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Sample records for regular cellular distribution

  1. Regular cellular distribution of plasmids by oscillating and filament-forming ParA ATPase of plasmid pB171

    DEFF Research Database (Denmark)

    Ebersbach, Gitte; Ringgaard, Simon; Møller-Jensen, Jakob;

    2006-01-01

    with each other in a bacterial two-hybrid assay but do not interact with FtsZ, eight other essential cell division proteins or MreB actin. Based on these observations, we propose a simple model for how oscillating ParA filaments can mediate regular cellular distribution of plasmids. The model functions......Centromere-like loci from bacteria segregate plasmids to progeny cells before cell division. The ParA ATPase (a MinD homologue) of the par2 locus from plasmid pB171 forms oscillating helical structures over the nucleoid. Here we show that par2 distributes plasmid foci regularly along the length...... of the cell even in cells with many plasmids. In vitro, ParA binds ATP and ADP and has a cooperative ATPase activity. Moreover, ParA forms ATP-dependent filaments and cables, suggesting that ParA can provide the mechanical force for the observed regular distribution of plasmids. ParA and ParB interact...

  2. Regular Cellular Distribution of Plasmids by Oscillating and Filament-forming ParA ATPase of Plasmid pB171

    DEFF Research Database (Denmark)

    Ebersbach, Gitte; Ringgaard, Simon; Møller-Jensen, Jakob;

    2006-01-01

    with each other in a bacterial two-hybrid assay but do not interact with FtsZ, eight other essential cell division proteins or MreB actin. Based on these observations, we propose a simple model for how oscillating ParA filaments can mediate regular cellular distribution of plasmids. The model functions......Centromere-like loci from bacteria segregate plasmids to progeny cells before cell division. The ParA ATPase (a MinD homologue) of the par2 locus from plasmid pB171 forms oscillating helical structures over the nucleoid. Here we show that par2 distributes plasmid foci regularly along the length...... of the cell even in cells with many plasmids. In vitro, ParA binds ATP and ADP and has a cooperative ATPase activity. Moreover, ParA forms ATP-dependent filaments and cables, suggesting that ParA can provide the mechanical force for the observed regular distribution of plasmids. ParA and ParB interact...

  3. On regularizations of the Dirac delta distribution

    Science.gov (United States)

    Hosseini, Bamdad; Nigam, Nilima; Stockie, John M.

    2016-01-01

    In this article we consider regularizations of the Dirac delta distribution with applications to prototypical elliptic and hyperbolic partial differential equations (PDEs). We study the convergence of a sequence of distributions SH to a singular term S as a parameter H (associated with the support size of SH) shrinks to zero. We characterize this convergence in both the weak-* topology of distributions and a weighted Sobolev norm. These notions motivate a framework for constructing regularizations of the delta distribution that includes a large class of existing methods in the literature. This framework allows different regularizations to be compared. The convergence of solutions of PDEs with these regularized source terms is then studied in various topologies such as pointwise convergence on a deleted neighborhood and weighted Sobolev norms. We also examine the lack of symmetry in tensor product regularizations and effects of dissipative error in hyperbolic problems.

  4. Half-Cell Law of Regular Cellular Detonations

    Institute of Scientific and Technical Information of China (English)

    WANG Chun; JIANG Zong-Lin; GAO Yun-Liang

    2008-01-01

    Numerical simulations illustrate the half-cell law of regular cellular detonations propagating in confined space,i.e., the number of cells always maintains an integral multiple of half cell. The cells adapt themselves larger or smaller to the size of the unconfined space by maintaining the cell scale larger or smaller than the original cells of detonation.

  5. Regularization and error assignment to unfolded distributions

    CERN Document Server

    Zech, Gunter

    2011-01-01

    The commonly used approach to present unfolded data only in graphical formwith the diagonal error depending on the regularization strength is unsatisfac-tory. It does not permit the adjustment of parameters of theories, the exclusionof theories that are admitted by the observed data and does not allow the com-bination of data from different experiments. We propose fixing the regulariza-tion strength by a p-value criterion, indicating the experimental uncertaintiesindependent of the regularization and publishing the unfolded data in additionwithout regularization. These considerations are illustrated with three differentunfolding and smoothing approaches applied to a toy example.

  6. Width Distributions for Convex Regular Polyhedra

    CERN Document Server

    Finch, Steven R

    2011-01-01

    The mean width is a measure on three-dimensional convex bodies that enjoys equal status with volume and surface area [Rota]. As the phrase suggests, it is the mean of a probability density f. We verify formulas for mean widths of the regular tetrahedron and the cube. Higher-order moments of f_tetra and f_cube have not been examined until now. Assume that each polyhedron has edges of unit length. We deduce that the mean square width of the regular tetrahedron is 1/3+(3+sqrt(3))/(3*pi) and the mean square width of the cube is 1+4/pi.

  7. Distribution Regularity of Muzzle Shock-Wave Inside Protective Cover

    Institute of Scientific and Technical Information of China (English)

    WU Jun; LIU Jingbo; DU Yixin

    2006-01-01

    The injury of gunners caused by muzzle shock-wave has always been a great problem when firing inside the protective cover.The distribution regularity and personnel injury from the muzzle blast-wave were investigated by both test and numerical simulation.Through the inside firing test,the changes of overpressure and noise have been measured at different measuring points in the thin-wall cover structure with different open widths and shallow covering thickness.The distribution regularity of muzzle shock-wave with different firing port widths is calculated by ANSYS/LSDYNA software.The overpressure distribution curves of muzzle shock-wave inside the structure can be obtained by comparing the test results with the numerical results.Then,the influence of open width and shallow covering thickness is proposed to give a reference to the protective design under the condition of the inside firing with the same cannon caliber.

  8. Regularized multivariate regression models with skew-t error distributions

    KAUST Repository

    Chen, Lianfu

    2014-06-01

    We consider regularization of the parameters in multivariate linear regression models with the errors having a multivariate skew-t distribution. An iterative penalized likelihood procedure is proposed for constructing sparse estimators of both the regression coefficient and inverse scale matrices simultaneously. The sparsity is introduced through penalizing the negative log-likelihood by adding L1-penalties on the entries of the two matrices. Taking advantage of the hierarchical representation of skew-t distributions, and using the expectation conditional maximization (ECM) algorithm, we reduce the problem to penalized normal likelihood and develop a procedure to minimize the ensuing objective function. Using a simulation study the performance of the method is assessed, and the methodology is illustrated using a real data set with a 24-dimensional response vector. © 2014 Elsevier B.V.

  9. Restriction enzyme cutting site distribution regularity for DNA looping technology.

    Science.gov (United States)

    Shang, Ying; Zhang, Nan; Zhu, Pengyu; Luo, Yunbo; Huang, Kunlun; Tian, Wenying; Xu, Wentao

    2014-01-25

    The restriction enzyme cutting site distribution regularity and looping conditions were studied systematically. We obtained the restriction enzyme cutting site distributions of 13 commonly used restriction enzymes in 5 model organism genomes through two novel self-compiled software programs. All of the average distances between two adjacent restriction sites fell sharply with increasing statistic intervals, and most fragments were 0-499 bp. A shorter DNA fragment resulted in a lower looping rate, which was also directly proportional to the DNA concentration. When the length was more than 500 bp, the concentration did not affect the looping rate. Therefore, the best known fragment length was longer than 500 bp, and did not contain the restriction enzyme cutting sites which would be used for digestion. In order to make the looping efficiencies reach nearly 100%, 4-5 single cohesive end systems were recommended to digest the genome separately.

  10. Regular conditional distributions of max infinitely divisible processes

    CERN Document Server

    Dombry, Clément

    2011-01-01

    This paper is devoted to the prediction problem in extreme value theory. Our main result is an explicit expression of the regular conditional distribution of a max-stable (or max-infinitely divisible) process $\\{\\eta(t)\\}_{t\\in T}$ given observations $\\{\\eta(t_i)=y_i,\\ 1\\leq i\\leq k\\}$. Our starting point is the point process representation of max-infinitely divisible processes by Gin\\'e, Hahn and Vatan (1990). We carefully analyze the structure of the underlying point process, introduce the notions of extremal function, sub-extremal function and hitting scenario associated to the constraints and derive the associated distributions. This allows us to explicit the conditional distribution as a mixture over all hitting scenarios compatible with the conditioning constraints. This formula extends a recent related result by Wang and Stoev (2011) dealing with the case of spectrally discrete max-stable random fields. We believe this work offers new tools and perspective for prediction in extreme value theory togethe...

  11. On minimal energy dipole moment distributions in regular polygonal agglomerates

    Science.gov (United States)

    Rosa, Adriano Possebon; Cunha, Francisco Ricardo; Ceniceros, Hector Daniel

    2017-01-01

    Static, regular polygonal and close-packed clusters of spherical magnetic particles and their energy-minimizing magnetic moments are investigated in a two-dimensional setting. This study focuses on a simple particle system which is solely described by the dipole-dipole interaction energy, both without and in the presence of an in-plane magnetic field. For a regular polygonal structure of n sides with n ≥ 3 , and in the absence of an external field, it is proved rigorously that the magnetic moments given by the roots of unity, i.e. tangential to the polygon, are a minimizer of the dipole-dipole interaction energy. Also, for zero external field, new multiple local minima are discovered for the regular polygonal agglomerates. The number of found local extrema is proportional to [ n / 2 ] and these critical points are characterized by the presence of a pair of magnetic moments with a large deviation from the tangential configuration and whose particles are at least three diameters apart. The changes induced by an in-plane external magnetic field on the minimal energy, tangential configurations are investigated numerically. The two critical fields, which correspond to a crossover with the linear chain minimal energy and with the break-up of the agglomerate, respectively are examined in detail. In particular, the numerical results are compared directly with the asymptotic formulas of Danilov et al. (2012) [23] and a remarkable agreement is found even for moderate to large fields. Finally, three examples of close-packed structures are investigated: a triangle, a centered hexagon, and a 19-particle close packed cluster. The numerical study reveals novel, illuminating characteristics of these compact clusters often seen in ferrofluids. The centered hexagon is energetically favorable to the regular hexagon and the minimal energy for the larger 19-particle cluster is even lower than that of the close packed hexagon. In addition, this larger close packed agglomerate has two

  12. First contact distributions for spatial patterns: regularity and estimation

    NARCIS (Netherlands)

    Hansen, M.B.; Baddeley, A.J.; Gill, R.D.

    2001-01-01

    For applications in spatial statistics an important property of a random set X in Rk is its rst contact distribution This is the distribution of the distance from a xed point to the nearest point of X where distance is measured using scalar dilations of a xed test set B We show that if B is convex

  13. Elliptic partial differential equations existence and regularity of distributional solutions

    CERN Document Server

    Boccardo, Lucio

    2013-01-01

    Elliptic partial differential equations is one of the main and most active areas in mathematics. In our book we study linear and nonlinear elliptic problems in divergence form, with the aim of providing classical results, as well as more recent developments about distributional solutions. For this reason the book is addressed to master's students, PhD students and anyone who wants to begin research in this mathematical field.

  14. Bounds for Maximum Likelihood Regular and Non-Regular DoA Estimation in K-Distributed Noise

    Science.gov (United States)

    Abramovich, Yuri I.; Besson, Olivier; Johnson, Ben A.

    2015-11-01

    We consider the problem of estimating the direction of arrival of a signal embedded in $K$-distributed noise, when secondary data which contains noise only are assumed to be available. Based upon a recent formula of the Fisher information matrix (FIM) for complex elliptically distributed data, we provide a simple expression of the FIM with the two data sets framework. In the specific case of $K$-distributed noise, we show that, under certain conditions, the FIM for the deterministic part of the model can be unbounded, while the FIM for the covariance part of the model is always bounded. In the general case of elliptical distributions, we provide a sufficient condition for unboundedness of the FIM. Accurate approximations of the FIM for $K$-distributed noise are also derived when it is bounded. Additionally, the maximum likelihood estimator of the signal DoA and an approximated version are derived, assuming known covariance matrix: the latter is then estimated from secondary data using a conventional regularization technique. When the FIM is unbounded, an analysis of the estimators reveals a rate of convergence much faster than the usual $T^{-1}$. Simulations illustrate the different behaviors of the estimators, depending on the FIM being bounded or not.

  15. Distributed Velocity-Dependent Protocol for Multihop Cellular Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jagyasi Bhushan

    2009-01-01

    Full Text Available Abstract Cell phones are embedded with sensors form a Cellular Sensor Network which can be used to localize a moving event. The inherent mobility of the application and of the cell phone users warrants distributed structure-free data aggregation and on-the-fly routing. We propose a Distributed Velocity-Dependent (DVD protocol to localize a moving event using a Multihop Cellular Sensor Network (MCSN. DVD is based on a novel form of connectivity determined by the waiting time of nodes for a Random Waypoint (RWP distribution of cell phone users. This paper analyzes the time-stationary and spatial distribution of the proposed waiting time to explain the superior event localization and delay performances of DVD over the existing Randomized Waiting (RW protocol. A sensitivity analysis is also performed to compare the performance of DVD with RW and the existing Centralized approach.

  16. Distributed Velocity-Dependent Protocol for Multihop Cellular Sensor Networks

    Directory of Open Access Journals (Sweden)

    Deepthi Chander

    2009-01-01

    Full Text Available Cell phones are embedded with sensors form a Cellular Sensor Network which can be used to localize a moving event. The inherent mobility of the application and of the cell phone users warrants distributed structure-free data aggregation and on-the-fly routing. We propose a Distributed Velocity-Dependent (DVD protocol to localize a moving event using a Multihop Cellular Sensor Network (MCSN. DVD is based on a novel form of connectivity determined by the waiting time of nodes for a Random Waypoint (RWP distribution of cell phone users. This paper analyzes the time-stationary and spatial distribution of the proposed waiting time to explain the superior event localization and delay performances of DVD over the existing Randomized Waiting (RW protocol. A sensitivity analysis is also performed to compare the performance of DVD with RW and the existing Centralized approach.

  17. Weight Distributions of Regular Low-Density Parity-Check Codes over Finite Fields

    CERN Document Server

    Yang, Shengtian; Chen, Yan; Zhang, Zhaoyang; Qiu, Peiliang

    2010-01-01

    The average weight distribution of a regular low-density parity-check (LDPC) code ensemble over a finite field is thoroughly analyzed. In particular, a precise asymptotic approximation of the average weight distribution is derived for the small-weight case, and a series of fundamental qualitative properties of the asymptotic growth rate of the average weight distribution are proved. Based on this analysis, a general result, including all previous results as special cases, is established for the minimum distance of individual codes in a regular LDPC code ensemble.

  18. Behavior of impulsive fuzzy cellular neural networks with distributed delays

    Directory of Open Access Journals (Sweden)

    Kelin Li

    2007-04-01

    Full Text Available In this paper, we investigate a generalized model of fuzzy cellular neural networks with distributed delays and impulses. By employing the theory of topological degree, M-matrix and Lypunov functional, we find sufficient conditions for the existence, uniqueness and global exponential stability of both the equilibrium point and the periodic solution. Two examples are given to illustrate the results obtained here.

  19. A General Class of Regular Black Holes based on a Smeared Mass Distribution

    CERN Document Server

    Larranaga, Alexis; Torres, Daniel Alexdy

    2014-01-01

    We investigate the behavior of a new class of regular black holes based on a non-Gaussian smeared mass distribution. It is shown that the smeared mass distribution consideration cures the well known problems in the terminal phase of black hole evaporation. We find that there is a finite maximum temperature that the black hole reaches before cooling down to absolute zero so that the evaporation ends up in a zero temperature extremal black hole. Finally, we probe the regular characteristic of the new black holes by showing that there is no curvature singularity at the origin.

  20. Cellular- and micro-dosimetry of heterogeneously distributed tritium.

    Science.gov (United States)

    Chao, Tsi-Chian; Wang, Chun-Ching; Li, Junli; Li, Chunyan; Tung, Chuan-Jong

    2012-01-01

    The assessment of radiotoxicity for heterogeneously distributed tritium should be based on the subcellular dose and relative biological effectiveness (RBE) for cell nucleus. In the present work, geometry-dependent absorbed dose and RBE were calculated using Monte Carlo codes for tritium in the cell, cell surface, cytoplasm, or cell nucleus. Penelope (PENetration and Energy LOss of Positrins and Electrons) code was used to calculate the geometry-dependent absorbed dose, lineal energy, and electron fluence spectrum. RBE for the intestinal crypt regeneration was calculated using a lineal energy-dependent biological weighting function. RBE for the induction of DNA double strand breaks was estimated using a nucleotide-level map for clustered DNA lesions of the Monte Carlo damage simulation (MCDS) code. For a typical cell of 10 μm radius and 5 μm nuclear radius, tritium in the cell nucleus resulted in much higher RBE-weighted absorbed dose than tritium distributed uniformly. Conversely, tritium distributed on the cell surface led to trivial RBE-weighted absorbed dose due to irradiation geometry and great attenuation of beta particles in the cytoplasm. For tritium uniformly distributed in the cell, the RBE-weighted absorbed dose was larger compared to tritium uniformly distributed in the tissue. Cellular- and micro-dosimetry models were developed for the assessment of heterogeneously distributed tritium.

  1. Some Useful Distributions and Probabilities for Cellular Networks

    CERN Document Server

    Yu, Seung Min

    2011-01-01

    The cellular network is one of the most useful networks for wireless communications and now universally used. There have been a lot of analytic results about the performance of the mobile user at a specific location such as the cell center or edge. On the other hand, there have been few analytic results about the performance of the mobile user at an arbitrary location. Moreover, to the best of our knowledge, there is no analytic result on the performance of the mobile user at an arbitrary location considering the mobile user density. In this paper, we use the stochastic geometry approach and derive useful distributions and probabilities for cellular networks. Using those, we analyze the performance of the mobile user, e.g., outage probability at an arbitrary location considering the mobile user density. Under some assumptions, those can be expressed by closed form formulas. Our analytic results will provide a fundamental framework for the performance analysis of cellular networks, which will significantly red...

  2. Inversion of particle size distribution from light-scattering data using a modified regularization algorithm

    Institute of Scientific and Technical Information of China (English)

    Yanmin Wang; Guobiao Liang; Zhidong Pan

    2010-01-01

    A modified regularization algorithm with a more proper operator was proposed for the inversion of partide size distribution(PSD)from light-scattering data in a laser particle sizer based on the Mie scattering principle.The Generalized Cross-Validation(GCV)method and the L-curve method were used for determining the regularization parameter.The Successive Over-Relaxation(SOR)iterative method was used to increase the exactness and stability of the converged result.The simulated results based on the modified algorithm are in a good agreement with the experimental data measured for nine standard particulate samples,their mixtures as well as three natural particulate materials with irregular shapes,indicating that this modified regularization method is not only feasible but also effective for the simulation of PSD from corresponding light-scattering data.

  3. Statistical Evidence for the Preference of Frailty Distributions with Regularly-Varying-at-Zero Densities

    DEFF Research Database (Denmark)

    Missov, Trifon I.; Schöley, Jonas

    to this criterion admissible distributions are, for example, the gamma, the beta, the truncated normal, the log-logistic and the Weibull, while distributions like the log-normal and the inverse Gaussian do not satisfy this condition. In this article we show that models with admissible frailty distributions......Missov and Finkelstein (2011) prove an Abelian and its corresponding Tauberian theorem regarding distributions for modeling unobserved heterogeneity in fixed-frailty mixture models. The main property of such distributions is the regular variation at zero of their densities. According...... and a Gompertz baseline provide a better fit to adult human mortality data than the corresponding models with non-admissible frailty distributions. We implement estimation procedures for mixture models with a Gompertz baseline and frailty that follows a gamma, truncated normal, log-normal, or inverse Gaussian...

  4. Effective Structure Learning for Estimation of Distribution Algorithms via L1-Regularized Bayesian Networks

    Directory of Open Access Journals (Sweden)

    Hua Xu

    2013-01-01

    Full Text Available Estimation of distribution algorithms (EDAs, as an extension of genetic algorithms, samples new solutions from the probabilistic model, which characterizes the distribution of promising solutions in the search space at each generation. This paper introduces and evaluates a novel estimation of a distribution algorithm, called L1-regularized Bayesian optimization algorithm, L1BOA. In L1BOA, Bayesian networks as probabilistic models are learned in two steps. First, candidate parents of each variable in Bayesian networks are detected by means of L1-regularized logistic regression, with the aim of leading a sparse but nearly optimized network structure. Second, the greedy search, which is restricted to the candidate parent-child pairs, is deployed to identify the final structure. Compared with the Bayesian optimization algorithm (BOA, L1BOA improves the efficiency of structure learning due to the reduction and automated control of network complexity introduced with L1-regularized learning. Experimental studies on different types of benchmark problems show that L1BOA not only outperforms BOA when no prior knowledge about problem structure is available, but also achieves and even exceeds the best performance of BOA that applies explicit controls on network complexity. Furthermore, Bayesian networks built by L1BOA and BOA during evolution are analysed and compared, which demonstrates that L1BOA is able to build simpler, yet more accurate probabilistic models.

  5. Passive drug permeation through membranes and cellular distribution.

    Science.gov (United States)

    Scott, D O; Ghosh, A; Di, L; Maurer, T S

    2017-03-01

    Although often overlooked, passive mechanisms can lead to significant accumulation or restriction of drugs to intracellular sites of drug action. These mechanisms include lipoidal diffusion of ionized species and pH partitioning according to the electrochemical potential and to pH gradients that exist across subcellular compartments, respectively. These mechanisms are increasingly being exploited in the design of safe and effective drugs for the treatment of a wide variety of diseases. In this work, the authors review these efforts and the associated passive mechanisms of cellular drug permeation. A generic mathematical model of the cell is provided and used to illustrate concepts relevant to steady-state intracellular distribution. Finally, the authors review methods for estimating determinant parameters and measuring the net effect at the level of unbound intracellular drug concentrations.

  6. A Distributed Learning Method for ℓ 1 -Regularized Kernel Machine over Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xinrong Ji

    2016-07-01

    Full Text Available In wireless sensor networks, centralized learning methods have very high communication costs and energy consumption. These are caused by the need to transmit scattered training examples from various sensor nodes to the central fusion center where a classifier or a regression machine is trained. To reduce the communication cost, a distributed learning method for a kernel machine that incorporates ℓ 1 norm regularization ( ℓ 1 -regularized is investigated, and a novel distributed learning algorithm for the ℓ 1 -regularized kernel minimum mean squared error (KMSE machine is proposed. The proposed algorithm relies on in-network processing and a collaboration that transmits the sparse model only between single-hop neighboring nodes. This paper evaluates the proposed algorithm with respect to the prediction accuracy, the sparse rate of model, the communication cost and the number of iterations on synthetic and real datasets. The simulation results show that the proposed algorithm can obtain approximately the same prediction accuracy as that obtained by the batch learning method. Moreover, it is significantly superior in terms of the sparse rate of model and communication cost, and it can converge with fewer iterations. Finally, an experiment conducted on a wireless sensor network (WSN test platform further shows the advantages of the proposed algorithm with respect to communication cost.

  7. A Distributed Learning Method for ℓ1-Regularized Kernel Machine over Wireless Sensor Networks

    Science.gov (United States)

    Ji, Xinrong; Hou, Cuiqin; Hou, Yibin; Gao, Fang; Wang, Shulong

    2016-01-01

    In wireless sensor networks, centralized learning methods have very high communication costs and energy consumption. These are caused by the need to transmit scattered training examples from various sensor nodes to the central fusion center where a classifier or a regression machine is trained. To reduce the communication cost, a distributed learning method for a kernel machine that incorporates ℓ1 norm regularization (ℓ1-regularized) is investigated, and a novel distributed learning algorithm for the ℓ1-regularized kernel minimum mean squared error (KMSE) machine is proposed. The proposed algorithm relies on in-network processing and a collaboration that transmits the sparse model only between single-hop neighboring nodes. This paper evaluates the proposed algorithm with respect to the prediction accuracy, the sparse rate of model, the communication cost and the number of iterations on synthetic and real datasets. The simulation results show that the proposed algorithm can obtain approximately the same prediction accuracy as that obtained by the batch learning method. Moreover, it is significantly superior in terms of the sparse rate of model and communication cost, and it can converge with fewer iterations. Finally, an experiment conducted on a wireless sensor network (WSN) test platform further shows the advantages of the proposed algorithm with respect to communication cost. PMID:27376298

  8. A Distributed Learning Method for ℓ 1 -Regularized Kernel Machine over Wireless Sensor Networks.

    Science.gov (United States)

    Ji, Xinrong; Hou, Cuiqin; Hou, Yibin; Gao, Fang; Wang, Shulong

    2016-07-01

    In wireless sensor networks, centralized learning methods have very high communication costs and energy consumption. These are caused by the need to transmit scattered training examples from various sensor nodes to the central fusion center where a classifier or a regression machine is trained. To reduce the communication cost, a distributed learning method for a kernel machine that incorporates ℓ 1 norm regularization ( ℓ 1 -regularized) is investigated, and a novel distributed learning algorithm for the ℓ 1 -regularized kernel minimum mean squared error (KMSE) machine is proposed. The proposed algorithm relies on in-network processing and a collaboration that transmits the sparse model only between single-hop neighboring nodes. This paper evaluates the proposed algorithm with respect to the prediction accuracy, the sparse rate of model, the communication cost and the number of iterations on synthetic and real datasets. The simulation results show that the proposed algorithm can obtain approximately the same prediction accuracy as that obtained by the batch learning method. Moreover, it is significantly superior in terms of the sparse rate of model and communication cost, and it can converge with fewer iterations. Finally, an experiment conducted on a wireless sensor network (WSN) test platform further shows the advantages of the proposed algorithm with respect to communication cost.

  9. Distributional and regularized radiation fields of non-uniformly moving straight dislocations, and elastodynamic Tamm problem

    CERN Document Server

    Pellegrini, Yves-Patrick

    2016-01-01

    This work introduces original explicit solutions for the elastic fields radiated by non-uniformly moving, straight, screw or edge dislocations in an isotropic medium, in the form of time-integral representations in which acceleration-dependent contributions are explicitly separated out. These solutions are obtained by applying an isotropic regularization procedure to distributional expressions of the elastodynamic fields built on the Green tensor of the Navier equation. The obtained regularized field expressions are singularity-free, and depend on the dislocation density rather than on the plastic eigenstrain. They cover non-uniform motion at arbitrary speeds, including faster-than-wave ones. A numerical method of computation is discussed, that rests on discretizing motion along an arbitrary path in the plane transverse to the dislocation, into a succession of time intervals of constant velocity vector over which time-integrated contributions can be obtained in closed form. As a simple illustration, it is app...

  10. Hepatic expression and cellular distribution of the glucose transporter family

    Institute of Scientific and Technical Information of China (English)

    Sumera Karim; David H Adams; Patricia F Lalor

    2012-01-01

    Glucose and other carbohydrates are transported into cells using members of a family of integral membrane glucose transporter (GLUT) molecules.To date 14 members of this family,also called the solute carrier 2A proteins have been identified which are divided on the basis of transport characteristics and sequence similarities into several families (Classes 1 to 3).The expression of these different receptor subtypes varies between different species,tissues and cellular subtypes and each has differential sensitivities to stimuli such as insulin.The liver is a contributor to metabolic carbohydrate homeostasis and is a major site for synthesis,storage and redistribution of carbohydrates.Situations in which the balance of glucose homeostasis is upset such as diabetes or the metabolic syndrome can lead metabolic disturbances that drive chronic organ damage and failure,confirming the importance of understanding the molecular regulation of hepatic glucose homeostasis.There is a considerable literature describing the expression and function of receptors that regulate glucose uptake and release by hepatocytes,the most import cells in glucose regulation and glycogen storage.However there is less appreciation of the roles of GLUTs expressed by non parenchymal cell types within the liver,all of which require carbohydrate to function.A better understanding of the detailed cellular distribution of GLUTs in human liver tissue may shed light on mechanisms underlying disease pathogenesis.This review summarises the available literature on hepatocellular expression of GLUTs in health and disease and highlights areas where further investigation is required.

  11. Numerical simulation of distribution regularities of dust concentration during the ventilation process of coal roadway driving

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Jiang, Z.; Wang, S.; Liu, Y. [University of Science and Technology Beijing, Beijing (China)

    2007-04-15

    The paper examined the distribution regularities of dust, based on the theory of two-phase flow of gas and solid, and the characteristics of the coal mine driving working face, using the discrete phase models of computational fluid mechanics to simulate the dust concentration during the ventilation process of coal roadway driving with forced ventilation. In a coal roadway driving with forced ventilation, the concentration of whole dust and respirable dust is higher in the area close to the working face, the concentration will decrease towards the exit of the roadway. It was found that exhaust ventilation is better than forced ventilation for dust removal. 7 refs., 5 figs., 1 tab.

  12. Distributional and regularized radiation fields of non-uniformly moving straight dislocations, and elastodynamic Tamm problem

    Science.gov (United States)

    Lazar, Markus; Pellegrini, Yves-Patrick

    2016-11-01

    This work introduces original explicit solutions for the elastic fields radiated by non-uniformly moving, straight, screw or edge dislocations in an isotropic medium, in the form of time-integral representations in which acceleration-dependent contributions are explicitly separated out. These solutions are obtained by applying an isotropic regularization procedure to distributional expressions of the elastodynamic fields built on the Green tensor of the Navier equation. The obtained regularized field expressions are singularity-free, and depend on the dislocation density rather than on the plastic eigenstrain. They cover non-uniform motion at arbitrary speeds, including faster-than-wave ones. A numerical method of computation is discussed, that rests on discretizing motion along an arbitrary path in the plane transverse to the dislocation, into a succession of time intervals of constant velocity vector over which time-integrated contributions can be obtained in closed form. As a simple illustration, it is applied to the elastodynamic equivalent of the Tamm problem, where fields induced by a dislocation accelerated from rest beyond the longitudinal wave speed, and thereafter put to rest again, are computed. As expected, the proposed expressions produce Mach cones, the dynamic build-up and decay of which is illustrated by means of full-field calculations.

  13. Applying sequential Monte Carlo methods into a distributed hydrologic model: lagged particle filtering approach with regularization

    Directory of Open Access Journals (Sweden)

    S. J. Noh

    2011-04-01

    Full Text Available Applications of data assimilation techniques have been widely used to improve hydrologic prediction. Among various data assimilation techniques, sequential Monte Carlo (SMC methods, known as "particle filters", provide the capability to handle non-linear and non-Gaussian state-space models. In this paper, we propose an improved particle filtering approach to consider different response time of internal state variables in a hydrologic model. The proposed method adopts a lagged filtering approach to aggregate model response until uncertainty of each hydrologic process is propagated. The regularization with an additional move step based on Markov chain Monte Carlo (MCMC is also implemented to preserve sample diversity under the lagged filtering approach. A distributed hydrologic model, WEP is implemented for the sequential data assimilation through the updating of state variables. Particle filtering is parallelized and implemented in the multi-core computing environment via open message passing interface (MPI. We compare performance results of particle filters in terms of model efficiency, predictive QQ plots and particle diversity. The improvement of model efficiency and the preservation of particle diversity are found in the lagged regularized particle filter.

  14. Applying sequential Monte Carlo methods into a distributed hydrologic model: lagged particle filtering approach with regularization

    Directory of Open Access Journals (Sweden)

    S. J. Noh

    2011-10-01

    Full Text Available Data assimilation techniques have received growing attention due to their capability to improve prediction. Among various data assimilation techniques, sequential Monte Carlo (SMC methods, known as "particle filters", are a Bayesian learning process that has the capability to handle non-linear and non-Gaussian state-space models. In this paper, we propose an improved particle filtering approach to consider different response times of internal state variables in a hydrologic model. The proposed method adopts a lagged filtering approach to aggregate model response until the uncertainty of each hydrologic process is propagated. The regularization with an additional move step based on the Markov chain Monte Carlo (MCMC methods is also implemented to preserve sample diversity under the lagged filtering approach. A distributed hydrologic model, water and energy transfer processes (WEP, is implemented for the sequential data assimilation through the updating of state variables. The lagged regularized particle filter (LRPF and the sequential importance resampling (SIR particle filter are implemented for hindcasting of streamflow at the Katsura catchment, Japan. Control state variables for filtering are soil moisture content and overland flow. Streamflow measurements are used for data assimilation. LRPF shows consistent forecasts regardless of the process noise assumption, while SIR has different values of optimal process noise and shows sensitive variation of confidential intervals, depending on the process noise. Improvement of LRPF forecasts compared to SIR is particularly found for rapidly varied high flows due to preservation of sample diversity from the kernel, even if particle impoverishment takes place.

  15. On a general class of regular rotating black holes based on a smeared mass distribution

    Directory of Open Access Journals (Sweden)

    Alexis Larranaga

    2015-04-01

    Full Text Available In this work we investigate the behavior of a new general class of rotating regular black holes based on a non-Gaussian smeared mass distribution. It is shown that the existence of a fundamental minimal length cures the well-known problems in the terminal phase of black hole evaporation, since we find that there is a finite maximum temperature that the black hole reaches before cooling down to absolute zero, so that the evaporation ends up in a zero temperature extremal black hole whose mass and size depends on the value of the fundamental length and on the rotation parameter of the black hole. We also study the geodesic structure in these spacetimes and calculate the shadows that these black holes produce.

  16. Constitutive Laws for Visco-plastic Porous Medium Shaped by Regularly Distributed Circular Particles

    Institute of Scientific and Technical Information of China (English)

    Yunzhu Cai; Huaicui Li

    2016-01-01

    A numerical study is presented, using a homogenization technique to consider the plain strain problem of visco⁃plastic porous medium shaped by regularly distributed circular particles. Based on a rigid plastic material, the paper derives the macroscopic constitutive laws for homogenous equivalent medium. By changing the shape parameter of circular particles, the effect of pore shape on macroscopic constitutive laws is explored. Yield surfaces with different pore shapes are obtained. About voids, a two⁃scale conception is introduced, which regards main void as macroscopic scale and secondary cavities as microscopic scale. The macroscopic potential involving main and secondary voids is achieved. The proposed macroscopic constitutive law taking microscopic features as influence factors is helpful for exploring the macroscopic mechanical properties of porous medium when numerical simulation is required.

  17. Meteoroid velocity distribution derived from head echo data collected at Arecibo during regular world day observations

    Directory of Open Access Journals (Sweden)

    M. P. Sulzer

    2004-01-01

    Full Text Available We report the observation and analysis of ionization flashes associated with the decay of meteoroids (so-called head echos detected by the Arecibo 430 MHz radar during regular ionospheric observations in the spring and autumn equinoxes. These two periods allow pointing well-above and nearly-into the ecliptic plane at dawn when the event rate maximizes. The observation of many thousands of events allows a statistical interpretation of the results, which show that there is a strong tendency for the observed meteoroids to come from the apex as has been previously reported (Chau and Woodman, 2004. The velocity distributions agree with Janches et al. (2003a when they are directly comparable, but the azimuth scan used in these observations allows a new perspective. We have constructed a simple statistical model which takes meteor velocities as input and gives radar line of sight velocities as output. The intent is to explain the fastest part of the velocity distribution. Since the speeds interpreted from the measurements are distributed fairly narrowly about nearly 60 km s-1, double the speed of the earth in its orbit, is consistent with the interpretation that many of the meteoroids seen by the Arecibo radar are moving in orbits about the sun with similar parameters as the earth, but in the retrograde direction. However, it is the directional information obtained from the beam-swinging radar experiment and the speed that together provide the evidence for this interpretation. Some aspects of the measured velocity distributions suggest that this is not a complete description even for the fast part of the distribution, and it certainly says nothing about the slow part first described in Janches et al. (2003a. Furthermore, we cannot conclude anything about the entire dust population since there are probably selection effects that restrict the observations to a subset of the population.

  18. The limit distribution of the maximum increment of a random walk with dependent regularly varying jump sizes

    DEFF Research Database (Denmark)

    Mikosch, Thomas Valentin; Moser, Martin

    2013-01-01

    We investigate the maximum increment of a random walk with heavy-tailed jump size distribution. Here heavy-tailedness is understood as regular variation of the finite-dimensional distributions. The jump sizes constitute a strictly stationary sequence. Using a continuous mapping argument acting on...... on the point processes of the normalized jump sizes, we prove that the maximum increment of the random walk converges in distribution to a Fréchet distributed random variable....

  19. Clustered, regularly interspaced short palindromic repeat (CRISPR) diversity and virulence factor distribution in avian Escherichia coli.

    Science.gov (United States)

    Fu, Qiang; Su, Zhixin; Cheng, Yuqiang; Wang, Zhaofei; Li, Shiyu; Wang, Heng'an; Sun, Jianhe; Yan, Yaxian

    In order to investigate the diverse characteristics of clustered, regularly interspaced short palindromic repeat (CRISPR) arrays and the distribution of virulence factor genes in avian Escherichia coli, 80 E. coli isolates obtained from chickens with avian pathogenic E. coli (APEC) or avian fecal commensal E. coli (AFEC) were identified. Using the multiplex polymerase chain reaction (PCR), five genes were subjected to phylogenetic typing and examined for CRISPR arrays to study genetic relatedness among the strains. The strains were further analyzed for CRISPR loci and virulence factor genes to determine a possible association between their CRISPR elements and their potential virulence. The strains were divided into five phylogenetic groups: A, B1, B2, D and E. It was confirmed that two types of CRISPR arrays, CRISPR1 and CRISPR2, which contain up to 246 distinct spacers, were amplified in most of the strains. Further classification of the isolates was achieved by sorting them into nine CRISPR clusters based on their spacer profiles, which indicates a candidate typing method for E. coli. Several significant differences in invasion-associated gene distribution were found between the APEC isolates and the AFEC isolates. Our results identified the distribution of 11 virulence genes and CRISPR diversity in 80 strains. It was demonstrated that, with the exception of iucD and aslA, there was no sharp demarcation in the gene distribution between the pathogenic (APEC) and commensal (AFEC) strains, while the total number of indicated CRISPR spacers may have a positive correlation with the potential pathogenicity of the E. coli isolates. Copyright © 2016. Published by Elsevier Masson SAS.

  20. Regular and quasi black hole solutions for spherically symmetric charged dust distributions in Einstein-Maxwell theory

    CERN Document Server

    Horvat, D; Narancic, Z; Horvat, Dubravko; Ilijic, Sasa; Narancic, Zoran

    2004-01-01

    Spherically symmetric distributions of electrically counterpoised dust (ECD) are used to construct solutions to Einstein-Maxwell equations in Majumdar-Papapetrou formalism. Unexpected bifurcating behavior of regular and singular solutions with regard to source strength is found for localized, as well as for the delta-function ECD distributions. Unified treatment of general ECD distributions is accomplished and it is shown that for certain source strengths one class of regular solutions approaches Minkowski spacetime, while the other comes arbitrarily close to black hole solutions.

  1. Cellular copper distribution: a mechanistic systems biology approach.

    Science.gov (United States)

    Banci, Lucia; Bertini, Ivano; Cantini, Francesca; Ciofi-Baffoni, Simone

    2010-08-01

    Copper is an essential but potentially harmful trace element required in many enzymatic processes involving redox chemistry. Cellular copper homeostasis in mammals is predominantly maintained by regulating copper transport through the copper import CTR proteins and the copper exporters ATP7A and ATP7B. Once copper is imported into the cell, several pathways involving a number of copper proteins are responsible for trafficking it specifically where it is required for cellular life, thus avoiding the release of harmful free copper ions. In this study we review recent progress made in understanding the molecular mechanisms of copper transport in cells by analyzing structural features of copper proteins, their mode of interaction, and their thermodynamic and kinetic parameters, thus contributing to systems biology of copper within the cell.

  2. Regular patterns for proteome-wide distribution of protein abundance across species.

    Directory of Open Access Journals (Sweden)

    Fan Zhong

    Full Text Available A proteome of the bio-entity, including cell, tissue, organ, and organism, consists of proteins of diverse abundance. The principle that determines the abundance of different proteins in a proteome is of fundamental significance for an understanding of the building blocks of the bio-entity. Here, we report three regular patterns in the proteome-wide distribution of protein abundance across species such as human, mouse, fly, worm, yeast, and bacteria: in most cases, protein abundance is positively correlated with the protein's origination time or sequence conservation during evolution; it is negatively correlated with the protein's domain number and positively correlated with domain coverage in protein structure, and the correlations became stronger during the course of evolution; protein abundance can be further stratified by the function of the protein, whereby proteins that act on material conversion and transportation (mass category are more abundant than those that act on information modulation (information category. Thus, protein abundance is intrinsically related to the protein's inherent characters of evolution, structure, and function.

  3. Some regularities in the distribution of kenophytes in the Polish Carpathians and their foreland

    Directory of Open Access Journals (Sweden)

    Zając Maria

    2015-03-01

    Full Text Available The Polish Carpathians and their northern foreland are a rewarding object for the kenophyte distribution research. The study, using the cartogram method, showed that the number of kenophyte species decreases with increasing altitude. Only few kenophytes were found in the lower forest zone. This regularity concerns also the species that reach higher altitudes in the mountains of their native lands. A number of species migrated into the Carpathians through rivers and streams. River valleys generate many open habitats, which are easily colonized by kenophytes due to the lack of competition. In the Carpathians, towns used to be founded in the mountain valleys and this was also a favouring factor of kenophyte propagation. The arrangement of mountain ranges in the Polish Carpathians, including their foreland, hindered the migration of some species and allowed to discover the possible migration routes into the area covered by research. Tracing these migration routes was possible only for those species that have not occupied the whole available area yet. Additionally, the study indicated the most dangerous invasive species in the Polish Carpathians and their foreland.

  4. Energy Distribution of a Regular Black Hole Solution in Einstein-Nonlinear Electrodynamics

    Directory of Open Access Journals (Sweden)

    I. Radinschi

    2015-01-01

    Full Text Available A study about the energy momentum of a new four-dimensional spherically symmetric, static and charged, regular black hole solution developed in the context of general relativity coupled to nonlinear electrodynamics is presented. Asymptotically, this new black hole solution behaves as the Reissner-Nordström solution only for the particular value μ=4, where μ is a positive integer parameter appearing in the mass function of the solution. The calculations are performed by use of the Einstein, Landau-Lifshitz, Weinberg, and Møller energy momentum complexes. In all the aforementioned prescriptions, the expressions for the energy of the gravitating system considered depend on the mass M of the black hole, its charge q, a positive integer α, and the radial coordinate r. In all these pseudotensorial prescriptions, the momenta are found to vanish, while the Landau-Lifshitz and Weinberg prescriptions give the same result for the energy distribution. In addition, the limiting behavior of the energy for the cases r→∞, r→0, and q=0 is studied. The special case μ=4 and α=3 is also examined. We conclude that the Einstein and Møller energy momentum complexes can be considered as the most reliable tools for the study of the energy momentum localization of a gravitating system.

  5. The Evolution of Frequency Distributions: Relating Regularization to Inductive Biases through Iterated Learning

    Science.gov (United States)

    Reali, Florencia; Griffiths, Thomas L.

    2009-01-01

    The regularization of linguistic structures by learners has played a key role in arguments for strong innate constraints on language acquisition, and has important implications for language evolution. However, relating the inductive biases of learners to regularization behavior in laboratory tasks can be challenging without a formal model. In this…

  6. Distribution of cellular HSV-1 receptor expression in human brain.

    Science.gov (United States)

    Lathe, Richard; Haas, Juergen G

    2016-12-15

    Herpes simplex virus type 1 (HSV-1) is a neurotropic virus linked to a range of acute and chronic neurological disorders affecting distinct regions of the brain. Unusually, HSV-1 entry into cells requires the interaction of viral proteins glycoprotein D (gD) and glycoprotein B (gB) with distinct cellular receptor proteins. Several different gD and gB receptors have been identified, including TNFRSF14/HVEM and PVRL1/nectin 1 as gD receptors and PILRA, MAG, and MYH9 as gB receptors. We investigated the expression of these receptor molecules in different areas of the adult and developing human brain using online transcriptome databases. Whereas all HSV-1 receptors showed distinct expression patterns in different brain areas, the Allan Brain Atlas (ABA) reported increased expression of both gD and gB receptors in the hippocampus. Specifically, for PVRL1, TNFRFS14, and MYH9, the differential z scores for hippocampal expression, a measure of relative levels of increased expression, rose to 2.9, 2.9, and 2.5, respectively, comparable to the z score for the archetypical hippocampus-enriched mineralocorticoid receptor (NR3C2, z = 3.1). These data were confirmed at the Human Brain Transcriptome (HBT) database, but HBT data indicate that MAG expression is also enriched in hippocampus. The HBT database allowed the developmental pattern of expression to be investigated; we report that all HSV1 receptors markedly increase in expression levels between gestation and the postnatal/adult periods. These results suggest that differential receptor expression levels of several HSV-1 gD and gB receptors in the adult hippocampus are likely to underlie the susceptibility of this brain region to HSV-1 infection.

  7. Distribution Regularity of Debris Flow and Its Hazard in Upper Reaches of Yangtze River and Other Rivers of Southwestern China

    Institute of Scientific and Technical Information of China (English)

    WEI Fangqiang; JIANG Yuhong; GUI Peng; DING Mingtao

    2007-01-01

    In the upper reaches of Yangtze River and other rivers of southwestern China, the debris flows develop and lead to most serious disasters because of the various landforms, complex geological structures and abundant rainfall. The distribution of debris flows has regularity in the regions with different landform, geological structure, and precipitation. The regularities of distribution of debris flows are as following:① distributed in transition belts of different morphologic regions; ②distributed in the area with strong stream trenching; ③distributed along fracture zones and seismic belts: ④distributed in the area with abundant precipitation;⑤ distribution of debris flow is azonal. The activity of abundant debris flows not only brings harm to Towns, Villages and Farmlands, Main Lines of Communication, Water-Power Engineering, Stream Channels etc., but also induces strong water and soil loss. According to the present status of debris flow prevention, the problems in disasters mitigation and soil conservancy are found out, and the key works are brought up for the future disasters prevention and soil conservancy.

  8. DESIGN OF STRUCTURAL ELEMENTS IN THE EVENT OF THE PRE-SET RELIABILITY, REGULAR LOAD AND BEARING CAPACITY DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    Tamrazyan Ashot Georgievich

    2012-10-01

    Full Text Available Accurate and adequate description of external influences and of the bearing capacity of the structural material requires the employment of the probability theory methods. In this regard, the characteristic that describes the probability of failure-free operation is required. The characteristic of reliability means that the maximum stress caused by the action of the load will not exceed the bearing capacity. In this paper, the author presents a solution to the problem of calculation of structures, namely, the identification of reliability of pre-set design parameters, in particular, cross-sectional dimensions. If the load distribution pattern is available, employment of the regularities of distributed functions make it possible to find the pattern of distribution of maximum stresses over the structure. Similarly, we can proceed to the design of structures of pre-set rigidity, reliability and stability in the case of regular load distribution. We consider the element of design (a monolithic concrete slab, maximum stress S which depends linearly on load q. Within a pre-set period of time, the probability will not exceed the values according to the Poisson law. The analysis demonstrates that the variability of the bearing capacity produces a stronger effect on relative sizes of cross sections of a slab than the variability of loads. It is therefore particularly important to reduce the coefficient of variation of the load capacity. One of the methods contemplates the truncation of the bearing capacity distribution by pre-culling the construction material.

  9. An entropy regularization method applied to the identification of wave distribution function for an ELF hiss event

    Science.gov (United States)

    Prot, Olivier; SantolíK, OndřEj; Trotignon, Jean-Gabriel; Deferaudy, Hervé

    2006-06-01

    An entropy regularization algorithm (ERA) has been developed to compute the wave-energy density from electromagnetic field measurements. It is based on the wave distribution function (WDF) concept. To assess its suitability and efficiency, the algorithm is applied to experimental data that has already been analyzed using other inversion techniques. The FREJA satellite data that is used consists of six spectral matrices corresponding to six time-frequency points of an ELF hiss-event spectrogram. The WDF analysis is performed on these six points and the results are compared with those obtained previously. A statistical stability analysis confirms the stability of the solutions. The WDF computation is fast and without any prespecified parameters. The regularization parameter has been chosen in accordance with the Morozov's discrepancy principle. The Generalized Cross Validation and L-curve criterions are then tentatively used to provide a fully data-driven method. However, these criterions fail to determine a suitable value of the regularization parameter. Although the entropy regularization leads to solutions that agree fairly well with those already published, some differences are observed, and these are discussed in detail. The main advantage of the ERA is to return the WDF that exhibits the largest entropy and to avoid the use of a priori models, which sometimes seem to be more accurate but without any justification.

  10. Simulating the particle size distribution of rockfill materials based on its statistical regularity

    Institute of Scientific and Technical Information of China (English)

    YAN Zongling; QIU Xiande; YU Yongqiang

    2003-01-01

    The particle size distribution of rockfill is studied by using granular mechanics, mesomechanics and probability statistics to reveal the relationship of the distribution of particle size to that of the potential energy intensity before fragmentation,which finds out that the potential energy density has a linear relation to the logarithm of particle size and deduces that the distribution of the logarithm of particle size conforms to normal distribution because the distribution of the potential energy density does so. Based on this finding and by including the energy principle of rock fragmentation, the logarithm distribution model of particle size is formulated, which uncovers the natural characteristics of particle sizes on statistical distribution. Exploring the properties of the average value, the expectation, and the unbiased variance of particle size indicates that the expectation does notequal to the average value, but increases with increasing particle size and its ununiformity, and is always larger than the average value, and the unbiased variance increases as the ununiformity and geometric average value increase. A case study proves that the simulated results by the proposed logarithm distribution model accord with the actual data. It is concluded that the logarithm distribution model and Kuz-Ram model can be used to forecast the particle-size distribution of inartificial rockfill while for blasted rockfill, Kuz-Ram model is an option, and in combined application of the two models, it is necessary to do field tests to adjust some parameters of the model.

  11. Global exponential stability of mixed discrete and distributively delayed cellular neural network

    Institute of Scientific and Technical Information of China (English)

    Yao Hong-Xing; Zhou Jia-Yan

    2011-01-01

    This paper concernes analysis for the global exponential stability of a class of recurrent neural networks with mixed discrete and distributed delays. It first proves the existence and uniqueness of the balance point, then by employing the Lyapunov-Krasovskii functional and Young inequality, it gives the sufficient condition of global exponential stability of cellular neural network with mixed discrete and distributed delays, in addition, the example is provided to illustrate the applicability of the result.

  12. Measurement of nonuniform temperature and concentration distributions by combining line-of-sight tunable diode laser absorption spectroscopy with regularization methods.

    Science.gov (United States)

    Liu, Chang; Xu, Lijun; Cao, Zhang

    2013-07-10

    Regularization methods were combined with line-of-sight tunable diode laser absorption spectroscopy (TDLAS) to measure nonuniform temperature and concentration distributions along the laser path when a priori information of the temperature distribution tendency is available. Relying on measurements of 12 absorption transitions of water vapor from 1300 to 1350 nm, the nonuniform temperature and concentration distributions were retrieved by making the use of nonlinear and linear regularization methods, respectively. To examine the effectiveness of regularization methods, a simulated annealing algorithm for nonlinear regularization was implemented to reconstruct the temperature distribution, while three linear regularization methods, namely truncated singular value decomposition, Tikhonov regularization, and a revised Tikhonov regularization method, were implemented to retrieve the concentration distribution. The results show that regularization methods not only can be used to retrieve temperature and concentration distributions closer to the original but also are less sensitive to measurement noise. When no sufficient optical access is available for TDLAS tomography, the methods proposed in the paper can be used to obtain more details of the combustion field with higher accuracy and robustness, which are expected to play a more important role in combustion diagnosis.

  13. Regular variation, Paretian distributions, and the interplay of light and heavy tails in the fractality of asymptotic models

    Science.gov (United States)

    Pestana, Dinis D.; Aleixo, Sandra M.; Rocha, J. Leonel

    Classical central limit theorems, culminating in the theory of infinite divisibility, accurately describe the behaviour of stochastic phenomena with asymptotically negligible components. The classical theory fails when a single component may assume an extreme protagonism. The early developments of the speculation theory didn't incorporate the pioneer work of Pareto on heavy tailed models, and the proper setup to conciliate regularity and abrupt changes, in a wide range of natural phenomena, is Karamata's concept of regular variation and the role it plays in the theory of domains of attraction, [8], and Resnick's tail equivalence leading to the importance of generalized Pareto distribution is the scope of extreme value theory, [13]. Waliszewski and Konarski discussed the applicability of the Gompertz curve and its fractal behaviour for instance in modeling healthy and neoplasic cells tissue growth, [15]. Gompertz function is the Gumbel extreme value model, whose broad domain of attraction contains intermediate tail weight laws with a wide range of behaviour. Aleixo et al. investigated fractality associated with Beta (p,q) models, [1], [2], [10] and [11]. In this work, we introduce a new family of probability density functions tied to the classical beta family, the Beta*(p,q) models, some of which are generalized Pareto, that span the possible regular variation of tails. We extend the investigation to other extreme stable models, namely Fréchet's and Weibull's types in the General Extreme Value (GEV) model.

  14. New Results on Almost Periodic Solution of Shunting Inhibitory Cellular Neural Networks with Continuously Distributed Delays

    Institute of Scientific and Technical Information of China (English)

    Jing Liu; Pei-Yong Zhu

    2008-01-01

    In this paper, the existence, uniqueness and global attractivity are discussed on almost periodic solution of SICNNs (shunting inhibitory cellular neural networks) with continuously distributed delays. By using the fixed point theorem, differential inequality technique and Lyapunov functional method, giving the new ranges of parameters, several sufficient conditions are obtained to ensure the existence, uniqueness and global attractivity of almost periodic solution. Compared with the previous studies, our methods are more effective for almost periodic solution analysis of SICNNs with continuously distributed delays. Some existing results have been improved and extended. In order to show the effectiveness of the obtained results, an example is given in this paper.

  15. The Dynamic Simulation of Distribution Regularity of Solar Radiation in the Individual Tomato Plant inside the Chinese Solar Greenhouse

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2013-12-01

    Full Text Available In order to study the radiation regularity of the individual plant inside the Chinese solar greenhouse, the model of plant projection which is based on the geometric structure of tomato is established. In this model, parameters such as, geographic locations, seasons, growing and temporal variations were considered. It has been found that the imitative effect from 10 o’clock to 14 o’clock is better which is based on the error analysis and root-mean-square error detection of different days. Observed values and simulation values in the experimental field from March 28th to April 29th are analyzed by root-Mean-Square Error detection and the RMSE value of azimuth is 1.58 and the RMSE value of plant projected length is 3.38. The model established by this experiment could directly response the distribution regularity of solar radiation in the individual plant inside the Chinese solar greenhouse tomato and the model could provide reference for the solar radiation within the plant population of tomato

  16. Effect of serum on PEGylated quantum dots:Cellular uptake and intracellular distribution

    Institute of Scientific and Technical Information of China (English)

    Yeting Jian; Xianghui Xu; Yunkun Li; Zhongwei Gun

    2013-01-01

    Protein adsorption is closely related with the interactions between nanoparticles and physiological systems, and further influences the cellular uptake and distribution of nanoparticles in cells. Although polyethylene glycol (PEG)ylation can largely reduce specific protein adsorption, some protein components in whole serum still interact with nanoparticles. In this work, PEGylated quantum dots (QDs) were used for investigating the quantitative and qualitative relationships of fetal bovine serum (FBS) and the cellular uptake/intracellular distribution in human hepatoma (HepG2) cell line. Nondenaturing polyacrylamide gel electrophoresis and two dimensional electrophoresis were used to analyze the adsorption of protein by PEGylated QDs. Quantitative cellular uptake of PEGylated QDs was determined by fluorescence activated cell sorting (FACS) with different FBS concentrations and incubating durations. The intracellular location of PEGylated QDs in HepG2 cells was observed using a confocal laser scanning microscope (CLSM) and a transmission electron microscope (TEM). This work will be helpful to understand the interaction between nanoparticles and cells with serum.

  17. Distributed and boundary optimal control of the Allen-Cahn equation with regular potential and dynamic boundary conditions

    Science.gov (United States)

    Benincasa, T.; Donado Escobar, L. D.; Moroşanu, C.

    2016-08-01

    This paper is concerned with an optimal control problem (P) (both distributed control as well as boundary control) for the nonlinear phase-field (Allen-Cahn) equation, involving a regular potential and dynamic boundary condition. A family of approximate optimal control problems (Pɛ) is introduced and results for the existence of an optimal control for problems (P) and (Pɛ) are proven. Furthermore, the convergence result of the optimal solution of problem (Pɛ) to the optimal solution of problem (P) is proved. Besides the existence of an optimal control in problem (Pɛ), necessary optimality conditions (Pontryagin's principle) as well as a conceptual gradient-type algorithm to approximate the optimal control, were established in the end.

  18. Steady state speed distribution analysis for a combined cellular automaton traffic model

    Institute of Scientific and Technical Information of China (English)

    Wang Jun-Feng; Chen Gui-Sheng; Liu Jin

    2008-01-01

    Cellular Automaton (CA) baaed traffic flow models have been extensively studied due to their effectiveness and simplicity in recent years. This paper develops a discrete time Markov chain (DTMC) analytical framework for a Nagel-Schreckenberg and Fukui-Ishibashi combined CA model (W2H traffic flow model) from microscopic point of view to capture the macroscopic steady state speed distributions. The inter-vehicle spacing Markov chain and the steady state speed Markov chain are proved to be irreducible and ergodie. The theoretical speed probability distributions depending on the traffic density and stochastic delay probability are in good accordance with numerical simulations. The derived fundamental diagram of the average speed from theoretical speed distributions is equivalent to the results in the previous work.

  19. Secure Real-Time Monitoring and Management of Smart Distribution Grid using Shared Cellular Networks

    DEFF Research Database (Denmark)

    Nielsen, Jimmy Jessen; Ganem, Hervé; Jorguseski, Ljupco

    2017-01-01

    The electricity production and distribution is facing two major changes. First, the production is shifting from classical energy sources such as coal and nuclear power towards renewable resources such as solar and wind. Secondly, the consumption in the low voltage grid is expected to grow signifi......, where the smart grid ICT solutions are provided through shared cellular LTE networks.......The electricity production and distribution is facing two major changes. First, the production is shifting from classical energy sources such as coal and nuclear power towards renewable resources such as solar and wind. Secondly, the consumption in the low voltage grid is expected to grow...... significantly due to expected introduction of electrical vehicles. The first step towards more efficient operational capabilities is to introduce an observability of the distribution system and allow for lever- aging the flexibility of end connection points with manageable consumption, generation and storage...

  20. Cellular Neural Network-Based Methods for Distributed Network Intrusion Detection

    Directory of Open Access Journals (Sweden)

    Kang Xie

    2015-01-01

    Full Text Available According to the problems of current distributed architecture intrusion detection systems (DIDS, a new online distributed intrusion detection model based on cellular neural network (CNN was proposed, in which discrete-time CNN (DTCNN was used as weak classifier in each local node and state-controlled CNN (SCCNN was used as global detection method, respectively. We further proposed a new method for design template parameters of SCCNN via solving Linear Matrix Inequality. Experimental results based on KDD CUP 99 dataset show its feasibility and effectiveness. Emerging evidence has indicated that this new approach is affordable to parallelism and analog very large scale integration (VLSI implementation which allows the distributed intrusion detection to be performed better.

