fixed) charge. Transition scattering is closely connected with transition bremsstrahlung radiation. All these transition processes are essential for plasma physics. Transition radiation and transition scattering have analogues outside the framework of electrodynamics (like in the case of Vavilov-Cherenkov radiation). In the present report the corresponding range of phenomena is elucidated, as far as possible, in a generally physical aspect. (Auth.)
The Matrix Organization Revisited
DEFF Research Database (Denmark)
Gattiker, Urs E.; Ulhøi, John Parm
1999-01-01
This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively).......This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively)....
Google matrix analysis of DNA sequences.
Kandiah, Vivek; Shepelyansky, Dima L
2013-01-01
For DNA sequences of various species we construct the Google matrix [Formula: see text] of Markov transitions between nearby words composed of several letters. The statistical distribution of matrix elements of this matrix is shown to be described by a power law with the exponent being close to those of outgoing links in such scale-free networks as the World Wide Web (WWW). At the same time the sum of ingoing matrix elements is characterized by the exponent being significantly larger than those typical for WWW networks. This results in a slow algebraic decay of the PageRank probability determined by the distribution of ingoing elements. The spectrum of [Formula: see text] is characterized by a large gap leading to a rapid relaxation process on the DNA sequence networks. We introduce the PageRank proximity correlator between different species which determines their statistical similarity from the view point of Markov chains. The properties of other eigenstates of the Google matrix are also discussed. Our results establish scale-free features of DNA sequence networks showing their similarities and distinctions with the WWW and linguistic networks.
Google matrix analysis of DNA sequences.
Directory of Open Access Journals (Sweden)
Vivek Kandiah
Full Text Available For DNA sequences of various species we construct the Google matrix [Formula: see text] of Markov transitions between nearby words composed of several letters. The statistical distribution of matrix elements of this matrix is shown to be described by a power law with the exponent being close to those of outgoing links in such scale-free networks as the World Wide Web (WWW. At the same time the sum of ingoing matrix elements is characterized by the exponent being significantly larger than those typical for WWW networks. This results in a slow algebraic decay of the PageRank probability determined by the distribution of ingoing elements. The spectrum of [Formula: see text] is characterized by a large gap leading to a rapid relaxation process on the DNA sequence networks. We introduce the PageRank proximity correlator between different species which determines their statistical similarity from the view point of Markov chains. The properties of other eigenstates of the Google matrix are also discussed. Our results establish scale-free features of DNA sequence networks showing their similarities and distinctions with the WWW and linguistic networks.
Stress relief of transition zones
International Nuclear Information System (INIS)
Woodward, J.; van Rooyen, D.
1984-01-01
This paper considers the problem of intergranular stress corrosion cracking, initiated on the primary side, in the expansion transition region of roller expanded Alloy 600 tubing. In general it is believed that residual stresses, arising from the expansion process, are the cause of the problem. The work reported here concentrated on the identification of an optimal, in-situ stress relief treatment
Lee, Ah Young; Goo Park, Sung; Kho, Chang Won; Young Park, Sun; Cho, Sayeon; Lee, Sang Chul; Lee, Do Hee; Myung, Pyung Keun; Park, Byoung Chul
2004-11-01
Intracellular serine protease-1 (Isp-1) is a major intracellular serine protease of Bacillus subtilis, whose functions still remain largely unknown. Furthermore, physiological substrates are yet to be determined. To identify Isp-1 substrates, we digested extract obtained from an Isp-1 deficient Bacillus mutant with purified Isp-1 and examined eliminated or decreased spots by two-dimensional gel and matrix-assisted laser desorption/ionization-time of flight analyses. Proteins degraded by Isp-1, termed the Isp-1 degradome, are involved in a variety of cellular functions such as DNA packing, genetic competence, and protein secretion. From the degradome we selected ClpC and EF-Tu as putative Isp-1 substrates and studied their in vitro degradation. ClpC and EF-Tu contain putative cleavage sites for Isp-1. N-terminal sequencing of in vitro proteolytic fragments of ClpC and EF-Tu revealed that these sites are indeed recognized and cleaved by Isp-1. Moreover, the cellular levels of ClpC and EF-Tu were dramatically reduced at the late stationary phase, where the expression level of Isp-1 was greatly increased. These results suggest that the regulated proteolysis of ClpC by Isp-1 plays an important role in the stationary phase adaptive response. This degradomic approach could provide a powerful tool for finding physiological substrates of many proteolytic enzymes whose functions remain to be determined.
Bhatia, Rajendra
2013-01-01
This book is an outcome of the Indo-French Workshop on Matrix Information Geometries (MIG): Applications in Sensor and Cognitive Systems Engineering, which was held in Ecole Polytechnique and Thales Research and Technology Center, Palaiseau, France, in February 23-25, 2011. The workshop was generously funded by the Indo-French Centre for the Promotion of Advanced Research (IFCPAR). During the event, 22 renowned invited french or indian speakers gave lectures on their areas of expertise within the field of matrix analysis or processing. From these talks, a total of 17 original contribution or state-of-the-art chapters have been assembled in this volume. All articles were thoroughly peer-reviewed and improved, according to the suggestions of the international referees. The 17 contributions presented are organized in three parts: (1) State-of-the-art surveys & original matrix theory work, (2) Advanced matrix theory for radar processing, and (3) Matrix-based signal processing applications.
Sole, Ricard V; Solé, Ricard V; SolÃ©, Ricard V; Sol, Ricard V; Solé, Ricard V
2011-01-01
Phase transitions--changes between different states of organization in a complex system--have long helped to explain physics concepts, such as why water freezes into a solid or boils to become a gas. How might phase transitions shed light on important problems in biological and ecological complex systems? Exploring the origins and implications of sudden changes in nature and society, Phase Transitions examines different dynamical behaviors in a broad range of complex systems. Using a compelling set of examples, from gene networks and ant colonies to human language and the degradation of diverse ecosystems, the book illustrates the power of simple models to reveal how phase transitions occur. Introductory chapters provide the critical concepts and the simplest mathematical techniques required to study phase transitions. In a series of example-driven chapters, Ricard Solé shows how such concepts and techniques can be applied to the analysis and prediction of complex system behavior, including the origins of ...
Fast methods for resumming matrix polynomials and Chebyshev matrix polynomials
International Nuclear Information System (INIS)
Liang Wanzen; Baer, Roi; Saravanan, Chandra; Shao Yihan; Bell, Alexis T.; Head-Gordon, Martin
2004-01-01
Fast and effective algorithms are discussed for resumming matrix polynomials and Chebyshev matrix polynomials. These algorithms lead to a significant speed-up in computer time by reducing the number of matrix multiplications required to roughly twice the square root of the degree of the polynomial. A few numerical tests are presented, showing that evaluation of matrix functions via polynomial expansions can be preferable when the matrix is sparse and these fast resummation algorithms are employed
Praeger, Cheryl; Tao, Terence
2018-01-01
MATRIX is Australia’s international, residential mathematical research institute. It facilitates new collaborations and mathematical advances through intensive residential research programs, each lasting 1-4 weeks. This book is a scientific record of the five programs held at MATRIX in its first year, 2016: Higher Structures in Geometry and Physics (Chapters 1-5 and 18-21); Winter of Disconnectedness (Chapter 6 and 22-26); Approximation and Optimisation (Chapters 7-8); Refining C*-Algebraic Invariants for Dynamics using KK-theory (Chapters 9-13); Interactions between Topological Recursion, Modularity, Quantum Invariants and Low-dimensional Topology (Chapters 14-17 and 27). The MATRIX Scientific Committee selected these programs based on their scientific excellence and the participation rate of high-profile international participants. Each program included ample unstructured time to encourage collaborative research; some of the longer programs also included an embedded conference or lecture series. The artic...
Energy Technology Data Exchange (ETDEWEB)
Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory
2010-01-01
In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.
DEFF Research Database (Denmark)
Frandsen, Gudmund Skovbjerg; Frandsen, Peter Frands
2009-01-01
We consider maintaining information about the rank of a matrix under changes of the entries. For n×n matrices, we show an upper bound of O(n1.575) arithmetic operations and a lower bound of Ω(n) arithmetic operations per element change. The upper bound is valid when changing up to O(n0.575) entries...... in a single column of the matrix. We also give an algorithm that maintains the rank using O(n2) arithmetic operations per rank one update. These bounds appear to be the first nontrivial bounds for the problem. The upper bounds are valid for arbitrary fields, whereas the lower bound is valid for algebraically...... closed fields. The upper bound for element updates uses fast rectangular matrix multiplication, and the lower bound involves further development of an earlier technique for proving lower bounds for dynamic computation of rational functions....
Hu, S; Qiu, N; Liu, Y; Zhao, H; Gao, D; Song, R; Ma, M
2016-05-01
A proteomic study of egg white proteins from 2 major poultry species, namely quail (Coturnix coturnix) and duck (Anas platyrhynchos), was performed with comparison to those of chicken (Gallus gallus) through 2-dimensional polyacrylamide gel electrophoresis (2-DE) analysis. By using matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF MS/MS), 29 protein spots representing 10 different kinds of proteins as well as 17 protein spots designating 9 proteins were successfully identified in quail and duck egg white, respectively. This report suggested a closer relationship between quail and chicken egg white proteome patterns, whereas the duck egg white protein distribution on the 2-DE map was more distinct. In duck egg white, some well-known major proteins, such as ovomucoid, clusterin, extracellular fatty acid-binding protein precursor (ex-FABP), and prostaglandin D2 synthase (PG D2 synthase), were not detected, while two major protein spots identified as "deleted in malignant brain tumors 1" protein (DMBT1) and vitellogenin-2 were found specific to duck in the corresponding range on the 2-DE gel map. These interspecies diversities may be associated with the egg white protein functions in cell defense or regulating/supporting the embryonic development to adapt to the inhabiting environment or reproduction demand during long-term evolution. The findings of this work will give insight into the advantages involved in the application on egg white proteins from various egg sources, which may present novel beneficial properties in the food industry or related to human health. © 2016 Poultry Science Association Inc.
Hohn, Franz E
2012-01-01
This complete and coherent exposition, complemented by numerous illustrative examples, offers readers a text that can teach by itself. Fully rigorous in its treatment, it offers a mathematically sound sequencing of topics. The work starts with the most basic laws of matrix algebra and progresses to the sweep-out process for obtaining the complete solution of any given system of linear equations - homogeneous or nonhomogeneous - and the role of matrix algebra in the presentation of useful geometric ideas, techniques, and terminology.Other subjects include the complete treatment of the structur
Energy Technology Data Exchange (ETDEWEB)
Brown, T.W.
2010-11-15
The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)
Deconfinement in matrix models about the Gross-Witten point
International Nuclear Information System (INIS)
Dumitru, Adrian; Lenaghan, Jonathan; Pisarski, Robert D.
2005-01-01
We study the deconfining phase transition in SU(N) gauge theories at nonzero temperature using a matrix model of Polyakov loops. The most general effective action, including all terms up to two spatial derivatives, is presented. At large N, the action is dominated by the loop potential: following Aharony et al., we show how the Gross-Witten model represents an ultracritical point in this potential. Although masses vanish at the Gross-Witten point, the transition is of first order, as the fundamental loop jumps only halfway to its perturbative value. Comparing numerical analysis of the N=3 matrix model to lattice simulations, for three colors the deconfining transition appears to be near the Gross-Witten point. To see if this persists for N≥4, we suggest measuring within a window ∼1/N 2 of the transition temperature
Transition Radiation Detectors
Andronic, A
2012-01-01
We review the basic features of transition radiation and how they are used for the design of modern Transition Radiation Detectors (TRD). The discussion will include the various realizations of radiators as well as a discussion of the detection media and aspects of detector construction. With regard to particle identification we assess the different methods for efficient discrimination of different particles and outline the methods for the quantification of this property. Since a number of comprehensive reviews already exist, we predominantly focus on the detectors currently operated at the LHC. To a lesser extent we also cover some other TRDs, which are planned or are currently being operated in balloon or space-borne astro-particle physics experiments.
ALICE Transition Radiation Detector
Pachmayer, Y
2013-01-01
The Transition Radiation Detector (TRD) is the main electron detector in ALICE. In conduction with the TPC and the ITS, it provides the necessary electron identification capability to study: - Production of light and heavy vector mesons as well as the continuum in the di-electron channel, - Semi leptonic decays of hadrons with open charm and open beauty via the single-electron channel using the displaced vertex information provided by the ITS, - Correlated DD and BB pairs via coincidences of electrons in the central barrel and muons in the forward muon arm, - Jets with high Pτ tracks in one single TRD stack.
AFSC/RACE/GAP/Orr: Gulf of Alaska and Aleutian Islands groundfish surveys Identification Confidence
National Oceanic and Atmospheric Administration, Department of Commerce — This report includes an identification confidence matrix for all fishes and invertebrates identified from the GOA and AI surveys from 1980 through 2011. The matrix...
The algebras of large N matrix mechanics
Energy Technology Data Exchange (ETDEWEB)
Halpern, M.B.; Schwartz, C.
1999-09-16
Extending early work, we formulate the large N matrix mechanics of general bosonic, fermionic and supersymmetric matrix models, including Matrix theory: The Hamiltonian framework of large N matrix mechanics provides a natural setting in which to study the algebras of the large N limit, including (reduced) Lie algebras, (reduced) supersymmetry algebras and free algebras. We find in particular a broad array of new free algebras which we call symmetric Cuntz algebras, interacting symmetric Cuntz algebras, symmetric Bose/Fermi/Cuntz algebras and symmetric Cuntz superalgebras, and we discuss the role of these algebras in solving the large N theory. Most important, the interacting Cuntz algebras are associated to a set of new (hidden!) local quantities which are generically conserved only at large N. A number of other new large N phenomena are also observed, including the intrinsic nonlocality of the (reduced) trace class operators of the theory and a closely related large N field identification phenomenon which is associated to another set (this time nonlocal) of new conserved quantities at large N.
Alternative dimensional reduction via the density matrix
de Carvalho, C. A.; Cornwall, J. M.; da Silva, A. J.
2001-07-01
We give graphical rules, based on earlier work for the functional Schrödinger equation, for constructing the density matrix for scalar and gauge fields in equilibrium at finite temperature T. More useful is a dimensionally reduced effective action (DREA) constructed from the density matrix by further functional integration over the arguments of the density matrix coupled to a source. The DREA is an effective action in one less dimension which may be computed order by order in perturbation theory or by dressed-loop expansions; it encodes all thermal matrix elements. We term the DREA procedure alternative dimensional reduction, to distinguish it from the conventional dimensionally reduced field theory (DRFT) which applies at infinite T. The DREA is useful because it gives a dimensionally reduced theory usable at any T including infinity, where it yields the DRFT, and because it does not and cannot have certain spurious infinities which sometimes occur in the density matrix itself or the conventional DRFT; these come from ln T factors at infinite temperature. The DREA can be constructed to all orders (in principle) and the only regularizations needed are those which control the ultraviolet behavior of the zero-T theory. An example of spurious divergences in the DRFT occurs in d=2+1φ4 theory dimensionally reduced to d=2. We study this theory and show that the rules for the DREA replace these ``wrong'' divergences in physical parameters by calculable powers of ln T; we also compute the phase transition temperature of this φ4 theory in one-loop order. Our density-matrix construction is equivalent to a construction of the Landau-Ginzburg ``coarse-grained free energy'' from a microscopic Hamiltonian.
International Nuclear Information System (INIS)
Robb, W.D.
1978-01-01
The procedures used in the application of R-matrix theory to atomic and molecular collision processes are presented. The computationally advantageous features of these methods are high-lighted, and some applications to electron scattering and photoionization are briefly discussed
Indian Academy of Sciences (India)
The elusive ≡C-H· · ·O complex in the hydrogen bonded systems of Phenylacetylene: A Matrix Isolation Infrared and Ab Initio Study ... A comparison of the spectral shifts observed in the features of PhAc-MeOH and PhAc-DEE would therefore independently confirm the existence or not of n-σ* complex in both these systems.
DEFF Research Database (Denmark)
Jørnø, Rasmus Leth Vergmann; Gynther, Karsten; Christensen, Ove
2014-01-01
useful information, we question whether the axis of time and space comprising the matrix pertains to relevant defining properties of the tools, technology or learning environments to which they are applied. Subsequently we offer an example of an Adobe Connect e-learning session as an illustration...
International Nuclear Information System (INIS)
Dodder, D.C.
1975-01-01
Scattering and reaction processes involving very few nucleons are studied via the R matrix formalism of Wigner and Eisenbud. As examples, the d + 3 He, p + 4 He, 3 He + 4 He, and p + 6 Li are considered. (3 figures) (SDF)
Mitjana, Margarida
2018-01-01
This book contains the notes of the lectures delivered at an Advanced Course on Combinatorial Matrix Theory held at Centre de Recerca Matemàtica (CRM) in Barcelona. These notes correspond to five series of lectures. The first series is dedicated to the study of several matrix classes defined combinatorially, and was delivered by Richard A. Brualdi. The second one, given by Pauline van den Driessche, is concerned with the study of spectral properties of matrices with a given sign pattern. Dragan Stevanović delivered the third one, devoted to describing the spectral radius of a graph as a tool to provide bounds of parameters related with properties of a graph. The fourth lecture was delivered by Stephen Kirkland and is dedicated to the applications of the Group Inverse of the Laplacian matrix. The last one, given by Ángeles Carmona, focuses on boundary value problems on finite networks with special in-depth on the M-matrix inverse problem.
2012-07-01
Public transit agencies have employed intelligent systems for determining : schedules and routes and for monitoring the real-time location and status of their : vehicle fleets for nearly two decades. But until recently, the data generated by : daily ...
