WorldWideScience

Sample records for block pickard models

  1. Block Pickard Models for Two-Dimensional Constraints

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Justesen, Jørn

    2009-01-01

    whether a PRF consistent with the distribution on the boundary and a 2-D constraint exists. Iterative scaling is used as part of the algorithm, which also determines the conditional probabilities yielding the maximum entropy for the given boundary description if a solution exists. A PRF is defined......In Pickard random fields (PRF), the probabilities of finite configurations and the entropy of the field can be calculated explicitly, but only very simple structures can be incorporated into such a field. Given two Markov chains describing a boundary, an algorithm is presented which determines...

  2. Entretien avec Ully Pickard

    OpenAIRE

    Niogret, Hubert

    2007-01-01

    À l’occasion d’un entretien-témoignage pour un documentaire sur Jacques Becker, nous avions rencontré Ully Pickard, assistant de production ou assistant-réalisateur qui avait travaillé avec Jacques Becker (Casque d’or), Robert Siodmak, Max Ophuls, René Clément, Luis Buñuel (pour des films produits en France), et qui au moment de cet entretien était toujours le collaborateur du producteur Serge Silbermann. Parlant de la flexibilité de Becker et de sa faculté d’adaptation aux conditions de tour...

  3. Maximizing Entropy of Pickard Random Fields for 2x2 Binary Constraints

    DEFF Research Database (Denmark)

    Søgaard, Jacob; Forchhammer, Søren

    2014-01-01

    This paper considers the problem of maximizing the entropy of two-dimensional (2D) Pickard Random Fields (PRF) subject to constraints. We consider binary Pickard Random Fields, which provides a 2D causal finite context model and use it to define stationary probabilities for 2x2 squares, thus allo...... of the maximum PRF entropy. As examples, we consider the well known hard square constraint along with a few other constraints.......This paper considers the problem of maximizing the entropy of two-dimensional (2D) Pickard Random Fields (PRF) subject to constraints. We consider binary Pickard Random Fields, which provides a 2D causal finite context model and use it to define stationary probabilities for 2x2 squares, thus...... allowing us to calculate the entropy of the field. All possible binary 2x2 constraints are considered and all constraints are categorized into groups according to their properties. For constraints which can be modeled by a PRF approach and with positive entropy, we characterize and provide statistics...

  4. Taxonomic review of the New World spider genus Elaver O. Pickard-Cambridge, 1898 (Araneae, Clubionidae).

    Science.gov (United States)

    Saturnino, Regiane; Bonaldo, Alexandre Bragio

    2015-11-23

    Elaver O. Pickard-Cambridge, 1898 is characterized and redescribed, including 49 species occurring from the United States to Argentina. Thirty seven previously known species are redescribed: Elaver achuca (Roddy, 1966) revalidated, E. balboae (Chickering, 1937), E. barroana (Chickering, 1937), E. calcarata (Kraus, 1955), E. carlota (Bryant, 1940), E. chisosa (Roddy, 1966), E. crinophora (Franganillo, 1934), E. crocota (O. Pickard-Cambridge, 1896), E. albicans (Franganillo, 1930) name restored, E. depuncta O. Pickard-Cambridge, 1898, E. elaver (Bryant, 1940), E. excepta (L. Koch, 1866), E. grandivulva (Mello-Leitão, 1930), E. hortoni (Chickering, 1937), E. implicata (Gertsch, 1941), E. juana (Bryant, 1940), E. kohlsi (Gertsch & Jellison, 1939), E. linguata (F.O. Pickard-Cambridge, 1900), E. madera (Roddy, 1966), E. mirabilis (O. Pickard-Cambridge, 1896) new. comb., E. mulaiki (Gertsch, 1935), E. multinotata (Chickering, 1937), E. orvillei (Chickering, 1937), E. placida O. Pickard-Cambridge, 1898, E. portoricensis (Petrunkevitch, 1930), E. quadrata (Kraus, 1955), E. richardi (Gertsch, 1941), E. sericea O. Pickard-Cambridge, 1898, E. sigillata (Petrunkevitch, 1925), E. simplex (O. Pickard-Cambridge, 1896), E. texana (Gertsch, 1933), E. tigrina O. Pickard-Cambridge, 1898 name restored, E. tricuspis (F.O. Pickard-Cambridge, 1900), E. tristani (Banks, 1909), E. tumivulva (Banks, 1909), E. valvula (F.O. Pickard-Cambridge, 1900) and E. wheeleri (Roewer, 1933). Ten new species are described: E. candelaria n. sp. and E. helenae n. sp. from Mexico; E. arawakan n. sp. from Haiti; E. lizae n. sp. from Costa Rica; E. darwichi n. sp. from Ecuador; E. juruti n. sp., E. tourinhoae n. sp. and E. vieirae n. sp. from Brazil; E. shinguito n. sp. from Peru and E. beni n. sp. from Bolivia. The female of E. hortoni is described for the first time. Lectotypes are designated for E. sigillata and its actual female is described for the first time. Four new synonyms are proposed: E. languida

  5. Multi-block and path modelling procedures

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2008-01-01

    The author has developed a unified theory of path and multi-block modelling of data. The data blocks are arranged in a directional path. Each data block can lead to one or more data blocks. It is assumed that there is given a collection of input data blocks. Each of them is supposed to describe one...

  6. Modelling of multi-block data

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar; Svinning, K.

    2006-01-01

    Here is presented a unified approach to modelling multi-block regression data. The starting point is a partition of the data X into L data blocks, X = (X-1, X-2,...X-L), and the data Y into M data-blocks, Y = (Y-1, Y-2,...,Y-M). The methods of linear regression, X -> Y, are extended to the case...... these methods can be extended to a network of data blocks. Examples of the optimisation procedures in a network are shown. The examples chosen are the ones that are useful to work within industrial production environments. The methods are illustrated by simulated data and data from cement production....

  7. Mineral resources estimation based on block modeling

    Science.gov (United States)

    Bargawa, Waterman Sulistyana; Amri, Nur Ali

    2016-02-01

    The estimation in this paper uses three kinds of block models of nearest neighbor polygon, inverse distance squared and ordinary kriging. The techniques are weighting scheme which is based on the principle that block content is a linear combination of the grade data or the sample around the block being estimated. The case study in Pongkor area, here is gold-silver resource modeling that allegedly shaped of quartz vein as a hydrothermal process of epithermal type. Resources modeling includes of data entry, statistical and variography analysis of topography and geological model, the block model construction, estimation parameter, presentation model and tabulation of mineral resources. Skewed distribution, here isolated by robust semivariogram. The mineral resources classification generated in this model based on an analysis of the kriging standard deviation and number of samples which are used in the estimation of each block. Research results are used to evaluate the performance of OK and IDS estimator. Based on the visual and statistical analysis, concluded that the model of OK gives the estimation closer to the data used for modeling.

  8. Infinite-degree-corrected stochastic block model

    DEFF Research Database (Denmark)

    Herlau, Tue; Schmidt, Mikkel Nørgaard; Mørup, Morten

    2014-01-01

    corrected stochastic block model as a nonparametric Bayesian model, incorporating a parameter to control the amount of degree correction that can then be inferred from data. Additionally, our formulation yields principled ways of inferring the number of groups as well as predicting missing links...... in the network that can be used to quantify the model’s predictive performance. On synthetic data we demonstrate that including the degree correction yields better performance on both recovering the true group structure and predicting missing links when degree heterogeneity is present, whereas performance......In stochastic block models, which are among the most prominent statistical models for cluster analysis of complex networks, clusters are defined as groups of nodes with statistically similar link probabilities within and between groups. A recent extension by Karrer and Newman [Karrer and Newman...

  9. Cyrtarachne keralensis Jose, 2011 is a junior synonym of Anepsion maritatum (O. Pickard-Cambridge, 1877) (Araneae, Araneidae).

    Science.gov (United States)

    Malamel, Jobi J; Sankaran, Pradeep M; Joseph, Mathew M; Sebastian, Pothalil A

    2015-11-05

    The Indo-pacific araneid genus Anepsion, with A. rhomboides (L. Koch, 1867) as the type species, was erected by Strand in 1929. He proposed the name Anepsion as a replacement name for Anepsia L. Koch, 1871, preoccupied by Anepsia Gistl, 1848, a dipteran genus (OBIS Australia, 2015). The genus was revised by Chrysanthus (1961, 1969) and currently has 16 described species and 1 subspecies (World Spider Catalog 2015). In the present paper, we are reporting the genus from India for the first time and synonymising Cyrtarachne keralensis Jose, 2011 with Anepsion maritatum O. Pickard-Cambridge, 1877. A redescription and illustrations of both male and female of A. maritatum are provided.

  10. A Nonlinear Multi-Scale Interaction Model for Atmospheric Blocking: The Eddy-Blocking Matching Mechanism

    Science.gov (United States)

    Luo, Dehai; Cha, Jing; Zhong, Linhao; Dai, Aiguo

    2014-05-01

    In this paper, a nonlinear multi-scale interaction (NMI) model is used to propose an eddy-blocking matching (EBM) mechanism to account for how synoptic eddies reinforce or suppress a blocking flow. It is shown that the spatial structure of the eddy vorticity forcing (EVF) arising from upstream synoptic eddies determines whether an incipient block can grow into a meandering blocking flow through its interaction with the transient synoptic eddies from the west. Under certain conditions, the EVF exhibits a low-frequency oscillation on timescales of 2-3 weeks. During the EVF phase with a negative-over- positive dipole structure, a blocking event can be resonantly excited through the transport of eddy energy into the incipient block by the EVF. As the EVF changes into an opposite phase, the blocking decays. The NMI model produces life cycles of blocking events that resemble observations. Moreover, it is shown that the eddy north-south straining is a response of the eddies to a dipole- or Ω-type block. In our model, as in observations, two synoptic anticyclones (cyclones) can attract and merge with one another as the blocking intensifies, but only when the feedback of the blocking on the eddies is included. Thus, we attribute the eddy straining and associated vortex interaction to the feedback of the intensified blocking on synoptic eddies. The results illustrate the concomitant nature of the eddy deformation, whose role as a PV source for the blocking flow becomes important only during the mature stage of a block. Our EBM mechanism suggests that an incipient block flow is amplified (or suppressed) under certain conditions by the EVF coming from the upstream of the blocking region.

  11. Block Models and Personalized PageRank

    CERN Document Server

    Kloumann, Isabel; Kleinberg, Jon

    2016-01-01

    Methods for ranking the importance of nodes in a network have a rich history in machine learning and across domains that analyze structured data. Recent work has evaluated these methods though the seed set expansion problem: given a subset $S$ of nodes from a community of interest in an underlying graph, can we reliably identify the rest of the community? We start from the observation that the most widely used techniques for this problem, personalized PageRank and heat kernel methods, operate in the space of landing probabilities of a random walk rooted at the seed set, ranking nodes according to weighted sums of landing probabilities of different length walks. Both schemes, however, lack an a priori relationship to the seed set objective. In this work we develop a principled framework for evaluating ranking methods by studying seed set expansion applied to the stochastic block model. We derive the optimal gradient for separating the landing probabilities of two classes in a stochastic block model, and find, ...

  12. Optimal information diffusion in stochastic block models

    CERN Document Server

    Curato, Gianbiagio

    2016-01-01

    We use the linear threshold model to study the diffusion of information on a network generated by the stochastic block model. We focus our analysis on a two community structure where the initial set of informed nodes lies only in one of the two communities and we look for optimal network structures, i.e. those maximizing the asymptotic extent of the diffusion. We find that, constraining the mean degree and the fraction of initially informed nodes, the optimal structure can be assortative (modular), core-periphery, or even disassortative. We then look for minimal cost structures, i.e. those such that a minimal fraction of initially informed nodes is needed to trigger a global cascade. We find that the optimal networks are assortative but with a structure very close to a core-periphery graph, i.e. a very dense community linked to a much more sparsely connected periphery.

  13. Visible Geology - Interactive online geologic block modelling

    Science.gov (United States)

    Cockett, R.

    2012-12-01

    Geology is a highly visual science, and many disciplines require spatial awareness and manipulation. For example, interpreting cross-sections, geologic maps, or plotting data on a stereonet all require various levels of spatial abilities. These skills are often not focused on in undergraduate geoscience curricula and many students struggle with spatial relations, manipulations, and penetrative abilities (e.g. Titus & Horsman, 2009). A newly developed program, Visible Geology, allows for students to be introduced to many geologic concepts and spatial skills in a virtual environment. Visible Geology is a web-based, three-dimensional environment where students can create and interrogate their own geologic block models. The program begins with a blank model, users then add geologic beds (with custom thickness and color) and can add geologic deformation events like tilting, folding, and faulting. Additionally, simple intrusive dikes can be modelled, as well as unconformities. Students can also explore the interaction of geology with topography by drawing elevation contours to produce their own topographic models. Students can not only spatially manipulate their model, but can create cross-sections and boreholes to practice their visual penetrative abilities. Visible Geology is easy to access and use, with no downloads required, so it can be incorporated into current, paper-based, lab activities. Sample learning activities are being developed that target introductory and structural geology curricula with learning objectives such as relative geologic history, fault characterization, apparent dip and thickness, interference folding, and stereonet interpretation. Visible Geology provides a richly interactive, and immersive environment for students to explore geologic concepts and practice their spatial skills.; Screenshot of Visible Geology showing folding and faulting interactions on a ridge topography.

  14. An Asymmetric Block Dynamic Conditional Correlation Multivariate GARCH Model

    OpenAIRE

    Vargas, Gregorio A.

    2006-01-01

    The Block DCC model for determining dynamic correlations within and between groups of financial asset returns is extended to account for asymmetric effects. Simulation results show that the Asymmetric Block DCC model is competitive in in-sample forecasting and performs better than alternative DCC models in out-of-sample forecasting of conditional correlation in the presence of asymmetric effect between blocks of asset returns. Empirical results demonstrate that the model is able to capture ...

  15. Development of Deflection Prediction Model for Concrete Block Pavement Considering the Block Shapes and Construction Patterns

    Directory of Open Access Journals (Sweden)

    Wuguang Lin

    2016-01-01

    Full Text Available Concrete block pavement (CBP is distinct from typical concrete or asphalt pavements. It is built by using individual blocks with unique construction patterns forming a discrete surface layer to bear traffic loadings. The surface structure of CBP varies depending on the block shapes and construction patterns, so it is hard to apply a general equivalent elastic modulus estimation method to define the surface structural strength. In this study, FEM analysis and dynamic loading test were carried out to develop a deflection prediction model for CBP considering the block shapes and construction patterns. Based on the analysis results, it was found that block shapes did not have much effect on load distribution, whereas construction patterns did. By applying the deflection prediction model to the rutting model for CBP proposed by Sun, the herringbone bond pattern showed the best performance comparing with stretcher bond or basket weave bond pattern. As the load repetition increased to 1.2 million, the rutting depth of CBP constructed by herringbone bond pattern was 2 mm smaller than those constructed by the other two patterns.

  16. Completely random measures for modelling block-structured sparse networks

    DEFF Research Database (Denmark)

    Herlau, Tue; Schmidt, Mikkel Nørgaard; Mørup, Morten

    2016-01-01

    Many statistical methods for network data parameterize the edge-probability by attributing latent traits to the vertices such as block structure and assume exchangeability in the sense of the Aldous-Hoover representation theorem. Empirical studies of networks indicate that many real-world network...... is not significantly more difficult to implement than existing approaches to block-modelling and performs well on real network datasets.......Many statistical methods for network data parameterize the edge-probability by attributing latent traits to the vertices such as block structure and assume exchangeability in the sense of the Aldous-Hoover representation theorem. Empirical studies of networks indicate that many real-world networks...... [2014] proposed the use of a different notion of exchangeability due to Kallenberg [2006] and obtained a network model which admits power-law behaviour while retaining desirable statistical properties, however this model does not capture latent vertex traits such as block-structure. In this work we re...

  17. RF building block modelling : optimization and synthesis

    NARCIS (Netherlands)

    Cheng, Wei

    2012-01-01

    For circuit designers it is desirable to have relatively simple RF circuit models that do give decent estimation accuracy and provide sufficient understanding of circuits. Chapter 2 in this thesis shows a general weak nonlinearity model that meets these demands. Using a method that is related to har

  18. Block Entanglement in the Single-Hole Hubbard Model

    Institute of Scientific and Technical Information of China (English)

    YAO Kai-Lun; SUN Xiao-Zhong; LIU Zu-Li; LI Yan-Chao; YU Li; GAO Guo-Ying

    2006-01-01

    @@ We investigate the distribution of the entanglement of the one-dimensional single-hole Hubbard model (HM)and study the relationship between the entanglement and quantum phase transition in the model. The von Neumann entropy of a block with neighbouring spins L for a single-hole HM is calculated using the densitymatrix renormalization group.

  19. Internet of Things building blocks and business models

    CERN Document Server

    Hussain, Fatima

    2017-01-01

    This book describes the building blocks and introductory business models for Internet of Things (IoT). The author provide an overview of the entire IoT architecture and constituent layers, followed by detail description of each block . Various inter-connecting technologies and sensors are discussed in context of IoT networks. In addition to this, concepts of Big Data and Fog Computing are presented and characterized as per data generated by versatile IoT applications . Smart parking system and context aware services are presented as an hybrid model of cloud and Fog Afterwards, various IoT applications and respective business models are discussed. Finally, author summarizes the IoT building blocks and identify research issues in each, and suggest potential research projects worthy of pursuing. .

  20. Detection Block Model for SQL Injection Attacks

    Directory of Open Access Journals (Sweden)

    Diksha G. Kumar

    2014-10-01

    Full Text Available With the rapid development of Internet, more and more organizations connect their databases to the Internet for resource sharing. However, due to developers' lack of knowledge of all possible attacks, web applications become vulnerable to multiple attacks. Thus the network databases could face multiple threats. Web applications generally consist of a three tier architecture where database is in the third pole, which is the most valuable asset in any organization. SQL injection is an attack technique in which specially crafted input string is entered in user input field. It is submitted to server and result is returned to the user. In SQL injection vulnerability, the database server is forced to execute malicious operations which may cause the data loss or corruption, denial of access, and unauthentic access to sensitive data by crafting specific inputs. An attacker can directly compromise the database, and that is why this is a most threatening web attack. SQL injection attack occupies first position in top ten vulnerabilities as specified by Open Web Application Security Project. It is probably the most common Website vulnerability today. Current scenarios which provide solutions to SQL injection attack either have limited scope i.e. can’t be implemented across all platforms, or do not cover all types of SQL injection attacks. In this work we implement Message Authentication Code (MAC based solution against SQL injection attacks. The model works both on client and server side. Client side implements a filter function and server side is based on information theory. MAC of static and dynamic queries is compared to detect SQL injection attack.

  1. Block-Krylov component synthesis method for structural model reduction

    Science.gov (United States)

    Craig, Roy R., Jr.; Hale, Arthur L.

    1988-01-01

    A new analytical method is presented for generating component shape vectors, or Ritz vectors, for use in component synthesis. Based on the concept of a block-Krylov subspace, easily derived recurrence relations generate blocks of Ritz vectors for each component. The subspace spanned by the Ritz vectors is called a block-Krylov subspace. The synthesis uses the new Ritz vectors rather than component normal modes to reduce the order of large, finite-element component models. An advantage of the Ritz vectors is that they involve significantly less computation than component normal modes. Both 'free-interface' and 'fixed-interface' component models are derived. They yield block-Krylov formulations paralleling the concepts of free-interface and fixed-interface component modal synthesis. Additionally, block-Krylov reduced-order component models are shown to have special disturbability/observability properties. Consequently, the method is attractive in active structural control applications, such as large space structures. The new fixed-interface methodology is demonstrated by a numerical example. The accuracy is found to be comparable to that of fixed-interface component modal synthesis.

  2. A physical model for measuring thermally-induced block displacements

    Science.gov (United States)

    Bakun-Mazor, Dagan; Feldhiem, Aviran; Keissar, Yuval; Hatzor, Yossef H.

    2016-04-01

    A new model for thermally-induced block displacement in discontinuous rock slopes has been recently suggested. The model consists of a discrete block that is separated from the rock mass by a tension crack and rests on an inclined plane. The tension crack is filled with a wedge block or rock fragments. Irreversible block sliding is assumed to develop in response to climatic thermal fluctuations and consequent contraction and expansion of the sliding block material. While a tentative analytical solution for this model is already available, we are exploring here the possibility of obtaining such a permanent, thermally-induced, rock block displacement, under fully controlled conditions at the laboratory, and the sensitivity of the mechanism to geometry, mechanical properties, and temperature fluctuations. A large scale concrete physical model (50x150x60 cm^3) is being examined in a Climate-Controlled Room (CCR). The CCR permits accurate control of ambient temperature from 5 to 45 Celsius degrees. The permanent plastic displacement is being measured using four displacement transducers and a high resolution (29M pixel) visual range camera. A series of thermocouples measure the heating front inside the sliding block, hence thermal diffusivity is evaluated from the measured thermal gradient and heat flow. In order to select the appropriate concrete mixture, the mechanical and thermo-physical properties of concrete samples are determined in the lab. Friction angle and shear stiffness of the sliding interface are determined utilizing a hydraulic, servo-controlled direct shear apparatus. Uniaxial compression tests are performed to determine the uniaxial compressive strength, Young's modulus and Poison's ratio of the intact block material using a stiff triaxial load frame. Thermal conductivity and linear thermal expansion coefficient are determined experimentally using a self-constructed measuring system. Due to the fact that this experiment is still in progress, preliminary

  3. Analogue Behavioral Modeling of Switched-Current Building Block Circuits

    Institute of Scientific and Technical Information of China (English)

    ZENG Xuan; WANG Wei; SHI Jianlei; TANG Pushan; D.ZHOU

    2001-01-01

    This paper proposes a behavioral modeling technique for the second-generation switched-current building block circuits. The proposed models are capable of capturing the non-ideal behavior of switched-current circuits, which includes the charge injection effects and device mismatch effects. As a result, system performance degradations due to the building block imperfections can be detected at the early design stage by fast behavioral simulations. To evaluate the accuracy of the proposed models, we developed a time-domain behavioral simulator. Experimental results have shown that compared with SPICE, the behavioral modeling error is less than 2.15%, while behavioral simulation speed up is 4 orders in time-domain.

  4. Quantifying private benefits of control from a structural model of block trades

    NARCIS (Netherlands)

    Albuquerque, R.; Schroth, E.

    2010-01-01

    We study the determinants of private benefits of control in negotiated block transactions. We estimate the block pricing model in Burkart, Gromb and Panunzi (2000) explicitly accounting for both block premiums and block discounts in the data. The evidence suggests that the occurrence of a block prem

  5. Mathematical modeling and simulation of nanopore blocking by precipitation

    KAUST Repository

    Wolfram, M-T

    2010-10-29

    High surface charges of polymer pore walls and applied electric fields can lead to the formation and subsequent dissolution of precipitates in nanopores. These precipitates block the pore, leading to current fluctuations. We present an extended Poisson-Nernst-Planck system which includes chemical reactions of precipitation and dissolution. We discuss the mathematical modeling and present 2D numerical simulations. © 2010 IOP Publishing Ltd.

  6. Mixed-Membership Stochastic Block-Models for Transactional Networks

    CERN Document Server

    Shafiei, Mahdi

    2010-01-01

    Transactional network data can be thought of as a list of one-to-many communications(e.g., email) between nodes in a social network. Most social network models convert this type of data into binary relations between pairs of nodes. We develop a latent mixed membership model capable of modeling richer forms of transactional network data, including relations between more than two nodes. The model can cluster nodes and predict transactions. The block-model nature of the model implies that groups can be characterized in very general ways. This flexible notion of group structure enables discovery of rich structure in transactional networks. Estimation and inference are accomplished via a variational EM algorithm. Simulations indicate that the learning algorithm can recover the correct generative model. Interesting structure is discovered in the Enron email dataset and another dataset extracted from the Reddit website. Analysis of the Reddit data is facilitated by a novel performance measure for comparing two soft ...

  7. Model of rigid and elastic-plastic motion in intraplate blocks and strain status of principal blocks in Chinese mainland

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The model of rigid and elastic-plastic motion and strain in intraplate blocks is established in the paper. The unique of strain parameters and minimum root-mean-square error of velocity residual of blocks are tested in the model. Based on the velocity fields in Chinese mainland and its peripheral areas, the strain parameters of 8 blocks are estimated and their strain status analyzed. The estimated strain status of each block is well consistent with those derived by the methods of geology and geophysics. The principal direction of collision force from India plate to Eurasia plate estimated from the azimuth of principal compressive strain of Himalaya block might be N7.1°E.

  8. Application of blocking diagnosis methods to general circulation models. Part II: model simulations

    Energy Technology Data Exchange (ETDEWEB)

    Barriopedro, D.; Trigo, R.M. [Universidade de Lisboa, CGUL-IDL, Faculdade de Ciencias, Lisbon (Portugal); Garcia-Herrera, R.; Gonzalez-Rouco, J.F. [Universidad Complutense de Madrid, Departamento de Fisica de la Tierra II, Facultad de C.C. Fisicas, Madrid (Spain)

    2010-12-15

    A previously defined automatic method is applied to reanalysis and present-day (1950-1989) forced simulations of the ECHO-G model in order to assess its performance in reproducing atmospheric blocking in the Northern Hemisphere. Unlike previous methodologies, critical parameters and thresholds to estimate blocking occurrence in the model are not calibrated with an observed reference, but objectively derived from the simulated climatology. The choice of model dependent parameters allows for an objective definition of blocking and corrects for some intrinsic model bias, the difference between model and observed thresholds providing a measure of systematic errors in the model. The model captures reasonably the main blocking features (location, amplitude, annual cycle and persistence) found in observations, but reveals a relative southward shift of Eurasian blocks and an overall underestimation of blocking activity, especially over the Euro-Atlantic sector. Blocking underestimation mostly arises from the model inability to generate long persistent blocks with the observed frequency. This error is mainly attributed to a bias in the basic state. The bias pattern consists of excessive zonal winds over the Euro-Atlantic sector and a southward shift at the exit zone of the jet stream extending into in the Eurasian continent, that are more prominent in cold and warm seasons and account for much of Euro-Atlantic and Eurasian blocking errors, respectively. It is shown that other widely used blocking indices or empirical observational thresholds may not give a proper account of the lack of realism in the model as compared with the proposed method. This suggests that in addition to blocking changes that could be ascribed to natural variability processes or climate change signals in the simulated climate, attention should be paid to significant departures in the diagnosis of phenomena that can also arise from an inappropriate adaptation of detection methods to the climate of the

  9. Modelization of coupled heat transfer inside a cylindrical glass block

    Energy Technology Data Exchange (ETDEWEB)

    Tanguier, J.L.; Kheiri, A.; Kleinclauss, J. [Faculte des Sciences, 54 - Vandoeuvre-les-Nancy (France)

    1995-01-01

    Modelization of coupled heat transfer inside a cylindrical glass block. In crystal industry, the furnaces used to warm up glass before forming are supplied with 4 bar pressure gas. They are noisy, polluting and high consumers of energy. To limit these effects and improve the energetic performances, an electrical infrared furnace is studied. To perfect it, it is necessary to identify the mechanisms of heat transfer which govern the evolution of the temperature into a cylindrical semitransparent media. After a long and thorough bibliography relative to the thermo-optical properties of crystal, the measurement of the field of temperature into the cylindrical block during the phases of working is led into the factory. To do this, it was necessary to adapt a reliable technical measurement device adjusted to industrial surrounding. A fundamental analysis of the results allows us to propose a model of the coupled heat transfer (radiation, conduction and convection) inside glass and between glass and its surroundings. The model is built on brightness and it is based on a triple discretization: temporal, spectral and zonal. This model provides the spectral distribution of the infrared radiation and the electrical power necessary to obtain a good heating of the crystal according to the manufactory charges. The first tests made with the experimental furnace, built by us, show that it is possible to warm up glass with infrared radiation and that this proceeding reduces the energy consumption and the nuisances. (authors). 19 refs., 7 figs.

  10. Energy Blocks — A Physical Model for Teaching Energy Concepts

    Science.gov (United States)

    Hertting, Scott

    2016-01-01

    Most physics educators would agree that energy is a very useful, albeit abstract topic. It is therefore important to use various methods to help the student internalize the concept of energy itself and its related ideas. These methods include using representations such as energy bar graphs, energy pie charts, or energy tracking diagrams. Activities and analogies like Energy Theater and Richard Feynman's blocks, as well as the popular money (or wealth) analogy, can also be very effective. The goal of this paper is to describe a physical model of Feynman's blocks that can be employed by instructors to help students learn the following energy-related concepts: 1. The factors affecting each individual mechanical energy storage mode (this refers to what has been traditionally called a form of energy, and while the Modeling Method of instruction is not the focus of this paper, much of the energy related language used is specific to the Modeling Method). For example, how mass or height affects gravitational energy; 2. Energy conservation; and 3. The graphical relationships between the energy storage mode and a factor affecting it. For example, the graphical relationship between elastic energy and the change in length of a spring.

  11. Nonparametric Bayesian inference of the microcanonical stochastic block model

    CERN Document Server

    Peixoto, Tiago P

    2016-01-01

    A principled approach to characterize the hidden modular structure of networks is to formulate generative models, and then infer their parameters from data. When the desired structure is composed of modules or "communities", a suitable choice for this task is the stochastic block model (SBM), where nodes are divided into groups, and the placement of edges is conditioned on the group memberships. Here, we present a nonparametric Bayesian method to infer the modular structure of empirical networks, including the number of modules and their hierarchical organization. We focus on a microcanonical variant of the SBM, where the structure is imposed via hard constraints. We show how this simple model variation allows simultaneously for two important improvements over more traditional inference approaches: 1. Deeper Bayesian hierarchies, with noninformative priors replaced by sequences of priors and hyperpriors, that not only remove limitations that seriously degrade the inference on large networks, but also reveal s...

  12. Atmospheric blocking in a high resolution climate model: influences of mean state, orography and eddy forcing

    NARCIS (Netherlands)

    Berckmans, J.N.J.; Woollings, T.; Demory, M.; Vidale, P.; Roberts, M.

    2013-01-01

    An underestimate of atmospheric blocking occurrence is a well-known limitation of many climate models. This article presents an analysis of Northern Hemisphere winter blocking in an atmospheric model with increased horizontal resolution. European blocking frequency increases with model resolution, a

  13. Thin Filament Structure and the Steric Blocking Model.

    Science.gov (United States)

    Lehman, William

    2016-03-15

    By interacting with the troponin-tropomyosin complex on myofibrillar thin filaments, Ca2+ and myosin govern the regulatory switching processes influencing contractile activity of mammalian cardiac and skeletal muscles. A possible explanation of the roles played by Ca2+ and myosin emerged in the early 1970s when a compelling "steric model" began to gain traction as a likely mechanism accounting for muscle regulation. In its most simple form, the model holds that, under the control of Ca2+ binding to troponin and myosin binding to actin, tropomyosin strands running along thin filaments either block myosin-binding sites on actin when muscles are relaxed or move away from them when muscles are activated. Evidence for the steric model was initially based on interpretation of subtle changes observed in X-ray fiber diffraction patterns of intact skeletal muscle preparations. Over the past 25 years, electron microscopy coupled with three-dimensional reconstruction directly resolved thin filament organization under many experimental conditions and at increasingly higher resolution. At low-Ca2+, tropomyosin was shown to occupy a "blocked-state" position on the filament, and switched-on in a two-step process, involving first a movement of tropomyosin away from the majority of the myosin-binding site as Ca2+ binds to troponin and then a further movement to fully expose the site when small numbers of myosin heads bind to actin. In this contribution, basic information on Ca2+-regulation of muscle contraction is provided. A description is then given relating the voyage of discovery taken to arrive at the present understanding of the steric regulatory model.

  14. Identifying rock blocks based on hierarchical rock-mass structure model

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Rock-masses are divided into many closed blocks by deterministic and stochastic discontinuities and engineering interfaces in complex rock-mass engineering. Determining the sizes, shapes, and adjacent relations of blocks is important for stability analysis of fractured rock masses. Here we propose an algorithm for identifying spatial blocks based on a hierarchical 3D Rock-mass Structure Model (RSM). First, a model is built composed of deterministic discontinuities, engineering interfaces, and the earth’s surface, and the deterministic blocks surrounded by these interfaces are traced. Then, in each deter-ministic block, a network model of stochastic discontinuities is built and the stochastic blocks are traced. Building a unitary wire frame that connects all interfaces seamlessly is the key for our algorithm to identify the above two kinds of blocks. Using this algorithm, geometric models can be built for block theory, discrete element method, and discontinuous deformation analysis.

  15. Plastic deformation modelling of tempered martensite steel block structure by a nonlocal crystal plasticity model

    Directory of Open Access Journals (Sweden)

    Martin Boeff

    2014-01-01

    Full Text Available The plastic deformations of tempered martensite steel representative volume elements with different martensite block structures have been investigated by using a nonlocal crystal plasticity model which considers isotropic and kinematic hardening produced by plastic strain gradients. It was found that pronounced strain gradients occur in the grain boundary region even under homogeneous loading. The isotropic hardening of strain gradients strongly influences the global stress–strain diagram while the kinematic hardening of strain gradients influences the local deformation behaviour. It is found that the additional strain gradient hardening is not only dependent on the block width but also on the misorientations or the deformation incompatibilities in adjacent blocks.

  16. Nonparametric Bayesian inference of the microcanonical stochastic block model

    Science.gov (United States)

    Peixoto, Tiago P.

    2017-01-01

    A principled approach to characterize the hidden modular structure of networks is to formulate generative models and then infer their parameters from data. When the desired structure is composed of modules or "communities," a suitable choice for this task is the stochastic block model (SBM), where nodes are divided into groups, and the placement of edges is conditioned on the group memberships. Here, we present a nonparametric Bayesian method to infer the modular structure of empirical networks, including the number of modules and their hierarchical organization. We focus on a microcanonical variant of the SBM, where the structure is imposed via hard constraints, i.e., the generated networks are not allowed to violate the patterns imposed by the model. We show how this simple model variation allows simultaneously for two important improvements over more traditional inference approaches: (1) deeper Bayesian hierarchies, with noninformative priors replaced by sequences of priors and hyperpriors, which not only remove limitations that seriously degrade the inference on large networks but also reveal structures at multiple scales; (2) a very efficient inference algorithm that scales well not only for networks with a large number of nodes and edges but also with an unlimited number of modules. We show also how this approach can be used to sample modular hierarchies from the posterior distribution, as well as to perform model selection. We discuss and analyze the differences between sampling from the posterior and simply finding the single parameter estimate that maximizes it. Furthermore, we expose a direct equivalence between our microcanonical approach and alternative derivations based on the canonical SBM.

  17. Consistent adjacency-spectral partitioning for the stochastic block model when the model parameters are unknown

    CERN Document Server

    Fishkind, Donniell E; Tang, Minh; Vogelstein, Joshua T; Priebe, Carey E

    2012-01-01

    A stochastic block model consists of a random partition of n vertices into blocks 1,2,...,K for which, conditioned on the partition, every pair of vertices has probability of adjacency entirely determined by the block membership of the two vertices. (The model parameters are K, the distribution of the random partition, and a communication probability matrix M in [0,1]^(K x K) listing the adjacency probabilities associated with all pairs of blocks.) Suppose a realization of the n x n vertex adjacency matrix is observed, but the underlying partition of the vertices into blocks is not observed; the main inferential task is to correctly partition the vertices into the blocks with only a negligible number of vertices misassigned. For this inferential task, Rohe et al. (2011) prove the consistency of spectral partitioning applied to the normalized Laplacian, and Sussman et al. (2011) extend this to prove consistency of spectral partitioning directly on the adjacency matrix; both procedures assume that K and rankM a...

  18. Modelling of composite concrete block pavement systems applying a cohesive zone model

    DEFF Research Database (Denmark)

    Skar, Asmus; Poulsen, Peter Noe

    This paper presents a numerical analysis of the fracture behaviour of the cement bound base material in composite concrete block pavement systems, using a cohesive zone model. The functionality of the proposed model is tested on experimental and numerical investigations of beam bending tests...

  19. Clinic expert information extraction based on domain model and block importance model.

    Science.gov (United States)

    Zhang, Yuanpeng; Wang, Li; Qian, Danmin; Geng, Xingyun; Yao, Dengfu; Dong, Jiancheng

    2015-11-01

    To extract expert clinic information from the Deep Web, there are two challenges to face. The first one is to make a judgment on forms. A novel method based on a domain model, which is a tree structure constructed by the attributes of query interfaces is proposed. With this model, query interfaces can be classified to a domain and filled in with domain keywords. Another challenge is to extract information from response Web pages indexed by query interfaces. To filter the noisy information on a Web page, a block importance model is proposed, both content and spatial features are taken into account in this model. The experimental results indicate that the domain model yields a precision 4.89% higher than that of the rule-based method, whereas the block importance model yields an F1 measure 10.5% higher than that of the XPath method.

  20. Spring-block model for a single-lane highway traffic

    CERN Document Server

    Jarai-Szabo, Ferenc; Neda, Zoltan

    2010-01-01

    A simple one-dimensional spring-block chain with asymmetric interactions is considered to model an idealized single-lane highway traffic. The main elements of the system are blocks (modeling cars), springs with unidirectional interactions (modeling distance keeping interactions between neighbors), static and kinetic friction (modeling inertia of drivers and cars) and spatiotemporal disorder in the values of these friction forces (modeling differences in the driving attitudes). The traveling chain of cars correspond to the dragged spring-block system. Our statistical analysis for the spring-block chain predicts a non-trivial and rich complex behavior. As a function of the disorder level in the system a dynamic phase-transition is observed. For low disorder levels uncorrelated slidings of blocks are revealed while for high disorder levels correlated avalanches dominates.

  1. A Study of Debris Flow Block on the Model of Percolation

    Institute of Scientific and Technical Information of China (English)

    YaquanFANG; HouqiangLI; 等

    1999-01-01

    When adebris flow joins a main river,it may block the river.The collapse of the block is often a sudden change that can be simplified into a phase transition.In this paper we study the problem on the model of percolation which is a second order phase transition.Rather than general random percolation model,we introduce a self-similar percolation model and develop it from two dimensions to three dimensions.Under this model,we conclude that a block made of grains(for example stone,sandy grains,clay grains,silt grains,etc.) with more different sized has a better stability.Moreover,with the help of efflux theory,we explain why the joint on the other side of the block with the main river is easier to break than other places of the block.

  2. Improved Porosity and Permeability Models with Coal Matrix Block Deformation Effect

    Science.gov (United States)

    Zhou, Yinbo; Li, Zenghua; Yang, Yongliang; Zhang, Lanjun; Qi, Qiangqiang; Si, Leilei; Li, Jinhu

    2016-09-01

    Coal permeability is an important parameter in coalbed methane (CBM) exploration and greenhouse gas storage. A reasonable theoretical permeability model is helpful for analysing the influential factors of gas flowing in a coalbed. As an unconventional reservoir, the unique feature of a coal structure deformation determines the state of gas seepage. The matrix block and fracture change at the same time due to changes in the effective stress and adsorption; the porosity and permeability also change. Thus, the matrix block deformation must be ignored in the theoretical model. Based on the cubic model, we analysed the characteristics of matrix block deformation and fracture deformation. The new models were developed with the change in matrix block width a. We compared the new models with other models, such as the Palmer-Manson (P-M) model and the Shi-Durucan (S-D) model, and used a constant confining stress. By matching the experimental data, our model matches quite well and accurately predicts the evolution of permeability. The sorption-induced strain coefficient f differs between the strongly adsorbing gases and weakly adsorbing gases because the matrix block deformation is more sensitive for the weakly adsorbing gases and the coefficient f is larger. The cubic relationship between porosity and permeability overlooks the importance of the matrix block deformation. In our model, the matrix block deformation suppresses the permeability ratio growth. With a constant confining stress, the weight of the matrix block deformation for the strongly adsorbing gases is larger than that for weakly adsorbing gases. The weight values increase as the pore pressure increases. It can be concluded that the matrix block deformation is an important phenomenon for researching coal permeability and can be crucial for the prediction of CBM production due to the change in permeability.

  3. Transformation Strategies between Block-Oriented and Graph-Oriented Process Modelling Languages

    DEFF Research Database (Denmark)

    Mendling, Jan; Lassen, Kristian Bisgaard; Zdun, Uwe

    to abstract from concrete transformationstrategies by distinguishing two major paradigms for process modelling languages:block-oriented languages (such as BPEL and BPML) and graph-oriented languages(such as EPCs and YAWL). The contribution of this paper are generic strategiesfor transforming from block...

  4. On the type species of the genus Aetius O. Pickard-Cambridge, 1896: The first description of male with notes on cymbial notch and mating plug (Araneae: Corinnidae: Castianeirinae).

    Science.gov (United States)

    Sudhin, Puthoor Pattammal; Nafin, Karunnappilli Shamsudheen; Simmons, Zoë; Sudhikumar, Ambalaparambil Vasu

    2016-08-23

    The rare ant mimicking sac spider genus Aetius was erected by O. Pickard-Cambridge in 1896 based on an unspecified number of female specimen(s) collected from Sri Lanka. The type species of the genus, A. decollatus O. Pickard-Cambridge, 1896, has been redescribed twice based on the holotype (Majumder & Tikader 1991; Deeleman-Reinhold 2001). Reimoser (1934) recorded the genus for the first time from India, who collected a male specimen from Mudumalai Tiger Reserve in Tamil Nadu State of southern India. This specimen was identified as A. decollatus, but it was never formally described and was later recognised to be a penultimate male (Dankittipakul & Singtripop 2013). Deeleman-Reinhold (2001) described the second representative of the genus, A. nocturnus, based on a single female specimen from Borneo, 105 years after the establishment of the genus. Dankittipakul & Singtripop (2013) described the male of A. nocturnus, thereby revealing the male genitalia of the genus, but the type species was still known only from the female sex.

  5. Modelling time evolving interactions in networks through a non stationary extension of stochastic block models

    OpenAIRE

    2015-01-01

    National audience; In this paper, we focus on the stochastic block model (SBM),a probabilistic tool describing interactions between nodes of a network using latent clusters. The SBM assumes that the networkhas a stationary structure, in which connections of time varying intensity are not taken into account. In other words, interactions between two groups are forced to have the same features during the whole observation time. To overcome this limitation,we propose a partition of the whole time...

  6. A Working Model of Protein Synthesis Using Lego(TM) Building Blocks.

    Science.gov (United States)

    Templin, Mark A.; Fetters, Marcia K.

    2002-01-01

    Uses Lego building blocks to improve the effectiveness of teaching about protein synthesis. Provides diagrams and pictures for a 2-3 day student activity. Discusses mRNA, transfer RNA, and a protein synthesis model. (MVL)

  7. A new approach to modelling and designing mono-block dental implants

    OpenAIRE

    R. Hunter; F. Alister; Möller, J.; J. Alister

    2007-01-01

    Purpose: of this paper is present a new approach to modelling and design the low cost mono-block dental implants based on the integration of the computer aided techniques. This approach provides the automation of the design process of the mono-block dental implants.Design/methodology/approach: The approach used to develop the modelling and design of the mono-block dental implants are based on the parametrization of the main geometric features of the implants. This approach allows to generate ...

  8. THE USE OF SIMULINK BLOCK DIAGRAM TO SOLVE MATHEMATICAL MODELS AND CONTROL EQUATIONS

    OpenAIRE

    Ghasem, N. M.; Departamento de Biología Facultad de Ciencias Pontificia Universidad Javeriana; Hussain, M. A.; Department of Chemical Engineering University of Malaya, 50603 Kuala Lumpur, Malaysia, School of Engineering, Design and Technology, University of Bradford, Bradford BD7 1DP, UK; Mujtaba, I. M.; Department of Chemical Engineering University of Malaya, 50603 Kuala Lumpur, Malaysia, School of Engineering, Design and Technology, University of Bradford, Bradford BD7 1DP, UK

    2003-01-01

    In this paper, the simulink block diagram is used to solve a model consists of a set of ordinary differential and algebraic equations to control the temperature inside a simple stirred tank heater. The flexibility of simulink block diagram gives students a better understanding of the control systems. The simulink alsoallows solution of mathematical models and easy visualization of the system variables. A polyethylene fluidized bed reactor is considered as an industrial example and the effect ...

  9. Markovian Building Blocks for Individual-Based Modelling

    OpenAIRE

    Nilsson, Lars Anders Fredrik; Nielsen, Bo Friis; Thygesen, Uffe Høgsbro; Beyer, Jan

    2007-01-01

    The present thesis consists of a summary report, four research articles, one technical report and one manuscript. The subject of the thesis is individual-based stochastic models. The summary report is composed of three parts and a brief history of some basic models in population biology. This history is included in order to provide a reader that has no previous exposure to models in population biology with a sufficient background to understand some of the biological models that are mentioned ...

  10. Blocking performance of the hose model and the pipe model for VPN service provisioning over WDM optical networks

    Science.gov (United States)

    Wang, Haibo; Swee Poo, Gee

    2004-08-01

    We study the provisioning of virtual private network (VPN) service over WDM optical networks. For this purpose, we investigate the blocking performance of the hose model versus the pipe model for the provisioning. Two techniques are presented: an analytical queuing model and a discrete event simulation. The queuing model is developed from the multirate reduced-load approximation technique. The simulation is done with the OPNET simulator. Several experimental situations were used. The blocking probabilities calculated from the two approaches show a close match, indicating that the multirate reduced-load approximation technique is capable of predicting the blocking performance for the pipe model and the hose model in WDM networks. A comparison of the blocking behavior of the two models shows that the hose model has superior blocking performance as compared with pipe model. By and large, the blocking probability of the hose model is better than that of the pipe model by a few orders of magnitude, particularly at low load regions. The flexibility of the hose model allowing for the sharing of resources on a link among all connections accounts for its superior performance.

  11. Projected current density comparison in tDCS block and smooth FE modeling.

    Science.gov (United States)

    Indahlastari, Aprinda; Chauhan, Munish; Sadleir, Rosalind J

    2016-08-01

    Current density distribution and projected current density calculation following transcranial direct current stimulation (tDCS) forward model in a human head were compared between two modeling pipelines: block and smooth. Block model was directly constructed from MRI voxel resolution and simulated in C. Smooth models underwent a boundary smoothing process by applying recursive Gaussian filters and simulated in COMSOL. Three smoothing levels were added to determine their effects on current density distribution compared to block models. Median current density percentage differences were calculated in anterior superior temporal gyrus (ASTG), hippocampus (HIP), inferior frontal gyrus (IFG), occipital lobes (OCC) and precentral gyrus (PRC) and normalized against a baseline value. A maximum of + 20% difference in median current density was found for three standard electrode montages: F3-RS, T7-T8 and Cz-Oz. Furthermore, median current density percentage differences in each montage target brain structures were found to be within + 7%. Higher levels of smoothing increased median current density percentage differences in T7-T8 and Cz-Oz target structures. However, while demonstrating similar trends in each montage, additional smoothing levels showed no clear relationship between their smoothing effects and calculated median current density in the five cortical structures. Finally, relative L2 error in reconstructed projected current density was found to be 17% and 21% for block and smooth pipelines, respectively. Overall, a block model workflow may be a more attractive alternative for simulating tDCS stimulation because involves a shorter modeling time and independence from commercial modeling platforms.

  12. DETERMINATION OF RESOLUTION LIMITS OF ELECTRICAL TOMOGRAPHY ON THE BLOCK MODEL IN A HOMOGENOUS ENVIRONMENT BY MEANS OF ELECTRICAL MODELLING

    Directory of Open Access Journals (Sweden)

    Franjo Šumanovac

    2007-12-01

    Full Text Available The block model in a homogenous environment can generally serve for presentation of some geological models: changes of facies, changes of rock compactness-fragmentation, underground cavities, bauxite deposits, etc. Therefore, on the block model of increased resistivities in a homogenous environment of low resistivity, the potentials of the electrical tomography method were tested for the purpose of their detection. Regarding potentials of block detection, resolution methods depend on: depth of block location, ratio between block resistivity and the environment in which it is located as well as applied survey geometry, i.e. electrode array. Thus the analyses carried out for the most frequently used electrode arrays in the investigations are the following: the Wenner, Wenner-Schlumberger, dipole-dipole and pole-pole arrays. For each array, maximum depths at which a block can be detected relative to the ratio between block resistivity and parent rock environment were analyzed. The results are shown in the two-dimensional graphs, where the ratio between the block resistivity and the environment is shown on the X-axis, and the resolution depth on the Y-axis, after which the curves defining the resolution limits were drawn. These graphs have a practical use, since they enable a fast, simple determination of potentials of the method application on a specific geological model.

  13. Markovian Building Blocks for Individual-Based Modelling

    DEFF Research Database (Denmark)

    Nilsson, Lars Anders Fredrik

    2007-01-01

    The present thesis consists of a summary report, four research articles, one technical report and one manuscript. The subject of the thesis is individual-based stochastic models. The summary report is composed of three parts and a brief history of some basic models in population biology....... This history is included in order to provide a reader that has no previous exposure to models in population biology with a sufficient background to understand some of the biological models that are mentioned in the thesis. The first part of the rest of the summary is a description of the dramatic changes...... in the degree of aggregation of sprat or herring in the Baltic during the day, with special focus on the dispersion of the fish from schools at dusk. The next part is a brief introduction to Markovian arrival processes, a type of stochastic processes with potential applications as sub-models in population...

  14. Modeling of Video Sequences by Gaussian Mixture: Application in Motion Estimation by Block Matching Method

    Directory of Open Access Journals (Sweden)

    Nsiri Benayad

    2010-01-01

    Full Text Available This article investigates a new method of motion estimation based on block matching criterion through the modeling of image blocks by a mixture of two and three Gaussian distributions. Mixture parameters (weights, means vectors, and covariance matrices are estimated by the Expectation Maximization algorithm (EM which maximizes the log-likelihood criterion. The similarity between a block in the current image and the more resembling one in a search window on the reference image is measured by the minimization of Extended Mahalanobis distance between the clusters of mixture. Performed experiments on sequences of real images have given good results, and PSNR reached 3 dB.

  15. Excitation block in a nerve fibre model owing to potassium-dependent changes in myelin resistance

    DEFF Research Database (Denmark)

    Brazhe, Alexey; Maksimov, G. V.; Mosekilde, Erik;

    2011-01-01

    The myelinated nerve fibre is formed by an axon and Schwann cells or oligodendrocytes that sheath the axon by winding around it in tight myelin layers. Repetitive stimulation of a fibre is known to result in accumulation of extracellular potassium ions, especially between the axon and the myelin......-spiking states. Intermittent conduction blocks are accompanied by oscillations of extracellular potassium. The mechanism of conductance block based on myelin restructuring complements the already known and modelled block via hyperpolarization mediated by the axonal sodium pump and potassium depolarization....

  16. The initial establishment of the tectonic block motion model of China from space geodetic data

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Using the velocity fields of 28 GPS sites in China and its contiguous area and International Terrestrial Reference Frame ITRF96, an initial tectonic block motion model of China was established. The model was quite consistent with those obtained from the geologic data. The model could show the sketch of China crustal horizontal motion.

  17. Traffic Modelling for Moving-Block Train Control System

    Institute of Scientific and Technical Information of China (English)

    TANG Tao; LI Ke-Ping

    2007-01-01

    This paper presents a new cellular automaton (CA) model for train control system simulation.In the proposed CA model,the driver reactions to train movements are captured by some updated rules.The space-time diagram of traffic flow and the trajectory of train movement is used to obtain insight into the characteristic behavior of railway traffic flow.A number of simulation results demonstrate that the proposed CA model can be successfully used for the simulations of railway traffic.Not only the characteristic behavior of railway traffic flow can be reproduced,but also the simulation values of the minimum time headway are close to the theoretical values.

  18. Physical and theoretical modeling of rock slopes against block-flexure toppling failure

    Directory of Open Access Journals (Sweden)

    Mehdi Amini

    2015-12-01

    Full Text Available Block-flexure is the most common mode of toppling failure in natural and excavated rock slopes. In such failure, some rock blocks break due to tensile stresses and some overturn under their own weights and then all of them topple together. In this paper, first, a brief review of previous studies on toppling failures is presented. Then, the physical and mechanical properties of experimental modeling materials are summarized. Next, the physical modeling results of rock slopes with the potential of block-flexural toppling failures are explained and a new analytical solution is proposed for the stability analysis of such slopes. The results of this method are compared with the outcomes of the experiments. The comparative studies show that the proposed analytical approach is appropriate for the stability analysis of rock slopes against block-flexure toppling failure. Finally, a real case study is used for the practical verification of the suggested method.

  19. Estimation linear model using block generalized inverse of a matrix

    OpenAIRE

    Jasińska, Elżbieta; Preweda, Edward

    2013-01-01

    The work shows the principle of generalized linear model, point estimation, which can be used as a basis for determining the status of movements and deformations of engineering objects. The structural model can be put on any boundary conditions, for example, to ensure the continuity of the deformations. Estimation by the method of least squares was carried out taking into account the terms and conditions of the Gauss- Markov for quadratic forms stored using Lagrange function. The original sol...

  20. Block and parallel modelling of broad domain nonlinear continuous mapping based on NN

    Institute of Scientific and Technical Information of China (English)

    Yang Guowei; Tu Xuyan; Wang Shoujue

    2006-01-01

    The necessity of the use of the block and parallel modeling of the nonlinear continuous mappings with NN is firstly expounded quantitatively. Then, a practical approach for the block and parallel modeling of the nonlinear continuous mappings with NN is proposed. Finally, an example indicating that the method raised in this paper can be realized by suitable existed software is given. The results of the experiment of the model discussed on the 3-D Mexican straw hat indicate that the block and parallel modeling based on NN is more precise and faster in computation than the direct ones and it is obviously a concrete example and the development of the large-scale general model established by Tu Xuyan.

  1. Application of Seismic Data to Reservoir Modeling of the Chegu 201 Block

    Institute of Scientific and Technical Information of China (English)

    CaiYi; ZhangXiangzhong; ZhangXinshang

    2005-01-01

    Great uncertainty exists in reservoir models built for blocks where well spacing is uneven or large. The uncertainty in reservoir models can be significantly reduced by using Coordinate Cokriging Sequential Gaussian Simulation technology, in combination with the restriction of seismic characteristic data. Satisfactory reservoir parameter interpolation results, which are more accurate than those derived only from borehole data, are obtained, giving rise to a reasonable combination of widespread and dense-sampled seismic (soft data) data with borehole data (hard data). A significant effect has been made in reservoir parameter modeling in the Chegu 201 block of the Futai Oilfield by using this technology.

  2. Percutaneous sciatic nerve block with tramadol induces analgesia and motor blockade in two animal pain models

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, A.M.; Ashmawi, H.A.; Costa, L.S.; Posso, I.P. [LIM-08 - Anestesiologia Experimental, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Slullitel, A. [Departamento de Anestesiologia, Hospital Santa Paula, São Paulo, SP (Brazil)

    2011-12-23

    Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group) were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2% lidocaine or tramadol (1.25 and 5 mg) was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg) increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s) and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN) at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg) blocked motor function as well as 2% lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics.

  3. Percutaneous sciatic nerve block with tramadol induces analgesia and motor blockade in two animal pain models

    Directory of Open Access Journals (Sweden)

    A.M. Sousa

    2012-02-01

    Full Text Available Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2% lidocaine or tramadol (1.25 and 5 mg was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg blocked motor function as well as 2% lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics.

  4. The Local Balances of Vorticity and Heat for Blocking Anticyclones in a Spectral General Circulation Model.

    Science.gov (United States)

    Mullen, Steven L.

    1986-07-01

    Blocking anticyclones that appear in perpetual January simulations of a spectral general circulation model are examined. Blocks in three geographical regions are studied: the North Pacific, the North Atlantic and western North America. Local time-averaged balances of vorticity and heat are evaluated for composite cases of blocking. The following common relationships emerged from these budgets.The time-mean divergence term is, in general, a flat-order term in the vorticity balance throughout the troposphere and its pattern over severe orography is closely related to the underlying topography. Above the surface layer, the horizontal advection of time-mean absolute vorticity by the mean wind mainly balances the divergence term with the net effect of the time-mean vorticity forcing being a tendency for the blocking pattern to propagate downstream. The transient eddy vorticity transports act to shift the block upstream and hence they mainly offset the downstream tendency due to the time-mean flow; the magnitude of the eddy vorticity term is typically one-third to one-half that of the divergence or advection terms alone. Frictional dissipation is negligible everywhere except near the ground where it primarily offsets the divergence term.The horizontal advection of the time-mean temperature field by the mean wind throughout the troposphere is a first-order term in the beat balance and is mainly responsible for maintaining the block's thermal perturbations; it is predominately balanced by adiabatic heating in the free troposphere and by diabatic heating near the surface. Transient eddy heat transports act to dissipate the block's thermal perturbations at all levels, while diabatic heating does not exhibit a systematic relationship with the temperature field at any level.A quasi-geostrophic diagnosis of the ageostrophic motion field suggests that dynamical processes which strongly affect the vorticity balance may be more important to the maintenance of model blocks than

  5. Characterization of a Model Polyelectrolyte Membrane Using a Semi-crystalline Block Copolymer

    Science.gov (United States)

    Beers, Keith; Wang, Xin; Balsara, Nitash

    2011-03-01

    The microstructured block copolymer sulfonated polystyrene-block-polyethylene is studied as model system for use as a proton exchange membrane in a fuel cell. Self-assembly of this system creates proton conducting hydrophilic channels in the form of sulfonated polystyrene domains, while the polyethylene domains create a hydrophobic matrix to provide mechanical stability. This system serves as a powerful model system since the effects of domain size, morphology and crystallinity on water uptake and proton conductivity can be investigated. Similar systems have shown the ability of small hydrophilic channels to prevent drying at high temperatures in humid air, but have focused on amorphous hydrophobic blocks. The morphology, water uptake, and proton conductivity of this semi-crystalline model system will be discussed.

  6. Application of blocking diagnosis methods to general circulation models. Part I: a novel detection scheme

    Energy Technology Data Exchange (ETDEWEB)

    Barriopedro, D. [Universidade de Lisboa, CGUL-IDL, Faculdade de Ciencias, Ed. C-8, Lisbon (Portugal); Universidad de Extremadura, Departamento de Fisica, Facultad de Ciencias, Badajoz (Spain); Garcia-Herrera, R. [Universidad Complutense de Madrid, Departamento de Fisica de la Tierra II, Facultad de C.C. Fisicas, Madrid (Spain); Trigo, R.M. [Universidade de Lisboa, CGUL-IDL, Faculdade de Ciencias, Ed. C-8, Lisbon (Portugal)

    2010-12-15

    This paper aims to provide a new blocking definition with applicability to observations and model simulations. An updated review of previous blocking detection indices is provided and some of their implications and caveats discussed. A novel blocking index is proposed by reconciling two traditional approaches based on anomaly and absolute flows. Blocks are considered from a complementary perspective as a signature in the anomalous height field capable of reversing the meridional jet-based height gradient in the total flow. The method succeeds in identifying 2-D persistent anomalies associated to a weather regime in the total flow with blockage of the westerlies. The new index accounts for the duration, intensity, extension, propagation, and spatial structure of a blocking event. In spite of its increased complexity, the detection efficiency of the method is improved without hampering the computational time. Furthermore, some misleading identification problems and artificial assumptions resulting from previous single blocking indices are avoided with the new approach. The characteristics of blocking for 40 years of reanalysis (1950-1989) over the Northern Hemisphere are described from the perspective of the new definition and compared to those resulting from two standard blocking indices and different critical thresholds. As compared to single approaches, the novel index shows a better agreement with reported proxies of blocking activity, namely climatological regions of simultaneous wave amplification and maximum band-pass filtered height standard deviation. An additional asset of the method is its adaptability to different data sets. As critical thresholds are specific of the data set employed, the method is useful for observations and model simulations of different resolutions, temporal lengths and time variant basic states, optimizing its value as a tool for model validation. Special attention has been paid on the devise of an objective scheme easily applicable

  7. Total variation regularization of geodetically and geologically constrained block models for the Western United States

    Science.gov (United States)

    Evans, Eileen L.; Loveless, John P.; Meade, Brendan J.

    2015-08-01

    Geodetic observations of interseismic deformation in the Western United States provide constraints on microplate rotations, earthquake cycle processes, and slip partitioning across the Pacific-North America Plate boundary. These measurements may be interpreted using block models, in which the upper crust is divided into microplates bounded by faults that accumulate strain in a first-order approximation of earthquake cycle processes. The number and geometry of microplates are typically defined with boundaries representing a limited subset of the large number of potentially seismogenic faults. An alternative approach is to include a large number of potentially active faults bounding a dense array of microplates, and then algorithmically estimate the boundaries at which strain is localized. This approach is possible through the application of a total variation regularization (TVR) optimization algorithm, which simultaneously minimizes the L2 norm of data residuals and the L1 norm of the variation in the differential block motions. Applied to 3-D spherical block models, the TVR algorithm can be used to reduce the total variation between estimated rotation vectors, effectively grouping microplates that rotate together as larger blocks, and localizing fault slip on the boundaries of these larger block clusters. Here we develop a block model comprised of 137 microplates derived from published fault maps, and apply the TVR algorithm to identify the kinematically most important faults in the western United States. This approach reveals that of the 137 microplates considered, only 30 unique blocks are required to approximate deformation in the western United States at a residual level of <2 mm yr-1.

  8. Faulting and block rotation in the Afar triangle, East Africa: The Danakil "crank-arm" model

    Science.gov (United States)

    Souriot, T.; Brun, J.-P.

    1992-10-01

    Several domains of contrasted extensional deformation have been identified in the southern Afar triangle (East Africa) from fault patterns analyzed with panchromatic stereoscopic SPOT (Système Probatoire d'Observation de la Terre) images. Stretching directions and statistical orientation and offset variations of faults fit with the Danakii "crank-arm" model of Sichler: A 10° sinistral rotation of the Danakil block explains the fault geometry and dextral block rotation in the southern part of the Afar triangle, as well as the oblique extension in the Tadjoura Gulf. Analogue modeling supports this interpretation.

  9. Valuation model of exploratory blocks; Modelo de valoracao de blocos exploratorios

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Thiago Neves de; Sartori, Vanderlei [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Last year completed 10 years of the promulgations of the Brazilian Petroleum Act. This act has regulated the of the sector of exploration and production of oil and natural gas in Brazil, enabling these activities were granted to private or state companies, preceded by a bidding round. Since 1998, ANP have been doing these bids, using in the judgment of offers the following criteria: Minimum Exploration Program, Local Content and Bonuses of Signature. The objective of this article is to present a model of valuation of the blocks on offer, showing a model of estimation of the monetary value of the block. (author)

  10. Monte Carlo homogenized limit analysis model for randomly assembled blocks in-plane loaded

    Science.gov (United States)

    Milani, Gabriele; Lourenço, Paulo B.