  1. Cellular uptake, subcellular distribution and toxicity of arsenic compounds in methylating and non-methylating cells.

    Science.gov (United States)

    Dopp, E; von Recklinghausen, U; Diaz-Bone, R; Hirner, A V; Rettenmeier, A W

    2010-07-01

    Arsenic is a known human carcinogen, inducing tumors of the skin, urinary bladder, liver and lung. Inorganic arsenic, existing in highly toxic trivalent and significantly less toxic pentavalent forms, is methylated to mono- and di-methylated species mainly in the liver. Due to the low toxicity of pentavalent methylated species, methylation has been regarded as a detoxification process for many years; however, recent findings of a high toxicity of trivalent methylated species have indicated the contrary. In order to elucidate the role of speciation and methylation for the toxicity and carcinogenicity of arsenic, systematic studies were conducted comparing cellular uptake, subcellular distribution as well as toxic and genotoxic effects of organic and inorganic pentavalent and trivalent arsenic species in both non-methylating (urothelial cells and fibroblasts) and methylating cells (hepatocytes). The membrane permeability was found to be dependent upon both the arsenic species and the cell type. Uptake rates of trivalent methylated species were highest and exceeded those of their pentavalent counterparts by several orders of magnitude. Non-methylating cells (urothelial cells and fibroblasts) seem to accumulate higher amounts of arsenic within the cell than the methylating hepatocytes. Cellular uptake and extrusion seem to be faster in hepatocytes than in urothelial cells. The correlation of uptake with toxicity indicates a significant role of membrane permeability towards toxicity. Furthermore, cytotoxic effects are more distinct in hepatocytes. Differential centrifugation studies revealed that elevated concentrations of arsenic are present in the ribosomal fraction of urothelial cells and in nucleic and mitochondrial fractions of hepatic cells. Further studies are needed to define the implications of the observed enrichment of arsenic in specific cellular organelles for its carcinogenic activity. This review summarizes our recent research on cellular uptake

  2. Cellular Tolerance, Accumulation and Distribution of Cadmium in Leaves of Hyperaccumulator Picris divaricata

    Institute of Scientific and Technical Information of China (English)

    HU Peng-Jie; GAN Yuan-Yuan; TANG Ye-Tao; ZHANG Quan-Fang; JIANG Dan; YAO Nan; QIU Rong-Liang

    2012-01-01

    Knowledge of cellular metal homeostasis will provide a better understanding of the mechanisms involved in metal tolerance and hyperaccumulation in metal-hyperaccumulating plants.Energy dispersive X-ray spectrometry (EDS) was used to determine the localization of cadmium (Cd) in leaves of the Zn/Cd hyperaccumulator Picris divaricata which had a shoot Cd concentration of 565 mg kg-1 after 2 weeks of growth in solution culture supplying 10 μmol L-1 CdCl2.The results indicated that Cd was distributed mainly in the trichomes,upper and lower epidermis and bundle sheath cells,with a relatively low level of Cd in mesophyll cells.Mesophyli protoplasts isolated from leaves remained viable after 24 h exposure to CdCl2 at a concentration up to 1 mmol L-1,indicating their high tolerance to Cd.The intracellular Cd was visualized by staining with Leadmium Green dye,a cellular permeable Cd fluoresceuce probe.The results showed that the majority of protoplasts (> 82%) did not accumulate Cd,with only a minority (< 18%) showing Cd accumulation.In the Cd-accumulating protoplasts,Cd accumulation was depressed by the addition of Fe2+,Mn2+ and the metabolic inhibitor carbonyl cyanide m-chlorophenylhydrazone (CCCP),but not by Ca2+ or Zn2+.Furthermore,the entire process of Cd uptake from external solution into the cytoplasm and subsequent sequestration into vacuoles was successfully recorded by confocal images.These results suggested that reduced cellular Cd accumulation and efficient Cd vacuolar sequestration in mesophyll cells might be responsible for cellular Cd tolerance and distribution in the leaves of P.divaricata.

  3. On the Meta Distribution of Coverage Probability in Uplink Cellular Networks

    KAUST Repository

    Elsawy, Hesham

    2017-04-07

    This letter studies the meta distribution of coverage probability (CP), within a stochastic geometry framework, for cellular uplink transmission with fractional path-loss inversion power control. Using the widely accepted Poisson point process (PPP) for modeling the spatial locations of base stations (BSs), we obtain the percentiles of users that achieve a target uplink CP over an arbitrary, but fixed, realization of the PPP. To this end, the effect of the users activity factor (p) and the path-loss compensation factor () on the uplink performance are analyzed. The results show that decreasing p and/or increasing reduce the CP variation around the spatially averaged value.

  4. Spatial emission distribution and carrier recombination dynamics in regularly arrayed InGaN/GaN quantum structure nanocolumns

    Science.gov (United States)

    Oto, Takao; Mizuno, Yutaro; Miyagawa, Rin; Kano, Tatsuya; Yoshida, Jun; Ema, Kazuhiro; Kishino, Katsumi

    2016-10-01

    Emission mechanisms in regularly arrayed InGaN/GaN quantum structures on GaN nanocolumns were investigated, focusing on the spatial emission distribution at the nanocolumn tops and the carrier recombination dynamics. The double-peak emission originated from the dot- and well-like InGaN areas with different In compositions was observed. From the results regarding the spatial emission distribution, we proposed a simple analytical approach to evaluating the carrier recombination dynamics using the rate equations based on the two energy states. The considerable six lifetimes can be uniquely determined from the experimental results. Carrier transfer from the high- to the low-energy state is dominant at high temperatures, producing the increased total emission efficiency of the inner low-energy area. In addition, the internal quantum efficiency should not be simply discussed using only the integrated intensity ratio between low and room temperatures because of the carrier transfer from high- to low-energy states.

  5. -Regular Modules

    Directory of Open Access Journals (Sweden)

    Areej M. Abduldaim

    2013-01-01

    Full Text Available We introduced and studied -regular modules as a generalization of -regular rings to modules as well as regular modules (in the sense of Fieldhouse. An -module is called -regular if for each and , there exist and a positive integer such that . The notion of -pure submodules was introduced to generalize pure submodules and proved that an -module is -regular if and only if every submodule of is -pure iff   is a -regular -module for each maximal ideal of . Many characterizations and properties of -regular modules were given. An -module is -regular iff is a -regular ring for each iff is a -regular ring for finitely generated module . If is a -regular module, then .

  6. Cellular distribution and degradation of cobalt ferrite nanoparticles in Balb/3T3 mouse fibroblasts.

    Science.gov (United States)

    Marmorato, Patrick; Ceccone, Giacomo; Gianoncelli, Alessandra; Pascolo, Lorella; Ponti, Jessica; Rossi, François; Salomé, Murielle; Kaulich, Burkhard; Kiskinova, Maya

    2011-11-30

    The effect of the concentration of cobalt ferrite (CoFe(2)O(4)) nanoparticles (NPs) on their intracellular location and distribution has been explored by synchrotron radiation X-ray and fluorescence microscopy (SR-XRF) monitoring the evolution of NPs elemental composition as well. In cells exposed to low concentrations of CoFe(2)O(4) NPs, the NPs preferentially segregate in the perinuclear region preserving their initial chemical content. At concentrations exceeding 500 μM the XRF spectra indicate the presence of Co and Fe also in the nuclear region, accompanied by sensible changes in the cellular morphology. The increase of the Co/Fe ratio measured in the nuclear compartment indicates that above certain concentrations the CoFe(2)O(4) NPs intracellular distribution could be accompanied by biodegradation resulting in Co accumulation in the nucleus. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Statistical analysis of 3D images detects regular spatial distributions of centromeres and chromocenters in animal and plant nuclei.

    Directory of Open Access Journals (Sweden)

    Philippe Andrey

    Full Text Available In eukaryotes, the interphase nucleus is organized in morphologically and/or functionally distinct nuclear "compartments". Numerous studies highlight functional relationships between the spatial organization of the nucleus and gene regulation. This raises the question of whether nuclear organization principles exist and, if so, whether they are identical in the animal and plant kingdoms. We addressed this issue through the investigation of the three-dimensional distribution of the centromeres and chromocenters. We investigated five very diverse populations of interphase nuclei at different differentiation stages in their physiological environment, belonging to rabbit embryos at the 8-cell and blastocyst stages, differentiated rabbit mammary epithelial cells during lactation, and differentiated cells of Arabidopsis thaliana plantlets. We developed new tools based on the processing of confocal images and a new statistical approach based on G- and F- distance functions used in spatial statistics. Our original computational scheme takes into account both size and shape variability by comparing, for each nucleus, the observed distribution against a reference distribution estimated by Monte-Carlo sampling over the same nucleus. This implicit normalization allowed similar data processing and extraction of rules in the five differentiated nuclei populations of the three studied biological systems, despite differences in chromosome number, genome organization and heterochromatin content. We showed that centromeres/chromocenters form significantly more regularly spaced patterns than expected under a completely random situation, suggesting that repulsive constraints or spatial inhomogeneities underlay the spatial organization of heterochromatic compartments. The proposed technique should be useful for identifying further spatial features in a wide range of cell types.

  8. Expression and cellular distribution of ubiquitin in response to injury in the developing spinal cord of Monodelphis domestica

    DEFF Research Database (Denmark)

    Noor, Natassya M; Møllgård, Kjeld; Wheaton, Benjamin J;

    2013-01-01

    Ubiquitin, an 8.5 kDa protein associated with the proteasome degradation pathway has been recently identified as differentially expressed in segment of cord caudal to site of injury in developing spinal cord. Here we describe ubiquitin expression and cellular distribution in spinal cord up to pos...... changes in ubiquitin expression and cellular distribution in development and response to spinal injury suggest an intricate regulatory system that modulates these responses which, when better understood, may lead to potential therapeutic targets....

  9. Cellular cholesterol distribution influences proteolytic release of the LRP-1 ectodomain

    Directory of Open Access Journals (Sweden)

    Bassil eDEKKY

    2016-02-01

    Full Text Available Low-Density Lipoprotein Receptor-related Protein-1 (LRP-1 is a multifunctional matricellular receptor composed of a large ligand-binding subunit (515-kDa α-chain associated with a short trans-membrane subunit (85-kDa β-chain. LRP-1, which exhibits both endocytosis and cell signaling properties, plays a key role in tumor invasion by regulating the activity of proteinases such as matrix metalloproteinases (MMPs. LRP-1 is shed at the cell surface by proteinases such as membrane-type 1 MMP (MT1-MMP and a disintegrin and metalloproteinase-12 (ADAM-12. Here we show by using biophysical, biochemical and cellular imaging approaches that efficient extraction of cell cholesterol and increased LRP-1 shedding occur in MDA-MB-231 breast cancer cells but not in MDA-MB-435 cells. Our data show that cholesterol is differently distributed in both cell lines; predominantly intracellularly for MDA-MB-231 cells and at the plasma membrane for MDA-MB-435 cells. This study highlights the relationship between the rate and cellular distribution of cholesterol and its impact on LRP-1 shedding modulation. Altogether, our data strongly suggest that the increase of LRP-1 shedding upon cholesterol depletion induces a higher accessibility of the sheddase substrate, ie LRP-1, at the cell surface rather than an increase of expression of the enzyme.

  10. CFD analysis of a regular sector of the ITER vacuum vessel. Part I: Flow distribution and pressure drop

    Energy Technology Data Exchange (ETDEWEB)

    Savoldi Richard, L., E-mail: laura.savoldi@polito.it [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); Bonifetto, R. [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); Zanino, R., E-mail: roberto.zanino@polito.it [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); Corpino, S.; Obiols-Rabasa, G. [Dipartimento di Ingegneria Meccanica e Aerospaziale, Politecnico di Torino, 10129 Torino (Italy); Izquierdo, J. [F4E, Barcelona (Spain); Le Barbier, R.; Utin, Y. [ITER IO, Cadarache (France)

    2013-12-15

    The 3D steady-state Computational Fluid Dynamics (CFD) analysis of the ITER vacuum vessel (VV) regular sector no. 5 is presented, starting from the CATIA models and using a suite of tools from the commercial software ANSYS FLUENT{sup ®}. The peculiarity of the problem is linked to the wide range of spatial scales involved in the analysis, from the millimeter-size gaps between in-wall shielding (IWS) plates to the more than 10 m height of the VV itself. After performing several simplifications in the geometrical details, a computational mesh with ∼50 million cells is generated and used to compute the steady-state pressure and flow fields from a Reynolds-Averaged Navier–Stokes model with SST k-ω turbulence closure. The coolant mass flow rate turns out to be distributed 10% through the inboard and the remaining 90% through the outboard. The toroidal and poloidal ribs present in the VV structure constitute significant barriers for the flow, giving rise to large recirculation regions. The pressure drop is mainly localized in the inlet and outlet piping.

  11. Effect of inhomogeneous activity distributions and airway geometry on cellular doses in radon lung dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Szoke, Istvan; Balashazy, Imre; Farkas, Arpad [KFKI Atomic Energy Research Institute, PO Box 49, 1525 Budapest (Hungary); Hofmann, Werner [University of Salzburg, Hellbrunner Str. 34, 5020 Salzburg (Austria)

    2007-07-01

    The human tracheobronchial system has a very complex structure including cylindrical airway ducts connected by airway bifurcation units. The deposition of the inhaled aerosols within the airways exhibits a very inhomogeneous pattern. The formation of deposition hot spots near the carinal ridge has been confirmed by experimental and computational fluid and particle dynamics (CFPD) methods. In spite of these observations, current radon lung dosimetry models apply infinitely long cylinders as models of the airway system and assume uniform deposition of the inhaled radon progenies along the airway walls. The aim of this study is to investigate the effect of airway geometry and non-uniform activity distributions within bronchial bifurcations on cellular dose distributions. In order to answer these questions, the nuclear doses of the bronchial epithelium were calculated in three different irradiation situations. (1) First, CFPD methods were applied to calculate the distribution of the deposited alpha-emitting nuclides in a numerically constructed idealized airway bifurcation. (2) Second, the deposited radionuclides were randomly distributed along the surface of the above-mentioned geometry. (3) Finally, calculations were made in cylindrical geometries corresponding to the parent and daughter branches of the bifurcation geometry assuming random nuclide activity distribution. In all three models, the same {sup 218}Po and {sup 214}Po surface activities per tissue volumes were assumed. Two conclusions can be drawn from this analysis: (i) average nuclear doses are very similar in all three cases (minor differences can be attributed to differences in the linear energy transfer (LET) spectra) and (ii) dose distributions are significantly different in all three cases, with the highest doses at the carinal ridge in case 3. (authors)

  12. Active Degradation Explains the Distribution of Nuclear Proteins during Cellular Senescence.

    Directory of Open Access Journals (Sweden)

    Enrico Giampieri

    Full Text Available The amount of cellular proteins is a crucial parameter that is known to vary between cells as a function of the replicative passages, and can be important during physiological aging. The process of protein degradation is known to be performed by a series of enzymatic reactions, ranging from an initial step of protein ubiquitination to their final fragmentation by the proteasome. In this paper we propose a stochastic dynamical model of nuclear proteins concentration resulting from a balance between a constant production of proteins and their degradation by a cooperative enzymatic reaction. The predictions of this model are compared with experimental data obtained by fluorescence measurements of the amount of nuclear proteins in murine tail fibroblast (MTF undergoing cellular senescence. Our model provides a three-parameter stationary distribution that is in good agreement with the experimental data even during the transition to the senescent state, where the nuclear protein concentration changes abruptly. The estimation of three parameters (cooperativity, saturation threshold, and maximal velocity of the reaction, and their evolution during replicative passages shows that only the maximal velocity varies significantly. Based on our modeling we speculate the reduction of functionality of the protein degradation mechanism as a possible competitive inhibition of the proteasome.

  13. Active Degradation Explains the Distribution of Nuclear Proteins during Cellular Senescence.

    Science.gov (United States)

    Giampieri, Enrico; De Cecco, Marco; Remondini, Daniel; Sedivy, John; Castellani, Gastone

    2015-01-01

    The amount of cellular proteins is a crucial parameter that is known to vary between cells as a function of the replicative passages, and can be important during physiological aging. The process of protein degradation is known to be performed by a series of enzymatic reactions, ranging from an initial step of protein ubiquitination to their final fragmentation by the proteasome. In this paper we propose a stochastic dynamical model of nuclear proteins concentration resulting from a balance between a constant production of proteins and their degradation by a cooperative enzymatic reaction. The predictions of this model are compared with experimental data obtained by fluorescence measurements of the amount of nuclear proteins in murine tail fibroblast (MTF) undergoing cellular senescence. Our model provides a three-parameter stationary distribution that is in good agreement with the experimental data even during the transition to the senescent state, where the nuclear protein concentration changes abruptly. The estimation of three parameters (cooperativity, saturation threshold, and maximal velocity of the reaction), and their evolution during replicative passages shows that only the maximal velocity varies significantly. Based on our modeling we speculate the reduction of functionality of the protein degradation mechanism as a possible competitive inhibition of the proteasome.

  14. Computation of steady-state probability distributions in stochastic models of cellular networks.

    Directory of Open Access Journals (Sweden)

    Mark Hallen

    2011-10-01

    Full Text Available Cellular processes are "noisy". In each cell, concentrations of molecules are subject to random fluctuations due to the small numbers of these molecules and to environmental perturbations. While noise varies with time, it is often measured at steady state, for example by flow cytometry. When interrogating aspects of a cellular network by such steady-state measurements of network components, a key need is to develop efficient methods to simulate and compute these distributions. We describe innovations in stochastic modeling coupled with approaches to this computational challenge: first, an approach to modeling intrinsic noise via solution of the chemical master equation, and second, a convolution technique to account for contributions of extrinsic noise. We show how these techniques can be combined in a streamlined procedure for evaluation of different sources of variability in a biochemical network. Evaluation and illustrations are given in analysis of two well-characterized synthetic gene circuits, as well as a signaling network underlying the mammalian cell cycle entry.

  15. Distributed Compression for the Uplink of a Backhaul-Constrained Coordinated Cellular Network

    CERN Document Server

    del Coso, Aitor

    2008-01-01

    We consider a backhaul-constrained coordinated cellular network. That is, a single-frequency network with $N+1$ multi-antenna base stations (BSs) that cooperate in order to decode the users' data, and that are linked by means of a common lossless backhaul, of limited capacity $\\mathrm{R}$. To implement receive cooperation, we propose distributed compression: $N$ BSs, upon receiving their signals, compress them using a multi-source lossy compression code. Then, they send the compressed vectors to a central BS, which performs users' decoding. Distributed Wyner-Ziv coding is proposed to be used, and is optimally designed in this work. The first part of the paper is devoted to a network with a unique multi-antenna user, that transmits a predefined Gaussian space-time codeword. For such a scenario, the compression codebooks at the BSs are optimized, considering the user's achievable rate as the performance metric. In particular, for $N = 1$ the optimum codebook distribution is derived in closed form, while for $N>...

  16. Effects of insulin and actin on phosphofructokinase activity and cellular distribution in skeletal muscle

    Directory of Open Access Journals (Sweden)

    Silva Ana Paula P.

    2004-01-01

    Full Text Available In this work, we report evidences that the association of phosphofructokinase and F-actin can be affected by insulin stimulation in rabbit skeletal muscle homogenates and that this association can be a mechanism of phos-phofructokinase regulation. Through co-sedimentation techniques, we observed that on insulin-stimulated tissues, approximately 70% of phosphofructokinase activity is co-located in an actin-enriched fraction, against 28% in control. This phenomenon is accompanied by a 100% increase in specific phosphofructokinase activity in stimulated homogenates. Purified F-actin causes an increase of 230% in phosphofructokinase activity and alters its kinetic parameters. The presence of F-actin increases the affinity of phosphofructokinase for fructose 6-phosphate nevertheless, with no changes in maximum velocity (Vmax. Here we propose that the modulation of cellular distribution of phosphofructokinase may be one of the mechanisms of control of glycolytic flux in mammalian muscle by insulin.

  17. A celiac cellular phenotype, with altered LPP sub-cellular distribution, is inducible in controls by the toxic gliadin peptide P31-43.

    Directory of Open Access Journals (Sweden)

    Merlin Nanayakkara

    Full Text Available Celiac disease (CD is a frequent inflammatory intestinal disease, with a genetic background, caused by gliadin-containing food. Undigested gliadin peptides P31-43 and P57-68 induce innate and adaptive T cell-mediated immune responses, respectively. Alterations in the cell shape and actin cytoskeleton are present in celiac enterocytes, and gliadin peptides induce actin rearrangements in both the CD mucosa and cell lines. Cell shape is maintained by the actin cytoskeleton and focal adhesions, sites of membrane attachment to the extracellular matrix. The locus of the human Lipoma Preferred Partner (LPP gene was identified as strongly associated with CD using genome-wide association studies (GWAS. The LPP protein plays an important role in focal adhesion architecture and acts as a transcription factor in the nucleus. In this study, we examined the hypothesis that a constitutive alteration of the cell shape and the cytoskeleton, involving LPP, occurs in a cell compartment far from the main inflammation site in CD fibroblasts from skin explants. We analyzed the cell shape, actin organization, focal adhesion number, focal adhesion proteins, LPP sub-cellular distribution and adhesion to fibronectin of fibroblasts obtained from CD patients on a Gluten-Free Diet (GFD and controls, without and with treatment with A-gliadin peptide P31-43. We observed a "CD cellular phenotype" in these fibroblasts, characterized by an altered cell shape and actin organization, increased number of focal adhesions, and altered intracellular LPP protein distribution. The treatment of controls fibroblasts with gliadin peptide P31-43 mimics the CD cellular phenotype regarding the cell shape, adhesion capacity, focal adhesion number and LPP sub-cellular distribution, suggesting a close association between these alterations and CD pathogenesis.

  18. Regular figures

    CERN Document Server

    Tóth, L Fejes; Ulam, S; Stark, M

    1964-01-01

    Regular Figures concerns the systematology and genetics of regular figures. The first part of the book deals with the classical theory of the regular figures. This topic includes description of plane ornaments, spherical arrangements, hyperbolic tessellations, polyhedral, and regular polytopes. The problem of geometry of the sphere and the two-dimensional hyperbolic space are considered. Classical theory is explained as describing all possible symmetrical groupings in different spaces of constant curvature. The second part deals with the genetics of the regular figures and the inequalities fo

  19. The role of topography in the scaling distribution of landslide areas: A cellular automata modeling approach

    Science.gov (United States)

    Liucci, Luisa; Melelli, Laura; Suteanu, Cristian; Ponziani, Francesco

    2017-08-01

    Power law scaling has been widely observed in the frequency distribution of landslide sizes. The exponent of the power-law characterizes the probability of landslide magnitudes and it thus represents an important parameter for hazard assessment. The reason for the universal scaling behavior of landslides is still debated and the role of topography has been explored in terms of possible explanation for this type of behavior. We built a simple cellular automata model to investigate this issue, as well as the relationships between the scaling properties of landslide areas and the changes suffered by the topographic surface affected by landslides. The dynamics of the model is controlled by a temporal rate of weakening, which drives the system to instability, and by topography, which defines both the quantity of the displaced mass and the direction of the movement. Results show that the model is capable of reproducing the scaling behavior of real landslide areas and suggest that topography is a good candidate to explain their scale-invariance. In the model, the values of the scaling exponents depend on how fast the system is driven to instability; they are less sensitive to the duration of the driving rate, thus suggesting that the probability of landslide areas could depend on the intensity of the triggering mechanism rather than on its duration, and on the topographic setting of the area. Topography preserves the information concerning the statistical distribution of areas of landslides caused by a driving mechanism of given intensity and duration.

  20. An investigation of cellular distribution of manganese in hyperaccumlator plant Phytolacca acinosa Roxb. using SRXRF analysis

    Institute of Scientific and Technical Information of China (English)

    XU Xiang-hua; SHI Ji-yan; CHEN Ying-xu; XUE Sheng-guo; WU Bei; HUANG Yu-ying

    2006-01-01

    Phytolacca acinosa Roxb. (P. acinosa) is a recently discovered manganese hyperaccumulator plant from southern China. It is a good candidate for phytoremediation of manganese(Mn) polluted soil for its high biomass and fast growth. Knowledge of the tissue localization and identification of heavy metals can provide essential information on metal toxicity and bioaccumulation mechanisms. Synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe was used in this study to investigate the cellular distributions of Mn and other elements in root, stem, leaf, petiole and midrib ofP. acinosa. The highest Mn content was found in the vascular tissues of root, stem, petiole and midrib. Cortex in root played a key role in Mn absorption and Mn was limited in the vascular bundle during the process of transportation in stem. Moreover, Mn content in leaf epidermis was higher than that in mesophyll, which suggested that the sequestration of Mn in leaf epidermis might be one of the detoxification mechanisms of P.acinosa. The significance of other elemental (such as P, S, K, Ca, Fe, Zn and Cu) distribution patterns and the correlation with Mn were also discussed.

  1. Investigation on the Distribution of Regular Blood Donors in Urban Wenzhou%温州市区固定献血者分布调查

    Institute of Scientific and Technical Information of China (English)

    谢熙熙; 苏虹; 陈通; 陈李

    2012-01-01

    Objective To establish regular non-remunerated blood donors team through investigation on the urban regular blood donors in Wenzhou. Methods The relationship between donation times and the ages and blood types was analyzed, and the distribution of regular blood donors and blood components donors was contrasted. Results The difference of donation times among different aged regular donors is statistically significant (P 0.05 ). Occupation distribution and educational level distribution between regular blood donors and blood components donors were different. Conclusion Publicity should be strengthened, and identification of the target population of the fixed blood donors with components donors could improve the recruitment efficiency,consolidate and enlarge the regular blood donors population.%目的 通过对温州市区固定献血者人群分布调查,为建立一支固定献血者队伍提供依据.方法 分析献血次数与年龄、血型的关系,对固定献血者人群与其中成分献血者分布情况进行对比分析.结果 不同年龄固定献血者献血次数差异有统计学意义(P<0.05);不同血型固定献血者献血次数差异无有统计学意义(P>0.05).固定献血者与参与成分献血人群在职业与文化程度分布情况有差别.结论 加大宣传,明确招募固定献血者与成分献血者目标人群,可以提高固定献血者招募效率,巩固并扩大固定献血者队伍.

  2. Spatial distribution and cellular composition of adult brain proliferative zones in the teleost, Gymnotus omarorum

    Directory of Open Access Journals (Sweden)

    Valentina eOlivera-Pasilio

    2014-09-01

    Full Text Available Proliferation of stem/progenitor cells during development provides for the generation of mature cell types in the CNS. While adult brain proliferation is highly restricted in the mammals, it is widespread in teleosts. The extent of adult neural proliferation in the weakly electric fish, Gymnotus omarorum has not yet been described. To address this, we used double thymidine analog pulse-chase labeling of proliferating cells to identify brain proliferation zones, characterize their cellular composition, and analyze the fate of newborn cells in adult G. omarorum. Short thymidine analog chase periods revealed the ubiquitous distribution of adult brain proliferation, similar to other teleosts, particularly Apteronotus leptorhynchus. Proliferating cells were abundant at the ventricular-subventricular lining of the ventricular-cisternal system, adjacent to the telencephalic subpallium, the diencephalic preoptic region and hypothalamus, and the mesencephalic tectum opticum and torus semicircularis. Extraventricular proliferation zones, located distant from the ventricular-cisternal system surface, were found in all divisions of the rombencephalic cerebellum. We also report a new adult proliferation zone at the caudal-lateral border of the electrosensory lateral line lobe. All proliferation zones showed a heterogeneous cellular composition. The use of short (24hs and long (30d chase periods revealed abundant fast cycling cells (potentially intermediate amplifiers, sparse slow cycling (potentially stem cells, cells that appear to have entered a quiescent state, and cells that might correspond to migrating newborn neural cells. Their abundance and migration distance differed among proliferation zones: greater numbers and longer range and/or pace of migrating cells were associated with subpallial and cerebellar proliferation zones.

  3. TAp63γ demethylation regulates protein stability and cellular distribution during neural stem cell differentiation.

    Directory of Open Access Journals (Sweden)

    Maria B Fonseca

    Full Text Available p63 is a close relative of the p53 tumor suppressor and transcription factor that modulates cell fate. The full-length isoform of p63, containing a transactivation (TA domain (TAp63 is an essential proapoptotic protein in neural development. The role of p63 in epithelial development is also well established; however, its precise function during neural differentiation remains largely controversial. Recently, it has been demonstrated that several conserved elements of apoptosis are also integral components of cellular differentiation; p53 directly interacts with key regulators of neurogenesis. The aim of this study was to evaluate the role of p63 during mouse neural stem cell (NSC differentiation and test whether the histone H3 lysine 27-specific demethylase JMJD3 interacts with p63 to redirect NSCs to neurogenesis. Our results showed that JMJD3 and TAp63γ are coordinately regulated to establish neural-specific gene expression programs in NSCs undergoing differentiation. JMJD3 overexpression increased TAp63γ levels in a demethylase activity-dependent manner. Importantly, overexpression of TAp63γ increased β-III tubulin whereas downregulation of TAp63γ by specific p63 siRNA decreased β-III tubulin. Immunoprecipitation assays demonstrated direct interaction between TAp63γ and JMJD3, and modulation of TAp63γ methylation status by JMJD3-demethylase activity. Importantly, the demethylase activity of JMJD3 influenced TAp63γ protein stabilization and cellular distribution, as well as TAp63γ-regulated neurogenesis. These findings clarify the role of p63 in adult neural progenitor cells and reveal TAp63γ as a direct target for JMJD3-mediated neuronal commitment.

  4. In silico analyses of dystrophin Dp40 cellular distribution, nuclear export signals and structure modeling

    Directory of Open Access Journals (Sweden)

    Alejandro Martínez-Herrera

    2015-09-01

    Full Text Available Dystrophin Dp40 is the shortest protein encoded by the DMD (Duchenne muscular dystrophy gene. This protein is unique since it lacks the C-terminal end of dystrophins. In this data article, we describe the subcellular localization, nuclear export signals and the three-dimensional structure modeling of putative Dp40 proteins using bioinformatics tools. The Dp40 wild type protein was predicted as a cytoplasmic protein while the Dp40n4 was predicted to be nuclear. Changes L93P and L170P are involved in the nuclear localization of Dp40n4 protein. A close analysis of Dp40 protein scored that amino acids 93LEQEHNNLV101 and 168LLLHDSIQI176 could function as NES sequences and the scores are lost in Dp40n4. In addition, the changes L93/170P modify the tertiary structure of putative Dp40 mutants. The analysis showed that changes of residues 93 and 170 from leucine to proline allow the nuclear localization of Dp40 proteins. The data described here are related to the research article entitled “EF-hand domains are involved in the differential cellular distribution of dystrophin Dp40” (J. Aragón et al. Neurosci. Lett. 600 (2015 115–120 [1].

  5. Functional domains and sub-cellular distribution of the Hedgehog transducing protein Smoothened in Drosophila.

    Science.gov (United States)

    Nakano, Y; Nystedt, S; Shivdasani, A A; Strutt, H; Thomas, C; Ingham, P W

    2004-06-01

    The Hedgehog signalling pathway is deployed repeatedly during normal animal development and its inappropriate activity is associated with various tumours in human. The serpentine protein Smoothened (Smo) is essential for cells to respond to the Hedeghog (Hh) signal; oncogenic forms of Smo have been isolated from human basal cell carcinomas. Despite similarities with ligand binding G-protein coupled receptors, the molecular basis of Smo activity and its regulation remains unclear. In non-responding cells, Smo is suppressed by the activity of another multipass membrane spanning protein Ptc, which acts as the Hh receptor. In Drosophila, binding of Hh to Ptc has been shown to cause an accumulation of phosphorylated Smo protein and a concomitant stabilisation of the activated form of the Ci transcription factor. Here, we identify domains essential for Smo activity and investigate the sub-cellular distribution of the wild type protein in vivo. We find that deletion of the amino terminus and the juxtamembrane region of the carboxy terminus of the protein result in the loss of normal Smo activity. Using Green Fluorescent Protein (GFP) and horseradish peroxidase fusion proteins we show that Smo accumulates in the plasma membrane of cells in which Ptc activity is abrogated by Hh but is targeted to the degradative pathway in cells where Ptc is active. We further demonstrate that Smo accumulation is likely to be a cause, rather than a consequence, of Hh signal transduction.

  6. Expression and cellular distribution of multidrug resistance-related proteins in the hippocampus of patients with mesial temporal lobe epilepsy

    NARCIS (Netherlands)

    E. Aronica; J.A. Gorter; M. Ramkema; S. Redeker; F. Ozbas-Gercer; E.A. van Vliet; G.L. Scheffer; R.J. Scheper; P. van der Valk; J.C. Baayen; D. Troost

    2004-01-01

    Purpose: This study investigated the cellular distribution of different multidrug resistance (MDR)-related proteins such as P-glycoprotein (P-gp), the multidrug resistance-associated proteins (MRP) 1 and 2, and the major vault protein (MVP) in normal and sclerotic hippocampus of patients with medica

  7. On the gradient of the Green tensor in two-dimensional elastodynamic problems, and related integrals: Distributional approach and regularization, with application to nonuniformly moving sources

    CERN Document Server

    Pellegrini, Yves-Patrick

    2015-01-01

    The two-dimensional elastodynamic Green tensor is the primary building block of solutions of linear elasticity problems dealing with nonuniformly moving rectilinear line sources, such as dislocations. Elastodynamic solutions for these problems involve derivatives of this Green tensor, which stand as hypersingular kernels. These objects, well defined as distributions, prove cumbersome to handle in practice. This paper, restricted to isotropic media, examines some of their representations in the framework of distribution theory. A particularly convenient regularization of the Green tensor is introduced, that amounts to considering line sources of finite width. Technically, it is implemented by an analytic continuation of the Green tensor to complex times. It is applied to the computation of regularized forms of certain integrals of tensor character that involve the gradient of the Green tensor. These integrals are fundamental to the computation of the elastodynamic fields in the problem of nonuniformly moving d...

  8. Existence, uniqueness and regularity of a time-periodic probability density distribution arising in a sedimentation-diffusion problem

    Science.gov (United States)

    Nitsche, Ludwig C.; Nitsche, Johannes M.; Brenner, Howard

    1988-01-01

    The sedimentation and diffusion of a nonneutrally buoyant Brownian particle in vertical fluid-filled cylinder of finite length which is instantaneously inverted at regular intervals are investigated analytically. A one-dimensional convective-diffusive equation is derived to describe the temporal and spatial evolution of the probability density; a periodicity condition is formulated; the applicability of Fredholm theory is established; and the parameter-space regions are determined within which the existence and uniqueness of solutions are guaranteed. Numerical results for sample problems are presented graphically and briefly characterized.

  9. Non-regularized inversion method from light scattering applied to ferrofluid magnetization curves for magnetic size distribution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rijssel, Jos van; Kuipers, Bonny W.M.; Erné, Ben H., E-mail: B.H.Erne@uu.nl

    2014-03-15

    A numerical inversion method known from the analysis of light scattering by colloidal dispersions is now applied to magnetization curves of ferrofluids. The distribution of magnetic particle sizes or dipole moments is determined without assuming that the distribution is unimodal or of a particular shape. The inversion method enforces positive number densities via a non-negative least squares procedure. It is tested successfully on experimental and simulated data for ferrofluid samples with known multimodal size distributions. The created computer program MINORIM is made available on the web. - Highlights: • A method from light scattering is applied to analyze ferrofluid magnetization curves. • A magnetic size distribution is obtained without prior assumption of its shape. • The method is tested successfully on ferrofluids with a known size distribution. • The practical limits of the method are explored with simulated data including noise. • This method is implemented in the program MINORIM, freely available online.

  10. The determination of pair-distance distribution by double electron-electron resonance: regularization by the length of distance discretization with Monte Carlo calculations

    Science.gov (United States)

    Dzuba, Sergei A.

    2016-08-01

    Pulsed double electron-electron resonance technique (DEER, or PELDOR) is applied to study conformations and aggregation of peptides, proteins, nucleic acids, and other macromolecules. For a pair of spin labels, experimental data allows for the determination of their distance distribution function, P(r). P(r) is derived as a solution of a first-kind Fredholm integral equation, which is an ill-posed problem. Here, we suggest regularization by increasing the distance discretization length to its upper limit where numerical integration still provides agreement with experiment. This upper limit is found to be well above the lower limit for which the solution instability appears because of the ill-posed nature of the problem. For solving the integral equation, Monte Carlo trials of P(r) functions are employed; this method has an obvious advantage of the fulfillment of the non-negativity constraint for P(r). The regularization by the increasing of distance discretization length for the case of overlapping broad and narrow distributions may be employed selectively, with this length being different for different distance ranges. The approach is checked for model distance distributions and for experimental data taken from literature for doubly spin-labeled DNA and peptide antibiotics.

  11. Analytic approach to stochastic cellular automata: exponential and inverse power distributions out of Random Domino Automaton

    CERN Document Server

    Bialecki, Mariusz

    2010-01-01

    Inspired by extremely simplified view of the earthquakes we propose the stochastic domino cellular automaton model exhibiting avalanches. From elementary combinatorial arguments we derive a set of nonlinear equations describing the automaton. Exact relations between the average parameters of the model are presented. Depending on imposed triggering, the model reproduces both exponential and inverse power statistics of clusters.

  12. Measuring Cellular-scale Nutrient Distribution in Algal Biofilms with Synchrotron Confocal Infrared Microspectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    J Murdock; W Dodds; J Reffner; D Wetzel

    2011-12-31

    The microscope and infrared spectrometer are two of the most useful tools for the study of biological materials, and their combined analytical power far exceeds the sum of the two. Performing molecular spectroscopy through a microscope superimposes chemical information onto the physical microstructure obtained from the optical microscope when visible and infrared information are collected under the same conditions. The instrument developments that enable current infrared microspectroscopic studies began with the introduction of the first research-grade infrared microscope, patented in 1989 (1). By 1993, published reports using this method to determine macroalgae (seaweed) cell-wall composition appeared (2-4). Since these initial reports, the use of infrared microspectroscopy (IMS) in microalgal (single cells or groups of cells) research has grown. Primarily, cultured algae have been used to hone IMS methodology and evaluate its capabilities in algal research (5-8). Studies involving natural, mixed species assemblages, which can utilize the spatial resolution potential of this technique fully are rare (9-11). For instance, in a recent review of IMS microalgal ecological research (12), only 3 of the 29 peer-reviewed publications investigated natural algal assemblages. Both thermal and synchrotron infrared sources provide a resolution capable of measuring individual algae in mixed species assemblages, and each has its advantages. For example, thermal source IMS is more accessible, allowing more samples to be analyzed than synchrotron IMS. However, synchrotron IMS with confocal masking provides superior resolution, which can be critical in isolating small or contiguous cells. Algal ecology is the study of the interaction between algae and their environment. Infrared microspectroscopy addresses a major logistical problem in this field, obtaining species-specific cellular biochemical information from natural, mixed-species assemblages (11,12). Benthic (bottom

  13. Clustering, Randomness, and Regularity: Spatial Distributions and Human Performance on the Traveling Salesperson Problem and Minimum Spanning Tree Problem

    Science.gov (United States)

    Dry, Matthew J.; Preiss, Kym; Wagemans, Johan

    2012-01-01

    We investigated human performance on the Euclidean Traveling Salesperson Problem (TSP) and Euclidean Minimum Spanning Tree Problem (MST-P) in regards to a factor that has previously received little attention within the literature: the spatial distributions of TSP and MST-P stimuli. First, we describe a method for quantifying the relative degree of…

  14. Adaptive regularization

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Rasmussen, Carl Edward; Svarer, C.

    1994-01-01

    Regularization, e.g., in the form of weight decay, is important for training and optimization of neural network architectures. In this work the authors provide a tool based on asymptotic sampling theory, for iterative estimation of weight decay parameters. The basic idea is to do a gradient descent...... in the estimated generalization error with respect to the regularization parameters. The scheme is implemented in the authors' Designer Net framework for network training and pruning, i.e., is based on the diagonal Hessian approximation. The scheme does not require essential computational overhead in addition...... to what is needed for training and pruning. The viability of the approach is demonstrated in an experiment concerning prediction of the chaotic Mackey-Glass series. The authors find that the optimized weight decays are relatively large for densely connected networks in the initial pruning phase, while...

  15. Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc

    Institute of Scientific and Technical Information of China (English)

    Jun-guo YANG; Hai-ning YU; Shi-li SUN; Lan-cui ZHANG; Guo-qing HE; Undurti N. DAS; Hui RUAN; Sheng-rong SHEN

    2009-01-01

    Objective: To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:l was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane,decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.

  16. Caenorhabditis elegans maintains highly compartmentalized cellular distribution of metals and steep concentration gradients of manganese.

    Directory of Open Access Journals (Sweden)

    Gawain McColl

    Full Text Available Bioinorganic chemistry is critical to cellular function. Homeostasis of manganese (Mn, for example, is essential for life. A lack of methods for direct in situ visualization of Mn and other biological metals within intact multicellular eukaryotes limits our understanding of management of these metals. We provide the first quantitative subcellular visualization of endogenous Mn concentrations (spanning two orders of magnitude associated with individual cells of the nematode, Caenorhabditis elegans.

  17. PhosphoregDB: The tissue and sub-cellular distribution of mammalian protein kinases and phosphatases

    Directory of Open Access Journals (Sweden)

    Suzuki Harukazu

    2006-02-01

    Full Text Available Abstract Background Protein kinases and protein phosphatases are the fundamental components of phosphorylation dependent protein regulatory systems. We have created a database for the protein kinase-like and phosphatase-like loci of mouse http://phosphoreg.imb.uq.edu.au that integrates protein sequence, interaction, classification and pathway information with the results of a systematic screen of their sub-cellular localization and tissue specific expression data mined from the GNF tissue atlas of mouse. Results The database lets users query where a specific kinase or phosphatase is expressed at both the tissue and sub-cellular levels. Similarly the interface allows the user to query by tissue, pathway or sub-cellular localization, to reveal which components are co-expressed or co-localized. A review of their expression reveals 30% of these components are detected in all tissues tested while 70% show some level of tissue restriction. Hierarchical clustering of the expression data reveals that expression of these genes can be used to separate the samples into tissues of related lineage, including 3 larger clusters of nervous tissue, developing embryo and cells of the immune system. By overlaying the expression, sub-cellular localization and classification data we examine correlations between class, specificity and tissue restriction and show that tyrosine kinases are more generally expressed in fewer tissues than serine/threonine kinases. Conclusion Together these data demonstrate that cell type specific systems exist to regulate protein phosphorylation and that for accurate modelling and for determination of enzyme substrate relationships the co-location of components needs to be considered.

  18. Reconstruction of full electron energy distributions by Poisson-regularized spectral inversion of x-ray Bremsstrahlung emissions in the PFRC device

    Science.gov (United States)

    Swanson, Charles; Jandovitz, Peter; Bosh, Alexandra; Cohen, Samuel

    2016-10-01

    The PFRC is an odd-parity Rotating Magnetic Field (RMF) driven Field-Reversed Configuration plasma confinement experiment equipped with Si-PIN and SDD x-ray detectors. It is predicted that the electron energy distribution is non-thermal when the RMF is active. Using a novel inversion technique, we present full electron distribution functions as reconstructed (``spectrally inverted'') from the x-ray Bremsstrahlung emissions. This method regularizes the inverse treating the measurement as a Poisson random variable, as opposed to state-of-the-art methods which assume a Normal random variable. The method maximizes the log-likelihood of the solution, determined from Bayes' Theorem. This work was supported, in part, by DOE Contract Number DE-AC02-09CH11466.

  19. [Cellular distribution and behavior of metallothionein in mammalian cells following exposure to silver nanoparticles and silver ions].

    Science.gov (United States)

    Miyayama, Takamitsu; Arai, Yuta; Suzuki, Noriyuki; Hirano, Seishiro

    2014-01-01

    Silver nanoparticles (AgNPs) are commercially used mainly as antibacterial reagents in wound dressing and deodorant powders. However, the mechanisms underlying Ag toxicity in mammals are not fully understood. In the present study, we assessed cellular distribution and toxicity of AgNPs and AgNO3 in mouse macrophage cell line (J774.1) and those of AgNO3 in human bronchial epithelial cell line (BEAS-2B) focusing on behavior of metallothionein (MT). J774.1 cells were exposed to 0-100 μg Ag/mL AgNPs or AgNO3 and BEAS-2B cells were exposed to 0-100 μM AgNO3 for 24 h. The cytotoxicity was assayed by a modified MTT method. The cellular concentration and distribution of Ag were evaluated by inductively coupled plasma-mass spectorometry (ICP-MS) and laser scanning microscopy. Distribution of Ag to MT and other proteins was determined using HPLC-ICP-MS. Most AgNPs were found in lysosomes in J774.1 at 3 h after post exposure. Ag was distributed to high molecular weight proteins in AgNPs-exposed cells, while most Ag was bound to MT in AgNO3-exposed cells. In AgNO3-exposed BEAS-2B cells cellular Ag concentration and Ag-bound MT (Ag-MT) were sharply increased up to 3 h and then decreased. ROS production appeared to cause relocation of MT-bound Ag to mitochondria, which evoked inhibition of electron transport chain. AgNPs were sequestered by high-molecular weight proteins rather than MT, probably because they were taken up by lysosomes before induction of MT.

  20. Effect of solid distribution on elastic properties of open-cell cellular solids using numerical and experimental methods.

    Science.gov (United States)

    Zargarian, A; Esfahanian, M; Kadkhodapour, J; Ziaei-Rad, S

    2014-09-01

    Effect of solid distribution between edges and vertices of three-dimensional cellular solid with an open-cell structure was investigated both numerically and experimentally. Finite element analysis (FEA) with continuum elements and appropriate periodic boundary condition was employed to calculate the elastic properties of cellular solids using tetrakaidecahedral (Kelvin) unit cell. Relative densities between 0.01 and 0.1 and various values of solid fractions were considered. In order to validate the numerical model, three scaffolds with the relative density of 0.08, but different amounts of solid in vertices, were fabricated via 3-D printing technique. Good agreement was observed between numerical simulation and experimental results. Results of numerical simulation showed that, at low relative densities (numerical simulation and considering the relative density and solid fraction in vertices, empirical relations were derived for Young׳s modulus and Poisson׳s ratio.

  1. Cellular distribution of arsenic and other elements in hyperaccumulator Pteris nervosa and their relations to arsenic accumulation

    Institute of Scientific and Technical Information of China (English)

    CHEN Tongbin; HUANG Zechun; HUANG Yuying; XIE Hua; LIAO Xiaoyong

    2003-01-01

    Synchrotron radiation X-ray fluorescencespectroscopy (SRXRF) was used to study the cellular distri-butions of arsenic and other elements in root, petiole, pinna of a newly discovered arsenic hyperaccumulator, Pteris nervosa. It was shown that there was a trend in P. nervosa totransport arsenic from cortex tissue to vascular tissue in root, and keep arsenic in vascular during transportation in petiole, and transport arsenic from vascular tissue to adaxial cortex tissues in midrib of pinnae. More arsenic was accumulated in mesophyll than in epidermis in pinnae. The distributions of some elements, such as K, Ca, Mn, Fe, Cu, Zn, in petiole, midrib and pinna were similar to that of arsenic, indicating that those cations might cooperate with arsenic in those transportation processes; whereas the distributions of Cl and Br in pinna were the reverse of that of arsenic, indicating that those anions might compete with arsenic in pinna of P. nervosa.

  2. Regular polytopes

    CERN Document Server

    Coxeter, H S M

    1973-01-01

    Polytopes are geometrical figures bounded by portions of lines, planes, or hyperplanes. In plane (two dimensional) geometry, they are known as polygons and comprise such figures as triangles, squares, pentagons, etc. In solid (three dimensional) geometry they are known as polyhedra and include such figures as tetrahedra (a type of pyramid), cubes, icosahedra, and many more; the possibilities, in fact, are infinite! H. S. M. Coxeter's book is the foremost book available on regular polyhedra, incorporating not only the ancient Greek work on the subject, but also the vast amount of information

  3. Stochastic fluctuations and distributed control of gene expression impact cellular memory.

    Directory of Open Access Journals (Sweden)

    Guillaume Corre

    Full Text Available Despite the stochastic noise that characterizes all cellular processes the cells are able to maintain and transmit to their daughter cells the stable level of gene expression. In order to better understand this phenomenon, we investigated the temporal dynamics of gene expression variation using a double reporter gene model. We compared cell clones with transgenes coding for highly stable mRNA and fluorescent proteins with clones expressing destabilized mRNA-s and proteins. Both types of clones displayed strong heterogeneity of reporter gene expression levels. However, cells expressing stable gene products produced daughter cells with similar level of reporter proteins, while in cell clones with short mRNA and protein half-lives the epigenetic memory of the gene expression level was completely suppressed. Computer simulations also confirmed the role of mRNA and protein stability in the conservation of constant gene expression levels over several cell generations. These data indicate that the conservation of a stable phenotype in a cellular lineage may largely depend on the slow turnover of mRNA-s and proteins.

  4. Formation of a regular domain structure in TGS–TGS + Cr crystals with a profile impurity distribution

    Energy Technology Data Exchange (ETDEWEB)

    Belugina, N. V., E-mail: alla@ns.crys.ras.ru; Gainutdinov, R. V.; Tolstikhina, A. L.; Ivanova, E. S. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Kashevich, I. F. [Vitebsk State University (Belarus); Shut, V. N.; Mozzharov, S. E. [Belarussian Academy of Sciences, Institute of Technical Acoustics (Belarus)

    2015-07-15

    A complex investigation of TGS–TGS + Cr crystals with a profile impurity distribution of chromium ions Cr{sup 3+} has been carried out at the macrolevel (measurement of dielectric properties by the method of nematic liquid crystals) and microlevel (domain structure according to atomic force microscopy data). It is established that periodic doped layers are formed only in individual growth pyramids in the regions where the polarization vector has a nonzero component along the normal to the growth faces rather than throughout the entire crystal volume. The domain configuration at the boundary of growth layers with different impurity compositions has been studied by piezoelectric force microscopy. The static unipolarity of layers with and without chromium impurity is approximately identical, whereas the domain-wall density in doped regions is higher than that in undoped ones by a factor of about 7.

  5. THREE-DIMENSIONAL REGULARITIES OF DISTRIBUTION OF AIR-INLET CHARACTERISTIC VELOCITY IN NATURAL-DRAFT WET COOLING TOWER

    Institute of Scientific and Technical Information of China (English)

    WANG Kai; SUN Feng-zhong; ZHAO Yuan-bin; GAO Ming; SHI Yue-tao

    2008-01-01

    A model for heat and mass transfer in a natural-draft wet cooling tower was established. Numerical simulation with the k-ε turbulent model was conducted. Distribution rules of air inlet aerodynamic field were studied. Field experiments were done in a cooling tower in power plant, and the test data was compared with the related results. The definition of characteristic air velocity was proposed and its influencing factors, such as the cross-wind velocity and circumferential angle, were quantitatively studied. It can be used to evaluate the performance of cooling tower and to calculate the ventilation quantity and resistance of air inlet. It is also a theoretical basis for cooling tower design and performance optimization.

  6. The regular distribution and expression pattern of immunosuppressive cytokine IL-35 in mouse uterus during early pregnancy.

    Science.gov (United States)

    Jin, Erhui; Wang, Chenfang; Hu, Qianqian; Jin, Guangming; Li, Shenghe

    2014-01-01

    Cytokines within the uterus are critical in the maternal-fetal immune regulation. Immunosuppressive cytokine IL-35 was recently discovered inhibitory cytokine, which were pivotal in the establishment of immune tolerance against self-antigens and antigens encountered in foreign implantation. In order to analyze the role of IL-35 in maternal-fetal immune tolerance, the expression patterns of IL-35 in mouse endometrium were studied during early pregnancy by immunohistochemistry, ELISA and quantitative real-time PCR. As results, we found that IL-35 positive cells in the uterus showed significant distribution difference after fetal implantation, which mainly distributed in luminal epithelium and glandular epithelium of mouse uterus from gestational day 1 to 2, and glandular epithelium and stroma from gestational day 4 to 7. The number of positive cells, immunoreactive scores, protein and mRNA expression of IL-35 showed firstly increased and then decreased with the increase of pregnancy day. The largest contents of IL-35 in the uterus were detected on gestational day 4. Compared with non-pregnant mice, pregnant mice showed the significantly increased mRNA expression of Ebi3 (Epstein-Barr virus-induced gene 3, IL-35 subunit) in the endometrium on gestational day 2 and the highest level of expression on gestational day 4. The mRNA expression of p35 (IL-35 subunit) was significantly lower than that of Ebi3 gene and showed the inconsistent change from gestational day 5 to 7. However, the significant correlation existed between the immunohistochemical expression, contents and mRNA expression of IL-35. These results indicated that IL-35 contributed to the establishment and maintenance of maternal-fetal tolerance during early pregnancy.

  7. Changes in weight loss, body composition and cardiovascular disease risk after altering macronutrient distributions during a regular exercise program in obese women

    Science.gov (United States)

    2010-01-01

    Background This study's purpose investigated the impact of different macronutrient distributions and varying caloric intakes along with regular exercise for metabolic and physiological changes related to weight loss. Methods One hundred forty-one sedentary, obese women (38.7 ± 8.0 yrs, 163.3 ± 6.9 cm, 93.2 ± 16.5 kg, 35.0 ± 6.2 kg•m-2, 44.8 ± 4.2% fat) were randomized to either no diet + no exercise control group (CON) a no diet + exercise control (ND), or one of four diet + exercise groups (high-energy diet [HED], very low carbohydrate, high protein diet [VLCHP], low carbohydrate, moderate protein diet [LCMP] and high carbohydrate, low protein [HCLP]) in addition to beginning a 3x•week-1 supervised resistance training program. After 0, 1, 10 and 14 weeks, all participants completed testing sessions which included anthropometric, body composition, energy expenditure, fasting blood samples, aerobic and muscular fitness assessments. Data were analyzed using repeated measures ANOVA with an alpha of 0.05 with LSD post-hoc analysis when appropriate. Results All dieting groups exhibited adequate compliance to their prescribed diet regimen as energy and macronutrient amounts and distributions were close to prescribed amounts. Those groups that followed a diet and exercise program reported significantly greater anthropometric (waist circumference and body mass) and body composition via DXA (fat mass and % fat) changes. Caloric restriction initially reduced energy expenditure, but successfully returned to baseline values after 10 weeks of dieting and exercising. Significant fitness improvements (aerobic capacity and maximal strength) occurred in all exercising groups. No significant changes occurred in lipid panel constituents, but serum insulin and HOMA-IR values decreased in the VLCHP group. Significant reductions in serum leptin occurred in all caloric restriction + exercise groups after 14 weeks, which were unchanged in other non-diet/non-exercise groups

  8. Changes in weight loss, body composition and cardiovascular disease risk after altering macronutrient distributions during a regular exercise program in obese women

    Directory of Open Access Journals (Sweden)

    Roberts Mike D

    2010-11-01

    Full Text Available Abstract Background This study's purpose investigated the impact of different macronutrient distributions and varying caloric intakes along with regular exercise for metabolic and physiological changes related to weight loss. Methods One hundred forty-one sedentary, obese women (38.7 ± 8.0 yrs, 163.3 ± 6.9 cm, 93.2 ± 16.5 kg, 35.0 ± 6.2 kg•m-2, 44.8 ± 4.2% fat were randomized to either no diet + no exercise control group (CON a no diet + exercise control (ND, or one of four diet + exercise groups (high-energy diet [HED], very low carbohydrate, high protein diet [VLCHP], low carbohydrate, moderate protein diet [LCMP] and high carbohydrate, low protein [HCLP] in addition to beginning a 3x•week-1 supervised resistance training program. After 0, 1, 10 and 14 weeks, all participants completed testing sessions which included anthropometric, body composition, energy expenditure, fasting blood samples, aerobic and muscular fitness assessments. Data were analyzed using repeated measures ANOVA with an alpha of 0.05 with LSD post-hoc analysis when appropriate. Results All dieting groups exhibited adequate compliance to their prescribed diet regimen as energy and macronutrient amounts and distributions were close to prescribed amounts. Those groups that followed a diet and exercise program reported significantly greater anthropometric (waist circumference and body mass and body composition via DXA (fat mass and % fat changes. Caloric restriction initially reduced energy expenditure, but successfully returned to baseline values after 10 weeks of dieting and exercising. Significant fitness improvements (aerobic capacity and maximal strength occurred in all exercising groups. No significant changes occurred in lipid panel constituents, but serum insulin and HOMA-IR values decreased in the VLCHP group. Significant reductions in serum leptin occurred in all caloric restriction + exercise groups after 14 weeks, which were unchanged in other non

  9. Changes in weight loss, body composition and cardiovascular disease risk after altering macronutrient distributions during a regular exercise program in obese women.

    Science.gov (United States)

    Kerksick, Chad M; Wismann-Bunn, Jennifer; Fogt, Donovan; Thomas, Ashli R; Taylor, Lem; Campbell, Bill I; Wilborn, Colin D; Harvey, Travis; Roberts, Mike D; La Bounty, Paul; Galbreath, Melyn; Marcello, Brandon; Rasmussen, Christopher J; Kreider, Richard B

    2010-11-22

    This study's purpose investigated the impact of different macronutrient distributions and varying caloric intakes along with regular exercise for metabolic and physiological changes related to weight loss. One hundred forty-one sedentary, obese women (38.7 ± 8.0 yrs, 163.3 ± 6.9 cm, 93.2 ± 16.5 kg, 35.0 ± 6.2 kg•m(-2), 44.8 ± 4.2% fat) were randomized to either no diet + no exercise control group (CON) a no diet + exercise control (ND), or one of four diet + exercise groups (high-energy diet [HED], very low carbohydrate, high protein diet [VLCHP], low carbohydrate, moderate protein diet [LCMP] and high carbohydrate, low protein [HCLP]) in addition to beginning a 3x•week(-1) supervised resistance training program. After 0, 1, 10 and 14 weeks, all participants completed testing sessions which included anthropometric, body composition, energy expenditure, fasting blood samples, aerobic and muscular fitness assessments. Data were analyzed using repeated measures ANOVA with an alpha of 0.05 with LSD post-hoc analysis when appropriate. All dieting groups exhibited adequate compliance to their prescribed diet regimen as energy and macronutrient amounts and distributions were close to prescribed amounts. Those groups that followed a diet and exercise program reported significantly greater anthropometric (waist circumference and body mass) and body composition via DXA (fat mass and % fat) changes. Caloric restriction initially reduced energy expenditure, but successfully returned to baseline values after 10 weeks of dieting and exercising. Significant fitness improvements (aerobic capacity and maximal strength) occurred in all exercising groups. No significant changes occurred in lipid panel constituents, but serum insulin and HOMA-IR values decreased in the VLCHP group. Significant reductions in serum leptin occurred in all caloric restriction + exercise groups after 14 weeks, which were unchanged in other non-diet/non-exercise groups. Overall and over the entire

  10. [Supplemental data to the ultrastructural study of Trichomonas tenax. Intra-cellular distribution of acid phosphatase].

    Science.gov (United States)

    Ribaux, C L; Magloire, H

    1980-09-01

    In scanning electron microscopy, the flagella come out from the cellular body following different configurations: either separately or in groups. The undulating membrane lasted up to 2/3 of the cell body: at its end the recurrent flagella seems to penetrate again into the cell. The costa starts from the cinetosome of the recurrent flagella: the two parabasal filaments start from two different cinetosomes and follow the costa for a small distance. The nucleus is surrounded by a membrane which is not always visible. The axostyle has a cylindrical shape in the posterior two thirds of the cell. Bacteria at different stages of phagocytosis have been observed. The acid phosphatase is localized in the saccules and vesicles of the Golgi apparatus, in the lysosomes and phagolysosomes and in the terminal lamina of the undulating membrane.