Li, Leilei; Cleenwerck, Ilse; De Vuyst, Luc; Vandamme, Peter
2017-04-01
The classification and identification of acetic acid bacteria (AAB) underwent much change during the last two decades. However, several closely related AAB species are difficult to differentiate and rapid and correct species level identification remains challenging. In the present study, 281 well-characterized AAB strains representing AAB species of the family Acetobacteraceae were used to construct a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) identification database. The database was evaluated using 270 poorly characterized AAB strains. 16S rRNA and/or multilocus gene sequence analysis and whole-genome sequencing for the calculation of average nucleotide identity values were performed on a selection of strains to verify the accuracy of the obtained results. Virtually all poorly characterized AAB strains were accurately identified to the species level. Most of the remaining strains were considered to represent novel AAB species or belonged to species represented by too few strains in the identification database. The data also revealed that Gluconobacter nephelii and Gluconobacter uchimurae are later heterotypic synonyms of Gluconobacter japonicus and Gluconobacter oxydans, respectively. Copyright © 2017 Elsevier GmbH. All rights reserved.
Geometric transitions and integrable systems
International Nuclear Information System (INIS)
Diaconescu, D.-E.; Dijkgraaf, R.; Donagi, R.; Hofman, C.; Pantev, T.
2006-01-01
We consider B-model large N duality for a new class of noncompact Calabi-Yau spaces modeled on the neighborhood of a ruled surface in a Calabi-Yau threefold. The closed string side of the transition is governed at genus zero by an A 1 Hitchin integrable system on a genus g Riemann surface Σ. The open string side is described by a holomorphic Chern-Simons theory which reduces to a generalized matrix model in which the eigenvalues lie on the compact Riemann surface Σ. We show that the large N planar limit of the generalized matrix model is governed by the same A 1 Hitchin system therefore proving genus zero large N duality for this class of transitions
Calculation of transition matrix elements by nonsingular orbital transformations
Czech Academy of Sciences Publication Activity Database
Kývala, Mojmír
2009-01-01
Roč. 109, č. 6 (2009), s. 1200-1227 ISSN 0020-7608 R&D Projects: GA MŠk LC512; GA ČR GA203/05/0936 Institutional research plan: CEZ:AV0Z40550506 Keywords : full CI * CASSGF * CASSI * corresponding orbital transformation * localized Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.315, year: 2009
Imagining transitions in old age through the Visual Matrix method
DEFF Research Database (Denmark)
Liveng, Anne; Ramvi, Ellen; Froggett, Lynn
2017-01-01
, from mental health to dementia and from life to death. Because, for some, these topics are hard to bear and therefore defended against and routinely excluded from everyday awareness, we used a method led by imagery and affect–the Visual Matrix–to elicit participant s’ free associative personal......-generational continuity, which together link life and death, hope and despair, separation and connectedness....
Haebel, S; Kehr, J
2001-08-01
A combination of gel electrophoresis and mass spectrometry was used to analyze the soluble proteins from phloem sap of Cucurbita maxima Duch. Phloem proteins were separated using two-dimensional gel electrophoresis. Coomassie-stained spots were cut out and subjected to tryptic digestion. To identify proteins, peptide mass fingerprints were determined by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. In addition, MALDI-TOF post source decay measurements were used to obtain partial sequence information for the proteins. Results from both approaches were used for database searches. In this study, 17 proteins in the mass range 5-50 kDa were analyzed. Of these proteins six could be clearly identified, seven showed significant homologies to known plant proteins, and four were not significantly homologous to database entries. The present study suggests that the applied method is feasible for a large-scale analysis and identification of phloem proteins derived from different organs or from plants kept under various physiological conditions.
Sparse matrix decompositions for clustering
Blumensath, Thomas
2014-01-01
Clustering can be understood as a matrix decomposition problem, where a feature vector matrix is represented as a product of two matrices, a matrix of cluster centres and a matrix with sparse columns, where each column assigns individual features to one of the cluster centres. This matrix factorisation is the basis of classical clustering methods, such as those based on non-negative matrix factorisation but can also be derived for other methods, such as k-means clustering. In this paper we de...
Calculation of weak transitions in lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Brower, R.C.; Maturana, G.; Gavela, M.B.; Gupta, R.
1984-10-01
We propose the use of Monte Carlo simulations of QCD to evaluate hadronic matrix elements of local operators encountered in electroweak and grand-unified-theory transitions. Preliminary Monte Carlo estimates are made of the ..delta..S = 2 matrix elements responsible for the K/sub l/-K/sub S/ mass difference and the ..delta..S = 1 operators believed to explain the ..delta..I = (1/2) enhancement.
Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang
2015-09-15
Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions.
International Nuclear Information System (INIS)
Sasakawa, T.; Okuno, H.; Ishikawa, S.; Sawada, T.
1982-01-01
The off-shell t matrix is expressed as a sum of one nonseparable and one separable terms so that it is useful for applications to more-than-two body problems. All poles are involved in this one separable term. Both the nonseparable and the separable terms of the kernel G 0 t are regular at the origin. The nonseparable term of this kernel vanishes at large distances, while the separable term behaves asymptotically as the spherical Hankel function. These properties make our expression free from defects inherent in the Jost or the K-matrix expressions, and many applications are anticipated. As the application, a compact expression of the many-level formula is presented. Also the application is suggested to the breakup threebody problem based on the Faddeev equation. It is demonstrated that the breakup amplitude is expressed in a simple and physically interesting form and we can calculate it in coordinate space
Wilkinson, Michael; Grant, John
2018-03-01
We consider a stochastic process in which independent identically distributed random matrices are multiplied and where the Lyapunov exponent of the product is positive. We continue multiplying the random matrices as long as the norm, ɛ, of the product is less than unity. If the norm is greater than unity we reset the matrix to a multiple of the identity and then continue the multiplication. We address the problem of determining the probability density function of the norm, \
International Nuclear Information System (INIS)
Felder, Giovanni; Riser, Roman
2004-01-01
We study a class of holomorphic matrix models. The integrals are taken over middle-dimensional cycles in the space of complex square matrices. As the size of the matrices tends to infinity, the distribution of eigenvalues is given by a measure with support on a collection of arcs in the complex planes. We show that the arcs are level sets of the imaginary part of a hyperelliptic integral connecting branch points
Extracellular matrix structure.
Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K
2016-02-01
Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented. Copyright © 2015 Elsevier B.V. All rights reserved.
Goto, Hiroyuki
We provide a useful method for calculating the state vector of a state equation efficiently in a max-plus algebraic system. For a discrete event system whose precedence relationships are represented by a directed acyclic graph, computing the transition matrix, which includes the Kleene star operation of a weighted adjacency matrix, is occasionally the bottleneck. On the other hand, the common objective is to compute the state equation, rather than the transition matrix itself. Since the state equation is essentially the multiplication of the transition matrix and vector, we propose algorithms for efficiently calculating the multiplication and left division of the Kleene star of an adjacency matrix and a vector.
Standard Errors for Matrix Correlations.
Ogasawara, Haruhiko
1999-01-01
Derives the asymptotic standard errors and intercorrelations for several matrix correlations assuming multivariate normality for manifest variables and derives the asymptotic standard errors of the matrix correlations for two factor-loading matrices. (SLD)
DEFF Research Database (Denmark)
Raahauge, Kirsten Marie
2008-01-01
and the interaction of cultural, social, and spatial organizations, as seen from the point of view of people living in Skåde Bakker and Fedet. The focus is on the city dwellers’ representations of the central district of Århus with specific reference to the concept of transit space. When applied to various Århusian...
Directory of Open Access Journals (Sweden)
Abdelhakim Chillali
2017-05-01
Full Text Available In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra. In this work, we proposed a new problem applicable to the public key cryptography, based on the Matrices, called “Matrix discrete logarithm problem”, it uses certain elements formed by matrices whose coefficients are elements in a finite field. We have constructed an abelian group and, for the cryptographic part in this unreliable group, we then perform the computation corresponding to the algebraic equations, Returning the encrypted result to a receiver. Upon receipt of the result, the receiver can retrieve the sender’s clear message by performing the inverse calculation.
Matrix string partition function
Kostov, Ivan K; Kostov, Ivan K.; Vanhove, Pierre
1998-01-01
We evaluate quasiclassically the Ramond partition function of Euclidean D=10 U(N) super Yang-Mills theory reduced to a two-dimensional torus. The result can be interpreted in terms of free strings wrapping the space-time torus, as expected from the point of view of Matrix string theory. We demonstrate that, when extrapolated to the ultraviolet limit (small area of the torus), the quasiclassical expressions reproduce exactly the recently obtained expression for the partition of the completely reduced SYM theory, including the overall numerical factor. This is an evidence that our quasiclassical calculation might be exact.
Eisenman, Richard L
2005-01-01
This outstanding text and reference applies matrix ideas to vector methods, using physical ideas to illustrate and motivate mathematical concepts but employing a mathematical continuity of development rather than a physical approach. The author, who taught at the U.S. Air Force Academy, dispenses with the artificial barrier between vectors and matrices--and more generally, between pure and applied mathematics.Motivated examples introduce each idea, with interpretations of physical, algebraic, and geometric contexts, in addition to generalizations to theorems that reflect the essential structur
Some Comments on Quasi-Birth-and-Death Processes and Matrix Measures
Directory of Open Access Journals (Sweden)
Holger Dette
2010-01-01
Full Text Available We explore the relation between matrix measures and quasi-birth-and-death processes. We derive an integral representation of the transition function in terms of a matrix-valued spectral measure and corresponding orthogonal matrix polynomials. We characterize several stochastic properties of quasi-birth-and-death processes by means of this matrixmeasure and illustrate the theoretical results by several examples.
International Nuclear Information System (INIS)
David, F.
1990-01-01
In these lectures, I shall focus on the matrix formulation of 2-d gravity. In the first one, I shall discuss the main results of the continuum formulation of 2-d gravity, starting from the first renormalization group calculations which led to the concept of the conformal anomaly, going through the Polyakov bosonic string and the Liouville action, up to the recent results on the scaling properties of conformal field theories coupled to 2-d gravity. In the second lecture, I shall discuss the discrete formulation of 2-d gravity in term of random lattices, and the mapping onto random matrix models. The occurrence of critical points in the planar limit and the scaling limit at those critical points will be described, as well as the identification of these scaling limits with continuum 2-d gravity coupled to some matter field theory. In the third lecture, the double scaling limit in the one matrix model, and its connection with continuum non perturbative 2-d gravity, will be presented. The connection with the KdV hierarchy and the general form of the string equation will be discuted. In the fourth lecture, I shall discuss the non-perturbative effects present in the non perturbative solutions, in the case of pure gravity. The Schwinger-Dyson equations for pure gravity in the double scaling limit are described and their compatibility with the solutions of the string equation for pure gravity is shown to be somewhat problematic
Matrix algebra for linear models
Gruber, Marvin H J
2013-01-01
Matrix methods have evolved from a tool for expressing statistical problems to an indispensable part of the development, understanding, and use of various types of complex statistical analyses. This evolution has made matrix methods a vital part of statistical education. Traditionally, matrix methods are taught in courses on everything from regression analysis to stochastic processes, thus creating a fractured view of the topic. Matrix Algebra for Linear Models offers readers a unique, unified view of matrix analysis theory (where and when necessary), methods, and their applications. Written f
2011-01-01
NASA is interested in developing technology that leads to more routine, safe, and affordable access to space. Access to space using airbreathing propulsion systems has potential to meet these objectives based on Airbreathing Access to Space (AAS) system studies. To this end, the NASA Fundamental Aeronautics Program (FAP) Hypersonic Project is conducting fundamental research on a Turbine Based Combined Cycle (TBCC) propulsion system. The TBCC being studied considers a dual flow-path inlet system. One flow-path includes variable geometry to regulate airflow to a turbine engine cycle. The turbine cycle provides propulsion from take-off to supersonic flight. The second flow-path supports a dual-mode scramjet (DMSJ) cycle which would be initiated at supersonic speed to further accelerate the vehicle to hypersonic speed. For a TBCC propulsion system to accelerate a vehicle from supersonic to hypersonic speed, a critical enabling technology is the ability to safely and effectively transition from the turbine to the DMSJ-referred to as mode transition. To experimentally test methods of mode transition, a Combined Cycle Engine (CCE) Large-scale Inlet testbed was designed with two flow paths-a low speed flow-path sized for a turbine cycle and a high speed flow-path designed for a DMSJ. This testbed system is identified as the CCE Large-Scale Inlet for Mode Transition studies (CCE-LIMX). The test plan for the CCE-LIMX in the NASA Glenn Research Center (GRC) 10- by 10-ft Supersonic Wind Tunnel (10x10 SWT) is segmented into multiple phases. The first phase is a matrix of inlet characterization (IC) tests to evaluate the inlet performance and establish the mode transition schedule. The second phase is a matrix of dynamic system identification (SysID) experiments designed to support closed-loop control development at mode transition schedule operating points for the CCE-LIMX. The third phase includes a direct demonstration of controlled mode transition using a closed loop control
DEFF Research Database (Denmark)
Hansen, Ole Erik; Søndergård, Bent
2014-01-01
What. The chapter addresses designing for sustainability as interventions in socio-technical systems and social practices of users and communities. It calls for reflexive design practices challenging dominant regimes and shaping alternative design spaces. The specific case is the reconfiguration...... of agendas/vision, technologies, actors and institutions in the emergent design of an urban mobility system based on an electric car sharing system. Why. Designing for sustainability is a fundamental challenge for future design practices; designers have to obtain an ability to contribute to sustainable...... transition processes. Where. Addresses design processes aimed at sustainable transition enacted in complex social settings, socio-technical systems involving many different actors and agendas. How. The chapter outlines a conceptual and analytic framework for a reflexive design practice for sustainability...
2006-06-09
done to facilitate the transition.52 CRS-12 53 David T. Stanley, Changing Administrations (Washington: Brookings Institution, 1965), p. 6. 54 “Pre...Conference of Mayors; Sharleen Hirsch, an educational administrator; and Jule Sugarman , a public administrator. Staff members were assigned to task forces...Issues,” Washington Post, Nov. 13, 1980, p. Al. 77 David Hoffman, “Bush Names Baker Secretary of State,” Washington Post, Nov. 10, 1988, pp. Al and
Ceramic matrix and resin matrix composites - A comparison
Hurwitz, Frances I.
1987-01-01
The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.
Ceramic matrix and resin matrix composites: A comparison
Hurwitz, Frances I.
1987-01-01
The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.
Identification of formation scales and design of compatible matrix ...
African Journals Online (AJOL)
Though 15% HCl was faster than 7.5% HCL in dissolving the scales, 7.5% HCl with corrosion inhibitors should be used for field application to avoid intense corrosion of pipes. The emulsion break and compatibility tests also indicated an effective treatment fluid system which had 100% separation within 10 minutes at the ...
Matrix theory interpretation of discrete light cone quantization string worldsheets
Grignani; Orland; Paniak; Semenoff
2000-10-16
We study the null compactification of type-IIA string perturbation theory at finite temperature. We prove a theorem about Riemann surfaces establishing that the moduli spaces of infinite-momentum-frame superstring worldsheets are identical to those of branched-cover instantons in the matrix-string model conjectured to describe M theory. This means that the identification of string degrees of freedom in the matrix model proposed by Dijkgraaf, Verlinde, and Verlinde is correct and that its natural generalization produces the moduli space of Riemann surfaces at all orders in the genus expansion.
2008-12-01
65 1. Traceability for Asset Visibility........................................................65 2. Purposes of RFID and IUID... Traceability Matrix for Asset Visibility...........................................................66 Table 7. IUID vs. RFID ...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA MBA PROFESSIONAL REPORT Feasibility of Radio Frequency Identification ( RFID ) and
Scattering theory of topological phase transitions
Fulga, Ion Cosma
2013-01-01
This thesis deals with characterizing topological phases as well as the transitions between them, focusing on transport properties and the effects of disorder. In Chapters 2 and 3 we derived scattering matrix expressions for the topological invariants of systems. This approach is oftentimes
Polarized Moessbauer transitions in mixed hyperfine interactions
International Nuclear Information System (INIS)
Barb, D.; Tarina, D.
1975-01-01
A contribution to the theory of elliptical polarization in the Moessbauer effect for transitions between mixed nuclear states is reported. A relation between the two-dimensional complex vector parameterization and the photon polarization density matrix was used in describing changes in the polarization of the gamma-ray involved. (A.K.)
Craps, Ben; Sethi, Savdeep; Verlinde, Erik
2005-10-01
The light-like linear dilaton background represents a particularly simple time-dependent 1/2 BPS solution of critical type-IIA superstring theory in ten dimensions. Its lift to M-theory, as well as its Einstein frame metric, are singular in the sense that the geometry is geodesically incomplete and the Riemann tensor diverges along a light-like subspace of codimension one. We study this background as a model for a big bang type singularity in string theory/M-theory. We construct the dual Matrix theory description in terms of a (1+1)-d supersymmetric Yang-Mills theory on a time-dependent world-sheet given by the Milne orbifold of (1+1)-d Minkowski space. Our model provides a framework in which the physics of the singularity appears to be under control.
Energy Technology Data Exchange (ETDEWEB)
Hastings, Matthew B [Los Alamos National Laboratory
2009-01-01
We show how to combine the light-cone and matrix product algorithms to simulate quantum systems far from equilibrium for long times. For the case of the XXZ spin chain at {Delta} = 0.5, we simulate to a time of {approx} 22.5. While part of the long simulation time is due to the use of the light-cone method, we also describe a modification of the infinite time-evolving bond decimation algorithm with improved numerical stability, and we describe how to incorporate symmetry into this algorithm. While statistical sampling error means that we are not yet able to make a definite statement, the behavior of the simulation at long times indicates the appearance of either 'revivals' in the order parameter as predicted by Hastings and Levitov (e-print arXiv:0806.4283) or of a distinct shoulder in the decay of the order parameter.