    2010-11-01

    A simple rigid-plastic homogenization model for the limit analysis of masonry walls in-plane loaded and constituted by the random assemblage of blocks with variable dimensions is proposed. In the model, blocks constituting a masonry wall are supposed infinitely resistant with a Gaussian distribution of height and length, whereas joints are reduced to interfaces with frictional behavior and limited tensile and compressive strength. Block by block, a representative element of volume (REV) is considered, constituted by a central block interconnected with its neighbors by means of rigid-plastic interfaces. The model is characterized by a few material parameters, is numerically inexpensive and very stable. A sub-class of elementary deformation modes is a-priori chosen in the REV, mimicking typical failures due to joints cracking and crushing. Masonry strength domains are obtained equating the power dissipated in the heterogeneous model with the power dissipated by a fictitious homogeneous macroscopic plate. Due to the inexpensiveness of the approach proposed, Monte Carlo simulations can be repeated on the REV in order to have a stochastic estimation of in-plane masonry strength at different orientations of the bed joints with respect to external loads accounting for the geometrical statistical variability of blocks dimensions. Two cases are discussed, the former consisting on full stochastic REV assemblages (obtained considering a random variability of both blocks height an length) and the latter assuming the presence of a horizontal alignment along bed joints, i.e. allowing blocks height variability only row by row. The case of deterministic blocks height (quasi-periodic texture) can be obtained as a subclass of this latter case. Masonry homogenized failure surfaces are finally implemented in an upper bound FE limit analysis code for the analysis at collapse of entire walls in-plane loaded. Two cases of engineering practice, consisting on the prediction of the failure

  11. Polypeptoids: A model system for exploring sequence and shape effects on block copolymer self-assembly

    Science.gov (United States)

    Segalman, Rachel

    2015-03-01

    While our ability to understand the detailed relationship between block copolymer chemistry and mesoscopic self-assembly has made remarkable progress over the last many years, yet we are still limited to a relatively small number of blocks in terms of structure-property understanding. Thus, there is a need to explore self-assembly phase space with sequence using a model system. Polypeptoids are non-natural, sequence specific polymers that offer the opportunity to probe the effect of sequence on self-assembly with much simpler molecular interactions and more scalable synthesis than traditional polypeptides. In this talk, I will discuss the use of this model system to understand the role of sequence on chain collapse and globule formation in solution, polymer crystallization, and block copolymer self-assembly. I will then discuss potential application as surface active agents for anti-fouling.

  12. Adaptive Noise Model for Transform Domain Wyner-Ziv Video using Clustering of DCT Blocks

    DEFF Research Database (Denmark)

    Luong, Huynh Van; Huang, Xin; Forchhammer, Søren

    2011-01-01

    The noise model is one of the most important aspects influencing the coding performance of Distributed Video Coding. This paper proposes a novel noise model for Transform Domain Wyner-Ziv (TDWZ) video coding by using clustering of DCT blocks. The clustering algorithm takes advantage of the residual...... information of all frequency bands, iteratively classifies blocks into different categories and estimates the noise parameter in each category. The experimental results show that the coding performance of the proposed cluster level noise model is competitive with state-ofthe- art coefficient level noise...... modelling. Furthermore, the proposed cluster level noise model is adaptively combined with a coefficient level noise model in this paper to robustly improve coding performance of TDWZ video codec up to 1.24 dB (by Bjøntegaard metric) compared to the DISCOVER TDWZ video codec....

  13. A viscoelastic spring-block model for investigating subglacial water pressure pulse generation

    Science.gov (United States)

    Kavanaugh, J. L.

    2009-12-01

    A viscoelastic spring-block model of glacier motion has been developed to investigate the mechanisms responsible for generating brief pulses in subglacial water pressure recorded at Trapridge Glacier, Yukon. In this model, the glacier is treated as an array of ice blocks, each of which is connected to its nearest neighbors by spring-and-dashpot linkages. The model glacier is gravitationally driven, and down-slope flow is resisted by a basal shear stress determined by the Mohr-Coulomb failure criterion. This model is forced with realistic basal water pressure conditions. With prescribed summer-mode, diurnally-varying pressures, the model produces elevated slip activity at times of rising (rather than peak) water pressures; with steady, elevated winter-mode pressures, slip events occur at non-uniform intervals due to the effects of elastic loading and the (nonlinear) viscous relaxation of stresses. Magnitude and interevent time statistics for model slip events and basal water pressure pulses are compared.

  14. On the Use of Self-Assembling Block Copolymers to Toughen A Model Epoxy

    Science.gov (United States)

    Chen, Yilin

    Block copolymers have been receiving considerable attention in toughening epoxy due to their ability to form a wide variety of nanostructures. This study focuses on using both triblock and diblock copolymers to improve the fracture toughness of an aromatic-amine cured epoxy system. The curing system consisted of 1,3- phenylenediamine (mPDA) as curing agent and aniline as a chain extender. Three triblock copolymers and three diblock copolymers were incorporated in the same lightly crosslinked model epoxy system, which was chosen to mimic an underfill material in flip-chip packaging for the microelectronics industry. In this research, rubber particles were formed in situ using self-assembling block copolymers. Mechanical, thermal and microscopic studies were conducted with the main goal to study the relationship between the block parameters and the final morphologies and their effects on static and dynamic mechanical properties of the toughened resin, especially fracture toughness. In these block-copolymer-modified epoxies, spherical micelles and wormlike micelles were obtained by varying block lengths, molecular weight, polarities and compositions. It was found that miscibility of the epoxy-miscible block played a crucial role in the formation of different types of morphologies. At a low loading level, diblock copolymers were able to toughen the model epoxy as effectively as triblock copolymers. The fracture toughness was improved to almost three times with respect to that of the neat resin with addition of 10 phr AM*-27. At the same time, other mechanical properties, such as yield strength and modulus, were well retained. Incorporation of block copolymers did not have a significant effect on glass transition temperature but caused an increase in coefficient of thermal expansion (CTE) of the modified epoxy. Particle cavitation and matrix void growth were proved to be the toughening mechanisms for SBM-Modified epoxies. However, these typical toughening mechanisms for

  15. Modeling and estimating change in temporal networks via a dynamic degree corrected stochastic block model

    CERN Document Server

    Wilson, James D; Woodall, William H

    2016-01-01

    In many applications it is of interest to identify anomalous behavior within a dynamic interacting system. Such anomalous interactions are reflected by structural changes in the network representation of the system. We propose and investigate the use of a dynamic version of the degree corrected stochastic block model (DCSBM) as a means to model and monitor dynamic networks that undergo a significant structural change. Our model provides a means to simulate a variety of local and global changes in a time-varying network. Furthermore, one can efficiently detect such changes using the maximum likelihood estimates of the parameters that characterize the DCSBM. We assess the utility of the dynamic DCSBM on both simulated and real networks. Using a simple monitoring strategy on the DCSBM, we are able to detect significant changes in the U.S. Senate co-voting network that reflects both times of cohesion and times of polarization among Republican and Democratic members. Our analysis suggests that the dynamic DCSBM pr...

  16. Visible calculation of mining index based on stope 3D surveying and block modeling

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaoming; Luo Zhouquan; Yang Biao; Lu Guang; Cao Shengxiang; Jiang Xinjian

    2012-01-01

    Aimed at the CMS laser scanning theory and characteristic,a combined actual situation of stope N4-5 of Fankou Lead-Zinc Mine and complementary monitoring of the stope were carried out by carefully choosing two measuring points.The cavity 3D visible model was created by large-scale mining industry software Surpac after changing the measured data.The stope mine design model,bottom structural model and backfill model of the south and north sides of the stope N4-5 were established according to the stope design data.On this basis,the stope block model was established,and then block attribute was estimated.The amount the ore remains,mullock,backfill and total mined ore were calculated through the solid model restrains.Finally,the stope mining dilution rate and loss rate reached 8.2%and 1.47%,respectively.The practice indicates that the mining index visible calculation method based on cavity 3D monitoring and stope block modeling can make up the deficiency of adopting the solid model to directly carry out the Boolean operation.The stope mining indexes obtained by this method are accurate and reliable,and can be used to guide the actual production management and estimate the mining quality.

  17. Shape Optimization of Hollow Concrete Blocks Using the Lattice Discrete Particle Model

    Directory of Open Access Journals (Sweden)

    Fatemeh Javidan

    2013-01-01

    Full Text Available Hollow concrete blocks are one of the widely used building elements of masonry structures in whichthey are normally loaded under combined action of shear and compression. Accordingly and due to theirstructural importance, the present study intends to numerically search for an optimum shape of such blocks.The optimality index is selected to be the ratio of block’s failure strength to its weight, a non-dimensionalparameter, which needs to be maximized. The nonlinear analysis has been done using a homemade code writtenbased on the recently developed Lattice Discrete Particle Model (LDPM for the meso-scale simulation ofconcrete. This numerical approach accounts for the different aspects of concrete’s complex behavior such astensile fracturing, cohesive and frictional shearing and also its nonlinear compressive response. The modelparameters were calibrated against previously reported experimental data. Various two-core configurations forthe hollow blocks are examined, compared and discussed.

  18. Modeling the Heat Capacity of Spider Silk Inspired Di-block Copolymers

    Science.gov (United States)

    Huang, W.; Krishnaji, S.; Kaplan, D.; Cebe, P.

    2011-03-01

    We synthesized and characterized a new family of di-block copolymers based on the amino acid sequences of Nephila clavipes major ampulate dragline spider silk, having the form HABn and HBAn (n=1-6), comprising an alanine-rich hydrophobic block, A, a glycine-rich hydrophilic block, B, and a histidine tag, H. Using temperature modulated differential scanning calorimetry (TMDSC), we captured the effect of bound water acting as a plasticizer for copolymer films which had been cast from water solution and dried. We determined the water content by thermogravimetry and used the weight loss vs. temperature to correct the mass in TMDSC experiments. Our result shows that non-freezing bound water has a strong plasticization effect which lowers the onset of the glass transition by about 10circ; C. The reversing heat capacities, Cp(T), for temperatures below and above the glass transition were also characterized by TMDSC. We then calculated the solid state heat capacities of our novel block copolymers below the glass transition (Tg) based on the vibrational motions of the constituent poly(amino acid)s, whose heat capacities are known from the ATHAS Data Bank. Excellent agreement was found between the measured and calculated values of the heat capacity, showing that this model can serve as a standard method to predict the solid state Cp for other biologically inspired block copolymers. Support was provided from the NSF CBET-0828028 and the MRI Program under DMR-0520655 for thermal analysis instrumentation.

  19. Use of generalised Procrustes analysis for the photogrammetric block adjustment by independent models

    Science.gov (United States)

    Crosilla, Fabio; Beinat, Alberto

    The paper reviews at first some aspects of the generalised Procrustes analysis (GP) and outlines the analogies with the block adjustment by independent models. On this basis, an innovative solution of the block adjustment problem by Procrustes algorithms and the related computer program implementation are presented and discussed. The main advantage of the new proposed method is that it avoids the conventional least squares solution. For this reason, linearisation algorithms and the knowledge of a priori approximate values for the unknown parameters are not required. Once the model coordinates of the tie points are available and at least three control points are known, the Procrustes algorithms can directly provide, without further information, the tie point ground coordinates and the exterior orientation parameters. Furthermore, some numerical block adjustment solutions obtained by the new method in different areas of North Italy are compared to the conventional solution. The very simple data input process, the less memory requirements, the low computing time and the same level of accuracy that characterise the new algorithm with respect to a conventional one are verified with these tests. A block adjustment of 11 models, with 44 tie points and 14 control points, takes just a few seconds on an Intel PIII 400 MHz computer, and the total data memory required is less than twice the allocated space for the input data. This is because most of the computations are carried out on data matrices of limited size, typically 3×3.

  20. Climatological features of blocking anticyclones: a study of Northern Hemisphere CCM1 model blocking events in present-day and double CO{sub 2} concentration atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Lupo, A.R. [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth and Atmospheric Sciences; Oglesby, R.J. [Purdue Univ., West Lafayette, IN (United States). Dept. of Earth and Atmospheric Sciences; Mokhov, I.I. [Russian Acad. of Sci., Moscow (Russian Federation). Inst. of Atmospheric Phys.

    1997-03-01

    Using output made with the national center for atmospheric research (NCAR) community climate model version 1 (CCM1), the characteristics of blocking events over the Northern Hemisphere in a ten-year present day control simulation with a CO{sub 2} concentration of 330 ppm were compared to those in a previously analyzed observational three-year climatology. The characteristics of blocking events in a double present-day CO{sub 2} concentration simulation were then compared to those in the control simulation in order to evaluate how these characteristics might change in an increased CO{sub 2} atmosphere. The results demonstrated that in the Northern Hemisphere the CCM1 correctly simulated many characteristics of blocking events such as average annual number of occurrences, annual variations is size and intensity, and preferred formation regions. A more detailed analysis (i.e., by region and season) revealed some differences between the CCM1 and observed blocking events for characteristics such as mean frequency of occurrence, intensity, size and duration. In addition, the model failed to capture adequately the occurrence of blocking events over the western Asian continent. A comparison of the double CO{sub 2} concentration run to the control showed that, in general, blocking events were more persistent and weaker, but of similar size in the increased CO{sub 2} atmosphere. Also, some statistically significant regional and seasonally dependent changes were found in the frequency of occurrence, duration, and intensity. Finally, a correlation between block size and intensity, significant at the 99% confidence level, was found in each climatology. This result is similar to a correlation found in the analysis of observations. (orig.). With 9 figs., 5 tabs.

  1. Classification and estimation in the Stochastic Block Model based on the empirical degrees

    CERN Document Server

    Channarond, Antoine; Robin, Stéphane

    2011-01-01

    The Stochastic Block Model (Holland et al., 1983) is a mixture model for heterogeneous network data. Unlike the usual statistical framework, new nodes give additional information about the previous ones in this model. Thereby the distribution of the degrees concentrates in points conditionally on the node class. We show under a mild assumption that classification, estimation and model selection can actually be achieved with no more than the empirical degree data. We provide an algorithm able to process very large networks and consistent estimators based on it. In particular, we prove a bound of the probability of misclassification of at least one node, including when the number of classes grows.

  2. AN EFFECTIVE MODEL TO EVALUATE BLOCKING PROBABILITY OF TIME-SLOTTED OPTICAL BURST SWITCHED NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Yang Zongkai; Ou Liang; Tan Xiansi

    2006-01-01

    Time-slotted optical burst switched network is a potential technique to support IP over Wavelength Division Multiplexing (WDM) by introduce Time Division Multiplexing (TDM) channel to Optical Burst Switching (OBS) technology. This paper presents a framework to evaluate blocking performance of time-slotted OBS networks with multi-fiber wavelength channels. The proposed model is efficient for not only single class traffic such as individual circuit switch traffics or best-effort traffics but also mixed multi-class traffics.The effectiveness of the proposed model is validated by simulation results. The study shows that blocking performance of multi-fiber TS-OBS network is acceptable for future Internet services.

  3. BSIRT: a block-iterative SIRT parallel algorithm using curvilinear projection model.

    Science.gov (United States)

    Zhang, Fa; Zhang, Jingrong; Lawrence, Albert; Ren, Fei; Wang, Xuan; Liu, Zhiyong; Wan, Xiaohua

    2015-03-01

    Large-field high-resolution electron tomography enables visualizing detailed mechanisms under global structure. As field enlarges, the distortions of reconstruction and processing time become more critical. Using the curvilinear projection model can improve the quality of large-field ET reconstruction, but its computational complexity further exacerbates the processing time. Moreover, there is no parallel strategy on GPU for iterative reconstruction method with curvilinear projection. Here we propose a new Block-iterative SIRT parallel algorithm with the curvilinear projection model (BSIRT) for large-field ET reconstruction, to improve the quality of reconstruction and accelerate the reconstruction process. We also develop some key techniques, including block-iterative method with the curvilinear projection, a scope-based data decomposition method and a page-based data transfer scheme to implement the parallelization of BSIRT on GPU platform. Experimental results show that BSIRT can improve the reconstruction quality as well as the speed of the reconstruction process.

  4. Discrete matrix models for partial sums of conformal blocks associated to Painlev\\'e transcendents

    CERN Document Server

    Balogh, F

    2014-01-01

    A recently formulated conjecture of Gamayun, Iorgov and Lisovyy gives an asymptotic expansion of the Jimbo--Miwa--Ueno isomonodromic $\\tau$-function for certain Painlev\\'e transcendents. The coefficients in this expansion are given in terms of conformal blocks of a two-dimensional conformal field theory, which can be written as infinite sums over pairs of partitions. In this note a discrete matrix model is proposed on a lattice whose partition function can be used to obtain a multiple integral representation for the length restricted partial sums of the Painlev\\'e conformal blocks. This leads to expressions of the partial sums involving H\\"ankel determinants associated to the discrete measure of the matrix model, or equivalently, Wronskians of the corresponding moment generating function which is shown to be of the generalized hypergeometric type.

  5. Transformation Strategies between Block-Oriented and Graph-Oriented Process Modelling Languages

    DEFF Research Database (Denmark)

    Mendling, Jan; Lassen, Kristian Bisgaard; Zdun, Uwe

    2006-01-01

    Much recent research work discusses the transformation between different process modelling languages. This work, however, is mainly focussed on specific process modelling languages, and thus the general reusability of the applied transformation concepts is rather limited. In this paper, we aim...... to abstract from concrete transformation strategies by distinguishing two major paradigms for representing control flow in process modelling languages: block-oriented languages (such as BPEL and BPML) and graph-oriented languages (such as EPCs and YAWL). The contribution of this paper are generic strategies...

  6. 3D seismic modeling and reverse‐time migration with the parallel Fourier method using non‐blocking collective communications

    KAUST Repository

    Chu, Chunlei

    2009-01-01

    The major performance bottleneck of the parallel Fourier method on distributed memory systems is the network communication cost. In this study, we investigate the potential of using non‐blocking all‐to‐all communications to solve this problem by overlapping computation and communication. We present the runtime comparison of a 3D seismic modeling problem with the Fourier method using non‐blocking and blocking calls, respectively, on a Linux cluster. The data demonstrate that a performance improvement of up to 40% can be achieved by simply changing blocking all‐to‐all communication calls to non‐blocking ones to introduce the overlapping capability. A 3D reverse‐time migration result is also presented as an extension to the modeling work based on non‐blocking collective communications.

  7. Selective source blocking for Gamma Knife radiosurgery of trigeminal neuralgia based on analytical dose modelling

    Energy Technology Data Exchange (ETDEWEB)

    Li Kaile; Ma Lijun [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD 21210 (United States)

    2004-08-07

    We have developed an automatic critical region shielding (ACRS) algorithm for Gamma Knife radiosurgery of trigeminal neuralgia. The algorithm selectively blocks 201 Gamma Knife sources to minimize the dose to the brainstem while irradiating the root entry area of the trigeminal nerve with 70-90 Gy. An independent dose model was developed to implement the algorithm. The accuracy of the dose model was tested and validated via comparison with the Leksell GammaPlan (LGP) calculations. Agreements of 3% or 3 mm in isodose distributions were found for both single-shot and multiple-shot treatment plans. After the optimized blocking patterns are obtained via the independent dose model, they are imported into the LGP for final dose calculations and treatment planning analyses. We found that the use of a moderate number of source plugs (30-50 plugs) significantly lowered ({approx}40%) the dose to the brainstem for trigeminal neuralgia treatments. Considering the small effort involved in using these plugs, we recommend source blocking for all trigeminal neuralgia treatments with Gamma Knife radiosurgery.

  8. Selective source blocking for Gamma Knife radiosurgery of trigeminal neuralgia based on analytical dose modelling

    Science.gov (United States)

    Li, Kaile; Ma, Lijun

    2004-08-01

    We have developed an automatic critical region shielding (ACRS) algorithm for Gamma Knife radiosurgery of trigeminal neuralgia. The algorithm selectively blocks 201 Gamma Knife sources to minimize the dose to the brainstem while irradiating the root entry area of the trigeminal nerve with 70-90 Gy. An independent dose model was developed to implement the algorithm. The accuracy of the dose model was tested and validated via comparison with the Leksell GammaPlan (LGP) calculations. Agreements of 3% or 3 mm in isodose distributions were found for both single-shot and multiple-shot treatment plans. After the optimized blocking patterns are obtained via the independent dose model, they are imported into the LGP for final dose calculations and treatment planning analyses. We found that the use of a moderate number of source plugs (30-50 plugs) significantly lowered (~40%) the dose to the brainstem for trigeminal neuralgia treatments. Considering the small effort involved in using these plugs, we recommend source blocking for all trigeminal neuralgia treatments with Gamma Knife radiosurgery.

  9. Block modeling of crustal deformation in Tierra del Fuego from GNSS velocities

    Science.gov (United States)

    Mendoza, L.; Richter, A.; Fritsche, M.; Hormaechea, J. L.; Perdomo, R.; Dietrich, R.

    2015-05-01

    The Tierra del Fuego (TDF) main island is divided by a major transform boundary between the South America and Scotia tectonic plates. Using a block model, we infer slip rates, locking depths and inclinations of active faults in TDF from inversion of site velocities derived from Global Navigation Satellite System observations. We use interseismic velocities from 48 sites, obtained from field measurements spanning 20 years. Euler vectors consistent with a simple seismic cycle are estimated for each block. In addition, we introduce far-field information into the modeling by applying constraints on Euler vectors of major tectonic plates. The difference between model and observed surface deformation near the Magallanes Fagnano Fault System (MFS) is reduced by considering finite dip in the forward model. For this tectonic boundary global plate circuits models predict relative movements between 7 and 9 mm yr- 1, while our regional model indicates that a strike-slip rate of 5.9 ± 0.2 mm yr- 1 is accommodated across the MFS. Our results indicate faults dipping 66- 4+ 6° southward, locked to a depth of 11- 5+ 5 km, which are consistent with geological models for the MFS. However, normal slip also dominates the fault perpendicular motion throughout the eastern MFS, with a maximum rate along the Fagnano Lake.

  10. Reconstruction of a Phreatic Explosion from Block Dispersion Modeling at King's Bowl, Idaho

    Science.gov (United States)

    Kobs-Nawotniak, S. E.; Sears, D. W. G.; Hughes, S. S.; Borg, C.; Sears, H.; Skok, J. R.; Elphic, R. C.; Lim, D. S. S.; Heldmann, J. L.; Haberle, C. W.; Guy, H.; Kobayashi, L.; Garry, B.; Neish, C.; Kim, K. J.

    2014-12-01

    King's Bowl (KB), located in Idaho's eastern Snake River Plain, was formed by a phreatic blast through a mostly-congealed lava lake. Blocks up to ~2m diameter were ejected from the vent to form a ballistic ejecta blanket extending radially more than 100m. The blocks on the western side of the KB fissure are extraordinarily well exposed, as the fine fraction was blown eastward by ambient winds during the explosion. We present preliminary modeling results using the western ballistic blocks of KB to calculate the energy of the eruption, and the water volume necessary to create the blast. This work is presented in conjunction with two other 2014 AGU conference abstracts submitted by NASA SSERVI funded FINESSE (Field Investigations to Enable Solar System Science and Exploration) team members: Hughes et al., which introduces the geology of KB and Sears et al., which discusses field observation and data trends. Results of this research are extensible to steam-driven pits on other solar system bodies, including those observed on Mars, Phobos, Deimos, and the asteroids. Over 600 blocks ranging from .2 to 2m in diameter were mapped using differential GPS and measured for 3 axial lengths and vesicularity. Mass calculations were corrected using a scaling factor determined from measurements of 100 blocks at KB, coupled with targeted density measurements. The dispersed block trajectories were modeled using a fourth order Runge-Kutta solution of the equations of motion to calculate suites of possible ejection speeds and angles. The resulting characteristic vent velocities were used to calculate the kinetic energy necessary to evacuate the crater at KB; energy required for fragmentation is neglected at this time. Total mass in the kinetic energy calculations was calculated by two separate methods: 1) current volume expression of the KB crater and 2) an additive solution of the ejecta field as determined from radial transect surveys. From the kinetic energy we calculated the

  11. Fem Modelling and Analysis of Reinforced Concrete Section with Light Weight Blocks Infill

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-06-01

    Full Text Available In an attempt to reduce the self weight of reinforced concrete structures, a new development of lightweight sandwich reinforced concrete (LSRC section has been proposed as an alternative option to solid section. LSRC section is a reinforced concrete section which contains lightweight blocks as infill material. An experimental investigation into the strength of LSRC beams has shown promising results under flexural tests. To ensure the serviceability of LSRC members under service load, it is necessary to accurately predict the cracking and deflection of this section. This paper will focus on analysing the behaviour of the tested beam specimens after cracking occurs. ANSYS 12.1 was employed to study the crack propagation of LSRC beams under bending. The numerical model shows the crack in the area of AAC blocks which associates with the brittle failure of LSRC beams. The crack propagation of the beams analysed by ANSYS agrees well with the results from the experimental investigation.

  12. Iterating block spin transformations of the O(3) nonlinear {sigma} model

    Energy Technology Data Exchange (ETDEWEB)

    Gottlob, A.P. [Fachbereich Physik, Universitaet Kaiserslautern, D-67653 Kaiserslautern (Germany); Hasenbusch, M. [DAMTP, Silver Street, Cambridge, CB3 9EW (England); Pinn, K. [Institut fuer Theoretische Physik I, Universitaet Muenster, Wilhelm-Klemm-Strasse 9, D-48149 Muenster (Germany)

    1996-07-01

    We study the iteration of block spin transformations in the O(3) symmetric nonlinear {sigma} model on a two-dimensional square lattice with the help of the Monte Carlo method. In contrast with the classical Monte Carlo renormalization group approach, we {ital do} attempt to explicitly compute the block spin effective actions. Using two different methods for the determination of effective couplings, we study the renormalization group flow for various parametrization and truncation schemes. The largest ansatz for the effective action contains thirteen coupling constants. Actions on the renormalized trajectory should describe theories with no lattice artifacts, even at a small correlation length. However, tests with the step scaling function of L{umlt u}scher, Weisz, and Wolff reveal that our truncated effective actions show sizable scaling violations indicating that the {ital Ans{umlt a}tze} are still too small. {copyright} {ital 1996 The American Physical Society.}

  13. Efficient Monte Carlo and greedy heuristic for the inference of stochastic block models

    CERN Document Server

    Peixoto, Tiago P

    2014-01-01

    We present an efficient algorithm for the inference of stochastic block models in large networks. The algorithm can be used as an optimized Markov chain Monte Carlo (MCMC) method, with a fast mixing time and a much reduced susceptibility to getting trapped in metastable states, or as a greedy agglomerative heuristic, with an almost linear $O(N\\ln^2N)$ complexity, where $N$ is the number of nodes in the network, independent on the number of blocks being inferred. We show that the heuristic is capable of delivering results which are indistinguishable from the more exact and numerically expensive MCMC method in many artificial and empirical networks, despite being much faster. The method is entirely unbiased towards any specific mixing pattern, and in particular it does not favor assortative community structures.

  14. On intrinsic time measure in the modeling of cyclic behavior of a Nitinol cubic block

    Science.gov (United States)

    Chiroiu, Veturia; Florinel Ionescu, Marius; Sireteanu, Tudor; Ioan, Rodica; Munteanu, Ligia

    2015-03-01

    In this paper, the cyclic behavior of a superelastic-plastic nitinol cubic block is described by using the Bouc-Wen model coupled to an intrinsic time measure other than clock time, which governs the behavior of the materials. As a consequence, the thermodynamic admissibility of the Bouc-Wen model is provided by the endochronic theory of plasticity. The role of the intrinsic time measure is described by capturing the stiffness and strength degradation and the opposite phenomena. Such behavior is due to the permanent-strain addition of residual martensite and alterations in the properties of the texture during phase transformation.

  15. Transformation of frequency-magnitude relation prior to large events in the model of block structure dynamics

    Directory of Open Access Journals (Sweden)

    A. Soloviev

    2008-02-01

    Full Text Available The b-value change in the frequency-magnitude (FM distribution for a synthetic earthquake catalogue obtained by means of the model of block structure dynamics has been studied. The catalogue is divided into time periods preceding strong earthquakes and time periods that do not precede strong earthquakes. The separate analysis of these periods shows that the b-value is smaller before strong earthquakes. The similar phenomenon has been found also for the observed seismicity of the Southern California. The model of block structure dynamics represents a seismic region as a system of perfectly rigid blocks divided by infinitely thin plane faults. The blocks interact between themselves and with the underlying medium. The system of blocks moves as a consequence of prescribed motion of the boundary blocks and of the underlying medium. As the blocks are perfectly rigid, all deformation takes place in the fault zones and at the block base in contact with the underlying medium. Relative block displacements take place along the fault zones. Block motion is defined so that the system is in a quasistatic equilibrium state. The interaction of blocks along the fault zones is viscous-elastic ("normal state" while the ratio of the stress to the pressure remains below a certain strength level. When the critical level is exceeded in some part of a fault zone, a stress-drop ("failure" occurs (in accordance with the dry friction model, possibly causing failure in other parts of the fault zones. These failures produce earthquakes. Immediately after the earthquake and for some time after, the affected parts of the fault zones are in a state of creep. This state differs from the normal state because of a faster growth of inelastic displacements, lasting until the stress falls below some other level. This numerical simulation gives rise a synthetic earthquake catalogue.

  16. A new kinematic approach for the Danakil block using a Digital Elevation Model representation

    Science.gov (United States)

    Collet, B.; Taud, H.; Parrot, J. F.; Bonavia, F.; Chorowicz, J.

    2000-01-01

    Data from the literature are integrated in a regional Digital Elevation Model (DEM) in order to analyse the motion of the Danakil block with regard to the Arabian and Somalian plates. The application of the poles and angles of rotation taken from the literature, induces a superposition of the Danakil block on the Arabian plate, and the formation of a gap in the Afar region. The determination of new poles of rotation using a best-fitting procedure allows one to avoid these drawbacks. In all cases, calculations are carried out keeping the Nubian plate stationary. The present approach shows that the Danakil block is an independent entity and is not related to the Nubian and Arabian plates. Between the Oligocene and the Miocene, it has been submitted to a N20°E sinistral strike-slip motion anterior to the rotation itself that was started in the middle Miocene. This rotation is directed by a mechanical couple due to the combination of the Red Sea and North Afar extensions.

  17. On the limit distribution of layer block spin variables in the mean spherical model

    Energy Technology Data Exchange (ETDEWEB)

    Amin, Magdy E

    2004-01-12

    The limit distribution of the layer block spin variables of the mean spherical model under Neumann-Dirichlet boundary conditions is investigated in the presence of an inhomogeneous external field which changes sign at distance Lx (0{<=}x{<=}1) from the Neumann boundary. The behaviour of the equation of state is studied in different temperature and field regimes: high-temperature bulk limit, critical finite-size scaling regime, and low-temperature moderate-field regime. A new classes of critical behaviour for the characteristic function of the limit distributions are obtained and studied in the three different regimes.

  18. Final report of the TRUE Block Scale project. 1. Characterisation and model development

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Peter; Byegaard, Johan [Geosigma AB, Uppsala (Sweden); Dershowitz, Bill; Doe, Thomas [Golder Associates Inc., Redmond, WA (United States); Hermanson, Jan [Golder Associates AB (Sweden); Meier, Peter [ANDRA, Chatenay-Malabry (France); Tullborg, Eva-Lena [Terralogica AB (Sweden); Winberg, Anders (ed.) [Conterra AB, Partille (Sweden)

    2002-04-01

    The general objectives of the TRUE Block Scale Project were to 1) increase understanding of tracer transport in a fracture network and to improve predictive capabilities, 2) assess the importance of tracer retention mechanisms (diffusion and sorption) in a fracture network, and 3) assess the link between flow and transport data as a means for predicting transport phenomena. During the period mid 1996 through mid 1999 a 200x250x100 m rock volume was characterised with the purpose of furnishing the basis for successful tracer experiments in a network of conductive structures in the block scale (10-100 m). In total five cored boreholes were drilled as part of the project in an iterative mode with a period of analysis following completion of characterisation, and with a strong component of inter activity with numerical modelling and experimental design, particularly towards the end of the characterisation. The combined use of pressure responses due to drilling and drilling records provided important early information/confirmation of the existence and location of a given structure. Verification of conductors identified from pressure responses was achieved through the use of various flow logging techniques. The usage of the Posiva difference flow log towards the end of the characterisation work enabled identification of discrete conductive fractures with a high resolution. Pressure responses collected during drilling were used to obtain a first assessment of connectivity between boreholes. The transient behaviour of the responses collected during cross-hole interference tests in packed-off boreholes were used to identify families of responses, which correlated well with the identified principal families of structures/fracture networks. The conductive geometry of the investigated rock block is made up of steeply dipping deterministic NW structures and NNW structures. High inflows in the boreholes were for the most part associated with geologically/geometrically identified

  19. Development of a simple model for batch and boundary information updation for a similar ship's block model

    Institute of Scientific and Technical Information of China (English)

    LEE Hyeon-deok; SON Myeong-jo; OH Min-jae; LEE Hyung-woo; KIM Tae-wan

    2012-01-01

    In early 2000,large domestic shipyards introduced shipbuilding 3D computer-aided design (CAD)to the hull production design process to define manufacturing and assembly information.The production design process accounts for most of the man-hours (M/H) of the entire design process and is closely connected to yard production because designs must take into account the production schedule of the shipyard,the current state of the dock needed to mount the ship's block,and supply information.Therefore,many shipyards are investigating the complete automation of the production design process to reduce the M/H for designers.However,these problems are still currently unresolved,and a clear direction is needed for research on the automatic design base of manufacturing rules,batches reflecting changed building specifications,batch updates of boundary information for hull members,and management of the hull model change history to automate the production design process.In this study,a process was developed to aid production design engineers in designing a new ship's hull block model from that of a similar ship previously built,based on AVEVA Marine.An automation system that uses the similar ship's hull block model is proposed to reduce M/H and human errors by the production design engineer.First,scheme files holding important information were constructed in a database to automatically update hull block model modifications.Second,for batch updates,the database's table,including building specifications and the referential integrity of a relational database were compared.In particular,this study focused on reflecting the frequent modification of building specifications and regeneration of boundary information of the adjacent panel due to changes in a specific panel.Third,the rollback function is proposed in which the database (DB) is used to return to the previously designed panels.

  20. Model for impedance of an ionic conductor sandwiched between blocking electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.C.

    1992-06-24

    The simplest model for the impedance of an ionic conductor sandwiched between two blocking electrodes is a resistor in series with a capacitor (rc pair) representing the bulk material and the conductor-electrode interface, respectively, and a second capacitor parallel to the rc pair representing the electronic dielectric response of the system. In practice, to describe the experimental data satisfactorily, one needs to replace the interface capacitor with a constant-phase-angle (CPA) element and to add a non-Debye dielectric element parallel to the resistor to represent the local ionic movement. In this paper, some of the existing physical models for the CPA and non-Debye dielectric elements are discussed, and an example is presented for analyzing the impedance data using the resultant circuit model.

  1. Model for impedance of an ionic conductor sandwiched between blocking electrodes. [Example: yttria-stabilized zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.C.

    1992-06-24

    The simplest model for the impedance of an ionic conductor sandwiched between two blocking electrodes is a resistor in series with a capacitor (rc pair) representing the bulk material and the conductor-electrode interface, respectively, and a second capacitor parallel to the rc pair representing the electronic dielectric response of the system. In practice, to describe the experimental data satisfactorily, one needs to replace the interface capacitor with a constant-phase-angle (CPA) element and to add a non-Debye dielectric element parallel to the resistor to represent the local ionic movement. In this paper, some of the existing physical models for the CPA and non-Debye dielectric elements are discussed, and an example is presented for analyzing the impedance data using the resultant circuit model.

  2. Mechanism for cocaine blocking the transport of dopamine: insights from molecular modeling and dynamics simulations.

    Science.gov (United States)

    Huang, Xiaoqin; Gu, Howard H; Zhan, Chang-Guo

    2009-11-12

    Molecular modeling and dynamics simulations have been performed to study how cocaine inhibits dopamine transporter (DAT) for the transport of dopamine. The computationally determined DAT-ligand binding mode is totally different from the previously proposed overlap binding mode in which cocaine- and dopamine-binding sites are the same (Beuming, T.; et al. Nat. Neurosci. 2008, 11, 780-789). The new cocaine-binding site does not overlap with, but is close to, the dopamine-binding site. Analysis of all results reveals that when cocaine binds to DAT, the initial binding site is likely the one modeled in this study because this binding site can naturally accommodate cocaine. Then cocaine may move to the dopamine-binding site after DAT makes some necessary conformational change and expands the binding site cavity. It has been demonstrated that cocaine may inhibit the transport of dopamine through both blocking the initial DAT-dopamine binding and reducing the kinetic turnover of the transporter following the DAT-dopamine binding. The relative contributions to the phenomenological inhibition of the transport of dopamine from blocking the initial binding and reducing the kinetic turnover can be different in different types of assays. The obtained general structural and mechanistic insights are consistent with available experimental data and could be valuable for guiding future studies toward understanding cocaine's inhibiting of other transporters.

  3. Ricci time in the Lemaître-Tolman model and the block universe

    Science.gov (United States)

    Elmahalawy, Yasser; Hellaby, Charles; Ellis, George F. R.

    2015-10-01

    It is common to think of our universe according to the "block universe" concept, which says that spacetime consists of many "stacked" three-surfaces, labelled by some kind of proper time, . Standard ideas do not distinguish past and future, but Ellis' "evolving block universe" tries to make a fundamental distinction. One proposal for this proper time is the proper time measured along the timelike Ricci eigenlines, starting from the big bang. This work investigates the shape of the "Ricci time" surfaces relative to the the null surfaces. We use the Lemaître-Tolman metric as our inhomogeneous spacetime model, and we find the necessary and sufficient conditions for these constant surfaces, , to be spacelike or timelike. Furthermore, we look at the effect of strong gravity domains by determining the location of timelike S regions relative to apparent horizons. We find that constant Ricci time surfaces are always spacelike near the big bang, while at late times (near the crunch or the extreme far future), they are only timelike under special circumstances. At intermediate times, timelike S regions are common unless the variation of the bang time is restricted. The regions where these surfaces become timelike are often adjacent to apparent horizons, but always outside them, and in particular timelike S regions do not occur inside the horizons of black-hole-like models.

  4. Digital imaging and 3D virtual modeling of a block of travertine rock

    Directory of Open Access Journals (Sweden)

    Victor de Albuquerque Silva

    2014-09-01

    Full Text Available Methodological procedures adopted in the digital imagery process, in a non-conventional scale, of a block of travertine rock from the quaternary age were presented on this paper. The rock, named T-Block, weighting 21.2 ton and measuring 1.60 x 1.60 x 2.70 m, was stored in the courtyard of the Laboratório Experimental de Petróleo “Kelsen Valente” (LabPetro at the Universidade Estadual de Campinas (UNICAMP. Petrobras, the Brazilian Petroleum Company, had sponsored its shipment from Italy to Brazil in order to perform geological studies and petrophysical essays, mainly by research groups from universities and research centers of Brazil that work in the areas of reservoir characterization and 3D digital imaging. The purpose of this work was to develop a Digital Solid Model involving 3D digital imaging techniques of internal and external surfaces of the T-Block. Light Detection and Range technology and Ground Penetrating Radar were used to capture the imaging of the external and internal surfaces, respectively. Additionally, gamma ray profiles were generated by using a portable gamma-spectrometer. The use of Light Detection and Range technology combined with Ground Penetrating Radar enabled the identification and 3D mapping of three distinct radar facies, which were correlated to the three sedimentary facies already defined: “Travertine in Domes Radarfacies”, “Transitional Travertine Radarfacies” and “Laminated Travertine Radarfacies”. The gamma ray profiles revealed slight variation, in amplitude, of the radioactivity values. This is likely due to the fact that the sedimentary layers have the same mineralogical composition, which is mainly composed of carbonate sediments, with no siliciclastic clay and/or other radioactive mineral elements inside the more pelitic layers.

  5. Potential L-Type Voltage-Operated Calcium Channel Blocking Effect of Drotaverine on Functional Models.

    Science.gov (United States)

    Patai, Zoltán; Guttman, András; Mikus, Endre G

    2016-12-01

    Drotaverine is considered an inhibitor of cyclic-3',5'-nucleotide-phophodiesterase (PDE) enzymes; however, published receptor binding data also support the potential L-type voltage- operated calcium channel (L-VOCC) blocking effect of drotaverine. Hence, in this work, we focus on the potential L-VOCC blocking effect of drotaverine by using L-VOCC-associated functional in vitro models. Accordingly, drotaverine and reference agents were tested on KCl-induced guinea pig tracheal contraction. Drotaverine, like the L-VOCC blockers nifedipine or diltiazem, inhibited the KCl-induced inward Ca(2+)- induced contraction in a concentration- dependent fashion. The PDE inhibitor theophylline had no effect on the KCl-evoked contractions, indicating its lack of inhibition on inward Ca(2+) flow. Drotaverine was also tested on the L-VOCC-mediated resting Ca(2+) refill model. In this model, the extracellular Ca(2+) enters the cells to replenish the emptied intracellular Ca(2+) stores. Drotaverine and L-VOCC blocker reference molecules inhibited Ca(2+) replenishment of Ca(2+)-depleted preparations detected by agonist-induced contractions in post-Ca(2+) replenishment Ca(2+)-free medium. Theophylline did not modify the Ca(2+) store replenishment after contraction. It seems that drotaverine, but not theophylline, inhibits inward Ca(2+) flux. The addition of CaCl2 to Ca(2+)-free medium containing the agonist induced inward Ca(2+) flow and subsequent contraction of Ca(2+)-depleted tracheal preparations. Drotaverine, similar to the L-VOCC blockers, inhibited inward Ca(2+) flow and blunted the slope of CaCl2-induced contraction in agonist containing Ca(2+)-free medium with Ca(2+)-depleted tracheal preparations. These results show that drotaverine behaves like L-VOCC blockers but, unlike PDE inhibitors using L-VOCC associated in vitro experimental models.

  6. Exploring Mixed Membership Stochastic Block Models via Non-negative Matrix Factorization

    KAUST Repository

    Peng, Chengbin

    2014-12-01

    Many real-world phenomena can be modeled by networks in which entities and connections are represented by nodes and edges respectively. When certain nodes are highly connected with each other, those nodes forms a cluster, which is called community in our context. It is usually assumed that each node belongs to one community only, but evidences in biology and social networks reveal that the communities often overlap with each other. In other words, one node can probably belong to multiple communities. In light of that, mixed membership stochastic block models (MMB) have been developed to model those networks with overlapping communities. Such a model contains three matrices: two incidence matrices indicating in and out connections and one probability matrix. When the probability of connections for nodes between communities are significantly small, the parameter inference problem to this model can be solved by a constrained non-negative matrix factorization (NMF) algorithm. In this paper, we explore the connection between the two models and propose an algorithm based on NMF to infer the parameters of MMB. The proposed algorithms can detect overlapping communities regardless of knowing or not the number of communities. Experiments show that our algorithm can achieve a better community detection performance than the traditional NMF algorithm. © 2014 IEEE.

  7. Control of intrachain charge transfer in model systems for block copolymer photovoltaic materials.

    Science.gov (United States)

    Johnson, Kerr; Huang, Ya-Shih; Huettner, Sven; Sommer, Michael; Brinkmann, Martin; Mulherin, Rhiannon; Niedzialek, Dorota; Beljonne, David; Clark, Jenny; Huck, Wilhelm T S; Friend, Richard H

    2013-04-01

    We report the electronic properties of the conjugated coupling between a donor polymer and an acceptor segment serving as a model for the coupling in conjugated donor-acceptor block copolymers. These structures allow the study of possible intrachain photoinduced charge separation, in contrast to the interchain separation achieved in conventional donor-acceptor blends. Depending on the nature of the conjugated linkage, we observe varying degrees of modification of the excited states, including the formation of intrachain charge transfer excitons. The polymers comprise a block (typically 18 repeat units) of P3HT, poly(3-hexyl thiophene), coupled to a single unit of F8-TBT (where F8 is dioctylfluorene, and TBT is thiophene-benzothiadiazole-thiophene). When the P3HT chain is linked to the TBT unit, we observe formation of a localized charge transfer state, with red-shifted absorption and emission. Independent of the excitation energy, this state is formed very rapidly (<40 fs) and efficiently. Because there is only a single TBT unit present, there is little scope for long-range charge separation and it is relatively short-lived, <1 ns. In contrast, when the P3HT chain and TBT unit are separated by the wider bandgap F8 unit, there is little indication for modification of either ground or excited electronic states, and longer-lived charge separated states are observed.

  8. Ricci Time in the Lemaitre-Tolman Model and the Block Universe

    CERN Document Server

    Elmahalawy, Yasser

    2015-01-01

    It is common to think of our universe according to the "block universe" concept, which says that spacetime consists of many "stacked" 3-surfaces, labelled by some kind of proper time, $\\tau$. Standard ideas do not distinguish past and future, but Ellis "evolving block universe" tries to make a fundamental distinction. One proposal for this proper time is the proper time measured along the timelike Ricci eigenlines, starting from the big bang. This work investigates the shape of the "Ricci time" surfaces relative to the the null surfaces. We use the Lemaitre-Tolman metric as our inhomogeneous spacetime model, and we find the necessary and sufficient conditions for these $\\{\\tau$= constant$\\}$ surfaces, $S(\\tau)$, to be spacelike or timelike. Furthermore, we look at the effect of strong gravity domains by determining the location of timelike $S$ regions relative to apparent horizons. We find that constant Ricci time surfaces are always spacelike near the big bang, while at late times (near the crunch or the ext...

  9. Meso-scale Modeling of Block Copolymers Self-Assembly in Casting Solutions for Membrane Manufacture

    KAUST Repository

    Moreno Chaparro, Nicolas

    2016-05-01

    Isoporous membranes manufactured from diblock copolymer are successfully produced at laboratory scale under controlled conditions. Because of the complex phenomena involved, membrane preparation requires trial and error methodologies to find the optimal conditions, leading to a considerable demand of resources. Experimental insights demonstrate that the self-assembly of the block copolymers in solution has an effect on the final membrane structure. Nevertheless, the complete understanding of these multi-scale phenomena is elusive. Herein we use the coarse-grained method Dissipative Particle Dynamics to study the self-assembly of block copolymers that are used for the preparation of the membranes. To simulate representative time and length scales, we introduce a framework for model reduction of polymer chain representations for dissipative particle dynamics, which preserves the properties governing the phase equilibria. We reduce the number of degrees of freedom by accounting for the correlation between beads in fine-grained models via power laws and the consistent scaling of the simulation parameters. The coarse-graining models are consistent with the experimental evidence, showing a morphological transition of the aggregates as the polymer concentration and solvent affinity change. We show that hexagonal packing of the micelles can occur in solution within different windows of polymer concentration depending on the solvent affinity. However, the shape and size dispersion of the micelles determine the characteristic arrangement. We describe the order of crew-cut micelles using a rigid-sphere approximation and propose different phase parameters that characterize the emergence of monodisperse-spherical micelles in solution. Additionally, we investigate the effect of blending asymmetric diblock copolymers (AB/AC) over the properties of the membranes. We observe that the co-assembly mechanism localizes the AC molecules at the interface of A and B domains, and induces

  10. Quantizing the Complexity of the Western United States Fault System with Geodetically and Geologically Constrained Block Models

    Science.gov (United States)

    Evans, E. L.; Meade, B. J.

    2014-12-01

    Geodetic observations of interseismic deformation provide constraints on miroplate rotations, earthquake cycle processes, slip partitioning, and the geometric complexity of the Pacific-North America plate boundary. Paleoseismological observations in the western United States provide a complimentary dataset of Quaternary fault slip rate estimates. These measurements may be integrated and interpreted using block models, in which the upper crust is divided into microplates bounded by mapped faults, with slip rates defined by the differential relative motions of adjacent microplates. The number and geometry of microplates are typically defined with boundaries representing a limited sub-set of the large number of potentially seismogenic faults. An alternative approach is to include large number of potentially active faults in a dense array of microplates, and then deterministically estimate the boundaries at which strain is localized, while simultaneously satisfying interseismic geodetic and geologic observations. This approach is possible through the application of total variation regularization (TVR) which simultaneously minimizes the L2 norm of data residuals and the L1 norm of the variation in the estimated state vector. Applied to three-dimensional spherical block models, TVR reduces the total variation between estimated rotation vectors, creating groups of microplates that rotate together as larger blocks, and localizing fault slip on the boundaries of these larger blocks. Here we consider a suite of block models containing 3-137 microplates, where active block boundaries have been determined by TVR optimization constrained by both interseismic GPS velocities and geologic slip rate estimates.

  11. Towards a phenomena-based model assessment: The Case of Blocking over Europe

    Science.gov (United States)

    Jury, Martin W.; Barriopedro, David

    2016-04-01

    Atmospheric Blocking (AB) is a main phenomenon influencing the future climate change in Europe. Results of Global Circulation Models (GCMs) state with medium confidence that the frequency of AB over the Northern Hemisphere will not increase, while AB-related regional changes in Europe are uncertain especially in connection to AB intensity and its persistence. Here, we present results of a study connecting GCMs' ability to reproduce AB patterns and its abilities to correctly reproduce Temperature near the surface (tas) and Precipitation (pr). The used method detects AB by localizing high pressure systems between 55°N and 65°N with the use of geopotential height gradients on the 500 hPa level (zg500). Daily fields of tas and pr are connected to the results of the AB detection over continental Europe. The AB detection method accounts for AB frequency, AB duration and AB intensity and henceforth allowing a detailed comparison of AB representations in GCMs. Furthermore, the number of AB episodes, average AB duration, longitudinal extension and longitudinal propagation are taken into account. The AB detection is applied on zg500 fields of 3 Reanalysis (ERA40, JRA55 and NCEP/NCAR) and 10 GCMs of the CMIP5 between 1961 and 1990 over the Atlantic and over Europe. Most of the evaluated models underrepresent the spatial distribution of annual blocking days over Europe. This is also the case on seasonal timescales, with the largest underestimations during winter and only some overestimations during summer. There are indications that biases in the representation of AB are connected to overall GCM biases concerning the representation of surface fields. Especially when taking into account the seasonal as well as localized characteristics of the AB representation and the surface biases.

  12. Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearest block bootstrap approach

    Institute of Scientific and Technical Information of China (English)

    CHAN Kung-Sik; TONG Howell; STENSETH Nils Chr

    2009-01-01

    The study of the rodent fluctuations of the North was initiated in its modern form with Elton's pioneering work. Many scientific studies have been designed to collect yearly rodent abundance data, but the resulting time series are generally subject to at least two "problems": being short and non-linear. We explore the use of the continuous threshold autoregressive (TAR) models for analyzing such data. In the simplest case, the continuous TAR models are additive autoregressive models, being piecewise linear in one lag, and linear in all other lags. The location of the slope change is called the threshold parameter. The continuous TAR models for rodent abundance data can be derived from a general prey-predator model under some simplifying assumptions. The lag in which the threshold is located sheds important insights on the structure of the prey-predator system. We propose to assess the uncertainty on the location of the threshold via a new bootstrap called the nearest block bootstrap (NBB) which combines the methods of moving block bootstrap and the nearest neighbor bootstrap.The NBB assumes an underlying finite-order time-homogeneous Markov process. Essentially, the NBB bootstraps blocks of random block sizes, with each block being drawn from a non-parametric estimate of the future distribution given the realized past bootstrap series. We illustrate the methods by simulations and on a particular rodent abundance time series from Kilpisjarvi, Northern Finland.

  13. Feasibility of establishing cerebral ischemia models by using aerocyst-blocking bilateral ascending pharyngeal artery of piglets Imaging assessment

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: The cerebral ischemia and ischemia/reperfusion animal models are used to simulate the human cerebrovascular diseases is one of the popular topics of neurological science recently. To study the pathophysiology, pathogenesis, prophylaxis and treatment of ischemic cerebrovascular diseases and to establish the ideal animal model that is the most similar to the human cerebral ischemia, are the topics that the people generally cared about.OBJECTIVE: To evaluate the effects of aerocyst-blocking bilateral ascending pharyngeal artery on the establishment of cerebral ischemia models by using digital subtraction angiography (DSA), magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance perfusion-weighted imaging (PWI). DESIGN: Repetitive measure animal experiment.SETTING: Zhongshan Hospital Affiliated to Dalian University.MATERIALS: The experiment was carried out in the Animal Laboratory (Provincial Laboratory),Zhongshan Hospital of Dalian Univeristy from January to May 2006. A total of 14 domestic piglets, of 6 months old, weighing 12 - 15 kg, of either gender, were selected from Animal Experimental Center, Dalian University. Multistar T.O.P digital subtraction angiography machine was provided by Siemens Company,German.METHODS: Aerocyst-blocking bilateral ascending pharyngeal artery was used to establish cerebral ischemia models. And then, Multistar T.O.P. DSA was used for imaging of cerebral vessels before blocking, during blocking and at 0.5 and 2 hours after ischemia perfusion. GE Signa 1.5 T supraconduction magnetic resonance imaging was used for DWI examination; in addition, PWI was used based on focal sites and areas.Otherwise, magnetic resonance imaging (MRI) was used to detect signal changes of T1WI and T2WI in ischemic areas.MAIN OUTCOME MEASURES: Analytic results of DSA, DWI, PWI and MRI.RESULTS: All 14 experimental piglets were involved in the final analysis. ① DSA: The blood flow of bilateral ascending pharyngeal arteries and its

  14. Block-sparse Lamb wave structural health monitoring using generic scattering models

    Science.gov (United States)

    Levine, Ross M.; Michaels, Jennifer E.

    2014-02-01

    A well-known damage detection paradigm is the use of ultrasonic guided waves that are generated and recorded by a spatially-distributed array of piezoelectric transducers. This type of configuration is capable of interrogating a defect from a variety of angles and over a large region of interest by analyzing all pairwise transducer signals. By subtracting prerecorded baseline signals, differential signals are obtained that can be analyzed for the purpose of detecting, locating, and characterizing newly-introduced scatterers. Typical analysis techniques such as delay-and-sum imaging have the ability to detect flaws, but their performance is limited, especially when the potential scatterers may have high directionality or introduce phase shifts. Signal envelopes are frequently used to avoid the problem of unknown phase shifts, which further reduces performance. The sparsity-based technique described here uses a different approach, where each potential damage location has its own generic linear scattering model that allows for unknown variations in amplitude and phase between each transducer pair. The differential signals are then assumed to be a linear combination of a small number of these models, and an image is generated using a block-sparse reconstruction algorithm that splits the signals into location-based components. Results are presented for experimental data. The images exhibit smaller spot size and fewer artifacts than those obtained via delay-and-sum imaging, provided the model is reasonably well-matched to the data.

  15. A general U-block model-based design procedure for nonlinear polynomial control systems

    Science.gov (United States)

    Zhu, Q. M.; Zhao, D. Y.; Zhang, Jianhua

    2016-10-01

    The proposition of U-model concept (in terms of 'providing concise and applicable solutions for complex problems') and a corresponding basic U-control design algorithm was originated in the first author's PhD thesis. The term of U-model appeared (not rigorously defined) for the first time in the first author's other journal paper, which established a framework for using linear polynomial control system design approaches to design nonlinear polynomial control systems (in brief, linear polynomial approaches → nonlinear polynomial plants). This paper represents the next milestone work - using linear state-space approaches to design nonlinear polynomial control systems (in brief, linear state-space approaches → nonlinear polynomial plants). The overall aim of the study is to establish a framework, defined as the U-block model, which provides a generic prototype for using linear state-space-based approaches to design the control systems with smooth nonlinear plants/processes described by polynomial models. For analysing the feasibility and effectiveness, sliding mode control design approach is selected as an exemplary case study. Numerical simulation studies provide a user-friendly step-by-step procedure for the readers/users with interest in their ad hoc applications. In formality, this is the first paper to present the U-model-oriented control system design in a formal way and to study the associated properties and theorems. The previous publications, in the main, have been algorithm-based studies and simulation demonstrations. In some sense, this paper can be treated as a landmark for the U-model-based research from intuitive/heuristic stage to rigour/formal/comprehensive studies.

  16. Rock blocks

    OpenAIRE

    Turner, W.

    2007-01-01

    Consider representation theory associated to symmetric groups, or to Hecke algebras in type A, or to q-Schur algebras, or to finite general linear groups in non-describing characteristic. Rock blocks are certain combinatorially defined blocks appearing in such a representation theory, first observed by R. Rouquier. Rock blocks are much more symmetric than general blocks, and every block is derived equivalent to a Rock block. Motivated by a theorem of J. Chuang and R. Kessar in the case of sym...

  17. Gravity Data Analysis and Modelling for Basin Sedimen of Eastern Java Blocks

    Science.gov (United States)

    Khoirunnia, Luthfia

    2016-11-01

    The study of Eastern Java Basin was conducted by 3D modelling subsurface structure using gravity anomaly. The aims of this research are to describe and 3D modelling basin sedimentary system of Eastern Java Blocks based on gravity anomaly. The modelling construction was performed by inversion technique applying Singular Value Decomposition (SVD) method and Occam optimization. This projection method used equivalent central mass of Dampney with height 5.5 km and error data 1,84 × 10-17. Separation of residual anomaly from the complete Bouguer anomaly on a flat plane was done using the upward continuation. This process uses the principle of low pass filter which passes low frequency. Sedimentary basin appears at a depth of 0.2 km to 1.4 km, is shown by their low anomaly in the area, as well as the visible appearance of basin in 3D modeling shown in figure. The result of inversion with Occam h has an error of 1,2% and the SVD has an error of 11%. Sedimentary basin was dominant in Probolinggo, partially in Besuki and Lumajang. The formation occurs due to tectonic processes where the tectonic evolution of the material without significant lateral shift is called as the otokton models, and accompanied by the formation of the basin that follows the development of the subduction system, which is semi-concentric pattern. Sediments are dominated by volcanic sediment, the result of sedimentation because of volcanism events and types of volcanic sediments pyroclasts generally occur in a process or event explosive volcanic magma degassing

  18. Two-state model based on the block-localized wave function method

    Science.gov (United States)

    Mo, Yirong

    2007-06-01

    The block-localized wave function (BLW) method is a variant of ab initio valence bond method but retains the efficiency of molecular orbital methods. It can derive the wave function for a diabatic (resonance) state self-consistently and is available at the Hartree-Fock (HF) and density functional theory (DFT) levels. In this work we present a two-state model based on the BLW method. Although numerous empirical and semiempirical two-state models, such as the Marcus-Hush two-state model, have been proposed to describe a chemical reaction process, the advantage of this BLW-based two-state model is that no empirical parameter is required. Important quantities such as the electronic coupling energy, structural weights of two diabatic states, and excitation energy can be uniquely derived from the energies of two diabatic states and the adiabatic state at the same HF or DFT level. Two simple examples of formamide and thioformamide in the gas phase and aqueous solution were presented and discussed. The solvation of formamide and thioformamide was studied with the combined ab initio quantum mechanical and molecular mechanical Monte Carlo simulations, together with the BLW-DFT calculations and analyses. Due to the favorable solute-solvent electrostatic interaction, the contribution of the ionic resonance structure to the ground state of formamide and thioformamide significantly increases, and for thioformamide the ionic form is even more stable than the covalent form. Thus, thioformamide in aqueous solution is essentially ionic rather than covalent. Although our two-state model in general underestimates the electronic excitation energies, it can predict relative solvatochromic shifts well. For instance, the intense π →π* transition for formamide upon solvation undergoes a redshift of 0.3eV, compared with the experimental data (0.40-0.5eV).

  19. DIAGRAM SOLVE THE USE OF SIMULINK BLOCK DIAGRAM TO SOLVE MATHEMA THEMATICAL CONTROL EQU MATHEMATICAL MODELS AND CONTROL EQUATIONS

    Directory of Open Access Journals (Sweden)

    N.M. Ghasem

    2003-12-01

    Full Text Available In this paper, the simulink block diagram is used to solve a model consists of a set of ordinary differential and algebraic equations to control the temperature inside a simple stirred tank heater. The flexibility of simulink block diagram gives students a better understanding of the control systems. The simulink also allows solution of mathematical models and easy visualization of the system variables. A polyethylene fluidized bed reactor is considered as an industrial example and the effect of the Proportional, Integral and Derivative control policy is presented for comparison.

  20. Model Predictive Wind Turbine Control with Move-Blocking Strategy for Load Alleviation and Power Leveling

    Science.gov (United States)

    Jassmann, U.; Dickler, S.; Zierath, J.; Hakenberg, M.; Abel, D.

    2016-09-01

    This contribution presents a Model Predictive Controller (MPC) with moveblocking strategy for combined power leveling and load alleviation in wind turbine operation with a focus on extreme loads. The controller is designed for a 3 MW wind turbine developed by W2E Wind to Energy GmbH and compared to a baseline controller, using a classic control scheme, which currently operates the wind turbine. All simulations are carried out with a detailed multibody simulation turbine model implemented in alaska/Wind. The performance of the two different controllers is compared using a 50-year Extreme Operation Gust event, since it is one of the main design drivers for the wind turbine considered in this work. The implemented MPC is able to level electrical output power and reduce mechanical loads at the same time. Without de-rating the achieved control results, a move-blocking strategy is utilized and allowed to reduce the computational burden of the MPC by more than 50% compared to a baseline MPC implementation. This even allows to run the MPC on a state of the art Programmable Logic Controller.

  1. Automation of block assignment planning using a diagram-based scenario modeling method

    Science.gov (United States)

    Hwang, In Hyuck; Kim, Youngmin; Lee, Dong Kun; Shin, Jong Gye

    2014-03-01

    Most shipbuilding scheduling research so far has focused on the load level on the dock plan. This is be¬cause the dock is the least extendable resource in shipyards, and its overloading is difficult to resolve. However, once dock scheduling is completed, making a plan that makes the best use of the rest of the resources in the shipyard to minimize any additional cost is also important. Block assignment planning is one of the midterm planning tasks; it assigns a block to the facility (factory/shop or surface plate) that will actually manufacture the block according to the block characteristics and current situation of the facility. It is one of the most heavily loaded midterm planning tasks and is carried out manu¬ally by experienced workers. In this study, a method of representing the block assignment rules using a diagram was su¬ggested through analysis of the existing manual process. A block allocation program was developed which automated the block assignment process according to the rules represented by the diagram. The planning scenario was validated through a case study that compared the manual assignment and two automated block assignment results.

  2. Automation of block assignment planning using a diagram-based scenario modeling method

    Directory of Open Access Journals (Sweden)

    Hwang In Hyuck

    2014-03-01

    Full Text Available Most shipbuilding scheduling research so far has focused on the load level on the dock plan. This is be¬cause the dock is the least extendable resource in shipyards, and its overloading is difficult to resolve. However, once dock scheduling is completed, making a plan that makes the best use of the rest of the resources in the shipyard to minimize any additional cost is also important. Block assignment planning is one of the midterm planning tasks; it assigns a block to the facility (factory/shop or surface plate that will actually manufacture the block according to the block characteristics and current situation of the facility. It is one of the most heavily loaded midterm planning tasks and is carried out manu¬ally by experienced workers. In this study, a method of representing the block assignment rules using a diagram was su¬ggested through analysis of the existing manual process. A block allocation program was developed which automated the block assignment process according to the rules represented by the diagram. The planning scenario was validated through a case study that compared the manual assignment and two automated block assignment results.

  3. Designing and Implementing Service Learning Projects in an Introductory Oceanography Course Using the ``8-Block Model''

    Science.gov (United States)

    Laine, E. P.; Field, C.