  11. Identification, cellular distribution and potential function of the metalloprotease-disintegrin MDC9 in the kidney.

    Science.gov (United States)

    Mahimkar, R M; Baricos, W H; Visaya, O; Pollock, A S; Lovett, D H

    2000-04-01

    The complex interactions of glomerular and tubular epithelial cells with the basal laminae play a critical role in renal function. Disruption of these interactions has been widely implicated in glomerular diseases and acute renal failure. MDC are a large family of membrane-bound proteins containing metalloprotease, disintegrin (integrin interaction sites), and cysteine-rich domains. Little information is available concerning the presence of MDC in the kidney or their role in renal pathophysiology. Using degenerate PCR primers for the conserved metalloprotease and disintegrin domains of this protein family, cDNA templates from tubules, whole glomeruli, and glomerular epithelial cells (GEC) yielded a single, 195-bp product, which on sequence analysis corresponded to a region in the disintegrin domain of MDC9. Northern analysis of poly(A)+ RNA from tubules, whole glomeruli, and GEC revealed a 3.9-kb transcript, identical to that of mouse MDC9. Using antibodies generated against a 21-amino acid peptide present in the metalloprotease domain of MDC9, Western analysis of concanavalin A-enriched glomerular microsomal extracts demonstrated both processed (76 kD) and unprocessed (116 kD) forms of MDC9, which upon reduction changed to the corresponding 84- and 124-kD forms. Histochemical studies revealed a basolateral localization of intrinsic MDC9 protein in renal cortical tubule cells and glomerular visceral epithelial cells, which colocalized with the beta1 integrin chain. Expression of green fluorescence protein MDC9 chimeric constructs in GEC or polarized Madin-Darby canine kidney epithelial cells revealed a similar punctate basolateral surface localization. Transient overexpression of the soluble disintegrin domain-green fluorescence protein chimera in GEC led to dramatic changes in cellular morphology with rounding and detachment from cell monolayers. These studies document the presence of MDC9 in renal epithelial cells and suggest an important role for MDC9 in renal

  12. Secure Real-Time Monitoring and Management of Smart Distribution Grid using Shared Cellular Networks

    DEFF Research Database (Denmark)

    Nielsen, Jimmy Jessen; Ganem, Hervé; Jorguseski, Ljupco

    2017-01-01

    The electricity production and distribution is facing two major changes. First, the production is shifting from classical energy sources such as coal and nuclear power towards renewable resources such as solar and wind. Secondly, the consumption in the low voltage grid is expected to grow...... significantly due to expected introduction of electrical vehicles. The first step towards more efficient operational capabilities is to introduce an observability of the distribution system and allow for lever- aging the flexibility of end connection points with manageable consumption, generation and storage...... capabilities. Thanks to the advanced measurement devices, management framework, and secure communication infrastructure developed in the FP7 SUNSEED project, the Distribution System Operator (DSO) now has full observability of the energy flows at the medium/low voltage grid. Furthermore, the prosumers are able...

  13. Distinct cellular and subcellular distributions of G protein-coupled receptor kinase and arrestin isoforms in the striatum.

    Directory of Open Access Journals (Sweden)

    Evgeny Bychkov

    Full Text Available G protein-coupled receptor kinases (GRKs and arrestins mediate desensitization of G protein-coupled receptors (GPCR. Arrestins also mediate G protein-independent signaling via GPCRs. Since GRK and arrestins demonstrate no strict receptor specificity, their functions in the brain may depend on their cellular complement, expression level, and subcellular targeting. However, cellular expression and subcellular distribution of GRKs and arrestins in the brain is largely unknown. We show that GRK isoforms GRK2 and GRK5 are similarly expressed in direct and indirect pathway neurons in the rat striatum. Arrestin-2 and arrestin-3 are also expressed in neurons of both pathways. Cholinergic interneurons are enriched in GRK2, arrestin-3, and GRK5. Parvalbumin-positive interneurons express more of GRK2 and less of arrestin-2 than medium spiny neurons. The GRK5 subcellular distribution in the human striatal neurons is altered by its phosphorylation: unphosphorylated enzyme preferentially localizes to synaptic membranes, whereas phosphorylated GRK5 is found in plasma membrane and cytosolic fractions. Both GRK isoforms are abundant in the nucleus of human striatal neurons, whereas the proportion of both arrestins in the nucleus was equally low. However, overall higher expression of arrestin-2 yields high enough concentration in the nucleus to mediate nuclear functions. These data suggest cell type- and subcellular compartment-dependent differences in GRK/arrestin-mediated desensitization and signaling.

  14. A formal power series expansion-regularization approach for Lévy stable distributions: the symmetric case with \\alpha =2/M (M positive integer)

    Science.gov (United States)

    Crisanto-Neto, J. C.; da Luz, M. G. E.; Raposo, E. P.; Viswanathan, G. M.

    2016-09-01

    In practice, the Lévy α-stable distribution is usually expressed in terms of the Fourier integral of its characteristic function. Indeed, known closed form expressions are relatively scarce given the huge parameters space: 0\\lt α ≤slant 2 ({{L\\'{e}vy}} {{index}}), -1≤slant β ≤slant 1 ({{skewness}}),σ \\gt 0 ({{scale}}), and -∞ \\lt μ \\lt ∞ ({{shift}}). Hence, systematic efforts have been made towards the development of proper methods for analytically solving the mentioned integral. As a further contribution in this direction, here we propose a new way to tackle the problem. We consider an approach in which one first solves the Fourier integral through a formal (thus not necessarily convergent) series representation. Then, one uses (if necessary) a pertinent sum-regularization procedure to the resulting divergent series, so as to obtain an exact formula for the distribution, which is amenable to direct numerical calculations. As a concrete study, we address the centered, symmetric, unshifted and unscaled distribution (β =0, μ =0, σ =1), with α ={α }M=2/M, M=1,2,3\\ldots . Conceivably, the present protocol could be applied to other sets of parameter values.

  15. Lead tolerance and cellular distribution in Elsholtzia splendens using synchrotron radiation micro-X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Tian, Shengke [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Lu, Lingli; Shohag, M.J.I.; Liao, Haibing [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Xiaoe, E-mail: xyang@zju.edu.cn [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Elsholtzia splendens had a good ability of lead tolerance and accumulation. Black-Right-Pointing-Pointer Pb was mostly restricted to the vascular bundles and epidermis tissues. Black-Right-Pointing-Pointer Pb and Ca shared most similar distribution patterns in E. splendens. - Abstract: Hydroponic experiments were conducted to investigate the tolerance and spatial distribution of lead (Pb) in Elsholtzia splendens-a copper (Cu) accumulator plant using synchrotron-based micro-X-ray fluorescence. According to chlorophyll concentration and chlorophyll fluorescence parameters, E. splendens displayed certain tolerance at 100 {mu}M Pb treatment. Lead concentration in roots, stems and leaves of E. splendens reached 45,183.6, 1657.6, and 380.9 mg kg{sup -1}, respectively. Pb was mostly accumulated in the roots, and there were also high concentrations of Pb been transported into stems and leaves. Micro-XRF analysis of the stem and leaf cross section revealed that Pb was mostly restricted in the vascular bundles and epidermis tissues of both stem and leaf of E. splendens. The correlation between distribution of K, Ca, Zn and Pb were analyzed. There were significant positive correlations (P < 0.01) among Pb and Ca, K, Zn distribution both in stem and leaf of E. splendens. However, among the three elements, Ca shared the most similar distribution pattern and the highest correlation coefficients with Pb in both stem and leaf cross section of E. splendens. This suggests that Ca may play an important role in Pb accumulation in stem and leaf of E. splendens.

  16. Toxicity of silver nanoparticles in human macrophages: uptake, intracellular distribution and cellular responses

    Energy Technology Data Exchange (ETDEWEB)

    Haase, A; Tentschert, J; Jungnickel, H; Goetz, M E; Luch, A [BfR - Federal Institute for Risk Assessment, Department of Product Safety, Thielallee 88-92, 14195 Berlin (Germany); Graf, P [University of Basel, Department of Chemistry, Klingelbergstrasse 80, 4056 Basel (Switzerland); Mantion, A; Thuenemann, A F [BAM - Federal Institute for Materials Research and Testing, Richard-Willstaetter-Strasse 11, 12489 Berlin (Germany); Draude, F; Galla, S; Arlinghaus, H F [University of Muenster, Institute of Physics, Wilhelm Klemm Strasse 10, 48149 Muenster (Germany); Plendl, J [Free University of Berlin, Department of Veterinary Medicine, Institute of Veterinary Anatomy, Koserstrasse 20, 14195 Berlin (Germany); Masic, A; Taubert, A, E-mail: andrea.haase@bfr.bund.de, E-mail: alexandre.mantion@bam.de [University of Potsdam, Institute of Chemistry, Karl- Liebknecht- Strasse 24-25, 14476 Potsdam-Golm (Germany)

    2011-07-06

    Silver nanoparticles (SNP) are among the most commercialized nanoparticles worldwide. They can be found in many diverse products, mostly because of their antibacterial properties. Despite its widespread use only little data on possible adverse health effects exist. It is difficult to compare biological data from different studies due to the great variety in sizes, coatings or shapes of the particles. Here, we applied a novel synthesis approach to obtain SNP, which are covalently stabilized by a small peptide. This enables a tight control of both size and shape. We applied these SNP in two different sizes of 20 or 40 nm (Ag20Pep and Ag40Pep) and analyzed responses of THP-1-derived human macrophages. Similar gold nanoparticles with the same coating (Au20Pep) were used for comparison and found to be non-toxic. We assessed the cytotoxicity of particles and confirmed their cellular uptake via transmission electron microscopy and confocal Raman microscopy. Importantly a majority of the SNP could be detected as individual particles spread throughout the cells. Furthermore we studied several types of oxidative stress related responses such as induction of heme oxygenase I or formation of protein carbonyls. In summary, our data demonstrate that even low doses of SNP exerted adverse effects in human macrophages.

  17. Cellular uptake and distribution of graphene oxide coated with layer-by-layer assembled polyelectrolytes

    Science.gov (United States)

    Li, Yiye; Lu, Zhenzhen; Li, Zhongjun; Nie, Guangjun; Fang, Ying

    2014-05-01

    We report a facile approach for the fabrication of a new class of graphene oxide (GO)-based nanoassemblies by layer-by-layer (LbL) technique. The single-layer thickness and intrinsic negatively charged carboxyl groups of GO nanosheets provide a natural platform for LbL assembly of polyelectrolyte nanofilms by electrostatic forces at mild and aqueous conditions. The general applicability of our approach is demonstrated by the preparation of GO nanoassemblies with sizes of 100-200 nm using various charged polyelectrolytes, including synthetic polymers, polypeptides, and DNA oligonucleotides. Systemic assessment of cytotoxicity and acute stress response show that no discernable signs of cytotoxicity are associated with exposure of GO and its nanoassemblies [GO/PLL (poly ( l-lysine)), GO/PLL/PSS (poly(sodium-4-styrenesulfonate)), GO/PLL-PEG (PEGlayted PLL), GO/PLL/PLGA-PEG (PEGlayted poly ( l-glutamic acid))] up to 1 μg/mL. Studies on cellular uptake and subcellular localization show that a representative nanoassembly, GO/PLL-PEG, can effectively cross cell membranes and localize mainly in lysosomal compartments, without induction of noticeable harmful effects as confirmed by detection of mitochondrial depolarization and lysosomal pH.

  18. Changes in the level and distribution of Ku proteins during cellular senescence

    Science.gov (United States)

    Seluanov, Andrei; Danek, Jacquelynn; Hause, Nola; Gorbunova, Vera

    2009-01-01

    Aging is associated with accumulation of genomic rearrangements consistent with aberrant repair of DNA breaks. We have shown previously that DNA repair by nonhomologous end joining (NHEJ) becomes less efficient and more error-prone in senescent cells. Here we show that the levels of Ku70 and Ku80 drop approximately two fold in replicatively senescent cells. Intracellular distribution of Ku also changes. In the young cells roughly half of Ku is located in the nucleus and half in the cytoplasm. In senescent cells the nuclear levels of Ku do not change, while the cytoplasmic Ku fraction disappears. Upon treatment with gamma-irradiation, in the young cells cytoplasmic Ku moved into the nuclear and membrane fractions, while no change in the Ku distribution occurred in senescent cells. Upon treatment with UVC Ku moved out of the nucleus in the young cells, while most Ku remained nuclear in senescent cells. This suggests that the nuclear Ku in senescent cells is unable to respond to DNA damage. We hypothesize that overall decline in Ku levels, changes in Ku intracellular distribution, and the loss of appropriate response of Ku to DNA damage in senescent cells contribute to the decline of NHEJ and to age-related genomic instability. PMID:17686666

  19. General inverse problems for regular variation

    DEFF Research Database (Denmark)

    Damek, Ewa; Mikosch, Thomas Valentin; Rosinski, Jan

    2014-01-01

    Regular variation of distributional tails is known to be preserved by various linear transformations of some random structures. An inverse problem for regular variation aims at understanding whether the regular variation of a transformed random object is caused by regular variation of components ...

  20. Effect of surface properties of silica nanoparticles on their cytotoxicity and cellular distribution in murine macrophages

    Directory of Open Access Journals (Sweden)

    Nagano Kazuya

    2011-01-01

    Full Text Available Abstract Surface properties are often hypothesized to be important factors in the development of safer forms of nanomaterials (NMs. However, the results obtained from studying the cellular responses to NMs are often contradictory. Hence, the aim of this study was to investigate the relationship between the surface properties of silica nanoparticles and their cytotoxicity against a murine macrophage cell line (RAW264.7. The surface of the silica nanoparticles was either unmodified (nSP70 or modified with amine (nSP70-N or carboxyl groups (nSP70-C. First, the properties of the silica nanoparticles were characterized. RAW264.7 cells were then exposed to nSP70, nSP70-N, or nSP70-C, and any cytotoxic effects were monitored by analyzing DNA synthesis. The results of this study show that nSP70-N and nSP70-C have a smaller effect on DNA synthesis activity by comparison to unmodified nSP70. Analysis of the intracellular localization of the silica nanoparticles revealed that nSP70 had penetrated into the nucleus, whereas nSP70-N and nSP70-C showed no nuclear localization. These results suggest that intracellular localization is a critical factor underlying the cytotoxicity of these silica nanoparticles. Thus, the surface properties of silica nanoparticles play an important role in determining their safety. Our results suggest that optimization of the surface characteristics of silica nanoparticles will contribute to the development of safer forms of NMs.

  1. Resistance to degradation and cellular distribution are important features for the antitumor activity of gomesin.

    Science.gov (United States)

    Buri, Marcus V; Domingues, Tatiana M; Paredes-Gamero, Edgar J; Casaes-Rodrigues, Rafael L; Rodrigues, Elaine Guadelupe; Miranda, Antonio

    2013-01-01

    Many reports have shown that antimicrobial peptides exhibit anticancer abilities. Gomesin (Gm) exhibits potent cytotoxic activity against cancer cells by a membrane pore formation induced after well-orchestrated intracellular mechanisms. In this report, the replacements of the Cys by Ser or Thr, and the use D-amino acids in the Gm structure were done to investigate the importance of the resistance to degradation of the molecule with its cytotoxicity. [Thr(2,6,11,15)]-Gm, and [Ser(2,6,11,15)]-Gm exhibits low cytotoxicity, and low resistance to degradation, and after 24 h are present in localized area near to the membrane. Conversely, the use of D-amino acids in the analogue [D-Thr(2,6,11,15)]-D-Gm confers resistance to degradation, increases its potency, and maintained this peptide spread in the cytosol similarly to what happens with Gm. Replacements of Cys by Thr and Gln by L- or D-Pro ([D-Thr(2,6,11,15), Pro(9)]-D-Gm, and [Thr(2,6,11,15), D-Pro(9)]-Gm), which induced a similar β-hairpin conformation, also increase their resistance to degradation, and cytotoxicity, but after 24 h they are not present spread in the cytosol, exhibiting lower cytotoxicity in comparison to Gm. Additionally, chloroquine, a lysosomal enzyme inhibitor potentiated the effect of the peptides. Furthermore, the binding and internalization of peptides was determined, but a direct correlation among these factors was not observed. However, cholesterol ablation, which increase fluidity of cellular membrane, also increase cytotoxicity and internalization of peptides. β-hairpin spatial conformation, and intracellular localization/target, and the capability of entry are important properties of gomesin cytotoxicity.

  2. Resistance to degradation and cellular distribution are important features for the antitumor activity of gomesin.

    Directory of Open Access Journals (Sweden)

    Marcus V Buri

    Full Text Available Many reports have shown that antimicrobial peptides exhibit anticancer abilities. Gomesin (Gm exhibits potent cytotoxic activity against cancer cells by a membrane pore formation induced after well-orchestrated intracellular mechanisms. In this report, the replacements of the Cys by Ser or Thr, and the use D-amino acids in the Gm structure were done to investigate the importance of the resistance to degradation of the molecule with its cytotoxicity. [Thr(2,6,11,15]-Gm, and [Ser(2,6,11,15]-Gm exhibits low cytotoxicity, and low resistance to degradation, and after 24 h are present in localized area near to the membrane. Conversely, the use of D-amino acids in the analogue [D-Thr(2,6,11,15]-D-Gm confers resistance to degradation, increases its potency, and maintained this peptide spread in the cytosol similarly to what happens with Gm. Replacements of Cys by Thr and Gln by L- or D-Pro ([D-Thr(2,6,11,15, Pro(9]-D-Gm, and [Thr(2,6,11,15, D-Pro(9]-Gm, which induced a similar β-hairpin conformation, also increase their resistance to degradation, and cytotoxicity, but after 24 h they are not present spread in the cytosol, exhibiting lower cytotoxicity in comparison to Gm. Additionally, chloroquine, a lysosomal enzyme inhibitor potentiated the effect of the peptides. Furthermore, the binding and internalization of peptides was determined, but a direct correlation among these factors was not observed. However, cholesterol ablation, which increase fluidity of cellular membrane, also increase cytotoxicity and internalization of peptides. β-hairpin spatial conformation, and intracellular localization/target, and the capability of entry are important properties of gomesin cytotoxicity.

  3. Formation Conditions and Distribution Regularities of Oil—gas Pools in Tertiary Volcanic Rocks in Western Huimin Depression,Shandong Province

    Institute of Scientific and Technical Information of China (English)

    刘泽容; 王永杰; 等

    1989-01-01

    The formation conditions and distribution regularities of oil-gas pools in volcanic rocks in western Huimin Depression have been studied in terms of geolgic,sesmic and well logging information,This paper discusses the types and lithofacies,development and distribution of Tertiary volcanic rocks in the area.The results demonstrate that volcanic activity occurred mainly during the period from the Sha-4 stage to the Guantao episode,i.e.,before the oil-generating period(before the end of the Guantao episode and the Minghuazhen episode).The activity did not destroy oil and gas formation and accumulation,but was favourable for the concentration of organic matter and its conversion to hydrocarbons;besides,volcanic rocks can serve as reservoir rocks and cap rocks,playing a role very similar to that of a syndepositional anticline,The volcanic rocks are distributed near the margins of the oil-generating depression;there are many secondary interstices in the rocks,which are connected with each other.These are the leading conditions for the formation of oil-generating period and their self-sealing or good combination with other cap rocks are important factors for forming volcanic rock-hosted oil and gas pools.The oil-gas pools associated with volcanic rocks in western Huimin are mainly distributed around the deep oil-generating depression,in the central up lift or the high structural levels on the margins of the depression.In particular,the sites where several faults cross are usually locatons where hith-yielding oil-gas pools in volcanic rocks are concentrated.

  4. Cellular distribution of calmodulin and calmodulin-binding proteins in Vicia faba L

    Science.gov (United States)

    Ling, V.; Assmann, S. M.

    1992-01-01

    The distribution of calmodulin (CaM) and CaM-binding proteins within Vicia faba was investigated. Both CaM and CaM-binding proteins were found to be differentially distributed among organs, tissues, and protoplast types. CaM levels, on a per protein basis, were found to be the highest in leaf epidermis, containing 3-fold higher levels of CaM than in total leaf. Similarly, guard cell and epidermal cell protoplasts were also found to have higher levels of CaM than mesophyll cell protoplasts. 125I-CaM blot overlay assays were performed to qualitatively examine CaM-binding proteins in these protoplast types as well as in whole tissues and organs. CaM-binding proteins with Mr 52,000, 78,000, and 115,000 were common in all metabolically active plant parts. Unique CaM-binding protein bands were detected in guard cell protoplasts (Mr 39,000, 88,000), stems (Mr 45,000, 60,000, 64,000), and roots (Mr 62,000), suggesting the presence of specialized CaM-dependent processes in these cells and organs.

  5. ANALYSIS OF REGULARITIES IN DISTRIBUTION OF EARTHQUAKES BY FOCAL DISPLACEMENT IN THE KURIL-OKHOTSK REGION BEFORE THE CATASTROPHIC SIMUSHIR EARTHQUAKE OF 15 NOVEMBER 2006

    Directory of Open Access Journals (Sweden)

    Timofei K. Zlobin

    2015-09-01

    Full Text Available The catastrophic Simushir earthquake occurred on 15 November 2006 in the Kuril-Okhotsk region in the Middle Kuril Islands which is a transition zone between the Eurasian continent and the Pacific Ocean. It was followed by numerous strong earthquakes. It is established that the catastrophic earthquake was prepared on a site characterized by increased relative effective pressures which is located at the border of the low-pressure area (Figure 1.Based on data from GlobalCMT (Harvard, earthquake focal mechanisms were reconstructed, and tectonic stresses, the seismotectonic setting and the earthquakes distribution pattern were studied for analysis of the field of stresses in the region before to the Simushir earthquake (Figures 2 and 3; Table 1.Five areas of various types of movement were determined. Three of them are stretched along the Kuril Islands. It is established that seismodislocations in earthquake focal areas are regularly distributed. In each of the determined areas, displacements of a specific type (shear or reverse shear are concentrated and give evidence of the alteration and change of zones characterized by horizontal stretching and compression.The presence of the horizontal stretching and compression zones can be explained by a model of subduction (Figure 4. Detailed studies of the state of stresses of the Kuril region confirm such zones (Figure 5. Recent GeodynamicsThe established specific features of tectonic stresses before the catastrophic Simushir earthquake of 15 November 2006 contribute to studies of earthquake forecasting problems. The state of stresses and the geodynamic conditions suggesting occurrence of new earthquakes can be assessed from the data on the distribution of horizontal compression, stretching and shear areas of the Earth’s crust and the upper mantle in the Kuril region.

  6. Cellular distribution of Glut-1 and Glut-5 in benign and malignant human prostate tissue.

    Science.gov (United States)

    Reinicke, Karin; Sotomayor, Paula; Cisterna, Pedro; Delgado, Carolina; Nualart, Francisco; Godoy, Alejandro

    2012-02-01

    Over-expression of hexose transporters (Gluts), specifically Glut-1, is a common event in human malignancies. In prostate cancer (CaP), however, expression of Gluts has been characterized poorly. In this study, expression and distribution of Glut-1 and Glut-5 proteins were characterized using immunohistochemistry in 76 specimens of benign prostate, 10 specimens of high-grade intraepithelial neoplasia (HGPIN), and 28 specimens of CaP. In addition, mRNA expression of Glut-2, Glut-7, Glut-9, and Glut-11 was analyzed in a set of five specimens of benign prostate and CaP. In benign prostate, Glut-1 localized to the basal cells and to the basolateral membrane of secretory/luminal epithelial cells. Glut-5, however, localized to the apical membrane of secretory/luminal epithelial cells. In HGPIN, Glut-1 was immunohistochemically undetectable. Glut-5, however, localized to the apical membrane of the neoplastic epithelial cells. In CaP, Glut-1 and Glut-5, were immunohistochemically undetectable. However, over-expression of GLUT1 was observed in some specimens of highly proliferative intraductal CaP. Glut-7, Glut-9, and Glut-11 mRNAs were detected in benign prostate and CaP, however, only Glut-11 mRNA was consistently up-regulated in CaP compared to benign prostate. Low levels of expression of Glut-1 protein in the majority of CaP could explain, at least in part, the limited clinical applicability of positron emission tomography using 2-[18F]-fluoro-2-deoxy-D-glucose for imaging CaP. Moreover, expression of Glut-5 in HGPIN suggested that fructose could be utilized as potential metabolic substrate in HGPIN. Understanding the molecular mechanisms involved in regulation/dysregulation of Gluts in CaP could provide insight in the understanding of hexose metabolism in CaP.

  7. Classifier Design Given an Uncertainty Class of Feature Distributions via Regularized Maximum Likelihood and the Incorporation of Biological Pathway Knowledge in Steady-State Phenotype Classification.

    Science.gov (United States)

    Esfahani, Mohammad Shahrokh; Knight, Jason; Zollanvari, Amin; Yoon, Byung-Jun; Dougherty, Edward R

    2013-10-01

    Contemporary high-throughput technologies provide measurements of very large numbers of variables but often with very small sample sizes. This paper proposes an optimization-based paradigm for utilizing prior knowledge to design better performing classifiers when sample sizes are limited. We derive approximate expressions for the first and second moments of the true error rate of the proposed classifier under the assumption of two widely-used models for the uncertainty classes; ε-contamination and p-point classes. The applicability of the approximate expressions is discussed by defining the problem of finding optimal regularization parameters through minimizing the expected true error. Simulation results using the Zipf model show that the proposed paradigm yields improved classifiers that outperform traditional classifiers that use only training data. Our application of interest involves discrete gene regulatory networks possessing labeled steady-state distributions. Given prior operational knowledge of the process, our goal is to build a classifier that can accurately label future observations obtained in the steady state by utilizing both the available prior knowledge and the training data. We examine the proposed paradigm on networks containing NF-κB pathways, where it shows significant improvement in classifier performance over the classical data-only approach to classifier design. Companion website: http://gsp.tamu.edu/Publications/supplementary/shahrokh12a.

  8. Typical reconstruction performance for distributed compressed sensing based on ℓ2,1-norm regularized least square and Bayesian optimal reconstruction: influences of noise

    Science.gov (United States)

    Shiraki, Yoshifumi; Kabashima, Yoshiyuki

    2016-06-01

    A signal model called joint sparse model 2 (JSM-2) or the multiple measurement vector problem, in which all sparse signals share their support, is important for dealing with practical signal processing problems. In this paper, we investigate the typical reconstruction performance of noisy measurement JSM-2 problems for {{\\ell}2,1} -norm regularized least square reconstruction and the Bayesian optimal reconstruction scheme in terms of mean square error. Employing the replica method, we show that these schemes, which exploit the knowledge of the sharing of the signal support, can recover the signals more precisely as the number of channels increases. In addition, we compare the reconstruction performance of two different ensembles of observation matrices: one is composed of independent and identically distributed random Gaussian entries and the other is designed so that row vectors are orthogonal to one another. As reported for the single-channel case in earlier studies, our analysis indicates that the latter ensemble offers better performance than the former ones for the noisy JSM-2 problem. The results of numerical experiments with a computationally feasible approximation algorithm we developed for this study agree with the theoretical estimation.

  9. [Study on the regular pattern of the distribution of skin epidermal stem cells in the different parts of a healthy human body].

    Science.gov (United States)

    Chen, Xiao-dong; Li, Tian-zeng; Qi, Shao-hai; Xie, Ju-lin; Xu, Ying-bin; Pan, Shu; Yuan, Ji-Shan; Zhang, Tao; Liang, Hui-zhen

    2006-02-01

    To investigate the regular pattern of the distribution of skin epidermal stem cells (ESCs) in the different parts of a healthy human body, and to evaluate the feasibility of the identification of ESCs by P63 and CD29 with single and double labeling. Full-thickness skin samples from 21 parts (including scalp, dorsum of foot, sole of foot, pubic region, and scrotum) of 5 healthy persons were harvested for the study. Immunohistochemistry method with biotin-streptavidin-horseradish peroxidase (SP) was employed with P63 and CD29 as the first antibody to carry out single and double labeling. The staining results were subjected to image analysis. The distribution of the ESCs in the skin from the above parts was observed and expressed as positive unit (PU) value. It was found by P63 single labeling and P63 and CD29 double labeling that the PU value in the dorsum of foot was the lowest while that in the scalp was the highest among all the parts of a healthy body. It was also found by CD29 single labeling that the PU value in the dorsum of foot was the lowest [(11.9 +/- 1.5)%] while highest in the scalp [(29.1 +/- 5.0)%]. The PU value in the hairy region of a human body was evidently higher than that in the non-hairy region (P 0.05). There are more ESCs in the skin from the scalp, mons pubis and scrotum than other parts of the body. Single P63 or CD29 labeling exhibits higher sensitivity but lower specificity in the identification of ESCs. While the double labeling method exhibits higher specificity but lower sensitivity. Above all, it seems that the double labeling may be a simple and effective method for the identification of ESCs.

  10. Physiological, cellular and biochemical thermal stress response of intertidal shrimps with different vertical distributions: Palaemon elegans and Palaemon serratus.

    Science.gov (United States)

    Madeira, Diana; Mendonça, Vanessa; Dias, Marta; Roma, Joana; Costa, Pedro M; Larguinho, Miguel; Vinagre, Catarina; Diniz, Mário S

    2015-05-01

    The ability to cope with high temperature variations is a critical factor in intertidal communities. Two species of intertidal rocky shore shrimps (Palaemon sp.) with different vertical distributions were collected from the Portuguese coast in order to test if they were differentially sensitive to thermal stress. Three distinct levels of biological organization (organismal, biochemical, and cellular) were surveyed. The shrimp were exposed to a constant rate of temperature increase of 1°C x h(-1), starting at 20°C until reaching the CTMax (critical thermal maximum). During heat stress, two biomarkers of protein damage were quantified in the muscle via enzyme-linked immunosorbent assays: heat shock proteins HSP70 (hsp70/hsc70) and total ubiquitin. Muscle histopathological alterations caused by temperature were also evaluated. CTMax values were not significantly different between the congeners (P. elegans 33.4 ± 0.5 °C; P. serratus 33.0 ± 0.5 °C). Biomarker levels did not increase along the temperature trial, but P. elegans (higher intertidal) showed higher amounts of HSP70 and total ubiquitin than P. serratus (lower intertidal). HSP70 and total ubiquitin levels showed a positive significant correlation in both species, suggesting that their association is important in thermal tolerance. Histopathological observations of muscle tissue in P. serratus showed no gross alterations due to temperature but did show localized atrophy of muscle fibers at CTMax. In P. elegans, alterations occurred at a larger scale, showing multiple foci of atrophic muscular fascicles caused by necrotic or autolytic processes. In conclusion, Palaemon congeners displayed different responses to stress at a cellular level, with P. elegans having greater biomarker levels and histopathological alterations.

  11. Greedy scheduling of cellular self-replication leads to optimal doubling times with a log-Frechet distribution.

    Science.gov (United States)

    Pugatch, Rami

    2015-02-24

    Bacterial self-replication is a complex process composed of many de novo synthesis steps catalyzed by a myriad of molecular processing units, e.g., the transcription-translation machinery, metabolic enzymes, and the replisome. Successful completion of all production tasks requires a schedule-a temporal assignment of each of the production tasks to its respective processing units that respects ordering and resource constraints. Most intracellular growth processes are well characterized. However, the manner in which they are coordinated under the control of a scheduling policy is not well understood. When fast replication is favored, a schedule that minimizes the completion time is desirable. However, if resources are scarce, it is typically computationally hard to find such a schedule, in the worst case. Here, we show that optimal scheduling naturally emerges in cellular self-replication. Optimal doubling time is obtained by maintaining a sufficiently large inventory of intermediate metabolites and processing units required for self-replication and additionally requiring that these processing units be "greedy," i.e., not idle if they can perform a production task. We calculate the distribution of doubling times of such optimally scheduled self-replicating factories, and find it has a universal form-log-Frechet, not sensitive to many microscopic details. Analyzing two recent datasets of Escherichia coli growing in a stationary medium, we find excellent agreement between the observed doubling-time distribution and the predicted universal distribution, suggesting E. coli is optimally scheduling its replication. Greedy scheduling appears as a simple generic route to optimal scheduling when speed is the optimization criterion. Other criteria such as efficiency require more elaborate scheduling policies and tighter regulation.

  12. A CFD study of hygro-thermal stresses distribution in tubular-shaped ambient air-breathing PEM micro fuel cell during regular cell operation

    Directory of Open Access Journals (Sweden)

    Maher A.R. Sadiq Al-Baghdadi

    2010-03-01

    mechanical, hygro and thermal stresses into actual three-dimensional fuel cell model. The results show that the non-uniform distribution of stresses, caused by the temperature gradient in the cell, induces localized bending stresses, which can contribute to delaminating between the membrane and the gas diffusion layers. The non-uniform distribution of stresses can also contribute to delaminating between the gas diffusion layers and the current collectors. These stresses may explain the occurrence of cracks and pinholes in the fuel cells components under steady–state loading during regular cell operation, especially in the high loading conditions.

  13. Shroom3 functions downstream of planar cell polarity to regulate myosin II distribution and cellular organization during neural tube closure

    Directory of Open Access Journals (Sweden)

    Erica M. McGreevy

    2015-01-01

    Full Text Available Neural tube closure is a critical developmental event that relies on actomyosin contractility to facilitate specific processes such as apical constriction, tissue bending, and directional cell rearrangements. These complicated processes require the coordinated activities of Rho-Kinase (Rock, to regulate cytoskeletal dynamics and actomyosin contractility, and the Planar Cell Polarity (PCP pathway, to direct the polarized cellular behaviors that drive convergent extension (CE movements. Here we investigate the role of Shroom3 as a direct linker between PCP and actomyosin contractility during mouse neural tube morphogenesis. In embryos, simultaneous depletion of Shroom3 and the PCP components Vangl2 or Wnt5a results in an increased liability to NTDs and CE failure. We further show that these pathways intersect at Dishevelled, as Shroom3 and Dishevelled 2 co-distribute and form a physical complex in cells. We observed that multiple components of the Shroom3 pathway are planar polarized along mediolateral cell junctions in the neural plate of E8.5 embryos in a Shroom3 and PCP-dependent manner. Finally, we demonstrate that Shroom3 mutant embryos exhibit defects in planar cell arrangement during neural tube closure, suggesting a role for Shroom3 activity in CE. These findings support a model in which the Shroom3 and PCP pathways interact to control CE and polarized bending of the neural plate and provide a clear illustration of the complex genetic basis of NTDs.

  14. Shroom3 functions downstream of planar cell polarity to regulate myosin II distribution and cellular organization during neural tube closure.

    Science.gov (United States)

    McGreevy, Erica M; Vijayraghavan, Deepthi; Davidson, Lance A; Hildebrand, Jeffrey D

    2015-01-16

    Neural tube closure is a critical developmental event that relies on actomyosin contractility to facilitate specific processes such as apical constriction, tissue bending, and directional cell rearrangements. These complicated processes require the coordinated activities of Rho-Kinase (Rock), to regulate cytoskeletal dynamics and actomyosin contractility, and the Planar Cell Polarity (PCP) pathway, to direct the polarized cellular behaviors that drive convergent extension (CE) movements. Here we investigate the role of Shroom3 as a direct linker between PCP and actomyosin contractility during mouse neural tube morphogenesis. In embryos, simultaneous depletion of Shroom3 and the PCP components Vangl2 or Wnt5a results in an increased liability to NTDs and CE failure. We further show that these pathways intersect at Dishevelled, as Shroom3 and Dishevelled 2 co-distribute and form a physical complex in cells. We observed that multiple components of the Shroom3 pathway are planar polarized along mediolateral cell junctions in the neural plate of E8.5 embryos in a Shroom3 and PCP-dependent manner. Finally, we demonstrate that Shroom3 mutant embryos exhibit defects in planar cell arrangement during neural tube closure, suggesting a role for Shroom3 activity in CE. These findings support a model in which the Shroom3 and PCP pathways interact to control CE and polarized bending of the neural plate and provide a clear illustration of the complex genetic basis of NTDs.

  15. Interaction of cadmium and zinc on accumulation and sub-cellular distribution in leaves of hyperaccumulator Potentilla griffithii.

    Science.gov (United States)

    Qiu, Rong-Liang; Thangavel, Palaniswamy; Hu, Peng-Jie; Senthilkumar, Palaninaicker; Ying, Rong-Rong; Tang, Ye-Tao

    2011-02-28

    Potentilla griffithii Hook is a newly found hyperaccumulator plant capable of high tolerance and accumulation of Zn and Cd. We investigated the interactive effects between Cd and Zn on accumulation and vacuolar sequestration in P. griffithii. Stimulatory effect of growth was noted at 0.2 mM Cd and 1.25 and 2.5 mM Zn tested. Accumulation of Zn and Cd in roots, petioles and leaves were increased significantly with addition of these metals individually. However, the Zn supplement decreased root Cd accumulation but increased the concentration of Cd in petioles and leaves. The results from sub-cellular distribution showed that up to 94% and 70% of the total Zn and Cd in the leaves were present in the protoplasts, and more than 90% Cd and Zn in the protoplasts were localized in the vacuoles. Nearly, 88% and 85% of total Cd and Zn were extracted in the cell sap of the leaves suggesting that most of the Cd and Zn in the leaves were available in soluble form. The present results indicate that Zn supplement significantly enhanced the petiole accumulation of Cd and further vacuolar sequestration plays an important role in tolerance, detoxification and hyperaccumulation of these metals in P. griffithii. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Effect of FCCP on tight junction permeability and cellular distribution of ZO-1 protein in epithelial (MDCK) cells.

    Science.gov (United States)

    Li, C X; Poznansky, M J

    1990-12-14

    The effect of the uncoupler of oxidative phosphorylation, FCCP (carbonylcyanide p-trifluoromethoxyphenylhydrazone), on the tight junction of Madin-Darby canine kidney cells was examined. FCCP induced an abrupt decrease in the transepithelial electrical resistance of the confluent monolayers over a period of 20 s. When FCCP was withdrawn from the incubation medium, the monolayer resistance recovered to close to the original level in less than 2 h. Staining of the tight junction-associated protein ZO-1 showed that the changes in transepithelial electrical resistance were accompanied by a diffusing of the protein away from cell peripheries and a reconcentration to the tight junction areas following resistance recovery. Intracellular pH was decreased by FCCP on a similar time-scale with no obvious changes in ATP levels over this time-course. These data suggest that the uncoupler FCCP has a profound effect on tight junction permeability and cellular distribution of the tight junction protein ZO-1 in the epithelial cells and that it probably acts by breaking down proton gradients and altering intracellular pH.

  17. Interaction of cadmium and zinc on accumulation and sub-cellular distribution in leaves of hyperaccumulator Potentilla griffithii

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Rongliang, E-mail: eesqrl@mail.sysu.edu.cn [School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology, Guangzhou 510275 (China); Thangavel, Palaniswamy; Hu Pengjie; Senthilkumar, Palaninaicker; Ying Rongrong [School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Tang Yetao [School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology, Guangzhou 510275 (China)

    2011-02-28

    Potentilla griffithii Hook is a newly found hyperaccumulator plant capable of high tolerance and accumulation of Zn and Cd. We investigated the interactive effects between Cd and Zn on accumulation and vacuolar sequestration in P. griffithii. Stimulatory effect of growth was noted at 0.2 mM Cd and 1.25 and 2.5 mM Zn tested. Accumulation of Zn and Cd in roots, petioles and leaves were increased significantly with addition of these metals individually. However, the Zn supplement decreased root Cd accumulation but increased the concentration of Cd in petioles and leaves. The results from sub-cellular distribution showed that up to 94% and 70% of the total Zn and Cd in the leaves were present in the protoplasts, and more than 90% Cd and Zn in the protoplasts were localized in the vacuoles. Nearly, 88% and 85% of total Cd and Zn were extracted in the cell sap of the leaves suggesting that most of the Cd and Zn in the leaves were available in soluble form. The present results indicate that Zn supplement significantly enhanced the petiole accumulation of Cd and further vacuolar sequestration plays an important role in tolerance, detoxification and hyperaccumulation of these metals in P. griffithii.

  18. Sequence boundaries and regularities in the oil-gas distribution of the low swelling slope belt in the continental rift basin

    Institute of Scientific and Technical Information of China (English)

    Xie Zongkui

    2011-01-01

    Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problems to be solved during exploration of a region.Taking the Paleogene system developed along the east slope belt of Chengdao as an example the concepts of sequence stratigraphy and sedimentary sequenc are applied.A new research method likened to a way "to get a melon by following the vine"is proposed to determine the direction for exploring within un-drilled or less-drilled areas.This is the process:"the characteristics of the sequence boundary → the forming mechanism of the stratigraphic sequence → the conditions of oil and gas accumulation → the distribution zones of oil and gas".The relationship between the dynamic mechanism of stratigraphic sequence and the forming conditions for oil and gas accumulation establishes that the tectonic disturbance of the slope belt has significant responses as denudation and deposition.Above the stratigraphic sequence boundary there are large scale sand bodies of the low stand system tract (LST) that have developed in the low swelling slope belt and its deep depression.Below the sequence boundary there are the remaining sand bodies of the high stand system tract (HST).On the slope there is a convergence of mudstone layers of the extended system tract (EST)with the mudstone of the underlying strata,which constitutes the screening conditions for the reservoir of the down slope and deep depression.The distribution regularities in preferred sand bodies on the surface of the sequence boundary,and in the system tract,indicate the ordering of oil-gas deposits.From the higher stand down to the depth of the slope there are,in order,areas where exploration was unfavorable.major areas of stratigraphic overlap of oil-gas reservoirs,unconformity screened oil-gas reservoirs,and,finally,sandstone lens oil-gas reservoirs.The low

  19. STUDY ON THE REGULARITY OF P DISTRIBUTION AND ACCUMULATION OF OIL- SUNFLOWERS%油用向日葵磷素积累分配规律研究

    Institute of Scientific and Technical Information of China (English)

    张君; 张润生; 段玉; 妥德宝; 赵沛义; 李焕春; 安昊; 刘亚红

    2011-01-01

    In order to improve the utilization of sunflower's cultivation techniques and phosphate fertilizer, this study chose the oilsunflower variety named S31, the research studied the effect of the regularity of phosphorus's absorption, distribution, accumulation and phosphate fertilizer through the methods combined field experiments, indoor chemical analysis and biological statistics. In result, the phosphorus accumulation of sunflower showed the "S" curve. In the 110th day of emergence ( mature stage), the phosphorus accumulation of organ showed grain > stem > leaf > disc. In the 70th day of emergence ( end of flowering), the P content of leaf, stem and disc reached to the maximum, and the grain phosphorus uptake of sunflowers showed a trend of the upward linear; in the 110th day of emergence ( mature stage), the P content reached to the maximum. The day accumulation of phosphorus of sunflower showed a single peak curve. The phosphorus absorption rate changed maximally in OPT treatment, and the maximum was 31.01 mg / ( plant o days), while it changed minimally in CK treatment, and the maximum was 21.48mg / ( plant o days). The phosphorus distributed in leaves reached the highest in the seedling state, and it reduced to17% ~21% in the mature stage. The distribution of phosphorus in stem showed that increased first and then decreased. The sunflower using phosphate fertilizer increased the yield by 10%; and the phosphate fertilizer increased the yield of sunflower 2.7 kg per kilogram. The utilization rate of phosphate fertilizers was 19.3%, and 9.6 kg potassium was absorbed to produce 1 t sunflower grains.%为进一步提高向日葵的栽培技术及肥料利用率,本试验选用油用型向日葵品种S31作为供试材料,采用田间试验和室内分析化验相结合的方法,研究了向日葵各器官对磷素的积累分配规律及磷肥施肥肥效.结果表明:向日葵植株磷素积累量呈"S"型增长趋势,成熟期时,各器官磷素积

  20. Quantitative studies of the regular distribution pattern for Salmonella enteritidis in the internal organs of mice after oral challenge by a specific real-time polymerase chain reaction

    Institute of Scientific and Technical Information of China (English)

    Shu-Xuan Deng; An-Chun Cheng; Ming-Shu Wang; Ping Cao; Bin Yan; Nian-Chun Yin; Sheng-Yan Cao; Zhen-Hua Zhang

    2008-01-01

    AIM:To identify and understand the regular distribution pattern for Salmonella enteritidis (S.enteritidis) in the internal organs of mice after an oral challenge over a 3 wk period.METHODS:Assays based on the serovar-specific DNA sequence of S.enteritidis from GenBank,and a serovar-specific real-time,fluorescence-based quantitative polymerase chain reaction (FQ-PCR) were developed for the detection of S.enteritidis.We used this assay to detect genomic DNA of S.enteritidis in the blood and the internal organs,including heart,liver,spleen,kidney,pancreas,and gallbladder,from mice after oral challenge at different time points respectively.RESULTS:The results showed that the spleen was positive at 12 h post inoculation (PI),and the blood was at 14 h PI.The organism was detected in the liver and heart at 16 h PI,the pancreas was positive at 20 h PI,and the final organs to show positive results were the kidney and gallbladder at 22 h PI.The copy number of S.enteritidis DNA in each tissue reached a peak at 24-36 h PI,with the liver and spleen containing high concentrations of S.enteritidis,whereas the blood,heart,kidney,pancreas,and gallbladder had low concentrations.S.enteritidis populations began to decrease and were not detectable at 3 d PI,but were still present up to 12 d PI in the gallbladder,2 wk for the liver,and 3 wk for the spleen without causing apparent symptoms.CONCLUSION:The results provided significant data for understanding the life cycle of S.enteritidis in the internal organs,and showed that the liver and spleen may be the primary sites for setting itself up as a commensa over a long time after oral challenge.Interestingly,it may be the first time reported that the gallbladder is a site of carriage for S.enteritidis over a 12 d period.This study will help to understand the mechanisms of action of S.enteritidis infection in vivo.

  1. Bufalin-loaded mPEG-PLGA-PLL-cRGD nanoparticles: preparation, cellular uptake, tissue distribution, and anticancer activity.

    Science.gov (United States)

    Yin, Peihao; Wang, Yan; Qiu, YanYan; Hou, LiLi; Liu, Xuan; Qin, Jianmin; Duan, Yourong; Liu, Peifeng; Qiu, Ming; Li, Qi

    2012-01-01

    Recent studies have shown that bufalin has a good antitumor effect but has high toxicity, poor water solubility, a short half-life, a narrow therapeutic window, and a toxic dose that is close to the therapeutic dose, which all limit its clinical application. This study aimed to determine the targeting efficacy of nanoparticles (NPs) made of methoxy polyethylene glycol (mPEG), polylactic-co-glycolic acid (PLGA), poly-L-lysine (PLL), and cyclic arginine-glycine-aspartic acid (cRGD) loaded with bufalin, ie, bufalin-loaded mPEG-PLGA-PLL-cRGD nanoparticles (BNPs), in SW620 colon cancer-bearing mice. BNPs showed uniform size. The size, shape, zeta potential, drug loading, encapsulation efficiency, and release of these nanoparticles were studied in vitro. The tumor targeting, cellular uptake, and growth-inhibitory effect of BNPs in vivo were tested. BNPs were of uniform size with an average particle size of 164 ± 84 nm and zeta potential of 2.77 mV. The encapsulation efficiency was 81.7% ± 0.89%, and the drug load was 3.92% ± 0.16%. The results of in vitro cytotoxicity studies showed that although the blank NPs were nontoxic, they enhanced the cytotoxicity of bufalin in BNPs. Drug release experiments showed that the release of the drug was prolonged and sustained. The results of confocal laser scanning microscopy indicated that BNPs could effectively bind to human umbilical vein endothelial cells. In the SW620 xenograft mice model, the BNPs could effectively target the tumor in vivo. The BNPs were significantly more effective than other NPs in preventing tumor growth. BNPs had even size distribution, were stable, and had a slow-releasing and tumor-targeting effect. BNPs significantly inhibited colon cancer growth in vitro and in vivo. As a novel drug carrier system, BNPs are a potentially promising targeting treatment for colon cancer.

  2. Distribution of dipeptide repeat proteins in cellular models and C9orf72 mutation cases suggests link to transcriptional silencing.

    Science.gov (United States)

    Schludi, Martin H; May, Stephanie; Grässer, Friedrich A; Rentzsch, Kristin; Kremmer, Elisabeth; Küpper, Clemens; Klopstock, Thomas; Arzberger, Thomas; Edbauer, Dieter

    2015-10-01

    A massive expansion of a GGGGCC repeat upstream of the C9orf72 coding region is the most common known cause of amyotrophic lateral sclerosis and frontotemporal dementia. Despite its intronic localization and lack of a canonical start codon, both strands are translated into aggregating dipeptide repeat (DPR) proteins: poly-GA, poly-GP, poly-GR, poly-PR and poly-PA. To address conflicting findings on the predominant toxicity of the different DPR species in model systems, we compared the expression pattern of the DPR proteins in rat primary neurons and postmortem brain and spinal cord of C9orf72 mutation patients. Only poly-GA overexpression closely mimicked the p62-positive neuronal cytoplasmic inclusions commonly observed for all DPR proteins in patients. In contrast, overexpressed poly-GR and poly-PR formed nucleolar p62-negative inclusions. In patients, most of the less common neuronal intranuclear DPR inclusions were para-nucleolar and p62 positive. Neuronal nucleoli in C9orf72 cases showed normal size and morphology regardless of the presence of poly-GR and poly-PR inclusions arguing against widespread nucleolar stress, reported in cellular models. Colocalization of para-nucleolar DPR inclusions with heterochromatin and a marker of transcriptional repression (H3K9me2) indicates a link to gene transcription. In contrast, we detected numerous intranuclear DPR inclusions not associated with nucleolar structures in ependymal and subependymal cells. In patients, neuronal inclusions of poly-GR, poly-GP and the poly-GA interacting protein Unc119 were less abundant than poly-GA inclusions, but showed similar regional and subcellular distribution. Regardless of neurodegeneration, all inclusions were most abundant in neocortex, hippocampus and thalamus, with few inclusions in brain stem and spinal cord. In the granular cell layer of the cerebellum, poly-GA and Unc119 inclusions were significantly more abundant in cases with FTLD than in cases with MND and FTLD/MND. Poly

  3. On Weak Regular *-semigroups

    Institute of Scientific and Technical Information of China (English)

    Yong Hua LI; Hai Bin KAN; Bing Jun YU

    2004-01-01

    In this paper, a special kind of partial algebras called projective partial groupoids is defined.It is proved that the inverse image of all projections of a fundamental weak regular *-semigroup under the homomorphism induced by the maximum idempotent-separating congruence of a weak regular *-semigroup has a projective partial groupoid structure. Moreover, a weak regular *-product which connects a fundamental weak regular *-semigroup with corresponding projective partial groupoid is defined and characterized. It is finally proved that every weak regular *-product is in fact a weak regular *-semigroup and any weak regular *-semigroup is constructed in this way.

  4. Adaptive regularization of noisy linear inverse problems

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Madsen, Kristoffer Hougaard; Lehn-Schiøler, Tue

    2006-01-01

    In the Bayesian modeling framework there is a close relation between regularization and the prior distribution over parameters. For prior distributions in the exponential family, we show that the optimal hyper-parameter, i.e., the optimal strength of regularization, satisfies a simple relation: T...

  5. Bufalin-loaded mPEG-PLGA-PLL-cRGD nanoparticles: preparation, cellular uptake, tissue distribution, and anticancer activity

    Directory of Open Access Journals (Sweden)

    Duan YR

    2012-07-01

    Full Text Available Peihao Yin,1,* Yan Wang,1,* YanYan Qiu,1 LiLi Hou,1 Xuan Liu,1 Jianmin Qin,1 Yourong Duan,2 Peifeng Liu,2 Ming Qiu,3 Qi Li11Department of Clinical Oncology, Putuo Hospital and Interventional Cancer Institute of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China; 2Shanghai Cancer Institute, Jiaotong University, Shanghai, China; 3Department of General Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China *These authors contributed equally to this workBackground: Recent studies have shown that bufalin has a good antitumor effect but has high toxicity, poor water solubility, a short half-life, a narrow therapeutic window, and a toxic dose that is close to the therapeutic dose, which all limit its clinical application. This study aimed to determine the targeting efficacy of nanoparticles (NPs made of methoxy polyethylene glycol (mPEG, polylactic-co-glycolic acid (PLGA, poly-L-lysine (PLL, and cyclic arginine-glycine-aspartic acid (cRGD loaded with bufalin, ie, bufalin-loaded mPEG-PLGA-PLL-cRGD nanoparticles (BNPs, in SW620 colon cancer-bearing mice.Methods: BNPs showed uniform size. The size, shape, zeta potential, drug loading, encapsulation efficiency, and release of these nanoparticles were studied in vitro. The tumor targeting, cellular uptake, and growth-inhibitory effect of BNPs in vivo were tested.Results: BNPs were of uniform size with an average particle size of 164 ± 84 nm and zeta potential of 2.77 mV. The encapsulation efficiency was 81.7% ± 0.89%, and the drug load was 3.92% ± 0.16%. The results of in vitro cytotoxicity studies showed that although the blank NPs were nontoxic, they enhanced the cytotoxicity of bufalin in BNPs. Drug release experiments showed that the release of the drug was prolonged and sustained. The results of confocal laser scanning microscopy indicated that BNPs could effectively bind to human umbilical vein endothelial cells. In the SW620

  6. Literature Analysis on Distribution Regularity of Traditional Chinese Medicine Syndromes in Wilson's Disease%Wilson病中医证候文献分析

    Institute of Scientific and Technical Information of China (English)

    王共强; 王伟; 薛本春; 胡文彬; 胡纪源; 韩咏竹

    2011-01-01

    Objective To investigate the distribution regularity of traditional Chinese medicine (TCM) syndromes in an attempt to provide a basis for the standardization of TCM syndromes in Wilson’s disease (WD). Methods The TCM literatures about WD were collected from Chinese Biomedical Literature online Database, Chinese Journal Full Text Database, and Chinese Technology Journal Database from 1979 to 2010. The 736 cases from 21 literatures in line with inclusion criteria were analyzed by frequency analysis and cluster analysis using SPSS 19. 0 software. Results There was 13 TCM syndrome types in WD, the top four types included liver-gallbladder damp-heat, liver-kidney yin deficiency, liver-wind stirring, and phlegm-damp accumulation in collaterals. Cluster analysis results were slightly different from the frequencies of TCM syndromes in literatures. Among syndrome factors, viscera factors included liver, kidney, bile and spleen, successively; nature factors included damp-heat, yin deficiency, endogenous wind, and phlegmdamp, successively. Conclusion Liver-gallbladder damp-heat, liver-kidney yin deficiency, liver-wind stirring, and phlegm-damp accumulation in collaterals were the common TCM syndrome types of WD, especially liver-gallbladder damp-heat. Excess syndrome factors were mainly characterized as damp-heat, and phlegm-turbid; deficiency syndrome factors were mainly characterized as yin deficiency and endogenous wind.%目的 探讨Wilson病(Wilson's disease,WD)中医证候分布规律,为WD中医证候规范化研究提供依据.方法 从中国生物医学文献网络版数据库、中国期刊全文数据库、中文科技期刊数据库中检索1979-2010年间有关WD的中医药文献,对符合纳入标准的21篇文献中736例患者证候分布情况运用SPSS 19.0软件进行频数分析和聚类分析.结果 WD共出现13个中医证型,频数前4位依次为肝胆湿热、肝肾阴虚、肝风内动、痰湿阻络.聚类分析结果与中医证型频数分

  7. The UL24 protein of herpes simplex virus 1 affects the sub-cellular distribution of viral glycoproteins involved in fusion

    Energy Technology Data Exchange (ETDEWEB)

    Ben Abdeljelil, Nawel; Rochette, Pierre-Alexandre; Pearson, Angela, E-mail: angela.pearson@iaf.inrs.ca

    2013-09-15

    Mutations in UL24 of herpes simplex virus type 1 can lead to a syncytial phenotype. We hypothesized that UL24 affects the sub-cellular distribution of viral glycoproteins involved in fusion. In non-immortalized human foreskin fibroblasts (HFFs) we detected viral glycoproteins B (gB), gD, gH and gL present in extended blotches throughout the cytoplasm with limited nuclear membrane staining; however, in HFFs infected with a UL24-deficient virus (UL24X), staining for the viral glycoproteins appeared as long, thin streaks running across the cell. Interestingly, there was a decrease in co-localized staining of gB and gD with F-actin at late times in UL24X-infected HFFs. Treatment with chemical agents that perturbed the actin cytoskeleton hindered the formation of UL24X-induced syncytia in these cells. These data support a model whereby the UL24 syncytial phenotype results from a mislocalization of viral glycoproteins late in infection. - Highlights: • UL24 affects the sub-cellular distribution of viral glycoproteins required for fusion. • Sub-cellular distribution of viral glycoproteins varies in cell-type dependent manner. • Drugs targeting actin microfilaments affect formation of UL24-related syncytia in HFFs.

  8. Subcellular distribution and cellular self-repair ability of fluorescent quantum dots emitting in the visible to near-infrared region

    Science.gov (United States)

    Peng, Fei; Su, Yuanyuan; Zhong, Yiling; He, Yao

    2017-01-01

    Semiconductor II-VI quantum dots (QDs), as high-performance fluorescent biological probes, have garnered significant attention due to their superior optical properties. To enable QDs for wide-ranging bioapplications, concerns about their in vitro behavior need to be fully addressed. Herein, for the first time, cellular behaviors of aqueous synthesized-QDs (aqQDs), whose maximum emission wavelength (λ emission) covers the visible to near-infrared spectral window, are systematically investigated. Our results demonstrate that three different sized aqQDs feature distinct cellular distributions, i.e. aqQD530 (aqQDs whose λ emission is 530 nm) and aqQD620 (aqQDs whose λ emission is 620 nm) mainly distribute in the cytoplasm and nucleus, while aqQD730 (aqQDs whose λ emission is 730 nm) mainly accumulates in the cytoplasm. Most significantly, the phenomenon that cellular self-repair ability is dependent on diameters of aqQDs is revealed for the first time. In particular, small-sized QDs (e.g. aqQD530 and aqQD620) severely deteriorate cellular self-repair ability, leading to an irreversible decrease in cell viability. In striking contrast, large-sized QDs (e.g. aqQD730) have little effect on cellular self-repair ability, and the cell viability is restored after removal of aqQD730 from the culture medium. Our results provide invaluable information for QD-relevant biosafety analysis, as well as suggest available guidance for the design of biocompatible QDs for wide utilization in biological and biomedical studies.

  9. NOETHERIAN GR-REGULAR RINGS ARE REGULAR

    Institute of Scientific and Technical Information of China (English)

    LIHUISHI

    1994-01-01

    It is proved that for a left Noetherian z-graded ring A,if every finitely generated graded A-module has finite projective dimension(i.e-,A is gr-regular)then every finitely generated A-module has finite projective dimension(i.e.,A is regular).Some applications of this result to filtered rings and some classical cases are also given.

  10. 基于复合元胞自动机的分布式计算模型%A distributed computing model based on compound cellular automata

    Institute of Scientific and Technical Information of China (English)

    朱晓敏; 耿建东; 陈东华; 张润彤

    2012-01-01

    针对目前的分布式计算网络仍然缺乏较高的自治管理和自主认知能力,只能提供独立状态的服务,经常出现多点故障而造成分布式网络运作成本增加、延时加剧甚至网络崩溃等问题,将元胞自动机的相关概念及模型引入到分布式网络计算中,通过修正元胞自动机的原有机制,提出了复合元胞自动机模型,并建立了基于复合元胞自动机的分布式计算模型来提高分布式网络中认知自主管理能力,从而降低分布式计算成本和提高工作效率.通过模拟程序和GridSim软件包验证和展示了复合元胞自动机应用于分布式计算领域的可行性及优越性.%The concept of cellular automation and its model were introduced into distributed computation to solve current distributed computing networks' problems of high operating cost, serious time delay, and even debacle due to the multi-point failure caused by lack of high self-management and self-awareness and only providing independent services. By amending the original cellular automaton mechanism, a compound cellular automata model was proposed, and the distributed computing model based on compound cellular automata was established to enhance distributed networks' efficiency and reduce the operating cost. The comprehensive simulations and comparisons via GridSim verified the feasibility and efficiency of the proposed compound cellular automata model in the field of distributed computing.