International Nuclear Information System (INIS)
Craps, Ben; Sethi, Savdeep; Verlinde, Erik
2005-01-01
The light-like linear dilaton background represents a particularly simple time-dependent 1/2 BPS solution of critical type-IIA superstring theory in ten dimensions. Its lift to M-theory, as well as its Einstein frame metric, are singular in the sense that the geometry is geodesically incomplete and the Riemann tensor diverges along a light-like subspace of codimension one. We study this background as a model for a big bang type singularity in string theory/M-theory. We construct the dual Matrix theory description in terms of a (1+1)-d supersymmetric Yang-Mills theory on a time-dependent world-sheet given by the Milne orbifold of (1+1)-d Minkowski space. Our model provides a framework in which the physics of the singularity appears to be under control
Energy Technology Data Exchange (ETDEWEB)
Craps, Ben [Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands); Sethi, Savdeep [Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States); Verlinde, Erik [Instituut voor Theoretische Fysica, Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands)
2005-10-15
The light-like linear dilaton background represents a particularly simple time-dependent 1/2 BPS solution of critical type-IIA superstring theory in ten dimensions. Its lift to M-theory, as well as its Einstein frame metric, are singular in the sense that the geometry is geodesically incomplete and the Riemann tensor diverges along a light-like subspace of codimension one. We study this background as a model for a big bang type singularity in string theory/M-theory. We construct the dual Matrix theory description in terms of a (1+1)-d supersymmetric Yang-Mills theory on a time-dependent world-sheet given by the Milne orbifold of (1+1)-d Minkowski space. Our model provides a framework in which the physics of the singularity appears to be under control.
Correntropy Based Matrix Completion
Directory of Open Access Journals (Sweden)
Yuning Yang
2018-03-01
Full Text Available This paper studies the matrix completion problems when the entries are contaminated by non-Gaussian noise or outliers. The proposed approach employs a nonconvex loss function induced by the maximum correntropy criterion. With the help of this loss function, we develop a rank constrained, as well as a nuclear norm regularized model, which is resistant to non-Gaussian noise and outliers. However, its non-convexity also leads to certain difficulties. To tackle this problem, we use the simple iterative soft and hard thresholding strategies. We show that when extending to the general affine rank minimization problems, under proper conditions, certain recoverability results can be obtained for the proposed algorithms. Numerical experiments indicate the improved performance of our proposed approach.
Andric, I; Jurman, D; Nielsen, H B
2007-01-01
We discuss a dynamical matrix model by which probability distribution is associated with Gaussian ensembles from random matrix theory. We interpret the matrix M as a Hamiltonian representing interaction of a bosonic system with a single fermion. We show that a system of second-quantized fermions influences the ground state of the whole system by producing a gap between the highest occupied eigenvalue and the lowest unoccupied eigenvalue.
Multivariate Matrix-Exponential Distributions
DEFF Research Database (Denmark)
Bladt, Mogens; Nielsen, Bo Friis
2010-01-01
be written as linear combinations of the elements in the exponential of a matrix. For this reason we shall refer to multivariate distributions with rational Laplace transform as multivariate matrix-exponential distributions (MVME). The marginal distributions of an MVME are univariate matrix......-exponential distributions. We prove a characterization that states that a distribution is an MVME distribution if and only if all non-negative, non-null linear combinations of the coordinates have a univariate matrix-exponential distribution. This theorem is analog to a well-known characterization theorem...
Energy Technology Data Exchange (ETDEWEB)
Hamrin, J.G.
1980-01-01
Solar energy programs are entering a critical transitional period as we move from the initial marketing of solar technologies into a phase of widespread commercialization. We face the dual challenge of trying to get enough solar systems in place fast enough to prove solar is a viable alternative, while trying to ensure the systems are designed and installed properly, proving the energy savings as promised. This is a period of both great opportunity and high risk as the field becomes crowded with new solar cheerleaders and supporters but seldom enough competent players. The status of existing and proposed programs for the accelerated commercialization of solar energy in California is described.
DEFF Research Database (Denmark)
Raahauge, Kirsten Marie
2008-01-01
This article deals with representations of one specific city, Århus, Denmark, especially its central district. The analysis is based on anthropological fieldwork conducted in Skåde Bakker and Fedet, two well-off neighborhoods. The overall purpose of the project is to study perceptions of space...... and the interaction of cultural, social, and spatial organizations, as seen from the point of view of people living in Skåde Bakker and Fedet. The focus is on the city dwellers’ representations of the central district of Århus with specific reference to the concept of transit space. When applied to various Århusian...
International Nuclear Information System (INIS)
Perdicakis, Michel
2012-01-01
Document available in extended abstract form only. In many countries, it is planned that the long life highly radioactive nuclear spent fuel will be stored in deep argillaceous rocks. The sites selected for this purpose are anoxic and satisfy several recommendations as mechanical stability, low permeability and low redox potential. Pyrite (FeS 2 ), iron(II) carbonate, iron(II) bearing clays and organic matter that are present in very small amounts (about 1% w:w) in soils play a major role in their reactivity and are considered today as responsible for the low redox potential values of these sites. In this communication, we describe an electrochemical technique derived from 'Salt matrix voltammetry' and allowing the almost in-situ voltammetric characterization of air-sensitive samples of soils after the only addition of the minimum humidity required for electrolytic conduction. Figure 1 shows the principle of the developed technique. It consists in the entrapment of the clay sample between a graphite working electrode and a silver counter/quasi-reference electrode. The sample was previously humidified by passing a water saturated inert gas through the electrochemical cell. The technique leads to well-defined voltammetric responses of the electro-active components of the clays. Figure 2 shows a typical voltammogram relative to a Callovo-Oxfordian argillite sample from Bure, the French place planned for the underground nuclear waste disposal. During the direct scan, one can clearly distinguish the anodic voltammetric signals for the oxidation of the iron (II) species associated with the clay and the oxidation of pyrite. The reverse scan displays a small cathodic signal for the reduction of iron (III) associated with the clay that demonstrates that the majority of the previously oxidized iron (II) species were transformed into iron (III) oxides reducible at lower potentials. When a second voltammetric cycle is performed, one can notice that the signal for iron (II
Energy Technology Data Exchange (ETDEWEB)
Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-09-18
The objective of this training modules is to examine the process of using gamma spectroscopy for radionuclide identification; apply pattern recognition to gamma spectra; identify methods of verifying energy calibration; and discuss potential causes of isotope misidentification.
Ceramic matrix composite article and process of fabricating a ceramic matrix composite article
Cairo, Ronald Robert; DiMascio, Paul Stephen; Parolini, Jason Robert
2016-01-12
A ceramic matrix composite article and a process of fabricating a ceramic matrix composite are disclosed. The ceramic matrix composite article includes a matrix distribution pattern formed by a manifold and ceramic matrix composite plies laid up on the matrix distribution pattern, includes the manifold, or a combination thereof. The manifold includes one or more matrix distribution channels operably connected to a delivery interface, the delivery interface configured for providing matrix material to one or more of the ceramic matrix composite plies. The process includes providing the manifold, forming the matrix distribution pattern by transporting the matrix material through the manifold, and contacting the ceramic matrix composite plies with the matrix material.
Calkins, Noel C.
1991-01-01
An armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material. The glass may be in monolithic form or particles of ceramic may be dispersed in a glass matrix. The ceramic material may be in monolithic form or may be in the form of particles dispersed in glass or dispersed in said polymer.
In-depth, high-accuracy proteomics of sea urchin tooth organic matrix
Directory of Open Access Journals (Sweden)
Mann Matthias
2008-12-01
Full Text Available Abstract Background The organic matrix contained in biominerals plays an important role in regulating mineralization and in determining biomineral properties. However, most components of biomineral matrices remain unknown at present. In sea urchin tooth, which is an important model for developmental biology and biomineralization, only few matrix components have been identified. The recent publication of the Strongylocentrotus purpuratus genome sequence rendered possible not only the identification of genes potentially coding for matrix proteins, but also the direct identification of proteins contained in matrices of skeletal elements by in-depth, high-accuracy proteomic analysis. Results We identified 138 proteins in the matrix of tooth powder. Only 56 of these proteins were previously identified in the matrices of test (shell and spine. Among the novel components was an interesting group of five proteins containing alanine- and proline-rich neutral or basic motifs separated by acidic glycine-rich motifs. In addition, four of the five proteins contained either one or two predicted Kazal protease inhibitor domains. The major components of tooth matrix were however largely identical to the set of spicule matrix proteins and MSP130-related proteins identified in test (shell and spine matrix. Comparison of the matrices of crushed teeth to intact teeth revealed a marked dilution of known intracrystalline matrix proteins and a concomitant increase in some intracellular proteins. Conclusion This report presents the most comprehensive list of sea urchin tooth matrix proteins available at present. The complex mixture of proteins identified may reflect many different aspects of the mineralization process. A comparison between intact tooth matrix, presumably containing odontoblast remnants, and crushed tooth matrix served to differentiate between matrix components and possible contributions of cellular remnants. Because LC-MS/MS-based methods directly
Strategy BMT Al-Ittihad Using Matrix IE, Matrix SWOT 8K, Matrix SPACE and Matrix TWOS
Directory of Open Access Journals (Sweden)
Nofrizal Nofrizal
2018-03-01
Full Text Available This research aims to formulate and select BMT Al-Ittihad Rumbai strategy to face the changing of business environment both from internal environment such as organization resources, finance, member and external business such as competitor, economy, politics and others. This research method used Analysis of EFAS, IFAS, IE Matrix, SWOT-8K Matrix, SPACE Matrix and TWOS Matrix. our hope from this research it can assist BMT Al-Ittihad in formulating and selecting strategies for the sustainability of BMT Al-Ittihad in the future. The sample in this research is using purposive sampling technique that is the manager and leader of BMT Al-IttihadRumbaiPekanbaru. The result of this research shows that the position of BMT Al-Ittihad using IE Matrix, SWOT-8K Matrix and SPACE Matrix is in growth position, stabilization and aggressive. The choice of strategy after using TWOS Matrix is market penetration, market development, vertical integration, horizontal integration, and stabilization (careful.
Jairam, Dharmananda; Kiewra, Kenneth A.; Kauffman, Douglas F.; Zhao, Ruomeng
2012-01-01
This study investigated how best to study a matrix. Fifty-three participants studied a matrix topically (1 column at a time), categorically (1 row at a time), or in a unified way (all at once). Results revealed that categorical and unified study produced higher: (a) performance on relationship and fact tests, (b) study material satisfaction, and…
Quantum mechanics in matrix form
Ludyk, Günter
2018-01-01
This book gives an introduction to quantum mechanics with the matrix method. Heisenberg's matrix mechanics is described in detail. The fundamental equations are derived by algebraic methods using matrix calculus. Only a brief description of Schrödinger's wave mechanics is given (in most books exclusively treated), to show their equivalence to Heisenberg's matrix method. In the first part the historical development of Quantum theory by Planck, Bohr and Sommerfeld is sketched, followed by the ideas and methods of Heisenberg, Born and Jordan. Then Pauli's spin and exclusion principles are treated. Pauli's exclusion principle leads to the structure of atoms. Finally, Dirac´s relativistic quantum mechanics is shortly presented. Matrices and matrix equations are today easy to handle when implementing numerical algorithms using standard software as MAPLE and Mathematica.
S-matrix singularities and CFT correlation functions
Cardona, Carlos; Huang, Yu-tin
2017-08-01
In this note, we explore the correspondence between four-dimensional flat space S-matrix and two-dimensional CFT proposed by Pasterski et al. We demonstrate that the factorisation singularities of an n-point cubic diagram reproduces the AdS Witten diagrams if mass conservation is imposed at each vertex. Such configuration arises naturally if we consider the 4-dimensional S-matrix as a compactified massless 5-dimensional theory. This identification allows us to rewrite the massless S-matrix in the CHY formulation, where the factorisation singularities are re-interpreted as factorisation limits of a Riemann sphere. In this light, the map is recast into a form of 2 d/2 d correspondence.
Phase transition in tensor models
Energy Technology Data Exchange (ETDEWEB)
Delepouve, Thibault [Laboratoire de Physique Théorique, CNRS UMR 8627, Université Paris Sud,91405 Orsay Cedex (France); Centre de Physique Théorique, CNRS UMR 7644, École Polytechnique,91128 Palaiseau Cedex (France); Gurau, Razvan [Centre de Physique Théorique, CNRS UMR 7644, École Polytechnique,91128 Palaiseau Cedex (France); Perimeter Institute for Theoretical Physics,31 Caroline St. N, N2L 2Y5, Waterloo, ON (Canada)
2015-06-25
Generalizing matrix models, tensor models generate dynamical triangulations in any dimension and support a 1/N expansion. Using the intermediate field representation we explicitly rewrite a quartic tensor model as a field theory for a fluctuation field around a vacuum state corresponding to the resummation of the entire leading order in 1/N (a resummation of the melonic family). We then prove that the critical regime in which the continuum limit in the sense of dynamical triangulations is reached is precisely a phase transition in the field theory sense for the fluctuation field.
International Nuclear Information System (INIS)
Anon.
2013-01-01
The yearly environmental conference will hold on September 2013 to evaluate the negotiations led at the national and local levels for december 2012. The government will have then to decide of an energy programming bill which will be submitted to the Parliament at the beginning of the year 2014. 30 main propositions have emerged of the decentralised debates. One of them is the ecological taxation which raise the question of the gas oil and petrol taxation. The current environmental taxes are for almost three quarters of them taxes on energy consumptions and mainly on fossil energies. The Economic, Social and Environmental Council, gives his opinion on the way to find resources to ensure the ecological and energy transition while reducing the public deficit of the State. (O.M.)
Spectral statistics in semiclassical random-matrix ensembles
International Nuclear Information System (INIS)
Feingold, M.; Leitner, D.M.; Wilkinson, M.
1991-01-01
A novel random-matrix ensemble is introduced which mimics the global structure inherent in the Hamiltonian matrices of autonomous, ergodic systems. Changes in its parameters induce a transition between a Poisson and a Wigner distribution for the level spacings, P(s). The intermediate distributions are uniquely determined by a single scaling variable. Semiclassical constraints force the ensemble to be in a regime with Wigner P(s) for systems with more than two freedoms
Double β-decay nuclear matrix elements and lepton conservation
International Nuclear Information System (INIS)
Vergados, J.D.
1976-01-01
The nuclear matrix elements involved in the double β-decay of 48 Ca, 130 Te, and 128 Te were calculated using realistic nuclear interactions and shell model nuclear wave functions. The double doorway state is not appreciably mixed in the ground state of the final nuclei. So the ground state transitions contain a small fraction of the sum rule. A lepton nonconservation parameter eta -4 was deduced
Matrix-Bound Nanovesicles Recapitulate Extracellular Matrix Effects on Macrophage Phenotype.
Huleihel, Luai; Bartolacci, Joseph G; Dziki, Jenna L; Vorobyov, Tatiana; Arnold, Brooke; Scarritt, Michelle E; Pineda Molina, Catalina; LoPresti, Samuel T; Brown, Bryan N; Naranjo, Juan Diego; Badylak, Stephen F
2017-11-01
The early macrophage response to biomaterials has been shown to be a critical and predictive determinant of downstream outcomes. When properly prepared, bioscaffolds composed of mammalian extracellular matrix (ECM) have been shown to promote a transition in macrophage behavior from a proinflammatory to a regulatory/anti-inflammatory phenotype, which in turn has been associated with constructive and functional tissue repair. The mechanism by which ECM bioscaffolds promote this phenotypic transition, however, is poorly understood. The present study shows that matrix-bound nanovesicles (MBV), a component of ECM bioscaffolds, are capable of recapitulating the macrophage activation effects of the ECM bioscaffold from which they are derived. MBV isolated from two different source tissues, porcine urinary bladder and small intestinal submucosa, were found to be enriched in miRNA125b-5p, 143-3p, and 145-5p. Inhibition of these miRNAs within macrophages was associated with a gene and protein expression profile more consistent with a proinflammatory rather than an anti-inflammatory/regulatory phenotype. MBV and their associated miRNA cargo appear to play a significant role in mediating the effects of ECM bioscaffolds on macrophage phenotype.
Grassi, Alba; Mariño, Marcos
2015-02-01
Some matrix models admit, on top of the usual 't Hooft expansion, an M-theory-like expansion, i.e. an expansion at large N but where the rest of the parameters are fixed, instead of scaling with N . These models, which we call M-theoretic matrix models, appear in the localization of Chern-Simons-matter theories, and also in two-dimensional statistical physics. Generically, their partition function receives non-perturbative corrections which are not captured by the 't Hooft expansion. In this paper, we discuss general aspects of these type of matrix integrals and we analyze in detail two different examples. The first one is the matrix model computing the partition function of supersymmetric Yang-Mills theory in three dimensions with one adjoint hypermultiplet and N f fundamentals, which has a conjectured M-theory dual, and which we call the N f matrix model. The second one, which we call the polymer matrix model, computes form factors of the 2d Ising model and is related to the physics of 2d polymers. In both cases we determine their exact planar limit. In the N f matrix model, the planar free energy reproduces the expected behavior of the M-theory dual. We also study their M-theory expansion by using Fermi gas techniques, and we find non-perturbative corrections to the 't Hooft expansion.