    2010-12-01

    The Campus Compact for New Hampshire (Gordon, 2003) introduced a practical model for designing service-learning exercises or components for new or existing courses. They divided the design and implementation process into eight concrete areas, the “8-Block Model”. Their goal was to demystify the design process of service learning courses by breaking it down into interconnected components. These components include: project design, community partner relations, the problem statement, building community in the classroom, building student capacity, project management, assessment of learning, and reflection and connections. The project design component of the “8-Block Model” asks that the service performed be consistent with the learning goals of the course. For science courses students carry out their work as a way of learning science and the process of science, not solely for the sake of service. Their work supports the goals of a community partner and the community partner poses research problems for the class in a letter on their letterhead. Linking student work to important problems in the community effectively engages students and encourages them to work at more sophisticated levels than usually seen in introductory science classes. Using team-building techniques, the classroom becomes a safe, secure learning environment that encourages sharing and experimentation. Targeted lectures, labs, and demonstrations build the capacity of students to do their research. Behind the scenes project management ensures student success. Learning is assessed using a variety of tools, including graded classroom presentations, poster sessions, and presentations and reports to community partners. Finally, students reflect upon their work and make connections between their research and its importance to the well being of the community. Over the past 10 years, we have used this approach to design and continually modify an introductory oceanography course for majors and non

  4. Block of GABA(A) receptor ion channel by penicillin: electrophysiological and modeling insights toward the mechanism.

    Science.gov (United States)

    Rossokhin, Alexey V; Sharonova, Irina N; Bukanova, Julia V; Kolbaev, Sergey N; Skrebitsky, Vladimir G

    2014-11-01

    GABA(A) receptors (GABA(A)R) mainly mediate fast inhibitory neurotransmission in the central nervous system. Different classes of modulators target GABA(A)R properties. Penicillin G (PNG) belongs to the class of noncompetitive antagonists blocking the open GABA(A)R and is a prototype of β-lactam antibiotics. In this study, we combined electrophysiological and modeling approaches to investigate the peculiarities of PNG blockade of GABA-activated currents recorded from isolated rat Purkinje cells and to predict the PNG binding site. Whole-cell patch-сlamp recording and fast application system was used in the electrophysiological experiments. PNG block developed after channel activation and increased with membrane depolarization suggesting that the ligand binds within the open channel pore. PNG blocked stationary component of GABA-activated currents in a concentration-dependent manner with IC50 value of 1.12mM at -70mV. The termination of GABA and PNG co-application was followed by a transient tail current. Protection of the tail current from bicuculline block and dependence of its kinetic parameters on agonist affinity suggest that PNG acts as a sequential open channel blocker that prevents agonist dissociation while the channel remains blocked. We built the GABA(A)R models based on nAChR and GLIC structures and performed an unbiased systematic search of the PNG binding site. Monte-Carlo energy minimization was used to find the lowest energy binding modes. We have shown that PNG binds close to the intracellular vestibule. In both models the maximum contribution to the energy of ligand-receptor interactions revealed residues located on the level of 2', 6' and 9' rings formed by a bundle of M2 transmembrane segments, indicating that these residues most likely participate in PNG binding. The predicted structural models support the described mechanism of PNG block.

  5. β/δ-PrIT1, a highly insecticidal toxin from the venom of the Brazilian spider Phoneutria reidyi (F.O. Pickard-Cambridge, 1897).

    Science.gov (United States)

    de Oliveira, Leida Calegário; Campos, Fabiana V; Figueiredo, Suely Gomes; Cordeiro, Marta N; Adaime, Beatriz R; Richardson, Michael; Pimenta, Adriano M C; Martin-Eauclaire, Marie-France; Beirão, Paulo S L; De Lima, Maria Elena

    2015-09-15

    A potent insecticidal toxin, β/δ-PrIT1, molecular mass of 5598.86 [M+H](+), was characterized from Phoneutria reidyi spider venom. Its partial amino acid sequence showed high similarity with insecticidal spider toxins from the genus Phoneutria. β/δ-PrIT1 was very toxic (LD50 = 4 nmol/g) to flies (Musca domestica), but not to mice (Mus musculus). Kinetic studies showed that (125)I-β/δ-PrIT1 binds to two distinct sites in insect sodium channels, with close affinity (Kd1 = 34.7 pM and Kd2 = 35.1 pM). Its association is rather fast (t1/2(1) = 1.4 min, t1/2(2) = 8.5 min) and its dissociation is a slower process (t1/2(1) = 5.4 min, t1/2(2) = 32.8 min). On rat brain synaptosomes β/δ-PrIT1 partially competed (∼30%) with the beta-toxin (125)I-CssIV, but did not compete with the alpha-toxin of reference (125)I-AaII, nor with the beta-toxin (125)I-TsVII. On cockroach nerve cord synaptosomes, β/δ-PrIT1 did not compete with the anti-insect toxin (125)I-LqqIT1, but it competed (IC50 = 80 pM) with the "alpha-like" toxin (125)I-BomIV. In cockroach neurons, β/δ-PrIT1 inhibited the inactivation of Nav-channels and it shifted the sodium channel activation to hyperpolarizing potentials. These results indicate two different binding sites for β/δ-PrIT1, leading to two different pharmacological responses. β/δ-PrIT1 is one of the most toxic spider toxins to insects without apparent toxicity to mammals, and provide new model for the development of insecticides.

  6. Identifying influential nodes in dynamic social networks based on degree-corrected stochastic block model

    Science.gov (United States)

    Wang, Tingting; Dai, Weidi; Jiao, Pengfei; Wang, Wenjun

    2016-05-01

    Many real-world data can be represented as dynamic networks which are the evolutionary networks with timestamps. Analyzing dynamic attributes is important to understanding the structures and functions of these complex networks. Especially, studying the influential nodes is significant to exploring and analyzing networks. In this paper, we propose a method to identify influential nodes in dynamic social networks based on identifying such nodes in the temporal communities which make up the dynamic networks. Firstly, we detect the community structures of all the snapshot networks based on the degree-corrected stochastic block model (DCBM). After getting the community structures, we capture the evolution of every community in the dynamic network by the extended Jaccard’s coefficient which is defined to map communities among all the snapshot networks. Then we obtain the initial influential nodes of the dynamic network and aggregate them based on three widely used centrality metrics. Experiments on real-world and synthetic datasets demonstrate that our method can identify influential nodes in dynamic networks accurately, at the same time, we also find some interesting phenomena and conclusions for those that have been validated in complex network or social science.

  7. Neoproterozoic paleogeography of the Tarim Block: An extended or alternative "missing-link" model for Rodinia?

    Science.gov (United States)

    Wen, Bin; Evans, David A. D.; Li, Yong-Xiang

    2017-01-01

    Recent reconstructions of the Rodinia supercontinent and its breakup incorporate South China as a ;missing link; between Australia and Laurentia, and place the Tarim craton adjacent to northwestern Australia on the supercontinent's periphery. However, subsequent kinematic evolution toward Gondwana amalgamation requires complex geometric shuffling between South China and Tarim, which cannot be easily resolved with the stratigraphic records of those blocks. Here we present new paleomagnetic data from early Ediacaran strata of northwest Tarim, and document large-scale rotation at near-constant paleolatitudes during Cryogenian time. The rotation is coeval with Rodinia breakup, and Tarim's paleolatitudes are compatible with its placement between Australia and Laurentia, either by itself as an alternative ;missing link; or joined with South China in that role. At the same time, indications of subduction-related magmatism in Tarim's Neoproterozoic record suggest that Rodinia breakup was dynamically linked to subduction retreat along its northern margin. Such a model is akin to early stages of Jurassic fragmentation within southern Gondwana, and implies more complicated subduction-related dynamics of supercontinent breakup than superplume impingement alone.

  8. Contemporary crustal deformation of the Chinese continent and tectonic block model

    Institute of Scientific and Technical Information of China (English)

    王敏; 沈正康; 牛之俊; 张祖胜; 孙汉荣; 甘卫军; 王琪; 任群

    2003-01-01

    We obtain the preliminary result of crustal deformation velocity field for the Chinese con-tinent by analyzing GPS data from the Crustal Motion Observation Network of China (CMONOC), particularly the data from the regional networks of CMONOC observed in 1999 and 2001. We de-lineate 9 tectonically active blocks and 2 broadly distributed deformation zones out of a denseGPS velocity field, and derive block motion Euler poles for the blocks and their relative motionrates. Our result reveals that there are 3 categories of deformation patterns in the Chinese conti-nent. The first category, associated with the interior of the Tibetan Plateau and the Tianshan oro-genic belt, shows broadly distributed deformation within the regions. The third category, associatedwith the Tarim Basin and the region east of the north-south seismic belt of China, shows block-likemotion, with deformation accommodated along the block boundaries only. The second category, mainly associated with the borderland of the Tibetan Plateau, such as the Qaidam, Qilian, Xining(in eastern Qinghai), and the Diamond-shaped (in western Sichuan and Yunnan) blocks, has thedeformation pattern between the first and the third, i.e. these regions appear to deform block-like,but with smaller sizes and less strength for the blocks. Based on the analysis of the lithosphericstructures and the deformation patterns of the regions above, we come to the inference that thedeformation modes of the Chinese continental crust are mainly controlled by the crustal structure.The crust of the eastern China and the Tarim Basin is mechanically strong, and its deformationtakes the form of relative motion between rigid blocks. On the other hand, the northward indentation of the Indian plate into the Asia continent has created the uplift of the Tibetan Plateau and the Tianshan Mountains, thickened their crust, and raised the temperature in the crust. The lower crust thus has become ductile, evidenced in low seismic velocity and high

  9. Wave Current Interactions and Wave-blocking Predictions Using NHWAVE Model

    Science.gov (United States)

    2013-03-01

    release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) Wave blocking in river inlets is examined using the...14. SUBJECT TERMS wave blocking, wave-current interactions, SWASH, NHWAVE 15. NUMBER OF PAGES 61 16. PRICE CODE 17. SECURITY CLASSIFICATION...Renold’s Averaged Navier-Stokes Equations VOF Volume of Fluid MAC Marker and Cell SPH Smoothed Partical Hydrodynamics SWASH Simulating Waves

  10. Analyzing short time series data from periodically fluctuating rodent populations by threshold models:A nearest block bootstrap approach

    Institute of Scientific and Technical Information of China (English)

    CHAN; Kung-Sik; TONG; Howell; STENSETH; Nils; Chr

    2009-01-01

    The study of the rodent fluctuations of the North was initiated in its modern form with Elton’s pioneering work.Many scientific studies have been designed to collect yearly rodent abundance data,but the resulting time series are generally subject to at least two "problems":being short and non-linear.We explore the use of the continuous threshold autoregressive(TAR) models for analyzing such data.In the simplest case,the continuous TAR models are additive autoregressive models,being piecewise linear in one lag,and linear in all other lags.The location of the slope change is called the threshold parameter.The continuous TAR models for rodent abundance data can be derived from a general prey-predator model under some simplifying assumptions.The lag in which the threshold is located sheds important insights on the structure of the prey-predator system.We propose to assess the uncertainty on the location of the threshold via a new bootstrap called the nearest block bootstrap(NBB) which combines the methods of moving block bootstrap and the nearest neighbor bootstrap.The NBB assumes an underlying finite-order time-homogeneous Markov process.Essentially,the NBB bootstraps blocks of random block sizes,with each block being drawn from a non-parametric estimate of the future distribution given the realized past bootstrap series.We illustrate the methods by simulations and on a particular rodent abundance time series from Kilpisjrvi,Northern Finland.

  11. A Physics-Based Charge-Control Model for InP DHBT Including Current-Blocking Effect

    Institute of Scientific and Technical Information of China (English)

    GE Ji; JIN Zhi; SU Yong-Bo; CHENG Wei; WANG Xian-Wai; CHEN Gao-Peng; LIU Xin-Yu

    2009-01-01

    We develop a physics-based charge-control InP double heterojunction bipolar transistor model including three important effects: current blocking, mobile-charge modulation of the base-collector capacitance and velocity-field modulation in the transit time. The bias-dependent base-collector depletion charge is obtained analytically, which takes into account the mobile-charge modulation. Then, a measurement based voltage-dependent transit time formulation is implemented. As a result, over a wide range of biases, the developed model shows good agreement between the modeled and measured S-parameters and cutoff frequency. Also, the model considering current blocking effect demonstrates more accurate prediction of the output characteristics than conventional vertical bipolar inter company results.

  12. Stability of proton and maximally symmetric minimal unification model for basic forces and building blocks of matter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    With the hypothesis that all independent degrees of freedom of basic building blocks should be treated equally on the same footing and correlated by a possible maximal symmetry, we arrive at a 4-dimensional space-time unification model. In this model the basic building blocks are Majorana fermions in the spinor repre- sentation of 14-dimensional quantum space-time with a gauge symmetry GM4D = SO(1,3)×SU(32)×U(1)A×SU(3)F. The model leads to new physics including mirror particles of the standard model. It enables us to issue some fundamental questions that include: why our living space-time is 4-dimensional, why parity is not con- served in our world, how the stability of proton is, what the origin of CP violation is and what the dark matter can be.

  13. Stability of proton and maximally symmetric minimal unification model for basic forces and building blocks of matter

    Institute of Scientific and Technical Information of China (English)

    WU YueLiang

    2007-01-01

    With the hypothesis that all independent degrees of freedom of basic building blocks should be treated equally on the same footing and correlated by a possible maximal symmetry, we arrive at a 4-dimensional space-time unification model. In this model the basic building blocks are Majorana fermions in the spinor representation of 14-dimensional quantum space-time with a gauge symmetry G4MD =SO(1,3)× SU(32)× U(1)A× SU(3)F. The model leads to new physics including mirror particles of the standard model. It enables us to issue some fundamental questions that include: why our living space-time is 4-dimensional, why parity is not conserved in our world, how the stability of proton is, what the origin of CP violation is and what the dark matter can be.

  14. Submyelin potassium accumulation may functionally block subsets of local axons during deep brain stimulation: a modeling study

    Science.gov (United States)

    Bellinger, S. C.; Miyazawa, G.; Steinmetz, P. N.

    2008-09-01

    Deep brain stimulation has been used for over a decade to relieve the symptoms of Parkinson's disease, although its mechanism of action remains poorly understood. To better understand the direct effects of DBS on central neurons, a computational model of a myelinated axon has been constructed which includes the effects of K+ accumulation within the peri-axonal space. Using best estimates of anatomic and electrogenic model parameters for in vivo STN axons, the model predicts a functional block along the axon due to K+ accumulation in the submyelin space. The functional block occurs for a range of model parameters: high stimulation frequencies (>130 Hz); high extracellular K+ concentrations (>3 × 10-3 M); low maximum Na+/K+ ATPase current densities (stimulating frequency.

  15. “Over-inlay” block graft and differential morphometry: a novel block graft model to study bone regeneration and host-to-graft interfaces in rats

    Science.gov (United States)

    2016-01-01

    Purpose The aim of this study was to present new a model that allows the study of the bone healing process, with an emphasis on the biological behavior of different graft-to-host interfaces. A standardized “over-inlay” surgical technique combined with a differential histomorphometric analysis is presented in order to optimize the use of critical-size calvarial defects in pre-clinical testing. Methods Critical-size defects were created into the parietal bone of 8 male Wistar rats. Deproteinized bovine bone (DBBM) blocks were inserted into the defects, so that part of the block was included within the calvarial thickness and part exceeded the calvarial height (an “over-inlay” graft). All animals were sacrificed at 1 or 3 months. Histomorphometric and immunohistochemical evaluation was carried out within distinct regions of interest (ROIs): the areas adjacent to the native bone (BA), the periosteal area (PA) and the central area (CA). Results The animals healed without complications. Differential morphometry allowed the examination of the tissue composition within distinct regions: the BA presented consistent amounts of new bone formation (NB), which increased over time (24.53%±1.26% at 1 month; 37.73%±0.39% at 3 months), thus suggesting that this area makes a substantial contribution toward NB. The PA was mainly composed of fibrous tissue (71.16%±8.06% and 78.30%±2.67%, respectively), while the CA showed high amounts of DBBM at both time points (78.30%±2.67% and 74.68%±1.07%, respectively), demonstrating a slow remodeling process. Blood vessels revealed a progressive migration from the interface with native bone toward the central area of the graft. Osterix-positive cells observed at 1 month within the PA suggested that the periosteum was a source of osteoprogenitor elements. Alkaline phosphatase data on matrix deposition confirmed this observation. Conclusions The present model allowed for a standardized investigation of distinct graft

  16. Streptococcus pneumoniae Transmission Is Blocked by Type-Specific Immunity in an Infant Mouse Model

    Science.gov (United States)

    Zangari, Tonia; Wang, Yang

    2017-01-01

    ABSTRACT Epidemiological studies on Streptococcus pneumoniae show that rates of carriage are highest in early childhood and that the major benefit of the pneumococcal conjugate vaccine (PCV) is a reduction in the incidence of nasopharyngeal colonization through decreased transmission within a population. In this study, we sought to understand how anti-S. pneumoniae immunity affects nasal shedding of bacteria, the limiting step in experimental pneumococcal transmission. Using an infant mouse model, we examined the role of immunity (passed from mother to pup) on shedding and within-litter transmission of S. pneumoniae by pups infected at 4 days of life. Pups from both previously colonized immune and PCV-vaccinated mothers had higher levels of anti-S. pneumoniae IgG than pups from non-immune or non-vaccinated mothers and shed significantly fewer S. pneumoniae over the first 5 days of infection. By setting up cross-foster experiments, we demonstrated that maternal passage of antibody to pups either in utero or post-natally decreases S. pneumoniae shedding. Passive immunization experiments showed that type-specific antibody to capsular polysaccharide is sufficient to decrease shedding and that the agglutinating function of immunoglobulin is required for this effect. Finally, we established that anti-pneumococcal immunity and anti-PCV vaccination block host-to-host transmission of S. pneumoniae. Moreover, immunity in either the donor or recipient pups alone was sufficient to reduce rates of transmission, indicating that decreased shedding and protection from acquisition of colonization are both contributing factors. Our findings provide a mechanistic explanation for the reduced levels of S. pneumoniae transmission between hosts immune from prior exposure and among vaccinated children. PMID:28292980

  17. Solid images for geostructural mapping and key block modeling of rock discontinuities

    Science.gov (United States)

    Assali, Pierre; Grussenmeyer, Pierre; Villemin, Thierry; Pollet, Nicolas; Viguier, Flavien

    2016-04-01

    Rock mass characterization is obviously a key element in rock fall hazard analysis. Managing risk and determining the most adapted reinforcement method require a proper understanding of the considered rock mass. Description of discontinuity sets is therefore a crucial first step in the reinforcement work design process. The on-field survey is then followed by a structural modeling in order to extrapolate the data collected at the rock surface to the inner part of the massif. Traditional compass survey and manual observations can be undoubtedly surpassed by dense 3D data such as LiDAR or photogrammetric point clouds. However, although the acquisition phase is quite fast and highly automated, managing, handling and exploiting such great amount of collected data is an arduous task and especially for non specialist users. In this study, we propose a combined approached using both 3D point clouds (from LiDAR or image matching) and 2D digital images, gathered into the concept of ''solid image''. This product is the connection between the advantages of classical true colors 2D digital images, accessibility and interpretability, and the particular strengths of dense 3D point clouds, i.e. geometrical completeness and accuracy. The solid image can be considered as the information support for carrying-out a digital survey at the surface of the outcrop without being affected by traditional deficiencies (lack of data and sampling difficulties due to inaccessible areas, safety risk in steep sectors, etc.). Computational tools presented in this paper have been implemented into one standalone software through a graphical user interface helping operators with the completion of a digital geostructural survey and analysis. 3D coordinates extraction, 3D distances and area measurement, planar best-fit for discontinuity orientation, directional roughness profiles, block size estimation, and other tools have been experimented on a calcareous quarry in the French Alps.

  18. THE DYNAMIC FRICTION TERM IN THE SPRING-BLOCK MODELS FOR EARTHQUAKES: A CONSTRAINT FROM SEISMIC MOMENT AND ENERGY CATALOGUE

    Institute of Scientific and Technical Information of China (English)

    吴忠良

    2001-01-01

    In the spring-block models of earthquakes, one of the key factors is the dynamic friction term which determines the complexity of the faulting process. Generally, two kinds of friction, namely velocity-dependent friction and slipdependent friction, are used in the modelling. But until now there has still been a lack of information on which kind of friction term is more suitable for modelling the phenomenology of earthquakes. Based on the numerical studies of Shaw (1998 Bull. Seismol. Soc. Am. 88 1457), we have examined the ratio of the broadband radiated energy and the scalar seismic moment of shallow earthquakes worldwide from 1987 to 1998. The result shows that for earthquakes with strike-slip mechanisms, velocity-dependent friction seems to be predominant, while for thrust and normal events,slip-dependent friction seems predominant. This suggests that in the spring-block models for earthquakes, the type of focal mechanism has to be accounted for, and different types of earthquakes require different dynamic friction terms in the corresponding spring-block model.

  19. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  20. Realizing block planning concepts in make-and-pack production using MILP modelling and SAP APO

    DEFF Research Database (Denmark)

    Günther, H.O.; Grunow, M.; Neuhaus, U.

    2006-01-01

    of a major producer of hair dyes as a case study. We present two different implementations of the block planning concept. One utilizes the Production Planning/Detailed Scheduling module of the SAP APO© software. The other approach is based on a mixed-integer linear programming formulation. In contrast...

  1. Deformation of the Western Caribbean: Insights from Block and Geodynamic Models of Geodetic, Seismic and Geologic Data

    Science.gov (United States)

    La Femina, P. C.; Geirsson, H.; Kobayashi, D.

    2012-12-01

    Cocos - Caribbean convergence along the Middle America Trench, including subduction of the Cocos Ridge and seamount domain, and Nazca - Caribbean oblique convergence along the South Panama Deformed Belt have resulted in complex plate boundary zone deformation since Miocene - Pliocene time. Plate boundary evolution and upper plate deformation in the western Caribbean is well studied and indicates, 1) Quaternary migration of the volcanic arc toward the back-arc northwest of the Cocos Ridge; 2) Pleistocene to present northwestward motion of the Central American Fore Arc (CAFA); 3) Quaternary to present deformation within the Central Costa Rica Deformed Belt; 4) Miocene-Pliocene cessation of volcanism and uplift of the Cordillera de Talamanca inboard the ridge; 5) Quaternary to present shortening across the fore-arc Fila Costeña fold and thrust belt and back-arc North Panama Deformed Belt (NPDB); 6) Quaternary to present outer fore-arc uplift above the seamount domain (Nicoya Peninsula), and above (Osa Peninsula) and flanking (Burica Peninsula) the ridge; and 7) Quaternary to present faulting along the Sona-Azuero and Canal Discontinuity fault systems. We investigate the dynamic effects of Cocos and Nazca convergence along the entire Central American margin, and the implications on western Caribbean plate boundary evolution with a new GPS derived three-dimensional (horizontal and vertical) velocity field and kinematic block and geodynamic models. Specifically, we test the hypotheses that the Cocos Ridge is the main driver for upper plate deformation and that there is an independent Panama block. Our model results provide new Euler vectors for the CAFA and Panama block, rates of relative plate and block motions in the region, and constraints on interseismic coupling along the Middle America Trench and other major block bounding fault systems. These results are compared to existing geophysical and geologic data for the region and add insights into the rates of

  2. Effect of rock mass structure and block size on the slope stability--Physical modeling and discrete element simulation

    Institute of Scientific and Technical Information of China (English)

    LI; Shihai; LIAN; Zhenzhong; J.; G.; Wang

    2005-01-01

    This paper studies the stability of jointed rock slopes by using our improved three-dimensional discrete element methods (DEM) and physical modeling. Results show that the DEM can simulate all failure modes of rock slopes with different joint configurations. The stress in each rock block is not homogeneous and blocks rotate in failure development. Failure modes depend on the configuration of joints. Toppling failure is observed for the slope with straight joints and sliding failure is observed for the slope with staged joints. The DEM results are also compared with those of limit equilibrium method (LEM). Without considering the joints in rock masses, the LEM predicts much higher factor of safety than physical modeling and DEM. The failure mode and factor of safety predicted by the DEM are in good agreement with laboratory tests for any jointed rock slope.

  3. Enrichment with wood blocks does not affect toxicity assessment in an exploratory toxicology model using Sprague-Dawley rats.

    Science.gov (United States)

    Ditewig, Amy C; Bratcher, Natalie A; Davila, Donna R; Dayton, Brian D; Ebert, Paige; Lesuisse, Philippe; Liguori, Michael J; Wetter, Jill M; Yang, Hyuna; Buck, Wayne R

    2014-05-01

    Environmental enrichment in rodents may improve animal well-being but can affect neurologic development, immune system function, and aging. We tested the hypothesis that wood block enrichment affects the interpretation of traditional and transcriptomic endpoints in an exploratory toxicology testing model using a well-characterized reference compound, cyclophosphamide. ANOVA was performed to distinguish effects of wood block enrichment separate from effects of 40 mg/kg cyclophosphamide treatment. Biologically relevant and statistically significant effects of wood block enrichment occurred only for body weight gain. ANOVA demonstrated the expected effects of cyclophosphamide on food consumption, spleen weight, and hematology. According to transcriptomic endpoints, cyclophosphamide induced fewer changes in gene expression in liver than in spleen. Splenic transcriptomic pathways affected by cyclophosphamide included: iron hemostasis; vascular tissue angiotensin system; hepatic stellate cell activation and fibrosis; complement activation; TGFβ-induced hypertrophy and fibrosis; monocytes, macrophages, and atherosclerosis; and platelet activation. Changes in these pathways due to cyclophosphamide treatment were consistent with bone marrow toxicity regardless of enrichment. In a second study, neither enrichment nor type of cage flooring altered body weight or food consumption over a 28-d period after the first week. In conclusion, wood block enrichment did not interfere with a typical exploratory toxicology study; the effects of ingested wood on drug level kinetics may require further consideration.

  4. MODELING STRATEGIES FOR THE ANALYSIS OF EXPERIMENTS IN AUGMENTED BLOCK DESIGN IN CLONAL TESTS OF Eucalyptus spp.

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo Rodrigues Prado

    2013-08-01

    Full Text Available http://dx.doi.org/10.5902/1980509810546The objective of this work was to compare analyses of experiment strategies when there is a large number of clones and a reduced number of seedlings to be evaluated. Data from girth at breast height of two seasons of evaluation, 30 and 90 months, from a clonal test of Eucalyptus were analyzed in three locations. The experiments were carried out in the augmented block design with 400 regular clones distributed in 20 blocks and with four common clones (controls.  Each plot consisted of five plants spaced 3 x 3 meters. The individual statistic analyses were carried out by season and local, a combined one by local at each season and a combined one involving the three locals and the two seasons. Each analysis was carried out according to two models: augmented design (AD and one way classification (OWC. The variance components, the heritability, the Speaman’s rank correlation and the coincidence indexes in the clone selection at the two models were estimated. It was found that the augmented block design and the one way classification provide similar results in Eucalyptus clone evaluation. The coincidence indexes between the two models in the clone selection, in general, were high, showing values of 100% in the local combined analyses at 90 months. The Spearman’s rank

  5. A Modified Heuristic-Block Protocol Model for Privacy and Concurrency in Cloud

    Directory of Open Access Journals (Sweden)

    Akhilesh Kumar Bhardwaj

    2015-09-01

    Full Text Available With boost in the figure of cloud users and the magnitude of sensitive data on cloud, shielding of cloud has become more important. Competent methods are consistently desirable to ensure the information privacy and load management of outsource data on un-trusted cloud servers. The base of our proposed idea is the chronological display of metaheuristic firefly algorithm and blocks based Merkle hash tree protocol. This pool of combination significantly reduces the communication delay and I/O costs. The projected scheme in addition considers the dynamic data operations at block level while maintaining the equivalent security assurance. Our method makes use of third party auditor to periodically verify the data stored at cloud provider side. Our elucidation removes the burden of verification from the user side and alleviates both the user’s and storage service’s fear about data outburst and data corruptions.

  6. Modelling radiation exposure in homes from siporex blocks by using exhalation rates of radon

    Directory of Open Access Journals (Sweden)

    Nikolić Mladen D.

    2015-01-01

    Full Text Available Building materials are the second major source of indoor radon, after soil. The contribution of building materials to indoor radon amount depends upon the radium content and exhalation rates, which can be used as a primary index for radon levels in the dwellings. This paper presents the results of using the experimentally determined exhalation rates of siporex blocks and concrete plates, to assess the radiation exposure in dwellings built of siporex blocks. The annual doses in rooms have been estimated depending on the established modes of ventilation. Realistic scenario was created to predict an annual effective dose for an old person, a housewife, a student, and an employed tenant, who live in the same apartment, spending different periods of time in it. The results indicate the crucial importance of good ventilation of the living space.

  7. Numerical simulations of tests masonry walls from ceramic block using a detailed finite element model

    Directory of Open Access Journals (Sweden)

    V. Salajka

    2017-01-01

    Full Text Available This article deals with an analysis of the behaviour of brick ceramic walls. The behaviour of the walls was analysed experimentally in order to obtain their bearing capacity under static loading and their seismic resistance. Simultaneously, numerical simulations of the experiments were carried out in order to obtain additional information on the behaviour of masonry walls made of ceramic blocks. The results of the geometrically and materially nonlinear computations were compared to the results of the performed tests.

  8. A Combinatorial Method Based on Function Block and Object-Orientation Concepts for Modeling Distributed Real-Time Control Systems

    Directory of Open Access Journals (Sweden)

    Mohsen Sadighi Moshkenani

    2007-06-01

    Full Text Available This paper presents a novel modeling method for distributed real-time control systems. The method uses function blocks model of IEC 61499 standard related to industrial control systems in combination with object-oriented approach for software production. The new modeling technique is named OO+FB. This method models distribution characteristics and real-time constraints accurately and provides a proper background for analysis and design of controllers. The new methodology, gives a complete framework for facing with modern industrial processes, using the good characteristics of both fundamental method. In this paper, different steps of OO+FB is described and advantages of using such a model is discussed, so a reliable approach is introduced for modeling.

  9. Zitongdong Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ The Zitongdong Block (Eastern Zitong Block) is located in the northwest of the Sichuan Basin. Tectonically, it is situated in the east part of Zitong Depression, southeast of mid-Longmenshan folded and faulted belt( as shown on Fig. 8 ), covering an area of 1 730 km2. The traffic is very convenient, the No. 108 national highway passes through the north of the block. Topographically, the area belongs to low hilly land at the elevation of 500-700 m.

  10. A tribo-mechanical analysis of PVA-based building-blocks for implementation in a 2-layered skin model.

    Science.gov (United States)

    Morales Hurtado, M; de Vries, E G; Zeng, X; van der Heide, E

    2016-09-01

    Poly(vinyl) alcohol hydrogel (PVA) is a well-known polymer widely used in the medical field due to its biocompatibility properties and easy manufacturing. In this work, the tribo-mechanical properties of PVA-based blocks are studied to evaluate their suitability as a part of a structure simulating the length scale dependence of human skin. Thus, blocks of pure PVA and PVA mixed with Cellulose (PVA-Cel) were synthesised via freezing/thawing cycles and their mechanical properties were determined by Dynamic Mechanical Analysis (DMA) and creep tests. The dynamic tests addressed to elastic moduli between 38 and 50kPa for the PVA and PVA-Cel, respectively. The fitting of the creep compliance tests in the SLS model confirmed the viscoelastic behaviour of the samples with retardation times of 23 and 16 seconds for the PVA and PVA-Cel, respectively. Micro indentation tests were also achieved and the results indicated elastic moduli in the same range of the dynamic tests. Specifically, values between 45-55 and 56-81kPa were obtained for the PVA and PVA-Cel samples, respectively. The tribological results indicated values of 0.55 at low forces for the PVA decreasing to 0.13 at higher forces. The PVA-Cel blocks showed lower friction even at low forces with values between 0.2 and 0.07. The implementation of these building blocks in the design of a 2-layered skin model (2LSM) is also presented in this work. The 2LSM was stamped with four different textures and their surface properties were evaluated. The hydration of the 2LSM was also evaluated with a corneometer and the results indicated a gradient of hydration comparable to the human skin.

  11. The fracture network model of Shen 229 block buried hill:A case study from Liaohe Basin, China

    Institute of Scientific and Technical Information of China (English)

    XING Yu-zhong; FAN Tai-liang; ZHENG Li-hui

    2006-01-01

    High oil production from the Proterozoic formation of Shen 229 block in Damingtun Depression, Liaohe Basin, China,indicates the presence of natural fractured reservoir whose production potential is dominated by the structural fracture. A consistent structural model and good knowledge of the fracture systems are therefore of key importance in reducing risk in the development strategies. So data from cores and image logs have been collected to account for the basic characteristics of fracture, and then the analyzed results were integrated with the structural model in order to restrict the fracture network development during the structural evolvement. The structural evolution of the Proterozoic reservoir with time forms the basis for understanding the development of the 3D fracture system. Seismic interpretation and formation correlation were used to build a 3D geological model.The fault blocks that compose the Proterozoic formation reservoir were subsequently restored to their pre-deformation. From here,the structures were kinematically modeled to simulate the structural evolution of the reservoirs. At each time step, the dilatational and cumulative strain was calculated throughout the modelling history. The total strain which records the total spatial variation in the reservoir due to its structural history, together with core data, well data and the lithology distribution, was used to simulate geologically realistic discrete fracture networks. The benefit of this technique over traditional curvature analysis is that the structural evolution is taken into account, a factor that mostly dominates fracture formation.

  12. Single and multiple object tracking using log-euclidean Riemannian subspace and block-division appearance model.

    Science.gov (United States)

    Hu, Weiming; Li, Xi; Luo, Wenhan; Zhang, Xiaoqin; Maybank, Stephen; Zhang, Zhongfei

    2012-12-01

    Object appearance modeling is crucial for tracking objects, especially in videos captured by nonstationary cameras and for reasoning about occlusions between multiple moving objects. Based on the log-euclidean Riemannian metric on symmetric positive definite matrices, we propose an incremental log-euclidean Riemannian subspace learning algorithm in which covariance matrices of image features are mapped into a vector space with the log-euclidean Riemannian metric. Based on the subspace learning algorithm, we develop a log-euclidean block-division appearance model which captures both the global and local spatial layout information about object appearances. Single object tracking and multi-object tracking with occlusion reasoning are then achieved by particle filtering-based Bayesian state inference. During tracking, incremental updating of the log-euclidean block-division appearance model captures changes in object appearance. For multi-object tracking, the appearance models of the objects can be updated even in the presence of occlusions. Experimental results demonstrate that the proposed tracking algorithm obtains more accurate results than six state-of-the-art tracking algorithms.

  13. Definition and kinematics of the northern of the Puerto Rico-Virgin Islands block and the Lesser Antilles forearc based on an updated and improved GPS velocity field and revised block models

    Science.gov (United States)

    Mattioli, G. S.; Jansma, P. E.; Stafford-Glenn, M.; Calais, E.

    2011-12-01

    The presence of small tectonic blocks the Greater Antilles, for example the Puerto Rico-Virgin Islands block (PRVI), which may be translating, rotating, and possibly internally deforming, has been proposed and some cases well-documented by several workers. In addition, the existence of a Lesser Antilles forearc has been proposed based on interplate earthquake slip vectors (Lopez et al. 2006). Manaker et al. (2008) used sparse GPS and earthquake slip data from the northeastern Caribbean to construct a DEFNODE block and fault model to constrain interseismic fault coupling among the microplates in the northeastern Caribbean. They concluded that the Enriquillo fault in Haiti could produce a Mw7.2, if the entire accumulated elastic strain was released in one event. On January 12, 2010, the strain was released in a Mw7.0 earthquake that left Port-au-Prince in rubble. The interseismic GPS velocity field has been updated for Hispanolia (Calais et al, 2010); in addition, new data have been collected in the northern Lesser Antilles (NLA) in 2009 as well as throughout the PRVI block in 2007 and 2011, and the existing GPS time series updated and transformed into ITRF05 (IGS05). GPS data from the NLA are consistent with a NLA forearc sliver that moves differently from the Caribbean and North American plates as originally proposed by Lopez et al. (2006). The forearc does not, however, continue as single tectonic entity across the Anegada Passage as previously suggested. Here we report revised DEFNODE models using both the original geometry and constraints of Manaker et al. (2008) with an updated GPS data set as well as new models that explicitly include a forearc block. The models may be used to explicitly define the rotation parameters of the block as well as the coupling along block bounding faults. The original model geometry (without a forearc sliver) yields a higher reduced chi-squared (2.57 vs. 2.01), when additional the GPS velocities from NLA are used to condition the

  14. Zitongxi Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Zitongxi Block (Western Zitong Block), is located in Zitong County, northwest of Sichuan Province (as shown on Fig. 8 ). Geologically. it is situated in the Zitong Depression, southwest of the middle Longmenshan faulted and folded belt, covering an area of 1 830 km2. Transportation is very convenient. A crisscross network of highways run through the block and the Baocheng railway is nearby. The climate is moderate. Most area belongs to hilly land with the elevation of 500-600 m.The Tongjiang River runs across the area.

  15. Comparison of Stable and Transient Wolbachia Infection Models in Aedes aegypti to Block Dengue and West Nile Viruses.

    Science.gov (United States)

    Joubert, Dirk Albert; O'Neill, Scott L

    2017-01-01

    Pathogen replication and transmission in Wolbachia infected insects are currently studied using three Wolbachia infection systems: naturally infected Wolbachia hosts, hosts transinfected with Wolbachia (stably maintained and inherited infections) and hosts transiently infected with Wolbachia. All three systems have been used to test the effect of Wolbachia on mosquito transmitted pathogens such as dengue virus (DENV), West Nile virus (WNV) and Plasmodium. From these studies it is becoming increasingly clear that the interaction between a particular pathogen and Wolbachia is heavily influenced by the host-Wolbachia interaction and the model of infection. In particular, there is some evidence that under very specific conditions, Wolbachia can enhance pathogen infection in some hosts. In this study, we compared the effect of Wolbachia in two infection models (stable transinfected and transiently infected) on the replication, infection- and transmission rates of two flaviviruses, DENV and WNV (Kunjin strain). Our results indicate that Wolbachia had similar blocking effects in both stable and transient models of infection, however, the magnitude of the blocking effect was significantly lower in mosquitoes transiently infected with Wolbachia. More importantly, no evidence was found for any enhancement of either DENV or WNV (Kunjin strain) infection in Ae. aegypti infected with Wolbachia, supporting a role for Wolbachia as an effective and safe means for restricting transmission of these viruses.

  16. Comparison of Stable and Transient Wolbachia Infection Models in Aedes aegypti to Block Dengue and West Nile Viruses

    Science.gov (United States)

    Joubert, Dirk Albert; O’Neill, Scott L.

    2017-01-01

    Pathogen replication and transmission in Wolbachia infected insects are currently studied using three Wolbachia infection systems: naturally infected Wolbachia hosts, hosts transinfected with Wolbachia (stably maintained and inherited infections) and hosts transiently infected with Wolbachia. All three systems have been used to test the effect of Wolbachia on mosquito transmitted pathogens such as dengue virus (DENV), West Nile virus (WNV) and Plasmodium. From these studies it is becoming increasingly clear that the interaction between a particular pathogen and Wolbachia is heavily influenced by the host-Wolbachia interaction and the model of infection. In particular, there is some evidence that under very specific conditions, Wolbachia can enhance pathogen infection in some hosts. In this study, we compared the effect of Wolbachia in two infection models (stable transinfected and transiently infected) on the replication, infection- and transmission rates of two flaviviruses, DENV and WNV (Kunjin strain). Our results indicate that Wolbachia had similar blocking effects in both stable and transient models of infection, however, the magnitude of the blocking effect was significantly lower in mosquitoes transiently infected with Wolbachia. More importantly, no evidence was found for any enhancement of either DENV or WNV (Kunjin strain) infection in Ae. aegypti infected with Wolbachia, supporting a role for Wolbachia as an effective and safe means for restricting transmission of these viruses. PMID:28052065

  17. CONSTRUCTION OF POLYNOMIAL MATRIX USING BLOCK COEFFICIENT MATRIX REPRESENTATION AUTO-REGRESSIVE MOVING AVERAGE MODEL FOR ACTIVELY CONTROLLED STRUCTURES

    Institute of Scientific and Technical Information of China (English)

    LI Chunxiang; ZHOU Dai

    2004-01-01

    The polynomial matrix using the block coefficient matrix representation auto-regressive moving average (referred to as the PM-ARMA) model is constructed in this paper for actively controlled multi-degree-of-freedom (MDOF) structures with time-delay through equivalently transforming the preliminary state space realization into the new state space realization. The PM-ARMA model is a more general formulation with respect to the polynomial using the coefficient representation auto-regressive moving average (ARMA) model due to its capability to cope with actively controlled structures with any given structural degrees of freedom and any chosen number of sensors and actuators. (The sensors and actuators are required to maintain the identical number.) under any dimensional stationary stochastic excitation.

  18. Chengzikou Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Chengzikou Block is located in the north of Hekou district, Dongying City, Shandong Province, adjacent to Bohai Bay. It can be geographically divided into three units: onshore, transitional zone and offshore ultrashallow zone, totally covering an area of 470 km2. The southern onshore area is low and gentle in topography;the northern shallow sea is at water depths of 2-8 m below sea level, and the transitional zone occupies more than 60% of the whole block. The climate belongs to temperate zone with seasonal wind. Highways are welldeveloped here, and the traffic is very convenient. The Chengzikou Block is about 80 km away from Dongying City and 290 km from Jinan City in the south. The northern offshore area of the block is 160 km away from Longkou port in the east and only 38 km away in the west from Zhuangxi port.

  19. Longmenshan Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Longmenshan Block is located in Jiange County of Jiangyou City in the northwest of Sichuan Basin. covering an area of 2 628 km2. Geologically, it is situated in the Mid-Longmenshan fault and fold belt, neighbouring Zitong Depression in its southeast. There are mountains surrounding its northwest , the rest area being hilly land,with the elevation of 500-700 m. The BaoCheng railway and the No. 108 highway run through the block, the traffic is very convenient.

  20. Theoretical modeling of 2D porous matrices with tunable architecture: From cruciform molecular building blocks to enantioselective adsorbents

    Science.gov (United States)

    Kasperski, Adam; Rżysko, Wojciech; Szabelski, Paweł

    2016-12-01

    The ability of capturing guest molecules in a selective way is one of desirable properties of modern structured adsorbents. This refers to a wide class of guest molecules, especially to those which are chiral and whose enantiomers are to be efficiently separated. In this contribution, using Monte Carlo modeling, we show how simple molecular building blocks with cruciform shape can be used to create 2D porous matrices with tunable adsorptive properties. To that end we consider different self-assembled structures comprising cross-shaped molecules and probe their ability to retain model guest molecules differing in size and shape. In particular we focus on the adsorption of enantiomeric pairs on these substrates and quantify the associated selectivity. The obtained results show that a suitable choice of the building block, including size and aspect ratio allows for the creation of 2D functional matrices with programmed adsorption performance. The findings of our theoretical investigations can be helpful in designing molecular guest-host systems with potential applications in separations, sensing and heterogeneous catalysis.

  1. Caffeine blocks disruption of blood brain barrier in a rabbit model of Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Ghribi Othman

    2008-04-01

    Full Text Available Abstract High levels of serum cholesterol and disruptions of the blood brain barrier (BBB have all been implicated as underlying mechanisms in the pathogenesis of Alzheimer's disease. Results from studies conducted in animals and humans suggest that caffeine might be protective against Alzheimer's disease but by poorly understood mechanisms. Using rabbits fed a cholesterol-enriched diet, we tested our hypothesis that chronic ingestion of caffeine protects against high cholesterol diet-induced disruptions of the BBB. New Zealand rabbits were fed a 2% cholesterol-enriched diet, and 3 mg caffeine was administered daily in drinking water for 12 weeks. Total cholesterol and caffeine concentrations from blood were measured. Olfactory bulbs (and for some studies hippocampus and cerebral cortex as well were evaluated for BBB leakage, BBB tight junction protein expression levels, activation of astrocytes, and microglia density using histological, immunostaining and immunoblotting techniques. We found that caffeine blocked high cholesterol diet-induced increases in extravasation of IgG and fibrinogen, increases in leakage of Evan's blue dye, decreases in levels of the tight junction proteins occludin and ZO-1, increases in astrocytes activation and microglia density where IgG extravasation was present. Chronic ingestion of caffeine protects against high cholesterol diet-induced increases in disruptions of the BBB, and caffeine and drugs similar to caffeine might be useful in the treatment of Alzheimer's disease.

  2. Changes in atmospheric blocking characteristics within Euro-Atlantic region and Northern Hemisphere as a whole in the 21st century from model simulations using RCP anthropogenic scenarios

    Science.gov (United States)

    Mokhov, Igor I.; Timazhev, Alexander V.; Lupo, Anthony R.

    2014-11-01

    An analysis of simulations using the IPSL-CM5 climate model of general circulation shows the ability of this model to reproduce the current climate of the main blocking characteristics obtained from reanalysis data, including number of blocking events and their duration, intensity and frequency. Possible changes of blocking characteristics in the Euro-Atlantic region (EA) and for the Northern Hemisphere (NH) as a whole are estimated from model simulations with the RCP2.6 and RCP8.5 scenarios for the 21st century. Results of the model simulations show a general increase in the blocking frequency for the EA in winter, summer and for the entire year during the 21st century for both analyzed RCP scenarios, while changes of the opposite sign are characteristic for NH as a whole. It is also noted that there is a tendency for an increase in the blocking intensity in the EA during the winter from model simulations with both analyzed RCP scenarios for the 21st century. A significant increase is obtained in the EA for the likelihood of extreme winter with the total blocking duration longer than seven weeks. Also, a similar tendency is characteristic for the EA summer.

  3. Integrin-blocking antibodies delay keratinocyte re-epithelialization in a human three-dimensional wound healing model.

    Directory of Open Access Journals (Sweden)

    Christophe Egles

    Full Text Available The alpha6beta4 integrin plays a significant role in tumor growth, angiogenesis and metastasis through modulation of growth factor signaling, and is a potentially important therapeutic target. However, alpha6beta4-mediated cell-matrix adhesion is critical in normal keratinocyte attachment, signaling and anchorage to the basement membrane through its interaction with laminin-5, raising potential risks for targeted therapy. Bioengineered Human Skin Equivalent (HSE, which have been shown to mimic their normal and wounded counterparts, have been used here to investigate the consequences of targeting beta4 to establish toxic effects on normal tissue homeostasis and epithelial wound repair. We tested two antibodies directed to different beta4 epitopes, one adhesion-blocking (ASC-8 and one non-adhesion blocking (ASC-3, and determined that these antibodies were appropriately localized to the basal surface of keratinocytes at the basement membrane interface where beta4 is expressed. While normal tissue architecture was not altered, ASC-8 induced a sub-basal split at the basement membrane in non-wounded tissue. In addition, wound closure was significantly inhibited by ASC-8, but not by ASC-3, as the epithelial tongue only covered 40 percent of the wound area at 120 hours post-wounding. These results demonstrate beta4 adhesion-blocking antibodies may have adverse effects on normal tissue, whereas antibodies directed to other epitopes may provide safer alternatives for therapy. Taken together, we conclude that these three-dimensional tissue models provide a biologically relevant platform to identify toxic effects induced by candidate therapeutics, which will allow generation of findings that are more predictive of in vivo responses early in the drug development process.

  4. Methodology for Constructing Reduced-Order Power Block Performance Models for CSP Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M.

    2010-10-01

    The inherent variability of the solar resource presents a unique challenge for CSP systems. Incident solar irradiation can fluctuate widely over a short time scale, but plant performance must be assessed for long time periods. As a result, annual simulations with hourly (or sub-hourly) timesteps are the norm in CSP analysis. A highly detailed power cycle model provides accuracy but tends to suffer from prohibitively long run-times; alternatively, simplified empirical models can run quickly but don?t always provide enough information, accuracy, or flexibility for the modeler. The ideal model for feasibility-level analysis incorporates both the detail and accuracy of a first-principle model with the low computational load of a regression model. The work presented in this paper proposes a methodology for organizing and extracting information from the performance output of a detailed model, then using it to develop a flexible reduced-order regression model in a systematic and structured way. A similar but less generalized approach for characterizing power cycle performance and a reduced-order modeling methodology for CFD analysis of heat transfer from electronic devices have been presented. This paper builds on these publications and the non-dimensional approach originally described.

  5. Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

    Science.gov (United States)

    Dou, Jianhong; Xia, Ling; Zhang, Yu; Shou, Guofa; Wei, Qing; Liu, Feng; Crozier, Stuart

    2009-01-01

    Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

  6. A population pharmacokinetic model for the complex systemic absorption of ropivacaine after femoral nerve block in patients undergoing knee surgery.

    Science.gov (United States)

    Gaudreault, François; Drolet, Pierre; Fallaha, Michel; Varin, France

    2012-12-01

    Because of its slow systemic absorption and flip-flop kinetics, ropivacaine's pharmacokinetics after a peripheral nerve block has never been thoroughly characterized. The purpose of this study was to develop a population pharmacokinetic model for ropivacaine after loco-regional administration and to identify patient characteristics that may influence the drug's absorption and disposition. Frequent plasma samples were taken up to 93 h after a 100 mg dose given as femoral block for postoperative analgesia in 15 orthopedic patients. Ropivacaine plasma concentration-time data were analyzed using a nonlinear mixed effects modeling method. A one-compartment model with parallel inverse Gaussian and time-dependent inputs best described ropivacaine plasma concentration-time curves. Ropivacaine systemic absorption was characterized by a rapid phase (mean absorption time of 25 ± 4.8 min) followed by a much slower phase (half-life of 3.9 ± 0.65 h). Interindividual variability (IIV) for these parameters, 58 and 9 %, indicated that the initial absorption phase was more variable. The apparent volume of distribution (V/F = 77.2 ± 11.5 L, IIV = 26 %) was influenced by body weight (Δ 1.49 % per kg change) whereas the absorption rate constant (slower phase) of ropivacaine was affected by age (Δ 2.25 % per year change). No covariate effects were identified for the apparent clearance of the drug (CL/F =10.8 ± 1.0 L/h, 34  IIV = 34 %). These findings support our hypothesis that modeling a complex systemic absorption directly from plasma concentration-time curves exhibiting flip-flop kinetics is possible. Only the age-effect was considered as relevant for possible dosing adjustments.

  7. Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

    Energy Technology Data Exchange (ETDEWEB)

    Dou Jianhong; Xia Ling; Zhang Yu; Shou Guofa [Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027 (China); Wei Qing; Liu Feng; Crozier, Stuart [School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, Brisbane, Queensland 4072 (Australia)], E-mail: xialing@zju.edu.cn

    2009-01-21

    Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

  8. A multiscale modeling study of loss processes in block-copolymer-based solar cell nanodevices

    Science.gov (United States)

    Donets, Sergii; Pershin, Anton; Christlmaier, Martin J. A.; Baeurle, Stephan A.

    2013-03-01

    Flexible photovoltaic devices possess promising perspectives in opto-electronic technologies, where high mobility and/or large-scale applicability are important. However, their usefulness in such applications is currently still limited due to the low level of optimization of their performance and durability. For the improvement of these properties, a better understanding and control of small-scale annihilation phenomena involved in the photovoltaic process, such as exciton loss and charge carrier loss, is necessary, which typically implicates multiple length- and time-scales. Here, we study the causes for their occurrence on the example of nanostructured diblock- and triblock-copolymer systems by making use of a novel solar-cell simulation algorithm and explore new routes to optimize their photovoltaic properties. A particular focus is set on the investigation of exciton and charge carrier loss phenomena and their dependence on the inter-monomeric interaction strength, chain architecture, and external mechanical loading. Our simulation results reveal that in the regime from low up to intermediate χ-parameters an increasing number of continuous percolation paths is created. In this parameter range, the internal quantum efficiency (IQE) increases up to a maximum, characterized by a minimum in the number of charge losses due to charge recombination. In the regime of high χ-parameters both block-copolymer systems form nanostructures with a large number of bottlenecks and dead ends. These lead to a large number of charge losses due to charge recombination, charge trapping, and a deteriorated exciton dissociation, resulting in a significant drop in the IQE. Moreover, we find that the photovoltaic performance of the triblock-copolymer material decreases with increasing mechanical loading, caused by a growing number of charge losses due to charge recombination and charge accumulation. Finally, we demonstrate that the process of charge trapping in defects can be reversed

  9. Mean field J{sub C} estimation for levitation device simulations in the bean model using permanent magnets and YBCO superconducting blocks

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Marcelo Azevedo; Andrade Junior, Rubens de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Eletrotecnica. Lab. de Aplicacoes de Supercondutores (LASUP); Costa, Giancarlo Cordeiro da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Lab. de Metodos Computacionais em Engenharia; Pereira, Agnaldo Souza; Nicolsky, Roberto [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Fisica

    2002-09-01

    This work presents a mean field estimation of J{sub C} as a bulk characteristic of YBCO blocks. That average J{sub C} allows a good fitting of the finite-element-method simulation of the levitation forces to experimental results. That agreement is quite enough for levitation requirements of device projects, at short gaps and zero field cooling process, within the Bean model. The physical characterization for that estimation was made measuring the interaction force between the PM and one YBCO block in 1-D and mapping the trapped magnetic field in those blocks in 2-D. (author)

  10. Chadong Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ The Chadong Block, located in the east of Qaidam Basin, Qinghai Province, covers an area of 12 452 km2. It is bounded by Kunlum Mountains in the south and the northwest is closely adjacent to Aimunike Mountain.Rivers are widely distributed, which always run in NWSE direction, including the Sulunguole, Qaidam and Haluwusu Rivers. The traffic condition is good, the Qinghai-Tibet highway stretching through the whole area and the Lan-Qing railway, 20-50 km away from the block, passing from north to west. A lot of Mongolia minority people have settled there, of which herdsmen always live nearby the Qaidam River drainage area.

  11. HADOOP+Big Data: Analytics Using Series Queue with Blocking Model

    Directory of Open Access Journals (Sweden)

    S. Koteeswaran

    2014-07-01

    Full Text Available Big data deals with large volumes of tons and tons of data. Since managing this much amount of data is not in the mere way for the traditional data mining techniques. Technology is in the world of pervasive environment i.e., technology follows up with its tremendous growth. Hence coordinating these amount of data in a linear way is mere little difficult, hence we proposed a new scheme in order to draw the data and data transformation in large data base. We extended our work in HADOOP (one of the big data managing tool. Our model is fully based on aggregation of data and data modelling. Our proposed model leads to high end data transformation for big data processing. We achieved our analytical result by applying our model with 2 HADOOP clusters, 4 nodes and with 25 jobs in MR functionality.

  12. Indirect decompression and vertebral body endplate strength after lateral interbody spacer impaction: cadaveric and foam-block models.

    Science.gov (United States)

    Kwon, Anthony J; Hunter, William D; Moldavsky, Mark; Salloum, Kanaan; Bucklen, Brandon

    2016-05-01

    OBJECTIVE The lateral transpsoas approach to the lumbar spine is a well-defined procedure for the management of discogenic spinal pathology necessitating surgical intervention. Intervertebral device subsidence is a postoperative clinical risk that can lead to recurrence of symptomatic pathology and the need for surgical reintervention. The current study was designed to investigate static versus expandable lateral intervertebral spacers in indirect decompression for preserving vertebral body endplate strength. METHODS Using a cadaveric biomechanical study and a foam-block vertebral body model, researchers compared vertebral body endplate strength and distraction potential. Fourteen lumbar motion segments (7 L2-3 and 7 L4-5 specimens) were distributed evenly between static and expandable spacer groups. In each specimen discectomy was followed by trialing and spacer impaction. Motion segments were axially sectioned through the disc, and a metal stamp was used to apply a compressive load to superior and inferior vertebral bodies to quantify endplate strength. A paired, 2-sample for means t-test was performed to determine statistically significant differences between groups (p ≤ 0.05). A foam-block endplate model was used to control simulated disc tension when a spacer with 2- and 3-mm desired distraction was inserted. One-way ANOVA and a post hoc Student Newman-Keuls test were performed (p ≤ 0.05) to determine differences in distraction. RESULTS Both static and expandable spacers restored intact neural foramen and disc heights after device implantation (p > 0.05). Maximum peak loads at endplate failure for static and expandable spacers were 1764 N (± 966 N) and 2284 N (± 949 N), respectively (p ≤ 0.05). The expandable spacer consistently produced greater desired distraction than was created by the static spacer in the foam-block model (p ≤ 0.05). Distraction created by fully expanding the spacer was significantly greater than the predetermined goals of 2 mm

  13. Changes in the Intensity and Frequency of Atmospheric Blocking and Associated Heat Waves During Northern Summer Over Eurasia in the CMIP5 Model Simulations

    Science.gov (United States)

    Kim, Kyu-Myong; Lau, K. M.; Wu, H. T.; Kim, Maeng-Ki; Cho, Chunho

    2012-01-01

    The Russia heat wave and wild fires of the summer of 2010 was the most extreme weather event in the history of the country. Studies show that the root cause of the 2010 Russia heat wave/wild fires was an atmospheric blocking event which started to develop at the end of June and peaked around late July and early August. Atmospheric blocking in the summer of 2010 was anomalous in terms of the size, duration, and the location, which shifted to the east from the normal location. This and other similar continental scale severe summertime heat waves and blocking events in recent years have raised the question of whether such events are occurring more frequently and with higher intensity in a warmer climate induced by greenhouse gases. We studied the spatial and temporal distributions of the occurrence and intensity of atmospheric blocking and associated heat waves for northern summer over Eurasia based on CMIPS model simulations. To examine the global warming induced change of atmospheric blocking and heat waves, experiments for a high emissions scenario (RCP8.S) and a medium mitigation scenario (RCP4.S) are compared to the 20th century simulations (historical). Most models simulate the mean distributions of blockings reasonably well, including major blocking centers over Eurasia, northern Pacific, and northern Atlantic. However, the models tend to underestimate the number of blockings compared to MERRA and NCEPIDOE reanalysis, especially in western Siberia. Models also reproduced associated heat waves in terms of the shifting in the probability distribution function of near surface temperature. Seven out of eight models used in this study show that the frequency of atmospheric blocking over the Europe will likely decrease in a warmer climate, but slightly increase over the western Siberia. This spatial pattern resembles the blocking in the summer of 2010, indicating the possibility of more frequent occurrences of heat waves in western Siberia. In this talk, we will also

  14. Modeling and Optimization of the Thermal Performance of a Wood-Cement Block in a Low-Energy House Construction

    Directory of Open Access Journals (Sweden)

    Iole Nardi

    2016-08-01

    Full Text Available The reduction of building energy consumption requires appropriate planning and design of the building’s envelope. In the last years, new innovative materials and construction technologies used in new or refurbished buildings have been developed in order to achieve this objective, which are also needed for reducing greenhouse gases emissions and building maintenance costs. In this work, the thermal conductance of a brick, made of wood and cement, used in a low-rise building, was investigated with a heat flow meter (HFM and with numerical simulation using the Ansys® software package (Canonsburg, PA, USA. Due to their influence on the buildings’ thermal efficiency, it is important to choose an appropriate design for the building blocks. Results obtained by the finite element modeling of the construction material and by in-situ analysis conducted on a real building are compared, and furthermore a thermal optimization of the shape of the material is suggested.

  15. Inhibition of apoptosis blocks human motor neuron cell death in a stem cell model of spinal muscular atrophy.

    Directory of Open Access Journals (Sweden)

    Dhruv Sareen

    Full Text Available Spinal muscular atrophy (SMA is a genetic disorder caused by a deletion of the survival motor neuron 1 gene leading to motor neuron loss, muscle atrophy, paralysis, and death. We show here that induced pluripotent stem cell (iPSC lines generated from two Type I SMA subjects-one produced with lentiviral constructs and the second using a virus-free plasmid-based approach-recapitulate the disease phenotype and generate significantly fewer motor neurons at later developmental time periods in culture compared to two separate control subject iPSC lines. During motor neuron development, both SMA lines showed an increase in Fas ligand-mediated apoptosis and increased caspase-8 and-3 activation. Importantly, this could be mitigated by addition of either a Fas blocking antibody or a caspase-3 inhibitor. Together, these data further validate this human stem cell model of SMA, suggesting that specific inhibitors of apoptotic pathways may be beneficial for patients.

  16. Measurement and Modeling of Blocking Contacts for Cadmium Telluride Gamma Ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Patrick R. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States)

    2010-01-07

    Gamma ray detectors are important in national security applications, medicine, and astronomy. Semiconductor materials with high density and atomic number, such as Cadmium Telluride (CdTe), offer a small device footprint, but their performance is limited by noise at room temperature; however, improved device design can decrease detector noise by reducing leakage current. This thesis characterizes and models two unique Schottky devices: one with an argon ion sputter etch before Schottky contact deposition and one without. Analysis of current versus voltage characteristics shows that thermionic emission alone does not describe these devices. This analysis points to reverse bias generation current or leakage through an inhomogeneous barrier. Modeling the devices in reverse bias with thermionic field emission and a leaky Schottky barrier yields good agreement with measurements. Also numerical modeling with a finite-element physics-based simulator suggests that reverse bias current is a combination of thermionic emission and generation. This thesis proposes further experiments to determine the correct model for reverse bias conduction. Understanding conduction mechanisms in these devices will help develop more reproducible contacts, reduce leakage current, and ultimately improve detector performance.

  17. Hierarchical block structures and high-resolution model selection in large networks

    CERN Document Server

    Peixoto, Tiago P

    2013-01-01

    Discovering the large-scale topological features in empirical networks is a crucial tool in understanding how complex systems function. However most existing methods used to obtain the modular structure of networks suffer from serious problems, such as the resolution limit on the size of communities, where smaller but well-defined clusters are not detectable when the network becomes large. This phenomenon occurs for the very popular approach of modularity optimization, but also for more principled ones based on statistical inference and model selection. Here we construct a nested generative model which, through a complete description of the entire network hierarchy at multiple scales, is capable of avoiding this limitation, and enables the detection of modular structure at levels far beyond those possible by current approaches. Even with this increased resolution, the method is based on the principle of parsimony, and is capable of separating signal from noise, and thus will not lead to the identification of ...

  18. Optimal three-field block-preconditioners for models of coupled magma/mantle dynamics

    CERN Document Server

    Rhebergen, Sander; Wathen, Andrew J; Katz, Richard F

    2014-01-01

    For a prescribed porosity, the coupled magma/mantle flow equations can be formulated as a two field system of equations with velocity and pressure unknowns. Previous work has shown that while optimal preconditioners for the two field formulation can be constructed, the construction of preconditioners that are uniform with respect to model parameters is difficult. This limits the applicability of two field preconditioners in certain regimes of practical interest. We address this issue by reformulating the governing equations as a three field problem, which removes a term that was problematic in the two field formulation in favour of an additional equation for a pressure-like field. For the three-field problem, we develop and analyse new preconditioners and we show numerically that the new three-field preconditioners are optimal in terms of problem size and less sensitive to model parameters compared to the two-field preconditioner. This extends the applicability of optimal preconditioners for coupled mantle/ma...

  19. Toward a Collaborative, Transformative Model of Non-Profit Leadership: Some Conceptual Building Blocks

    OpenAIRE

    Bramwell Osula; Eddie C. W. Ng

    2014-01-01

    In this paper, the authors propose extending the construct of non-profit leadership to accommodate collaborative and transformational themes. The suggestion is that the resultant broader definition accords with the modern context within which non-profits now operate and feeds into a more resilient model of non-profit leadership. The paper begins with a review of emergent trends in leadership theory and the changing context of the non-profit sector. The argument is made that the extraordinary...

  20. Toward a Collaborative, Transformative Model of Non-Profit Leadership: Some Conceptual Building Blocks

    Directory of Open Access Journals (Sweden)

    Bramwell Osula

    2014-04-01

    Full Text Available In this paper, the authors propose extending the construct of non-profit leadership to accommodate collaborative and transformational themes. The suggestion is that the resultant broader definition accords with the modern context within which non-profits now operate and feeds into a more resilient model of non-profit leadership. The paper begins with a review of emergent trends in leadership theory and the changing context of the non-profit sector. The argument is made that the extraordinary challenges facing the sector signal the need for fresh new perspectives in leadership. The authors then proceed to examine the significance of a nascent non-profit culture point to a re-alignment of the sector that is informed by transformational principles and a values-orientation. The result is said to be a new model of non-profit and public sector leadership that raises important methodological questions which the authors maintain can inform future analyses of the structure, role, and responsibilities of non-profit leadership. Finally, a world of new possibilities is envisioned, one in which non-profit organizations are strategically repositioned to take advantage of a new values-based ethic that is rooted in principles of integrity, increased self-awareness, a collaborative agenda, intentionality, emphasis of followership, cultural competence, and orientation toward the future.