  11. The Neurona at Home project: Simulating a large-scale cellular automata brain in a distributed computing environment

    Science.gov (United States)

    Acedo, L.; Villanueva-Oller, J.; Moraño, J. A.; Villanueva, R.-J.

    2013-01-01

    The Berkeley Open Infrastructure for Network Computing (BOINC) has become the standard open source solution for grid computing in the Internet. Volunteers use their computers to complete an small part of the task assigned by a dedicated server. We have developed a BOINC project called Neurona@Home whose objective is to simulate a cellular automata random network with, at least, one million neurons. We consider a cellular automata version of the integrate-and-fire model in which excitatory and inhibitory nodes can activate or deactivate neighbor nodes according to a set of probabilistic rules. Our aim is to determine the phase diagram of the model and its behaviour and to compare it with the electroencephalographic signals measured in real brains.

  12. IN ABSENCE OF THE CELLULAR PRION PROTEIN, ALTERATIONS IN COPPER METABOLISM AND COPPER-DEPENDENT OXIDASE ACTIVITY AFFECT IRON DISTRIBUTION

    OpenAIRE

    Lisa Gasperini; Elisa Meneghetti; Giuseppe Legname; Federico Benetti

    2016-01-01

    Essential elements as copper and iron modulate a wide range of physiological functions. Their metabolism is strictly regulated by cellular pathways, since dysregulation of metal homeostasis is responsible for many detrimental effects. Neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease and prion diseases are characterized by alterations of metal ions. These neurodegenerative maladies involve proteins that bind metals and mediate their metabolism through not well-defin...

  13. In Absence of the Cellular Prion Protein, Alterations in Copper Metabolism and Copper-Dependent Oxidase Activity Affect Iron Distribution

    OpenAIRE

    Gasperini, Lisa; Meneghetti, Elisa; Legname, Giuseppe; Benetti, Federico

    2016-01-01

    Essential elements as copper and iron modulate a wide range of physiological functions. Their metabolism is strictly regulated by cellular pathways, since dysregulation of metal homeostasis is responsible for many detrimental effects. Neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and prion diseases are characterized by alterations of metal ions. These neurodegenerative maladies involve proteins that bind metals and mediate their metabolism through not well-defin...

  14. Regular Expression Pocket Reference

    CERN Document Server

    Stubblebine, Tony

    2007-01-01

    This handy little book offers programmers a complete overview of the syntax and semantics of regular expressions that are at the heart of every text-processing application. Ideal as a quick reference, Regular Expression Pocket Reference covers the regular expression APIs for Perl 5.8, Ruby (including some upcoming 1.9 features), Java, PHP, .NET and C#, Python, vi, JavaScript, and the PCRE regular expression libraries. This concise and easy-to-use reference puts a very powerful tool for manipulating text and data right at your fingertips. Composed of a mixture of symbols and text, regular exp

  15. New Regularization Method in Electrical Impedance Tomography

    Institute of Scientific and Technical Information of China (English)

    侯卫东; 莫玉龙

    2002-01-01

    Image reconstruction in elecrical impedance tomography(EIT)is a highly ill-posed inverse problem,Regularization techniques must be used in order to solve the problem,In this paper,a new regularization method based on the spatial filtering theory is proposed.The new regularized reconstruction for EIT is independent of the estimation of impedance distribution,so it can be implemented more easily than the maxiumum a posteriori(MAP) method.The regularization level in our proposed method varies spatially so as to be suited to the correlation character of the object's impedance distribution.We implemented our regularization method with two dimensional computer simulations.The experimental results indicate that the quality of the reconstructed impedance images with the descibed regularization method based on spatial filtering theory is better than that with Tikhonov method.

  16. Dimensional regularization is generic

    CERN Document Server

    Fujikawa, Kazuo

    2016-01-01

    The absence of the quadratic divergence in the Higgs sector of the Standard Model in the dimensional regularization is usually regarded to be an exceptional property of a specific regularization. To understand what is going on in the dimensional regularization, we illustrate how to reproduce the results of the dimensional regularization for the $\\lambda\\phi^{4}$ theory in the more conventional regularization such as the higher derivative regularization; the basic postulate involved is that the quadratically divergent induced mass, which is independent of the scale change of the physical mass, is kinematical and unphysical. This is consistent with the derivation of the Callan-Symanzik equation, which is a comparison of two theories with slightly different masses, for the $\\lambda\\phi^{4}$ theory without encountering the quadratic divergence. We thus suggest that the dimensional regularization is generic in a bottom-up approach starting with a successful low-energy theory. We also define a modified version of t...

  17. 山东省煤炭资源与赋煤规律研究%Research Coal Distributions and Coal-accumulation Regularities in Shandong Province

    Institute of Scientific and Technical Information of China (English)

    张增奇; 梁吉坡; 李增学; 张义江; 孙斌; 程伟; 冯婷婷; 陈军

    2015-01-01

    The Shandong is rich coal resources,with the cumulative known coal reserves go to 31.23 billion tons and the coal resours to mainly 27.41 billion tons.The coal type is bituminous with minor of the lignite, anthracite coal and natural coke.The main coal accumulating periods in Shandong are Carboniferous-Permian,Fangzi period of middle Jurassic and the Wutu period of Paleogene with the Carboniferous-Permian being the most important coal accumulating period.The coal seams of Taiyuan Formation formed in the lagoon and tidal delta distal part and local areas can reach minable thickness.The fluvial-dominated shallow water delta of Shanxi Formation developed rapidly in large scale,forming the main mineable coal seams of large thickness and wide distribution area.The coal accumulating effect of Fangzi Formation and Lijiaya Formation occurred in the early period of basin water expansion-contraction,coal accumulating extended from the fan delta plain and front to the basin edge.Coal occurrence has suffered varying degrees of erosion a series of tectonic movement after coal accumulating stages.We can conclude from the research that the coal occurrence regularity of Shandong is characterized by “tilted-type structure,faulting in the north and overlapping in the south”,and the tectonic style by “the concave block alternate with convex block”.The coal seams with economic significance occur in “the edge and concave of block,horst of the latent sag,the graben of bump”,pointing out that the coal exploration direction of Shandong is “the base in concave,and the graben in convex”.The Shandong uplift zone is a rifted basin with lgcal at edge of graben basin.According to our research results,we found the Shanxian coalfield and Caoxian coalfield. On this basis,we have forecast the coal target areas in Shandong,and optimized six coal surveying target areas in Heze,Liaocheng,Jinan,Jining,Dezhou and parts of central area in Shangdon.%山东煤炭资源丰富,已

  18. In Absence of the Cellular Prion Protein, Alterations in Copper Metabolism and Copper-Dependent Oxidase Activity Affect Iron Distribution

    Science.gov (United States)

    Gasperini, Lisa; Meneghetti, Elisa; Legname, Giuseppe; Benetti, Federico

    2016-01-01

    Essential elements as copper and iron modulate a wide range of physiological functions. Their metabolism is strictly regulated by cellular pathways, since dysregulation of metal homeostasis is responsible for many detrimental effects. Neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and prion diseases are characterized by alterations of metal ions. These neurodegenerative maladies involve proteins that bind metals and mediate their metabolism through not well-defined mechanisms. Prion protein, for instance, interacts with divalent cations via multiple metal-binding sites and it modulates several metal-dependent physiological functions, such as S-nitrosylation of NMDA receptors. In this work we focused on the effect of prion protein absence on copper and iron metabolism during development and adulthood. In particular, we investigated copper and iron functional values in serum and several organs such as liver, spleen, total brain and isolated hippocampus. Our results show that iron content is diminished in prion protein-null mouse serum, while it accumulates in liver and spleen. Our data suggest that these alterations can be due to impairments in copper-dependent cerulopalsmin activity which is known to affect iron mobilization. In prion protein-null mouse total brain and hippocampus, metal ion content shows a fluctuating trend, suggesting the presence of homeostatic compensatory mechanisms. However, copper and iron functional values are likely altered also in these two organs, as indicated by the modulation of metal-binding protein expression levels. Altogether, these results reveal that the absence of the cellular prion protein impairs copper metabolism and copper-dependent oxidase activity, with ensuing alteration of iron mobilization from cellular storage compartments. PMID:27729845

  19. In Absence of the Cellular Prion Protein, Alterations in Copper Metabolism and Copper-Dependent Oxidase Activity Affect Iron Distribution.

    Science.gov (United States)

    Gasperini, Lisa; Meneghetti, Elisa; Legname, Giuseppe; Benetti, Federico

    2016-01-01

    Essential elements as copper and iron modulate a wide range of physiological functions. Their metabolism is strictly regulated by cellular pathways, since dysregulation of metal homeostasis is responsible for many detrimental effects. Neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and prion diseases are characterized by alterations of metal ions. These neurodegenerative maladies involve proteins that bind metals and mediate their metabolism through not well-defined mechanisms. Prion protein, for instance, interacts with divalent cations via multiple metal-binding sites and it modulates several metal-dependent physiological functions, such as S-nitrosylation of NMDA receptors. In this work we focused on the effect of prion protein absence on copper and iron metabolism during development and adulthood. In particular, we investigated copper and iron functional values in serum and several organs such as liver, spleen, total brain and isolated hippocampus. Our results show that iron content is diminished in prion protein-null mouse serum, while it accumulates in liver and spleen. Our data suggest that these alterations can be due to impairments in copper-dependent cerulopalsmin activity which is known to affect iron mobilization. In prion protein-null mouse total brain and hippocampus, metal ion content shows a fluctuating trend, suggesting the presence of homeostatic compensatory mechanisms. However, copper and iron functional values are likely altered also in these two organs, as indicated by the modulation of metal-binding protein expression levels. Altogether, these results reveal that the absence of the cellular prion protein impairs copper metabolism and copper-dependent oxidase activity, with ensuing alteration of iron mobilization from cellular storage compartments.

  20. Effects of fade distribution on a mobile satellite downlink and uplink performance in a frequency reuse cellular configuration

    Science.gov (United States)

    Boutin, Karl; Lecours, Michel; Pelletier, Marcel; Delisle, Gilles Y.

    1990-01-01

    In a mobile satellite system with a frequency reuse cellular configuration, significant co-channel interference can be experienced due to the antenna sidelobe level. The signal will be subjected not only to its own fading, but also to the effect of the varying degree of fading on co-channel interferer, and this interference will behave differently in the up and in the down link. This paper presents a quantitative evaluation of the combined effects of fades and co-channel interference on a mobile satellite link.

  1. The effect of oil-water partition coefficient on the distribution and cellular uptake of liposome-encapsulated gold nanoparticles.

    Science.gov (United States)

    Bao, Quan-Ying; Liu, Ai-Yun; Ma, Yu; Chen, Huan; Hong, Jin; Shen, Wen-Bin; Zhang, Can; Ding, Ya

    2016-10-01

    The shape, size, and surface features of nanoparticles greatly influence the structure and properties of resulting hybrid nanosystems. In this work, gold nanoparticles (GNPs) were modified via S-Au covalent bonding by glycol monomethyl ether thioctate with poly(ethylene glycol) methyl ether of different molecular weights (i.e., 350, 550, and 750Da). These modified GNPs (i.e., GNP350, GNP550, and GNP750) showed different oil-water partition coefficients (Kp), as detected using inductively coupled plasma-atomic emission spectroscopy. The different Kp values of the gold conjugates (i.e., 13.98, 2.11, and 0.036 for GNP350, GNP550, and GNP750, respectively) resulted in different conjugate localization within liposomes, as observed by transmission electron microscopy. In addition, the cellular uptake of hybrid liposomes co-encapsulating gold conjugates and Nile red was evaluated using intracellular fluorescence intensity. The results indicated that precise GNP localization in the hydrophilic or hydrophobic liposome cavity could be achieved by regulating the GNP oil-water partition coefficient via surface modification; such localization could further affect the properties and functions of hybrid liposomes, including their cellular uptake profiles. This study furthers the understanding not only of the interaction between liposomes and inorganic nanoparticles but also of adjusting liposome-gold hybrid nanostructure properties via the surface chemistry of gold materials.

  2. Perfringolysin O Theta Toxin as a Tool to Monitor the Distribution and Inhomogeneity of Cholesterol in Cellular Membranes.

    Science.gov (United States)

    Maekawa, Masashi; Yang, Yanbo; Fairn, Gregory D

    2016-03-08

    Cholesterol is an essential structural component of cellular membranes in eukaryotes. Cholesterol in the exofacial leaflet of the plasma membrane is thought to form membrane nanodomains with sphingolipids and specific proteins. Additionally, cholesterol is found in the intracellular membranes of endosomes and has crucial functions in membrane trafficking. Furthermore, cellular cholesterol homeostasis and regulation of de novo synthesis rely on transport via both vesicular and non-vesicular pathways. Thus, the ability to visualize and detect intracellular cholesterol, especially in the plasma membrane, is critical to understanding the complex biology associated with cholesterol and the nanodomains. Perfringolysin O (PFO) theta toxin is one of the toxins secreted by the anaerobic bacteria Clostridium perfringens and this toxin forms pores in the plasma membrane that causes cell lysis. It is well understood that PFO recognizes and binds to cholesterol in the exofacial leaflets of the plasma membrane, and domain 4 of PFO (D4) is sufficient for the binding of cholesterol. Recent studies have taken advantage of this high-affinity cholesterol-binding domain to create a variety of cholesterol biosensors by using a non-toxic PFO or the D4 in isolation. This review highlights the characteristics and usefulness of, and the principal findings related to, these PFO-derived cholesterol biosensors.

  3. Mechanical models of the cellular cytoskeletal network for the analysis of intracellular mechanical properties and force distributions: a review.

    Science.gov (United States)

    Chen, Ting-Jung; Wu, Chia-Ching; Su, Fong-Chin

    2012-12-01

    The cytoskeleton, which is the major mechanical component of cells, supports the cell body and regulates the cellular motility to assist the cell in performing its biological functions. Several cytoskeletal network models have been proposed to investigate the mechanical properties of cells. This review paper summarizes these models with a focus on the prestressed cable network, the semi-flexible chain network, the open-cell foam, the tensegrity, and the granular models. The components, material parameters, types of connection joints, tension conditions, and the advantages and disadvantages of each model are evaluated from a structural and biological point of view. The underlying mechanisms that are associated with the morphological changes of spreading cells are expected to be simulated using a cytoskeletal model; however, it is still paid less attention most likely due to the lack of a suitable cytoskeletal model that can accurately model the spreading process. In this review article, the established cytoskeletal models are hoped to provide useful information for the development of future cytoskeletal models with different degrees of cell attachment for the study of the mechanical mechanisms underlying the cellular behaviors in response to external stimulations.

  4. Global Exponential Stability of Almost Periodic Solution for Neutral-Type Cohen-Grossberg Shunting Inhibitory Cellular Neural Networks with Distributed Delays and Impulses.

    Science.gov (United States)

    Xu, Lijun; Jiang, Qi; Gu, Guodong

    2016-01-01

    A kind of neutral-type Cohen-Grossberg shunting inhibitory cellular neural networks with distributed delays and impulses is considered. Firstly, by using the theory of impulsive differential equations and the contracting mapping principle, the existence and uniqueness of the almost periodic solution for the above system are obtained. Secondly, by constructing a suitable Lyapunov functional, the global exponential stability of the unique almost periodic solution is also investigated. The work in this paper improves and extends some results in recent years. As an application, an example and numerical simulations are presented to demonstrate the feasibility and effectiveness of the main results.

  5. Global Exponential Stability of Almost Periodic Solution for Neutral-Type Cohen-Grossberg Shunting Inhibitory Cellular Neural Networks with Distributed Delays and Impulses

    Directory of Open Access Journals (Sweden)

    Lijun Xu

    2016-01-01

    Full Text Available A kind of neutral-type Cohen-Grossberg shunting inhibitory cellular neural networks with distributed delays and impulses is considered. Firstly, by using the theory of impulsive differential equations and the contracting mapping principle, the existence and uniqueness of the almost periodic solution for the above system are obtained. Secondly, by constructing a suitable Lyapunov functional, the global exponential stability of the unique almost periodic solution is also investigated. The work in this paper improves and extends some results in recent years. As an application, an example and numerical simulations are presented to demonstrate the feasibility and effectiveness of the main results.

  6. Robust Sparse Analysis Regularization

    CERN Document Server

    Vaiter, Samuel; Dossal, Charles; Fadili, Jalal

    2011-01-01

    This paper studies the properties of L1-analysis regularization for the resolution of linear inverse problems. Most previous works consider sparse synthesis priors where the sparsity is measured as the L1 norm of the coefficients that synthesize the signal in a given dictionary. In contrast, the more general analysis regularization minimizes the L1 norm of the correlations between the signal and the atoms in the dictionary. The corresponding variational problem includes several well-known regularizations such as the discrete total variation and the fused lasso. We first prove that a solution of analysis regularization is a piecewise affine function of the observations. Similarly, it is a piecewise affine function of the regularization parameter. This allows us to compute the degrees of freedom associated to sparse analysis estimators. Another contribution gives a sufficient condition to ensure that a signal is the unique solution of the analysis regularization when there is no noise in the observations. The s...

  7. Regular expressions cookbook

    CERN Document Server

    Goyvaerts, Jan

    2009-01-01

    This cookbook provides more than 100 recipes to help you crunch data and manipulate text with regular expressions. Every programmer can find uses for regular expressions, but their power doesn't come worry-free. Even seasoned users often suffer from poor performance, false positives, false negatives, or perplexing bugs. Regular Expressions Cookbook offers step-by-step instructions for some of the most common tasks involving this tool, with recipes for C#, Java, JavaScript, Perl, PHP, Python, Ruby, and VB.NET. With this book, you will: Understand the basics of regular expressions through a

  8. Regular patterns of Cs-137 distribution in natural conjugated elementary landscapes as a result of a balanced surface and depth water migration

    Science.gov (United States)

    Korobova, Elena; Romanov, Sergey

    2016-04-01

    Distribution of artificial radionuclides in the environment has long been used successfully for revealing migration pathways of their stable analogues. Migration of water in natural conjugated elementary landscapes characterizing the system of top-slope-resulting depression, has a specific structure and the radionuclide tracer is inevitably reflecting it by specific sorption and exchange processes. Other important issues are the concentration levels and the difference in characteristic time of chemical element dispersion. Modern biosphere has acquired its sustainable structure within a long period of time and is formed by basic macroelements allowing the water soluble portion of elements functioning as activators of chemical exchange. Water migration is controlled by gravitation, climate and relief while fixation depends upon the parameters of surfaces and chemical composition. The resulting structure depends on specificity and duration of the process. The long-term redistribution of chemical elements in terrestrial environment has led to a distinct geochemical structure of conjugated landscapes with a specific geometry of redistribution and accumulation of chemical elements. Migration of the newly born anthropogenic radionuclides followed natural pathways in biosphere. The initial deposition of the Chernobyl's radionuclides within the elementary landscape-geochemical system was even by condition of aerial deposition. But further exchange process is controlled by the strength of fixation and migration ability of the carriers. Therefore patterns of spatial distribution of artificial radionuclides in natural landscapes are considerably different as compared to those of the long-term forming the basic structure of chemical fields in biosphere. Our monitoring of Cs-137 radial and lateral distribution in the test plots characterizing natural undisturbed conjugated elementary landscapes performed in the period from 2005 until now has revealed a stable and specifically

  9. Hidden Regular Variation: Detection and Estimation

    CERN Document Server

    Mitra, Abhimanyu

    2010-01-01

    Hidden regular variation defines a subfamily of distributions satisfying multivariate regular variation on $\\mathbb{E} = [0, \\infty]^d \\backslash \\{(0,0, ..., 0) \\} $ and models another regular variation on the sub-cone $\\mathbb{E}^{(2)} = \\mathbb{E} \\backslash \\cup_{i=1}^d \\mathbb{L}_i$, where $\\mathbb{L}_i$ is the $i$-th axis. We extend the concept of hidden regular variation to sub-cones of $\\mathbb{E}^{(2)}$ as well. We suggest a procedure of detecting the presence of hidden regular variation, and if it exists, propose a method of estimating the limit measure exploiting its semi-parametric structure. We exhibit examples where hidden regular variation yields better estimates of probabilities of risk sets.

  10. Regularization in kernel learning

    CERN Document Server

    Mendelson, Shahar; 10.1214/09-AOS728

    2010-01-01

    Under mild assumptions on the kernel, we obtain the best known error rates in a regularized learning scenario taking place in the corresponding reproducing kernel Hilbert space (RKHS). The main novelty in the analysis is a proof that one can use a regularization term that grows significantly slower than the standard quadratic growth in the RKHS norm.

  11. Regular database update logics

    NARCIS (Netherlands)

    Spruit, Paul; Wieringa, Roel; Meyer, John-Jules

    2001-01-01

    We study regular first-order update logic (FUL), which is a variant of regular dynamic logic in which updates to function symbols as well as to predicate symbols are possible. We fi1rst study FUL without making assumptions about atomic updates. Second, we look at relational algebra update logic (RAU

  12. Quantitative interferometric microscopy cytometer based on regularized optical flow algorithm

    Science.gov (United States)

    Xue, Liang; Vargas, Javier; Wang, Shouyu; Li, Zhenhua; Liu, Fei

    2015-09-01

    Cell detections and analysis are important in various fields, such as medical observations and disease diagnoses. In order to analyze the cell parameters as well as observe the samples directly, in this paper, we present an improved quantitative interferometric microscopy cytometer, which can monitor the quantitative phase distributions of bio-samples and realize cellular parameter statistics. The proposed system is able to recover the phase imaging of biological samples in the expanded field of view via a regularized optical flow demodulation algorithm. This algorithm reconstructs the phase distribution with high accuracy with only two interferograms acquired at different time points simplifying the scanning system. Additionally, the method is totally automatic, and therefore it is convenient for establishing a quantitative phase cytometer. Moreover, the phase retrieval approach is robust against noise and background. Excitingly, red blood cells are readily investigated with the quantitative interferometric microscopy cytometer system.

  13. Distribution of antimicrobial resistance determinants, virulence-associated factors and clustered regularly interspaced palindromic repeats loci in isolates of Enterococcus faecalis from various settings and genetic lineages.

    Science.gov (United States)

    Gawryszewska, Iwona; Malinowska, Katarzyna; Kuch, Alicja; Chrobak-Chmiel, Dorota; Trokenheim, Lucja Laniewska-; Hryniewicz, Waleria; Sadowy, Ewa

    2017-03-01

    Enterococcus faecalis represents an important factor of hospital-associated infections (HAIs). The knowledge on its evolution from a commensal to an opportunistic pathogen is still limited; thus, we performed a study to characterise distribution of factors that may contribute to this adaptation. Using a collection obtained from various settings (hospitalised patients, community carriers, animals, fresh food, sewage, water), we investigated differences in antimicrobial susceptibility, distribution of antimicrobial resistance genes, virulence-associated determinants and phenotypes, and CRISPR loci in the context of the clonal relatedness of isolates. Bayesian Analysis of Population Structure revealed the presence of three major groups; two subgroups comprised almost exclusively HAI isolates, belonging to previously proposed enterococcal high-risk clonal complexes (HiRECCs) 6 and 28. Isolates of these two subgroups were significantly enriched in antimicrobial resistance genes, presumably produced a polysaccharide capsule and often carried the aggregation substance asa1; distribution of other virulence-associated genes, such as esp and cyl, formation of a biofilm and gelatinase production were more variable. Moreover, both subgroups showed a low prevalence of CRISPR-Cas 1 and 3 and presence of small CRISPR2 variants. Our study confirms the importance of HiRECCs in the population of E. faecalis and their confinement to the hospital settings. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Copper changes the yield and cadmium/zinc accumulation and cellular distribution in the cadmium/zinc hyperaccumulator Sedum plumbizincicola.

    Science.gov (United States)

    Li, Zhu; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Christie, Peter

    2013-10-15

    Non-accumulated metals in mixed metal contaminated soils may affect hyperaccumulator growth and metal accumulation and thus remediation efficiency. Two hydroponics experiments were conducted to investigate the effects of copper (Cu) on cadmium (Cd) and zinc (Zn) accumulation by the Cd/Zn hyperaccumulator Sedum plumbizincicola, Cu toxicity and plant detoxification using chemical sequential extraction of metals, sub-cellular separation, micro synchrotron radiation based X-ray fluorescence, and transmission electron microscopy. Compared with the control (0.31 μM Cu), 5-50 μM Cu had no significant effect on Cd/Zn accumulation, but Cu at 200 μM induced root cell plasmolysis and disordered chloroplast structure. The plants held Cu in the roots and cell walls and complexed Cu in insoluble forms as their main detoxification mechanisms. Exposure to 200 μM Cu for 4 days inhibited plant Cd uptake and translocation but did not affect Zn concentrations in roots and stems. Moreover, unloading of Cd and Zn from stem to leaf was restrained compared to control plants, perhaps due to Cu accumulation in leaf veins. Copper may thus interfere with root Cd uptake and restrain Cd/Zn unloading to the leaves. Further investigation of how Cu affects plant metal uptake may help elucidate the Cd/Zn hyper-accumulating mechanisms of S. plumbizincicola. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Accretion onto some well-known regular black holes

    Energy Technology Data Exchange (ETDEWEB)

    Jawad, Abdul; Shahzad, M.U. [COMSATS Institute of Information Technology, Department of Mathematics, Lahore (Pakistan)

    2016-03-15

    In this work, we discuss the accretion onto static spherically symmetric regular black holes for specific choices of the equation of state parameter. The underlying regular black holes are charged regular black holes using the Fermi-Dirac distribution, logistic distribution, nonlinear electrodynamics, respectively, and Kehagias-Sftesos asymptotically flat regular black holes. We obtain the critical radius, critical speed, and squared sound speed during the accretion process near the regular black holes. We also study the behavior of radial velocity, energy density, and the rate of change of the mass for each of the regular black holes. (orig.)

  16. Accretion onto Some Well-Known Regular Black Holes

    CERN Document Server

    Jawad, Abdul

    2016-01-01

    In this work, we discuss the accretion onto static spherical symmetric regular black holes for specific choices of equation of state parameter. The underlying regular black holes are charged regular black hole using Fermi-Dirac Distribution, logistic distribution, nonlinear electrodynamics, respectively and Kehagias-Sftesos asymptotically flat regular black hole. We obtain the critical radius, critical speed and squared sound speed during the accretion process near the regular black holes. We also study the behavior of radial velocity, energy density and rate of change of mass for each regular black holes.

  17. Quantitative evaluation of berberine subcellular distribution and cellular accumulation in non-small cell lung cancer cells by UPLC-MS/MS.

    Science.gov (United States)

    Yuan, Zhong-Wen; Leung, Elaine Lai-Han; Fan, Xing-Xing; Zhou, Hua; Ma, Wen-Zhe; Liu, Liang; Xie, Ying

    2015-11-01

    Berberine, an isoquinoline alkaloid, has been demonstrated to be a safe anti-cancer agent with multiple effects on mitochondria. Intracellular concentration and distribution around the targeting sites are determinants of efficacy, but subcellular distribution of berberine has not been fully elucidated yet, which relies on the sensitive and robustness assay. In this study, a sensitive and robust UPLC-MS/MS method has been developed and validated with optimized extraction solvents and detection conditions. Key factors such as the purity and integrity of isolated organelle fractions, and the effects of isolation procedures on the subcellular concentration of berberine were systemically evaluated. With the developed assay, we found that the intracellular accumulations of berberine in two gefitinib resistant NSCLC cell lines H1650 and H1975 were 2-3 folds higher than that of normal epithelial cells BEAS-2B. Moreover, significantly different subcellular distribution profiles in NSCLC cancer cells from that of BEAS-2B cells with a striking increase in content in most organelles may contribute to its selective cytotoxicity to cancer cells. Furthermore, a predominant accumulation of berberine was observed for the first time in microsomal fraction for all three cell lines. Therefore, this method could be used for quantitative evaluation of subcellular distribution and cellular accumulation of berberine and for further evaluation of the concentration-effects relationship.

  18. Copper changes the yield and cadmium/zinc accumulation and cellular distribution in the cadmium/zinc hyperaccumulator Sedum plumbizincicola

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhu [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu, Longhua, E-mail: lhwu@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Hu, Pengjie [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Luo, Yongming [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Yantai Institute of Coastal Zone Research, Yantai 264003 (China); Christie, Peter [Agri-Environment Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX (United Kingdom)

    2013-10-15

    Highlights: • Low Cu has no significant effect on Sedum plumbizincicola plant growth and Cd and Zn uptake. • Plant held Cu in unactive areas and insoluble forms as de-toxification mechanisms. • Influence of Cu on Zn and Cd uptake and translocation were different. • Cu accumulation in leaf veins may restrain Cd/Zn unloading to the leaves -- Abstract: Non-accumulated metals in mixed metal contaminated soils may affect hyperaccumulator growth and metal accumulation and thus remediation efficiency. Two hydroponics experiments were conducted to investigate the effects of copper (Cu) on cadmium (Cd) and zinc (Zn) accumulation by the Cd/Zn hyperaccumulator Sedum plumbizincicola, Cu toxicity and plant detoxification using chemical sequential extraction of metals, sub-cellular separation, micro synchrotron radiation based X-ray fluorescence, and transmission electron microscopy. Compared with the control (0.31 μM Cu), 5–50 μM Cu had no significant effect on Cd/Zn accumulation, but Cu at 200 μM induced root cell plasmolysis and disordered chloroplast structure. The plants held Cu in the roots and cell walls and complexed Cu in insoluble forms as their main detoxification mechanisms. Exposure to 200 μM Cu for 4 days inhibited plant Cd uptake and translocation but did not affect Zn concentrations in roots and stems. Moreover, unloading of Cd and Zn from stem to leaf was restrained compared to control plants, perhaps due to Cu accumulation in leaf veins. Copper may thus interfere with root Cd uptake and restrain Cd/Zn unloading to the leaves. Further investigation of how Cu affects plant metal uptake may help elucidate the Cd/Zn hyper-accumulating mechanisms of S. plumbizincicola.

  19. Regularization by External Variables

    DEFF Research Database (Denmark)

    Bossolini, Elena; Edwards, R.; Glendinning, P. A.

    2016-01-01

    Regularization was a big topic at the 2016 CRM Intensive Research Program on Advances in Nonsmooth Dynamics. There are many open questions concerning well known kinds of regularization (e.g., by smoothing or hysteresis). Here, we propose a framework for an alternative and important kind of regula...... of regularization, by external variables that shadow either the state or the switch of the original system. The shadow systems are derived from and inspired by various applications in electronic control, predator-prey preference, time delay, and genetic regulation....

  20. [Regularities of lateral distribution of uranium and thorium decay series radionuclides in the anthropogenically changed soils from the area of radium production waste storage].

    Science.gov (United States)

    Evseeva, T I; Belykh, E S; Maĭstrenko, T A; Geras'kin, S A; Taskaev, A I; Vakhrusheva, O M

    2012-01-01

    Cartographical investigations of the territory of radium production waste storage has shown some changes in lateral differentiation of radionuclides of uranium and thorium decay series to occur during 27 years (1981-2008). Those changes are caused mostly by flat denudation typical for fluvial terrace. At present radionuclides of uranium and thorium decay series are concentrated mostly in flood lands and relief depressions. At the same time, decrease in the radionuclide activity concentration in 0-20 cm soil layer is observed with changes in lateral distribution. Total stocks of 226Ra, 210Pb and 210Po within catena soils studied in the northern and southern parts of the waste storage decreased 3-6 times, 238U - 2 times, and did not significantly change in case of 232Th during 27 years. Nonetheless, most of the samples studied are referred to radioactive waste both according to Russian standards (SPORO-2002) and IAEA safety norms (IAEA, 2004).

  1. Persistent Morbillivirus Infection Leads to Altered Cortactin Distribution in Histiocytic Sarcoma Cells with Decreased Cellular Migration Capacity

    Science.gov (United States)

    Pfankuche, Vanessa Maria; Sayed-Ahmed, Mohamed; Contioso, Vanessa Bono; Spitzbarth, Ingo; Rohn, Karl; Ulrich, Reiner; Deschl, Ulrich; Kalkuhl, Arno; Baumgärtner, Wolfgang; Puff, Christina

    2016-01-01

    Histiocytic sarcomas represent rare but fatal neoplasms in humans. Based on the absence of a commercially available human histiocytic sarcoma cell line the frequently affected dog displays a suitable translational model. Canine distemper virus, closely related to measles virus, is a highly promising candidate for oncolytic virotherapy. Therapeutic failures in patients are mostly associated with tumour invasion and metastasis often induced by misdirected cytoskeletal protein activities. Thus, the impact of persistent canine distemper virus infection on the cytoskeletal protein cortactin, which is frequently overexpressed in human cancers with poor prognosis, was investigated in vitro in a canine histiocytic sarcoma cell line (DH82). Though phagocytic activity, proliferation and apoptotic rate were unaltered, a significantly reduced migration activity compared to controls (6 hours and 1 day after seeding) accompanied by a decreased number of cortactin mRNA transcripts (1 day) was detected. Furthermore, persistently canine distemper virus infected DH82 cells showed a predominant diffuse intracytoplasmic cortactin distribution at 6 hours and 1 day compared to controls with a prominent membranous expression pattern (p ≤ 0.05). Summarized, persistent canine distemper virus infection induces reduced tumour cell migration associated with an altered intracellular cortactin distribution, indicating cytoskeletal changes as one of the major pathways of virus-associated inhibition of tumour spread. PMID:27911942

  2. Ultrasound enhances calcium absorption of jujube fruit by regulating the cellular calcium distribution and metabolism of cell wall polysaccharides.

    Science.gov (United States)

    Zhi, Huanhuan; Liu, Qiqi; Xu, Juan; Dong, Yu; Liu, Mengpei; Zong, Wei

    2017-04-26

    Ultrasound has been applied in fruit pre-washing processes. However, it is not sufficient to protect fruit from pathogenic infection throughout the entire storage period, and sometimes ultrasound causes tissue damage. The goal of this study was to investigate the effects of calcium chloride (CaCl2 , 10 g L(-1) ) and ultrasound (350 W at 40 kHz), separately and in combination, on jujube fruit quality, antioxidant status, tissue Ca(2+) content and distribution along with cell wall metabolism at 20 °C for 6 days. All three treatments significantly maintained fruit firmness and peel color, reduced respiration rate, decay incidence, superoxide anion, hydrogen peroxide and malondialdehyde and preserved higher enzymatic (superoxide dismutase, catalase and peroxidase) and non-enzymatic (ascorbic acid and glutathione) antioxidants compared with the control. Moreover, the combined treatment was more effective in increasing tissue Ca(2+) content and distribution, inhibiting the generation of water-soluble and CDTA-soluble pectin fractions, delaying the solubilization of Na2 CO3 -soluble pectin and having lower activities of cell wall-modifying enzymes (polygalacturonase and pectate lyase) during storage. These results demonstrated that the combination of CaCl2 and ultrasound has potential commercial application to extend the shelf life of jujube fruit by facilitating Ca(2+) absorption and stabilizing the cell wall structure. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Regularized maximum correntropy machine

    KAUST Repository

    Wang, Jim Jing-Yan

    2015-02-12

    In this paper we investigate the usage of regularized correntropy framework for learning of classifiers from noisy labels. The class label predictors learned by minimizing transitional loss functions are sensitive to the noisy and outlying labels of training samples, because the transitional loss functions are equally applied to all the samples. To solve this problem, we propose to learn the class label predictors by maximizing the correntropy between the predicted labels and the true labels of the training samples, under the regularized Maximum Correntropy Criteria (MCC) framework. Moreover, we regularize the predictor parameter to control the complexity of the predictor. The learning problem is formulated by an objective function considering the parameter regularization and MCC simultaneously. By optimizing the objective function alternately, we develop a novel predictor learning algorithm. The experiments on two challenging pattern classification tasks show that it significantly outperforms the machines with transitional loss functions.

  4. Regular Expression Containment

    DEFF Research Database (Denmark)

    Henglein, Fritz; Nielsen, Lasse

    2011-01-01

    We present a new sound and complete axiomatization of regular expression containment. It consists of the conventional axiomatiza- tion of concatenation, alternation, empty set and (the singleton set containing) the empty string as an idempotent semiring, the fixed- point rule E* = 1 + E × E......* for Kleene-star, and a general coin- duction rule as the only additional rule. Our axiomatization gives rise to a natural computational inter- pretation of regular expressions as simple types that represent parse trees, and of containment proofs as coercions. This gives the axiom- atization a Curry......-Howard-style constructive interpretation: Con- tainment proofs do not only certify a language-theoretic contain- ment, but, under our computational interpretation, constructively transform a membership proof of a string in one regular expres- sion into a membership proof of the same string in another regular expression. We...

  5. Regularities of Multifractal Measures

    Indian Academy of Sciences (India)

    Hun Ki Baek

    2008-05-01

    First, we prove the decomposition theorem for the regularities of multifractal Hausdorff measure and packing measure in $\\mathbb{R}^d$. This decomposition theorem enables us to split a set into regular and irregular parts, so that we can analyze each separately, and recombine them without affecting density properties. Next, we give some properties related to multifractal Hausdorff and packing densities. Finally, we extend the density theorem in [6] to any measurable set.

  6. On Regular Linear Relations

    Institute of Scientific and Technical Information of China (English)

    T. (A)LVAREZ

    2012-01-01

    For a closed linear relation in a Banach space the concept of regularity is introduced and studied.It is shown that many of the results of Mbekhta and other authors for operators remain valid in the context of multivalued linear operators.We also extend the punctured neighbourhood theorem for operators to linear relations and as an application we obtain a characterization of semiFredholm linear relations which are regular.

  7. Cellular distribution of {sup 111}In-LDTPA galactose BSA in normal and asialoglycoprotein receptor-deficient mouse liver

    Energy Technology Data Exchange (ETDEWEB)

    Deal, Kim A.; Cristel, Michael E.; Welch, Michael J

    1998-05-01

    {sup 111}In-LDTPA galactose BSA (bovine serum albumin) was used to evaluate the asialoglycoprotein receptor (ASGPR) system in both normal and ASGPR-deficient mice. The radiolabeled glycoprotein had complete liver uptake in both normal and ASGPR-deficient mice. Metabolism and hepatic cell-type distribution studies were performed. The normal mouse excreted greater than 60% of the hepatic activity, while the ASGPR-deficient mouse excreted less than 40% of the hepatic activity. {sup 111}In-LDTPA galactose BSA was metabolized to {sup 111}In-LDTPA-L-lysine in both mouse types. Normal mice showed 70% of the radioactivity in the hepatocyte, whereas the homozygous ASGPR-deficient mouse had equal activity in the hepatocyte and the hepatic endothelial cell.

  8. The Corona Limit of Penrose Tilings Is a Regular Decagon

    OpenAIRE

    Akiyama, Shigeki; Imai, Katsunobu

    2016-01-01

    Part 2: Regular Papers; International audience; We define and study the corona limit of a tiling, by investigating the signal propagations on cellular automata (CA) on tilings employing the simple growth CA. In particular, the corona limit of Penrose tilings is the regular decagon.

  9. Degradable gene delivery systems based on Pluronics-modified low-molecular-weight polyethylenimine: preparation, characterization, intracellular trafficking, and cellular distribution

    Directory of Open Access Journals (Sweden)

    Ding X

    2012-02-01

    homogeneous distribution in the cytoplasm; those with a lower hydrophilic-lipophilic balance value prefer to localize in the nucleus.Conclusion: This Pluronic-polyethyleneimine system may be worth exploring as components in the cationic copolymers as the DNA or small interfering RNA/microRNA delivery system in the near future.Keywords: Pluronics, gene transfer, nonviral vectors, transfection efficiency, cellular uptake

  10. Involvement of Lipid Rafts and Cellular Actin in AcMNPV GP64 Distribution and Virus Budding

    Institute of Scientific and Technical Information of China (English)

    F. J. Haines; C. M. Griffiths; R. D. Possee; C. R. Hawes; L. A. King

    2009-01-01

    GP64 is the major envelope glycoprotein associated with the budded virus (BV) of Autographa californica nucleopolyhedrovirus (AcMNPV) and is essential for attachment and budding of BV particles.Confocal microscopy and flotation assays established the presence of lipid raft domains within the plasma membranes of AcMNPV-infected Sf9 cells and suggested the association of GP64 with lipid rafts during infection. GP64 and filamentous actin (F-actin) were found to co-localise at the cell cortex at 24 and 48 hpi and an additional restructuring of F-actin during infection was visualised, resulting in a strongly polarised distribution of both F-actin and GP64 at the cell cortex. Depletion of F-actin, achieved by treatment of St9 cells with latrunculin B (LB), resulted in the redistribution of GP64 with significant cytoplasmic aggregation and reduced presence at the plasma membrane. Treatment with LB also resulted in reduced production of BV in Sf9 cells. Analysis of virus gene transcription confirmed this reduction was not due to decreased trafficking of nucleocapsids to the nucleus or to decreased production of infectious progeny nucleoeapsids. Reduced BV production due to a lack of GP64 at the plasma membrane of AcMNPV-infected Sf9 cells treated with LB, suggests a key role for F-actin in the egress of BV.

  11. Cellular distribution of uranium after acute exposure of renal epithelial cells: SEM, TEM and nuclear microscopy analysis

    Science.gov (United States)

    Carrière, Marie; Gouget, Barbara; Gallien, Jean-Paul; Avoscan, Laure; Gobin, Renée; Verbavatz, Jean-Marc; Khodja, Hicham

    2005-04-01

    The major health effect of uranium exposure has been reported to be chemical kidney toxicity, functional and histological damages being mainly observed in proximal tubule cells. Uranium enters the proximal tubule as uranyl-bicarbonate or uranyl-citrate complexes. The aim of our research is to investigate the mechanisms of uranium toxicity, intracellular accumulation and repartition after acute intoxication of rat renal proximal tubule epithelial cells, as a function of its chemical form. Microscopic observations of renal epithelial cells after acute exposure to uranyl-bicarbonate showing the presence of intracellular precipitates as thin needles of uranyl-phosphate localized in cell lysosomes have been published. However the initial site of precipitates formation has not been identified yet: they could either be formed outside the cells before internalization, or directly inside the cells. Uranium solubility as a function and initial concentration was specified by ICP-MS analysis of culture media. In parallel, uranium uptake and distribution in cell monolayers exposed to U-bicarbonate was investigated by nuclear microprobe analyses. Finally, the presence of uranium precipitates was tested out by scanning electron microscopic observations (SEM), while extracellular and/or intracellular precipitates were observed on thin sections of cells by transmission electron microscopy (TEM).

  12. Cellular distribution of uranium after acute exposure of renal epithelial cells: SEM, TEM and nuclear microscopy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Carriere, Marie [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France)]. E-mail: carriere@drecam.cea.fr; Gouget, Barbara [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France); Gallien, Jean-Paul [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France); Avoscan, Laure [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France); Gobin, Renee [Laboratoire d' imagerie cellulaire et moleculaire, DBJC/SBFM/LTMD, CEA/Saclay, 91191 Gif sur Yvette (France); Verbavatz, Jean-Marc [Laboratoire d' imagerie cellulaire et moleculaire, DBJC/SBFM/LTMD, CEA/Saclay, 91191 Gif sur Yvette (France); Khodja, Hicham [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2005-04-01

    The major health effect of uranium exposure has been reported to be chemical kidney toxicity, functional and histological damages being mainly observed in proximal tubule cells. Uranium enters the proximal tubule as uranyl-bicarbonate or uranyl-citrate complexes. The aim of our research is to investigate the mechanisms of uranium toxicity, intracellular accumulation and repartition after acute intoxication of rat renal proximal tubule epithelial cells, as a function of its chemical form. Microscopic observations of renal epithelial cells after acute exposure to uranyl-bicarbonate showing the presence of intracellular precipitates as thin needles of uranyl-phosphate localized in cell lysosomes have been published. However the initial site of precipitates formation has not been identified yet: they could either be formed outside the cells before internalization, or directly inside the cells. Uranium solubility as a function and initial concentration was specified by ICP-MS analysis of culture media. In parallel, uranium uptake and distribution in cell monolayers exposed to U-bicarbonate was investigated by nuclear microprobe analyses. Finally, the presence of uranium precipitates was tested out by scanning electron microscopic observations (SEM), while extracellular and/or intracellular precipitates were observed on thin sections of cells by transmission electron microscopy (TEM)

  13. Study about property and flavor and meridian distribution regularity on hyperuricemia medication%高尿酸血症用药的性味归经规律研究

    Institute of Scientific and Technical Information of China (English)

    王先敏; 马丽

    2011-01-01

    Objective: To investigate the property and flavor and meridian distribution regularity, the regularity and characteristics of prescription to treatment of hyperuricemia, then provide references for the treatment of Chinese medicine to hypericemia. Methods: On the base of reference ideas and methods of evidence-based medicine and epidemiology, the inclusion criteria and exclusion criteria of the 78 Chinese medicine treatment of hyperuricemia and drug treatment in the literature are classified, respectively, then their property and flavor and meridian distribution are found with SPSS 17.0 software for statistical analysis. Results: The involved 'property' to describe the statistical treatment of hypeniricemia found mainly even, followed by the temperature of the drug, the property counted for 69.9% of all medicinal drugs; medication to sweet taste as the most, followed by the bitter, pungent drugs, the three flavors accounted for 76% of all drug flavor, the use of other flavors areless; meridian distribution to the liver by the drugs as the most, followed by the kidney, stomach medicine, the three meridian distributions accounting for 52. l%of all the drugs. Conclusion: From the regularity of property and flavor and meridian distribution, we could see that the commonly used drugs closely located in the liver, spleen and kidney dysfunction of liver-based, and the liver toxicity is the key risk factor for the etiology and pathogenesis.%目的:探讨治疗高尿酸血症方剂药物性味、归经的规律和特点,为高尿酸血症的中医治疗提供参考和借鉴.方法:借鉴循证医学和流行病学的思路与方法,将符合纳入标准和排除标准的78篇高尿酸血症的中医治疗文献中的用药和药物归类,并分别查出其性、味、归经,用SPSS 17.0软件进行统计分析.结果:对所涉及的“性”进行描述统计发现高尿酸血症用药主要是平性,其次是温件药物,此两性占到了全部用药药性的69.9%;用

  14. Regularized Structural Equation Modeling.

    Science.gov (United States)

    Jacobucci, Ross; Grimm, Kevin J; McArdle, John J

    A new method is proposed that extends the use of regularization in both lasso and ridge regression to structural equation models. The method is termed regularized structural equation modeling (RegSEM). RegSEM penalizes specific parameters in structural equation models, with the goal of creating easier to understand and simpler models. Although regularization has gained wide adoption in regression, very little has transferred to models with latent variables. By adding penalties to specific parameters in a structural equation model, researchers have a high level of flexibility in reducing model complexity, overcoming poor fitting models, and the creation of models that are more likely to generalize to new samples. The proposed method was evaluated through a simulation study, two illustrative examples involving a measurement model, and one empirical example involving the structural part of the model to demonstrate RegSEM's utility.

  15. Cellular automata

    CERN Document Server

    Codd, E F

    1968-01-01

    Cellular Automata presents the fundamental principles of homogeneous cellular systems. This book discusses the possibility of biochemical computers with self-reproducing capability.Organized into eight chapters, this book begins with an overview of some theorems dealing with conditions under which universal computation and construction can be exhibited in cellular spaces. This text then presents a design for a machine embedded in a cellular space or a machine that can compute all computable functions and construct a replica of itself in any accessible and sufficiently large region of t

  16. Aldehyde dehydrogenase 3B1 (ALDH3B1): immunohistochemical tissue distribution and cellular-specific localization in normal and cancerous human tissues.

    Science.gov (United States)

    Marchitti, Satori A; Orlicky, David J; Brocker, Chad; Vasiliou, Vasilis

    2010-09-01

    Aldehyde dehydrogenase (ALDH) enzymes are critical in the detoxification of endogenous and exogenous aldehydes. Our previous findings indicate that the ALDH3B1 enzyme is expressed in several mouse tissues and is catalytically active toward aldehydes derived from lipid peroxidation, suggesting a potential role against oxidative stress. The aim of this study was to elucidate by immunohistochemistry the tissue, cellular, and subcellular distribution of ALDH3B1 in normal human tissues and in tumors of human lung, colon, breast, and ovary. Our results indicate that ALDH3B1 is expressed in a tissue-specific manner and in a limited number of cell types, including hepatocytes, proximal convoluted tubule cells, cerebellar astrocytes, bronchiole ciliated cells, testis efferent ductule ciliated cells, and histiocytes. ALDH3B1 expression was upregulated in a high percentage of human tumors (lung > breast = ovarian > colon). Increased ALDH3B1 expression in tumor cells may confer a growth advantage or be the result of an induction mechanism mediated by increased oxidative stress. Subcellular localization of ALDH3B1 was predominantly cytosolic in tissues, with the exception of normal human lung and testis, in which localization appeared membrane-bound or membrane-associated. The specificity of ALDH3B1 distribution may prove to be directly related to the functional role of this enzyme in human tissues.

  17. Regularity of Bound States

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  18. Manifold Regularized Reinforcement Learning.

    Science.gov (United States)

    Li, Hongliang; Liu, Derong; Wang, Ding

    2017-01-27

    This paper introduces a novel manifold regularized reinforcement learning scheme for continuous Markov decision processes. Smooth feature representations for value function approximation can be automatically learned using the unsupervised manifold regularization method. The learned features are data-driven, and can be adapted to the geometry of the state space. Furthermore, the scheme provides a direct basis representation extension for novel samples during policy learning and control. The performance of the proposed scheme is evaluated on two benchmark control tasks, i.e., the inverted pendulum and the energy storage problem. Simulation results illustrate the concepts of the proposed scheme and show that it can obtain excellent performance.

  19. Study on connexin gene and protein expression and cellular distribution in relation to real-time proliferation of porcine granulosa cells.

    Science.gov (United States)

    Kempisty, B; Ziółkowska, A; Ciesiółka, S; Piotrowska, H; Antosik, P; Bukowska, D; Nowicki, M; Brüssow, K P; Zabel, M

    2014-01-01

    Granulosa cells (GCs) play an important role during follicle growth and development in preovulatory stage. Moreover, the proteins such as connexins are responsible for formation of protein channel between follicular-cumulus cells and oocyte. This study was aimed to investigate the role of connexin expression in porcine GCs in relation to their cellular distribution and real-time cell proliferation. In the present study, porcine GCs were isolated from the follicles of puberal gilts and then cultured in a real-time cellular analyzer (RTCA) system for 168 h. The expression levels of connexins (Cxs) Cx36, Cx37, Cx40 and Cx43 mRNA were measured by RQ-PCR analysis, and differences in the expression and distribution of Cx30, Cx31, Cx37, Cx43 and Cx45 proteins were analyzed by confocal microscopic visualization. We found higher level of Cx36, Cx37, and Cx43 mRNA expression in GCs at recovery (at 0 h of in vitro culture, IVC) compared to all analyzed time periods of IVC (24, 48, 72, 96, 120, 144 and 168 h; Pproteins were higher before (0 h) compared to after 168 h of IVC. The expression of Cx30 and Cx43, however, did not vary between the groups. In all, the proteins were distributed throughout the cell membrane rather than in the cytoplasm both before and after IVC. After 24 h of IVC, we observed a significant increase in the proliferation of GCs (log phase). We found differences in the proliferation index between 72-96 and 96- 140 h within the same population of GCs. In conclusion, the decrease in the expression of Cx mRNAs and proteins following IVC could be associated with a breakdown in gap-junction connections (GJCs), and leads to the decreased of their activity, which may be a reason of non-functional existence of connexon in follicular granulosa cells. These data indicated that the differentiation and proliferation of GCs and lutein cells are regulated by distinct mechanisms in pigs.

  20. Small and intermediate conductance Ca(2+)-activated K+ channels confer distinctive patterns of distribution in human tissues and differential cellular localisation in the colon and corpus cavernosum.

    Science.gov (United States)

    Chen, Mao Xiang; Gorman, Shelby A; Benson, Bill; Singh, Kuljit; Hieble, J Paul; Michel, Martin C; Tate, Simon N; Trezise, Derek J

    2004-06-01

    The SK/IK family of small and intermediate conductance calcium-activated potassium channels contains four members, SK1, SK2, SK3 and IK1, and is important for the regulation of a variety of neuronal and non-neuronal functions. In this study we have analysed the distribution of these channels in human tissues and their cellular localisation in samples of colon and corpus cavernosum. SK1 mRNA was detected almost exclusively in neuronal tissues. SK2 mRNA distribution was restricted but more widespread than SK1, and was detected in adrenal gland, brain, prostate, bladder, liver and heart. SK3 mRNA was detected in almost every tissue examined. It was highly expressed in brain and in smooth muscle-rich tissues including the clitoris and the corpus cavernosum, and expression in the corpus cavernosum was upregulated up to 5-fold in patients undergoing sex-change operations. IK1 mRNA was present in surface-rich, secretory and inflammatory cell-rich tissues, highest in the trachea, prostate, placenta and salivary glands. In detailed immunohistochemical studies of the colon and the corpus cavernosum, SK1-like immunoreactivity was observed in the enteric neurons. SK3-like immunoreactivity was observed strongly in smooth muscle and vascular endothelium. IK1-like immunoreactivity was mainly observed in inflammatory cells and enteric neurons of the colon, but absent in corpus cavernosum. These distinctive patterns of distribution suggest that these channels are likely to have different biological functions and could be specifically targeted for a number of human diseases, such as irritable bowel syndrome, hypertension and erectile dysfunction.

  1. Annotation of Regular Polysemy

    DEFF Research Database (Denmark)

    Martinez Alonso, Hector

    Regular polysemy has received a lot of attention from the theory of lexical semantics and from computational linguistics. However, there is no consensus on how to represent the sense of underspecified examples at the token level, namely when annotating or disambiguating senses of metonymic words...

  2. Effect of Carbon Distribution During the Microstructure Evolution of Dual-Phase Steels Studied Using Cellular Automata, Genetic Algorithms, and Experimental Strategies

    Science.gov (United States)

    Halder, Chandan; Karmakar, Anish; Hasan, Sk. Md.; Chakrabarti, Debalay; Pietrzyk, Maciej; Chakraborti, Nirupam

    2016-12-01

    The development of ferrite-martensite dual-phase microstructures by cold-rolling and intercritical annealing of 0.06 wt pct carbon steel was systematically studied using a dilatometer for two different heating rates (1 and 10 K/s). A step quenching treatment has been designed to develop dual-phase structures having a similar martensite fraction for two different heating rates. An increase in heating rate seemed to refine the ferrite grain size, but it increased the size and spacing of the martensitic regions. As a result, the strength of the steel increased with heating rate; however, the formability was affected. It has been concluded that the distribution of C during the annealing treatment of cold-rolled steel determines the size, distribution, and morphology of martensite, which ultimately influences the mechanical properties. Experimental detection of carbon distribution in austenite is difficult during annealing of the cold-rolled steel as the phase transformation occurs at a high temperature and C is an interstitial solute, which diffuses fast at that temperature. Therefore, a cellular automata (CA)-based phase transformation model is proposed in the present study for the prediction of C distribution in austenite during annealing of steel as the function of C content and heating rate. The CA model predicts that the carbon distribution in austenite becomes more inhomogeneous when the heating rate increases. In the CA model, the extent of carbon inhomogeneity is measured using a kernel averaging method for different orders of neighbors, which accounts for the different physical space during calculation. The obtained results reveal that the 10th order (covering 10- µm physical spaces around the cell of interest) is showing the maximum inhomogeneity of carbon and the same effect has been investigated and confirmed using auger electron spectroscopy (AES) for 0.06 wt pct carbon steel. Furthermore, the optimization of carbon homogeneity with respect to heating

  3. Multiple graph regularized protein domain ranking

    KAUST Repository

    Wang, Jim Jing-Yan

    2012-11-19

    Background: Protein domain ranking is a fundamental task in structural biology. Most protein domain ranking methods rely on the pairwise comparison of protein domains while neglecting the global manifold structure of the protein domain database. Recently, graph regularized ranking that exploits the global structure of the graph defined by the pairwise similarities has been proposed. However, the existing graph regularized ranking methods are very sensitive to the choice of the graph model and parameters, and this remains a difficult problem for most of the protein domain ranking methods.Results: To tackle this problem, we have developed the Multiple Graph regularized Ranking algorithm, MultiG-Rank. Instead of using a single graph to regularize the ranking scores, MultiG-Rank approximates the intrinsic manifold of protein domain distribution by combining multiple initial graphs for the regularization. Graph weights are learned with ranking scores jointly and automatically, by alternately minimizing an objective function in an iterative algorithm. Experimental results on a subset of the ASTRAL SCOP protein domain database demonstrate that MultiG-Rank achieves a better ranking performance than single graph regularized ranking methods and pairwise similarity based ranking methods.Conclusion: The problem of graph model and parameter selection in graph regularized protein domain ranking can be solved effectively by combining multiple graphs. This aspect of generalization introduces a new frontier in applying multiple graphs to solving protein domain ranking applications. 2012 Wang et al; licensee BioMed Central Ltd.

  4. Sparse structure regularized ranking

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-04-17

    Learning ranking scores is critical for the multimedia database retrieval problem. In this paper, we propose a novel ranking score learning algorithm by exploring the sparse structure and using it to regularize ranking scores. To explore the sparse structure, we assume that each multimedia object could be represented as a sparse linear combination of all other objects, and combination coefficients are regarded as a similarity measure between objects and used to regularize their ranking scores. Moreover, we propose to learn the sparse combination coefficients and the ranking scores simultaneously. A unified objective function is constructed with regard to both the combination coefficients and the ranking scores, and is optimized by an iterative algorithm. Experiments on two multimedia database retrieval data sets demonstrate the significant improvements of the propose algorithm over state-of-the-art ranking score learning algorithms.

  5. Regularized Reduced Order Models

    CERN Document Server

    Wells, David; Xie, Xuping; Iliescu, Traian

    2015-01-01

    This paper puts forth a regularization approach for the stabilization of proper orthogonal decomposition (POD) reduced order models (ROMs) for the numerical simulation of realistic flows. Two regularized ROMs (Reg-ROMs) are proposed: the Leray ROM (L-ROM) and the evolve-then-filter ROM (EF-ROM). These new Reg-ROMs use spatial filtering to smooth (regularize) various terms in the ROMs. Two spatial filters are used: a POD projection onto a POD subspace (Proj) and a new POD differential filter (DF). The four Reg-ROM/filter combinations are tested in the numerical simulation of the one-dimensional Burgers equation with a small diffusion coefficient and the three-dimensional flow past a circular cylinder at a low Reynolds number (Re = 100). Overall, the most accurate Reg-ROM/filter combination is EF-ROM-DF. Furthermore, the DF generally yields better results than Proj. Finally, the four Reg-ROM/filter combinations are computationally efficient and generally more accurate than the standard Galerkin ROM.