Semiclassical S-matrix for black holes
Bezrukov, Fedor; Sibiryakov, Sergey
2015-01-01
We propose a semiclassical method to calculate S-matrix elements for two-stage gravitational transitions involving matter collapse into a black hole and evaporation of the latter. The method consistently incorporates back-reaction of the collapsing and emitted quanta on the metric. We illustrate the method in several toy models describing spherical self-gravitating shells in asymptotically flat and AdS space-times. We find that electrically neutral shells reflect via the above collapse-evaporation process with probability exp(-B), where B is the Bekenstein-Hawking entropy of the intermediate black hole. This is consistent with interpretation of exp(B) as the number of black hole states. The same expression for the probability is obtained in the case of charged shells if one takes into account instability of the Cauchy horizon of the intermediate Reissner-Nordstrom black hole. Our semiclassical method opens a new systematic approach to the gravitational S-matrix in the non-perturbative regime.
Containment Code Validation Matrix
International Nuclear Information System (INIS)
Chin, Yu-Shan; Mathew, P.M.; Glowa, Glenn; Dickson, Ray; Liang, Zhe; Leitch, Brian; Barber, Duncan; Vasic, Aleks; Bentaib, Ahmed; Journeau, Christophe; Malet, Jeanne; Studer, Etienne; Meynet, Nicolas; Piluso, Pascal; Gelain, Thomas; Michielsen, Nathalie; Peillon, Samuel; Porcheron, Emmanuel; Albiol, Thierry; Clement, Bernard; Sonnenkalb, Martin; Klein-Hessling, Walter; Arndt, Siegfried; Weber, Gunter; Yanez, Jorge; Kotchourko, Alexei; Kuznetsov, Mike; Sangiorgi, Marco; Fontanet, Joan; Herranz, Luis; Garcia De La Rua, Carmen; Santiago, Aleza Enciso; Andreani, Michele; Paladino, Domenico; Dreier, Joerg; Lee, Richard; Amri, Abdallah
2014-01-01
The Committee on the Safety of Nuclear Installations (CSNI) formed the CCVM (Containment Code Validation Matrix) task group in 2002. The objective of this group was to define a basic set of available experiments for code validation, covering the range of containment (ex-vessel) phenomena expected in the course of light and heavy water reactor design basis accidents and beyond design basis accidents/severe accidents. It was to consider phenomena relevant to pressurised heavy water reactor (PHWR), pressurised water reactor (PWR) and boiling water reactor (BWR) designs of Western origin as well as of Eastern European VVER types. This work would complement the two existing CSNI validation matrices for thermal hydraulic code validation (NEA/CSNI/R(1993)14) and In-vessel core degradation (NEA/CSNI/R(2001)21). The report initially provides a brief overview of the main features of a PWR, BWR, CANDU and VVER reactors. It also provides an overview of the ex-vessel corium retention (core catcher). It then provides a general overview of the accident progression for light water and heavy water reactors. The main focus is to capture most of the phenomena and safety systems employed in these reactor types and to highlight the differences. This CCVM contains a description of 127 phenomena, broken down into 6 categories: - Containment Thermal-hydraulics Phenomena; - Hydrogen Behaviour (Combustion, Mitigation and Generation) Phenomena; - Aerosol and Fission Product Behaviour Phenomena; - Iodine Chemistry Phenomena; - Core Melt Distribution and Behaviour in Containment Phenomena; - Systems Phenomena. A synopsis is provided for each phenomenon, including a description, references for further information, significance for DBA and SA/BDBA and a list of experiments that may be used for code validation. The report identified 213 experiments, broken down into the same six categories (as done for the phenomena). An experiment synopsis is provided for each test. Along with a test description
Oehlmann, Dietmar; Ohlmann, Odile M.; Danzebrink, Hans U.
2005-04-01
perform this exchange, as a matrix, understood as source, of new ideas.
Zhang, Jianhua; Klos, Matthew; Wilson, Gisela F.; Herman, Amanda M.; Lian, Xiaojun; Raval, Kunil K.; Barron, Matthew R.; Hou, Luqia; Soerens, Andrew G.; Yu, Junying; Palecek, Sean P.; Lyons, Gary E.; Thomson, James A.; Herron, Todd J.; Jalife, José; Kamp, Timothy J.
2012-01-01
Rationale Cardiomyocytes differentiated from human pluripotent stem cells (PSCs) are increasingly being used for cardiovascular research including disease modeling and hold promise for clinical applications. Current cardiac differentiation protocols exhibit variable success across different PSC lines and are primarily based on the application of growth factors. However, extracellular matrix (ECM) is also fundamentally involved in cardiac development from the earliest morphogenetic events such as gastrulation. Objective We sought to develop a more effective protocol for cardiac differentiation of human PSCs by using ECM in combination with growth factors known to promote cardiogenesis. Methods and Results PSCs were cultured as monolayers on Matrigel, an ECM preparation, and subsequently overlayed with Matrigel. The matrix sandwich promoted an epithelial-to-mesenchymal transition as in gastrulation with the generation of N-cadherin+ mesenchymal cells. Combining the matrix sandwich with sequential application of growth factors (Activin A, BMP4, and bFGF) generated cardiomyocytes with high purity (up to 98%) and yield (up to 11 cardiomyocytes/input PSC) from multiple PSC lines. The resulting cardiomyocytes progressively mature over 30 days in culture based on myofilament expression pattern and mitotic activity. Action potentials typical of embryonic nodal, atrial and ventricular cardiomyocytes were observed, and monolayers of electrically coupled cardiomyocytes modeled cardiac tissue and basic arrhythmia mechanisms. Conclusions Dynamic ECM application promoted EMT of human PSCs and complemented growth factor signaling to enable robust cardiac differentiation. PMID:22912385
Lin, Jian-Shian; Su, Chih-Chieh; Chou, Ta-Hsin; Wu, Mount-Learn; Lai, Chieh-Lung; Hsu, Che-Lung; Lan, Hsiao-Chin; Huang, Hung-I.; Liu, Yung-Chih; Tu, Zong-Ru; Lee, Chien-Chieh; Chang, Jenq-Yang
2007-09-01
In this Letter, the identification device disclosed in the present invention is comprised of: a carrier and a plurality of pseudo-pixels; wherein each of the plural pseudo-pixels is formed on the carrier and is further comprised of at least a light grating composed of a plurality of light grids. In a preferred aspect, each of the plural light grids is formed on the carrier while spacing from each other by an interval ranged between 50nm and 900nm. As the aforesaid identification device can present specific colors and patterns while it is being viewed by naked eye with respect to a specific viewing angle, the identification device is preferred for security and anti-counterfeit applications since the specific colors and patterns will become invisible when it is viewed while deviating from the specific viewing angle.
Sequential blind identification of underdetermined mixtures using a novel deflation scheme.
Zhang, Mingjian; Yu, Simin; Wei, Gang
2013-09-01
In this brief, we consider the problem of blind identification in underdetermined instantaneous mixture cases, where there are more sources than sensors. A new blind identification algorithm, which estimates the mixing matrix in a sequential fashion, is proposed. By using the rank-1 detecting device, blind identification is reformulated as a constrained optimization problem. The identification of one column of the mixing matrix hence reduces to an optimization task for which an efficient iterative algorithm is proposed. The identification of the other columns of the mixing matrix is then carried out by a generalized eigenvalue decomposition-based deflation method. The key merit of the proposed deflation method is that it does not suffer from error accumulation. The proposed sequential blind identification algorithm provides more flexibility and better robustness than its simultaneous counterpart. Comparative simulation results demonstrate the superior performance of the proposed algorithm over the simultaneous blind identification algorithm.
On matrix diffusion: formulations, solution methods and qualitative effects
Carrera, Jesús; Sánchez-Vila, Xavier; Benet, Inmaculada; Medina, Agustín; Galarza, Germán; Guimerà, Jordi
(traçages de longue durée) ne dépend que de φmRm, et non pas du coefficient de diffusion matricielle ou de la forme et de la taille des blocs. Ceci est toujours vrai pour le temps moyen d'arrivée. Ces propriétés permettent: (a) d'analyser le comportement de la diffusion matricielle; (b) d'expliquer un paradoxe du transport de soluté dans les roches fracturées (la dépendance apparente entre la porosité et le temps de transit); (c) de faire la distinction entre la diffusion matricielle et d'autres problèmes, tels que la sorption cinétique ou l'hétérogénéité et (d) de décrire les problèmes d'identification et les façons de les résoudre. Resumen La difusión en la matriz está reconocida en la actualidad como un importante mecanismo de transporte de solutos. Desgraciadamente, tener en cuenta este proceso complica las simulaciones de transporte. Esto ha llevado a una serie de formulaciones simplificadas, motivadas en parte por el propio método de solución. Como resultado, se ha producido cierta confusión respecto a cuál es la manera adecuada de formular el problema. Uno de los objetivos de este trabajo es encontrar una cierta unidad entre las formulaciones existentes y los métodos de solución, lo que conduce a algunas propiedades asintóticas de la difusión en la matriz; específicamente, se comprueba que el comportamiento para tiempos cortos depende únicamente del parámetro φm2RmDm / Lm2, mientras que el de tiempos largos depende sólo de φmRm, y no del coeficiente de difusión en la matriz o del tamaño o forma del bloque. Esto último también es cierto, en todos los casos, respecto al tiempo medio de llegada (definido como el valor esperado de la distribución de tiempos de llegada). Estas propiedades son útiles para: (a) analizar el comportamiento cualitativo de la difusión en la matriz; (b) explicar una de las paradojas del transporte de solutos en medios fracturados, la aparente dependencia entre porosidad y tiempo de llegada; (c
Matrix Converter in Hybrid Drives
Czech Academy of Sciences Publication Activity Database
Lettl, Jiří; Flígl, S.
-, č. 3 (2004), s. 77-80 ISSN 0204-3599 Institutional research plan: CEZ:AV0Z2057903 Keywords : matrix converter * hybrid drive * electric power splitting Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
National Oceanic and Atmospheric Administration, Department of Commerce — This data set was taken from CRD 08-18 at the NEFSC. Specifically, the Gulf of Maine diet matrix was developed for the EMAX exercise described in that center...
Radiation resistant ceramic matrix composites
International Nuclear Information System (INIS)
Jones, R.H.; Steiner, D.; Heinisch, H.L.; Newsome, G.A.; Kerch, H.M.
1997-01-01
Ceramic matrix composites are of interest for nuclear applications because of their high-temperature properties, corrosion resistance, fracture toughness relative to monolithic ceramics, and low neutron activation and after heat. Evaluations of the radiation resistance of commercially available SiC/SiC composites have revealed their promise for this application, but also the need for further development to achieve the desired performance. This paper summarizes the results of a workshop cosponsored by the Offices of Fusion Energy and Basic Energy Sciences of the US Department of Energy and Lockheed-Martin Corporation with forty attendees from national laboratories, universities and industry. A number of promising routes for optimizing the radiation stability of ceramic matrix composites were identified at this workshop. These routes included the newer, more stoichiometric fibers and alternate fiber/matrix interfaces and matrix processing routes. (orig.)
International Nuclear Information System (INIS)
Descouvemont, P; Baye, D
2010-01-01
The different facets of the R-matrix method are presented pedagogically in a general framework. Two variants have been developed over the years: (i) The 'calculable' R-matrix method is a calculational tool to derive scattering properties from the Schroedinger equation in a large variety of physical problems. It was developed rather independently in atomic and nuclear physics with too little mutual influence. (ii) The 'phenomenological' R-matrix method is a technique to parametrize various types of cross sections. It was mainly (or uniquely) used in nuclear physics. Both directions are explained by starting from the simple problem of scattering by a potential. They are illustrated by simple examples in nuclear and atomic physics. In addition to elastic scattering, the R-matrix formalism is applied to inelastic and radiative-capture reactions. We also present more recent and more ambitious applications of the theory in nuclear physics.
Matrix analysis of electrical machinery
Hancock, N N
2013-01-01
Matrix Analysis of Electrical Machinery, Second Edition is a 14-chapter edition that covers the systematic analysis of electrical machinery performance. This edition discusses the principles of various mathematical operations and their application to electrical machinery performance calculations. The introductory chapters deal with the matrix representation of algebraic equations and their application to static electrical networks. The following chapters describe the fundamentals of different transformers and rotating machines and present torque analysis in terms of the currents based on the p
Bilateral matrix-exponential distributions
DEFF Research Database (Denmark)
Bladt, Mogens; Esparza, Luz Judith R; Nielsen, Bo Friis
2012-01-01
In this article we define the classes of bilateral and multivariate bilateral matrix-exponential distributions. These distributions have support on the entire real space and have rational moment-generating functions. These distributions extend the class of bilateral phasetype distributions of [1]....... As an application we demonstrate that certain multivariate disions, which are governed by the underlying Markov jump process generating a phasetype distribution, have a bilateral matrix-exponential distribution at the time of absorption, see also [4]....
Matrix Effects in XRF Measurements
International Nuclear Information System (INIS)
Kandil, A.T.; Gabr, N.A.; El-Aryan, S.M.
2015-01-01
This research treats the matrix effect on XRF measurements. The problem is treated by preparing general oxide program, which contains many samples that represent all materials in cement factories, then by using T rail Lachance m ethod to correct errors of matrix effect. This work compares the effect of using lithium tetraborate or sodium tetraborate as a fluxing agent in terms of accuracy and economic cost
Capacitance matrix method in TRAC and MELPROG
International Nuclear Information System (INIS)
Steinke, R.G.; Dearing, J.F.
1989-01-01
The capacitance matrix method has been used in the TRAC and MELPROG transient, thermal-hydraulic, safety-analysis computer programs to solve the multi-dimensional-vessel matrix equations. A full-matrix solver rather than a more efficient banded-matrix solver was used previously because of nonzero elements lying outside the matrix bandwidth. These outlying nonzero elements result from vessel external and internal pipe flow channels connecting non-adjacent cells in the multidimensional vessel component. The capacitance matrix method provides a more efficient solution algorithm by solving the banded portion of the vessel-matrix equation with a banded-matrix solver. The effect of the nonzero outlying elements on that solution is accounted for through matrix algebra and a lower order capacitance-matrix equation solution that modifies the banded-matrix solution to give the full-matrix solution. 5 refs., 2 figs
Energy Technology Data Exchange (ETDEWEB)
Sousa Teixeira, Maurilo de [Fundacao Universidade de Sao Joao del Rei (FUNREI), MG (Brazil); Lima, Rolando N.O. [Escola Federal de Engenharia de Itajuba, MG (Brazil)
1991-12-31
The identification of energetic residues in the industrial plants has been appointed unappropriated ways of energy uses in the conversion processes. There is an urgent need of making a detailed energetic matrix. Moreover, it will become easy to adopt optimization measures in such plants. In this paper, the Brazilian energetic matrix has been discussed and compared with the American one. Finally, some suggestions were presented. 4 refs., 2 tabs
NASA Technologies for Product Identification
Schramm, Fred, Jr.
2006-01-01
Since 1975 bar codes on products at the retail counter have been accepted as the standard for entering product identity for price determination. Since the beginning of the 21st century, the Data Matrix symbol has become accepted as the bar code format that is marked directly on a part, assembly or product that is durable enough to identify that item for its lifetime. NASA began the studies for direct part marking Data Matrix symbols on parts during the Return to Flight activities after the Challenger Accident. Over the 20 year period that has elapsed since Challenger, a mountain of studies, analyses and focused problem solutions developed by and for NASA have brought about world changing results. NASA Technical Standard 6002 and NASA Handbook 6003 for Direct Part Marking Data Matrix Symbols on Aerospace Parts have formed the basis for most other standards on part marking internationally. NASA and its commercial partners have developed numerous products and methods that addressed the difficulties of collecting part identification in aerospace operations. These products enabled the marking of Data Matrix symbols in virtually every situation and the reading of symbols at great distances, severe angles, under paint and in the dark without a light. Even unmarkable delicate parts now have a process to apply a chemical mixture called NanocodesTM that can be converted to a Data Matrix. The accompanying intellectual property is protected by 10 patents, several of which are licensed. Direct marking Data Matrix on NASA parts virtually eliminates data entry errors and the number of parts that go through their life cycle unmarked, two major threats to sound configuration management and flight safety. NASA is said to only have people and stuff with information connecting them. Data Matrix is one of the most significant improvements since Challenger to the safety and reliability of that connection. This presentation highlights the accomplishments of NASA in its efforts to develop
Patterns of Work Identification
Hebden, J. E.
1975-01-01
The paper examines ways in which the concept of work identification may provide a useful means of delineating the boundaries of occupational groups. Two kinds of identification are discussed: identification with employing organizations and identification with occupation.
Localization of soft modes at the depinning transition
Cao, Xiangyu; Bouzat, Sebastian; Kolton, Alejandro B.; Rosso, Alberto
2018-02-01
We characterize the soft modes of the dynamical matrix at the depinning transition, and compare the matrix with the properties of the Anderson model (and long-range generalizations). The density of states at the edge of the spectrum displays a universal linear tail, different from the Lifshitz tails. The eigenvectors are instead very similar in the two matrix ensembles. We focus on the ground state (soft mode), which represents the epicenter of avalanche instabilities. We expect it to be localized in all finite dimensions, and make a clear connection between its localization length and the Larkin length of the depinning model. In the fully connected model, we show that the weak-strong pinning transition coincides with a peculiar localization transition of the ground state.
A survey of matrix theory and matrix inequalities
Marcus, Marvin
2010-01-01
Written for advanced undergraduate students, this highly regarded book presents an enormous amount of information in a concise and accessible format. Beginning with the assumption that the reader has never seen a matrix before, the authors go on to provide a survey of a substantial part of the field, including many areas of modern research interest.Part One of the book covers not only the standard ideas of matrix theory, but ones, as the authors state, ""that reflect our own prejudices,"" among them Kronecker products, compound and induced matrices, quadratic relations, permanents, incidence
3-Loop massive O(T2F) contributions to the DIS operator matrix element Agg
International Nuclear Information System (INIS)
Ablinger, J.; Schneider, C.; Bluemlein, J.; Freitas, A. de; Hasselhuhn, A.; Round, M.; Manteuffel, A. von
2014-09-01
Contributions to heavy flavour transition matrix elements in the variable flavour number scheme are considered at 3-loop order. In particular a calculation of the diagrams with two equal masses that contribute to the massive operator matrix element A (3) gg,Q is performed. In the Mellin space result one finds finite nested binomial sums. In x-space these sums correspond to iterated integrals over an alphabet containing also square-root valued letters.