  1. Solubility of block copolymer surfactants in compressed CO{sub 2} using a lattice fluid hydrogen-bonding model

    Energy Technology Data Exchange (ETDEWEB)

    Takishima, Shigeki; O`Neill, M.L.; Johnston, K.P. [Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering

    1997-07-01

    Supercritical carbon dioxide (CO{sub 2}) is an environmentally benign alternative to organic solvents in chemical processing. The solubilities of the homopolymers poly(ethylene glycol), poly(ethylene glycol) dimethyl ether (PEGDME), and poly(propylene glycol) (PPG) in CO{sub 2} were correlated with a lattice fluid hydrogen-bonding (LFHB) model, which was then used to predict solubilities of Pluronic L (PEG-PPG-PEG) and Pluronic R (PPG-PEG-PPG) triblock copolymers. Simple averaging rules were developed to evaluate the physical properties of the copolymers without introducing any adjustable parameters. For a given average molecular weight, the predictions of the model were quite reasonable and in some cases perhaps more accurate than the data, due to the large polydispersity of the samples. The model predicts the effects of total molecular weight, PEG/PPG ratio, terminal functional groups, temperature, and density on solubility. The much higher solubility of PPG versus PEG is due primarily to steric hindrance from the methyl branch, which weakens segment-segment interactions, and to a lesser extent to the stronger hydrogen bond donor strength of a primary (in the case of PEG) versus a secondary (in the case of PPG) alcohol terminal group. Consequently, the predicted solubilities of Pluronic L surfactants, which have stronger hydrogen bond donors on the terminal groups, are not much smaller than those of Pluronic R surfactants for given molecular weights of the blocks.

  2. Community Detection Algorithm Combining Stochastic Block Model and Attribute Data Clustering

    Science.gov (United States)

    Kataoka, Shun; Kobayashi, Takuto; Yasuda, Muneki; Tanaka, Kazuyuki

    2016-11-01

    We propose a new algorithm to detect the community structure in a network that utilizes both the network structure and vertex attribute data. Suppose we have the network structure together with the vertex attribute data, that is, the information assigned to each vertex associated with the community to which it belongs. The problem addressed this paper is the detection of the community structure from the information of both the network structure and the vertex attribute data. Our approach is based on the Bayesian approach that models the posterior probability distribution of the community labels. The detection of the community structure in our method is achieved by using belief propagation and an EM algorithm. We numerically verified the performance of our method using computer-generated networks and real-world networks.

  3. Community Detection Algorithm Combining Stochastic Block Model and Attribute Data Clustering

    CERN Document Server

    Kataoka, Shun; Yasuda, Muneki; Tanaka, Kazuyuki

    2016-01-01

    We propose a new algorithm to detect the community structure in a network that utilizes both the network structure and vertex attribute data. Suppose we have the network structure together with the vertex attribute data, that is, the information assigned to each vertex associated with the community to which it belongs. The problem addressed this paper is the detection of the community structure from the information of both the network structure and the vertex attribute data. Our approach is based on the Bayesian approach that models the posterior probability distribution of the community labels. The detection of the community structure in our method is achieved by using belief propagation and an EM algorithm. We numerically verified the performance of our method using computer-generated networks and real-world networks.

  4. The primary cilium as sensor of fluid flow: new building blocks to the model

    DEFF Research Database (Denmark)

    Prætorius, Helle

    2015-01-01

    functionally as an organelle that makes cells more susceptible to changes in fluid flow. Thus the primary cilium was suggested to function as a flow-sensing device. This characterization has been substantiated for many epithelial cell types over the years. Nevertheless, part of the central mechanism of signal......The primary cilium is an extraordinary organelle. For many years, it had the full attention of only a few dedicated scientists fascinated by its uniqueness. Unexpectedly, after decades of obscurity, it has moved very quickly into the limelight with the increasing evidence of its central role...... transduction has not been explained, largely because of the substantial technical challenges of working with this delicate organelle. The current review considers the recent advances that allow us to fill some of the holes in the model of signal transduction in cilium-mediated responses to fluid flow...

  5. Structures of PEP–PEO Block Copolymer Micelles: Effects of Changing Solvent and PEO Length and Comparison to a Thermodynamic Model

    DEFF Research Database (Denmark)

    Jensen, Grethe Vestergaard; Shi, Qing; Deen, G. Roshan;

    2012-01-01

    Structures of poly(ethylene propylene)–poly(ethylene oxide) (PEP–PEO) block copolymer micelles were determined from small-angle X-ray scattering and static light scattering and compared to predictions from a thermodynamic model. Both the corona block length and the solvent water–ethanol ratio were...... changed, leading to a thorough test of this model. With increasing ethanol fraction, the PEP core–solvent interfacial tension decreases, and the solvent quality for PEO changes. The weight-average block masses were 5.0 kDa for PEP and 2.8–49 kDa for PEO. For the lowest PEO molar mass and samples in pure...... water (except for the highest PEO molar mass), the micelles were cylindrical; for other conditions they were spherical. The structural parameters can be reasonably well described by the thermodynamic model by Zhulina et al. [Macromolecules2005, 38 (12), 5330–5351]; however, they have a stronger...

  6. Dynamic interaction of slip displacement accumulation in a two-block Newmark model

    DEFF Research Database (Denmark)

    Zania, Varvara; Tsompanakis, Y.; Psarropoulos, Prodromos N.

    2011-01-01

    Engineering structures may include discontinuities or predefined interfaces separating different construction materials, or failure planes generated for example within soil in the case of geotechnical applications. Due to seismic motion permanent slip displacements may accumulate along the aforem......Engineering structures may include discontinuities or predefined interfaces separating different construction materials, or failure planes generated for example within soil in the case of geotechnical applications. Due to seismic motion permanent slip displacements may accumulate along......, being separated by prescribed interfaces of finite shear strength, thus, they are capable of developing relative displacements under seismic loading. For this purpose, a semi-analytical procedure was formulated and the accuracy of the calculated slip displacements was verified by finite element analyses...... of the corresponding model. In addition, parametric analyses were performed in order to address the impact of the main factors influencing the interaction of the slip displacement accumulation along the two interfaces. It is shown, that taking into account the effect of the interaction leads to reduction...

  7. Virulence Inhibitors from Brazilian Peppertree Block Quorum Sensing and Abate Dermonecrosis in Skin Infection Models.

    Science.gov (United States)

    Muhs, Amelia; Lyles, James T; Parlet, Corey P; Nelson, Kate; Kavanaugh, Jeffery S; Horswill, Alexander R; Quave, Cassandra L

    2017-02-10

    Widespread antibiotic resistance is on the rise and current therapies are becoming increasingly limited in both scope and efficacy. Methicillin-resistant Staphylococcus aureus (MRSA) represents a major contributor to this trend. Quorum sensing controlled virulence factors include secreted toxins responsible for extensive damage to host tissues and evasion of the immune system response; they are major contributors to morbidity and mortality. Investigation of botanical folk medicines for wounds and infections led us to study Schinus terebinthifolia (Brazilian Peppertree) as a potential source of virulence inhibitors. Here, we report the inhibitory activity of a flavone rich extract "430D-F5" against all S. aureus accessory gene regulator (agr) alleles in the absence of growth inhibition. Evidence for this activity is supported by its agr-quenching activity (IC50 2-32 μg mL(-1)) in transcriptional reporters, direct protein outputs (α-hemolysin and δ-toxin), and an in vivo skin challenge model. Importantly, 430D-F5 was well tolerated by human keratinocytes in cell culture and mouse skin in vivo; it also demonstrated significant reduction in dermonecrosis following skin challenge with a virulent strain of MRSA. This study provides an explanation for the anti-infective activity of peppertree remedies and yields insight into the potential utility of non-biocide virulence inhibitors in treating skin infections.

  8. Virulence Inhibitors from Brazilian Peppertree Block Quorum Sensing and Abate Dermonecrosis in Skin Infection Models

    Science.gov (United States)

    Muhs, Amelia; Lyles, James T.; Parlet, Corey P.; Nelson, Kate; Kavanaugh, Jeffery S.; Horswill, Alexander R.; Quave, Cassandra L.

    2017-01-01

    Widespread antibiotic resistance is on the rise and current therapies are becoming increasingly limited in both scope and efficacy. Methicillin-resistant Staphylococcus aureus (MRSA) represents a major contributor to this trend. Quorum sensing controlled virulence factors include secreted toxins responsible for extensive damage to host tissues and evasion of the immune system response; they are major contributors to morbidity and mortality. Investigation of botanical folk medicines for wounds and infections led us to study Schinus terebinthifolia (Brazilian Peppertree) as a potential source of virulence inhibitors. Here, we report the inhibitory activity of a flavone rich extract “430D-F5” against all S. aureus accessory gene regulator (agr) alleles in the absence of growth inhibition. Evidence for this activity is supported by its agr-quenching activity (IC50 2–32 μg mL−1) in transcriptional reporters, direct protein outputs (α-hemolysin and δ-toxin), and an in vivo skin challenge model. Importantly, 430D-F5 was well tolerated by human keratinocytes in cell culture and mouse skin in vivo; it also demonstrated significant reduction in dermonecrosis following skin challenge with a virulent strain of MRSA. This study provides an explanation for the anti-infective activity of peppertree remedies and yields insight into the potential utility of non-biocide virulence inhibitors in treating skin infections. PMID:28186134

  9. BriX: a database of protein building blocks for structural analysis, modeling and design.

    Science.gov (United States)

    Vanhee, Peter; Verschueren, Erik; Baeten, Lies; Stricher, Francois; Serrano, Luis; Rousseau, Frederic; Schymkowitz, Joost

    2011-01-01

    High-resolution structures of proteins remain the most valuable source for understanding their function in the cell and provide leads for drug design. Since the availability of sufficient protein structures to tackle complex problems such as modeling backbone moves or docking remains a problem, alternative approaches using small, recurrent protein fragments have been employed. Here we present two databases that provide a vast resource for implementing such fragment-based strategies. The BriX database contains fragments from over 7000 non-homologous proteins from the Astral collection, segmented in lengths from 4 to 14 residues and clustered according to structural similarity, summing up to a content of 2 million fragments per length. To overcome the lack of loops classified in BriX, we constructed the Loop BriX database of non-regular structure elements, clustered according to end-to-end distance between the regular residues flanking the loop. Both databases are available online (http://brix.crg.es) and can be accessed through a user-friendly web-interface. For high-throughput queries a web-based API is provided, as well as full database downloads. In addition, two exciting applications are provided as online services: (i) user-submitted structures can be covered on the fly with BriX classes, representing putative structural variation throughout the protein and (ii) gaps or low-confidence regions in these structures can be bridged with matching fragments.

  10. Rapamycin Blocks Fibrocyte Migration and Attenuates Bronchiolitis Obliterans in a Murine Model

    Science.gov (United States)

    Gillen, Jacob R.; Zhao, Yunge; Harris, David A.; LaPar, Damien J.; Stone, Matthew L.; Fernandez, Lucas G.; Kron, Irving L.; Lau, Christine L.

    2014-01-01

    Background Fibrocytes are integral in the development of fibroproliferative disease. The CXCL12/CXCR4 chemokine axis has been shown to play a central role in fibrocyte migration and the development of bronchiolitis obliterans post lung transplantation. Inhibition of the mTOR (mammalian target of rapamycin) pathway with rapamycin has been shown to decrease expression of both CXCR4 and its receptor agonist, CXCL12. Thus, we hypothesize that rapamycin treatment would decrease fibrocyte trafficking into tracheal allografts and prevent bronchiolitis obliterans. Methods A total alloantigenic mismatch, murine heterotopic tracheal transplant model of bronchiolitis obliterans was used. Animals were either treated with rapamycin or dimethyl sulfoxide (DMSO) for 14 days post tracheal transplant. Fibrocyte levels were assessed via flow cytometry, and allograft neutrophil, CD3+ T-cell, macrophage, and smooth muscle actin levels were assessed via immunohistochemistry. Tracheal luminal obliteration was assessed on hematoxylin and eosin stains. Results Compared to DMSO controls, rapamycin-treated mice showed a significant decrease in fibrocyte levels in tracheal allografts. Fibrocytes levels in recipient’s blood showed a similar pattern, although not statistically significant. Furthermore, animals treated with rapamycin showed a significant decrease in tracheal allograft luminal obliteration compared to controls. Based on immunohistochemistry analyses, populations of α-SMA positive cells, neutrophils, CD3+ T-cells, and macrophages were all decreased in rapamycin-treated allograft versus DMSO controls. Conclusions Rapamycin effectively reduces recruitment of fibrocytes into tracheal allografts and mitigates development of tracheal luminal fibrosis. Further studies are needed to determine the cellular and molecular mechanisms that mediate the protective effect of rapamycin against bronchiolitis obliterans. PMID:23561805

  11. Phase equilibrium modeling, fluid inclusions and origin of charnockites in the Datian region of the northeastern Cathaysia Block, South China

    Science.gov (United States)

    Yang, Xiao-Qiang; Li, Zi-Long; Yu, Sheng-Qiang

    2016-08-01

    Charnockites in the Datian region of the northeastern Cathaysia Block, South China have an assemblage of garnet, clinopyroxene, orthopyroxene, plagioclase, anti-perthite, K-feldspar, biotite, quartz and ilmenite. Phase equilibrium modeling indicates that the Datian charnockite was formed at T = 845-855 °C and P = 8.2-8.4 kbar with corresponding water activity lower than 0.50. Fluid inclusions in the Datian charnockite are dominated by N2 and CO2 with minor CH4. The fluids homogenized to liquid at -153.0 to -138.8 °C and 18.3-21.6 °C, respectively, showing a low-density nature. The low-density fluids could be attributed to selective leakage of water due to the affinity of water to melt and decompression-dominated retrograde process. Combined with previous studies, a two-stage formation model is proposed to interpret the petrogenesis of the Datian charnockite, viz emplaced at the Paleoproterozoic and underwent the granulite-facies metamorphism during the Phanerozoic tectonic event.

  12. Experimental Research on the Thermal Performance of Composite PCM Hollow Block Walls and Validation of Phase Transition Heat Transfer Models

    Directory of Open Access Journals (Sweden)

    Yuan Zhang

    2016-01-01

    Full Text Available A type of concrete hollow block with typical structure and a common phase change material (PCM were adopted. The PCM was filled into the hollow blocks by which the multiform composite PCM hollow blocks were made. The temperature-changing hot chamber method was used to test the thermal performance of block walls. The enthalpy method and the effective heat capacity method were used to calculate the heat transfer process. The results of the two methods can both reach the reasonable agreement with the experimental data. The unsteady-state thermal performance of the PCM hollow block walls is markedly higher than that of the wall without PCM. Furthermore, if the temperature of the PCM in the wall does not exceed its phase transition temperature range, the PCM wall can reach high thermal performance.

  13. Rapamycin targeting mTOR and hedgehog signaling pathways blocks human rhabdomyosarcoma growth in xenograft murine model

    Energy Technology Data Exchange (ETDEWEB)

    Kaylani, Samer Z. [Division of Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Avenue South, ACC 414, Birmingham, AL 35233 (United States); Xu, Jianmin; Srivastava, Ritesh K. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, Bethesda (United States); Pressey, Joseph G. [Division of Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Avenue South, ACC 414, Birmingham, AL 35233 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)

    2013-06-14

    Graphical abstract: Intervention of poorly differentiated RMS by rapamycin: In poorly differentiated RMS, rapamycin blocks mTOR and Hh signaling pathways concomitantly. This leads to dampening in cell cycle regulation and induction of apoptosis. This study provides a rationale for the therapeutic intervention of poorly differentiated RMS by treating patients with rapamycin alone or in combination with other chemotherapeutic agents. -- Highlights: •Rapamycin abrogates RMS tumor growth by modulating proliferation and apoptosis. •Co-targeting mTOR/Hh pathways underlie the molecular basis of effectiveness. •Reduction in mTOR/Hh pathways diminish EMT leading to reduced invasiveness. -- Abstract: Rhabdomyosarcomas (RMS) represent the most common childhood soft-tissue sarcoma. Over the past few decades outcomes for low and intermediate risk RMS patients have slowly improved while patients with metastatic or relapsed RMS still face a grim prognosis. New chemotherapeutic agents or combinations of chemotherapies have largely failed to improve the outcome. Based on the identification of novel molecular targets, potential therapeutic approaches in RMS may offer a decreased reliance on conventional chemotherapy. Thus, identification of effective therapeutic agents that specifically target relevant pathways may be particularly beneficial for patients with metastatic and refractory RMS. The PI3K/AKT/mTOR pathway has been found to be a potentially attractive target in RMS therapy. In this study, we provide evidence that rapamycin (sirolimus) abrogates growth of RMS development in a RMS xenograft mouse model. As compared to a vehicle-treated control group, more than 95% inhibition in tumor growth was observed in mice receiving parenteral administration of rapamycin. The residual tumors in rapamycin-treated group showed significant reduction in the expression of biomarkers indicative of proliferation and tumor invasiveness. These tumors also showed enhanced apoptosis

  14. Seamount characteristics and mine-site model applied to exploration- and mining-lease-block selection for cobalt-rich ferromanganese crusts

    Science.gov (United States)

    Hein, James R.; Conrad, Tracey A.; Dunham, Rachel E.

    2009-01-01

    Regulations are being developed through the International Seabed Authority (ISBA) for the exploration and mining of cobalt-rich ferromanganese crusts. This paper lays out geologic and geomorphologic criteria that can be used to determine the size and number of exploration and mine-site blocks that will be the focus of much discussion within the ISBA Council deliberations. The surface areas of 155 volcanic edifices in the central equatorial Pacific were measured and used to develop a mine-site model. The mine-site model considers areas above 2,500 m water depth as permissive, and narrows the general area available for exploration and mining to 20% of that permissive area. It is calculated that about eighteen 100 km2 explora-tion blocks, each composed of five 20km2 contiguous sub-blocks, would be adequate to identify a 260 km2 20-year-mine site; the mine site would be composed of thirteen of the 20km2 sub-blocks. In this hypothetical example, the 260 km2 mine site would be spread over four volcanic edifices and comprise 3.7% of the permissive area of the four edifices and 0.01% of the total area of those four edifices. The eighteen 100km2 exploration blocks would be selected from a limited geographic area. That confinement area is defined as having a long dimension of not more than 1,000 km and an area of not more than 300,000 km2.

  15. Molecular modeling of directed self-assembly of block copolymers: Fundamental studies of processing conditions and evolutionary pattern design

    Science.gov (United States)

    Khaira, Gurdaman Singh

    Rapid progress in the semi-conductor industry has pushed for smaller feature sizes on integrated electronic circuits. Current photo-lithographic techniques for nanofabrication have reached their technical limit and are problematic when printing features small enough to meet future industrial requirements. "Bottom-up'' techniques, such as the directed self-assembly (DSA) of block copolymers (BCP), are the primary contenders to compliment current "top-down'' photo-lithography ones. For industrial requirements, the defect density from DSA needs to be less than 1 defect per 10 cm by 10 cm. Knowledge of both material synthesis and the thermodynamics of the self-assembly process are required before optimal operating conditions can be found to produce results adequate for industry. The work present in this thesis is divided into three chapters, each discussing various aspects of DSA as studied via a molecular model that contains the essential physics of BCP self-assembly. Though there are various types of guiding fields that can be used to direct BCPs over large wafer areas with minimum defects, this study focuses only on chemically patterned substrates. The first chapter addresses optimal pattern design by describing a framework where molecular simulations of various complexities are coupled with an advanced optimization technique to find a pattern that directs a target morphology. It demonstrates the first ever study where BCP self-assembly on a patterned substrate is optimized using a three-dimensional description of the block-copolymers. For problems pertaining to DSA, the methodology is shown to converge much faster than the traditional random search approach. The second chapter discusses the metrology of BCP thin films using TEM tomography and X-ray scattering techniques, such as CDSAXS and GISAXS. X-ray scattering has the advantage of being able to quickly probe the average structure of BCP morphologies over large wafer areas; however, deducing the BCP morphology

  16. 3D Geological Modeling of CoalBed Methane (CBM) Resources in the Taldykuduk Block Karaganda Coal Basin, Kazakhstan

    Science.gov (United States)

    Sadykov, Raman; Kiponievich Ogay, Evgeniy; Royer, Jean-Jacques; Zhapbasbayev, Uzak; Panfilova, Irina

    2015-04-01

    Coal Bed Methane (CBM) is gas stored in coal layers. It can be extracted from wells after hydraulic fracturing and/or solvent injection, and secondary recovery techniques such as CO2 injection. Karaganda Basin is a very favorable candidate region to develop CBM production for the following reasons: (i) Huge gas potential; (ii) Available technologies for extracting and commercializing the gas produced by CBM methods; (iii) Experience in degassing during underground mining operations for safety reasons; (iv) Local needs in energy for producing electricity for the industrial and domestic market. The objectives of this work are to model the Taldykuduk block coal layers and their properties focusing on Coal Bed Methane production. It is motivated by the availability of large coal bed methane resources in Karaganda coal basin which includes 4 300 Bm3 equivalent 2 billion tons of coal (B = billion = 109) with gas content 15-25 m3/t of coal (for comparison San Juan basin (USA) has Methane (CH4) can be considered as an environmentally-friendly fuel compared to coal. Actually, the methane extracted during mining is released in the atmosphere, collecting it for recovering energy will reduce CO2 equivalent emissions by 36 Mt, good news regarding climate warming issues. The exploitation method will be based on a EOR technology consisting in injecting CO2 which replaces methane in pores because it has a higher adsorption capacity than CH4; exploiting CBM by CO2 injection provides thus a safe way to sequestrate CO2 in adsorbed form. The 3D geological model was built on Gocad/Skua using the following available data set: 926 wells and large area (7 x 12 km). No seismic data; coal type and chemical components (S, ash, …); unreliable available cross-section & maps due to old acquisition; quality mature coal; complex heterogeneous fractures network reported on geological cross sections; and utilization issues of the water extracted in the early stages of exploitation. The resulting

  17. Long-term anodal block stimulation at sacral anterior roots promoted recovery of neurogenic bladder function in a rabbit model of complete spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Xiaoran Wang; Yongjie Wang; Jihu Lian; Chaoling Shi; Yao Wang; Li Fan; Qi Gao; Xiaoyu Yang; Weihua Wang; Xinquan Gu; Guifeng Liu; Peng Yan; Ge Gao; Xin Yu

    2012-01-01

    A complete spinal cord injury model was established in experimental rabbits using the spinal cord clip compression method. Urodynamic examination was performed 2 weeks later to determine neurogenic bladder status. The rabbits were treated with anodal block stimulation at sacral anterior roots for 4 weeks. Electrical stimulation of sacral anterior roots improved urodynamic parameters of neurogenic bladder in rabbit models of complete spinal cord injury, effectively promoted urinary function, and relieved urinary retention. Immunohistochemistry results showed that a balance was achieved among expression of muscarinic receptor subunits M2, M3, ATP-gated ion channel P2X3 receptors, and β2-adrenergic receptor, and nerve growth factor expression decreased. These results suggested that long-term sacral anterior root stimulation of anodal block could be used to treat neurogenic bladder in a rabbit model of complete spinal cord injury.

  18. Large Block Test Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W

    2001-12-01

    This report documents the Large-Block Test (LBT) conducted at Fran Ridge near Yucca Mountain, Nevada. The LBT was a thermal test conducted on an exposed block of middle non-lithophysal Topopah Spring tuff (Tptpmn) and was designed to assist in understanding the thermal-hydrological-mechanical-chemical (THMC) processes associated with heating and then cooling a partially saturated fractured rock mass. The LBT was unique in that it was a large (3 x 3 x 4.5 m) block with top and sides exposed. Because the block was exposed at the surface, boundary conditions on five of the six sides of the block were relatively well known and controlled, making this test both easier to model and easier to monitor. This report presents a detailed description of the test as well as analyses of the data and conclusions drawn from the test. The rock block that was tested during the LBT was exposed by excavation and removal of the surrounding rock. The block was characterized and instrumented, and the sides were sealed and insulated to inhibit moisture and heat loss. Temperature on the top of the block was also controlled. The block was heated for 13 months, during which time temperature, moisture distribution, and deformation were monitored. After the test was completed and the block cooled down, a series of boreholes were drilled, and one of the heater holes was over-cored to collect samples for post-test characterization of mineralogy and mechanical properties. Section 2 provides background on the test. Section 3 lists the test objectives and describes the block site, the site configuration, and measurements made during the test. Section 3 also presents a chronology of events associated with the LBT, characterization of the block, and the pre-heat analyses of the test. Section 4 describes the fracture network contained in the block. Section 5 describes the heating/cooling system used to control the temperature in the block and presents the thermal history of the block during the test

  19. RVMAB: Using the Relevance Vector Machine Model Combined with Average Blocks to Predict the Interactions of Proteins from Protein Sequences.

    Science.gov (United States)

    An, Ji-Yong; You, Zhu-Hong; Meng, Fan-Rong; Xu, Shu-Juan; Wang, Yin

    2016-01-01

    Protein-Protein Interactions (PPIs) play essential roles in most cellular processes. Knowledge of PPIs is becoming increasingly more important, which has prompted the development of technologies that are capable of discovering large-scale PPIs. Although many high-throughput biological technologies have been proposed to detect PPIs, there are unavoidable shortcomings, including cost, time intensity, and inherently high false positive and false negative rates. For the sake of these reasons, in silico methods are attracting much attention due to their good performances in predicting PPIs. In this paper, we propose a novel computational method known as RVM-AB that combines the Relevance Vector Machine (RVM) model and Average Blocks (AB) to predict PPIs from protein sequences. The main improvements are the results of representing protein sequences using the AB feature representation on a Position Specific Scoring Matrix (PSSM), reducing the influence of noise using a Principal Component Analysis (PCA), and using a Relevance Vector Machine (RVM) based classifier. We performed five-fold cross-validation experiments on yeast and Helicobacter pylori datasets, and achieved very high accuracies of 92.98% and 95.58% respectively, which is significantly better than previous works. In addition, we also obtained good prediction accuracies of 88.31%, 89.46%, 91.08%, 91.55%, and 94.81% on other five independent datasets C. elegans, M. musculus, H. sapiens, H. pylori, and E. coli for cross-species prediction. To further evaluate the proposed method, we compare it with the state-of-the-art support vector machine (SVM) classifier on the yeast dataset. The experimental results demonstrate that our RVM-AB method is obviously better than the SVM-based method. The promising experimental results show the efficiency and simplicity of the proposed method, which can be an automatic decision support tool. To facilitate extensive studies for future proteomics research, we developed a freely

  20. Establishing an Appropriate Level of Detail (LoD) for a Building Information Model (BIM) - West Block, Parliament Hill, Ottawa, Canada

    Science.gov (United States)

    Fai, S.; Rafeiro, J.

    2014-05-01

    In 2011, Public Works and Government Services Canada (PWGSC) embarked on a comprehensive rehabilitation of the historically significant West Block of Canada's Parliament Hill. With over 17 thousand square meters of floor space, the West Block is one of the largest projects of its kind in the world. As part of the rehabilitation, PWGSC is working with the Carleton Immersive Media Studio (CIMS) to develop a building information model (BIM) that can serve as maintenance and life-cycle management tool once construction is completed. The scale and complexity of the model have presented many challenges. One of these challenges is determining appropriate levels of detail (LoD). While still a matter of debate in the development of international BIM standards, LoD is further complicated in the context of heritage buildings because we must reconcile the LoD of the BIM with that used in the documentation process (terrestrial laser scan and photogrammetric survey data). In this paper, we will discuss our work to date on establishing appropriate LoD within the West Block BIM that will best serve the end use. To facilitate this, we have developed a single parametric model for gothic pointed arches that can be used for over seventy-five unique window types present in the West Block. Using the AEC (CAN) BIM as a reference, we have developed a workflow to test each of these window types at three distinct levels of detail. We have found that the parametric Gothic arch significantly reduces the amount of time necessary to develop scenarios to test appropriate LoD.

  1. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  2. A province-scale block model of Walker Lane and western Basin and Range crustal deformation constrained by GPS observations (Invited)

    Science.gov (United States)

    Hammond, W. C.; Bormann, J.; Blewitt, G.; Kreemer, C.

    2013-12-01

    The Walker Lane in the western Great Basin of the western United States is an 800 km long and 100 km wide zone of active intracontinental transtension that absorbs ~10 mm/yr, about 20% of the Pacific/North America plate boundary relative motion. Lying west of the Sierra Nevada/Great Valley microplate (SNGV) and adjoining the Basin and Range Province to the east, deformation is predominantly shear strain overprinted with a minor component of extension. The Walker Lane responds with faulting, block rotations, structural step-overs, and has distinct and varying partitioned domains of shear and extension. Resolving these complex deformation patterns requires a long term observation strategy with a dense network of GPS stations (spacing ~20 km). The University of Nevada, Reno operates the 373 station Mobile Array of GPS for Nevada transtension (MAGNET) semi-continuous network that supplements coverage by other networks such as EarthScope's Plate Boundary Observatory, which alone has insufficient density to resolve the deformation patterns. Uniform processing of data from these GPS mega-networks provides a synoptic view and new insights into the kinematics and mechanics of Walker Lane tectonics. We present velocities for thousands of stations with time series between 3 to 17 years in duration aligned to our new GPS-based North America fixed reference frame NA12. The velocity field shows a rate budget across the southern Walker Lane of ~10 mm/yr, decreasing northward to ~7 mm/yr at the latitude of the Mohawk Valley and Pyramid Lake. We model the data with a new block model that estimates rotations and slip rates of known active faults between the Mojave Desert and northern Nevada and northeast California. The density of active faults in the region requires including a relatively large number of blocks in the model to accurately estimate deformation patterns. With 49 blocks, our the model captures structural detail not represented in previous province-scale models, and

  3. 无信号路段行人过街决策行为模型%Pedestrian Crossing Decision-Making Model at Unsignalized Mid-Block

    Institute of Scientific and Technical Information of China (English)

    廖明军; 王凯英; 史钰莹; 吴晗; 孟宪强; 姜卉

    2015-01-01

    以吉林市吉林大街2个路段过街行人为对象,以车辆间隙、相邻车道拥挤度为变量,通过视频观测获取行人过街决策行为数据,利用Binary Logit模型建模。结果发现:该模型预测准确率达到89%,可应用于无信号交叉口或者无信号路段行人和车辆交互微观仿真模型中。%The paper takes the two mid-blocks of Jilin Street with pedestrian crossing as examples,chooses time headway and the traffic congestion degree of its neighbor lane as variables. The data of pedestrian crossing decision-making behavior are collected by the video in the field. Binary Logit model is used to model pedestrian crossing decision-making behavior,and the results show that the forecast accuracy of the model reaches 89%. The developed Logit models can provide the basis for representing pedestrian crossing behavior at unsignalized mid-block or unsignalized intersection in a pedestrian-vehicle interaction microsimulation modeling.

  4. Hillslope-derived blocks retard river incision

    Science.gov (United States)

    Shobe, Charles M.; Tucker, Gregory E.; Anderson, Robert S.

    2016-05-01

    The most common detachment-limited river incision models ignore the effects of sediment on fluvial erosion, yet steep reaches of mountain rivers often host clusters of large (>1 m) blocks. We argue that this distribution of blocks is a manifestation of an autogenic negative feedback in which fast vertical river incision steepens adjacent hillslopes, which deliver blocks to the channel. Blocks inhibit incision by shielding the bed and enhancing form drag. We explore this feedback with a 1-D channel-reach model in which block delivery by hillslopes depends on the river incision rate. Results indicate that incision-dependent block delivery can explain the block distribution in Boulder Creek, Colorado. The proposed negative feedback may significantly slow knickpoint retreat, channel adjustment, and landscape response compared to rates predicted by current theory. The influence of hillslope-derived blocks may complicate efforts to extract base level histories from river profiles.

  5. A New Arabia-Africa-Eurasia GPS Velocity Field (1994-2014) and E Mediterranean Block Model: Implications for Continental Deformation in a Zone of Active Plate Interaction

    Science.gov (United States)

    Vernant, P.; Floyd, M.; Ozener, H.; Ergintav, S.; Karakhanian, A.; Kadirov, F. A.; Sokhadze, G.; ArRajehi, A.; Nankali, H. R.; Georgiev, I.; Ganas, A.; Paradissis, D.; McClusky, S.; Gomez, F. G.; Reilinger, R. E.

    2014-12-01

    We present new GPS velocities for the Arabia-Africa-Eurasia region determined with GAMIT/GLOBK (>830 velocities) spanning the period 1994-2014. Here we consider the E Mediterranean region of plate interaction. We use DEFNODE software to develop block models and estimate slip rates on major faults and strain of some blocks. The wrms of residual velocities from our new model is 1.3 mm/yr. We identify small E-W extension within the newly defined Anatolian block confined to a 100-200 km wide zone south of the North Anatolian Fault (NAF) reaching 2-3 mm/yr with rates increasing towards the west. Possible causes we consider include, un-modeled postseismic effects of the 1999 Izmit/Duzce earthquake sequence, continuing post-seismic effects of the 20th Century sequence of M>7 earthquakes, and/or toroidal sub-lithospheric flow towards the subducting Hellenic slab. The overall strain rate of the Marmara Sea block is dominantly N-S extension, and the Van block, N-S compression. Present slip rates along the NAF increase from E to W, 22-24 mm/yr along the E to E-central segment and 27-28 mm/yr along the W segment. We quantify extension in the G. of Corinth, central Greece, and G. of Evia; the W, central and E sections of the Hellenic Trench are shortening with extension in the back-arc. The W Hellenic Trench and W Peloponnese have right-lateral strike-slip and the E Hellenic Trench, left-lateral ss. N-S extension (2-4 mm/yr) in N Greece and the N Aegean Sea extends at least to 42°N. Arabia-Sinai left-lateral motion across the Dead Sea Fault is ~5 mm/yr along the S segment; significant residual velocities along the N and S segments indicate lower slip rates in the N and require fault segmentation to account for slip rate variations along strike. We identify E-W contraction of the Arabian (Persian) Gulf (~3-5 mm/yr) that extends into the E part of the Arabian Plate. We will quantify and present these and other observed deformation patterns and discuss their tectonic implications.

  6. Block Cipher Analysis

    DEFF Research Database (Denmark)

    Miolane, Charlotte Vikkelsø

    Block ciphersarecryptographicprimitivesthatoperateon fixed sizetexts(blocks). Mostdesigns aim towards secure andfastencryption oflarge amounts ofdata. Block ciphers also serve as the building block of a number of hash functions and message authentication codes(MAC).Thetask of cryptanalysisisto en...... on small scale variants of AES. In the final part of the thesis we present a new block cipher proposal Present and examine its security against algebraic and differential cryptanalysis in particular.......Block ciphersarecryptographicprimitivesthatoperateon fixed sizetexts(blocks). Mostdesigns aim towards secure andfastencryption oflarge amounts ofdata. Block ciphers also serve as the building block of a number of hash functions and message authentication codes(MAC).Thetask of cryptanalysisisto...... ensurethat no attack violatesthe securitybounds specifiedbygeneric attack namely exhaustivekey search and table lookup attacks. This thesis contains a general introduction to cryptography with focus on block ciphers and important block cipher designs, in particular the Advanced Encryption Standard...

  7. Modelling of Shaded and Unshaded Shallow-Ground Heat Pump System for a Residential Building Block in a Mediterranean Climate

    Science.gov (United States)

    Bottarelli, M.; Yousif, C.

    2017-01-01

    Heat pumps may be coupled to shallow-ground geothermal fields and used for the purpose of space heating and cooling of buildings. However, quite often it is not possible to locate the geothermal field in cleared grounds, especially in cities where building density is high and land has a high premium. This leads to the possibility of burying the geothermal field under the basement of new building blocks, before construction of the building. In the present work, the shaded-unshaded arrangement is numerically studied by coupling the software DesignBuilder-EnergyPlus to assess the building’s energy requirement with the software FEFLOW to solve the heat transfer equation in porous media. Assuming a standard residential building block, the coupling between the two software is performed by assigning the thermal energy requirement for air conditioning, as calculated by EnergyPlus, to a flat-panel typology of ground heat exchanger simplified in a 2D FEFLOW’s domain. The results show that it is necessary to opt for a dual-source heat pump (air/geothermal) system to ensure that the ground is not frozen or over-heated at peak times and to improve the overall performance of the system.

  8. Mesomorphic structure of poly(styrene)-block-poly(4-vinylpyridine) with oligo(ethylene oxide)sulfonic acid side chains as a model for molecularly reinforced polymer electrolyte

    NARCIS (Netherlands)

    Kosonen, H; Valkama, S; Hartikainen, J; Eerikainen, H; Torkkeli, M; Jokela, K; Serimaa, R; Sundholm, F; ten Brinke, G; Ikkala, O; Eerikäinen, Hannele

    2002-01-01

    We report self-organized polymer electrolytes based on poly(styrene)-block-poly(4-vinylpyridine) (PS-block-P4VP). Liquidlike ethylene oxide (EO) oligomers with sulfonic acid end groups are bonded to the P4VP block, leading to comb-shaped supramolecules with the PS-block-P4VP backbone. Lithium perchl

  9. Molecular modeling of the elastomeric properties of repeating units and building blocks of resilin, a disordered elastic protein.

    Science.gov (United States)

    Khandaker, Md Shahriar K; Dudek, Daniel M; Beers, Eric P; Dillard, David A; Bevan, David R

    2016-08-01

    The mechanisms responsible for the properties of disordered elastomeric proteins are not well known. To better understand the relationship between elastomeric behavior and amino acid sequence, we investigated resilin, a disordered rubber-like protein, found in specialized regions of the cuticle of insects. Resilin of Drosophila melanogaster contains Gly-rich repetitive motifs comprised of the amino acids, PSSSYGAPGGGNGGR, which confer elastic properties to resilin. The repetitive motifs of insect resilin can be divided into smaller partially conserved building blocks: PSS, SYGAP, GGGN and GGR. Using molecular dynamics (MD) simulations, we studied the relative roles of SYGAP, and its less common variants SYSAP and TYGAP, on the elastomeric properties of resilin. Results showed that SYGAP adopts a bent structure that is one-half to one-third the end-to-end length of the other motifs having an equal number of amino acids but containing SYSAP or TYGAP substituted for SYGAP. The bent structure of SYGAP forms due to conformational freedom of glycine, and hydrogen bonding within the motif apparently plays a role in maintaining this conformation. These structural features of SYGAP result in higher extensibility compared to other motifs, which may contribute to elastic properties at the macroscopic level. Overall, the results are consistent with a role for the SYGAP building block in the elastomeric properties of these disordered proteins. What we learned from simulating the repetitive motifs of resilin may be applicable to the biology and mechanics of other elastomeric biomaterials, and may provide us the deeper understanding of their unique properties.

  10. Compression-extension transition of continental crust in a subduction zone: A parametric numerical modeling study with implications on Mesozoic-Cenozoic tectonic evolution of the Cathaysia Block

    Science.gov (United States)

    Chan, Lung Sang; Gao, Jian-Feng

    2017-01-01

    The Cathaysia Block is located in southeastern part of South China, which situates in the west Pacific subduction zone. It is thought to have undergone a compression-extension transition of the continental crust during Mesozoic-Cenozoic during the subduction of Pacific Plate beneath Eurasia-Pacific Plate, resulting in extensive magmatism, extensional basins and reactivation of fault systems. Although some mechanisms such as the trench roll-back have been generally proposed for the compression-extension transition, the timing and progress of the transition under a convergence setting remain ambiguous due to lack of suitable geological records and overprinting by later tectonic events. In this study, a numerical thermo-dynamical program was employed to evaluate how variable slab angles, thermal gradients of the lithospheres and convergence velocities would give rise to the change of crustal stress in a convergent subduction zone. Model results show that higher slab dip angle, lower convergence velocity and higher lithospheric thermal gradient facilitate the subduction process. The modeling results reveal the continental crust stress is dominated by horizontal compression during the early stage of the subduction, which could revert to a horizontal extension in the back-arc region, combing with the roll-back of the subducting slab and development of mantle upwelling. The parameters facilitating the subduction process also favor the compression-extension transition in the upper plate of the subduction zone. Such results corroborate the geology of the Cathaysia Block: the initiation of the extensional regime in the Cathaysia Block occurring was probably triggered by roll-back of the slowly subducting slab. PMID:28182640

  11. Gelatin-agar lumbosacral spine phantom: a simple model for learning the basic skills required to perform real-time sonographically guided central neuraxial blocks.

    Science.gov (United States)

    Li, Jia Wei; Karmakar, Manoj K; Li, Xiang; Kwok, Wing Hong; Ngan Kee, Warwick Dean

    2011-02-01

    This report describes the preparation of a gelatin-agar spine phantom that was used for spinal sonography and to practice the hand-eye coordination skills required to perform sonographically guided central neuraxial blocks. The phantom was prepared by embedding a lumbosacral spine model into a mixture of gelatin and agar in a plastic box. Cellulose powder and chlorhexidine were also added to the mixture, after which it was allowed to solidify. Sonography of the osseous elements of the lumbosacral spine in the phantom was then performed, and their sonographic appearances were compared to those in volunteers. Simulated real-time sonographically guided paramedian spinal needle insertions were also performed in the phantom. The texture and echogenicity of the phantom were subjectively comparable to those of tissue in vivo. The osseous elements of the spine in the phantom were clearly delineated, and their sonographic appearances were comparable to those seen in vivo in the volunteers. During the simulated sonographically guided spinal injections, the needle could be clearly visualized, but the phantom provided little tactile feedback. In conclusion, the gelatin-agar spine phantom is a simple and inexpensive sonographic spine model that has a tissuelike texture and echogenicity. It can be used to study the osseous anatomy of the lumbar spine and practice the skills required to perform sonographically guided central neuraxial blocks.

  12. Facile realization of efficient blocking from ZnO/TiO2 mismatch interface in dye-sensitized solar cells and precise microscopic modeling adapted by circuit analysis

    Science.gov (United States)

    Ameri, Mohsen; Samavat, Feridoun; Mohajerani, Ezeddin; Fathollahi, Mohammad-Reza

    2016-06-01

    In the present research, the effect of \\text{ZnO} -based blocking layers on the operational features of \\text{Ti}{{\\text{O}}2} -based dye-sensitized solar cells is investigated. A facile solution-based coating method is applied to prepare an interfacial highly transparent \\text{ZnO} compact blocking layer (CBL) to enhance the efficiency of dye-sensitized solar cells. Different precursor molar concentration were tested to find the optimum concentration. Optical and electrical measurements were carried out to confirm the operation of the CBLs. Morphological characterizations were performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) to investigate the structure of the compact layers. We have also developed a set of modeling procedures to extract the effective electrical parameters including the parasitic resistances and charged carrier profiles to investigate the effect of CBLs on the dye-sensitized solar cell (DSSC) performance. The adopted modeling approach should establish a versatile framework for diagnosis of DSSCs and facilitates the exploration of critical factors influencing device performance.

  13. Comparison of the PHISICS/RELAP5-3D Ring and Block Model Results for Phase I of the OECD MHTGR-350 Benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard Strydom

    2014-04-01

    The INL PHISICS code system consists of three modules providing improved core simulation capability: INSTANT (performing 3D nodal transport core calculations), MRTAU (depletion and decay heat generation) and a perturbation/mixer module. Coupling of the PHISICS code suite to the thermal hydraulics system code RELAP5-3D has recently been finalized, and as part of the code verification and validation program the exercises defined for Phase I of the OECD/NEA MHTGR 350 MW Benchmark were completed. This paper provides an overview of the MHTGR Benchmark, and presents selected results of the three steady state exercises 1-3 defined for Phase I. For Exercise 1, a stand-alone steady-state neutronics solution for an End of Equilibrium Cycle Modular High Temperature Reactor (MHTGR) was calculated with INSTANT, using the provided geometry, material descriptions, and detailed cross-section libraries. Exercise 2 required the modeling of a stand-alone thermal fluids solution. The RELAP5-3D results of four sub-cases are discussed, consisting of various combinations of coolant bypass flows and material thermophysical properties. Exercise 3 combined the first two exercises in a coupled neutronics and thermal fluids solution, and the coupled code suite PHISICS/RELAP5-3D was used to calculate the results of two sub-cases. The main focus of the paper is a comparison of the traditional RELAP5-3D “ring” model approach vs. a much more detailed model that include kinetics feedback on individual block level and thermal feedbacks on a triangular sub-mesh. The higher fidelity of the block model is illustrated with comparison results on the temperature, power density and flux distributions, and the typical under-predictions produced by the ring model approach are highlighted.

  14. Simulation of mixed models in augmented block design Simulação de modelos mistos no delineamento em blocos aumentado

    Directory of Open Access Journals (Sweden)

    Aladir Horacio Santos

    2002-09-01

    Full Text Available The augmented block design is widely used in breeding programs, with non-replicated treatments generally being selection units, and replicated treatments being standard cultivars. Originally, an intrablock analysis (fixed model was proposed. Although non-replicated treatments and/or blocks can be considered of random nature, mixed linear models could be used instead. This work evaluated such an approach, using computer simulation. Populations consisted of sets of randomly generated inbred lines. Molecular marker data were also simulated to allow the estimation of the genetic covariance matrix. Different conditions were considered, varying heritability and the coefficient b of Smith of soil heterogeneity. For each condition 100 simulations were performed, considering four linear models, varying respectively the nature of the effects of blocks and non-replicated treatments (fixed - F, or random - R: FF, FR, RF and RR. In relation to FF, the mixed models were more efficient under low to intermediate heritability and high b. Mixed models could improve inference in breeding programs using the augmented block design and the choice of the model should rely on the kind of selection. If this is truncated, the RF model should be preferred; if it is not, then the RR model would be more suitable.O delineamento em blocos aumentados é amplamente utilizado em programas de melhoramento, geralmente com tratamentos não-repetidos correspondentes a unidades de seleção, e tratamentos repetidos sendo cultivares comerciais. Originalmente, uma análise intrablocos (modelo fixo foi sugerida. No entanto, se os tratamentos não-repetidos e/ou blocos puderem ser considerados de natureza aleatória, modelos lineares mistos poderiam ser utilizados. Este estudo objetivou a avaliação de tal abordagem, utilizando simulação. Linhagens endogâmicas foram geradas aleatoriamente, bem como dados de marcação molecular, para estimar a matriz de covariâncias gen

  15. An Evaluation of Recently Developed RANS-Based Turbulence Models for Flow Over a Two-Dimensional Block Subjected to Different Mesh Structures and Grid Resolutions

    Science.gov (United States)

    Kardan, Farshid; Cheng, Wai-Chi; Baverel, Olivier; Porté-Agel, Fernando

    2016-04-01

    Understanding, analyzing and predicting meteorological phenomena related to urban planning and built environment are becoming more essential than ever to architectural and urban projects. Recently, various version of RANS models have been established but more validation cases are required to confirm their capability for wind flows. In the present study, the performance of recently developed RANS models, including the RNG k-ɛ , SST BSL k-ω and SST ⪆mma-Reθ , have been evaluated for the flow past a single block (which represent the idealized architecture scale). For validation purposes, the velocity streamlines and the vertical profiles of the mean velocities and variances were compared with published LES and wind tunnel experiment results. Furthermore, other additional CFD simulations were performed to analyze the impact of regular/irregular mesh structures and grid resolutions based on selected turbulence model in order to analyze the grid independency. Three different grid resolutions (coarse, medium and fine) of Nx × Ny × Nz = 320 × 80 × 320, 160 × 40 × 160 and 80 × 20 × 80 for the computational domain and nx × nz = 26 × 32, 13 × 16 and 6 × 8, which correspond to number of grid points on the block edges, were chosen and tested. It can be concluded that among all simulated RANS models, the SST ⪆mma-Reθ model performed best and agreed fairly well to the LES simulation and experimental results. It can also be concluded that the SST ⪆mma-Reθ model provides a very satisfactory results in terms of grid dependency in the fine and medium grid resolutions in both regular and irregular structure meshes. On the other hand, despite a very good performance of the RNG k-ɛ model in the fine resolution and in the regular structure grids, a disappointing performance of this model in the coarse and medium grid resolutions indicates that the RNG k-ɛ model is highly dependent on grid structure and grid resolution. These quantitative validations are essential

  16. Selective nickel-catalyzed conversion of model and lignin-derived phenolic compounds to cyclohexanone-based polymer building blocks.

    Science.gov (United States)

    Schutyser, Wouter; Van den Bosch, Sander; Dijkmans, Jan; Turner, Stuart; Meledina, Maria; Van Tendeloo, Gustaaf; Debecker, Damien P; Sels, Bert F

    2015-05-22

    Valorization of lignin is essential for the economics of future lignocellulosic biorefineries. Lignin is converted into novel polymer building blocks through four steps: catalytic hydroprocessing of softwood to form 4-alkylguaiacols, their conversion into 4-alkylcyclohexanols, followed by dehydrogenation to form cyclohexanones, and Baeyer-Villiger oxidation to give caprolactones. The formation of alkylated cyclohexanols is one of the most difficult steps in the series. A liquid-phase process in the presence of nickel on CeO2 or ZrO2 catalysts is demonstrated herein to give the highest cyclohexanol yields. The catalytic reaction with 4-alkylguaiacols follows two parallel pathways with comparable rates: 1) ring hydrogenation with the formation of the corresponding alkylated 2-methoxycyclohexanol, and 2) demethoxylation to form 4-alkylphenol. Although subsequent phenol to cyclohexanol conversion is fast, the rate is limited for the removal of the methoxy group from 2-methoxycyclohexanol. Overall, this last reaction is the rate-limiting step and requires a sufficient temperature (>250 °C) to overcome the energy barrier. Substrate reactivity (with respect to the type of alkyl chain) and details of the catalyst properties (nickel loading and nickel particle size) on the reaction rates are reported in detail for the Ni/CeO2 catalyst. The best Ni/CeO2 catalyst reaches 4-alkylcyclohexanol yields over 80 %, is even able to convert real softwood-derived guaiacol mixtures and can be reused in subsequent experiments. A proof of principle of the projected cascade conversion of lignocellulose feedstock entirely into caprolactone is demonstrated by using Cu/ZrO2 for the dehydrogenation step to produce the resultant cyclohexanones (≈80 %) and tin-containing beta zeolite to form 4-alkyl-ε-caprolactones in high yields, according to a Baeyer-Villiger-type oxidation with H2 O2 .

  17. A cellular automaton simulation model for pedestrian and vehicle interaction behaviors at unsignalized mid-block crosswalks.

    Science.gov (United States)

    Lu, Lili; Ren, Gang; Wang, Wei; Chan, Ching-Yao; Wang, Jian

    2016-10-01

    At unsignalized crosswalks, interactions between pedestrians and vehicles often lead to traffic safety hazards due to absence of traffic control and unclear right-of-ways. To address this safety problem, there is a need to understand the interaction behaviors of pedestrians and vehicles that are complicated by a variety of traffic and roadway attributes. The prime objective of this study is to establish a reliable simulation model to represent the vehicle yielding and pedestrian crossing behaviors at unsignalized crosswalks in a realistic way. The model is calibrated with detailed behavioral data collected and extracted from field observations. The capability of the calibrated model in predicting the pedestrian-interaction events as well as estimating the driver yielding rate and pedestrian delay are also tested and demonstrated. Meanwhile, the traffic dynamics in the vicinity of the crosswalk can be meaningfully represented with simulation results based on the model. Moreover, with the definitions of the vehicle-pedestrian conflicts, the proposed model is capable to evaluate the pedestrian safety. Thereby, the simulation model has the potential to serve as a useful tool for assessing safety performance and traffic operations at existing facilities. Furthermore, the model can enable the evaluation of policy effectiveness and the selection of engineering treatments at unsignalized crosswalks to improve safety and efficiency of pedestrian crossing.

  18. Inhibition of Pyk2 blocks lung inflammation and injury in a mouse model of acute lung injury

    Directory of Open Access Journals (Sweden)

    Duan Yingli

    2012-01-01

    Full Text Available Abstract Background Proline-rich tyrosine kinase 2 (Pyk2 is essential in neutrophil degranulation and chemotaxis in vitro. However, its effect on the process of lung inflammation and edema formation during LPS induced acute lung injury (ALI remains unknown. The goal of the present study was to determine the effect of inhibiting Pyk2 on LPS-induced acute lung inflammation and injury in vivo. Methods C57BL6 mice were given either 10 mg/kg LPS or saline intratracheally. Inhibition of Pyk2 was effected by intraperitoneal administration TAT-Pyk2-CT 1 h before challenge. Bronchoalveolar lavage analysis of cell counts, lung histology and protein concentration in BAL were analyzed at 18 h after LPS treatment. KC and MIP-2 concentrations in BAL were measured by a mouse cytokine multiplex kit. The static lung compliance was determined by pressure-volume curve using a computer-controlled small animal ventilator. The extravasated Evans blue concentration in lung homogenate was determined spectrophotometrically. Results Intratracheal instillation of LPS induced significant neutrophil infiltration into the lung interstitium and alveolar space, which was attenuated by pre-treatment with TAT-Pyk2-CT. TAT-Pyk2-CT pretreatment also attenuated 1 myeloperoxidase content in lung tissues, 2 vascular leakage as measured by Evans blue dye extravasation in the lungs and the increase in protein concentration in bronchoalveolar lavage, and 3 the decrease in lung compliance. In each paradigm, treatment with control protein TAT-GFP had no blocking effect. By contrast, production of neutrophil chemokines MIP-2 and keratinocyte-derived chemokine in the bronchoalveolar lavage was not reduced by TAT-Pyk2-CT. Western blot analysis confirmed that tyrosine phosphorylation of Pyk2 in LPS-challenged lungs was reduced to control levels by TAT-Pyk2-CT pretreatment. Conclusions These results suggest that Pyk2 plays an important role in the development of acute lung injury in mice and

  19. Total Spinal Block after Thoracic Paravertebral Block.

    Science.gov (United States)

    Beyaz, Serbülent Gökhan; Özocak, Hande; Ergönenç, Tolga; Erdem, Ali Fuat; Palabıyık, Onur

    2014-02-01

    Thoracic paravertebral block (TPVB) can be performed with or without general anaesthesia for various surgical procedures. TPVB is a popular anaesthetic technique due to its low side effect profile and high analgesic potency. We used 20 mL of 0.5% levobupivacaine for a single injection of unilateral TPVB at the T7 level with neurostimulator in a 63 year old patient with co-morbid disease who underwent cholecystectomy. Following the application patient lost consciousness, and was intubated. Haemodynamic instability was normalised with rapid volume replacement and vasopressors. Anaesthetic drugs were stopped at the end of the surgery and muscle relaxant was antagonised. Return of mucle strenght was shown with neuromuscular block monitoring. Approximately three hours after TPVB, spontaneous breathing started and consciousness returned. A total spinal block is a rare and life-threatening complication. A total spinal block is a complication of spinal anaesthesia, and it can also occur after peripheral blocks. Clinical presentation is characterised by hypotension, bradicardia, apnea, and cardiac arrest. An early diagnosis and appropriate treatment is life saving. In this case report, we want to present total spinal block after TPVB.

  20. Acoustic modelling by using block and polynomial trigonometric parametrization; Modelagem acustica usando parametrizacoes em bloco e polinomial trigonometrica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Roberto Hugo Melo dos; Figueiro, Wilson Mouzer [Bahia Univ., Salvador, BA (Brazil). Inst. de Geociencias]. E-mail: rms@cpgg.ufba.br; fgueiro@cpgg.ufba.br

    2003-07-01

    The developed algorithm in this work was based on the finite difference method applied to the wave equation, assuming that the Earth has an acoustic behavior. The seismic modeling was implemented numerically by means of the finite differences method (MDF), employing regular nets, and applied to the derivatives of time and fourth order to derivatives of the space. Two-dimensional geological models was represented by two distinct kind of parametrizations: in blocs (P B) and using trigonometric polynomials (PPT). With the objective of jumping the advantages of using the PPT front P B, mainly in what it tells respect the economy of space of memory in program of finite difference and simplification of the equation in the inversion strategies, simulations of the propagation of waves ware presented in several models acted by different parametrizations (P B and PPT) using applied MDF the equation of the wave and generating synthetic seismograms that they are compared amongst themselves. As a result of this work we can detach the great economy of space of memory in the use of PPT, in whole PPT the model is defined for the coefficients of the polynomial that start to be the parameters of the model, and PPT simplifies the representation of more complicated models. (author)

  1. Generalized Block Failure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2015-01-01

    Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... yield lines around the block leads to simple interaction formulas similar to other interaction formulas in the codes.......Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...

  2. Ultrasound-guided direct delivery of 3-bromopyruvate blocks tumor progression in an orthotopic mouse model of human pancreatic cancer.

    Science.gov (United States)

    Ota, Shinichi; Geschwind, Jean-Francois H; Buijs, Manon; Wijlemans, Joost W; Kwak, Byung Kook; Ganapathy-Kanniappan, Shanmugasundaram

    2013-06-01

    Studies in animal models of cancer have demonstrated that targeting tumor metabolism can be an effective anticancer strategy. Previously, we showed that inhibition of glucose metabolism by the pyruvate analog, 3-bromopyruvate (3-BrPA), induces anticancer effects both in vitro and in vivo. We have also documented that intratumoral delivery of 3-BrPA affects tumor growth in a subcutaneous tumor model of human liver cancer. However, the efficacy of such an approach in a clinically relevant orthotopic tumor model has not been reported. Here, we investigated the feasibility of ultrasound (US) image-guided delivery of 3-BrPA in an orthotopic mouse model of human pancreatic cancer and evaluated its therapeutic efficacy. In vitro, treatment of Panc-1 cells with 3-BrPA resulted in a dose-dependent decrease in cell viability. The loss of viability correlated with a dose-dependent decrease in the intracellular ATP level and lactate production confirming that disruption of energy metabolism underlies these 3-BrPA-mediated effects. In vivo, US-guided delivery of 3-BrPA was feasible and effective as demonstrated by a marked decrease in tumor size on imaging. Further, the antitumor effect was confirmed by (1) a decrease in the proliferative potential by Ki-67 immunohistochemical staining and (2) the induction of apoptosis by terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphospate nick end labeling staining. We therefore demonstrate the technical feasibility of US-guided intratumoral injection of 3-BrPA in a mouse model of human pancreatic cancer as well as its therapeutic efficacy. Our data suggest that this new therapeutic approach consisting of a direct intratumoral injection of antiglycolytic agents may represent an exciting opportunity to treat patients with pancreas cancer.

  3. Spintronics: Conceptual Building Blocks

    Science.gov (United States)

    Ansermet, J.-Ph.

    The purpose of this introduction to spintronics is to provide some elementary description of its conceptual building blocks. Thus, it is intended for a newcomer to the field. After recalling rudimentary descriptions of spin precession and spin relaxation, spin-dependent transport is treated within the Boltzmann formalism. This suffices to introduce key notions such as the spin asymmetry of the conductivities in the two-current model, the spin diffusion length, and spin accumulation. Two basic mechanisms of spin relaxation are then presented, one arising from spin-orbit scattering and the other from electron-magnon collisions. Finally, the action of a spin-polarized current on magnetization is presented in a thermodynamics framework. This introduces the notion of spin torque and the characteristic length scale over which the transverse spin polarization of conduction electron decays as it is injected into a magnet.

  4. Combining cluster analysis, feature selection and multiple support vector machine models for the identification of human ether-a-go-go related gene channel blocking compounds.

    Science.gov (United States)

    Nisius, Britta; Göller, Andreas H; Bajorath, Jürgen

    2009-01-01

    Blockade of the human ether-a-go-go related gene potassium channel is regarded as a major cause of drug toxicity and associated with severe cardiac side-effects. A variety of in silico models have been reported to aid in the identification of compounds blocking the human ether-a-go-go related gene channel. Herein, we present a classification approach for the detection of diverse human ether-a-go-go related gene blockers that combines cluster analysis of training data, feature selection and support vector machine learning. Compound learning sets are first divided into clusters of similar molecules. For each cluster, independent support vector machine models are generated utilizing preselected MACCS structural keys as descriptors. These models are combined to predict human ether-a-go-go related gene inhibition of our large compound data set with consistent experimental measurements (i.e. only patch clamp measurements on mammalian cell lines). Our combined support vector machine model achieves a prediction accuracy of 85% on this data set and performs better than alternative methods used for comparison. We also find that structural keys selected on the basis of statistical criteria are associated with molecular substructures implicated in human ether-a-go-go related gene channel binding.

  5. 地震资料在车古201块储层建模中的应用%Application of Seismic Data to Reservoir Modeling of the Chegu 201 Block

    Institute of Scientific and Technical Information of China (English)

    蔡毅; 张祥忠; 张新赏

    2005-01-01

    Great uncertainty exists in reservoir models built for blocks where well spacing is uneven or large. The uncertainty in reservoir models can be significantly reduced by using Coordinate Cokriging Sequential Gaussian Simulation technology, in combination with the restriction of seismic characteristic data. Satisfactory reservoir parameter interpolation results, which are more accurate than those derived only from borehole data, are obtained, giving rise to a reasonable combination of widespread and dense-sampled seismic (soft data) data with borehole data (hard data). A significant effect has been made in reservoir parameter modeling in the Chegu 201 block of the Futai Oilfield by using this technology.

  6. Nuclear geyser model of the origin of life: Driving force to promote the synthesis of building blocks of life

    Directory of Open Access Journals (Sweden)

    Toshikazu Ebisuzaki

    2017-03-01

    Full Text Available We propose the nuclear geyser model to elucidate an optimal site to bear the first life. Our model overcomes the difficulties that previously proposed models have encountered. Nuclear geyser is a geyser driven by a natural nuclear reactor, which was likely common in the Hadean Earth, because of a much higher abundance of 235U as nuclear fuel. The nuclear geyser supplies the following: (1 high-density ionizing radiation to promote chemical chain reactions that even tar can be used for intermediate material to restart chemical reactions, (2 a system to maintain the circulation of material and energy, which includes cyclic environmental conditions (warm/cool, dry/wet, etc. to enable to produce complex organic compounds, (3 a lower temperature than 100 °C as not to break down macromolecular organic compounds, (4 a locally reductive environment depending on rock types exposed along the geyser wall, and (5 a container to confine and accumulate volatile chemicals. These five factors are the necessary conditions that the birth place of life must satisfy. Only the nuclear geyser can meet all five, in contrast to the previously proposed birth sites, such as tidal flat, submarine hydrothermal vent, and outer space. The nuclear reactor and associated geyser, which maintain the circulations of material and energy with its surrounding environment, are regarded as the nuclear geyser system that enables numerous kinds of chemical reactions to synthesize complex organic compounds, and where the most primitive metabolism could be generated.

  7. BLOCK H-MATRICES AND SPECTRUM OF BLOCK MATRICES

    Institute of Scientific and Technical Information of China (English)

    黄廷祝; 黎稳

    2002-01-01

    The block H-matrices are studied by the concept of G-functions, several concepts of block matrices are introduced. Equivalent characters of block H-matrices are obtained. Spectrum localizations claracterized by Gfunctions for block matrices are got.

  8. Block TERM factorization of block matrices

    Institute of Scientific and Technical Information of China (English)

    SHE Yiyuan; HAO Pengwei

    2004-01-01

    Reversible integer mapping (or integer transform) is a useful way to realize Iossless coding, and this technique has been used for multi-component image compression in the new international image compression standard JPEG 2000. For any nonsingular linear transform of finite dimension, its integer transform can be implemented by factorizing the transform matrix into 3 triangular elementary reversible matrices (TERMs) or a series of single-row elementary reversible matrices (SERMs). To speed up and parallelize integer transforms, we study block TERM and SERM factorizations in this paper. First, to guarantee flexible scaling manners, the classical determinant (det) is generalized to a matrix function, DET, which is shown to have many important properties analogous to those of det. Then based on DET, a generic block TERM factorization,BLUS, is presented for any nonsingular block matrix. Our conclusions can cover the early optimal point factorizations and provide an efficient way to implement integer transforms for large matrices.

  9. Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes

    Science.gov (United States)

    Mehl, S.; Hill, M.C.