  6. Regularizing portfolio optimization

    Science.gov (United States)

    Still, Susanne; Kondor, Imre

    2010-07-01

    The optimization of large portfolios displays an inherent instability due to estimation error. This poses a fundamental problem, because solutions that are not stable under sample fluctuations may look optimal for a given sample, but are, in effect, very far from optimal with respect to the average risk. In this paper, we approach the problem from the point of view of statistical learning theory. The occurrence of the instability is intimately related to over-fitting, which can be avoided using known regularization methods. We show how regularized portfolio optimization with the expected shortfall as a risk measure is related to support vector regression. The budget constraint dictates a modification. We present the resulting optimization problem and discuss the solution. The L2 norm of the weight vector is used as a regularizer, which corresponds to a diversification 'pressure'. This means that diversification, besides counteracting downward fluctuations in some assets by upward fluctuations in others, is also crucial because it improves the stability of the solution. The approach we provide here allows for the simultaneous treatment of optimization and diversification in one framework that enables the investor to trade off between the two, depending on the size of the available dataset.

  7. The UL24 protein of herpes simplex virus 1 affects the sub-cellular distribution of viral glycoproteins involved in fusion.

    Science.gov (United States)

    Ben Abdeljelil, Nawel; Rochette, Pierre-Alexandre; Pearson, Angela

    2013-09-01

    Mutations in UL24 of herpes simplex virus type 1 can lead to a syncytial phenotype. We hypothesized that UL24 affects the sub-cellular distribution of viral glycoproteins involved in fusion. In non-immortalized human foreskin fibroblasts (HFFs) we detected viral glycoproteins B (gB), gD, gH and gL present in extended blotches throughout the cytoplasm with limited nuclear membrane staining; however, in HFFs infected with a UL24-deficient virus (UL24X), staining for the viral glycoproteins appeared as long, thin streaks running across the cell. Interestingly, there was a decrease in co-localized staining of gB and gD with F-actin at late times in UL24X-infected HFFs. Treatment with chemical agents that perturbed the actin cytoskeleton hindered the formation of UL24X-induced syncytia in these cells. These data support a model whereby the UL24 syncytial phenotype results from a mislocalization of viral glycoproteins late in infection.

  8. k-Walk-Regular Digraphs

    Institute of Scientific and Technical Information of China (English)

    Wen LIU; Jing LIN

    2011-01-01

    In this paper,we define a class of strongly connected digraph,called the k-walk-regular digraph,study some properties of it,provide its some algebraic characterization and point out that the O-walk-regular digraph is the same as the walk-regular digraph discussed BY Liu and Lin in 2010 and the D-walk-regular digraph is identical with the weakly distance-regular digraph defined by Comellas et al in 2004.

  9. 茭白对铬的吸收积累及其亚细胞分布%Cr Accumulation and Sub-cellular Distribution in Zizania latifolia

    Institute of Scientific and Technical Information of China (English)

    朱四喜; 王凤友; 刘文; 史云勋; 杨秀琴; 吴云杰

    2014-01-01

    为茭白在水体铬污染修复的运用提供科学依据,在模拟小型湿地试验系统中,用不同浓度(0,5 mg/L,10 mg/L,20 mg/L,40 mg/L,60 mg/L)的含铬(Ⅵ)废水进行污染胁迫,研究在不同 Cr(Ⅵ)浓度处理下,茭白的生长状况、各器官中铬的含量与积累量及其亚细胞的分布特征。结果表明,不同铬浓度处理下,茭白各器官生物量表现为根>叶>茎,且在铬胁迫浓度为20 mg/L时,株高、根长、生物量均较大;相同 Cr浓度胁迫下,不同器官中铬含量不同,总趋势为茎>根>叶;茭白对铬的耐性指数与转运系数均较高,且在20 mg/L时最高;茭白各器官亚细胞中铬分布总趋势为胞液>细胞壁>细胞器。结论:茭白对低浓度(0~20 mg/L)水体铬污染具有较强的积累力、转运力和耐受力,在水体铬污染植物修复中具有一定的应用价值。%Z.latifolia plants were cultivated in waste water with different Cr concentrations to study their growth status,Cr accumulation in different organs and sub-cellular distribution characteristics under different Cr stress and to provide the scientific basis for phytoremediation of;Z.latifolia in Cr pollution of water.The biomass of different organs was root leaf stem under different Cr concentrations and Z. latifolia had higher height,root length and biomass when Cr concentration was 20mg/L.The general trend of Cr content and Cr accumulation in different organs was stem root leaf and root stem leaf under the same Cr concentration.Z.latifolia had higher Cr tolerance index and transfer coefficient and the Cr tolerance index and transfer coefficient was up to the highest when Cr concentration was 20mg/L.Cr was distributed in cell wall and cytosol mainly and the general trend of Cr distribution in sub-cellular level was cytosol cell wall organelle.In conclusion,Z.latifolia with the strong accumulation ability,transfer ability and tolerance

  10. Annotation of Regular Polysemy

    DEFF Research Database (Denmark)

    Martinez Alonso, Hector

    Regular polysemy has received a lot of attention from the theory of lexical semantics and from computational linguistics. However, there is no consensus on how to represent the sense of underspecified examples at the token level, namely when annotating or disambiguating senses of metonymic words...... like “London” (Location/Organization) or “cup” (Container/Content). The goal of this dissertation is to assess whether metonymic sense underspecification justifies incorporating a third sense into our sense inventories, thereby treating the underspecified sense as independent from the literal...

  11. Annotation of regular polysemy and underspecification

    DEFF Research Database (Denmark)

    Martínez Alonso, Héctor; Pedersen, Bolette Sandford; Bel, Núria

    2013-01-01

    We present the result of an annotation task on regular polysemy for a series of seman- tic classes or dot types in English, Dan- ish and Spanish. This article describes the annotation process, the results in terms of inter-encoder agreement, and the sense distributions obtained with two methods...

  12. From regular modules to von Neumann regular rings via coordinatization

    Directory of Open Access Journals (Sweden)

    Leonard Daus

    2014-07-01

    Full Text Available In this paper we establish a very close link (in terms of von Neu- mann's coordinatization between regular modules introduced by Zel- manowitz, on one hand, and von Neumann regular rings, on the other hand: we prove that the lattice L^{fg}(M of all finitely generated submodules of a finitely generated regular module M, over an arbitrary ring, can be coordinatized as the lattice of all principal right ideals of some von Neumann regular ring S.

  13. Modular Regularization Algorithms

    DEFF Research Database (Denmark)

    Jacobsen, Michael

    2004-01-01

    The class of linear ill-posed problems is introduced along with a range of standard numerical tools and basic concepts from linear algebra, statistics and optimization. Known algorithms for solving linear inverse ill-posed problems are analyzed to determine how they can be decomposed into indepen......The class of linear ill-posed problems is introduced along with a range of standard numerical tools and basic concepts from linear algebra, statistics and optimization. Known algorithms for solving linear inverse ill-posed problems are analyzed to determine how they can be decomposed...... into independent modules. These modules are then combined to form new regularization algorithms with other properties than those we started out with. Several variations are tested using the Matlab toolbox MOORe Tools created in connection with this thesis. Object oriented programming techniques are explained...... and used to set up the illposed problems in the toolbox. Hereby, we are able to write regularization algorithms that automatically exploit structure in the ill-posed problem without being rewritten explicitly. We explain how to implement a stopping criteria for a parameter choice method based upon...

  14. Structure for Regular Inclusions

    CERN Document Server

    Pitts, David R

    2012-01-01

    We study pairs (C,D) of unital C*-algebras where D is an abelian C*-subalgebra of C which is regular in C. When D is a MASA in C, there exists a unique completely positive unital map E of C into the injective envelope I(D) of D whose restriction to D is the identity on D. We show that the left kernel of E is the unique closed two-sided ideal of C maximal with respect to having trivial intersection with D. We introduce a new class of well behaved state extensions, the compatible states; we identify compatible states when D is a MASA in C in terms of groups constructed from local dynamics near a pure state on D. When C is separable, D is a MASA in C, and the pair (C,D) is regular, the set of pure states on D with unique state extensions to C is dense in D. The map E can be used as a substitute for a conditional expectation in the construction of coordinates for C relative to D. We show that certain classes of compatible states have natural groupoid operations, and we show that constructions of Kumjian and Renau...

  15. Immunohistochemical cellular distribution of proteins related to M phase regulation in early proliferative lesions induced by tumor promotion in rat two-stage carcinogenesis models.

    Science.gov (United States)

    Yafune, Atsunori; Taniai, Eriko; Morita, Reiko; Akane, Hirotoshi; Kimura, Masayuki; Mitsumori, Kunitoshi; Shibutani, Makoto

    2014-01-01

    We have previously reported that 28-day treatment with hepatocarcinogens increases liver cells expressing p21(Cip1), a G1/S checkpoint protein, and M phase proteins, i.e., nuclear Cdc2, Aurora B, phosphorylated-Histone H3 (p-Histone H3) and heterochromatin protein 1α (HP1α), in rats. To examine the roles of these markers in the early stages of carcinogenesis, we investigated their cellular distribution in several carcinogenic target organs using rat two-stage carcinogenesis models. Promoting agents targeting the liver (piperonyl butoxide and methapyrilene hydrochloride), thyroid (sulfadimethoxine), urinary bladder (phenylethyl isothiocyanate), and forestomach and glandular stomach (catechol) were administered to rats after initiation treatment for the liver with N-diethylnitrosamine, thyroid with N-bis(2-hydroxypropyl)nitrosamine, urinary bladder with N-butyl-N-(4-hydroxybutyl)nitrosamine, and forestomach and glandular stomach with N-methyl-N'-nitro-N-nitrosoguanidine. Numbers of cells positive for nuclear Cdc2, Aurora B, p-Histone H3 and HP1α increased within preneoplastic lesions as determined by glutathione S-transferase placental form in the liver or phosphorylated p44/42 mitogen-activated protein kinase in the thyroid, and hyperplastic lesions having no known preneoplastic markers in the urinary bladder, forestomach and glandular stomach. Immunoreactive cells for p21(Cip1) were decreased within thyroid preneoplastic lesions; however, they were increased within liver preneoplastic lesions and hyperplastic lesions in other organs. These results suggest that M phase disruption commonly occur during the formation of preneoplastic lesions and hyperplastic lesions. Differences in the expression patterns of p21(Cip1) between thyroid preneoplastic and proliferative lesions in other organs may reflect differences in cell cycle regulation involving G1/S checkpoint function between proliferative lesions in each organ.

  16. THE RELATIONSHIPS OF THREE ELEMENTARY CELLULAR AUTOMATA

    Institute of Scientific and Technical Information of China (English)

    Zhisong JIANG

    2006-01-01

    Limit language complexity of cellular automata which is first posed by S. Wolfram has become a new branch of cellular automata. In this paper, we obtain two interesting relationships between elementary cellular automata of rules 126, 146(182) and 18, and prove that if the limit language of rule 18 is not regular, nor are the limit languages of rules 126 and 146(182).

  17. Cellular Telephone

    Institute of Scientific and Technical Information of China (English)

    杨周

    1996-01-01

    Cellular phones, used in automobiles, airliners, and passenger trains, are basically low-power radiotelephones. Calls go through radio transmitters that are located within small geographical units called cells. Because each cell’s signals are too weak to interfere with those of other cells operating on the same fre-

  18. Occurrence Regularity and Distributions of Tobacco Root-knot Nematodes in Wenshan%文山州烟草根结线虫发生规律及分布研究

    Institute of Scientific and Technical Information of China (English)

    余清; 刘月静

    2013-01-01

    [目的]了解文山州旱地土壤根结线虫的分布及发生流行趋势.[方法]调查和分析了不同作物土壤中根结线虫的发生密度和分布状况.[结果]土壤中根结线虫的发生密度与种植作物种类密切相关,种植烤烟的地块根结线虫密度在烤烟生长季节呈直线上升趋势,与烤烟生育期呈极显著正相关,线虫密度由5月中旬的437.73条/kg干土上升为9月中旬的2 205.93条/kg干土,增幅达403.95%,而种植玉米、辣椒地块根结线虫密度在作物整个生长季节变化较小.文山州文山、广南、麻栗坡、丘北、砚山县旱地土壤中根结线虫数量较多且分布广泛,线虫密度多在200~ 800条/kg干土.根结线虫在0~100 cm的土壤中均有分布,且主要集中在0~40cm的耕作层中,40 cm以下随着土层的加深根结线虫数量逐渐减少.[结论]为烤烟种植规划、抗病品种选择及根结线虫的防治提供了理论依据.%[Objective] The aim was to understand the occurrence regularity and distributions of tobacco root-knot nematodes in Wenshan.[Method] An investigation and analysis of the different crops root knot nematodes was carried out in the soil density and distribution.[Result]The density of root-knot nematodes in soil be bound up with plant crops species.In flue-cured tobacco growing season that the density of rootknot nematodes was increasing rapidly in planting flue-cured tobacco field,and positive correlation was found between density of root-knot nematodes and flue-cured tobacco growth season.The density of nematodes from 437.73 individuals/(kg dry soil) in the middle of May increased to 2 205.93 individuals/(kg dry soil) in the middle of September and it,s increase rate was 403.95%,but the density of root-knot nematodes in planting maize and hot pepper fields changed smaller during crops growing season.The results of general investigation for Wenshan,Guangnan,Malipo,Qiubai and Yanshan county indicated that the number

  19. Evolutionary internalized regularities.

    Science.gov (United States)

    Schwartz, R

    2001-08-01

    Roger Shepard's proposals and supporting experiments concerning evolutionary internalized regularities have been very influential in the study of vision and in other areas of psychology and cognitive science. This paper examines issues concerning the need, nature, explanatory role, and justification for postulating such internalized constraints. In particular, I seek further clarification from Shepard on how best to understand his claim that principles of kinematic geometry underlie phenomena of motion perception. My primary focus is on the ecological validity of Shepard's kinematic constraint in the context of ordinary motion perception. First, I explore the analogy Shepard draws between internalized circadian rhythms and the supposed internalization of kinematic geometry. Next, questions are raised about how to interpret and justify applying results from his own and others' experimental studies of apparent motion to more everyday cases of motion perception in richer environments. Finally, some difficulties with Shepard's account of the evolutionary development of his kinematic constraint are considered.

  20. Adaptive Regularization of Neural Classifiers

    DEFF Research Database (Denmark)

    Andersen, Lars Nonboe; Larsen, Jan; Hansen, Lars Kai

    1997-01-01

    We present a regularization scheme which iteratively adapts the regularization parameters by minimizing the validation error. It is suggested to use the adaptive regularization scheme in conjunction with optimal brain damage pruning to optimize the architecture and to avoid overfitting. Furthermo...

  1. Learning Rates for -Regularized Kernel Classifiers

    Directory of Open Access Journals (Sweden)

    Hongzhi Tong

    2013-01-01

    Full Text Available We consider a family of classification algorithms generated from a regularization kernel scheme associated with -regularizer and convex loss function. Our main purpose is to provide an explicit convergence rate for the excess misclassification error of the produced classifiers. The error decomposition includes approximation error, hypothesis error, and sample error. We apply some novel techniques to estimate the hypothesis error and sample error. Learning rates are eventually derived under some assumptions on the kernel, the input space, the marginal distribution, and the approximation error.

  2. Clinical Study of Regularities in Sinew Lesion Distribution in Knee Osteoarthritis%膝骨关节炎经筋病变分布规律的临床研究

    Institute of Scientific and Technical Information of China (English)

    岳建兴; 陈莉秋; 张春侠; 刘立飞

    2016-01-01

    目的:探寻膝骨关节炎患者经筋病变分布的基本规律。方法选择230例膝骨关节炎患者253个患膝,以经筋理论为指导,采用触诊法,统计经筋病灶点在膝关节周围出现的部位及频次。结果在病灶点的分布上,足阳明出现的总频次占39.1%,其中单一足阳明经筋型占23.3%,复合型占48.5%。足太阳出现的总频次占32.4%,其中单一足太阳经筋型占21.3%,复合型占44.5%。足阳明经筋+足太阳经筋病变占14.6%,单一足三阴经筋型占15.0%。结论对于足阳明、足太阳经筋型膝骨关节炎的治疗,应该多从“筋”论治。%Objective To explore basic regularities in sinew lesion distribution in patients with knee osteoarthritis. Method Two hundred and thirty knee osteoarthritis patients with 253 affected knees were selected. Under the sinew theory, the positions and frequency of sinew foci around the knee joint were counted by palpation. Result In the distribution of foci, the total frequency accounted for 39.1% in the Foot-Yangming. Of them, the single Foot-Yangming sinew type accounted for 23.3% and the complex type accounted for 48.5%. The total frequency accounted for 32.4% in the Foot-Taiyang. Of them, the single Foot-Taiyang sinew type accounted for 21.3%, the complex type accounted for 44.5%. The Foot-Yangming + Foot-Taiyang sinew lesions accounted for 14.6% and the single foot-three-yin sinew type accounted for 15.0%. Conclusion Knee osteoarthritis of Foot-Yangming or Foot-Taiyang sinew type should be treated from “sinew”.

  3. Analysis of reservoir forming factors and distribution regularities of North Gabon sub-basin%北加蓬次盆成藏要素分析与油气分布规律

    Institute of Scientific and Technical Information of China (English)

    房大志; 张建球; 郑绍贵; 杨媛媛

    2012-01-01

    By comprehensive study on the regional tectonic setting, reservior-forming factors and distribution regularities of North Gabon sub-basin, it is considered to be a rift and passive continental margin superimposed basin, in which four sedimentary forma-tions were developed: pre-rift period, rift period, transition period and drift period. At present, North sub-basin, in which a number of oilfields are found and large hydrocarbon resources and high yield are proved to be, is proved to have a better hydrocarbon accu-mulation conditions. The conditions have post-salt Azile-Anguille shale as the main mother rock for hydrocarbon generation, and large deep-water turbidite fan body as a good reservoirs. The activities of salt rocks have generated a series of salt structure which become the most important traps for hydrocarbon accumulation. The oil and gas reserviors are mainly structural type and mainly dis-tributed in the sea which are controlled by Senomian turbidite fan sand bodies vertically.%通过对北加蓬次盆区域构造背景的研究,综合分析各成藏要素条件,结合油气田类型、平面及纵向上的分布,认为北加蓬次盆地是典型的裂谷和被动大陆边缘叠合盆地,发育裂谷前、裂谷、过渡阶段和漂移阶段4套沉积地层。目前北次盆已发现油田数量多,已探明油气资源量较大且产量较高,证实具备较好的油气成藏条件:其中盐上Azile-Anguille组海相页岩为主力优质源岩,大型深水浊积扇体作为有利储层。盐岩活动形成了一系列盐构造作为规模型油气聚集圈闭。目前已发现油气田以构造型为主,油气田主要分布在海上,纵向上油气主要分布在森诺期浊积扇砂体。

  4. Extreme values, regular variation and point processes

    CERN Document Server

    Resnick, Sidney I

    1987-01-01

    Extremes Values, Regular Variation and Point Processes is a readable and efficient account of the fundamental mathematical and stochastic process techniques needed to study the behavior of extreme values of phenomena based on independent and identically distributed random variables and vectors It presents a coherent treatment of the distributional and sample path fundamental properties of extremes and records It emphasizes the core primacy of three topics necessary for understanding extremes the analytical theory of regularly varying functions; the probabilistic theory of point processes and random measures; and the link to asymptotic distribution approximations provided by the theory of weak convergence of probability measures in metric spaces The book is self-contained and requires an introductory measure-theoretic course in probability as a prerequisite Almost all sections have an extensive list of exercises which extend developments in the text, offer alternate approaches, test mastery and provide for enj...

  5. Landweber iterative regularization for nearfield acoustic holography

    Institute of Scientific and Technical Information of China (English)

    BI Chuanxing; CHEN Xinzhao; ZHOU Rong; CHEN Jian

    2006-01-01

    On the basis of the distributed source boundary point method (DSBPM)-based nearfield acoustic holography (NAH), Landweber iterative regularization method is proposed to stabilize the NAH reconstruction process, control the influence of measurement errors on the reconstructed results and ensure the validity of the reconstructed results. And a new method, the auxiliary surface method, is proposed to determine the optimal iterative number for optimizing the regularization effect. Here, the optimal number is determined by minimizing the relative error between the calculated pressure on the auxiliary surface corresponding to each iterative number and the measured pressure. An experiment on a speaker is investigated to demonstrate the high sensitivity of the reconstructed results to measurement errors and to validate the chosen method of the optimal iterative number and the Landweber iterative regularization method for controlling the influence of measurement errors on the reconstructed results.

  6. A novel combined regularization algorithm of total variation and Tikhonov regularization for open electrical impedance tomography.

    Science.gov (United States)

    Liu, Jinzhen; Ling, Lin; Li, Gang

    2013-07-01

    A Tikhonov regularization method in the inverse problem of electrical impedance tomography (EIT) often results in a smooth distribution reconstruction, with which we can barely make a clear separation between the inclusions and background. The recently popular total variation (TV)regularization method including the lagged diffusivity (LD) method can sharpen the edges, and is robust to noise in a small convergence region. Therefore, in this paper, we propose a novel regularization method combining the Tikhonov and LD regularization methods. Firstly, we clarify the implementation details of the Tikhonov, LD and combined methods in two-dimensional open EIT by performing the current injection and voltage measurement on one boundary of the imaging object. Next, we introduce a weighted parameter to the Tikhonov regularization method aiming to explore the effect of the weighted parameter on the resolution and quality of reconstruction images with the inclusion at different depths. Then, we analyze the performance of these algorithms with noisy data. Finally, we evaluate the effect of the current injection pattern on reconstruction quality and propose a modified current injection pattern.The results indicate that the combined regularization algorithm with stable convergence is able to improve the reconstruction quality with sharp contrast and more robust to noise in comparison to the Tikhonov and LD regularization methods solely. In addition, the results show that the current injection pattern with a bigger driver angle leads to a better reconstruction quality.

  7. Rotating regular black holes

    CERN Document Server

    Bambi, Cosimo

    2013-01-01

    The formation of spacetime singularities is a quite common phenomenon in General Relativity and it is regulated by specific theorems. It is widely believed that spacetime singularities do not exist in Nature, but that they represent a limitation of the classical theory. While we do not yet have any solid theory of quantum gravity, toy models of black hole solutions without singularities have been proposed. So far, there are only non-rotating regular black holes in the literature. These metrics can be hardly tested by astrophysical observations, as the black hole spin plays a fundamental role in any astrophysical process. In this letter, we apply the Newman-Janis algorithm to the Hayward and to the Bardeen black hole metrics. In both cases, we obtain a family of rotating solutions. Every solution corresponds to a different matter configuration. Each family has one solution with special properties, which can be written in Kerr-like form in Boyer-Lindquist coordinates. These special solutions are of Petrov type ...

  8. Rotating regular black holes

    Energy Technology Data Exchange (ETDEWEB)

    Bambi, Cosimo, E-mail: bambi@fudan.edu.cn; Modesto, Leonardo, E-mail: lmodesto@fudan.edu.cn

    2013-04-25

    The formation of spacetime singularities is a quite common phenomenon in General Relativity and it is regulated by specific theorems. It is widely believed that spacetime singularities do not exist in Nature, but that they represent a limitation of the classical theory. While we do not yet have any solid theory of quantum gravity, toy models of black hole solutions without singularities have been proposed. So far, there are only non-rotating regular black holes in the literature. These metrics can be hardly tested by astrophysical observations, as the black hole spin plays a fundamental role in any astrophysical process. In this Letter, we apply the Newman–Janis algorithm to the Hayward and to the Bardeen black hole metrics. In both cases, we obtain a family of rotating solutions. Every solution corresponds to a different matter configuration. Each family has one solution with special properties, which can be written in Kerr-like form in Boyer–Lindquist coordinates. These special solutions are of Petrov type D, they are singularity free, but they violate the weak energy condition for a non-vanishing spin and their curvature invariants have different values at r=0 depending on the way one approaches the origin. We propose a natural prescription to have rotating solutions with a minimal violation of the weak energy condition and without the questionable property of the curvature invariants at the origin.

  9. Ensemble manifold regularization.

    Science.gov (United States)

    Geng, Bo; Tao, Dacheng; Xu, Chao; Yang, Linjun; Hua, Xian-Sheng

    2012-06-01

    We propose an automatic approximation of the intrinsic manifold for general semi-supervised learning (SSL) problems. Unfortunately, it is not trivial to define an optimization function to obtain optimal hyperparameters. Usually, cross validation is applied, but it does not necessarily scale up. Other problems derive from the suboptimality incurred by discrete grid search and the overfitting. Therefore, we develop an ensemble manifold regularization (EMR) framework to approximate the intrinsic manifold by combining several initial guesses. Algorithmically, we designed EMR carefully so it 1) learns both the composite manifold and the semi-supervised learner jointly, 2) is fully automatic for learning the intrinsic manifold hyperparameters implicitly, 3) is conditionally optimal for intrinsic manifold approximation under a mild and reasonable assumption, and 4) is scalable for a large number of candidate manifold hyperparameters, from both time and space perspectives. Furthermore, we prove the convergence property of EMR to the deterministic matrix at rate root-n. Extensive experiments over both synthetic and real data sets demonstrate the effectiveness of the proposed framework.

  10. Regular Bisimple ω2-semigroups

    Institute of Scientific and Technical Information of China (English)

    汪立民; 商宇

    2008-01-01

    @@ The regular semigroups S with an idempotent set Es = {e0,e1,…,en,…} such that e0 > e1 >…> en >… is called a regular ω-semigroup. In [5] Reilly determined the structure of a regular bisimple ω-semigroup as BR(G,θ),which is the classical Bruck-Reilly extension of a group G.

  11. Completely regular fuzzifying topological spaces

    Directory of Open Access Journals (Sweden)

    A. K. Katsaras

    2005-12-01

    Full Text Available Some of the properties of the completely regular fuzzifying topological spaces are investigated. It is shown that a fuzzifying topology τ is completely regular if and only if it is induced by some fuzzy uniformity or equivalently by some fuzzifying proximity. Also, τ is completely regular if and only if it is generated by a family of probabilistic pseudometrics.

  12. Regularities of Distribution and Infection of Human Papillomavirus among Patients with Cervical Cancer%宫颈癌患者人乳头状瘤病毒(HPV)感染情况及分布规律

    Institute of Scientific and Technical Information of China (English)

    叶芬; 张慧丽

    2015-01-01

    are regional differences. And HPV genotype distri-bution of the observed objects meets the regularities of distribution in Asia. Furthermore, HPV vaccine should be strengthened the research for HPV52 and HPV58 genotype to improve preventive ability of vaccine for Chinese women to against cervical cancer.

  13. On regular rotating black holes

    Science.gov (United States)

    Torres, R.; Fayos, F.

    2017-01-01

    Different proposals for regular rotating black hole spacetimes have appeared recently in the literature. However, a rigorous analysis and proof of the regularity of this kind of spacetimes is still lacking. In this note we analyze rotating Kerr-like black hole spacetimes and find the necessary and sufficient conditions for the regularity of all their second order scalar invariants polynomial in the Riemann tensor. We also show that the regularity is linked to a violation of the weak energy conditions around the core of the rotating black hole.

  14. Constrained and regularized system identification

    Directory of Open Access Journals (Sweden)

    Tor A. Johansen

    1998-04-01

    Full Text Available Prior knowledge can be introduced into system identification problems in terms of constraints on the parameter space, or regularizing penalty functions in a prediction error criterion. The contribution of this work is mainly an extension of the well known FPE (Final Production Error statistic to the case when the system identification problem is constrained and contains a regularization penalty. The FPECR statistic (Final Production Error with Constraints and Regularization is of potential interest as a criterion for selection of both regularization parameters and structural parameters such as order.

  15. On regular rotating black holes

    CERN Document Server

    Torres, Ramon

    2016-01-01

    Different proposals for regular rotating black hole spacetimes have appeared recently in the literature. However, a rigorous analysis and proof of the regularity of this kind of spacetimes is still lacking. In this note we analyze rotating Kerr-like black hole spacetimes and find the necessary and sufficient conditions for the regularity of all their second order scalar invariants polynomial in the Riemann tensor. We also show that the regularity is linked to a violation of the weak energy conditions around the core of the rotating black hole.

  16. On Ideals of Regular Rings

    Institute of Scientific and Technical Information of China (English)

    CHEN Huan Yin; LI Fu An

    2002-01-01

    In this paper, we investigate ideals of regular rings and give several characterizations for an ideal to satisfy the comparability. In addition, it is shown that, if Ⅰ is a minimal two-sided ideal of a regular ring R, then Ⅰ satisfies the comparability if and only if Ⅰ is separative. Furthermore, we prove that, for ideals with stable range one, Roth's problem has an affirmative solution. These extend the corresponding results on unit-regularity and one-sided unit-regularity.

  17. Full L1-regularized Traction Force Microscopy over whole cells.

    Science.gov (United States)

    Suñé-Auñón, Alejandro; Jorge-Peñas, Alvaro; Aguilar-Cuenca, Rocío; Vicente-Manzanares, Miguel; Van Oosterwyck, Hans; Muñoz-Barrutia, Arrate

    2017-08-10

    Traction Force Microscopy (TFM) is a widespread technique to estimate the tractions that cells exert on the surrounding substrate. To recover the tractions, it is necessary to solve an inverse problem, which is ill-posed and needs regularization to make the solution stable. The typical regularization scheme is given by the minimization of a cost functional, which is divided in two terms: the error present in the data or data fidelity term; and the regularization or penalty term. The classical approach is to use zero-order Tikhonov or L2-regularization, which uses the L2-norm for both terms in the cost function. Recently, some studies have demonstrated an improved performance using L1-regularization (L1-norm in the penalty term) related to an increase in the spatial resolution and sensitivity of the recovered traction field. In this manuscript, we present a comparison between the previous two regularization schemes (relying in the L2-norm for the data fidelity term) and the full L1-regularization (using the L1-norm for both terms in the cost function) for synthetic and real data. Our results reveal that L1-regularizations give an improved spatial resolution (more important for full L1-regularization) and a reduction in the background noise with respect to the classical zero-order Tikhonov regularization. In addition, we present an approximation, which makes feasible the recovery of cellular tractions over whole cells on typical full-size microscope images when working in the spatial domain. The proposed full L1-regularization improves the sensitivity to recover small stress footprints. Moreover, the proposed method has been validated to work on full-field microscopy images of real cells, what certainly demonstrates it is a promising tool for biological applications.

  18. Regularly timed events amid chaos

    Science.gov (United States)

    Blakely, Jonathan N.; Cooper, Roy M.; Corron, Ned J.

    2015-11-01

    We show rigorously that the solutions of a class of chaotic oscillators are characterized by regularly timed events in which the derivative of the solution is instantaneously zero. The perfect regularity of these events is in stark contrast with the well-known unpredictability of chaos. We explore some consequences of these regularly timed events through experiments using chaotic electronic circuits. First, we show that a feedback loop can be implemented to phase lock the regularly timed events to a periodic external signal. In this arrangement the external signal regulates the timing of the chaotic signal but does not strictly lock its phase. That is, phase slips of the chaotic oscillation persist without disturbing timing of the regular events. Second, we couple the regularly timed events of one chaotic oscillator to those of another. A state of synchronization is observed where the oscillators exhibit synchronized regular events while their chaotic amplitudes and phases evolve independently. Finally, we add additional coupling to synchronize the amplitudes, as well, however in the opposite direction illustrating the independence of the amplitudes from the regularly timed events.

  19. Online co-regularized algorithms

    NARCIS (Netherlands)

    Ruijter, T. de; Tsivtsivadze, E.; Heskes, T.

    2012-01-01

    We propose an online co-regularized learning algorithm for classification and regression tasks. We demonstrate that by sequentially co-regularizing prediction functions on unlabeled data points, our algorithm provides improved performance in comparison to supervised methods on several UCI benchmarks

  20. Online co-regularized algorithms

    NARCIS (Netherlands)

    Ruijter, T. de; Tsivtsivadze, E.; Heskes, T.

    2012-01-01

    We propose an online co-regularized learning algorithm for classification and regression tasks. We demonstrate that by sequentially co-regularizing prediction functions on unlabeled data points, our algorithm provides improved performance in comparison to supervised methods on several UCI benchmarks

  1. Nonconvex Regularization in Remote Sensing

    Science.gov (United States)

    Tuia, Devis; Flamary, Remi; Barlaud, Michel

    2016-11-01

    In this paper, we study the effect of different regularizers and their implications in high dimensional image classification and sparse linear unmixing. Although kernelization or sparse methods are globally accepted solutions for processing data in high dimensions, we present here a study on the impact of the form of regularization used and its parametrization. We consider regularization via traditional squared (2) and sparsity-promoting (1) norms, as well as more unconventional nonconvex regularizers (p and Log Sum Penalty). We compare their properties and advantages on several classification and linear unmixing tasks and provide advices on the choice of the best regularizer for the problem at hand. Finally, we also provide a fully functional toolbox for the community.

  2. Conservative regularization of compressible flow

    CERN Document Server

    Krishnaswami, Govind S; Thyagaraja, Anantanarayanan

    2015-01-01

    Ideal Eulerian flow may develop singularities in vorticity w. Navier-Stokes viscosity provides a dissipative regularization. We find a local, conservative regularization - lambda^2 w times curl(w) of compressible flow and compressible MHD: a three dimensional analogue of the KdV regularization of the one dimensional kinematic wave equation. The regulator lambda is a field subject to the constitutive relation lambda^2 rho = constant. Lambda is like a position-dependent mean-free path. Our regularization preserves Galilean, parity and time-reversal symmetries. We identify locally conserved energy, helicity, linear and angular momenta and boundary conditions ensuring their global conservation. Enstrophy is shown to remain bounded. A swirl velocity field is identified, which transports w/rho and B/rho generalizing the Kelvin-Helmholtz and Alfven theorems. A Hamiltonian and Poisson bracket formulation is given. The regularized equations are used to model a rotating vortex, channel flow, plane flow, a plane vortex ...

  3. Approximate Sparse Regularized Hyperspectral Unmixing

    Directory of Open Access Journals (Sweden)

    Chengzhi Deng

    2014-01-01

    Full Text Available Sparse regression based unmixing has been recently proposed to estimate the abundance of materials present in hyperspectral image pixel. In this paper, a novel sparse unmixing optimization model based on approximate sparsity, namely, approximate sparse unmixing (ASU, is firstly proposed to perform the unmixing task for hyperspectral remote sensing imagery. And then, a variable splitting and augmented Lagrangian algorithm is introduced to tackle the optimization problem. In ASU, approximate sparsity is used as a regularizer for sparse unmixing, which is sparser than l1 regularizer and much easier to be solved than l0 regularizer. Three simulated and one real hyperspectral images were used to evaluate the performance of the proposed algorithm in comparison to l1 regularizer. Experimental results demonstrate that the proposed algorithm is more effective and accurate for hyperspectral unmixing than state-of-the-art l1 regularizer.

  4. Regular Small-World Network

    Institute of Scientific and Technical Information of China (English)

    ZOU Zhi-Yun; MAO Bao-Hua; HAO Hai-Ming; GAO Jian-Zhi; YANG Jie-Jiao

    2009-01-01

    According to the deficiencies in Watts and Strogatz's small-world network model, we present a new regular model to establish the small-world network. Besides the property of the small-world, this model has other properties such as accuracy in controlling the average shortest path length L, and the average clustering coefficient C, also regular network topology as well as enhanced network robustness. This method improves the construction of the small-world network essentially, so that the regular small-world network closely resembles the actual network. We also present studies on the relationships among the quantities of a variety of edges, L and C in regular small-world network in detail. This research lays the foundation for the establishment of the regular small-world network and acts as a good guidance for further research of this model and its applications.

  5. Temporal-spatial Distribution Regularities of Forest Fire Casualties in China%我国森林火灾中人员伤亡时空分布特征研究

    Institute of Scientific and Technical Information of China (English)

    杨光; 舒立福; 孙思琦; 邸雪颖; 刘畅

    2015-01-01

    Based on forest fire statistics (2000-2012) and typical cases available in China, and by using statistical analysis method and ARCMAP spatial analysis method, the forest fire statistics with the same period of the countries where the forest fire frequently occurred in the world are compared, and the temporal-spatial distribu-tion regularities of forest fire casualties in China are analyzed.Results indicate that the forest fires caused heavy casualties during the period of 1988-2012 in China, the proportion of forest fire casualties was much higher than that of North America in that period.There were more forest fire casualties in seriously arid years.Spring was high-occurrence seasons for forest fire casualties, and the forest fire casualties of spring account for 54.2% of the total according to the statistics of 2000-2012.March was high-occurrence months for forest fire casualties, and the for-est fire casualties of March account for 33.7% of the total according to the statistics of 1999-2012.The central and southwestern areas were densely injured areas, the forest fire casualties of the southwestern areas account for 35.5%of the total and the forest fire casualties of the center areas account for 24.3%of the total during the period of 2000-2012.The Yunnan and Hunan were densely injured provinces, the forest fire casualties were found most in Yunnan and mainly involving in minor injury, and the number of minor injury casualties in Yunnan account for 73.0%of the total during the period of 2000-2012 .%基于我国1988-2012年森林火灾统计资料及典型案例,运用统计分析方法和ARCMAP空间分析方法,对比同时期世界上几个森林火灾多发国家的统计数据,分析了我国森林火灾中人员伤亡时空特征。结果表明:1988-2012年我国森林火灾造成的人员伤亡情况较为严重,森林火灾中人员伤亡比例远高于同时期的北美国家;森林火灾中人员伤亡高发于干旱严重的年份;春

  6. 急性腹泻中医证候季节性分布规律的临床研究%Clinical Research of Seasonal Distribution Regularity of Chinese Medicine Patterns in Acute Diarrhea

    Institute of Scientific and Technical Information of China (English)

    崔宁; 谢春娥; 李安德; 王晓才; 张秋林

    2011-01-01

    as damp heat pattern,cold damp pattern and food retention in the stomach and intestine pattern. The other patterns accounted for less than 5 %. Damp heat pattern in spring was predominated as compared with that in autumn. Cold damp pattern in winter was dominated as compared with that in spring. Damp heat pattern in summer was more popular than that in autumn. Cold damp pattern in autumn was more common than that in summer. Damp heat pattern in summer and autumn was more prevalent than that in spring and winter. Cold damp pattern in winter and spring were more obvious than that in summer and autumn. Conclusion The synthesis of seasonal distribution regularity of Chinese medicine patterns of acute diarrhea contributes to the analysis of the etiology and pathogenesis for the early stage of acute diarrhea and may provide much more objective evidences for pattern differentiation and treatment of acute diarrhea in terms of traditional Chinese medicine.

  7. A Criterion for Regular Sequences

    Indian Academy of Sciences (India)

    D P Patil; U Storch; J Stückrad

    2004-05-01

    Let be a commutative noetherian ring and $f_1,\\ldots,f_r \\in R$. In this article we give (cf. the Theorem in $\\mathcal{x}$2) a criterion for $f_1,\\ldots,f_r$ to be regular sequence for a finitely generated module over which strengthens and generalises a result in [2]. As an immediate consequence we deduce that if $V(g_1,\\ldots,g_r) \\subseteq V(f_1,\\ldots,f_r)$ in Spec and if $f_1,\\ldots,f_r$ is a regular sequence in , then $g_1,\\ldots,g_r$ is also a regular sequence in .

  8. 5G Ultra-Dense Cellular Networks

    OpenAIRE

    Ge, Xiaohu; Tu, Song; Mao, Guoqiang; Wang, Cheng-xiang; Han, Tao

    2015-01-01

    Traditional ultra-dense wireless networks are recommended as a complement for cellular networks and are deployed in partial areas, such as hotspot and indoor scenarios. Based on the massive multiple-input multi-output (MIMO) antennas and the millimeter wavecommunication technologies, the 5G ultra-dense cellular network is proposed to deploy in overall cellular scenarios. Moreover, a distribution network architecture is presented for 5G ultra-dense cellular networks. Furthermore, the backhaul ...

  9. Multiuser Cellular Network

    CERN Document Server

    Bao, Yi; Chen, Ming

    2011-01-01

    Modern radio communication is faced with a problem about how to distribute restricted frequency to users in a certain space. Since our task is to minimize the number of repeaters, a natural idea is enlarging coverage area. However, coverage has restrictions. First, service area has to be divided economically as repeater's coverage is limited. In this paper, our fundamental method is to adopt seamless cellular network division. Second, underlying physics content in frequency distribution problem is interference between two close frequencies. Consequently, we choose a proper frequency width of 0.1MHz and a relevantly reliable setting to apply one frequency several times. We make a few general assumptions to simplify real situation. For instance, immobile users yield to homogenous distribution; repeaters can receive and transmit information in any given frequency in duplex operation; coverage is mainly decided by antenna height. Two models are built up to solve 1000 users and 10000 users situations respectively....

  10. On Regular Power-Substitution

    Institute of Scientific and Technical Information of China (English)

    Huanyin CHEN

    2009-01-01

    The necessary and sufficient conditions under which a ring satisfies regular power-substitution are investigated. It is shown that a ring R satisfies regular power-substitution if and only if a(-~)b in R implies that there exist n ∈ N and a U ∈ GLn(R) such that aU =Ub if and only if for any regular x ∈ R there exist m,n ∈ N and U ∈ GLn(R) such that xmIn = xmUxm, where a(-~)b means that there exists x, y, z ∈ R such that a = ybx, b = xaz and x = xyx = xzx. It is proved that every directly finite simple ring satisfies regular power-substitution. Some applications for stably free R-modules are also obtained.

  11. Power-law regularities in human language

    Science.gov (United States)

    Mehri, Ali; Lashkari, Sahar Mohammadpour

    2016-11-01

    Complex structure of human language enables us to exchange very complicated information. This communication system obeys some common nonlinear statistical regularities. We investigate four important long-range features of human language. We perform our calculations for adopted works of seven famous litterateurs. Zipf's law and Heaps' law, which imply well-known power-law behaviors, are established in human language, showing a qualitative inverse relation with each other. Furthermore, the informational content associated with the words ordering, is measured by using an entropic metric. We also calculate fractal dimension of words in the text by using box counting method. The fractal dimension of each word, that is a positive value less than or equal to one, exhibits its spatial distribution in the text. Generally, we can claim that the Human language follows the mentioned power-law regularities. Power-law relations imply the existence of long-range correlations between the word types, to convey an especial idea.

  12. NONCONVEX REGULARIZATION FOR SHAPE PRESERVATION

    Energy Technology Data Exchange (ETDEWEB)

    CHARTRAND, RICK [Los Alamos National Laboratory

    2007-01-16

    The authors show that using a nonconvex penalty term to regularize image reconstruction can substantially improve the preservation of object shapes. The commonly-used total-variation regularization, {integral}|{del}u|, penalizes the length of the object edges. They show that {integral}|{del}u|{sup p}, 0 < p < 1, only penalizes edges of dimension at least 2-p, and thus finite-length edges not at all. We give numerical examples showing the resulting improvement in shape preservation.

  13. Regularization with a pruning prior

    DEFF Research Database (Denmark)

    Goutte, Cyril; Hansen, Lars Kai

    1997-01-01

    We investigate the use of a regularization priorthat we show has pruning properties. Analyses areconducted both using a Bayesian framework and withthe generalization method, on a simple toyproblem. Results are thoroughly compared withthose obtained with a traditional weight decay.......We investigate the use of a regularization priorthat we show has pruning properties. Analyses areconducted both using a Bayesian framework and withthe generalization method, on a simple toyproblem. Results are thoroughly compared withthose obtained with a traditional weight decay....

  14. Regular and Periodic Tachyon Kinks

    OpenAIRE

    Bazeia, D.; Menezes, R.; Ramos, J. G.

    2004-01-01

    We search for regular tachyon kinks in an extended model, which includes the tachyon action recently proposed to describe the tachyon field. The extended model that we propose adds a new contribution to the tachyon action, and seems to enrich the present scenario for the tachyon field. We have found stable tachyon kinks of regular profile, which may appropriately lead to the singular kink found by Sen sometime ago. Also, under specific conditions we may find periodic array of kink-antikink co...

  15. Commuting Π-regular rings

    Directory of Open Access Journals (Sweden)

    Shervin Sahebi

    2014-05-01

    Full Text Available ‎$R$ is called commuting regular ring (resp‎. ‎semigroupif‎ for each $x,y\\in R$ there exists $a\\in R$‎ such that$xy=yxayx$‎. ‎In this paper‎, ‎we introduce the concept of‎‎commuting $\\pi$-regular rings (resp‎. ‎semigroups and‎‎study various properties of them.

  16. Critical Finite Size Scaling Relation of the Order-Parameter Probability Distribution for the Three-Dimensional Ising Model on the Creutz Cellular Automaton

    Institute of Scientific and Technical Information of China (English)

    B. Kutlu; M. Civi

    2006-01-01

    @@ We study the order parameter probability distribution at the critical point for the three-dimensional spin-1/2 and spin-1 Ising models on the simple cubic lattice under periodic boundary conditions.

  17. Condition Number Regularized Covariance Estimation.

    Science.gov (United States)

    Won, Joong-Ho; Lim, Johan; Kim, Seung-Jean; Rajaratnam, Bala

    2013-06-01

    Estimation of high-dimensional covariance matrices is known to be a difficult problem, has many applications, and is of current interest to the larger statistics community. In many applications including so-called the "large p small n" setting, the estimate of the covariance matrix is required to be not only invertible, but also well-conditioned. Although many regularization schemes attempt to do this, none of them address the ill-conditioning problem directly. In this paper, we propose a maximum likelihood approach, with the direct goal of obtaining a well-conditioned estimator. No sparsity assumption on either the covariance matrix or its inverse are are imposed, thus making our procedure more widely applicable. We demonstrate that the proposed regularization scheme is computationally efficient, yields a type of Steinian shrinkage estimator, and has a natural Bayesian interpretation. We investigate the theoretical properties of the regularized covariance estimator comprehensively, including its regularization path, and proceed to develop an approach that adaptively determines the level of regularization that is required. Finally, we demonstrate the performance of the regularized estimator in decision-theoretic comparisons and in the financial portfolio optimization setting. The proposed approach has desirable properties, and can serve as a competitive procedure, especially when the sample size is small and when a well-conditioned estimator is required.

  18. Condition Number Regularized Covariance Estimation*

    Science.gov (United States)

    Won, Joong-Ho; Lim, Johan; Kim, Seung-Jean; Rajaratnam, Bala

    2012-01-01

    Estimation of high-dimensional covariance matrices is known to be a difficult problem, has many applications, and is of current interest to the larger statistics community. In many applications including so-called the “large p small n” setting, the estimate of the covariance matrix is required to be not only invertible, but also well-conditioned. Although many regularization schemes attempt to do this, none of them address the ill-conditioning problem directly. In this paper, we propose a maximum likelihood approach, with the direct goal of obtaining a well-conditioned estimator. No sparsity assumption on either the covariance matrix or its inverse are are imposed, thus making our procedure more widely applicable. We demonstrate that the proposed regularization scheme is computationally efficient, yields a type of Steinian shrinkage estimator, and has a natural Bayesian interpretation. We investigate the theoretical properties of the regularized covariance estimator comprehensively, including its regularization path, and proceed to develop an approach that adaptively determines the level of regularization that is required. Finally, we demonstrate the performance of the regularized estimator in decision-theoretic comparisons and in the financial portfolio optimization setting. The proposed approach has desirable properties, and can serve as a competitive procedure, especially when the sample size is small and when a well-conditioned estimator is required. PMID:23730197

  19. Total variation regularization for bioluminescence tomography with the split Bregman method.

    Science.gov (United States)

    Feng, Jinchao; Qin, Chenghu; Jia, Kebin; Zhu, Shouping; Liu, Kai; Han, Dong; Yang, Xin; Gao, Quansheng; Tian, Jie

    2012-07-01

    Regularization methods have been broadly applied to bioluminescence tomography (BLT) to obtain stable solutions, including l2 and l1 regularizations. However, l2 regularization can oversmooth reconstructed images and l1 regularization may sparsify the source distribution, which degrades image quality. In this paper, the use of total variation (TV) regularization in BLT is investigated. Since a nonnegativity constraint can lead to improved image quality, the nonnegative constraint should be considered in BLT. However, TV regularization with a nonnegativity constraint is extremely difficult to solve due to its nondifferentiability and nonlinearity. The aim of this work is to validate the split Bregman method to minimize the TV regularization problem with a nonnegativity constraint for BLT. The performance of split Bregman-resolved TV (SBRTV) based BLT reconstruction algorithm was verified with numerical and in vivo experiments. Experimental results demonstrate that the SBRTV regularization can provide better regularization quality over l2 and l1 regularizations.

  20. Seasonal and spatial distribution of Bacterioplankton in a fluvial-lagunar system of a tropical region: density, biomass, cellular volume and morphologic variation

    Directory of Open Access Journals (Sweden)

    Magnólia Fernandes Florêncio de Araújo

    2008-02-01

    Full Text Available The temporal and spatial fluctuations of Bacterioplankton in a fluvial-lagunar system of a tropical region (Pitimbu River and Jiqui Lake, RN were studied during the dry and the rainy periods. The bacterial abundance varied from 2.67 to 5.1 Cells10(7mL-1 and did not show a typical temporal variation, presenting only small oscillations between the rainy and the dry periods. The bacterial biomass varied from 123 µgC L-1 to 269 µgC L-1 in the sampling sites and the average cellular volume varied from 0.12 to 0.54µm³, showing a predominance of the rods. The temperature showed a positive correlation with the cellular volume of the rods (R=0.55; p=0.02 and vibrio (R=0.53; p=0.03. Significant spatial differences of biomass (Mann Whitney: p=0.01 and cellular volume of the morphotypes (Mann Whitney: p=0.003 were found between the sampling sites. The strong positive correlations of the water temperature and oxygen with bacterioplankton showed a probable high bacterial activity in this system.A variação temporal e espacial do bacterioplâncton em um sistema fluvial-lagunar de região tropical foi estudada em períodos seco e chuvoso. As médias da abundância bacteriana variaram de 2,67 a 5,1 x 10(7 e não exibiram uma variação temporal marcante, tendo apresentado apenas pequenas oscilações entre os períodos chuvoso e seco. A biomassa bacteriana variou de 123 µg C L-1 a 269 µg C L-1 entre os locais de coleta e o volume celular médio de 0,12µm³ a 0,54µm³, ocorrendo predominância de bacilos. A temperatura mostrou correlação positiva com o volume celular de bacilos (R=0,55; p=0,02 e de vibriões (R=0,53; p=0,03. Foram encontradas diferenças espaciais significativas de biomassa (Mann Whitney: p=0,01 e volume celular dos morfotipos (Mann Whitney: p= 0,003, entre os locais de coleta. As fortes correlações positivas da temperatura da água e do oxigênio, com o bacterioplâncton, são sugestivas de uma provavelmente elevada atividade

  1. Adolescence methylphenidate treatment in a rodent model of attention deficit/hyperactivity disorder: Dopamine transporter function and cellular distribution in adulthood

    Science.gov (United States)

    Somkuwar, Sucharita S.; Darna, Mahesh; Kantak, Kathleen M.; Dwoskin, Linda P.

    2013-01-01

    Attention deficit/hyperactivity disorder (ADHD) is attributed to dysfunction of the prefrontal cortex. Methylphenidate, an inhibitor of dopamine and norepinephrine transporters (DAT and NET, respectively), is a standard treatment for ADHD. The Spontaneously Hypertensive Rat (SHR) is a well-established animal model of ADHD. Our previous results showed that methylphenidate treatment in adolescent SHR enhanced cocaine self-administration during adulthood, and alterations in DAT function in prefrontal cortex play a role in this response. Importantly, prefrontal cortex subregions, orbitofrontal cortex (OFC) and medial prefrontal cortex (mPFC), have been shown to have distinct roles in ADHD and cocaine self-administration. In the current study, SHR, Wistar-Kyoto (WKY) and Wistar (WIS) rats received a therapeutically relevant dose of methylphenidate (1.5 mg/kg, p.o.) or vehicle during adolescence and then OFC and mPFC DAT function and cellular expression were assessed during adulthood. In both OFC and mPFC, no strain differences in Vmax or Km for dopamine uptake into synaptosomes were found between vehicle-treated SHR, WKY and WIS. Methylphenidate increased DAT Vmax in SHR mPFC and decreased DAT Vmax in WKY OFC. Also, methylphenidate decreased DAT Km in WIS OFC. Further, methylphenidate did not alter DAT cellular localization, indicating that methylphenidate treatment during adolescence regulated DAT function in SHR mPFC in a traffickingindependent manner. Thus, the increase in mPFC DAT function was an SHR-specific long term consequence of methylphenidate treatment during adolescence, which may be responsible for the treatment-induced alterations in behavior including the observed increases in cocaine self-administration. PMID:23623751

  2. Multiscale Modeling of Antibody-Drug Conjugates: Connecting Tissue and Cellular Distribution to Whole Animal Pharmacokinetics and Potential Implications for Efficacy.

    Science.gov (United States)

    Cilliers, Cornelius; Guo, Hans; Liao, Jianshan; Christodolu, Nikolas; Thurber, Greg M

    2016-09-01

    Antibody-drug conjugates exhibit complex pharmacokinetics due to their combination of macromolecular and small molecule properties. These issues range from systemic concerns, such as deconjugation of the small molecule drug during the long antibody circulation time or rapid clearance from nonspecific interactions, to local tumor tissue heterogeneity, cell bystander effects, and endosomal escape. Mathematical models can be used to study the impact of these processes on overall distribution in an efficient manner, and several types of models have been used to analyze varying aspects of antibody distribution including physiologically based pharmacokinetic (PBPK) models and tissue-level simulations. However, these processes are quantitative in nature and cannot be handled qualitatively in isolation. For example, free antibody from deconjugation of the small molecule will impact the distribution of conjugated antibodies within the tumor. To incorporate these effects into a unified framework, we have coupled the systemic and organ-level distribution of a PBPK model with the tissue-level detail of a distributed parameter tumor model. We used this mathematical model to analyze new experimental results on the distribution of the clinical antibody-drug conjugate Kadcyla in HER2-positive mouse xenografts. This model is able to capture the impact of the drug-antibody ratio (DAR) on tumor penetration, the net result of drug deconjugation, and the effect of using unconjugated antibody to drive ADC penetration deeper into the tumor tissue. This modeling approach will provide quantitative and mechanistic support to experimental studies trying to parse the impact of multiple mechanisms of action for these complex drugs.

  3. Quotient Complexity of Regular Languages

    Directory of Open Access Journals (Sweden)

    Janusz Brzozowski

    2009-07-01

    Full Text Available The past research on the state complexity of operations on regular languages is examined, and a new approach based on an old method (derivatives of regular expressions is presented. Since state complexity is a property of a language, it is appropriate to define it in formal-language terms as the number of distinct quotients of the language, and to call it "quotient complexity". The problem of finding the quotient complexity of a language f(K,L is considered, where K and L are regular languages and f is a regular operation, for example, union or concatenation. Since quotients can be represented by derivatives, one can find a formula for the typical quotient of f(K,L in terms of the quotients of K and L. To obtain an upper bound on the number of quotients of f(K,L all one has to do is count how many such quotients are possible, and this makes automaton constructions unnecessary. The advantages of this point of view are illustrated by many examples. Moreover, new general observations are presented to help in the estimation of the upper bounds on quotient complexity of regular operations.

  4. Multi-scale modeling for prediction of distributed cellular properties in response to substrate spatial gradients in a continuously run microreactor

    DEFF Research Database (Denmark)

    Lencastre Fernandes, Rita; Krühne, Ulrich; Nopens, Ingmar;

    2012-01-01

    microbioreactor is simulated. A multiscale model consisting of the coupling of a population balance model, a kinetic model and a flow model was developed in order to predict simultaneously local concentrations of substrate (glucose), product (ethanol) and biomass, as well as the local cell size distributions....

  5. Regular

    Indian Academy of Sciences (India)

    Ratanpal B S; Sharma Jaita

    2016-03-01

    The charged anisotropic star on paraboloidal space-time is reported by choosing a particular form of radial pressure and electric field intensity. The non-singular solution of Einstein–Maxwell system of equation has been derived and it is shown that the model satisfies all the physical plausibility conditions. It is observed that in the absence of electric field intensity, the model reducesto a particular case of uncharged Sharma and Ratanpal model. It is also observed that the parameter used in the electric field intensity directly affects mass of the star.

  6. A regularized GMRES method for inverse blackbody radiation problem

    Directory of Open Access Journals (Sweden)

    Wu Jieer

    2013-01-01

    Full Text Available The inverse blackbody radiation problem is focused on determining temperature distribution of a blackbody from measured total radiated power spectrum. This problem consists of solving a first kind of Fredholm integral equation and many numerical methods have been proposed. In this paper, a regularized GMRES method is presented to solve the linear ill-posed problem caused by the discretization of such an integral equation. This method projects the orignal problem onto a lower dimensional subspaces by the Arnoldi process. Tikhonov regularization combined with GCV criterion is applied to stabilize the numerical iteration process. Three numerical examples indicate the effectiveness of the regularized GMRES method.

  7. Efficient Hyperelastic Regularization for Registration

    DEFF Research Database (Denmark)

    Darkner, Sune; Hansen, Michael Sass; Larsen, Rasmus;

    2011-01-01

    For most image registration problems a smooth one-to-one mapping is desirable, a diffeomorphism. This can be obtained using priors such as volume preservation, certain kinds of elasticity or both. The key principle is to regularize the strain of the deformation which can be done through penalizat......For most image registration problems a smooth one-to-one mapping is desirable, a diffeomorphism. This can be obtained using priors such as volume preservation, certain kinds of elasticity or both. The key principle is to regularize the strain of the deformation which can be done through...... penalization of the eigen values of the stress tensor. We present a computational framework for regularization of image registration for isotropic hyper elasticity. We formulate an efficient and parallel scheme for computing the principal stain based for a given parameterization by decomposing the left Cauchy...

  8. Regular algebra and finite machines

    CERN Document Server

    Conway, John Horton

    2012-01-01

    World-famous mathematician John H. Conway based this classic text on a 1966 course he taught at Cambridge University. Geared toward graduate students of mathematics, it will also prove a valuable guide to researchers and professional mathematicians.His topics cover Moore's theory of experiments, Kleene's theory of regular events and expressions, Kleene algebras, the differential calculus of events, factors and the factor matrix, and the theory of operators. Additional subjects include event classes and operator classes, some regulator algebras, context-free languages, communicative regular alg

  9. Regularized Statistical Analysis of Anatomy

    DEFF Research Database (Denmark)

    Sjöstrand, Karl

    2007-01-01

    This thesis presents the application and development of regularized methods for the statistical analysis of anatomical structures. Focus is on structure-function relationships in the human brain, such as the connection between early onset of Alzheimer’s disease and shape changes of the corpus cal...

  10. Regularization in Matrix Relevance Learning

    NARCIS (Netherlands)

    Schneider, Petra; Bunte, Kerstin; Stiekema, Han; Hammer, Barbara; Villmann, Thomas; Biehl, Michael

    2010-01-01

    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 displa

  11. Singularities of slice regular functions

    CERN Document Server

    Stoppato, Caterina

    2010-01-01

    Beginning in 2006, G. Gentili and D.C. Struppa developed a theory of regular quaternionic functions with properties that recall classical results in complex analysis. For instance, in each Euclidean ball centered at 0 the set of regular functions coincides with that of quaternionic power series converging in the same ball. In 2009 the author proposed a classification of singularities of regular functions as removable, essential or as poles and studied poles by constructing the ring of quotients. In that article, not only the statements, but also the proving techniques were confined to the special case of balls centered at 0. In a subsequent paper, F. Colombo, G. Gentili, I. Sabadini and D.C. Struppa (2009) identified a larger class of domains, on which the theory of regular functions is natural and not limited to quaternionic power series. The present article studies singularities in this new context, beginning with the construction of the ring of quotients and of Laurent-type expansions at points other than ...