Parametric Level Statistics in Random Matrix Theory: Exact Solution
International Nuclear Information System (INIS)
Kanzieper, E.
1999-01-01
During recent several years, the theory of non-Gaussian random matrix ensembles has experienced a sound progress motivated by new ideas in quantum chromodynamics (QCD) and mesoscopic physics. Invariant non-Gaussian random matrix models appear to describe universal features of low-energy part of the spectrum of Dirac operator in QCD, and electron level statistics in normal conducting-superconducting hybrid structures. They also serve as a basis for constructing the toy models of universal spectral statistics expected at the edge of the metal-insulator transition. While conventional spectral statistics has received a detailed study in the context of RMT, quite a bit is known about parametric level statistics in non-Gaussian random matrix models. In this communication we report about exact solution to the problem of parametric level statistics in unitary invariant, U(N), non-Gaussian ensembles of N x N Hermitian random matrices with either soft or strong level confinement. The solution is formulated within the framework of the orthogonal polynomial technique and is shown to depend on both the unfolded two-point scalar kernel and the level confinement through a double integral transformation which, in turn, provides a constructive tool for description of parametric level correlations in non-Gaussian RMT. In the case of soft level confinement, the formalism developed is potentially applicable to a study of parametric level statistics in an important class of random matrix models with finite level compressibility expected to describe a disorder-induced metal-insulator transition. In random matrix ensembles with strong level confinement, the solution presented takes a particular simple form in the thermodynamic limit: In this case, a new intriguing connection relation between the parametric level statistics and the scalar two-point kernel of an unperturbed ensemble is demonstrated to emerge. Extension of the results obtained to higher-order parametric level statistics is
DEFF Research Database (Denmark)
Jacobsen, Torben Krogsdal; Brøndsted, Povl
1997-01-01
A study of the strain redistribution around holes in two different cross-woven ceramic matrix composites is presented. The strain redistribution around holes in C-f/SiCm and SiCf/SiCm has been measured experimentally under plane stress conditions. Using micro-mechanics and Continuum Damage...... Mechanics, and an identification procedure based on a uni-axial tensile test and a shear test the strain redistribution around a hole or a notch due to matrix cracking can be predicted. Damage due to fiber breakage is not included in the model. Initial matrix damage in the C-f/SiCm material has...
Matrix isolation as a tool for studying interstellar chemical reactions
International Nuclear Information System (INIS)
Ball, D.W.; Ortman, B.J.; Hauge, R.H.; Margrave, J.L.
1989-01-01
Since the identification of the OH radical as an interstellar species, over 50 molecular species were identified as interstellar denizens. While identification of new species appears straightforward, an explanation for their mechanisms of formation is not. Most astronomers concede that large bodies like interstellar dust grains are necessary for adsorption of molecules and their energies of reactions, but many of the mechanistic steps are unknown and speculative. It is proposed that data from matrix isolation experiments involving the reactions of refractory materials (especially C, Si, and Fe atoms and clusters) with small molecules (mainly H2, H2O, CO, CO2) are particularly applicable to explaining mechanistic details of likely interstellar chemical reactions. In many cases, matrix isolation techniques are the sole method of studying such reactions; also in many cases, complexations and bond rearrangements yield molecules never before observed. The study of these reactions thus provides a logical basis for the mechanisms of interstellar reactions. A list of reactions is presented that would simulate interstellar chemical reactions. These reactions were studied using FTIR-matrix isolation techniques
McDonnell, Mark D; Yaveroğlu, Ömer Nebil; Schmerl, Brett A; Iannella, Nicolangelo; Ward, Lawrence M
2014-01-01
Complex networks are frequently characterized by metrics for which particular subgraphs are counted. One statistic from this category, which we refer to as motif-role fingerprints, differs from global subgraph counts in that the number of subgraphs in which each node participates is counted. As with global subgraph counts, it can be important to distinguish between motif-role fingerprints that are 'structural' (induced subgraphs) and 'functional' (partial subgraphs). Here we show mathematically that a vector of all functional motif-role fingerprints can readily be obtained from an arbitrary directed adjacency matrix, and then converted to structural motif-role fingerprints by multiplying that vector by a specific invertible conversion matrix. This result demonstrates that a unique structural motif-role fingerprint exists for any given functional motif-role fingerprint. We demonstrate a similar result for the cases of functional and structural motif-fingerprints without node roles, and global subgraph counts that form the basis of standard motif analysis. We also explicitly highlight that motif-role fingerprints are elemental to several popular metrics for quantifying the subgraph structure of directed complex networks, including motif distributions, directed clustering coefficient, and transitivity. The relationships between each of these metrics and motif-role fingerprints also suggest new subtypes of directed clustering coefficients and transitivities. Our results have potential utility in analyzing directed synaptic networks constructed from neuronal connectome data, such as in terms of centrality. Other potential applications include anomaly detection in networks, identification of similar networks and identification of similar nodes within networks. Matlab code for calculating all stated metrics following calculation of functional motif-role fingerprints is provided as S1 Matlab File.
Directory of Open Access Journals (Sweden)
Mark D McDonnell
Full Text Available Complex networks are frequently characterized by metrics for which particular subgraphs are counted. One statistic from this category, which we refer to as motif-role fingerprints, differs from global subgraph counts in that the number of subgraphs in which each node participates is counted. As with global subgraph counts, it can be important to distinguish between motif-role fingerprints that are 'structural' (induced subgraphs and 'functional' (partial subgraphs. Here we show mathematically that a vector of all functional motif-role fingerprints can readily be obtained from an arbitrary directed adjacency matrix, and then converted to structural motif-role fingerprints by multiplying that vector by a specific invertible conversion matrix. This result demonstrates that a unique structural motif-role fingerprint exists for any given functional motif-role fingerprint. We demonstrate a similar result for the cases of functional and structural motif-fingerprints without node roles, and global subgraph counts that form the basis of standard motif analysis. We also explicitly highlight that motif-role fingerprints are elemental to several popular metrics for quantifying the subgraph structure of directed complex networks, including motif distributions, directed clustering coefficient, and transitivity. The relationships between each of these metrics and motif-role fingerprints also suggest new subtypes of directed clustering coefficients and transitivities. Our results have potential utility in analyzing directed synaptic networks constructed from neuronal connectome data, such as in terms of centrality. Other potential applications include anomaly detection in networks, identification of similar networks and identification of similar nodes within networks. Matlab code for calculating all stated metrics following calculation of functional motif-role fingerprints is provided as S1 Matlab File.
QCD Matrix Elements + Parton Showers
Catani, S; Kühn, R; Webber, Bryan R
2001-01-01
We propose a method for combining QCD matrix elements and parton showers in Monte Carlo simulations of hadronic final states in $e^+e^-$ annihilation. The matrix element and parton shower domains are separated at some value $y_{ini}$ of the jet resolution, defined according to the $k_T$-clustering algorithm. The matrix elements are modified by Sudakov form factors and the parton showers are subjected to a veto procedure to cancel dependence on $y_{ini}$ to next-to-leading logarithmic accuracy. The method provides a leading-order description of hard multi-jet configurations together with jet fragmentation, while avoiding the most serious problems of double counting. We present first results of an approximate implementation using the event generator APACIC++.
Lectures on matrix field theory
Ydri, Badis
2017-01-01
These lecture notes provide a systematic introduction to matrix models of quantum field theories with non-commutative and fuzzy geometries. The book initially focuses on the matrix formulation of non-commutative and fuzzy spaces, followed by a description of the non-perturbative treatment of the corresponding field theories. As an example, the phase structure of non-commutative phi-four theory is treated in great detail, with a separate chapter on the multitrace approach. The last chapter offers a general introduction to non-commutative gauge theories, while two appendices round out the text. Primarily written as a self-study guide for postgraduate students – with the aim of pedagogically introducing them to key analytical and numerical tools, as well as useful physical models in applications – these lecture notes will also benefit experienced researchers by providing a reference guide to the fundamentals of non-commutative field theory with an emphasis on matrix models and fuzzy geometries.
Noncommutative spaces from matrix models
Lu, Lei
Noncommutative (NC) spaces commonly arise as solutions to matrix model equations of motion. They are natural generalizations of the ordinary commutative spacetime. Such spaces may provide insights into physics close to the Planck scale, where quantum gravity becomes relevant. Although there has been much research in the literature, aspects of these NC spaces need further investigation. In this dissertation, we focus on properties of NC spaces in several different contexts. In particular, we study exact NC spaces which result from solutions to matrix model equations of motion. These spaces are associated with finite-dimensional Lie-algebras. More specifically, they are two-dimensional fuzzy spaces that arise from a three-dimensional Yang-Mills type matrix model, four-dimensional tensor-product fuzzy spaces from a tensorial matrix model, and Snyder algebra from a five-dimensional tensorial matrix model. In the first part of this dissertation, we study two-dimensional NC solutions to matrix equations of motion of extended IKKT-type matrix models in three-space-time dimensions. Perturbations around the NC solutions lead to NC field theories living on a two-dimensional space-time. The commutative limit of the solutions are smooth manifolds which can be associated with closed, open and static two-dimensional cosmologies. One particular solution is a Lorentzian fuzzy sphere, which leads to essentially a fuzzy sphere in the Minkowski space-time. In the commutative limit, this solution leads to an induced metric that does not have a fixed signature, and have a non-constant negative scalar curvature, along with singularities at two fixed latitudes. The singularities are absent in the matrix solution which provides a toy model for resolving the singularities of General relativity. We also discussed the two-dimensional fuzzy de Sitter space-time, which has irreducible representations of su(1,1) Lie-algebra in terms of principal, complementary and discrete series. Field
Supersymmetry in random matrix theory
Energy Technology Data Exchange (ETDEWEB)
Kieburg, Mario
2010-05-04
I study the applications of supersymmetry in random matrix theory. I generalize the supersymmetry method and develop three new approaches to calculate eigenvalue correlation functions. These correlation functions are averages over ratios of characteristic polynomials. In the first part of this thesis, I derive a relation between integrals over anti-commuting variables (Grassmann variables) and differential operators with respect to commuting variables. With this relation I rederive Cauchy- like integral theorems. As a new application I trace the supermatrix Bessel function back to a product of two ordinary matrix Bessel functions. In the second part, I apply the generalized Hubbard-Stratonovich transformation to arbitrary rotation invariant ensembles of real symmetric and Hermitian self-dual matrices. This extends the approach for unitarily rotation invariant matrix ensembles. For the k-point correlation functions I derive supersymmetric integral expressions in a unifying way. I prove the equivalence between the generalized Hubbard-Stratonovich transformation and the superbosonization formula. Moreover, I develop an alternative mapping from ordinary space to superspace. After comparing the results of this approach with the other two supersymmetry methods, I obtain explicit functional expressions for the probability densities in superspace. If the probability density of the matrix ensemble factorizes, then the generating functions exhibit determinantal and Pfaffian structures. For some matrix ensembles this was already shown with help of other approaches. I show that these structures appear by a purely algebraic manipulation. In this new approach I use structures naturally appearing in superspace. I derive determinantal and Pfaffian structures for three types of integrals without actually mapping onto superspace. These three types of integrals are quite general and, thus, they are applicable to a broad class of matrix ensembles. (orig.)
Supersymmetry in random matrix theory
International Nuclear Information System (INIS)
Kieburg, Mario
2010-01-01
I study the applications of supersymmetry in random matrix theory. I generalize the supersymmetry method and develop three new approaches to calculate eigenvalue correlation functions. These correlation functions are averages over ratios of characteristic polynomials. In the first part of this thesis, I derive a relation between integrals over anti-commuting variables (Grassmann variables) and differential operators with respect to commuting variables. With this relation I rederive Cauchy- like integral theorems. As a new application I trace the supermatrix Bessel function back to a product of two ordinary matrix Bessel functions. In the second part, I apply the generalized Hubbard-Stratonovich transformation to arbitrary rotation invariant ensembles of real symmetric and Hermitian self-dual matrices. This extends the approach for unitarily rotation invariant matrix ensembles. For the k-point correlation functions I derive supersymmetric integral expressions in a unifying way. I prove the equivalence between the generalized Hubbard-Stratonovich transformation and the superbosonization formula. Moreover, I develop an alternative mapping from ordinary space to superspace. After comparing the results of this approach with the other two supersymmetry methods, I obtain explicit functional expressions for the probability densities in superspace. If the probability density of the matrix ensemble factorizes, then the generating functions exhibit determinantal and Pfaffian structures. For some matrix ensembles this was already shown with help of other approaches. I show that these structures appear by a purely algebraic manipulation. In this new approach I use structures naturally appearing in superspace. I derive determinantal and Pfaffian structures for three types of integrals without actually mapping onto superspace. These three types of integrals are quite general and, thus, they are applicable to a broad class of matrix ensembles. (orig.)
Directory of Open Access Journals (Sweden)
Longbiao Li
2016-05-01
Full Text Available In this paper, the cyclic fatigue hysteresis loops of 2D woven SiC/SiC ceramic matrix composites (CMCs at elevated temperatures in steam have been investigated. The interface slip between fibers and the matrix existing in matrix cracking modes 3 and 5, in which matrix cracking and interface debonding occurred in longitudinal yarns, is considered as the major reason for hysteresis loops of 2D woven CMCs. The hysteresis loops of 2D SiC/SiC composites corresponding to different peak stresses, test conditions, and loading frequencies have been predicted using the present analysis. The damage parameter, i.e., the proportion of matrix cracking mode 3 in the entire matrix cracking modes of the composite, and the hysteresis dissipated energy increase with increasing fatigue peak stress. With increasing cycle number, the interface shear stress in the longitudinal yarns decreases, leading to transition of interface slip types of matrix cracking modes 3 and 5.
Polychoric/Tetrachoric Matrix or Pearson Matrix? A methodological study
Directory of Open Access Journals (Sweden)
Dominguez Lara, Sergio Alexis
2014-04-01
Full Text Available The use of product-moment correlation of Pearson is common in most studies in factor analysis in psychology, but it is known that this statistic is only applicable when the variables related are in interval scale and normally distributed, and when are used in ordinal data may to produce a distorted correlation matrix . Thus is a suitable option using polychoric/tetrachoric matrices in item-level factor analysis when the items are in level measurement nominal or ordinal. The aim of this study was to show the differences in the KMO, Bartlett`s Test and Determinant of the Matrix, percentage of variance explained and factor loadings in depression trait scale of Depression Inventory Trait - State and the Neuroticism dimension of the short form of the Eysenck Personality Questionnaire -Revised, regarding the use of matrices polychoric/tetrachoric matrices and Pearson. These instruments was analyzed with different extraction methods (Maximum Likelihood, Minimum Rank Factor Analysis, Unweighted Least Squares and Principal Components, keeping constant the rotation method Promin were analyzed. Were observed differences regarding sample adequacy measures, as well as with respect to the explained variance and the factor loadings, for solutions having as polychoric/tetrachoric matrix. So it can be concluded that the polychoric / tetrachoric matrix give better results than Pearson matrices when it comes to item-level factor analysis using different methods.
Symmetries and Interactions in Matrix String Theory
Hacquebord, F.H.
1999-01-01
This PhD-thesis reviews matrix string theory and recent developments therein. The emphasis is put on symmetries, interactions and scattering processes in the matrix model. We start with an introduction to matrix string theory and a review of the orbifold model that flows out of matrix string theory
Engwerda, J.C.
2005-01-01
In this note we consider the question under which conditions all entries of the matrix I-(I+X)-1 are nonnegative in case matrix X is a real positive definite matrix.Sufficient conditions are presented as well as some necessary conditions.One sufficient condition is that matrix X-1 is an inverse
International Nuclear Information System (INIS)
Makeenko, Yu.
1994-01-01
I review recent works on the problem of inducing large-N QCD by matrix fields. In the first part of the talk I describe the matrix models which induce large-N QCD and present the results of studies of their phase structure by the standard lattice technology (in particular, by the mean field method). The second part is devoted to the exact solution of these models in the strong coupling region by means of the loop equations. I describe the solution of the Kazakov-Migdal model with the quadratic and logarithmic potentials as well as that of analogous fermionic models with the quadratic potential. (orig.)
Inverse Interval Matrix: A Survey
Czech Academy of Sciences Publication Activity Database
Rohn, Jiří; Farhadsefat, R.
2011-01-01
Roč. 22, - (2011), s. 704-719 E-ISSN 1081-3810 R&D Projects: GA ČR GA201/09/1957; GA ČR GC201/08/J020 Institutional research plan: CEZ:AV0Z10300504 Keywords : interval matrix * inverse interval matrix * NP-hardness * enclosure * unit midpoint * inverse sign stability * nonnegative invertibility * absolute value equation * algorithm Subject RIV: BA - General Mathematics Impact factor: 0.808, year: 2010 http://www.math.technion.ac.il/iic/ela/ela-articles/articles/vol22_pp704-719.pdf
DEFF Research Database (Denmark)
Martensen, Anne; Jensen, J.S; Gyrd-Jones, Richard
Consumers often share opinions and personal consumption experiences on web-based consumer opinion platforms. These e-Word-of-Mouth (eWOM) reviews are powerful as they can prompt other consumers to consider a company and its offerings, but they can also cause the opposite effect. This article......WOM Matrix - where the customers’ touch points are the strategic connection between analysis and implementation of eWOM issues. The eWOM Matrix serves as a management tool, visually assisting companies to explore about which touch-points their customers’ primarily construct negative or positive e...