    2002-01-01

    A new method of local grid refinement for two-dimensional block-centered finite-difference meshes is presented in the context of steady-state groundwater-flow modeling. The method uses an iteration-based feedback with shared nodes to couple two separate grids. The new method is evaluated by comparison with results using a uniform fine mesh, a variably spaced mesh, and a traditional method of local grid refinement without a feedback. Results indicate: (1) The new method exhibits quadratic convergence for homogeneous systems and convergence equivalent to uniform-grid refinement for heterogeneous systems. (2) Coupling the coarse grid with the refined grid in a numerically rigorous way allowed for improvement in the coarse-grid results. (3) For heterogeneous systems, commonly used linear interpolation of heads from the large model onto the boundary of the refined model produced heads that are inconsistent with the physics of the flow field. (4) The traditional method works well in situations where the better resolution of the locally refined grid has little influence on the overall flow-system dynamics, but if this is not true, lack of a feedback mechanism produced errors in head up to 3.6% and errors in cell-to-cell flows up to 25%. ?? 2002 Elsevier Science Ltd. All rights reserved.

  10. Lesson Thirteen Trifascicular Block

    Institute of Scientific and Technical Information of China (English)

    鲁端; 王劲

    2005-01-01

    @@ A complete trifascicular block would result in complete AV block. The idio ventricular rhythm has a slower rate and a wide QRS complex because the pacemaker is located at the peripheral part of the conduction system distal to the sites of the block1. Such a rhythm may be difficult to differentiate from bifascicular or bundle branch block combined with complete block at a higher level such as the AV node or His bundle2. Besides a slower ventricular rate, a change in the morphology of the QRS complex from a previous known bifascicular pattern would be strongly suggestive of a trifascicular origin of the complete AV block3. A His bundle recording is required for a definitive diagnosis, however.

  11. Nonmonotonic Relaxation as a Result of Spatial Heterogeneity in the Model of In-series Blocks Chain

    CERN Document Server

    Bedulina, A A

    2013-01-01

    Recently the materials possessing structure of molecular and supramolecular matrix are more and more actively studied. They are relative to many polymeric materials of a technological origin, such as rubber, and living biological tissues. Processes of mechanical deformation of such continuous media have peculiarities connected, first, with accounting for internal friction and dissipation of energy, and secondly, with nonlinearity of their elastic and viscous properties, that is with violation of Hook and Newtons laws. Problem of modeling of these systems reduce to the analysis of the corresponding equivalent mechanical or electric circuit (see examples in the classical monograph by Frenkel). Rheological properties of described medium are governed by the differential equations of the first order on time (the evolution equations), as well as a huge variety of other physical processes. The physical phenomena in nonlinear systems with dissipation have a big community, including such it would seem far areas, as dy...

  12. Prevention of Defective Placentation and Pregnancy Loss by Blocking Innate Immune Pathways in a Syngeneic Model of Placental Insufficiency.

    Science.gov (United States)

    Gelber, Shari E; Brent, Elyssa; Redecha, Patricia; Perino, Giorgio; Tomlinson, Stephen; Davisson, Robin L; Salmon, Jane E

    2015-08-01

    Defective placentation and subsequent placental insufficiency lead to maternal and fetal adverse pregnancy outcome, but their pathologic mechanisms are unclear, and treatment remains elusive. The mildly hypertensive BPH/5 mouse recapitulates many features of human adverse pregnancy outcome, with pregnancies characterized by fetal loss, growth restriction, abnormal placental development, and defects in maternal decidual arteries. Using this model, we show that recruitment of neutrophils triggered by complement activation at the maternal/fetal interface leads to elevation in local TNF-α levels, reduction of the essential angiogenic factor vascular endothelial growth factor, and, ultimately, abnormal placentation and fetal death. Blockade of complement with inhibitors specifically targeted to sites of complement activation, depletion of neutrophils, or blockade of TNF-α improves spiral artery remodeling and rescues pregnancies. These data underscore the importance of innate immune system activation in the pathogenesis of placental insufficiency and identify novel methods for treatment of pregnancy loss mediated by abnormal placentation.

  13. Thrusting between exhumed mantle blocks at the Gorringe Bank (SW Iberian margin): Evidence from combined seismic and gravity modeling

    Science.gov (United States)

    Sallarès, V.; Martinez-Loriente, S.; Prada, M.; Gailler, A.; Gutscher, M.-A.; Bartolome, R.; Gracia, E.

    2012-04-01

    The Gorringe Bank is a massive seamount located offshore the SW Iberian margin that displays one of the largest gravity anomalies on Earth's oceans. To determine its deep seismic structure, a wide-angle seismic transect with OBS/H crossing it from the Tagus to Horseshoe Abyssal plains, was acquired in 2008. The corresponding velocity model, obtained by joint refraction and reflection travel-time inversion, displays a variably-thick sedimentary layer on top of a basement showing a strong vertical velocity gradient and no evidence for a crust-mantle boundary, not only in the Gorringe Bank but also in the adjacent segments of the deep oceanic basins. The seismic structure closely resembles that of exhumed mantle sections described along the Western Iberian margin and largely differs from that of either oceanic or extended continental crust. A velocity-derived density model assuming that the basement is made of serpentinized peridotite matches well the observed gravity anomaly, showing a basement with a variable degree of serpentinization, decreasing from ~90 % at the seafloor to ~20 % at 10 km deep. Our preferred interpretation is that the Gorringe Bank was initially the central segment of an exhumed mantle band that included also the present-day Eastern Tagus and Western Horseshoe basins. This band, which constitutes the southernmost and oldest section of the Western Iberia oceanic domain, was probably exhumed in the Earliest Cretaceous, during the onset of the North Atlantic opening. During the WNW-ESE Neogene compression, the westernmost Horseshoe basin was thrust on top of the easternmost Tagus basin, uplifting the Gorringe Bank.

  14. The selective GABAB antagonist CGP-35348 blocks spike-wave bursts in the cholesterol synthesis rat absence epilepsy model.

    Science.gov (United States)

    Smith, K A; Fisher, R S

    1996-08-12

    Slow IPSPs, which are believed to be involved in generation of the wave of spike-wave epileptiform discharges, are mediated by the GABAB receptor. We therefore examined the effect of the GABAB antagonist, Ciba Geigy Product, CGP-35348, in the cholesterol synthesis inhibitor model of absence epilepsy in rat. Rats received Ayerst-9944 (AY-9944), from 6-45 mg i.p. in the first few weeks of life. By 2 months after AY-9944 administration these rats exhibited recurrent spike-waves and behavioral arrests. In 10 such animals CGP-35348 was administered intraperitoneally in doses of 0 (vehicle), 10, 25 or 100 mg/kg. EEG recordings were obtained via previously implanted bone screws. Technologists blinded to treatment group counted spike-waves over a 4 h period post-injection. The average number of spike-wave burst seconds per 4 h of recording for all dosages and times was 52.4 +/- 81.4 (mean +/- S.D.) s. Mean burst times (seconds) were vehicle = 93.5 +/- 106.5; 10 mg/kg = 69.9 +/- 79.7; 25 mg/kg = 30.8 +/- 46.9; 100 mg/kg = 15.2 +/- 54, a mean 84% reduction at 100 mg/kg (ANOVA regression significant at 0.0001). Spike-waves were suppressed for at least 4 h after injection of CGP-35348. These findings supplement similar findings in other absence models, and support a potential role for GABAB antagonists in treatment of absence seizures.

  15. Modeling the impact on virus transmission of Wolbachia-mediated blocking of dengue virus infection of Aedes aegypti.

    Science.gov (United States)

    Ferguson, Neil M; Kien, Duong Thi Hue; Clapham, Hannah; Aguas, Ricardo; Trung, Vu Tuan; Chau, Tran Nguyen Bich; Popovici, Jean; Ryan, Peter A; O'Neill, Scott L; McGraw, Elizabeth A; Long, Vo Thi; Dui, Le Thi; Nguyen, Hoa L; Chau, Nguyen Van Vinh; Wills, Bridget; Simmons, Cameron P

    2015-03-18

    Dengue is the most common arboviral infection of humans and is a public health burden in more than 100 countries. Aedes aegypti mosquitoes stably infected with strains of the intracellular bacterium Wolbachia are resistant to dengue virus (DENV) infection and are being tested in field trials. To mimic field conditions, we experimentally assessed the vector competence of A. aegypti carrying the Wolbachia strains wMel and wMelPop after challenge with viremic blood from dengue patients. We found that wMelPop conferred strong resistance to DENV infection of mosquito abdomen tissue and largely prevented disseminated infection. wMel conferred less resistance to infection of mosquito abdomen tissue, but it did reduce the prevalence of mosquitoes with infectious saliva. A mathematical model of DENV transmission incorporating the dynamics of viral infection in humans and mosquitoes was fitted to the data collected. Model predictions suggested that wMel would reduce the basic reproduction number, R0, of DENV transmission by 66 to 75%. Our results suggest that establishment of wMelPop-infected A. aegypti at a high frequency in a dengue-endemic setting would result in the complete abatement of DENV transmission. Establishment of wMel-infected A. aegypti is also predicted to have a substantial effect on transmission that would be sufficient to eliminate dengue in low or moderate transmission settings but may be insufficient to achieve complete control in settings where R0 is high. These findings develop a framework for selecting Wolbachia strains for field releases and for calculating their likely impact.

  16. Embryonic tongue morphogenesis in an organ culture model of mouse mandibular arches: blocking Sonic hedgehog signaling leads to microglossia.

    Science.gov (United States)

    Torii, Daisuke; Soeno, Yuuichi; Fujita, Kazuya; Sato, Kaori; Aoba, Takaaki; Taya, Yuji

    2016-01-01

    Mouse tongue development is initiated with the formation of lateral lingual swellings just before fusion between the mediodorsal surfaces of the mandibular arches at around embryonic day 11.0. Here, we investigated the role of Sonic hedgehog (Shh) signaling in embryonic mouse tongue morphogenesis. For this, we used an organ culture model of the mandibular arches from mouse embryos at embryonic day 10.5. When the Shh signaling inhibitor jervine was added to the culture medium for 24-96 h, the formation of lateral lingual swellings and subsequent epithelial invagination into the mesenchyme were impaired markedly, leading to a hypoplastic tongue with an incomplete oral sulcus. Notably, jervine treatment reduced the proliferation of non-myogenic mesenchymal cells at the onset of forming the lateral lingual swellings, whereas it did not affect the proliferation and differentiation of a myogenic cell lineage, which created a cell community at the central circumferential region of the lateral lingual swellings as seen in vivo and in control cultures lacking the inhibitor. Thus, epithelium-derived Shh signaling stimulates the proliferation of non-myogenic mesenchymal cells essential for forming lateral lingual swellings and contributes to epithelial invagination into the mesenchyme during early tongue development.

  17. Effects of JAM-A deficiency or blocking antibodies on neutrophil migration and lung injury in a murine model of ALI.

    Science.gov (United States)

    Lakshmi, Sowmya P; Reddy, Aravind T; Naik, Meghna U; Naik, Ulhas P; Reddy, Raju C

    2012-11-01

    Transmigration of neutrophils (PMNs) from the vasculature into inflamed tissues, mediated by interactions between PMNs and adhesion molecules on endothelial cells, is an essential aspect of inflammation. The crucial adhesion molecules include junctional adhesion molecule (JAM)-A. Investigation of the role of this molecule in models of inflammatory disease has been limited, however, and results in different disease models have varied. No previous study has addressed JAM-A in lung disease or effects on oxidant stress and proinflammatory cytokines. We use JAM-A knockout mice and blocking antibodies to investigate the role of JAM-A in a murine model of acute lung injury (ALI). With either experimental system, we find that absence of JAM-A activity significantly reduces migration of PMNs into the alveolar space, with a resulting decrease in oxidative stress. However, there is no reduction in whole lung activity of PMN-associated myeloperoxidase, presumably reflecting the histologically observed retention of PMNs in lung tissue. Activity of these retained PMNs may account for our failure to find significant change in markers of lung oxidative stress or cytokine and chemokine levels in plasma, lung, and bronchoalveolar lavage fluid. We likewise see no JAM-A-related changes in markers of capillary permeability or lung injury. A similar lack of congruence between effects on PMN migration and tissue injury has been reported in other disease models and for other adhesion molecules in models of ALI. Our results thus confirm the crucial role of JAM-A in PMN transmigration but demonstrate that transmigration is not essential for other aspects of inflammation or for lung injury in ALI.

  18. 呼叫中心分块回归话务量预测%Block regression traffic prediction model for call center

    Institute of Scientific and Technical Information of China (English)

    张沪寅; 胡瑞芸; 何政

    2016-01-01

    为获得前瞻性话务量数据,解决呼叫中心坐席安排的问题,实现人力资源合理配置,分析历史话务量特性,提出了基于支持向量机和K 近邻算法的分块回归(SKBR)话务量预测模型。将话务量按日期类型分为工作日话务量、周末话务量以及节假日话务量,采用不同的模型预测相应的话务量。以某省电力呼叫中心话务量为例,在Matlab平台上进行实验。结果证明,相比SVM模型和改进寻参方法的SVM模型,SKBR模型在预测准确性上有所提升。%In order to obtain the prospective traffic data, solve the seats arrangement problem of call center, realize the rational allocation of human resources, block regression traffic prediction model, based on support vector machine and K-nearest neighbor algorithm is proposed(SKBR), after analyzing the characteristics of historical traffic data. According to the date type, traffic can be divided into weekday traffic, weekend traffic and holiday traffic, and different model is used to predict the corresponding traffic. Taking the traffic of a province electric power call center for example, experiments are carried on the MATLAB platform. Results show that compared with the SVM model and improved SVM model for its method of searching parameters, SKBR model has improved the prediction accuracy.

  19. Smoothing of geoelectrical resistivity profiles in order to build a 3D model: A case study from an outcropping limestone block

    Science.gov (United States)

    Tóth, Krisztina; Kovács, Gábor

    2014-05-01

    Geoelectrical imaging is one of the most common survey methods in the field of shallow geophysics. In order to get information from the subsurface electric current is induced into the ground. In our summer camp organized by the Department of Geophysics and Space Sciences, Eötvös Loránd University we have carried out resistivity surveys to get more accurate information about the lithology of the Dorog basin located in the Transdanubian range, Middle Hungary. This study focused on the outcropping limestone block located next to the village Leányvár in the Dorog basin. The main aim of the research is the impoundment of the subsurface continuation of the limestone outcrop. Cable problems occurred during field survey therefore the dataset obtained by the measurement have become very noisy thus we had to gain smoothed data with the appropriate editing steps. The goal was to produce an optimized model to demonstrate the reality beneath the subsurface. In order to achieve better results from the noisy dataset we changed some parameters based on the description of the program. Whereas cable problems occurred we exterminated the bad datum points visually and statistically as well. Because of the noisiness we increased the value of the so called damping factor which is a variable parameter in the equation used by the inversion routine responsible for smoothing the data. The limitation of the range of model resistivity values based on our knowledge about geological environment was also necessary in order to avoid physically unrealistic results. The purpose of the modification was to obtain smoothed and more interpretable geoelectric profiles. The geological background combined with the explanation of the profiles gave us the approximate location of the block. In the final step of the research we created a 3D model with proper location and smoothed resistivity data included. This study was supported by the Hungarian Scientific Research Fund (OTKA NK83400) and was realized

  20. PEO-related block copolymer surfactants

    DEFF Research Database (Denmark)

    Mortensen, K.

    2001-01-01

    Non-ionic block copolymer systems based on hydrophilic poly(ethylene oxide) and more hydrophobic co-polymer blocks are used intensively in a variety of industrial and personal applications. A brief description on the applications is presented. The physical properties of more simple model systems ...

  1. A novel generalized DCT-based JND profile based on an elaborate CM-JND model for variable block-sized transforms in monochrome images.

    Science.gov (United States)

    Bae, Sung-Ho; Kim, Munchurl

    2014-08-01

    In this paper, we propose a new DCT-based just noticeable difference (JND) profile incorporating the spatial contrast sensitivity function, the luminance adaptation effect, and the contrast masking (CM) effect. The proposed JND profile overcomes two limitations of conventional JND profiles: 1) the CM JND models in the conventional JND profiles employed simple texture complexity metrics, which are not often highly correlated with perceived complexity, especially for unstructured patterns. So, we proposed a new texture complexity metric that considers not only contrast intensity, but also structureness of image patterns, called the structural contrast index. We also newly found out that, as the structural contrast index of a background texture pattern increases, the modulation factors for CM-JND show a bandpass property in frequency. Based on this observation, a new CM-JND is modeled as a function of DCT frequency and the proposed structural contrast index, showing significantly high correlations with measured CM-JND values and 2) while the conventional DCT-based JND profiles are only applicable for specific transform block sizes, our proposed DCT-based JND profile is first designed to be applicable to any size of transform by deriving a new summation effect function, which can also be appropriately applied for quad-tree transform of high efficiency video coding. For the overall performance, the proposed DCT-based JND profile shows more tolerance for distortions with better perceptual quality than other JND profiles under comparison.

  2. Partial BACE1 reduction in a Down syndrome mouse model blocks Alzheimer-related endosomal anomalies and cholinergic neurodegeneration: role of APP-CTF.

    Science.gov (United States)

    Jiang, Ying; Rigoglioso, Andrew; Peterhoff, Corrinne M; Pawlik, Monika; Sato, Yutaka; Bleiwas, Cynthia; Stavrides, Philip; Smiley, John F; Ginsberg, Stephen D; Mathews, Paul M; Levy, Efrat; Nixon, Ralph A

    2016-03-01

    β-amyloid precursor protein (APP) and amyloid beta peptide (Aβ) are strongly implicated in Alzheimer's disease (AD) pathogenesis, although recent evidence has linked APP-βCTF generated by BACE1 (β-APP cleaving enzyme 1) to the development of endocytic abnormalities and cholinergic neurodegeneration in early AD. We show that partial BACE1 genetic reduction prevents these AD-related pathological features in the Ts2 mouse model of Down syndrome. Partially reducing BACE1 by deleting one BACE1 allele blocked development of age-related endosome enlargement in the medial septal nucleus, cerebral cortex, and hippocampus and loss of choline acetyltransferase (ChAT)-positive medial septal nucleus neurons. BACE1 reduction normalized APP-βCTF elevation but did not alter Aβ40 and Aβ42 peptide levels in brain, supporting a critical role in vivo for APP-βCTF in the development of these abnormalities. Although ameliorative effects of BACE1 inhibition on β-amyloidosis and synaptic proteins levels have been previously noted in AD mouse models, our results highlight the additional potential value of BACE1 modulation in therapeutic targeting of endocytic dysfunction and cholinergic neurodegeneration in Down syndrome and AD.

  3. Discussion on the paper "Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearest block bootstrap approach"

    Institute of Scientific and Technical Information of China (English)

    HALL Peter

    2009-01-01

    @@ This is a very attractive article. It combines fascinating new methodology with a most interesting dataset, and a highly motivating presentation. However, despite the many opportunities for discussion, I am going to confine attention to the issue of the block bootstrap, ingeniously developed in this paper into the nearest block bootstrap.

  4. Block ground interaction of rockfalls

    Science.gov (United States)

    Volkwein, Axel; Gerber, Werner; Kummer, Peter

    2016-04-01

    During a rockfall the interaction of the falling block with the ground is one of the most important factors that define the evolution of a rockfall trajectory. It steers the rebound, the rotational movement, possibly brake effects, friction losses and damping effects. Therefore, if most reliable rockfall /trajectory simulation software is sought a good understanding of the block ground interaction is necessary. Today's rockfall codes enable the simulation of a fully 3D modelled block within a full 3D surface . However, the details during the contact, i.e. the contact duration, the penetration depth or the dimension of the marks in the ground are usually not part of the simulation. Recent field tests with rocks between 20 and 80 kg have been conducted on a grassy slope in 2014 [1]. A special rockfall sensor [2] within the blocks measured the rotational velocity and the acting accelerations during the tests. External video records and a so-called LocalPositioningSystem deliver information on the travel velocity. With these data not only the flight phases of the trajectories but also the contacts with the ground can be analysed. During the single jumps of a block the flight time, jump length, the velocity, and the rotation are known. During the single impacts their duration and the acting accelerations are visible. Further, the changes of rotational and translational velocity influence the next jump of the block. The change of the rotational velocity over the whole trajectory nicely visualizes the different phases of a rockfall regarding general acceleration and deceleration in respect to the inclination and the topography of the field. References: [1] Volkwein A, Krummenacher B, Gerber W, Lardon J, Gees F, Brügger L, Ott T (2015) Repeated controlled rockfall trajectory testing. [Abstract] Geophys. Res. Abstr. 17: EGU2015-9779. [2] Volkwein A, Klette J (2014) Semi-Automatic Determination of Rockfall Trajectories. Sensors 14: 18187-18210.

  5. Blocked Urethral Valves

    Science.gov (United States)

    ... Blocked Urethral Valves Health Issues Listen Español Text Size Email Print Share Blocked Urethral Valves Page Content Article Body Urine leaves the bladder through a tube called the urethra, which in boys passes through the penis. Rarely, small membranes form across the urethra in ...

  6. Types of Heart Block

    Science.gov (United States)

    ... P wave as it normally would. If an electrical signal is blocked before it reaches the ventricles, they won't contract and pump blood to the lungs and the rest of the body. Second-degree heart block is divided into two ...

  7. Related Drupal Nodes Block

    NARCIS (Netherlands)

    Van der Vegt, Wim

    2010-01-01

    Related Drupal Nodes Block This module exposes a block that uses Latent Semantic Analysis (Lsa) internally to suggest three nodes that are relevant to the node a user is viewing. This module performs three tasks. 1) It periodically indexes a Drupal site and generates a Lsa Term Document Matrix. Inde

  8. The Block Neighborhood

    CERN Document Server

    Arrighi, Pablo

    2010-01-01

    We define the block neighborhood of a reversible CA, which is related both to its decomposition into a product of block permutations and to quantum computing. We give a purely combinatorial characterization of the block neighborhood, which helps in two ways. First, it makes the computation of the block neighborhood of a given CA relatively easy. Second, it allows us to derive upper bounds on the block neighborhood: for a single CA as function of the classical and inverse neighborhoods, and for the composition of several CAs. One consequence of that is a characterization of a class of "elementary" CAs that cannot be written as the composition of two simpler parts whose neighborhoods and inverse neighborhoods would be reduced by one half.

  9. 现场总线功能块的建模与分析%Modeling and Analysis of Fieldbus Function Block

    Institute of Scientific and Technical Information of China (English)

    王智; 于海斌; 王天然; 宋国宁

    2001-01-01

    功能块是实现现场智能仪表互操作、自诊断和自适应功能的基础。为了形式化地分析和模拟功能块及其构成的控制系统,本文建立了功能块的着色Petri网(CPN)模型。文中不但利用CPN模型分析了单一功能块内部的模式转换和参数状态传播过程,并且分析了功能块构成控制系统中的不同功能块的模式和参数状态之间的相互关系。基于功能块的锅炉水位控制系统应用过程的建模与分析表明,CPN模型完全胜任上述要求。%Function Blocks (FBs) play important roles in interoperability,auto\\|diagnose and control of intelligent instrument. For effectively realizing and applying FBs and FBs based control system, Colored Petri Net (CPN) models of FBs are constructed, and through which the internal procedure of FBs and the relationship of mode and parameter status between different FBs are analyzed. The modeling and analysis of FBs based boiler control system indicates that CPN model is capable of graphically simulating FBs, and also normally analyzing their operation mechanism.

  10. Prebiotic synthesis of nucleic acids and their building blocks at the atomic level - merging models and mechanisms from advanced computations and experiments.

    Science.gov (United States)

    Šponer, Judit E; Szabla, Rafał; Góra, Robert W; Saitta, A Marco; Pietrucci, Fabio; Saija, Franz; Di Mauro, Ernesto; Saladino, Raffaele; Ferus, Martin; Civiš, Svatopluk; Šponer, Jiří

    2016-07-27

    The origin of life on Earth is one of the most fascinating questions of contemporary science. Extensive research in the past decades furnished diverse experimental proposals for the emergence of first informational polymers that could form the basis of the early terrestrial life. Side by side with the experiments, the fast development of modern computational chemistry methods during the last 20 years facilitated the use of in silico modelling tools to complement the experiments. Modern computations can provide unique atomic-level insights into the structural and electronic aspects as well as the energetics of key prebiotic chemical reactions. Many of these insights are not directly obtainable from the experimental techniques and the computations are thus becoming indispensable for proper interpretation of many experiments and for qualified predictions. This review illustrates the synergy between experiment and theory in the origin of life research focusing on the prebiotic synthesis of various nucleic acid building blocks and on the self-assembly of nucleotides leading to the first functional oligonucleotides.

  11. Discovery of a novel class of targeted kinase inhibitors that blocks protein kinase C signaling and ameliorates retinal vascular leakage in a diabetic rat model.

    Science.gov (United States)

    Grant, Stephan; Tran, Phong; Zhang, Qin; Zou, Aihua; Dinh, Dac; Jensen, Jordan; Zhou, Sue; Kang, Xiaolin; Zachwieja, Joseph; Lippincott, John; Liu, Kevin; Johnson, Sarah Ludlum; Scales, Stephanie; Yin, Chunfeng; Nukui, Seiji; Stoner, Chad; Prasanna, Ganesh; Lafontaine, Jennifer; Wells, Peter; Li, Hui

    2010-02-10

    Protein kinase C (PKC) family members such as PKCbetaII may become activated in the hyperglycemic state associated with diabetes. Preclinical and clinical data implicate aberrant PKC activity in the development of diabetic microvasculature abnormalities. Based on this potential etiological role for PKC in diabetic complications, several therapeutic PKC inhibitors have been investigated in clinical trials for the treatment of diabetic patients. In this report, we present the discovery and preclinical evaluation of a novel class of 3-amino-pyrrolo[3,4-c]pyrazole derivatives as inhibitors of PKC that are structurally distinct from the prototypical indolocarbazole and bisindolylmaleimide PKC inhibitors. From this pyrrolo-pyrazole series, several compounds were identified from biochemical assays as potent, ATP-competitive inhibitors of PKC activity with high specificity for PKC over other protein kinases. These compounds were also found to block PKC signaling activity in multiple cellular functional assays. PF-04577806, a representative from this series, inhibited PKC activity in retinal lysates from diabetic rats stimulated with phorbol myristate acetate. When orally administered, PF-04577806 showed good exposure in the retina of diabetic Long-Evans rats and ameliorated retinal vascular leakage in a streptozotocin-induced diabetic rat model. These novel PKC inhibitors represent a promising new class of targeted protein kinase inhibitors with potential as therapeutic agents for the treatment of patients with diabetic microvascular complications.

  12. Expression of mRNA-encoding subunits of N-methyl-D-aspartate receptor in the hypothalamus in sustained monaural block of auditory air-conduction model rats

    Institute of Scientific and Technical Information of China (English)

    Ping Wan; Xiaojian Lai; Cheng Huang; Xinde Sun

    2011-01-01

    A sustained monaural block of auditory air-conduction model was established in rats through subcutaneous suture in the right ear canal. The gene expression levels of hypothalamic N-methyl-D-aspartate receptor NR1, NR2A, NR2B and NR2C mRNA in the auditory central nervous system of Sprague-Dawley rats at postnatal 9, 23, 37 days were determined after an environmental change. Reverse transcription-PCR assay showed that the critical period for the development of NR1, NR2A, and NR2B subunits in the left hypothalamus and NR1- and NR2B-dependent auditory neurons in the right hypothalamus terminated 23 days after the suture in the right ear. The critical period for the development of NR2A subunit-dependent auditory neurons in the right hypothalamus was terminated by postnatal day 37. The results confirmed that N-methyl-D-aspartate receptor subunits in the hypothalamus may be regulated by the auditory environment.

  13. Laser-guided cervical selective nerve root block with the Dyna-CT: initial experience of three-dimensional puncture planning with an ex-vivo model.

    Directory of Open Access Journals (Sweden)

    Miriam I E Freundt

    Full Text Available BACKGROUND: Cervical selective nerve root block (CSNRB is a well-established, minimally invasive procedure to treat radicular cervical pain. However, the procedure is technically challenging and might lead to major complications. The objective of this study was to evaluate the feasibility of a three-dimensional puncture planning and two-dimensional laser-guidance system for CSNRB in an ex-vivo model. METHODS: Dyna-CT of the cervical spine of an ex-vivo lamb model was performed with the Artis Zee® Ceiling (Siemens Medical Solutions, Erlangen, Germany to acquire multiplanar reconstruction images. 15 cervical nerve root punctures were planned and conducted with the syngo iGuide® laser-guidance system. Needle tip location and contrast dye distribution were analyzed by two independent investigators. Procedural, planning, and fluoroscopic time, tract length, and dose area product (DAP were acquired for each puncture. RESULTS: All 15 punctures were rated as successful with 12 punctures on the first attempt. Total procedural time was approximately 5 minutes. Mean planning time for the puncture was 2.03 (±0.39 min. Mean puncture time was 2.16 (±0.32 min, while mean fluoroscopy time was 0.17 (±0.06 min. Mean tract length was 2.68 (±0.23 cm. Mean total DAP was 397.45 (±15.63 µGy m(2. CONCLUSION: CSNRB performed with Dyna-CT and the tested laser guidance system is feasible. 3D pre-puncture planning is easy and fast and the laser-guiding system ensures very accurate and intuitive puncture control.

  14. Repetitive self-grooming behavior in the BTBR mouse model of autism is blocked by the mGluR5 antagonist MPEP.

    Science.gov (United States)

    Silverman, Jill L; Tolu, Seda S; Barkan, Charlotte L; Crawley, Jacqueline N

    2010-03-01

    Autism is a neurodevelopmental disorder characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. BTBR T+tf/J (BTBR) is an inbred mouse strain that shows robust behavioral phenotypes with analogies to all three of the diagnostic symptoms of autism, including well-replicated deficits in reciprocal social interactions and social approach, unusual patterns of ultrasonic vocalization, and high levels of repetitive self-grooming. These phenotypes offer straightforward behavioral assays for translational investigations of pharmacological compounds. Two suggested treatments for autism were evaluated in the BTBR mouse model. Methyl-6-phenylethynyl-pyridine (MPEP), an antagonist of the mGluR5 metabotropic glutamate receptor, blocks aberrant phenotypes in the Fmr1 mouse model of Fragile X, a comorbid neurodevelopmental disorder with autistic features. Risperidone has been approved by the United States Food and Drug Administration for the treatment of irritability, tantrums, and self-injurious behavior in autistic individuals. We evaluated the actions of MPEP and risperidone on two BTBR phenotypes, low sociability and high repetitive self-grooming. Open field activity served as an independent control for non-social exploratory activity and motor functions. C57BL/6J (B6), an inbred strain with high sociability and low self-grooming, served as the strain control. MPEP significantly reduced repetitive self-grooming in BTBR, at doses that had no sedating effects on open field activity. Risperidone reduced repetitive self-grooming in BTBR, but only at doses that induced sedation in both strains. No overall improvements in sociability were detected in BTBR after treatment with either MPEP or risperidone. Our findings suggest that antagonists of mGluR5 receptors may have selective therapeutic efficacy in treating repetitive behaviors in autism.

  15. Block copolymer battery separator

    Science.gov (United States)

    Wong, David; Balsara, Nitash Pervez

    2016-04-26

    The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

  16. Hawaii Census 2000 Blocks

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer represents Census 2000 demographic data derived from the PL94-171 redistricting files and SF3. Census geographic entities include blocks, blockgroups...

  17. Steroidal neuromuscular blocking agents

    NARCIS (Netherlands)

    Wierda, JMKH; Mori, K; Ohmura, A; Toyooka, H; Hatano, Y; Shingu, K; Fukuda, K

    1998-01-01

    Since 1964 approximately 20 steroidal neuromuscular blocking agents have been evaluated clinically. Pancuronium, a bisquaternary compound designed on the drawingboard, was the first steroidal relaxant introduced into clinical practice worldwide in the 1970's. Although a major improvement, pancuroniu

  18. Superalloy Lattice Block Structures

    Science.gov (United States)

    Nathal, M. V.; Whittenberger, J. D.; Hebsur, M. G.; Kantzos, P. T.; Krause, D. L.

    2004-01-01

    Initial investigations of investment cast superalloy lattice block suggest that this technology will yield a low cost approach to utilize the high temperature strength and environmental resistance of superalloys in lightweight, damage tolerant structural configurations. Work to date has demonstrated that relatively large superalloy lattice block panels can be successfully investment cast from both IN-718 and Mar-M247. These castings exhibited mechanical properties consistent with the strength of the same superalloys measured from more conventional castings. The lattice block structure also accommodates significant deformation without failure, and is defect tolerant in fatigue. The potential of lattice block structures opens new opportunities for the use of superalloys in future generations of aircraft applications that demand strength and environmental resistance at elevated temperatures along with low weight.

  19. Adaptive cosine transform image coding with variable block size and constant block distortion

    Science.gov (United States)

    Daut, David G.; Wu, Jia-Chyi

    1996-02-01

    An adaptive discrete cosine transform (DCT) image coding system is implemented with the same average distortion designated for each variable size image block. The variable block size segmentation is performed using a quadtree data structure by dividing the perceptually more important regions of an image into smaller size blocks compared to the size of blocks containing lesser amounts of spatial activity. Due to the nonstationarity of real-world images, each image block is described by a space-varying nonstationary Gauss-Markov random field. The space-varying autoregressive parameters are estimated using an on-line modified least- squares estimator. For each assumed space-varying nonstationary image block, a constant average distortion is assigned and the code rate for each image block is allowed to vary in order to meet the fixed distortion criterion. Simulation results show that reconstructed images coded at low average distortion, based on an assumed space-varying nonstationary image model, using variable size blocks and with variable bit rate per block possess high-quality subjective (visual) and objective (measured) quality at low average bit rates. Performance gains are achieved due to the distortion being distributed more uniformly among the blocks as compared with fixed-rate, stationary image transform coding schemes.

  20. The Octree Ore Body Block Model and its Application in Sandaozhuang Open Pit%八叉树矿体块状模型及其在三道庄露天矿的应用

    Institute of Scientific and Technical Information of China (English)

    张影; 杨春; 李发本

    2011-01-01

    矿体块状模型广泛应用于品位、储量计算,也可用于露天矿最终开采境界优化和开采计划优化.在研究了八叉树存储结构和基于分离轴的OBB相交测试理论的基础上,提出首先应用八叉树对矿体三维空间进行块状划分,将矿体用一系列的小单元块来逼近,然后利用OBB理论检测单元块与矿体边界的空间关系,对相交单元块进行细分,利用点在多面体内外判断确保块状模型约束在表面模型内,从而以最佳状态逼近矿体边界.最后运用该方法建立了三道庄露天矿矿体块状模型.该方法快速有效,能够满足矿山生产设计需求.%The ore-body block model is not only widely used in ore grade and reserve calculation, but used in the optimization of the final mining boundary and mining plan in the open pit. According to the investigation on octree storage structure and OBB intersection test theory based on the separating axis, it is proposed that the three dimensional space of ore body is firstly subdivided into small blocks by the octree, and the ore-body is approximated by a series of small unit blocks; Then, the spatial relationship between unit blocks and the ore boundary is detected by the OBB theory to subdivide the unit blocks of intersection. According to judgment of the point in the polyhedron or not to ensure block model constrained in the surface model, ore-body boundary can be fully approximated. Finally the ore body block model of Sandaozhuang open pit is created by this method, showing it an effective method which can meet needs of production design for the mine.

  1. 三维地质结构模型中闭合地质块体的构建%Sealed Geological Block Modeling in 3D Geological Structural Model

    Institute of Scientific and Technical Information of China (English)

    杨洋; 潘懋; 吴耕宇; 刘殷; 李魁星

    2015-01-01

    In 3D geological modeling, the existing geological sealed block recognition algorithms were based on topology between cells of geological surfaces. These algorithms faced some obvious weaknesses such as topology data redundancy and high computational complexity. To solve these problems, with research objective of recog-nizing topological closed 3D geological blocks, this paper presented a topology model that is suitable for ex-pressing complex topological relationship between geological surfaces to separate geometry and topology of geological surfaces, and proposed a rapid construction process of this model. Geological sealed block is area sur-rounded by geological surfaces that are topological closed in the underground space; therefore, geological sealed block recognition is a topological problem in essence, not relating to geometry. From the perspective of this point, the defined topology model include topological node, topological border, topological facet, topological surface, and topological block. Its construction process follows four steps: search topological node in geological surfaces boundary; construct topological border; build topological facet composed of closed topological borders; search topological block in all topological facets. When searching geological sealed blocks, the built topology model transfers searching process from geometric space to topological space. The rapid construction process due to the only use of boundary information of geological surfaces during construction process of the topology model. Ex-perimental results show that this algorithm has a good performance of time complexity and can satisfy all kinds of relationship between complex geological surfaces because of the integrity of topology model in theory.%三维地质建模中现有地质闭合区块搜索算法基于网格单元间的拓扑进行拓扑搜索,面临着拓扑信息冗余、计算量大、计算复杂度高等缺点。针对这一问题,以搜索拓扑

  2. Application of multi-block methods in cement production

    DEFF Research Database (Denmark)

    Svinning, K.; Høskuldsson, Agnar

    2008-01-01

    Compressive strength at 1 day of Portland cement as a function of the microstructure of cement was statistically modelled by application of multi-block regression method. The observation X-matrix was partitioned into four blocks, the first block representing the mineralogy, the second particle size...

  3. Mosquito-Disseminated Insecticide for Citywide Vector Control and Its Potential to Block Arbovirus Epidemics: Entomological Observations and Modeling Results from Amazonian Brazil

    Science.gov (United States)

    Abad-Franch, Fernando; Luz, Sérgio L. B.

    2017-01-01

    Background Mosquito-borne viruses threaten public health worldwide. When the ratio of competent vectors to susceptible humans is low enough, the virus’s basic reproductive number (R0) falls below 1.0 (each case generating, on average, <1.0 additional case) and the infection fades out from the population. Conventional mosquito control tactics, however, seldom yield R0 < 1.0. A promising alternative uses mosquitoes to disseminate a potent growth-regulator larvicide, pyriproxyfen (PPF), to aquatic larval habitats; this kills most mosquito juveniles and substantially reduces adult mosquito emergence. We tested mosquito-disseminated PPF in Manacapuru, a 60,000-inhabitant city (~650 ha) in Amazonian Brazil. Methods and Findings We sampled juvenile mosquitoes monthly in 100 dwellings over four periods in February 2014–January 2016: 12 baseline months, 5 mo of citywide PPF dissemination, 3 mo of focal PPF dissemination around Aedes-infested dwellings, and 3 mo after dissemination ended. We caught 19,434 juvenile mosquitoes (66% Aedes albopictus, 28% Ae. aegypti) in 8,271 trap-months. Using generalized linear mixed models, we estimated intervention effects on juvenile catch and adult emergence while adjusting for dwelling-level clustering, unequal sampling effort, and weather-related confounders. Following PPF dissemination, Aedes juvenile catch decreased by 79%–92% and juvenile mortality increased from 2%–7% to 80%–90%. Mean adult Aedes emergence fell from 1,077 per month (range 653–1,635) at baseline to 50.4 per month during PPF dissemination (range 2–117). Female Aedes emergence dropped by 96%–98%, such that the number of females emerging per person decreased to 0.06 females per person-month (range 0.002–0.129). Deterministic models predict, under plausible biological-epidemiological scenarios, that the R0 of typical Aedes-borne viruses would fall from 3–45 at baseline to 0.004–0.06 during PPF dissemination. The main limitations of our study were

  4. Right bundle branch block

    DEFF Research Database (Denmark)

    Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse;

    2013-01-01

    AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included.......5%/2.3% in women, P Right bundle branch block was associated with significantly.......60-1.62). The presence of IRBBB was not associated with any adverse outcome.ConclusionIn this cohort study, RBBB and IRBBB were two to three times more common among men than women. Right bundle branch block was associated with increased cardiovascular risk and all-cause mortality, whereas IRBBB was not. Contrary...

  5. Phase equilibrium modeling of incipient charnockite formation in NCKFMASHTO and MnNCKFMASHTO systems: A case study from Rajapalaiyam, Madurai Block, southern India

    Directory of Open Access Journals (Sweden)

    Takahiro Endo

    2012-11-01

    Full Text Available Incipient charnockites represent granulite formation on a mesoscopic scale and have received considerable attention in understanding fluid processes in the deep crust. Here we report new petrological data from an incipient charnockite locality at Rajapalaiyam in the Madurai Block, southern India, and discuss the petrogenesis based on mineral phase equilibrium modeling and pseudosection analysis. Rajapalaiyam is a key locality in southern India from where diagnostic mineral assemblages for ultrahigh-temperature (UHT metamorphism have been reported. Proximal to the UHT rocks are patches and lenses of charnockite (Kfs + Qtz + Pl + Bt + Opx + Grt + Ilm occurring within Opx-free Grt-Bt gneiss (Kfs + Pl + Qtz + Bt + Grt + Ilm + Mt which we report in this study. The application of mineral equilibrium modeling on the charnockitic assemblage in NCKFMASHTO system yields a p-T range of ∼820 °C and ∼9 kbar. Modeling of the charnockite assemblage in the MnNCKFMASHTO system indicates a slight shift of the equilibrium condition toward lower p and T (∼760 °C and ∼7.5 kbar, which is consistent with the results obtained from geothermobarometry (710–760 °C, 6.7–7.5 kbar, but significantly lower than the peak temperatures (>1000 °C recorded from the UHT rocks in this locality, suggesting that charnockitization is a post-peak event. The modeling of T versus molar H2O content in the rock (M(H2O demonstrates that the Opx-bearing assemblage in charnockite and Opx-free assemblage in Grt-Bt gneiss are both stable at M(H2O = 0.3 mol%–0.6 mol%, and there is no significant difference in water activity between the two domains. Our finding is in contrast to the previous petrogenetic model of incipient charnockite formation which envisages lowering of water activity and stabilization of orthopyroxene through breakdown of biotite by dehydration caused by the infiltration of CO2-rich fluid. T-XFe3+ (=Fe2O3/(FeO + Fe2O3 in

  6. Exploring Energy Efficiency of Lightweight Block Ciphers

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco

    2016-01-01

    lightweight block ciphers, and thereby try to predict the optimal value of r at which an r-round unrolled architecture for a cipher is likely to be most energy efficient. We also try to relate our results to some physical design parameters like the signal delay across a round and algorithmic parameters like......In the last few years, the field of lightweight cryptography has seen an influx in the number of block ciphers and hash functions being proposed. One of the metrics that define a good lightweight design is the energy consumed per unit operation of the algorithm. For block ciphers, this operation...... is the encryption of one plaintext. By studying the energy consumption model of a CMOS gate, we arrive at the conclusion that the energy consumed per cycle during the encryption operation of an r-round unrolled architecture of any block cipher is a quadratic function in r. We then apply our model to 9 well known...

  7. A conformal block Farey tail

    CERN Document Server

    Maloney, Alexander; Ng, Gim Seng

    2016-01-01

    We investigate the constraints of crossing symmetry on CFT correlation functions. Four point conformal blocks are naturally viewed as functions on the upper-half plane, on which crossing symmetry acts by PSL(2,Z) modular transformations. This allows us to construct a unique, crossing symmetric function out of a given conformal block by averaging over PSL(2,Z). In some two dimensional CFTs the correlation functions are precisely equal to the modular average of the contributions of a finite number of light states. For example, in the two dimensional Ising and tri-critical Ising model CFTs, the correlation functions of identical operators are equal to the PSL(2,Z) average of the Virasoro vacuum block; this determines the 3 point function coefficients uniquely in terms of the central charge. The sum over PSL(2,Z) in CFT2 has a natural AdS3 interpretation as a sum over semi-classical saddle points, which describe particles propagating along rational tangles in the bulk. We demonstrate this explicitly for the corre...

  8. Contaminated soil concrete blocks

    NARCIS (Netherlands)

    Korte, de A.C.J.; Brouwers, H.J.H.; Limbachiya, Mukesh C.; Kew, Hsein Y.

    2009-01-01

    According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In ord

  9. Effects of Block Scheduling

    Directory of Open Access Journals (Sweden)

    William R. Veal

    1999-09-01

    Full Text Available This study examined the effects of a tri-schedule on the academic achievement of students in a high school. The tri-schedule consists of traditional, 4x4 block, and hybrid schedules running at the same time in the same high school. Effectiveness of the schedules was determined from the state mandated test of basic skills in reading, language, and mathematics. Students who were in a particular schedule their freshman year were tested at the beginning of their sophomore year. A statistical ANCOVA test was performed using the schedule types as independent variables and cognitive skill index and GPA as covariates. For reading and language, there was no statistically significant difference in test results. There was a statistical difference mathematics-computation. Block mathematics is an ideal format for obtaining more credits in mathematics, but the block format does little for mathematics achievement and conceptual understanding. The results have content specific implications for schools, administrations, and school boards who are considering block scheduling adoption.

  10. Concrete Block Pavements

    Science.gov (United States)

    1983-03-01

    1967, Cedergren 1974, Federal Highway .’,U .. V,47 -’":: 37 Administration 1980). Block pavements have essentially the same prob- lems with moisture...Vicksburg, Miss. Cedergren , H. R. 1974. Drainage of Highway and Airfield Pavements, John Wiley and Sons, New VOk. I Cement and Concrete Association

  11. Block That Pain!

    Science.gov (United States)

    ... along with the National Institute of Dental and Craniofacial Research (NIDCR) and the National Institute of General Medical Sciences (NIGMS). This finding shows that a specific combination of two molecules can block only pain-related neurons. It holds the promise of major ...

  12. DYNAMIC BEHAVIOR OF TYRE TREAD BLOCK

    Directory of Open Access Journals (Sweden)

    K. Sridharan

    2012-01-01

    Full Text Available The Tyre tread pattern is the arrangement of blocks, grooves and voids, sipes and channels designed into the tread to enhance its grip on the road. Tread is the uppermost part of any tyre which contact into the road and it has its own performance towards mileage, traction, low noise and heat built up properties. It would be meaningful to conduct an extended analysis on the tyre tread blocks for its performance in static and dynamic condition to predict its behavior and wear of tread block in on-road condition. The Finite Element software Abaqus is used for the present analysis of the tread block and its behavior was studied on two different contact surfaces. The tread block is modeled in six different shapes and analyzed for is performance. The deformation stress strain characteristic of different blocks is studied which will be useful in deciding the contact behavior, friction and road grip. The regular shape/geometry has common behavior and the mixed type geometry shows a distinguished variation in the analysis. The dynamic stiffness and deformed shape was analyzed in this study and it has its own effect in tyre design. The tread block dynamics study by geometric shape would be vital in tread pattern optimization to enhance the traction, better hydroplaning and rolling resistance under all operating conditions.

  13. Circular block matching based video stabilization

    Science.gov (United States)

    Xu, Lidong; Fu, Fangwen; Lin, Xinggang

    2005-07-01

    Video sequences captured by handheld digital camera need to be stabilized to eliminate the tiresome effects caused by camera"s undesirable shake or jiggle. The key issue of video stabilization is to estimate the global motion parameters between two successive frames. In this paper, a novel circular block matching algorithm is proposed to estimate the global motion parameters. This algorithm can deal with not only translational motion but even large rotational motion. For an appointed circular block in current frame, a four-dimensional rotation invariant feature vector is firstly extracted from it and used to judge if it is an effective block. Then the rotation invariant features based circular block matching process is performed to find the best matching blocks in reference frame for those effective blocks. With the matching results of any two effective blocks, a two-dimensional motion model is constructed to produce one group of frame motion parameters. A statistical method is proposed to calculate the estimated global motion parameters with all groups of global motion parameters. Finally, using the estimated motion parameters as the initial values, an iteration algorithm is introduced to obtain the refined global motion parameters. The experimental results show that the proposed algorithm is excellent in stabilizing frames with even burst global translational and rotational motions.

  14. 西非北加蓬次盆G区块UPC段油气成藏模式及主控因素%Reservior Formation Model and Main Controlling Factors of G Block in North Gabon Sub-basin

    Institute of Scientific and Technical Information of China (English)

    房大志; 卫秋婷

    2012-01-01

    model in the G block, including the generation and feed from the deeper source rock, the migration through faults, salt and sandstone, the oil and gas accumulation in structural traps, and the main factors for the hydrocarbon accumulation are traps related with salt structure.

  15. 考虑大宗交易的均值-方差投资组合优化模型及其分支定界算法%Portfolio optimization model and branch-bound algorithm under block trading

    Institute of Scientific and Technical Information of China (English)

    薛宏刚; 张川; 胡春萍; 徐成贤

    2011-01-01

    In this paper, we consider the portfolio optimal problem under block trading. As the decrease of marginal transaction cost under block trading, we establish the mean-variance portfolio optimization model and the corresponding algorithm by means of fit transaction cost function with linear and concave form. Computational results are presented by considering the stocks involved in Hang Seng Index to show that: The efficient frontier under block trading is between that with linear transaction cost and without transaction cost; The investment risk can be eliminated by portfolio diversification, but the effect of that is dilute under block trading; In terms of linear transaction cost, the greater the transaction cost under block trading, the higher the portfolio concentration.%由于大宗交易下边际交易费用递减,因此用线性加凹的函数拟合实际交易费用函数,建立了均值-方差框架下的组合优化模型并给出了相应的求解算法.通过对恒生指数样本股的实证分析发现:考虑大宗交易的组合有效边缘介于线性交易费用和无交易费用的组合有效边缘之间;大宗交易稀释了“分散化降低风险”的效应;大宗交易下交易费用越大,相对于线性交易费用而言组合集中度越高.

  16. 复杂断块油藏精细地质建模研究--以大65断块为例%Study on the Fine Geological Model of Complex Fault-Block Reservior:A Case Study of Da 65 Fault-Block for Example

    Institute of Scientific and Technical Information of China (English)

    王冰; 刘太勋; 王凯; 牛海瑞

    2016-01-01

    At present the accurate and quantitative characterization of fault-block reservoir is difficulty and research hotspot for reservoir geological modeling.Da 65 fault-block in DaWang Bei oilfield have the characteristics of complex reservoir structural, strong heterogeneity, large difference of block development effect.Based on the date from geological, well logging interpretation,core analysis,well drilling data,the seismic interpretation and so on,Da 65 fault-block fine structure mode was established according to the point-surface-body modeling steps.The sand body model was researched using the method of bounding surface restriction and deterministic modeling.And on this basis single well facies data of well log interpretation were used to construct the sedimentary microfacies mode using deterministic algorithm.Finally under the constraint of sedimentary microfacies,the reservoir parameter model was established by stochastic modeling technique.The fine 3D geological model of complex fault-block reservoir complete the quantitative characterization of structure and attributes,provide a reliable basis for accurate evaluation of the reservoir properties and potential,and also provide geological basis for later adjustment of reservoir development scheme.%针对大王北油田大65断块油藏构造复杂、非均质性强、不同断块开发效果差异大等特点,以地质、测井解释、岩心分析、钻井、地震解释等各方面资料为基础,首先按照点-面-体的建模步骤建立大65断块精细构造模型;通过界面约束法确定性建模方法建立砂体模型;在此基础上,以测井解释单井相数据为基准,采用确定性算法构建了沉积微相模型;并以相控随机建模技术为指导,建立了储层参数模型。大65断块复杂断块油藏精细三维地质模型的建立,实现构造和属性的空间定量表征,为准确评价储层性质及潜能提供了可靠依据,也为后期油藏开发方

  17. Helical Ordering in Chiral Block Copolymers

    Science.gov (United States)

    Zhao, Wei; Hong, Sung Woo; Chen, Dian; Grason, Gregory; Russell, Thomas

    2012-02-01

    Introducing molecular chirality into the segments of block copolymers can influence the nature of the resultant morphology. Such an effect was found for poly(styrene-b-L-lactide) (PS-b-PLLA) diblock copolymers where hexagonally packed PLLA helical microdomains (H* phase) form in a PS matrix. However, molecular ordering of PLLA within the helical microdomains and the transfer of chirality from the segmental level to the mesoscale is still not well understood. We developed a field theoretic model to describe the interactions between segments of chiral blocks, which have the tendency to form a ``cholesteric'' texture. Based on the model, we calculated the bulk morphologies of chiral AB diblock copolymers using self-consistent field theory (SCFT). Experiments show that the H* phase only forms when microphase separation between PS and PLLA block happens first and crystallization of PLLA block is suppressed or happens within confined microdomain. Hence, crystalline ordering is not necessary for H* phase formation. The SCFT offers the chance to explore the range of thermodynamic stability of helical structures in the phase diagram of chiral block copolymer melts, by tuning parameters not only like the block segregation strength and composition, but also new parameters such as the ratio between preferred helical pitch to the radius of gyration and the Frank elastic constant for inter-segment distortions.

  18. Blocking Type I Interferon Signaling Rescues Lymphocytes from Oxidative Stress, Exhaustion, and Apoptosis in a Streptozotocin-Induced Mouse Model of Type I Diabetes

    OpenAIRE

    Ibrahim, Hany M.; El-Elaimy, Ibrahim A.; Saad Eldien, Heba M.; Badr Mohamed Badr; Rabah, Danny M.; Gamal Badr

    2013-01-01

    Elevated levels of type I interferon (IFN) during type 1 diabetes mellitus (T1D) are associated with a defective immune response. In the present study, we investigated whether blocking type I IFN signaling during streptozotocin- (STZ-) induced T1D in mice improves lymphocyte proliferation and escape from continuous apoptosis. Three groups of mice were examined: diabetic mice, type I IFN signaling-incompetent diabetic mice, and control nondiabetic mice. We first found that diabetes induction w...

  19. Recovery from blocking between outcomes.

    Science.gov (United States)

    Wheeler, Daniel S; Miller, Ralph R

    2005-10-01

    Contemporary associative learning research largely focuses on cue competition phenomena that occur when 2 cues are paired with a common outcome. Little research has been conducted to investigate similar phenomena occurring when a single cue is trained with 2 outcomes. Three conditioned lick suppression experiments with rats assessed whether treatments known to alleviate blocking between cues would also attenuate blocking between outcomes. In Experiment 1, conditioned responding recovered from blocking between outcomes when a long retention interval was interposed between training and testing. Experiment 2 obtained recovery from blocking between outcomes when the blocking outcome was extinguished after the blocking treatment. In Experiment 3, a recovery from blocking between outcomes occurred when a reminder stimulus was presented in a novel context prior to testing. Collectively, these studies demonstrate that blocking of outcomes, like blocking of cues, appears to be caused by a deficit in the expression of an acquired association.

  20. Blocking Type I Interferon Signaling Rescues Lymphocytes from Oxidative Stress, Exhaustion, and Apoptosis in a Streptozotocin-Induced Mouse Model of Type I Diabetes

    Directory of Open Access Journals (Sweden)

    Hany M. Ibrahim

    2013-01-01

    Full Text Available Elevated levels of type I interferon (IFN during type 1 diabetes mellitus (T1D are associated with a defective immune response. In the present study, we investigated whether blocking type I IFN signaling during streptozotocin- (STZ- induced T1D in mice improves lymphocyte proliferation and escape from continuous apoptosis. Three groups of mice were examined: diabetic mice, type I IFN signaling-incompetent diabetic mice, and control nondiabetic mice. We first found that diabetes induction was accompanied by an elevation in the plasma levels of reactive oxygen species (ROS, hydroperoxide, malondialdehyde (MDN, and the proinflammatory cytokines IL-1α, IL-1β, IL-6, and CXCL10. Blocking type 1 IFN signaling in diabetic mice significantly decreased the levels of oxidative stress and proinflammatory cytokines. In addition, lymphocytes from diabetic mice exhibited a marked reduction in their proliferative capacity, increased apoptosis, upregulation of the exhaustion marker PD-1, and aberrant phosphorylation of STAT1, STAT2, AKT and IκB-α. Interestingly, following the blocking of type I IFN signaling in diabetic mice, the lymphocytes exhibited restored proliferative capacity, decreased apoptosis, normal expression of PD-1, and normal phosphorylation of STAT1, STAT2, AKT and IκB-α. Our data suggest that elevated levels of type I IFN during T1D trigger lymphocyte exhaustion and a defective lymphocyte-medicated immune response.

  1. SUPERFICIAL CERVICAL PLEXUS BLOCK

    Directory of Open Access Journals (Sweden)

    Komang Mega Puspadisari

    2014-01-01

    Full Text Available Superficial cervical plexus block is one of the regional anesthesia in  neck were limited to thesuperficial fascia. Anesthesia is used to relieve pain caused either during or after the surgery iscompleted. This technique can be done by landmark or with ultrasound guiding. The midpointof posterior border of the Sternocleidomastoid was identified and the prosedure done on thatplace or on the level of cartilage cricoid.

  2. 基于分块重要度和二维条件随机场的Web信息抽取%Web Information extraction based on block importance model and 2D conditional random fields

    Institute of Scientific and Technical Information of China (English)

    吴秦; 胡丽娟; 梁久祯

    2014-01-01

    Traditional methods for Web information extraction are mainly based on linear conditional random fields model,which firstly converts the two dimensional structure of Web pages into a one dimensional sequence and then extract information.One of the shortcomings of this type of methods is that the two dimensional dependence of Web obj ects is overlooked,which may influence the effectiveness of Web information extraction.In this paper,a Web in-formation extraction method is proposed based on the block importance model and two-dimensional conditional random fields(2D CRFs).The proposed method firstly applies the vision-based page segmentation algorithm to divide the Web page into different blocks.Then support vector machine are used to learn the importance of different blocks.Unimportant blocks are removed so that Web object could be identified more accurately.Finally,the 2D CRFs model is applied to extract information from the Web page.Comparing with linear conditional random fields model, 2D CRFs model fits the two dimensional structure of Web page blocks better,which also improves the accuracy of Web information extraction.Experiments are presented on two datasets and the results show that the proposed method performs excellently on Web information extraction.%网页分块方法使得 Web信息抽取的单位由原来的页面缩小为分块。结合分块重要度模型与二维条件随机场的优点,提出一种 Web对象信息抽取方法。该方法利用分块重要度模型对网页分块进行重要度标注,过滤掉大量与主题无关信息,更加准确的定位待抽取信息的位置。二维条件随机场模型相比传统的线性条件随机场模型更好的适应了网页分块的二维结构,有效的提高信息抽取准确率。实验结果表明,该方法对 Web 对象信息抽取具有良好的效果。

  3. Managing access block.

    Science.gov (United States)

    Cameron, Peter; Scown, Paul; Campbell, Donald

    2002-01-01

    There is pessimism regarding the ability of the Acute Health Sector to manage access block for emergency and elective patients. Melbourne Health suffered an acute bed crisis in 2001 resulting in record ambulance diversions and emergency department (ED) delays. We conducted an observational study to reduce access block for emergency patients whilst maintaining elective throughput at Melbourne Health. This involved a clinician-led taskforce using previously proven principles for organisational change to implement 51 actions to improve patient access over a three-month period. The primary outcome measures were ambulance diversion, emergency patients waiting more than 12 hours for an inpatient bed, elective throughput and theatre cancellations. Despite a reduction in multi-day bed numbers all primary objectives were met, ambulance diversion decreased to minimal levels, 12-hour waits decreased by 40% and elective throughput was maintained. Theatre cancellations were also minimised. We conclude that access block can be improved by clinician-led implementation of proven process improvements over a short time frame. The ability to sustain change over the longer term requires further study.

  4. 基于分块重要性模型与Xpath的Web信息抽取的研究%Research on Web Information Extraction Based on Combining Block Importance Model and Xpath

    Institute of Scientific and Technical Information of China (English)

    庞秋奔; 顾平; 杨小梅

    2009-01-01

    网页分块方法使得Web信息抽取的单位由页面缩小为块.文中研究了网页分块的主要方法与基于学习的分块重要性模型,对Xpath的Web抽取方法进行分析.结合两者的优势提出一种基于分块重要性模型与Xpath结合的Web信息抽取方法,探讨了其设计过程,并给出形式化描述与实验结果,结果表明该方法适合于抽取多记录型的网页.%Approaches of page segment reduce the unit of Web information extraction from page to block. This paper studies the main approaches of page segment and the based-learning block importance model, and analyses the approach of Xpath-based Web information extraction. Combining the advantages of the two approaches, this paper proposes a new Web information extraction based on combining block importance model and Xpath, discusses its design process, and gives its formalized description and experimental result. The result shows that this approach is fit for extracting from the Web which has many records.

  5. Incorporating GIS building data and census housing statistics for sub-block-level population estimation

    Science.gov (United States)

    Wu, S.-S.; Wang, L.; Qiu, X.

    2008-01-01

    This article presents a deterministic model for sub-block-level population estimation based on the total building volumes derived from geographic information system (GIS) building data and three census block-level housing statistics. To assess the model, we generated artificial blocks by aggregating census block areas and calculating the respective housing statistics. We then applied the model to estimate populations for sub-artificial-block areas and assessed the estimates with census populations of the areas. Our analyses indicate that the average percent error of population estimation for sub-artificial-block areas is comparable to those for sub-census-block areas of the same size relative to associated blocks. The smaller the sub-block-level areas, the higher the population estimation errors. For example, the average percent error for residential areas is approximately 0.11 percent for 100 percent block areas and 35 percent for 5 percent block areas.

  6. Block Transfer Handbook: Constructing and Negotiating Block Transfer Agreements.

    Science.gov (United States)

    Finlay, Finola

    The purpose of this handbook is to provide resources for institutions or articulation committees who are engaged in the task of investigating the feasibility of block transfer agreements. Block transfer is the process whereby a block of credits is granted to students who have successfully completed a certificate, diploma, or cluster of courses…

  7. Demographic Data - MDC_Block

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — A polygon feature class of Miami-Dade Census 2000 Blocks. Census blocks are areas bounded on all sides by visible and/or invisible features shown on a map prepared...

  8. Habitat Blocks and Wildlife Corridors

    Data.gov (United States)

    Vermont Center for Geographic Information — Habitat blocks are areas of contiguous forest and other natural habitats that are unfragmented by roads, development, or agriculture. Vermonts habitat blocks are...

  9. Porous block nanofiber composite filters

    Energy Technology Data Exchange (ETDEWEB)

    Ginley, David S.; Curtis, Calvin J.; Miedaner, Alexander; Weiss, Alan J.; Paddock, Arnold

    2016-08-09

    Porous block nano-fiber composite (110), a filtration system (10) and methods of using the same are disclosed. An exemplary porous block nano-fiber composite (110) includes a porous block (100) having one or more pores (200). The porous block nano-fiber composite (110) also includes a plurality of inorganic nano-fibers (211) formed within at least one of the pores (200).

  10. Properties of blocked linear systems.

    Science.gov (United States)

    Chen, Weitian; Anderson, Brian D O; Deistler, Manfred; Filler, Alexander

    2012-10-01

    This paper presents a systematic study on the properties of blocked linear systems that have resulted from blocking discrete-time linear time invariant systems. The main idea is to explore the relationship between the blocked and the unblocked systems. Existing results are reviewed and a number of important new results are derived. Focus is given particularly on the zero properties of the blocked system as no such study has been found in the literature.

  11. Appropriate schemata and building blocks

    Institute of Scientific and Technical Information of China (English)

    Yang Haijun; Li Minqiang

    2005-01-01

    Appropriate schemata as a novel concept to characterize building blocks are introduced, and then, the traits of appropriate schemata are presented. The effects of building blocks by search operators are analyzed. Hence, the experiments on RR-8X8 are employed to verify that appropriate schemata construct the building blocks. The validity of appropriate schemata and building blocks from the views of theory and practice is presented.

  12. Blocking the Hawking radiation

    DEFF Research Database (Denmark)

    Autzen, M.; Kouvaris, C.

    2014-01-01

    grows after its formation (and eventually destroys the star) instead of evaporating. The fate of the black hole is dictated by the two opposite mechanics, i.e., accretion of nuclear matter from the center of the star and Hawking radiation that tends to decrease the mass of the black hole. We study how...... the assumptions for the accretion rate can in fact affect the critical mass beyond which a black hole always grows. We also study to what extent degenerate nuclear matter can impede Hawking radiation due to the fact that emitted particles can be Pauli blocked at the core of the star....

  13. Property Blocks: Games and Activities.

    Science.gov (United States)

    Humphreys, Alan, Ed.; Dailey, Jean, Ed.