  12. Regular inference as vertex coloring

    NARCIS (Netherlands)

    Costa Florêncio, C.; Verwer, S.

    2012-01-01

    This paper is concerned with the problem of supervised learning of deterministic finite state automata, in the technical sense of identification in the limit from complete data, by finding a minimal DFA consistent with the data (regular inference). We solve this problem by translating it in its enti

  13. Regularized Generalized Structured Component Analysis

    Science.gov (United States)

    Hwang, Heungsun

    2009-01-01

    Generalized structured component analysis (GSCA) has been proposed as a component-based approach to structural equation modeling. In practice, GSCA may suffer from multi-collinearity, i.e., high correlations among exogenous variables. GSCA has yet no remedy for this problem. Thus, a regularized extension of GSCA is proposed that integrates a ridge…

  14. Regular inference as vertex coloring

    NARCIS (Netherlands)

    Costa Florêncio, C.; Verwer, S.

    2012-01-01

    This paper is concerned with the problem of supervised learning of deterministic finite state automata, in the technical sense of identification in the limit from complete data, by finding a minimal DFA consistent with the data (regular inference). We solve this problem by translating it in its

  15. 76 FR 3629 - Regular Meeting

    Science.gov (United States)

    2011-01-20

    ... meeting of the Board will be held at the offices of the Farm Credit Administration in McLean, Virginia, on...Lean, Virginia 22102. SUPPLEMENTARY INFORMATION: This meeting of the Board will be open to the ] public... CORPORATION Farm Credit System Insurance Corporation Board Regular Meeting SUMMARY: Notice is hereby given of...

  16. Convergence and fluctuations of Regularized Tyler estimators

    KAUST Repository

    Kammoun, Abla

    2015-10-26

    This article studies the behavior of regularized Tyler estimators (RTEs) of scatter matrices. The key advantages of these estimators are twofold. First, they guarantee by construction a good conditioning of the estimate and second, being a derivative of robust Tyler estimators, they inherit their robustness properties, notably their resilience to the presence of outliers. Nevertheless, one major problem that poses the use of RTEs in practice is represented by the question of setting the regularization parameter p. While a high value of p is likely to push all the eigenvalues away from zero, it comes at the cost of a larger bias with respect to the population covariance matrix. A deep understanding of the statistics of RTEs is essential to come up with appropriate choices for the regularization parameter. This is not an easy task and might be out of reach, unless one considers asymptotic regimes wherein the number of observations n and/or their size N increase together. First asymptotic results have recently been obtained under the assumption that N and n are large and commensurable. Interestingly, no results concerning the regime of n going to infinity with N fixed exist, even though the investigation of this assumption has usually predated the analysis of the most difficult N and n large case. This motivates our work. In particular, we prove in the present paper that the RTEs converge to a deterministic matrix when n → ∞ with N fixed, which is expressed as a function of the theoretical covariance matrix. We also derive the fluctuations of the RTEs around this deterministic matrix and establish that these fluctuations converge in distribution to a multivariate Gaussian distribution with zero mean and a covariance depending on the population covariance and the parameter.

  17. Cellularity of diagram algebras as twisted semigroup algebras

    CERN Document Server

    Wilcox, Stewart

    2010-01-01

    The Temperley-Lieb and Brauer algebras and their cyclotomic analogues, as well as the partition algebra, are all examples of twisted semigroup algebras. We prove a general theorem about the cellularity of twisted semigroup algebras of regular semigroups. This theorem, which generalises a recent result of East about semigroup algebras of inverse semigroups, allows us to easily reproduce the cellularity of these algebras.

  18. THE COMPLEXITY OF LIMIT LANGUAGES OF CELLULAR AUTOMATA: AN EXAMPLE

    Institute of Scientific and Technical Information of China (English)

    XIE Huimin

    2001-01-01

    The limit languages of cellular automata are defined and theircomplexity are discussed. New tools, which include skew evolution, skew periodic string, trace string, some algebraic calculation method, and restricted membership problem, are developed through a discussion focusing on the limit language of an elementary cellular automata of rule 94.It is proved that this language is non-regular.

  19. The cellular distribution of Na+/H+ exchanger regulatory factor 1 is determined by the PDZ-I domain and regulates the malignant progression of breast cancer

    Science.gov (United States)

    Du, Guifang; Gu, Yanan; Hao, Chengcheng; Yuan, Zhu; He, Junqi; Jiang, Wen G.; Cheng, Shan

    2016-01-01

    The oncogenic role of ectopic expression of Na+/H+ exchanger regulatory factor 1 (NHERF1) was recently suggested. Here, we show that NHERF1 was upregulated in high grades compared with low grades. Increased NHERF1 expression was correlated with poor prognosis and poor survival. NHERF1 expression was higher in the nucleus of cancer cells than in contiguous non- mammary epithelial cells. A novel mutation, namely NHERF1 Y24S, was identified in human breast cancer tissues and shown to correspond to a conserved residue in the PDZ-I domain of NHERF1. Truncation and mutation of the PDZ-I domain of NHERF1 increased the nuclear distribution of the NHERF1 protein, and this redistribution was associated with the malignant phenotype of breast cancer cells, including growth, migration, and adhesion. The present results suggest a role for NHERF1 in the progression of breast cancer mediated by the nuclear distribution of the NHERF1 protein, as determined by the truncation or key site mutation of the PDZ-I domain. PMID:27097111

  20. Recursively-regular subdivisions and applications

    Directory of Open Access Journals (Sweden)

    Rafel Jaume

    2016-05-01

    Full Text Available We generalize regular subdivisions (polyhedral complexes resulting from the projection of the lower faces of a polyhedron introducing the class of recursively-regular subdivisions. Informally speaking, a recursively-regular subdivision is a subdivision that can be obtained by splitting some faces of a regular subdivision by other regular subdivisions (and continue recursively. We also define the finest regular coarsening and the regularity tree of a polyhedral complex. We prove that recursively-regular subdivisions are not necessarily connected by flips and that they are acyclic with respect to the in-front relation. We show that the finest regular coarsening of a subdivision can be efficiently computed, and that whether a subdivision is recursively regular can be efficiently decided. As an application, we also extend a theorem known since 1981 on illuminating space by cones and present connections of recursive regularity to tensegrity theory and graph-embedding problems.     

  1. Sub-cellular distribution of UNC-104(KIF1A) upon binding to adaptors as UNC-16(JIP3), DNC-1(DCTN1/Glued) and SYD-2(Liprin-α) in C. elegans neurons.

    Science.gov (United States)

    Hsu, C-C; Moncaleano, J D; Wagner, O I

    2011-03-10

    The accumulation of cargo (tau, amyloid precursor protein, neurofilaments etc.) in neurons is a hallmark of various neurodegenerative diseases while we have only little knowledge how axonal transport is regulated. Kinesin-3 UNC-104(KIF1A) is the major transporter of synaptic vesicles and recent reports suggest that a cargo itself can affect the motor's activity. Inspecting an interactome map, we identify three putative UNC-104 interactors, namely UNC-16(JIP3), DNC-1(DCTN1/Glued) and SYD-2(Liprin-α), known to be adaptors in essential neuronal protein complexes. We then employed the novel method bimolecular fluorescence complementation (BiFC) assay to visualize motor-adaptor complexes in the nervous system of living C. elegans. Interestingly, the binding of UNC-104 to each adaptor protein results in different sub-cellular distributions and has distinctive effects on the motor's motility. Specifically, if UNC-104 bound to UNC-16, the motor is primarily localized in the soma of neurons while bound to DNC-1, the motor is basically found in axonal termini. On the other hand, if UNC-104 is bound to SYD-2 we identify motor populations mostly along axons. Therefore, these three adaptors inherit different functions in steering the motor to specific sub-cellular locations in the neuron.

  2. 具分布时滞和脉冲的Cohen-Grossberg SICNNs的概周期解%Almost Periodic Solutions for Cohen-Grossberg Shunting Inhibitory Cellular Neural Networks with Distributed Delays and Impulses

    Institute of Scientific and Technical Information of China (English)

    农秀丽; 杨莉

    2014-01-01

    研究一类具分布时滞和脉冲的Cohen-Grossberg SICNNs模型。利用不动点定理,得到一些保证所考虑模型存在概周期解的充分条件,并举例说明了所得结果的可行性。%In this paper, a class of Cohen-Grossberg Shunting Inhibitory cellular neural net-works with distributed delays and impulses are considered. Some criteria for the exis-tence of nonzero almost period⁃ic solutions are established by Banach fixed point theorem.Moreover, an example is employed to illus⁃trate our feasible results.

  3. Regular Motions of Resonant Asteroids

    Science.gov (United States)

    Ferraz-Mello, S.

    1990-11-01

    RESUMEN. Se revisan resultados analiticos relativos a soluciones regulares del problema asteroidal eliptico promediados en la vecindad de una resonancia con jupiten Mencionamos Ia ley de estructura para libradores de alta excentricidad, la estabilidad de los centros de liberaci6n, las perturbaciones forzadas por la excentricidad de jupiter y las 6rbitas de corotaci6n. ABSTRAC This paper reviews analytical results concerning the regular solutions of the elliptic asteroidal problem averaged in the neighbourhood of a resonance with jupiter. We mention the law of structure for high-eccentricity librators, the stability of the libration centers, the perturbations forced by the eccentricity ofjupiter and the corotation orbits. Key words: ASThROIDS

  4. Energy functions for regularization algorithms

    Science.gov (United States)

    Delingette, H.; Hebert, M.; Ikeuchi, K.

    1991-01-01

    Regularization techniques are widely used for inverse problem solving in computer vision such as surface reconstruction, edge detection, or optical flow estimation. Energy functions used for regularization algorithms measure how smooth a curve or surface is, and to render acceptable solutions these energies must verify certain properties such as invariance with Euclidean transformations or invariance with parameterization. The notion of smoothness energy is extended here to the notion of a differential stabilizer, and it is shown that to void the systematic underestimation of undercurvature for planar curve fitting, it is necessary that circles be the curves of maximum smoothness. A set of stabilizers is proposed that meet this condition as well as invariance with rotation and parameterization.

  5. Physical model of dimensional regularization

    Energy Technology Data Exchange (ETDEWEB)

    Schonfeld, Jonathan F.

    2016-12-15

    We explicitly construct fractals of dimension 4-ε on which dimensional regularization approximates scalar-field-only quantum-field theory amplitudes. The construction does not require fractals to be Lorentz-invariant in any sense, and we argue that there probably is no Lorentz-invariant fractal of dimension greater than 2. We derive dimensional regularization's power-law screening first for fractals obtained by removing voids from 3-dimensional Euclidean space. The derivation applies techniques from elementary dielectric theory. Surprisingly, fractal geometry by itself does not guarantee the appropriate power-law behavior; boundary conditions at fractal voids also play an important role. We then extend the derivation to 4-dimensional Minkowski space. We comment on generalization to non-scalar fields, and speculate about implications for quantum gravity. (orig.)

  6. Maximum mutual information regularized classification

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-09-07

    In this paper, a novel pattern classification approach is proposed by regularizing the classifier learning to maximize mutual information between the classification response and the true class label. We argue that, with the learned classifier, the uncertainty of the true class label of a data sample should be reduced by knowing its classification response as much as possible. The reduced uncertainty is measured by the mutual information between the classification response and the true class label. To this end, when learning a linear classifier, we propose to maximize the mutual information between classification responses and true class labels of training samples, besides minimizing the classification error and reducing the classifier complexity. An objective function is constructed by modeling mutual information with entropy estimation, and it is optimized by a gradient descend method in an iterative algorithm. Experiments on two real world pattern classification problems show the significant improvements achieved by maximum mutual information regularization.

  7. Central charges in regular mechanics

    CERN Document Server

    Cabo-Montes de Oca, Alejandro; Villanueva, V M

    1997-01-01

    We consider the algebra associated to a group of transformations which are symmetries of a regular mechanical system (i.e. system free of constraints). For time dependent coordinate transformations we show that a central extension may appear at the classical level which is coordinate and momentum independent. A cochain formalism naturally arises in the argument and extends the usual configuration space cochain concepts to phase space.

  8. Fast regularized image interpolation method

    Institute of Scientific and Technical Information of China (English)

    Hongchen Liu; Yong Feng; Linjing Li

    2007-01-01

    The regularized image interpolation method is widely used based on the vector interpolation model in which down-sampling matrix has very large dimension and needs large storage consumption and higher computation complexity. In this paper, a fast algorithm for image interpolation based on the tensor product of matrices is presented, which transforms the vector interpolation model to matrix form. The proposed algorithm can extremely reduce the storage requirement and time consumption. The simulation results verify their validity.

  9. Efficient Hyperelastic Regularization for Registration

    DEFF Research Database (Denmark)

    Darkner, Sune; Hansen, Michael S; Larsen, Rasmus;

    2011-01-01

    For most image registration problems a smooth one-to-one mapping is desirable, a diffeomorphism. This can be obtained using priors such as volume preservation, certain kinds of elasticity or both. The key principle is to regularize the strain of the deformation which can be done through penalizat......For most image registration problems a smooth one-to-one mapping is desirable, a diffeomorphism. This can be obtained using priors such as volume preservation, certain kinds of elasticity or both. The key principle is to regularize the strain of the deformation which can be done through...... penalization of the eigen values of the stress tensor. We present a computational framework for regularization of image registration for isotropic hyper elasticity. We formulate an efficient and parallel scheme for computing the principal stain based for a given parameterization by decomposing the left Cauchy...... elastic priors such at the Saint Vernant Kirchoff model, the Ogden material model or Riemanian elasticity. We exemplify the approach through synthetic registration and special tests as well as registration of different modalities; 2D cardiac MRI and 3D surfaces of the human ear. The artificial examples...

  10. Three-dimensional cellular distribution in polymeric scaffolds for bone regeneration: a microCT analysis compared to SEM, CLSM and DNA content.

    Science.gov (United States)

    Parrilli, A; Pagani, S; Maltarello, M C; Santi, S; Salerno, A; Netti, P A; Giardino, R; Rimondini, L; Fini, M

    2014-07-01

    In orthopaedic surgery the tissues damaged by injury or disease could be replaced using constructs based on biocompatible materials, cells and growth factors. Scaffold design, porosity and early colonization are key components for the implant success. From biological point of view, attention may be also given to the number, type and size of seeded cells, as well as the seeding technique and cell morphological and volumetric alterations. This paper describes the use of the microCT approach (to date used principally for mineralized matrix quantification) to observe construct colonization in terms of cell localization, and make a direct comparison of the microtomographic sections with scanning electron microscopy images and confocal laser scanning microscope analysis. Briefly, polycaprolactone scaffolds were seeded at different cell densities with MG63 osteoblastic-like cells. Two different endpoints, 1 and 2 weeks, were selected for the three-dimensional colonization and proliferation analysis of the cells. By observing all images obtained, in addition to a more extensive distribution of cells on scaffolds surfaces than in the deeper layers, cell volume increased at 2 weeks compared to 1 week after seeding. Combining the cell number quantification by deoxyribonucleic acid analysis and the single cell volume changes by confocal laser scanning microscope, we validated the microCT segmentation method by finding no statistical differences in the evaluation of the cell volume fraction of the scaffold. Furthermore, the morphological results of this study suggest that an effective scaffold colonization requires a precise balance between different factors, such as number, type and size of seeded cells in addition to scaffold porosity.

  11. From Dimensional to Cut-Off Regularization

    CERN Document Server

    Dillig, M

    2006-01-01

    We extent the standard approach of dimensional regularization of Feynman diagrams: we replace the transition to lower dimensions by a 'natural' cut-off regulator. Introducing an external regulator of mass Lambda^(2e), we regain in the limit e -> 0 and e > 0 the results of dimensional and cut-off regularization, respectively. We demonstrate the versatility and adequacy of the different regularization schemes for practical examples (such as non covariant regularization, the axial anomaly or regularization in effective field theories).

  12. Cellular image classification

    CERN Document Server

    Xu, Xiang; Lin, Feng

    2017-01-01

    This book introduces new techniques for cellular image feature extraction, pattern recognition and classification. The authors use the antinuclear antibodies (ANAs) in patient serum as the subjects and the Indirect Immunofluorescence (IIF) technique as the imaging protocol to illustrate the applications of the described methods. Throughout the book, the authors provide evaluations for the proposed methods on two publicly available human epithelial (HEp-2) cell datasets: ICPR2012 dataset from the ICPR'12 HEp-2 cell classification contest and ICIP2013 training dataset from the ICIP'13 Competition on cells classification by fluorescent image analysis. First, the reading of imaging results is significantly influenced by one’s qualification and reading systems, causing high intra- and inter-laboratory variance. The authors present a low-order LP21 fiber mode for optical single cell manipulation and imaging staining patterns of HEp-2 cells. A focused four-lobed mode distribution is stable and effective in optical...

  13. Supporting Regularized Logistic Regression Privately and Efficiently.

    Directory of Open Access Journals (Sweden)

    Wenfa Li

    Full Text Available As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc.

  14. Supporting Regularized Logistic Regression Privately and Efficiently.

    Science.gov (United States)

    Li, Wenfa; Liu, Hongzhe; Yang, Peng; Xie, Wei

    2016-01-01

    As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc.

  15. Supporting Regularized Logistic Regression Privately and Efficiently

    Science.gov (United States)

    Li, Wenfa; Liu, Hongzhe; Yang, Peng; Xie, Wei

    2016-01-01

    As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc. PMID:27271738

  16. 基于手机信令数据的上海市域职住空间分析%Job-Housing Spatial Distribution Analysis in Shanghai Metropolitan Area Based on Cellular Sig-naling Data

    Institute of Scientific and Technical Information of China (English)

    张天然

    2016-01-01

    The spatial relationship between residence and workplace primarily determines the urban spatial layout. This paper proposes a methodology to calculate commuting distance between residence and work-place by region with cellular signaling data. The comparison result shows that job-housing spatial distribu-tion and commuting distance obtained from both travel surveys and cellular phone data are very similar. Through analyzing the job-housing spatial distribution and commuting distance in the central district and surrounding areas in Shanghai, the paper proposes a concept of balance in job-housing corridors. By re-viewing the relationship between regions with imbalanced job-housing corridors and the degree of rail tran-sit congestion, the paper emphasizes the importance of land use development for the balanced job-housing corridors. The paper discusses the zoning size impact of a new town on the statistical analysis through ana-lyzing job-housing spatial characteristics at different new towns. The result shows that the job-housing dis-tribution of new towns are relatively independent, and the employment rate of residents within new towns is relatively high.%居民居住地与工作地的空间关系是城市空间布局的重要依据.基于手机信令数据,提出分区域的居民通勤距离和就业岗位通勤距离计算方法.通过对比验证了手机信令数据与居民出行调查数据的职住空间和距离分布特征较为吻合.重点分析上海市中心城区及周边地区的职住空间关系及通勤距离.提出职住通道平衡概念,并分析职住通道不平衡地区与轨道交通拥挤程度的关系,指出土地利用布局优化对职住通道平衡的重要性.通过分析不同新城的职住空间特征,探讨新城范围划定对统计分析的影响,总结了新城职住空间较为独立、居民内部就业率较高的特征.

  17. Regularized degenerate multi-solitons

    CERN Document Server

    Correa, Francisco

    2016-01-01

    We report complex PT-symmetric multi-soliton solutions to the Korteweg de-Vries equation that asymptotically contain one-soliton solutions, with each of them possessing the same amount of finite real energy. We demonstrate how these solutions originate from degenerate energy solutions of the Schroedinger equation. Technically this is achieved by the application of Darboux-Crum transformations involving Jordan states with suitable regularizing shifts. Alternatively they may be constructed from a limiting process within the context Hirota's direct method or on a nonlinear superposition obtained from multiple Baecklund transformations. The proposed procedure is completely generic and also applicable to other types of nonlinear integrable systems.

  18. Academic Training Lecture - Regular Programme

    CERN Multimedia

    PH Department

    2011-01-01

    Regular Lecture Programme 9 May 2011 ACT Lectures on Detectors - Inner Tracking Detectors by Pippa Wells (CERN) 10 May 2011 ACT Lectures on Detectors - Calorimeters (2/5) by Philippe Bloch (CERN) 11 May 2011 ACT Lectures on Detectors - Muon systems (3/5) by Kerstin Hoepfner (RWTH Aachen) 12 May 2011 ACT Lectures on Detectors - Particle Identification and Forward Detectors by Peter Krizan (University of Ljubljana and J. Stefan Institute, Ljubljana, Slovenia) 13 May 2011 ACT Lectures on Detectors - Trigger and Data Acquisition (5/5) by Dr. Brian Petersen (CERN) from 11:00 to 12:00 at CERN ( Bldg. 222-R-001 - Filtration Plant )

  19. Regularization methods in Banach spaces

    CERN Document Server

    Schuster, Thomas; Hofmann, Bernd; Kazimierski, Kamil S

    2012-01-01

    Regularization methods aimed at finding stable approximate solutions are a necessary tool to tackle inverse and ill-posed problems. Usually the mathematical model of an inverse problem consists of an operator equation of the first kind and often the associated forward operator acts between Hilbert spaces. However, for numerous problems the reasons for using a Hilbert space setting seem to be based rather on conventions than on an approprimate and realistic model choice, so often a Banach space setting would be closer to reality. Furthermore, sparsity constraints using general Lp-norms or the B

  20. Transient Lunar Phenomena: Regularity and Reality

    CERN Document Server

    Crotts, Arlin P S

    2007-01-01

    Transient lunar phenomena (TLPs) have been reported for centuries, but their nature is largely unsettled. A review of TLP reports shows regularities in the observations; a key question is whether this structure is imposed by human observer effects, terrestrial atmospheric effects or processes tied to the lunar surface. I interrogate an extensive TLP catalog to determine if human factors determine the distribution of TLP reports. I divide the sample according to variables which should produce varying results if determining factors involve humans e.g., historical epoch or geographical location of the observer, not reflecting phenomena tied to the lunar surface. Regardless of how we split the ample, the results are similar: ~50% of the reports involve crater Aristarchus nd vicinity, ~16% from Plato, ~6% from other recent, major impacts, plus a few at Grimaldi. Mare Crisium produces a robust signal for three of five averages of up to 7% of the reports (however, Crisium is an extended feature). The consistency in ...

  1. Essays on regular variations in classical and free setup

    CERN Document Server

    Hazra, Rajat Subhra

    2011-01-01

    This is a thesis on some applications of regularly varying functions. Three problems are considered. The first problem is about the randomly weighted sums, the second is on the behavior of the product under conditional extreme value model and the final problem studies heavy tailed measures under free convolution. The first chapter gives a brief overview of the heavy tailed distributions.

  2. Portfolio Diversification Effects and Regular Variation in Financial Data

    NARCIS (Netherlands)

    N. Hyung (Namwon); C.G. de Vries (Casper)

    2001-01-01

    textabstractPortfolio risk is in an important way driven by 'abnormal' returns emanating from heavy tailed distributed asset returns. The theory of regular variation and extreme values provides a model for this feature of financial data. We first review this theory and subsequently study the problem

  3. On the number of spanning trees in random regular graphs

    DEFF Research Database (Denmark)

    Greenhill, Catherine; Kwan, Matthew; Wind, David Kofoed

    2014-01-01

    Let d >= 3 be a fixed integer. We give an asympotic formula for the expected number of spanning trees in a uniformly random d-regular graph with n vertices. (The asymptotics are as n -> infinity, restricted to even n if d is odd.) We also obtain the asymptotic distribution of the number of spanni...

  4. Portfolio Diversification Effects and Regular Variation in Financial Data

    NARCIS (Netherlands)

    N. Hyung (Namwon); C.G. de Vries (Casper)

    2001-01-01

    textabstractPortfolio risk is in an important way driven by 'abnormal' returns emanating from heavy tailed distributed asset returns. The theory of regular variation and extreme values provides a model for this feature of financial data. We first review this theory and subsequently study the problem

  5. Wave dynamics of regular and chaotic rays

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, S.W.

    1983-09-01

    In order to investigate general relationships between waves and rays in chaotic systems, I study the eigenfunctions and spectrum of a simple model, the two-dimensional Helmholtz equation in a stadium boundary, for which the rays are ergodic. Statistical measurements are performed so that the apparent randomness of the stadium modes can be quantitatively contrasted with the familiar regularities observed for the modes in a circular boundary (with integrable rays). The local spatial autocorrelation of the eigenfunctions is constructed in order to indirectly test theoretical predictions for the nature of the Wigner distribution corresponding to chaotic waves. A portion of the large-eigenvalue spectrum is computed and reported in an appendix; the probability distribution of successive level spacings is analyzed and compared with theoretical predictions. The two principal conclusions are: 1) waves associated with chaotic rays may exhibit randomly situated localized regions of high intensity; 2) the Wigner function for these waves may depart significantly from being uniformly distributed over the surface of constant frequency in the ray phase space.

  6. 渤海湾盆地沾化凹陷富林洼陷油气来源及分布规律研究%Hydrocarbon origin and distribution regularity in Fulin sub-Sag, Zhanhua Sag, Bohai Bay Basin

    Institute of Scientific and Technical Information of China (English)

    王秀红

    2013-01-01

      通过对渤海湾盆地沾化凹陷富林洼陷原油的生物标志物分布与组合特征分析,认为该区主要存在3类原油:Ⅰ类原油主要分布于东次洼,呈植烷优势,伽马蜡烷含量高,重排甾烷与4-甲基甾烷含量较低,来源于东次洼本身的沙四上亚段烃源岩;Ⅱ类原油分布于中次洼洼陷内部,具有姥鲛烷优势、伽马蜡烷含量低、重排甾烷含量高的特征,纵向上不同储层油气来源存在差异,其中浅部储层油气来源于孤南洼陷沙三下亚段烃源岩,深部储层油气主要来自于富林洼陷沙三下亚段烃源岩;Ⅲ类原油分布于中次洼断裂带附近,成熟度较低,姥鲛烷优势,伽马蜡烷含量中等,C28甾烷含量丰富,孕甾烷和重排甾烷含量较低,为孤南洼陷沙一段与富林洼陷沙三下亚段烃源岩所形成的混源油。%Based on the studies of biomarker distribution and composition of crude oils in the Fulin sub-Sag of the Zhanhua Sag of the Bohai Bay Basin, there are 3 types of crude oil in the study area. The crude oils of typeⅠ mainly exist in the east of the sub-sag, characterized by low Pr/ Ph ratio, high gammacerence content as well as low diasterane and 4-methyl-sterane contents. They are originated from source rocks in the upper subsection of the 4th member of the Shahejie Formation in the east of the sub-sag. The crude oils of type Ⅱ mainly locate in the center of the sub-sag, featured by high Pr/ Ph ratio, low gammacerence content and high diasterane content. The origin for oil and gas is different vertically. Hydrocarbon in the middle and shallow reservoirs is mainly origi-nated from source rocks in the lower subsection of the 3rd member of the Shahejie Formation in the Gunan sub-Sag while hydrocarbon in the deep reservoir is mainly originated from source rocks in the lower subsection of the 3rd member of the Shahejie Formation in the Fulin sub-Sag. The crude oils of type Ⅲ mainly distribute around fault

  7. DISTRIBUTION REGULARITY AND GENESIS OF HIGH-FLUORINE UNDERGROUND WATER IN SHOUGUANG CITY%寿光市高氟地下水的分布规律和成因

    Institute of Scientific and Technical Information of China (English)

    王存龙; 王增辉; 陈磊; 王红晋; 郑伟军; 胡雪平

    2012-01-01

    Shouguang was once the key area of preventing endemic fluorine disease in Shandong Province. Based on field survey and soil and water sample test, this paper summarizes the distribution of fluorine disease area and geochemical environment characteristics and studies the relationship between fluorine disease and geochemical environments such as lithologic character, soil, terrain, shallow groundwater and water for human living. On the basis of systematic environment geochemical survey, the cause of high-fluorine ground-water was studied. It is considered that rock, soil and seawater constitute the main sources of high-fluorine groundwater. There probably exist two patterns for the formation of high-fluorine shallow groundwater, seawater invasion enrichment and evaporation concentration. The factors and processes of fluorine enrichment in groundwater are studied and the preventing measures are proposed.%寿光市曾经是山东省地氟病防治的重点地区,通过在病区开展野外调查和岩土、水样测试等工作,总结了该区地氟病分布及地球化学环境特征,探讨了地氟病与地层岩性、土壤、地形地貌、浅层地下水、生活用水等的关系.在系统环境地球化学调查的基础上,研究了当地高氟地下水的成因,认为岩石、土壤、海水是高氟浅层地下水的主要来源,高氟浅层地下水形成可能有海侵富集型和蒸发浓缩型.分析了地下水中氟富集的因素与过程,提出了地氟病的防治措施.

  8. Robust integral stabilization of regular linear systems

    Institute of Scientific and Technical Information of China (English)

    XU Chengzheng; FENG Dexing

    2004-01-01

    We consider regular systems with control and observation. We prove some necessary and sufficient condition for an exponentially stable regular system to admit an integral stabilizing controller. We propose also some robust integral controllers when they exist.

  9. Generalization performance of regularized neural network models

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai

    1994-01-01

    Architecture optimization is a fundamental problem of neural network modeling. The optimal architecture is defined as the one which minimizes the generalization error. This paper addresses estimation of the generalization performance of regularized, complete neural network models. Regularization...

  10. Flat Cellular (UMTS) Networks

    NARCIS (Netherlands)

    Bosch, H.G.P.; Samuel, L.G.; Mullender, S.J.; Polakos, P.; Rittenhouse, G.

    2007-01-01

    Traditionally, cellular systems have been built in a hierarchical manner: many specialized cellular access network elements that collectively form a hierarchical cellular system. When 2G and later 3G systems were designed there was a good reason to make system hierarchical: from a cost-perspective i

  11. A FAST CONVERGENT METHOD OF ITERATED REGULARIZATION

    Institute of Scientific and Technical Information of China (English)

    Huang Xiaowei; Wu Chuansheng; Wu Di

    2009-01-01

    This article presents a fast convergent method of iterated regularization based on the idea of Landweber iterated regularization, and a method for a-posteriori choice by the Morozov discrepancy principle and the optimum asymptotic convergence order of the regularized solution is obtained. Numerical test shows that the method of iterated regu-larization can quicken the convergence speed and reduce the calculation burden efficiently.

  12. Weakly and Strongly Regular Near-rings

    Institute of Scientific and Technical Information of China (English)

    N.Argac; N.J.Groenewald

    2005-01-01

    In this paper, we prove some basic properties of left weakly regular near-rings.We give an affirmative answer to the question whether a left weakly regular near-ring with left unity and satisfying the IFP is also right weakly regular. In the last section, we use among others left 0-prime and left completely prime ideals to characterize strongly regular near-rings.

  13. MAXIMAL POINTS OF A REGULAR TRUTH FUNCTION

    Science.gov (United States)

    Every canonical linearly separable truth function is a regular function, but not every regular truth function is linearly separable. The most...promising method of determining which of the regular truth functions are linearly separable r quires finding their maximal and minimal points. In this...report is developed a quick, systematic method of finding the maximal points of any regular truth function in terms of its arithmetic invariants. (Author)

  14. Natural frequency of regular basins

    Science.gov (United States)

    Tjandra, Sugih S.; Pudjaprasetya, S. R.

    2014-03-01

    Similar to the vibration of a guitar string or an elastic membrane, water waves in an enclosed basin undergo standing oscillatory waves, also known as seiches. The resonant (eigen) periods of seiches are determined by water depth and geometry of the basin. For regular basins, explicit formulas are available. Resonance occurs when the dominant frequency of external force matches the eigen frequency of the basin. In this paper, we implement the conservative finite volume scheme to 2D shallow water equation to simulate resonance in closed basins. Further, we would like to use this scheme and utilizing energy spectra of the recorded signal to extract resonant periods of arbitrary basins. But here we first test the procedure for getting resonant periods of a square closed basin. The numerical resonant periods that we obtain are comparable with those from analytical formulas.

  15. Regularized degenerate multi-solitons

    Science.gov (United States)

    Correa, Francisco; Fring, Andreas

    2016-09-01

    We report complex {P}{T} -symmetric multi-soliton solutions to the Korteweg de-Vries equation that asymptotically contain one-soliton solutions, with each of them possessing the same amount of finite real energy. We demonstrate how these solutions originate from degenerate energy solutions of the Schrödinger equation. Technically this is achieved by the application of Darboux-Crum transformations involving Jordan states with suitable regularizing shifts. Alternatively they may be constructed from a limiting process within the context Hirota's direct method or on a nonlinear superposition obtained from multiple Bäcklund transformations. The proposed procedure is completely generic and also applicable to other types of nonlinear integrable systems.

  16. Modeling polycrystals with regular polyhedra

    Directory of Open Access Journals (Sweden)

    Paulo Rangel Rios

    2006-06-01

    Full Text Available Polycrystalline structure is of paramount importance to materials science and engineering. It provides an important example of a space-filling irregular network structure that also occurs in foams as well as in certain biological tissues. Therefore, seeking an accurate description of the characteristics of polycrystals is of fundamental importance. Recently, one of the authors (MEG published a paper in which a method was devised of representation of irregular networks by regular polyhedra with curved faces. In Glicksman's method a whole class of irregular polyhedra with a given number of faces, N, is represented by a single symmetrical polyhedron with N curved faces. This paper briefly describes the topological and metric properties of these special polyhedra. They are then applied to two important problems of irregular networks: the dimensionless energy 'cost' of irregular networks, and the derivation of a 3D analogue of the von Neumann-Mullins equation for the growth rate of grains in a polycrystal.

  17. Genus Ranges of 4-Regular Rigid Vertex Graphs.

    Science.gov (United States)

    Buck, Dorothy; Dolzhenko, Egor; Jonoska, Nataša; Saito, Masahico; Valencia, Karin

    2015-01-01

    A rigid vertex of a graph is one that has a prescribed cyclic order of its incident edges. We study orientable genus ranges of 4-regular rigid vertex graphs. The (orientable) genus range is a set of genera values over all orientable surfaces into which a graph is embedded cellularly, and the embeddings of rigid vertex graphs are required to preserve the prescribed cyclic order of incident edges at every vertex. The genus ranges of 4-regular rigid vertex graphs are sets of consecutive integers, and we address two questions: which intervals of integers appear as genus ranges of such graphs, and what types of graphs realize a given genus range. For graphs with 2n vertices (n > 1), we prove that all intervals [a, b] for all a genus ranges. For graphs with 2n - 1 vertices (n ≥ 1), we prove that all intervals [a, b] for all a genus ranges. We also provide constructions of graphs that realize these ranges.

  18. REGULARITY FOR CERTAIN QUASILINEARELLIPTIC SYSTEMS OF DIVERGENCESTRUCTURE

    Institute of Scientific and Technical Information of China (English)

    周树清; 冉启康

    2001-01-01

    The regularity of the gradient of H lder continuous solutions of quasi-linear elliptic systems of the form -Dj(aij(x, u, Du)Diuk) = -Difik + gkis investigated. Partial regularity and ε-regularity are shown to hold under the structural assumption-Dj(aij(x,u, Du)) = hi ∈ L∞.

  19. Technology Corner: A Regular Expression Training App

    Directory of Open Access Journals (Sweden)

    Nick Flor

    2012-12-01

    Full Text Available Regular expressions enable digital forensic analysts to find information in files. The best way for an analyst to become proficient in writing regular expressions is to practice. This paper presents the code for an app that allows an analyst to practice writing regular expressions.

  20. Counting Rooted Nearly 2-regular Planar Maps

    Institute of Scientific and Technical Information of China (English)

    郝荣霞; 蔡俊亮

    2004-01-01

    The number of rooted nearly 2-regular maps with the valency of rootvertex, the number of non-rooted vertices and the valency of root-face as three parameters is obtained. Furthermore, the explicit expressions of the special cases including loopless nearly 2-regular maps and simple nearly 2-regular maps in terms of the above three parameters are derived.

  1. On the Construction of Regular Orthocryptogroups

    Institute of Scientific and Technical Information of China (English)

    Xiang Zhi KONG

    2002-01-01

    The aim of this paper is to study regular orthocryptogroups. After obtaining some charac-terizations of such semigroups, we establish the construction theorem of regular orthocryptogroups. Asan application, we give the construction theorem of right quasi-normal orthocryptogroups and studyhomomorphisms between two regular orthocryptogroups.

  2. REGULAR RELATIONS AND MONOTONE NORMAL ORDERED SPACES

    Institute of Scientific and Technical Information of China (English)

    XU XIAOQUAN; LIU YINGMING

    2004-01-01

    In this paper the classical theorem of Zareckii about regular relations is generalized and an intrinsic characterization of regularity is obtained. Based on the generalized Zareckii theorem and the intrinsic characterization of regularity, the authors give a characterization of monotone normality of ordered spaces. A new proof of the UrysohnNachbin lemma is presented which is quite different from the classical one.

  3. Regular Pentagons and the Fibonacci Sequence.

    Science.gov (United States)

    French, Doug

    1989-01-01

    Illustrates how to draw a regular pentagon. Shows the sequence of a succession of regular pentagons formed by extending the sides. Calculates the general formula of the Lucas and Fibonacci sequences. Presents a regular icosahedron as an example of the golden ratio. (YP)

  4. 扁平形多频超声辐射反应器内停留时间的分布规律%Distribution Regularity of Residence Time in Flatted Reactor Radiated by Multi-Frequency Ulrt asonic

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    作为生物柴油连续生产装置的核心单元,扁平形超声反应器的停留时间分布直接反映反应器内的流型、返混程度和反应效果,对反应器设计、操作和控制具有重要意义.文中采用pHB-3型pH仪,以纯净水作流体、KOH溶液作示踪剂,采用脉冲法实时测定了扁平形多频超声辐射反应器的出口KOH应答信号,得到了反应器内流体的停留时间分布曲线,研究了超声功率和流体流量对反应器内流体流动形态及非理想性的影响.同时,用多釜串联模型对实验数据进行相关模拟,得到以下结论:在超声功率为200 W,流量分别为20、30 L/h时,理论串联釜数目分别为6.06、6.76,且流量较大时模拟效果较理想,此时槽内流体更趋于平推流.%Flatted ultrasonic reactor is the core component of the continuous biodiesel production equipment .As a reflection of the flow pattern , the back-mixing degree and the reaction effect , the residence time distribution ( RTD) is significant to the design , manipulation and control of flatted ultrasonic reactors .In this paper , the RTD curves were obtained through measuring the outlet KOH concentration of the flatted multi-frequency ultrasonic reac-tor with a pHB-3 type pH tester in real time , with KOH solution as the tracer in the pulse method and with purified water as the main fluid .Then, the contributions of ultrasonic power and fluid flow to the flow condition and non-ideality of the fluid in the reactor were investigated , and a fitting of the experimental data was performed by using a continuous-flow stirred tank reactor (CSTR) model.The results show that, under the action of 200W ultrasonic, the theoretical number of series kettles is respectively 6.06 and 6.76 when the flow rate is respectively 20 and 30 L/h;and that, at a high flow rate, the simulation effect becomes better and the flow pattern most likely tends to plug flow.

  5. 新疆典型草原黑钙土腐殖质组分的垂直变化规律%Study on the Vertical Distribution Regularity of Soil Humus Contents in Typical Grassland Chernozem Soil in Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    比买热木·阿不都艾海提; 艾克拜尔·伊拉洪; 热依汗古丽·阿布力孜; 艾力江·买买提; 帕丽扎提·艾合买提

    2012-01-01

    [目的]研究新疆不同海拔高度典型草原黑钙土有机碳总量、腐殖酸种类和腐殖质矿物复合体等土壤剖面变化规律.[方法]采用改良的B.B.Пономарёва和плотникова法进行分组重铬酸钾-外加热法测定.[结果]新疆典型草原黑钙土有机碳总量变化范围为71.08 ~44.21 g/kg,胡敏酸(HA)含量变化范围为8.09 ~44.63 g/kg,而富啡酸(FA)变化范围为10.35~36.72 g/kg.腐殖质矿物复合体以粘土矿物复合体为主,即胡敏酸紧结合态为75.13% ~85.14%,而富啡酸紧结合态的是33.92% ~ 38.48%.腐殖质矿物复合体随土壤剖面的分布规律为胡敏酸和富啡酸都是随土层深度的加深而在波动中逐渐减少,即45.54、27.36、19.90、32.71、26.25和13.85 g/kg.[结论]新疆典型草原黑钙土有机碳总量和腐殖质不同组分在不同海拔高度和土壤剖面中的含量差异都达到显著水平,且腐殖酸类型以富啡酸胡敏酸型为主,HA/HF>1.%[Objective ] Our aim was to analyze the total organic carbon, humic acid species and humic substances mineral complexes of different elevations and soil profile changes of the typical grassland chernozem soil. [ Method ] The improved B. B. TIoHOMapeBa and T. A. FDioraHKOBa method for grouping external heating method for the determination of potassium dichromate was used in this research. [ Result ] The total organic carbon variation range of typical grassland chernozem soil was between 71.08 -44. 21 g/kg, brown acid content change was in the range of 8.09 -44.63 g/kg,and fulvic acid change was in the range of 10.35 -36.72 g/kg. Humus mineral complex was mainly clay mineral complexes, namely brown acid tight binding state of 75.13 -85.14% ,and fulvic acid tight bound is 33. 92% -38.48%. Humus soil mineral complexes with sugar profile distribution law is not only a brown acid but also a fulvic acid. They all decrease with the soil depth decreased gradually,namely 45. 54,27. 36

  6. Models with hidden regular variation: Generation and detection

    Directory of Open Access Journals (Sweden)

    Bikramjit Das

    2015-12-01

    Full Text Available We review the notions of multivariate regular variation (MRV and hidden regular variation (HRV for distributions of random vectors and then discuss methods for generating models exhibiting both properties concentrating on the non-negative orthant in dimension two. Furthermore we suggest diagnostic techniques that detect these properties in multivariate data and indicate when models exhibiting both MRV and HRV are plausible fits for the data. We illustrate our techniques on simulated data, as well as two real Internet data sets.

  7. Effect of regularization parameters on geophysical reconstruction

    Institute of Scientific and Technical Information of China (English)

    Zhou Hui; Wang Zhaolei; Qiu Dongling; Li Guofa; Shen Jinsong

    2009-01-01

    In this paper we discuss the edge-preserving regularization method in the reconstruction of physical parameters from geophysical data such as seismic and ground-penetrating radar data.In the regularization method a potential function of model parameters and its corresponding functions are introduced.This method is stable and able to preserve boundaries, and protect resolution.The effect of regularization depends to a great extent on the suitable choice of regularization parameters.The influence of the edge-preserving parameters on the reconstruction results is investigated and the relationship between the regularization parameters and the error of data is described.

  8. Regularities development of entrepreneurial structures in regions

    Directory of Open Access Journals (Sweden)

    Julia Semenovna Pinkovetskaya

    2012-12-01

    Full Text Available Consider regularities and tendencies for the three types of entrepreneurial structures — small enterprises, medium enterprises and individual entrepreneurs. The aim of the research was to confirm the possibilities of describing indicators of aggregate entrepreneurial structures with the use of normal law distribution functions. Presented proposed by the author the methodological approach and results of construction of the functions of the density distribution for the main indicators for the various objects: the Russian Federation, regions, as well as aggregates ofentrepreneurial structures, specialized in certain forms ofeconomic activity. All the developed functions, as shown by the logical and statistical analysis, are of high quality and well-approximate the original data. In general, the proposed methodological approach is versatile and can be used in further studies of aggregates of entrepreneurial structures. The received results can be applied in solving a wide range of problems justify the need for personnel and financial resources at the federal, regional and municipal levels, as well as the formation of plans and forecasts of development entrepreneurship and improvement of this sector of the economy.

  9. Regular Black Holes with Cosmological Constant

    Institute of Scientific and Technical Information of China (English)

    MO Wen-Juan; CAI Rong-Gen; SU Ru-Keng

    2006-01-01

    We present a class of regular black holes with cosmological constant Λ in nonlinear electrodynamics. Instead of usual singularity behind black hole horizon, all fields and curvature invariants are regular everywhere for the regular black holes. Through gauge invariant approach, the linearly dynamical stability of the regular black hole is studied. In odd-parity sector, we find that the Λ term does not appear in the master equations of perturbations, which shows that the regular black hole is stable under odd-parity perturbations. On the other hand, for the even-parity sector, the master equations are more complicated than the case without the cosmological constant. We obtain the sufficient conditions for stability of the regular black hole. We also investigate the thermodynamic properties of the regular black hole, and find that those thermodynamic quantities do not satisfy the differential form of first law of black hole thermodynamics. The reason for violating the first law is revealed.

  10. Symmetry-Preserving Loop Regularization and Renormalization of QFTs

    Science.gov (United States)

    Wu, Yue-Liang

    A new symmetry-preserving loop regularization method proposed in Ref. 1 is further investigated. It is found that its prescription can be understood by introducing a regulating distribution function to the proper-time formalism of irreducible loop integrals. The method simulates in many interesting features to the momentum cutoff, Pauli-Villars and dimensional regularization. The loop regularization method is also simple and general for the practical calculations to higher loop graphs and can be applied to both underlying and effective quantum field theories including gauge, chiral, supersymmetric and gravitational ones as the new method does not modify either the Lagrangian formalism or the spacetime dimension of original theory. The appearance of characteristic energy scale Mc and sliding energy scale μs offers a systematic way for studying the renormalization-group evolution of gauge theories in the spirit of Wilson-Kadanoff and for exploring important effects of higher dimensional interaction terms in the infrared regime.

  11. An inverse method with regularity condition for transonic airfoil design

    Science.gov (United States)

    Zhu, Ziqiang; Xia, Zhixun; Wu, Liyi

    1991-01-01

    It is known from Lighthill's exact solution of the incompressible inverse problem that in the inverse design problem, the surface pressure distribution and the free stream speed cannot both be prescribed independently. This implies the existence of a constraint on the prescribed pressure distribution. The same constraint exists at compressible speeds. Presented here is an inverse design method for transonic airfoils. In this method, the target pressure distribution contains a free parameter that is adjusted during the computation to satisfy the regularity condition. Some design results are presented in order to demonstrate the capabilities of the method.

  12. Learning regularized LDA by clustering.

    Science.gov (United States)

    Pang, Yanwei; Wang, Shuang; Yuan, Yuan

    2014-12-01

    As a supervised dimensionality reduction technique, linear discriminant analysis has a serious overfitting problem when the number of training samples per class is small. The main reason is that the between- and within-class scatter matrices computed from the limited number of training samples deviate greatly from the underlying ones. To overcome the problem without increasing the number of training samples, we propose making use of the structure of the given training data to regularize the between- and within-class scatter matrices by between- and within-cluster scatter matrices, respectively, and simultaneously. The within- and between-cluster matrices are computed from unsupervised clustered data. The within-cluster scatter matrix contributes to encoding the possible variations in intraclasses and the between-cluster scatter matrix is useful for separating extra classes. The contributions are inversely proportional to the number of training samples per class. The advantages of the proposed method become more remarkable as the number of training samples per class decreases. Experimental results on the AR and Feret face databases demonstrate the effectiveness of the proposed method.

  13. Cellular distribution of the renal bumetanide-sensitive Na-K-2Cl cotransporter BSC-1 in the inner stripe of the outer medulla during the development of hypertension in the spontaneously hypertensive rat.

    Science.gov (United States)

    Sonalker, Prajakta A; Tofovic, Stevan P; Jackson, Edwin K

    2007-12-01

    1. The renal bumetanide-sensitive Na-K-2Cl cotransporter (BSC-1) is expressed only in the thick ascending limb and selectively traffics from intracellular vesicles (IVs) to apical plasma membranes (PMs), where BSC-1 regulates sodium reabsorption. We showed previously that in kidneys from adult spontaneously hypertensive rats (SHR; model of essential hypertension) total protein expression of BSC-1 was higher compared with kidneys from normotensive Wistar-Kyoto (WKY) rats. However, whether this change is associated with an increased trafficking of BSC-1 from IVs to PMs is unknown. The goal of the present study was to test the hypothesis that the increase in total renal BSC-1 protein expression in SHR is accompanied by an augmented distribution of BSC-1 from IVs to PMs. 2. To test the hypothesis, we obtained renal tissue from the inner stripe of the outer medulla (ISOM; enriched in thick ascending limbs) and isolated IVs and PMs from this tissue by differential centrifugation. Total BSC-1 protein expression in ISOM and BSC-1 protein expression in ISOM IVs and PMs were measured by semiquantitative western blotting in SHR and aged-matched WKY rats at different ages and stages of hypertension. 3. At 5 weeks of age, SHR were prehypertensive (mean arterial blood pressure (MABP) 97 mmHg). At this age, both the total abundance and cellular distribution of BSC-1 were similar in ISOM from SHR and WKY rats. 4. As SHR aged, their hypertension progressed (MABP 137 and 195 mmHg at 8 and 14 weeks of age, respectively). Associated with the increase in MABP was an increase in both steady state protein levels of ISOM BSC-1 and the distribution of ISOM BSC-1 to PMs (four- and sixfold increases at 8 and 14 weeks of age, respectively, compared with age-matched WKY rats; P BSC-1 mRNA was measured and was found not to differ between SHR and WKY rat ISOM at any age or level of MABP. 6. We conclude that as SHR transition from prehypertensive to established hypertension, there is a marked

  14. Elasticity imaging for regularly spaced structures utilizing WT matched filtering method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on wavelet transform of time-scale domain, a new strain estimation method is presented to position the regular scatterers, calculate the local scatterer spacing and its change, and estimate the internal strain distribution of tissue mimicking phantom. Simulation and experiment results for uniform and nonuniform phantoms show the internal strain of regularly spaced structures can be estimated accurately using this method and the influence of global boundary condition on the estimated strain distribution can be eliminated by reconstructing the real elasticity distribution. This approach has the potentials to become a valuable tool for the regularly spaced structures.

  15. Distribution Regularities and Favorable Exploration areas of Lithologic Gas Reservoir in Sanhu Area,Qaidam Basin%柴达木盆地三湖地区岩性气藏分布规律和有利区块预测

    Institute of Scientific and Technical Information of China (English)

    郭泽清; 刘卫红; 冯刚

    2011-01-01

    柴达木盆地三湖地区第四系的形成是在第三纪末期新构造运动作用下,盆地沉积中心由西向东整体迁移的产物,在第四系中发现了世界上最大的生物气田。近年来三湖地区发现岩性气藏,将现已发现的岩性气(层)藏分为砂岩上倾尖灭型、砂岩透镜体型和物性侧向变化型3种。并提出岩性气藏分布规律是:分布于北斜坡,依附于构造背景,位于k9标志层以下,赋存于薄层砂体中,限于一定的深度范围内。根据分布规律,提出三湖地区岩性气藏的有利勘探区块,为研究区下一步进行岩性气藏勘探提供了理路依据和现实依据。%The occurrence of the Quaternary in Sanhu area of Qaidam basin, which has trapped the largest biologic gas field,is the product of migration of basin depositional center from west to east under the tectonic movements at the end of Tertiary. In recent years,lithologic gas reservoirs have been found in this area and been divided into three types including sand updip pinch-out, sand lens and sand property change in the lateral direction. The distribution regularities of lithologic gas reservoirs in the Sanhu area are summarized as distribution in the northern slope, development on the tectonic background, location below the marker bed kg,accumulation in thin sandstone and limitation to a certain depth. At last, according to the distribution regularity of lithologic gas reservoir, the authors point out favorable exploration areas of lithologic gas reservoir. This study has important theoretical and practical significances for lithologic gas reservoirs exploration in the Sanhu area of Qaidam basin.

  16. SPECT reconstruction using DCT-induced tight framelet regularization

    Science.gov (United States)

    Zhang, Jiahan; Li, Si; Xu, Yuesheng; Schmidtlein, C. R.; Lipson, Edward D.; Feiglin, David H.; Krol, Andrzej

    2015-03-01

    Wavelet transforms have been successfully applied in many fields of image processing. Yet, to our knowledge, they have never been directly incorporated to the objective function in Emission Computed Tomography (ECT) image reconstruction. Our aim has been to investigate if the ℓ1-norm of non-decimated discrete cosine transform (DCT) coefficients of the estimated radiotracer distribution could be effectively used as the regularization term for the penalized-likelihood (PL) reconstruction, where a regularizer is used to enforce the image smoothness in the reconstruction. In this study, the ℓ1-norm of 2D DCT wavelet decomposition was used as a regularization term. The Preconditioned Alternating Projection Algorithm (PAPA), which we proposed in earlier work to solve penalized likelihood (PL) reconstruction with non-differentiable regularizers, was used to solve this optimization problem. The DCT wavelet decompositions were performed on the transaxial reconstructed images. We reconstructed Monte Carlo simulated SPECT data obtained for a numerical phantom with Gaussian blobs as hot lesions and with a warm random lumpy background. Reconstructed images using the proposed method exhibited better noise suppression and improved lesion conspicuity, compared with images reconstructed using expectation maximization (EM) algorithm with Gaussian post filter (GPF). Also, the mean square error (MSE) was smaller, compared with EM-GPF. A critical and challenging aspect of this method was selection of optimal parameters. In summary, our numerical experiments demonstrated that the ℓ1-norm of discrete cosine transform (DCT) wavelet frame transform DCT regularizer shows promise for SPECT image reconstruction using PAPA method.

  17. Comparative economical evaluation among photovoltaic system, motor generator, and regular electric energy rural distribution lines for the supply of small rural properties and schools; Avaliacao economica comparativa entre sistema solar fotovoltaico, comjunto moto-gerador e rede de distribuicao rural para suprimento de pequenas propriedades e escolas rurais

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, Soraya S.; Martins, Paulo M.; Lima Torres, Manuel E. de; Silva, Luiz Carlos S. [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)

    1996-12-31

    The State of Minas Gerais, Brazil, has presently about 190,00 small rural properties which are not yet served by electric energy. This great number is due to among other factors, the lack of funds for the construction of rural distribution lines, which demand high investments to small charges reduced intensive use. The photovoltaic energy is presented as an electrification option, especially for isolated small rural properties, located far from the electric lines and presenting low demand potential. An alternative to the photovoltaic system is the installation of low power gasoline generators. This paper is divided in two parts: the first one compares the photovoltaic energy system unitary costs with the gasoline generator for the supply of small residential and community demands such as schools and public health assistance buildings. The second part of this paper presents not served by electric energy yet which an installation of the photovoltaic system is preferable to the regular electric energy rural distribution, using as main criteria the cost-benefit relationship 4 figs., 4 tabs.

  18. Ideal regularization for learning kernels from labels.

    Science.gov (United States)

    Pan, Binbin; Lai, Jianhuang; Shen, Lixin

    2014-08-01

    In this paper, we propose a new form of regularization that is able to utilize the label information of a data set for learning kernels. The proposed regularization, referred to as ideal regularization, is a linear function of the kernel matrix to be learned. The ideal regularization allows us to develop efficient algorithms to exploit labels. Three applications of the ideal regularization are considered. Firstly, we use the ideal regularization to incorporate the labels into a standard kernel, making the resulting kernel more appropriate for learning tasks. Next, we employ the ideal regularization to learn a data-dependent kernel matrix from an initial kernel matrix (which contains prior similarity information, geometric structures, and labels of the data). Finally, we incorporate the ideal regularization to some state-of-the-art kernel learning problems. With this regularization, these learning problems can be formulated as simpler ones which permit more efficient solvers. Empirical results show that the ideal regularization exploits the labels effectively and efficiently.

  19. Regularity extraction from non-adjacent sounds

    Directory of Open Access Journals (Sweden)

    Alexandra eBendixen

    2012-05-01

    Full Text Available The regular behavior of sound sources helps us to make sense of the auditory environment. Regular patterns may, for instance, convey information on the identity of a sound source (such as the acoustic signature of a train moving on the rails. Yet typically, this signature overlaps in time with signals emitted from other sound sources. It is generally assumed that auditory regularity extraction cannot operate upon this mixture of signals because it only finds regularities between adjacent sounds. In this view, the auditory environment would be grouped into separate entities by means of readily available acoustic cues such as separation in frequency and location. Regularity extraction processes would then operate upon the resulting groups. Our new experimental evidence challenges this view. We presented two interleaved sound sequences which overlapped in frequency range and shared all acoustic parameters. The sequences only differed in their underlying regular patterns. We inserted deviants into one of the sequences to probe whether the regularity was extracted. In the first experiment, we found that these deviants elicited the mismatch negativity (MMN component. Thus the auditory system was able to find the regularity between the non-adjacent sounds. Regularity extraction was not influenced by sequence cohesiveness as manipulated by the relative duration of tones and silent inter-tone-intervals. In the second experiment, we showed that a regularity connecting non-adjacent sounds was discovered only when the intervening sequence also contained a regular pattern, but not when the intervening sounds were randomly varying. This suggests that separate regular patterns are available to the auditory system as a cue for identifying signals coming from distinct sound sources. Thus auditory regularity extraction is not necessarily confined to a processing stage after initial sound grouping, but may precede grouping when other acoustic cues are unavailable.

  20. Information fusion in regularized inversion of tomographic pumping tests

    Science.gov (United States)

    Bohling, G.C.; ,

    2008-01-01

    In this chapter we investigate a simple approach to incorporating geophysical information into the analysis of tomographic pumping tests for characterization of the hydraulic conductivity (K) field in an aquifer. A number of authors have suggested a tomographic approach to the analysis of hydraulic tests in aquifers - essentially simultaneous analysis of multiple tests or stresses on the flow system - in order to improve the resolution of the estimated parameter fields. However, even with a large amount of hydraulic data in hand, the inverse problem is still plagued by non-uniqueness and ill-conditioning and the parameter space for the inversion needs to be constrained in some sensible fashion in order to obtain plausible estimates of aquifer properties. For seismic and radar tomography problems, the parameter space is often constrained through the application of regularization terms that impose penalties on deviations of the estimated parameters from a prior or background model, with the tradeoff between data fit and model norm explored through systematic analysis of results for different levels of weighting on the regularization terms. In this study we apply systematic regularized inversion to analysis of tomographic pumping tests in an alluvial aquifer, taking advantage of the steady-shape flow regime exhibited in these tests to expedite the inversion process. In addition, we explore the possibility of incorporating geophysical information into the inversion through a regularization term relating the estimated K distribution to ground penetrating radar velocity and attenuation distributions through a smoothing spline model. ?? 2008 Springer-Verlag Berlin Heidelberg.

  1. EVOLUTION COMPLEXITY OF THEELEMENTARY CELLULAR AUTOMATON OF RULE 22

    Institute of Scientific and Technical Information of China (English)

    WangYi; JiangZhisong

    2002-01-01

    Cellular automata are the discrete dynamical systems of simple construction but with complex and varied behaviors. In this paper, the elementary cellular automaton of rule 22 is studied by the tools of formal language theory and symbolic dynamics. Its temporal evolution orbits are coarse-grained into evolution sequences and the evolution languages are defined. It is proved that for every n≥2 its width n evolution language is not regular.