Towards Google matrix of brain
Energy Technology Data Exchange (ETDEWEB)
Shepelyansky, D.L., E-mail: dima@irsamc.ups-tlse.f [Laboratoire de Physique Theorique (IRSAMC), Universite de Toulouse, UPS, F-31062 Toulouse (France); LPT - IRSAMC, CNRS, F-31062 Toulouse (France); Zhirov, O.V. [Budker Institute of Nuclear Physics, 630090 Novosibirsk (Russian Federation)
2010-07-12
We apply the approach of the Google matrix, used in computer science and World Wide Web, to description of properties of neuronal networks. The Google matrix G is constructed on the basis of neuronal network of a brain model discussed in PNAS 105 (2008) 3593. We show that the spectrum of eigenvalues of G has a gapless structure with long living relaxation modes. The PageRank of the network becomes delocalized for certain values of the Google damping factor {alpha}. The properties of other eigenstates are also analyzed. We discuss further parallels and similarities between the World Wide Web and neuronal networks.
Towards Google matrix of brain
International Nuclear Information System (INIS)
Shepelyansky, D.L.; Zhirov, O.V.
2010-01-01
We apply the approach of the Google matrix, used in computer science and World Wide Web, to description of properties of neuronal networks. The Google matrix G is constructed on the basis of neuronal network of a brain model discussed in PNAS 105 (2008) 3593. We show that the spectrum of eigenvalues of G has a gapless structure with long living relaxation modes. The PageRank of the network becomes delocalized for certain values of the Google damping factor α. The properties of other eigenstates are also analyzed. We discuss further parallels and similarities between the World Wide Web and neuronal networks.
Optimizations for the EcoPod field identification tool
Directory of Open Access Journals (Sweden)
Yu YuanYuan
2008-03-01
Full Text Available Abstract Background We sketch our species identification tool for palm sized computers that helps knowledgeable observers with census activities. An algorithm turns an identification matrix into a minimal length series of questions that guide the operator towards identification. Historic observation data from the census geographic area helps minimize question volume. We explore how much historic data is required to boost performance, and whether the use of history negatively impacts identification of rare species. We also explore how characteristics of the matrix interact with the algorithm, and how best to predict the probability of observing a previously unseen species. Results Point counts of birds taken at Stanford University's Jasper Ridge Biological Preserve between 2000 and 2005 were used to examine the algorithm. A computer identified species by correctly answering, and counting the algorithm's questions. We also explored how the character density of the key matrix and the theoretical minimum number of questions for each bird in the matrix influenced the algorithm. Our investigation of the required probability smoothing determined whether Laplace smoothing of observation probabilities was sufficient, or whether the more complex Good-Turing technique is required. Conclusion Historic data improved identification speed, but only impacted the top 25% most frequently observed birds. For rare birds the history based algorithms did not impose a noticeable penalty in the number of questions required for identification. For our dataset neither age of the historic data, nor the number of observation years impacted the algorithm. Density of characters for different taxa in the identification matrix did not impact the algorithms. Intrinsic differences in identifying different birds did affect the algorithm, but the differences affected the baseline method of not using historic data to exactly the same degree. We found that Laplace smoothing
Thermosetting Polymer-Matrix Composites for Strucutral Repair Applications
Energy Technology Data Exchange (ETDEWEB)
Goertzen, William Kirby [Iowa State Univ., Ames, IA (United States)
2007-12-01
Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporate of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy.
Thermosetting polymer-matrix composites for structural repair applications
Goertzen, William Kirby
2007-12-01
Several classes of thermosetting polymer matrix composites were evaluated for use in structural repair applications. Initial work involved the characterization and evaluation of woven carbon fiber/epoxy matrix composites for structural pipeline repair. Cyanate ester resins were evaluated as a replacement for epoxy in composites for high-temperature pipe repair applications, and as the basis for adhesives for resin infusion repair of high-temperature composite materials. Carbon fiber/cyanate ester matrix composites and fumed silica/cyanate ester nanocomposites were evaluated for their thermal, mechanical, viscoelastic, and rheological properties as they relate to their structure, chemistry, and processing characteristics. The bisphenol E cyanate ester under investigation possesses a high glass transition temperature, excellent mechanical properties, and unique ambient temperature processability. The incorporation of fumed silica served to enhance the mechanical and rheological properties of the polymer and reduce thermal expansion without sacrificing glass transition or drastically altering curing kinetics. Characterization of the composites included dynamic mechanical analysis, thermomechanical analysis, differential scanning calorimetry, thermogravimetric analysis, rheological and rheokinetic evaluation, and transmission electron microscopy.
High strain carbon nanotubes based epoxy matrix nanocomposite
Manocha, L. M.; Basak, Arpana; Bhandari, T.; Baishya, T.; Manocha, S.
2013-06-01
Multiwalled carbon nanotubes, synthesized by catalytic chemical vapour deposition using xylene as the carbon precursor and ferrocene as the catalyst source, were used as reinforcements for the preparation of carbon nanotubes based epoxy matrix composites. For higher degree of dispersion in the matrix system, oxygen containing groups (C=O, COOH) were attached to the surface of carbon nanotubes by acid treatment followed by rigorous sonication of reinforcement in the matrix system. FTIR confirms the formation of oxygen containing groups on the surface of the carbon nanotubes. Tensile strength and glass transition temperature of the epoxy resin as well as nanocomposite samples have been determined. Carbon nanotubes reinforced composites exhibited ten times higher elongation than as such epoxy mainly due to the strengthening effect of the dispersed nanotubes and the development of moderate interfacial bonding between the resin and the reinforcing agent. A noticeable increase in the glass transition temperature of ˜20°C in the nanocomposites is attributable to the restricted movement of the polymeric chains on account of addition of carbon nanotubes.
Matrix theory selected topics and useful results
Mehta, Madan Lal
1989-01-01
Matrices and operations on matrices ; determinants ; elementary operations on matrices (continued) ; eigenvalues and eigenvectors, diagonalization of normal matrices ; functions of a matrix ; positive definiteness, various polar forms of a matrix ; special matrices ; matrices with quaternion elements ; inequalities ; generalised inverse of a matrix ; domain of values of a matrix, location and dispersion of eigenvalues ; symmetric functions ; integration over matrix variables ; permanents of doubly stochastic matrices ; infinite matrices ; Alexander matrices, knot polynomials, torsion numbers.
Mixing and Phase Separation in Liquid Crystal/matrix Systems
Smith, George W.
We review mixing and phase separation (demixing) in mixtures of low molecular weight liquid crystals (LCs) and organic matrices, with emphasis on aspects relevant to the formation of polymer-dispersed liquid crystal films. These films, which contain a myriad of micron-sized LC droplets, are of interest because of their electro-optic properties. Film formation is simple: A liquid crystal and a liquid polymer precursor are initially mixed to form a single phase. Subsequently the polymer is hardened, and LC microdroplets phase-separate from the matrix. Although matrix hardening can be achieved in several ways, this review focuses on curing, during which cross-linking reactions lead to an increased matrix molecular weight. Topics discussed include: phase behavior of the binary system before, during, and after cure and LC/matrix solubilities. The Flory-Huggins model for phase separation (as modified by several workers) has provided a theoretical basis for the studies. Principal experimental tools have been calorimetry and light scattering. Uncured LC/matrix binaries possess phase diagrams with an upper critical solution temperature. Such systems, when heated through the mixing temperature, exhibit a decrease in specific heat, the (negative) excess specific heat of mixing, °Cmix. A plot of °Cmix vs. LC concentration exhibits a minimum, from which we can estimate LC and uncured-matrix solubilities. Matrix cure plays a major role in the phase separation process: In partially-cured samples, °Cmix transitions persist until cure is nearly complete, at which time a fraction of the LC is permanently phase-separated, with the rest remaining dissolved in the matrix. The kinetics of phase separation can be determined by calorimetry or light scattering. Cure rates have been shown to control LC microdroplet size, with fast cures leading to small droplets. Calorimetry of the fully cured system also allows us to determine the solubility of liquid crystal in the polymer matrix, as
Matrix Treatment of Ray Optics.
Quon, W. Steve
1996-01-01
Describes a method to combine two learning experiences--optical physics and matrix mathematics--in a straightforward laboratory experiment that allows engineering/physics students to integrate a variety of learning insights and technical skills, including using lasers, studying refraction through thin lenses, applying concepts of matrix…
Parallel Sparse Matrix - Vector Product
DEFF Research Database (Denmark)
Alexandersen, Joe; Lazarov, Boyan Stefanov; Dammann, Bernd
This technical report contains a case study of a sparse matrix-vector product routine, implemented for parallel execution on a compute cluster with both pure MPI and hybrid MPI-OpenMP solutions. C++ classes for sparse data types were developed and the report shows how these class can be used...
Czech Academy of Sciences Publication Activity Database
Rohn, Jiří
2013-01-01
Roč. 26, 15 December (2013), s. 836-841 ISSN 1537-9582 Institutional support: RVO:67985807 Keywords : two-matrix alternative * solution * algorithm Subject RIV: BA - General Mathematics Impact factor: 0.514, year: 2013 http://www.math.technion.ac.il/iic/ela/ela-articles/articles/vol26_pp836-841.pdf
Amorphous metal matrix composite ribbons
International Nuclear Information System (INIS)
Barczy, P.; Szigeti, F.
1998-01-01
Composite ribbons with amorphous matrix and ceramic (SiC, WC, MoB) particles were produced by modified planar melt flow casting methods. Weldability, abrasive wear and wood sanding examinations were carried out in order to find optimal material and technology for elevated wear resistance and sanding durability. The correlation between structure and composite properties is discussed. (author)
Extracellular matrix and wound healing.
Maquart, F X; Monboisse, J C
2014-04-01
Extracellular matrix has been known for a long time as an architectural support for the tissues. Many recent data, however, have shown that extracellular matrix macromolecules (collagens, elastin, glycosaminoglycans, proteoglycans and connective tissue glycoproteins) are able to regulate many important cell functions, such as proliferation, migration, protein synthesis or degradation, apoptosis, etc., making them able to play an important role in the wound repair process. Not only the intact macromolecules but some of their specific domains, that we called "Matrikines", are also able to regulate many cell activities. In this article, we will summarize main findings showing the effects of extracellular matrix macromolecules and matrikines on connective tissue and epithelial cells, particularly in skin, and their potential implication in the wound healing process. These examples show that extracellular matrix macromolecules or some of their specific domains may play a major role in wound healing. Better knowledge of these interactions may suggest new therapeutic targets in wound healing defects. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
Concept for Energy Security Matrix
International Nuclear Information System (INIS)
Kisel, Einari; Hamburg, Arvi; Härm, Mihkel; Leppiman, Ando; Ots, Märt
2016-01-01
The following paper presents a discussion of short- and long-term energy security assessment methods and indicators. The aim of the current paper is to describe diversity of approaches to energy security, to structure energy security indicators used by different institutions and papers, and to discuss several indicators that also play important role in the design of energy policy of a state. Based on this analysis the paper presents a novel Energy Security Matrix that structures relevant energy security indicators from the aspects of Technical Resilience and Vulnerability, Economic Dependence and Political Affectability for electricity, heat and transport fuel sectors. Earlier publications by different authors have presented energy security assessment methodologies that use publicly available indicators from different databases. Current paper challenges viability of some of these indicators and introduces new indicators that would deliver stronger energy security policy assessments. Energy Security Matrix and its indicators are based on experiences that the authors have gathered as high-level energy policymakers in Estonia, where all different aspects of energy security can be observed. - Highlights: •Energy security should be analysed in technical, economic and political terms; •Energy Security Matrix provides a framework for energy security analyses; •Applicability of Matrix is limited due to the lack of statistical data and sensitivity of output.
The COMPADRE Plant Matrix Database
DEFF Research Database (Denmark)
2014-01-01
COMPADRE contains demographic information on hundreds of plant species. The data in COMPADRE are in the form of matrix population models and our goal is to make these publicly available to facilitate their use for research and teaching purposes. COMPADRE is an open-access database. We only request...
Unravelling the nuclear matrix proteome
DEFF Research Database (Denmark)
Albrethsen, Jakob; Knol, Jaco C; Jimenez, Connie R
2009-01-01
The nuclear matrix (NM) model posits the presence of a protein/RNA scaffold that spans the mammalian nucleus. The NM proteins are involved in basic nuclear function and are a promising source of protein biomarkers for cancer. Importantly, the NM proteome is operationally defined as the proteins...
Hyper-systolic matrix multiplication
Lippert, Th.; Petkov, N.; Palazzari, P.; Schilling, K.
A novel parallel algorithm for matrix multiplication is presented. It is based on a 1-D hyper-systolic processor abstraction. The procedure can be implemented on all types of parallel systems. (C) 2001 Elsevier Science B,V. All rights reserved.
Regularization in Matrix Relevance Learning
Schneider, Petra; Bunte, Kerstin; Stiekema, Han; Hammer, Barbara; Villmann, Thomas; Biehl, Michael
A In this paper, we present a regularization technique to extend recently proposed matrix learning schemes in learning vector quantization (LVQ). These learning algorithms extend the concept of adaptive distance measures in LVQ to the use of relevance matrices. In general, metric learning can
Transition sum rules in the shell model
Lu, Yi; Johnson, Calvin W.
2018-03-01
An important characterization of electromagnetic and weak transitions in atomic nuclei are sum rules. We focus on the non-energy-weighted sum rule (NEWSR), or total strength, and the energy-weighted sum rule (EWSR); the ratio of the EWSR to the NEWSR is the centroid or average energy of transition strengths from an nuclear initial state to all allowed final states. These sum rules can be expressed as expectation values of operators, which in the case of the EWSR is a double commutator. While most prior applications of the double commutator have been to special cases, we derive general formulas for matrix elements of both operators in a shell model framework (occupation space), given the input matrix elements for the nuclear Hamiltonian and for the transition operator. With these new formulas, we easily evaluate centroids of transition strength functions, with no need to calculate daughter states. We apply this simple tool to a number of nuclides and demonstrate the sum rules follow smooth secular behavior as a function of initial energy, as well as compare the electric dipole (E 1 ) sum rule against the famous Thomas-Reiche-Kuhn version. We also find surprising systematic behaviors for ground-state electric quadrupole (E 2 ) centroids in the s d shell.
Transition and Regional Inequality in Russia; Reorganization or Procrastination?
Irina Dolinskaya; Irina Tytell
2002-01-01
This paper analyzes the evolution of interregional income inequality during transition in Russia. The transition matrix approach reveals that between 1991 and 1997 income mobility tended toward a highly uneven long-term distribution with the majority of regions at low income levels and a minority of higher-income regions, in sharp contrast to pretransition times. The ordered logit analysis suggests that the more successful regions prospered on account of their natural resources, while continu...
Yoshinaga, N.; Yanase, K.; Higashiyama, K.; Teruya, E.; Taguchi, D.
2018-02-01
Nuclear shell-model calculations are carried out for isobaric nuclei with masses 76 and 82. Energy spectra and electromagnetic transition rates are compared with the experimental data. Using the wavefunctions thus obtained, nuclear matrix elements for the neutrinoless double beta decay are estimated. In order to investigate the model dependence on the nuclear matrix elements, pair-truncated shell-model calculations are also performed. By comparing the results with those in other models, the nuclear matrix elements are found to be sensitive to the ground-state correlations. In particular, nuclear matrix elements have strong correlations with pairing gaps.
Gritsan, N. P.
2007-12-01
Results of investigations of organic azide photochemistry in inert gas matrices and the most important spectroscopic studies of the last decade, which formed the basis for the modern views on the photochemistry of azides, are analysed. The unique potential of the matrix isolation technique for the reliable identification of reaction intermediates is demonstrated.
Knowledge of damage identification about tensegrities via flexibility disassembly
Jiang, Ge; Feng, Xiaodong; Du, Shigui
2017-12-01
Tensegrity structures composing of continuous cables and discrete struts are under tension and compression, respectively. In order to determine the damage extents of tensegrity structures, a new method for tensegrity structural damage identification is presented based on flexibility disassembly. To decompose a tensegrity structural flexibility matrix into the matrix represention of the connectivity between degress-of-freedoms and the diagonal matrix comprising of magnitude informations. Step 1: Calculate perturbation flexibility; Step 2: Compute the flexibility connectivity matrix and perturbation flexibility parameters; Step 3: Calculate the perturbation stiffness parameters. The efficiency of the proposed method is demonstrated by a numeical example comprising of 12 cables and 4 struts with pretensioned. Accurate identification of local damage depends on the availability of good measured data, an accurate and reasonable algorithm.
Financial Accounting Constitution or its Referential Matrix
Directory of Open Access Journals (Sweden)
Niculae Feleaga
2006-07-01
Full Text Available Using a simplified approach it may be stated that the financial accounting theoretical framework is structured on three levels. At the first level, reference is made to the accounting objectives. These objectives are fundamental for the theoretical framework. At the second level, we find the accounting information characteristics and explicit mentions about the headings of financial statements. The mentioned characteristics of accounting information represent the basic issues for ensuring its utility. The headings represent the main categories of elements disclosed in the financial statements, like assets and liabilities – these two elements’ definitions brought radical changes both in the accounting thinking and practices. Overall, the second level’s components represent the basis for building the practice directives as a matter of recognition (identification and measurement (evaluation. Inside the third level, the recognition and measurement directives are being detailed, which will be further used by the accounting specialist in order to identify and apply the accounting standards. These two directives enclose postulates, principles and restrictions. Such specifications prove to be useful whenever precise answers must be given to relative financial information issues. Usually, it is accepted that the theoretical framework, also called the accounting framework is the standard-setting, metaphorically speaking is actually the constitution of financial accounting, or in other words, its reference matrix.