    This pamphlet describes the property blocks produced by MINNEMAST, and discusses their use in the development of thinking processes. Classification systems, including block diagrams and tree diagrams, are discussed. Sixteen classroom activities and eleven games which use the blocks are described. Suggestions to the teacher for further reading are…

  14. Structure of Block Copolymer Hydrogel Formed by Complex Coacervate Process

    Science.gov (United States)

    Choi, Soohyung; Ortony, Julia; Krogstad, Daniel; Spruell, Jason; Lynd, Nathaniel; Han, Songi; Kramer, Edward

    2012-02-01

    Complex coacervation occurs when oppositely charged polyelectrolytes associate in solution, forming dense micron-sized droplets. Hydrogels with coacervate block domains were formed by mixing two ABA and A'BA' triblock copolymer solutions in water where the A and A' blocks are oppositely charged. Small-angle neutron scattering (SANS) was used to investigate the structure of hydrogels formed by ABA triblock copolymers (A block: poly(allyl glycidyl ether) functionalized with guanidinium (A) or sulfonate (A'), B block: poly(ethylene oxide)). By using an appropriate fitting model, structural information such as coacervate core block radius and water volume fraction w can be extracted from SANS data. The results reveal that w in the coacervate core block was significantly higher than in conventional triblock copolymer hydrogels where microphase separation is driven by the hydrophobicity of the core-forming blocks.

  15. Humanoid by ROBO-BLOCK

    Science.gov (United States)

    Niimi, Hirofumi; Koike, Minoru; Takeuchi, Seiichi; Douhara, Noriyoshi

    2007-12-01

    Humanoid by ROBO-BLOCK (robot block system) and the rational formula of robots were proposed. ROBO-BLOCK is composed of servo motors, the parts for servomotor rotor, the brackets for servomotor fixation, the board parts and the controllers. A robot can be assembled easily by ROBO-BLOCK. Meanwhile, it is convenient when the structure of the robot can be described easily as a character. The whole structure of the robot is expressed as rational formula of the robot to show molecule structure in chemistry. ROBO-BLOCK can be useful for not only the research but also the education. Creative student experiment was done in the college of industrial technology.

  16. Natural convection through enclosed disconnected solid blocks

    Energy Technology Data Exchange (ETDEWEB)

    Lao, Fernando Cesar De; Junqueira, Silvio L.M.; Franco, Admilson T. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)]. E-mails: fernandodelai@gmail.com; silvio@utfpr.edu.br; admilson@utfpr.edu.br; Lage, Jose L. [Southern Methodist University (SMU), Dallas, TX (United States)]. E-mail: JLL@smu.edu

    2008-07-01

    In this study, the natural convection inside a fluid filled, enclosure containing several solid obstructions and being heated from the side is modeled and numerically simulated. The solid obstructions are equally spaced, conducting, and disconnected square blocks. The mathematical model is based on the balance equations of mass, momentum and energy, which are then solved numerically via the finite-volume method with the SIMPLEST algorithm and the HYBRID scheme. The effects of varying the solid-fluid thermal conductivity ratio (K), the fluid volume-fraction or porosity ({phi}), the number of solid blocks (N) and the heating strength (represented by the Rayleigh number, Ra) of the enclosure on the Nusselt number based on the surface-averaged heat transfer coefficient along the heated wall of the enclosure are studied. The results indicate a competing effect caused by the proximity of the solid blocks to the heated and cooled walls, vis-a-vis hindering the boundary layer growth, hence reducing the heat transfer effectiveness, and at the same time enhancing the heat transfer when the blocks' thermal conductivity is larger than that of the fluid. An analytical estimate of the minimum number of blocks beyond which the convection hindrance becomes predominant is presented and validated by the numerical results. (author)

  17. Beneficial and Adverse Effects of Electro-acupuncture Assessed in the Canine Chronic Atrio-ventricular Block Model Having Severe Hypertension and Chronic Heart Failure.

    Science.gov (United States)

    Cao, Xin; Lu, Shengfeng; Ohara, Hiroshi; Nakamura, Yuji; Izumi-Nakaseko, Hiroko; Ando, Kentaro; Zhu, Bingmei; Xu, Bin; Sugiyama, Atsushi

    2015-01-01

    Regarding the effects of electro-acupuncture for severe hypertension, we assessed its acute cardiovascular consequences with 4 subjects of the chronic atrioventricular block dogs having severe hypertension and chronic heart failure. The electro-acupuncture consisting of 2 mA at 2 Hz frequency was carried out for 30 min at Renying (ST-9) and Taichong (LR-3) every other day. Seven sessions were performed within 2 weeks. In the 1st and 7th sessions, the animals were anesthetized with pentobarbital to analyze the effects of the electro-acupuncture on cardiovascular variables. No significant change was detected in any of the basal control values of the cardiohemodynamic or electrophysiological variables between the 1st and 7th sessions. During the 1st session, electo-acupuncture produced a peak increase in mean blood pressure by 8.7% at 35 min (p hypertensive crisis at the beginning, clinicians have to pay attention on its use for patients with hypertension.

  18. Photovoltaic building blocks

    DEFF Research Database (Denmark)

    Hanberg, Peter Jesper; Jørgensen, Anders Michael

    2014-01-01

    it directcompetitive with fossil energy sources a further reduction is needed. By increasing the efficiency of the solar cells one gain an advantage through the whole chain of cost. So that per produced Watt of power less material is spent, installation costs are lower, less area is used etc. With an average...... efficiency of about 15% for commercial Silicon solar cells there is still much to gain. DTU Danchip provides research facilities, equipment and expertise for the building blocks that comprises fabricating the efficient solar cell. In order to get more of the sun light into the device we provide thin film......Photovoltaics (PV), better known as solar cells, are now a common day sight on many rooftops in Denmark.The installed capacity of PV systems worldwide is growing exponentially1 and is the third most importantrenewable energy source today. The cost of PV is decreasing fast with ~10%/year but to make...

  19. Celiac ganglia block

    Energy Technology Data Exchange (ETDEWEB)

    Akinci, Devrim [Department of Radiology, Hacettepe University School of Medicine, Sihhiye, 06100 Ankara (Turkey); Akhan, Okan [Department of Radiology, Hacettepe University School of Medicine, Sihhiye, 06100 Ankara (Turkey)]. E-mail: oakhan@hacettepe.edu.tr

    2005-09-01

    Pain occurs frequently in patients with advanced cancers. Tumors originating from upper abdominal viscera such as pancreas, stomach, duodenum, proximal small bowel, liver and biliary tract and from compressing enlarged lymph nodes can cause severe abdominal pain, which do not respond satisfactorily to medical treatment or radiotherapy. Percutaneous celiac ganglia block (CGB) can be performed with high success and low complication rates under imaging guidance to obtain pain relief in patients with upper abdominal malignancies. A significant relationship between pain relief and degree of tumoral celiac ganglia invasion according to CT features was described in the literature. Performing the procedure in the early grades of celiac ganglia invasion on CT can increase the effectiveness of the CGB, which is contrary to World Health Organization criteria stating that CGB must be performed in patients with advanced stage cancer. CGB may also be effectively performed in patients with chronic pancreatitis for pain palliation.

  20. Atomic Basic Blocks

    Science.gov (United States)

    Scheler, Fabian; Mitzlaff, Martin; Schröder-Preikschat, Wolfgang

    Die Entscheidung, einen zeit- bzw. ereignisgesteuerten Ansatz für ein Echtzeitsystem zu verwenden, ist schwierig und sehr weitreichend. Weitreichend vor allem deshalb, weil diese beiden Ansätze mit äußerst unterschiedlichen Kontrollflussabstraktionen verknüpft sind, die eine spätere Migration zum anderen Paradigma sehr schwer oder gar unmöglich machen. Wir schlagen daher die Verwendung einer Zwischendarstellung vor, die unabhängig von der jeweils verwendeten Kontrollflussabstraktion ist. Für diesen Zweck verwenden wir auf Basisblöcken basierende Atomic Basic Blocks (ABB) und bauen darauf ein Werkzeug, den Real-Time Systems Compiler (RTSC) auf, der die Migration zwischen zeit- und ereignisgesteuerten Systemen unterstützt.

  1. Anti-blocking model and experimental research on vibrating screen of asphalt mixing plant%沥青搅拌设备振动筛防堵模型与试验研究

    Institute of Scientific and Technical Information of China (English)

    刘洪海; 曾凡记; 程旭; 周峰

    2015-01-01

    The stability of production gradation of mixture is determined by the screening efficiency of vibrating screen of asphalt mixing plant, and the blocking sieve may result in the change of effi-ciency. To study the problem of blocking sieve, a kinematics model of vibrating screen is established and the relationships of vibration parameters, the qualities of eccentric block and vibrating screen, and equivalent rotation radius are determined by analyzing the structure, working mechanism and motion characteristics of vibrating screen;mechanical models of rigid sieve and elastic sieve are es-tablished respectively and the influence of parameters of vibrating screen, such as kinetic parame-ters, physical properties of the material, the size of vibration sieve mesh and mesh stiffness, on blocking screen is explored by analyzing the motion characteristics and dynamics of particles under the condition of blocking screen. The result shows that the blocking rate of 5 mmí5 mm rigid square-hole vibration screen is larger ( more than 10%) , and the escape ability of particles is rela-tively lower under the conventional design of frequency ( 16 Hz ) and amplitude ( 5 mm ) . There-fore, it is necessary to raise the vibration strength and to reduce the blocking rate when the mesh size is less than 6 mm;the elastic sieve of a smaller stiffness is the best solution to avoid increasing tech-nical difficulties or affecting the structure strength of equipment as a result of the increased vibration parameters.%沥青混合料搅拌设备振动筛的筛分效率决定了混合料生产级配的稳定性,堵筛会使筛分效率发生变化。为了研究堵筛问题,通过对振动筛的结构、工作机理和运动特性分析,建立了振动筛的运动学模型,确定了振动参数与偏心块质量、振动筛质量、当量转动半径等参数之间关系;通过对堵筛条件下颗粒的运动特性和动力学分析,分别建立了刚性筛网和弹

  2. The vagus nerve blocking effects on cerebral ischemia in rat model%迷走神经阻断对脑缺血大鼠模型的影响

    Institute of Scientific and Technical Information of China (English)

    王忠; 孙建新; 连军; 吕晓敏; 安娟; 朱虎虎

    2013-01-01

    目的探讨阻断大鼠颈总迷走神经对脑缺血模型大鼠的脑缺血体征和生理指标的影响。方法取雄性SD大鼠40只,随机分为对照组、左侧迷走神经阻断组、右侧迷走神经阻断组和双侧迷走神经阻断组,每组10只。4组大鼠均采取结扎颈总动脉(CCA)的方法建立脑缺血大鼠模型;脑缺血模型建立后,除对照组大鼠不阻断迷走神经外,其余3组大鼠均阻断相应的迷走神经。手术后评价各组大鼠脑缺血体征,检测各组大鼠血压、呼吸和心率指标。结果4组大鼠均出现脑缺血体征,其中双侧迷走神经阻断组大鼠脑缺血体征最为显著,左侧迷走神经和右侧迷走神经阻断组次之,模型对照组最不明显,并且有3只大鼠无脑缺血症状。与对照组大鼠比较,其余3组大鼠呼吸频率减低,心率和血压明显增加,差异具有统计学意义(P <0.05)。结论阻断大鼠颈总迷走神经可加重脑缺血模型大鼠的脑缺血体征,同时可促使大鼠的呼吸变慢变深、心率加快及血压上升。%Objective To discuss vagus nerve blocking effects on the changes of cerebral ischemia symptoms and physiological indexes in rat model .Methods 40 SD male rats were randomly divided into 4 groups(10 each):control group ,left vagal blockade group ,the right vagus nerve block group and bilateral vagotomy group .Four groups were established the model of cerebral ischemia by taking ligation of common carotid artery (CCA) method;the rats in intomodel group were not blocked the vagus nerve ,while the other groups were blocked the vagus nerve .The rats cerebral ischemia ,rats were measured blood pressure , heart rate and respiratory rate of index evaluation after operation .Results 4 groups showed symptoms of cerebral ischemia ,in w hich the cerebral ischemia symptoms of bilateral vagotomy rats are the most signifi-cant ;then the left vagus nerve and the right vagus nerve block

  3. Stopping Condition for Greedy Block Sparse Signal Recovery

    OpenAIRE

    Luo, Yu; Xie, Ronggui; Yin, Huarui; Wang, Weidong

    2016-01-01

    For greedy block sparse recovery where the sparsity level is unknown, we derive a stopping condition to stop the iteration process. Focused on the block orthogonal matching pursuit (BOMP) algorithm, we model the energy of residual signals at each iteration from a probabilistic perspective. At the iteration when the last supporting block is detected, the resulting energy of residual signals is supposed to suffer an obvious decrease. Based on this, we stop the iteration process when the energy ...

  4. Understanding dwarf galaxies as galactic building blocks

    CERN Document Server

    Tosi, M P

    2003-01-01

    This is a summary of a general discussion held during the third EuroConference on galaxy evolution. Various observational features of the stellar populations in present--day dwarf galaxies were presented to introduce the discussion on the possibility that these systems be the main building blocks of spiral and elliptical galaxies. Many people in the audience turned out to think that the inconsistencies among the observed properties of large and dwarf galaxies are too many to believe that the former are built up only by means of successive accretions of the latter. However, theorists of hierarchical galaxy formation suggested that present--day dwarfs are not representative of the galactic building blocks, which may be completely invisible nowadays. Some of them suggested that, contrary to what is usually assumed in hierarchical modelling, the actual building blocks were still fully gaseous systems when their major mergers occurred. If this is the case, then most of the inconsistencies can be overcome, and the ...

  5. Discussion on the paper "Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearest block bootstrap approach"

    Institute of Scientific and Technical Information of China (English)

    LI W.K.; LI GuoDong

    2009-01-01

    @@ The authors are to be congratulated for an innovative paper in terms of both modelling methodology and subject matter significance. The analysis of short time series is known to be difficult even for linear models.

  6. Modelling of current-voltage characteristics of infrared photo-detectors based on type – II InAs/GaSb super-lattice diodes with unipolar blocking layers

    Directory of Open Access Journals (Sweden)

    Vishnu Gopal

    2015-09-01

    Full Text Available It is shown that current-voltage characteristics of infrared photo-detectors based on type-II InAs/GaSb super-lattices with uni-polar blocking layers can be modelled similar to a junction diode with a finite series resistance on account of blocking barriers. As an example this paper presents the results of a study of current-voltage characteristics of a type II InAs/GaSb super-lattice diode with PbIbN architecture using a recently proposed [J. Appl. Phys. 116, 084502 (2014] method for modelling of illuminated photovoltaic detectors. The thermal diffusion, generation – recombination (g-r, and ohmic currents are found as principal components besides a component of photocurrent due to background illumination. The experimentally observed reverse bias diode current in excess of thermal current (diffusion + g-r, photo-current and ohmic shunt current is reported to be best described by an exponential function of the type, Iexcess = Ir0 + K1exp(K2 V, where Ir0, K1 and K2 are fitting parameters and V is the applied bias voltage. The present investigations suggest that the exponential growth of excess current with the applied bias voltage may be taking place along the localized regions in the diode. These localized regions are the shunt resistance paths on account of the surface leakage currents and/or defects and dislocations in the base of the diode.

  7. Face Detection Based on 3×3 Block Gradient Image Partition and Face Geometric Model%基于3×3块梯度图像划分和人脸几何模型的人脸检测

    Institute of Scientific and Technical Information of China (English)

    盛光磊; 张腾; 裴铮

    2013-01-01

      提出一个人脸检测算法,该算法使用3×3块划分的梯度图像和几何人脸模型来进行人脸检测.3×3块划分用来初步检测特定区域中是否有人脸,接下来利用几何人脸模型把人脸检测出来.实验结果表明所提出的人脸检测算法检测结果比较好,并且对于光照并不敏感.%This paper presents a face detection algorithm, the algorithm uses a gradient image of 3 Í3 block partition and geometric human face model for face detection. 3 Í 3 block partition is used to and preliminary detect whether someone in the specific area of the face, followed by the use of geometric face model face detection. The experimental results show that the proposed face detection algorithms to detect better results,and is not sensitive to light.

  8. Dimensional Reduction for Conformal Blocks

    CERN Document Server

    Hogervorst, Matthijs

    2016-01-01

    We consider the dimensional reduction of a CFT, breaking multiplets of the d-dimensional conformal group SO(d+1,1) up into multiplets of SO(d,1). This leads to an expansion of d-dimensional conformal blocks in terms of blocks in d-1 dimensions. In particular, we obtain a formula for 3d conformal blocks as an infinite sum over 2F1 hypergeometric functions with closed-form coefficients.

  9. Analysis of frozen startup of high-temperature heat pipes and three-dimensional modeling of block-heated heat pipes

    Science.gov (United States)

    Faghri, Amir

    1991-11-01

    The use of high-temperature heat pipes has been proposed for cooling the leading edges and nose cones of re-entry vehicles, rail guns, and laser mirrors, as well as for the thermal management of future hypersonic vehicle structures. The startup behavior of high temperature heat pipes from the frozen state was investigated both numerically and experimentally for various heat loads and input locations. A high temperature sodium/stainless steel heat pipe with multiple heat sources and sinks was fabricated, processed, and tested. A numerical simulation of the transient heat pipe performance including the vapor region, wick structure, and the heat pipe wall is given. Furthermore, experimental and numerical analyses of several operating parameters of a low-temperature copper-water heat pipe under uniform circumferential heating and block heating has been performed. Finally, a numerical analysis of transient heat pipe performance including nonconventional heat pipes with nonuniform heat distributions is presented. Numerical calculations were then made for a leading edge heat pipe with localized high heat fluxes.

  10. Common blocks for ASQS(12

    Directory of Open Access Journals (Sweden)

    Lorenzo Milazzo

    1997-05-01

    Full Text Available An ASQS(v is a particular Steiner system featuring a set of v vertices and two separate families of blocks, B and G, whose elements have a respective cardinality of 4 and 6. It has the property that any three vertices of X belong either to a B-block or to a G-block. The parameter cb is the number of common blocks in two separate ASQSs, both defined on the same set of vertices X . In this paper it is shown that cb ≤ 29 for any pair of ASQSs(12.

  11. Combined KHFAC + DC nerve block without onset or reduced nerve conductivity after block

    Science.gov (United States)

    Franke, Manfred; Vrabec, Tina; Wainright, Jesse; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

    2014-10-01

    Objective. Kilohertz frequency alternating current (KHFAC) waveforms have been shown to provide peripheral nerve conductivity block in many acute and chronic animal models. KHFAC nerve block could be used to address multiple disorders caused by neural over-activity, including blocking pain and spasticity. However, one drawback of KHFAC block is a transient activation of nerve fibers during the initiation of the nerve block, called the onset response. The objective of this study is to evaluate the feasibility of using charge balanced direct current (CBDC) waveforms to temporarily block motor nerve conductivity distally to the KHFAC electrodes to mitigate the block onset-response. Approach. A total of eight animals were used in this study. A set of four animals were used to assess feasibility and reproducibility of a combined KHFAC + CBDC block. A following randomized study, conducted on a second set of four animals, compared the onset response resulting from KHFAC alone and combined KHFAC + CBDC waveforms. To quantify the onset, peak forces and the force-time integral were measured during KHFAC block initiation. Nerve conductivity was monitored throughout the study by comparing muscle twitch forces evoked by supra-maximal stimulation proximal and distal to the block electrodes. Each animal of the randomized study received at least 300 s (range: 318-1563 s) of cumulative dc to investigate the impact of combined KHFAC + CBDC on nerve viability. Main results. The peak onset force was reduced significantly from 20.73 N (range: 18.6-26.5 N) with KHFAC alone to 0.45 N (range: 0.2-0.7 N) with the combined CBDC and KHFAC block waveform (p < 0.001). The area under the force curve was reduced from 6.8 Ns (range: 3.5-21.9 Ns) to 0.54 Ns (range: 0.18-0.86 Ns) (p < 0.01). No change in nerve conductivity was observed after application of the combined KHFAC + CBDC block relative to KHFAC waveforms. Significance. The distal application of CBDC can significantly reduce or even

  12. Eikonalization of Conformal Blocks

    CERN Document Server

    Fitzpatrick, A Liam; Walters, Matthew T; Wang, Junpu

    2015-01-01

    Classical field configurations such as the Coulomb potential and Schwarzschild solution are built from the $t$-channel exchange of many light degrees of freedom. We study the CFT analog of this phenomenon, which we term the `eikonalization' of conformal blocks. We show that when an operator $T$ appears in the OPE $\\mathcal{O}(x) \\mathcal{O}(0)$, then the large spin $\\ell$ Fock space states $[TT \\cdots T]_{\\ell}$ also appear in this OPE with a computable coefficient. The sum over the exchange of these Fock space states in an $\\langle \\mathcal{O} \\mathcal{O} \\mathcal{O} \\mathcal{O} \\rangle$ correlator build the classical `$T$ field' in the dual AdS description. In some limits the sum of all Fock space exchanges can be represented as the exponential of a single $T$ exchange in the 4-pt correlator of $\\mathcal{O}$. Our results should be useful for systematizing $1/\\ell$ perturbation theory in general CFTs and simplifying the computation of large spin OPE coefficients. As examples we obtain the leading $\\log \\ell$...

  13. 多层断块油藏台阶水平井渗流模型研究%Seepage Model Research of Multi-layer Fault Block Reservoir of Horizontal Steps

    Institute of Scientific and Technical Information of China (English)

    庞进; 雷光伦; 刘洪

    2013-01-01

    The seepage mechanism and law of the multilayer complex fault block reservoirs benching horizontal well drilling is complex.Based on the transient flow mathematical model,a seepage mathematical model has been established about the benching horizontal well with the reservoir coupling through the multiple non-connected reservoirs in a closed reservoirs.It is solved by Laplace transformation,Stehfest inversion and conjugate gradient methods.And the pressure distribution in different times and production distribution in different intervals are obtained.When comparing the calculation results with those of Saphir,the model is proved high reliability.A two-layer block fault reservoir has carried on the case study through the model.On the basis of the simplification of reservoir shape,and by using two benching horizontal well model simulation calculate is studied.It can accurately calculate the bottom hole pressure and the wellbore production distribution at different production stages.It provides a theoretical basis for the reservoir engineering research and production engineering design of the multilayer fault block reservoir benching horizontal well development.%多层复杂断块油藏台阶式水平井开采的渗流机理和规律复杂.以非稳态流动数学模型为基础,建立了封闭油藏中一口穿过多个互不连通油藏的台阶式水平井与油藏耦合的渗流数学模型,并采用拉普拉斯变化、Stehfest反演以及共轭梯度法等方法进行求解,获取了不同时刻的压力分布结果和不同井段的产量分布结果.利用该模型与saphir软件计算结果进行对比,模型的可靠性强.利用该模型对某两层断块油藏进行了实例研究,在对油藏形状简化的基础上,利用两台阶水平井模型进行了模拟计算,能够准确计算出不同生产阶段的井底压力和井筒产量分布.为多层断块油藏采用台阶水平井开发的油藏工程研究和采油工程设计提供了理论依据.

  14. Adductor Canal Block versus Femoral Nerve Block and Quadriceps Strength

    DEFF Research Database (Denmark)

    Jæger, Pia Therese; Nielsen, Zbigniew Jerzy Koscielniak; Henningsen, Lene Marianne;

    2013-01-01

    : The authors hypothesized that the adductor canal block (ACB), a predominant sensory blockade, reduces quadriceps strength compared with placebo (primary endpoint, area under the curve, 0.5-6 h), but less than the femoral nerve block (FNB; secondary endpoint). Other secondary endpoints were...

  15. DYNAMIC DESIGN OF INTERNAL COMBUSTION ENGINE BLOCK STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Several main steps of internal combustion engine block structure dynamic design,such as model set-up,structure dynamic response analysis,optimizing design and vibration and noise control,are discussed for the type of EQ6100 gasoline engine block.

  16. Reports on block rotations, fault domains and crustal deformation

    Science.gov (United States)

    Nur, Amos

    1990-01-01

    Studies of block rotations, fault domains and crustal deformation in the western United States, Israel, and China are discussed. Topics include a three-dimensional model of crustal fracture by distributed fault sets, distributed deformation and block rotation in 3D, stress field rotation, and multiple strike slip fault sets.

  17. Building a Case for Blocks as Kindergarten Mathematics Learning Tools

    Science.gov (United States)

    Kinzer, Cathy; Gerhardt, Kacie; Coca, Nicole

    2016-01-01

    Kindergarteners need access to blocks as thinking tools to develop, model, test, and articulate their mathematical ideas. In the current educational landscape, resources such as blocks are being pushed to the side and being replaced by procedural worksheets and academic "seat time" in order to address standards. Mathematics research…

  18. Three-dimensional local grid refinement for block-centered finite-difference groundwater models using iteratively coupled shared nodes: A new method of interpolation and analysis of errors

    Science.gov (United States)

    Mehl, S.; Hill, M.C.

    2004-01-01

    This paper describes work that extends to three dimensions the two-dimensional local-grid refinement method for block-centered finite-difference groundwater models of Mehl and Hill [Development and evaluation of a local grid refinement method for block-centered finite-difference groundwater models using shared nodes. Adv Water Resour 2002;25(5):497-511]. In this approach, the (parent) finite-difference grid is discretized more finely within a (child) sub-region. The grid refinement method sequentially solves each grid and uses specified flux (parent) and specified head (child) boundary conditions to couple the grids. Iteration achieves convergence between heads and fluxes of both grids. Of most concern is how to interpolate heads onto the boundary of the child grid such that the physics of the parent-grid flow is retained in three dimensions. We develop a new two-step, "cage-shell" interpolation method based on the solution of the flow equation on the boundary of the child between nodes shared with the parent grid. Error analysis using a test case indicates that the shared-node local grid refinement method with cage-shell boundary head interpolation is accurate and robust, and the resulting code is used to investigate three-dimensional local grid refinement of stream-aquifer interactions. Results reveal that (1) the parent and child grids interact to shift the true head and flux solution to a different solution where the heads and fluxes of both grids are in equilibrium, (2) the locally refined model provided a solution for both heads and fluxes in the region of the refinement that was more accurate than a model without refinement only if iterations are performed so that both heads and fluxes are in equilibrium, and (3) the accuracy of the coupling is limited by the parent-grid size - A coarse parent grid limits correct representation of the hydraulics in the feedback from the child grid.

  19. Using Reliability Block Diagrams and Fault Tree circuits, to develop a Condition Based Maintenance Model for a Vessel’s Main Propulsion System and Related Subsystems

    Directory of Open Access Journals (Sweden)

    Mohan Anantharaman

    2013-09-01

    Full Text Available Merchant shipping has undergone a great transformation over the past three decades. The shipping market is highly competitive, which coupled with high crewing and fuel costs, leads to high operational costs. One of the paramount factor involved in vessel operation is the Maintenance cost and there is a dire need to keep this cost to a minimum. Fortunately the earlier policy of repair only maintenance in commercial shipping has been done away with, and was replaced by the policy of preventive maintenance. Planned Maintenance System was introduced by ship management companies in the early 90’s. Planned Maintenance offered benefits over the repair only policy, but has its own demerits. Many a time machinery equipment is opened up for routine maintenance after a specified time interval, irrespective of the need. This could lead to potential failures, which is explained by the fact that preventive maintenance resulted in meddling of a well set piece of machinery equipment, leading to its subsequent failure. This is where Condition based maintenance or CBM steps into prominence. CBM monitors the health of the machinery equipment, analyses the condition and helps you in decision making. The Main Propulsion system forms the heart of a vessel and we need to ensure its reliability, together with the reliability of its associated sub-systems. The entire system can be represented by reliability block diagrams, to show the interdependence of various components comprising the system. This helps in the decision making process of CBM whereby ship’s engineer may decide to stop the running machinery equipment, open and overhaul the same, else postpone the overhaul for a later safe date.

  20. Osmosis and thermodynamics explained by solute blocking

    CERN Document Server

    Nelson, Peter Hugo

    2016-01-01

    A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed, others can be tested experimentally or by simulation.

  1. Osmosis and thermodynamics explained by solute blocking.

    Science.gov (United States)

    Nelson, Peter Hugo

    2017-01-01

    A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.

  2. Block Transfer Agreement Evaluation Project

    Science.gov (United States)

    Bastedo, Helena

    2010-01-01

    The objective of this project is to evaluate for the British Columbia Council on Admissions and Transfer (BCCAT) the effectiveness of block transfer agreements (BTAs) in the BC Transfer System and recommend steps to be taken to improve their effectiveness. Findings of this study revealed that institutions want to expand block credit transfer;…

  3. Four-block beam collimator

    CERN Multimedia

    1977-01-01

    The photo shows a four-block collimator installed on a control table for positioning the alignment reference marks. Designed for use with the secondary beams, the collimators operated in vacuum conditions. The blocks were made of steel and had a standard length of 1 m. The maximum aperture had a square coss-section of 144 cm2. (See Annual Report 1976.)

  4. OPAL Various Lead Glass Blocks

    CERN Multimedia

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  5. Block storage subsystem performance analysis

    CERN Document Server

    CERN. Geneva

    2016-01-01

    You feel that your service is slow because of the storage subsystem? But there are too many abstraction layers between your software and the raw block device for you to debug all this pile... Let's dive on the platters and check out how the block storage sees your I/Os! We can even figure out what those patterns are meaning.

  6. 摆宴井复杂断块油藏地质建模技术研究%The techniques of the building geologic model in complicate fault block oil reservoir

    Institute of Scientific and Technical Information of China (English)

    常水涛; 侯亚云; 李坪东; 张鹏刚; 赵辉

    2009-01-01

    摆宴井油田属于复杂断块油藏,开发历史长,受前期地质资料的影响,无论测井资料及地震资料都相对较老,质量不高,可靠性较差.着重阐述了测井数据标准化处理及结合生产动态重新认识和划分复杂断块下地质模型建立,以挖掘剩余油分布的研究.%Baiyanjing oil filed is a complicate fault block oil reservoir with long exploitation history. Based on earlier geologic information,No matter well log information or seismologic date are relative old,low quality and short of dependability. In order to digging remaining oil distribution,this paper mainly presents log date normslization processing and geologic model building,which is going after re-cognizance and divide complicate fault block combining production performance.

  7. Dynamics and sensitivity analysis of high-frequency conduction block

    Science.gov (United States)

    Ackermann, D. Michael; Bhadra, Niloy; Gerges, Meana; Thomas, Peter J.

    2011-10-01

    The local delivery of extracellular high-frequency stimulation (HFS) has been shown to be a fast acting and quickly reversible method of blocking neural conduction and is currently being pursued for several clinical indications. However, the mechanism for this type of nerve block remains unclear. In this study, we investigate two hypotheses: (1) depolarizing currents promote conduction block via inactivation of sodium channels and (2) the gating dynamics of the fast sodium channel are the primary determinate of minimal blocking frequency. Hypothesis 1 was investigated using a combined modeling and experimental study to investigate the effect of depolarizing and hyperpolarizing currents on high-frequency block. The results of the modeling study show that both depolarizing and hyperpolarizing currents play an important role in conduction block and that the conductance to each of three ionic currents increases relative to resting values during HFS. However, depolarizing currents were found to promote the blocking effect, and hyperpolarizing currents were found to diminish the blocking effect. Inward sodium currents were larger than the sum of the outward currents, resulting in a net depolarization of the nodal membrane. Our experimental results support these findings and closely match results from the equivalent modeling scenario: intra-peritoneal administration of the persistent sodium channel blocker ranolazine resulted in an increase in the amplitude of HFS required to produce conduction block in rats, confirming that depolarizing currents promote the conduction block phenomenon. Hypothesis 2 was investigated using a spectral analysis of the channel gating variables in a single-fiber axon model. The results of this study suggested a relationship between the dynamical properties of specific ion channel gating elements and the contributions of corresponding conductances to block onset. Specifically, we show that the dynamics of the fast sodium inactivation gate are

  8. Bridging Block and Bundesen

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik

    that some fields in cognitive science are already gaining ground on the hard problem. An interesting model is Claus Bundesen‘s (1990) Theory of Visual Attention (TVA) that seems to be compatible with Ned Block‘s (1995) distinction between access consciousness and phenomenal consciousness. TVA proposes a two......-part stochastic model where 1) every stimulus is given a weight in terms of belonging to a certain visual category and 2) every stimulus then enters a race for a place in a limited-capacity visual short-term memory store. TVA seems to be a good model to describe access consciousness; by expanding this model......Consciousness seems to present a special challenge for scientific investigation. Much research has been done on the so-called "easy" aspects of consciousness such as perception, attention, and memory. The "hard problem", however, still seems to elude scientific methods. In this paper I argue...

  9. Exploring atmospheric blocking with GPS radio occultation observations

    Directory of Open Access Journals (Sweden)

    L. Brunner

    2015-12-01

    Full Text Available Atmospheric blocking has been closely investigated in recent years due to its impact on weather and climate, such as heat waves, droughts, and flooding. We use, for the first time, satellite-based observations from Global Positioning System (GPS radio occultation (RO and explore their ability to resolve blocking in order to potentially open up new avenues complementing models and re-analyses. RO delivers globally available and vertically high resolved profiles of atmospheric variables such as temperature and geopotential height (GPH. Applying a standard blocking detection algorithm we find that RO data robustly capture blocking as demonstrated for two well-known blocking events over Russia in summer 2010 and over Greenland in late winter 2013. During blocking episodes, vertically resolved GPH gradients show a distinct anomalous behavior compared to climatological conditions up to 300 hPa and sometimes even further up to the tropopause. The accompanied increase in GPH of up to 300 m in the upper troposphere yields a pronounced tropopause height increase. Corresponding temperatures rise up to 10 K in the middle and lower troposphere. These results demonstrate the feasibility and potential of RO to detect and resolve blocking and in particular to explore the vertical structure of the atmosphere during blocking episodes. This new observation-based view is available globally at the same quality so that also blocking in the Southern Hemisphere can be studied with the same reliability as in the Northern Hemisphere.

  10. Mechanisms and Rates of Plucking of Experimental Bedrock Blocks

    Science.gov (United States)

    Harbor, D. J.; Wilkinson, C.; Helgans, E.; Kuehner, J. P.

    2015-12-01

    Plucking in bedrock channels can be the dominant erosional mechanism but is difficult to predict numerically due to variation in block shape and orientation in the flow, and the general lack of experimental data compared to alluvial sediments. In a 250 cm-long, 14 cm-wide flume, we modeled bedrock channels using a bedrock test zone consisting of flow over an upstream step of 0 to 1.6 cm, a bed slope of 0.5 to1.24%, and a changing downstream backwater control on the location of a hydraulic jump. With flow velocity from 50 to 100 cm/s and depth from 3 to 10 cm, the low-density bedrock may well characterize natural bedrock plucking events in larger rivers in flood. Plucking initiated in critical to supercritical flow near hydraulic jumps. The first blocks to move lift from both the upstream and downstream sides and then other blocks slide both up- and downstream or laterally once neighbors are removed. Initiation of motion from each new bedrock slab began with different size and shape of blocks exhibiting no protrusion relative to the surrounding bed. Block erodibility increased with step height and channel slope and following the removal of the first block. A pressure gradient within the block mass near the jump and velocity differential within the channel margin set the stage for block uplift, but flow structures likely provide the variability that initiates lift. Preliminary flow visualization using Particle Image Velocimetry aids the understanding of flow structures contributing to blocks lift. Negative and positive feedback to further plucking was observed by erosion and deposition of plucked blocks. After their initial removal, blocks can accumulate downstream and slow the flow over the eroded reach or the position of jumps and jets shift with block removal to promote further plucking.

  11. Systemic Administration of Polymeric Nanoparticle-Encapsulated Curcumin (NanoCurc) Blocks Tumor Growth and Metastases in Preclinical Models of Pancreatic Cancer

    NARCIS (Netherlands)

    Bisht, Savita; Mizuma, Masamichi; Feldmann, Georg; Ottenhof, Niki A.; Hong, Seung-Mo; Pramanik, Dipankar; Chenna, Venugopal; Karikari, Collins; Sharma, Rajni; Goggins, Michael G.; Rudek, Michelle A.; Ravi, Rajani; Maitra, Amarnath; Maitra, Anirban

    2010-01-01

    Curcumin or diferuloylmethane is a yellow polyphenol extracted from the rhizome of turmeric (Curcuma longa). A large volume (several hundreds) of published reports has established the anticancer and chemopreventative properties of curcumin in preclinical models of every known major cancer type. Neve

  12. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-03-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  13. Nanostructured Block Copolymer Coatings for Biofouling Inhibition

    Science.gov (United States)

    2015-06-30

    biofouling program contractors. 15. SUBJECT TERMS antifouling; coatings; block copolymers; IR nanoscale imaging ; biocides 16. SECURITY CLASSIFICATION OF...diagnostics and drug delivery. In our scanned probe microscopy studies on collaborator coatings and marine organisms, we have provided teamwork . We have...Studies of Organisms on model fouiants: • H. elegans studies 3. Testing of other contractor materials 4. Imaging technology. We applied our organic

  14. MarineMineralsProgramBlocks

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains OCS block outlines and delineated polygons in ESRI ArcGIS shape file format for the BOEM Gulf of Mexico Region that contain sediment resources...

  15. Hawaii Census 2000 Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer represents Census 2000 demographic data derived from the PL94-171 redistricting files and SF3. Census geographic entities include blocks, blockgroups...

  16. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter;

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  17. SKLB023 blocks joint inflammation and cartilage destruction in arthritis models via suppression of nuclear factor-kappa B activation in macrophage.

    Directory of Open Access Journals (Sweden)

    Caifeng Xie

    Full Text Available Rheumatoid arthritis (RA is the most common arthritis and is mainly characterized by symmetric polyarticular joint disorders. Our previous study demonstrated a novel small molecule compound (Z-N-(3-Chlorophenyl-2-(4-((2,4-dioxothiazolidin-5-ylidene methyl phenoxy acet-amide (SKLB023 showed potently anti-arthritic effects in a rat arthritis model, however, the underlying mechanisms for this are largely unknown. Both NF-κB and macrophages were reported to play important roles in the pathologic processes of RA. The purposes of this study were to indicate whether NF-κB and macrophages contributed to anti-arthritic effects of SKLB023 in two experimental arthritis models. Our results showed that SKLB023 could significantly improve joint inflammation and cartilage destruction both in adjuvant induced arthritis (AIA and collagen-induced arthritis (CIA models. We further found that the binding activation of NF-κB to DNA in joint tissues and RAW264.7 macrophages were suppressed by SKLB023. SKLB023 also inhibited the NF-κB activity in peritoneal macrophages by luciferase assay. Furthermore, the number of macrophages in synovial tissues was decreased after the treatment of different doses of SKLB023. The levels of TNF-α, IL-1β, and IL-6 in plasma, and the levels of TNF-α, NO, and IL-1β in peritoneal macrophages were down-regulated by SKLB023. Finally, SKLB023 attenuated the expression of iNOS and COX-2 in vivo and suppressed the phosphorylations of components of the mitogen-activated protein kinases (MAPKs. These observations identify a novel function for SKLB023 as an inhibitor of NF-κB in macrophages of RA, highlighting that SKLB023 was a potential therapeutic strategy for RA.

  18. NANOSTRUCTURES OF FUNCTIONAL BLOCK COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    Guojun Liu

    2000-01-01

    Nanostructure fabrication from block copolymers in my group normally involves polymer design, synthesis, selfassembly, selective domain crosslinking, and sometimes selective domain removal. Preparation of thin films with nanochannels was used to illustrate the strategy we took. In this particular case, a linear triblock copolymer polyisopreneblock-poly(2-cinnamoylethyl methacrylate)-block-poly(t-butyl acrylate), PI-b-PCEMA-b-PtBA, was used. Films, 25 to50μm thick, were prepared from casting on glass slides a toluene solution of PI-b-PCEMA-b-PtBA and PtBA homopolymer,hPtBA, where hPtBA is shorter than the PtBA block. At the hPtBA mass fraction of 20% relative to the triblock or the total PtBA (hPtBA and PtBA block) volume fraction of 0.44, hPtBA and PtBA formed a seemingly continuous phase in the matrix of PCEMA and PI. Such a block segregation pattern was locked in by photocrosslinking the PCEMA domain. Nanochannels were formed by extracting out hPtBA with solvent. Alternatively, larger channels were obtained from extracting out hPtBA and hydrolyzing the t-butyl groups of the PtBA block. Such membranes were not liquid permeable but had gas permeability constants ~6 orders of magnitude higher than that of low-density polyethylene films.

  19. Examining the meaning of the peptide transfer free energy obtained from blocked (Gly)_n and cyclic-diglycine model compounds

    CERN Document Server

    Asthagiri, D; Weber, V

    2013-01-01

    In experiments, the free energy of transferring the peptide group from water to an osmolyte solution is obtained using the transfer free energy of (Gly)_n with the added assumption that a constant incremental change in free energy with n implies that each additional unit makes an independent contribution to the free energy. Here we test this assumption and uncover its limitations. Together with results for cyclic-diglycine, we show that, in principle, it is not possible to obtain a peptide group transfer free energy that is independent of the model system. We calculate the hydration free energy of acetyl-(Gly)_n-methyl amide (n=1..7) peptides modeled in the extended conformation in water and osmolyte solutions and find that the hydration free energy is linear in n, suggestive of independent, additive group-contributions. To probe the observed linearity further, we study the hydration of the solute bereft of water molecules in the first hydration shell. This conditioned solute arises naturally in the theoretic...

  20. Deletion of caspase-8 in mouse myeloid cells blocks microglia pro-inflammatory activation and confers protection in MPTP neurodegeneration model.

    Science.gov (United States)

    Kavanagh, Edel; Burguillos, Miguel Angel; Carrillo-Jimenez, Alejandro; Oliva-Martin, María José; Santiago, Martiniano; Rodhe, Johanna; Joseph, Bertrand; Venero, Jose Luis

    2015-09-01

    Increasing evidence involves sustained pro-inflammatory microglia activation in the pathogenesis of different neurodegenerative diseases, particularly Parkinson's disease (PD). We recently uncovered a completely novel and unexpected role for caspase-8 and its downstream substrates caspase-3/7 in the control of microglia activation and associated neurotoxicity to dopaminergic cells. To demonstrate the genetic evidence, mice bearing a floxed allele ofCASP8 were crossed onto a transgenic line expressing Cre under the control of Lysozyme 2 gene. Analysis of caspase-8 gene deletion in brain microglia demonstrated a high efficiency in activated but not in resident microglia. Mice were challenged with lipopolysaccharide, a potent inducer of microglia activation, or with MPTP, which promotes specific dopaminergic cell damage and consequent reactive microgliosis. In neither of these models, CASP8 deletion appeared to affect the overall number of microglia expressing the pan specific microglia marker, Iba1. In contrast, CD16/CD32 expression, a microglial pro-inflammatory marker, was found to be negatively affected upon CASP8 deletion. Expression of additional proinflammatory markers were also found to be reduced in response to lipopolysaccharide. Of importance, reduced pro-inflammatory microglia activation was accompanied by a significant protection of the nigro-striatal dopaminergic system in the MPTP mouse model of PD.

  1. Biodegradable nanofiber-membrane for sustainable release of lidocaine at the femoral fracture site as a periosteal block: In vitro and in vivo studies in a rabbit model.

    Science.gov (United States)

    Chou, Ying-Chao; Cheng, Yi-Shiun; Hsu, Yung-Heng; Yu, Yi-Hsun; Liu, Shih-Jung

    2016-04-01

    The aim of this study was to evaluate the efficacy of a biodegradable, lidocaine-embedded, nanofibrous membrane for the sustainable analgesic release onto fragments of a segmental femoral fracture site. Membranes of three different lidocaine concentrations (10%, 30%, and 50%) were produced via an electrospinning technique. In vitro lidocaine release was assessed by high-performance liquid chromatography. A femoral segmental fracture, with intramedullary Kirschner-wire fixation and polycaprolactone stent enveloping the fracture site, was set-up in a rabbit model for in vivo assessment of post-operative recovery of activity. Eighteen rabbits were randomly assigned to three groups (six rabbits per group): group A comprised of rabbits with femoral fractures and underwent fixation; group B comprised of a comparable fracture model to that of group A with the implantation of lidocaine-loaded nanofibers; and group C, the control group, received only anesthesia. The following variables were measured: change in body weight, food and water intake before and after surgery, and total activity count post-surgery. All membranes eluted effective levels of lidocaine for more than 3 weeks post-surgery. Rabbits in group B showed faster recovery of activity post-operatively, compared with those in group A, which confirmed the pain relief efficacy of the lidocaine-embedded nanofibers. Nanofibers with sustainable lidocaine release have adequate efficacy and durability for pain relief in rabbits with segmental long bone fractures.

  2. Study of the Optimal Precursors for Blocking Events

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhina; LUO Dehai

    2005-01-01

    The precursors of dipole blocking are obtained by a numerical approach based upon a quasi-geostrophic barotropic planetary- to synoptic-scale interaction model without topography and with a localized synopticscale wave-maker. The optimization problem related to the precursors of blocking is formulated and the nonlinear optimization method is used to examine the optimal synoptic-scale initial field successfully. The results show that the prominent characteristics of the optimal synoptic-scale initial field are that the synoptic-scale wave train structures exist upstream of the incipient blocking. In addition, the large-scale low/high eddy-forcing pattern upstream of the incipient blocking is an essential precondition for the onset of dipole blocking.

  3. Yard crane scheduling model and algorithm in mixture storage block%混堆集装箱箱区内场桥调度模型与算法

    Institute of Scientific and Technical Information of China (English)

    郑红星; 于凯

    2015-01-01

    在混堆模式下的集装箱港口中,场桥(YC)调度是否合理直接影响着堆场的作业效率。考虑到混堆箱区内各任务对应的内集卡或外集卡到达时刻的不同,以及内外集卡优先级别的差异,构建了一个以所有集卡的等待成本和场桥的总移动成本最小为目标的场桥调度(YCS)模型,并设计了对应的遗传算法,给出了相应遗传算子的操作规则,通过算例的求解验证了模型与算法的有效性。%In the mixture storage mode of container port, Yard Crane(YC)scheduling that is reasonable or not will directly affect the yard operation efficiency. The arrival time of container truck corresponding to each task is different, but internal and external container truck have different priority levels. Considering all the above situations, this paper establishes a Yard Cranes Scheduling(YCS)model to minimize the waiting cost of trucks and moving cost of yard cranes. Then it designs a Genetic Algorithm(GA)and gives the corresponding operators. A numerical experiment is used to validate the efficiency of the model and the algorithm.

  4. Skin delivery by block copolymer nanoparticles (block copolymer micelles).

    Science.gov (United States)

    Laredj-Bourezg, Faiza; Bolzinger, Marie-Alexandrine; Pelletier, Jocelyne; Valour, Jean-Pierre; Rovère, Marie-Rose; Smatti, Batoule; Chevalier, Yves

    2015-12-30

    Block copolymer nanoparticles often referred to as "block copolymer micelles" have been assessed as carriers for skin delivery of hydrophobic drugs. Such carriers are based on organic biocompatible and biodegradable materials loaded with hydrophobic drugs: poly(lactide)-block-poly(ethylene glycol) copolymer (PLA-b-PEG) nanoparticles that have a solid hydrophobic core made of glassy poly(d,l-lactide), and poly(caprolactone)-block-poly(ethylene glycol) copolymer (PCL-b-PEG) nanoparticles having a liquid core of polycaprolactone. In vitro skin absorption of all-trans retinol showed a large accumulation of retinol in stratum corneum from both block copolymer nanoparticles, higher by a factor 20 than Polysorbate 80 surfactant micelles and by a factor 80 than oil solution. Additionally, skin absorption from PLA-b-PEG nanoparticles was higher by one order of magnitude than PCL-b-PEG, although their sizes (65nm) and external surface (water-swollen PEG layer) were identical as revealed by detailed structural characterizations. Fluorescence microscopy of histological skin sections provided a non-destructive picture of the storage of Nile Red inside stratum corneum, epidermis and dermis. Though particle cores had a different physical states (solid or liquid as measured by (1)H NMR), the ability of nanoparticles for solubilization of the drug assessed from their Hildebrand solubility parameters appeared the parameter of best relevance regarding skin absorption.

  5. Computational fluid dynamics analysis of core bypass flow and crossflow in a prismatic very high temperature gas-cooled nuclear reactor based on a two-layer block model

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huhu, E-mail: huhuwang@tamu.edu [Department of Nuclear Engineering, Texas A and M University, 3133 TAMU, College Station, TX 77840 (United States); Dominguez-Ontiveros, Elvis, E-mail: elvisdom@tamu.edu [Department of Nuclear Engineering, Texas A and M University, 3133 TAMU, College Station, TX 77840 (United States); Hassan, Yassin A., E-mail: y-hassan@tamu.edu [Department of Nuclear Engineering, Texas A and M University, 3133 TAMU, College Station, TX 77840 (United States); Department of Mechanical Engineering, Texas A and M University, 3123 TAMU, College Station, TX 77840 (United States)

    2014-03-15

    Highlights: • A CFD model was built based on a two-layer block experimental facility at Texas A and M University. • The coolant characterizations within the uniform and wedge-shaped crossflow gap regions were investigated. • The influence on the coolant distribution from the bypass flow gap width was studied. • Discretization and iterative errors involved in the simulations were quantified. - Abstract: The very high temperature gas-cooled nuclear reactor (VHTR) has been designated as one of the promising reactors that will serve for the Next Generation (Generation IV) Nuclear Plant. For a prismatic VHTR core, the bypass flow and crossflow phenomena are important design considerations. To investigate the coolant distribution in the reactor core based on the two-layer block facility built at Texas A and M University, a three-dimensional steady-state CFD analysis was performed using the commercial code STAR-CCM+ v6.04. Results from this work serve as a guideline and validating source for the related experiments. A grid independence study was conducted to quantify related errors in the simulations. The simulation results show that the bypass flow fraction was not a strong function of the Reynolds number. The presence of the crossflow gap had a significant effect on the distribution of the coolant in the core. Uniform and wedge-shape crossflow gaps were studied. It was found that a significant secondary flow in the crossflow gap region moved from the bypass flow gap toward coolant holes, which resulted in up to a 28% reduction of the coolant mass flow rate in the bypass flow gap.

  6. Research on Small and Medium-sized Enterprises Financing Models from the Perspective of Blocks Economy%街区经济视角下的中小企业融资模式研究

    Institute of Scientific and Technical Information of China (English)

    洪增林; 李微山

    2011-01-01

    针对中小企业融资难的问题,结合复杂适应系统理论分析中小企业融资的复杂性.从街区经济的视角,分析了街区经济的发展对中小企业融资的促进作用,引入了中小企业集合债券融资,联保贷款融资、商圈担保融资、经营权质押融资和知识产权质押融资等融资模式,以西安市莲湖区西大街和海纳汽配城融资为例进行分析,为地方政府扶持中小企业融资提供依据.%Aiming at research of the problem about small and medium-sized enterprises financing, by applying CAS theory to analyzing complexity of SMEs financing system. From the perspective of blocks economic, it is found out that the development of the blocks economy was helpful for SMEs financing. On the research of small collection of bonds, peer-selection financing model, business circle guarantee financing, intellectual property mortgage loan and franchise mortgage loan, analyzing two examples about XiDaJie and HaiNa of lianHu area of Xi'an city, which is helpful for policy-making of local governments.

  7. Self-assembly of semiflexible-flexible block copolymers

    Science.gov (United States)

    Kumar, Arun; Ganesan, Venkat

    2012-02-01

    We apply self-consistent Brownian dynamics simulations to study the self-assembly behavior of semiflexible-flexible block copolymers. A Maier-Saupe interaction model was applied for the orientational interactions between the semiflexible polymers, while the enthalpic interactions between semiflexible and flexible polymers were modeled through a standard Flory-Huggins approach. To develop a physical understanding of the phases and their regimes of occurrence as a function of varying persistence length of the semiflexible block, we computed the 2D phase diagram for our model. We quantify the progression of the self-assembly morphologies in transitioning from coil-coil block copolymers on the one hand to rod-coil block copolymers on the other hand. The results obtained are in qualitative agreement with the existing experimental and numerical results.

  8. Essential Building Blocks of Human Nature

    CERN Document Server

    Frey, Ulrich J; Willführ, Kai P

    2011-01-01

    To understand why we humans are as we are, it is necessary to look at the essential building blocks that comprise our nature. The foundations of this structure are our evolutionary origins as primates and our social roots. Upon these rest features such as our emotions, language and aesthetic preferences, with our self-perceptions, self-deceptions and thirst for knowledge right at the top. The unifying force holding these blocks together is evolutionary theory. Evolution provides a deeper understanding of human nature and, in particular, of the common roots of these different perspectives. To build a reliable and coherent model of man, leading authors from fields as diverse as primatology, anthropology, neurobiology and philosophy have joined forces to present essays  each describing their own expert perspective. Together they provide a convincing and complete picture of our own human nature.

  9. Shifting wavelengths of ultraweak photon emissions from dying melanoma cells: their chemical enhancement and blocking are predicted by Cosic's theory of resonant recognition model for macromolecules.

    Science.gov (United States)

    Dotta, Blake T; Murugan, Nirosha J; Karbowski, Lukasz M; Lafrenie, Robert M; Persinger, Michael A

    2014-02-01

    During the first 24 h after removal from incubation, melanoma cells in culture displayed reliable increases in emissions of photons of specific wavelengths during discrete portions of this interval. Applications of specific filters revealed marked and protracted increases in infrared (950 nm) photons about 7 h after removal followed 3 h later by marked and protracted increases in near ultraviolet (370 nm) photon emissions. Specific wavelengths within the visible (400 to 800 nm) peaked 12 to 24 h later. Specific activators or inhibitors for specific wavelengths based upon Cosic's resonant recognition model elicited either enhancement or diminishment of photons at the specific wavelength as predicted. Inhibitors or activators predicted for other wavelengths, even within 10 nm, were less or not effective. There is now evidence for quantitative coupling between the wavelength of photon emissions and intrinsic cellular chemistry. The results are consistent with initial activation of signaling molecules associated with infrared followed about 3 h later by growth and protein-structural factors associated with ultraviolet. The greater-than-expected photon counts compared with raw measures through the various filters, which also function as reflective material to other photons, suggest that photons of different wavelengths might be self-stimulatory and could play a significant role in cell-to-cell communication.

  10. The influence of the Gulf Stream on wintertime European blocking

    Science.gov (United States)

    O'Reilly, Christopher H.; Minobe, Shoshiro; Kuwano-Yoshida, Akira

    2016-09-01

    Wintertime blocking is responsible for extended periods of anomalously cold and dry weather over Europe. In this study, the influence of the Gulf Stream sea surface temperature (SST) front on wintertime European blocking is investigated using a reanalysis dataset and a pair of atmospheric general circulation model (AGCM) simulations. The AGCM is forced with realistic and smoothed Gulf Stream SST, and blocking frequency over Europe is found to depend crucially on the Gulf Stream SST front. In the absence of the sharp SST gradient European blocking is significantly reduced and occurs further downstream. The Gulf Stream is found to significantly influence the surface temperature anomalies during blocking periods and the occurrence of associated cold spells. In particular the cold spell peak, located in central Europe, disappears in the absence of the Gulf Stream SST front. The nature of the Gulf Stream influence on European blocking development is then investigated using composite analysis. The presence of the Gulf Stream SST front is important in capturing the observed quasi-stationary development of European blocking. The development is characterised by increased lower-tropospheric meridional eddy heat transport in the Gulf Stream region and increased eddy kinetic energy at upper-levels, which acts to reinforce the quasi-stationary jet. When the Gulf Stream SST is smoothed the storm track activity is weaker, the development is less consistent and European blocking occurs less frequently.

  11. Optimal Backward Perturbation Analysis for the Block Skew Circulant Linear Systems with Skew Circulant Blocks

    Directory of Open Access Journals (Sweden)

    Zhaolin Jiang

    2014-01-01

    Full Text Available We first give the block style spectral decomposition of arbitrary block skew circulant matrix with skew circulant blocks. Secondly, we obtain the singular value of block skew circulant matrix with skew circulant blocks as well. Finally, based on the block style spectral decomposition, we deal with the optimal backward perturbation analysis for the block skew circulant linear system with skew circulant blocks.

  12. Erosion patterns on dissolving blocks

    Science.gov (United States)

    Courrech du Pont, Sylvain; Cohen, Caroline; Derr, Julien; Berhanu, Michael

    2016-04-01

    Patterns in nature are shaped under water flows and wind action, and the understanding of their morphodynamics goes through the identification of the physical mechanisms at play. When a dissoluble body is exposed to a water flow, typical patterns with scallop-like shapes may appear [1,2]. These shapes are observed on the walls of underground rivers or icebergs. We experimentally study the erosion of dissolving bodies made of salt, caramel or ice into water solutions without external flow. The dissolving mixture, which is created at the solid/liquid interface, undergoes a buoyancy-driven instability comparable to a Rayleigh-Bénard instability so that the dissolving front destabilizes into filaments. This mechanism yields to spatial variations of solute concentration and to differential dissolution of the dissolving block. We first observe longitudinal stripes with a well defined wavelength, which evolve towards chevrons and scallops that interact and move again the dissolving current. Thanks to a careful analysis of the competing physical mechanisms, we propose scaling laws, which account for the characteristic lengths and times of the early regime in experiments. The long-term evolution of patterns is understood qualitatively. A close related mechanism has been proposed to explain structures observed on the basal boundary of ice cover on brakish lakes [3] and we suggest that our experiments are analogous and explain the scallop-like patterns on iceberg walls. [1] P. Meakin and B. Jamtveit, Geological pattern formation by growth and dissolution in aqueous systems, Proc. R. Soc. A 466, 659-694 (2010). [2] P.N. Blumberg and R.L. Curl, Experimental and theoretical studies of dissolution roughness, J. Fluid Mech. 65, 735-751 (1974). [3] L. Solari and G. Parker, Morphodynamic modelling of the basal boundary of ice cover on brakish lakes, J.G.R. 118, 1432-1442 (2013).

  13. Neuraminidase-1 contributes significantly to the degradation of neuronal B-series gangliosides but not to the bypass of the catabolic block in Tay-Sachs mouse models.

    Science.gov (United States)

    Timur, Z K; Akyildiz Demir, S; Marsching, C; Sandhoff, R; Seyrantepe, V

    2015-09-01

    Tay–Sachs disease is a severe lysosomal storage disorder caused by mutations in the HEXA gene coding for α subunit of lysosomal β-Hexosaminidase A enzyme, which converts GM2 to GM3 ganglioside. HexA(−/−) mice, depleted of the β-Hexosaminidase A iso-enzyme, remain asymptomatic up to 1 year of age because of a metabolic bypass by neuraminidase(s). These enzymes remove a sialic acid residue converting GM2 to GA2, which is further degraded by the still intact β-Hexosaminidase B iso-enzyme into lactosylceramide. A previously identified ganglioside metabolizing neuraminidase, Neu4, is abundantly expressed in the mouse brain and has activity against gangliosides like GM2in vitro. Neu4(−/−) mice showed increased GD1a and decreased GM1 ganglioside in the brain suggesting the importance of the Neu4 in ganglioside catabolism. Mice with targeted disruption of both HexA and Neu4 genes showed accumulating GM2 ganglioside and epileptic seizures with 40% penetrance, indicating that the neuraminidase Neu4 is a modulatory gene, but may not be the only neuraminidase contributing to the metabolic bypass in HexA(−/−) mice. Therefore, we elucidated the biological role of neuraminidase-1 in ganglioside degradation in mouse. Analysis of HexA(−/−) Neu1(−/−) and HexA(−/−) Neu4(−/−) Neu1(−/−) mice models showed significant contribution of neuraminidase-1 on B-series ganglioside degradation in the brain. Therefore, we speculate that other neuraminidase/neuraminidases such as Neu2 and/or Neu3 might be also involved in the ganglioside degradation pathway in HexA(−/−) mice.

  14. Neuraminidase-1 contributes significantly to the degradation of neuronal B-series gangliosides but not to the bypass of the catabolic block in Tay–Sachs mouse models

    Directory of Open Access Journals (Sweden)

    Z.K. Timur

    2015-09-01

    Full Text Available Tay–Sachs disease is a severe lysosomal storage disorder caused by mutations in the HEXA gene coding for α subunit of lysosomal β-Hexosaminidase A enzyme, which converts GM2 to GM3 ganglioside. HexA−/− mice, depleted of the β-Hexosaminidase A iso-enzyme, remain asymptomatic up to 1 year of age because of a metabolic bypass by neuraminidase(s. These enzymes remove a sialic acid residue converting GM2 to GA2, which is further degraded by the still intact β-Hexosaminidase B iso-enzyme into lactosylceramide. A previously identified ganglioside metabolizing neuraminidase, Neu4, is abundantly expressed in the mouse brain and has activity against gangliosides like GM2 in vitro. Neu4−/− mice showed increased GD1a and decreased GM1 ganglioside in the brain suggesting the importance of the Neu4 in ganglioside catabolism. Mice with targeted disruption of both HexA and Neu4 genes showed accumulating GM2 ganglioside and epileptic seizures with 40% penetrance, indicating that the neuraminidase Neu4 is a modulatory gene, but may not be the only neuraminidase contributing to the metabolic bypass in HexA−/− mice. Therefore, we elucidated the biological role of neuraminidase-1 in ganglioside degradation in mouse. Analysis of HexA−/−Neu1−/− and HexA−/−Neu4−/−Neu1−/− mice models showed significant contribution of neuraminidase-1 on B-series ganglioside degradation in the brain. Therefore, we speculate that other neuraminidase/neuraminidases such as Neu2 and/or Neu3 might be also involved in the ganglioside degradation pathway in HexA−/− mice.

  15. Selectivity in associative learning: a cognitive stage framework for blocking and cue competition phenomena

    NARCIS (Netherlands)

    Boddez, Y.; Haesen, K.; Baeyens, F.; Beckers, T.

    2014-01-01

    Blocking is the most important phenomenon in the history of associative learning theory: for over 40 years, blocking has inspired a whole generation of learning models. Blocking is part of a family of effects that are typically termed "cue competition" effects. Common amongst all cue competition eff

  16. Ship Block Transportation Scheduling Problem Based on Greedy Algorithm

    Directory of Open Access Journals (Sweden)

    Chong Wang

    2016-05-01

    Full Text Available Ship block transportation problems are crucial issues to address in reducing the construction cost and improving the productivity of shipyards. Shipyards aim to maximize the workload balance of transporters with time constraint such that all blocks should be transported during the planning horizon. This process leads to three types of penalty time: empty transporter travel time, delay time, and tardy time. This study aims to minimize the sum of the penalty time. First, this study presents the problem of ship block transportation with the generalization of the block transportation restriction on the multi-type transporter. Second, the problem is transformed into the classical traveling salesman problem and assignment problem through a reasonable model simplification and by adding a virtual node to the proposed directed graph. Then, a heuristic algorithm based on greedy algorithm is proposed to assign blocks to available transporters and sequencing blocks for each transporter simultaneously. Finally, the numerical experiment method is used to validate the model, and its result shows that the proposed algorithm is effective in realizing the efficient use of the transporters in shipyards. Numerical simulation results demonstrate the promising application of the proposed method to efficiently improve the utilization of transporters and to reduce the cost of ship block logistics for shipyards.