  2. Regularized Laplacian Estimation and Fast Eigenvector Approximation

    CERN Document Server

    Perry, Patrick O

    2011-01-01

    Recently, Mahoney and Orecchia demonstrated that popular diffusion-based procedures to compute a quick \\emph{approximation} to the first nontrivial eigenvector of a data graph Laplacian \\emph{exactly} solve certain regularized Semi-Definite Programs (SDPs). In this paper, we extend that result by providing a statistical interpretation of their approximation procedure. Our interpretation will be analogous to the manner in which $\\ell_2$-regularized or $\\ell_1$-regularized $\\ell_2$-regression (often called Ridge regression and Lasso regression, respectively) can be interpreted in terms of a Gaussian prior or a Laplace prior, respectively, on the coefficient vector of the regression problem. Our framework will imply that the solutions to the Mahoney-Orecchia regularized SDP can be interpreted as regularized estimates of the pseudoinverse of the graph Laplacian. Conversely, it will imply that the solution to this regularized estimation problem can be computed very quickly by running, e.g., the fast diffusion-base...

  3. Total variation regularization with bounded linear variations

    Science.gov (United States)

    Makovetskii, Artyom; Voronin, Sergei; Kober, Vitaly

    2016-09-01

    One of the most known techniques for signal denoising is based on total variation regularization (TV regularization). A better understanding of TV regularization is necessary to provide a stronger mathematical justification for using TV minimization in signal processing. In this work, we deal with an intermediate case between one- and two-dimensional cases; that is, a discrete function to be processed is two-dimensional radially symmetric piecewise constant. For this case, the exact solution to the problem can be obtained as follows: first, calculate the average values over rings of the noisy function; second, calculate the shift values and their directions using closed formulae depending on a regularization parameter and structure of rings. Despite the TV regularization is effective for noise removal; it often destroys fine details and thin structures of images. In order to overcome this drawback, we use the TV regularization for signal denoising subject to linear signal variations are bounded.

  4. A multiplicative regularization for force reconstruction

    Science.gov (United States)

    Aucejo, M.; De Smet, O.

    2017-02-01

    Additive regularizations, such as Tikhonov-like approaches, are certainly the most popular methods for reconstructing forces acting on a structure. These approaches require, however, the knowledge of a regularization parameter, that can be numerically computed using specific procedures. Unfortunately, these procedures are generally computationally intensive. For this particular reason, it could be of primary interest to propose a method able to proceed without defining any regularization parameter beforehand. In this paper, a multiplicative regularization is introduced for this purpose. By construction, the regularized solution has to be calculated in an iterative manner. In doing so, the amount of regularization is automatically adjusted throughout the resolution process. Validations using synthetic and experimental data highlight the ability of the proposed approach in providing consistent reconstructions.

  5. Regular Disjunction-Free Default Theories

    Institute of Scientific and Technical Information of China (English)

    Xi-ShunZhao

    2004-01-01

    In this paper, the class of regular disjunction-free default theories is introduced and investigated. A transformation from regular default theories to normal default theories is established. The initial theory and the transformed theory have the same extensions when restricted to old variables. Hence, regular default theories enjoy some similar properties (e.g., existence of extensions, semi-monotonicity) as normal default theories. Then, a new algorithm for credulous reasoning of regular theories is developed. This algorithm runs in a time not more than O(1.45n), where n is the number of defaults. In case of regular prerequisite-free or semi-2CNF default theories, the credulous reasoning can be solved in polynomial time. However, credulous reasoning for semi-Horn default theories is shown to be NP-complete although it is tractable for Horn default theories. Moreover, skeptical reasoning for regular unary default theories is co-NP-complete.

  6. Regular Disjunction-Free Default Theories

    Institute of Scientific and Technical Information of China (English)

    Xi-Shun Zhao

    2004-01-01

    In this paper, the class of regular disjunction-free default theories is introduced and investigated.A transformation from regular default theories to normal default theories is established. The initial theory and the transformed theory have the same extensions when restricted to old variables. Hence, regular default theories enjoy some similar properties (e.g., existence of extensions, semi-monotonicity) as normal default theories. Then,a new algorithm for credulous reasoning of regular theories is developed. This algorithm runs in a time not more than O(1.45n), where n is the number of defaults. In case of regular prerequisite-free or semi-2CNF default theories, the credulous reasoning can be solved in polynomial time. However, credulous reasoning for semi-Horn default theories is shown to be NP-complete although it is tractable for Horn default theories. Moreover, skeptical reasoning for regular unary default theories is co-NP-complete.

  7. An adaptive regularization parameter choice strategy for multispectral bioluminescence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Feng Jinchao; Qin Chenghu; Jia Kebin; Han Dong; Liu Kai; Zhu Shouping; Yang Xin; Tian Jie [Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, P. O. Box 2728, Beijing 100190 (China); College of Electronic Information and Control Engineering, Beijing University of Technology, Beijing 100124 (China); Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, P. O. Box 2728, Beijing 100190 (China); Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, P. O. Box 2728, Beijing 100190 (China) and School of Life Sciences and Technology, Xidian University, Xi' an 710071 (China)

    2011-11-15

    Purpose: Bioluminescence tomography (BLT) provides an effective tool for monitoring physiological and pathological activities in vivo. However, the measured data in bioluminescence imaging are corrupted by noise. Therefore, regularization methods are commonly used to find a regularized solution. Nevertheless, for the quality of the reconstructed bioluminescent source obtained by regularization methods, the choice of the regularization parameters is crucial. To date, the selection of regularization parameters remains challenging. With regards to the above problems, the authors proposed a BLT reconstruction algorithm with an adaptive parameter choice rule. Methods: The proposed reconstruction algorithm uses a diffusion equation for modeling the bioluminescent photon transport. The diffusion equation is solved with a finite element method. Computed tomography (CT) images provide anatomical information regarding the geometry of the small animal and its internal organs. To reduce the ill-posedness of BLT, spectral information and the optimal permissible source region are employed. Then, the relationship between the unknown source distribution and multiview and multispectral boundary measurements is established based on the finite element method and the optimal permissible source region. Since the measured data are noisy, the BLT reconstruction is formulated as l{sub 2} data fidelity and a general regularization term. When choosing the regularization parameters for BLT, an efficient model function approach is proposed, which does not require knowledge of the noise level. This approach only requests the computation of the residual and regularized solution norm. With this knowledge, we construct the model function to approximate the objective function, and the regularization parameter is updated iteratively. Results: First, the micro-CT based mouse phantom was used for simulation verification. Simulation experiments were used to illustrate why multispectral data were used

  8. Regularity effect in prospective memory during aging

    Directory of Open Access Journals (Sweden)

    Geoffrey Blondelle

    2016-10-01

    Full Text Available Background: Regularity effect can affect performance in prospective memory (PM, but little is known on the cognitive processes linked to this effect. Moreover, its impacts with regard to aging remain unknown. To our knowledge, this study is the first to examine regularity effect in PM in a lifespan perspective, with a sample of young, intermediate, and older adults. Objective and design: Our study examined the regularity effect in PM in three groups of participants: 28 young adults (18–30, 16 intermediate adults (40–55, and 25 older adults (65–80. The task, adapted from the Virtual Week, was designed to manipulate the regularity of the various activities of daily life that were to be recalled (regular repeated activities vs. irregular non-repeated activities. We examine the role of several cognitive functions including certain dimensions of executive functions (planning, inhibition, shifting, and binding, short-term memory, and retrospective episodic memory to identify those involved in PM, according to regularity and age. Results: A mixed-design ANOVA showed a main effect of task regularity and an interaction between age and regularity: an age-related difference in PM performances was found for irregular activities (older < young, but not for regular activities. All participants recalled more regular activities than irregular ones with no age effect. It appeared that recalling of regular activities only involved planning for both intermediate and older adults, while recalling of irregular ones were linked to planning, inhibition, short-term memory, binding, and retrospective episodic memory. Conclusion: Taken together, our data suggest that planning capacities seem to play a major role in remembering to perform intended actions with advancing age. Furthermore, the age-PM-paradox may be attenuated when the experimental design is adapted by implementing a familiar context through the use of activities of daily living. The clinical

  9. Ambiguities in Pauli-Villars regularization

    CERN Document Server

    Kleiss, Ronald H P

    2014-01-01

    We investigate regularization of scalar one-loop integrals in the Pauli- Villars subtraction scheme. The results depend on the number of sub- tractions, in particular the finite terms that survive after the diver- gences have been absorbed by renormalization. Therefore the process of Pauli-Villars regularization is ambiguous. We discuss how these am- biguities may be resolved by applying an asymptotically large number of subtractions, which results in a regularization that is automatically valid in any number of dimensions.

  10. Regularized brain reading with shrinkage and smoothing

    OpenAIRE

    Wehbe, Leila; Ramdas, Aaditya; Steorts, Rebecca C.; Shalizi, Cosma Rohilla

    2014-01-01

    Functional neuroimaging measures how the brain responds to complex stimuli. However, sample sizes are modest, noise is substantial, and stimuli are high dimensional. Hence, direct estimates are inherently imprecise and call for regularization. We compare a suite of approaches which regularize via shrinkage: ridge regression, the elastic net (a generalization of ridge regression and the lasso), and a hierarchical Bayesian model based on small area estimation (SAE). We contrast regularization w...

  11. Branch Processes of Regular Magnetic Monopole

    Institute of Scientific and Technical Information of China (English)

    MO Shu-Fan; REN Ji-Rong; ZHU Tao

    2009-01-01

    In this paper, by making use of Duan's topological current theory, the branch process of regular magnetic monopoles is discussed in detail Regular magnetic monopoles are found generating or annihilating at the limit point and encountering, splitting, or merging at the bifurcation point and the degenerate point systematically of the vector order parameter field φ(x).Furthermore, it is also shown that when regular magnetic monopoles split or merge at the degenerate point of field function φ, the total topological charges of the regular magnetic monopoles axe still unchanged.

  12. Iterative Regularization with Minimum-Residual Methods

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Hansen, Per Christian

    2007-01-01

    We study the regularization properties of iterative minimum-residual methods applied to discrete ill-posed problems. In these methods, the projection onto the underlying Krylov subspace acts as a regularizer, and the emphasis of this work is on the role played by the basis vectors of these Krylov...... subspaces. We provide a combination of theory and numerical examples, and our analysis confirms the experience that MINRES and MR-II can work as general regularization methods. We also demonstrate theoretically and experimentally that the same is not true, in general, for GMRES and RRGMRES their success...... as regularization methods is highly problem dependent....

  13. Iterative regularization with minimum-residual methods

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Hansen, Per Christian

    2006-01-01

    We study the regularization properties of iterative minimum-residual methods applied to discrete ill-posed problems. In these methods, the projection onto the underlying Krylov subspace acts as a regularizer, and the emphasis of this work is on the role played by the basis vectors of these Krylov...... subspaces. We provide a combination of theory and numerical examples, and our analysis confirms the experience that MINRES and MR-II can work as general regularization methods. We also demonstrate theoretically and experimentally that the same is not true, in general, for GMRES and RRGMRES - their success...... as regularization methods is highly problem dependent....

  14. Ideal-comparability over Regular Rings

    Institute of Scientific and Technical Information of China (English)

    Huan Yin CHEN; Miao Sen CHEN

    2006-01-01

    We introduce the concept of ideal-comparability condition for regular rings. Let I be an ideal of a regular ring R. If R satisfies the Ⅰ-comparability condition, then R is one-sided unit-regular if and only if so is R/I. Also, we show that a regular ring R satisfies the general comparability if and only if the following hold: (1) R/I satisfies the general comparability; (2) R satisfies the general Ⅰ-comparability condition; (3) The natural map B(R) → B(R/I) is surjective.

  15. Local and Nonlocal Regularization to Image Interpolation

    Directory of Open Access Journals (Sweden)

    Yi Zhan

    2014-01-01

    Full Text Available This paper presents an image interpolation model with local and nonlocal regularization. A nonlocal bounded variation (BV regularizer is formulated by an exponential function including gradient. It acts as the Perona-Malik equation. Thus our nonlocal BV regularizer possesses the properties of the anisotropic diffusion equation and nonlocal functional. The local total variation (TV regularizer dissipates image energy along the orthogonal direction to the gradient to avoid blurring image edges. The derived model efficiently reconstructs the real image, leading to a natural interpolation which reduces blurring and staircase artifacts. We present experimental results that prove the potential and efficacy of the method.

  16. Bit-coded regular expression parsing

    DEFF Research Database (Denmark)

    Nielsen, Lasse; Henglein, Fritz

    2011-01-01

    Regular expression parsing is the problem of producing a parse tree of a string for a given regular expression. We show that a compact bit representation of a parse tree can be produced efficiently, in time linear in the product of input string size and regular expression size, by simplifying...... the DFA-based parsing algorithm due to Dub ´e and Feeley to emit the bits of the bit representation without explicitly materializing the parse tree itself. We furthermore show that Frisch and Cardelli’s greedy regular expression parsing algorithm can be straightforwardly modified to produce bit codings...

  17. The regularity of quotient paratopological groups

    CERN Document Server

    Banakh, Taras

    2010-01-01

    Let $H$ be a closed subgroup of a regular abelian paratopological group $G$. The group reflexion $G^\\flat$ of $G$ is the group $G$ endowed with the strongest group topology, weaker that the original topology of $G$. We show that the quotient $G/H$ is Hausdorff (and regular) if $H$ is closed (and locally compact) in $G^\\flat$. On the other hand, we construct an example of a regular abelian paratopological group $G$ containing a closed discrete subgroup $H$ such that the quotient $G/H$ is Hausdorff but not regular.

  18. Statistical regularities in the rank-citation profile of scientists

    Science.gov (United States)

    Petersen, Alexander M.; Stanley, H. Eugene; Succi, Sauro

    2011-12-01

    Recent science of science research shows that scientific impact measures for journals and individual articles have quantifiable regularities across both time and discipline. However, little is known about the scientific impact distribution at the scale of an individual scientist. We analyze the aggregate production and impact using the rank-citation profile ci(r) of 200 distinguished professors and 100 assistant professors. For the entire range of paper rank r, we fit each ci(r) to a common distribution function. Since two scientists with equivalent Hirsch h-index can have significantly different ci(r) profiles, our results demonstrate the utility of the βi scaling parameter in conjunction with hi for quantifying individual publication impact. We show that the total number of citations Ci tallied from a scientist's Ni papers scales as . Such statistical regularities in the input-output patterns of scientists can be used as benchmarks for theoretical models of career progress.

  19. Irregular and regular LDPC codes with high spectrum efficiency modulation in image transmission over fading channel

    Institute of Scientific and Technical Information of China (English)

    Ma Piming; Yuan Dongfeng

    2005-01-01

    If the degree distribution is chosen carefully, the irregular low-density parity-check (LDPC) codes can outperform the regular ones. An image transmission system is proposed by combining regular and irregular LDPC codes with 16QAM/64QAM modulation to improve both efficiency and reliability. Simulaton results show that LDPC codes are good coding schemes over fading channel in image communication with lower system complexity. More over, irregular codes can obtain a code gain of about 0.7 dB compared with regular ones when BER is 10-4. So the irregular LDPC codes are more suitable for image transmission than the regular codes.

  20. Information theoretic regularization in diffuse optical tomography.

    Science.gov (United States)

    Panagiotou, Christos; Somayajula, Sangeetha; Gibson, Adam P; Schweiger, Martin; Leahy, Richard M; Arridge, Simon R

    2009-05-01

    Diffuse optical tomography (DOT) retrieves the spatially distributed optical characteristics of a medium from external measurements. Recovering the parameters of interest involves solving a nonlinear and highly ill-posed inverse problem. This paper examines the possibility of regularizing DOT via the introduction of a priori information from alternative high-resolution anatomical modalities, using the information theory concepts of mutual information (MI) and joint entropy (JE). Such functionals evaluate the similarity between the reconstructed optical image and the prior image while bypassing the multimodality barrier manifested as the incommensurate relation between the gray value representations of corresponding anatomical features in the two modalities. By introducing structural information, we aim to improve the spatial resolution and quantitative accuracy of the solution. We provide a thorough explanation of the theory from an imaging perspective, accompanied by preliminary results using numerical simulations. In addition we compare the performance of MI and JE. Finally, we have adopted a method for fast marginal entropy evaluation and optimization by modifying the objective function and extending it to the JE case. We demonstrate its use on an image reconstruction framework and show significant computational savings.

  1. Reversible quantum cellular automata

    CERN Document Server

    Schumacher, B

    2004-01-01

    We define quantum cellular automata as infinite quantum lattice systems with discrete time dynamics, such that the time step commutes with lattice translations and has strictly finite propagation speed. In contrast to earlier definitions this allows us to give an explicit characterization of all local rules generating such automata. The same local rules also generate the global time step for automata with periodic boundary conditions. Our main structure theorem asserts that any quantum cellular automaton is structurally reversible, i.e., that it can be obtained by applying two blockwise unitary operations in a generalized Margolus partitioning scheme. This implies that, in contrast to the classical case, the inverse of a nearest neighbor quantum cellular automaton is again a nearest neighbor automaton. We present several construction methods for quantum cellular automata, based on unitaries commuting with their translates, on the quantization of (arbitrary) reversible classical cellular automata, on quantum c...

  2. Manifold regularized multitask feature learning for multimodality disease classification.

    Science.gov (United States)

    Jie, Biao; Zhang, Daoqiang; Cheng, Bo; Shen, Dinggang

    2015-02-01

    Multimodality based methods have shown great advantages in classification of Alzheimer's disease (AD) and its prodromal stage, that is, mild cognitive impairment (MCI). Recently, multitask feature selection methods are typically used for joint selection of common features across multiple modalities. However, one disadvantage of existing multimodality based methods is that they ignore the useful data distribution information in each modality, which is essential for subsequent classification. Accordingly, in this paper we propose a manifold regularized multitask feature learning method to preserve both the intrinsic relatedness among multiple modalities of data and the data distribution information in each modality. Specifically, we denote the feature learning on each modality as a single task, and use group-sparsity regularizer to capture the intrinsic relatedness among multiple tasks (i.e., modalities) and jointly select the common features from multiple tasks. Furthermore, we introduce a new manifold-based Laplacian regularizer to preserve the data distribution information from each task. Finally, we use the multikernel support vector machine method to fuse multimodality data for eventual classification. Conversely, we also extend our method to the semisupervised setting, where only partial data are labeled. We evaluate our method using the baseline magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography (FDG-PET), and cerebrospinal fluid (CSF) data of subjects from AD neuroimaging initiative database. The experimental results demonstrate that our proposed method can not only achieve improved classification performance, but also help to discover the disease-related brain regions useful for disease diagnosis.

  3. Continuum regularization of quantum field theory

    Energy Technology Data Exchange (ETDEWEB)

    Bern, Z.

    1986-04-01

    Possible nonperturbative continuum regularization schemes for quantum field theory are discussed which are based upon the Langevin equation of Parisi and Wu. Breit, Gupta and Zaks made the first proposal for new gauge invariant nonperturbative regularization. The scheme is based on smearing in the ''fifth-time'' of the Langevin equation. An analysis of their stochastic regularization scheme for the case of scalar electrodynamics with the standard covariant gauge fixing is given. Their scheme is shown to preserve the masslessness of the photon and the tensor structure of the photon vacuum polarization at the one-loop level. Although stochastic regularization is viable in one-loop electrodynamics, two difficulties arise which, in general, ruins the scheme. One problem is that the superficial quadratic divergences force a bottomless action for the noise. Another difficulty is that stochastic regularization by fifth-time smearing is incompatible with Zwanziger's gauge fixing, which is the only known nonperturbaive covariant gauge fixing for nonabelian gauge theories. Finally, a successful covariant derivative scheme is discussed which avoids the difficulties encountered with the earlier stochastic regularization by fifth-time smearing. For QCD the regularized formulation is manifestly Lorentz invariant, gauge invariant, ghost free and finite to all orders. A vanishing gluon mass is explicitly verified at one loop. The method is designed to respect relevant symmetries, and is expected to provide suitable regularization for any theory of interest. Hopefully, the scheme will lend itself to nonperturbative analysis. 44 refs., 16 figs.

  4. Regular Decompositions for H(div) Spaces

    Energy Technology Data Exchange (ETDEWEB)

    Kolev, Tzanio [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Center for Applied Scientific Computing; Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Center for Applied Scientific Computing

    2012-01-01

    We study regular decompositions for H(div) spaces. In particular, we show that such regular decompositions are closely related to a previously studied “inf-sup” condition for parameter-dependent Stokes problems, for which we provide an alternative, more direct, proof.

  5. 12 CFR 725.3 - Regular membership.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Regular membership. 725.3 Section 725.3 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS NATIONAL CREDIT UNION ADMINISTRATION CENTRAL LIQUIDITY FACILITY § 725.3 Regular membership. (a) A natural person...

  6. Fast and compact regular expression matching

    DEFF Research Database (Denmark)

    Bille, Philip; Farach-Colton, Martin

    2008-01-01

    We study 4 problems in string matching, namely, regular expression matching, approximate regular expression matching, string edit distance, and subsequence indexing, on a standard word RAM model of computation that allows logarithmic-sized words to be manipulated in constant time. We show how...

  7. Regularity of harmonic maps with the potential

    Institute of Scientific and Technical Information of China (English)

    CHU; Yuming

    2006-01-01

    The aim of this work is to prove the partial regularity of the harmonic maps with potential. The main difficulty caused by the potential is how to find the equation satisfied by the scaling function. Under the assumption on the potential we can obtain the equation, however, for a general potential, even if it is smooth, the partial regularity is still open.

  8. On the Equivalence of Regularization Schemes

    Institute of Scientific and Technical Information of China (English)

    YANG Ji-Feng

    2002-01-01

    We illustrate via the sunset diagram that dimensional regularization ‘deforms' the nonlocal contentsof multi-loop diagrams with its equivalence to cutoff regularization scheme recovered only after sub-divergence wassubtracted. Then we employed a differential equation approach for calculating loop diagrams to verify that dimensionalare argued especially in nonperturbativc perspective.

  9. Regular Event Structures and Finite Petri Nets

    DEFF Research Database (Denmark)

    Nielsen, M.; Thiagarajan, P.S.

    2002-01-01

    We present the notion of regular event structures and conjecture that they correspond exactly to finite 1-safe Petri nets. We show that the conjecture holds for the conflict-free case. Even in this restricted setting, the proof is non-trivial and involves a natural subclass of regular event...

  10. Regularity Re-Revisited: Modality Matters

    Science.gov (United States)

    Tsapkini, Kyrana; Jarema, Gonia; Kehayia, Eva

    2004-01-01

    The issue of regular-irregular past tense formation was examined in a cross-modal lexical decision task in Modern Greek, a language where the orthographic and phonological overlap between present and past tense stems is the same for both regular and irregular verbs. The experiment described here is a follow-up study of previous visual lexical…

  11. Regularization algorithms based on total least squares

    DEFF Research Database (Denmark)

    Hansen, Per Christian; O'Leary, Dianne P.

    1996-01-01

    Discretizations of inverse problems lead to systems of linear equations with a highly ill-conditioned coefficient matrix, and in order to compute stable solutions to these systems it is necessary to apply regularization methods. Classical regularization methods, such as Tikhonov's method or trunc...

  12. A regularized stationary mean-field game

    KAUST Repository

    Yang, Xianjin

    2016-04-19

    In the thesis, we discuss the existence and numerical approximations of solutions of a regularized mean-field game with a low-order regularization. In the first part, we prove a priori estimates and use the continuation method to obtain the existence of a solution with a positive density. Finally, we introduce the monotone flow method and solve the system numerically.

  13. Minimal regular 2-graphs and applications

    Institute of Scientific and Technical Information of China (English)

    FAN; Hongbing; LIU; Guizhen; LIU; Jiping

    2006-01-01

    A 2-graph is a hypergraph with edge sizes of at most two. A regular 2-graph is said to be minimal if it does not contain a proper regular factor. Let f2(n) be the maximum value of degrees over all minimal regular 2-graphs of n vertices. In this paper, we provide a structure property of minimal regular 2-graphs, and consequently, prove that f2(n) = n+3-i/3where 1 ≤i≤6, i=n (mod 6) andn≥ 7, which solves a conjecture posed by Fan, Liu, Wu and Wong. As applications in graph theory, we are able to characterize unfactorable regular graphs and provide the best possible factor existence theorem on degree conditions. Moreover, f2(n) and the minimal 2-graphs can be used in the universal switch box designs, which originally motivated this study.

  14. Regular Expression Matching and Operational Semantics

    CERN Document Server

    Rathnayake, Asiri; 10.4204/EPTCS.62.3

    2011-01-01

    Many programming languages and tools, ranging from grep to the Java String library, contain regular expression matchers. Rather than first translating a regular expression into a deterministic finite automaton, such implementations typically match the regular expression on the fly. Thus they can be seen as virtual machines interpreting the regular expression much as if it were a program with some non-deterministic constructs such as the Kleene star. We formalize this implementation technique for regular expression matching using operational semantics. Specifically, we derive a series of abstract machines, moving from the abstract definition of matching to increasingly realistic machines. First a continuation is added to the operational semantics to describe what remains to be matched after the current expression. Next, we represent the expression as a data structure using pointers, which enables redundant searches to be eliminated via testing for pointer equality. From there, we arrive both at Thompson's lock...

  15. A linear functional strategy for regularized ranking.

    Science.gov (United States)

    Kriukova, Galyna; Panasiuk, Oleksandra; Pereverzyev, Sergei V; Tkachenko, Pavlo

    2016-01-01

    Regularization schemes are frequently used for performing ranking tasks. This topic has been intensively studied in recent years. However, to be effective a regularization scheme should be equipped with a suitable strategy for choosing a regularization parameter. In the present study we discuss an approach, which is based on the idea of a linear combination of regularized rankers corresponding to different values of the regularization parameter. The coefficients of the linear combination are estimated by means of the so-called linear functional strategy. We provide a theoretical justification of the proposed approach and illustrate them by numerical experiments. Some of them are related with ranking the risk of nocturnal hypoglycemia of diabetes patients.

  16. Five lectures on optimal transportation: Geometry, regularity and applications

    CERN Document Server

    Guillen, Nestor

    2010-01-01

    In this series of lectures we introduce the Monge-Kantorovich problem of optimally transporting one distribution of mass onto another, where optimality is measured against a cost function c(x,y). Connections to geometry, inequalities, and partial differential equations will be discussed, focusing in particular on recent developments in the regularity theory for Monge-Ampere type equations. An application to microeconomics will also be described, which amounts to finding the equilibrium price distribution for a monopolist marketing a multidimensional line of products to a population of anonymous agents whose preferences are known only statistically.

  17. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  18. Quantitative regularities in floodplain formation

    Science.gov (United States)

    Nevidimova, O.

    2009-04-01

    Quantitative regularities in floodplain formation Modern methods of the theory of complex systems allow to build mathematical models of complex systems where self-organizing processes are largely determined by nonlinear effects and feedback. However, there exist some factors that exert significant influence on the dynamics of geomorphosystems, but hardly can be adequately expressed in the language of mathematical models. Conceptual modeling allows us to overcome this difficulty. It is based on the methods of synergetic, which, together with the theory of dynamic systems and classical geomorphology, enable to display the dynamics of geomorphological systems. The most adequate for mathematical modeling of complex systems is the concept of model dynamics based on equilibrium. This concept is based on dynamic equilibrium, the tendency to which is observed in the evolution of all geomorphosystems. As an objective law, it is revealed in the evolution of fluvial relief in general, and in river channel processes in particular, demonstrating the ability of these systems to self-organization. Channel process is expressed in the formation of river reaches, rifts, meanders and floodplain. As floodplain is a periodically flooded surface during high waters, it naturally connects river channel with slopes, being one of boundary expressions of the water stream activity. Floodplain dynamics is inseparable from the channel dynamics. It is formed at simultaneous horizontal and vertical displacement of the river channel, that is at Y=Y(x, y), where х, y - horizontal and vertical coordinates, Y - floodplain height. When dу/dt=0 (for not lowering river channel), the river, being displaced in a horizontal plane, leaves behind a low surface, which flooding during high waters (total duration of flooding) changes from the maximum during the initial moment of time t0 to zero in the moment tn. In a similar manner changed is the total amount of accumulated material on the floodplain surface

  19. Regularization Techniques for Linear Least-Squares Problems

    KAUST Repository

    Suliman, Mohamed

    2016-04-01

    Linear estimation is a fundamental branch of signal processing that deals with estimating the values of parameters from a corrupted measured data. Throughout the years, several optimization criteria have been used to achieve this task. The most astonishing attempt among theses is the linear least-squares. Although this criterion enjoyed a wide popularity in many areas due to its attractive properties, it appeared to suffer from some shortcomings. Alternative optimization criteria, as a result, have been proposed. These new criteria allowed, in one way or another, the incorporation of further prior information to the desired problem. Among theses alternative criteria is the regularized least-squares (RLS). In this thesis, we propose two new algorithms to find the regularization parameter for linear least-squares problems. In the constrained perturbation regularization algorithm (COPRA) for random matrices and COPRA for linear discrete ill-posed problems, an artificial perturbation matrix with a bounded norm is forced into the model matrix. This perturbation is introduced to enhance the singular value structure of the matrix. As a result, the new modified model is expected to provide a better stabilize substantial solution when used to estimate the original signal through minimizing the worst-case residual error function. Unlike many other regularization algorithms that go in search of minimizing the estimated data error, the two new proposed algorithms are developed mainly to select the artifcial perturbation bound and the regularization parameter in a way that approximately minimizes the mean-squared error (MSE) between the original signal and its estimate under various conditions. The first proposed COPRA method is developed mainly to estimate the regularization parameter when the measurement matrix is complex Gaussian, with centered unit variance (standard), and independent and identically distributed (i.i.d.) entries. Furthermore, the second proposed COPRA

  20. Factors determining the stability, size distribution, and cellular accumulation of small, monodisperse chitosan nanoparticles as candidate vectors for anticancer drug delivery: application to the passive encapsulation of [14C]-doxorubicin

    Directory of Open Access Journals (Sweden)

    Masarudin MJ

    2015-12-01

    Full Text Available Mas Jaffri Masarudin,1 Suzanne M Cutts,2 Benny J Evison,3 Don R Phillips,2 Paul J Pigram4 1Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Malaysia; 2Department of Biochemistry, La Trobe University, Melbourne, Victoria, Australia; 3Department of Chemical Biology and Therapeutics, St Jude Children's Hospital, Memphis, TN, USA; 4Department of Physics, La Trobe University, Melbourne, Victoria, Australia Abstract: Development of parameters for the fabrication of nanosized vectors is pivotal for its successful administration in therapeutic applications. In this study, homogeneously distributed chitosan nanoparticles (CNPs with diameters as small as 62 nm and a polydispersity index (PDI of 0.15 were synthesized and purified using a simple, robust method that was highly reproducible. Nanoparticles were synthesized using modified ionic gelation of the chitosan polymer with sodium tripolyphosphate. Using this method, larger aggregates were mechanically isolated from single particles in the nanoparticle population by selective efficient centrifugation. The presence of disaggregated monodisperse nanoparticles was confirmed using atomic force microscopy. Factors such as anions, pH, and concentration were found to affect the size and stability of nanoparticles directly. The smallest nanoparticle population was ~62 nm in hydrodynamic size, with a low PDI of 0.15, indicating high particle homogeneity. CNPs were highly stable and retained their monodisperse morphology in serum-supplemented media in cell culture conditions for up to 72 hours, before slowly degrading over 6 days. Cell viability assays demonstrated that cells remained viable following a 72-hour exposure to 1 mg/mL CNPs, suggesting that the nanoparticles are well tolerated and highly suited for biomedical applications. Cellular uptake studies using fluorescein isothiocyanate-labeled CNPs showed that cancer cells

  1. 蜂窝网中基于分布式约束满足算法的改进信道分配%Distributed Constraint Satisfaction of an Improved Channel Assignment Approach in Cellular Network

    Institute of Scientific and Technical Information of China (English)

    韦沙; 刘威; 陈小慧; 程文青

    2012-01-01

    随着蜂窝网业务需求的不断增长,如何利用有限的信道资源在各小区间进行复用,以便既能避免移动用户之间的干扰,又能满足所有移动用户的话务请求,使蜂窝系统容量大大增加,已成为一项重要研究课题.此类问题属于NP-hard的信道分配问题(Channel Assignment Problem,CAP),将CAP问题形式化为分布式约束满足问题(DCSP),然后提出基于改进现有的信道分配策略,以获得更高的信道利用率、较令人满意的系统服务质量,尽可能满足所有用户的话务请求.将利用尽可能简单、搜寻时间短的算法,并将现有的benchmark问题进行仿真.实验表明,该方案对有效改进信道分配问题,充分利用有限的信道资源,降低系统的阻塞率,有着较好的应用前景.%As demands grow for wireless communication systems and the limited number of channel resources, the channel assignment problem(CAP) becomes increasingly important The goal of channel assignment is to reduce the interferences, and enhance the capacity. CAP is a well-known NP-hard problem. In this paper, we modeled CAP as a Distributed Constraint Satisfaction Problem(DSCP) with fully considerations on all constraints of interferences, then proposed an improve channel assignment approach to minimized more required number of channels in cellular mobile system and minimize the number of blocked hosts. We also provided one kind of complete search algorithms, which outperforms others by providing quasi-optimal solutions at a related lower cost and time. We evaluated the performance of our approach in solving CAP, which is based on the existing benchmark. The simulation result shows that our approach provides optimal solutions and minimizes call failures, which is more feasible and easy to be applied in practical engineering.

  2. Modeling cellular systems

    CERN Document Server

    Matthäus, Franziska; Pahle, Jürgen

    2017-01-01

    This contributed volume comprises research articles and reviews on topics connected to the mathematical modeling of cellular systems. These contributions cover signaling pathways, stochastic effects, cell motility and mechanics, pattern formation processes, as well as multi-scale approaches. All authors attended the workshop on "Modeling Cellular Systems" which took place in Heidelberg in October 2014. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  3. Epigenetics and Cellular Metabolism

    OpenAIRE

    Wenyi Xu; Fengzhong Wang; Zhongsheng Yu; Fengjiao Xin

    2016-01-01

    Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc.) is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the proce...

  4. Nanostructured cellular networks.

    Science.gov (United States)

    Moriarty, P; Taylor, M D R; Brust, M

    2002-12-01

    Au nanocrystals spin-coated onto silicon from toluene form cellular networks. A quantitative statistical crystallography analysis shows that intercellular correlations drive the networks far from statistical equilibrium. Spin-coating from hexane does not produce cellular structure, yet a strong correlation is retained in the positions of nanocrystal aggregates. Mechanisms based on Marangoni convection alone cannot account for the variety of patterns observed, and we argue that spinodal decomposition plays an important role in foam formation.

  5. 岷江流域映秀-茂县段地震次生地质灾害分布规律及发展趋势分析%Analysis of distribution regularity and development tendency of earthquake secondary geohazards in Yingxiu-Maoxian section along the Minjiang River

    Institute of Scientific and Technical Information of China (English)

    魏永明; 魏显虎; 陈玉

    2014-01-01

    2008年汶川大地震引发了岷江流域映秀-茂县段极为严重的地震次生地质灾害。利用震后多期高分辨率航空遥感数据并结合解译标志,快速、准确地分析研究区灾害的分布规律及发展趋势,对科学指导灾后重建具有重要意义。次生地质灾害分布规律主要表现为:①滑坡、崩塌及其过渡类型---崩滑为主要的次生地质灾害类型(占90%以上);②次生地质灾害广泛分布在岷江两岸山坡,但在映秀-汶川段的发育程度和规模比汶川-茂县段大得多。研究区次生地质灾害发展趋势分析结果表明:①地震形成的滑坡体趋于稳定,但解译的21个潜在滑坡体中部分已出现活动迹象,其中斗簇和沏底关2个潜在滑坡群更为明显,应对其进行遥感连续动态监测;②泥石流为研究区今后最主要的灾害类型,其中映秀-汶川段为最主要的发生地段。%The 2008 Wenchuan earthquak led to fatal secondary geological disasters in the Yingxiu - Maoxian segments along the Minjiang River. Through using multi -phase high -resolution airborne remote sensing data obtained after the earthquake in combination with interpretation signs of various geohazards, we can analyze the distribution regularity and development tendency of earthquake secondary geohazards quickly and accurately,which is of great significance in guiding reconstruction of the disaster area scientifically. The distribution regularity of secondary geohazards finds expression in the following aspects: ① avalanche, landslide and landslide-avalanche ( the transition type between the landslide and avalanche ) constitute the main types, with landslide -avalanche taking up over 90%; ② the geohazards are widely distributed on the both slopes of the Minjiang River in the Yingxiu-Maoxian segment,but their scales and intensities are much larger in the Yingxiu-Maoxian segment than in the Wenchuan-Maoxian segment. Through continuous

  6. J-regular rings with injectivities

    OpenAIRE

    Shen, Liang

    2010-01-01

    A ring $R$ is called a J-regular ring if R/J(R) is von Neumann regular, where J(R) is the Jacobson radical of R. It is proved that if R is J-regular, then (i) R is right n-injective if and only if every homomorphism from an $n$-generated small right ideal of $R$ to $R_{R}$ can be extended to one from $R_{R}$ to $R_{R}$; (ii) R is right FP-injective if and only if R is right (J, R)-FP-injective. Some known results are improved.

  7. Low power implementation of datapath using regularity

    Institute of Scientific and Technical Information of China (English)

    LAI Li-ya; LIU Peng

    2005-01-01

    Datapath accounts for a considerable part of power consumption in VLSI circuit design. This paper presents a method for physical implementation of datapath to achieve low power consumption. Regularity is a characteristic of datapath and the key of the proposed method, where synthesis is tightly combined with placement to make full use of regularity, so that low power consumption is achieved. In This paper, a new concept of Synthesis In Relative Placement (SIRP) is given to deal with the semi-regularity in some datapath. Experimental results of a sample circuit validated the proposed method.

  8. REGULARIZATION OF SINGULAR SYSTEMS BY OUTPUT FEEDBACK

    Institute of Scientific and Technical Information of China (English)

    De-lin Chu; Da-yong Cai

    2000-01-01

    Problem of regularization of a singular system by derivative and proportional output feedback is studied. Necessary and sufficient conditions are obtained under which a singular system can be regularized into a closed-loop system that is regular and of index at most one. The reduced form is given that can easily explore the system properties as well as the feedback to be determined. The main results of the present paper are based on orthogonal transformations. Therefore, they can be implemented by numerically stable ways.

  9. Limitations on Dimensional Regularization in Renyi Entropy

    CERN Document Server

    Bao, Ning

    2016-01-01

    Dimensional regularization is a common method used to regulate the UV divergence of field theoretic quantities. When it is used in the context of Renyi entropy, however, it is important to consider whether such a procedure eliminates the statistical interpretation thereof as a measure of entanglement of states living on a Hilbert space. We therefore examine the dimensionally regularized Renyi entropy of a 4d unitary CFT and show that it admits no underlying Hilbert space in the state-counting sense. This gives a concrete proof that dimensionally regularized Renyi entropy cannot always be obtained as a limit of the Renyi entropy of some finite-dimensional quantum system.

  10. Iterative Regularization with Minimum-Residual Methods

    DEFF Research Database (Denmark)

    Jensen, Toke Koldborg; Hansen, Per Christian

    2007-01-01

    We study the regularization properties of iterative minimum-residual methods applied to discrete ill-posed problems. In these methods, the projection onto the underlying Krylov subspace acts as a regularizer, and the emphasis of this work is on the role played by the basis vectors of these Krylov...... subspaces. We provide a combination of theory and numerical examples, and our analysis confirms the experience that MINRES and MR-II can work as general regularization methods. We also demonstrate theoretically and experimentally that the same is not true, in general, for GMRES and RRGMRES their success...

  11. Calculus of spatial distribution of absorbed dose to cellular level by Monte Carlo simulation for a radio-labelled peptide with {sup 188}Re and with nuclear internalization : preliminary results; Calculo de la distribucion espacial de dosis absorbida a nivel celular por simulacion Monte Carlo para un peptido radiomarcado con {sup 188}Re y con internalizacion nuclear : resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E. L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Santos C, C. L. [Universidad Autonoma del Estado de Mexico, Paseo Tollocan y Jesus Carranza, Toluca 50120, Estado de Mexico (Mexico)], e-mail: leticia.rojas@inin.gob.mx

    2009-10-15

    The {sup 188}Re is a radionuclide of radiation gamma emitter, useful in obtaining of gamma-graphic images, but it is also emitter of beta radiations and Auger electrons. A bio-molecule directed to a specific receptor of a cancer cell labeled with a emitter radionuclide of beta particles and Auger electrons, as the {sup 188}Re-Tat-Bombesin, it has the potential to be used in radiotherapy of molecular targets for its capacity to penetrate to cellular nucleus. In this system, the radiation dose is distributed in way located at microscopic levels in sub cellular specific places, where Auger emissions contributes of significant way in absorbed dose. The cellular dosimetry is realized in most of cases, using analytic or semi analytical methods, for example the cellular MIRD methodology. However, it is required to complement these calculations simulating the electrons transport and considering experimental bio kinetics data. Therefore, in this work preliminary results are presented of dosimetric calculation to sub cellular level for {sup 188}Re-Tat-Bombesin by Monte Carlo simulation, using the 2008 version of PENELOPE: PENEASY code. The spatial distribution of absorbed dose in membrane, cytoplasm and nucleus, was calculated with geometry of a cell of 10 {mu}m of diameter, a nucleus of 2 {mu}m of ratio and membrane of 0.2 {mu}m of thickness, considering elementary constitution for each cellular compartment proposal in literature. The total number of disintegrations at sub cellular level was evaluated integrating the activity in function of time starting from experimental bio kinetics data in mamma cancer cells MDA-MB231. The preliminary results show that 46.4% of total disintegrations for unit of captured activity by cell occurs in nucleus, 38.4% in membrane and 15.2% in cytoplasm. The due absorbed dose to Auger electrons for 1 Bq of {sup 188}Re located in cellular membrane were respectively of 1.32E-1 and 1.43E-1 Gy in cytoplasm and nucleus. (Author)

  12. Could Regular Pot Smoking Harm Vision?

    Science.gov (United States)

    ... fullstory_162441.html Could Regular Pot Smoking Harm Vision? Study suggests that it might slow signaling among ... may be linked to a limited degree of vision impairment, a new French study suggests. The finding ...

  13. Regular-fat dairy and human health

    DEFF Research Database (Denmark)

    Astrup, Arne; Bradley, Beth H Rice; Brenna, J Thomas

    2016-01-01

    In recent history, some dietary recommendations have treated dairy fat as an unnecessary source of calories and saturated fat in the human diet. These assumptions, however, have recently been brought into question by current research on regular fat dairy products and human health. In an effort...... dairy foods have on human health. The emerging scientific evidence indicates that the consumption of regular fat dairy foods is not associated with an increased risk of cardiovascular disease and inversely associated with weight gain and the risk of obesity. Dairy foods, including regular-fat milk...... to disseminate, explore and discuss the state of the science on the relationship between regular fat dairy products and health, symposia were programmed by dairy industry organizations in Europe and North America at The Eurofed Lipids Congress (2014) in France, The Dairy Nutrition Annual Symposium (2014...

  14. The regularization of Old English weak verbs

    Directory of Open Access Journals (Sweden)

    Marta Tío Sáenz

    2015-07-01

    Full Text Available This article deals with the regularization of non-standard spellings of the verbal forms extracted from a corpus. It addresses the question of what the limits of regularization are when lemmatizing Old English weak verbs. The purpose of such regularization, also known as normalization, is to carry out lexicological analysis or lexicographical work. The analysis concentrates on weak verbs from the second class and draws on the lexical database of Old English Nerthus, which has incorporated the texts of the Dictionary of Old English Corpus. As regards the question of the limits of normalization, the solution adopted are, in the first place, that when it is necessary to regularize, normalization is restricted to correspondences based on dialectal and diachronic variation and, secondly, that normalization has to be unidirectional.

  15. On π-regularity of General Rings

    Institute of Scientific and Technical Information of China (English)

    CHEN WEI-XING; CUI SHU-YING

    2010-01-01

    A general ring means an associative ring with or without identity. An idempotent e in a general ring I is called left (right) semicentral if for every x∈ I,xe = exe (ex = exe). And I is called semiabelian ff every idempotent in I is left or right semicentral. It is proved that a semiabelian general ring I is π-regular if and only ff the set N(I) of nilpotent elements in I is an ideal of I and I/N(I) is regular. It follows that if I is a semiabelian general ring and K is an ideal of I,then I is π-regular if and only if both K and I/K are r-regular. Based on this we prove that every semiabelian GVNL-ring is an SGVNL-ring. These generalize several known results on the relevant subject. Furthermore we give a characterization of a semiabelian GVNL-ring.

  16. A Biordered Set Representation of Regular Semigroups

    Institute of Scientific and Technical Information of China (English)

    Bing Jun YU; Mang XU

    2005-01-01

    In this paper, for an arbitrary regular biordered set E, by using biorder-isomorphisms between the ω-ideals of E, we construct a fundamental regular semigroup WE called NH-semigroup of E, whose idempotent biordered set is isomorphic to E. We prove further that WE can be used to give a new representation of general regular semigroups in the sense that, for any regular semigroup S with the idempotent biordered set isomorphic to E, there exists a homomorphism from S to WE whose kernel is the greatest idempotent-separating congruence on S and the image is a full symmetric subsemigroup of WE. Moreover, when E is a biordered set of a semilattice E0, WE is isomorphic to the Munn-semigroup TE0; and when E is the biordered set of a band B, WE is isomorphic to the Hall-semigroup WB.

  17. Regularities and Radicals in Near-rings

    Institute of Scientific and Technical Information of China (English)

    N.J. Groenewald

    2002-01-01

    Let F be a regularity for near-rings and F(R) the largest FR-regular ideal in R. In the first part of this paper, we introduce the concepts of maximal Fmodular ideals and F-primitive near-rings to characterize F(R) for any near-ring regularity F. Under certain conditions, F(R) is equal to the intersection of all the maximal F-modular ideals of R. As examples, we apply this to the different analogs of the Brown-McCoy radicals and also the Behrens radicals. In the last part of this paper, we show that for certain regularities, the class of F-primitive near-rings forms a special class.

  18. Spectral partitioning of random regular blockmodels

    CERN Document Server

    Barucca, Paolo

    2016-01-01

    Graph partitioning problems emerge in a wide variety of complex systems, ranging from biology to finance, but can be rigorously analyzed and solved only for a few graph ensembles. Here, an ensemble of random graphs with regular block structure is introduced, for which analytical results can be obtained. In particular, the spectral density of such random regular blockmodels is computed exactly for a modular, bipartite and core-periphery structure. McKay's law for random regular graphs is found analytically to apply also for regular modular and bipartite structures when blocks are homogeneous. In core-periphery structures, where blocks are intrinsically heterogeneous, a new law is found to apply for the spectral density. Exact solution to the inference problem is provided for the models discussed. All analytical results show perfect agreement with numerical experiments. Final discussion summarizes results and outlines the relevance of the results for the solution of graph partitioning problems in other graph en...

  19. Comparability for ideals of regular rings

    Institute of Scientific and Technical Information of China (English)

    CHEN Huanyin

    2005-01-01

    In this paper we investigate necessary and sufficient conditions under which the ideals possess comparability structure. For regular rings, we prove that every square matrix over ideals satisfying general comparability admits a diagonal reduction by quasi invertible matrices.

  20. Regularity of optimal transport maps and applications

    CERN Document Server

    Philippis, Guido

    2013-01-01

    In this thesis, we study the regularity of optimal transport maps and its applications to the semi-geostrophic system. The first two chapters survey the known theory, in particular there is a self-contained proof of Brenier’ theorem on existence of optimal transport maps and of Caffarelli’s Theorem on Holder continuity of optimal maps. In the third and fourth chapter we start investigating Sobolev regularity of optimal transport maps, while in Chapter 5 we show how the above mentioned results allows to prove the existence of Eulerian solution to the semi-geostrophic equation. In Chapter 6 we prove partial regularity of optimal maps with respect to a generic cost functions (it is well known that in this case global regularity can not be expected). More precisely we show that if the target and source measure have smooth densities the optimal map is always smooth outside a closed set of measure zero.

  1. Chaos at Uranus Spreads Dust Across the Regular Satellites

    Science.gov (United States)

    Tamayo, Dan; Burns, J. A.; Nicholson, P. D.; Hamilton, D. P.

    2012-05-01

    The short collision timescales between the Uranian irregular satellites argue for the past generation of vast quantities of dust at the outer reaches of Uranus’ Hill sphere (Bottke et al. 2010). Uranus’ extreme obliquity (98 degrees) renders the orbits of large objects unstable to eccentricity perturbations in the radial range a ≈ 60 - 75 Rp. (Tremaine et al. 2009). We study the effect on dust by investigating how the instability is modified by radiation pressure. We find that dust particles generated at the orbits of the irregular satellites move inward as radiation forces cause their orbits to decay (Burns et al. 1979). When they reach the unstable region, grain orbits undergo chaotic large-amplitude eccentricity oscillations that bring their pericenters inside the orbits of the regular satellites. We argue that the impact probabilities and expected spatial distribution across the satellite surfaces might explain the observed hemispherical color asymmetries common to the outer four regular satellites.

  2. Global Optimization methods for Gravitational Lens Systems with Regularized Sources

    CERN Document Server

    Rogers, Adam

    2012-01-01

    Several approaches exist to model gravitational lens systems. In this study, we apply global optimization methods to find the optimal set of lens parameters using a genetic algorithm. We treat the full optimization procedure as a two-step process: an analytical description of the source plane intensity distribution is used to find an initial approximation to the optimal lens parameters. The second stage of the optimization uses a pixelated source plane with the semilinear method to determine an optimal source. Regularization is handled by means of an iterative method and the generalized cross validation (GCV) and unbiased predictive risk estimator (UPRE) functions that are commonly used in standard image deconvolution problems. This approach simultaneously estimates the optimal regularization parameter and the number of degrees of freedom in the source. Using the GCV and UPRE functions we are able to justify an estimation of the number of source degrees of freedom found in previous work. We test our approach ...

  3. Periodic Walks on Large Regular Graphs and Random Matrix Theory

    CERN Document Server

    Oren, Idan

    2011-01-01

    We study the distribution of the number of (non-backtracking) periodic walks on large regular graphs. We propose a formula for the ratio between the variance of the number of $t$-periodic walks and its mean, when the cardinality of the vertex set $V$ and the period $t$ approach $\\infty$ with $t/V\\rightarrow \\tau$ for any $\\tau$. This formula is based on the conjecture that the spectral statistics of the adjacency eigenvalues is given by Random Matrix Theory (RMT). We provide numerical and theoretical evidence for the validity of this conjecture. The key tool used in this study is a trace formula which expresses the spectral density of $d$-regular graphs, in terms of periodic walks.

  4. A new approach to nonlinear constrained Tikhonov regularization

    KAUST Repository

    Ito, Kazufumi

    2011-09-16

    We present a novel approach to nonlinear constrained Tikhonov regularization from the viewpoint of optimization theory. A second-order sufficient optimality condition is suggested as a nonlinearity condition to handle the nonlinearity of the forward operator. The approach is exploited to derive convergence rate results for a priori as well as a posteriori choice rules, e.g., discrepancy principle and balancing principle, for selecting the regularization parameter. The idea is further illustrated on a general class of parameter identification problems, for which (new) source and nonlinearity conditions are derived and the structural property of the nonlinearity term is revealed. A number of examples including identifying distributed parameters in elliptic differential equations are presented. © 2011 IOP Publishing Ltd.

  5. A new small-world network created by Cellular Automata

    Science.gov (United States)

    Ruan, Yuhong; Li, Anwei

    2016-08-01

    In this paper, we generate small-world networks by the Cellular Automaton based on starting with one-dimensional regular networks. Besides the common properties of small-world networks with small average shortest path length and large clustering coefficient, the small-world networks generated in this way have other properties: (i) The edges which are cut in the regular network can be controlled that whether the edges are reconnected or not, and (ii) the number of the edges of the small-world network model equals the number of the edges of the original regular network. In other words, the average degree of the small-world network model equals to the average degree of the original regular network.

  6. On Comparison of Adaptive Regularization Methods

    DEFF Research Database (Denmark)

    Sigurdsson, Sigurdur; Larsen, Jan; Hansen, Lars Kai

    2000-01-01

    , a very flexible regularization may substitute the need for selection procedures. This paper investigates recently suggested adaptive regularization schemes. Some methods focus directly on minimizing an estimate of the generalization error (either algebraic or empirical), whereas others start from...... different criteria, e.g., the Bayesian evidence. The evidence expresses basically the probability of the model, which is conceptually different from generalization error; however, asymptotically for large training data sets they will converge. First the basic model definition, training and generalization...

  7. Infrared image enhancement using Cellular Automata

    Science.gov (United States)

    Qi, Wei; Han, Jing; Zhang, Yi; Bai, Lian-fa

    2016-05-01

    Image enhancement is a crucial technique for infrared images. The clear image details are important for improving the quality of infrared images in computer vision. In this paper, we propose a new enhancement method based on two priors via Cellular Automata. First, we directly learn the gradient distribution prior from the images via Cellular Automata. Second, considering the importance of image details, we propose a new gradient distribution error to encode the structure information via Cellular Automata. Finally, an iterative method is applied to remap the original image based on two priors, further improving the quality of enhanced image. Our method is simple in implementation, easy to understand, extensible to accommodate other vision tasks, and produces more accurate results. Experiments show that the proposed method performs better than other methods using qualitative and quantitative measures.

  8. Emergence of linguistic-like structures in one-dimensional cellular automata

    Science.gov (United States)

    Bertacchini, Francesca; Bilotta, Eleonora; Caldarola, Fabio; Pantano, Pietro; Bustamante, Leonardo Renteria

    2016-10-01

    In this paper we give a summary of some empirical investigations which show high analogies between Cellular Automata and linguistic structures. In particular we show as coupling regular domains of Cellular Automata we find complex emerging structures similar to combination of words, phonemes and morphemes in natural languages.

  9. Sparse regularization techniques provide novel insights into outcome integration processes.

    Science.gov (United States)

    Mohr, Holger; Wolfensteller, Uta; Frimmel, Steffi; Ruge, Hannes

    2015-01-01

    By exploiting information that is contained in the spatial arrangement of neural activations, multivariate pattern analysis (MVPA) can detect distributed brain activations which are not accessible by standard univariate analysis. Recent methodological advances in MVPA regularization techniques have made it feasible to produce sparse discriminative whole-brain maps with highly specific patterns. Furthermore, the most recent refinement, the Graph Net, explicitly takes the 3D-structure of fMRI data into account. Here, these advanced classification methods were applied to a large fMRI sample (N=70) in order to gain novel insights into the functional localization of outcome integration processes. While the beneficial effect of differential outcomes is well-studied in trial-and-error learning, outcome integration in the context of instruction-based learning has remained largely unexplored. In order to examine neural processes associated with outcome integration in the context of instruction-based learning, two groups of subjects underwent functional imaging while being presented with either differential or ambiguous outcomes following the execution of varying stimulus-response instructions. While no significant univariate group differences were found in the resulting fMRI dataset, L1-regularized (sparse) classifiers performed significantly above chance and also clearly outperformed the standard L2-regularized (dense) Support Vector Machine on this whole-brain between-subject classification task. Moreover, additional L2-regularization via the Elastic Net and spatial regularization by the Graph Net improved interpretability of discriminative weight maps but were accompanied by reduced classification accuracies. Most importantly, classification based on sparse regularization facilitated the identification of highly specific regions differentially engaged under ambiguous and differential outcome conditions, comprising several prefrontal regions previously associated with

  10. *-Regular Leavitt Path Algebras of Arbitrary Graphs

    Institute of Scientific and Technical Information of China (English)

    Gonzalo ARANDA PINO; Kulumani RANGASWAMY; Lia VA(S)

    2012-01-01

    If K is a field with involution and E an arbitrary graph,the involution from K naturally induces an involution of the Leavitt path algebra LK(E).We show that the involution on LK(E) is proper if the involution on K is positive-definite,even in the case when the graph E is not necessarily finite or row-finite.It has been shown that the Leavitt path algebra LK(E) is regular if and only if E is acyclic.We give necessary and sufficient conditions for LK(E) to be *-regular (i.e.,regular with proper involution).This characterization of *-regularity of a Leavitt path algebra is given in terms of an algebraic property of K,not just a graph-theoretic property of E.This differs from the.known characterizations of various other algebraic properties of a Leavitt path algebra in terms of graphtheoretic properties of E alone.As a corollary,we show that Handelman's conjecture (stating that every *-regular ring is unit-regular) holds for Leavitt path algebras.Moreover,its generalized version for rings with local units also continues to hold for Leavitt path algebras over arbitrary graphs.

  11. The 2D Density Distribution Inversion of Gravity Data Based on the Differential Form of Tikhonov Regularization and Its Application in Poyang Basin%基于Tikhonov正则化微分形式的重力2D密度反演方法及其在鄱阳盆地的应用

    Institute of Scientific and Technical Information of China (English)

    殷卓

    2013-01-01

    详细讨论了用于计算重力密度分布的2D密度模型方法.该方法将已知地质地球物理数据作为先验信息以相对和绝对约束的形式引入反演方程中,从而在很大程度上减少了反演的多解性.首次利用洪吉诺夫正则化方法的微分形式处理重力数据的反问题,解决了方程解的病态性的同时进一步提高了反演结果的精度.将该反演方法应用于鄱阳湖盆地的剖面重力数据反演中,根据反演结果及重震综合解释结果将该盆地划分为三个构造分区.%The method of 2D density model of gravity data to calculate the density distribution is discussed in detail. The known geological and geophysical data is as the priori information in the form of relative and absolute constraints which are introduced into the inversion equations, so the multiplicity of solutions is reduced. The differential form of the Tikhonov Regularization method is firstly applied in the inversion of the gravity data. The illness of the equations is solved while the calculation accuracy is improved. The gravity data inversion method is applied to the cross-section of the Poyang Lake basin. According to the interpretation about the results of the basin of the inversion results and re-shock, the Poyang basin is divided into three tectonic divisions.

  12. Architected Cellular Materials

    Science.gov (United States)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  13. Epigenetics and Cellular Metabolism

    Science.gov (United States)

    Xu, Wenyi; Wang, Fengzhong; Yu, Zhongsheng; Xin, Fengjiao

    2016-01-01

    Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc.) is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the processing of epigenetic memory. Here, we summarize the recent research progress in the epigenetic regulation of cellular metabolism and discuss how the dysfunction of epigenetic machineries influences the development of metabolic disorders such as diabetes and obesity; then, we focus on discussing the notion that manipulating metabolites, the fuel of cell metabolism, can function as a strategy for interfering epigenetic machinery and its related disease progression as well. PMID:27695375

  14. Cellular structural biology.

    Science.gov (United States)

    Ito, Yutaka; Selenko, Philipp

    2010-10-01

    While we appreciate the complexity of the intracellular environment as a general property of every living organism, we collectively lack the appropriate tools to analyze protein structures in a cellular context. In-cell NMR spectroscopy represents a novel biophysical tool to investigate the conformational and functional characteristics of biomolecules at the atomic level inside live cells. Here, we review recent in-cell NMR developments and provide an outlook towards future applications in prokaryotic and eukaryotic cells. We hope to thereby emphasize the usefulness of in-cell NMR techniques for cellular studies of complex biological processes and for structural analyses in native environments. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Cellular blue naevus

    Directory of Open Access Journals (Sweden)

    Mittal R

    2001-01-01

    Full Text Available A 31-year-old man had asymptomatic, stationary, 1.5X2 cm, shiny, smooth, dark blue nodule on dorsum of right hand since 12-14 years. In addition he had developed extensive eruption of yellow to orange papulonodular lesions on extensors of limbs and buttocks since one and half months. Investigations confirmed that yellow papules were xanthomatosis and he had associated diabetes mellitus and hyperlipidaemia. Biopsy of blue nodule confirmed the clinical diagnosis of cellular blue naevus. Cellular blue naevus is rare and its association with xanthomatosis and diabetes mellitus were interesting features of above patients which is being reported for its rarity.