Force spectroscopy of hepatocytic extracellular matrix components
Energy Technology Data Exchange (ETDEWEB)
Yongsunthon, R., E-mail: YongsuntR@Corning.com [Corning Incorporated, SP-FR-01, R1S32D, Corning, NY 14831 (United States); Baker, W.A.; Bryhan, M.D.; Baker, D.E.; Chang, T.; Petzold, O.N.; Walczak, W.J.; Liu, J.; Faris, R.A.; Senaratne, W.; Seeley, L.A.; Youngman, R.E. [Corning Incorporated, SP-FR-01, R1S32D, Corning, NY 14831 (United States)
2009-07-15
We present atomic force microscopy and force spectroscopy data of live hepatocytes (HEPG2/C3A liver cell line) grown in Eagle's Minimum Essential Medium, a complex solution of salts and amino acids commonly used for cell culture. Contact-mode imaging and force spectroscopy of this system allowed correlation of cell morphology and extracellular matrix (ECM) properties with substrate properties. Force spectroscopy analysis of cellular 'footprints' indicated that the cells secrete large polymers (e.g., 3.5 {mu}m contour length and estimated MW 1000 kDa) onto their substrate surface. Although definitive identification of the polymers has not yet been achieved, fluorescent-labeled antibody staining has specified the presence of ECM proteins such as collagen and laminin in the cellular footprints. The stretched polymers appear to be much larger than single molecules of known ECM components, such as collagen and heparan sulfate proteoglycan, thus suggesting that the cells create larger entangled, macromolecular structures from smaller components. There is strong evidence which suggests that the composition of the ECM is greatly influenced by the hydrophobicity of the substrate surface, with preferential production and/or adsorption of larger macromolecules on hydrophobic surfaces.
Matrix-Free Preconditioning using Partial Matrix Estimation
Czech Academy of Sciences Publication Activity Database
Cullum, J. K.; Tůma, Miroslav
2006-01-01
Roč. 46, č. 4 (2006), s. 711-729 ISSN 0006-3835 R&D Projects: GA AV ČR 1ET400300415; GA AV ČR IAA1030405 Institutional research plan: CEZ:AV0Z10300504 Keywords : matrix-free algorithms * linear algebraic equations * large sparse matrices * preconditioned iterative methods Subject RIV: BA - General Mathematics Impact factor: 0.841, year: 2006
Matrix metalloproteinases in fish biology and matrix turnover.
Pedersen, Mona E; Vuong, Tram T; Rønning, Sissel B; Kolset, Svein O
2015-01-01
Matrix metalloproteinases have important functions for tissue turnover in fish, with relevance both for the fish industry and molecular and cellular research on embryology, inflammation and tissue repair. These metalloproteinases have been studied in different fish types, subjected to both aquaculture and experimental conditions. This review highlights studies on these metalloproteinases in relation to both fish quality and health and further, the future importance of fish for basic research studies. Copyright © 2015. Published by Elsevier B.V.
Google matrix of the world network of economic activities
Kandiah, Vivek; Escaith, Hubert; Shepelyansky, Dima L.
2015-07-01
Using the new data from the OECD-WTO world network of economic activities we construct the Google matrix G of this directed network and perform its detailed analysis. The network contains 58 countries and 37 activity sectors for years 1995 and 2008. The construction of G, based on Markov chain transitions, treats all countries on equal democratic grounds while the contribution of activity sectors is proportional to their exchange monetary volume. The Google matrix analysis allows to obtain reliable ranking of countries and activity sectors and to determine the sensitivity of CheiRank-PageRank commercial balance of countries in respect to price variations and labor cost in various countries. We demonstrate that the developed approach takes into account multiplicity of network links with economy interactions between countries and activity sectors thus being more efficient compared to the usual export-import analysis. The spectrum and eigenstates of G are also analyzed being related to specific activity communities of countries.
Strange mesonic transition form factor
International Nuclear Information System (INIS)
Goity, J.L.; Musolf, M.J.
1996-01-01
The strange-quark vector current ρ-to-π meson transition form factor is computed at one-loop order using strange meson intermediate states. A comparison is made with a φ-meson dominance model estimate. We find that one-loop contributions are comparable in magnitude to those predicted by φ-meson dominance. It is possible that the one-loop contribution can make the matrix element as large as those of the electromagnetic current mediating vector meson radiative decays. However, due to the quadratic dependence of the one-loop results on the hadronic form factor cutoff mass, a large uncertainty in the estimate of the loops is unavoidable. These results indicate that non-nucleonic strange quarks could contribute appreciable in moderate-parallel Q 2 parallel parity-violating electron-nucleus scattering measurements aimed at probing the strange-quark content of the nucleon. copyright 1996 The American Physical Society
Omentin-1 prevents cartilage matrix destruction by regulating matrix metalloproteinases.
Li, Zhigang; Liu, Baoyi; Zhao, Dewei; Wang, BenJie; Liu, Yupeng; Zhang, Yao; Li, Borui; Tian, Fengde
2017-08-01
Matrix metalloproteinases (MMPs) play a crucial role in the degradation of the extracellular matrix and pathological progression of osteoarthritis (OA). Omentin-1 is a newly identified anti-inflammatory adipokine. Little information regarding the protective effects of omentin-1 in OA has been reported before. In the current study, our results indicated that omentin-1 suppressed expression of MMP-1, MMP-3, and MMP-13 induced by the proinflammatory cytokine interleukin-1β (IL-1β) at both the mRNA and protein levels in human chondrocytes. Importantly, administration of omentin-1 abolished IL-1β-induced degradation of type II collagen (Col II) and aggrecan, the two major extracellular matrix components in articular cartilage, in a dose-dependent manner. Mechanistically, omentin-1 ameliorated the expression of interferon regulatory factor 1 (IRF-1) by blocking the JAK-2/STAT3 pathway. Our results indicate that omentin-1 may have a potential chondroprotective therapeutic capacity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Directory of Open Access Journals (Sweden)
Agnieszka Bargenda
2016-07-01
Full Text Available Background: Epithelial–mesenchymal transition (EMT is defined as a transformation of tubular epithelial cells into mesenchymal ones. These cells migrate through the extracellular matrix and change into active myofibroblasts, which are responsible for excessive matrix deposition. Such changes may lead to tubular dysfunction and fibrosis of the renal parenchyma, characteristic of chronic kidney disease (CKD. However, there are no data on potential EMT markers in children with CKD. The aim of our study was to assess the usefulness of fractional excretion (FE of survivin, E-cadherin, extracellular matrix metalloproteinase inducer (EMMPRIN, matrix metalloproteinase (MMP7, and transforming growth factor beta 1 (TGF-β1 as potential markers of CKD-related complications such as tubular damage and fibrosis. Methods: Forty-one pre-dialysis children with CKD Stages 3–5 and 23 age-matched controls were enrolled in the study. The serum and urine concentrations of analysed parameters were assessed by an enzyme-linked immunosorbent assay test. Results: Tubular reabsorption of all analysed parameters was >99% in the control group. All FE values rose significantly in children with CKD, yet they remained 1%. Conclusions: FE of the examined markers may become a useful tool in the assessment of tubular dysfunction during the course of CKD. The FE of survivin, EMMPRIN, and MMP7 warrant further research as potential independent markers of kidney-specific EMT.
Random matrix model of adiabatic quantum computing
International Nuclear Information System (INIS)
Mitchell, David R.; Adami, Christoph; Lue, Waynn; Williams, Colin P.
2005-01-01
We present an analysis of the quantum adiabatic algorithm for solving hard instances of 3-SAT (an NP-complete problem) in terms of random matrix theory (RMT). We determine the global regularity of the spectral fluctuations of the instantaneous Hamiltonians encountered during the interpolation between the starting Hamiltonians and the ones whose ground states encode the solutions to the computational problems of interest. At each interpolation point, we quantify the degree of regularity of the average spectral distribution via its Brody parameter, a measure that distinguishes regular (i.e., Poissonian) from chaotic (i.e., Wigner-type) distributions of normalized nearest-neighbor spacings. We find that for hard problem instances - i.e., those having a critical ratio of clauses to variables - the spectral fluctuations typically become irregular across a contiguous region of the interpolation parameter, while the spectrum is regular for easy instances. Within the hard region, RMT may be applied to obtain a mathematical model of the probability of avoided level crossings and concomitant failure rate of the adiabatic algorithm due to nonadiabatic Landau-Zener-type transitions. Our model predicts that if the interpolation is performed at a uniform rate, the average failure rate of the quantum adiabatic algorithm, when averaged over hard problem instances, scales exponentially with increasing problem size
The doubly negative matrix completion problem
Araújo, C. Mendes; Torregrosa, Juan R.; Urbano, Ana M.
2005-01-01
An $n\\times n$ matrix over the field of real numbers is a doubly negative matrix if it is symmetric, negative definite and entry-wise negative. In this paper, we are interested in the doubly negative matrix completion problem, that is when does a partial matrix have a doubly negative matrix completion. In general, we cannot guarantee the existence of such a completion. In this paper, we prove that every partial doubly negative matrix whose associated graph is a $p$-chorda...
Minimal solution for inconsistent singular fuzzy matrix equations
Directory of Open Access Journals (Sweden)
M. Nikuie
2013-10-01
Full Text Available The fuzzy matrix equations $Ailde{X}=ilde{Y}$ is called a singular fuzzy matrix equations while the coefficients matrix of its equivalent crisp matrix equations be a singular matrix. The singular fuzzy matrix equations are divided into two parts: consistent singular matrix equations and inconsistent fuzzy matrix equations. In this paper, the inconsistent singular fuzzy matrix equations is studied and the effect of generalized inverses in finding minimal solution of an inconsistent singular fuzzy matrix equations are investigated.
Giddings, Steven B
2010-01-01
We investigate the hypothesized existence of an S-matrix for gravity, and some of its expected general properties. We first discuss basic questions regarding existence of such a matrix, including those of infrared divergences and description of asymptotic states. Distinct scattering behavior occurs in the Born, eikonal, and strong gravity regimes, and we describe aspects of both the partial wave and momentum space amplitudes, and their analytic properties, from these regimes. Classically the strong gravity region would be dominated by formation of black holes, and we assume its unitary quantum dynamics is described by corresponding resonances. Masslessness limits some powerful methods and results that apply to massive theories, though a continuation path implying crossing symmetry plausibly still exists. Physical properties of gravity suggest nonpolynomial amplitudes, although crossing and causality constrain (with modest assumptions) this nonpolynomial behavior, particularly requiring a polynomial bound in c...
Matrix Factorization for Evolution Data
Directory of Open Access Journals (Sweden)
Xiao-Yu Huang
2014-01-01
Full Text Available We study a matrix factorization problem, that is, to find two factor matrices U and V such that R≈UT×V, where R is a matrix composed of the values of the objects O1,O2,…,On at consecutive time points T1,T2,…,Tt. We first present MAFED, a constrained optimization model for this problem, which straightforwardly performs factorization on R. Then based on the interplay of the data in U, V, and R, a probabilistic graphical model using the same optimization objects is constructed, in which structural dependencies of the data in these matrices are revealed. Finally, we present a fitting algorithm to solve the proposed MAFED model, which produces the desired factorization. Empirical studies on real-world datasets demonstrate that our approach outperforms the state-of-the-art comparison algorithms.
Random matrix improved subspace clustering
Couillet, Romain
2017-03-06
This article introduces a spectral method for statistical subspace clustering. The method is built upon standard kernel spectral clustering techniques, however carefully tuned by theoretical understanding arising from random matrix findings. We show in particular that our method provides high clustering performance while standard kernel choices provably fail. An application to user grouping based on vector channel observations in the context of massive MIMO wireless communication networks is provided.
Coherence matrix of plasmonic beams
DEFF Research Database (Denmark)
Novitsky, Andrey; Lavrinenko, Andrei
2013-01-01
We consider monochromatic electromagnetic beams of surface plasmon-polaritons created at interfaces between dielectric media and metals. We theoretically study non-coherent superpositions of elementary surface waves and discuss their spectral degree of polarization, Stokes parameters, and the for...... of the spectral coherence matrix. We compare the polarization properties of the surface plasmonspolaritons as three-dimensional and two-dimensional fields concluding that the latter is superior....
Effects of quenching and partial quenching on QCD penguin matrix elements
Golterman, Maarten; Pallante, Elisabetta
2002-01-01
We point out that chiral transformation properties of penguin operators change in the transition from unquenched to (partially) quenched QCD. The way in which this affects the lattice determination of weak matrix elements can be understood in the framework of (partially) quenched chiral perturbation
Biodiesel Mass Transit Demonstration
2010-04-01
The Biodiesel Mass Transit Demonstration report is intended for mass transit decision makers and fleet managers considering biodiesel use. This is the final report for the demonstration project implemented by the National Biodiesel Board under a gran...
Department of Homeland Security — fixed rail transit stations within the Continental United States, Alaska, Hawaii, the District of Columbia, and Puerto Rico. The modes of transit that are serviced...
1985-01-01
A nationwide survey of transit operators indicated that absenteeism among transit operators is a significant problem and that the associated costs are substantial. The objective of the research reported here was to determine the scope of operator abs...
International Nuclear Information System (INIS)
Sachdev, S.
1999-01-01
Phase transitions are normally associated with changes of temperature but a new type of transition - caused by quantum fluctuations near absolute zero - is possible, and can tell us more about the properties of a wide range of systems in condensed-matter physics. Nature abounds with phase transitions. The boiling and freezing of water are everyday examples of phase transitions, as are more exotic processes such as superconductivity and superfluidity. The universe itself is thought to have passed through several phase transitions as the high-temperature plasma formed by the big bang cooled to form the world as we know it today. Phase transitions are traditionally classified as first or second order. In first-order transitions the two phases co-exist at the transition temperature - e.g. ice and water at 0 deg., or water and steam at 100 deg. In second-order transitions the two phases do not co-exist. In the last decade, attention has focused on phase transitions that are qualitatively different from the examples noted above: these are quantum phase transitions and they occur only at the absolute zero of temperature. The transition takes place at the ''quantum critical'' value of some other parameter such as pressure, composition or magnetic field strength. A quantum phase transition takes place when co-operative ordering of the system disappears, but this loss of order is driven solely by the quantum fluctuations demanded by Heisenberg's uncertainty principle. The physical properties of these quantum fluctuations are quite distinct from those of the thermal fluctuations responsible for traditional, finite-temperature phase transitions. In particular, the quantum system is described by a complex-valued wavefunction, and the dynamics of its phase near the quantum critical point requires novel theories that have no analogue in the traditional framework of phase transitions. In this article the author describes the history of quantum phase transitions. (UK)
Rapid identification of DNA-binding proteins by mass spectrometry
DEFF Research Database (Denmark)
Nordhoff, E; Krogsdam, A M; Jorgensen, H F
1999-01-01
We report a protocol for the rapid identification of DNA-binding proteins. Immobilized DNA probes harboring a specific sequence motif are incubated with cell or nuclear extract. Proteins are analyzed directly off the solid support by matrix-assisted laser desorption/ionization time-of-flight mass...... was validated by the identification of known prokaryotic and eukaryotic DNA-binding proteins, and its use provided evidence that poly(ADP-ribose) polymerase exhibits DNA sequence-specific binding to DNA....
Phase transitions in crystalline solids 1
International Nuclear Information System (INIS)
Walker, J.R.
1993-09-01
Many crystalline materials of interest to the Canadian Nuclear Program have the potential to undergo phase transitions in their range of application. During such phase transitions, a representation of the space group of the higher symmetry polymorph softens to induce the transition. This report is the first in a series of reports concerned with the group-theoretic properties of phase transitions in crystalline materials. The object of the research is to identify all spectroscopically-active soft modes for the 230 three-dimensional space groups. Identification of these soft modes will enable a detailed examination of phase transitions in materials of interest to the Canadian Nuclear Program and aid in the optimization of material properties. In this report, the group-theoretic properties of crystal structures and phase transitions are reviewed. It is demonstrated that the problem of extending a group reduces to that of determining its automorphisms. The automorphism groups of the crystallographic and icosahedral point groups are derived using a consistent presentation
Spectra of matrix isolated metal atoms and clusters. [In rare gases
Energy Technology Data Exchange (ETDEWEB)
Meyer, B.
1977-09-30
The matrix isolation spectra of all of the 40 presently known atomic metal species show strong matrix effects. The transition energies are increased, and the bands are broad and exhibit splitting of sublevels which are degenerate in the gas phase. Several models have been proposed for splitting of levels, but basic effects are not yet understood, and spectra cannot be predicted, yet it is possible to correlate gas phase and matrix in many of the systems. Selective production of diatomics and clusters via thermal and optical annealing of atomic species can be monitored by optical spectra, but yields spectroscopically complex systems which, however, especially in the case of transition metals, can be used as precursors in novel chemical reactions. A combination of absorption, emission, ir, Raman, ESR, and other methods is now quickly yielding data which will help correlate the increasing wealth of existing data. 55 references, 6 figures.
Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system.
Worsøe, Jonas; Fynne, Lotte; Gregersen, Tine; Schlageter, Vincent; Christensen, Lisbet A; Dahlerup, Jens F; Rijkhoff, Nico J M; Laurberg, Søren; Krogh, Klaus
2011-12-29
Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system. A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4) giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, φ). Eight healthy subjects were each investigated three times: (1) with a small magnet mounted on a capsule endoscope (PillCam); (2) with the magnet alone and the small intestine in the fasting state; and (3) with the magnet alone and the small intestine in the postprandial state. Experiment (1) showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min) and small intestinal transit time (median difference 0.5 min; range: 0-52 min). Comparing experiments (1) and (2) there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2) and (3), short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1) (p = 0.03). MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.