  17. Analytical modeling of mercury injection in high-rank coalbed methane reservoirs based on pores and microfractures: a case study of the upper carboniferous Taiyuan Formation in the Heshun block of the Qinshui Basin, central China

    Science.gov (United States)

    Gu, Yang; Ding, Wenlong; Yin, Shuai; Wang, Ruyue; Mei, Yonggui; Liu, Jianjun

    2017-03-01

    The coalbed gas reservoirs in the Qinshui Basin in central China are highly heterogeneous; thus, the reservoir characteristics are difficult to assess. Research on the pore structure of a reservoir can provide a basis for understanding the occurrence and seepage mechanisms of coal reservoirs, rock physics modeling and the formulation of rational development plans. Therefore, the pore structure characteristics of the coalbed gas reservoirs in the high rank bituminous coal in the No. 15 coal seam of the Carboniferous Taiyuan Group in the Heshun coalbed methane (CBM) blocks in the northeastern Qinshui Basin were analyzed based on pressure mercury and scanning electron microscopy data. The results showed that the effective porosity system of the coal reservoir was mainly composed of pores and microfractures and that the pore throat configuration of the coal reservoir was composed of pores and microthroats. A model was developed based on the porosity and microfractures of the high rank coal rock and the mercury injection and drainage curves. The mercury injection curve model and the coal permeability are well correlated and were more reliable for the analysis of coal and rock pore system connectivity than the mercury drainage curve model. Coal rocks with developed microfractures are highly permeable; the production levels are often high during the initial drainage stages, but they decrease rapidly. A significant portion of the natural gas remains in the strata and cannot be exploited; therefore, the ultimate recovery is rather low. Coal samples with underdeveloped microfractures have lower permeabilities. While the initial production levels are lower, the production cycle is longer, and the ultimate recovery is higher. Therefore, the initial production levels of coal reservoirs with poorly developed microfractures in some regions of China may be low. However, over the long term, due to their higher ultimate recoveries and longer production cycles, the total gas

  18. Contrasting reduced overshadowing and blocking.

    Science.gov (United States)

    Wheeler, Daniel S; Miller, Ralph R

    2007-07-01

    Preexposure of a cue without an outcome (X-) prior to compound pairings with the outcome (XZ-->O) can reduce overshadowing of a target cue (Z). Moreover, pairing a cue with an outcome (X-->O) before compound training can enhance its ability to compete with another cue (i.e., blocking). Four experiments were conducted in a conditioned bar-press suppression preparation with rats to determine whether spacing of the X- or X-->O trials would differentially affect reduced overshadowing and blocking. Experiment 1a showed that reduced overshadowing was larger with massed trials than with spaced trials. Experiment 1b found that blocking was larger with spaced trials than with massed trials. Experiments 2a and 2b indicated that these effects of trial spacing were both mediated by the associative status of the context at test. The results are interpreted in the framework of contemporary learning theories.

  19. Diversity Gain through Antenna Blocking

    Directory of Open Access Journals (Sweden)

    V. Dehghanian

    2012-01-01

    Full Text Available As part of the typical usage mode, interaction between a handheld receiver antenna and the operator's RF absorbing body and nearby objects is known to generate variability in antenna radiation characteristics through blocking and pattern changes. It is counterintuitive that random variations in blocking can result in diversity gain of practical applicability. This diversity gain is quantified from a theoretical and experimental perspective. Measurements carried out at 1947.5 MHz verify the theoretical predictions, and a diversity gain of 3.1 dB was measured through antenna blocking and based on the utilized measurement setup. The diversity gain can be exploited to enhance signal detectability of handheld receivers based on a single antenna in indoor multipath environments.

  20. 组织贴块法建立人气道平滑肌细胞体外培养模型的研究%Construction of Model of Human Airway Smooth Muscle in Vitro by Attachment-block Culture

    Institute of Scientific and Technical Information of China (English)

    刘媛; 黄茂; 李涛; 刘红

    2011-01-01

    背景:人气道平滑肌已被证实参与气道重塑,气道平滑肌的重塑已成为慢性呼吸道疾病的主要病理改变之一.人气道平滑肌细胞的培养对慢性呼吸道疾病的研究有重要意义.组织贴块法培养人气道平滑肌细胞是原代培养人气遭平滑肌细胞的基本方法之一.目的:采用组织贴块法建立人气道平滑肌体外培养模型.方法:采集人气道组织,用组织贴块法进行人气道平滑肌细胞的原代培养,获得的细胞经形态学和免疫细胞化学染色鉴定.结果:培养的细胞呈典型的"谷峰"状生长,胞浆内特异性的平滑肌肌动蛋白阳性表达,符合平滑肌细胞的形态学特征和生物学特性.结论:组织贴块法易操作,结果可信,并可培养出高纯度活性好的人气道平滑肌细胞,成功建立了体外人气道平滑肌细胞增殖模型,提供了研究慢性呼吸道疾病的细胞培养模型.%Objective: To establish the model of human airway smooth muscle in vitro by attachment-block culture. Methods: The human airway wall was separated from lung resection carefully and cut into small pieces about 1 mm3, and then these pieces were attached on the wall of culture bottle. After 3 hours, those tissue pieces were cultivated in DMEM with 20 % calf serum. Results: Cells had grown on the bottom of culture bottle like peak-valley in shape. All cells almost were smooth muscle cells identified through An- tiα-actin immunohistochemistry stain. Conclusion: Attachment-block culture of human airway smooth muscle cells is simple to operate, reliable in result, high in purity and useful as a cellular model for study of respiratory diseases.

  1. Modelación y Simulación de la Transferencia de Calor en Muros de Bloque de Concreto Hueco Modeling and Simulation of Heat Transfer in Hollow Concrete Block Walls

    Directory of Open Access Journals (Sweden)

    Ana C Borbón

    2010-01-01

    Full Text Available Se presenta el estudio de transferencia de calor en un muro de bloques de concreto con cavidades, para conocer su resistencia térmica. Se plantea un modelo teórico unidimensional en estado estacionario, considerando conducción, radiación y convección. El problema se resuelve numéricamente utilizando el método iterativo de Gauss-Seidel. La simulación se efectúa en forma horaria para dos días en condiciones extremas de temperatura ambiente. Se obtiene un valor promedio de la resistencia térmica de 0.18 °Cm²/W, con variaciones de 2.3% a 23%. Las aportaciones al flujo total de calor por cada mecanismo son de 25%, 19% y 56%, para conducción, convección y radiación respectivamente. El muro presenta valores de resistencia térmica que tienden a disminuir con el aumento de los diferenciales de temperatura, aspecto que desfavorece su uso para climas cálidos, siendo la radiación el mecanismo que más favorece la transferencia de calor.This paper presents a heat transfers study in a hollow concrete blocks wall to know its thermal resistance. A one dimensional steady-state model was developed, which includes conduction, radiation and convection. The model was solved numerically using Gauss-Seidel iterative method. The simulation was run hourly for two days in climatic extreme conditions. The thermal resistance average value obtained was 0.18 °Cm²/W with variations of 2.3% to 23%. The average contribution to the total heat flow for every transfer mechanism is: 25%, 19% and 56% by conduction, convection and radiation respectively. The wall presents thermal resistance values which tend to decrease with the increase of temperature differential. This aspect presents disadvantages for thermal behavior in warm climate and the radiation into the block cavity is the most important heat transfer process across the wall.

  2. OPAL 96 Blocks Lead Glass

    CERN Multimedia

    This array of 96 lead glass bricks formed part of the OPAL electromagnetic calorimeter. One half of the complete calorimeter is shown in the picture above. There were 9440 lead glass counters in the OPAL electromagnetic calorimeter. These are made of Schott type SF57 glass and each block weighs about 25 kg and consists of 76% PbO by weight. Each block has a Hamamatsu R2238 photomultiplier glued on to it. The complete detector was in the form of a cylinder 7m long and 6m in diameter. It was used to measure the energy of electrons and photons produced in LEP interactions.

  3. Non-Perturbative Topological Strings And Conformal Blocks

    CERN Document Server

    Cheng, Miranda C N; Vafa, Cumrun

    2010-01-01

    We give a non-perturbative completion of a class of closed topological string theories in terms of building blocks of dual open strings. In the specific case where the open string is given by a matrix model these blocks correspond to a choice of integration contour. We then apply this definition to the AGT setup where the dual matrix model has logarithmic potential and is conjecturally equivalent to Liouville conformal field theory. By studying the natural contours of these matrix integrals and their monodromy properties, we propose a precise map between topological string blocks and Liouville conformal blocks. Remarkably, this description makes use of the light-cone diagrams of closed string field theory, where the critical points of the matrix potential correspond to string interaction points.

  4. Non-perturbative topological strings and conformal blocks

    Science.gov (United States)

    Cheng, Miranda C. N.; Dijkgraaf, Robbert; Vafa, Cumrun

    2011-09-01

    We give a non-perturbative completion of a class of closed topological string theories in terms of building blocks of dual open strings. In the specific case where the open string is given by a matrix model these blocks correspond to a choice of integration contour. We then apply this definition to the AGT setup where the dual matrix model has logarithmic potential and is conjecturally equivalent to Liouville conformal field theory. By studying the natural contours of these matrix integrals and their monodromy properties, we propose a precise map between topological string blocks and Liouville conformal blocks. Remarkably, this description makes use of the light-cone diagrams of closed string field theory, where the critical points of the matrix potential correspond to string interaction points.

  5. Numerical Analysis of a Blocking Mass Attenuating Wave Propagation

    Institute of Scientific and Technical Information of China (English)

    Xianzhong Wang; Xiongliang Yao; Qiangyong Wang; Shuai Lv

    2011-01-01

    Based on wave theory,blocking mass impeding propagation of flexural waves was analyzed with force excitation applied on a ship pedestal.The analysis model of a complex structure was developed by combining statistical energy analysis and the finite element method.Based on the hybrid FE-SEA method,the vibro-acoustic response of a complex structure was solved.Then,the sound radiation of a cylindrical shell model influenced by blocking mass was calculated in mid/high frequency.The result shows that blocking mass has an obvious effect on impeding propagation.The study provides a theoretical and experimental basis for application of the blocking mass to structure-borne sound propagation control.

  6. A C-Testable Multiple-Block Carry Select Adder

    Science.gov (United States)

    Kito, Nobutaka; Fujii, Shinichi; Takagi, Naofumi

    We propose a C-testable multiple-block carry select adder with respect to the cell fault model. Full adders and 2: 1 multiplexers are considered as cells. By an additional external input, we obtain a C-testable carry select adder. We only modify the least significant position of each block. The adder is testable with a test set consisting of 16 patterns regardless of the size of each block and the number of blocks. This is the minimum test set for the adder. We show two gate-level implementations of the adder which are testable with a test set of 9 patterns and 7 patterns respectively, with respect to the single stuck-at fault model.

  7. Morphology-properties relationship on nanocomposite films based on poly(styrene-block-diene-block-styrene copolymers and silver nanoparticles

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available A comparative study on the self-assembled nanostructured morphology and the rheological and mechanical properties of four different triblock copolymers, based on poly(styrene-block-diene-block-styrene and poly(styrene-block-diene-block-styrene matrices, and of their respective nanocomposites with 1 wt% silver nanoparticles, is reported in this work. In order to obtain well-dispersed nanoparticles in the block copolymer matrix, dodecanethiol was used as surfactant, showing good affinity with both nanoparticles and the polystyrene phase of the matrices as predicted by the solubility parameters calculated based on Hoftyzer and Van Krevelen theory. The block copolymer with the highest PS content shows the highest tensile modulus and tensile strength, but also the smallest elongation at break. When silver nanoparticles treated with surfactant were added to the block copolymer matrices, each system studied shows higher mechanical properties due to the good dispersion and the good interface of Ag nanoparticles in the matrices. Furthermore, it has been shown that semiempirical models such as Guth and Gold equation and Halpin-Tsai model can be used to predict the tensile modulus of the analyzed nanocomposites.

  8. Crustal blocks and seismicity in the Central Apennines of Italy

    Energy Technology Data Exchange (ETDEWEB)

    Bella, F.; Della Monica, G. (Rome, Univ. ' Roma III' (Italy). Dip di Fisica ' E. Amaldi' ); Caputo, M. (Rome, Univ. ' La Sapienza' (Italy). Dip. di Fisica ' E. Fermi' )

    Kinematics and geo dynamics of crustal-block structures separated by compliant zones with viscoelastic rheology play an important role in defining the conditions for many deformation events such as ordinary seismic ruptures, silent and slow earthquakes and aseismic fault creep phenomena. New seismological data from the Latium-Abruzzi carbonatic platform of central Italy fit a block-tectonic modelling previously proposed for this area on the basis of structural and paleomagnetic evidences.

  9. Sympathetic blocks for visceral cancer pain management

    DEFF Research Database (Denmark)

    Mercadante, Sebastiano; Klepstad, Pal; Kurita, Geana Paula

    2015-01-01

    The neurolytic blocks of sympathetic pathways, including celiac plexus block (CPB) and superior hypogastric plexus block (SHPB) , have been used for years. The aim of this review was to assess the evidence to support the performance of sympathetic blocks in cancer patients with abdominal visceral...

  10. Scattering matrices with block symmetries

    OpenAIRE

    Życzkowski, Karol

    1997-01-01

    Scattering matrices with block symmetry, which corresponds to scattering process on cavities with geometrical symmetry, are analyzed. The distribution of transmission coefficient is computed for different number of channels in the case of a system with or without the time reversal invariance. An interpolating formula for the case of gradual time reversal symmetry breaking is proposed.

  11. Architectures for block Toeplitz systems

    NARCIS (Netherlands)

    Bouras, Ilias; Glentis, George-Othon; Kalouptsidis, Nicholas

    1996-01-01

    In this paper efficient VLSI architectures of highly concurrent algorithms for the solution of block linear systems with Toeplitz or near-to-Toeplitz entries are presented. The main features of the proposed scheme are the use of scalar only operations, multiplications/divisions and additions, and th

  12. Building Blocks for Personal Brands

    Science.gov (United States)

    Thomas, Lisa Carlucci

    2011-01-01

    In this article, the author discusses the four essential building blocks for personal brands: (1) name; (2) message; (3) channels; and (4) bridges. However, outstanding building materials can only take a person so far. The author emphasizes that vision, determination, faith, a sense of humor, and humility are also required.

  13. First Degree Pacemaker Exit Block

    Directory of Open Access Journals (Sweden)

    Johnson Francis

    2016-10-01

    Full Text Available Usually atrial and ventricular depolarizations follow soon after the pacemaker stimulus (spike on the ECG. But there can be an exit block due to fibrosis at the electrode - tissue interface at the lead tip. This can increase the delay between the spike and atrial or ventricular depolarization.

  14. Application of modeling and numerical simulation in Sha second stage of Da-43 block%建模、数模在大43沙二段的应用

    Institute of Scientific and Technical Information of China (English)

    林群

    2015-01-01

    油藏数值模拟技术能够解决油田开发过程中难以解析的复杂渗流问题,将该技术的运用可以实现可视化、定量化的油藏管理模式;地质模型和数值模拟结合,可以分析预测大43沙二段不同的地层压力和采油速度下的采收率。%The numerical simulation technology of oil reservoir can solve the problem of complex seepage hard to analyze in the process of oil field development and applying the technology can realize the visualization and quantification of oil reservoir management.Combining geologic model with numerical simulation can analyze the oil production rate of Sha second stage of Da-43 block in different formation pressures and oil production rates.

  15. Chain exchange kinetics of block copolymer micelles in ionic liquids

    Science.gov (United States)

    Ma, Yuanchi; Lodge, Timothy

    The chain exchange kinetics of block copolymer micelles has been studied using time-resolved small-angle neutron scattering (TR-SANS), a key tool in determining the average micelle composition in contrast-matched solvents. In this work, PMMA-block-PnBMA was selected as the model block copolymer, which has a LCST behavior in the common ionic liquids, [EMIM][TFSI] and [BMIM][TFSI]. We examined the chain exchange kinetics of three PMMA-block-PnBMA copolymers, with identical PMMA block length (MPMMA = 25000) and different PnBMA block lengths (MPnBMA = 24000, 35000 and 53000); the Flory-Huggins interaction parameter (χ) between the core (PnBMA) and the solvent were varied by mixing [EMIM][TFSI] and [BMIM][TFSI] in different ratios. We found that the relaxation of the initial segregation of h- and d- micelles followed the same form with the time as previously developed by our group. Assuming that single chain expulsion is the rate limiting step, the thermal barrier was found to depend linearly on the core block length (Ncore) . Furthermore, the effect of χ on the chain exchange kinetics will also be discussed.

  16. NANOSTRUCTURED METAL OXIDE CATALYSTS VIA BUILDING BLOCK SYNTHESES

    Energy Technology Data Exchange (ETDEWEB)

    Craig E. Barnes

    2013-03-05

    A broadly applicable methodology has been developed to prepare new single site catalysts on silica supports. This methodology requires of three critical components: a rigid building block that will be the main structural and compositional component of the support matrix; a family of linking reagents that will be used to insert active metals into the matrix as well as cross link building blocks into a three dimensional matrix; and a clean coupling reaction that will connect building blocks and linking agents together in a controlled fashion. The final piece of conceptual strategy at the center of this methodology involves dosing the building block with known amounts of linking agents so that the targeted connectivity of a linking center to surrounding building blocks is obtained. Achieving targeted connectivities around catalytically active metals in these building block matrices is a critical element of the strategy by which single site catalysts are obtained. This methodology has been demonstrated with a model system involving only silicon and then with two metal-containing systems (titanium and vanadium). The effect that connectivity has on the reactivity of atomically dispersed titanium sites in silica building block matrices has been investigated in the selective oxidation of phenols to benezoquinones. 2-connected titanium sites are found to be five times as active (i.e. initial turnover frequencies) than 4-connected titanium sites (i.e. framework titanium sites).

  17. Pourfour Du Petit syndrome after interscalene block.

    Science.gov (United States)

    Santhosh, Mysore Chandramouli Basappji; Pai, Rohini B; Rao, Raghavendra P

    2013-04-01

    Interscalene block is commonly associated with reversible ipsilateral phrenic nerve block, recurrent laryngeal nerve block, and cervical sympathetic plexus block, presenting as Horner's syndrome. We report a very rare Pourfour Du Petit syndrome which has a clinical presentation opposite to that of Horner's syndrome in a 24-year-old male who was given interscalene block for open reduction and internal fixation of fracture upper third shaft of left humerus.

  18. Endoscopic sphenopalatine ganglion block for pain relief

    OpenAIRE

    Murty, P. S. N.; Prasanna, Atma

    1998-01-01

    The anaesthetic effect of the sphenopalatine (SPG) block has been well utilized for intranasal topical anaesthesia but the analgesic efficacy of (SPG) block, though well documented in literature, has not been put into practice. The methods available for SPG block till date were blind as they do not visualize the foramen. Nasal endoscopies have been used to visualize the foramen for an effective block. The authors present their experience with the endoscopic sphenopalatine ganglion block for p...

  19. Pourfour Du Petit syndrome after interscalene block

    Directory of Open Access Journals (Sweden)

    Mysore Chandramouli Basappji Santhosh

    2013-01-01

    Full Text Available Interscalene block is commonly associated with reversible ipsilateral phrenic nerve block, recurrent laryngeal nerve block, and cervical sympathetic plexus block, presenting as Horner′s syndrome. We report a very rare Pourfour Du Petit syndrome which has a clinical presentation opposite to that of Horner′s syndrome in a 24-year-old male who was given interscalene block for open reduction and internal fixation of fracture upper third shaft of left humerus.

  20. Limiting Spectral Distribution of Block Matrices with Toeplitz Block Structure

    CERN Document Server

    Basu, Riddhipratim; Ganguly, Shirshendu; Hazra, Rajat Subhra

    2011-01-01

    We study two specific symmetric random block Toeplitz (of dimension $k \\times k$) matrices: where the blocks (of size $n \\times n$) are (i) matrices with i.i.d. entries, and (ii) asymmetric Toeplitz matrices. Under suitable assumptions on the entries, their limiting spectral distributions (LSDs) exist (after scaling by $\\sqrt{nk}$) when (a) $k$ is fixed and $n \\to\\infty$ (b) $n$ is fixed and $k\\rightarrow \\infty$ (c) $n$ and $k$ go to $\\infty$ simultaneously. Further the LSD's obtained in (a) and (b) coincide with those in (c) when $n$ or respectively $k$ tends to infinity. This limit in (c) is the semicircle law in case (i). In Case (ii) the limit is related to the limit of the random symmetric Toepiltz matrix as obtained by Bryc et al.(2006) and Hammond and Miller(2005).

  1. COMPUTER-AIDED BLOCK ASSEMBLY PROCESS PLANNING IN SHIPBUILD-ING BASED ON RULE-REASONING

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhiying; LI Zhen; JIANG Zhibin

    2008-01-01

    Computer-aided block assembly process planning based on rule-reasoning are developed in order to improve the assembly efficiency and implement the automated block assembly process planning generation in shipbuilding. First, weighted directed liaison graph (WDLG) is proposed to represent the model of block assembly process according to the characteristics of assembly relation, and edge list (EL) is used to describe assembly sequences. Shapes and assembly attributes of block parts are analyzed to determine the assembly position and matched parts of parts used frequently. Then, a series of assembly rules are generalized, and assembly sequences for block are obtained by means of rule reasoning. Final, a prototype system of computer-aided block assembly process planning is built. The system has been tested on actual block, and the results were found to be quite efficiency. Meanwhile, the fundament for the automation of block assembly process generation and integration with other systems is established.

  2. The response of high-impact blocking weather systems to climate change

    Science.gov (United States)

    Kennedy, Daniel; Parker, Tess; Woollings, Tim; Harvey, Benjamin; Shaffrey, Len

    2016-07-01

    Midlatitude weather and climate are dominated by the jet streams and associated eastward moving storm systems. Occasionally, however, these are blocked by persistent anticyclonic regimes known as blocking. Climate models generally predict a small decline in blocking frequency under anthropogenic climate change. However, confidence in these predictions is undermined by, among other things, a lack of understanding of the physical mechanisms underlying the change. Here we analyze blocking (mostly in the Euro-Atlantic sector) in a set of sensitivity experiments to determine the effect of different parts of the surface global warming pattern. We also analyze projected changes in the impacts of blocking such as temperature extremes. The results show that enhanced warming both in the tropics and over the Arctic act to strengthen the projected decline in blocking. The tropical changes are more important for the uncertainty in projected blocking changes, though the Arctic also affects the temperature anomalies during blocking.

  3. Mathematics model evaluation of soft tissue changes after Twin-block treatment%计算机辅助数学模型分析Twin-block功能矫治后的组织相关性

    Institute of Scientific and Technical Information of China (English)

    闫宝勇; 左艳萍; 刘亚非; 崔丽娟

    2011-01-01

    背景:功能矫治器的观察对象都是处于生长期的青少年,在研究功能矫治是否有效的问题时,必须要考虑儿童本身的生长发育条件.目的:排除自然生长因素对实验结果的影响,采用计算机辅助数学分析Twin-block矫治器治疗后Ⅱ类错牙合患者颅颌面软硬组织的相关性.方法:选择Hagg手腕骨片为FG-G期的安氏Ⅱ类1分类下颌后缩患者31例,其中接受Twin-block功能矫治的Ⅱ类错牙合患者17例,放弃正畸治疗的Ⅱ类错牙合患者14例,2组患者年龄、性别相匹配.分别在治疗前后和自然生长前后拍摄头颅侧位片,观察Twin-block功能矫治前后和自然生长前后侧位片软硬组织头影测量值的变化规律,建立两组数学对比模型.结果与结论:通过数学对比模型发现,在Twin-block矫治后软组织测量项目Ls-EP、Pn-HP、NB-Pg’-Ls与硬组织测量项目ANB之间存在明显的曲线关系,方程为:NB-Pg’ -Ls=-0.119 1(ANB)2 +3.002 9(ANB)+ 6.148 5,Pn-HP=0.021 4(ANB)2 -1.026 7(ANB)+ 0.347 4,Ls-EP =0.132 4(ANB)2 -0.536 4(ANB)+1.553 7.在自然生长前后,软硬组织的改变差异无显著性意义.提示Twin-block矫治后ANB的角度是改善Ⅱ类错牙合患者软组织侧貌的决定性因素.%BACKGROUND: Because the subjects of fu nctional appliance are young people in the growing period, child ren's growth anddevelopment need to be considered to study whether the functional appliance is valid. OBJECTIVE: To build a mathematical model to analyze the correlation between craniofacial soft and hard tissues after the correction of Class Ⅱ malocclusion with twin-block treatment. METHODS: Thirty-one Class Ⅱ Division 1 malocclusion subjects with hand-wrist radiographs in FG-G stage were selected.Among the 31 cases, 14 abandoned treatment. The remaining 17 subjects received Twin-block treatment. All the subjects were taken cephalometric radiographs before and after twin-block treatment as well as before and after

  4. TRUE Block Scale Continuation Project. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Peter; Byegaard, Johan [Geosigma AB (Sweden); Billaux, Daniel [Itasca Consultants SA (France); Cvetkovic, Vladimir [Royal Inst. of Technology, Stockholm (Sweden); Dershowitz, William; Doe, Thomas [Golder Associates Inc. (United States); Hermanson, Jan [Golder Associates AB (Sweden); Poteri, Antti [VTT (Finland); Tullborg, Eva-Lena [Terralogica AB (Sweden); Winberg, Anders [Conterra AB (SE)] (ed.)

    2007-03-15

    The TRUE Block Scale project was carried out during 1996-2002. This project focused on site characterisation and building of hydrostructural and microstructural models, sorbing tracer experiments in single structures and networks of structures over distances ranging between 1 and 100 m and also involved a unified application of various model approaches for modelling the in situ experiments. In 2002, ANDRA, Posiva, JNC and SKB decided to pursue some remaining issues in the so-called TRUE Block Scale Continuation project (TRUE BS2). The specific objectives of BS2 can be summarised as: 'Improve understanding of transport pathways at the block scale, including assessment of effects of geology and geometry, macrostructure and microstructure'. In order to cater to addressing the stated objective a series of hypotheses were formulated which explored the importance of geological information for predicting transport and retention and the possible differences between transport and retention between transport paths dominated by faults and those dominated by non-fault fractures (background fractures). In the process, prospects for carrying out experiments in fracture networks over longer distances (c 20-100 m) were explored. It was identified that experiments with sorbing tracers over these distances were prohibitive because of the time frames involved and the projected low mass recoveries. Instead the experimental locus was shifted to a geological structure previously not investigated by tracer tests in the TRUE Block Scale experiments. The lower immobile zone retention material properties assigned to background fractures compared to those assigned to the fault-type Structure 19 have been verified by means of back-calculations. The evaluated Type 1 flow path (Structure 19, Flow path I) retention material properties, as expressed by {kappa} parameter, are one order of magnitude higher than for the background fracture flow path. This finding is consistent with the

  5. On the Eigenvalues and Eigenvectors of Block Triangular Preconditioned Block Matrices

    KAUST Repository

    Pestana, Jennifer

    2014-01-01

    Block lower triangular matrices and block upper triangular matrices are popular preconditioners for 2×2 block matrices. In this note we show that a block lower triangular preconditioner gives the same spectrum as a block upper triangular preconditioner and that the eigenvectors of the two preconditioned matrices are related. © 2014 Society for Industrial and Applied Mathematics.

  6. Channel Coding over Multiple Coherence Blocks with Queueing Constraints

    CERN Document Server

    Qiao, Deli; Velipasalar, Senem

    2010-01-01

    This paper investigates the performance of wireless systems that employ finite-blocklength channel codes for transmission and operate under queueing constraints in the form of limitations on buffer overflow probabilities. A block fading model, in which fading stays constant in each coherence block and change independently between blocks, is considered. It is assumed that channel coding is performed over multiple coherence blocks. An approximate lower bound on the transmission rate is obtained from Feintein's Lemma. This lower bound is considered as the service rate and is incorporated into the effective capacity formulation, which characterizes the maximum constant arrival rate that can be supported under statistical queuing constraints. Performances of variable-rate and fixed-rate transmissions are studied. The optimum error probability for variable rate transmission and the optimum coding rate for fixed rate transmission are shown to be unique. Moreover, the tradeoff between the throughput and the number of...

  7. Multicompartment Micelles From π-Shaped ABC Block Copolymers

    Institute of Scientific and Technical Information of China (English)

    XIA Jun; ZHONG Chong-Li

    2007-01-01

    Dissipative particle dynamics simulations were performed on the morphology and structure of multicompartment micelles formed from n-shaped ABC block copolymers in water. The influences of chain architectures were studied in a systematic way, and a rich variety of morphologies were observed, such as spherical, wormlike,X-shaped, Y-shaped, ribbon-like, layered rod-like, layered disk-like, as well as network morphologies. The simulations show that the distance between the two grafts plays an important role in control of the morphology. Since π-shaped ABC block copolymers can be reduced to linear ABC and star ABC block copolymers, they are good model copolymers for studying the self-assembly of complex block copolymers into micelles. The knowledge obtained in this work as well as the new morphologies identified provide useful information for future rational design and synthesis of novel multicompartment micelles.

  8. Does obturator nerve block always occur in 3-1 block?

    Directory of Open Access Journals (Sweden)

    İbrahim Tekdemir

    2011-06-01

    Full Text Available In the femoral “3-in-1 block”, obturator nerve block is routinely unsuccessful. Anatomical studies are not available to explain why blockade of obturator nerve or lumbar plexus does not occur. The aim of this study was to examine the effectiveness of femoral “3-in-1 block” obturator nerve block on a cadaver model.Materials and methods: Totally, 12 mature adult human cadavers were selected. Methylene blue dye (30 ml was injected under the fascia iliaca in eight cadavers and into the femoral nerve sheath in four cadavers. Careful bilateral dissections were performed following dye injections.Results: It was seen that the dye did not spread to the medial part of the psoas major muscle and the obturator nerve was not stained with the dye in eight cadavers in whom dye was injected laterally into the femoral sheat. In four cadavers in whom dye was injected into the femoral nerve sheat, metylene blue spread through fascial layers in the plane under the psoas muscle and stained the obturator nerve just before emerging medially from the fascia psoas. At this point, the obturator nerve pierced the psoas fascia and extended extrafascially in the medial and deep borders of the psoas muscle. In this area, the upper section of the obturator nerve was found also to be stained with the dye.Conclusion: We concluded that the cause of an unsuccessful obturator nerve block might be the fascial anatomy of this region. The lateral cutaneous femoral nerve and the femoral nerve easily can be blocked in the fascia iliaca compartment, but the obturator nerve block fails because of its being extrafascial in this region. J Clin Exp Invest 2011;2(2:149-51

  9. Graphs obtained from collections of blocks

    Directory of Open Access Journals (Sweden)

    Colton Magnant

    2015-03-01

    Full Text Available Given a collection of $d$-dimensional rectangular solids called blocks, no two of which sharing interior points, construct a block graph by adding a vertex for each block and an edge if the faces of the two corresponding blocks intersect nontrivially.  It is known that if $d \\geq 3$, such block graphs can have arbitrarily large chromatic number.  We prove that the chromatic number can be bounded with only a mild restriction on the sizes of the blocks.  We also show that block graphs of block configurations arising from partitions of $d$-dimensional hypercubes into sub-hypercubes are at least $d$-connected.  Bounds on the diameter and the hamiltonicity of such block graphs are also discussed.

  10. Building blocks of the Milky Way's accreted spheroid

    NARCIS (Netherlands)

    van Oirschot, Pim; Starkenburg, Else; Helmi, Amina; Nelemans, Gijs

    2017-01-01

    In the $\\Lambda$CDM model of structure formation, a stellar spheroid grows by the assembly of smaller galaxies, the so-called building blocks. Combining the Munich-Groningen semi-analytical model of galaxy formation with the high resolution Aquarius simulations of dark matter haloes, we study the as

  11. 岩体结构面精细化空间模型及块体失稳分析%Spatial Modeling of Refined Structural Plane of Rock Mass and Block Stability Analysis

    Institute of Scientific and Technical Information of China (English)

    王述红; 穆檄江; 张航; 张世超

    2012-01-01

    提出了将确定性结构面与随机结构面相结合来模拟岩体结构面的方法.确定性结构面依据工程地质勘测等资料通过多源数据耦合获得;而随机结构面则根据采用数字摄像测量技术现场测量的数据,运用三维网络模拟技术生成.同时引入结构面动态校核机制,利用掘进开挖过程中不断测量得到的数据对模拟的结构面进行动态校核及实时调整,从而建立比较精细的结构面空间模型.基于上述结构面模型,采用作者自行研发的GeoSMA-3D系统可以搜索出失稳块体,这对工程岩体稳定性预报和动态设计施工都有重要意义.%A method for modeling structural planes of rock mass was proposea Dy combining definite structural planes with random ones. Definite structural planes were obtained according to the data from engineering geological exploratory survey, while random ones were generated by 3D network simulation technique using the data from digital photogrammetry. A mechanism was introduced to dynamically check/adjust the random structural planes based on the real-time data acquired from the construction in progress,thus a more accurate model was established. Based on the model, unstable blocks can be found out using the GeoSMA-3D system developed by the authors, which has great significance for rock mass stability forecast and dynamic design/ construction.

  12. Sorafenib blocks tumour growth, angiogenesis and metastatic potential in preclinical models of osteosarcoma through a mechanism potentially involving the inhibition of ERK1/2, MCL-1 and ezrin pathways

    Directory of Open Access Journals (Sweden)

    Ferrari Stefano

    2009-12-01

    Full Text Available Abstract Background Osteosarcoma (OS is the most common primary bone tumour in children and young adults. Despite improved prognosis, metastatic or relapsed OS remains largely incurable and no significant improvement has been observed in the last 20 years. Therefore, the search for alternative agents in OS is mandatory. Results We investigated phospho-ERK 1/2, MCL-1, and phospho-Ezrin/Radixin/Moesin (P-ERM as potential therapeutic targets in OS. Activation of these pathways was shown by immunohistochemistry in about 70% of cases and in all OS cell lines analyzed. Mutational analysis revealed no activating mutations in KRAS whereas BRAF gene was found to be mutated in 4/30 OS samples from patients. Based on these results we tested the multi-kinase inhibitor sorafenib (BAY 43-9006 in preclinical models of OS. Sorafenib inhibited OS cell line proliferation, induced apoptosis and downregulated P-ERK1/2, MCL-1, and P-ERM in a dose-dependent manner. The dephosphorylation of ERM was not due to ERK inhibition. The downregulation of MCL-1 led to an increase in apoptosis in OS cell lines. In chick embryo chorioallantoic membranes, OS supernatants induced angiogenesis, which was blocked by sorafenib and it was also shown that sorafenib reduced VEGF and MMP2 production. In addition, sorafenib treatment dramatically reduced tumour volume of OS xenografts and lung metastasis in SCID mice. Conclusion In conclusion, ERK1/2, MCL-1 and ERM pathways are shown to be active in OS. Sorafenib is able to inhibit their signal transduction, both in vitro and in vivo, displaying anti-tumoural activity, anti-angiogenic effects, and reducing metastatic colony formation in lungs. These data support the testing of sorafenib as a potential therapeutic option in metastatic or relapsed OS patients unresponsive to standard treatments.

  13. Demographic Data - MDC_BlockGroup

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — A polygon feature class of Miami-Dade County Census 2000 Block Groups. A census Block Group is a statistical subdivision of a census Tract consisting of a cluster...

  14. An Efficient Block Matching Algorithm Using Logical Image

    Directory of Open Access Journals (Sweden)

    Manisha Pal

    2014-12-01

    Full Text Available Motion estimation, which has been widely used in various image sequence coding schemes, plays a key role in the transmission and storage of video signals at reduced bit rates. There are two classes of motion estimation methods, Block matching algorithms (BMA and Pel-recursive algorithms (PRA. Due to its implementation simplicity, block matching algorithms have been widely adopted by various video coding standards such as CCITT H.261, ITU-T H.263, and MPEG. In BMA, the current image frame is partitioned into fixed-size rectangular blocks. The motion vector for each block is estimated by finding the best matching block of pixels within the search window in the previous frame according to matching criteria. The goal of this work is to find a fast method for motion estimation and motion segmentation using proposed model. Recent day Communication between ends is facilitated by the development in the area of wired and wireless networks. And it is a challenge to transmit large data file over limited bandwidth channel. Block matching algorithms are very useful in achieving the efficient and acceptable compression. Block matching algorithm defines the total computation cost and effective bit budget. To efficiently obtain motion estimation different approaches can be followed but above constraints should be kept in mind. This paper presents a novel method using three step and diamond algorithms with modified search pattern based on logical image for the block based motion estimation. It has been found that, the improved PSNR value obtained from proposed algorithm shows a better computation time (faster as compared to original Three step Search (3SS/TSS method .The experimental results based on the number of video sequences were presented to demonstrate the advantages of proposed motion estimation technique.

  15. Slickenside developed in chert block

    Science.gov (United States)

    Ando, J.; Hayasaka, Y.; Nishiwaki, T.

    2011-12-01

    We observe the microstructures of slickenside developed in chert block mainly with a TEM, in order to clarify generation mechanism of the slickenside. This chert block occurs in the Jurassic accretionary complex in eastern Yamaguchi Prefecture, Japan. The complex, chaotic sediment, is composed of allochthonous blocks, mainly of chert, limestone, sandstone and mudstone in the argillaceous matrix. The color of the undeformed chert is pale blue to white, while the surface of slickenside is black. The stereo microscopy indicates the top surface of slickenside is covered with a transparent material, whose composition is mainly Si, measured by EPMA. The striation is well developed on the transparent-Si-material. We made thin sections, parallel and perpendicular to striation and slickenside, respectively. On the thin sections, the elongated quartz grains are oriented obliquely to the slickenside with 20-30 degree. Many fluid inclusions, which represent healed microcracks, are observed within the quartz grains. These quartz grains show strong undulose extinction and bulging-recrystallization. Apatite grains are also observed as a main constituent mineral. We made TEM foils from the above thin section by FIB. TEM observation indicates the amorphous layer with several ten nanometers in width distributes along the slickenside. (We speculate the most part of the amorphous layer are taken away during polishing of the thin section, because the strength of the amorphous layer is weak. Therefore we now make thin section again with care.) The tangled dislocations are developed within the quartz grains. They make subgrains with ca. 1 micrometer in size. These results suggest the slickenside was generated by the frictional melting of quartz grains on slip plane under very high stress condition, same as pseudotachylyte.

  16. Practical Binary Adaptive Block Coder

    CERN Document Server

    Reznik, Yuriy A

    2007-01-01

    This paper describes design of a low-complexity algorithm for adaptive encoding/ decoding of binary sequences produced by memoryless sources. The algorithm implements universal block codes constructed for a set of contexts identified by the numbers of non-zero bits in previous bits in a sequence. We derive a precise formula for asymptotic redundancy of such codes, which refines previous well-known estimate by Krichevsky and Trofimov, and provide experimental verification of this result. In our experimental study we also compare our implementation with existing binary adaptive encoders, such as JBIG's Q-coder, and MPEG AVC (ITU-T H.264)'s CABAC algorithms.

  17. New Considerations of Turbo Block Codes

    Institute of Scientific and Technical Information of China (English)

    YUEDianwu; EdSHWEDYK

    2004-01-01

    It is shown that (1) a general linear systematic block code can be expressed as a turbo block code and therefore can be decoded using any turbo decoding algorithm; (2) a turbo block code can be also encoded and decoded without any interleaver with the same performance as when an interleaver is present.

  18. Writer's block in a Chinese sample.

    Science.gov (United States)

    Lee, Sy-Ying; Krashen, Stephen

    2003-10-01

    To assess whether writer's block occurs in languages other than English, a Chinese language translation of Rose's Writer's Block questionnaire was administered to 98 university students in Taiwan. Analysis suggests that writer's block occurs for Chinese students, and, as in English, it is related to premature editing and to a lack of strategies for dealing with complex writing tasks.

  19. Micellization and Dynamics of a Block Copolymer

    DEFF Research Database (Denmark)

    Hvidt, Søren

    2006-01-01

    Triblock copolymers of the type EPE, where E and P denote ethylene oxide and propylene oxide blocks, respectively, are industrially important copolymers often called Pluronics or Poloxamers. EPE copolymers form micelles with a core of P blocks and different micellar shapes depending on block leng...

  20. Data Policy Construction Set - Building Blocks from Childhood Constructions

    Science.gov (United States)

    Fleischer, Dirk; Paul-Stueve, Thilo; Jobmann, Alexandra; Farrenkopf, Stefan

    2016-04-01

    A complete construction set of building blocks usually comes with instructions and these instruction include building stages. The products of these building stages usually build from very general parts become highly specialized building parts for very unique features of the whole construction model. This sounds very much like the construction or organization of an interdisciplinary research project, institution or association, doesn't it! The creation process of an overarching data policy for a project group or institution is exactly the combination of individual interests with the common goal of a collaborative data policy and can be compared with the building stages of a construction set of building blocks and the building instructions. Keeping this in mind we created the data policy construction set of textual building blocks. This construction set is subdivided into several building stages or parts each containing multiple building blocks as text blocks. By combining building blocks of all subdivisions it is supposed to create a cascading data policy document. Cascading from the top level as a construction set provider for all further down existing levels such as project, themes, work packages or Universities, faculties, institutes down to the working level of working groups. The working groups are picking from the remaining building blocks in the provided construction set the suitable blocks for its working procedures to create a very specific policy from the available construction set provided by the top level community. Nevertheless, if a working group realized that there are missing building blocks or worse that there are missing building parts, then they have the chance to add the missing pieces to the construction set of direct an future use. This cascading approach enables project or institution wide application of the encoded rules from the textual level on access to data storage infrastructure. This structured approach is flexible enough to allow for

  1. Cutaneous Sensory Block Area, Muscle-Relaxing Effect, and Block Duration of the Transversus Abdominis Plane Block

    DEFF Research Database (Denmark)

    Støving, Kion; Rothe, Christian; Rosenstock, Charlotte V

    2015-01-01

    into a medial and lateral part by a vertical line through the anterior superior iliac spine. We measured muscle thickness of the 3 lateral abdominal muscle layers with ultrasound in the relaxed state and during maximal voluntary muscle contraction. The volunteers reported the duration of the sensory block...... and the abdominal muscle-relaxing effect. RESULTS: The lateral part of the cutaneous sensory block area was a median of 266 cm2 (interquartile range, 191-310 cm2) and the medial part 76 cm 2(interquartile range, 54-127 cm2). In all the volunteers, lateral wall muscle thickness decreased significantly by 9.2 mm (6......BACKGROUND AND OBJECTIVES: The transversus abdominis plane (TAP) block is a widely used nerve block. However, basic block characteristics are poorly described. The purpose of this study was to assess the cutaneous sensory block area, muscle-relaxing effect, and block duration. METHODS: Sixteen...

  2. Random matrix theory for pseudo-Hermitian systems: Cyclic blocks

    Indian Academy of Sciences (India)

    Sudhir R Jain; Shashi C L Srivastava

    2009-12-01

    We discuss the relevance of random matrix theory for pseudo-Hermitian systems, and, for Hamiltonians that break parity and time-reversal invariance . In an attempt to understand the random Ising model, we present the treatment of cyclic asymmetric matrices with blocks and show that the nearest-neighbour spacing distributions have the same form as obtained for the matrices with scalar entries. We also summarize the theory for random cyclic matrices with scalar entries. We have also found that for block matrices made of Hermitian and pseudo-Hermitian sub-blocks of the form appearing in Ising model depart from the known results for scalar entries. However, there is still similarity in trends even in log–log plots.

  3. Seismicity of the Jalisco Block

    Science.gov (United States)

    Nunez-Cornu, F. J.; Rutz, M.; Camarena-Garcia, M.; Trejo-Gomez, E.; Reyes-Davila, G.; Suarez-Plascencia, C.

    2002-12-01

    In April 2002 began to transmit the stations of the first phase of Jalisco Telemetric Network located at the northwest of Jalisco Block and at the area of Volcan de Fuego (Colima Volcano), in June were deployed four additional MarsLite portable stations in the Bahia de Banderas area, and by the end of August one more portable station at Ceboruco Volcano. The data of these stations jointly with the data from RESCO (Colima Telemetric Network) give us the minimum seismic stations coverage to initiate in a systematic and permanent way the study of the seismicity in this very complex tectonic region. A preliminary analysis of seismicity based on the events registered by the networks using a shutter algorithm, confirms several important features proposed by microseismicity studies carried out between 1996 and 1998. A high level of seismicity inside and below of Rivera plate is observed, this fact suggest a very complex stress pattern acting on this plate. Shallow seismicity at south and east of Bahia de Banderas also suggest a complex stress pattern in this region of the Jalisco Block, events at more than 30 km depth are located under the mouth of the bay and in face of it, a feature denominated Banderas Boundary mark the change of the seismic regime at north of this latitude (20.75°N), however some shallow events were located at the region of Nayarit.

  4. Isostatic compression of buffer blocks. Middle scale

    Energy Technology Data Exchange (ETDEWEB)

    Ritola, J.; Pyy, E. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2012-01-15

    Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

  5. 基于分块极大值模型的商业银行操作风险计量研究%Measuring Operational Risk of Commercial Banks Based on the Block Maxima Model

    Institute of Scientific and Technical Information of China (English)

    陆静

    2012-01-01

    尽管高级计量法由于具有计算精确和节约监管资本等优点而被多数商业银行所青睐,但对于采用哪一种方法来刻画低频高危的操作风险尾部数据却没有一致认识.本文根据巴塞尔委员会关于操作风险计量的原则,采用分块极大值方法和概率加权矩参数估计法,对中国商业银行1990-2009年间的操作风险数据进行了实证.从图形检验和数值检验结果来看,该模型估计的参数具有较高的拟合优度,能够较好地拟舍操作风险极端值的尾部分布,为商业银行计量操作风险资本提供了较高的参考价值.%Basel II theory asserts that operational risk market risk and credit risk are three major risks for commercial banks and commercial banks to measure operational risks and allocate regulatory capital. However, in practice commercial banks have been challenging with operational risks that have high loss and low frequency. These events have a significant fat-tail nature of modeling. . The traditional econometric models generally require a considerable amount of loss data be used. Therefore, the construction of operational risk measurement model to measure credit and market risks is more difficult. This paper uses the publicly disclosed data of operational risks from 1990 to 2009 about China's commercial banks, and adopts the block maxima method and probability weighted moments to estimates the operational risk of Chinese commercial banks. Although the Basel Committee does not provide any specific methods and statistical distribution assumptions, banks must demonstrate that their risk assessment approaches take into account the probability distribution of serious tail loss events. The bank must also show that the operational risk measurement methods comply with IRB method and fairly robust standards when assessing credit risk. The Basel II is more concerned about the size of operational risk of banks in a given time period. Although traditional POT

  6. Simulation of spinal nerve blocks for training anesthesiology residents

    Science.gov (United States)

    Blezek, Daniel J.; Robb, Richard A.; Camp, Jon J.; Nauss, Lee A.; Martin, David P.

    1998-06-01

    Deep nerve regional anesthesiology procedures, such as the celiac plexus block, are challenging to learn. The current training process primarily involves studying anatomy and practicing needle insertion is cadavers. Unfortunately, the training often continues on the first few patients subjected to the care of the new resident. To augment the training, we have developed a virtual reality surgical simulation designed to provide an immersive environment in which an understanding of the complex 3D relationships among the anatomic structures involved can be obtained and the mechanics of the celiac block procedure practiced under realistic conditions. Study of the relevant anatomy is provided by interactive 3D visualization of patient specific data nd the practice simulated using a head mounted display, a 6 degree of freedom tracker, and a haptic feedback device simulating the needle insertion. By training in a controlled environment, the resident may practice procedures repeatedly without the risks associated with actual patient procedures, and may become more adept and confident in the ability to perform nerve blocks. The resident may select a variety of different nerve block procedures to practice, and may place the virtual patient in any desired position and orientation. The preliminary anatomic models used in the simulation have been computed from the Visible Human Male; however, patient specific models may be generated from patient image data, allowing the physician to evaluate, plan, and practice difficult blocks and/or understand variations in anatomy before attempting the procedure on any specific patient.

  7. Gas Permeation through Polystyrene-Poly(ethylene oxide) Block Copolymers

    Science.gov (United States)

    Hallinan, Daniel, Jr.; Minelli, Matteo; Giacinti-Baschetti, Marco; Balsara, Nitash

    2013-03-01

    Lithium air batteries are a potential technology for affordable energy storage. They consist of a lithium metal anode and a porous air cathode separated by a solid polymer electrolyte membrane, such as PEO/LiTFSI (PEO = poly(ethylene oxide), LiTFSI = lithium bis-trifluoromethane sulfonimide). For extended operation of such a battery, the polymer electrolyte must conduct lithium ions while blocking electrons and gases present in air. In order to maintain a pressure difference the membrane must be mechanically robust, which can be achieved by incorporating the PEO into a block copolymer with a glassy block such as PS (PS = polystyrene). To protect the lithium electrode, the membrane must have low permeability to gases in air such as CO2, N2, and O2. We have therefore studied the permeation of pure gases through a PS-PEO block copolymer. A high molecular weight, symmetric block copolymer with a lamellar morphology was used to cast free-standing membranes. Gas permeability was measured through these membranes with a standard, pressure-based technique. A model was developed to account for transport through the polymer membrane consisting of semi-crystalline PEO lamellae and amorphous PS lamellae. PEO crystallinity was extracted from the permeation model and compares well with values from differential scanning calorimetry measurements.

  8. System Synthesis for Networks of Programmable Blocks

    CERN Document Server

    Mannion, Ryan; Cotterell, Susan; Vahid, Frank

    2011-01-01

    The advent of sensor networks presents untapped opportunities for synthesis. We examine the problem of synthesis of behavioral specifications into networks of programmable sensor blocks. The particular behavioral specification we consider is an intuitive user-created network diagram of sensor blocks, each block having a pre-defined combinational or sequential behavior. We synthesize this specification to a new network that utilizes a minimum number of programmable blocks in place of the pre-defined blocks, thus reducing network size and hence network cost and power. We focus on the main task of this synthesis problem, namely partitioning pre-defined blocks onto a minimum number of programmable blocks, introducing the efficient but effective PareDown decomposition algorithm for the task. We describe the synthesis and simulation tools we developed. We provide results showing excellent network size reductions through such synthesis, and significant speedups of our algorithm over exhaustive search while obtaining...

  9. 3D Geologic Modeling Technology of Complex Fault-block Reservoirs---A Case of An Overseas Oilfield%复杂断块油藏的三维地质建模方法--以国外某油田为例

    Institute of Scientific and Technical Information of China (English)

    金春玉; 宋扬

    2015-01-01

    随着油气勘探开发的不断深入,一些具有复杂断块构造特征的油藏已逐渐成为开发的主体目标。建立精准的复杂断块油藏三维地质模型对指导油田开发有着重要的意义。三维地质建模技术能够更细致、准确地研究地下的油藏,为油藏的后续开发提供可靠的地质依据。以国外某油田断块构造发育区块为研究对象,针对研究区地质条件复杂、断层发育的特点,以地质、地震、测井资料为基础,搭建构造框架模型,应用地质统计学理论建立储层岩相及物性参数模型,揭示构造和储层空间分布特征,最终建立一个三维定量的油藏地质模型,在储层计算中各断块误差均小于5%,符合精度要求。该模型将为该区块数值模拟和井位设计等后续工作提供可靠的地质依据,同时也为同类复杂断块油藏的三维地质建模提供借鉴。%With the development of oil and gas exploration,some complex fault-block reservoirs have be-come the main objective.3D geologic modeling of complex fault-block reservoirs is an important significance to guide oilfield development.Study on underground reservoirs,3D geologic modeling technology is more particular and accurate,which supplies reliable data for future development.Study on an overseas oilfield which has the complex fault-block,the geologic condition of the complex fault-block is complex.Based on geological,seismic and logging data,the structural modeling had been built.The lithofacies modeling and physical property modeling had been built by geostatistics theory which reveal the structural attitude and spatial distribution.3D geologic modeling of the block had been built at last.The results showed that the reserves error of these fault-blocks were within 5%,which meet the requirement.The 3D geologic modeling of the block will provide reliable geological basis for the numerical simulation and the location and so on, and provide

  10. General Floorplans with L/T-Shaped Blocks Using Corner Block List

    Institute of Scientific and Technical Information of China (English)

    Yu-Chun Ma; Xian-Long Hong; She-Qin Dong; C.K.Cheng; Jun Gu

    2006-01-01

    With the recent advent of deep submicron technology and new packing schemes, the components in the integrated circuit are often not rectangular. On the basis of the representation of Corner Block List (CBL), we propose a new method of handling rectilinear blocks. In this paper, the handling of the rectilinear blocks is simplified by transforming the L/T-shaped block problem into the align-abutment constraint problem. We devise the block rejoining process and block alignment operation for forming the L/T-shaped blocks into their original configurations. The shape flexibility of the soft blocks, and the rotation and reflection of L/T-shaped blocks are exploited to obtain a tight packing. The empty rooms are introduced to the process of block rejoining. The efficiency and effectiveness of the proposed method are demonstrated by the experimental results on a set of some benchmark examples.

  11. Polystyrene-Polylactide Bottlebrush Block Copolymer at the Air/Water Interface

    Science.gov (United States)

    Zhao, Lei; Byun, Myunghwan; Rzayev, Javid; Lin, Zhiqun

    2010-03-01

    Hydrophobic ultrahigh molecular weight bottlebrush block copolymer and linear block copolymer of polystyrene-polylactide (PS-PLA) were shown to be capable of forming Langmuir monolayers and exhibiting unique assembly behaviors at the air/water interface, which cannot be addressed by the classic theory of Langmuir monolayer of amphiphilic copolymers. New models were proposed to illustrate these intriguing surface behaviors. The self-assembled structure of Langmuir monolayer of bottlebrush block copolymer was determined by a combination of AFM measurement, thermal annealing, and enzymatic degradation experiment. To the best of our knowledge, this is among few studies on hydrophobic block copolymers at the air/water interface. As such, it not only complements the well-known models of self-assembly of amphiphilic block copolymers at the air/water interface but also expands the use of Langmuir-Blodgett (LB) technique to hydrophobic block copolymers.

  12. Cryptanalysis of Selected Block Ciphers

    DEFF Research Database (Denmark)

    Alkhzaimi, Hoda A.

    thoroughly, no security assessment is given. We present a series of observations on the presented construction that, in some cases, yield attacks, while in other cases may provide basis of further analysis by the cryptographic community. Specifically, The attacks obtained are using classical- as well...... ciphers initiatives, and the Competition for Authenticated Encryption: Security, Applicability, and Robustness (CAESAR). In this thesis, we first present cryptanalytic results on different ciphers. We propose attack named the Invariant Subspace Attack. It is utilized to break the full block cipher...... PRINTcipher for a significant fraction of its keys. This new attack also gives us new insights into other, more well-established attacks. In addition, we also show that for weak keys, strongly biased linear approximations exists for any number of rounds. Furthermore, we provide variety of attacks...

  13. Distributed deformation and block rotation in 3D

    Science.gov (United States)

    Scotti, Oona; Nur, Amos; Estevez, Raul

    1990-01-01

    The authors address how block rotation and complex distributed deformation in the Earth's shallow crust may be explained within a stationary regional stress field. Distributed deformation is characterized by domains of sub-parallel fault-bounded blocks. In response to the contemporaneous activity of neighboring domains some domains rotate, as suggested by both structural and paleomagnetic evidence. Rotations within domains are achieved through the contemporaneous slip and rotation of the faults and of the blocks they bound. Thus, in regions of distributed deformation, faults must remain active in spite of their poor orientation in the stress field. The authors developed a model that tracks the orientation of blocks and their bounding faults during rotation in a 3D stress field. In the model, the effective stress magnitudes of the principal stresses (sigma sub 1, sigma sub 2, and sigma sub 3) are controlled by the orientation of fault sets in each domain. Therefore, adjacent fault sets with differing orientations may be active and may display differing faulting styles, and a given set of faults may change its style of motion as it rotates within a stationary stress regime. The style of faulting predicted by the model depends on a dimensionless parameter phi = (sigma sub 2 - sigma sub 3)/(sigma sub 1 - sigma sub 3). Thus, the authors present a model for complex distributed deformation and complex offset history requiring neither geographical nor temporal changes in the stress regime. They apply the model to the Western Transverse Range domain of southern California. There, it is mechanically feasible for blocks and faults to have experienced up to 75 degrees of clockwise rotation in a phi = 0.1 strike-slip stress regime. The results of the model suggest that this domain may first have accommodated deformation along preexisting NNE-SSW faults, reactivated as normal faults. After rotation, these same faults became strike-slip in nature.

  14. [Ultrasound for peripheral neural block].

    Science.gov (United States)

    Kefalianakis, F

    2005-03-01

    Ultrasound is well established in medicine. Unfortunately, ultrasound is still rarely used in the area of anesthesia. The purpose of the article is to illustrate the possibilities and limitations of ultrasound in regional anesthesia. The basic principles of ultrasound are the piezoelectric effect and the behaviour of acoustic waveforms in human tissue. Ultrasound imaging in medicine uses high frequency pulses of sound waves (2.5-10 MHz). The following images are built up from the reflected sounds. The ultrasound devices used in regional anesthesia (commonly by 10 MHz) deliver a two-dimensional view. The main step for a successful regional anaesthesia is to identify the exact position of the nerve. In addition, specific surface landmarks and the use of peripheral nerve stimulator help to detect the correct position of the needle. Nerves are demonstrated as an composition of hyperechogenic (white) and hypoechogenic (black) areas. The surrounding hyperechogenic parts are epi- and perineurium, the dark hypoechogenic part is the neural tissue. The composition of peripheral nerves are always similar, but the quantities of each part, of surrounding perineurium and nerval structures, differ. Further the imaging of nerves is significantly influenced by the angle of beam to the nerve and the surrounding anatomic structures. Only experience and correct interpretation make the ultrasound a valid method in clinical practice. Correct interpretation has to be learned by standardized education. Three examples of peripheral nerve blocks are described. The detection of nerves and the visualization of the correct spread of local anesthetics to the nerves are the main principles of effective ultrasound-guided regional anesthesia, whereas closest proximity of the needle to the target nerve is not necessary. The described examples of ultrasound guidance for nerval block illustrates the specific procedures with reduced probability of nerval irritation, high success and low rate of

  15. MECHANICAL MODEL AND ELASTIC MODULUS OF GROUTED CONCRETE BLOCK MASONRY IN COMPRESSION%灌孔混凝土砌块砌体受压力学模型及其弹性模量

    Institute of Scientific and Technical Information of China (English)

    梁建国; 龙腾

    2012-01-01

    灌孔混凝土砌块砌体是由砌体和灌孔混凝土两部分组合而成,为了得到竖向压力作用下两种材料的相互作用机理,该文基于最小势能原理推导了砌体对灌孔混凝土的套箍系数以及灌孔混凝土砌块砌体内的应力分布,得到了灌孔混凝土砌块砌体的弹性模量可近似按材料力学组合截面公式进行计算,其计算结果与收集的全国65组281个试件试验结果符合良好,并通过试验结果统计得到了灌孔混凝土砌块砌体弹性模量的建议公式。理论分析和试验结果表明,我国现行规范中灌孔混凝土砌块砌体弹性模量取值偏低,将使配筋砌块砌体结构的设计计算结果偏于不安全。%In order to obtain the interaction mechanism between the grout and masonry in grouted concrete block masonry structures under vertical load, the hooping factor which denotes the hooping action of the masonry to the grouted concrete and the stress distribution in the grouted concrete block masonry is studied based on the minimum potential energy principle. The elastic modulus of grouted concrete block masonry can be approximately calculated according to the assembled section formula in material mechanics, and the calculation results of this formula agree well with the test results of 281 specimens in 65 groups. Another proposed formula to calculate the elastic modulus of the grouted concrete block is derived base on the test results by regression analysis method. Theoretical analysis and test results show that the value of elastic modulus of grouted concrete block masonry in our current code is low, indicating it is unsafe to guide the design of reinforced concrete block masonry structures.

  16. Seismic waves in a three-dimensional block medium

    Science.gov (United States)

    Aleksandrova, N. I.

    2016-08-01

    We study numerically the propagation of seismic waves in a three-dimensional block medium. The medium is modelled by a spatial lattice of masses connected by elastic springs and viscous dampers. We study Lamb's problem under a surface point vertical load. The cases of both step and pulse load are considered. The displacements and velocities are calculated for surface masses. The influence of the viscosity of the dampers on the attenuation of perturbations is studied. We compare our numerical results for the block medium with known analytical solutions for the elastic medium.

  17. Seismic waves in a three-dimensional block medium

    CERN Document Server

    Aleksandrova, Nadezhda

    2016-01-01

    We study numerically the propagation of seismic waves in a three-dimensional block medium. The medium is modeled by a spatial lattice of masses connected by elastic springs and viscous dampers. We study Lamb's problem under a surface point vertical load. The cases of both step and pulse load are considered. The displacements and velocities are calculated for surface masses. The influence of the viscosity of the dampers on the attenuation of perturbations is studied. We compare our numerical results for the block medium with known analytical solutions for the elastic medium.

  18. Development of traffic induced permanent strain in concrete block pavements

    OpenAIRE

    1996-01-01

    Concrete block pavements (c.b.p.) commonly consist of concrete blocks placed over a granular substructure. As a result of wheel load passages permanent strains will slowly develop in the substructure and cause rutting. This paper is about the prediction of the permanent strain development in the substructure and the associated rutting on the basis of the results of repeated load triaxial tests and analytical models. By discussing the behaviour of three c.b.p.'s it is shown that insight into c...

  19. Masonry macro-block analysis

    OpenAIRE

    Mendes, N

    2015-01-01

    The structural analysis involves the definition of the model and selection of the analysis type. The model should represent the stiffness, the mass and the loads of the structure. The structures can be represented using simplified models, such as the lumped mass models, and advanced models resorting the Finite Element Method (FEM) and Discrete Element Method (DEM). Depending on the characteristics of the structure, different types of analysis can be used such as limit analysis, linear and non...

  20. Link Prediction via Convex Nonnegative Matrix Factorization on Multiscale Blocks

    Directory of Open Access Journals (Sweden)

    Enming Dong

    2014-01-01

    Full Text Available Low rank matrices approximations have been used in link prediction for networks, which are usually global optimal methods and lack of using the local information. The block structure is a significant local feature of matrices: entities in the same block have similar values, which implies that links are more likely to be found within dense blocks. We use this insight to give a probabilistic latent variable model for finding missing links by convex nonnegative matrix factorization with block detection. The experiments show that this method gives better prediction accuracy than original method alone. Different from the original low rank matrices approximations methods for link prediction, the sparseness of solutions is in accord with the sparse property for most real complex networks. Scaling to massive size network, we use the block information mapping matrices onto distributed architectures and give a divide-and-conquer prediction method. The experiments show that it gives better results than common neighbors method when the networks have a large number of missing links.

  1. Building Blocks of the Milky Way's Accreted Spheroid

    CERN Document Server

    van Oirschot, Pim; Helmi, Amina; Nelemans, Gijs

    2016-01-01

    In the $\\Lambda$CDM model of structure formation, a stellar spheroid grows by the assembly of smaller galaxies, the so-called building blocks. Combining the Munich-Groningen semi-analytical model of galaxy formation with the high resolution Aquarius simulations of dark matter haloes, we study the assembly history of the stellar spheroids of six Milky Way-mass galaxies, focussing on building block properties such as mass, age and metallicity. These properties are compared to those of the surviving satellites in the same models. We find that the building blocks have higher star formation rates on average, and this is especially the case for the more massive objects. At high redshift these dominate in star formation over the satellites, whose star formation timescales are longer on average. These differences ought to result in a larger $\\alpha$-element enhancement from Type II supernovae in the building blocks (compared to the satellites) by the time Type Ia supernovae would start to enrich them in iron, explain...