  16. The Least Regular Order with Respect to a Regular Congruence on Ordered Γ-Semigroups

    Institute of Scientific and Technical Information of China (English)

    Manoj SIRIPITUKDET; Aiyared IAMPAN

    2012-01-01

    The motivation mainly comes from the conditions of congruences to be regular that are of importance and interest in ordered semigroups.In 1981,Sen has introduced the concept of the Γ-semigroups.We can see that any semigroup can be considered as a Γ-semigroup.In this paper,we introduce and characterize the concept of the regular congruences on ordered Γ-semigroups and prove the following statements on an ordered Γ-semigroup M:(1) Every ordered semilattice congruences is a regular congruence.(2) There exists the least regular order on the T-semigroup M/p with respect to a regular congruence p on M.(3) The regular congruences are not ordered semilattice congruences in general.

  17. Spatial distribution

    DEFF Research Database (Denmark)

    Borregaard, Michael Krabbe; Hendrichsen, Ditte Katrine; Nachman, Gøsta Støger

    2008-01-01

    Living organisms are distributed over the entire surface of the planet. The distribution of the individuals of each species is not random; on the contrary, they are strongly dependent on the biology and ecology of the species, and vary over different spatial scale. The structure of whole...... populations reflects the location and fragmentation pattern of the habitat types preferred by the species, and the complex dynamics of migration, colonization, and population growth taking place over the landscape. Within these, individuals are distributed among each other in regular or clumped patterns......, depending on the nature of intraspecific interactions between them: while the individuals of some species repel each other and partition the available area, others form groups of varying size, determined by the fitness of each group member. The spatial distribution pattern of individuals again strongly...

  18. Coordinated Precoding for D2D Communications Underlay Uplink MIMO Cellular Networks

    Directory of Open Access Journals (Sweden)

    Bing Fang

    2016-01-01

    Full Text Available We study the coordinated precoding problem for device-to-device (D2D communications underlay multiple-input multiple-output (MIMO cellular networks. The system model considered here constitutes multiple D2D user pairs attempting to share the uplink radio resources of a cellular network. We first formulate the coordinated precoding problem for the D2D user pairs as a sum-rate maximization (SRM problem, which is subject to a total interference power constraint imposed to protect the base station (BS and individual transmit power budgets available for each D2D user pair. Since the formulated SRM problem is nonconvex in general, we reformulate it as a difference convex- (DC- type programming problem, which can be iteratively solved by employing the famous successive convex approximation (SCA method. Moreover, a proximal-point-based regularization approach is also pursued here to ensure the convergence of the proposed algorithm. Interestingly, the centralized precoding algorithm can also lend itself to a distributed implementation. By introducing a price-based interference management mechanism, we reformulate the coordinated precoding problem as a Stackelberg game. Then, a distributed precoding algorithm is developed based on the concept of Stackelberg equilibrium (SE. Finally, numerical simulations are also provided to demonstrate the proposed algorithms. Results show that our algorithms can converge fast to a satisfactory solution with guaranteed convergence.

  19. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation....

  20. Electromagnetic cellular interactions.

    Science.gov (United States)

    Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan

    2011-05-01

    Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Cellular rehabilitation of photobiomodulation

    Science.gov (United States)

    Liu, Timon Cheng-Yi; Yuan, Jian-Qin; Wang, Yan-Fang; Xu, Xiao-Yang; Liu, Song-Hao

    2007-05-01

    Homeostasis is a term that refers to constancy in a system. A cell in homeostasis normally functions. There are two kinds of processes in the internal environment and external environment of a cell, the pathogenic processes (PP) which disrupts the old homeostasis (OH), and the sanogenetic processes (SP) which restores OH or establishes a new homeostasis (NH). Photobiomodualtion (PBM), the cell-specific effects of low intensity monochromatic light or low intensity laser irradiation (LIL) on biological systems, is a kind of modulation on PP or SP so that there is no PBM on a cell in homeostasis. There are two kinds of pathways mediating PBM, the membrane endogenetic chromophores mediating pathways which often act through reactive oxygen species, and membrane proteins mediating pathways which often enhance cellular SP so that it might be called cellular rehabilitation. The cellular rehabilitation of PBM will be discussed in this paper. It is concluded that PBM might modulate the disruption of cellular homeostasis induced by pathogenic factors such as toxin until OH has been restored or NH has been established, but can not change homeostatic processes from one to another one.

  2. Cellular Response to Irradiation

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; YAN Shi-Wei

    2011-01-01

    To explore the nonlinear activities of the cellular signaling system composed of one transcriptional arm and one protein-interaction arm, we use an irradiation-response module to study the dynamics of stochastic interactions.It is shown that the oscillatory behavior could be described in a unified way when the radiation-derived signal and noise are incorporated.

  3. A Construction for P-Regular Semigroups

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@A regular semigroup S with a special involution *, i.e., a unaryoperation on S satisfying (x*)*=x, xx*x=x, (xy)*=y*x* x, y S, is called a regular *-semigroup[1]. It has been shown by Yamada[2] that a regular semigroup S is a regular *-semigroup if and only if ithas a P-system, that is to say, there is a subset P ofE(S) such that   (c.1) (1) ( p, q P) pq E(S), pqp P;   (2) ( a S) ( | a+ V(a)) aP1a+, a+P1a P.As a generalization of regular *-semigroup and orthodox semigroup,Yamada[3] defined P-regular semigroup. Let S be a regularsemigroup. A subset P of E(S) is called a C-set in S if   (c.2) (1) ( p, q P) pq E(S), pqp P;   (2) ( a S) ( a+ V(a)) aP1a+, a+P1a P.   In this case, (S,P) forms a P-regular semigroup, innotation S(P). The element a+ in(c.2) (2) is called a P-inverse of a. The set of all P-inverses of a is denoted by VP(a). S(P) is said to bestrongly, meanwhile P is called a strong C-set in S, ifVP(p) P for all p P. A partial groupoid E as well as its partial subgroupoid Pforms a P-regular partial band and is denoted by E(P) if itis exactly the subalgebra of the idempotents in some P-regularsemigroup S(P). In this case, S(P) is called an adjacentsemigroup E(P). All P-regular partial bands are obtained inZhang and He[4].

  4. Counting colorings of a regular graph

    CERN Document Server

    Galvin, David

    2012-01-01

    At most how many (proper) q-colorings does a regular graph admit? Galvin and Tetali conjectured that among all n-vertex, d-regular graphs with 2d|n, none admits more q-colorings than the disjoint union of n/2d copies of the complete bipartite graph K_{d,d}. In this note we give asymptotic evidence for this conjecture, giving an upper bound on the number of proper q-colorings admitted by an n-vertex, d-regular graph of the form a^n b^{n(1+o(1))/d} (where a and b depend on q and where o(1) goes to 0 as d goes to infinity) that agrees up to the o(1) term with the count of q-colorings of n/2d copies of K_{d,d}. An auxiliary result is an upper bound on the number of colorings of a regular graph in terms of its independence number. For example, we show that for all even q and fixed \\epsilon > 0 there is \\delta=\\delta(\\epsilon,q) such that the number of proper q-colorings admitted by an n-vertex, d-regular graph with no independent set of size n(1-\\epsilon)/2 is at most (a-\\delta)^n.

  5. Modified sparse regularization for electrical impedance tomography.

    Science.gov (United States)

    Fan, Wenru; Wang, Huaxiang; Xue, Qian; Cui, Ziqiang; Sun, Benyuan; Wang, Qi

    2016-03-01

    Electrical impedance tomography (EIT) aims to estimate the electrical properties at the interior of an object from current-voltage measurements on its boundary. It has been widely investigated due to its advantages of low cost, non-radiation, non-invasiveness, and high speed. Image reconstruction of EIT is a nonlinear and ill-posed inverse problem. Therefore, regularization techniques like Tikhonov regularization are used to solve the inverse problem. A sparse regularization based on L1 norm exhibits superiority in preserving boundary information at sharp changes or discontinuous areas in the image. However, the limitation of sparse regularization lies in the time consumption for solving the problem. In order to further improve the calculation speed of sparse regularization, a modified method based on separable approximation algorithm is proposed by using adaptive step-size and preconditioning technique. Both simulation and experimental results show the effectiveness of the proposed method in improving the image quality and real-time performance in the presence of different noise intensities and conductivity contrasts.

  6. Regular Expression Matching and Operational Semantics

    Directory of Open Access Journals (Sweden)

    Asiri Rathnayake

    2011-08-01

    Full Text Available Many programming languages and tools, ranging from grep to the Java String library, contain regular expression matchers. Rather than first translating a regular expression into a deterministic finite automaton, such implementations typically match the regular expression on the fly. Thus they can be seen as virtual machines interpreting the regular expression much as if it were a program with some non-deterministic constructs such as the Kleene star. We formalize this implementation technique for regular expression matching using operational semantics. Specifically, we derive a series of abstract machines, moving from the abstract definition of matching to increasingly realistic machines. First a continuation is added to the operational semantics to describe what remains to be matched after the current expression. Next, we represent the expression as a data structure using pointers, which enables redundant searches to be eliminated via testing for pointer equality. From there, we arrive both at Thompson's lockstep construction and a machine that performs some operations in parallel, suitable for implementation on a large number of cores, such as a GPU. We formalize the parallel machine using process algebra and report some preliminary experiments with an implementation on a graphics processor using CUDA.

  7. Regularities, Natural Patterns and Laws of Nature

    Directory of Open Access Journals (Sweden)

    Stathis Psillos

    2014-02-01

    Full Text Available  The goal of this paper is to sketch an empiricist metaphysics of laws of nature. The key idea is that there are regularities without regularity-enforcers. Differently put, there are natural laws without law-makers of a distinct metaphysical kind. This sketch will rely on the concept of a natural pattern and more significantly on the existence of a network of natural patterns in nature. The relation between a regularity and a pattern will be analysed in terms of mereology.  Here is the road map. In section 2, I will briefly discuss the relation between empiricism and metaphysics, aiming to show that an empiricist metaphysics is possible. In section 3, I will offer arguments against stronger metaphysical views of laws. Then, in section 4 I will motivate nomic objectivism. In section 5, I will address the question ‘what is a regularity?’ and will develop a novel answer to it, based on the notion of a natural pattern. In section 6, I will raise the question: ‘what is a law of nature?’, the answer to which will be: a law of nature is a regularity that is characterised by the unity of a natural pattern.

  8. Mining High Utility Itemsets with Regular Occurrence

    Directory of Open Access Journals (Sweden)

    Komate Amphawan

    2016-09-01

    Full Text Available High utility itemset mining (HUIM plays an important role in the data mining community and in a wide range of applications. For example, in retail business it is used for finding sets of sold products that give high profit, low cost, etc. These itemsets can help improve marketing strategies, make promotions/ advertisements, etc. However, since HUIM only considers utility values of items/itemsets, it may not be sufficient to observe product-buying behavior of customers such as information related to “regular purchases of sets of products having a high profit margin”. To address this issue, the occurrence behavior of itemsets (in the term of regularity simultaneously with their utility values was investigated. Then, the problem of mining high utility itemsets with regular occurrence (MHUIR to find sets of co-occurrence items with high utility values and regular occurrence in a database was considered. An efficient single-pass algorithm, called MHUIRA, was introduced. A new modified utility-list structure, called NUL, was designed to efficiently maintain utility values and occurrence information and to increase the efficiency of computing the utility of itemsets. Experimental studies on real and synthetic datasets and complexity analyses are provided to show the efficiency of MHUIRA combined with NUL in terms of time and space usage for mining interesting itemsets based on regularity and utility constraints.

  9. On a correspondence between regular and non-regular operator monotone functions

    DEFF Research Database (Denmark)

    Gibilisco, P.; Hansen, Frank; Isola, T.

    2009-01-01

    We prove the existence of a bijection between the regular and the non-regular operator monotone functions satisfying a certain functional equation. As an application we give a new proof of the operator monotonicity of certain functions related to the Wigner-Yanase-Dyson skew information.......We prove the existence of a bijection between the regular and the non-regular operator monotone functions satisfying a certain functional equation. As an application we give a new proof of the operator monotonicity of certain functions related to the Wigner-Yanase-Dyson skew information....

  10. Almost Regularity Conditions of Spectral Problems for a Second Order Equation

    Institute of Scientific and Technical Information of China (English)

    Yu.A. Mamedov; H.I. Ahmadov

    2004-01-01

    The asymptotic distributions are exactly solved for linearly independent solutions considering problem of the second order and for the coefficients of asymptotic distribution the recurrent formulas are obtained. Further, using obtained recurrent formulas the necessary and sufficient conditions for almost regularity of spectral problem for the equation of the second order is proved.

  11. Regularization of binomial differential equations with singular coefficients

    CERN Document Server

    Goriunov, Andrii

    2011-01-01

    We propose a regularization of the formal differential expression of order $m \\geqslant 3$ $$ l(y) = i^my^{(m)}(t) + q(t)y(t), \\,t \\in (a, b), $$ applying quasi-derivatives. The distribution coefficient $q$ is supposed to have an antiderivative $Q \\in L([a,b];\\mathbb{C})$. For the symmetric case ($Q = \\bar{Q}$) self-adjoint and maximal dissipative extensions of the minimal operator and its generalized resolvents are described. The resolvent approximation with resrect to the norm of the considered operators is also investigated. The case $m = 2$ for $Q \\in L_2([a, b];\\mathbb{C})$ was investigated earlier.

  12. Absolute regularity and ergodicity of Poisson count processes

    CERN Document Server

    Neumann, Michael H

    2012-01-01

    We consider a class of observation-driven Poisson count processes where the current value of the accompanying intensity process depends on previous values of both processes. We show under a contractive condition that the bivariate process has a unique stationary distribution and that a stationary version of the count process is absolutely regular. Moreover, since the intensities can be written as measurable functionals of the count variables, we conclude that the bivariate process is ergodic. As an important application of these results, we show how a test method previously used in the case of independent Poisson data can be used in the case of Poisson count processes.

  13. The entire regularization path for the support vector domain description

    DEFF Research Database (Denmark)

    Sjöstrand, Karl; Larsen, Rasmus

    2006-01-01

    -class support vector machine classifier. Recently, it was shown that the regularization path of the support vector machine is piecewise linear, and that the entire path can be computed efficiently. This pa- per shows that this property carries over to the support vector domain description. Using our results......The support vector domain description is a one-class classi- fication method that estimates the shape and extent of the distribution of a data set. This separates the data into outliers, outside the decision boundary, and inliers on the inside. The method bears close resemblance to the two...

  14. Regularized Image Reconstruction for Ultrasound Attenuation Transmission Tomography

    Directory of Open Access Journals (Sweden)

    I. Peterlik

    2008-06-01

    Full Text Available The paper is focused on ultrasonic transmission tomography as a potential medical imaging modality, namely for breast cancer diagnosis. Ultrasound attenuation coefficient is one of the tissue parameters which are related to the pathological tissue state. A technique to reconstruct images of attenuation distribution is presented. Furthermore, an alternative to the commonly used filtered backprojection or algebraic reconstruction techniques is proposed. It is based on regularization of the image reconstruction problem which imposes smoothness in the resulting images while preserving edges. The approach is analyzed on synthetic data sets. The results show that it stabilizes the image restoration by compensating for main sources of estimation errors in this imaging modality.

  15. SAR image regularization with fast approximate discrete minimization.

    Science.gov (United States)

    Denis, Loïc; Tupin, Florence; Darbon, Jérôme; Sigelle, Marc

    2009-07-01

    Synthetic aperture radar (SAR) images, like other coherent imaging modalities, suffer from speckle noise. The presence of this noise makes the automatic interpretation of images a challenging task and noise reduction is often a prerequisite for successful use of classical image processing algorithms. Numerous approaches have been proposed to filter speckle noise. Markov random field (MRF) modelization provides a convenient way to express both data fidelity constraints and desirable properties of the filtered image. In this context, total variation minimization has been extensively used to constrain the oscillations in the regularized image while preserving its edges. Speckle noise follows heavy-tailed distributions, and the MRF formulation leads to a minimization problem involving nonconvex log-likelihood terms. Such a minimization can be performed efficiently by computing minimum cuts on weighted graphs. Due to memory constraints, exact minimization, although theoretically possible, is not achievable on large images required by remote sensing applications. The computational burden of the state-of-the-art algorithm for approximate minimization (namely the alpha -expansion) is too heavy specially when considering joint regularization of several images. We show that a satisfying solution can be reached, in few iterations, by performing a graph-cut-based combinatorial exploration of large trial moves. This algorithm is applied to joint regularization of the amplitude and interferometric phase in urban area SAR images.

  16. Extended, regular HI structures around early-type galaxies

    CERN Document Server

    Oosterloo, T; Sadler, E M; Van der Hulst, J M; Serra, P

    2007-01-01

    We discuss the morphology and kinematics of the HI of a sample of 30 southern gas-rich early-type galaxies selected from the HI Parkes All-Sky Survey (HIPASS). This is the largest collection of high-resolution HI data of a homogeneously selected sample. Given the sensitivity of HIPASS, these galaxies represent the most HI-rich early-type galaxies. In two-thirds of the galaxies, we find the HI to be in a large, regular disk- or ring-like structure that in some cases is strongly warped. In the remaining cases we find the HI distributed in irregular tails or clouds offset from the galaxy. The giant, regular HI structures can be up to ~200 kpc in diameter and contain up to 10^10 M_sun of HI. The incidence of irregular HI structures appears to be somewhat higher in elliptical galaxies, but the large, regular structures are observed in both elliptical and S0 galaxies and are not strictly connected to the presence of a stellar disk. If these two types of galaxies are the result of different formation paths, this is ...

  17. Shadow of rotating regular black holes

    CERN Document Server

    Abdujabbarov, Ahmadjon; Ahmedov, Bobomurat; Ghosh, Sushant G

    2016-01-01

    We study the shadows cast by the different types of rotating regular black holes viz. Ay\\'on-Beato-Garc\\'ia {(ABG)}, Hayward, and Bardeen. These black holes have in addition to the total mass ($M$) and rotation parameter ($a$), different parameters as electric charge ($Q$), deviation parameter ($g$), and magnetic charge ($g_{*}$), respectively. Interestingly, the size of the shadow is affected by these parameters in addition to the rotation parameter. We found that the radius of the shadow in each case decreases monotonically and the distortion parameter increases when the value of these parameters increase. A comparison with the standard Kerr case is also investigated. We have also studied the influence of the plasma environment around regular black holes to discuss its shadow. The presence of the plasma affects the apparent size of the regular black hole's shadow to be increased due to two effects (i) gravitational redshift of the photons and (ii) radial dependence of plasma density.

  18. Fractional Regularization Term for Variational Image Registration

    Directory of Open Access Journals (Sweden)

    Rafael Verdú-Monedero

    2009-01-01

    Full Text Available Image registration is a widely used task of image analysis with applications in many fields. Its classical formulation and current improvements are given in the spatial domain. In this paper a regularization term based on fractional order derivatives is formulated. This term is defined and implemented in the frequency domain by translating the energy functional into the frequency domain and obtaining the Euler-Lagrange equations which minimize it. The new regularization term leads to a simple formulation and design, being applicable to higher dimensions by using the corresponding multidimensional Fourier transform. The proposed regularization term allows for a real gradual transition from a diffusion registration to a curvature registration which is best suited to some applications and it is not possible in the spatial domain. Results with 3D actual images show the validity of this approach.

  19. Regular non-twisting S-branes

    CERN Document Server

    Obregón, O; Ryan, M P; Obregon, Octavio; Quevedo, Hernando; Ryan, Michael P.

    2004-01-01

    We construct a family of time and angular dependent, regular S-brane solutions which corresponds to a simple analytical continuation of the Zipoy-Voorhees 4-dimensional vacuum spacetime. The solutions are asymptotically flat and turn out to be free of singularities without requiring a twist in space. They can be considered as the simplest non-singular generalization of the singular S0-brane solution. We analyze the properties of a representative of this family of solutions and show that it resembles to some extent the asymptotic properties of the regular Kerr S-brane. The R-symmetry corresponds, however, to the general Lorentzian symmetry. Several generalizations of this regular solution are derived which include a charged S-brane and an additional dilatonic field.

  20. Robust super-resolution without regularization

    Energy Technology Data Exchange (ETDEWEB)

    Pham, T Q [Canon Information Systems Research Australia, 1 Thomas Holt drive, North Ryde, NSW 2113 (Australia); Vliet, L J v [Quantitative Imaging Group, Department of Imaging Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Schutte, K [Electro-Optics Group, TNO Defence, Security and Safety, PO Box 96864, 2509 JG The Hague (Netherlands)

    2008-07-15

    Super-resolution restoration is the problem of restoring a high-resolution scene from multiple degraded low-resolution images under motion. Due to imaging blur and noise, this problem is ill-posed. Additional constraints such as smoothness of the solution (i.e. regularization) is often required to obtain a stable solution. While regularizing the cost function is a standard practice in image restoration, we propose a restoration algorithm that does not require this extra regularization term. The robustness of the algorithm is achieved by a robust error norm that does not response to intensity outliers. With the outliers suppressed, our solution behaves similarly to a maximum-likelihood solution under the presence of Gaussian noise. The effectiveness of our algorithm is demonstrated with super-resolution restoration of real infrared image sequences under severe aliasing and intensity outliers.

  1. Implementing regularization implicitly via approximate eigenvector computation

    CERN Document Server

    Mahoney, Michael W

    2010-01-01

    Regularization is a powerful technique for extracting useful information from noisy data. Typically, it is implemented by adding some sort of norm constraint to an objective function and then exactly optimizing the modified objective function. This procedure typically leads to optimization problems that are computationally more expensive than the original problem, a fact that is clearly problematic if one is interested in large-scale applications. On the other hand, a large body of empirical work has demonstrated that heuristics, and in some cases approximation algorithms, developed to speed up computations sometimes have the side-effect of performing regularization implicitly. Thus, we consider the question: What is the regularized optimization objective that an approximation algorithm is exactly optimizing? We address this question in the context of computing approximations to the smallest nontrivial eigenvector of a graph Laplacian; and we consider three random-walk-based procedures: one based on the heat ...

  2. Nonlinear electrodynamics and regular black holes

    Science.gov (United States)

    Sajadi, S. N.; Riazi, N.

    2017-03-01

    In this work, an exact regular black hole solution in General Relativity is presented. The source is a nonlinear electromagnetic field with the algebraic structure T00=T11 for the energy-momentum tensor, partially satisfying the weak energy condition but not the strong energy condition. In the weak field limit, the EM field behaves like the Maxwell field. The solution corresponds to a charged black hole with q≤0.77 m. The metric, the curvature invariants, and the electric field are regular everywhere. The BH is stable against small perturbations of spacetime and using the Weinhold metric, geometrothermodynamical stability has been investigated. Finally we investigate the idea that the observable universe lives inside a regular black hole. We argue that this picture might provide a viable description of universe.

  3. Regularization and Migration Policy in Europe

    Directory of Open Access Journals (Sweden)

    Philippe de Bruycker

    2001-05-01

    Full Text Available The following pages present, in a general way, the contents of Regularization of illegal immigrants in the European Union, which includes a comparative synthesis and statistical information for each of the eight countries involved; a description of actions since the beginning of the year 2000; and a systematic analysis of the different categories of foreigners, the types of regularization carried out, and the rules that have governed these actions.In relation to regularization, the author considers the political coherence of the actions taken by the member states as well as how they relate to two ever more crucial aspects of immigration policy –the integration of legal resident immigrants and the fight againstillegal immigration in the context of a control of migratory flows.

  4. The Ruin Probability in the Presence of Extended Regular Variation and Optimal Investment

    Institute of Scientific and Technical Information of China (English)

    Li Wei

    2008-01-01

    Considering the classical model with risky investment, we are interested in the ruin probability that is minimized by a suitably chosen investment strategy for a capital market index. For claim sizes with common distribution of extended regular variation, starting from an integro-differential equation for the maximal survival probability, we find that the corresponding ruin probability as a function of the initial surplus is also extended regular variation.

  5. Optimization of regularization parameter of inversion in particle sizing using light extinction method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In particle sizing by light extinction method, the regularization parameter plays an important role in applying regularization to find the solution to ill-posed inverse problems. We combine the generalized cross-validation (GCV) and L-curve criteria with the Twomey-NNLS algorithm in parameter optimization. Numerical simulation and experimental validation show that the resistance of the newly developed algorithms to measurement errors can be improved leading to stable inversion results for unimodal particle size distribution.

  6. Image reconstruction based on L1 regularization and projection methods for electrical impedance tomography.

    Science.gov (United States)

    Wang, Qi; Wang, Huaxiang; Zhang, Ronghua; Wang, Jinhai; Zheng, Yu; Cui, Ziqiang; Yang, Chengyi

    2012-10-01

    Electrical impedance tomography (EIT) is a technique for reconstructing the conductivity distribution by injecting currents at the boundary of a subject and measuring the resulting changes in voltage. Image reconstruction in EIT is a nonlinear and ill-posed inverse problem. The Tikhonov method with L(2) regularization is always used to solve the EIT problem. However, the L(2) method always smoothes the sharp changes or discontinue areas of the reconstruction. Image reconstruction using the L(1) regularization allows addressing this difficulty. In this paper, a sum of absolute values is substituted for the sum of squares used in the L(2) regularization to form the L(1) regularization, the solution is obtained by the barrier method. However, the L(1) method often involves repeatedly solving large-dimensional matrix equations, which are computationally expensive. In this paper, the projection method is combined with the L(1) regularization method to reduce the computational cost. The L(1) problem is mainly solved in the coarse subspace. This paper also discusses the strategies of choosing parameters. Both simulation and experimental results of the L(1) regularization method were compared with the L(2) regularization method, indicating that the L(1) regularization method can improve the quality of image reconstruction and tolerate a relatively high level of noise in the measured voltages. Furthermore, the projected L(1) method can also effectively reduce the computational time without affecting the quality of reconstructed images.

  7. Refining cellular automata with routing constraints

    OpenAIRE

    Millo, Jean-Vivien; De Simone, Robert

    2012-01-01

    A cellular automaton (CA) is an infinite array of cells, each containing the same automaton. The dynamics of a CA is distributed over the cells where each computes its next state as a function of the previous states of its neighborhood. Thus, the transmission of such states between neighbors is considered as feasible directly, in no time. When considering the implementation of a cellular automaton on a many-cores System-on-Chip (SoC), this state transmission is no longer abstract and instanta...

  8. Sensing Phosphatidylserine in Cellular Membranes

    Directory of Open Access Journals (Sweden)

    Jason G. Kay

    2011-01-01

    Full Text Available Phosphatidylserine, a phospholipid with a negatively charged head-group, is an important constituent of eukaryotic cellular membranes. On the plasma membrane, rather than being evenly distributed, phosphatidylserine is found preferentially in the inner leaflet. Disruption of this asymmetry, leading to the appearance of phosphatidylserine on the surface of the cell, is known to play a central role in both apoptosis and blood clotting. Despite its importance, comparatively little is known about phosphatidylserine in cells: its precise subcellular localization, transmembrane topology and intracellular dynamics are poorly characterized. The recent development of new, genetically-encoded probes able to detect phosphatidylserine within live cells, however, is leading to a more in-depth understanding of the biology of this phospholipid. This review aims to give an overview of the current methods for phosphatidylserine detection within cells, and some of the recent realizations derived from their use.

  9. Stability Analysis for Regularized Least Squares Regression

    OpenAIRE

    Rudin, Cynthia

    2005-01-01

    We discuss stability for a class of learning algorithms with respect to noisy labels. The algorithms we consider are for regression, and they involve the minimization of regularized risk functionals, such as L(f) := 1/N sum_i (f(x_i)-y_i)^2+ lambda ||f||_H^2. We shall call the algorithm `stable' if, when y_i is a noisy version of f*(x_i) for some function f* in H, the output of the algorithm converges to f* as the regularization term and noise simultaneously vanish. We consider two flavors of...

  10. Interaction of Regular and Chaotic States

    CERN Document Server

    De Pace, A; Weidenmüller, H A

    2006-01-01

    Modelling the chaotic states in terms of the Gaussian Orthogonal Ensemble of random matrices (GOE), we investigate the interaction of the GOE with regular bound states. The eigenvalues of the latter may or may not be embedded in the GOE spectrum. We derive a generalized form of the Pastur equation for the average Green's function. We use that equation to study the average and the variance of the shift of the regular states, their spreading width, and the deformation of the GOE spectrum non-perturbatively. We compare our results with various perturbative approaches.

  11. Regular transport dynamics produce chaotic travel times.

    Science.gov (United States)

    Villalobos, Jorge; Muñoz, Víctor; Rogan, José; Zarama, Roberto; Johnson, Neil F; Toledo, Benjamín; Valdivia, Juan Alejandro

    2014-06-01

    In the hope of making passenger travel times shorter and more reliable, many cities are introducing dedicated bus lanes (e.g., Bogota, London, Miami). Here we show that chaotic travel times are actually a natural consequence of individual bus function, and hence of public transport systems more generally, i.e., chaotic dynamics emerge even when the route is empty and straight, stops and lights are equidistant and regular, and loading times are negligible. More generally, our findings provide a novel example of chaotic dynamics emerging from a single object following Newton's laws of motion in a regularized one-dimensional system.

  12. No finite $5$-regular matchstick graph exists

    OpenAIRE

    2014-01-01

    A graph $G=(V,E)$ is called a unit-distance graph in the plane if there is an injective embedding of $V$ in the plane such that every pair of adjacent vertices are at unit distance apart. If additionally the corresponding edges are non-crossing and all vertices have the same degree $r$ we talk of a regular matchstick graph. Due to Euler's polyhedron formula we have $r\\le 5$. The smallest known $4$-regular matchstick graph is the so called Harborth graph consisting of $52$ vertices. In this ar...

  13. On d-Walk Regular Graphs

    OpenAIRE

    Estrada, Ernesto; de la Pena, Jose A.

    2013-01-01

    Let G be a graph with set of vertices 1,...,n and adjacency matrix A of size nxn. Let d(i,j)=d, we say that f_d:N->N is a d-function on G if for every pair of vertices i,j and k>=d, we have a_ij^(k)=f_d(k). If this function f_d exists on G we say that G is d-walk regular. We prove that G is d-walk regular if and only if for every pair of vertices i,j at distance

  14. 5G and Cellular Networks in the Smart Grid

    DEFF Research Database (Denmark)

    Nielsen, Jimmy Jessen; Jorguseski, Ljupco; Zhang, Haibin

    2017-01-01

    Wireless cellular networks will help Distribution System Operators (DSOs) to achieve observability below the substation level, which is needed to ensure stable operation in the smart grid. Both existing and upcoming cellular technologies are considered as candidates for helping to enable the smart...... the challenges and possible solutions for ensuring end-to-end security in smart grid systems....

  15. Regularities of formation of ternary alloy phases between non-transition metals

    Institute of Scientific and Technical Information of China (English)

    姚莉秀; 陈瑞亮; 钦佩; 陈念贻; 陆文聪

    2000-01-01

    Using a four-parameter model based on extended Miedema’ s cellular model of alloy phases and pattern recognition methods, the regularities of formation of ternary intermetallic compounds between non-transition metals have been investigated. The criterion of formation can be expressed as some empirical functions of Φ (electronegativity), nws1/3( valence electron density in Wagn-er-Seitz cell), R (Pauling’s metallic radius) and Z (number of valence electrons in atom).

  16. Regularities of formation of ternary alloy phases between non-transition metals

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Using a four-parameter model based on extended Miedema's cellular model of alloy phases and pattern recognition methods, the regularities of formation of ternary intermetallic compounds between non-transition metals have been investigated. The criterion of formation can be expressed as some empirical functions of Ф (electronegativity), n1/3WS (valence electron density in Wagner-Seitz cell), R (Pauling's metallic radius) and Z (number of valence electrons in atom).

  17. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  18. Reconstruction Method for Optical Tomography Based on the Linearized Bregman Iteration with Sparse Regularization

    Directory of Open Access Journals (Sweden)

    Chengcai Leng

    2015-01-01

    Full Text Available Optical molecular imaging is a promising technique and has been widely used in physiology, and pathology at cellular and molecular levels, which includes different modalities such as bioluminescence tomography, fluorescence molecular tomography and Cerenkov luminescence tomography. The inverse problem is ill-posed for the above modalities, which cause a nonunique solution. In this paper, we propose an effective reconstruction method based on the linearized Bregman iterative algorithm with sparse regularization (LBSR for reconstruction. Considering the sparsity characteristics of the reconstructed sources, the sparsity can be regarded as a kind of a priori information and sparse regularization is incorporated, which can accurately locate the position of the source. The linearized Bregman iteration method is exploited to minimize the sparse regularization problem so as to further achieve fast and accurate reconstruction results. Experimental results in a numerical simulation and in vivo mouse demonstrate the effectiveness and potential of the proposed method.

  19. Multi-omic data integration enables discovery of hidden biological regularities

    DEFF Research Database (Denmark)

    Ebrahim, Ali; Brunk, Elizabeth; Tan, Justin

    2016-01-01

    Rapid growth in size and complexity of biological data sets has led to the 'Big Data to Knowledge' challenge. We develop advanced data integration methods for multi- level analysis of genomic, transcriptomic, ribosomal profiling, proteomic and fluxomic data. First, we show that pairwise integration...... of primary omics data reveals regularities that tie cellular processes together in Escherichia coli: the number of protein molecules made per mRNA transcript and the number of ribosomes required per translated protein molecule. Second, we show that genome- scale models, based on genomic and bibliomic data......, enable quantitative synchronization of disparate data types. Integrating omics data with models enabled the discovery of two novel regularities: condition invariant in vivo turnover rates of enzymes and the correlation of protein structural motifs and translational pausing. These regularities can...

  20. Dynamic stabilization of regular linear systems

    NARCIS (Netherlands)

    Weiss, G; Curtain, RF

    We consider a general class of infinite-dimensional linear systems, called regular linear systems, for which convenient representations are known to exist both in time and in frequency domain, For this class of systems, we investigate the concepts of stabilizability and detectability, in particular,

  1. Regular and context-free nominal traces

    DEFF Research Database (Denmark)

    Mezzetti, Gianluca

    2016-01-01

    Two kinds of automata are presented, for recognising new classes of regular and context-free nominal languages. We compare their expressive power with analogous proposals in the literature, showing that they express novel classes of languages. Although many properties of classical languages hold ...

  2. Neural Classifier Construction using Regularization, Pruning

    DEFF Research Database (Denmark)

    Hintz-Madsen, Mads; Hansen, Lars Kai; Larsen, Jan;

    1998-01-01

    In this paper we propose a method for construction of feed-forward neural classifiers based on regularization and adaptive architectures. Using a penalized maximum likelihood scheme, we derive a modified form of the entropic error measure and an algebraic estimate of the test error. In conjunction...

  3. Deconvolution and Regularization with Toeplitz Matrices

    DEFF Research Database (Denmark)

    Hansen, Per Christian

    2002-01-01

    of these discretized deconvolution problems, with emphasis on methods that take the special structure of the matrix into account. Wherever possible, analogies to classical DFT-based deconvolution problems are drawn. Among other things, we present direct methods for regularization with Toeplitz matrices, and we show...

  4. The moduli space of regular stable maps

    CERN Document Server

    Robbin, Joel; Salamon, Dietmar; 10.1007/s00209-007-0237-x

    2012-01-01

    The moduli space of regular stable maps with values in a complex manifold admits naturally the structure of a complex orbifold. Our proof uses the methods of differential geometry rather than algebraic geometry. It is based on Hardy decompositions and Fredholm intersection theory in the loop space of the target manifold.

  5. Regular conformal system for Einstein equations

    Energy Technology Data Exchange (ETDEWEB)

    Choquet-Bruhat, Y.; Novello, M.

    1987-06-21

    We give a system of partial differential equations satisfied by a metric g conformal to an Einstein metric and by the conformal factor ..omega.., regular system in the sense that it does not contain negative powers of ..omega... We use the ideas of Friedrich but we obtain here a hyperbolic system in the sense of Leray, by a different method.

  6. Optimal Regularizing Effect for Scalar Conservation Laws

    CERN Document Server

    Golse, François

    2011-01-01

    We investigate the regularity of bounded weak solutions of scalar conservation laws with uniformly convex flux in space dimension one, satisfying an entropy condition with entropy production term that is a signed Radon measure. The proof is based on the kinetic formulation of scalar conservation laws and on an interaction estimate in physical space.

  7. Bayesian regularization of diffusion tensor images

    DEFF Research Database (Denmark)

    Frandsen, Jesper; Hobolth, Asger; Østergaard, Leif;

    2007-01-01

    several directions. The measured diffusion coefficients and thereby the diffusion tensors are subject to noise, leading to possibly flawed representations of the three dimensional fibre bundles. In this paper we develop a Bayesian procedure for regularizing the diffusion tensor field, fully utilizing...

  8. Regularity of rotational travelling water waves.

    Science.gov (United States)

    Escher, Joachim

    2012-04-13

    Several recent results on the regularity of streamlines beneath a rotational travelling wave, along with the wave profile itself, will be discussed. The survey includes the classical water wave problem in both finite and infinite depth, capillary waves and solitary waves as well. A common assumption in all models to be discussed is the absence of stagnation points.

  9. Contour Propagation With Riemannian Elasticity Regularization

    DEFF Research Database (Denmark)

    Bjerre, Troels; Hansen, Mads Fogtmann; Sapru, W.;

    2011-01-01

    the planning CT onto the rescans and correcting to reflect actual anatomical changes. For deformable registration, a free-form, multi-level, B-spline deformation model with Riemannian elasticity, penalizing non-rigid local deformations, and volumetric changes, was used. Regularization parameters was defined...

  10. NOTE ON REGULAR D-OPTIMAL MATRICES

    Institute of Scientific and Technical Information of China (English)

    李乔良

    2003-01-01

    Let A be aj ×d (0,1) matrix. It is known that ifj = 2k-1is odd, then det(AAT) ≤(j+1)((j+1)d/4j)j; ifj is even, then det(AAT) ≤ (j+1)((j+2)d/4(j+1))j. A is called a regularD-optimal matrix if it satisfies the equality of the above bounds. In this note, it is proved thatifj = 2k - 1 is odd, then A is a regular D-optimal matrix if and only if A is the adjacent matrixof a (2k - 1, k, (j + 1)d/4j)-BIBD; if j = 2k is even, then A is a regular D-optimal matrix ifand only if A can be obtained from the adjacent matrix B of a (2k + 1, k + 1, (j + 2)d/4(j + 1))-BIBD by deleting any one row from B. Three 21 × 42 regular D-optimal matrices, which wereunknown in [11], are also provided.

  11. A Note on Left Regular Semiring

    Directory of Open Access Journals (Sweden)

    N. Sulochana

    2016-08-01

    Full Text Available In this paper we have focused on the additive and multiplicative identity „e‟ and determine the additive and multiplicative semigroups. Here we established that, A semiring S in which (S, + and (S, • are left singular semigroups, then S is a left regular semiring. We have framed an example for this proposition by considering a two element set

  12. Tikhonov Regularization and Total Least Squares

    DEFF Research Database (Denmark)

    Golub, G. H.; Hansen, Per Christian; O'Leary, D. P.

    2000-01-01

    formulation involves a least squares problem, can be recast in a total least squares formulation suited for problems in which both the coefficient matrix and the right-hand side are known only approximately. We analyze the regularizing properties of this method and demonstrate by a numerical example that...

  13. Creativity Workshops in the Regular Classroom.

    Science.gov (United States)

    Mildrum, Nancy King

    2000-01-01

    This article describes implementation of a creativity curriculum, Ten Lessons in Creativity, with gifted and typical students in elementary and middle school settings. It discusses creativity instruction as a bridge between gifted and regular education, ways that creativity workshops affirm the highly creative child, creativity and self-esteem,…

  14. Regularization of turbulence - a comprehensive modeling approach

    Science.gov (United States)

    Geurts, B. J.

    2011-12-01

    Turbulence readily arises in numerous flows in nature and technology. The large number of degrees of freedom of turbulence poses serious challenges to numerical approaches aimed at simulating and controlling such flows. While the Navier-Stokes equations are commonly accepted to precisely describe fluid turbulence, alternative coarsened descriptions need to be developed to cope with the wide range of length and time scales. These coarsened descriptions are known as large-eddy simulations in which one aims to capture only the primary features of a flow, at considerably reduced computational effort. Such coarsening introduces a closure problem that requires additional phenomenological modeling. A systematic approach to the closure problem, know as regularization modeling, will be reviewed. Its application to multiphase turbulent will be illustrated in which a basic regularization principle is enforced to physically consistently approximate momentum and scalar transport. Examples of Leray and LANS-alpha regularization are discussed in some detail, as are compatible numerical strategies. We illustrate regularization modeling to turbulence under the influence of rotation and buoyancy and investigate the accuracy with which particle-laden flow can be represented. A discussion of the numerical and modeling errors incurred will be given on the basis of homogeneous isotropic turbulence.

  15. Coprime factorization for regular linear systems

    NARCIS (Netherlands)

    Curtain, R; Weiss, G; Weiss, M

    1996-01-01

    Mild sufficient conditions are given for the existence of a doubly coprime factorization of the transfer function of a regular linear system, as well as formulae for such a factorization. The results are illustrated by two examples of delay systems, one of which has infinitely many unstable poles. C

  16. Dynamic stabilization of regular linear systems

    NARCIS (Netherlands)

    Weiss, G; Curtain, RF

    1997-01-01

    We consider a general class of infinite-dimensional linear systems, called regular linear systems, for which convenient representations are known to exist both in time and in frequency domain, For this class of systems, we investigate the concepts of stabilizability and detectability, in particular,

  17. Strategies of Teachers in the Regular Classroom

    Science.gov (United States)

    De Leeuw, Renske Ria; De Boer, Anke Aaltje

    2016-01-01

    It is known that regular schoolteachers have difficulties in educating students with social, emotional and behavioral difficulties (SEBD), mainly because of their disruptive behavior. In order to manage the disruptive behavior of students with SEBD many advices and strategies are provided in educational literature. However, very little is known…

  18. Strategies of teachers in the regular classroom

    NARCIS (Netherlands)

    de Leeuw, Renske Ria; de Boer, Anke Aaltje

    2016-01-01

    It is known that regular schoolteachers have difficulties in educating students with social, emotional and behavioral difficulties (SEBD), mainly because of their disruptive behavior. In order to manage the disruptive behavior of students with SEBD many advices and strategies are provided in educati

  19. On the regularity in some variational problems

    Science.gov (United States)

    Ragusa, Maria Alessandra; Tachikawa, Atsushi

    2017-01-01

    Our main goal is the study some regularity results where are considered estimates in Morrey spaces for the derivatives of local minimizers of variational integrals of the form 𝒜 (u ,Ω )= ∫Ω F (x ,u ,D u ) dx where Ω is a bounded domain in ℝm and the integrand F have some different forms.

  20. Regular-fat dairy and human health

    DEFF Research Database (Denmark)

    Astrup, Arne; Bradley, Beth H Rice; Brenna, J Thomas;

    2016-01-01

    to disseminate, explore and discuss the state of the science on the relationship between regular fat dairy products and health, symposia were programmed by dairy industry organizations in Europe and North America at The Eurofed Lipids Congress (2014) in France, The Dairy Nutrition Annual Symposium (2014...

  1. Regular Submanifolds in Conformal Space Qnp

    Institute of Scientific and Technical Information of China (English)

    Changxiong NIE; Chuanxi WU

    2012-01-01

    The authors study the regular submanifolds in the conformal space Qnp and introduce the submanifold theory in the conformal space Qnp.The first variation formula of the Willmore volume functional of pseudo-Riemannian submanifolds in the conformal space Qnp is given.Finally,the conformal isotropic submanifolds in the conformal space Qnp are classified.

  2. On the regularization procedure in classical electrodynamics

    CERN Document Server

    Yaremko, Yu

    2003-01-01

    We consider the self-action problem in classical electrodynamics. A strict geometrical sense of commonly used renormalization of mass is made. A regularization procedure is proposed which relies on energy-momentum and angular momentum balance equations. We correct the expression for angular momentum tensor obtained by us in a previous paper (2002 J. Phys. A: Math. Gen. 35 831).

  3. The canonical controller and its regularity

    NARCIS (Netherlands)

    Willems, Jan C.; Belur, Madhu N.; Anak Agung Julius, A.A.J.; Trentelman, Harry L.

    2003-01-01

    This paper deals with properties of canonical controllers. We first specify the behavior that they implement. It follows that a canonical controller implements the desired controlled behavior if and only if the desired behavior is implementable. We subsequently investigate the regularity of the cont

  4. Stabilization, Pole Placement, and Regular Implementability

    NARCIS (Netherlands)

    Belur, Madhu N.; Trentelman, H.L.

    2002-01-01

    In this paper, we study control by interconnection of linear differential systems. We give necessary and sufficient conditions for regular implementability of a given linear differential system. We formulate the problems of stabilization and pole placement as problems of finding a suitable, regularl

  5. Generalisation of Regular and Irregular Morphological Patterns.

    Science.gov (United States)

    Prasada, Sandeep; and Pinker, Steven

    1993-01-01

    When it comes to explaining English verbs' patterns of regular and irregular generalization, single-network theories have difficulty with the former, rule-only theories with the latter process. Linguistic and psycholinguistic evidence, based on observation during experiments and simulations in morphological pattern generation, independently call…

  6. Asymptotic Behavior of Excitable Cellular Automata

    CERN Document Server

    Durrett, R; Durrett, Richard; Griffeath, David

    1993-01-01

    Abstract: We study two families of excitable cellular automata known as the Greenberg-Hastings Model (GHM) and the Cyclic Cellular Automaton (CCA). Each family consists of local deterministic oscillating lattice dynamics, with parallel discrete-time updating, parametrized by the range of interaction, the "shape" of its neighbor set, threshold value for contact updating, and number of possible states per site. GHM and CCA are mathematically tractable prototypes for the spatially distributed periodic wave activity of so-called excitable media observed in diverse disciplines of experimental science. Earlier work by Fisch, Gravner, and Griffeath studied the ergodic behavior of these excitable cellular automata on Z^2, and identified two distinct (but closely-related) elaborate phase portraits as the parameters vary. In particular, they noted the emergence of asymptotic phase diagrams (and Euclidean dynamics) in a well-defined threshold-range scaling limit. In this study we present several rigorous results and som...

  7. Quantification of fetal heart rate regularity using symbolic dynamics

    Science.gov (United States)

    van Leeuwen, P.; Cysarz, D.; Lange, S.; Geue, D.; Groenemeyer, D.

    2007-03-01

    Fetal heart rate complexity was examined on the basis of RR interval time series obtained in the second and third trimester of pregnancy. In each fetal RR interval time series, short term beat-to-beat heart rate changes were coded in 8bit binary sequences. Redundancies of the 28 different binary patterns were reduced by two different procedures. The complexity of these sequences was quantified using the approximate entropy (ApEn), resulting in discrete ApEn values which were used for classifying the sequences into 17 pattern sets. Also, the sequences were grouped into 20 pattern classes with respect to identity after rotation or inversion of the binary value. There was a specific, nonuniform distribution of the sequences in the pattern sets and this differed from the distribution found in surrogate data. In the course of gestation, the number of sequences increased in seven pattern sets, decreased in four and remained unchanged in six. Sequences that occurred less often over time, both regular and irregular, were characterized by patterns reflecting frequent beat-to-beat reversals in heart rate. They were also predominant in the surrogate data, suggesting that these patterns are associated with stochastic heart beat trains. Sequences that occurred more frequently over time were relatively rare in the surrogate data. Some of these sequences had a high degree of regularity and corresponded to prolonged heart rate accelerations or decelerations which may be associated with directed fetal activity or movement or baroreflex activity. Application of the pattern classes revealed that those sequences with a high degree of irregularity correspond to heart rate patterns resulting from complex physiological activity such as fetal breathing movements. The results suggest that the development of the autonomic nervous system and the emergence of fetal behavioral states lead to increases in not only irregular but also regular heart rate patterns. Using symbolic dynamics to

  8. Environment Aware Cellular Networks

    KAUST Repository

    Ghazzai, Hakim

    2015-02-01

    The unprecedented rise of mobile user demand over the years have led to an enormous growth of the energy consumption of wireless networks as well as the greenhouse gas emissions which are estimated currently to be around 70 million tons per year. This significant growth of energy consumption impels network companies to pay huge bills which represent around half of their operating expenditures. Therefore, many service providers, including mobile operators, are looking for new and modern green solutions to help reduce their expenses as well as the level of their CO2 emissions. Base stations are the most power greedy element in cellular networks: they drain around 80% of the total network energy consumption even during low traffic periods. Thus, there is a growing need to develop more energy-efficient techniques to enhance the green performance of future 4G/5G cellular networks. Due to the problem of traffic load fluctuations in cellular networks during different periods of the day and between different areas (shopping or business districts and residential areas), the base station sleeping strategy has been one of the main popular research topics in green communications. In this presentation, we present several practical green techniques that provide significant gains for mobile operators. Indeed, combined with the base station sleeping strategy, these techniques achieve not only a minimization of the fossil fuel consumption but also an enhancement of mobile operator profits. We start with an optimized cell planning method that considers varying spatial and temporal user densities. We then use the optimal transport theory in order to define the cell boundaries such that the network total transmit power is reduced. Afterwards, we exploit the features of the modern electrical grid, the smart grid, as a new tool of power management for cellular networks and we optimize the energy procurement from multiple energy retailers characterized by different prices and pollutant

  9. Statistical regularities in the rank-citation profile of scientists.

    Science.gov (United States)

    Petersen, Alexander M; Stanley, H Eugene; Succi, Sauro

    2011-01-01

    Recent science of science research shows that scientific impact measures for journals and individual articles have quantifiable regularities across both time and discipline. However, little is known about the scientific impact distribution at the scale of an individual scientist. We analyze the aggregate production and impact using the rank-citation profile c(i)(r) of 200 distinguished professors and 100 assistant professors. For the entire range of paper rank r, we fit each c(i)(r) to a common distribution function. Since two scientists with equivalent Hirsch h-index can have significantly different c(i)(r) profiles, our results demonstrate the utility of the β(i) scaling parameter in conjunction with h(i) for quantifying individual publication impact. We show that the total number of citations C(i) tallied from a scientist's N(i) papers scales as [Formula: see text]. Such statistical regularities in the input-output patterns of scientists can be used as benchmarks for theoretical models of career progress.

  10. Statistical regularities in the rank-citation profile of scientists

    CERN Document Server

    Petersen, Alexander M; Succi, Sauro

    2011-01-01

    Recent "science of science" research shows common regularities in the publication patterns of scientific papers across time and discipline. Here we analyze the complete publication careers of 300 scientists and find remarkable regularity in the functional form of the rank-citation profile c_{i}(r) for each scientist i =1...300. We find that the rank-ordered citation distribution c_{i}(r) can be approximated by a discrete generalized beta distribution (DGBD) over the entire range of ranks r, which allows for the characterization and comparison of c_{i}(r) using a common framework. The functional form of the DGBD has two scaling exponents, beta_i and gamma_i, which determine the scaling behavior of c_{i}(r) for both small and large rank r. The crossover between two scaling regimes suggests a complex reinforcement or positive-feedback relation between the impact of a scientist's most famous papers and the impact of his/her other papers. Moreover, since two scientists with equivalent Hirsch h-index values may hav...

  11. Clustering, randomness and regularity in cloud fields. I - Theoretical considerations. II - Cumulus cloud fields

    Science.gov (United States)

    Weger, R. C.; Lee, J.; Zhu, Tianri; Welch, R. M.

    1992-01-01

    The current controversy existing in reference to the regularity vs. clustering in cloud fields is examined by means of analysis and simulation studies based upon nearest-neighbor cumulative distribution statistics. It is shown that the Poisson representation of random point processes is superior to pseudorandom-number-generated models and that pseudorandom-number-generated models bias the observed nearest-neighbor statistics towards regularity. Interpretation of this nearest-neighbor statistics is discussed for many cases of superpositions of clustering, randomness, and regularity. A detailed analysis is carried out of cumulus cloud field spatial distributions based upon Landsat, AVHRR, and Skylab data, showing that, when both large and small clouds are included in the cloud field distributions, the cloud field always has a strong clustering signal.

  12. Cellular communication through light.

    Directory of Open Access Journals (Sweden)

    Daniel Fels

    Full Text Available Information transfer is a fundamental of life. A few studies have reported that cells use photons (from an endogenous source as information carriers. This study finds that cells can have an influence on other cells even when separated with a glass barrier, thereby disabling molecule diffusion through the cell-containing medium. As there is still very little known about the potential of photons for intercellular communication this study is designed to test for non-molecule-based triggering of two fundamental properties of life: cell division and energy uptake. The study was performed with a cellular organism, the ciliate Paramecium caudatum. Mutual exposure of cell populations occurred under conditions of darkness and separation with cuvettes (vials allowing photon but not molecule transfer. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UV-light to longer waves. Even through glass, the cells affected cell division and energy uptake in neighboring cell populations. Depending on the cuvette material and the number of cells involved, these effects were positive or negative. Also, while paired populations with lower growth rates grew uncorrelated, growth of the better growing populations was correlated. As there were significant differences when separating the populations with glass or quartz, it is suggested that the cell populations use two (or more frequencies for cellular information transfer, which influences at least energy uptake, cell division rate and growth correlation. Altogether the study strongly supports a cellular communication system, which is different from a molecule-receptor-based system and hints that photon-triggering is a fine tuning principle in cell chemistry.

  13. The regular representation and regular covariant representation of crossed products of Woronowicz C*-algebras

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Xiaoxia; GUO; Maozheng

    2005-01-01

    In this paper, it is shown that the regular representation and regular covariant representation of the crossed products A×α G correspond to the twisted multiplicative unitary operators, where A is a Woronowicz C*-algebra acted upon by a discrete group G. Meanwhile, it is also shown that the regular covariant C*-algebra is the Woronowicz C*-algebra which corresponds to a multiplicative unitary. Finally, an explicit description of the multiplicative unitary operator for C(SUq(2))×α Z is given in terms of those of the Woronowicz C*-algebra C(SUq(2)) and the discrete group G.

  14. Failover in cellular automata

    CERN Document Server

    Kumar, Shailesh

    2010-01-01

    A cellular automata (CA) configuration is constructed that exhibits emergent failover. The configuration is based on standard Game of Life rules. Gliders and glider-guns form the core messaging structure in the configuration. The blinker is represented as the basic computational unit, and it is shown how it can be recreated in case of a failure. Stateless failover using primary-backup mechanism is demonstrated. The details of the CA components used in the configuration and its working are described, and a simulation of the complete configuration is also presented.

  15. Review of cellular mechanotransduction

    Science.gov (United States)

    Wang, Ning

    2017-06-01

    Living cells and tissues experience physical forces and chemical stimuli in the human body. The process of converting mechanical forces into biochemical activities and gene expression is mechanochemical transduction or mechanotransduction. Significant advances have been made in understanding mechanotransduction at the cellular and molecular levels over the last two decades. However, major challenges remain in elucidating how a living cell integrates signals from mechanotransduction with chemical signals to regulate gene expression and to generate coherent biological responses in living tissues in physiological conditions and diseases.

  16. Cellular automata: structures

    OpenAIRE

    Ollinger, Nicolas

    2002-01-01

    Jury : François Blanchard (Rapporteur), Marianne Delorme (Directeur), Jarkko Kari (Président), Jacques Mazoyer (Directeur), Dominique Perrin, Géraud Sénizergues (Rapporteur); Cellular automata provide a uniform framework to study an important problem of "complex systems" theory: how and why do system with a easily understandable -- local -- microscopic behavior can generate a more complicated -- global -- macroscopic behavior? Since its introduction in the 40s, a lot of work has been done to ...

  17. Power Control in Multi-Layer Cellular Networks

    CERN Document Server

    Davaslioglu, Kemal

    2012-01-01

    We investigate the possible performance gains of power control in multi-layer cellular systems where microcells and picocells are distributed within macrocells. Although multilayers in cellular networks help increase system capacity and coverage, and can reduce total energy consumption; they cause interference, reducing the performance of the network. Therefore, downlink transmit power levels of multi-layer hierarchical cellular networks need to be controlled in order to fully exploit their benefits. In this work, we present an analytical derivation to determine optimum power levels for two-layer cellular networks and generalize our solution to multi-layer cellular networks. We also simulate our results in a typical multi-layer network setup and observe significant power savings compared to single-layer cellular networks.

  18. Assessment of Tikhonov-type regularization methods for solving atmospheric inverse problems

    Science.gov (United States)

    Xu, Jian; Schreier, Franz; Doicu, Adrian; Trautmann, Thomas

    2016-11-01

    Inverse problems occurring in atmospheric science aim to estimate state parameters (e.g. temperature or constituent concentration) from observations. To cope with nonlinear ill-posed problems, both direct and iterative Tikhonov-type regularization methods can be used. The major challenge in the framework of direct Tikhonov regularization (TR) concerns the choice of the regularization parameter λ, while iterative regularization methods require an appropriate stopping rule and a flexible λ-sequence. In the framework of TR, a suitable value of the regularization parameter can be generally determined based on a priori, a posteriori, and error-free selection rules. In this study, five practical regularization parameter selection methods, i.e. the expected error estimation (EEE), the discrepancy principle (DP), the generalized cross-validation (GCV), the maximum likelihood estimation (MLE), and the L-curve (LC), have been assessed. As a representative of iterative methods, the iteratively regularized Gauss-Newton (IRGN) algorithm has been compared with TR. This algorithm uses a monotonically decreasing λ-sequence and DP as an a posteriori stopping criterion. Practical implementations pertaining to retrievals of vertically distributed temperature and trace gas profiles from synthetic microwave emission measurements and from real far infrared data, respectively, have been conducted. Our numerical analysis demonstrates that none of the parameter selection methods dedicated to TR appear to be perfect and each has its own advantages and disadvantages. Alternatively, IRGN is capable of producing plausible retrieval results, allowing a more efficient manner for estimating λ.

  19. Cellular Distribution and Gene Expression Pattern of Metastasin (S100A4), Calgranulin A (S100A8), and Calgranulin B (S100A9) in Oral Lesions as Markers for Molecular Pathology.

    Science.gov (United States)

    Reckenbeil, Jan; Kraus, Dominik; Probstmeier, Rainer; Allam, Jean-Pierre; Novak, Natalija; Frentzen, Matthias; Martini, Markus; Wenghoefer, Matthias; Winter, Jochen

    2016-07-02

    The objective of this study was to analyze cellular localization and expression levels of oncologic relevant members of the S100 family in common oral lesions.Biopsies of various oral lesions were analyzed. S100A4 showed a higher expression rate in leukoplakias and oral squamous cell carcinomas. Transcript levels of S100A8 and S100A9 were significantly decreased in malignant OSCCs. A correlation could be drawn between the expression levels of these genes and the pathological characteristics of the investigated lesions. S100A4, A8, and A9 proteins represent promising marker genes to evaluate the risk potential of suspicious oral lesions in molecular pathology.

  20. Regularization and Iterative Methods for Monotone Variational Inequalities

    Directory of Open Access Journals (Sweden)

    Xiubin Xu

    2010-01-01

    Full Text Available We provide a general regularization method for monotone variational inequalities, where the regularizer is a Lipschitz continuous and strongly monotone operator. We also introduce an iterative method as discretization of the regularization method. We prove that both regularization and iterative methods converge in norm.