Origins of evolutionary transitions
Indian Academy of Sciences (India)
An `evolutionary transition in individuality' or `major transition' is a transformation in the hierarchical level at which natural selection operates on a population. In this article I give an abstract (i.e. level-neutral and substrate-neutral) articulation of the transition process in order to precisely understand how such processes can ...
Microwave stability at transition
International Nuclear Information System (INIS)
Holt, J.A.; Colestock, P.L.
1995-05-01
The question of microwave stability at transition is revisited using a Vlasov approach retaining higher order terms in the particle dynamics near the transition energy. A dispersion relation is derived which can be solved numerically for the complex frequency in terms of the longitudinal impedance and other beam parameters. Stability near transition is examined and compared with simulation results
2011-09-01
This handbook provides an overview of public transit in Iowa and how to do business with the Iowa Department of Transportation (Iowa DOT) Office of Public Transit (OPT). It is intended to be a tool to assist transit managers navigate through the many...
Modeling for Transition Management
Chappin, Emile J L; Dijkema, Gerard P.J.
2015-01-01
A framework for the modeling and simulation of transitions is presented. A transition, “substantial change in the state of a socio-technical system”, typically unfolds over a long timespan. We therefore suggest to use simulation to inform transition managers on the effect of their decisions.
2001-09-01
This report is designed as a guide for those involved in labor relations in the transit industry. It begins with a history of transit labor relations. The economic, political, and legal environment of transit relations is then discussed. A section fo...
Cubic Matrix, Nambu Mechanics and Beyond
Yoshiharu, KAWAMURA; Department of Physics, Shinshu University
2003-01-01
We propose a generalization of cubic matrix mechanics by introducing a canonical triplet and study its relation to Nambu mechanics. The generalized cubic matrix mechanics we consider can be interpreted as a 'quantum' generalization of Nambu mechanics.
Matrix Models and String World Sheet Duality
de Alwis, S. P.
1997-01-01
The scaling limit used recently to derive matrix models, and a certain analyticity assumption, are invoked to argue that the agreement between some matrix model calculations and supergravity is a consequence of string world sheet duality.
Cubic Matrix, Nambu Mechanics and Beyond
Kawamura, Yoshiharu
2002-01-01
We propose a generalization of cubic matrix mechanics by introducing a canonical triplet and study its relation to Nambu mechanics. The generalized cubic matrix mechanics we consider can be interpreted as a “quantum” generalization of Nambu mechanics.
Glomerular extracellular matrix components and integrins
Sterk, L. M.; de Melker, A. A.; Kramer, D.; Kuikman, I.; Chand, A.; Claessen, N.; Weening, J. J.; Sonnenberg, A.
1998-01-01
It has become apparent that extracellular matrix components and their cellular receptors, the integrins, are important regulators of glomerular development and function. In this rapidly evolving field we studied the production of extracellular matrix components and integrins by rat glomerular
Description of radiative transitions in the relativistic string model
International Nuclear Information System (INIS)
Berdnikov, E.B.; Nanobashvili, G.G.; Pron'ko, G.P.
1991-01-01
The transition operator for a straight-line string in the electromagnetic field has been built. It's matrix elements between the states of arbitrary spin are calculated in lowest order of perturbation theory. The consistensy conditions for the operator of interaction arising due to quantum constraints are also discussed. 12 refs
High-temperature phase transition in hadron matter
International Nuclear Information System (INIS)
Bugrij, A.I.; Trushevsky, A.A.
1976-01-01
A possible phase transition in hadronic systems at temperatures of few of GeV is shown in the framework of the S-matrix formulation of statistical mechanics given by Dashen, Ma, Bernstein by using Regge pole model for the scattering amplitude
Calculating pure rotational transitions of water molecule with a ...
Indian Academy of Sciences (India)
Abstract. We have calculated pure rotational transitions of water molecule from a kinetic energy operator (KEO) with the z-axis perpendicular to the molecular plane. We have used rotational basis functions which are linear combinations of symmetric top functions so that all matrix elements are real. The calculated spectra ...
Calculating pure rotational transitions of water molecule with a ...
Indian Academy of Sciences (India)
We have calculated pure rotational transitions of water molecule from a kinetic energy operator (KEO) with the -axis perpendicular to the molecular plane. We have used rotational basis functions which are linear combinations of symmetric top functions so that all matrix elements are real. The calculated spectra agree well ...
Spectroscopic properties of transition elements and their related magnetic properties
International Nuclear Information System (INIS)
Porcher, P.; Malta, O.L.
1988-01-01
The optical and magnetic properties of transition elements (nd N and nf N ions) are analysed. The phenomenological parameters introduced in the crystal-ligand field theory, the free ion interactions and crystalline matrix as well as electrostatic repulsion are studied. (M.J.C.) [pt
Analytic matrix elements with shifted correlated Gaussians
DEFF Research Database (Denmark)
Fedorov, D. V.
2017-01-01
Matrix elements between shifted correlated Gaussians of various potentials with several form-factors are calculated analytically. Analytic matrix elements are of importance for the correlated Gaussian method in quantum few-body physics.......Matrix elements between shifted correlated Gaussians of various potentials with several form-factors are calculated analytically. Analytic matrix elements are of importance for the correlated Gaussian method in quantum few-body physics....
A quenched c = 1 critical matrix model
International Nuclear Information System (INIS)
Qiu, Zongan; Rey, Soo-Jong.
1990-12-01
We study a variant of the Penner-Distler-Vafa model, proposed as a c = 1 quantum gravity: 'quenched' matrix model with logarithmic potential. The model is exactly soluble, and exhibits a two-cut branching as observed in multicritical unitary matrix models and multicut Hermitian matrix models. Using analytic continuation of the power in the conventional polynomial potential, we also show that both the Penner-Distler-Vafa model and our 'quenched' matrix model satisfy Virasoro algebra constraints
A Convex Model for Nonnegative Matrix Factorization and Dimensionality Reduction on Physical Space
Esser, Ernie; Moller, Michael; Osher, Stanley; Sapiro, Guillermo; Xin, Jack
2012-07-01
A collaborative convex framework for factoring a data matrix $X$ into a non-negative product $AS$, with a sparse coefficient matrix $S$, is proposed. We restrict the columns of the dictionary matrix $A$ to coincide with certain columns of the data matrix $X$, thereby guaranteeing a physically meaningful dictionary and dimensionality reduction. We use $l_{1,\\infty}$ regularization to select the dictionary from the data and show this leads to an exact convex relaxation of $l_0$ in the case of distinct noise free data. We also show how to relax the restriction-to-$X$ constraint by initializing an alternating minimization approach with the solution of the convex model, obtaining a dictionary close to but not necessarily in $X$. We focus on applications of the proposed framework to hyperspectral endmember and abundances identification and also show an application to blind source separation of NMR data.
Construction of covariance matrix for experimental data
International Nuclear Information System (INIS)
Liu Tingjin; Zhang Jianhua
1992-01-01
For evaluators and experimenters, the information is complete only in the case when the covariance matrix is given. The covariance matrix of the indirectly measured data has been constructed and discussed. As an example, the covariance matrix of 23 Na(n, 2n) cross section is constructed. A reasonable result is obtained
Transition Theory – Sustainable Transition of Socio-Technical Systems
DEFF Research Database (Denmark)
Søndergård, Bent; Holm, Jesper; Stauning, Inger
2015-01-01
Theories of transition management, transition studies and social practise theory Applied to studies of hosuing and construction......Theories of transition management, transition studies and social practise theory Applied to studies of hosuing and construction...
Flavor changing neutral current transitions on the lattice for heavy-light systems
International Nuclear Information System (INIS)
Bernard, C.W.
1992-01-01
Flavor changing neutral current transitions are a very important test of the standard model. Some of the channels can also be very useful for extracting the Kobayashi-Maskawa mixing matrix elements. However, their potential applications are limited by the uncertainties in the relevant hadronic matrix elements. We show that these matrix elements are also amenable to lattice techniques. In this study, we focus on radiative transitions such as B → K*γ and present preliminary results obtained by using 24 3 x 40 lattices at Β = 6.0
Asymptotics for incidence matrix classes
Cameron, Peter; Prellberg, Thomas; Stark, Dudley
2005-01-01
We define {\\em incidence matrices} to be zero-one matrices with no zero rows or columns. A classification of incidence matrices is considered for which conditions of symmetry by transposition, having no repeated rows/columns, or identification by permutation of rows/columns are imposed. We find asymptotics and relationships for the number of matrices with $n$ ones in these classes as $n\\to\\infty$.
Hexagonal response matrix using symmetries
International Nuclear Information System (INIS)
Gotoh, Y.
1991-01-01
A response matrix for use in core calculations for nuclear reactors with hexagonal fuel assemblies is presented. It is based on the incoming currents averaged over the half-surface of a hexagonal node by applying symmetry theory. The boundary conditions of the incoming currents on the half-surface of the node are expressed by a complete set of orthogonal vectors which are constructed from symmetrized functions. The expansion coefficients of the functions are determined by the boundary conditions of incoming currents. (author)
Geometric phase from dielectric matrix
International Nuclear Information System (INIS)
Banerjee, D.
2005-10-01
The dielectric property of the anisotropic optical medium is found by considering the polarized photon as two component spinor of spherical harmonics. The Geometric Phase of a polarized photon has been evaluated in two ways: the phase two-form of the dielectric matrix through a twist and the Pancharatnam phase (GP) by changing the angular momentum of the incident polarized photon over a closed triangular path on the extended Poincare sphere. The helicity in connection with the spin angular momentum of the chiral photon plays the key role in developing these phase holonomies. (author)
Distributively generated matrix near rings
International Nuclear Information System (INIS)
Abbasi, S.J.
1993-04-01
It is known that if R is a near ring with identity then (I,+) is abelian if (I + ,+) is abelian and (I,+) is abelian if (I*,+) is abelian [S.J. Abbasi, J.D.P. Meldrum, 1991]. This paper extends these results. We show that if R is a distributively generated near ring with identity then (I,+) is included in Z(R), the center of R, if (I + ,+) is included in Z(M n (R)), the center of matrix near ring M n (R). Furthermore (I,+) is included in Z(R) if (I*,+) is included in Z(M n (R)). (author). 5 refs
The COMPADRE Plant Matrix Database
DEFF Research Database (Denmark)
Salguero-Gomez, Roberto; Jones, Owen; Archer, C. Ruth
2015-01-01
growth or decline, such data furthermore help us understand how different biomes shape plant ecology, how plant populations and communities respond to global change, and how to develop successful management tools for endangered or invasive species. 2. Matrix population models summarize the life cycle......Bank), functional plant ecology (TRY, BIEN, D3), and grassland community ecology (NutNet). Here we present COMPADRE, a similar data-rich and ecologically relevant resource for plant demography. Open access to this information, its frequent updates, and its integration with other online resources will allow...
Matrix regularization of 4-manifolds
Trzetrzelewski, M.
2012-01-01
We consider products of two 2-manifolds such as S^2 x S^2, embedded in Euclidean space and show that the corresponding 4-volume preserving diffeomorphism algebra can be approximated by a tensor product SU(N)xSU(N) i.e. functions on a manifold are approximated by the Kronecker product of two SU(N) matrices. A regularization of the 4-sphere is also performed by constructing N^2 x N^2 matrix representations of the 4-algebra (and as a byproduct of the 3-algebra which makes the regularization of S...
Interaction between the enamel matrix proteins amelogenin and ameloblastin
International Nuclear Information System (INIS)
Ravindranath, Hanumanth H.; Chen, Li-Sha; Zeichner-David, Margaret; Ishima, Rieko; Ravindranath, Rajeswari M.H.
2004-01-01
Enamel matrix consists of amelogenin and non-amelogenins. Though amelogenin is not involved in nucleation of minerals, the enamel mineralization is impaired when amelogenin or other matrix protein (ameloblastin/enamelin) genes are mutated. We hypothesize that amelogenin may promote enamel mineralization by interacting with the calcium-binding matrix proteins. Specific binding of amelogenin to N-acetylglucosamine (GlcNAc), GlcNAc-mimicking peptides (GMps), and their carrier proteins and the identification of amelogenin-trityrosyl-motif-peptide (ATMP) as a GlcNAc/GMp-binding domain in amelogenin favor the hypothesis. This study tested the interaction of amelogenin with ameloblastin, a carrier of GMp sequence at intermittent sites. Neither GlcNAc nor sialic acids were identified in the recombinant-ameloblastin. Amelogenin bound to recombinant-ameloblastin in both Western blots and in ELISA. More specifically, [ 3 H]ATMP bound to both recombinant and native ameloblastins. Dosimetry and Scatchard analyses showed the specific interaction between ATMP and ameloblastin, suggesting that amelogenin may interact with ameloblastin to form a heteromolecular assembly
Interaction between the enamel matrix proteins amelogenin and ameloblastin.
Ravindranath, Hanumanth H; Chen, Li-Sha; Zeichner-David, Margaret; Ishima, Rieko; Ravindranath, Rajeswari M H
2004-10-22
Enamel matrix consists of amelogenin and non-amelogenins. Though amelogenin is not involved in nucleation of minerals, the enamel mineralization is impaired when amelogenin or other matrix protein (ameloblastin/enamelin) genes are mutated. We hypothesize that amelogenin may promote enamel mineralization by interacting with the calcium-binding matrix proteins. Specific binding of amelogenin to N-acetylglucosamine (GlcNAc), GlcNAc-mimicking peptides (GMps), and their carrier proteins and the identification of amelogenin-trityrosyl-motif-peptide (ATMP) as a GlcNAc/GMp-binding domain in amelogenin favor the hypothesis. This study tested the interaction of amelogenin with ameloblastin, a carrier of GMp sequence at intermittent sites. Neither GlcNAc nor sialic acids were identified in the recombinant-ameloblastin. Amelogenin bound to recombinant-ameloblastin in both Western blots and in ELISA. More specifically, [(3)H]ATMP bound to both recombinant and native ameloblastins. Dosimetry and Scatchard analyses showed the specific interaction between ATMP and ameloblastin, suggesting that amelogenin may interact with ameloblastin to form a heteromolecular assembly.
Digital Data Matrix Scanner Developnent At Marshall Space Flight Center
2004-01-01
Research at NASA's Marshall Space Flight Center has resulted in a system for reading hidden identification codes using a hand-held magnetic scanner. It's an invention that could help businesses improve inventory management, enhance safety, improve security, and aid in recall efforts if defects are discovered. Two-dimensional Data Matrix symbols consisting of letters and numbers permanently etched on items for identification and resembling a small checkerboard pattern are more efficient and reliable than traditional bar codes, and can store up to 100 times more information. A team led by Fred Schramm of the Marshall Center's Technology Transfer Department, in partnership with PRI,Torrance, California, has developed a hand-held device that can read this special type of coded symbols, even if covered by up to six layers of paint. Before this new technology was available, matrix symbols were read with optical scanners, and only if the codes were visible. This latest improvement in digital Data Matrix technologies offers greater flexibility for businesses and industries already using the marking system. Paint, inks, and pastes containing magnetic properties are applied in matrix symbol patterns to objects with two-dimensional codes, and the codes are read by a magnetic scanner, even after being covered with paint or other coatings. The ability to read hidden matrix symbols promises a wide range of benefits in a number of fields, including airlines, electronics, healthcare, and the automotive industry. Many industries would like to hide information on a part, so it can be read only by the party who put it there. For instance, the automotive industry uses direct parts marking for inventory control, but for aesthetic purposes the marks often need to be invisible. Symbols have been applied to a variety of materials, including metal, plastic, glass, paper, fabric and foam, on everything from electronic parts to pharmaceuticals to livestock. The portability of the hand
Fragmentation of extracellular matrix by hypochlorous acid
DEFF Research Database (Denmark)
Woods, Alan A; Davies, Michael Jonathan
2003-01-01
of the MPO-derived oxidant hypochlorous acid (HOCl) with extracellular matrix from vascular smooth muscle cells and healthy pig arteries has been examined. HOCl is rapidly consumed by such matrix samples, with the formation of matrix-derived chloramines or chloramides. The yield of these intermediates....../chloramide decomposition, with copper and iron ions being effective catalysts, and decreased by compounds which scavenge chloramines/chloramides, or species derived from them. The effect of such matrix modifications on cellular behaviour is poorly understood, though it is known that changes in matrix materials can have...
Confocal microscopy imaging of the biofilm matrix
DEFF Research Database (Denmark)
Schlafer, Sebastian; Meyer, Rikke L
2017-01-01
The extracellular matrix is an integral part of microbial biofilms and an important field of research. Confocal laser scanning microscopy is a valuable tool for the study of biofilms, and in particular of the biofilm matrix, as it allows real-time visualization of fully hydrated, living specimens....... Confocal microscopes are held by many research groups, and a number of methods for qualitative and quantitative imaging of the matrix have emerged in recent years. This review provides an overview and a critical discussion of techniques used to visualize different matrix compounds, to determine...... the concentration of solutes and the diffusive properties of the biofilm matrix....
Linear algebra and matrix analysis for statistics
Banerjee, Sudipto
2014-01-01
Matrices, Vectors, and Their OperationsBasic definitions and notations Matrix addition and scalar-matrix multiplication Matrix multiplication Partitioned matricesThe ""trace"" of a square matrix Some special matricesSystems of Linear EquationsIntroduction Gaussian elimination Gauss-Jordan elimination Elementary matrices Homogeneous linear systems The inverse of a matrixMore on Linear EquationsThe LU decompositionCrout's Algorithm LU decomposition with row interchanges The LDU and Cholesky factorizations Inverse of partitioned matrices The LDU decomposition for partitioned matricesThe Sherman-W