  2. Efficient Distribution of Triggered Synchronous Block Diagrams

    Science.gov (United States)

    2011-10-21

    called a trigger. At a given synchronous step, if the trigger is true , the block fires normally; otherwise, the block stutters , that is, keeps its...outputs have the same value as in the previous step, but they are still transmitted to downstream blocks. In this paper we present an implementation...optimizations that apply to general Triggered SBDs, we also present further optimizations for the case of Timed SBDs. 1.1 Motivating Examples Fig. 1

  3. Advanced heart block in acute rheumatic fever.

    Science.gov (United States)

    Hubail, Zakariya; Ebrahim, Ishaq M

    2016-04-01

    First degree heart block is considered a minor criterion for the diagnosis of this condition. The cases presented here demonstrate that higher degrees of heart block do occur in rheumatic fever. Children presenting with acquired heart block should be worked-up for rheumatic fever. Likewise, it is imperative to serially follow the electrocardiogram in patients already diagnosed with acute rheumatic fever, as the conduction abnormalities can change during the course of the disease.

  4. Advanced heart block in acute rheumatic fever

    OpenAIRE

    2015-01-01

    First degree heart block is considered a minor criterion for the diagnosis of this condition. The cases presented here demonstrate that higher degrees of heart block do occur in rheumatic fever. Children presenting with acquired heart block should be worked-up for rheumatic fever. Likewise, it is imperative to serially follow the electrocardiogram in patients already diagnosed with acute rheumatic fever, as the conduction abnormalities can change during the course of the disease.

  5. Snow and ice blocking of tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Lia, Leif

    1998-12-31

    Hydroelectric power development in cold regions causes much concern about operational reliability and dam safety. This thesis studies the temperature distribution in tunnels by means of air temperature measurements in six tunnel spillways and five diversion tunnels. The measurements lasted for two consecutive winters. The air through flow tunnel is used as it causes cooling of both rock and water. In open spillway tunnels, frost reaches the entire tunnel. In spillway tunnels with walls, the frost zones reach about 100 m from the downstream end. In mildly-inclined diversion tunnels, a frost free zone is located in the middle of the tunnel and snow and ice problems were only observed in the inlet and outlet. Severe aufeis is accumulation is observed in the frost zones. The heat transfer from rock to air, water and ice is calculated and used in a prediction model for the calculation of aufeis build-up together with local field observation data. The water penetration of snow plugs is also calculated, based on the heat balance. It takes 20 to 50 days for water to enter the blocked tunnel. The empirical values are 30 to 60 days, but only 1 day if the temperature of the snow pack is 0{sup o}C. Sensitivity analyses are carried out for temperature variations in rock, snow, water and ice. Systematic field observation shows that it is important for hydropower companies to know about the effects of snow and ice blocking in an area. A risk analysis of dam safety is presented for a real case. Finally, the thesis proposes solutions which can reduce the snow and ice problems. 79 refs., 63 figs., 11 tabs.

  6. Using Interference to Block RFID Tags

    DEFF Research Database (Denmark)

    Krigslund, Rasmus; Popovski, Petar; Pedersen, Gert Frølund

    We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag.......We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag....

  7. A New Relationship between Block Designs

    Directory of Open Access Journals (Sweden)

    Alexander Shramchenko

    2016-01-01

    Full Text Available We propose a procedure of constructing new block designs starting from a given one by looking at the intersections of its blocks with various sets and grouping those sets according to the structure of the intersections. We introduce a symmetric relationship of friendship between block designs built on a set V and consider families of block designs where all designs are friends of each other, the so-called friendly families. We show that a friendly family admits a partial ordering. Furthermore, we exhibit a map from the power set of V, partially ordered by inclusion, to a friendly family of a particular type which preserves the partial order.

  8. Recent developments in paediatric neuraxial blocks

    Directory of Open Access Journals (Sweden)

    Vrushali Chandrashekhar Ponde

    2012-01-01

    Full Text Available Paediatric anaesthesia and paediatric regional anaesthesia are intertwined. Almost all surgeries unless contradicted could be and should be supplemented with a regional block. The main objective of this review is to elaborate on the recent advances of the central neuraxial blocks, such as application of ultrasound guidance and electrical stimulation in the pursuit of safety and an objective end point. This review also takes account of the traditional technique and understand the benefits as well the risk of each as compared with the recent technique. The recent trends in choosing the most appropriate peripheral block for a given surgery thereby sparing the central neuroaxis is considered. A penile block for circumcision or a sciatic block for unilateral foot surgery, rather than caudal epidural would have a better risk benefit equation. Readers will find a special mention on the recent thoughts on continuous epidural analgesia in paediatrics, especially its rise and fall, yet its unique importance. Lastly, the issue of block placements under sedation or general anaesthesia with its implication in this special population is dealt with. We conducted searches in MEDLINE (PubMed and assessed the relevance of the abstracts of citations identified from literature searches. The search was carried out in English, for last 10 years, with the following key words: Recent advances in paediatric regional anaesthesia; ultrasound guidance for central neuraxial blocks in children; role of electrical stimulation in neuraxial blocks in children; complications in neuraxial block. Full-text articles of potentially relevant abstracts were retrieved for further review.

  9. PACS photometer calibration block analysis

    CERN Document Server

    Moór, A; Kiss, Cs; Balog, Z; Billot, N; Marton, G

    2013-01-01

    The absolute stability of the PACS bolometer response over the entire mission lifetime without applying any corrections is about 0.5% (standard deviation) or about 8% peak-to-peak. This fantastic stability allows us to calibrate all scientific measurements by a fixed and time-independent response file, without using any information from the PACS internal calibration sources. However, the analysis of calibration block observations revealed clear correlations of the internal source signals with the evaporator temperature and a signal drift during the first half hour after the cooler recycling. These effects are small, but can be seen in repeated measurements of standard stars. From our analysis we established corrections for both effects which push the stability of the PACS bolometer response to about 0.2% (stdev) or 2% in the blue, 3% in the green and 5% in the red channel (peak-to-peak). After both corrections we still see a correlation of the signals with PACS FPU temperatures, possibly caused by parasitic h...

  10. Testing alternative tectonic models of Palaeotethys in the E Mediterranean region: new U-Pb and Lu-Hf isotopic analyses of detrital zircons from Late Carboniferous and Late Triassic sandstones associated with the Anatolide and Tauride blocks (S Turkey)

    Science.gov (United States)

    Ustaömer, Timur; Ayda Ustaömer, Petek; Robertson, Alastair; Gerdes, Axel

    2016-04-01

    Alternative tectonic models of Palaeotethys during Late Palaeozoic-Early Mesozoic time infer: 1. southward subduction beneath the north margin of Gondwana; 2. northward subduction beneath the south margin of Eurasia, or 3. double subduction (northwards and southwards), at least during Late Carboniferous. U-Pb and Lu-Hf isotopic analysis of detrital zircons, extracted from sandstones, can provide strong indications of age and identity of source terranes. Here, we consider the provenance of both Late Carboniferous and Late Triassic sandstones from both relatively allochthonous and relatively autochthonous units that are all spatially associated with the Anatolide and Tauride continental blocks. The relatively allochthonous units are sandstones (3 samples) from the Late Carboniferous Aladaǧ Nappe (Tauride; in the east), the Konya Complex (Anatolide; central area) and the Karaburun Mélange (Tauride-related; in the west). The relatively autochthonous units are Late Triassic sandstones (4 samples) from the Üzümdere Formation, the Kasımlar Formation (both western Taurides) and the Güvercinlik Formation (Karaburun Peninsula-Tauride related; far west). The Late Carboniferous sandstones from the three relatively allochthonous units are dominated by Precambrian zircon populations, the age distribution of which suggests derivation from two contrasting source regions: First, a NE African-type source (i.e. Saharan craton) for the sandstones of the Konya Mélange and the Aladaǧ Nappe because these sediments have prominent zircon populations dated at 0.5-0.7, 0.8 and 0.9-1.1 Ga. Palaeozoic zircons are minimal in the sandstones of the Aladaǧ Nappe and the Konya Complex (3 and 5% of the whole data, respectively) and are confined to Cambrian to Ordovician. Secondly, a contrasting NW African-type source is inferred for sandstone from the Karaburun Mélange because of the marked absence of Tonian-Stenian zircons and the predominance of ~2 Ga zircons over ~2.5 Ga zircons. In

  11. 3D Identification and Stability Analysis of Key Surface Blocks of Rock Slope

    Institute of Scientific and Technical Information of China (English)

    李明超; 周四宝; 王刚

    2016-01-01

    Complicated geological structures make it difficult to analyze the stability of rock slopes, such as faults, weak intercalated layers or joint fissures. Based on 3D geological modeling and surface block identifying methods, an integrated methodology framework was proposed and realized to analyze the stability of surface blocks in rock slopes. The surface blocks cut by geological structures, fissures or free faces could be identified subjected to the four principles of closure, completeness, uniqueness and validity. The factor of safety(FOS)of single key block was calculated by the limit equilibrium method. If there were two or more connected blocks, they were defined as a block-group. The FOS of a block-group was computed by the Sarma method. The proposed approach was applied to an actual rock slope of a hydropower project, and some possible instable blocks were demonstrated and analyzed visually. The obtained results on the key blocks or block-groups provide essential information for determining po-tential instable region of rock slopes and designing effective support scheme in advance.

  12. Comparative study between ultrasound guided tap block and paravertebral block in upper abdominal surgeries. Randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Ruqaya M. Elsayed

    2017-01-01

    Conclusion: We concluded that ultrasound guided transversus abdominis plane block and thoracic paravertebral block were safe and effective anesthetic technique for upper abdominal surgery with longer and potent postoperative analgesia in thoracic paravertebral block than transversus abdominis block.

  13. Structure–property relations of segmented block copolymers with liquid–liquid demixed morphologies

    NARCIS (Netherlands)

    Schuur, van der Martijn; Heide, van der Evert; Feijen, Jan; Gaymans, Reinoud J.

    2005-01-01

    Poly(propylene oxide) based polyether(ester-amide)s (PEEA) with non-crystallisable amide segments were synthesized and their structure–property relations studied. These model segmented block copolymers were used to gain insight in the structure–property relations of block copolymers with liquid–liqu

  14. Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

    Science.gov (United States)

    Hoarfrost, Megan Lane

    Incorporating an ionic liquid into one block copolymer microphase provides a platform for combining the outstanding electrochemical properties of ionic liquids with a number of favorable attributes provided by block copolymers. In particular, block copolymers thermodynamically self-assemble into well-ordered nanostructures, which can be engineered to provide a durable mechanical scaffold and template the ionic liquid into continuous ion-conducting nanochannels. Understanding how the addition of an ionic liquid affects the thermodynamic self-assembly of block copolymers, and how the confinement of ionic liquids to block copolymer nanodomains affects their ion-conducting properties is essential for predictable structure-property control. The lyotropic phase behavior of block copolymer/ionic liquid mixtures is shown to be reminiscent of mixtures of block copolymers with selective molecular solvents. A variety of ordered microstructures corresponding to lamellae, hexagonally close-packed cylinders, body-centered cubic, and face-centered cubic oriented micelles are observed in a model system composed of mixtures of imidazolium bis(trifluoromethylsulfonyl)imide ([Im][TFSI]) and poly(styrene- b-2-vinyl pyridine) (PS-b-P2VP). In contrast to block copolymer/molecular solvent mixtures, the interfacial area occupied by each PS-b-P2VP chain decreases upon the addition of [Im][TFSI], indicating a considerable increase in the effective segregation strength of the PS-b-P2VP copolymer with ionic liquid addition. The relationship between membrane structure and ionic conductivity is illuminated through the development of scaling relationships that describe the ionic conductivity of block copolymer/ionic liquid mixtures as a function of membrane composition and temperature. It is shown that the dominant variable influencing conductivity is the overall volume fraction of ionic liquid in the mixture, which means there is incredible freedom in designing the block copolymer architecture

  15. Topological blocking in quantum quench dynamics

    Science.gov (United States)

    Kells, G.; Sen, D.; Slingerland, J. K.; Vishveshwara, S.

    2014-06-01

    We study the nonequilibrium dynamics of quenching through a quantum critical point in topological systems, focusing on one of their defining features: ground-state degeneracies and associated topological sectors. We present the notion of "topological blocking," experienced by the dynamics due to a mismatch in degeneracies between two phases, and we argue that the dynamic evolution of the quench depends strongly on the topological sector being probed. We demonstrate this interplay between quench and topology in models stemming from two extensively studied systems, the transverse Ising chain and the Kitaev honeycomb model. Through nonlocal maps of each of these systems, we effectively study spinless fermionic p-wave paired topological superconductors. Confining the systems to ring and toroidal geometries, respectively, enables us to cleanly address degeneracies, subtle issues of fermion occupation and parity, and mismatches between topological sectors. We show that various features of the quench, which are related to Kibble-Zurek physics, are sensitive to the topological sector being probed, in particular, the overlap between the time-evolved initial ground state and an appropriate low-energy state of the final Hamiltonian. While most of our study is confined to translationally invariant systems, where momentum is a convenient quantum number, we briefly consider the effect of disorder and illustrate how this can influence the quench in a qualitatively different way depending on the topological sector considered.

  16. New routes to the synthesis of amylose-block-polystyrene rod-coil block copolymers

    NARCIS (Netherlands)

    Loos, Katja; Müller, Axel H.E.

    2002-01-01

    Hybrid block copolymers amylose-block-polystyrene were synthesized by covalent attachment of maltoheptaose derivatives to end-functionalized polystyrene and subsequent enzymatic grafting from polymerization. The maltoheptaose derivatives were attached by reductive amination or hydrosilation to amino

  17. Block-based image hashing with restricted blocking strategy for rotational robustness

    Science.gov (United States)

    Xiang, Shijun; Yang, Jianquan

    2012-12-01

    Image hashing is a potential solution for image content authentication (a desired image hashing algorithm should be robust to common image processing operations and various geometric distortions). In the literature, researchers pay more attention to block-based image hashing algorithms due to their robustness to common image processing operations (such as lossy compression, low-pass filtering, and additive noise). However, the block-based hashing strategies are sensitive to rotation processing operations. This indicates that the robustness of the block-based hashing methods against rotation operations is an important issue. Towards this direction, in this article we propose a restricted blocking strategy by investigating effect of two rotation operations on an image and its blocks in both theoretical and experimental ways. Furthermore, we apply the proposed blocking strategy for the recently reported non-negative matrix factorization (NMF) hashing. Experimental results have demonstrated the validity of the block-based hashing algorithms with restricted blocking strategy for rotation operations.

  18. Spatial ability in children's play with Lego blocks.

    Science.gov (United States)

    Brosnan, M J

    1998-08-01

    Sex differences in spatial ability have been argued to originate from sex differences in children's play preferences. Child (30 boys and 20 girls) were asked to construct a specific three-dimensional model using Lego blocks and were also given the Shepard and Metzler test of mental rotation. Those who completed the Lego model scored significantly higher in spatial ability than those who did not. Constructional ability was also related to errors made during the construction of the model, but spatial ability was the best predictor of completion of the model.

  19. Instantaneous Wavelet Energetic Transfers between Atmospheric Blocking and Local Eddies.

    Science.gov (United States)

    Fournier, Aimé

    2005-07-01

    A new wavelet energetics technique, based on best-shift orthonormal wavelet analysis (OWA) of an instantaneous synoptic map, is constructed for diagnosing nonlinear kinetic energy (KE) transfers in five observed blocking cases. At least 90% of the longitudinal variance of time and latitude band mean 50-kPa geopotential is reconstructed by only two wavelets using best shift. This superior efficiency to the standard OWAs persists for time-evolving structures. The cases comprise two categories, respectively dominated by zonal-wavenumber sets {1} and {1, 2}. Further OWA of instantaneous residual nonblocking structures, combined with new “nearness” criteria, yields three more orthogonal components, representing smaller-scale eddies near the block (upstream and downstream) and distant structures. This decomposition fulfills a vision expressed to the author by Saltzman. Such a decomposition is not obtainable by simple Fourier analysis.Eddy patterns apparent in the components' contours suggest inferring geostrophic energetic interactions, but the component Rossby numbers may be too large to support the inference. However, a new result enabled by this method is the instantaneous attribution of blocking strain-field effects to particular energetically interactive eddies, consistent with Shutts' hypothesis. Such attribution was only possible before in simplified models or in a time-average sense. In four of five blocks, the upstream eddies feed KE to the block, which in turn, in three of four cases, transmits KE to the downstream eddies. The small case size precludes statistically significant conclusions. The appendixes link low-order blocking structure and dynamics to some wavelet design principles and propose a new interaction diagnosis, similar to E-vector analysis, but instantaneous.

  20. Block Gas Sol Unit in Haderslev

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    2000-01-01

    Investigation of a SDHW system based on a Block Gas Sol Unit from Baxi A/S installed by a consumer i Haderslev, Denmark.......Investigation of a SDHW system based on a Block Gas Sol Unit from Baxi A/S installed by a consumer i Haderslev, Denmark....

  1. Light extraction block with curved surface

    Science.gov (United States)

    Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.

    2016-03-22

    Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.

  2. Benchmarking Block Ciphers for Wireless Sensor Networks

    NARCIS (Netherlands)

    Law, Y.W.; Doumen, J.M.; Hartel, P.H.

    2004-01-01

    Choosing the most storage- and energy-efficient block cipher specifically for wireless sensor networks (WSNs) is not as straightforward as it seems. To our knowledge so far, there is no systematic evaluation framework for the purpose. We have identified the candidates of block ciphers suitable for W

  3. The Block Grant Record: Lessons from Experience.

    Science.gov (United States)

    Hastings, Anne H.

    1982-01-01

    Evaluates the performance of federal block grants in health, law enforcement, peoplepower training, community development, and Social Security programs, to help forecast the effects of such grants in education. Finds that block grants did not improve local control, accountability, citizen participation, efficiency, targeting of funds, or program…

  4. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

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

    1995-01-01

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

  5. Earthquake Resistant Submarine Drydock Block System Design

    Science.gov (United States)

    1988-05-01

    acceleration time history. It Is observed that the block on block surfaces for this system had been painted. According to Rabinowicz (1987) [13J, a...Maryland, 1982, p. 272. 166 13. Rabinowicz , Ernest, Lecture, "Tribology", M.I.T., Course 2.800, Fall 1987. 14. Telephone conversation between Tingley

  6. Micellization and Characterization of Block Copolymer Detergents

    DEFF Research Database (Denmark)

    Hvidt, Søren

    Triblock copolymers of the type EPE, where E and P denote ethylene oxide and propylene oxide blocks, respectively, are used widely in industry as emulsifiers, anti-foaming agents, and in delayed drug release. EPE copolymers form micelles with a core of P blocks and different micellar shapes depen...

  7. Haplotype block structure is conserved across mammals

    NARCIS (Netherlands)

    Guryev, Victor; Smits, Bart M G; van de Belt, Jose; Verheul, Mark; Hubner, Norbert; Cuppen, Edwin

    2006-01-01

    Genetic variation in genomes is organized in haplotype blocks, and species-specific block structure is defined by differential contribution of population history effects in combination with mutation and recombination events. Haplotype maps characterize the common patterns of linkage disequilibrium i

  8. C++ application development with Code::Blocks

    CERN Document Server

    Modak, Biplab Kumar

    2013-01-01

    This is a comprehensive tutorial with step-by-step instructions on how to develop applications with Code::Blocks.This book is for C++ developers who wish to use Code::Blocks to create applications with a consistent look and feel across multiple platforms. This book assumes that you are familiar with the basics of the C++ programming language.

  9. Ultrasonographic evaluation of neck hematoma and block salvage after failed neurostimulation-guided interscalene block.

    Science.gov (United States)

    Howell, Stephen M; Unger, M W Todd; Colson, James D; Serafini, Mario

    2010-11-01

    Ultrasound-guided regional anesthetic techniques have shown some advantages over conventional paresthesia and neurostimulation techniques. We report the case of a neurostimulation-guided continuous interscalene block that would have ended in complication were it not for experience with ultrasound-guided regional anesthesia. Familiarity with ultrasound-guided block techniques permitted assessment of a neck hematoma during interscalene block and ultimately allowed successful peripheral nerve block.

  10. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    OpenAIRE

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing sulfonated units were prepared by blending styrene-block-butadiene-block-styrene (SBS), with both sulfonated PS and sulfonated SEBS in a Brabender mixer. Such a procedure was performed as an alter...

  11. The undesirable effects of neuromuscular blocking drugs

    DEFF Research Database (Denmark)

    Claudius, C; Garvey, L H; Viby-Mogensen, J

    2009-01-01

    Neuromuscular blocking drugs are designed to bind to the nicotinic receptor at the neuromuscular junction. However, they also interact with other acetylcholine receptors in the body. Binding to these receptors causes adverse effects that vary with the specificity for the cholinergic receptor...... in question. Moreover, all neuromuscular blocking drugs may cause hypersensitivity reactions. Often the symptoms are mild and self-limiting but massive histamine release can cause systematic reactions with circulatory and respiratory symptoms and signs. At the end of anaesthesia, no residual effect...... of a neuromuscular blocking drug should be present. However, the huge variability in response to neuromuscular blocking drugs makes it impossible to predict which patient will suffer postoperative residual curarization. This article discusses the undesirable effects of the currently available neuromuscular blocking...

  12. Fermion RG blocking transformations and IR structure

    CERN Document Server

    Cheng, X

    2011-01-01

    We explore fermion RG block-spinning transformations on the lattice with the aim of studying the IR structure of gauge theories and, in particular, the existence of IR fixed points for varying fermion content. In the case of light fermions the main concern and difficulty is ensuring locality of any adopted blocking scheme. We discuss the problem of constructing a local blocked fermion action in the background of arbitrary gauge fields. We then discuss the carrying out of accompanying gauge field blocking. In the presence of the blocked fermions implementation of MCRG is not straightforward. By adopting judicious approximations we arrive at an easily implementable approximate RG recursion scheme that allows quick, inexpensive estimates of the location of conformal windows for various groups and fermion representations. We apply this scheme to locate the conformal windows in the case of SU(2) and SU(3) gauge groups. Some of the reasons for the apparent efficacy of this and similar decimation schemes are discuss...

  13. STUDY ON POLYSULFONE-POLYESTER BLOCK COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    DING Youjun; QI Daquan

    1988-01-01

    Synthesis and characterization of a series of Polysulfone (PSF)-Polyester (PEs) block copolymers were studied.The degree of randomness (B) of these block copolymers was calculated from the intensities of their proton signals in 1H NMR spectra and lies in the region of 0 < B < 1. It was shown that the degree of randomness (B) and the average sequence length (L) in block copolymers were relatively dependent on the reaction conditions, various feed ratios and structure of diols.The phenomenon was observed, when the PSF-PEs block copolymers dissolved in different solvents they had different viscosities and molecular conformations.The PSF-PEs block copolymers had better solvent resistance than homo-polysulfone.

  14. A note on "Block H-matrices and spectrum of block matrices"

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-zhou; HUANG Ze-jun

    2008-01-01

    In this paper, we make further discussions and improvements on the results presented in the previously published work "Block H-matrices and spectrum of block matrices". Furthermore, a new bound for eigenvalues of block matrices is given with examples to show advantages of the new result.

  15. The Effect of Haplotype-Block Definitions on Inference of Haplotype-Block Structure and htSNPs Selection

    Institute of Scientific and Technical Information of China (English)

    KeyueDing; KaixinZhou; JingZhang; JoanneKnight; XuegongZhang; YanShen

    2005-01-01

    It has been recently suggested that the human genome is organized as a series of haplotype blocks, and efforts to create a genome-wide haplotype map are already underway. Several computational algorithms have been proposed to partition the genome. However, little is known about their behaviors in relation to the haplotype-block partitioning and haplotypetagging SNPs selection. Here, we present a systematic comparison of three classes of haplotype-block partition definitions, a diversity-based method, a linkage-disequilibrium (LD)-based method, and a recombination-based method.The data used were derived from a coalescent simulation under both a uniform recombination model and one that assumes recombination hotspots. There were considerable differences in haplotype information loss in the measure of entropy when the partition methods were compared under different population-genetics scenarios. Under both recombination models, the results from the LD-based definition and the recombination-based definition were more similar to each other than were the results from the diversity-based definition. This work demonstrates that when undertaking haplotype-based association mapping, the choice of haplotype-block definition and SNP selection requires careful consideration.

  16. Building Blocks of the Universe

    CERN Document Server

    The ATLAS collaboration

    2015-01-01

    This article presents possibilities to impart knowledge of and enthusiasm for particle physics to essentially all non-expert target audiences by the use of LEGO bricks and models of particle physics experiments built from these. Methods of using LEGO models, both as a passive exhibit and as part of interactive outreach events, are presented, along with a historical review of the “Build Your Own Particle Detector” programme and the corresponding idea of hosting competitions in building detector models in LEGO pieces as a perfect setting to grasp people’s attention, get them involved and ultimately convey knowledge in particle physics to them.

  17. Block share ownership and corporate earning: Evidence from Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Somayye Adhami

    2013-01-01

    Full Text Available During the past few years, there have been growing interests among researchers to study the effect of block share ownership on corporate earning especially in developing countries. The purpose of this paper is to consider the impact of block ownership on performance of firms in terms of profitability. The proposed study develops two econometric models and applies them on selected firms from Tehran Stock Exchange over the period 2002-2010. The primary objective of this survey is to find the relationship between return of assets and Tobin's Q as dependent variables with eight independent variables including company size, sales growth, block ownership, debt and liability ratios, etc. The results of implementation of ordinary least squares on two econometric models reveal that while there is no meaningful relationship between return of asset and block ownership there is a meaningful relationship between block ownership and Tobin's Q.

  18. Robust Face Recognition via Block Sparse Bayesian Learning

    Directory of Open Access Journals (Sweden)

    Taiyong Li

    2013-01-01

    Full Text Available Face recognition (FR is an important task in pattern recognition and computer vision. Sparse representation (SR has been demonstrated to be a powerful framework for FR. In general, an SR algorithm treats each face in a training dataset as a basis function and tries to find a sparse representation of a test face under these basis functions. The sparse representation coefficients then provide a recognition hint. Early SR algorithms are based on a basic sparse model. Recently, it has been found that algorithms based on a block sparse model can achieve better recognition rates. Based on this model, in this study, we use block sparse Bayesian learning (BSBL to find a sparse representation of a test face for recognition. BSBL is a recently proposed framework, which has many advantages over existing block-sparse-model-based algorithms. Experimental results on the Extended Yale B, the AR, and the CMU PIE face databases show that using BSBL can achieve better recognition rates and higher robustness than state-of-the-art algorithms in most cases.

  19. Development of Alkali Activated Geopolymer Masonry Blocks

    Science.gov (United States)

    Venugopal, K.; Radhakrishna; Sasalatti, Vinod

    2016-09-01

    Cement masonry units are not considered as sustainable since their production involves consumption of fuel, cement and natural resources and therefore it is essential to find alternatives. This paper reports on making of geopolymer solid & hollow blocks and masonry prisms using non conventional materials like fly ash, ground granulated blast furnace slag (GGBFS) and manufactured sand and curing at ambient temperature. They were tested for water absorption, initial rate of water absorption, dry density, dimensionality, compressive, flexural and bond-strength which were tested for bond strength with and without lateral confinement, modulus of elasticity, alternative drying & wetting and masonry efficiency. The properties of geopolymer blocks were found superior to traditional masonry blocks and the masonry efficiency was found to increase with decrease in thickness of cement mortar joints. There was marginal difference in strength between rendered and unrendered geopolymer masonry blocks. The percentage weight gain after 7 cycles was less than 6% and the percentage reduction in strength of geopolymer solid blocks and hollow blocks were 26% and 28% respectively. Since the properties of geopolymer blocks are comparatively better than the traditional masonry they can be strongly recommended for structural masonry.

  20. A droplet-based building block approach for bladder smooth muscle cell (SMC) proliferation.

    Science.gov (United States)

    Xu, F; Moon, S J; Emre, A E; Turali, E S; Song, Y S; Hacking, S A; Nagatomi, J; Demirci, U

    2010-03-01

    Tissue engineering based on building blocks is an emerging method to fabricate 3D tissue constructs. This method requires depositing and assembling building blocks (cell-laden microgels) at high throughput. The current technologies (e.g., molding and photolithography) to fabricate microgels have throughput challenges and provide limited control over building block properties (e.g., cell density). The cell-encapsulating droplet generation technique has potential to address these challenges. In this study, we monitored individual building blocks for viability, proliferation and cell density. The results showed that (i) SMCs can be encapsulated in collagen droplets with high viability (>94.2 +/- 3.2%) for four cases of initial number of cells per building block (i.e. 7 +/- 2, 16 +/- 2, 26 +/- 3 and 37 +/- 3 cells/building block). (ii) Encapsulated SMCs can proliferate in building blocks at rates that are consistent (1.49 +/- 0.29) across all four cases, compared to that of the controls. (iii) By assembling these building blocks, we created an SMC patch (5 mm x 5 mm x 20 microm), which was cultured for 51 days forming a 3D tissue-like construct. The histology of the cultured patch was compared to that of a native rat bladder. These results indicate the potential of creating 3D tissue models at high throughput in vitro using building blocks.

  1. Evidence that a transient but cognitively demanding process underlies forward blocking.

    Science.gov (United States)

    Liu, Pei-Pei; Luhmann, Christian C

    2013-01-01

    Blocking is a learning phenomenon in which prior experience inhibits learning about novel cues. Though the phenomenon itself has been well documented, the details of blocking-related processes still remain contentious. Two experiments investigated whether participants were engaged in demanding cognitive processing during different portions of a standard blocking paradigm. Participants in Experiment 1 engaged in a simple secondary task while completing a standard blocking procedure. Results showed that performance on the secondary task was briefly diminished early in the second phase of the blocking paradigm, when the novel cue is first paired with the pretrained cue. Participants in Experiment 2 performed a difficult cognitive load task during either the early or the late portions of the second phase of blocking. The blocking effect was eliminated when learners were under load early in the second phase, but not when learners were under load late in the second phase. These results suggest that blocking relies on a cognitively demanding process with a distinct time course. Computational simulations illustrate how a model that includes top-down (i.e., cognitively demanding) attentional modulation can reproduce the observed behaviour. This suggests that purely associative processes are not sufficient to explain the observed behaviour. Implications for current accounts of blocking are discussed.

  2. Gaussian curvature analysis allows for automatic block placement in multi-block hexahedral meshing.

    Science.gov (United States)

    Ramme, Austin J; Shivanna, Kiran H; Magnotta, Vincent A; Grosland, Nicole M

    2011-10-01

    Musculoskeletal finite element analysis (FEA) has been essential to research in orthopaedic biomechanics. The generation of a volumetric mesh is often the most challenging step in a FEA. Hexahedral meshing tools that are based on a multi-block approach rely on the manual placement of building blocks for their mesh generation scheme. We hypothesise that Gaussian curvature analysis could be used to automatically develop a building block structure for multi-block hexahedral mesh generation. The Automated Building Block Algorithm incorporates principles from differential geometry, combinatorics, statistical analysis and computer science to automatically generate a building block structure to represent a given surface without prior information. We have applied this algorithm to 29 bones of varying geometries and successfully generated a usable mesh in all cases. This work represents a significant advancement in automating the definition of building blocks.

  3. Coset conformal blocks and N=2 gauge theories

    CERN Document Server

    Wyllard, Niclas

    2011-01-01

    It was recently suggested that the su(N)_k+su(N)_p/su(N)_{k+p} coset conformal field theories should be related to N=2 SU(N) gauge theories on R^4/Z_p. In this paper we study various aspects of this proposal. We perform explicit checks of the relation for (N,p)=(2,4), where the symmetry algebra of the coset is the so called S_3 parafermion algebra. Even though the symmetry algebra of the coset is unknown for generic (N,p) models, we manage to perform non-trivial checks in the general case by using knowledge of the Kac determinant of the coset CFT. We also find evidence that the conformal blocks of the (N,p) model should factorise into a certain product of p (N,1) conformal blocks. Precisely this structure is present in the instanton partition function on R^4/Z_p.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    load to provide a response to the power system and the subsequent need to recover. The conventional system dispatch algorithm is altered to facilitate the dispatch of demand response units alongside generating units using the proposed offer structure. The value of demand response is assessed through...... case studies that dispatch flexible supermarket refrigeration loads for the provision of regulating power. The demand resource is described by a set of asymmetric blocks, and a set of four blocks offers is shown to offer cost savings for the procurement of regulating power in excess of 20......%. For comparative purposes, the cost savings achievable with a fully observable and controllable demand response resource are evaluated, using a time series model of the refrigeration loads. The fully modeled resource offers greater savings; however the difference is small and potentially insufficient to justify...

  5. Effects of bite blocks and hearing status on vowel production

    Science.gov (United States)

    Lane, Harlan; Denny, Margaret; Guenther, Frank H.; Matthies, Melanie L.; Menard, Lucie; Perkell, Joseph S.; Stockmann, Ellen; Tiede, Mark; Vick, Jennell; Zandipour, Majid

    2005-09-01

    This study explores the effects of hearing status and bite blocks on vowel production. Normal-hearing controls and postlingually deaf adults read elicitation lists of /hVd/ syllables with and without bite blocks and auditory feedback. Deaf participants' auditory feedback was provided by a cochlear prosthesis and interrupted by switching off their implant microphones. Recording sessions were held before prosthesis was provided and one month and one year after. Long-term absence of auditory feedback was associated with heightened dispersion of vowel tokens, which was inflated further by inserting bite blocks. The restoration of some hearing with prosthesis reduced dispersion. Deaf speakers' vowel spaces were reduced in size compared to controls. Insertion of bite blocks reduced them further because of the speakers' incomplete compensation. A year of prosthesis use increased vowel contrast with feedback during elicitation. These findings support the inference that models of speech production must assign a role to auditory feedback in error-based correction of feedforward commands for subsequent articulatory gestures.

  6. Cavitation and pore blocking in nanoporous glasses.

    Science.gov (United States)

    Reichenbach, C; Kalies, G; Enke, D; Klank, D

    2011-09-06

    In gas adsorption studies, porous glasses are frequently referred to as model materials for highly disordered mesopore systems. Numerous works suggest that an accurate interpretation of physisorption isotherms requires a complete understanding of network effects upon adsorption and desorption, respectively. The present article deals with nitrogen and argon adsorption at different temperatures (77 and 87 K) performed on a series of novel nanoporous glasses (NPG) with different mean pore widths. NPG samples contain smaller mesopores and significantly higher microporosity than porous Vycor glass or controlled pore glass. Since the mean pore width of NPG can be tuned sensitively, the evolution of adsorption characteristics with respect to a broadening pore network can be investigated starting from the narrowest nanopore width. With an increasing mean pore width, a H2-type hysteresis develops gradually which finally transforms into a H1-type. In this connection, a transition from a cavitation-induced desorption toward desorption controlled by pore blocking can be observed. Furthermore, we find concrete hints for a pore size dependence of the relative pressure of cavitation in highly disordered pore systems. By comparing nitrogen and argon adsorption, a comprehensive insight into adsorption mechanisms in novel disordered materials is provided.

  7. Temperature alters Plasmodium blocking by Wolbachia

    Science.gov (United States)

    Murdock, Courtney C.; Blanford, Simon; Hughes, Grant L.; Rasgon, Jason L.; Thomas, Matthew B.

    2014-02-01

    Very recently, the Asian malaria vector (Anopheles stephensi) was stably transinfected with the wAlbB strain of Wolbachia, inducing refractoriness to the human malaria parasite Plasmodium falciparum. However, conditions in the field can differ substantially from those in the laboratory. We use the rodent malaria P. yoelii, and somatically transinfected An. stephensi as a model system to investigate whether the transmission blocking potential of wAlbB is likely to be robust across different thermal environments. wAlbB reduced malaria parasite prevalence and oocyst intensity at 28°C. At 24°C there was no effect on prevalence but a marked increase in oocyst intensity. At 20°C, wAlbB had no effect on prevalence or intensity. Additionally, we identified a novel effect of wAlbB that resulted in reduced sporozoite development across temperatures, counterbalancing the oocyst enhancement at 24°C. Our results demonstrate complex effects of temperature on the Wolbachia-malaria interaction, and suggest the impacts of transinfection might vary across diverse environments.

  8. Molecular Exchange Dynamics in Block Copolymer Micelles

    Science.gov (United States)

    Bates, Frank; Lu, Jie; Choi, Soohyung; Lodge, Timothy

    2012-02-01

    Poly(styrene-b-ethylene propylene) (PS-PEP) diblock copolymers were mixed with squalane (C30H62) at 1% by weight resulting in the formation of spherical micelles. The structure and dynamics of molecular exchange were characterized by synchrotron small-angle x-ray scattering (SAXS) and time resolved small-angle neutron scattering (TR-SANS), respectively, between 100 C and 160 C. TR-SANS measurements were performed with solutions initially containing deuterium labeled micelle cores and normal cores dispersed in a contrast matched squalane. Monitoring the reduction in scattering intensity as a function of time at various temperatures revealed molecular exchange dynamics highly sensitive to the core molecular weight and molecular weight distribution. Time-temperature superposition of data acquired at different temperatures produced a single master curve for all the mixtures. Experiments conducted with isotopically labeled micelle cores, each formed from two different but relatively mondisperse PS blocks, confirmed a simple dynamical model based on first order kinetics and core Rouse single chain relaxation. These findings demonstrate a dramatic transition to nonergodicity with increasing micelle core molecular weight and confirm the origins of the logarithmic exchange kinetics in such systems.

  9. Measurement of soil moisture using gypsum blocks

    DEFF Research Database (Denmark)

    Friis Dela, B.

    the building. Consequently, measuring the moisture of the surrounding soil is of great importance for detecting the source of moisture in a building. Up till now, information has been needed to carry out individual calibrations for the different types of gypsum blocks available on the market and to account......For the past 50 years, gypsum blocks have been used to determine soil moisture content. This report describes a method for calibrating gypsum blocks for soil moisture measurements. Moisture conditions inside a building are strongly influenced by the moisture conditions in the soil surrounding...

  10. Theory of circuit block switch-off

    Directory of Open Access Journals (Sweden)

    S. Henzler

    2004-01-01

    Full Text Available Switching-off unused circuit blocks is a promising approach to supress static leakage currents in ultra deep sub-micron CMOS digital systems. Basic performance parameters of Circuit Block Switch-Off (CBSO schemes are defined and their dependence on basic circuit parameters is estimated. Therefore the design trade-off between strong leakage suppression in idle mode and adequate dynamic performance in active mode can be supported by simple analytic investigations. Additionally, a guideline for the estimation of the minimum time for which a block deactivation is useful is derived.

  11. Lidocaine block of cardiac sodium channels

    OpenAIRE

    Bean, BP; Cohen, CJ; Tsien, RW

    1983-01-01

    Lidocaine block of cardiac sodium channels was studied in voltage-clamped rabbit purkinje fibers at drug concentrations ranging from 1 mM down to effective antiarrhythmic doses (5-20 μM). Dose-response curves indicated that lidocaine blocks the channel by binding one-to-one, with a voltage-dependent K(d). The half-blocking concentration varied from more than 300 μM, at a negative holding potential where inactivation was completely removed, to approximately 10 μM, at a depolarized holding pote...

  12. Comparative Analysis of Sandcrete Hollow Blocks and Laterite Interlocking Blocks as Walling Elements

    Directory of Open Access Journals (Sweden)

    Akeem Ayinde Raheem

    2012-04-01

    Full Text Available This study considered the production and testing of sandcrete hollow blocks and laterite interlocking blocks with a view to comparing their physical characteristics and production cost. Some units of sandcrete hollow blocks and laterite interlocking blocks were made using machine vibrated sandcrete block mould and hydraulic interlocking block making machine respectively. The blocks were tested to determine their density and compressive strength. The results obtained from the tests were compared with the specifications of Nigerian Building and Road Research Institute (2006, Nigerian Building Code (2006, and Nigerian Industrial Standards (2000. The results indicated that the compressive strength of 225mm and 150mm sandcrete hollow blocks varies from 1.59 N/mm2 to 4.25 N/mm2 and 1.48N/mm2 to 3.35N/mm2 respectively, as the curing age increases from 7 to 28 days. For laterite interlocking blocks, the strength varies from 1.70N/mm2 at 7 days to 5.03N/mm2 at 28 days. All the blocks produced satisfied the minimum requirements in terms of compressive strength, by all available codes. The cost per square metre of 225mm and 150mm sandcrete hollow blocks are ₦2,808:00 and ₦2,340:00 respectively, while that of laterite interlocking blocks is ₦2,121:20.It was concluded that laterite interlocking blocks have better strength and are cheaper than sandcrete hollow blocks.

  13. Lexical Retrieval is not by Competition: Evidence from the Blocked Naming Paradigm.

    Science.gov (United States)

    Navarrete, Eduardo; Del Prato, Paul; Peressotti, Francesca; Mahon, Bradford Z

    2014-10-01

    A central issue in research on speech production is whether or not the retrieval of words from the mental lexicon is a competitive process. An important experimental paradigm to study the dynamics of lexical retrieval is the blocked naming paradigm, in which participants name pictures of objects that are grouped by semantic category ('homogenous' or 'related' blocks) or not grouped by semantic category ('heterogeneous' or 'unrelated' blocks). Typically, pictures are repeated multiple times (or cycles) within both related and unrelated blocks. It is known that participants are slower in related than in unrelated blocks when the data are collapsed over all within-block repetitions. This semantic interference effect, as observed in the blocked naming task, is the strongest empirical evidence for the hypothesis of lexical selection by competition. Here we show, contrary to the accepted view, that the default polarity of semantic context effects in the blocked naming paradigm is facilitation, rather than interference. In a series of experiments we find that interference arises only when items repeat within a block, and only because of that repetition: What looks to be 'semantic interference' in the blocked naming paradigm is actually less repetition priming in related compared to unrelated blocks. These data undermine the theory of lexical selection by competition and indicate a model in which the most highly activated word is retrieved, regardless of the activation levels of nontarget words. We conclude that the theory of lexical selection by competition, and by extension the important psycholinguistic models based on that assumption, are no longer viable, and frame a new way to approach the question of how words are retrieved in spoken language production.

  14. Galactic Building Blocks Seen Swarming Around Andromeda

    Science.gov (United States)

    2004-02-01

    Green Bank, WV - A team of astronomers using the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) has made the first conclusive detection of what appear to be the leftover building blocks of galaxy formation -- neutral hydrogen clouds -- swarming around the Andromeda Galaxy, the nearest large spiral galaxy to the Milky Way. This discovery may help scientists understand the structure and evolution of the Milky Way and all spiral galaxies. It also may help explain why certain young stars in mature galaxies are surprisingly bereft of the heavy elements that their contemporaries contain. Andromeda Galaxy This image depicts several long-sought galactic "building blocks" in orbit of the Andromeda Galaxy (M31). The newfound hydrogen clouds are depicted in a shade of orange (GBT), while gas that comprises the massive hydrogen disk of Andromeda is shown at high-resolution in blue (Westerbork Sythesis Radio Telescope). CREDIT: NRAO/AUI/NSF, WSRT (Click on Image for Larger Version) "Giant galaxies, like Andromeda and our own Milky Way, are thought to form through repeated mergers with smaller galaxies and through the accretion of vast numbers of even lower mass 'clouds' -- dark objects that lack stars and even are too small to call galaxies," said David A. Thilker of the Johns Hopkins University in Baltimore, Maryland. "Theoretical studies predict that this process of galactic growth continues today, but astronomers have been unable to detect the expected low mass 'building blocks' falling into nearby galaxies, until now." Thilker's research is published in the Astrophysical Journal Letters. Other contributors include: Robert Braun of the Netherlands Foundation for Research in Astronomy; Rene A.M. Walterbos of New Mexico State University; Edvige Corbelli of the Osservatorio Astrofisico di Arcetri in Italy; Felix J. Lockman and Ronald Maddalena of the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia; and Edward Murphy of the

  15. Parallel Sorted Neighborhood Blocking with MapReduce

    OpenAIRE

    Kolb, Lars; Thor, Andreas; Rahm, Erhard

    2010-01-01

    Cloud infrastructures enable the efficient parallel execution of data-intensive tasks such as entity resolution on large datasets. We investigate challenges and possible solutions of using the MapReduce programming model for parallel entity resolution. In particular, we propose and evaluate two MapReduce-based implementations for Sorted Neighborhood blocking that either use multiple MapReduce jobs or apply a tailored data replication.

  16. Nanostructured photovoltaic materials using block polymer assemblies

    Science.gov (United States)

    Mastroianni, Sarah Elizabeth

    Despite its potential as an abundant, sustainable alternative to non-renewable energy sources, solar energy currently is underutilized. Photovoltaics, which convert energy from sunlight into electricity, commonly are made from inorganic semiconductor materials that require expensive manufacturing and processing techniques. Alternatively, organic materials can be used to produce flexible and lightweight organic photovoltaic (OPV) devices, which can be prepared using solution-based processing techniques. However, OPV devices are limited by low efficiencies and short lifetimes compared to their inorganic counterparts. In OPV systems, charge carriers are generated in the active layer via the separation of excitons (electron-hole pairs) at interfaces between donor and acceptor materials. Because excitons have a limited diffusion length (˜10 nm), they may recombine before reaching a donor-acceptor interface if domain sizes are large. This exciton recombination can limit device efficiency; thus, the design parameters for improved active layer morphologies include large interfacial areas, small size scales, and continuous conducting pathways. Currently, most OPV devices are prepared by blending donor and acceptor materials in bulk heterojunction (BHJ) devices, often resulting in non-ideal, process-dependent morphologies. Alternatively, the self-assembly of block polymers (BP)s offers a reproducible means to generate nanostructured active layers. The work presented in this dissertation examines the synthetic approaches to preparing BPs containing different electroactive materials: non-conjugated, amorphous poly(vinyl-m-triphenylamine) [PVmTPA] and conjugated poly(3-alkythiophene) [P3AT] p-type materials as well as fullerene-based n-type materials. The synthesis and self-assembly of a model poly(methyl methacrylate)- b-PVmTPA system is presented. This work was extended to synthesize PVmTPA BPs with complementary poly(methyl methacrylate- co-hydroxyethyl methacrylate) [P

  17. Nazca - South America Convergence and Motion of the North Andes Block

    Science.gov (United States)

    La Femina, P. C.; Mora-paez, H.; Mothes, P. A.; Ruiz, G.

    2012-12-01

    The North Andes block (NAB) is a hypothesized tectonic block that moves (escapes) north-northeast relative to a stable South American reference frame. The motion of this block is thought to be derived by the collision of the Carnegie Ridge in southern Ecuador and/or by oblique convergence and high degrees of interplate coupling north of the ridge (i.e., strain partitioning). We investigate the kinematics of NAB motion utilizing a velocity field based on new continuous GPS networks and existing episodic GPS data in Ecuador and Colombia. The new velocity field and published earthquake slip vectors are inverted to solve for the Euler vector of the NAB and interseismic elastic strain accumulation on block-bounding faults using a block modeling approach. At the latitude of Ecuador, the NAB is rigid with transpressional deformation accommodating northeastward motion along its boundary with South America. In central to northern Colombia, the NAB is dissected by several prominent shear zones. We test a suite of block models to investigate the tectonic nature of the NAB and the style of faulting in the upper plate accommodating block motion. Through the estimation of elastic strain accumulation on all block-bounding faults, we improve the understanding of interseismic coupling along a convergent margin capable of producing M>8 earthquakes and upper plate faults capable of generating M>6 earthquakes.

  18. Finite Element Analysis of Reinforced Concrete Plate Impacted by Block

    Institute of Scientific and Technical Information of China (English)

    LUO Xiaoyang; Pascal PERROTIN; YAN Quansheng

    2006-01-01

    A new concept of structurally dissipating rock-shed (SDR) was developed by the lab of Tonello IC and LOCIE-ESIGEC (France).To decide the dimension of the plate used in SDR,an ANSYS model which could simulate the impact of rock in the centre of the plate was established by Fabien Delhomme.By using this model,some finite element analyses are carried out in the present paper Firstly,a plate impacted by a block is numerically simulated,the numerical results obtained from different mesh sizes are compared and the accuracy of the finite element model is verified.Then,the dynamic response of the plate impacted at the boundary and in the medium part is computed.By analyzing the stress in rebar,the most dangerous region of impact of plate was found.For a rectangular plate,the most dangerous region is at the corner of the plate when a block drops in.Finally,the whole deformation process of the plate under dropping block was simulated and a simplified definition (effect zone) to describe the deformation process in different positions of plate was given.From this study,it is found that the impact only affects heavily within the effect zone.

  19. Develop mono-block tooth implants using automate design and FEM analysis

    OpenAIRE

    J.P. Alister; J. Moller,; F. Alister; R. Hunter

    2007-01-01

    Purpose: Purpose of this paper is present a new approach to modelling and design the low cost mono-block dental implants based on the integration of the computer aided techniques. This approach provides the automation of the design process of the mono-block dental implants.Design/methodology/approach: The approach used to develop the modelling and design of the mono-block dental implants are based on the parametrization of the main geometric features of the implants. This approach allows to ...

  20. Formation of Anisotropic Block Copolymer Gels

    Science.gov (United States)

    Liaw, Chya Yan; Shull, Kenneth; Henderson, Kevin; Joester, Derk

    2011-03-01

    Anisotropic, fibrillar gels are important in a variety of processes. Biomineralization is one example, where the mineralization process often occurs within a matrix of collagen or chitin fibers that trap the mineral precursors and direct the mineralization process. We wish to replicate this type of behavior within block copolymer gels. Particularly, we are interested in employing gels composed of cylindrical micelles, which are anisotropic and closely mimic biological fibers. Micelle geometry is controlled in our system by manipulating the ratio of molecular weights of the two blocks and by controlling the detailed thermal processing history of the copolymer solutions. Small-Angle X-ray Scattering and Dynamic Light Scattering are used to determine the temperature dependence of the gel formation process. Initial experiments are based on a thermally-reversible alcohol-soluble system, that can be subsequently converted to a water soluble system by hydrolysis of a poly(t-butyl methacrylate) block to a poly (methacrylic acid) block. MRSEC.

  1. EnviroAtlas - Milwaukee, WI - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Milwaukee, WI EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  2. Extrinsic germanium Blocked Impurity Bank (BIB) detectors

    Science.gov (United States)

    Krabach, Timothy N.; Huffman, James E.; Watson, Dan M.

    1989-01-01

    Ge:Ga blocked-impurity-band (BIB) detectors with long wavelength thresholds greater than 190 microns and peak quantum efficiencies of 4 percent, at an operating temperature of 1.8 K, have been fabricated. These proof of concept devices consist of a high purity germanium blocking layer epitaxially grown on a Ga-doped Ge substrate. This demonstration of BIB behavior in germanium enables the development of far infrared detector arrays similar to the current silicon-based devices. Present efforts are focussed on improving the chemical vapor deposition process used to create the blocking layer and on the lithographic processing required to produce monolithic detector arrays in germanium. Approaches to test the impurity levels in both the blocking and active layers are considered.

  3. EnviroAtlas - Fresno, CA - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Fresno, CA EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  4. Functionalization of Block Copolymer Vesicle Surfaces

    Directory of Open Access Journals (Sweden)

    Wolfgang Meier

    2011-01-01

    Full Text Available In dilute aqueous solutions certain amphiphilic block copolymers self-assemble into vesicles that enclose a small pool of water with a membrane. Such polymersomes have promising applications ranging from targeted drug-delivery devices, to biosensors, and nanoreactors. Interactions between block copolymer membranes and their surroundings are important factors that determine their potential biomedical applications. Such interactions are influenced predominantly by the membrane surface. We review methods to functionalize block copolymer vesicle surfaces by chemical means with ligands such as antibodies, adhesion moieties, enzymes, carbohydrates and fluorophores. Furthermore, surface-functionalization can be achieved by self-assembly of polymers that carry ligands at their chain ends or in their hydrophilic blocks. While this review focuses on the strategies to functionalize vesicle surfaces, the applications realized by, and envisioned for, such functional polymersomes are also highlighted.

  5. EnviroAtlas - Portland, OR - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Portland, OR EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  6. EnviroAtlas - Cleveland, OH - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Cleveland, OH EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded...

  7. EnviroAtlas - Paterson, NJ - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Paterson, NJ EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  8. EnviroAtlas - Memphis, TN - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Memphis, TN EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded based...

  9. EnviroAtlas - Phoenix, AZ - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Phoenix, AZ EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  10. The New Block Cipher Design (Tigris Cipher

    Directory of Open Access Journals (Sweden)

    Omar A. Dawood

    2015-11-01

    Full Text Available In the present paper we have proposed a new variant of AES cipher with high level of security and an elegant construction called TIGRIS cipher. The TIGRIS name has been derived from one of the two famous rivers in Iraq. The proposed TIGRIS cipher is a revision for the proposed Euphrates cipher which has already been published. It has been designed with a good coherent structure that is based on solid algebraic and well mathematical opinions. The proposed cipher uses the SPN structure and what is known by the Galois Field GF (28. It is an iterated cipher that has a conservative design which is easily implemented on both hardware and software. It operates with block size of 128-bits and with three variable key lengths of 128-bits, 192-bits and 256-bits in addition to sixteen rounds or multiples of four rounds. The proposed cipher works with good invertible operations' stages and a compact duplicated ciphering key. The Tigris cipher construction strategy includes the adoption of construction a new S-box with high non-linearity that uses the same routines of the AES-S-box stage but with different modular arithmetic of irreducible polynomial and different affine matrix in addition to the distinct constant vector. The second and the third layers of the proposed model are based on the shifting concept for the confusion and diffusion process with reversible operations. The last layer of the proposed model is the key addition layer that is responsible for the expanding and generating the ciphering key by two directions those of row and column expansion, which are associated with two constant vectors of golden ratio and base nature algorithm as a fixed word to eliminate any weak or semi-weak ciphering key.

  11. Algorithms for Finding the Inverses of Factor Block Circulant Matrices

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, algorithms for finding the inverse of a factor block circulant matrix,a factor block retrocirculant matrix and partitioned matrix with factor block circulant blocks over the complex field are presented respectively. In addition, two algorithms for the inverse of a factor block circulant matrix over the quaternion division algebra are proposed.

  12. Building-block selectivity of polyketide synthases.

    Science.gov (United States)

    Liou, Grace F; Khosla, Chaitan

    2003-04-01

    For the past decade, polyketide synthases have presented an exciting paradigm for the controlled manipulation of complex natural product structure. These multifunctional enzymes catalyze the biosynthesis of polyketide natural products by stepwise condensation and modification of metabolically derived building blocks. In particular, regioselective modification of polyketide structure is possible by alterations in either intracellular acyl-CoA pools or, more commonly, by manipulation of acyl transferases that act as the primary gatekeepers for building blocks.

  13. Permutations with Ascending and Descending Blocks

    CERN Document Server

    Steinhardt, Jacob

    2009-01-01

    We investigate permutations in terms of their cycle structure and descent set. To do this, we generalize the classical bijection of Gessel and Reutenauer to deal with permutations that have some ascending and some descending blocks. We then provide the first bijective proofs of some known results. We also solve some problems posed in [3] by Eriksen, Freij, and Wastlund, who study derangements that descend in blocks of prescribed lengths.

  14. Hydration effects on the electronic properties of eumelanin building blocks

    Science.gov (United States)

    Assis Oliveira, Leonardo Bruno; L. Fonseca, Tertius; Costa Cabral, Benedito J.; Coutinho, Kaline; Canuto, Sylvio

    2016-08-01

    Theoretical results for the electronic properties of eumelanin building blocks in the gas phase and water are presented. The building blocks presently investigated include the monomeric species DHI (5,6-dihydroxyindole) or hydroquinone (HQ), DHICA (5,6-dihydroxyindole-2-carboxylic acid), indolequinone (IQ), quinone methide (MQ), two covalently bonded dimers [HM ≡ HQ + MQ and IM ≡ IQ + MQ], and two tetramers [HMIM ≡ HQ + IM, IMIM ≡ IM + IM]. The electronic properties in water were determined by carrying out sequential Monte Carlo/time dependent density functional theory calculations. The results illustrate the role played by hydrogen bonding and electrostatic interactions in the electronic properties of eumelanin building blocks in a polar environment. In water, the dipole moments of monomeric species are significantly increased ([54-79]%) relative to their gas phase values. Recently, it has been proposed that the observed enhancement of the higher-energy absorption intensity in eumelanin can be explained by excitonic coupling among eumelanin protomolecules [C.-T. Chen et al., Nat. Commun. 5, 3859 (2014)]. Here, we are providing evidence that for DHICA, IQ, and HMIM, the electronic absorption toward the higher-energy end of the spectrum ([180-220] nm) is enhanced by long-range Coulombic interactions with the water environment. It was verified that by superposing the absorption spectra of different eumelanin building blocks corresponding to the monomers, dimers, and tetramers in liquid water, the behaviour of the experimental spectrum, which is characterised by a nearly monotonic decay from the ultraviolet to the infrared, is qualitatively reproduced. This result is in keeping with a "chemical disorder model," where the broadband absorption of eumelanin pigments is determined by the superposition of the spectra associated with the monomeric and oligomeric building blocks.

  15. Dietary cholesterol modulates pathogen blocking by Wolbachia.

    Directory of Open Access Journals (Sweden)

    Eric P Caragata

    Full Text Available The bacterial endosymbiont Wolbachia pipientis protects its hosts from a range of pathogens by limiting their ability to form infections inside the insect. This "pathogen blocking" could be explained by innate immune priming by the symbiont, competition for host-derived resources between pathogens and Wolbachia, or the direct modification of the cell or cellular environment by Wolbachia. Recent comparative work in Drosophila and the mosquito Aedes aegypti has shown that an immune response is not required for pathogen blocking, implying that there must be an additional component to the mechanism. Here we have examined the involvement of cholesterol in pathogen blocking using a system of dietary manipulation in Drosophila melanogaster in combination with challenge by Drosophila C virus (DCV, a common fly pathogen. We observed that flies reared on cholesterol-enriched diets infected with the Wolbachia strains wMelPop and wMelCS exhibited reduced pathogen blocking, with viral-induced mortality occurring 2-5 days earlier than flies reared on Standard diet. This shift toward greater virulence in the presence of cholesterol also corresponded to higher viral copy numbers in the host. Interestingly, an increase in dietary cholesterol did not have an effect on Wolbachia density except in one case, but this did not directly affect the strength of pathogen blocking. Our results indicate that host cholesterol levels are involved with the ability of Wolbachia-infected flies to resist DCV infections, suggesting that cholesterol contributes to the underlying mechanism of pathogen blocking.

  16. Tunable Morphologies from Charged Block Copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, Monojoy [ORNL; Sumpter, Bobby G [ORNL; Mays, Jimmy [ORNL; Messman, Jamie M [ORNL

    2010-01-01

    The bulk morphologies formed by a new class of charged block copolymers, 75 vol % fluorinated polyisoprene (FPI) 25 vol% sulfonated polystyrene (PSS) with 50% sulfonation, are characterized, and the fundamental underlying forces that promote the self-assembly processes are elucidated. The results show how the bulk morphologies are substantially different from their uncharged diblock counterparts (PS-PI) and also how morphology can be tuned with volume fraction of the charged block and the casting solvent. A physical understanding based on the underlying strong electrostatic interactions between the charged block and counterions is obtained using Monte Carlo (MC) and Molecular Dynamics (MD) simulations. The 75/25 FPI-PSS shows hexagonal morphologies with the minority blocks (PSS) forming the continuous phase due to charge percolation and the FPI blocks arranged in hexagonal cylinders. Some long-range order can be sustained even if lipophobicity is increased (addition of water), albeit with lower dimensional structures. However, thermal annealing provides sufficient energy to disrupt the percolated charges and promotes aggregation of ionic sites which leads to a disordered system. Diverse and atypical morphologies are readily accessible by simply changing the number distribution of the charges on PSS block.

  17. Block copolymer membranes for aqueous solution applications

    KAUST Repository

    Nunes, Suzana Pereira

    2016-03-22

    Block copolymers are known for their intricate morphology. We review the state of the art of block copolymer membranes and discuss perspectives in this field. The main focus is on pore morphology tuning with a short introduction on non-porous membranes. The two main strategies for pore formation in block copolymer membranes are (i) film casting and selective block sacrifice and (ii) self-assembly and non-solvent induced phase separation (SNIPS). Different fundamental aspects involved in the manufacture of block copolymer membranes are considered, including factors affecting the equilibrium morphology in solid films, self-assembly of copolymer in solutions and macrophase separation by solvent-non-solvent exchange. Different mechanisms are proposed for different depths of the SNIPS membrane. Block copolymer membranes can be prepared with much narrower pore size distribution than homopolymer membranes. Open questions and indications of what we consider the next development steps are finally discussed. They include the synthesis and application of new copolymers and specific functionalization, adding characteristics to respond to stimuli and chemical environment, polymerization-induced phase separation, and the manufacture of organic-inorganic hybrids.

  18. Adaptive overlapped sub-blocks contrast enhancement

    Science.gov (United States)

    Chen, Anqiu; Yuan, Fei; Liu, Jing; Liu, Siqi; Li, An; Zheng, Zhenrong

    2016-09-01

    In this paper, an overlapped sub-block gray-level average method for contrast enhancement is presented. The digital image correction of uneven illumination under microscope transmittance is a problem in image processing, also sometimes the image in the dark place need to correct the uneven problem. A new correction method was proposed based on the mask method and sub-blocks gray-level average method because Traditional mask method and background fitting method are restricted due to application scenarios, and the corrected image brightness is low by using background fitting method, so it has some limitations of the application. In this paper, we introduce a new method called AOSCE for image contrast enhancement. The image is divided into many sub-blocks which are overlapped, calculate the average gray-level of the whole image as M and the calculate the average gray-level of each one as mi, next for each block it can get d = mi - m, each block minus d to get a new image, and then get the minimum gray-level of each block into a matrix DD to get the background, and use bilinearity to get the same scale of the image. over fitting the image in matlab in order to get smoother image, then minus the background to get the contrast enhancement image.

  19. Evolution History of Asteroid Itokawa Based on Block Distribution Analysis

    Science.gov (United States)

    Mazrouei, Sara; Daly, Michael; Barnouin, Olivier; Ernst, Carolyn

    2013-04-01

    This work investigates trends in the global and regional distribution of blocks on asteroid 25143 Itokawa in order to discover new findings to better understand the history of this asteroid. Itokawa is a near-Earth object, and the first asteroid that was targeted for a sample return mission. Trends in block population provide new insights in regards to Itokawa's current appearance following the disruption of a possible parent body, and how its surface might have changed since then. Here blocks are defined as rocks or features with distinctive positive relief that are larger than a few meters in size. The size and distribution of blocks are measured by mapping the outline of the blocks using the Small Body Mapping Tool (SBMT) created by the Johns Hopkins University Applied Physics Laboratory [1]. The SBMT allows the user to overlap correctly geo-located Hayabusa images [2] onto the Itokawa shape model. This study provides additional inferences on the original disruption and subsequent re-accretion of Itokawa's "head" and "body" from block analyses. A new approach is taken by analyzing the population of blocks with respect to latitude for both Itokawa's current state, and a hypothetical elliptical body. Itokawa currently rotates approximately about its maximum moment of inertia, which is expected due to conservation of momentum and minimum energy arguments. After the possible disruption of the parent body of Itokawa, the "body" of Itokawa would have tended to a similar rotation. The shape of this body is made by removing the head of Itokawa and applying a semispherical cap. Using the method of [3] inertial properties of this object are calculated. With the assumption that this object had settled to its stable rotational axis, it is found that the pole axis could have been tilted about 13° away from the current axis in the direction opposite the head, equivalent to a 33 meter change in the center of mass. The results of this study provide means to test the hypothesis

  20. A Comparison of Pseudo-Maximum Likelihood and Asymptotically Distribution-Free Dynamic Factor Analysis Parameter Estimation in Fitting Covariance-Structure Models to Block-Toeplitz Representing Single-Subject Multivariate Time-Series

    NARCIS (Netherlands)

    Molenaar, P.C.M.; Nesselroade, J.R.

    1998-01-01

    The study of intraindividual variability pervades empirical inquiry in virtually all subdisciplines of psychology. The statistical analysis of multivariate time-series data - a central product of intraindividual investigations - requires special modeling techniques. The dynamic factor model (DFM), w